STEPPING MOTOR

摘要

PROBLEM TO BE SOLVED: To prevent increase in size or lowering in torque by bringing a pole plate and a case into sufficiently tight contact. SOLUTION: The stepping motor comprises: a yoke (pole plate) 21 made of a magnetic material having pole teeth (magnetic pole parts) 21d arranged along the inner circumferential surface of a bobbin 22 applied with a winding (coil) 23 and a hollow disc part (planar part) 21c arranged along the end face in the axial direction of the bobbin 22; a circumferential wall part (tubular part) 41 being fitted over the outer circumferential edge 21b of the hollow disc part 21c while arranging the hollow disc part 21c of the yoke 21 inward; and a case 4 made of a magnetic material to constitute a part of a magnetic circuit together with the yoke 21. A recess 21f is made in the outer circumferential edge 21b of the hollow disc part 21c and a coupling recess 41a is made in the circumferential wall part 41 to be embedded in the recess 21f while being fitted over the outer circumferential edge 21b of the hollow disc part 21c. COPYRIGHT: (C)2005,JPO&NCIPI