The fatigue failure of Koyo imported bearing is a surface form of failure, which is mainly manifested in the initiation, propagation and fracture process of fatigue crack, and the long-term impact of load failure under alternating conditions. Cracks are in two ways:
1. On the surface, this is the effect of external load caused by the plastic deformation on the working surface and the periodic change of contact stress on the strain hardened surface during the rolling contact process of
Koyo imported bearing, and finally the formation of surface cracks between small cracks from the developing inner surface, due to the lubricant and opening force on the working surface, Crack down on the wall and force the crack to move forward;
2. From the surface layer, under repeated pressure, the contact of the surface will initially produce cracks at a certain depth at the place where the surface is exposed,
and from the angle along the surface direction to a certain depth, from behind the surface of the contact surface, and beyond the surface, and finally form corrosion stripping, leaving a horse pit.
From the surface of Koyo imported bearing, or from the cracks in the surface layer, these two objectives (carburization, quenching and other surface heat treatment of parts. If there are uneven hardness, microstructure,
non-uniform internal stress and other disadvantages, the contact stress is generally affected by the opposite underground cracks. If the surface quality of parts is poor, there is a defect (oxidation, decarburization), Poor friction or lubrication, cracks from the surface.
The methods to control the sound of raceway are: select the low-noise Koyo imported bearing, that is, the bearing with small waviness, and carefully select the service conditions. Raceway noise often affects the noise of the whole machinery. Reducing raceway noise can reduce the noise of the whole machinery.
The bearing has long service life and can be used correctly If the damage occurs prematurely, it is likely to be caused by wrong type selection, improper use or poor lubrication.
Therefore, when installing Koyo imported bearings, we need to record the type of machine, installation position, service conditions and surrounding cooperation. By studying and summarizing the types of bearing damage and the service environment when problems occur, so as to avoid similar situations from happening again.
Generally speaking, the rolling bearing itself does not produce noise. The “bearing noise” usually felt is actually the sound effect of vibration between the bearing and the surrounding structure directly or indirectly. This is why many times noise problems can be regarded as vibration problems involving the whole bearing application.
(1) Excitation caused by the change of the number of loaded rolling Koyo Imported Bearing elements: when a radial load is loaded on a fag bearing,
the number of loaded rolling elements will change slightly during operation, which causes the deviation of the load direction. The resulting vibration is inevitable, but can be reduced by axial preloading, which is applied to all rolling Koyo Imported Bearing elements (not applicable to cylindrical roller bearings).
(2) Local damage: due to incorrect operation or installation, a small part of fag bearing raceway and rolling element may be damaged. During operation, rolling over Koyo Imported Bearing damaged bearing parts will produce specific vibration frequency.
Vibration frequency analysis can identify damaged bearing components. This principle has been applied to condition Koyo Imported Bearing monitoring equipment to detect bearing damage. To calculate the bearing frequency, refer to the calculation program “bearing frequency”.
(3) Accuracy of relevant parts: in the case of close fit between fag bearing ring and bearing seat or transmission shaft, the bearing ring may be deformed by matching with the shape of adjacent parts. If deformation occurs, vibration may occur during operation.
(4) Pollutants: if operating in a polluted environment, impurities Koyo Imported Bearing may enter the bearing and be rolled by the rolling element. It depends on the vibration frequency and the amount of impurities that can be heard by people, but it will not produce noise.
The causes of rolling bearing noise are complex. One is the wear of the mating surfaces of the inner and outer rings of the bearing. Due to Koyo Imported Bearing this kind of wear, the matching relationship between bearing and shell, FAG bearing and shaft is damaged,
resulting in the axis deviation from the correct position and abnormal sound when the shaft moves at high speed. When the bearing is tired, the metal on its surface will peel off, which will also increase the radial clearance of the bearing and produce abnormal noise.
In addition, insufficient bearing lubrication, dry friction and bearing breakage will produce abnormal sound. After the bearing is worn and loose, the cage is loose and damaged, which will also produce abnormal noise.
1. Bearing maintenance: in order to maintain the original performance of fag bearing in good condition for as long as possible, it is necessary to maintain and repair in order to prevent accidents, ensure the reliability of operation and improve productivity and economy.
Maintain the operation standard of corresponding mechanical operation conditions and carry out it regularly. The contents include monitoring the operation status, replenishing or changing the lubricant,
and regular disassembly inspection. The maintenance items during operation include the rotating sound, vibration, temperature, lubricant state of fag bearing, etc.
2. Bearing maintenance: bearing cleaning: when removing the lower bearing for maintenance, first record the appearance of fag bearing, confirm the residual amount of lubricant, and then wash the bearing after sampling the lubricant for inspection. As a cleaning agent, gasoline and kerosene are commonly used.
The cleaning of the removed bearing is divided into coarse cleaning and fine cleaning. They are placed in the container respectively. First, put the metal mesh bottom so that the bearing does not directly contact the dirt of the container.
During rough cleaning, if the bearing rotates with dirt, it will damage the rolling surface of the bearing, which should be paid attention to. In the coarse cleaning oil, use a brush to remove the grease and adhesion. After it is roughly clean, turn to fine cleaning.
Fine cleaning is to carefully clean the bearing while rotating in the cleaning oil. In addition, the cleaning oil should always be kept clean.
3. Maintenance and judgment of bearing: in order to judge whether the disassembled bearing can be used, it should be checked after the fag bearing is cleaned. Check the state of raceway surface, rolling surface and mating surface,
the wear of cage, the increase of bearing clearance and the damage of irrelevant dimensional accuracy, which are abnormal. For non separable small ball bearings, support the inner ring horizontally with one hand and rotate the outer ring to confirm whether it is smooth.