Most of China's coal mines are underground mining, and the working environment is very complex and harsh, so the performance and technical requirements of machinery and equipment are very high.First of all, coal mining machinery and equipment must have the function of continuous operation. Coal mining work is sometimes uninterrupted, so the machinery and equipment can also meet the requirements of running time.Secondly, the mining environment is harsh, and a large amount of dust may be generated, which will damage the performance of machinery and equipment and affect its normal operation.Finally, friction, excessive load and vibration will occur during the operation of machinery and equipment. In addition, the underground mining space is small. In order to ensure the effective transportation of coal, the size design requirements of machinery and equipment are also very high.Because machinery and equipment operate in harsh environments for a long time, failures are inevitable, and once a failure occurs, it is very difficult to repair it. This requires a good job of usual equipment maintenance and overhaul, and improve the overall level of fault diagnosis of machinery and equipment.