About major use of bearings and it's applications

2. BEARIN
G
When there is relative rotating motion between
two machine parts. One of which supports the
other, the supporting member is called
BEARING. Bearing is very importent element in
any machine.
FUNCTIONS OF BEARING
1. It bears load.
2. It locates rotating part in correct position.
3. It provides free motion to the rotating part by
reducing friction.

3. Bearing bears the load in machinery. The term 'load'
refers to the force of weight that is placed on the
bearing. A bearing must be able to support a load placed
on it. Locating the rotating parts in correct position
means hold the rotating part in predetermined place.
Bearings are required to resist motion in one or more
directions while allowing motion to occur in other
directions. Bearings must be able to reduce friction to
provide free motion to a rotating part. Friction is the
resistance to motion that exists between two surfaces
that are in contact with each other. Too much friction can
prevent movement of machine parts, and equipment
may be damaged.

4. CLASSIFICATION OF BEARING
BEARING
SLIDING CONTECT
OR FRICRIONAL
BEARING
ROLLING CONTECT
OR ANTI FRICTIONAL
BEARING

5. SLIDING CONTACT BEARING OR
FRICTIONAL BEARING
Bearings in which the contact surfaces either
make sliding contact separated by a film of
lubricant. It operates on the basis of sliding
friction.

6. Advantages of Sliding contact bearing:
1. Easy to manufacture,
2. Cost manufacture is low,
3. Quieter in operation particularly after a
suitable running- in period,
4. It has unlimited life,
5. High load carrying capacity.
6. Less sensitive to injury,
7. Less radial space required,

7. Disadvantages of Sliding Contact Bearing:
1. There required higher starting torque,
2. Continuous or more lubricant is
needed for lubrication,
3. Loss of lubricant is more,
4. More power is needed for
driving,
5. More axial space is required.

8. ROLLING CONTACT BEARING OR ANTIFRICCTIONAL
BEARING.
Bearings which have rolling contact between
surfaces. It operates on the basis of rolling friction.
.

9. Advantages of R.C. bearings:
1. Lower axial space required,
2. Operates on minimum friction,
3. Lower Power consumption,
4. Low starting torque,
5. Less lubricant is needed for lubrications,
6. Easy maintenance,
7. More axial rigidity in this case.

10. Disadvantages of R.C. bearings:
1) Manufacturing Process is complex in
nature,
2) Cost of manufacturing is higher,
3) It has limited life in term s of
millions of revolutions,
4) More sensitive to foreign
bodies & injury's

11. PARTS OF ROLLING CONTACT
BEARINGS
Rolling element
Outer race
Retainer
or Cage
Inner race
Shield

12. Rolling contact Bearing consists of the
following main parts.
1. Outer ring OR outer race.
2. Inner ring OR Inner race
3. Retainer or Cage
4. Rolling elements.

13. Bearings can be classified according to
type of load carried by the bearing.
1. Bearings for radial load (Radial bearings).
2. Bearings for axial load (Thrust bearings).
3. Bearings for combined load (It takes both
radial and axial load).

14. Axial
load
Combine
load
Redial
load

15. BEARINGS FOR RADIAL LOAD
Different types of R. C. bearings which can be
used for radial loads are,
1. Single or double row deep groove
ball bearings.
2. Double row self-aligning ball bearing.
3. Cylindrical roller bearings.
4. Single or double row self-aligning
ball bearings.

16. BEARINGS FOR COMBINED LOAD
The following bearings are suitable when loads are
made up of one component perpendicular to the axis
of the rotation and other parallel to the axis of
rotation.
1. Angular contact ball bearings either of the single
row type (to be fitted in opposite pairs) or of
the double row type.
2. Spherical roller thrust bearings.
3. Taper roller bearings single or paired (for axial
load in either one or both directions
respectively.)

