The current state of the bearing was developed towards the end of the 19th century. It was made by hand in the first place.
Bearings are one of the most widely used machine parts today, the rotational movement facilitating almost all movements and helping to reduce friction.
Bearings have two key functions:
They transfer motion, for example, support and guide interrelated components.
They transfer forces.
Roller bearings and sleeve bearings
In a sleeved or plain bearing, the axle and bearing move in different directions on the sliding surface. In contrast, the two components of the bearings - the inner and outer rings - that move towards each other are separated by rolling elements. This design causes much less friction than a sleeve bearing.
Radial bearings and thrust bearings
Bearings can transfer loads in the radial or axial direction, and in most cases they transmit a combination of radial and axial loads.
Both designs are available as both ball bearing and roller bearing. The choice of bearing design depends on the application.