Patent ID: 9455610
Filing Date: 2016-09-27
CPC Classification: B60L,H02K,Y02T

Claim Text:
1. A motor drive apparatus comprising: a motor including a motor case of a cylindrical shape, a stator housed inside the motor case, a rotor provided rotatably relative to the stator, and a shaft provided on a rotation axis of the rotor; a control unit case provided at one axial side of the motor case in an axial direction; a control unit substrate housed in the control unit case and including a control circuit to control currents supplied to the motor; a rear end frame provided between the motor case and the control unit case; a bearing fixed to the rear end frame to support rotatably one end of the shaft; a magnet provided at one axial end of the shaft extending from the bearing toward the control unit substrate, the magnet having different magnetic poles in a rotation direction; a rotation angle sensor provided on the control unit substrate to output a detection signal of a magnetic field of the magnet; a positioning part formed on the rear end frame to fixedly place the control unit substrate in position thereby to provide the rotation angle sensor on the rotation axis of the shaft; and a heat sink attached to the control unit substrate, wherein: the positioning part includes an inside fitting surface formed on a radially inside wall surface of the rear end frame; the heat sink includes an outside fitting surface, which is fitted with the inside fitting surface; the inside fitting surface and the outside fitting surface are formed in an arcuate shape or a cylindrical shape having a radial center on the rotation axis of the shaft; the inside fitting surface is formed of a single cylindrical surface that is continuous over a whole inner circumference of the inside wall surface of the rear end frame; the outside fitting surface is formed of plural arcuate surfaces; and the inside fitting surface and the outside fitting surface are both socket-spigot fitting surfaces to be fitted tightly.