A ball bearing, also known as a rotating-arm bearing, is a kind of non-spinning rolling-arm bearing that employs balls on their inner and outer arches to keep the inner bearing surfaces separate from each other.
The bearing rollers are located inside the rolling arms, while the rollers of the ball bearing are often located outside the bearing housing. The outer rolling arm of the bearing housing has contact with a set of spindles that spin, while the inner bearing surface has contact with a magnet or a source of electrical power. Because of the way the ball bearing assembly is designed, the balls of different sizes can contact either one another, or a number of other balls at once. This can cause friction in the bearing, so ball bearings are often incorporated into high-performance engines to eliminate such issues.
A ball bearing does not use any moving parts, so the amount of friction created is entirely due to the rolling balls themselves. In order to allow the balls of varying sizes to spin, they must be able to contact every part of the bearing housing at the same time, which greatly increases the amount of friction. The balls spin on two different axes, with each axis having a different amount of angular momentum. Due to the angular momentum, the balls travel in a random pattern, which is why they tend to run up and down the roller tracks.
The amount of friction created by ball bearings is dependent upon both their design and the materials they are made out of. Because of this, plastic and polycarbonate are typically more efficient in creating high levels of friction. While polycarbonate ball bearings tend to have lower levels of friction than plastic, they can still work well with plastics that have a lower melting point. Plastic ball bearings also tend to be durable and strong, allowing them to be used on some of the more weight-sensitive equipment.
There are two main types of ball bearing designs: axial loads and radial loads. An axial load is one that is formed by two balls moving in the same direction. Radial loads are similar to those of a bearing's axial load, but they are formed on an axial load that travels in a different direction. The most common radial load found in industrial equipment is generated by a machine's rotors. They are used to provide smooth operation in instances where a roller bearing needs to be turned. They are also sometimes used to counterbalance the weight of other, heavier components.
A common problem that can occur with steel balls bearings is rust build up. Rust is commonly caused by improper care, especially with regards to cleaning. It can also be caused by the heat generated during processing, as well as the oil used in some machinery. If not properly maintained, it can also lead to corrosion by rust particles.
Steel balls bearings tend to be much less expensive to produce. This is because they do not require nearly as much machinery to produce them. Their main limitation is their inability to provide significant lateral or axial friction. Radial and axial friction is necessary for smoother, safer operation and can reduce the risk of fatigue failure in machinery. Unfortunately, because of the cost of steel balls it is often not practical to install more than a few in a machine. It is also very difficult to add a ball bearing to a design that already contains balls or a cage, due to potential contamination.