Abstract：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 directdrive 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.

Keyword：direct drive permanent magnet motor;outer-rotor;robot;finite element simulation;