Rolling bearing fault diagnosis

Rolling bearing is most widely used mechanical parts, at the same time, it is also one of the most easily damaged components of the machine. Many of the rotating machinery fault are associated with the state of rolling bearing. According to statistics, in the use of roller bearing of rotating machinery, about 30% of mechanical failures are caused by bearing. Visible, the stand or fall of bearing great influence on machine working state. Usually, due to the defects of bearing can cause the machine to produce vibration and noise, and even cause the damage of the machine. In the precision machinery ( Such as precision machine tool spindle, gyro, etc. ) , the requirement of bearing is higher, even on the bearing has a micron grade defect, will cause damage to the precision of machine system. The first to use bearing diagnosis method is to listen to the sound of the rod bearing contact, rely on the hearing to determine bearing for XXX. This method is still in use, but has been gradually used electronic stethoscope instead of listening to in order to improve the sensitivity. Then gradually adopt various types of vibration equipment, instrument and use the displacement, velocity or acceleration RMS values or fengfeng to determine bearing for XXX. This can reduce the dependence on experience of equipment maintenance personnel, but it is still hard to find early failure. Rolling bearing is very extensive application in the equipment, rolling bearing status is good or not directly related to the rotating equipment running status, especially in the continuity of production enterprises, a large number of applied to the important parts of the large rotary equipment, therefore, in practical production for rolling bearing condition monitoring and fault diagnosis is an important part of the good equipment maintenance and management. We through long-term practice and exploration, has accumulated some practical skills actual rolling bearing fault diagnosis. A, the way and the key points of rolling bearing fault diagnosis of rolling bearing condition monitoring and fault diagnosis of vibration analysis is practical method. In the practical need to pay attention to choose the location of the measuring point and sampling method. To accurately reflect the real state of rolling bearing vibration, must pay attention to collect accurate signal, so bearing in the nearest place arrangement of measuring points, the motor fan cover after generally have free end, the selecting the fan cover screw has good monitoring effect. In addition must pay attention to many times of the vibration signal acquisition and analysis, comprehensive comparison. To get accurate conclusion. Second, the characteristics of the normal operation of rolling bearing and practical diagnosis techniques we found in the long-term production status monitoring, rolling bearing in the process of its use showed a strong regularity, and the repeatability is very good. Normal high quality bearing, at the beginning of the use of vibration and noise are relatively small, but there are some scattered of spectrum amplitude is small, may be due to some defects in the process of manufacturing, such as surface caused by burrs, etc. 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 into the use of late, after 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 and kurtosis value