The working principle of automotive wheel bearings, in detail

One, wheel bearing working principle

Wheel bearings are divided into one generation, two generations and three generations of wheel bearings according to their structural forms. The first generation wheel bearing is mainly composed of inner ring, outer ring, steel ball and cage, and its working principle is shown in Figure 1. The working principle of the first generation, second generation and third generation wheel bearings is similar to that of ordinary bearings, all of which use steel balls to roll in the inner ring, outer ring or flange raceway, carry and rotate relative to each other, thus making the car drive.

Two, wheel bearing noise

1. Wheel bearing noise characteristics

According to the working principle and force characteristics of wheel bearings, there are three important characteristics of wheel bearing reverberation: ① wheel bearings rotate together with the wheels, and the frequency of reverberation is proportional to the wheel speed. As the speed of the vehicle increases, the wheel bearing reverberation becomes stronger continuously, and generally does not appear only in a narrow speed band reverberation situation. ②The intensity of wheel bearing reverberation is directly proportional to the load it is subjected to. When the car is turning, the wheel bearing is subjected to a larger load and the reverberation is more obvious. ③The wheel bearing reverberation is easily confused with the reverberation of tyres, engines, transmissions, drive shafts, universal joints and other transmission systems.

2. Wheel bearing reverberation performance form

The main manifestations of wheel bearing reverberations are as follows 3 kinds:

(1) humming sound

Wheel bearing internal raceway wear, spalling, indentation and other defects, or bearing loose, will continue to produce "grunt", "buzzing" noise. As the speed of the vehicle increases, the periodic grunting sound gradually changes into a buzzing sound, and when driving at high speed, it eventually gradually changes into a high frequency whistling sound.

(2) Squeaking sound

When the wheel bearing seal fails and the amount of internal lubricating grease is insufficient, the grease cannot form an oil film on the surface of the groove and the steel ball, resulting in the contact friction between the groove and the surface of the steel ball, producing a sharp squeaking sound.

(3) Staring sound

If there are bruises on the surface of the steel ball inside the bearing, broken steel balls or hard foreign objects inside the bearing, the steel ball will crush the abnormal part of the raceway during the driving process, producing a "gurgling" sound.

Post time: Aug-02-2023