Most roller bearings consist of bearing rings (inner and outer rings) with raceways, rolling elements (balls or rollers), and cages. The cages separate the rolling elements at a distance and fix them in the inner and outer raceways. and allow it to spin freely.
The surface on which the rolling elements roll is called the "raceway surface", and the load applied to the bearing is supported by this contact surface. Typically, the inner ring is mounted on the axle or shaft and the outer ring is mounted in the housing. It should be noted that the raceway of the thrust bearing is usually called a "raceway washer", the inner ring is called a "shaft raceway washer", and the outer ring is called a "shell raceway washer".
Rolling elements are divided into balls and rollers. There are four types of rollers: cylindrical, needle-shaped, conical, and spherical. The balls are in geometric contact with the raceway surfaces of the inner and outer rings at "points", while The contact surface of the child is a "line" contact, and in theory, the construction of roller bearings allows the rolling element to rotate along the track, while also rotating about its axis.
The function of the cage is to keep the rolling elements on a uniform pitch and prevent the rolling elements from falling off when handling the bearing. The bearing does not directly apply a load to the cage. The type of cage varies depending on the manufacturing method, including pressed cages, Machined cages, one-piece cages, etc.
Roller bearings are divided into two categories: ball bearings and roller bearings. According to the configuration of their bearing rings, ball bearings are divided into two types: deep groove type and angular contact type. Roller bearings are classified into cylindrical, needle, tapered, and spherical bearings according to the shape of the rollers. Roller bearings can be divided into two types: radial and axial according to the applied load. The radial bearing bears the radial load, and the thrust bearing bears the axial load. Other classification methods include the number of rows of rolling elements (single, double, or four), separable and non-separable types, etc.
In addition to the above classifications, there are also bearings designed for special applications, such as precision roller bearings for machine tools, bearings for special environments, and linear motion bearings (linear ball bearings, linear roller bearings, and linear flat roller bearings).
