Successfully reported this slideshow.
We use your LinkedIn profile and activity data to personalize ads and to show you more relevant ads. You can change your ad preferences anytime.
NGUYEN TRQNG HIEP

CHI TIEIT MAY

TAP HAI

 

GD NHA xu/ “(T BAN eIAo Dl_JC
csrrs.  NGUYEN TRONG map

CHI TIET MAY

TAP HA1
(Téi bcin ldn rim bay)

VNHA XUKT BAN GIAO nuc
Chuong 12

TRUYEN DONG xtcH

12.1. KHAI NIEM CHUNG

12.1.1; Cfiu tgo chfinh cfia ho truyén xlch

Xich IA mot chuéi céc mét xi...
— So voi truyén dong dai,  kich thuoc bu truyén xich nhé gun hon,  lam viec

khong co truot,  hiéu sufit khé cam (11 =  0,9...
Buoc xich t 15 thong s6 chm‘:  yé’u c1’1a'xich truyén dong.  Céc kich thuoc chinh cua
xich duoc quy dinh theo buoc xich.  ...
Xich fing céu tao gidng nhu xich con Ian nhung khong c6 con Ian.  Gié.  thanh ché
tao ré hon kh6i hrong xlch cfing nhd hon,...
Bang 12.2 cho mm:  96 thong 36 c1'1a xich rang (Lien X0 cfi) (céc ky hieu kich thubc
xem hinh 12.5).  Cubng :10 thi trgng p...
12.2.3. vat liéu xich via an.  xich

Mi xich thuong duoc lam hing thép can nguoi,  him loong cic bon trung binh
hoac thép ...
6n.  Do do cin ban chi’ 36 ring nhb nhfit Z1'mm'c11a dfa din.  Trén co so th1_1c nghiem
ngooi ta liy Zlmin 3 19 khi van t6c...
vx =  0,5w1dlcosai =  vmaxcoszxl ; 

vn =  vmaxsinal
Gdc 0:1 thay ddi trong khoing tit - gal/2 dén + pl/2 ;  gal/2 =  Jt/ ...
Va dip vi tii trgng dong inh hudng lbn ddn khi nang lam viec vi tudi tho cfia bf)
truyén xich,  gay nhiéu tiéng 611. V1 vay...
tmngddqm = fJA-khdiluqngl métxich.  L1_1cFVtinhbingNiutcIn (N) ;  vintdcv—m/ s.
Ta cd Inc tic dung len nhanh xich din F1 v...
V31 a =  (30 + 50)t,  K,  = 1 ;  a < 251,15, =  1,25 ;  a =  (60 + 30»,  Ka . —. 0,3;

KO - he 36 xét dén céch b6 tri b0 t...
dia xich dén (bang 12.4),  sau khi tinh duoc buoc xich t,  ta qui tron theo tri 36 tiéu
chufin gain nhdt vn kiém nghiem lni...
D6i voi xich rang tri s6 cong suit cho phép cho trong hing 12.5 ting vdi xich c6
chiéu tong 10 mm.  Chiéu tong B ct'1a xic...
Lfiy Z2 =  63 rang. 
Tjr s6 truyén th1_Ic cfia ht) truyén xich
u =  Z2/Z1 =  63/25 =  2,52

3. Xéc ctinh budc xich t theo co...
Chuung 13

'mUYi§: N DONG DAI

13.1 KHA1 NLEM CHUNG

13.1.1. C£1’u tao chinh cfia bf) truyén dai

BC) truyén dai thubng gém...
nhb an khép cua dai véi céc rang trén banh dai.  Dai det Va dai hinh thang dugc dung
tong rii hon ca,  con dai tron chi du...
tai trong chinh duoc lam hing soi vai hen hone soi kim logi,  b6 tri theo mot trung
hoa eua dai.  Lop vé boe cua dai duoc ...
.‘ lop sqli hen 1 chiu kéo,  lap vai cao au 2

M9: 36 tri s6 chiéu r¢ng tiéu chufin ctia dai véi cao su :  20, 25, (30),  3...
Bing 13.3
Kick" thztdc dai hinh thong (Lien X0 ca)

Kich thttéc tié't dién,  mm A1, 10, Chiéu dai Khdi lttqng
rnmz mm gioi...
Bang 13.4
Kiqh thudc dai hinh luqc (Lién X0 ca)

6Loai Kich thucc,  mm Dien tic};  Chiéu dai Kh6i hrong
t‘ 1 «re -
1  1533...
13.2.2. Bénh dai . 

Hlnh dang ké’t cfiu bénh dai duqc quyeft dinh béi kich thuac (thttbng la dubng kinh
ngoéi),  loai dai ...
Chiéu rcng ‘B cue.  bénh dai
< B =  (x - D1: + 2S
x - s6 dai. 
_ Bang 13.6
Kick thudc ch11 yéu aria rdnh bdnh dai hinh tho...
D61 vai dai.  hlnh thang nén my among kinh bénh dai 11115 ‘:11
dlmin — dubng kinh t6i thiéu,  tra bang 13.5.

Dubng ldnh b...
(13-6)

F1 19. luc c6 ich,  N ;  dl - dubng
kinh bfinh d§n,  mm ;  Tl - momen
xoén tren true dfin,  N. m ;  Q - cong
suit,  ...
'I‘t‘1 ding thfic (13-10) c6 thé viét

“  =  f‘da
F -qm V
Tich phan hai var (ting thflc t1-en theo cé cung truqt at,  ta c6
...
13.4.2. frag suat trong dai

Ung suit cang ban dfiu do F0 gay nén
F
0
a0 =  T 1 (13-17)
A - dien tlch tiét dien dai.  D6 da...
trong dd yo - khoing cich t1‘:  lap trung hba din day 1611' cits.  tiét dien hlnh thang. 

Cic cong thtic (13-20) vi (13-2...
13.4.4. Dating cong truqt va hiéu suit bé truyén dai

& Khé.  nang tai cua ba. '_. ’a truyén dai dugc dac trung béi luc vb...
dai sé bi mon nhanh,  hieu suit gifim va tang mflt mét van t6c.  Qua céc s6 lieu thi
nghiem tim duoc ‘(po =  0,4 + 0,5 ddi v...
- Tai trong co va dap va thay dd!  nhiau May cat tam.  baa may,  may nghiin ;  thong may ;  may
Tai trong md may darn 300%...
13.5.2. Tin}:  dai det
T5'ng sufit cd {ch cho phép cfia dai dot
[a, ] =  15,10 Cb ca CV (13-35)

trong do [6l]° - ting suit ...
Dien tich A - tié’t dien dai dot phai thoa man diéu kien (13-34),  do do
FlKd
A =  h ,  —-—- 3-36
h > [63 (1 )
Thong thubn...
. 4" I111 ¢

IIII Eda‘

      
    

         
   
   

   
 

   
       
   
  

  
  

  

 

3
4.4 x%°¢ — ' ‘
 ‘II 6*’...
C1 - he s6 xét dé’n énh hudng cfxa téi trong (bang 13.10) ', 
V AT!  - s6 gia momen xoén (N. m) la mmfin téi trong cd thé t...
13.5.4. Tinh dai rang
D6i véi bo truyén dai rang,  céc thong 36 hinh hgc chi’:  ye'u la modun m =  t/ at, 

t — bufic cfia d...
trong dd (11 - gdc Om ct'1a dai tren bénh nhb.  Nén my s6 rang dai Z61 as 6. Néu
Z G‘ < 6 ca‘: -1 tang khoéng céch true 9....
Kiém nghiem diéu kien _
a 3 2 (£11 -1- dz)

Néu khang théa man diéu kien nay,  cfin My :1 =  2 (dl + dz) va tinh lei L theo...
7. Xéc dinh 56 dai cfin thiét x theo cbng thlic (13-39).  S6 dai x khong nén qué
5 + 6 dai d6i V61 céc tié’t dien O,  A,  B...
6. Tinh gdc om oz,  theo cong thdc (13-3).  150° 150°

0:,  > 120°. 
7. Xdc 6131. 36 dai 3..  thiét x theo cong
thdc (13-3...
Gifxa van me tin]:  tién cua vft v(m/ s) vb s6 vbng quay trong 1 phut n(vg/ ph) qua
dai 6c (hinh 14.1.b) c6 he thdc '

nZP...
D6 tang hiou suit V9. giém mon gin day ngttoi ta dong truyén dong vit - dai 61:
hi,  nhb dd ma sat trugt trén ren ctuoc th...
Ap suit cho phép [p] (161 vdi thép mi — dong thanh 11 + 13 MPa,  doi vai thép
khong toi — dong thanh 8 + 10 MPa.  doi voi ...
Dé don gién,  cd thé kié’m nghiom vit co’ chiéu dai hot 115; theo diéu kién chung vé
hén vb on dinh

4F

 

(I: 

n mill, ...
Doi voi ren co buoc P =  20mm (dz =  75mm)

20
1 =  °'°*€ T475 7 5°

khong an toan vé tt_1 ham (vi y xdp xl bong ,0). 
Vay...
Phéin th1i' tlr

TRUC,  6 TRUC,  KHO'P N61 VA.  LO X0

Chuong 15
TRUC

15.1. KHA1 Nlmu CHUNG

15.1.1. Cong dung vi phan lo...
. dung,  bao dufmg true v. v.. ., la cac nhan

truyén ehuyén dung quay va momen xoan gifta cac bo phan may hoac gifra cac,...
v. v.. . Cac tn’ s6 tiéu chudn ezia duong kink (mm) than true lap bdnh rang,  bdnh dai,  khép
n6iv. v.. .l0;l0,5;11;11,5;1...
* Su tap trung Ling suit do ké’t edu gay nén (gde luun,  rénh then,  16 v.  v. ..),  hoac
do chét luung ehé’ tuo xfiu (vé’t...
A 13xr'r Du6i40 3000*) 1000 soo Tham than,  toi
4o_-so.  27o(*) 950 ‘ 750

Bang 15.1

Ca tinh mot so’ mac thép she’ too tr...
Co’ thé tién hanh thiét ké’ true theo cac buoe :  tinh so ho duong ldnh true ;  dinh
ké’t eau va cac kieh thuoc true ;  ki...
Chi tiet may_tap_2
Chi tiet may_tap_2
Chi tiet may_tap_2
Chi tiet may_tap_2
Chi tiet may_tap_2
Chi tiet may_tap_2
Chi tiet may_tap_2
Chi tiet may_tap_2
Chi tiet may_tap_2
Chi tiet may_tap_2
Chi tiet may_tap_2
Chi tiet may_tap_2
Chi tiet may_tap_2
Chi tiet may_tap_2
Chi tiet may_tap_2
Chi tiet may_tap_2
Chi tiet may_tap_2
Chi tiet may_tap_2
Chi tiet may_tap_2
Chi tiet may_tap_2
Chi tiet may_tap_2
Chi tiet may_tap_2
Chi tiet may_tap_2
Chi tiet may_tap_2
Chi tiet may_tap_2
Chi tiet may_tap_2
Chi tiet may_tap_2
Chi tiet may_tap_2
Chi tiet may_tap_2
Chi tiet may_tap_2
Chi tiet may_tap_2
Chi tiet may_tap_2
Chi tiet may_tap_2
Chi tiet may_tap_2
Chi tiet may_tap_2
Chi tiet may_tap_2
Chi tiet may_tap_2
Chi tiet may_tap_2
Chi tiet may_tap_2
Chi tiet may_tap_2
Chi tiet may_tap_2
Chi tiet may_tap_2
Chi tiet may_tap_2
Chi tiet may_tap_2
Chi tiet may_tap_2
Chi tiet may_tap_2
Chi tiet may_tap_2
Chi tiet may_tap_2
Chi tiet may_tap_2
Chi tiet may_tap_2
Chi tiet may_tap_2
Chi tiet may_tap_2
Chi tiet may_tap_2
Chi tiet may_tap_2
Chi tiet may_tap_2
Chi tiet may_tap_2
Chi tiet may_tap_2
Chi tiet may_tap_2
Chi tiet may_tap_2
Chi tiet may_tap_2
Chi tiet may_tap_2
Chi tiet may_tap_2
Chi tiet may_tap_2
Chi tiet may_tap_2
Chi tiet may_tap_2
Chi tiet may_tap_2
Chi tiet may_tap_2
Chi tiet may_tap_2
Chi tiet may_tap_2
Chi tiet may_tap_2
Chi tiet may_tap_2
Chi tiet may_tap_2
Chi tiet may_tap_2
Chi tiet may_tap_2
Chi tiet may_tap_2
Chi tiet may_tap_2
Chi tiet may_tap_2
Chi tiet may_tap_2
Chi tiet may_tap_2
Chi tiet may_tap_2
Chi tiet may_tap_2
Chi tiet may_tap_2
Chi tiet may_tap_2
Chi tiet may_tap_2
Chi tiet may_tap_2
Chi tiet may_tap_2
Chi tiet may_tap_2
Chi tiet may_tap_2
Chi tiet may_tap_2
Chi tiet may_tap_2
Chi tiet may_tap_2
Chi tiet may_tap_2
Chi tiet may_tap_2
Upcoming SlideShare
Loading in …5
×

