COOLING ARRANGEMENT FOR AN ELECTRIC MACHINE

• US 20110234029A1
• Filed: 03/23/2010
• Published: 09/29/2011
• 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
• Granted Patent: US 8,525,375 B2
• Time in Patent Office: Days
• US Class Current: 310/54
• 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 first channels, and a second wall adjoining the first walls and arranged about the outer circumference providing a second channel in fluid communication with the first channels and providing a tortuous fluid flow path about the circumference, 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 and at least partially defining the tortuous fluid flow path between the outer and inner surfaces.

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.

4. The electric machine according to claim 3, 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.

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, comprising at least one orifice plate spaced from the second wall and including multiple exits, the stator including an end turn extending from a main stack of the stator, the exits provided near the end turns and configured to spray the cooling fluid onto the end turns.

9. The electric machine according to claim 8, comprising an end cap extending from the main stack exit and radially outward and providing an enclosure about the end turn in fluid communication with the exit, the end cap including an outlet in fluid communication with the inlet and configured to drain the cooling fluid from the enclosure.

10. The electric machine according to claim 1, wherein the structure is provided by a fin core including rows of corrugations, the corrugations providing the outer surface.

11. The electric machine according to claim 10, wherein the rows are offset from one another.

12. The electric machine according to claim 10, wherein the fin core is brazed to a sleeve mounted on the stator.

13. An electric machine comprising:

a housing;

a stator arranged in the housing and including a main stack with an end turn extending generally axially from the main stack;

cooling channels provided in at least one of the housing and stator having an exit provided near the end turn configured to provide cooling fluid to the end turn; and

an end cap extending from the main stack axially and radially outward and providing an enclosure about the end turn in fluid communication with the exit, the end cap including an outlet in fluid communication with the inlet configured to drain the cooling fluid from the enclosure.

14. The electric machine according to claim 13, wherein the main stack includes opposing end turns with a cap arranged about each end turn.

15. The electric machine according to claim 13, comprising a sleeve mounted on the stator, and an orifice plate supported on the stator, the orifice plate providing the exit.

16. The electric machine according to claim 13, comprising spaced apart first walls arranged about the outer circumference providing generally parallel first channels, and a second wall adjoining the first walls and arranged about the outer circumference providing a second channel in fluid communication with the first channels and providing a tortuous path about the circumference.

17. The electric machine according to claim 16, comprising an inlet in the housing upstream of the tortuous path.

18. The electric machine according to claim 13, comprising a rotor disposed with the stator, an end cap arranged radially outwardly of the rotor.

19. The electric machine according to claim 18, wherein the end cap is sealed between the stator and the housing.