Research on Nondestructive Testing Based Back Projection Method in the Bearing Inspection

The quality of the bearing parts directly affects the overall level of the finished bearing and the reliability of the operation. It is necessary to detect defects such as cracks, pores and inclusions. Because of the ultrasonic sensitivity for the internal defects of bearing parts, it is considered as the most potential for the development of bearing defects detection technology. Pulse method is the most widely used method in ultrasonic detection. However, the method is poor in high accuracy of quantitative detection, and there are some problems such as high defect detection rate and difficult blind detection. These problems limit the ultrasonic detection in many high precision applications. In this paper, the shortcomings of traditional detection methods are studied and make improvement, the method no longer relies on the sound pressure, uses linear FM ultrasonic signal as a transmission signal source, the ultrasonic echo signal coherent processing, so as to get more high detection reliability and accuracy. In this paper, a distributed multi- probe simulation system is used to demonstrate that the new method has excellent performance in defect detection