Causes of failure of operation caused by automobile wheel bearing failure

After a period of exercise, the vibration and noise are maintained at a certain level, and the spectrum is very single, only one or two times the frequency appears. There are very few spectrums above the power frequency, and the bearing status is very stable and enters a stable working period.

After continuing to run, the vibration and noise of the automobile hub bearing began to increase, and sometimes abnormal sound appeared, but the change of vibration increased slowly. At this time, the bearing kurtness value suddenly reached a certain value. We believe that the bearing is an initial failure at this time.
At this time, it is required to closely monitor the bearing and pay close attention to its changes. After that, the bearing kurtness value begins to drop rapidly and approaches the normal value, while the vibration and noise begin to increase significantly, and the increase rate begins to accelerate. When the vibration exceeds the vibration standard (such as ISO2372 standard), the bearing kurtness value also begins. Rapid increase, when both exceed the vibration standard, and the kurtosis value also exceeds the normal value (the available kurtosis relative standard), we believe that the bearing has entered the late fault production, it is necessary to repair the equipment in time and replace the bearing.

Automobile wheel bearings exhibit late failure characteristics to serious failures (generally bearing damage such as axles, burns, sand cracks, raceways, bead wear, etc.) are not more than one week, the larger the equipment capacity, the faster the speed The shorter the interval. Therefore, in the actual bearing fault diagnosis, once the late fault characteristics are found, the bearing should be judged decisively and the repair should be arranged as soon as possible.

1. Do not drill, groove, chamfer or end face on the bearing during installation. Otherwise, it is easy to cause deformation of the bearing ring, affecting the bearing accuracy and life, while the cut metal easily enters the working surface of the bearing, accelerating the wear of the raceway and the rolling element, causing premature failure of the bearing.

2. Do not directly hit the bearing ring with a hand hammer during installation. The reference end face of the bearing is mounted in close proximity to the shoulder. The reference end face of the bearing is distinguished according to whether the end face of the automobile wheel bearing is typed or not. The deep groove ball bearing, the self-aligning ball bearing, the cylindrical roller bearing, the spherical roller bearing and the needle bearing are based on the non-word end face; Angular contact ball bearings and tapered roller bearings have a word end surface as a reference surface.
3. The pressure during installation should be added to the end face of the ferrule with the interference fit. When installed on the shaft, the pressure should be added to the end face of the inner ring of the bearing; when it is installed in the hole of the bearing housing, the pressure should be added outside the bearing. On the end of the ring. It is not allowed to pass the rolling elements and keep the pressure transmitted.

4. For the inner ring is the tight fit and the outer ring is the sliding fit. When installing, if it is inseparable, the bearing should be installed on the shaft first, then the shaft and the bearing are installed together in the bearing housing hole; For detachable models, the inner and outer rings can be installed separately.
5. To prevent the bearing from being tilted, the center line of the shaft and bearing hole must be coincident during installation. If the installation is not correct, when reinstalling, the bearing must be pulled out through the inner ring end face.
The main task of automobile wheel bearing failure analysis is to find out the main factors causing bearing failure based on a large amount of background materials, analysis data and failure modes, so as to propose improvement measures in a targeted manner and extend the service life of spherical roller bearings. Avoid sudden early failure of the bearing.