WHAT IS A BEARING :

 

The bearing makes many of the machines we use every day possible.

Without bearings, we would constantly be replacing parts that wear out from friction.

Objects roll more easily than they slide.

The wheels on your car are like big bearings. If you had something like skis instead of wheels, your car would be much more difficult to push down the road.

Bearing Loads

Bearings typically experience two kinds of loading radial and thrust.

Depending on where the bearing is used, it may see radial loading, thrust loading, or a combination of both.

The bearings in an electric motor and pulley combination face only a radial load.

Most of the load comes from the tension in the belt connecting the pulleys.

The bearings in barstools and lazy Susan’s are totally thrust loaded. The entire load comes from the weight of the objects.

The bearing in the hub of your car wheel must support both radial and thrust loads.

The radial load comes from the weight of the car; the thrust load comes from the cornering forces when you go around a turn.

 

Parts Of A Standard Bearing

 

 

The standard essential components of a bearing are as follows:

 

1.   Inner Ring

The Inner Ring is the smaller of the two bearing rings.

It has a groove on its outer diameter to form a raceway for the balls.

The surface of the outside diameter path is finished to extremely tight tolerances and is honed to be a very smooth surface.

The inner ring is mounted on the shaft and it is the rotating element.

2. Outer Ring

The Outer Ring is the larger of the two bearing rings.

On the outer ring, there is a groove on its inside diameter to form a pathway for the balls. It also has the same high-precision finish as the inner ring.

The outer ring is usually held stationary.

3. Rolling Element (Balls, Cylindrical Rollers, Spherical Rollers, Tapered Rollers, Needle Rollers)

The rolling elements separate the inner ring and outer ring and permit the bearing to rotate with minimal friction.

The dimension of the rolling elements is made slightly smaller than the track on the inner and outer rings.

 

Rolling element dimensions are controlled to very high accuracy. Surface finish and size variations are important attributes.

These attributes are controlled to a micro inch level.

4. Cage (Retainer)

The purpose of the cage in bearings is to separate the rolling elements, maintain a constant spacing between the inner and outer rings, accurately guide the rolling elements in the path during rotation, and to prevent the rolling elements from falling out.

 

5. Lubrication

The lubricant is an integral part of a bearing’s standard components.

Lubrication is added to reduce friction losses in bearing between inner and outer rings.

6. Other Optional Bearing Components

The other additional components shields and seals enhance the performance and life of the ball bearing.

These optional components are added to the bearing as per the customer’s requirement to increase the performance of the bearing.

7. Shields

The shield is a stamped, profiled sheet metal disc.

 The shield is pressed into a very small groove on the inside edge diameter of the outer ring.

A small space or gap remains open between the outside diameter of the inner ring and shield.

Because the shield does not contact the inner ring of the bearing, there is no added friction between the shield and bearing.

This results in a bearing that has very low torque. The purpose of shields is to keep larger particles of contamination from entering the bearing.

8 . Seals

The seal is also inserted into the very small groove on the inside, edge diameter of the outer ring.

The inner edge of the seal is molded into a specifically designed lip configuration.