Motor cooling system for e-boosting device

1. A motor assembly for an e-boosting device comprising:

a motor case;

a motor cavity within the motor case configured to receive an electric motor that is configured to drivingly rotate a rotor about an axis of rotation;

a through-hole independently defined by the motor case to pass through the motor case; and

the motor case configured to be received in an outer housing to cooperatively define a coolant jacket with the outer housing, the coolant jacket including a fluid flow path defined partly by the through-hole, the motor case defining a shell portion that covers over the electric motor and a projecting portion that projects from the shell portion in an outboard direction, the through-hole being defined at least partly by the projecting portion, and the shell portion and the projecting portion being made of different materials.

2. The motor assembly of claim 1 , wherein the shell portion is made of a metallic material and the projecting portion is made of a polymeric material.

3. The motor assembly of claim 1 , wherein the projecting portion is configured to cooperatively define a fluid boundary with the outer housing for a coolant in the coolant jacket.

4. The motor assembly of claim 3 , further comprising a sealing member that seals to the projecting portion and the outer housing to define a sealed fluid boundary.

5. The motor assembly of claim 4 , wherein the projecting portion includes a groove that receives the sealing member.

6. The motor assembly of claim 1 , herein the projecting portion includes an attached area that is attached to an outer surface of the shell portion;

wherein the projecting portion includes a detached area that extends from the attached area and that is spaced apart in the outboard direction from the outer surface to at least partly define the through-hole.

7. The motor assembly of claim 6 , wherein the detached area extends in a circumferential direction about the axis.

8. The motor assembly of claim 6 , wherein the attached area projects in the radial direction relative to the axis in the outboard direction.

9. The motor assembly of claim 1 , wherein the through-hole extends longitudinally through the motor case with respect to the axis.

10. The motor assembly of claim 1 , wherein the motor case includes a first casing member and a second casing member that are attached to cooperatively define the motor cavity;

wherein the first casing member includes a first shell portion and a first projecting portion made of different materials;

wherein the second casing member includes a second shell portion and a second projecting portion made of different materials; and

wherein the through-hole is defined between the second shell portion and the second projecting portion.

11. The motor assembly of claim 10 , wherein the first shell portion is made of metal and the first projecting portion is made of a polymer;

wherein the second shell portion is made of metal and the second projecting portion is made of a polymer.

12. The motor assembly of claim 10 , wherein the first casing member and the second casing member are attached to cooperatively encase the electric motor; and

wherein the first projecting portion and the second projecting portion partition the coolant jacket.

13. The motor assembly of claim 1 , wherein the motor case includes an end face that extends radially relative to the axis and a side that extends about the axis;

wherein the coolant jacket includes an end chamber partly defined by the end face and a side chamber partly defined by the side of the motor case; and

wherein the through-hole fluidly connects the end chamber and the side chamber.

14. A method of manufacturing an e-boosting device comprising:

providing an electric motor that is configured to drivingly rotate a rotor;

forming a motor case to include a shell portion and a projecting portion that projects from the shell portion in an outboard direction, including forming the shell portion from a first material and forming the projecting portion from a second material that is different from the first material, and including forming a through-hole that is independently defined by the motor case to pass through the motor case, the through-hole being defined at least partly by the projecting portion;

encasing the electric motor within a motor cavity of the motor case;

disposing the motor cavity within an outer housing to define a coolant jacket of a cooling system, the coolant jacket cooperatively defined by the outer housing and the motor case, the coolant jacket including a fluid passage defined by the through-hole.

15. The method of manufacturing of claim 14 , wherein forming the shell portion from a metallic material and forming the projecting portion from a polymeric material.

16. The method of manufacturing of claim 14 , further comprising providing a sealing member that seals to the projecting portion and the outer housing to define a fluid boundary for the coolant.

17. The method of claim 16 , further comprising forming the projecting portion to include a groove; and

further comprising placing the sealing member in the groove.

18. The method of manufacturing of claim 14 ,

wherein the motor case includes an end face that extends radially relative to the axis and a side that extends about the axis;

wherein the coolant jacket includes an end chamber partly defined by the end face and a side chamber partly defined by the side of the motor case; and

wherein the through-hole fluidly connects the end chamber and the side chamber.