STATOR OF DC MOTOR AND ITS MANUFACTURE

PROBLEM TO BE SOLVED: To reduce copper losses in windings in slots while the machining and assembly man-hours of stator steel sheets are not particularly increased. SOLUTION: A stator 1 for a DC motor consists of belt steel sheets 2 piled into a plurality of layers so as to have a cylindrical form which has a plurality of slots 3 on its inner circumference. Each slot 3 is formed narrow at the entrance 3a and gradually widened toward its bottom in which a wedge-shaped cut 6 extended in the radial direction of the stator 1 is formed. Each cut 6 has an aperture 6a with a width of not larger than half the thickness of the steel sheet 2. A distance between the tip of the cut 6 and the outer part of the stator 1 is set so as to be 1-2 times the thickness of the steel sheet 2. Therefore, if the outer circumference of the stator 1 is pushed, the deformation of the stator 1 can be allowed by the cuts 6 in the respective slots 3 to widen the entrance 3a of the specific slot 3. With this constitution, a plurality of bundled thick wires can be inserted into the slot in the bundled state.