1. Spalling caused by impact load and alternating stress.
The rolling bearing body of the bearing and the raceway surface of the inner and outer rings are subjected to the action of periodic pulsating loads, resulting in periodic varying contact stress. When the number of stress cycles reaches a certain value, fatigue spalling occurs on the working surface of the rolling body or inner and outer raceway. If the bearing load is too large, this fatigue will be aggravated. In addition, bearing installation is not correct, shaft bending will also produce a raceway peeling phenomenon. The engine flywheel and pulley are set on the balanced weight, the rotational inertia torque generated and the engine rotating part of the rotational inertia torque balance. If the generated inertia moment is not balanced, the engine will vibrate greatly after ignition, increasing the alternating stress and the number of stress cycles, causing the raceway and rolling body surface to peel off prematurely.
In order to avoid the raceway and the surface of the rolling body spalling, in use should avoid extra load and undue vibration, in the process of operation to reasonable use of the throttle and speed, prevent tractor turbulence, to often check the fixed body bolts, to prevent loosening.
2. Distortion of raceway shape is caused by external hard particles falling into the matching surface of the shell or between the shaft and the matching surface of the ring.
This is where the rolling bearing mass exerts the most pressure, resulting in rapid wear and metal spalling of the raceway. Rolling bearing is a very precise part, which is very sensitive to foreign matter. In the maintenance, the process to use clean, not easy to fuzzing wipe cloth, wipe cloth must not be replaced by an old cotton thread, because the yarn in the old cotton thread is easy to mix in lubricating oil and into bearings, which is very harmful. Before assembly, the surface of the journal, seat hole and bearing inner and outer ring should be thoroughly cleaned to prevent dirt from entering the matching surface.
3. Damage caused by raceway damage during installation.
If the installation, the pressure is transmitted by the outer ring and the ball, it will inevitably cause pits in the ring raceway in contact with the ball, these pits are the source of damage, increasing extremely fierce, only a very short time to make the bearing spalling scrap. So in the disassembly of the application of special tools, force parts to be correct and uniform.
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