17. BEARINGS FOR THRUST LOAD
Different types of R. C. bearings which can
be used for thrust loads are :
1. Single or double thrust ball bearings
(for thrust load in either one or
both directions respectively).
2. Cylindrical roller thrust bearings

18. Bearings can be classified according to
type of rolling element used. They are:
•Ball Bearing.
•Roller Bearing
Difference between Ball and Roller bearings.
1. Can carry lighter load. 1. Can generally carry
heavier load.
2. Can run at higher speed. 2. Can run at lower
speed
3. Maximum friction that may occur is
0.0015. 0.003

19. BALL BEARINGS
• Single row deep groove ball bearings.
This is the most common type of ball bearings in general
engineering. This type has the following advantages.
1. It can withstand considerable amount of thrust load in
addition to radial load
2. It can function successfully at very high speed.
3. As there is no flexibility is provided in this type,
alignment of the shaft and housing should be as
correct as possible. Bearings of this type are available
with side shields, seals and snap rings.

20. Single row deep groove ball bearings.

21. Double row deep groove ball Bearings.
These are the same as single row bearings but
are wider to allow a double row of ball with the
object of increasing the load capacity.

22. •Single row angular contact ball
bearings.
These are designated to take a combination of
thrust and radial load. These should be used in
pairs in opposite direction and their axial
adjustment must be made very carefully. High
supporting shoulders on both inner and outer
rings affect the thrust load and axial rigidity.

23. •Double row angular contact ball
bearing
This is rigid bearing whose raceway is so
designated that the direction of load through the
balls is oblique to the axis. The angle of contact is
30 deg. And is made with filling slots. These
bearings are used where the thrust load is equal
to or greater than radial load. These bearings can
be substituted by two bearings of single row
angular contact either face to face or back to back
and also two bearings in tandem.

24. •Self aligning ball bearing.
This is a double ball bearing with spherical
raceway in the outer ring thus permitting it to
swivel. It is particularly suitable where there is
possibility of miss-alignment of shafts.

25. •Single row thrust ball bearings.
This type comprises a row of balls running
between two flat grooved washers with ball track
designated to absorb thrust load in one direction.
This does not with stand and any radial load also,
this is not suitable for high speeds.

26. •Double row thrust ball bearings.
These comprise two rows of balls, one for each
direction of thrust. It is only used to absorb thrust
loads in either direction at low moderate speed.
These cannot withstand any radial load. These are
occasionally mounted on spherical seating for self
aligning purpose.

27. Roller Bearings:
Single row cylindrical roller bearings.
This bearing is a rigid bearing comprising a single row of
cylindrical rollers and raceway. The open form bearings can be
withdrawn in both directions. Those of the half-closed form can
be withdrawn in one direction only. Whilst the close forms type
serves to locate the shaft axially.

28. Double row cylindrical roller bearings.
These are twice as wide as the single row type.
These are also called Duplex bearings and can
sustain extremely heavy loads. These are a
available in either separable in either separable
inner or outer races.

29. Spherical roller bearings.
The race of the outer ring is ensuring correct operation
when the axes of the two rings are inclined to each other.
These bearings are therefore suitable for use with
independent support housings and wherever there is
possibility of a lack of alignment. They are designed to
carry medium or heavy radial or combined load.

30. •Taper roller bearings
These bearings consist of two parts; the inner
ring, complete with the row of rollers, is
retained by a pressed steel cage, forming an
integral sub-assembly (cone) and outer ring
(cup). These bearings carry heavy radial and
thrust loads at moderate Speeds. These
should always be mounted in pairs with
opposed taper because in each bearing the
radial load. produces a axial component which
needs counter balance. The assembly of
paired bearings is available in various styles.

31. 1. Cylindrical roller
thrust bearings.
These have tow flat washers without any
grooves. The specially designed cage retains the
rollers in position. These can take heavy thrust
loads at moderate speeds. These cannot take
radial loads.

