Excessive temperature of INA bearing：During the operation of the mechanism, a certain temperature is allowed at the part where INA bearing is installed. When touching the mechanism shell by hand, it should be normal that it doesn’t feel hot; otherwise, it indicates that the temperature of INA bearing is too high.The reasons for the high temperature of INA bearings are: the quality of lubricating oil does not meet the requirements or deteriorates, and the viscosity of lubricating oil is too high; Too tight assembly of mechanism (insufficient clearance); INA bearing assembly is too tight; INA bearing ring rotates on the shaft or in the shell; Overload; INA bearing cage or rolling element is broken, etc.This is the causes of INA bearing failure.
Noise of INA bearing: slight running noise of rolling bearing is allowed in the work. If the noise is too loud or there is abnormal noise or impact, it indicates that INA bearing is faulty. The causes of noise generated by INA bearings are complicated: 1) the mating surfaces of the inner and outer rings of INA bearings are worn. Because of this kind of wear and tear, the matching relationship between INA bearing and shell, INA bearing and shaft is destroyed, resulting in the axis deviating from the correct position, resulting in abnormal noise when the shaft moves at high speed. When INA bearing is fatigued, its surface metal will peel off, which will also increase the radial clearance of INA bearing and produce abnormal noise. 2)INA bearing lubrication is insufficient, resulting in dry friction, and INA bearing breakage will produce abnormal sound. 3) When the INA bearing is worn loose and loose, the cage is loose and damaged, and the INA bearing with abnormal noise will also be damaged. When the rolling INA bearing is disassembled and inspected, the fault and damage reason of INA bearing can be judged according to the damage of INA bearing.This is the causes of INA bearing failure.
Metal peeling off on raceway surface: the rolling elements of INA bearing and the raceway surfaces of inner and outer rings are subjected to periodic pulsating loads, resulting in periodically changing contact stress. When the number of stress cycles reaches a certain value, fatigue spalling will occur on the working surface of the roller or the raceway of the inner and outer rings. If the load of INA bearing is too large, this kind of fatigue will be aggravated. In addition, improper installation of INA bearing and bending of shaft will also lead to raceway peeling. The fatigue spalling of INA raceway will reduce the running accuracy of shaft and cause vibration and noise of mechanism.This is the causes of INA bearing failure.
Burn of INA bearing: the burned INA bearing has tempered color on its raceway and rolling body. The causes of burns are generally insufficient lubrication, substandard or deteriorated lubricating oil quality, and too tight assembly of INA bearings.This is the causes of INA bearing failure.
Plastic deformation: Uneven pits appear on the contact surface between the raceway and roller of INA bearing, indicating that INA bearing has plastic deformation. The reason is that the local stress on the working surface of INA bearing exceeds the yield limit of the material under the action of large static load or impact load, which generally happens on INA bearing rotating at low speed.This is the causes of INA bearing failure.
Cracks in INA bearing race: Cracks in INA bearing race may be caused by too tight fit of INA bearing, looseness of foreign or inner ring of INA bearing, deformation of the container of INA bearing, poor surface processing of INA bearing, etc.This is the causes of INA bearing failure.
Broken cage: the reasons are insufficient lubrication, broken rolling elements, skewed seat ring, etc.This is the causes of INA bearing failure.
The metal of the cage adheres to the rolling elements：The possible reason is that the rolling elements are stuck in the cage or lack of lubrication.This is the causes of INA bearing failure.
The raceway of the race is seriously worn: it may be that foreign bodies fall into the race, the lubricating oil is insufficient or the lubricating oil grade is not suitable.This is the causes of INA bearing failure.
Installation is also the cause of INA bearing failure
INA imported bearing inner ring does not match the fit clearance interference of the shaft, and it is easy to cause bearing failure. The interference is large, and it is easy to cause the bearing inner ring to crack due to excessive tensile stress. If the interference is too small, it is also easy to cause the bearing inner ring to “relax”.
Inappropriate assembly and fitting clearance of bearings can easily lead to bearing failure, and small clearance can easily lead to friction and heating between rollers and raceways. With the rising of temperature, the temperatures of inner ring, rolling body, cage, outer ring and end cover of bearings are not the same, and there is a temperature difference between them, so the expansion amount is slightly different, which will further reduce the fitting clearance and increase the heat generation of bearings.
If the clearance is too large, the vibration of the roller will increase, which will aggravate the impact of the roller and the raceway. At the same time, it is easy to cause uneven distribution of the internal load, decrease of the bearing roller and excessive load of the central roller.This is the causes of INA bearing failure.