PURPOSE: To reduce dimensional variation and occurrence of crack of a cylindrical body by fixing disc type yoke members having a central shaft hole to the opposite open end sections of a cylindrical composite magnet body and then inserting a shaft into the shaft hole thereby assembling integrally.
CONSTITUTION: Four protrusions 1a are provided at the opposite open end sections of a cylindrical body 1, and recesses 3a to be engaged with the protrusions 1a are made in two sheets of yoke members 3. The protrusions 1a of the cylindrical body 1 are then fitted in the recesses 3a of the yoke member 3 so that the cylindrical body 1 and the yoke member 3 can rotate integrally. A shaft hole 4 is made in the center of the yoke member 3 and cylindrical shaft fixing sections 5 are projected in the axial direction thus integrating the shaft 2 and the yoke member 3. By such arrangement, dimensional variation and occurrence of crack of the cylindrical body 1 can be reduced.
KIMURA KIYOSHI
HIRAI NOBUYUKI