Chi tiet may_tap_2

1,379 views

Published on

Chi tiet may_tap_2
http://tailieukythuat.net/

Published in: Engineering
  • Be the first to comment

Chi tiet may_tap_2

  1. 1. NGUYEN TRQNG HIEP CHI TIEIT MAY TAP HAI GD NHA xu/ “(T BAN eIAo Dl_JC
  2. 2. csrrs. NGUYEN TRONG map CHI TIET MAY TAP HA1 (Téi bcin ldn rim bay) VNHA XUKT BAN GIAO nuc
  3. 3. Chuong 12 TRUYEN DONG xtcH 12.1. KHAI NIEM CHUNG 12.1.1; Cfiu tgo chfinh cfia ho truyén xlch Xich IA mot chuéi céc mét xich n6i v6i nhau hing ban lé. Xich truyén chuyén dong va téi trqng tit true dfin (true chfi dong), sang true bi din (true bi dong) 11116 sq in khdp ctia céc mat xich vdi cac rang dla xich. Cfiu tao chinh cfia ho truyén xich gdm dia dén Z1, dia bi din Z2 vi-xich (hinh 12.1). Ngoai ra t1‘1y trufmg hqp, G6 the’ cd thém bo phan cang xfch, bo phan boi tron, hop che. C6 khi dung mot xich dé’ truyén dgng tit dis. din sang nhiéu dis. bi din (hinh 12.20). Hinh 12.1 Hinh 12.2 12.1.2. Uu, nhuqc diém vh phgm vi st’: dung Uu diém c1'1a truyén dgng xich la : - C6 thé’ truyén chuyén dong gifta cfic true each nhau tudng 1161 am.
  4. 4. — So voi truyén dong dai, kich thuoc bu truyén xich nhé gun hon, lam viec khong co truot, hiéu sufit khé cam (11 = 0,96 + 0,98) va luc téc dung lén truc tuong ctfii nhé. - C6 the’ cfmg mot lfic truyén chuyéfn dong vi cong suit cho nhiéu truc. Truyén dong xich cd nhfxng nhuoc diém sau : - C6 nhiéu tiéng 6n khi lam viéc. — Van t6c ttic thoi cfia xich va die. bi dén khong 6n dinh. - Yéu céu cham sdc thufmg xuyén (boi tron, diéu chinh lam cang xich). -- Chéng mon, nhét la khi lam viec noi nhiéu bui va boi tron khbng t6t. Truyén dong xich chm‘: yé’u dugc dung trong céc trufmg hop céc truc c6 khoéng csich trung binh (né’u dung truyén dong hénh rang can co thém céc bénh rang trung gian. ..) ; yéu cfiu kich thuoc tuong d6i nhé gun hoac lam viéc khong truot (do khong dimg duoc I truyén dang dai). Truyén dong xich duoc dung dé giém 1260 do quay hoac tang t6c doc quay gifra calc ' truc song song. Cong su§t truyén thuong khong qué 100 kW, khoéng czich true a dén . 8 mét. 'I‘rong céc bx) truyén t6c dc} cao (dia dfin lép voi truc dong co), van t6c xich ‘v = — 6 + 25 mls, ty s6 truyén u s 3. D6i voi céc bu truyén we do cham (truyén din t1‘: truc ra Gina hop giém t6c dén bf; phan Gong téc), van tdc xich v = 2 + 6 m/ s, 1:57 36 truyén u s 6“; né’u v ~<. 2 mfs :3: s6 truyén c6 thé téi 10 + 15. Bo truyén xich . duoc b6 tri ném ngang (hinh 12.23) houc d6c nghiéng, duong ndi hai tam tuo thémh voi mat phéng ngang 1 got: 1;: (hinh 12.2b). Hién naytruyén dong xich duoc dung rcfmg rai trong céc may van chuyén (mote, . xe dup, xich té. i.. .), may nong nghiép, may cong cu, tay may. .. 12.2. GAG LOAI xicH TRUYEN. DONG VA on xicH 12.2.1. Céc loui xich truyén dong Ceic loui xich truyén dong thuong dimg hién nay gém xich con Ian, xich ting, vi xich «rang. (Ngoai céc lo: -_1i xich truyén dong, _trong ché too may con co’ céc loui xich true, xich kéo dé nang ha, van chuyén vat nang). C511 too, kich thuoc, vat lieu, co tinh vi do chinh xéc cua xich duoc quy dinh trong tiéu chufin. Xich con Ian co can tgo nhu trinh bay trén hinh 12.3, gdm céc mé trong 1 xen ké vdi céc mé ngohi 2, co thé xoay tuong d6i ddi voi nhau. Cat: ma trong 1 lép chat voi (‘Eng 3, céc mé ngoai lép chat voi chfit 4, dng va ch6t ed khe ho, co‘ thé xoay tu do dffi vdi nhau, tuo thanh ban lé. Nhém muc dich giam mbn rang dla xich, phia ngohi 6ng co lép con Ian 5, cfing c6 thé xoay tu do. D5 n6i hai mét cu_6i cfia xich lui voi nhau thénh vbng kin, thuong dung ch6t ché (hinh 12.4a). Né'u s6 m_§t xich 151 lé, phéi dimg mét chuyé"n ed ma cong (hinh 12.4b) vé cfing duoc ch6t hing ch6t ché. Dung mét chuyén, xich bi yé’u do tai day trong mé xich _c6 thém wing suit udn. Vi vay nén My 36 mét xich 19. s6 chin. 4
  5. 5. Buoc xich t 15 thong s6 chm‘: yé’u c1’1a'xich truyén dong. Céc kich thuoc chinh cua xich duoc quy dinh theo buoc xich. Trong bang 12.1 cho mot S6 thong s6 cfia céc cc": xich con Ian (Lién X0 cfi) co‘ buéc t = 12,7 + 50,8 mm. 4 / ,.< . . I: 7‘; 4", ; 2,3’. , rl/ I R 1 l1 I 1 I I/ /A$§7// //2%--_-9- % I)II A "EIEIE - I A _ - ’ '1 Hill Hinh 12.3 Hinh 12.4 HP — 12,7 - 9000 ~ 2 9000 HP - 12,7 — 18000 — 1 18000 HP — 12,7_— 1800 — 2 18000 0,75 HP — 15,875 — 23000 — 1 23000 0,80 HP — 15,875 - 23000 - 2 23000 1,00 HP — 19,05 - 32000 32000 1,52 HP — 25,4 — 56700 56700 2,57 HP - 31,75 - 8850.0 88500 3,73- HP — 33,1 — 127000 127000 5,50 HP — 44,45 — 172400 172400 7,50 HP — 50,3 — 226800 226800 Khi téi trong Ion, van t6c cao, dé' khéi phéi chqn buoc xich qua Ion, gay nén nhfrng va (tap mgnh pd hai, nguoi ta dung xich nhiéu day (2 day, 3 day). Cfiu tao c1’1a xich nhiéu day c1'1n'g tuong tu nhu xich 1 day, chi tn‘! chiéu dai chdtdogc tang thém. Tat trqng phé. héng vb. Gong suit truyén cua xich tjr le thuan voi 36 day. V_'I‘r0ng céc may xay dung hoac may lam duong, ht) truyén lam viec c6 tai trong dong, va dap hoac quay hai chiéu, ngubi ta dung xich con Ian G6 ma cong, gdm céc mét xich cd hinh dang nhu céc mét chuyén. D0 mé. xich cong cho nén do dhi c1'1a xféh tang lén, lam tang khé nang chiu téi trong dong. -
  6. 6. Xich fing céu tao gidng nhu xich con Ian nhung khong c6 con Ian. Gié. thanh ché tao ré hon kh6i hrong xlch cfing nhd hon, nhung icich vé. rang cfia chdng mbn, do dd tuong d6i it dung. Xich rang (hlnh 12.5) gfim nhiéu mé xich 1 va 2 lién két voi nhau, hing cac chdt hinh quat lang tru. Céc mé. xich 1 13 ma lam viec, méi imi co hai rang vé hai 16 dinh hinh dé xuyén chdt. Céc ma xich 2 khong co’ rang, c6 tsic dung d§n hufmg, gift cho xich khong bi dich chuyén khéi dia khi lam viéc. Bé mat lam viéc cda m6i__mé xich 13 hai mat phia ngoai, cc dung mat phéng. Céc bé mat nay sé ty len hai rang cfia dla xich (hinh 12.65.). . F I ‘ I '/ /A X 2'/ J L I . ’ . . ‘ *0 7/I. '/ /1 ' 2 ' I ‘ I X. ‘ / //4 I ’II. II- I 7/: ‘ : .‘. ‘: :: X’ . ‘ : . B V: ./—'/ / 1'1/ljj . I >‘ I A C 71/; - 72 I ‘- 1 7/1 I '/ /4 I . 1 N Hinh 12.5 I Izr/11/z — «‘ I 'f/ I// II/ I . ~ I '/ //I/ /II4 . .. ... .. .. — '1/1:/ n/. . Q‘ 1 I ~'« ‘it. ’ 1 § 3.‘ ~ / . . ,. 'l/ /4/rl/ I I ~- = '1/2/I/ //, -, . _ - I . I: -»; n., I I 7171/1 I . I 5) Hinh 12.6 Mat Liam viec c1'1a céc ch6t la céc mat cong l6i (hinh 12.6b), khi céc mé xich xoay ddi voi nhau, céc ch6t sé Ian khong truot, nho dd ban lé do mon. Xich rang c6 khé néng téi cao hon xfch con lan, lam viec ém v31 It 6n hon, song ché’ tuo phtic tap v3 khfii luong nang hon, do do it dung. 6
  7. 7. Bang 12.2 cho mm: 96 thong 36 c1'1a xich rang (Lien X0 cfi) (céc ky hieu kich thubc xem hinh 12.5). Cubng :10 thi trgng phi héng, 19. téi trong phé hbng xich cd chiéu rong 1 mm, duqc tinh bang N/ mm. Bang 12.2‘ Xich rang (Lien X0 ca) (bdn 1% ma sat Ian) Cubng dc} téi trong 1 mét xich Chiéu mug xich B, mm phé héng c<S chiéu (d6i vdi 1 rgng 1 cm, mm chiéu qm, kg rfing xich) N / mm 22,5 - 52,5 (tang tfmg 6 mm) 30 - 70 (ting timg 8 mm) 45 — 93 (tang tfing 12 mm) 57 5 105 (tang tfmg 12 mm) 69 - 117 (tang titng 12 mm) 12.2.2. Dia xich Dia xich cd hinh dgng két cdu ttwng t1_1 nhu bénh rang. Hinh dang ldch thuac profin rang dugc quy djnh theo tieu chufin. ‘ ‘x I I I! 2| 4 3)‘ Hinh 12.7 ' Profin rang dia xich con Ian gdm céc dean cong dinh rang AB ban kinh R1, dean thing BC chuydn tiép, cung CD c6 ban kinh R vb. ranh ban kinh r (hlnh 12.7). Chiéu rang b cfia vanh rang dugc My hai nhb hon . khoang céch bl giixa hai mé trong. Profin ‘ ,5) rang dis. xich cd hinh thang (hinh 12.69.). Dia xich c6 dating kinh nhé dugic ché tgo H371}! 12-3 hing dap (hinh 12.83). Dia xich dubng kinh trung blnh Va lén duqc ché’ tao rieng mayo V9. vanh rang rdi ghép lai béng han (hlnh 12.8b) hoac bulong (hinh 12.8c) v. v.. . §§Il Ill! /2. 3|: ' "/ §. (<’~
  8. 8. 12.2.3. vat liéu xich via an. xich Mi xich thuong duoc lam hing thép can nguoi, him loong cic bon trung binh hoac thép hop kim can nguoi : thép 45, 50, 40X, 40XH (Lien X6 cfi) v. v.. . toi co do rin 40 + 50 HRC. Vat lieu lim bin lé (ch6t, 6ng, con lin) thuong li thép 15, 20, 15X, 20X, l2XH3A v. v.. . thim than rdi tfii dot do rin 50+ 65 HRC. Ddi vdi nhfxng dia xich chin tij trong nho, van t6c thfip (v < 3 m/ s) co thé ché’ too hing gang CH 20 hoac gang co do bén cao hon vi toi. Truong hop tii trong vi vfin tdc cao hon, dla xich door: ché’ too hing thép céc bon hoac thép hop kim nhu thép 45, 40X, 40XH tbi boat: thép 15, 20, 12X2 H4A v. v.. . thim than vi toi voi chiéu siu lop thim 1:01 1 + 1,5 mm. Do rin bé mit ring ,50 -: - 60 HRC. 12.3. CA0 THONG s6 H1NH Hoc CHINH 12.3.1. Bttdc xfch I: li thong 56 co bin cfia bt_5_ truyén xich. Xich cd buoc cing lon ‘ thl khi ning tii trong going Ion nhung téi trong dong, va dip vi tiéng 6n cing tang, nhit li khi vin t6c cing cao. Do do khi gxich lam viec voi van t6c cao, nén chon buoc xic_h nhé vi néu cin thi tang s6 day xich (d6i voi xich con lin) hoic tang chiéu rong . xich_ (d6i voi xich ring) d6 xich cddn khi ning tii. Bing 12.3 cho tr: so vbng quay gioi ban his (vg/ ph) c1'1a dia x{ch din (xich 1 day), pho. thucc s6 rang dia din 21 vi buoc xich t. Bing 12.3 86 vbng quay gioi hon nlg (vg/ ph) cfaa din xich din nl, vg/ ph, khi bttoc xich t, mm E% Xfch oon Ian - Xich ring - 17 - 35 3300 2650 2200 1650 1300 12.3.2. Duong kinh vi 36 rang aia xich . Dubng kinh vbng chia (hinh 12.6 vi 12.7) c1‘1a dia xich din dl vi cfza (119. hi din dz tinh theo cong thdc. t t d1 ' sin(7r/ Z1) dz = sin(: z/Z2). - (mm Z1 vi Z2 - so ring dIa din vi din bi din. I B5 truyén xich thuong duoc dttng dé giim we do, do do’ 36 ring dia din Z1 nhé hon so rang dia bi din Z2. Néu 36 ring cing it, gdc quay tuong d6i cfaa bin lé khi xich vio dia vi ra khéi dia (hing 27:/ Z) cing lon, xich sé mbn cing nhanh. Mat khac va dip cfia mit xich khi tié’p xfic véi ring (119. cfing tang lén vi xich lim viéc cing 8
  9. 9. 6n. Do do cin ban chi’ 36 ring nhb nhfit Z1'mm'c11a dfa din. Trén co so th1_1c nghiem ngooi ta liy Zlmin 3 19 khi van t6c xich v > 2 min. Trong cic ho truyén c6 van t6c v < 2 mls co the’ My Zlmin = 13 -1- 15. D6i voi cic ho truyén chiu téi trong va dip nén liy Z1 mi n as 23. De’ bfo dim cho bo truyén xich lam vigc liu dii, it 6n, trong truong hop van t6c trung binhvi cao nén 16y Z1 = 29 — 211 as 19 vi nén quy tron theo 56 16 (u - ti s6 truyén). S6 ring t6i thiéu Zlmin 36 trén day. S6 ring dia Ion (dia bi din) Z2 = uZ1, nhung khong nen. my vuot qué tri s6 gioi han Zzmax S 100 + 120 d6i voi xich con Ian va Zzmx as 120 + 140 d6i voi xich ring. so dl co so gidi hgn niy vi sau mot"-thoi gian lém viec, xich sé bi mon, buoc xich sé tang them so -co vi tri 6 xa tam dia hon so voi vi tri ban din. khi xich chua bi mbn. N61 ‘each khic, duong kinh vong tron di qua tam cic bin lé xich sé Ion hon ‘doting kinh vbng chia (hinh 12.9) mot tri s6 Ad, say to cong thdc (12-1) At Ad — sinm/ Z) (12-1) Hinh 129 R6 ring Ii voi xich dd mbn, do tang buoc xich 12 At. Néu s6 rang dis xich Z cing Ion thi Ad cing ldn, xich cing dé tuot khéi dia. 86 ring Z2 cfing nén Ii s6 lé, nhu viy voi s6 mit xich ohin, céc bin 16 vi rang dia sé mon déu hon. 12.3.3. Khoing cich true a (hlnh 12.1) cfing c6 inh hudng dén khi néng lim viec c1'1a bo truyén xich. N611 khoing cich true a nhd, tin s6 chin tii cda cic bin lé tang lén. Ngoii ra, gdc im cna. xich trén die. nhd al sing giim néfu giim khoing céch true a. Khoing céch nho nhit amm gifra hai true dia xich duoc dinh theo diéu kien gdc om tren dia nhé :21 an 120° vi hai dia xich khong chnm nhau. Gdc Om tron dia nhb duoc tinh theo cong thfic dz" — d1 cl = 180° - . 57° (12-2) D6 théa min diéu kién <21 >.120°, tit cong thdc (12-2) ta dinh duoc amm amm 3 dz - dl. Diéu kien dé hai dis. xich khong chgm nhau . ‘a . n 3 0,5(da + daz) + (30 + 50) mm 1 trong do : as vi dag - dobng kinh vbng’ dinh ring an din va am hi din. . 1 N51: khoing cich true a Ion qua xich so chdng bi chitng (vi s6 mit xich é nhiéu, voi do ting buoc xich At tuong d6i nhé cfing lim xich (195 than: nhiéu), khi lim viec hi rung nhiéu. Do do cfing cin hon ché khoing céch tmc t6i da am 4 80t. Th1_1c té’ (cho thiy khoing cich true nan Iiy a = (30 + 50)t. Khi di dinh duoc khoing cich true a, co thé tlm duoc chiéu dii xich L = X. t ; X — s6 mit xich, tinh theo cong thdc. ctia dia xich rang liy ting 20 + 30% so voi cic tr: 1 luong 19. At. Khi an khop voi ring dla, céc mét xich.
