Question

In a ball bearing, if the balls are mot present, what will happen

Answer 1

A ball bearing is a type of rolling-element bearing that uses balls to maintain the separation between the bearing races.
The purpose of a ball bearing is to reduce rotational friction and support radial and axial loads. It achieves this by using at least three races to contain the balls and transmit the loads through the balls. In most applications, one race is stationary and the other is attached to the rotating assembly (e.g., a hub or shaft). As one of the bearing races rotates it causes the balls to rotate as well. Because the balls are rolling they have a much lower coefficient of friction than if two flat surfaces were sliding against each other.

Now if we remove the balls from a ball bearing attach it to a device,say a fan.
The fan won't rotate because,there is no friction between the input and output shaft.
Remember that balls only reduce friction,we need a small friction to carry the load from input to output shaft.
Thus a ball bearing without balls is useless.