Ball Bearing
A Ball Bearing is a type of rolling-element bearing these are often used in engineering .The purpose of a Ball Bearing is to reduce rotational friction and support radial and axial loads. It achieves this by using at least two races to contain the balls and transmit the loads through the balls. Usually one of the races is held fixed. As one of the bearing races rotates it causes the balls to rotate as well. This can be used for all sorts of machinery. Because the balls are rolling they have a much lower coefficient of friction than if two flat surfaces were rotating on each other. This in turn makes it much more effective .A Ball Bearing tends to have lower load capacity for their size than other kinds of rolling-element bearings due to the smaller contact space between the Ball Bearing and races. They can tolerate some misalignment of the inner and outer races. There all different types available on line which cover all the possible uses you may need them for. There are clear examples of these for you see on the internet. They also come at very competitive prices.