ELECTRIC MOTOR/GENERATOR LOW HYDRAULIC RESISTANCE COOLING MECHANISM

• US 20100102647A1
• Filed: 10/28/2008
• Published: 04/29/2010
• Est. Priority Date: 10/28/2008
• Status: Active Grant

• Current Assignee: Caterpillar Incorporated
• Original Assignee: Caterpillar Incorporated
• Inventors: Savant, Satish D.
• Granted Patent: US 8,067,865 B2
• Time in Patent Office: Days
• 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 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; and

integrated spiral groove cooling passages provided in said outer coaxial surface, said cooling passages having substantially rectangular cross sections with 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.

2. The electric motor/generator low hydraulic resistance cooling mechanism of claim 1, wherein an outer housing having inlet and outlet ports is configured to fit onto said hollow cooling stator case.

3. The electric motor/generator low hydraulic resistance cooling mechanism of claim 2, 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.

4. The electric motor/generator low hydraulic resistance cooling mechanism of claim 2, wherein said inlet port is configured to receive a cooling fluid and flows in a radial direction toward said outlet port.

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

6. 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.

7. 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.

8. The electric motor/generator low hydraulic resistance cooling mechanism of claim 1, wherein the cross-section of said cooling passages are substantially elliptical.

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.

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

12. The electric motor/generator low hydraulic resistance cooling mechanism of claim 6, wherein said first and second ends of said helical core are located in close proximity radially.

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

15. The electric motor/generator low hydraulic resistance cooling mechanism of claim 1, 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.

16. The electric motor/generator low hydraulic resistance cooling mechanism of claim 15, further including a vent positioning with the spiral groove cooling passages.

17. The electric motor/generator low hydraulic resistance cooling mechanism of claim 16, wherein the vent is located 180 degrees apart from the outlet port.

18. 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.

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

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

a hollow cooling stator case having an inner coaxial surface and an out 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 spiral groove cooling passages having a pitch, the pitch being variable.

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

a hollow cooling stator case having an inner coaxial surface and an out 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 spiral groove cooling passages being provided by a helical core cast into the stator case, the helical core including first and second ends located in close proximity radially, the helical core further including at least two continuously interconnecting outer tabs.

19. The electric motor/generator low hydraulic resistance cooling mechanism of claim 13, wherein the cooling passage has a variable pitch along an axial length of the cooling passage.