  10. 10. vx = 0,5w1dlcosai = vmaxcoszxl ; vn = vmaxsinal Gdc 0:1 thay ddi trong khoing tit - gal/2 dén + pl/2 ; gal/2 = Jt/ Z1. Van tdc xich c6 tr: 56 Ian nhit khi a1 - 0, vx = vmx = 0,5cu1d1 va cd‘tri s6 nhb nhdt V, ‘ = vmin = 0,5w1dlcos(: p1/2) khi a = :t tpl/2. Véi céch xem xét tuong tyt nhu trén, ta cd van t6c gdc cfxa dia xich bi d n wz = vx/ (0,5d2cosa) = coldlcoaal/ dzcosa (12-7) trong <16 gdc or thay ddi trong khoing - qp2[2'< a < + 402/2 ; (p2/2 = J1:/22. I-Ilnh 12.10d trinh bay dd thi van t6c xich vx vi gia tdc ax cfia xfch. Cong thxic (12-7) cho thfiy van tdc gdc 002 cfia dia bi din thay ddi theo chu kjr, din bi din chuyén dcng khong déu cho dil cIIa din quay déu. Tjr s6 truyén tdc thdi un = clzcosa/ dlcosal (12-8) C6 thé giém b6t st; chuyén dqng khong déu cfia dia bi din hing each tang 36 rang I dia xich, dé cho khoéng bié'n thien cfia céc gdc al vb. ‘ or 11116 cti va cosal, cosa cang gin t6i 1. V1 36 rang dla din (die nhé) it cho nén tang Z1 c6 téc dung ldn hon. 12.4.2. 'I‘&i trong dong vi va dip trong truyén dong xich Trong truyén dong xfch, do van tdc cfia xich vi dia bi din thay ddi -cho nen sinh ra tii trgng dong. Khi xich c6 kh6i luqng m chuyén dong véi van t6c vx they ddi theo thbi gian, nghia la chuydn dong vbi gia t(5c'ax, sé sinh ta téi trong dong (ll_Ic quén tinh). 'I‘Ai trgng (Ring 13 cue dgi khi gia tdc dgt tr: 36 cut: dai (ax = am“) Fa = maxmax vdi m = q ma - kh6i luqng cfia nhénh xich din ; qm - khdi luqng 1 mét xich ; a - khoing céch gifta hai trnc dia xich, mét. Nghién ctiu cho thiy gia tdc xich cuc dgi khi mit xich bit diu vio khép vai ring on cfla din, lac nay am = — ax 2 t - buéc xich. 'Ih tlm dugc qmanft F (12-9) 6 “‘ 130000 trong d6 Fa tinh bing N ; a - mét ; qm - kg/ m ; nl - vg/ ph ; t - mm. Cong thfxc (12-9) cho thiy khi tang budc xich vi tin s6 quay cfia dia din, tai trqng dong F d 55 tang 1911. A Va dip gifra bin lé xich vdi rang dia sinh ra khi ban lé vao khép v6i rang dia vdi nhfxng van t6c khéc nhau. Tai thbi di6m vao kh6p, ban lé B c6 van we 19. $7; = 3;, c6 phuong vuong gdc vdi ban kinh OA (hinh 12.11), cbn van tdc cfla rang C’ 13 7:: c6 phuong vuong gdc v6i OC. Deng nang va dglp tang len khi tang buéc xich vi: taln 36 quay ctia die. din. Hinh 12.11 11
  11. 11. Va dip vi tii trgng dong inh hudng lbn ddn khi nang lam viec vi tudi tho cfia bf) truyén xich, gay nhiéu tiéng 611. V1 vay cin han ché 36 vbng quay nl cfia dia din (hing 12.3) vi khong nén liy budc xich t ldn qua. 12.4.3. L1_rc tic dung trong truyén dong xich - Khi chua lam viec bo truyén x{ch- chin luc cang ban dfiu F0 do trqng luong bin than xich gay nén. L1_xc cang ban din duqc tinh theo cong thdc gin dfing ‘F0 = gqmaz/ (8y) = gqma(1 + 5cos21p) (12-10) trong dd qm - khdi luqng 1 mét xich ; a — khoing cich gifxa hai trnc ; y - dd vdng cfxa xich (hinh 12.1) ; qt: - gdc nghiéng cfia dubng ndi hai tam dia xich (hinh 12.1) ; g 2 10 m/ s2 - gia tdc trong trtrbng. ‘ , D6 vdng cfia nhinh bi din can duqc my vfza phij dd bo truyén lam viéc tudng ddi em vi It mbn bin lé : Khi gdc nghieng cda b0 truyén 1;: & 40° nén lay y = 0,023 vi khi go > 40° My y = (0,015 -2- 0,01)a, tris6 nhé dimg khi op ldn. Trong tinh toin thuc t6 cd thé liy F0 as kyqma . (12-11) trong dd . ky = 60 khi bo truyén nim ngang vi y -'= 0,0211 ; ndui gdc nghiéng cfia b9 truyén 1;/ > 40° liy ky'= 40 + 20, tri s6 nhd khi 1/) Mn vi ky = 10 khi «p = 90°. Khi bd truyén lam viec luc vbng F, dude truyén tr‘: rang dia din qua céc mét xich nhénh din, tit céc mit xich nay lén cic yang dla hi din : F, = 1000:7av -. - 6.107!B(znt), . N (12-12) vdi R - cong suit, kW, v - van t6c xich, mls ; t - budc xich, mm ; Z, n - 36 rang va s6 vbng quay trong 1 phfit cfia dia xich. _Ne'u cho trudc tri s6 mOm'en xoin T, trén true din vi dl la dubng kfnh vbng chia c1.'1a _d1a din ta cd : ’ F, = 2'1‘, /:1, = F1.— F2 . - (12-13) trong dd F, vi F2 - luc tic dung len nhfinh xich din vi nhfinh xich bi din (hinh 12.123). ' Khi cic mil: xich chay vbng qua dia xich vdi van tdc v aé sinh ra lyre ly tam. Crii st’: phin t6 xich cd khdi luqng dm, 11_xc ly tam sé la (hinh 12.12). _ d 2 2»? “Fu= '1m; §‘° = "smT 'Lt_Ic Iy tam dF“ gay 11611 11.11: cang phu Fv trong xich. T1‘: diéu kien can bang phan td xich (hlnh 12—12b). dF da = 2Fvsin —— z Fda / ;' 11 2 v v2 D0 (16 F‘, = Vi dm = PA 521- do: ;f’ - khdi luqng riéng; ' A - dien tich tie’t dien ngang (trung binh) /5 3) min xic}1,cho nan F, = pm? = qmvz (12-14) Hinh 12.12 12
  12. 12. tmngddqm = fJA-khdiluqngl métxich. L1_1cFVtinhbingNiutcIn (N) ; vintdcv—m/ s. Ta cd Inc tic dung len nhanh xich din F1 vi nhénh xich bi din F2 bing : F, = F, + F2 ; F2 = F0 + Fv (12-15) L1_Ic tic dung lén truc dia xich F F do Inc vong F, vi trgng luqng xich gay nen, dnqc tinh gin dnng theo cong thdc Fr = 1,11, = k, .e.1079e/ (zm) (12-16) trong dd kl - he s6 xét din tic‘ dung cda trong ltrqng xich lén true, khi bi) trnyén nim ngang k, = 1,15 ; khi bo truyén thing dfing k, = 1,05 ; Z vi n - s6 ring vi s6 vong quay trong 1 phut c1'1a dia din (hoac dfa bi din) ; {R - cong suit cfia bo truyén, kW. 12.5. TiNH TRUYEN DONG xI‘CH 12.5.1. Cic dang hong Trong ba truyén xich c6 thé xay ra cac dang héng sau : - Mbn ban lé xich do khi lim viec cac bin lé chin ap suit (dng suit tiép xnc) ldn vi ed 811 xoay tnong ddi (giita chdt 4 vfii dng 3). Ban lé bi mbn khiin budc xich ‘ t ting lén, xich an khdp khong chinh xéc vdi rang dia. Nén bin lé bi min qua nhiéu, . ,bO trnyén sé khong lim viac duqc vi xich thubng xuyén tuat khbi din hoac xich sé bi ‘dfit (do min lim yén cic mat xich). De’ giim mean can boi tron xich vi han che’ ap suit trong bin 16 xich. - Cac phin t1’: xich bi hdng do mdi, din dén xich bi ddt, con Ian bi r6 hoic vi). Xich bi hfmg vi méi do tic dung cda dug suit thay ddi gay nan béi tii trong lam viac, tii trong dong hoac va dap. Hien tnqng hdng vi moi thubng chi xay ra ddi vdi cac ba trnyén xich chin tai trong 1611, van tdc cao, lam viac trong can hop kin (duqc boi tron tdt nen it man). Ngoai ra do chit luqng chd tao khong tdt hoac do lam viec vdi van t6c v > 15 m/ s b¢ truyén chiu tii trong va dap 1611 mi xich cd thé bi long, con Ian bi vd. Trong cac dang hdng tran, mbn bin la 19. dang hing chd yé'u cda bC_) t1-uyén xich. ' 12.5.2. . T1nh bo truyén xich con Ian Thnc nghiem chdng to ring ap suit trong ban lé x. {ch la mat tmng cac nhan td chd yéu quydt dinh tndi tho (dd bén mon) cda xich. Xich cd thé lam viec trong thbi gian tuong ddi _ liu niu nhn ap suit p sinh 1-a trong bin 16 nhd hon ap nit cho phép [p] 11.1“, A. K X p =2 [p] (12-17) trong dd F, — luc vong ; . A = dobo — dien tich tinh toan cda bin 16 xfch 1 day ; do - dudng kinh chdt ; bo- chién dii dng (hinh 12.3) ; cd thé my A z 0,28t2 ; 1 '- buac xich. K — he 36 diéu kien st‘! dung xich. . K = Kd. Ka. Ko. Kdc. Kb (12-18) Kd - he 36 tai trong dang, néu din dong bang dang co dian vi tii trong ngoii tic dung len b0 truyén tuong d6i ém Kd = 1, néu tii trong (:6 Va dip Kd = 1,2 + 1,5 ; nén va dip manh Kd 1,8 ; K8-has6xétdé‘nchiéudiixich, x1chcingdiith1s61inviokhdpcfzaméimitxich trong mat don vi thbi gian cing it, xich 516 it mon hon (khi cic diéu kien khan: nhn nhau). 13
  13. 13. V31 a = (30 + 50)t, K, = 1 ; a < 251,15, = 1,25 ; a = (60 + 30», Ka . —. 0,3; KO - he 36 xét dén céch b6 tri b0 truyén, néu ho truyén dat chug nghieng (so voi duong nhm ngang) thl do mon (hoigc do tang tuong d6i c1‘1a buoc xich) cho phép cang gifim vi xich cflng dé tuot. Khi doting n6i hai tan: dia xlch lam voi dubng nfirn ngang mot gdc nhd hon 30°, KO = 1; 11511 105 hon 50°, K0 c6 thé my 131 1,25 , Kdc - he 36 xét dé’n khé. nang diéu chinh l1,1c cang xich, né’u true co thé diéu chlnh duoc Kdc = 1, new: dimg dis. cang xich hofic con Ian cang xich K“ = 1,1 ; néu true khong diéu chlnh duoc Va cfing khong co bo phgn caug xich Kdc -- 1,25 ; Kb - he 6 xét dén diéu kien hai tron, néu boi tron lien tuc (xich nhfing dfiu hone duoc phun dfiu lien tuc) Kb = 0,8,. ndu boi tron nho giot Kb = 1, ne’u boi tron dinh ky (boi tron gién dean) Kb = 1,5 ; Kx-hesdxétdénsddayxichx, vdix=1;2;3;4thiKx= l;1,7;2,5; 3tuong11ng. Tri 36 ép suit cho phép [p] theo diéupkien bén xnon cua xich cho trong bang 12.4. Cong th1’1c (12-17) duoc dimg dé chon xich. Chon mot trj s6 budc xich 1; vi My s6 ring (113 xich nhé Z1 theo huong din trong mnc 12.8.2 1-6i tinh ép suit p va so sénh voi ép suit [p] cho phép. Nén khong phi: hop thi chon va tlnh lgi. Bang 12.4 Kp sud: cho phép [p] U! bén mbn ctia xich [p], MP9,, khi nl, vg/ ph EMEEE Xich con Ian 12,7 - 15,375 19,05 — 25,4 31,75 — 38,1 44,45 — 50,3 12,7 — 15,375 19,05 - 25,4 31,75 C6 thé bién ddi cong thdc (12.17) dd tinh true tiép buoc xich t. Biéu thj I1_Ic vong F, = 2'1‘, /51 ; '1', = 9,55.l0°9?n1 ; 5, 3 2111:: ; A 3 0,238 ; ae1-11 nl - oong sufit v5 36 vbng quaytronglphfitcfiadiaxichdfinmacdcongthtictinhbuocxichtcfiaxichcon1511 ta 2,82 ‘V TIK (12-19) z. K.n=1 ' mm 13‘ . ’RK hogc t 3 600 'z , mm (12-20) Trong céc cong thdc tr-en T1 tinh hing N. mm ; Q5 kW ; [p] — MP1: ; nl - vg/ ph. Tr: 36 ép suit cho phép [p] co the’ My ti‘: s6 trung binh, ting vdi 36 vong quay nl cue. 14
  14. 14. dia xich dén (bang 12.4), sau khi tinh duoc buoc xich t, ta qui tron theo tri 36 tiéu chufin gain nhdt vn kiém nghiem lni ép suit theo cong thdc (12-17). D6 tfnh toén thiét ke’ xich duoc thuagm tien hon, co‘ the’ bién d6i diéu kien (12-17) ra dang duéi day. T1‘: (12-17) ta co Ftv [p] . A . K3 Zlnlt “‘~‘=1oTo5“m5‘. ?~5o’. im “H” Nhan ca mfiu s6 V9. tit 36 0119. ve’ phéi bat ding thdc (12-21) voi Z01 vé no, via dat me = [p]. A.Zo1.n°lt . K2 = 20-1. K = 32 e.107_ ’ Z1’ " n, 10 (12-21), c6 thé viét [fl. Kx Rs; Ihoéc K. Kz. Kn. R 0?, = ——-T—— S we (12-22) trong dd Q — cong tinh to1in, '[! H -‘cong su§t cho phép cua bo truyén xich mot day (Lien X6 co) co buoc t, 36 rang dia dén Z01 = 25 Va 56 vong quay din din nol, cho trong bang 12.5. Khi st’: dung czic s6 lieu trong bang 12.5 taldy K2 = 25/21 ; Kn = nol/ nx, tri 96 nm tuy thuoc viec chon tri 36 [Q theo cot nao trong bang. ' Bing 12.5 Tri 36 cong sud’! cho phép RH, kW, crla bo truyén xich (véi Z01 = 25) Buoc [03, kW, khi s6 vong quay din nhé n01 vglph t, mm Xich con Ian '1 day IIP12,'7 - 9000 - 2 IIP12,7 - 18000 - 1 HP 12,7 - 18000 - 2° HP15,875 - 23000 - 1 15,875 HP15,875 - 23000 - 2' 15,875 HP 19,05 - 32000‘ IIP25,4 — 567007 HP31,75 - 88500’ l'IP38,1 - 127000‘ HP44,45 - 1V72400' HP50,8 - 226800’ 12,7 Ch’é B . -. 10 15,875 1 u rang mm 19,05 25,4 cm; thich . - Xich c6 dénh dau ' duoc ché tan 1 day, 2 day V5. 3 day . 15
  15. 15. D6i voi xich rang tri s6 cong suit cho phép cho trong hing 12.5 ting vdi xich c6 chiéu tong 10 mm. Chiéu tong B ct'1a xich ring lam viee voi eong suit R 1099. KKZKH V , 13 5 —W—- , mm (12-23) Ngoéi eéch tinh xich vé mon trén day, nguoi ta con tinh xich theo do bén moi, dé trénh xiy rs. hong vi moi cic phin tt't xich (thuong 15 cic mi xich). Tinh toén 'tie’n hanh theo phuong phép kiém nghiem he s6 an toin vé do bén moi no cua ma xich tui tié’t dien di qua 16. Vi bien do ting suit sinh ra trong t'ie't dien nguy hiém mi xich cung ty le thuin voi ip suit trong bin lé xich, cho non dd tinh toén duoc don giin, 7 each tinh vé moi cfing duoc quy vé kiétn nghiem tip suit trong bin lé xich, tuong tu nhu tinh vé mon [cong thuc (12-17)], nhung ip suit cho phép [p]‘ duoc liy theo diéu kien dim bio do bén moi. Vi du d6i voi mi xich con lin (Lien X6 cu) co buoc t = 15,875, lam bang thép 45 tr‘; 56 [p]' = 24 MPa. 12.0. TR1NH TU 'rH1fi'r Kfi. mi 01,) 12.8.1. T1-inh tu thiét k6 be truyén xich 1. 011911 loui xieh 2. Chon 36 ring dia nho Z1 = 29 - 2n 3 19, trong do u — ty s6 truyén. Tinh s6 rang dia ion Z2 = uZ, . 3. Tinh buoc xich t. Kiérn nghiem xem buoc xich nay co nho hon tri s6 gioi ban cho. trong bong 12.3 khong. Ne'u lon hon, d6i voi xieh con Ian phii ting s6 day xich vi giim buoc xich dd diéu kien (12-17) dttoc thoa min, con d6i voi xich rang phii ting chiéu tong xich B (d6 giant buoc xich t)» 4. Dinh so ho khoong cich true 9. (niu a. chua cho truoc) 1-6i tinh s6 mit xich X theo cong thtlc (12-3) vi qui tron X theo s6 chin gin nhit. Tinh chinh xic khoing each true a theo cong thtie ('12-4). D6 xieh khong qui sing, ein giim bot khoéng each a (15 tinh mot lttong An = (0,002 + 0,004)a. 5. Tinh dttong kinh céc dia xieh {theo cong thde (12-1)]. 6. Tinh luc tic dung len true [theo eong thtic (12.-16)]. 12.6.2. Thi du 7 Thiét~ke' bo truyén xich trongdfin dong hing tii, van t6c dia xich din n1 = 140 vg/ ph, t)? 36 truyén u = 2,5, cong suit ER = 2,5 kW, tii trong em. Xich nim nghieng mot goo Ion hon 60° so voi duong nim ngang, tru-c din xich c6 thé diéu chinh duoc, boi tron xich bang phuong phép nho giot. Gidi : ‘ 1. Chon loui xich. Vi van toe khong cao cho nén chon loui xich con Ian. 2. Chon s6 rang dia nho theo diéu kien Z1 = 29 - 2u 3 19,. liy Z1 = 25 ring. Tinh 56 ring dia Ion z, = uZ1 = 25.25 = 62,5 15
  16. 16. Lfiy Z2 = 63 rang. Tjr s6 truyén th1_Ic cfia ht) truyén xich u = Z2/Z1 = 63/25 = 2,52 3. Xéc ctinh budc xich t theo cong sufit tinh toén Q [cong thflc (12—22)] Va tra bang 12.5. Laiy Kd = 1 (téi trong ém) ; kg = 1 (vi 15y khoang céch true a z 400 ; K0 = 1,25 (bo truyén c6 gdc nghieng 1;; > 60°) ; Kd'c = 1 (M truyén cd thé diéu chinh ctuqc) ; Kb = 1 (boi tron nhé giot). He 6 diéu kien st’! dung xich [cong thllc (12-18)] K= l.1.1,25.1.l=1,25 He 36 rang dia din : K2 = Z01/Z1 = 25/25 : 1 He 36 36 vbng quay (lay no! = 200 vg/ ph) K" = no! /n1 = 200/140 = 1,42 Cong suit tinh toén :3 . —. 1,25 . 1 . 1,42 . 2,5 = 4,44 kW Theo béng 12.5 (vbi 1101 = 200 vg/ ph) chon xich 1 day c6 buéc t = 19,05 co’ kg? hieu up 19,05 — 32000, cong sum cho phép [091 - 4,8‘ kW. Tri s6 1: mm hon tri as giéi han (bang 12.3). 4. Dinh so ho khoéng céch true a -— 40_t = 40.19,05 = 762 mm. Tinh as rnét xich theo cong mac (12-3) ’ ‘ x = o,5(25 + 53) + 2,762/19,05 + 0,25(63_— 25)2.19,o5/08.762) = 124,9 Lfiy 36 mét xich X = 124. Tinh chinh xéc khoang céch true a lcong thfrc (12-4)] a = 0,25 . 19,o5[124 — o,5(25 + 63) + J [124 — o,5(25 + 63)]? — 2[(s3 — 25)/ n11] = ‘ 753,2 mm D6 xich khbi chiu lt_Ic cang qua Ian, rfit bat khoang each a mot luqng Aa = 0,002; = 1,5 mm. Vay My :1 = 752 mm. * 5. Tinh dufing kinh céc dla idch [cOng thtic (12-1)] Dating kinh din xich dfin ' K - 19,05 ‘ - d1 = ————sin(fl/25) - 152 mm Dubng ldnh dia xlch bi din 19 05 #2 = sin(2;/63) = 382 mm 6. Tinh luc téc dung lén true theo cong fhtic (12-16). Lafy he 36 kt = 1,1. Ll_Ic vbng [cong thtic (l2—l2)] Ft = 6.107.2,5/(25.l40.19,05) = 2250N 2.CTMT2-A 17
