The Fundamentals of Bearings

Topics for Consideration Definition History Types Correct Fitting Methods Lubrication and Care Fault Diagnosis Bearing Failure Closing Facts

What is a Bearing? In engineering terms, a bearing is a device which provides support between at least 2 surfaces, usually 1 being static, other dynamic The static may be in the form a stationary supporting plane, such as a housing or body The dynamic may be a shaft providing rotary action, possibly a drive between a motor and gear wheel. https://www.youtube.com/watch?v=RihQOUNsN9c

Roller Bearings History ?BC - Tree trunks to move stone blocks 40BC - Wooden roller on Roman Nemi Ships rotating table 1500AD - Leonardo Da Vinci’s design within his helicopter designs 1745 – First Caged Roller Bearings in a Clock 1794 – First Patented Roller Bearings (UK)

Roller Bearing 1st Real Design

Why we use Bearings With parts moving against each other, friction is caused Friction causes wear, which leads to premature failure This also causes heat, which leads to damage Bearings are used to overcome these effects

Load Types on a Bearing

Some Types of Bearing Ball Cylindrical Roller Needle Roller Taper Roller

Ball Bearing These consist of an inner race, an outer race and a set of balls that are supported with a cage Are generally used for supporting radial loads These have point contact and have the advantage of being the highest speed bearings Disadvantages include having poor static load ability, are not adjustable and are poor in supporting axial loads General applications of use are with electric motors, rollers, small gearboxes and light vehicles

Ball Bearing

Roller Bearing Detail

Races & Ball Contact Points

Cylindrical Roller Bearing These consist of an inner race, an outer race and a set of straight rollers that are supported with a cage These can be used for moderately high speed and operate at low torque which uses less energy The separate race makes installation easier but do not tolerate misalignment well do not support axial load well These are intended for supporting radial load Ideal applications include larger electric motors and steel rolling mills

Cylindrical Roller Bearing

Races & Roller Contact Points

Needle Roller Bearing These consist of an inner race, an outer race and a set of straight rollers that are supported with or without a cage Are like a Cylindrical Roller Bearing but rollers are much smaller in diameter Advantages include being inexpensive, can accommodate a large diameter shaft , have good stiffness / rigidity and can be used in higher torque instances Typical applications include in gearboxes, drive shafts and rollers used in low speed applications

Needle Roller Bearing

Taper Roller Bearing This consists of an inner ring or cone, outer ring or cup, cage and a set of rollers These are capable of carry high axial & radial loads and accommodating high speed These can be adjusted to give desired clearance, which can maximise machine performance and extend bearing life Typical applications include turbines, railways axles, gearboxes & car wheel bearings

Taper Roller Bearing

Taper Roller Bearing Arrangements

Other Bearing Types Rod Eye Bearing Cooper Split Bearing Clevite Bearing Shell Bearing Sleeve Bearing Track Runner Bearing Slewing Bearing Cup Needle Roller Bearing Multi Row Ball or Roller Bearing

Recess: As small groups: Consider where we may find bearings in the college What types may these bearings be? Tell me your ideas 

Bearing Identification Number

Correct Methods used for Fitting a Bearing Keep bearing well oiled, this will prevent rusting Do not subject the bearing to excessive heat if trying to expand inner race before a shrink on fit (never to exceed 120 deg C) http://www.youtube.com/watch?v=hr9wTC9dw7s

Correct Methods used for Fitting a Bearing Wherever possible, bearings must be assembled in a clean environment Use only a soft hammer and / or soft metal drift; this will prevent causing damage

Correct Methods used for Fitting a Bearing When fitting a bearing using a press, ensure the bearing enters squarely Do not use excessive pressure, this will only cause irreversible damage the bearing A press can also be used to remove bearings!

Is this correct??

Bearing Lubrication Tell me all about this pls………….

Bearing Lubrication The primary function of lubricating a bearing is: Prevention of wear Minimising the frictional power loss To act as heat transfer medium Removal of debris from roller contact paths Prevent bearing corrosion

Bearing Fault Diagnosis Tell tale signs include: Excessive Heat Squealing or Squeaking Rumbling Sound Vibration

Bearing Failure Examples Seizing Cage Collapse Excessive Play Discolouring Bearing Disintegration

The World’s Smallest Ball Bearing? Introducing the world’s smallest deep groove ball bearing, in which we have concentrated our technologies on micro processing, assembling and measurement to achieve a top notched manufacturing technology and in house made jigs and tools. Outer Diameter ： φ２．０mm Inner Diameter ： φ０．６mm Width ： ０．８mm Ball Diameter ： φ０．３mm (７pcs) Retainer ： ０．０４mm (thickness) Material ： Stainless (Inner/Outer rings, Balls) 〈 Specifications 〉 Even smaller than a grain of rice Achieved JIS P5 class on ultra precision and quietness.

World’s Largest Bearing?

GP7000 Turbofan Jet Engine

GP7000 Turbofan Jet Engine Temperatures in the engine core are half those on the surface of the sun The blades in the engine's high pressure system rotate at 12,500 rpm, with tip speeds reaching 1,200 miles per hour (2,000 kph)

GP7000 Turbofan Jet Engine What type of bearing do you think this uses?

Bearing Manufacture Bearings are made out of a very tough types of steel, chrome steel SAE 52100 http://www.youtube.com/watch?v=eGyoMuE4gDQ https://www.youtube.com/watch?v=7z-T0wI4ub0

Closing Facts ‘The L10 life of an anti-friction bearing is the minimum expected life, hours, of 90 percent of a group of bearings which are operating at a given speed and loading. The average expected life of the bearings is approximately five times the L10 life’ In reality the life expectancy is dependant upon - correct fitting method applied, lubricant type used lubrication amount / frequency correct loading / application

Now Identify What you See

How did this happen???!!!!

I do hope that none of this information caused you to lose you bearings!!!!!