32. •Spherical Roller thrust Bearings.
The roller of these bearings is controlled by a lip on
the ring which is secured to the shaft. The axis of
rollers with meets at one point one the bearing axis.
The track on the inner ring mostly fitted one the
housing in spherical and thus allows self-alignment
of the bearing. The special feature of this bearing is
its capacity to carry a light radial load.

33. •Needle roller bearings.
This is another form of cylindrical roller bearing with the rollers,
having a very small diameter in comparison with their length.
This diameter varies from 1.5mm to 5mm. these bearings are
made in various types and their application or their mounting
also varies. These are used with inner race and outer race,
only inner race with roller and cage or only outer race with
roller and cage. Owing to very small diameter size the spacing
cage is generally omitted. These bearings are used in places
where the speed is low or where oscillation takes place as in
wrist pin, rocker arm, and universal Joint, etc.

34. BEARING COMPONENTS AND MATERIALS
1. The rings and rolling elements of rolling bearings
are generally made form through hardened high
grade carbon chromium steel having a high
degree of cleanliness. Or special applications
case hardened or even stainless steel may be
used.
2. Each individual bearing receives optimum heat
treatment, resulting in hardness normally
between 59 and 65 HRC. Pressed steel, or brass
cages are normally used for small and medium
sized bearings.

35. 3. Injection molded plastic cages are, however,
used more and more as Standard or small and
medium size bearings.
4. Large bearings generally have machined
cages which are usually made of brass, but
even steel; spherical graphite cast iron and light
alloys are used for machined cages.
5. Shields are made of steel sheet only and
form a narrow gap with the inner ring. Seals
protect bearings better than shields do, but the
heat resulting from the friction between seal lip
and the inner ring will Reduce the limiting speed
by one third

36. INTERNAL CLEARANCE
The bearing internal clearance is defined as the total
distance through with one bearing ring can be made relative
to the other under zero measuring loads.
1. Movement in the radial direction called radial internal
clearance;
2. Movement in the Axial direction called Axial
internal clearance;
The internal clearance will vary from bearing type to bearing
type. The most common clearance is NORMAL (with no
suffix). Internal clearance smaller than normal are
designated by suffixes C1 and C2 while internal
clearances larger than normal are designated by C3, C4
and C5.

37. Internal Clearance

38. C1 Smaller than C2
C2 Smaller than normal
Normal
C3 Greater than normal
C4 Greater than C3
C5 C5 Greater than C4
Suffix internal Clearance
Example: 6210/C3 - Bearing with increased clearance.

39. Reasons for providing internal clearance:
1.In order to fit a bearing tightly on a shaft, it is
necessary that the shaft is slightly Larger than the bore of
inner ring. When the bearing is mounted, the inner ring will
expand and consequently the space available for the rolling
elements will be reduced. (Sometimes the housing
seating’s are made slightly smaller than the outside
diameter of the outer ring resulting in compression of the
outer ring and hence further reduction of available space
for rolling elements.) The reduction in space available
for rolling elements when the bearing mounted is
accommodated by the internal clearance.
2.Steel will expand with increased temperature. In
operation the temperature of the various parts of a
bearing will not remain uniform and resulting in varying
degrees of expansion which is compensated by the internal
clearance.

40. 3 0 2 06
code for Bearing Code for Code for Diameter Code for Bore
Type Wide (or Height) Series Diameter
Example: Series Example: Example: Code =
3 = Taper roller Example: Diameter Series = 3
Bearing Width Series = 0 2 i.e. Bore Dia. =
30mm
CODE FOR BEARING TYPE
The first digit (or letter) designates the type of
bearing. Following are the codes for bearing type:
CODE DESCRIPTION

41. 0 - Double row angular contact ball bearings.
1 - Self-aligning ball bearings.
2 - Spherical roller bearings and spherical
roller thrust bearings.
3 - Taper roller bearings
4- Double row deep groove ball bearings.
5 - Thrust ball bearings.

