Ring permanent magnet torque motor servo system,used in direct drive NC rotary table,suffers from the effect of load torque change,which greatly reduces the servo dynamic stiffness.

• 直接驱动数控转台采用环形永磁力矩电机的伺服系统易受负载转矩变化的影响,显著降低系统的伺服动态刚度。