Abstract: In order to slow down the wear and frequent maintenance of the sliding bearing of the ball mill，improve the operation rate and service life of the equipment，Fujian Makeng Mining Co.，Ltd. has carried out the research on the automatic forced lubrication system of the synchronous motor sliding bearing. Through the automatic forced lubrication system of the synchronous motor，the sliding bearing lu⁃ brication 'five fixed' is achieved. At the same time，the motor bearing lubricating oil is circulated， cooled，filtered outside the equipment，and the amount of lubricating oil can be adjusted according to the bearing temperature. The test results and field application show that the device has small investment and obvious effect，which can effectively save labor and production costs，improve the equipment integrity rate and operation rate，and lay a solid foundation for the automation and unmanned equipment of mining enterprises.

Key words: ball mill, synchronous motor, sliding shaft, automatic lubrication