  17. 17. Chuung 13 'mUYi§: N DONG DAI 13.1 KHA1 NLEM CHUNG 13.1.1. C£1’u tao chinh cfia bf) truyén dai BC) truyén dai thubng gém hai bénh dai, (hinh 13.1) bénh d£‘in 1 vii bénh bi déin 2, ubng dai 3 mile cang trén hai bzinh dai nhb bo phan cang dai 4. Do co’ ma sét gum dai vé. bénh, bénh dim quay sé truyén chuyé'n d<_5ng vb. co nang sang bénh bi dfin. Hinh 13.1 Theo hlnh dang tié’t dién dai, dai duqc chia lam b6n loai 2 dai det (hinh 18.2a) c6 tié't dién chi’! nhat, dai hlnh thang (hlnh 13.2b) c6 tié't dit; -n hinh thang, dai hlnh luqc (hlnh 13.2c) Va dai trbn (hlnh 13.2d). Dai hlnh luqc c6 céiu tao gfim nhiéu gfin d¢c co‘ tié-‘t dién hinh thang. Ngoai ra hién nay cbn dung dai rang (hlnh l3.2d), truyén luc 2/‘ -~ Hinh 13.2 1 3 2.CTMT2~8
  18. 18. nhb an khép cua dai véi céc rang trén banh dai. Dai det Va dai hinh thang dugc dung tong rii hon ca, con dai tron chi dung trong nhftng may cong sufit nho : méy khau, trong cac khi cu v. v.. . Thubng dung ho truyén dai dé’ truyén chuyén dong giiiia cac truc song song vé. quay cimg chiéu nhau (hlnh 13.1). Tuy nhién, né’u bit chéo dai (hinh 13.3a) bu truyén cd that truyén chuyén dang gifta cac truc song song quay nguoc chiéu nhau. Néu bit nfia chéo vbng dai (hinh 13.310) hoac dung banh dai trung gian (hinh 13.3c) ta sé co cac bu truyén dai truyén chuyén dung gifts. true 116 tri chéo gdc hogic an nhau. Trong céc truéing hqp may cnnh dai chdng bi man vi banh dai phtii khé rang, do 116 It duqc dung. ; Hinh 13.3. '. _ 13.1.2. Uuhhuqc diém vi phum vi st’: dung Truyén dong dai c6 cac zzwdiém sau : - — C6 ‘khi ‘nang truyénchuyén dung vh ca nang gifra cac true 131 kha xa. nhau. - Lam viec em, khong 611.2 — Git“: duqc an tohn cho can tiét may hhéc khi bi qua tai (luc nay dai sé trugt tron trén bénh). ' g - Két can don gian, gm thanh ré. cac nhuqc diém cua truyén dong dai : — Khuon khd kich thubc khi ldn (khi cung mut diéu kién lam viec, thutmg riéng dubng ldnh banh dai da ldn hon dating kinh banh rang khoang 5 ifin). - Tjv s6 truyén khong 6:: din! ) vi co truqt (1311 M1 cua dai tron banh. — Luc tac dung lén truc vb. 6 1611 do phai chug dai (luc téc dung lén truc va 6 tang them khoéng 2 + 3 l§. n so vfli trong truyén dung banh ring). - Tudi tho thfip khi lam viec vfii van t6c cao. B0 truyén dai thubng duoc dung d6 truyén cong suit khong qui 40 + 50 kW, van t6c thong thubng khoéng 5 + 30 tale. '1')’: s6 truyén u cua truyén dung dai dot thufmg khfing qué 5, d6i'v6i truyén dong dai hinh thang u s 10. B0 truyén dai thudng duqc b6 tri :3 cflp we do nhanh, bainh dén lip vac true dung ed (hinh 13.1). T1-ong trubng hop nay kich thuétc bo truyén tuung d6i nhb gon. 1 13.2. CA0 LOAI m1 VA BANH mu 13.2.1. Cac loui dai Vat lieu lam" dai phéi théa man cac yéu cfiu nhu co du (19 bén méi vi bén mon, he 6 ma sat tuong d6i lén va c6 tinh dim hdi cao (mo dun clan hdi thfip). Trong cac vat liéutu nhien, chi co dai da logi tdt la thba. man cac yéu caiu trén. D6i vdi dai lam bang vat lieu tdng hop, 1:16 1:110 dém dai cd dz‘: dc) bén, cac 16p chin 19
  19. 19. tai trong chinh duoc lam hing soi vai hen hone soi kim logi, b6 tri theo mot trung hoa eua dai. Lop vé boe cua dai duoc lam bang vat lieu c6 he so ma sat cao, chéng hon nhu cao su. Cac loui dai dot Dai do lam vioc hon lou, kha nang tfii cao, chiu va dop tot. Dai da raft bén mon non lam vioc tot trong cac ho truyén chéo. Nhuoc diém cua dai da 15 gia dét, khong dung duoc 6 noi co axit, fin: uat, cho non hion nay it dung. Dru" vdi cao su gom nhiéu lop vii va cao su duqc sunfua hoa. Dai vii cao su c6 do bén cao, don hoi tot, it ehiu énh huong cua thay ctdi nhiot do va do Em. Do do hion nay dai véi can su duoe dung rong 1-iii, dung dé’ truyén tai trong tuong ddi 6n dinh. Khong nen cho da‘u day vac dai véi eao su vi dé lam bong cao su. Loni dai nay khong chiu duoc va dop munh. ‘ Dan‘ 0911‘ bong co‘ hai loai : dai dot day va dai khau nhiéu lop. Dai soi bong co khoi luong nho, gia ré, dung. thich hop 6 cac truyén dong c6 von toe cao, cong suat nhé. Dai soi bong kha mém non co‘ thé lam vioc voi eac banh dai c6 duong kinh nho. Khé nang tai va tudi tho cua dai soi bong thap hon dai da V9. dai cao su. Khong nén dung dai soi bong (Y nhfxng noi am uot hoac nhiot do cao. Dai sot‘ len ché’ too to len dot (soi ngang la soi voi), tam h6n hop oxyt chi va dfiu gai. Dai co tinh don hoi kha cao nén co thé’ lam viec tot khi tai trgng khong on djnh huge co va dop va khi banh dai co’ duong kinh nho. Dai soi len it chiu huh huong c1'1a moi truong (nhiot do, do fim, bui, axit v. v. ..) nhung khi nang téi kém hon so voi cac _ loai dai‘ khac. Daj s51 len gia an. Dan’ bong cdc loot‘ vot lieu tong hop voi nén co bin 19 nhua poliamit lién két voi cae lop sqi tong hop la capron. .. co do bén vé tuoi tho cao, chiu duoc va dap, co’ thé’ lam vioc voi toe do cao don 80 + 100 m/ s.. '11-1‘! mot 6 loui dai det hing vot lieu tong hop duoc cho’ tao sfin thanh vong kin, con noi chung dai dot duoc che. ’ too thanhnhfrng bang dai. Khi dung, tuy theo khoéng each true nguoi ta cit ra vo. noi dau dai lui thanh vong dai. Dai duoc noi 'b§ng'cé. ch dan, khau hooc dung cac vot noi bong kim logi (dung cac tfim kep va bulong v. v.. .). . Ch§t luqng dfiu noi co énh huong Ion don su lam vioc cua bo truyén dai nhdt la khi van toe Ion va khoang each true ngan. Kieh thuoc chiéu tong 1) Va chiéu dai h m dai dot duoc tiou chufin 1169.. Bing 13.1 cho eéc ldch thuoc tieu chudn ct'1a mot so loui dai véi can an cfia Lion xo ci1.Chiéu day cua dai khong e6 aic lop lot bang cao su xen gifxa lop vii nho hon sovoi dai ed eac lop lot. A . ' _. Bing 13.1 Kich thuéc dai mii can 311 (Lien X0 czl) Chiéu day dai h, mm S6 11"" Cm“ ’°“"” dai Dai B-800 vs B—820 Dai BKHJI -05 va BKHJI 65-2 vé.1 b, mm 06 lop lot khong lop lot ed lop 16t khong lop 1o’t 4,5 3,0 3,0 6,0 4,3 4,0 7,5 6,0 5,0 9,0 7,2 6,0
  20. 20. .‘ lop sqli hen 1 chiu kéo, lap vai cao au 2 M9: 36 tri s6 chiéu r¢ng tiéu chufin ctia dai véi cao su : 20, 25, (30), 32, 40, 50, (60), 63, (70), 71, (75), 80, (86), 90, 100, 112, (115), (120), 125, 140, (150). (160), (175), 180, 200, 224, (225), 250 (nén trénh dimg céc tri 36 trong ngoac). Céc kich thuéc tieu chudn cxia dai sqi bang. (Lien X0 cfl) cho trong bang 13.2 Bang 13.2 Kich thudc dai sqi bong (Lien X6 ca) Chiéu tong b, m S6 16;: Chiéu day h, mm 30, 40, 50, 60, 75, 90, 100 4 4,5 30, 40, 50, 60, 75, 90, 100, 115, 125, 160, 175 8 6,5 50, 75, 110, 115, 125, 150, 175, 200, 225, 250 8 8,5 Dai hinh thang Ciu tao cfia dai hinh thang glim céc phén sau (hlnh 13.4) : 16p sqi xe'p hoac boc quanh dai va 16p cao an 3 chin nén. Mat lam viec cfia dai la hai mgt hen, ép vao ranh c6 tie’t dien hlnh thang cfia banh dai. Khi dai vbng qua bénh dai, gifxa mat trong cixa dai va déy rinh c6 khe hc‘: . Nhb téc dung chem ctia dai vao bénh dai cho nén ma sat gifts. dai va bénh dai tang lén : gdc chem «p cfia dai hinh thang béng 40°. Lép sqi 2 in lap chin mi chi’: yéu, lam béng céc vat lieu nhu sqi qapron, lép xan, visco v. v.. . c6 modun clan h6i cao hon nhiéu so vai cao su. Lop sqi nay Hinh 13.4 duqc b6 tr! tren mat trung boa cna dai cho nen khong phai chin fing sum; u6n ainh ra khi dai u6n quanh banh dai. Dal hinh thang duqc chd -tgo thanh vbng lién, do dd lam viec em hon so voi dai det, phéi n6i dai, Tieu chain quy dinh 6 logi tiét dien dai hlnh thang, theo thti tn tit nhé dén lcn Z, O, A, B, C va D, kich thudc tuang vdi 6’ 1031- dai tieu chudn cfia Lien X6 cf: 0, A, B, B, F, JI. T)" 86 giiia chiéu mug ldn hlnh thang v6i chiéu cao cfia dai hinh thang binh thubng b/ h =6 1,6, cbn d6i vdi dai hinh thang hep b/ h z 1,2. Tieu chufln TCVN 3210-79 quy dinh kich thuéc tiét dien dai hlnh thang hep gdm 3 loai SPZ, SPA va SPB, tuong ting ivéi dai YO, YA, YB ctia Lien X0 cfi (cd 4 loai dai hlnh thang hep YO, YA, YB, YB). Vdi cimg chiéu tong dai, dai hlnh thang hep c6 chiéu cao h ldn hon, do dd khé. néng ca: cao hon dai hinh thang binh thtrbng. Bang 13.3 cho céc thong s6 chi: yé’u vé kich thucc céc logi dai hinh thang Lien X0 cfi. 21
  21. 21. Bing 13.3 Kick" thztdc dai hinh thong (Lien X0 ca) Kich thttéc tié't dién, mm A1, 10, Chiéu dai Khdi lttqng rnmz mm gioi han, mm 1m dai, kg/ In Ell“ 8,5 10 6 2,1 400 - 2500 13 560 - 4000 800 -. - 6300 1800 - 10600 3150 — 15000 4500 - 18000 030 - 3550 800 — 4500 3550 — 8000 2000 — 8000 C'hz2 thick. Céc kich thuoc bo, b, h, yé — xem hinh 13.43, 10 — chiéu dé. i.ct’1a dai chufin ; A1 — dien tich tiét dien dai. 1 Loai tiét Loai dai dien Dai hinh 0 thang Dai hinh thang hep Chiéu dai tinh toén cfia dai hlnh thang, do theo mat phéng trung hba c1’1a dai, duoc quy dinh theo tiéu chudn. Céc tri s6 chiéu dai tiéu chufin (mm) cfia dai hinh thang : 400, (425), 450, (475), 500, (530), 500, (600), 630, (670), 710, (750), 800, (350), 900, ‘ (950), 1000, (1060), .ll20, (1180), 1250, (1320), 1400, (1500), 1600, (1700), 1800, (1900), 2000, (2120), 2240, (2360), 2500, (2650), 2800, (3000), 3150, (3350), 3550, (3750), 4000, (4250), 4500, (4750), 5000, (5300), 5600, (6000), 6300, (6700), 7100, (7500), 8000, (8500), 9000, (9500), 10000, (10600), 11200, (11800), 12500, (13200), 14000, (15000), 16000, (17000), 18000. Dai hinh luqc Dai hinh luoc c6 céc gan doc (1 mat trong cfia dai (hinh 13.20 Va 13.5), céc gan nay gai vac céc ranh hinh thang khi dai vbng qua bénh dai. S6 gan nén lay chin, thuong trong khoéng 2 + 20 gan, cho phép co thé ché' tno dai co dé’n 50 gan. Trong pha'n phéng cfza. dai co mm: 36 lop véi cao su v0 (:30 soi hen. Dai hinh l1Ioc'c6 uu diém 10 he s6 ma sét khé. cao dfing thbi cfing dé u0'n quanh bénh dai nhu dai dot, do do co thé’ giém duong kinh bénh dai va, _tang ti 35 truyén dén u s 15. Kich thudc dai hinh luoc "cao loni K, .11 Va M c1’1a Lién X0 cii cho Hinh, 13,5 trong bang 13.4. Loni dai hinh thang, dai hlnh luoc vé duong kinh t6i thién cfza bénh dai nhé d duoc chon theo mo men xoén Tl trén true quay nhanh, (béng 13.5). 1min 22
  22. 22. Bang 13.4 Kiqh thudc dai hinh luqc (Lién X0 ca) 6Loai Kich thucc, mm Dien tic}; Chiéu dai Kh6i hrong t‘ 1 «re - 1 15335-35m K 2,4 72 400 — 2000 2 — 36 36 0,09 . JI 4,8 356 1250 - 4000 4 — 20 50 0,45 M 9.5 1137 2000 — 4000 2 — 20 50 1,60 Am - dien tich cfia tié’t dien dai c6 10 gan. ' Bang 13.5 Dubng kinh t6i zhiéu czia bénh dai nhd va phgzm vi momen xodn ddi uéi edc logu’ dai hinh thang (Lien. X0 ca) Logi dai Ky‘ hieu Dai Ky’ hieu Momen trén true tiét dien quay nhanh T1-, N. m Momen trén dlmm, mm Logi dai £30 15 - 60 hinh 90 - 400 45 - 150 thang YB‘ ' 300 - 2000 120 - 600 '5 > 1500 420 - 2400 1600 - 6000 Chtt thich : 1. V61 tri s6 Tl cho, tie’ tang tudi tho vé. hieu susit néfi chon logi dai tiét dign nhé fzrong phgm vi ed thé’. 2. Lfiy dl I611 sé_ ting dtiqc hieu suit va tudi tho dai. Dai rang Dai rang duqc ché' tao thanh vbng kin, phia trong (:6 ring hlnh thang (hinh 13.2d) an khdp vdi céc rang trén bénh dai. Cflu tgo dai gdm céc sqi thép hen (cap) la phfin tit truyén téi trgng, va nén Ia cao su hoac chat déo, dai duqc bgc véi nylon dé’ tang dc bén mbn. Truyén d¢ng dai rang két hop duqc céc uu diém cfia truyén dong dai Va truyén déng xich. So véi truyén dtjng xich dai rang lam viec it 6n hon (khe hi! khi an khfip tuong d6i nhé) va khong dbi héi bbi trdn. Thong 56 1:61: cfiu chinh c1'1a dai rating 15 mfidun m = tin (t - buéc cfia dai rang) va gdt; 2gp (hlnh 13.26)-. ’ Dai rang ducjc dimg vfii van t6c v s 50 mls, ts’ s6 truyén u 4 12 (doilxhi u s 20) va cong suit défn 100 kW. 23
