Nidec Sankyo Corporation

Kabushiki Kaisha Sankyo Seiki Seisakusho

Tetsuo Hoshina

Shigeru Kasai

Takafumi Kuwazawa

Shigeru Nishida

In a motor, a magnet is configured so that four pairs of S-poles and N-poles are formed at equal angular intervals, and a stator core has six salient poles formed thereon. Of the plurality of salient poles, when the first salient pole or the second salient pole faces a position between an S-pole and an N-pole, the other salient pole faces the center of an S-pole or the center of an N-pole. The radial-direction lengths of the first salient pole and the second salient pole among the plurality of salient poles are longer than the other salient poles, and the radial-direction length of the portion of the first coil wound around the first salient pole and the radial-direction length of the portion of the second coil wound around the second salient pole are longer than the radial-direction lengths of the other salient poles.

Motor

A motor having rotor has a good balance of inertia and a magnetic characteristic that match the specifications of the motor with which those rotors are to be used. A rare-earth containing iron-base resin-bonded magnet is molded from an iron-base magnetic powder containing a rare earth metal such as neodymium and praseodymium in powder, a thermoplastic or thermosetting resin and additive. A density and magnetic characteristic is proportionally changed by adjusting a mixing ratio of a filler powder. Specifically, when a mixing ratio of filler powder containing tungsten having a density 19.1 g/cm.sup.3 is in 13 vol % is injected, or a mixing ratio of alloy powder containing tungsten an nickel, or tungsten and chromium having a density 10.5 g/cm.sup.3 is compression-mold, its magnetic flux assume the same value as those of compression-molded Sm--Co magnets.

Growing community of inventors

Nagano, Japan

Tetsuo Hoshina