Electric drive device and electric power steering device

Patent metadata

Field	Value
Publication number	US-2018248451-A1
Application number	US-201615757134-A
Country	US
Kind code	A1
Filing date	Aug 12, 2016
Priority date	Mar 9, 2016
Publication date	Aug 30, 2018
Grant date	—

Abstract

A position detecting purpose permanent magnet 51 constituting a position detection sensor is installed at an opposite side to an output side of a rotational shaft 45 of a rotor housed within a motor housing 11 A. A GMR element 56 which constitutes the position detection sensor and a position detection circuit thereof are installed on a side of a motor cover 48 on which a position detection purpose permanent magnet 51 is arranged. GMR element 56 is arranged on a position opposed against the position detection purpose permanent magnet. Thus, since the GMR element and the position detection purpose permanent magnet is installed, a mutually positioning assembly (attachment) accuracy can be improved. In addition, since the electric power conversion circuit and both of the GMR element and its position detection circuit are kept away, such an effect that an accurate detection signal can be obtained can be achieved.

First claim

1 . An electrically-driven drive apparatus, comprising:
an electrically-driven motor, housed within a motor housing space formed by a motor housing and a motor cover, having a rotor and a stator; an ECU housing, coupled to the motor housing, for forming an ECU housing space between the ECU housing and the motor cover; a an electronic control unit, housed in the ECU housing space between the ECU housing and the motor cover, for performing a driving control for the electrically-driven motor; a position detection purpose permanent magnet installed on a rotational shaft of the electrically-driven motor axially supported on the motor cover; and a position detection board directly or indirectly attached to the motor cover and on which a magneto resistive effect element detecting a magnet pole information signal of the rotor in cooperation with the position detection purpose permanent magnet is mounted.

2 . The electrically-driven drive apparatus as claimed in claim 1 , wherein, on the position detection board, either an amplifying circuit that amplifies the magnetic pole information signal of the magneto resistive effect element or a microcomputer and its peripheral circuit having a calculation function to calculate a magnetic pole information from the magnetic pole information signal of the magneto resistive effect element is mounted.

3 . The electrically-driven drive apparatus as claimed in claim 1 , wherein the electronic control unit includes: a power supply circuit section; an electric power conversion circuit section; and a control circuit section, a bus bar is fixed to the motor cover for connecting a winding of the stator to the electric power conversion circuit section, and the position detection board is fixed to an attachment boss installed on the bus bar or fixed to another attachment boss installed on the motor cover.

4 . The electrically-driven drive apparatus as claimed in claim 2 , wherein the electronic control unit is arranged in an order of the control circuit section, the electric power conversion circuit section, and the power supply circuit section, as viewed from motor cover, and the position detection board is arranged between the control circuit section and the motor cover.

5 . The electrically-driven drive apparatus as claimed in claim 4 , wherein the position detection purpose permanent magnet is attached to a terminal section of the rotational shaft, the magneto resistive effect element is mounted on the position detection board at a position opposed against the position detection purpose permanent magnet, and, furthermore, the motor housing space and the ECU housing space are shielded by the motor cover, the bus bar, and the position detection board.

6 . The electrically-driven drive apparatus as claimed in claim 4 , wherein the position detection purpose permanent magnet is attached to a terminal section of the rotational shaft, the magneto resistive effect element is mounted on the position detection board at a position opposed against the position detection purpose permanent magnet, and, furthermore, a magnetic shield plate is mounted on a surface of an opposite side to the position detection board on which the magneto resistive effect element is arranged.

7 . The electrically-driven drive apparatus as claimed in claim 4 , wherein the position detection purpose permanent magnet is attached to a terminal section of the rotational shaft, the magneto resistive effect element is mounted on the position detection board at a position opposed against the position detection purpose permanent magnet, and, furthermore, the position detection board and a board on which the control circuit section is mounted are connected together via a floating connector and the magnetic pole information signal or the magnetic pole information is transmitted to the control circuit section.

8 . An electrically-driven power steering apparatus, comprising:
an electrically-driven motor, housed within a motor housing space formed by a motor housing and a motor cover, for providing a steering assistance force for a steering shaft; an ECU housing, coupled to the motor housing, for forming an ECU housing space between the ECU housing and the motor cover; an electronic control unit, housed in the ECU housing space between the ECU housing and the motor cover, for at least detecting a turning direction and a turning torque of a steering shaft of an automotive vehicle through a torque sensor and for calculating a drive manipulated variable of the electrically-driven motor; a position detection purpose permanent magnet, installed on a rotational shaft of the electrically-driven motor axially supported on the motor cover; and a position detection board directly or indirectly attached to the motor cover and on which a magneto resistive effect element detecting a magnetic pole information signal of the rotor in cooperation with the position detection purpose permanent magnet is mounted.

9 . The electrically-driven power steering apparatus as claimed in claim 8 , wherein, on the position detection board, either an amplifying circuit that amplifies the magnetic pole information signal of the magneto resistive effect element or a microcomputer and its peripheral circuit having a calculation function to calculate a magnetic pole information from the magnetic pole information signal of the magneto resistive effect element is mounted.

10 . The electrically-driven power steering apparatus as claimed in claim 9 , wherein the electronic control unit includes: a power supply circuit section; an electric power conversion circuit section; and a control circuit section, a bus bar is fixed to the motor cover for connecting a winding of the stator to the electric power conversion circuit section, and the position detection board is fixed to an attachment boss installed on the bus bar or fixed to another attachment boss installed on the motor cover.

11 . The electrically-driven power steering apparatus as claimed in claim 9 , wherein the electronic control unit is arranged in an order of the control circuit section, the electric power conversion circuit section, and the power supply circuit section, as viewed from the motor cover, and the position detection board is arranged between the control circuit section and the motor cover.

12 . The electrically-driven power steering apparatus as claimed in claim 11 , wherein the position detection purpose permanent magnet is attached to a terminal section of the rotational shaft, the magneto resistive effect element is mounted on the position detection board at a position opposed against the position detection purpose permanent magnet, and, furthermore, the motor housing space and the ECU housing space are shielded by the motor cover, the bas bur, and the position detection board.

13 . The electrically-driven power steering apparatus as claimed in claim 11 , wherein the position detection purpose permanent magnet is attached to a terminal section of the rotational shaft, the magneto resistive effect element is mounted on the position detection board at a position opposed against the position detection purpose permanent magnet, and, furthermore, a magnetic shield plate is mounted on a surface of an opposite side to the position detection board on which the magneto resistive effect element is arranged.

14 . The electrically-driven power steering apparatus as claimed in claim 11 , wherein the position detection purpose permanent magnet is attached to a terminal section of the rotational shaft, the magneto resistive effect element is mounted on the position detection board at a position opposed against the position detection purpo

Assignees

• Hitachi Automotive Systems Ltd

Inventors

• Hagiwara Katsumasa

Classifications

• H02K11/33

  Drive circuits, e.g. power electronics (H02K11/38 takes precedence) · CPC title

• H02K11/215 Primary

  Magnetic effect devices, e.g. Hall-effect or magneto-resistive elements · CPC title

• H02K5/225

  Terminal boxes or connection arrangements (specially adapted for submersible motors H02K5/132) · CPC title

• G01L5/221

  to steering wheels, e.g. for power assisted steering · CPC title

• B62D5/0406 Primary

  including housing for electronic control unit · CPC title