1、 Bearing temperature is too high: when the mechanism is running, a specific temperature is allowed at the place where the bearing is installed. When touching the mechanism shell with hand, it is reasonable not to feel hot. Otherwise, it indicates that the bearing temperature is too high.
The reasons for the high temperature of the bearing are: the quality of the lubricating oil does not meet the requirements or deteriorates, the viscosity of the lubricating oil is too high;
2、 Bearing noise: the rolling bearing is allowed to have slight running noise during operation. If the sound is too loud or there is abnormal noise or impact noise, it indicates that the bearing is faulty.
The causes of rolling bearing noise: relatively complex,
(1) It is the wear of the mating surfaces of the inner and outer rings of the bearing.
(2) The bearing is not lubricated enough, the formation of dry friction, as well as bearing crushing, etc. will produce abnormal sound.
(3) After the bearing is worn and loosened, the cage is loose and damaged, which will also cause significant noise bearing damage.
3、 Metal spalling on raceway surface: bearing rolling body and inner and outer raceway surfaces are subjected to periodic fluctuating load, resulting in intermittent contact stress. When the number of stress cycles reaches an absolute value, fatigue spalling will occur on the working surface of the inner or outer raceway. If the load of the bearing is too large, the fatigue will be increased.
4、 Burn of bearing: the burned bearing has to backfire color on its raceway and rolling body. Generally, the causes of burn are insufficient lubrication, unqualified or deteriorated lubricating oil quality, and too tight bearing assembly.
5、 Bearing race crack: the reason for bearing race crack may be that the bearing fits too tightly, the bearing is loose, or the inner ring is free, the bearing’s containing parts are deformed, and the surface processing of the installed bearing is poor.