Transcript TOPIC: BEARINGS - University of Waterloo

TOPIC: BEARINGS
OBJECTIVE: TO TALK ABOUT THE
IMPORTANCE OF BEARINGS WHILE
DESCRIBING THE DIFFERENT TYPES OF
BEARINGS AND THEIR USES
Presenter: SHER AFZAL PARACHA
Introduction
• A bearing is a component used to reduce friction in a machine.
Bearings may be classified broadly according to the motions they
allow and according to their principle of operation.
• The concept behind a bearing is very simple: Things roll better than
they slide. Bearings reduce friction by providing smooth metal balls
or rollers, and a smooth inner and outer metal surface for the balls to
roll against. These balls or rollers "bear" the load, allowing the
device to spin smoothly.
• Common motions include linear and rotary. A linear bearing allows
motion along a straight line, for example a drawer being pulled out
and pushed in. A rotary bearing allows motion about a center, such
as a wheel on a shaft or a shaft through a housing. Common kinds
of rotary motion include both one-direction rotation and oscillation
where the motion only goes through part of a revolution.
Main Types of Bearings
• Ball Bearing, which is the most common of all the types. A sphere is
used in between two races which results in a very less contact area
making it move very smoothly. Used in applications where there is a
relatively small radial or thrust load.
• Roller Bearings, in which cylinders are used instead of spheres,
increasing the contact area so that it holds a greater radial load.
• Ball Thrust Bearings are used for low speed applications and cannot
handle much radial load.
• Roller Thrust Bearings, which can support large thrust loads.
• Tapered Roller Bearings can support large radial and thrust loads.
Ball bearing
Cutaway view of a ball bearing
Roller Bearing
Cutaway view of a Roller Bearing
Ball Thrust Bearings
Roller Thrust Bearings
Tapered Roller Bearings
Cutaway view of (left) a spherical roller thrust bearing and (right) a radial tapered roller
bearing
Some Uses
• Ball bearings are found in everything from inline skates to hard
drives.
• Roller Bearings are used in applications like Conveyer Belt Rollers.
• Bars Tools and Lazy Susan Turntables use ball thrust bearings.
• Roller Thrust Bearings are used to support thrust loads in car
transmission between gears, in between housing and the rotating
shafts, etc.
• 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.
Conclusion
Therefore bearings are used in a lot of different mechanical
devices and are very important to make different applications
durable, noiseless and efficient.
References:
 http://science.howstuffworks.com/bearing3.htm
 en.wikipedia.org/wiki/Bearings