Vibration in the fag
bearing In general, the rolling bearing itself does not produce noise. The "bearing noise" that is usually felt is in fact the sound effect of the bearing directly or indirectly vibrating with the surrounding structure. This is why many times noise problems can be considered as vibration problems involving the entire bearing application.
(1) Excitation caused by the change of the number of rolling elements: When a radial load is applied to a fag bearing, the number of rolling elements carrying the load will change slightly during operation, which causes the load direction to be biased. shift. The resulting vibration is unavoidable, but can be mitigated by axial preloading and applied to all rolling elements (not for cylindrical roller bearings).
(2) Partial damage: Small parts of the fag bearing raceways and rolling elements may be damaged due to handling or installation errors. In operation, rolling a damaged bearing component produces a specific vibration frequency. Vibration frequency analysis identifies damaged bearing components. This principle has been applied to condition monitoring equipment to detect bearing damage. To calculate the bearing frequency, please refer to the calculation program "bearing frequency".
(3) Accuracy of related components: In the case of a close fit between the fag bearing ring and the bearing housing or the transmission shaft, the bearing ring may be deformed in accordance with the shape of the adjacent component. If deformation occurs, vibration may occur during operation.
(4) Contaminants: If operating in a polluted environment, impurities may enter the bearing and be crushed by the rolling elements. The degree of vibration generated depends on the amount, size and composition of the particles being crushed, although it does not produce a typical frequency form, but an irritating noise can be heard.
The causes of noise generated by rolling bearings are more complicated. One is the wear of the inner and outer rings of the bearing. Due to this wear, the bearing and the housing, the fag bearing and the shaft are broken, resulting in the axis deviating from the correct position and generating an abnormal sound when the shaft is moving at a high speed. When the bearing is fatigued, the surface metal peeling off will also increase the radial clearance of the bearing to produce abnormal noise. In addition, insufficient bearing lubrication, dry friction, and bearing crushing can produce abnormal sounds. After the bearing wears loose, the cage is loose and damaged, and abnormal noise is also generated.
1. Bearing maintenance: In order to maintain the original performance of the fag bearing in a good condition for as long as possible, maintenance, overhaul, and accident prevention are required to ensure the reliability of operation and improve productivity and economy.
Maintenance is best carried out on a regular basis in accordance with the operating standards for the mechanical operating conditions. The content includes monitoring of operating conditions, replenishment or replacement of lubricants, and periodic disassembly inspections. The maintenance items in operation include the rotation sound of the fag bearing, vibration, temperature, and the state of the lubricant.
2. Inspection of the
bearing: Cleaning of the bearing: When disassembling the bearing for repair, first record the appearance of the fag bearing, confirm the residual amount of the lubricant, and wash the bearing after sampling the lubricant for inspection. As a cleaning agent, gasoline and kerosene are commonly used.
The cleaning of the removed bearings is divided into coarse cleaning and fine cleaning. They are placed in the container respectively, and the metal mesh bottom is placed first so that the bearing does not directly contact the container. In rough cleaning, if the bearing is rotated with dirt, it will damage the rolling surface of the bearing and should be noted. In the rough cleaning oil, use a brush to remove the grease and the adhesive. After it is almost clean, it is transferred to the fine wash.
Fine washing is to carefully clean the bearing while rotating it in the cleaning oil. In addition, the cleaning oil should always be kept clean.
3, bearing maintenance and judgment: In order to judge whether the removed bearing can be used, it is necessary to check after the fag bearing is cleaned. Check the raceway surface, the rolling surface, the state of the mating surface, the wear of the cage, the increase of the bearing clearance, and the damage and abnormality that are irrelevant in dimensional accuracy. For non-separable miniature ball bearings, use one hand to support the inner ring horizontally and rotate the outer ring to check if it is smooth.
