Car wheel hub bearing failure cause of operation failure

Movement after a period of time, maintain a certain level of vibration and noise, frequency spectrum is very single, only one or two times the frequency. More than three times the power frequency spectrum, seldom appears bearing condition is very stable, steady working period. Continue to run after the late into use, automobile wheel hub bearing vibration and noise began to increase, sometimes a different sound, but the change of vibration increase is relatively slow, at this point, the bearing kurtosis value began suddenly reaches a certain value. We believe that the bearing is characterized by the early failure. At this time, requires that the bearing is closely monitoring, pay close attention to the change. Since then, bearing kurtosis value began falling fast, and is close to normal, and significant increase in vibration and noise, it began to accelerate the increase, when the vibration more than standard ( Such as ISO2372 standard) , its bearing kurtosis value also began to increase rapidly, when more than vibration standard, and kurtosis value is more than normal ( Available kurtosis relative standard) When we think of bearing fault has entered the late production, should be timely maintenance equipment, replace the bearing. Car wheel hub bearing show late fault feature to severe fault ( For bearing damage, such as holding shaft commonly, burns, sand spallation, raceway, wear beads, etc. ) Most of time not more than a week, the bigger the equipment capacity, the faster the speed, the shorter the time interval. Therefore, in the actual bearing fault diagnosis, once found late fault characteristics, should be decisive judgment is bearing fault, arrange inspection as soon as possible. 1. When installation is not allowed on the bearing hole, groove, chamfering, and facing. Otherwise, easy to cause deformation of bearing ring, affecting the service life of bearings and precision, and cutting off the metal is easy to enter the bearing surface of the work, accelerate the raceway and rolling element wear and tear, causing premature failure. 2. When installation are not allowed to directly with hammer knock bearing ring. Bearing reference face the anniversary itself close to shoulder installation. Bearing reference face is according to the automobile wheel hub bearing end with or without typing to distinguish, deep groove ball bearings, self-aligning ball bearings, cylindrical roller bearing, spherical roller bearings and needle roller bearings, with no words face as the datum; Angular contact ball bearings and tapered roller bearings, in order to have a word face as the datum. 3. Pressure when installation should be added on the ring width of interference fit with installation, is installed on the shaft, the pressure should be added on the bearing inner ring end face; Load bearing hole, pressure should be added on the bearing outer ring end face. Don't allow through the rolling element and maintain delivery pressure. 4. For inner ring for tight fit, the bearing outer ring for slide fit, when installation, the integral type should be the first bearing on the shaft loaded, then shaft together with the bearing load bearing shell hole; Department of separable type, inner and outer ring can be installed separately. 5. Installed to prevent bearing, shaft and bearing hole centerline must coincide. Such as the installation is not straight, need to reinstall, must through the inner ring end face, pull the bearing. The main task of auto-hub bearing failure analysis, is based on a lot of background material, analyze data and failure forms, find out the main factors of bearing failure, so that the improvement measures are put forward, lengthen spherical roller bearing, avoid premature failure of the bearing of the sudden.