a descriptive explanation about drives used in purpose

1. FLAT AND V-BELT DRIVE
TEAM MEBERS:-
 G.VIJAY
 S.VETRISELVAN
 M.VIGNESH
 R.VENGADESH
GUIDED BY,
Mr.MANIVEL A.P(MECH)
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2. DESIGN OF TRANSMISSION
SYSTEMS
 Selection of V belts and pulleys – selection of Flat belts
and pulleys
 Selection of Wire ropes and pulleys
 Selection of Transmission chains and Sprockets.
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3. DESIGN OF TRANSMISSION
SYSTEMS FOR FLEXIBLE
ELEMENTS
 Belt
 Rope
 Chain
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4. BELT DRIVE
 To transmit power from one shaft to another by means of
pulleys which rotate at the same speed or at different speeds.
 Power transmission depends upon the following factors :
i. The velocity of the belt.
ii. The tension under which the belt is placed on the pulleys.
iii. The arc of contact between the belt and the smaller pulley.
iv. The conditions under which the belt is used.
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5. BELT DRIVE TERMINOLOGY 5

6. TYPES OF BELTS
There are 4 types of belts used in belt drives they are as,
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7. FLAT BELT
 Flat bets find their widest application where high speed
motion, rather than power, is the main concern.
 Flat belts are made from leather, woven c0tten, rubber,
balata(wood gum).
ROUND BELT
 Round belts are a circular cross section belt designed to
run in a pulley with a circular groove.
 The circular belt is mostly used in the factories where a
great amount of power is to be transmitted from one
pulley to another.
 When the two pulleys are more than 5 meters apart.
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8. V-BELT DRIVE
 Mostly used in the factories and workshops, where a
great amount of power is to be transmitted, from one
pulley to another, when the two pulleys are very near to
each other.
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9. NUMBER OF PLIES (PLY)
 A number of layers of belt material is cemented
together to achieve the desired thickness of belt. The
layer of belts is called as ply. The total number of belt
layers used in a belt is called number of plies.
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10. BELT MATERIALS 10

11. BELT PULLEYS 11

12. SELECTION OF A BELT
DRIVE Following are the important factors in selection of a
belt drive:
 Speed of the driving and driven shafts
 Speed reduction ratio
 Power to be transmitted
 Centre distance between the shafts
 Shafts layout
 Space available
 Service conditions
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13. TYPES OF BELT DRIVES
 LIGHT DRIVES:-These are used to transmit small powers
at belt speeds up to about 10 m/s as in agricultural
machines and small machine tools.
 MEDIUM DRIVES:-These are used to transmit medium
powers at belt speeds over 10 m/s but up to 22 m/s, as
in machine tools.
 HEAVY DRIVES:-These are used to transmit large
powers at belt speeds above 22 m/s as in compressors
and generators.
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14. COMMON TYPES OF BELTS
:
 FLAT BELT:-mostly used in the factories and workshops,
where a moderate amount of power is to be transmitted,
from one pulley to another when the two pulleys are not
more than 8 metres apart.
 V- BELT:-mostly used in the factories and workshops, where
a great amount of power is to be transmitted, from one
pulley to another, when the two pulleys are very near to
each other.
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15. TYPES OF BELT DRIVES
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16. OPEN BELT VS CLOSED BELT
DRIVE
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17. SOLVING DESIGN PROBLEMS
BASED ON FLAT BELTS
 There are two ways by which you can design a flat belt drive.
They are:
 Designing flat belt drive using manufacturer’s data
(or)
 Designing flat belt drive using basic equations
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18. USING MANUFATURER’S DATA
 Pulley Diameters (D and d)
 Speeds of Driving and Driven Pulleys (N1 and N2)
 Design Power in KW
 Velocity of belt (V m/s)
 Selection of belt
 Number of plies
 Load rating at V m/s
 Belt width (b)
 Pulley width Length of belt (L)
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19. ADVANTAGES OF BELT DRIVE
 They are simple. They are economical.
 Parallel shafts are not required.
 Overload and jam protection are provided.
 Noise and vibration are damped out.
 They are lubrication-free. They require only low
maintenance.
 They are highly efficient (90–98%, usually 95%).
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20. DISADVANTAGES OF BELT
DRIVE
 The angular-velocity ratio is not necessarily constant or
equal to the ratio of pulley diameters, because of belt
slip and stretch.
 Heat buildup occurs. Speed is limited to usually 7000
feet per minute (35 m/s). Power transmission is limited
to 370 kilowatts.
 Operating temperatures are usually restricted to –31 to
185°F .
 A means of disassembly must be provided to install
endless belts.
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