Asmo Co., Ltd.

Denso Corporation

Yoshihito Nishikawa

Yoshiyuki Takabe

Takahiro Nakayama

Keisuke Koide

Mitsuhiko Matsushita

Kazushi Sugishima

Hiroyuki Suzuki

Hirotaka Itoh

Makoto Morisaki

Mikitsugu Suzuki

Shinichi Naitou

Takanori Ozawa

An embedded magnet type motor is disclosed. The rotor core of the motor has radially extending first accommodation holes and V-shaped accommodation holes. Each V-shaped accommodation hole includes a second accommodation hole and a third accommodation hole. A first gap is formed in each first accommodation hole. The first gap is not occupied by the corresponding first magnet. A second gap is formed in each second accommodation hole. The second gap is not occupied by the corresponding second magnet. A third gap is formed in each third accommodation hole at a radially outer portion. The third gap is not occupied by the corresponding third magnet. Each second gap and the adjacent third gap form one V-shaped gap. The angular width &#x3b8;a of each first gap and the angular width &#x3b8;b of each V-shaped gap are determined to satisfy the expression: 0.60&#x3c;&#x3b8;a/&#x3b8;b&#x3c;1.60.

Embedded magnet type motor

A rotor of an embedded magnet type motor has a plurality of magnets forming magnetic poles, the number of which is represented by P. A rotor core includes first accommodation holes, the number of which is represented by P/2, extending in a radial direction, and V-shaped accommodation holes, the number of which is represented by P/2, having a V shape protruding outward in a radial direction. The first accommodation holes and the V-shaped accommodation holes are alternately arranged in a circumferential direction. The V-shaped accommodation holes include a second accommodation hole and a third accommodation hole corresponding to two straight lines forming the V shape. The first accommodation hole is adjacent to the second accommodation hole at one side in the circumferential direction, and is adjacent to the third accommodation hole at the other side. A plurality of magnets include a first magnet arranged in the first accommodation hole, a second magnet arranged in the second accommodation hole, and a third magnet arranged in the third accommodation hole. The first magnet and the second magnet form one magnetic pole. The first magnet and the third magnet form another magnet pole. Accordingly, it is possible to achieve a high torque while suppressing an increase of the number of parts of the embedded magnet type motor.

A first armature winding and a second armature winding each include a tubular member, a first conductor arranged in a radially inner side of the tubular member, and a second conductor arranged in a radially outer side of the tubular member. The first conductor includes a first coated portion, which is coated by a coating formed from an insulator, and a first wire connection portion, which is free from the insulator. The second conductor includes a second coated portion, which is coated by a coating formed from an insulator, and a second wire connection portion, which is free from the insulator. The first wire connection portion and the second wire connection portion are electrically connected to each other. A large output is obtained from a slotless motor including the first armature winding and the second armature winding.

Armature winding, method for manufacturing armature winding, and slotless motor

A brushless motor includes a motor housing, a stator, a positioning projection, and a groove. The stator is fitted in the motor housing and includes an outer core and teeth, which extend in the radial direction of the stator. A radially outward end of each tooth is coupled with the outer core. Each tooth has a predetermined width in the circumferential direction of the stator. The positioning projection is located on the inner circumferential surface of the motor housing. The groove is located on the outer circumferential surface of the outer core. The groove is arranged on a radial line that passes through the center of the width direction of one of the teeth. The positioning projection is fitted in the groove to determine the position of the stator with respect to the motor housing in the circumferential direction.

Brushless motor

A revolving magnetic field type motor has a rotor and a stator. The rotor has a plurality of permanent magnets. The permanent magnets defines a plurality of rotor magnetic poles. The number of the rotor magnetic poles is &ldquo;P&rdquo;. The rotor has a plurality of blocks aligned in the rotor's axial direction. The number of the blocks is &ldquo;m&rdquo;. Each block has a set of the rotor permanent magnets. One set of the permanent magnets is offset relative to an adjacent set of the permanent magnets by a predetermined offset angle in the rotor's rotational direction. The stator has a plurality of coils, the coils defining a plurality of stator magnetic poles around the axis of the stator, the number of the stator magnetic poles being &ldquo;T&rdquo;. The predetermined offset angle is selected from within a range from about zero degrees/((m&minus;1)&times;n) to about 22.5 degrees/((m&minus;1)&times;n). The number of the rotor magnetic poles &ldquo;P&rdquo; is 8n (n is an integer equal to or greater than one). The number of the stator magnetic poles &ldquo;T&rdquo; is 9n (n is an integer equal to or greater than one). This motor reliably decreases cogging torque.

Revolving magnetic field type motor

A brushless motor is composed of a stator for generating a rotating magnetic field by supplying three-phase alternating current consisting of U, V and W-phases thereto and a rotor having plural poles and rotatably disposed inside the stator. The rotor is rotated by the rotating magnetic field generated in the stator. The stator includes core teeth on which coils are wound. A tooth-group consisting of a center tooth and two side teeth is allocated to each phase, and excitation current in one phase is simultaneously supplied to three coils wound on the three teeth in the same tooth-group. The center teeth of each phase are positioned with equal intervals therebetween, while the side teeth are positioned so that they substantially coincide with the centers of the rotor poles when a center tooth in the same tooth-group coincides with the center of one of the rotor poles. Thus, the phase shift among the three coils in each phase is substantially eliminated, and thereby the excitation current is efficiently converted into the rotating magnetic field and output of the brushless motor is increased.

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Toyohashi, Japan

Yoshihito Nishikawa