42. 6 - Single row deep groove ball bearings.
Bearing with bore dia. Less than 10 mm are
designated by three figures where the last figure
represents the bore dia in mm.
7 - Single row angular contact ball bearings.
8 - Cylindrical roller thrust bearings.

43. N - Cylindrical roller bearings.
The symbol "N" which indicates the type of
bearings may be supplemented by one or two
letters to indicate different guide flange
combinations.
QJ - 4-point contact ball bearings.
T - Taper roller bearings. The prefix T is followed
by 3 symbols designated the bearing series and a
3- digit code indicating the bore dia, in mm.

44. CODE FOR BORE DIAMETER
1. The two digits indicate the diameter of bore between 20 to
490 mm. The bore Diameter is obtained by multiplying last
two digits by 5.
2. For bearings with bore diameter greater than 490 mm, the
bore diameter is directly Indicated after an oblique (e.g.
511/500).
3. Special coding applies for the bearings with bore
diameter less
than 20mm.
1. -- -- 10 mm
2. -- -- 12 mm
3. -- -- 15 mm
4. -- -- 17 mm
4. For the bore diameter less than 10 mm, the bore
diameter is
indicated by a single Digit which gives the value of bore

45. SUPPLEMENTARY DESIGNATIONS
Code letters additional to the basic designation
are used to distinguish bearings which differ from
standard or have modified components where
several code letters are required they are added
to the bearing designation in the order given
below.
Some of the most commonly used
supplementary designations are given below:

46. PREFIXES
BEARING
COMPONENTS
L – Removable ring (inner or outer) of a separable bearing.
e.g; LNU 207 – Inner ring of cylindrical roller bearing
NU207.
L30307 – Outer ring of taper roller bearing 30207.
R – Separable bearing less removable ring (inner or outer).
e.g: RNU207 – outer ring and roller cage assembly of
taper roller bearing 30207.
R30207 – Inner and roller and cage assembly or taper
roller bearing 30207.

47. SUFFIXES
INTERNAL DESIGN
Modified internal design of bearing.
e.g. 7205 D – Single row angular contact ball
bearing with a contact angle of 40 degree.
A – Contact angle 30 degree.
B – Contact angle 40 degree.
C – Contact angle 15 degree.
D – Contact angle 45 degree.

48. SUFFIXES
EXTERNAL DESIGN
X – Boundary dimensions altered to conform to ISO standards.
RS– Synthetic rubber seal fitted at one side of the bearing.
2LS – Synthetic rubber seal fitted on both side of the bearing.
Z – Shield fitted t one side of the bearing.
ZZ – Shield fitted at both sides of the bearing.
K – Tapered bore, taper 1:12 on diameter.
K30 – Tapered bore, taper 1:12 on diameter.
N – Snap ring groove on outer ring.
NR – Snap ring groove in outer ring with a snap ring.
ZN – Shield at one side and snap ring groove at other.
ZNR – As for ZN including snap ring.
N2 – Two diametrically opposed slots at one outside
corner of
outer ring.

49. N2 – Two diametrically opposed slots at one outside corner of outer
ring.
G – Single row angular contact ball bearing with ring faces
adjusted so that
any two bearings can be mounted in pairs, either in tandem, back to
back, or face to face.
CAGE
J – Pressed steel cage, unhardened.
Y – Pressed brass cage.
F – Machined steel or C.I cage
L – Machined light alloy cage.
M – Machined brass cage.
P – Polyamide 6-6 cage reinforced with 25% glass fiber.
T – Cage of fabric – reinforced phenolic resin.
TH – Fabric reinforced phenolic resin cage with snap type pockers.
TN9 – Reinforced plastic cage.

50. MOUNTING OF BEARINGS
In order to ensure proper mounting of bearings,
proper tools must be used, Especially when a
large number of bearings are to be frequently
mounted and Submitted. Bearings can be fitted
by the following methods depending on the size
and fit of the bearings.

