Multi-physical Field Analysis Of Permanent Magnet Synchronous Motor For Ultra-clean Vacuum Pump

With the continuous improvement of China's scientific and technological level,more and more industries need a vacuum environment for production operations,the demand for vacuum pumps is increasing.The traditional vacuum pump is used in asynchronous motor,according to the characteristics of the asynchronous motor operation,the rotor's aluminum consumption causes the rotor's temperature to rise.Because the shielding sleeve is in a high vacuum state,the heat dissipation condition of the heat convection is lost,the rotor can only be dissipated by heat conduction and heat radiation,rotor temperature increasing,heat is transmitted to bearings by heat transfer,raise the temperature of the inner race of the bearing.Because the inner and outer rings of the bearing are different in heat dissipation conditions,making the bearing inner ring temperature is much higher than the outer ring temperature,the inner and outer rings have different degrees of expansion,the effective clearance of the bearing is reduced,run for a long time,experienced a long dynamic transition process,it is difficult to build lubricating oil film in bearing raceway,the rolling sphere is squeezed,and ultimately may lead to friction due to rolling the ball is too large and glued to the lock,the consequences could be disastrous.In this paper,through the design of vacuum pump with permanent magnet synchronous motor,to solve the traditional vacuum pump rotor temperature is too high,the temperature difference of inner and outer rings of bearing,poor operation stability and so on.Firstly,the structural characteristics of the vacuum pump are introduced.According to the design characteristics of the shielded motor,the rotor structure of the asynchronous motor of the vacuum pump is modified.The permanent magnet synchronous motor of the vacuum pump is designed.The finite element analysis software Ansoft is used to simulate the electromagnetic field,verify the rationality of its electromagnetic design,comparative analysis of vacuum pump with permanent magnet synchronous motor and vacuum pump with asynchronous motor performance characteristics.Then,the load of the permanent magnet synchronous motor is used as the load of the temperature field.The finite element analysis software Ansys workbench is used to analyze the temperature field.The comparison between the permanent magnet synchronous motor and the vacuum pump asynchronous motor shield,rotor and bearing temperature field distribution characteristics.In order to improve the stability of permanent magnet synchronous motor for vacuum pumps,processed surface of the shaft and the rotor,to improve the radiation rate,and comparative analysis.Finally,the temperature field is used as the heat load and loaded into the stress field.Simulation of the stress field distribution characteristics of shielded motor shield and bearing for vacuum pump with three structures.Through simulation analysis,it can be concluded that the permanent magnet synchronous motor of vacuum pump is superior to the asynchronous motor of vacuum pump,and can effectively improve the stability and reliability of vacuum pump operation.When the rotor and the shaft surface treatment,to improve its emissivity,vacuum pump with permanent magnet synchronous motor effect is more obvious.The experimental test of the driving motor of the vacuum pump is experiment test,and the reliability of the simulation analysis is verified by the processing of the experimental data.