Patent ID: 6028377
Filing Date: 2000-02-22
Classification: H02K

Abstract:
A three-phase permanent magnet cascade claw type stepping motor comprising(1) a rotor consisting of a cylindrical magnet magnetized in a circumferential direction thereof so as to form M pieces of N pole and M pieces of S pole respectively, where M is an integer and is .gtoreq.2, and(2) a stator having annular three stator units spread in an axial direction of the rotor concentrically with a rotor axis, each of said stator units consisting of (a) two opposite stator cores having claw poles extending axially on the inner peripheral surface thereof, and b) a respective one of three stator windings of U, V and W phases held between said two stator cores, said windings of U, V and W phases being arranged sequentially in an axial direction of said stator, the claw poles of each stator winding being separated from one another by 180.degree./M, said three stator windings being connected to form a star or delta connection so that claw poles magnetized by the stator windings of U phase and V phase are deviated by 60.degree./M from each other in a circumferential direction of the stator and are magnetized in opposite polarities, and so that adjacent claw poles magnetized by the stator windings of V phase and W phase are deviated by 60.degree./M from each other in the circumferential direction of said stator and are magnetized in opposite polarities.