  23. 23. 13.2.2. Bénh dai . Hlnh dang ké’t cfiu bénh dai duqc quyeft dinh béi kich thuac (thttbng la dubng kinh ngoéi), loai dai va 96 luqng sén xufit (don chiéc, hang loat, hhng khdi) V9. khénang ché' tan can co s6 sin xuaft (hfnh 13.6). v/ A "/ /// //. : := H '/ //. ,7// /A ti) Hinh 13.6 341111 dai c6 auemg kinh 111.5 (duai 100mm) duqlc ché’ tao bang dap hoac dfic, khong khoét 16m (hlnh 13.611). Banh dai cd dttbng kinh lbn thttbng duqc khoét 16m, c6 16 hoac cd 4 + 6 nan hoa, dé’ gifim b6t kh6i lttqng. Céc bénh dai nay thubng bao gdm ba phaln : vanh ngoai, tie'p xfic v6i dai ; mayo (15 lip len true va nan hoa hoac C119. 1161 vanh v6i mayo. Trong san xnfit don chiéc hoac hang loat nhé bfinh dai dubng kinh 1611 che’ ta_. o tfr phoi can, phoi rén, dfic hoac han ; trong sfin xuflt hang loat ldn V9. hang kh6i bénh dai duqc dfic. Hinh dang vanh phu thuoc vao loai dai (hlnh l3.2). . . Béanh dai .151 ed 155‘ mat ngoai la mat tr1_1 (111111: l3.6c) hoac c6 1111111 trdng (phfin gifia hqi l6i) (hinh 13.6d) dd’ hgn ché khé nang tuot dai khéi bénh khi lam viec. V Ddi vdi nhitng ho truyén van t6c cao (v > 40 m/ s) ngubi ta lam nhfmg ranh vbng tren bé mat bénh dai dé’ giim téc dung cfla céc "chem khi dpng", sinh ra khi dai chgy vho bénh dai, cd énh hudng xéu dén khé. nang téi c1'1a bo truyén. Dubng kinh bénh dai nén 15y theo céc tri s6 tieu chufin (mm) : 40, 45, 50, 56, 63, 71, so, 90, 100, 112. 125, 140, 160, 130, 200, 224, 250, 315, 400, 450, 500, 560, 630, 710, 800, 900, 1000, 1250, 1400, 1600, 1300, 2000. -DuBng kinh tinh toén c119. bénh dai hinh thang, 15 dubng ldnh vbng £1-bn qua lap trung hba cfia dai cling My theo céc tri s6 tieu chufin trén day (tit 63 mm trd lén). Chiéu tong B bzinh dai det khi méc blnh thubng B '= 1,lb + (10 -1- 15) mm khi méc chéo hogc nfta chéo : B = l,4b + (10 + 15) mm b — chiéu rqng dai. Tri 56 B nén My trbn theo tieu chufin (mm) : 40, 50, 63, 71, 80, 100, 125, 140, 160, 200, 224, 250, 315, 355, 400, 450. Kich thuéc ctia ranh bénh. dai hinh thang duqc quy dinh theo tieu chudn. Gdc ranh zp trong khoang 34 -1- 40°, tiny theo dubng kinh banh dai, My tr; 56 nhb khi dating kinh nhé (vi c<5 bién dang cfia tiét dien dai khi bi u6n, dating kinh bfinh dai cang nhé, dai bi bién dang cang nhiéu). Bing 13.6 cho céc kich thuac chi: ye’u cfia ranh bénh dai hinh thang (Lien X0 cfi) (hinh 13.7). V ‘4 24
  24. 24. Chiéu rcng ‘B cue. bénh dai < B = (x - D1: + 2S x - s6 dai. _ Bang 13.6 Kick thudc ch11 yéu aria rdnh bdnh dai hinh thong (Lien. X6 cfi) (mm) Hinh 13.7 Kich thuéc két cfiu hénh dai hinh luqc va bénh dai rang cho trong céc tai lieu vé truyén dang dai. 13.3. CAO THONG S6 I-IiNH Hoe cHiNH Xét t1-ubng hqp ho truyén dai méc blnh thttbng nhu so C16 trén hinh 13.8 ; dl va dz - dubng kinh tinh toén c1'1a bénh dén va bénh bi din ; a — khoéng céch gifiah hai true ; a, , a2 — gdc om cfia dai tren bénh nhé V9. bénh l6n. y - gdc gifta hai nhénh day, 19. gdc gifta hai dubng tiép tuye’n vdi cao vbng tron dl vb. dz (gdc 19.m, b(’1i 1 nhénh day vdi dubng n6i hai tam 0102 hing y/2). Duemg kinh tlnh toén Ad, va dz ddi voi dai Hinh 13.8 det la dubng kinh ngoai cda bénh dai, d6i vdi . dai hinh thang hogc dai hlnh luqc 19. dubng kinh vbng trbn qua 16p trung hba c1'1a dai. Céc thongad hlnhhgc chinh cfia b0 truyén dai la dating kinh d1, d2, gdc Om al, chiéu dai dai L vb khoéng céch true a. Dubng-'k1nh banh dai khcng nennldy qua 11116 do’ trénh cho dai khéi échiu ting sufit u6n qué ldn, sinh ra khi dai vbng quanh bénh dai. . Dubng kinh d1 cfia bénh (19.1 11116 trong b0 truyén dai det ed thé xéc dinh theo cong thfic th1_1c nghiem c1‘1a Xaverin d1 = (1100 +1300) Wyn, hoac ' (13-1) :1, = (5,2 + 5,4) W, mm {R1 - cong suéit trentruc dén, kW ; T1 - momen xoén tren truc din, N. m 25
  25. 25. D61 vai dai. hlnh thang nén my among kinh bénh dai 11115 ‘:11 dlmin — dubng kinh t6i thiéu, tra bang 13.5. Dubng ldnh bénh dai Hm I! 1’2d1min 5 dz . = 111110 - 3) (13-2) trong dd 11 - 1:5: s6 truyén ; E - he s6 truqt. Gdc om oz] trén bénh nhb a1 = 130° — y 5- 130° - 57°01, - <11)/ a (13-3) Chiéu dai dai L = 2acos(y/2) + 0,57r(d2 + .11) + 0,5y(d2 - dl) Thong thubng y < 35°, do dd ta chi ehfi ,1 dén hai s6 hang aau cue day khai men, c6 thé lfiy cos(; v/2) z 1 - 72/8 vé lfiy y = (dz - dl)/ a. Do dd ta c0 7z(d +5) (32-3)? L=2a+-—--la-—-—3-+-4% (13-4) 1 Md, + =5) : c(d, + (12) Gdc 0111 0:1 nhé sé énh hudng xfiu dén khé nang kéo cfin dai, do dd (161 vdi dai det cfin thba man diéu kien a1 3 150° ; ddi vfii dai hlnh thang, do c6 tfic dung chem cfia _ dai vqi ranh bénh dai, cho. nén chi yeu can 0:, 3 120°. Khoéng each true a cang Ian thl gdc om al cang Ian (trong t1-uélng hop u as 1) v9. ' tan 6 thay d6i ling suit trong dai sé giém. Do dd (I61 vdi dai det nén My . a 3 2(d1 + dz). D6i voi dai hinh thang khoéng each true t6i thiéu ' ' am, “ as 0,55(d1 + dz) + h h - chiéu cao dai hinh thang. _ ' V Dd’ 1’ ban che’ kich thdbc, giém gié thanh vh ngan ngua dao dong ngang cua dai, khoéng eéch true ldn nhfit cua bl) truyén dai hinh thang am” = 2(d1 + dz). Tuy nhién khoéng céch true a chng nhé 36 vbng chgy eua dai trong 1 giay v/ L sé tang lén, khién tudi the cue. dai giam xudng. Nén My v/ L = 3 + 5 d6i v6i dai det vb. V/ L = 20 +‘ 30 (mi 1161 dai hinh thang vi dai hinh luqc. 13.4. C0 HOC TRUYEN DONG DAI 13.4,]. Lxrc téc dung lén dai Dé tgo nén luc ma sat gifta dai Va bénh dai, Cain‘ phéi cang dai vdi luc cdng ban dhu F0. Khi b0 t1-uyén lam viee, bénh din chiu téc dung cfia momen xoén Tl, trong nhzinh dén 11,10 sé tang len In F, va trong nhénh bi din lue aé giém xudng 0011 F2 (hinh 13.93). Ta c6 he thflc 26
  26. 26. (13-6) F1 19. luc c6 ich, N ; dl - dubng kinh bfinh d§n, mm ; Tl - momen xoén tren true dfin, N. m ; Q - cong suit, kW ; v - van t6c vbng cua bénh dai, In/ . De’ tim quan he giita luc cang ban (mu F0 vdi céc luc F1, F2, ta bé qua luc ly tam Va gin thiét vat lieu dai tuan theo dinh luat I-Itic, khi dai chiu tei trcng ngoai luqng den trend nhénh din bang lttqng co Hinh 1'19 t1-en nhénh bi din nghia 13 F, = F0 -1’ 0,511‘, va F2 = F0 —- 0,511, vay F0 = 0,509, + F2) (13-7) Ole da tlm ra he thdc gifts. cée luc cang Fl va F2 phu thu0e ma sét gifra dai V9. bénh dai. Trong trubng hop tdng quét ta xét dai hlnh thang. Cét mot phén t6 dai beng hai met cét theo hudng klnh (hlnh 13.93) v9.. dat céc lt_Ic phép tuyén v6i céc mat cét nay F + dF vb. F. Tren phan t6 dai nay (hinh l3.9b) cbn chiu : eée luc phép tuye’n dFn, luc ma sat hudng kinh ve luc ma sét vbng dFf = fdFn (f he 56 ma sat gifts dai vé bénh dai) va h_tc quén tinh ly tam cfza phan t6 dai dF" = qmvzda (qm — kh6i luong dai c6 cliiéu dai 1 mét ; v - . v$n t6c vbng eI’1a dai). - Diéu kien can hing cua phan 1:6 dai theo hudng bkinh da da (F + <11‘)? - F? + dF" + zdrnsing + zdrtcosg = 0 (13-3) Dieu kien can beng theo huéng tiép tuyenl _ _ F + 2dFf -- (F + dF) = O " ' (13-9) T1‘: ding thfic (13-9) ta ed (‘IF = 2dFf. 5 2fdFn vi they vac ding thdc (13-8), be qua s6 hang V6 cimg bé bgc cao, timduqc dF (F — qmv2)dn = ? ' (13-10) trong dd, f’ — he 36 ma sat tudng duang 1' = A (13-11) sin((o/2) + fcos(4p/2). 27
  27. 27. 'I‘t‘1 ding thfic (13-10) c6 thé viét “ = f‘da F -qm V Tich phan hai var (ting thflc t1-en theo cé cung truqt at, ta c6 F1 at I fig = I f’ <10 FZF "qm 0 hay 191 F1 - Fv , - _ r _ _ F2__Fv . _ e at _ A (13 12) trong dd F“ = qmvz — 11_Ic cang ph1_1 do lyre l_y tam gay nen. Luc ly tam c6 téc dung A lam giém ép sufit gifxa dai vb. bénh dai, nghia la lam giém téc dung cd ich c1'1a l1_Ic cang ban (mu F0 (Céc cong thtic tren luc tinh bang Niutdn, qm tinh hing kg/ Vm vé v . V tinh bhng m/3). Th1_Ic nghiem cho thfly khong cd chuyén vi hufmg kinh cfxa dai trén bénh din, do 116 t; =‘f/ sin((p/2) ’ (13-13) 1361 v6i dai den (0 = 180° va 1' = 1. Qfia day (:6 thé may to kha nang téi cfia dai det 1:116 thdp so viii dai hinh thang (khi gdc (p = 40° thl f' z 30. Giém gdc (p se tang duoc he 56 um sat tuong duong f‘, tuy nhien cd thé gay nén hien tuqng ket dai, lam hbng dai tit nhanh. . Trong cdc ho truyén dai cd van tdc v < 10 rn/ s, c6 thé b6 qua hm quén tinh va oong thflc (13-I2) 0'6 dgng thong thubng, ggi la cong thflc Ole F _1_: '_1 _ F2—e“; —}. ‘ (1314) T1‘: can he thfic (13-6) va (13-12)» ta cd _ / I A F1 . Fl= ;.tf1Ft+FV; F2=Fl-Fl= T_j+Fv (13-15) Luc me dung len truc bénh dai (hlnh 13.10) 1- ‘ ' Fr = F11 '+ F2: + 2FlF2cosy as 2F°oos(y/2) hoac ~ _ Fr = 2Fosin(czl/2) ‘ (13-16) vfii al - gdc om t1-en bénh dai nhé Hinh 13.10 '28
  28. 28. 13.4.2. frag suat trong dai Ung suit cang ban dfiu do F0 gay nén F 0 a0 = T 1 (13-17) A - dien tlch tiét dien dai. D6 dai lam viec duqc lau bén, qua kinh nghiém sit dung ho truyén dai, ngutii ta lay do = 1,_2 + 1,8 MP3. Khi chiu téc dung cua txii trgng ngoai, ting sufit trong nhénh din 0'1 v9. trong nhanh bi d§n 62 (hinh 13.1111) : V F 6l= Kl= Afl1dt+d F2 - 5! ' (13-18) 62 = X = A _ 1 4- av trong dd av = F V/ A -- qmvz/ A = Pmvz Pm - kh6i luqng riéng cI. ‘1a vat liéu dai, ddi. v1’1i dai was cao su pm = 1250 + 1400 kg/ m_3, A - dien tlch tié't dien dai. Ung suit av-_1a ting suat do'l1,tc ly tam gay nen. U'ng suit F1 __ 5. = X _ (1_*'f'2°’ duqc goi la ting suit c6 lch. - ’ j' ‘ Ngoai céc ting suit tron, trong cap _doan dai vbng qua banh dai cbn xufit hie! ) 13ng'su§t udn am, o'u2‘(hlnh 13.11). Theo dinh lufit Hfic, ling sudt ti lg bgc nhat vfii bié’n dang tuang cl6i E Y . . 35:33:? ‘ Hinh 13.11 ymax - khoang cach’t1‘1 thd dai ngoaj cimg dén 16p trung hba cfia dai ; r - ban kinh cong c1'1a vbng dai ; E - modun (Ian 1161, C161 véi dai véj cao su E = 200 -5- 350 MPa. [Tag sudt u6n 1611 nhfit trong dai det khi. dai vbng qua bénh nhé), dubng kinh dl ; yum = 0,5h vs 1- = 0,5 (dl + h) z 0,5dl ; h - chiéu day dai det (hinh 13.l1b) h 6 = —E (13-21) u] d1 Ddi vdi dai hinh thaug, ting suit 11611 ldn nhat 2y° a = — E (13-22) ul d1 29
  29. 29. trong dd yo - khoing cich t1‘: lap trung hba din day 1611' cits. tiét dien hlnh thang. Cic cong thtic (13-20) vi (13-21) cho thiy ting suit udn pht_1 thuoc chiéu day dai vi dubng kinh binh dai nhb. Dd han chi ting suit udn khong nén liy dudng ldnh bzinh dai qui nhd vs. dung dai cd chiéu day ldn. I)'ng suit tdng ldn nhit trén nhanh din ct‘1a dai, l1'1c. dai vio banh nhb (hlnh l3.11a) 2. am = A __ I at 51- av + cu} (13-23) 'Bié'u dd phin b6 ‘ting suit theo chiéu dai dai trlnh bay trén . hlnh 13.11. Khi dai lam viec mdi phan td dai chin ting suit thay ddi, tri sd lén nhit li omax vi tri sd nhd nhit 13. 62. [Tug suit thay ddi Ii nguyén nhan gay nén st; héng vi méi cue dai. _ 13.4.3. St! trtxqt cfia dai Tuong tt_1 nhu trong truyén dong binh ma sat, khi truyén tai trong gifxa dai va binh dai cung xiy ra hien tuong trugt dam hbi. Nhu da trlnh bay 6 t1-en, khi ho truyén‘ dai lam viec, cic nhiuh dai chiu tic dung lt_tc khic nhau (so dd luc cd nét lién t1-en hlnh 13.12). Cic phan t6 dai chay trén nhinh-din chiu luc Ii Fl, vbng qua bainh dai din sang nhinh bi din chiu lttc F2 4: F1. Do dd do din dii tttong ddi ct'1a dai cung giim xudng. Kit qui Ii xuit hien st; truot din hdi cits. dai t1-en binh dai, nghia Ii dai chay cham hon binh din. Khi phan td dai chay vbng qua binh bi din, do din dii tuong ddi cua dai tang lén (do me ting tit F2 lén Fl) va. xéy ra trtxqt dan hdi, dai chay nhanh hon bénh bi din. Nhu viy trttqt din hdi cd nguyén nhin do dai cd tinh din hdi, khi lam viec di qua nhfing vt‘1ng chiu luc khic nhau, litn thay ddi bién dang ct'1a dai, gay nén t_1 trtrot tuong ddi gifra dai vi binh dai. So truot din hdi khong xiy ra tren tonn ha cung am (11 vi a2, mi xiy ra trén mot phin cua cic cung nay la an vi am, ggi Ii cic cung truqt. Cung trtxqt (1 vé phla nhinh dai sip ra khdi bénh dai (hlnh 13.12). Tii trong ngoii cing ting len thl cung trttot cing ting len vi cit: cung khong truot am vi ‘am obn gqi 13 cung tlnh, giim xudng. Néu tiép tuc tang tii trong din‘ ‘ mdc cung truqt chain toin ho cung om, sé xiy ra truqt hoin toin, ta ggi la hien tuqng truqt tron. Vay hien tuqng truqt tron xay ra khi bo truyén bi qui tii, bénh bi din dtmg lai vi hieu suit ct'1a bo truyén , bang S6 khong Hmh 13.12 30
  30. 30. 13.4.4. Dating cong truqt va hiéu suit bé truyén dai & Khé. nang tai cua ba. '_. ’a truyén dai dugc dac trung béi luc vbng Ft hoac modun xoén T1 truyén qua banh din, phu thutfnc 11_Ic cang ban dfiu E0 va ma sat gifta dai va banh dai. That vay, b6 qua énh huong cfia lute ly tam, tit car: he thlic (13-6), (13-7) va (13-14) ta c6 2 #2(/1-1) I’ A+1 trong dd : 1}) '—- (/1 - 1)/ '(). + 1) - he s6 kéo. R6 rang la né’u tang l1_rc cang ban dfiu F0 thi 11_Ic vbng F, cfing tang lén. Thy nhién diéu nay cfing din toi la luc Fl = F0 + 0,5Ft cfl_ng tang lén, ting -suat trong dai tang lén va tu6i tho cfia dai giam xu6ng. Nguoc lai, néu luc cang ban aau nhé, luc ma sat sinh ra giira dai va bénh dai sé nhé va ho truyén khong thé truyén duoc luc vbng Ft Ion. Tri 36 hop 1)? cda luc cang ban dau F0 duoc xac dinh qua nghién cuu m6i lién he gifia hé S6 kéo : 1)» = (2 - 1)/ (). + 1) = F, /2Fo = 5,/250 (13-25) voi he 36 truqt 5 = (V1 — vz)/ vl (vl - van t6c vbng cua banh dén ; V2 - van t6c vbng cua banh bi din) va véi hiéu suat 7;. Cac (16 thi duong cong truot 5 - 1p va dd thj dutsng cong hieu suat 7; — ¢ (hinh 13.13) duoc lap theo ké’t qua thi nghiem céc loai dai, trén truc tung ghi ha; s6 truot 3 va hieu suat Q, tinh theo phan tram, trén true hoanh ghi he 56 kéo 1/2. Duong bié’u dién quan hé gifta § va 1): duqc goi la dztong cong tmot. Qua as thi ta thay doan dfiu cda doting cong truqt, khi 0 s 11: s 1/2° , 300 la he s6 kéo toi han, gan nhu dean thing; Diéu nay 9 , chfing 1:6 6 giai dean nay, voi mot tri s6 F 0 da ofz 0'4 w° as W"‘°"W dinh, né’u tang din ta: trong c6 ich F, thi he s6 . ’ Hinh 13.13 truot cung tang theo ti; 19 bac nhdt, nghia la “ ‘ . khi 0 as 1;: as 1;: O trong b9 truyén chi xay ra tnrot dan h6,i. Néu tang Ft dé up > zpo dai sé bi truot tron tfrng phdn (vfia trttot (Ian h_6i vita truqt tron), hé s6 trugt (,5 tang nhanh. _Né’u , tié’p tug: tang Ft dé 1/: dat tri. s6 wmx sé xay ra hien tugng truot tron hoan toan (trugt tron toan phan). F F0 hoac F, = 2 '90 F0 (13-24) Qua dd thi duong cough hieu audit :1 - 1,0 (hinb 13.13) ta thay (1 giai doan (Ian 11) -btang khi 1}; tang lén (chu yé’u do cong suat mat mat trong cac 6 true giam tuong d6i so dvoi 'c0ng sufit c6 Ich). Hieu suat 7;‘ dat tr; 36 we dai khi :1» = 2,00. Lfic nay cung suit mat mét chm’: yé’u do noi ma sat trong dai, vi vay mat mét cong suat cang tang khi duong kinh banh dai cang nhd. Khi 1,0 > 1120 hieu suat giam nhanh vi tang mat mét cong sufit do dai bi truot nhiéu, ngoai ra, dai bi mbn kha nhanh. Nghién cfm dd thi dubng cong truqt va duong cung hieu suat, co thé két luau rang ho truyén dai lam viéc ed 191 nhat khi 1) = ape, t. a'1 day men suit :1 1611 nhfit, den voi dai det 13 = 0,97 -: - 0,98, dfii véi dai hinh thang 21 = 0,92 + 0,97. Néu non hai (Ip < 1P0) kha nang cfia bi} truyén khfmg duqc dung hé’t, né'u lam viéc voi tai trong qua Ion (1/J > 300), 31