51. 1. By Hammering
Bearings can be mounted by tapping gently with a copper
or lead faced hammer on a suitable blind tube having its
open end against the bearing race to the pressed into the
seat. Pressure should not be used on outer race to press
fit the inner race or vice versa. Two separate tubes should
be used for pressing two races. Cage should be protected
against any shock or pressure. If a bearing has to be
mounted simultaneously on the shaft and housing, the
mounting sleeve should bear in both the outer and inner
races.
If a suitable mounting sleeve is used, bearings with a
cylindrical bore of 70 mm maximum can be mounted in
this way.

52. 2. Pressing by hydraulic press
When a quite a number of small bearings are
to be fitted, the use of hydraulic press may be
advantageous. The advantages of this method
is that it helps in ascertaining the maximum
and minimum pressure load to be applied for a
particular mounting.

53. 3. Mounting by heating
Larger bearings and those which demand
greater interference are usually mounted after
heating. The method of bearings may be either
in oil bath or by induction heating.

54. While hearting the bearing in oil bath, the
following points are to be noted:
a) Use suitable medium for heating, such as clean
transfer oil.
b) Do not allow the bath temperature to exceed
90ºC.
c) Use false bottom at the bath so that bearings do not
comes in contact with the bottom or sides.
d) Bearings should be handle by means of tongs. A
spring attached to the lifting gear will be an
added advantage for correctly centering the
bearing.

55. DISMOUNTING OF BEARINGS
1. Dis mounting by pulling ,The method of removing
bearings depends upon the design of the bearing
installation. If the seating’s are not too tight, withdrawal
appliance usual in the trade will be found sufficient for
dismantling from the shaft or the housing. It is important to
ensure that the force required for withdrawal is not
transmitted through the rolling elements.

56. 2. In the case of adapter sleeve bearings, after the nut of
the adapter sleeve has been loosened, the later must
be knocked out of the bearing bore by means of a
tubular bushing. Bearings with withdrawal sleeve are
dismantled by screwing a withdrawal nut on the thread
of the withdrawal sleeve so far that the withdrawal but
bears upon the face of the inner ring and then draws
the sleeve not of the bearing bore.

57. For large beating with specially tight seating’s, an oil pressure
method is used. The journals are provided with ducts and
grooves to allow the oil injection method for dismounting
the bearings. The method provides a supply of high
pressure oil to the interference surface, thereby reducing
the friction between the inner ring and journal and keeping
the mounting force to the minimum. Hydraulic nuts can
also be used for loosening the withdrawal sleeve. The nut
is screwed on the threads of the withdrawal sleeve like
normal withdrawal nuts and then pressurized to dismount
the bearings as stated earlier.
. `

58. Electrical induction heaters are also used for
withdrawing the inner rings of the cylindrical
roller bearings. This needs only 20 or 30
seconds for removing the inner race. The
greatest advantage of this method is that
seating remains undamaged even after any
number of repeated fittings.

59. LUBRICATION OF
BEARINGS
The purpose of lubrication is:
1. To reduce friction between the rolling members.
2. To protect bearing from corrosion.
3. To prevent the intrusion of drift into the bearing.
4. To reduce the running noise.
5. To dissipate heat.

60. 1. Before being packed, the bearings are
coated withpreservative greasewhich prevent
corrosion. Bearings, therefore, should be
left in their original packing until just
before they are fitted.
2. Never wash out bearings which are available in
the suppliers packing.
3. If due to any reason the bearings
become dirty, they should be cleaned
in fresh petrol and re lubricated
immediately.
4. Avoid using compressed air for
cleaning bearings as
compressed air very often

61. Oil Lubrication is confined to certain
cases:
1.Bearing running at very high temperatures. Oil
should be fed through them continuously
for cooling purposes. (The oil should be
sucked through the bearing and never forced
through.)
2.Bearings fitted on the vertical shafts where it is difficult
to seal in the grease, so that drip-lubrication with oil is
preferable.
3.Bearing installedin machines whichare already
lubricated with oil and in which it is difficult to
separate the lubrication of bearings from that of the
other components of the machine.
4.Self-aligning thrust roller bearings which are
almost always lubricated with oil.

