Invention Grant
US07902709B2 Brush-less motor and electric power steering device having brush-less motor
有权
具有无刷马达的无刷马达和电动助力转向装置
- Patent Title: Brush-less motor and electric power steering device having brush-less motor
- Patent Title (中): 具有无刷马达的无刷马达和电动助力转向装置
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Application No.: US12045240Application Date: 2008-03-10
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Publication No.: US07902709B2Publication Date: 2011-03-08
- Inventor: Noboru Niguchi
- Applicant: Noboru Niguchi
- Applicant Address: JP Osaka-shi
- Assignee: JTEKT Corporation
- Current Assignee: JTEKT Corporation
- Current Assignee Address: JP Osaka-shi
- Agency: Oblon, Spivak, McClelland, Maier & Neustadt, L.L.P.
- Priority: JP2007-063638 20070313
- Main IPC: H02K21/12
- IPC: H02K21/12

Abstract:
A permanent magnet included in a rotor of a brush-less motor is a radial anisotropic magnet in which multi-poles are magnetized in the circumferential direction and is skew magnetized along the axial direction in such a manner that a surface to one end part of an upper side from a central part in the axial direction and a surface to an end part of a lower side from the central part are axially shifted by a predetermined angle in the circumferential direction from each other. In accordance with this skew-magnetization, coggings including irregularly varying components generated in the rotor owing to the three-dimensional shapes of coil ends provided at opposite ends of a tooth 611a for fixing a winding have opposite phases to each other, so that the coggings are cancelled with each other. Accordingly, the coggings can be reduced or cancelled.
Public/Granted literature
- US20080224559A1 BRUSH-LESS MOTOR AND ELECTRIC POWER STEERING DEVICE HAVING BRUSH-LESS MOTOR Public/Granted day:2008-09-18
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