  31. 31. dai sé bi mon nhanh, hieu suit gifim va tang mflt mét van t6c. Qua céc s6 lieu thi nghiem tim duoc ‘(po = 0,4 + 0,5 ddi v6i dai det bang vat lieu tdng hop, 1;-O = 0,6 ddi voi dai det véi cao su ', we = 0,6 -1- 0,7 (161 vdi dai hinh thang. Ti s6 rpmmjvao = 1,15 -1- 1,50 biéu thi kha nang chiu qua 1.-.11 tuc thoi cua bo truyén. 13.4.5. Van tdc vi ti 56 truyén V1 co truot cho nén van tdc vong V2 cua banh bi din chgm hon van tdc vbng v1 cua bénh dén : v2=vl (1-5) He 36 truot c1'1a dai dot vai cao su hoac véi I; H 0,01, c1'1a dai hinh thang soi xép .1; = 0,02, soi ben 23 = 0,01. Van t6c vbng duoc xéc dinh theo cong 1311130 Jtdlnl "1 = 60 . 1000 W5 Jrdznz V2 = IBIS (13-26) trong do duong kinh d1, d2 tinh bang mm ; n1, n2 - 36 vbng quay trong 1 phut cua bénh d§n va bénh bi din, vg/ ph. T3’ 36‘ truyén u= w—= F= (13-27) E d1.’ Khi tinh gain dung co the’ b6 qua he s6 truot, do do u = 13.5. 'riNH TRUYEN DONG DAI 13.5.1. chi tiéu tinh toén. "ho truyén dai Qua nhfxng phan tich (3 trén ta thfiy chi tieu chu yéu dé tinh man but} truyén dai lb. khé nang kéo vb tudi tho. D§’dAm bao kha nang kéo c1'1a dai, nghla la khi dai lam viec khong _xay ra truot tron (dfi chi truqt tron tftng phfin) thi he 86 kéo 9': £ 1.00, hay Ii ti’! he thlic (13-25), to. co diéu kien q; = 6,1260 < goo or, us zvpoao W (13-28) Mat khac do téc dung cua ling suat thay d6i, sau mot 36 chu 115' lam viec dai ed thé bi hong do mdi. Quan he gifra ting suit 1611 nhfit am trong dai va 36 chu kjr lam viec NC cho cIe'n khi dai bi héng duoc biéu thi bang phuong trinh duong oong méi (1.6). «o‘D‘: axNc = C (13-29) 32
  32. 32. - Tai trong co va dap va thay dd! nhiau May cat tam. baa may, may nghiin ; thong may ; may Tai trong md may darn 300% so véi iai mic ; may 6p kiau v| ’t va may ép lach tam co vb ling my 1.5 + 1.6 Diéu kién dé dai khong bi héng do mbi am as CW/ N;/ m = C‘/ Nym (13-30) s6 m0 m = 6 d6i véi dai dot ; m = 11 ddi véi dai hlnh thang ; C‘ = 60 + 70 MP3. d6i vdi dai dot. bang cao su ; C‘ = ' 90 + 100 MPa d6i véi dai hlnh thang. Trong mién chu ks: lén (NC > 109) c' = 38 MPa. Ti! cac he thfic (13-23) Va (13-30) to co diéu kien A - 1 6‘ as —; _— (C"/ Ni“ — an — cm) (13-31) D6i v6i 13¢ truyén c6 Xb banh dai cimg dubng kinh (u = 1) s6 chu ky lam viec NC cho tdi khi héng duqc tinh theo cong thtic NC = 3600 (v/ L) Xbth (13-32) vfli th - s6 git! lam viec cho t6i héng ; v/ L - s6 vbng chay cfia dai trong 1 giay; Khi u at 1 ta dimg he s6 vu xiét dén anh huéng khac nhau cfia ting suat udn trén banh nhé va banh 16:1 (ting suit u6n tran banh 16‘n 06 tr: 56 nhb, do dd tudi the tang Ian) NC = 3600 (v/ L) xbthlvu (13-33) 'I‘sy theo tri s6 u (:6 th6 My vu = 1,2 -: - 2.. . Qua cac s6 lieu thuc nghiem cd thé dinh duqc tri s6 ting suat c6 {ch cho phép [6,] théa min cac diéu kién (13-28) va (13-31) (15 dai (:6 £115 lam viec khong bi truqt tron (dam bao kha nang kéo) va lav. bén. Nhu vay dai dugc tinh toan theo diéu kién F: Ka at = A trong do A - dien tich tiét dien dai. D6i vdi dai hinh thong A = ILA], x - s6 dai, A1 - dien tich tiét dien 1 dai hlnh thong ; (161 1:61 dai hinh lugc A. = x. Aw/10 ; x - s6 gan ; Aw -- dien tich tiét dien dai hinh luoc cd 10 gan ; Kd - he s6 tai trong dcng, xét dé'n anh hufdng cfia tai trong dong vé. ché’ d¢ lam viec cfia. ho truyén (bang 13.7). Bang 13.7 s [at] ' (13-34) He s6 tdi trong dong K G ‘ we duh W was Z Ta! trong tfnh. Tal ttong m6 may dan May phat dian. quot. may nan va may born Iy tam ; may 1.0 120% so véi ta} trong danh-nghia cat got Ian tuc ; bang tal Tai trong lam viac 06 date dang nha May bum va may nan khi kiau pitlong co ba xilanh trd Tai trong md may dan 150% so véi Iai Ian : xfch tal. may phay, may bian to van vs tong danh nghfa 1.1 an Iron: lam viac co duo dong lén. Ta: trong ma may dan 220% so véi mi trong danh nghfa Thlat bi din done Quay hai chiau : may burn va may nan khi’ kiau mot hoac hai pft tong : may baa va, may xoc -. vft van chuyan va mang cao : may ap vft va may ép Iech tam co vo Iang nang . 1,25 trong dsnh ngh| 'a cm: rhlch 1. Mi véi dong co c6 momen mé may t6_n. dang mt) nhiéu Ian. oac tri ad trong bang duoc tang tham 0.15 2. Ca: it‘; 36 ‘trong bang ding cho aha do lam vice 1 ca '. nau lam vibe 2 ca can tang {ham 0.15 vs nau lam viéc 3 ca can tang tham 0.35. 3.CTMT2-A
  33. 33. 13.5.2. Tin}: dai det T5'ng sufit cd {ch cho phép cfia dai dot [a, ] = 15,10 Cb ca CV (13-35) trong do [6l]° - ting suit cd {ch cho phép c1.°1a be truyén dai lam viec trong diéu kien thf nghiem tiéu chufin : be truyén nam ngang, gdc Om a = 180°, van t('5c vbng cfia dai v = l0mfs, tai trong khong c6 va dap (bang 13.8). Bang 13.8 mg sudt c6 ich cho phép [ago ctia dai det (uéi a0 = 1,8 MPa) EEEEEEIM Vai cao su Da Sgi bong Sqi len Chzi thick : V6160 = 2MPa can tr; 36 [6110 trong bang dugc tang them 10%, véi do = 1,6 MP9, - giam 10%. Czic he s6 : Cb — he 56 xét dé’n st; b6 tri be truyén va cach cang dai. Néfu be truyén cd be phan t1_t dong cang dai, bao dam 11,11: cang dai khong d6i Cb = 1. Tiny theo gdc nghiéng /3 cfia dufmg n6i hai tam be truyén so vdi duong nam ngang (hinh 13.1) : khi 0s,6s60°Cb=1;khi60°<,6s80°Cb=0,9;khi80°<,6<90"Cb=0,8. Ca — he s6 xét den anh huéng cfia gdc om, tra bang 13.9 theo tr: 9.6 gdc cm a, trén banh nhé, hogc tinh theo cong thfic C a = 1 — 0,003 (180 — al), a, tinh bang (10. Bang 13.9 He s6 ca (dai det) CV - he s6 xét dé’n anh hubng cfia van t6c ; van t6c cang ldn lI_Ic ly tam cang lén, lam giam ma sat giita dai vé banh dai ; CV dfii véi dai det vai cao su tra. theo bang 13.10 hoac tfnh theo cong thflc C = 1,04 - 0,0004 v2, van t6c dai v tinh bang m/ s. V Bang 13.10 H¢ so’ CV (dai det udi cao su) 34 3.CTMT2-B
  34. 34. Dien tich A - tié’t dien dai dot phai thoa man diéu kien (13-34), do do FlKd A = h , —-—- 3-36 h > [63 (1 ) Thong thubng chiéu day h cfxa dai duoc chon trufoc theo dating kinh banh dai nhé dl sao cho h/ dl khbng Ion qua. Né’u_ lay h/ dl 3 1/35 d6i vdi dai da, h/ dl 2 1/40 (161 voi dai vai cao su Va h/ dl 3 1/30 ddi vdi daitsqi bong. Chiéu day h c'1a dai lay theo cac tri s6 tieu chuan T1‘: (13-36) tim duqc chiéu reng b cfia dai : > FLK‘, [61]oCb ' Ca .7 C V b (13-37) 13.5.3. Tinh dai hinh thang» vi dai hinh hrqc Khi thiét ké’ b0 truyén dai hinh thong hoac dai hinh thang hep, loai tié’t dien dai duqc chgn theo trj S6 momen xoan T, (bang 13.5), ~do do da bié‘t dien tich Al cfia tié't dien 1 dai. TL‘! diéu kien (13-34) ta xac dinh duqc s6 dai x : FlKd A16.) 1: 3 (13-38) Chfi y rang [F, ] = A1 [6,] -— Inc vong cho phép d6i vdi 1 dai ; F . v = R va [Ft] . v = [ 93 ], trong do ER - cong suit can truyén ; [ 59] cong suattcho phép cfia 1 dai, ta (:6 the‘ viét he thtic (13-38) (11161 dang : 03 . Kd ‘ . . x 2‘ ml _ _ . (13-39) Cong suit cho phép [R cfia 1 dai duqc xac diiih theo cong thtic : AT1n1 ' 4 [$3] = (99ocacL + 9550) kW . . (13-40) véi {R0 — cong sufit truyén duqc béi 1 daj—Vt1_'ong diéu kieh s6 banh dai trong be truyén xb = 2, ti s6 truyén u = 1, gdc Om a = 180°, chiéu dai dai Lo, lam viec khong co tai trong dong (hinh 13.14a, b - cac~1oo. i"dai hinh thang Lien X0 0, A, B, B ; hinh 13.14c — cat: looi hlnh thang hep Lien xo Yo, YA) ; ca - he 36 xét den anh hudng c1‘1a gdc om -(bang 13.11) ; CL‘ - he 36 xét den anh httdng c1'1a chiéu dai dai den tudi tho dai ; phu thuec ty 36 ‘chiéu dai dai dang tinh toan vdi chiéu dai Lo . ; chiéu dai dai cang tang tan 36 thay as: ting suat cang giam vé tu6i tho sé tang lén (bang 13.12). Bang 13.11 He 36 Ca (dai hinh thong)
  35. 35. . 4" I111 ¢ IIII Eda‘ 3 4.4 x%°¢ — ' ‘ ‘II 6*’ #3; 1: IIII. am ‘II l@— IIIIV/ Vi IIIVIEI H M! 3'2 ,0 I. ,A, ‘ 9 r II[/ //.5 _h_ II/ /Alan 8 I]/ /ADZQE 7 Jmmgnl 6 was 5 I M AKIIII 05 5 1.01.5 20 25 v. mls “ MW IIIIIIII :2 ll -: %%m%%, 35 I0 15 20 25 30 35v, m/s Illllllll I%'fl, , I, /1/4%’ I‘ I I II III 3 5 10 I5 20 25 um]; Hinh. 13.14 ‘ Bang 13.12 He s6 CL L/ Lo. Dai hinh Dai hlnh thang hep L/ Lo Dai hinh . Dai hlnh thang hep va thang vé dai hinh ltwc thang dai hinh Iucyc 0,3 1,2 0,4 1:4 36
  36. 36. C1 - he s6 xét dé’n énh hudng cfxa téi trong (bang 13.10) ', V AT! - s6 gia momen xoén (N. m) la mmfin téi trong cd thé truyén thém ddi v6i céc bo truyén cd ty ~36 truyén u > 1, do ting suflt 1;6n_ duqc giém bat khi dai vbng qua bén’h Ian (bang 13.13) ; véi u = 1 + 1,02, AT] = 0 ; nl_ - s6 vbng quay trong 1 phfit cfia bzinh dai dén. Bing 13.13 S6 gia momen xodn AT‘ (N. m) Dai hinh thang Dai hlnh thang hep I 1,5 0,3 0,7 1,03—1,07 0,5 1,08-1,13 1,1 1,14-1,20 . 1,6 1,21-1,30 2,1 1,31-1,40 2,3 1,41-1,60 2,6 ; 1,6l—2,39 2,9 . , 2,40 V9. nan hon _ 3,1 Dai hinh luqc cfing duqc tinh toén tuong ta nhu dai hinh thang. S6 gfin 1o£RK x a we " ‘ (13-41) V trong (16 [Q - cong suit truyén duqc béi dai hinh luqc 06 10 gin, tinh theo oong thfic (13-40), trong dd 590 — ofimg sufit truyén duqc bbi 1 dai hinh lugc ca’ 10 gan lam viec vdi t9 S6 truyén u = 1, gdc om Q] _= 130°, chiéu dai dai Lo vh ms tmng tlnh (tra bang 13.14). Cong sud: 930 truyén duqc 456:‘ 1 dai hinh luqc rm uion dai ouang lu'nh (1., mm A V Bflng 13.14 91. (kW) khi van we dai v. we $31333 2.9 4.0 4.8 5.3 - 1.35 3.1 4.3 5.2 3.4 4.5- . , 5.7 35 4.9 an 3.7 52 3.9 5.4 pm, .55.: §§§§§ 2553328 sssuaas 37
  37. 37. 13.5.4. Tinh dai rang D6i véi bo truyén dai rang, céc thong 36 hinh hgc chi’: ye'u la modun m = t/ at, t — bufic cfia dai (hlnh 13.2), s6 rang cfisgdai Xd vi chiéu dai dai L. Modun dugc chqu A theo momen xoén Tl trén truc nhanh (bang 13.15). Dttbng kinh bénh dai at = mZl ; dz = mZ2 (13-42) trong dd Z1 vb. Z2 - s6 rang cfia bénh dai _ S6 rang bénh dai nhé Z1 chgn theo mfidun (bang 13.15). S6 rang bémh Ian 22 = Z1 . u (13-43) Thubng chon so bo khoéng céch true a a = (0,5 -: - 2,0) (dl + dz) (13-44) sau dd dinh so bi) chiéu dai L’ cfia dai theo cong thtic (13-4). Theo tri s6 L’ tinh so bo s6 rang Z’d cua dai Z’ d = L’/ (am) (13-45) Va qui trim theo céc s6 Iiéu chuin : 32, 40, 50, 63, 80, 100, 125, 160. Xéc dinh éhiéu déi dai theo tri 36 Z d tiéu chu§n L = mnzd ‘ ’ (13-46) Bing 13.15 Cdc thong 36 can dai rang Lien X6 ca -E Momen tren bénh nhé 4 24.102 as 22.103 4 49.103 s 19.104 T1, N. mm Outing do lyre vbng cho phép qo, Nlmm S6 rang bénh nhé Z1 86 rang dai Z G Chiéu rqng dai 11, mm Kh6i lugng lm dai rcng lmm qm, kglmmm * T1’! s6 IA céc tri s6 cfxa dai ring (:6 duimg kinh cép O,35m1n ; min 96 la cac tri s6 cfxa dai rang cd dudng kin}: cap 0,65rnm. Theo tri s6 L tinh lai khoéng céch true a. Tinh s6 rang dai an khép vdi bénh nhé Z“ = Zlal/360° (13-47) 38
  38. 38. trong dd (11 - gdc Om ct'1a dai tren bénh nhb. Nén my s6 rang dai Z61 as 6. Néu Z G‘ < 6 ca‘: -1 tang khoéng céch true 9.. Ti! diéu kien bén xaic dinh chiéu rqng 13 cm: dai cfin thidt dé’ tmyén duqc luc vbng Ft F1 . kd 2'1‘! . Kd [q] — q, ,,v2 = d, (tq1 — qmv? ) trong dd [q] — cuimg d0 l1_rc vbng cho phép, la luc vbng cd thé truyén duqc qua 1 mm chiéu rang cfia dai rang : b 3 ’ ' (13-48) [q]= qo‘Cu'Cz qo — cubng dg‘) lt_tc vbng cho phép khi u 3 1, s6 bénh dai xb = 2 vi Zdl 3 6 (bang 13.15) ; Cu - he 36 t3} s6 truyén, chi dimg ddi véi céc ho truyén tang’ t6c, né-‘u u 3 41, C = 1 ; CZ - he s6 xét dén s6 rang in khép véi bainh nhé Z61, ting vdi Z“ = 6 ‘; 1.1 5va41a'. yCZ=1;0,8va0,6; Kd — hé s6 téi trong dong (bang 13.7) ; v — van tdc cda dai ; qm - khéi lttqng 1 mét dai 1-(mg 1 mm (bang 13.15) Chiéu rang dai phéi quy trbn theo céc trj s6 tieu chudn (mm) ; 8 ; 10 ; 12,5 ; 16 ; '20;25;32;40;50;63;80. Truyén dang dai rang khong you cfiu lxjc cang dai lfin. Lt_Ic cang ban dfiu chi cfin lfm hon luc ly tam mot it. F0 = (1,1.+ 1,3) F“ = (1,1 -: - 1,3) qmvzb. 13.3. mima TU 'rH1fi'r KE no 'mUY1‘= :N 11.41. 'mi fiU 13.6.1 Trinh tg thiét ké ha truyén dai det 1. Ch9_n loai dai thy theo diéu kign lam vigc. 2. Djnh dubng kinh hénh dai nhé dl (nén _cluta cho trubc) theo cong th-tic (13.1). Kiém nghiem van tdc dai theo diéu kien udlnl 4 _ v = WW)-6 6 (25 -1- 30) m/ s _ (13-49) Né'u van tdc dai qua l6n phéi gifim dating kinhdbénh dai. ‘ 3. Tinh dubng kinh banh dai ldn thee; cong theo (13-2). Nén my an va dz theo cfic tri s6 tiéu chufin gain nhfit. Tinh lgi 36 vbng quay th11c- n’2 can bénh bi dén nu . = <1 — 9 amid. Néu n’2 chénh lech nhiéu so vdi 112 yen can (trén 3 + 5%) cdn chon lai dl Va dz. 4. Xéc dinh khoang céch true a va chiéu dai dai L. Cd thé’ chon a theo chiéu dai t6i thiéu c1'1a dai Lmm vl(3 + 5) sau dd tinh a theo Lmin Icong thfic (13-5)] 39
