Cooling system and method for electric motors with concentrated windings

• US 20070176499A1
• Filed: 01/27/2006
• Published: 08/02/2007
• Est. Priority Date: 01/27/2006
• Status: Active Grant

• Current Assignee: GM Global Technology Operations LLC (General Motors Company)
• Original Assignee: General Motors Corporation (Motors Liquidation Co. GUC Trust)
• Inventors: El-Antably, Ahmed, Holmes, Alan, Ordo, Richard
• Granted Patent: US 7,538,457 B2
• Time in Patent Office: Days
• US Class Current: 310/54
• CPC Class Codes: H02K 3/24 with channels or ducts for cooling medium between the conductors
• CPC Class Codes: H02K 9/19 for machines with closed casing and closed-circuit cooling using a liquid cooling medium, e.g. oil

Abstract

The present invention relates to a cooling system and method for the concentrated motor stator windings of an electric motor. The cooling system and method provides coolant directly onto the motor stator windings and between each adjacent stator winding. The motor housing assists in distributing coolant between each stator winding of the electric motor assembly. Moreover, an insulated sheet and/or tube is insertable between the concentrated motor stator windings. Each is configurable to direct coolant directly on to the stator windings.

Claims

1. An electric motor assembly, comprising:

circumferentially arranged adjacent concentrated motor stator windings spaced to define at least one channel for coolant passage;

a motor housing configured to cover said motor stator windings; and

an insert fittable between said motor stator windings configured to guide coolant flow within said channel directly onto said motor stator windings.

2. The motor assembly of claim 1, wherein said motor housing defines an inlet and outlet portion operative to cover an end turn of said concentrated motor stator windings;

wherein said inlet portion defines an inlet chamber operable to distribute coolant to the end turn of said concentrated motor stator windings; and

wherein said outlet portion defines an outlet chamber operable to distribute coolant away from the end turn of said concentrated motor stator windings.

3. The motor assembly of claim 2, wherein said inlet and outlet portion of said motor housing further defines an inlet orifice and outlet orifice operative to respectively facilitate the passage of coolant into said motor housing and the passage of coolant from said motor housing.

4. The motor assembly of claim 1, wherein said insert is a tube operable to guide the coolant between said motor stator windings.

5. The motor assembly of claim 4, wherein said tube defines a plurality of apertures for coolant flow from an outer perimeter of said tube directly onto said concentrated motor stator windings.

6. The motor assembly of claim 5, wherein said apertures of said tube are uniformly sized in a manner sufficient to provide an even flow rate of coolant flow from said tube within said channel.

7. The motor assembly of claim 1, wherein said motor housing includes an external sleeve configured to cover said motor stator windings;

wherein said external sleeve defines an aperture communicable with said motor stator windings.

8. The motor assembly of claim 1, wherein said insert is an insulated sheet insertable in said channel of said concentrated motor stator windings and operable to split coolant flow between adjacent motor stator windings.

9. The motor assembly of claim 8, further comprising:

at least one axially extending tube in said insulated sheet;

wherein said insulated sheet is hollowed.

10. The motor assembly of claim 9, wherein said at least one axially extending tube is filled with a deformable material configured to promote dispersion of coolant between said insulated sheet and said concentrated motor windings.

11. The motor assembly of claim 10, wherein said at least one axially extending tube is configured in a manner to deform an outer surface of said insulated sheet thereby increasing the turbulence of said coolant as it passes between said concentrated motor stator windings and said insulated sheet.

12. An electric motor assembly, comprising:

a motor housing configured for receiving coolant;

a rotor;

a plurality of axially extending concentrated motor stator windings circumferentially arranged in said motor housing around said rotor in air gap relationship to said rotor;

each pair of said stator windings being spaced apart to define a channel between said stator windings for distributing coolant received by said housing into heat transfer relationship with said stator windings; and

a coolant retainer configured to sufficiently enclose said channel at said air gap with said rotor so that said coolant is directed axially with respect to the electric motor assembly, along said stator windings for removing waste heat directly from said stator windings.

13. The motor assembly of claim 12, wherein said coolant retainer further defines an inlet orifice and outlet orifice operative to respectively facilitate the passage of coolant throughout said coolant retainer.

14. The motor assembly of claim 13, wherein said inlet and outlet orifices extend radially with respect to said coolant retainer, proximate an axial center;

and

wherein said coolant is introduced into said channel through said inlet orifice.

15. The motor assembly of claim 12, further comprising:

an insert fittable between said motor stator windings configured to guide coolant from within said channel directly onto said motor stator windings.

16. The motor assembly of claim 15, wherein said insert is a tube operable to guide the coolant between said stator windings.

17. The motor assembly of claim 16, wherein said tube defines a plurality of apertures for coolant flow from an outer perimeter of said tube onto the concentrated motor stator windings;

wherein said apertures of said insulated tube are uniformly sized in a manner to provide an even flow rate of coolant flow from said insulated tube to said channel.

18. The motor assembly of claim 15, wherein said insert is an insulated sheet, insertable in said channel of said concentrated motor stator windings, operable to separate coolant flow between each adjacent motor stator windings.

19. The motor assembly of claim 18, further comprising:

at least one axially extending tube in said insulated sheet;

wherein said insulted sheet is hollowed; and

wherein said at least one axially extending tube is filled with a deformable material configured to promote dispersion of coolant between said insulated sheet and said concentrated motor windings as the coolant passes through said concentrated motor stator windings.

20. The motor assembly of claim 19, further comprising:

at least one axially extending tube insertable in said insulated sheet;

wherein said insulted sheet is hollowed to accommodate said at least one axially extending tube; and

wherein said at least one axially extending tube is configured in a manner to deform an outer surface of said insulated sheet thereby increasing the turbulence of said coolant as it passes between said concentrated motor stator windings and said insulated sheet.

21. The motor assembly of claim 12, wherein said motor housing includes an external sleeve configured to cover said motor stator windings;

wherein said external sleeve defines an aperture communicable with said motor stator windings.

22. A method of cooling a hybrid electric vehicle motor comprising:

concentrating the stator wiring of said electric motor into a plurality of circumferentially arranged wiring coils defining concentrated motor stator windings;

spacing one of said concentrated motor stator windings from an adjacent other of said concentrated motor stator windings to form a channel; and

flowing coolant through said channel at sufficient speed and resistance to transfer heat from said concentrated motor stator windings to said coolant.

23. The method of claim 22, further comprising:

substantially preventing said coolant from flowing into a gap defined by a rotor and said stator wiring by means of a barrier to retain said coolant in said channel.