Drive device

• US 20050253465A1
• Filed: 05/08/2003
• Published: 11/17/2005
• Est. Priority Date: 09/13/2002
• Status: Active Grant

• Current Assignee: Aisin AW Company Limited (Aisin Corp.)
• Original Assignee: Aisin AW Company Limited (Aisin Corp.)
• Inventors: Takenaka, Masayuki, Yamaguchi, Kozo, Kutsuna, Naruhiko
• Granted Patent: US 7,525,224 B2
• Time in Patent Office: Days
• US Class Current: 310/52
• 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 5/20 with channels or ducts for flow of cooling medium
• CPC Class Codes: H02K 5/203 specially adapted for liquids, e.g. cooling jackets
• CPC Class Codes: H05K 7/20927 Liquid coolant without phase change

Abstract

A drive unit comprises an electric motor, a drive unit casing 2 accommodating therein the electric motor, an inverter 3 that controls the electric motor, and a flow passage of a refrigerant that cools the inverter. The inverter defines a space R between it and a heat sink 5 integral with a substrate of the inverter, and is mounted to the drive unit casing, the space being communicated to the flow passage of the refrigerant. The heat sink comprises fins 56 that cross the space R, and abuts against the drive unit casing in a state of low thermal conduction. Thereby, the heat sink is effectively cooled by heat exchange with a cooling refrigerant in wide areas. Also, the fins contact with the drive unit casing in a state of low thermal conduction via a heat insulation material, etc., whereby direct heat conduction is avoided and efficient cooling is enabled while temperature gradient conformed to heat-resistant temperatures of the inverter and the electric motor is maintained.

Claims

1. A drive unit including

an electric motor (1),

a drive unit casing (2) accommodating therein the electric motor,

an inverter (3) that controls the electric motor, and

a flow passage (4) of a refrigerant that cools the inverter, the drive unit characterized in that the inverter is mounted on the drive unit casing such that a heat sink (53) united with a substrate of the inverter defines a space (R) on a portion thereof opposed to the drive unit casing,

the space is communicated to the flow passage of the refrigerant,

the heat sink comprises heat-sink side fins (56) extending into the space toward the drive unit casing, and

the heat-sink side fins and the drive unit casing contact with each other in a state of low thermal conduction.

6. The drive unit according to claim 1, wherein the drive unit casing comprises drive-unit-casing side fins (22) extending into the space toward the heat sink.

7. The drive unit according to claim 6, wherein the space is compartmented by the separation means into a first chamber (R1) facing toward the heat sink and a second chamber (R2) facing toward the drive unit casing.

8. The drive unit according to claim 1, wherein the inverter is received in an inverter casing (5) composed of a member separate from the inverter with a substrate thereof fixed to a bottom wall of the inverter casing and constitutes a heat sink, of which a substrate is united with the bottom wall of the inverter casing.

9. The drive unit according to claim 1, wherein the inverter together with the heat sink (33) that is united with a substrate thereof are received in an inverter casing composed of a member separate from the inverter.

10. The drive unit according to claim 7, wherein the heat-sink side fins and the drive-unit-casing side fins cooperatively generate a common refrigerant flow pattern within the space.

2. A drive unit including

an electric motor,

a drive unit casing accommodating therein the electric motor,

an inverter that controls the electric motor, and

a flow passage of a refrigerant that cools the inverter, the drive unit characterized in that the inverter is mounted on the drive unit casing such that a heat sink united with a substrate of the inverter defines a space on a portion thereof opposed to the drive unit casing,

the space is communicated to the flow passage of the refrigerant,

the heat sink comprises heat-sink side fins extending into the space toward the drive unit casing,

separation means (6) for preventing thermal conduction is provided in the space, and

both the heat-sink side fins and the drive unit casing contact directly with the separation means.

3. The drive unit according to claim 2, wherein the separation means comprises a low thermal conductive member (61).

4. The drive unit according to claim 2, wherein the separation means comprises a plurality of separation members (60) with a space (R3) therebetween.

5. The drive unit according to claim 2, wherein the separation means comprises a laminated member formed by laminating a low thermal conductive member on a separation member.

11. The drive unit according to claim 3, wherein the low thermal conductive member is shaped to follow contact portions of the heat-sink side fins and the drive-unit-casing side fins.