Proposal of Claw Pole Type Double 2 Phase PM Stepping Motor

Abstract

This paper is concerned with the improvement of performance of claw pole type PM stepping motor. First, alternating torque and cogging torque of claw pole PM stepping motor are analyzed in relation to the harmonic components of winding currents and field flux, and the causes of generation of torque variation and their variation frequency are clarified.
Based on the above analytical results, the method for decreasing these torque variation is discussed, and the double 2 phase PM stepping motor is proposed, in which 2 sets of 2-phase PM motors are connected so that the generated variation torque of both motors may be canceled each other.
It becomes clear that the double 2 phase PM stepping motor not only brings small alternating torque and small cogging torque but also improves step accuracy and pull-out characteristics.