Electric power steering apparatus

摘要

An electric power steering apparatus (1) is provided with a heat sink (5) and an intermediate member (4) whose surface portions are perpendicularly placed with respect to an axial direction of a motor's shaft center, and arranged in such a way that each of power modules (51a, 51b) of a plurality of driving circuits is attached on a surface portion of the heat sink (5) so that an extending direction of a maximum outer dimension of the power modules (51a, 51b) is perpendicular to the axial direction, and each of electric devices (C1a-C1b) of the plurality of driving circuits is attached on a surface portion of the intermediate member (4) so that an extending direction of a maximum outer dimension of the electric devices (C1a-C1b) is perpendicular to the axial direction.

主权项

1. An electric power steering apparatus comprising:
a motor having a plurality of independent stator windings; a control device having a plurality of driving circuits for individually driving the plurality of stator windings, the control device being configured to assist in steering force of a driver based on an output of the motor driven by the control device; and an intermediate member being placed in the control device, and including a surface portion perpendicularly placed with respect to an axial direction of the motor, wherein the plurality of driving circuits includes a plurality of power modules configured to house a plurality of power devices made of switching devices for controlling electric power supplied to the stator windings corresponding to the driving circuits, and a plurality of electric devices as constituent components of the driving circuits, wherein each of the electric devices has a shape defined by a plurality of outer dimensions including a maximum outer dimension which is longer than the other outer dimensions; the electric power steering apparatus further comprises a heat sink configured to dissipate heat generated by the plurality of power modules, and the electric power steering apparatus is configured such that either: the plurality of power modules of the plurality of driving circuits is attached on the heat sink placed at a position spaced apart from the surface portion of the intermediate member so that a main surface of each of the power modules is perpendicular with respect to the axial direction of the motor, or the electric devices of the driving circuits are attached on the surface portion of the intermediate member so that an extending direction of the maximum outer dimension of the respective electric devices is perpendicular with respect to the axial direction of the motor.