The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Oct. 27, 2009
Filed:
Mar. 28, 2005
Akio Yamagiwa, Kusatsu, JP;
Akio Yamagiwa, Kusatsu, JP;
Daikin Industries, Ltd., Osaka, JP;
Abstract
It is an object of the present invention to provide techniques for improving efficiency and torque of a motor while achieving thinning of the motor. In a brushless DC motor, a rotor includes a magnetic-field creating magnet and a stator includes an armature winding. The magnetic-field creating magnet and the armature winding are placed to locally face in a radial direction orthogonal to an axial direction. This reduces a thickness of the brushless DC motor which extends in the axial direction. Also, a short-circuit yoke plate for joining and magnetically short-circuiting the north pole and the south pole of a permanent magnet is placed on a negative side in the axial direction with respect to the magnetic-field creating magnet. By provision of the short-circuit yoke plate, a magnetic path on a negative side in the axial direction with respect to the magnetic-field creating magnet can be shortened. Accordingly, magnetic reluctance occurring during rotational movement of the brushless DC motor can be reduced, to thereby improve efficiency and torque of the brushless DC motor.