The rotary table bearing usually consists of four parts: inner ring, outer ring, rolling element and spacer block. As the core components are slewing bearings, they can support both axial and radial forces. In general, the rotary table bearing itself is equipped with mounting holes, lubricating oil and sealing devices, which can meet the different requirements of different hosts working under different working conditions; on the other hand, the rotary table bearing itself has the characteristics of compact structure, convenient guide rotation, simple installation and easy maintenance.
Generally speaking, the rotary table bearing itself does not generate any noise. The "rotary table bearing noise" that is usually felt is actually the sound effect of the bearing vibrating directly or indirectly with the surrounding structure. Therefore, noise problems can often be considered as vibration problems affecting the entire bearing application.
1. Excitation due to change in number of loaded rollers:
When a radial load is applied to a bearing, the number of rolling elements carrying the load will change slightly during operation, causing the load direction to deviate. The resulting vibration is unavoidable but can be reduced by applying axial preload to all rolling elements (not applicable to cylindrical roller bearings).
2. Localised damage:
A small number of bearing raceways and rolling elements may be damaged due to incorrect operation or installation. During operation, rolling over damaged bearing parts will produce certain vibration frequencies. Vibration frequency analysis can identify damaged bearing components. This principle has been used in condition monitoring equipment to detect bearing damage. To calculate the bearing frequency, use the bearing frequency calculation program.
3. Accuracy of relevant components:
In the case of a tight fit between the bearing ring and the bearing seat or the transmission shaft, the bearing ring may be deformed due to its fit with the contour of the adjacent components. If deformation occurs, vibration may occur during operation.
4. Pollution:
When operating in a polluted environment, contaminants may enter the bearing and be rolled by the rolling element. The amount of vibration generated depends on the number, size and composition of the rolled impurity particles. Although the typical frequency shape is not generated, a disturbing noise can be heard.
The causes of noise in the rotary table bearing are relatively complex. One is the wear of the mating surfaces of the inner and outer rings of the bearing. Due to this kind of wear, the mating relationship between the bearing and the housing and between the bearing and the shaft is destroyed, which causes the axis to deviate from the correct position and produces abnormal noise when the shaft moves at high speed.When the bearing is fatigued, the metal on its surface will peel off, which also increases the radial clearance of the bearing and produces abnormal noise. In addition, insufficient lubrication of the bearing, the formation of dry friction and the crushing of the bearing will cause abnormal noise. If the bearing is worn and loose, the cage will become loose and damaged, which will also cause abnormal noise.