How do bearings work？

Bearing as a "joint" of mechanical parts, for the use of machinery, machine has an important role in principle, the bearing from ancient times are being discovered, and work as a simple rotation principle, by now, in the human constant research and exploration, today's bearing from the use of performance requirements and the use scope of work has the very big breakthrough,  Moreover, different types of bearings can be selected according to their specific use environmental conditions, so that the work can get twice the result with half the effort.

The following is a basic introduction to the working principle of bearings:

The rolling bearing developed on the basis of bearing, its working principle is rolling friction instead of sliding friction, generally consists of two rings, a group of rolling body and a cage composed of strong universality, standardization, high degree of serialization of mechanical foundation.  Due to the different working conditions of various machines, different requirements are put forward for rolling bearings in terms of load capacity, structure and performance.  To this end, rolling bearings need a variety of structures.  However, the most basic structure is composed of an inner ring, an outer ring, a rolling body and a cage -- often referred to as the four major pieces.  

For sealed bearings, plus lubricant and sealing ring (or dust cover) - also known as six pieces.

 Various bearing types are mostly named according to the name of the rolling body.  The roles of various parts in bearings are: for centripetal bearings, the inner ring is usually closely matched with the shaft, and operates with the shaft, and the outer ring is usually transitional with the bearing seat or mechanical shell hole, playing a supporting role.  However, in some cases, there is also an outer ring running, the inner ring fixed supporting role or the inner ring, the outer ring are running at the same time.  

For thrust bearings, the bearing ring is closely matched with the shaft and moves together, and the bearing seat or mechanical shell hole into a transition match and supporting the bearing ring.  The rolling body (steel ball, roller or needle) in the bearing usually with the help of the cage evenly arranged between the two rings for rolling movement, its shape, size and number directly affect the bearing load capacity and performance.  The cage can not only evenly separate the rolling body, but also guide the rotation of the rolling body and improve the lubrication performance of the bearing.  

The components of bearings, the following small series mainly take deep groove ball bearings as an example, as shown in the figure  

A rolling bearing, composed of several simple parts, plays a very important role, it can be said that rolling bearings support half of the rotating machinery.  There are only a few rolling bearings which are very important in many complicated machines.  Although the quantity is small, it plays an extremely important role in the normal operation and service life of the whole complex machinery.  It involves a very wide range, can be understood as no bearing, the shaft is a simple iron bar.