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BEARING(MECHANICAL)

©©DefinitionDefinition

©principles of operation©principles of operation

©animation of ball bearing©animation of ball bearing©types©types

©services in life©services in life

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DEFINITION

A bearing is a device to allowconstrained relative motion between

two or more parts, typically rotation orlinear movement

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Principle of operations There are at least six common

principles of operation:

plain bearing, also known by thespecific styles: bushings, journalbearings, sleeve bearings, riflebearings

rolling-element bearings such as ballbearings and roller bearings

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Continued͙͙..

 jewel bearings, in which the load is carried by

rolling the axle slightly off-center

fluid bearings, in which the load is carried by agas or liquid

magnetic bearings, in which the load is carried

by a magnetic field

flexure bearings, in which the motion is

supported by a load element which bends

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Types

Ball Bearings

Roller Bearings

Ball Thrust Bearing Roller Thrust Bearing

Tapered Roller Bearings

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BALL BEARING

Ball bearings, as shown above, are probablythe most common type of bearing. They are

found in everything from inline skates to hard

drives. These bearings can handle both radial

and thrust loads, and are usually found in

applications where the load is relatively small.

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ROLLER BEARING

Roller bearings like the one illustrated below areused in applications like conveyer belt rollers,where they must hold heavy radial loads. In thesebearings, the roller is a cylinder, so the contactbetween the inner and outer race is not a pointbut a line. This spreads the load out over a larger

area, allowing the bearing to handle much greater loads than a ball bearing. However, thistype of bearing is not designed to handle much thrust loading.

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Ball Thrust Bearing

Ball thrust bearings like the one shown above

are mostly used for low-speed applications

and cannot handle much radial load. Barstools

and Lazy Susan turntables use this type of 

bearing.

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Roller Thrust Bearing

Roller thrust bearings like the one illustrated below cansupport large thrust loads. They are often found in

gearsets like car transmissions between gears, and

between the housing and the rotating shafts. The helical

gears used in most transmissions have angled teeth --

this causes a thrust load that must be supported by a

bearing

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Tapered Roller Bearings

Tapered roller bearings can support large

radial and large thrust loads.

Tapered roller bearings are used in car

hubs,

where they are usually mounted in pairs

facing opposite directions so that they can

handle thrust in both directions.

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Services in life

Many bearings are used in our day to day life

For say ball bearing that is commonly sued to

reduce friction Many are used for dental and medical

instruments

And so on

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Leonardo da vinci͛s picture of ball

bearing

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