Patent ID: 6917132
Filing Date: 2005-07-12
Classification: H01F,H02K

Abstract:
1. A DC brush motor comprising: a housing; a permanent magnet, having a maximum energy product greater than 14 MGOe, arranged on an inner perimeter of the housing, that is a thin-walled hollow cylinder shaped anisotropic rare earth bonded magnet magnetized with at least 4 magnetic poles; and an electromagnetic rotor core arranged in a center of the DC brush motor, wherein for a motor housing outer diameter, an anisotropic rare earth bonded magnet radial thickness, an electromagnetic rotor core radius and a motor housing thickness, a ratio of the electromagnetic rotor core radius to the motor housing outer diameter is not less than 0.25 and not greater than 0.5, a ratio of the motor housing thickness to the rare earth bonded magnet radial thickness is not less than 1 and not greater than 4, and a ratio of the anisotropic rare earth bonded magnet radial thickness to the motor housing outer diameter is not les than 0.01 and not greater than 0.10.