US 7,843,107 B2Granted

Dynamoelectric machine

AssigneeMitsubishi Electric Corporation

InventorsMasaya Inoue, Kanji Shinkawa, Masao Morita, Haruyuki Kometani, Toshiyuki Yoshizawa, Moriyuki Hazeyama, Keiichi Ito, Takeshi Mori, Hiroyuki Akita, Yoshinori Miyamoto, Shinji Nishimura

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Abstract

A dynamoelectric machine including first and second permanent magnets held by first and second magnet seats on first and second yoke portions so as to face inner circumferential surfaces of tip end portions of first and second claw-shaped magnetic pole portions. The first and second permanent magnets are magnetically oriented in a reverse direction to orientation of a magnetic field that the field coil produces. The dynamoelectric machine enables permanent magnet holding reliability to be increased, induced voltage during no-load de-energization to be suppressed, and thermal demagnetization of magnets due to high-frequency magnetic fields that are induced by stator slots to be avoided.

Claims13

Dependent claims

A dynamoelectric machine comprising:

a rotor comprising:
a pole core comprising:
a boss portion;
a pair of yoke portions that are disposed so as to extend radially outward from two axial end edge portions of said boss portion;
and
a plurality of claw-shaped magnetic pole portions that are disposed so as to extend in an axial direction alternately from each of said pair of yoke portions, and that are arranged circumferentially so as to intermesh with each other,
said pole core being fixed to a shaft that is inserted through a central axial position of said boss portion;
and
a field coil that is housed inside a space that is surrounded by said boss portion, said pair of yoke portions, and said plurality of claw-shaped magnetic pole portions;
a stator that is disposed so as to surround said rotor with a predetermined air gap interposed;
and
a plurality of permanent magnets that are held near said pair of yoke portions so as to face an inner circumferential surface of a tip end portion of each of said plurality of claw-shaped magnetic pole portions, each of said plurality of permanent magnets being magnetically oriented in a reverse direction to an orientation of a magnetic field that said field coil produces.

9 more elements

Dependencies are inferred from the claim text.