Patent ID: 9124152
Filing Date: 2015-09-01
Classification: H02K

Abstract:
1. A permanent magnet motor comprising: a rotor comprising a shaft, a rotor core fixed on the shaft, a commutator fixed on the shaft and adjacent to the rotor core, and rotor windings wound about poles of the rotor core and electrically connected to the commutator; and a stator comprising an axially extending round housing with an open end and a mounting part integrally and outwardly extending from the open end, a ring magnet member fixed to an inner surface of the round housing, an endcap fixedly mounted to the housing, and at least one pair of brushes in sliding contact with the commutator, wherein the ratio of the axial length of the rotor core to L/N is from 1.27 to 2.31, where L is the circumference of a circle formed by outer surfaces of the rotor poles and N is the number of magnetic poles of the stator, wherein the endcap has a base plate fixed to the mounting part, a circular ring part axially extending from a side of the base plate and pressed into the open end of the round housing, a circular side part axially extending from the other side of the base plate, and a circular bearing holder for holding a bearing for supporting the shaft, and wherein the ring part, the base plate and the side part define a chamber and the commutator is completely received within the chamber; and wherein at least one pair of brush brackets is id on the side part and each brush bracket has a radially extending tubular portion being in commutation with the chamber and radially extending beyond the outer circular wall of the side part, the at least one pair of brushes being respectively received in the radially extending tubular portion of a corresponding brush bracket.