Design And Performance Of Nano Magnetic Liquid Sealed And Lubricated Idler

With the implementation of the national “energy saving,green production” strategy,as an indispensable coal transportation equipment in mine transportation,the energy consumption and transportation cost of belt conveyors are always the focus of attention and improvement.The idler is an important component used in the belt conveyor and occupying a large amount of cost.The performance of the idler is directly related to the working performance and service life of the belt conveyor.At present,due to the limitation of its special environment,the idlers used underground have the practical problems of excessive rotational resistance and unsatisfactory service life.Therefore,the development of a new type of idler with low rotational resistance and long service life is of great practical significance for improving the working performance and efficiency of the belt conveyor and reducing the cost of coal production and transportation.Based on nano-magnetic liquid sealing and lubrication technology,a new type of idler prototype for magnetic liquid sealing and lubrication was designed and manufactured.The feasibility and advancement of nano-magnetic liquid sealing and lubrication technology on the idler were verified by performance comparison test.Firstly,the failure mode of the idler is explored from the structure of the idler.Combined with the theoretical basis of magnetic liquid sealing and lubrication technology,the sealing and lubrication scheme of the bearing is formulated.Key components such as permanent magnets,pole pieces,magnetic isolation housings and magnetic bushings are designed.Secondly,the ANSYS software is used to simulate the magnetic line,magnetic field strength and magnetic induction distribution of the sealed structure,which verifies the rationality of the magnetic circuit design.The mathematical model of the sealing structure is constructed.The size of the seal is optimized by MATLAB software.The software compares the pressure resistance of the sealed structure before and after optimization.The results show that the optimized pressure resistance of the magnetic liquid seal is much greater than before optimization.Based on the ?108mm idler,the magnetic liquid seal was machined and assembled.Thirdly,in order to simulate the temperature,humidity and dust environment of the idler when working underground,the self-made idler rotation resistance test bench of the research group was modified,and a downhole environment simulation device was installed.Using a multi-channel high-speed data acquisition card,a simple and practical data acquisition program for the idler rotation resistance was written based on LABVIEW software.Finally,considering the characteristics of the downhole environment and working conditions of the idler,the performance comparison test scheme of the magnetic liquid sealed lubricating idler and the common labyrinth sealing grease idler is established.The comparison of the rotation resistance of the two idlers under the conditions of conventional laboratory environment,simulated downhole environment and coal water drenching was carried out.The results show that under the normal environment fixed load resistance test,the rotational resistance of the magnetic liquid sealed lubricating roller is reduced by 45% compared with the ordinary roller,and the average reduction is 17%.Under the normal environment fixed speed resistance test,the rotational resistance of the magnetic liquid sealed lubricating roller is reduced by 73% compared with the ordinary roller,and the average reduction is 54%.In the simulated downhole environment,the rotational resistance of the magnetic liquid sealed lubrication roller is reduced by 26% compared with the ordinary roller.After the coal slurry water is sprayed for 24 hours,the rotation resistance of the ordinary idler is increased by 7 times,but the rotational resistance of the magnetic liquid sealed and lubricated idler is substantially unchanged.The magnetic liquid sealed lubricating idler has excellent performances such as low rotational resistance and high water repellency in simulating the downhole environment and the water spray conditions of the slime water.It provides powerful technical support for the low energy consumption,high reliability and long life operation of the downhole belt conveyor.