PURPOSE: To facilitate assembling work, by constructing a holding body for a plurality of permanent magnets with two annular sections and a plurality of coupling sections made of synthetic resin.
CONSTITUTION: In a tubular metallic yoke 1, a bearing section 2a is formed on the bottom 2 thereof and circumferential and axial positioning protrusions 1a∼1d are formed on the circumference of the tubular section while facing each other. Two permanent magnets 3, 4 have arched shapes and magnetized with different polarities, and held through a holding member 5 in the inner circumference of the yoke. The holding member 5 comprises first and second annular sections 6a, 6b and two coupling sections 7a, 7b between them, where both sections are molded integrally of synthetic resin. Receiving sections 9a, 9b for the permanent magnets 3, 4, positioning grooves 10a, 10b for the protrusions 1a, 1b and engaging sections 11a, 11b for the protrusions 1c, 1d are provided in the coupling sections 7a, 7b. Furthermore, holding boards 13, 14 are provided in order to prevent dispersion of cut chips of the permanent magnets 3, 4.
UMEMARU NAOTO
MORIMOTO HIROYUKI