64. ROLLING BEARING DAMAGE AND ITS CAUSES
The life of ball or roller bearing depends upon the total
number of stress cycles and loads incurred by rolling
elements and raceways.
Normal fatigue manifests itself by flaking or Spalling of
the rolling surfaces. If the bearing continues in service an
increased localized stress may result in catastrophic ring
fracture.
If the bearing fails earlier than predicted by the fatigue life,
it should be checked for overloading. With this
failure cause excluded, thought shouldbe
given to the possibility of poor installation or
maintenance or to operational wear.

65. Why does a bearing
fail?
Faulty Mounting
An usual pattern of the running track suggest internal
nipping which may be caused by exceedingly
tight fits, excessive axial adjustment,
malformation of the bearing seats of the
shaftor the housing, misalignment, or when
the axial freedom of the floating
bearing is lost.
Localizeddamageto the raceway such as
nicks, score marks, or indentations
suggest faulty mounting.
This type of damage occurs if, for instance, the inner
ring of a cylindrical roller bearing is pushed into the
outer ring in a tilted position or if the mounting

66. Faults in
Design
Rolling bearing ring should be fully supported on the shaft
and in the housing. A groove in the seating area will
cause localized stress concentrations and subsequent
raceway destruction. Similar damage occurs when a set
screw is used to clamp the ring or when grooves or bores
are ground into the bearing after its completion in
manufacture.
Corrosion
Corrosion is caused by inadequate sealing against moisture,
Acid fumes, lubricant containing acids, condensation,
unsuitable storage.

67. Entrance of
Dirt
Entrance of dirt may be due to unclean parts,
sand in housing (castings), inadequate seals,
contaminatedlubricants, Metallicabrasion from
gears brought into the bearing by the lubricant.
Brinelling
Brinelling is caused by static overloading, shock
and vibration on stationary bearing (e.g. during
transportation), passage of electric current through
the bearing.

68. • Deep groove ball bearing.
•Inner ring, outer ring, and
balls are flaked.
• The cause is excessive load.
• Outer ring of angular
contact ball bearing
•Flaking of raceway
surface spacing equal to
distances between balls.
• The cause is improper
handling.

69. •Inner ring of deep
groove ball bearing
•Flaking on one side of
the raceway surface
•The cause is an
excessive axial load.
*Inner ring of
spherical roller
bearing.
*Flaking only on one
side of the raceway
surface.
*The cause is an
excessive axial load.

70. • Tapered roller
bearing
•Flaking on 1/4
circumference of
inner ring raceway
with outer ring and
rollers discolored
light brown.
•The cause is
excessive pre-load.
• Outer ring of double row
angular contact ball
bearing.
•Flaking on 1/4
circumference of outer
ring raceway.
• The cause is poor
installation.

71. • Thrust ball bearing
•Flaking on inner ring
raceway (bearing ring
fastened to shaft) and balls.
• The cause is poor
lubrication.
•Outer ring raceway of
double row tapered roller
bearing (RCT bearing)
•Flaking originated from
electric pitting on the
raceway
surface (refer to Section
5.13 “Electrical Pitting”)

72. •Rollers of spherical
roller bearing
• Peeling on rolling
contact
surfaces
•The cause is
poor lubrication.
• Tapered roller bearing
• Development of peelling to
flaking on inner ring and
rollers
• The cause is poor
lubrication.

73. •Inner ring of
cylindrical
roller bearing
• Spalling on
rib
•The cause is
excessive load.
•Inner ring of cylindrical
roller bearing
• Spallling on raceway
surface
and cone back face rib
• The cause is poor
lubrication.

