bearings

A bearing is a part that supports the shaft, which can guide the rotation of the shaft, and can also withstand the force from the shaft. A precision mechanical component that changes the sliding friction between the running shaft and the shaft seat into rolling friction, thereby reducing friction loss, is called rolling bearings.

The structure of rolling bearings

1. Inner ring, outer ring and rolling body

The rolling part of the rolling body on the inner ring and the outer ring is called the rolling surface. The rolling of the ball bearing ring is also called the channel. In general, the inner diameter of the inner ring and the outer diameter of the outer ring are properly matched with the shaft and the housing respectively during installation. The inner ring and outer ring of thrust bearing are called shaft ring and seat ring respectively.

2. Rolling element

The rolling body is divided into two categories: ball and roller, and the roller is divided into cylindrical roller, conical roller, spherical roller and needle roller according to its shape.

3. Cage

The cage encloses part of the rolling body so that it maintains a certain interval in the circumference direction. According to the different materials can be divided into steel cage, copper cage, nylon cage and phenolic resin cage.

Although there are many types and varieties of rolling bearings, and have their own fixed characteristics, they have the following common advantages compared with plain bearings:

(1) Starting friction coefficient is small, power consumption is small, mechanical efficiency is high, easy to start.

(2) International standards and specifications are unified, easy to get interchangeability, easy to install and disassemble, and easy to maintain.

(3) Easy lubrication, less lubricant consumption.

(4) In general, a set of bearings can bear both radial and axial loads.

(5) can be easily used at high or low temperatures.

(6) Bearing rigidity can be improved by applying prepressure.

The so-called internal bearing clearance refers to the amount of movement when the bearing is not installed in the shaft or bearing box, and the inner or outer ring is fixed, and then the unfixed side is moved in a radial or axial direction. According to the direction of movement, it can be divided into radial clearance and axial clearance.

When measuring the internal clearance of the bearing, in order to make the measured value stable, the test load is generally applied on the ring. Therefore, the test value is larger than the actual clearance value, that is, the amount of elastic deformation generated by applying the test load is more.