真空泵驱动用定子表贴式永磁电机转子热性能分析

Analysis of Rotor Thermal Performance of Stator Surface-Mounted Permanent Magnet Machine for Vacuum Pump Drive

真空泵驱动电机转子不易散热可能导致转子温升过高,其热量传导至轴承会有导致轴承抱死的风险,而损耗是发热的根源,将损耗由转子侧向定子侧转移是创新思路和工程可行措施。定子永磁型电机就是适合这种损耗转移思路的电机结构,虽然其转子侧无永磁体损耗,但是转子铁心仍存在一些损耗,在电机转速和频率较高的情况下更明显。为此,以1.5 kW、9000 r/min的电机为例,对同样外形尺寸的定子表贴式永磁电机(SSPMM)和转子表贴式永磁电机(RSPMM)进行了分析,对比了转子采用不同硅钢片材料时转子侧的损耗,以及两电机转子和轴承的温升、轴承热应力和热形变情况。比较结果表明,SSPMM在较高转速和频率的情况下,当转子侧采用高性能的硅钢片材料时,转子损耗和发热量比RSPMM更小,可降低轴承抱死的风险,提高真空泵长期运行的可靠性。

The rotor of the vacuum pump drive motor is not easy to dissipate heat,which may lead to excessive temperature rise of the rotor.The heat transfer to the bearing will cause the risk of bearing lockup.Loss is the root cause of heat generation,and it is an innovative idea and an engineering feasible measure to transfer the loss from the rotor side to the stator side.The stator permanent magnet motor is a motor structure suitable for this loss transfer idea.Although there is no permanent magnet loss on the rotor side,there is still some loss in the rotor core,which is more obvious when the motor speed and frequency are high.In response to this problem,taking a 1.5 kW,9000 r/min motor as an example,the rotor side loss,temperature rise,bearing thermal stress and thermal deformation of the surface-mounted permanent magnet motor(SSPMM)and rotor surface-mounted permanent magnet motor(RSPMM)with different silicon steel sheet materials are compared.The results show that when SSPMM uses high-performance silicon steel sheet material on the rotor side at a higher speed and frequency,its rotor loss and heat generation are smaller than that of RSPMM,which can reduce the risk of bearing lockup and improve the reliability of long-term operation of the vacuum pump.