机器人用外转子直驱永磁电机设计与性能分析

Analysis and design of the outer-rotor direct drive permanent magnet motor in robot

直驱永磁电机以其转矩大、波动小、效率高和结构紧凑等优越性能,取代了传统伺服电机和减速器联合使用的驱动模式,成为机器人驱动系统的核心部件之一。根据工业机器人的运行工况和实际要求,设计了一台直驱高速并联机器人的27槽24极外转子永磁电机,分析该电机主要结构参数的选取,建立该电机的二维有限元仿真模型。在空载状态下,计算气隙磁密分布,分析空载反电势及其谐波含量和齿槽转矩;在额定转矩和最大转矩的工作状态下,对电磁转矩、效率、功率因数和力能指标等电机性能进行对比分析。仿真结果表明,该电机的性能指标误差均在6. 5%以内,验证了电机设计的合理性和实用性,可为电机参数的进一步优化设计提供依据,也可为机器人驱动系统的优化提供参考。

The direct-drive permanent magnet motor,with its advantages such as large torque,small fluctuation,high efficiency and compact structure,has replaced the driving mode used by the traditional servo motor and the reducer,and has become one of the core parts of the robot drive system.According to the operating conditions and requirements for industrial robots,a 27-slots 24-poles outer-rotor permanent magnet motor for direct-drive high-speed parallel robot was designed.The selections of main structure parameters of the motor were introduced,and the two-dimensional finite element simulation model of the motor was established.Under no-load condition,the magnetic density distribution of the air gap was calculated,and the back EMF and its harmonic content and cogging torque were analyzed.Under the conditions of rated torque and maximum torque,the performances of electromagnetic torque,efficiency,power factor and force-energy index were analyzed and compared.The results showed that the performance index error of the motor was less than 6.5%,which verified the rationality and practicability of the design of the motor.It provided the basis for further optimization design of the motor parameters and the reference for the optimization of robot drive system.