  39. 39. Kiém nghiem diéu kien _ a 3 2 (£11 -1- dz) Néu khang théa man diéu kien nay, cfin My :1 = 2 (dl + dz) va tinh lei L theo a [cbng thtic (13-4)]. Dé’ ndi dai, sau khi tinh xong can tang chi: -‘. -1_1 dai dai thém 100 -: - 400mm, thy theo each ndi. I 5. Tinh gdc cm a1 Icong thtic (13-3)} Va kiém nghiem diéu kien al 3 150° (ddi véi dai bfing chdt déo a 3 120°), néu khong dgt can tang khoéng céch true a hoac dimg bénh cang dai. 6. Xaic dinh chiéu day va chiéu réng dai. Chen truce chiéu day h cfia dai (xem muc 13.5.2) My theo céc tr‘; s6 tieu chufin. Chiéu rang b cfia dai tinh dugc theo cong thtic (13-37) v9. lfiy theo tiéu chudn. 7. Tinh chiéu rcng B c1'1a bénh dai (xem m1_1c 13.2.2). 8. Tinh lL_tc téc cI¢ng len trI. _1c theo cong thfic (13-16). 1 ; 13.6.2. mun tn; thiét k6 b¢ truyén dai hinh thang ‘o_ 1. Chem loai dai (tiét dien dai) theo mcmen xoén 1:1-én tn_1c quay nhanh T1 = 9550 .9?‘/1.1, (N. m) (bang 13.5). Nén chon vai ba phuang an d6 so sénh va quyét djnh. 2. Dinh dubng kinh bénh dai nho d1 = 1,2alm ; am. " tra theo bang 13.5 tiny theo loai dai ‘duqc chgn. Tinh dubng kinh banh dai dz. Cfic tri s6 dl va dz nén My theo tieu chufin. Kiém nghiern lgi s6 vbng quay thuc n’2 cfia bénh lén (nhu ddi vdi dai det). Tinh van tdc v cfia dai. . 3. Kho&ng'§:5.c11*1?13L1c'l§y th’ebyeu cfiu cdaaixét cfiu méylthogic chon theo bang 13.16 theo ty 56 truyén u. ‘ Bang 13.18 Chou. lzhodng cdch truc a. and dai hinh thang' Khodng each true a cén théa man diéu kien 2 (dl+d2) 3 a 3 0,55 (d1+d2)+h 4. '1‘inh chiéu dai dai ‘L theo khoé. ng. céch. true a [cong thdc (13-4)] va quy tron L theo céc tri sd-tiéu chudn. 5. Xéc dinh chinh xéc khoéng each two a theo L tieu chudn [cong thfic (13-5)). V 6. Tinh gdc am a! [cOng thflc (13-3)] vi _kié'm nghiem diéu kien 1 3 120° (Trong trixbng hop cfin thiét cd thé lay al 3 ('?0° ~: - 90°), tuy nhién hic nay Ca khé. thdp - xem bang 3.11). G 40
  40. 40. 7. Xéc dinh 56 dai cfin thiét x theo cbng thlic (13-39). S6 dai x khong nén qué 5 + 6 dai d6i V61 céc tié’t dien O, A, B, B vs: YO, YA, khong nén qué. 8 + 12 d6i véi céc tié’t clién dai cfm lai. S6 dai cang lén thi s1_I phén b6 téi trgng gifxa céc dai cang khong déu. So sanh cao phuong an (19. tinh toan (vé kich thudc, s6 dai) de’ chgn phuang an thich hqp. 8. Tinh chiéu rfmg bénh dai B (xem m1_1c 13.2.2). 9. Tinh l1_Ic téc dung lén truc F = 2FO X sin (a1/2) (13-50) I’ trong dd : F0 - luc cang ban dfiu c1'1a 1' dai ; F0 = UOAI ; A1 — dien tich tiét dién 1 dai, mmz ; do - ting suit cang ban (1511, ed‘ thé’ laiy 60 = 1,2 MPa. 13.6.3. Thi an Thiét ké’ bo truyén dai hinh thang truyén din tit dong co dien dén hap giam t6c theo cac s6 liéu sau : cong sufit R] = 5,5 kW, 36 vbng quay trong 1 phut (t§n s6 quay) cfxa true din nl = l440vg/ ph ; s6 vbng quay cda true bi dén 112 = 550 vg/ ph, vdi sai s6 cho phép :1: 4% ; téi trong dn dinh, ho truyén lam viéc 1 ca. Gidi ' 1. Chen loai dai. Tinh momen xofin trén truc din “ ’ 5,6 ' ' T1 = 9550 . E1-4'-6 = 36,476 N. m Theo bang 13.5 cd chqn dai hinh thang A hoac dai hinh thang hep YO. Ta tinh toén theo hai phuong én. 4 A Y0 2. Dinh dubng kinh beinh dai _ Duémg kinh bénh dai nhé d1 = 1,2 dlmm, mm (dlmin 100 30 tra theo bang 13.5), lfiy theo tieu chudn. 'I‘}’', SEE truyén u = 1440/500 2 2,6. Dubng kinh banh dai l6n dz = udl, mm My theo tiéu chufin. 250 200 Tinh 131 36 vemg quay th1_1c n'2, vg/ ph‘ sai s6 vbng " 567 567 . - 550 quay i75-5~6-—- z 3% 11116 hon trj S6 cho phép. van tdc dai v = Jzdlnl/60.1000, m/ s. 6 7'5 3. Khoang each true a chon theo bang 13.15, vdi 280 ~ A224 u = 2,6 ldy a = 2,8dl, mrn Khoéng céch true a thdé man diéu kién 2(c11_+ d2)3a_3 0,55 (dl+d2)+h _ 4. Tinh chiéu dai dai L, mm) theo cong thdc (13-4) ; 1120 ' 900 va quy trén theo tiéu chudn. 5. Xac dinh chinh xéc khoang céch true 21, mm, 274-,9 222 theo cong thdc (13-5). ’ 41
  41. 41. 6. Tinh gdc om oz, theo cong thdc (13-3). 150° 150° 0:, > 120°. 7. Xdc 6131. 36 dai 3.. thiét x theo cong thdc (13-39) 990, kW (hinh 13.15) 1,2 1,4 Ca (béng 13.11) 0,92 0,92 C, (bang 13.12) 0,31 0,90 AT1, N. m_ (hing 13.13) 1,2 1,8 [R, kW ‘ 1,18 1,43 K, (bfing 13.7) 1 1 '1‘inh duqc x 4,7 3,8 Lay s6 dai 5 4 8. Chiéu tong banh dai B t, mm (bang 13.6) 15 12 S, mm (béng 13.6) 10 8 B = (x - 1)t + 2S, mm 3 80 52 9. Tinh lue téc dung lén truc F I, N 940 520 theo eong thlic (13-50) Két lucn : Chon phuong an dai Y0 6 dai it hon, kich thtxoc gen hon va l1_1c téc dung lén true nho hon so véi phuong an dai A. Chuong 14 IRUYEN DONG vtr - DA] 6c 14.1. mm N11:. M CHUNG 14.1.1. Cfio loai ‘truyén dong vit-dai 6c Truyén dong vit - dai 6c dooc dung dé ddi chuyén dong quay thanh chuyén dong tinh tién. Thy theo dang chuyén dong c1'1a vlt va dai dc ed thé chia raxclic loai 2 vit 1 quay v3 tinh tién, dai Ge 2 c6 dinh voi gié, nhu trubng hop vit ép trén hinh 14.13., hoi_§c dai 6c 2 quay con vit 1 tinh tién, (hinh 14.1.b) hoac vit quay dai 6c tinh tién nhu trén hinh 14.1c (vit chay dao trong méy tién. ..). Ngoai ra cd 1031 truyén dong vit - dai 6e cd dai Ge vita quay vita tinh tién con vit c6 dinh, nhttng it dude dung. 42
  42. 42. Gifxa van me tin]: tién cua vft v(m/ s) vb s6 vbng quay trong 1 phut n(vg/ ph) qua dai 6c (hinh 14.1.b) c6 he thdc ' nZP " = 60.1000 “/3 W“) trong dd : Z - s6 m6i ren ; P - buéc ren, mm. ‘ . ~. J / Truyén d¢ng vit — dai 6c x-fit. cd Iui vé luc va c6 thé thuc hien duqc céc dich chuyén cham va 3 chinh xéc. / g f Ren dung trong truyén d¢ng vit - dai 6c V” thubng la céc logi ren c6 gdc profin kha nhé , 1111!! ten hlnh thang, ren rang cua, ma sét tuong (Mi 11116, hieu suit cao. Trong céc ca céu truyén luc theo hai chiéu ngubi ta thudng dung ren hinh thang, ‘ cd (19 bén khé cao. Ran rang cua duqc dung trong céc bo truyén chiu luc 1 chiéu lén (trong vit kich, may ép v. v.. .). Hgnh 14_1 Ran tam giéc c6 buéc nhé dugc dung trong céc khi ‘cu dd thuc hien céc dich chuyén chinh xéc, b day khong quan tam lém dén hjeu suit truyén dqng. D6i véi céc b0 truyén dbi hbi chuyén vi rflt chinh xéc ngubi ta dung ren hlnh thang c6 gdc profin nhé vi: ren vuong. Céc 'loq. i- ten nay -cd 1111 diéfm la do chinh xéc dich chuyé’n it chju Anh huéng cua di d¢ng: huéng tam cua vit, ngoai ra mét mét do ma sat cfing khé nhé. Tuy nhien vi khd ché tgo cho nén ren vuong ngay cang it dung. . :' . . 7 14.1.2 Uu, nhuqc diém Truyén dong vft - dai 6c 06 céc uu diém : - Cfiu tgo don gién, théng luc Ian, thuc hien duqc dich chuyén cham. 5% - Klch thuéc nhé, chin duqc Iuc Ian. . . Thuc hien duqc céc dich chuyén chlnh xéc cao. Nhuqc diém la : — I-lieu sufit chap do ma sat trén ten. J, /~' — Chdng mbn ; ‘ 41 ‘Prong truyén déng vlt - dai 6c cong suit bi mét. mét chu yéu do ma sét tren ren. I-lieu sudt cua bo truyén (ddi quay thanh tinh tién) duqc tinh theo cong thfic: _ ‘S7 - '/ /:. w , -7;’: ” ‘ tgw + ,0) ‘I4 2’ trong dd : y - gdc vlt cua ren ; // /// flW/ /// //’ f>—g6c masét. Khiy=5+20"vA/3=5° chi 71 = 0.40 + 0.70. Hinh 14.2 43
  43. 43. D6 tang hiou suit V9. giém mon gin day ngttoi ta dong truyén dong vit - dai 61: hi, nhb dd ma sat trugt trén ren ctuoc thay'thé' hing ma sat Ian. Hinh 14.2 trinh bay ké’t c§u mot-logi truyén dong vit — dai 6c bi. T1-en vit va dai 60 cd rinh xoén chda céc vien bi ; khi lam viéc, bi lain trong rinh. Bi chuyén dong lien tt_1c nho ed ong dén ndi thong céc vong ranh déu va cu6i cua dai 6c. Hieu suét cua truyén dong vit - dai 6c bi cd thd dgt 0,9. -14. 1.3 Vfit liéu Ngoéi yeu cfiu vé do hén, vat lieu lam vit cfin co do hén mbn cao vb. dé gia cong. Vit khong toi duqo Ian: hing thép CT5, 35, 45, 50. Vit toi duqc lam béng thép 45, 50, 40X, 40 XH, 50 X1‘ v. v.. . Tbi cd do rén khong thép hon 50 HRC. Dai dc thuong dugc lam bhng dong thanh thiéc Bp_Od'>_ 10-1,'Bp0I. IC 6-6-3 v. v.. . _'1‘ruong hop téi trong nho vb van «t6c thfip ed thé’ dung gangxém C‘-I 15-32; C‘-I 18-36 v. v.. . D6 tiét kiem ddng co thé che’ tgo dai 61: c6 vo ngoai hing gang hoac thép bén trong ldt dong‘ (dung céch dfic 1y‘ tam). 14.2. TiNH TRUYEN DONG vi'r — DAI 6c Thuc nghiem. cho thfiy truyén dong vit. — dai 6c thuong bi hong do mon ren. Dé’ gifim mon cfin chon vgt lion vit vi dai 6c thich hop, boi tron dfiy :11’: Va tinh toén do’ 11:11 cho’ fip suit trend-‘en. ‘ Ngbai hion tuqng' hong ‘vi mon, bo truyén c6 thé' bi hong do khong do do hén (céc Vit chin luc Ion. ..) hogc khong 6n dinh (céc vit dai bi non doc). ‘ 14.2.1. Tinh theo do bén mon Phuong phép tfnh theo do bén mon duoc dung cho phfin 1611 céc bo truyén vii. - dai (So do x_:1c, dinh dubng kinh vit vh chiéu cao dai 6c. ' D6 giém'm‘_on, dp sudt p trén‘ mét ren khong duqc qua tr‘; so cho phép [p]. F "pb"= ndzhx < [p] . ‘ (14-3) trong dd Fa _- luc téc dung doc true, dz — duong kinh trung blnh c1'1a vit ; h - chiéu cao loin, vioc cua ren, h = ¢hP, ddi vdi ren hinh thang mph = 0,5 ; doi vdi ren rang cua tph = 0,75 ; P - buéc ren ; x - so vong ren cue. dai 6c ; x = H/ P ; I-I — chiéu cao dai "Ge. . ' . . A » - Thay h = g0hP vb. x = -H/ P vfio oong thdc (14-3) _ F _ y= xd2.ph. H _ D§t. .H _= up“ .112 , cong thdc xiic dinh dubng kinh trung binh dz ctia dai cd dang ’ F dz 3 ha _ (14-5) NH #2,, [pl _ Tri 86 VJH thdbng My trong khoéng 1,2 -1- 2,5. p é [pl (14-4) 44
  44. 44. Ap suit cho phép [p] (161 vdi thép mi — dong thanh 11 + 13 MPa, doi vai thép khong toi — dong thanh 8 + 10 MPa. doi voi thép khong toi - gang 4 -: - 6MPa. T1-ong céc co cfiu dich chuyén chinh xéc (nhu trong ho phgn phan do c1'1a may cét kim loai v. v.. .). [pl My hing 1/3 + 1/2 caic tri so trén. Sau khi tinh duqc duong kinh trung binh dz pm My tron theo tri so gin nhait trong tieu chufin vi tfx dd tra céc kich. thuoc khéc. Duong klnh D cda dai oc co thé lfiy bong (3 + 3,5)d, d — duong kinh ngoai cfxa ren vlt. 14.2.2 Tinh theo do bén Doi voi céc vit chiu tai lon coin kiém tra do bén vit dong thoi chiu nén (hoac kéo) va xoén cho nén phéi tinh dng ufit tuong dudng Um vb. kiém nghiem diéu kien 6“, = ‘Is: + 31:2 s [6] (14-6) trong do 0' — ting uoit do luc doc true Fa gay nén , _ 3 Jtdz 1.’ — ting suot do momen xoén T gay nén T 16T r: V’_= :1d? 0 "d1 - duong kinh: ‘trong c1.ia_ ren vii: _; Woo -' mbmen, can xoén cfia vitnffng suit cho _ phép [6] = 6chl3 ; o'ch-- gioi ban chay cua vgt lieu vit. 14.2.3. Tinh theo diodkion on dinh 1ruang. hqp .111.11;: ;;g1;; :va_. Z~, :;&; ;g_a&1V; §1a1:(¢h1au 5111 mung duong: can vit 1.1 > 7:1,), con kiom t_1;a diéu "idea on _di_n_h (tiinhggvouon doc). M ' D6 vit khong bong do non doc, luc‘ nén _Fa phoi thoa min diéu kien on dinh Ole. Fa = .1231/son)’ ' " 1 (14-7) trong dd E - -modun don hoi ofia vit"; J = gtd: /6Q. .___ momen quan tinh c11a3tie't- ‘diet! vlt ‘; - s = 2,5 + 4 - he as an man vs snfainli ; pal - chiéu dai tuung duong c1‘1a vit, doi vdi vit co hai goi ma, 1 la khoéng céch gifxa hai goi tua ; doi_v6i vit co mot goi tua thidai oc duqccoi nhu goi t1_Ia thd hai va 1 la khoéng céch 1-.1‘: nfta chiéu cao daiéoc don got tun kia ; he so ,1: cd tho xem trong giéo trinh "Sdc bén vat lieu". Rieng doi voi truong hop goi tt_1a lb. 6 "Ian hogc o truqt cd t3r so chién dai 6 lo voi duong klnh 6 do ': loldo 1: 2, goi tua duqc coi nhu "ban lé” vi , u = 1. Nguoi ta dimg cong thdc (14-7) khi pl 3 100 j hoac , ul a_25dl, trong do 3 = MIA = (1114 — bin klnh quén tlnh cfia tiét dien vit ', A - dien tich tiot dion vit. 45
  45. 45. Dé don gién, cd thé kié’m nghiom vit co’ chiéu dai hot 115; theo diéu kién chung vé hén vb on dinh 4F (I: n mill, 6 go[o'n] _ ‘ (14-3) trong ddzldnl - ting suit nén cho phép, cd I: hé' lsiy bong dd, /3 och - gidi hon chéy. (p - he so giém ting suotécho phép, pht_1 thuoc do mém pl/ j cua vit, p tra trong bang dtxoi day, céc tri so bang dtroi dung cho céc méc thép co do bén cao. 1 flflflflflflfl 0,91 0,39 0,36 0,82 0,76 0,70 0,37 0,24 0,91 0,87 0,83 0,79 0,72 0,65 0,30 0,19 14.3. mi DU 1 Tinh vit c1'1a kfch chiu ttli trong Fa = 150.000 N, chiétr dai lam viec ctia vit _ 1 = 1000 mm, goi tua 13 6 hi chan vb. xaic dinh hieu sufit ct'1a vit kich. Vlt con tu’ _ ham, dung ren ring cua. Gidi 1. Chen vat lion vit - thép 85, vat lieu dai oc ; gang C‘I18-36. 2. Xtic dinh dtiong kinh trung blnh cfia vit theo diéu kien bén mon [cong thtic (14-5)]. Loy op suit cho phép [p] = GMP11 ; 1/2“ = 2 ; 1,12,, = 0,75 (ren rang ctta), ta duct": 150000 ' dz ’ J 3,14.2.0,75.‘6 ”‘,73“““ Theo tieu chufln, ting voi duong kinh dz hai 1611 hon 73mm co tho chon céc buoc ran 5, 12 vi 20mm. Ren co’ buoc P = 5mm qua nho, chdng mon hong. '11: 011011 buoc ren 12 hose 20 mm tiiy diéu kion dam bio ttr ham : gdc vit y phéi nho hon gdc ma sét p. . Doi- voi vit duochoi dfiu, lay he so me sit-f = 0,1 ta co )0 = Varctgf = 5°40’ Doi voi ren cci budc P = 12mm (dz = 76mm), gdc vlt P . 12 7 = arctg—— = arctg ndz 3,14. 76 “ 205°’ thou man diéu kien tt_I ham y < f1. 46
