Electric machine including a stator having a stator sleeve and method of cooling a stator

1. An electric machine comprising:

a housing;

a stator mounted relative to the housing, the stator including a body having a first end portion that extends to a second end portion and a plurality of stator windings that extend between the first and second end portions; and

a sleeve member mounted to the stator and covering a portion of the stator windings at one of the first and second end portions, the sleeve member including a body member having an outer diametric wall and an inner diametric wall that collectively define an annular coolant channel, an inlet opening formed in the outer diametric wall for receiving coolant and a discharge opening formed in the outer diametric wall for passing coolant from the sleeve member, the sleeve member being configured and disposed to guide a coolant over the portion of the stator windings to remove heat from the stator.

2. The electric machine according to claim 1 , wherein the plurality of stator windings include end turn portions, the sleeve member covering the end turn portions of the plurality of stator windings at the one of the first and second end portions.

3. The electric machine according to claim 1 , wherein the inlet opening includes a metered orifice that guides a pressurized flow of coolant onto the portion of the stator windings.

4. The electric machine according to claim 1 , wherein the discharge opening includes a metered orifice for passing a pressurized flow from the sleeve member.

5. The electric machine according to claim 1 , wherein the inner diametric wall includes an opening.

6. The electric machine according to claim 1 , wherein the sleeve member is formed from a dielectric material.

7. The electric machine according to claim 6 , wherein the dielectric material is plastic.

8. The electric machine according to claim 6 , wherein the dielectric material is nylon.

9. The electric machine according to claim 6 , wherein the dielectric material is polyphenylene sulfide (PPS) plastic.

10. The electric machine according to claim 1 , wherein the sleeve member is operatively connected to the housing.

11. A method of cooling an electric machine stator, the method comprising:

guiding a coolant through an inlet formed in an outer diametric wall of a stator sleeve;

passing the coolant onto a portion of a plurality of stator windings of the electric machine stator;

flowing the coolant through an annular coolant channel defined by the outer diametric wall and an inner diametric wall of the stator sleeve circumferentially about the plurality of stator windings; and

discharging the coolant through a discharge opening formed in the outer diametric wall of the stator sleeve.

12. The method of claim 11 , wherein passing the coolant onto a portion of a plurality of stator windings includes passing the coolant onto end turn portions of the plurality of stator windings.

13. The method of claim 11 , wherein, guiding the coolant through an inlet of a stator sleeve includes passing a pressurized flow of coolant into the stator sleeve.

14. The method of claim 11 , further comprising: passing the coolant into a housing portion of the electric machine.

15. The method of claim 14 , wherein discharging the cooling through the discharge opening in the stator sleeve includes passing a pressurized flow of coolant from the stator sleeve.

16. The method of claim 15 , further comprising: flowing the coolant from an opening formed in the inner diametric wall of the stator sleeve onto a rotor of the electric machine.