Patent ID: 7884524
Filing Date: 2011-02-08
Classification: H02K

Abstract:
1. A brushless alternator, comprising: a case including a pair of brackets opposed to each other; a shaft provided on a central axis of the case; a rotor provided to the shaft; and a stator surrounding the rotor, wherein the rotor includes: a rotor main body fixed to the shaft to rotate with rotation of the shaft; and a coil body fixed to one of the pair of brackets, the rotor main body includes: a first pole core, which is fixed to the shaft, and includes a plurality of first claw-like magnetic pole portions formed at intervals in a circumferential direction; and a plurality of second claw-like magnetic pole portions respectively opposed to the plurality of first claw-like magnetic pole portions to mesh therewith, the plurality of second claw-like magnetic pole portions being coupled to the plurality of first claw-like magnetic pole portions neighboring through an intermediation of an annular ring, the coil body includes: an insulator provided in a space on an inner diameter side of the plurality of first claw-like magnetic pole portions and the plurality of second claw-like magnetic pole portions of a second pole core opposed to the first pole core; a field coil constituted by winding a conductor around the insulator, the field coil being for generating a magnetic flux by causing a current to flow therethrough; a yoke portion of the second magnetic pole, the yoke portion having one lateral surface being in close contact with a lateral surface of the insulator and another lateral surface being bonded to the one of the pair of brackets to serve as a passage of the magnetic flux; a spool provided on an inner circumferential surface of the yoke portion and an inner circumferential surface of the insulator; and a buffer member provided to a projecting portion at a distal end of the spool, and the buffer member is fitted into a concave portion formed in a portion of the one of the pair of brackets, the portion being opposed to a distal end surface of the spool.