A bearing is a device that supports load and reduces friction between moving parts. There are two main types: plain/slider bearings and rolling/anti-friction bearings. Rolling bearings use balls or rollers to create separation between surfaces and are more commonly used. Common bearing materials include metals, alloys, and some non-metals. Bearings must be properly selected, mounted, lubricated, and maintained to maximize their lifespan and prevent premature failure.

1. Topic Name Bearing
Name Muddassar Awan
THE UNIVERSITY OF LAHORE1

2. A Bearing is a device that support
load and reduces the friction of
motion between moving machine
parts.
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4.  Plain or slider bearing
 Rolling or anti-friction
bearing
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5. Plain or slider bearing : -
In which the rotating shaft has a sliding
contact with the bearing which is held
stationary. Due to large contact area
friction between mating parts is high
requiring greater lubrication.
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6. A linear table with four
linear bearings
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7. Metals and Alloys
(1) Bronze
(2) Cast iron
(3) Steel
(4) Silver
(5) Copper based alloys
(6)Aluminum Based
materials
Non- Metal
(1)Wood
(2) Rubber
(3) Plastics
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8. Collar bearing
Footstep bearing
Journal bearing
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9.  Journal bearing – in this the bearing
pressure is exerted at right angles to the
axis of the shaft. This journal bearing is
used for supporting a radial load. Shaft
are generally made of mild steel.
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10.  Foot step bearing – in this bearing the bearing
pressure is exerted parallel to the shaft whose
axis is vertical. Note that in this case the end of
the shaft rests within the bearing.
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11.  Collar bearing – Collar bearing mainly used on
horizontal which carry a large axial force.
Thrust bearing are used in bevel mountings,
propeller drives, turbines, etc.
 Collar bearing also known as “Thrust bearings ”.
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12.  Advantages Plain bearing are cheap to produce and
have noiseless operation. They can be easily
machined, and have vibration damping properties.
 Disadvantages are they require large supply of
lubricating oil, they are suitable only for relative
low temperature and speed.
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13.  Used rolling element between moving
parts.
 Due to less contact area rolling friction is
much lesser than the sliding friction ,
hence these bearings are also known as
antifriction bearing.
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14. Load on the Bearings
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15. Ball bearing
Roller bearing
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16. Ball bearing:
A bearing is type of rolling element bearing
which uses balls to maintain the separation
between the moving parts of the bearing. The
purpose of a ball bearing is to reduce rotational
friction and support axial and radial loads.
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17. Roller bearing:
Roller bearing use cylinder of greater length
than diameter. It is typically have higher radial
load capacity than ball bearing, but in low axial
capacity and higher friction.
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18. Races and balls are high carbon chrome steel (to provide resistance to wear)
machined and highly polished and hardened.
The cages are made of low-carbon steel.
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20.  Deep Groove Ball
Bearings
 Primarily radial
load carrying
 Deep groove radial
Bearing is one in
which the race
dimensions are close
to the dimensions of
the ball that run in
it.
http://my.ecplaza.net/nbsinobest/12l.asp
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22.  Double row deep
Groove
 Increases radial load
Single row deep
groove ball bearings
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23. Angular contact ball bearing
 Angular contact bearing better support combined
loads. The angle of contact on inner race is the same
as that on the outer race.
 Contact angle 10 to 45
www.hz-bearing.com
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25. Dingle row
angular contact
ball bearings
Double row
angular contact
ball bearings
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26.  Thrust ball Bearings
 A thrust bearing is a
particular type of
rotary bearing. Like
other rotary bearings
they permit rotation
between parts, but
they are designed to
support a high axial
load while doing this.
http://kianho.com
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28.  Needle Bearings
 Use long and thin
cylinder
 The greater the contact
area the greater the
load
 Support radial load
www.clworldwide.com
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29.  Tapered Roller
Bearing
 Support high combine
loads (wheel bearing)
 Wheel rotates with little
resistance/friction
 Noiseless
www.ahrinternational.com
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30. Cylindrical roller bearing :
Use thick and long cylinder.
Roller bearings typically have higher load
capacity than ball bearings. If the inner and
outer races are misaligned, the bearing
capacity often drops quickly compared to
either a ball bearing.
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32.  Tapered roller bearing (TRB):
 TRB can take both radial and axial loads and used for gear
boxes for heavy trucks, bevel-gear transmission, lathe
spindles, etc.
 Thrust ball bearing:
 Thrust ball bearing are used for heavy axial loads and low
speeds.
 Needle roller bearing:
 It use small diameter of rollers. They are used for radial load
at slow speed.
 They have the advantage of light weight and occupy small space.
 They are used in aircraft industry, bench-drill spindles, etc.
APPLICATIONS OF ROLLER BEARINGS
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34. Around 16% of all premature bearing failures
are a result of poor fitting or using incorrect
mounting techniques. Individual applications
may require mechanical, heat or hydraulic
mounting methods for correct and efficient
bearing mounting. Selecting the mounting
technique appropriate for your application will
help you extend your bearing’s service life and
reduce costs resulting from premature bearing
failure.
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35.  Mounting bearings in a cold condition
 Mounting bearings using heat
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36. Small and medium size bearings are generally
cold mounted. Traditionally the bearing is
mounted using a hammer and a length of old
pipe. This practice can cause forces to be
transmitted through the rolling elements,
causing damage to the raceways. Proper fitting
tools help prevent bearing damage by applying
the forces to the bearing ring with the
interference fit.
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38. Oil baths are often used for heating bearings
prior to mounting. However, this method can
contaminate the bearing, resulting in
premature bearing failure. Today, induction
heating is the most common technique for
heating bearings since it allows a high degree
of controllability, efficiency and safety.
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41. When dismounting bearings, care must be
taken not to damage other machine
components, such as the shaft or housing, as
damage can result in compromising the
machine’s efficiency and lifetime. Bearings are
sometimes dismounted to maintain or replace
other components of the machine. These
bearings are often re–used. Individual
applications may require mechanical, heat or
hydraulic dismounting methods and tools to
allow safe, correct and efficient bearing
dismounting.
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42.  Mechanical dismounting
 Dismounting using heat
 Hydraulic Techniques
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46.  Bearing life
 Bearing speed (rpm)
 Accuracy
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• Bearing load – radial, thrust (axial) or both
Radial loadRadial load
Thrust load
Bearings are selected from catalogs, before referring
to catalogs you should know the followings:

