Cooling arrangement for end turns and stator in an electric machine

• US 8,829,744 B2
• Filed: 04/18/2013
• Issued: 09/09/2014
• Est. Priority Date: 03/23/2010
• Status: Active Grant

• Current Assignee: Hamilton Sundstrand Corporation (Raytheon Technologies Corporation d/b/a RTX)
• Original Assignee: Hamilton Sundstrand Corporation (Raytheon Technologies Corporation d/b/a RTX)
• Inventors: Pal, Debabrata
• Primary Examiner(s): Leung, Quyen
• Assistant Examiner(s): DESAI, NAISHADH N
• Application Number:
  US13/865,273
• Publication Number:
  US 20130234545A1
• Time in Patent Office: 509 Days
• Field of Search: 310/54, 310 57- 59, 310/64
• US Class Current: 310/59
• CPC Class Codes: H02K 1/20 with channels or ducts for flow of cooling medium
• CPC Class Codes: H02K 5/18 with ribs or fins for improving heat transfer
• CPC Class Codes: H02K 5/203 specially adapted for liquids, e.g. cooling jackets
• CPC Class Codes: H02K 7/20 Structural association with auxiliary dynamo-electric machines, e.g. with electric starter motors or exciters
• CPC Class Codes: H02K 9/00 Arrangements for cooling or ventilating channels or ducts in parts of the magnetic circuit H02K1/20, H02K1/32; channels or ducts in or between conductors H02K3/22, H02K3/24
• CPC Class Codes: H02K 9/197 in which the rotor or stator space is fluid-tight, e.g. to provide for different cooling media for rotor and stator

Abstract

An electric machine includes a stator having an outer circumference. Spaced apart first walls are arranged about the outer circumference and provide generally parallel first channels. A second wall adjoins the first wall and is arranged about the outer circumference providing a second channel in fluid communication with the first channels, thus, providing a tortuous fluid flow path about the circumference. The first and second channels have an inner surface. A structure is provided within at least one of the first and second channels. The structure has an outer surface spaced radially outward from the inner surface and at least partially defines the tortuous flow path between the outer and inner surfaces. The stator includes an end turn. An end cap extends axially and radially outward from the stator and provides an enclosure about the end turn in fluid communication with the exit associated with the flow path.

Claims

1. An electric machine comprising:

a stator having an outer circumference;

spaced apart first walls arranged about the outer circumference providing generally parallel axially extending first channels, and a second wall adjoining the first walls and arranged about the outer circumference providing discrete, arcuate second channels in fluid communication with the first channels and providing a tortuous serpentine fluid flow path about the circumference that is configured to alternate between opposite axial fluid flow directions within the first channels, the first and second channels having an inner surface; and

a structure provided within at least one of the first and second channels and having an outer surface spaced radially outward from the inner surface to provide a flow passage and at least partially defining the tortuous fluid flow path between the outer and inner surfaces, wherein the structure is provided by a fin core including rows of corrugations, the corrugations include spaced apart legs and the outer surface, which is supported by the legs, the flow passage is defined by the inner and outer surfaces and the spaced apart legs.

2. The electric machine according to claim 1, wherein the stator includes at least one wire winding providing a main stack and end turns extending generally axially outwardly from the main stack in opposite directions from one another, and a rotor disposed within the stator.

3. The electric machine according to claim 1, wherein the first walls extend in a generally axial direction and are circumferentially spaced about the outer circumference, and the second wall is generally annular and arranged transverse from the first walls, the fluid configured to flow from one first channel through one second channel to another first channel that is adjacent the one first channel to provide the tortuous serpentine fluid flow path.

6. The electric machine according to claim 1, comprising a sleeve supported by the stator, the sleeve including the first and second walls, which extend radially outwardly to a housing within which the stator is disposed.

7. The electric machine according to claim 6, wherein the housing includes fins extending radially inwardly toward the sleeve and adjacent to the first walls.

8. The electric machine according to claim 1, wherein the rows are offset from one another.

9. The electric machine according to claim 1, wherein the fin core is brazed to a sleeve mounted on the stator.

10. The electric machine according to claim 1, wherein the corrugations are provided by a lanced material.

11. The electric machine according to claim 1, wherein the corrugations provide multiple undulations staggered with respect to one another to provide the tortuous fluid flow path.

4. An electric machine comprising:

a stator having an outer circumference;

spaced apart first walls arranged about the outer circumference providing generally parallel axially extending first channels, and a second wall adjoining the first walls and arranged about the outer circumference providing discrete, arcuate second channels in fluid communication with the first channels and providing a tortuous serpentine fluid flow path about the circumference that is configured to alternate between opposite axial fluid flow directions within the first channels, the first and second channels having an inner surface;

a structure provided within at least one of the first and second channels and having an outer surface spaced radially outward from the inner surface to provide a flow passage and at least partially defining the tortuous fluid flow path between the outer and inner surfaces; and

wherein the first walls extend in a generally axial direction and are circumferentially spaced about the outer circumference, and the second wall is generally annular and arranged transverse from the first walls, the fluid configured to flow from one first channel through one second channel to another first channel that is adjacent the one first channel to provide the tortuous serpentine fluid flow path, wherein the tortuous fluid flow path provides at least two sections with a second channel provided generally centrally about the outer circumference.

5. The electric machine according to claim 4, wherein at least one of the first walls includes gaps at either end between the first wall and spaced apart second walls, another first wall including a gap generally centrally located along the stator.