74. •Rollers of tapered
roller bearing
• Cycloidal spallling on
the
end faces (Scuffing)
•The cause is
poor lubrication.
•Roller of cyllindrical
roller bearing
•Score in axial direction
on rolling contact surface
caused during mounting.
•The cause is poor
mounting practice.

75. • Inner ring of cylindrical
roller
bearing
• Smearing on raceway
suface
•The cause is slippage of
rollers due to foreign
objects
trapped within.
•Roller of same bearing as
that of the inner ring shown
in
Photo D-1
• Smearing on rolling contact
surface
•The cause is slippage of
rollers due to foreign objects
trapped within.

76. •Rollers of spherical thrust
roller bearings
•Smearing at middle of
rolling contact surfaces
•The cause is slippage of rollers
due to foreign objectstrapped
within.
•Inner ring of double row tapered
roller bearing (RCTbearing)
• Smearing on raceway surface

77. •Inner ring of double
row tapered roller
bearing (RCT bearing)
• Raceway surface is
speckled
• The cause is electric
pitting.
Ball of deep groove ball
bearing
• Speckled all over
•The cause is foreign objects
and poor lubrication.

78. •Inner ring (cut off
piece) of self-aligning
roller bearing
•Dents on one side of
the raceway
•The cause is
trapping of solid
foreign objects.
•Rollers of spherical
roller bearing
•Dents on rolling
contact surfaces
•The cause is
trapping of solid
foreign objects.

79. • Rollers of tapered roller
bearings
• Dents all over rolling contact
surfaces. (Temper color attwo
ends.)
•The cause is foreign objects
carried by lubricating oil.
• Inner ring of tapered roller
bearing
• Dents on raceway surface
•The cause is trapping of
foreign objects.

80. • Cylindrical roller bearing
• Chipping of guide ribs of
inner
and outer rings
•The cause is excessive
impact load.
•Inner ring of spherical
roller bearing
• Rib chipped
•The cause is excessive
impact load.

81. • Outer ring of four-row
cylindrical roller bearing
•Split of raceway surface
in the circumferential
direction originated from
large flaking.
• The cause is large flaking.
• Inner ring of spherical
roller
bearing
•Split of raceway
surface in the axial
direction
•The cause is
excessive
interference fit.

82. • Inner ring of tapered roller
bearing
• Rusting on raceway surface
spacing
equivalent to the
distance between
rollers.
The cause is water in
lubricant.
•Outer ring of tapered
roller bearing
•Rusting on raceway
surface spacing
equivalent to the
distances between
rollers.
The cause is water in
lubricant. Some points are
corroded.

83. • Inner ring (split type) of self-
aligning roller bearing
•Rust and corrosion of the
raceway surface
• The cause is ingress of water.
• Inner ring of double row tapered
roller bearing
•Seizing-up discolors and softens
inner ring producing stepped wear
at spacing equal to distances
between the rollers.
• The cause is poor lubrication.

84. •Inner ring of cylindrical
roller bearing
• Raceway surface is
corrugated
by electric pitting
• Rollers of tapered roller
bearings
•Electric pitting at
middle of rolling contact
surfaces

85. •Retainer of angular contact
ball bearing
•Breakage of machined high
tension brass retainer L1
• The cause is poor
lubrication.
• Retainer of spherical roller
bearing
• Breakage of partitions between
pockets of pressed
steel retainer

86. • Retainer of tapered roller
bearing
•Breakage of pockets of
pressed steel retainer
•Retainer of cylindrical
roller bearing
•Breakage of partitions
between pockets of
machined high tension brass
casting retainer L1.

