Electric motor/generator low hydraulic resistance cooling mechanism

• US 8,067,865 B2
• Filed: 10/28/2008
• Issued: 11/29/2011
• Est. Priority Date: 10/28/2008
• Status: Active Grant

• Current Assignee: Caterpillar Incorporated
• Original Assignee: Caterpillar Incorporated
• Inventors: Savant, Satish D.
• Primary Examiner(s): Leung; Quyen
• Assistant Examiner(s): Quinones; Jose Gonzalez
• Application Number:
  US12/259,328
• Publication Number:
  US 20100102647A1
• Time in Patent Office: 1,127 Days
• Field of Search: 310/54, 310/51, 310/52, 310/53, 310/58, 310/57, 415/116, 417/80
• US Class Current: 310/52
• CPC Class Codes: H02K 5/203 specially adapted for liquids, e.g. cooling jackets
• CPC Class Codes: H02K 5/207 with openings in the casing specially adapted for ambient air

Abstract

The present disclosure, in one form, provides an electric motor/generator low hydraulic resistance cooling mechanism including a hollow cooling stator case having an inner and outer coaxial surface. The inner surface defines a generally cylindric cavity for receiving a stator in heat transference contact with the inner surface. The outer surface has integrated spiral groove cooling passages that are defined by filleted rectangular cross sections.

Claims

1. An electric motor/generator low hydraulic resistance cooling mechanism, comprising:

a cooling stator case having an inner coaxial surface and an outer coaxial surface, said inner coaxial surface defining a generally cylindrical cavity for receiving a stator in heat transference contact with said inner coaxial surface;

an outer housing having first and second inlet ports and an outlet port configured to fit onto said hollow cooling stator case; and

spiral groove cooling passages provided in said outer coaxial surface, the spiral groove cooling passages disposed between the first inlet port and the outlet port defining a cooling fluid flow path moving in a first radial direction, the spiral groove cooling passages disposed between the second inlet port and the outlet port defining a cooling fluid flow path moving in a second radial direction, the first radial direction being opposite to the second radial direction.

2. The electric motor/generator low hydraulic resistance cooling mechanism of claim 1, wherein a flanged end surface is located on an end of said outer housing for boltingly connecting said cooling stator case to said outer housing.

3. The electric motor/generator low hydraulic resistance cooling mechanism of claim 1, wherein said inlet port is configured to receive a cooling fluid and flows in a radial direction toward said outlet port.

4. The electric motor/generator low hydraulic resistance cooling mechanism of claim 1, wherein said cooling stator case is cast.

5. The electric motor/generator low hydraulic resistance cooling mechanism of claim 1, wherein said cooling passages are produced by a helical core cast into the stator case.

6. The electric motor/generator low hydraulic resistance cooling mechanism of claim 5, wherein said helical core includes a first end and a second end.

7. The electric motor/generator low hydraulic resistance cooling mechanism of claim 5, wherein said first and second ends of said helical core are located in close proximity radially.

8. The electric motor/generator low hydraulic resistance cooling mechanism of claim 1, wherein said cooling passages have at least the number of helical turns to wrap through the entire axial length.

9. The electric motor/generator low hydraulic resistance cooling mechanism of claim 1, wherein said cooling passage cross section has an axial length and includes a helix pitch.

10. The electric motor/generator low hydraulic resistance cooling mechanism of claim 9, wherein the helix pitch is variable along the axial length of the cooling passage.

11. The electric motor/generator low hydraulic resistance cooling mechanism of claim 1, wherein said cooling surface is machined into a smooth uniform diameter.

12. The electric motor/generator low hydraulic resistance cooling mechanism of claim 1, wherein the spiral cooling passage is machined into the stator case.

13. The electric motor/generator low hydraulic resistance cooling mechanism of claim 1, wherein said cooling passages have a bottom surface generally perpendicular to first and second generally parallel side surfaces, the bottom surface transitioning into the first and second parallel side surfaces at corners, the corners each having a filleted radius.

14. The electric motor/generator low hydraulic resistance cooling mechanism of claim 1, wherein said cooling passages have substantially elliptical cross-sections.

15. An electric motor/generator low hydraulic resistance cooling mechanism, comprising:

a hollow cooling stator case having an inner coaxial surface and an outer coaxial surface, the inner coaxial surface defining a generally cylindrical cavity for receiving a stator in heat transferring contact with said inner coaxial surface; and

spiral groove cooling passages integrated into the outer coaxial surface and having filleted radius cross sections, the cross-section of said cooling passages being substantially elliptical, the spiral groove cooling passages including first and second inlet ports and a single outlet port positioned between the first and second inlet ports, the spiral groove cooling passages between the first inlet port and the outlet port defining a cooling fluid flow path moving in a first radial direction, the spiral groove cooling passages between the second inlet port and the outlet port defining a cooling fluid flow path moving in a second radial direction, the first radial direction being opposite to the second radial direction.

16. An electric motor/generator low hydraulic resistance cooling mechanism, comprising:

a hollow cooling stator case having an inner coaxial surface and an outer coaxial surface, said inner coaxial surface defining a generally cylindrical cavity for receiving a stator in heat transference contact with said inner coaxial surface;

an outer housing having inlet and outlet ports configured to fit onto said hollow cooling stator case; and

integrated spiral groove cooling passages provided in said outer coaxial surface, said cooling passages having a bottom surface perpendicular to first and second parallel side surfaces, the bottom surface transitioning into the first and second parallel side surfaces at a corners, the corners each having a filleted radius, wherein the spiral groove cooling passages include first and second inlet ports and a single outlet port positioned between the first and second inlet ports, the spiral groove cooling passages between the first inlet port and the outlet port defining a cooling fluid flow path moving in a first radial direction, the spiral groove cooling passages between the second inlet port and the outlet port defining a cooling fluid flow path moving in a second radial direction, the first radial direction being opposite to the second radial direction.

17. The electric motor/generator low hydraulic resistance cooling mechanism of claim 16, further including a vent positioning with the spiral groove cooling passages.

18. The electric motor/generator low hydraulic resistance cooling mechanism of claim 17, wherein the vent is located 180 degrees apart from the outlet port.