Patent ID: 7173351

Claim:
A motor comprising: a rotor shaft; a cylindrical rotor magnet having a magnetized outer peripheral surface; drive coils of cylindrical bodies having respectively center holes into which said rotor shaft is to be inserted, said drive coils being arranged in an axial direction of the cylindrical rotor magnet; a curling case formed in a tubular shape by bending a flat plate made of a magnetic material, wherein both ends of said curling case have a same sized diameter opening, said curling case surrounding one of said drive coils and a cylindrical surface of said rotor magnet with a predetermined gap therebetween, wherein a first part of said curling case facing said one of said drive coils serves as a yoke part, and a second part of said curling case facing said rotor magnet is provided with pole teeth; and a yoke plate consisting of a yoke part and pole teeth bending from the yoke part, wherein said yoke part confronts an end face of said one of said drive coils that faces said rotor magnet, and wherein said pole teeth, which are formed separately from said curling case, face the cylindrical surface of the rotor magnet, and wherein said pole teeth of said curling case and said pole teeth of said yoke plate are alternately arranged in the circumferential direction.