Question

How does a Ball bearing work?

Answer 1

In various equipment, there are various components moving relative to each other. Often, this relative motion involves contact between two different components. Obviously, this creates friction.

The force required to impart desired motion and heat created due to the contact increases exponentially with the area of contact. The problem becomes quite critical if the parts are moving at high speed.

Hence, the solution would be reducing the area of contact between moving components. It would be great if we could reduce contact area to few points. Bearings enter the scene here.



Bearings are used to support the rotating components (like shafts) and bear the load which the rotating components carry.

Principally, it has four major components:

• Outer ring: This fits tightly inside the outer structure which is generally not moving e.g. Pump/Motor Casing
• Inner ring: This ring fits tightly on the shaft and rotates with it.
• Balls: These are the components which fill the gap between inner and outer ring and provide 'point contact' which we talked about to facilitate relative motion between inner and outer ring.
• Cage: This is a metal or ceramic structure which holds all the balls fixed at their relative positions while allowing them to rotate freely

Working

From the construction, working of bearing can be understood easily. Inner ring fits on a shaft, outer ring fits inside the stationary component through which the shaft passes. As the shaft rotates, along with the inner ring, balls start spinning inside the cage. And a relative motion between inner ring and outer ring is established with minimal contact area.