It may sound like an obvious question as you would think that ball bearings are ball shaped. To see the shape of a ball bearing lets first look at how they are made. It may be surprising but they actually start with a piece of thick wire. Using a process called Cold Heating, the wire is then cut of at both ends, via a machine, until it is a small piece, hence the name the wire is not heated during this process. The machine has a cavity the shape of a hemisphere on each side and slams into the wire to make the shape of a ball. This process leaves a flash around a ball, which is a piece of metal around the ball making it look a bit like the planet Saturn. The balls are then fed into a machine that rolls the flash away leaving a very smooth and very perfect shaped ball.
So the answer to ¡®what shape is a ball bearing?¡¯ is a ball shape right? Well yes and no, this part of the ball bearing is a ball that is correct but this is not entirely a ball bearing, you can¡¯t put a ball into a machine and expect it to work, it needs other parts to the ball bearing for the bearing to operate. So what shape are the other parts to a ball bearing I hear you ask. The shape of the other parts to a ball bearing depends on the type of ball bearing because there are several different designs.
What parts make up the shape of a ball bearing?
Typically within a ball bearing several components are used including an outer ring, an inner ring, a cage or a retainer inside, and the balls. All of this makes up the whole of a ball bearing, but because the rolling element inside the bearing are balls it is called a ball bearing but the shape of it is more a hula shape like a wheel, but they probably would not have wanted to have called it a hula bearing for obvious reasons!
How are these parts assembled to make a ball bearing?
First you take the inner race and place into the outer race placing it to one side as far as possible. Place the balls between the two races, the amount of balls you place depends on the size of the races and the type of bearing. Once the balls are in place the races are moved into the centre. The cage is installed to keep the races and balls in place. Rust and protective coats are placed over the bearing and then sealed. And hey presto that is how you make a ball bearing.