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Life – number of revolution or hours of operation, at constant
speed, required for the failure criterion to develop.
L10 = 500 (hours) x 33.33 (rpm) x 60 = 106 = 1 million
revolutions
For ball bearings and spherical bearings:
For tapered bearings manufactured by Timken:
L10 = 3000 (hours) x 500 (rpm) x 60 = 90 x 106 = 90 million
revolutions
– defines the number of revolution or hours of
operation, at constant speed, in such a way that of the
bearings tested (from the same group) will complete or exceed
before the first evidence of failure develops. This is known
as life.
Rating Life
L10
90%
– constant radial load that a group of
bearings can carry for L10 life.
Basic Dynamic Load Rating, C

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L10 = (C / F)
a
, a = 3 for ball bearings and a = 10/3 for roller bearings
F = applied radial load

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Select a deep groove ball bearing for a desired life of 5000 hours
at 1725 rpm with 90% reliability. The bearing radial load is 400
lb.

50.  Improper Lubrication - 43%
 Improper Mounting - 27%
 Other Lubrication Causes - 21%
 Separation in Storage
 Temperature Limit Exceeded
 Moisture Contamination
 Fatigue - 9% Ultimate L10 Life Expectancy
64% of Bearing Failures are Lubrication Related IS Not The Whole
Story
In the Industry We Serve, Most Bearings Fail Due To Some Form of
CORROSION
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51.  www.bocabearings.com
 www.evolution.skf.com
 www.bearings.com
 www.bardenbearings.com
 www.ceramicbearings.com
 www.bsahome.org/tools/index.shtml
 www.skf.com/
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