  46. 46. Doi voi ren co buoc P = 20mm (dz = 75mm) 20 1 = °'°*€ T475 7 5° khong an toan vé tt_1 ham (vi y xdp xl bong ,0). Vaychon rent-angctIa.85x l2;d= 85mrn; P = 12mm; dl = 64,2 mm; d2=76mm; h=9mm. ' 1 3. Tinh chiéu cao dai oc H. Theo cong thdc (14-3) tim so vong ren dai oc ' 150000 ' 5.76.9.6” 12 x= vay H = xt = 12.12 = 144 mm He so chiéu cao dai oc (pH = H/ dz = 144/76 = 1,9, trong khoéng cho phép 13 1,2 -: - 2,5. 4. Vi vit khé dai vs chiu lttc nén Ion cho nén phai kiom tra vé do bén vi on dinh. Tlnh gain dung theo diéu men (14-3), vdi vat lieu vit 13 thép 35 as (sch = 300 MPa ; [an] = 300/3 = 100M1>a ; he as ,5 tra theo , ul/ j = 41/6, = 4.1000/64,2 = 62. vay (0 = 0.8 Ta co 6 = -4399-9~ = 46,5 as o,3.100 = 80 MPa " 3,14.(64,2)2 5. X110 dinh hieu suit ctla vlt kich theo cong thtic (14-2) (1)0 qua khong chtft y don ma sét trong 6 hi chan vi khé nho). ,1 = __‘9’_ = ___£§? :L = 033 tgty + P) tg(2°50’ + 5°40’) ’ 47
  47. 47. Phéin th1i' tlr TRUC, 6 TRUC, KHO'P N61 VA. LO X0 Chuong 15 TRUC 15.1. KHA1 Nlmu CHUNG 15.1.1. Cong dung vi phan loai true 'I'rue. d1'1uc dung 4:15 :16 céc tiét may quay nhu banh rang, dis. xich v. v.. ., tie’ truyén momen xoén hoac dfi thuc hien ca hai nhiem vu trén. Theo duo diém chin tai, true duqe ehia ra hai logi ; true truyén vs. truc tam. ' ' True truyén vita da céc tiét may vita. truyén momen xoén, nghia in chin ca momen min 15.1: momen xoén. Vi du trén hinh 15.1 trinh bay true truyén 2 difbanii rang 1 va khéi 116i 3 ; momen xoén dupe truyén tn‘: khdp n6i qua truc sang bfinh rang. I 5 v/ /// /// _'. Khéc vdi true truyén, truc tam chi chin momen 11611. Trén hinh 15.2 gidi thiéu tang quay c1'1a may nang chuyén, momen duuc truyén ti: vanh rang qua tang quay sang day cap. True tam c6 ‘ thé quay (hinh 15.2a) houc khong quay (hinh Hmh I5“! ’I5.2b). Ngoai ra cbn c6 true truyén. chung la true chi chin mémen xoén, dung dé truyén momen xoan dén bu phan cong téc cfia may (vi du trong may nong nghiep, may lam dating v. v.. .). Theo hinh clung dubng tam true, chia ta : true thing (hinh 15.39,, b) true khuyu (15.3c) va true mém. True khuyu duqe dung trong céc may ed pit tong (dong ca d6t trong, may bam pit tong v. v.. .). Truc mém cd do 11611 oong khi ldn, duuc dung dé’ 48
  48. 48. . dung, bao dufmg true v. v.. ., la cac nhan truyén ehuyén dung quay va momen xoan gifta cac bo phan may hoac gifra cac, may ed vi tri thay ddi khi lam viec (vi du true mém dung trong may ehfxa rang). True khuyu va true mém thuec ioai chi tié't may ed cong dung riéng, duqe trinh bay trong cac giao trinh ehuyén men. ' ' '/ I// ;"I: ‘»v/ i“/ .s? 'ti"/ .1:/ /4 3 é/ //4/4!/ I/. wI'r'4. r‘/ //'6"z"-"I/ '// '1/41 K i / F Hinh 15.2 Theo can tao ehia ra : true tron (hinh l5.3a) va true bac (hinh 15.3b) ; true dac va true réng. "lrue lam viee t6t hay xau ed anh hudng true tiép dén su lam viee eua cac tié’t may lap trén true hoae eua ea bi) may. Khi thiét 1:5 true can xét (Ian cac van dé vé ké't can, do bén, do cung va dao dong eua true. Ngoai ra een phai chu y’ t6i qui trinh eong nghe ehe’ tao, nhiet luyen true va cac bien phap 31’! t6 ed anh hudng lfm dén de ban va tudi the eua true. 15.1.2. Két can can true Hinh 15.3 Kat can eua true duqe xae dinh theo tri 36 Va tinh hinh phan b6 lue tae dung lén true, each b6 tri va ed dinh cac tie’t may lap t1-en true, phuong phap gia eong va lap ghép v. v.. . True thubng duee ché’ tao c6 dang hinh tru trbn nhiéu bae (gém nhiéu dean ed during kinh khae nhau). It khi dimg true tron, ed dubng kinh khong d6i theo ehiéu dai vi khong thich hep vdi due diém phan b6 ting suit trong true : ting suat thay dcii theo chiéu dai true ; mat khae lap ghép va {Ia chfra khd khan, phfic tap. Khi can giam khdi luqng e6 thé lam true r6ng, my nhién, gia thanh ché tuo true 1-Gng kha eat. - 1 Tié't may db true duee gei la 6 true. Pha‘n‘truc tiefp x1’1e vdi 6 true gei la ngéng true. Phan true (16 lap véi eae tiéft may duuc goi ia than true. Dubng kinh ngcing true va than true phai lay theo tri $6 tiéu chuan dé thuan tien cho viee ehé tao va lap ghép. Cdc tn‘ . -:6 tieu chudn ctia dubng hinh (mm) ngdng true lap 0' (an : 15 ; 17 ; 20;25;30;35;40;45;50;55;60;65;70;75;80;85;90;95;100 d. CTMT2—A
  49. 49. v. v.. . Cac tn’ s6 tiéu chudn ezia duong kink (mm) than true lap bdnh rang, bdnh dai, khép n6iv. v.. .l0;l0,5;11;11,5;12;13;14;15;l6;17;18;19;20;21;22;24; 25;26;28;30;32;34;36;38;40;42;l45;48;50;52;55;60;63;65; 70;75;80;85',90;95;100;105 ;1l0;120;125;130;140;l50;160. D61 véi cac phan true khong lap cac tie’t may co the’ lay dubng kinh theo cac tri s6 khong tieu chuan. Khi dinh kich thuoc true bae, phai lay ducting kinh cac dean true sao cho moi tiét may lap len true ed thé long qua cac phan khac eua true cho t6i cho can lap ma khong bi vuong. ®4 @ W ll-i‘ =1) 45) ' Hinh 15.4 Hinh 15.5 De’ c6 dinh cac that may trén true theo ehiéu true thubng dung vai ‘true, go, mat hinh eon, bac, vong ehan, dai (Sc hoae lap bang do doi v. v.. . Vai true (hinh 15.4) ed mat dinh vi va gde lt1on. . De‘ tiét may co thé ty sat vao mat dinh vi thi ban kinh gee luon r cua vai true phai nho hon ban kinh goc luon R et’1a tiét may (hinh 15.411). Gee luqn cho vai true hoéc cho chuyén tiép cac doan true co dueng kinh khae nhau, nén ehe’ tao voi ban kinh Ion nhat trong pham vi co the’, de’ giam bot tap trung ting suat. Nguoi ta con lam gdc luqn co dang elip hoac lam gdc luon nhu hinh 15.4b, tron do ed them ranh veng. Ghép bang mat eon thuong dung trong truong hqp tai trong dong hoac va Bap. D6 git”: khoang each tuong d6i gifxa hai tié’t may, don gian nhat la dung bac (hinh 15.5). Dai 6e, vong ham, ke’t hop vdi ghép bang do doi thubng dung do’ e6 dinh 6 Ian. Dé e6 dinh eac tiét may tron true theo phueng tiép tuyén (gift tie’t may khong xoay tueng ddi d6i vai true) thuong dung then, then hoa hoac ghép bang do doi. Vi true chin ting suat thay d6i cho nén thuong bi hong do moi. Nhfmg vé't nut vi moi. thutmg sinh ra <3 nhimg cho tap trung ting suat nhu eh6 thay ddi duong kinh (vai true, go), eh6 ed ranh then, ranh lui da mai, cho ghép bang do doi v. v.. . Can chu y dung cac bion phap lam giam tap trung ting suat, vi du nhu tang ban kinh gde luqn ct'1a vai true, vat mép 16 tren true v. v.. . D6i voi moi ghép bang do doi ed thé dung each vat mép may 0 hoae tang do mam et‘1a map may 0. Vé eong nghe dung cac phudng phap Ian nén, phun bi, tham than, nito hoae xianua r6i toi, gia eong nhan bé mat true v. v.. . c6 thé nang cao do bén moi et’1a true. 15.2. cac DANG HONG VA viyr LIEU muc 15.2.1. Cae dang bong true True bi gay hong thubng 151 do moi. Nguyen nhan gay true c6 thé la : - True thttong xuyen lam vioe qua tai, do khi thiét ké’ khong danh gia dung tai trong tac dung. 50 4.CTMT2-B
  50. 50. * Su tap trung Ling suit do ké’t edu gay nén (gde luun, rénh then, 16 v. v. ..), hoac do chét luung ehé’ tuo xfiu (vé’t xufie do gia cong xéu, kfr thuat nhiet luyén kém v. v.. .). - Sit dung khéng dung ky thuut (6 true diéu ehinh khbng dung, khe hi: can thié’t qua nhé v. v.. .). ‘ Truong hop dung (5 truut, né’u tinh toén vé sf: dung sai, mung dé'u khéng hinh thunh duqe, ngéng true ndng Ién nhiéu, ldt true bi men nhanh, bi dinh houe bi xuéc, két qua hi: true khong lam viée duqc nfra. De cling uén efia true ed énh hudng lén dé’n su lam viéc eua cue tiét méy truyén . dung Va 6 true. Néu true bi vong nhiéu, khe ho gifla ngfmg true vi 6 truut thay ddi, énh hudng true tié’p dén mung déiu boi tron trong 6, dong thbi phai héng su tiép xfie chinh xéc gifra cée tiét may truyén dung. True ehinh cua may cit kim loai khfing din dc) cung u6n sé anh huéng dé’n du ehinh xéc vb. lam tang dt) nhém bé mat vat gia cung. "Prong mot s6 ké't c§u ed khi phai hun ehé bién dang xoén cua true (vi du nhu true c1’1a ea efiu di chuyén cfiu Ian). 'I‘rue eon co‘ thé bihéng do dao dong ngang va dao dung xoén, do do co nhfrng truélng hop phéi kiém nghiem true vé dao dung. . - — 15.2.2. vat liéu true Vat lieu dung dé’ ché’ tgo true can ed do bén cao, It nhay véi tap trung ting suit, co thé nhiét luyén duqc vé. dé gia cong. Thép cac bon vé. thép hop kim 15; nhfxng vat liéu chu-yéu dé ché’ tuo true. _ Nhfmg true chin ting sufit khfing 16-n lém duqc ehé tuo bung thép CT5 khong nhiet luyen. Né’u yéu eéu true co khé nang tai tuong cI6i cao thi dung thép 35, 45, 50 v. v.. . nhiet luyen, trong do‘ thép 45 duqe dung nhiéu nhfit. 'I‘ruf1ng hup chiu ling suit ldn, lam viee trong eée may quan treng, true duue ehé tuo bung thép 40X, 40XI-I, 40XH2MA, 30XI‘CA v. v.. . nhiet luyen houe t6i bé mat hing dong dien tfin s6 cao. D6i vai nhfrng true quay nhanh, lép 6 truut, ngong truc e§n co‘ dc» rén cao thi clung thép 20, 20X thfim than r6i toi ; né’u true chiu ting suit Ion, van t6c rat cao ‘ nu dung thép 12XH 331, l2X2H4A, 1sxr'r man: then va toi hoae thép 38X2MIOA thiim nito via t6i. Cfin 11m 9 ring thép hup kim nhiet luyén tuy e6 (10 bén vé dc rén cao nhung modun din hdi lei hfiu nhu khong khée eée loui thép cée bon thong thueng. Do do nén theo diéu kien du bén dé’ thiét ké’ true, kieh thufie true hing thép hqu kim sé tuong d6i nhé, nhung true ed thé khong du du cung e§. n thié't. Mat khaie, thép hep kim khi dét vi: nhay v6i tap trung ling sufit. W vay chi khi nae that cfin thiét (cfin giém kieh thuéc va khfii luqng true, nang cao tinh chong men c1'1a ngfing true. ..) va xét thfiy dc} cung efin thié’t eua true vfin duet: dam béo, thi moi dung thép hop kim dé che’ tuo true. Khi ehé' tuo true thubng dung phoi can houc phéi r‘en, rflt it dung phei due. Bang 15.1 cho tri s6 trung hinh vé ca tinh cfia mot 56 mac thép Lién X6 cu ché tgo true. 51
  51. 51. A 13xr'r Du6i40 3000*) 1000 soo Tham than, toi 4o_-so. 27o(*) 950 ‘ 750 Bang 15.1 Ca tinh mot so’ mac thép she’ too true Duong kinh phoi, mm Duoi 100 100 - 300 N hiét luyen Duéi 100 170 - 220 Thuong hoa -nt- 190 - 240 'IBi eai thion -nt- 240 - 285 'lbi céi thién 40X Duéi 60 260 - 280 1000 800 'Ibi eai thion 60 - 100 230 — 260 _ 750 520 ~ 40XH Duoi 100 250 — 280 850 600 ‘mi eai thion 100 - 300 230 - 260 800 580 35XI' CA Duoi 30 310 1700 1350 ‘mi cai thion 30 — 60 270 - 310 1000 900 12XH3A Duai 40 300("‘) 1000 800 Tharn than, 1:51 4 40 - 80 250(*) _ 920 700 "mam than, toi Chfi thfch. Tri so ed dau (“‘)’ch-I do ran trong loi ; do ran hé mat . cna eae mac thép nay dut -duoc 56 -1- 63 "sau khi tham than, toi va ram thép. 15.3. 'riNH no BEN COA moo 15.3.1. cac mac thiot ké true Doi vai true, do bén thuong la chi tiéu quan trong nhat vé kha nang lam vioc. Do do true thufong duoc thiétké’ theo diéu akion do hén. Ngoai ra thy truong hop cu thé, con phai xét dé’n do cung vé. dao dong e1'1a true. ' [Tug suat trong true chu yé’u do eae lue tae dung vao cac tiét may truyén dong l§p t1-on true gay nén. Cong thde xae dinh luc tac dung lén true da trlnh hay trong cac ehufang vé tiét may truyén dong. Cac lue nay gay nén uon, xoan, kéo hoac nén. 'I‘rong nhfxng truong hop khac, thi du nhu true eon chin tae dung eua luc cat got (true chinh cua may tien v. v.. .), chiu lue kéo cua cap (true tang, true puli) v. v.. ., each tinh cac lue nay’ duoe trinh bay trong cac giao trinh chuyén mon ("Nguyen ly cat kim loai", "Can true" v. v.. .). Ngoai ra, eon co’ trong luong ban than true va momen ma sat trong 6 true tac dung lén true, nhung nhiéu khi ho qua khong tinh dé’n vi tri so eua ehang kha nhé. 52
  52. 52. Co’ thé tién hanh thiét ké’ true theo cac buoe : tinh so ho duong ldnh true ; dinh ké’t eau va cac kieh thuoc true ; kiém nghiem true. Trude hét phai so ho dinh duong kinh true theo kinh nghiom hoae theo momen xoan. Tié’p theo la djnh ké't can true ; duong kinh va ehiéu dai cac doun true v. v.. . vi tri cac diém dot lue trén true va lap so do tinh toan true. Sau do tién hanh kiém nghiom do bén efia true theo he so an toan. Néu khi lam vioc true doi khi hi qua tai dot ngot, can kiém nghiem do bén eua true khi hi qua tai. 'I‘ruong hop can thié’t phai kiém nghiom true vé do cung va dao dong. 15.3.2. Tinh so bo dltong kinh true Dé tinh so ho duong kinh true, c6 thé dung eae cong thde kinh nghiém. Thi du duong kinh dau true vao eua hop giam toe duoe lay bang 0,8 + 1,2 duong kinh true dong co dion. Duong klnh true bi dan cua moi cap trong hop giam toe duoe 15y hang 0,3 + 0,35 khoang each gifra hai true. Khi khong ed eong thde kinh nghiém thieh hop, duong kinh true duoc dinh so ho theo momen xoan. So dl tinh theo momen xoén vi , lue nay chiéu dai true chua duoe xae dinh, do do ehua tlm duoe momen uon. Duoi tae dung eua momen xoan '1‘ = N. mm, trong true sinh ra ting gsuat xoén , = _T_ , , _'E_ , W,, 0,2113 trong d6 W0 — momen can xoan eua true, mm3 d - duong kinh true, mm. Theo diéu kion ; T 1.’ = — 0,253 as [I], MPa tinh duoe duong ldnh true 3' T 3!9,55.10‘€R d 3 0,2[r] = T)’— mm (15-1) trongido R - cong suat truyén qua true, kW ; [t] - ting suat xoan __eho phép ; ‘ n 5 so vong quay trong 1 phat efia true, vg/ ph. T1‘: eong thde (15.1) ta ed 3 . . d 3 C - % mm, (15-2) voi C’ - he so tinh toan, phu thuoe [I] C _ 3, 9,55. 10‘ ‘ 0.2[r] V1 khi tinh duong kinh true khong xét don ting suat uon, cho nén as be 151, phai lay [I] thap xuong kha nhiéu. Dé' dinh duong kinh dau true vao hop giam toe, vat lieu lhm true la thép 35, 40, 45 hooe CT5, ed the? lay [7] = = 20 + 30 MP3 hoac C = 130 + 120. 53

×