The noise caused by problems in bearing application is commonly divided into two types: scratch sound and dust sound, which are described as follows:

(1) Scar sound and its control methods

If there are cracks, indentations, or rust on the rolling surface of rolling bearings, periodic vibration and noise like riveting rivets will occur. The period may remain fixed but mostly corresponds to the rotational speed. Scars will occur continuously in the groove, and they will appear and disappear on the steel ball. Moreover, this noise varies with installation and lubrication conditions.

The control methods for this type of noise include: do not hit the bearings during installation, and prevent the bearings from being installed diagonally when assembling them with the shaft and then installing them into the bearing seat; Prevent bearing rust during inventory and prevent impact vibration during transportation; Use high viscosity lubricating grease.

(2) Dust Sound and Its Control Methods

There are dust and other foreign objects inside the rolling bearing, which can cause non periodic vibration and so-called dust noise. The magnitude of the vibration and noise varies, and may or may not be present.

The control methods for dust noise include improving the cleaning method of bearings, and before installation, ensuring that all bearings, shafts, seat holes, and matching parts are strictly clean and tidy; Remove foreign objects from the lubricant; Improve the sealing of bearings; Avoid using plastic cages with impure materials or embedded foreign objects.

(3) Noise caused by lubrication factors and its countermeasures

Incorrect selection of lubricants, insufficient lubricants, or aging hardening can all lead to vibration and noise in bearings, and this noise has no certain pattern. For this situation, only by selecting appropriate lubricants, adjusting the amount of lubricant, extending the service life of lubricants, and determining the replacement cycle reasonably.

Noise related to the host and its countermeasures

This kind of noise is not solely caused by bearings, so it is futile to search for the cause solely from the perspective of bearings. It is necessary to pay comprehensive attention to the main engine and improve its performance if necessary. This article mainly describes the common buzzing sounds and frame resonance sounds in electric motors.

(1) The buzzing sound of electric motors and its countermeasures

The axial vibration of the motor shaft can cause significant high-frequency noise - a buzzing sound, whose frequency is the same as the axial vibration frequency and can be either constant or variable. The prevention method for buzzing is the same as the method for preventing axial vibration.

(2) Resonant sound of bearing frame and its countermeasures

When the axial inherent vibration of the outer ring mass system causes the axial bending inherent vibration of the bearing frame, a noise called resonant sound is generated accordingly. The method of increasing preloading can increase the axial natural frequency of the outer ring mass system, disrupt resonance conditions, and reduce noise.