POWER ELECTRONIC MODULE COOLING SYSTEM AND METHOD

• US 20100079944A1
• Filed: 09/26/2008
• Published: 04/01/2010
• Est. Priority Date: 09/26/2008
• Status: Active Grant

• Current Assignee: Rockwell Automation Technologies Incorporated (Allen-Bradley Co., Inc.)
• Original Assignee: Rockwell Automation Technologies Incorporated (Allen-Bradley Co., Inc.)
• Inventors: Loth, Michael William
• Granted Patent: US 9,192,079 B2
• Time in Patent Office: Days
• US Class Current: 361/695
• CPC Class Codes: H05K 7/20163 the components being isolated from air flow, e.g. hollow heat sinks, wind tunnels or funnels
• CPC Class Codes: H05K 7/20918 the components being isolated from air flow, e.g. hollow heat sinks, wind tunnels or funnels

Abstract

An improved cooling mechanism for a power electronics device is provided. More specifically, a cooling mechanism is provided that includes an air passageway configured to allow cooling air to bypass a portion of a heatsink adjacent to the rectifier circuitry and direct cooling air into an area of the heatsink that is nearer to the inverter circuitry. Another embodiment employs an air passageway with an air directing structure configured to provide an air flow that impinges on a lateral surface of the heatsink. In another embodiment, the air directing structure is chosen to provide a turbulent air flow in the heat dissipating structure within the vicinity of the inverter circuitry.

Claims

1. A motor drive comprising:

rectifier circuitry configured to be coupled to an AC power source and to provide power to a DC bus;

inverter circuitry coupled to the DC bus and configured to generate drive signals for driving a motor;

a fan for directing a flow of cooling air through an air passageway;

a heat dissipating structure thermally coupled to the rectifier circuitry and to the inverter circuitry and extending into the air passageway and cooled by the flow of cooling air from the fan; and

a substantially open space disposed in the air passageway adjacent to the heat dissipating structure and configured to allow a portion of the cooling air to bypass an upstream portion of the heat dissipating structure;

wherein the air passageway comprises an air directing structure disposed at an end of the substantially open space and configured to direct air from the substantially open space into a downstream portion of the heat dissipating structure.

2. The motor drive of claim 1, wherein the rectifier circuitry is disposed adjacent to the upstream portion of the heat dissipating structure.

3. The motor drive of claim 1, wherein the inverter circuitry is disposed adjacent to the downstream portion of the heat dissipating structure.

4. The motor drive of claim 1, wherein the air directing structure comprises a solid barrier spanning the width of the air passageway.

5. The motor drive of claim 1, wherein the air directing structure is oriented at approximately a forty-five degree angle to the direction of the incoming air flow provided by the fans.

6. The motor drive of claim 1, wherein the air directing structure is oriented at approximately a ninety degree angle to the direction of the incoming air flow provided by the fans.

7. The motor drive of claim 1, wherein the air directing structure is configured to provide an impingent flow of cooling air to a portion of the heat dissipating structure that is adjacent to the inverter circuitry.

8. The motor drive of claim 1, wherein the air directing structure is configured to provide air turbulence in at least a portion of the heat dissipating structure that is adjacent to the inverter circuitry.

9. A motor drive comprising:

rectifier circuitry configured to be coupled to an AC power source and to provide power to a DC bus;

inverter circuitry coupled to the DC bus and configured to generate drive signals for driving a motor;

a fan for directing a flow of cooling air through an air passageway; and

a heat dissipating structure thermally coupled to the rectifier circuitry and to the inverter circuitry and extending into the air passageway and cooled by the flow of cooling air from the fan;

wherein the air passageway comprises an air directing structure with a setback distance and an angle;

the air directing structure directing cooling air into a lateral surface the heat dissipating structure.

10. The motor drive of claim 9, wherein the setback distance of the air directing structure is approximately ten percent to ninety percent of the length of the heat dissipating structure.

11. The motor drive of claim 9, wherein the setback distance of the air directing structure is approximately 30 to 70 percent of the length of the heat dissipating structure.

12. The motor drive of claim 9, wherein the angle of the air directing structure is approximately ten to ninety degrees.

13. The motor drive of claim 9, wherein the angle of the air directing structure is approximately thirty to sixty degrees.

14. The motor drive of claim 9, wherein the air directing structure directs an at least partially impingent air flow into the heat dissipating structure.

15. A method of cooling a motor drive unit, comprising:

forcing cooling air into a cooling channel comprising a heat sink and a substantially open space adjacent to the heat sink;

forcing a first portion of the cooling air into a leading edge of the heat sink;

forcing a second portion of the cooling air into an open space adjacent to the heat sink; and

forcing the second portion of the cooling air into a lateral surface of the heatsink at a location downstream from the leading edge of the heatsink.

16. The method of claim 16, wherein the second portion of the cooling air is forced into the lateral surface of the heatsink by an air deflecting surface disposed generally opposite the heatsink.

17. A method for making a motor drive comprising:

disposing a heatsink adjacent to a power electronic circuit in an enclosure, the heatsink extending into an open space forming a passageway for cooling air;

disposing a fan at an end of the enclosure to blow cooling air into the passageway;

closing the open space with an enclosure wall that is spaced from the heatsink to form the open space, and that includes a cooling air deflecting surface positioned to direct a portion of the cooling air from the passageway into contact with the heatsink at a location spaced from a forward edge of the heatsink.

18. The method of claim 18, wherein the cooling air directing surface directs the portion of air from the passageway into an air flow from the fan that enters the heatsink at the forward edge thereof.

19. The method of claim 18, wherein the cooling air deflecting surface is an inclined portion of the enclosure wall that forms an angle of between approximately forty five and ninety degrees with respect to an upstream portion of the enclosure wall.