87. Rolling Contact Bearing Trouble
Shooting
Some common bearing troubles are listed here
along with their possible causes and effects on
typical machinery .
Performance of
bearing
Possible Cause
: Noisy running
: Damage tracks and
rolling elements.
Examples
Automobile
s
Fans
Saw
Frames
I.C.
Engines
: Increasing shake in wheels.
Vibration in steering links
and associated components.
: Increasing vibration.
: Increasing shocks and
fluctuation in spindle
speed.
: Increasing vibration in

88. Performance of
bearing :
Possible cause :
Examples:
Lathes
Grinder
s
Cold rolling
Mills
Diminishing accuracy
in operation.
Wear and tear resulting
from the presence
of foreign
bodies, dirt, filings, chips,
of inadequate
lubrication. Damaged
Track and rolling
elements.
: Gradual appearance of
chatter
marks on work piece.
: Undulating surface on
ground section.
: Surface imperfection on
folled material, appearing

89. Performance of bearing : Extraordinary
running
noise. High pitch scream
or whistle.
Possible cause : Insufficient running
clearance.
Performance of bearing :
Possible cause
:
Rattling or noise of
varying intensity.
Excessive running
clearance. Damaged race
tracks. Foreign matter.
Unsuitable lubricant (too
heavy in consistency.)
Examples : Electric motor gears. (It is
very difficult to defect bearing noise in
gears due to the performance of gear whine
and noise emanating from the gears themselves).

90. Performance of bearing : Gradual change in running
noise .
Possible cause : Vibration in
running clearance due to influence
of temperature. Damaged race tracks due, for
example, too contaminated lubricant or fatigue.
Performance of bearing : Excessive
temperatureHigher temperature
than usual with identical working conditions.
Possible cause : At medium and
high speeds. Insufficient
running clearance. Unsuitable
and excessive lubrication. Faculty shafts seals or packing.
Rubbing seals with excessively tight fits. Labyrinth
seals rubbing against bearing.

91. Performance of bearing : Sudden
rise in temperature without any
change in working conditions.
Possible cause : Insufficient or
faulty lubrication commencement of
flanking.
Examples : Such faults in generally are
detected in the course of
maintenance.
Performance of bearing : Sluggish running.
Uniform high resistance in rotation.
Possible cause: Bearings mounted out tune. Miss-
alignment.
Excessive tight seals or packing. Excessive
amount of
lubricant or heavyconsistency of

92. DO'S & DON'TS FOR HANDLING ROLLER BEARINGS
DO'S
1. Work with clean tools, in clean surroundings.
2. Remove all outside dirt from housing before exposing
bearings.
3. Handle with clean dry hands.
4. Treat a used bearing as carefully as the new one.
5. Use clean solvents and flushing oils.
6. Lay bearings out on clean paper .
7. Protect disassemble bearing s from dirt & moisture.
8. Use clean lint-free cloths if bearings are wiped.
9. Keep bearings wrapped in oil-proof paper when not
in use.
10. Clean inside of housing before replacing bearings.
11. Install new bearings as removed from packages, without
washing.
12. Keep bearing lubricants clean when applying and

93. DON'TS
1. Don't work in dirty surroundings.
2. Don't use wood mallets or work on rough or dirty bench
tops.
3. Don't use dirty, brittle, or chipped tools.
4. Don't handle bearings with dirty moist hands.
5. Don't spin unclean bearings.
6. Don't spin any bearings with compressed air.
7. Don't use same container for cleaning and final rinsing of
bearings
8. Don't use cotton waste or dirty cloths to wipe bearings
9. Don't expose bearing to dirt or moisture at any time
10. Don't scratch or nick bearing surfaces.
11. Don't remove grease or oil from new bearings
12. Don't use incorrect kind or amount of lubricant

94. BEARINGS CONDITION MONITORING
Bearing accounts for the largest number of rotating
components in an industry and its healthy running can
ensure the productivity of the plant. Most of the
machine problems are accounted due to an ingenuity
developed in the bearings.
There are several methods for monitoring
bearing condition such as :
1. Vibration analysis.
2. Temperature
3. Sound, etc.

95. Shocks Pulse Analyzer
Shocks Pulse Analyzer is used to monitor
1. The mechanical condition of rolling
contact bearings (bearing damage
development)
2. The lubrication condition of rolling
bearings. (lubricant film il1 therolling
interface)