A rolling bearing is a precise mechanical component that converts sliding friction between a rotating shaft and its housing into rolling friction, reducing friction loss.

Rolling bearings generally consist of four components: the inner ring, outer ring, rolling element, and cage.
The inner ring works in conjunction with the shaft and rotates with it. The outer ring is designed to support the bearing and is matched with the bearing housing.
The rolling element, with the help of the cage, evenly distributes the rolling elements between the inner and outer rings. Its shape, size, and quantity have a direct impact on the performance and lifespan of the rolling bearing.
The cage serves to uniformly distribute the rolling elements and guide their rotation for proper lubrication.
Effect
The purpose of a rolling bearing is to support the rotating shaft and its components, maintain the normal working position and rotation accuracy of the shaft.
Rolling bearings are user-friendly and easy to maintain, with reliable operation, good starting performance, and high load capacity at medium speeds.
However, compared to sliding bearings, rolling bearings have a larger radial dimension, poor damping capacity, a shorter lifespan at low speeds, and tend to produce more noise.
Structure
- The outer ring – installed in the hole of the bearing housing and generally does not rotate.
- Inner ring – mounted on the journal, rotating with the shaft
- Rolling elements – the core components of rolling bearings
- Cage – evenly separate the rolling elements to avoid friction
Revised Version:
Lubricant is often considered to be the fifth component of rolling bearings. Its main functions are to provide lubrication, cooling, and cleaning.