ELECTRIC DRIVE APPARATUS, AND ELECTRIC POWER STEERING APPARATUS

• US 20200136473A1
• Filed: 12/23/2019
• Published: 04/30/2020
• Est. Priority Date: 06/01/2016
• Status: Active Grant

• Current Assignee: Hitachi Astemo Ltd. (Hitachi, Ltd.)
• Original Assignee: Hitachi Automotive Systems Limited (Hitachi, Ltd.)
• Inventors: HAMADA, Keiji
• Granted Patent: US 11,362,569 B2
• Time in Patent Office: Days
• CPC Class Codes: H02K 11/33 Drive circuits, e.g. power electronics H02K11/38 takes precedence
• CPC Class Codes: H02K 5/18 with ribs or fins for improving heat transfer
• CPC Class Codes: H02K 9/02 by ambient air flowing through the machine
• CPC Class Codes: H02K 9/22 by solid heat conducting material embedded in, or arranged in contact with, the stator or rotor, e.g. heat bridges
• CPC Class Codes: H02K 9/227 Heat sinks

Abstract

In an electric power steering apparatus, a motor housing includes an axial end part opposite to an output part of an electric motor. An electronic control section is arranged at the axial end part of the motor housing. The electronic control section includes a control circuit part, a power supply circuit part, and a power conversion circuit part. The axial end part of the motor housing includes a power conversion part thermal radiation region and a power supply part thermal radiation region. The power conversion circuit part is mounted to the power conversion part thermal radiation region to allow heat to be transferred from the power conversion circuit part to the motor housing. The power supply circuit part is mounted to the power supply part thermal radiation region to allow heat to be transferred from the power supply circuit part to the motor housing.

Claims

1. An electric drive apparatus comprising:

a motor housing configured to house an electric motor, wherein the electric motor is configured to drive a controlled object of a mechanical system; and

an electronic control section arranged to be closer to an axial end of the electric motor than to an output part of a rotating shaft of the electric motor, and configured to control the electric motor, wherein the electronic control section includes a control circuit part and a power supply circuit part, and wherein the control circuit part includes a microcomputer;

wherein the power supply circuit part is arranged at an axial end part of the motor housing opposite to the output part of the rotating shaft of the electric motor.

2. The electric drive apparatus as claimed in claim 1, further comprising:

a cover fixed to the motor housing so as to define an internal space, and structured to house the electronic control section in the internal space; and

a thermal conductor disposed in the internal space, and between the power supply circuit part and the axial end part of the motor housing.

3. The electric drive apparatus as claimed in claim 1, further comprising:

a cover fixed to the motor housing so as to define an internal space, and structured to house the electronic control section in the internal space; and

a thermal conductor disposed in the internal space, and between a board of the power supply circuit part and the axial end part of the motor housing.

4. The electric drive apparatus as claimed in claim 2, wherein the thermal conductor is an adhesive agent or radiation grease or radiation sheet.

14. The electric drive apparatus as claimed in claim 1, wherein:

the electronic control section is configured to be redundant to include first and second systems; and

the power supply circuit part is configured to be redundant to include first and second systems corresponding to the first and second systems of the electronic control section.

18. The electric drive apparatus as claimed in claim 3, wherein the thermal conductor is an adhesive agent or radiation grease or radiation sheet.

5. An electric drive apparatus comprising:

a motor housing configured to house an electric motor, wherein the electric motor is configured to drive a controlled object of a mechanical system; and

an electronic control section arranged to be closer to an axial end of the electric motor than to an output part of a rotating shaft of the electric motor, and configured to control the electric motor, wherein the electronic control section includes a control circuit part and a power supply circuit part, and wherein the control circuit part includes a microcomputer;

wherein the power supply circuit part includes a board fixed to an axial end part of the motor housing opposite to the output part of the rotating shaft of the electric motor.

6. The electric drive apparatus as claimed in claim 5, further comprising:

a cover fixed to the motor housing so as to define an internal space, and structured to house the electronic control section in the internal space; and

a thermal conductor disposed in the internal space, and between the board of the power supply circuit part and the axial end part of the motor housing.

15. The electric drive apparatus as claimed in claim 5, wherein:

the electronic control section is configured to be redundant to include first and second systems; and

the power supply circuit part is configured to be redundant to include first and second systems corresponding to the first and second systems of the electronic control section.

7. An electric drive apparatus comprising:

a motor housing configured to house an electric motor, wherein the electric motor is configured to drive a controlled object of a mechanical system; and

an electronic control section arranged to be closer to an axial end of the electric motor than to an output part of a rotating shaft of the electric motor, and configured to control the electric motor, wherein the electronic control section includes a control circuit part and a power conversion circuit part, wherein the control circuit part includes a microcomputer, and wherein the power conversion circuit part is configured to regulate electric power flowing through the electric motor;

wherein the power conversion circuit part is disposed between the control circuit part and the electric motor, and mounted to an axial end part of the motor housing opposite to the output part of the rotating shaft of the electric motor.

8. The electric drive apparatus as claimed in claim 7, wherein:

the axial end part of the motor housing includes a projecting part projecting in an axial direction of the motor housing; and

the power conversion circuit part is mounted to the projecting part.

16. The electric drive apparatus as claimed in claim 7, wherein:

the electronic control section is configured to be redundant to include first and second systems; and

the power conversion circuit part is configured to be redundant to include first and second systems corresponding to the first and second systems of the electronic control section.

9. An electric drive apparatus comprising:

a motor housing configured to house an electric motor, wherein the electric motor is configured to drive a controlled object of a mechanical system; and

an electronic control section arranged to be closer to an axial end of the electric motor than to an output part of a rotating shaft of the electric motor, and configured to control the electric motor, wherein the electronic control section includes a control circuit part, a power supply circuit part, and a power conversion circuit part, wherein the control circuit part includes a microcomputer, and wherein the power conversion circuit part is configured to regulate electric power flowing through the electric motor;

wherein the control circuit part is located farther from the electric motor than the power supply circuit part and the power conversion circuit part in an axial direction of the motor housing; and

wherein the power supply circuit part and the power conversion circuit part are arranged at an axial end part of the motor housing between the control circuit part and the electric motor.

10. The electric drive apparatus as claimed in claim 9, further comprising:

a cover fixed to the motor housing so as to define an internal space, and structured to house the electronic control section in the internal space; and

a thermal conductor disposed in the internal space, and between the power supply circuit part and the axial end part of the motor housing.

11. The electric drive apparatus as claimed in claim 9, further comprising:

a cover fixed to the motor housing so as to define an internal space, and structured to house the electronic control section in the internal space; and

a thermal conductor disposed in the internal space, and between a board of the power supply circuit part and the axial end part of the motor housing.

12. The electric drive apparatus as claimed in claim 10, wherein the thermal conductor is an adhesive agent or radiation grease or radiation sheet.

13. The electric drive apparatus as claimed in claim 9, wherein:

the axial end part of the motor housing includes a projecting part projecting in the axial direction of the motor housing; and

the power conversion circuit part is in contact with the projecting part.

17. The electric drive apparatus as claimed in claim 9, wherein:

the electronic control section is configured to be redundant to include first and second systems; and

each of the power supply circuit part and the power conversion circuit part is configured to be redundant to include first and second systems corresponding to the first and second systems of the electronic control section.

19. The electric drive apparatus as claimed in claim 11, wherein the thermal conductor is an adhesive agent or radiation grease or radiation sheet.