A rotary bearing is a component used in motion systems that allow rotation of moving parts. They have an inner and outer surface (races) with metal balls or rollers between them. This allows the surface to slide over a shaft when in motion, reducing friction as there is low surface area contact.
Rotary bearings are classified by the type of bearing that hold the loads in the cage between the races - ball or roller. Both types can support different primary load directions, known as radial loads or axial loads (thrust).
Ball bearings have round ball to separate the races, which creates a very small contact area, highly reducing friction and making them ideal for high-speed applications. They are categorised by the configuration of the outer race. Common types include deep groove and angular contact ball bearings.
Roller bearings have cylindrical rollers to separate the races which improves load distribution. They are available in different shapes and can handle high loads. They are categorised by the shape of the roller. Common types include tapered roller bearing and needle roller bearings.
Rotary bearing bearings are designed to be used in a wide range of machine motion systems to ensure continuous low friction movement. They can be usually found in:
Once the bearing type is known, there are many other varying specifications of rotary bearings for consideration that include:
Bearing failure is mainly caused by lack of lubrication so it is important to select the proper oil or grease for the application.