A Study Of Detection And Anti-friction Improvement Method For Shearer Wear

Shearer is one of the important equipment to realize mechanized mining and the main equipment to realize automatic mining of coal mine.Under the combined action of impact load,coal lump and gangue,the coal mining machine suffers the damage of friction and wear failure.It is a pity that a recognized detection and improvement method is still unavailable so far to detect the wear issue and offer corresponding improvement measures.This dissertation attempts to offer a systematic detection and improvement method for it.This detection method can determine the wear reason and provide improvement measures for the components to be worn,by employing a wear tester to simulate the actual working conditions,and reveal its worn mechanism.As for the improvement measures from the detection method,the improvement method can solve the wear issues from two aspects of mechanical structure optimization and film modification.The main conclusions include,(1)In view of the wear harms of coal mining machine in the rigid working conditions,a systematic detection and improvement method is put forward to deal with the wear problems of the shearer.The wear detection method can identify the wear problems;and themethod includes five links: analysis of the actual condition of coal mining machine,determination of the wear failure parameters,design wear tester to simulate the actual working conditions,wear experiment to verify the tester effectiveness,revealing the failure mechanism and putting forward the solutions.Based on the improvement measures given by the detection method,the improved method can solve the wear problems of the shearer.The method consists of four parts: discriminating wear category,mechanical optimization,heat treatment,and surface modification.(2)According to the proposed detection method,we use the designed detection mechanism to reveal the wear mechanism of the sliding shoe in actual working conditions.Using structural optimization and surface modification methods can reduce the wear of the height-adjustment mechanism.Combined with actual working conditions,the failure parameters of sliding shoes are determined as load and traction force.The design detection mechanism consists of loading device,driving device,and the sensor,to detect the failure parameters in time.Sliding shoe and pin row is tested to evaluate the suitability of the wear detection test.During analyzing sliding shoe failure,it is foundin a comparison of the surface morphology data of the various stages for the test specimen that,the wear mechanism of the sliding shoe is abrasive wear.(3)According to the improvement measures given by the detection method,the experimental results show that:(a)Using the methods of mechanical optimization can increase the stability of the height-regulating mechanism;(b)UsingCu-DLC film can significantly improve the sealing performance of the adjusting high cylinder.The mechanical optimization method can reduce the harmdue to the impact load on the height-regulating mechanism;the optimization measures include: replacing the electro-hydraulic proportional direction-changeover valve,and addingPID override controller.The improvement mechanism ofCu-DLC film for the sealing performance of the adjusting high cylinder is a consequence of three mechanisms:(i)contact force and friction heat cause graphitization of the film surface;(ii)Cu doping improves the toughness of the film and plays a role of solid lubricant;(iii)self-lubricating and long-duration protection of the transfer layer.