Electric drive unit cooling systems with annular oil distribution assembly and methods

Patent metadata

Field	Value
Publication number	US-12398797-B2
Application number	US-202117477402-A
Country	US
Kind code	B2
Filing date	Sep 16, 2021
Priority date	Jun 30, 2017
Publication date	Aug 26, 2025
Grant date	Aug 26, 2025

Abstract

Systems and methods for cooling power transmission systems are include providing oil through an aperture defined in a housing to a stator cooling ring, through the stator cooling ring and into stator cooling channels, through the stator cooling channels and into spaces defined between the housing and jet rings, and through holes in the jet rings and onto the end-windings. The stator cooling ring, stator cooling channels and jet rings can encircle the stator and end-windings and, via the holes in the jet rings, spray pressurized jets of oil from various angles onto the end-windings, and in particular middle regions thereof. Seals may be used between the jet rings and housing, and between the jet rings and stator ends. The seals may be compressed so as to form an interference fit between the jet rings and housing or stator ends as the case may be.

First claim

What is claimed is:

1. An electric drive unit of a drive motor for a vehicle comprising:
a housing of the drive motor;
a stator within the housing, wherein the stator defines an outer side surface and includes stator end-windings;
at least one annular stator cooling ring encircling the outer side surface of the stator;
a first plurality of stator cooling channels and extending radially from the at least one annular stator cooling ring and receiving cooling oil from the at least one annular stator cooling ring;
a second plurality of stator cooling channels extending radially from the at least one annular stator cooling ring and receiving cooling oil from the at least one annular stator cooling ring,
wherein an oil distribution assembly including the at least one annular stator cooling ring, the first plurality of stator cooling channels and the second plurality of stator cooling channels is formed as a unit and positioned around the outer side surface of the stator between the stator and the housing, and wherein the oil distribution assembly is separate from the housing and the stator; and
a plastic annular jet ring interposed between the housing and the stator to direct pressurized cooling oil from the first plurality of stator cooling channels or the second plurality of stator cooling channels through a direct path through a plurality of holes to spray pressurized jets of oil from multiple angles onto the stator end-windings.

2. The electric drive unit of claim 1 , wherein the annular jet ring is adjacent to and at least partially encircling the stator end-windings, wherein the jet ring is stationed at a non-parallel angle to the stator cooling channels.

3. The electric drive unit of claim 1 , wherein the annular jet ring produces pressurized jets of cooling oil through the plurality of holes onto the stator end- windings.

4. The electric drive unit of claim 1 , wherein the first plurality of stator cooling channels extends radially from the at least one annular stator cooling ring to the annular jet ring.

5. The electric drive unit of claim 1 , further comprising a seal between the housing and the annular jet ring.

6. The electric drive unit of claim 1 , wherein the at least one annular stator cooling ring is independent of the housing and the stator.

7. An electric drive unit of a drive motor for a vehicle comprising:
a housing of the drive motor;
a stator within the housing, wherein the stator defines an outer side surface and includes first stator end-windings and second stator end-windings;
at least one annular stator cooling ring encircling the outer side surface of the stator;
a first plurality of stator cooling channels extending radially from the at least one annular stator cooling ring to a first plastic annular jet ring, wherein the first plurality of stator cooling channels are configured to receive cooling oil from the at least one annular stator cooling ring and provide the cooling oil to the first plastic annular jet ring; and
a second plurality of stator cooling channels extending radially from the at least one annular stator cooling ring to a second plastic annular jet ring, wherein the second plurality of stator cooling channels are configured to receive the cooling oil from the at least one annular stator cooling ring and provide the cooling oil to the second plastic annular jet ring,
wherein an oil distribution assembly including the at least one annular stator cooling ring, the first plurality of stator cooling channels and the second plurality of stator cooling channels is formed as a unit and positioned around the outer side surface of the stator between the stator and the housing, and wherein the oil distribution assembly is separate from the housing and the stator,
wherein the first plastic annular jet ring is interposed between the housing and the stator to direct pressurized cooling oil through a direct path through a first plurality of holes to spray pressurized jets of oil from multiple angles onto the first stator end-windings,
wherein the second plastic annular jet ring is interposed between the housing and the stator to direct pressurized cooling oil through a direct path through a second plurality of holes to spray pressurized jets of oil from multiple angles onto the second stator end-windings.

8. The electric drive unit of claim 7 , wherein the first plastic annular jet ring is adjacent to, and at least partially encircling the first stator end-windings.

9. The electric drive unit of claim 7 , wherein the first plastic annular jet ring produces pressurized jets of cooling oil through the first plurality of holes onto the first stator end-windings.

10. The electric drive unit of claim 7 , wherein the second plastic annular jet ring is adjacent to, and at least partially encircling the second stator end-windings and-produces pressurized jets of cooling oil through the second plurality of holes onto the second stator end-windings.

11. The electric drive unit of claim 7 , wherein the housing comprises an aperture and wherein the at least one annular stator cooling ring receives cooling oil through the aperture.

12. The electric drive unit of claim 7 , wherein the at least one annular stator cooling ring is independent of the housing and the stator.

13. A method of use in an electric drive unit of a drive motor for a vehicle, comprising:
providing oil through an aperture defined in a housing of the electric drive unit for the drive motor, wherein the oil flows into an annular stator cooling ring of a unitary oil distribution assembly;
providing oil through the annular stator cooling ring and into a first plurality of stator cooling channels and into a second plurality of stator cooling channels;
allowing the oil to flow within the stator cooling ring and through the first plurality of stator cooling channels and into a first space defined between the housing and a first plastic annular jet ring having a first plurality of holes;
allowing the oil to flow within the stator cooling ring and through the second plurality of stator cooling channels and into a second space defined between the housing and a second plastic annular jet ring having a second plurality of holes;
providing oil through the first plurality of holes to spray pressurized jets of oil from multiple angles onto first stator end-windings of a stator within the housing; and
providing oil through the second plurality of holes to spray pressurized jets of oil from multiple angles onto second stator end-windings of the stator,
wherein an oil path from the aperture to the stator end windings through the plurality of holes in the first plastic annular jet ring and the second plastic annular jet ring is direct.

14. The method of claim 13 , further comprising providing oil to a first middle region of the first stator end-windings.

15. The method of claim 14 further comprising providing oil through the second plurality of holes onto the second stator end-windings includes providing oil to a second middle region of the second stator end-windings.

16. The method of claim 13 , wherein providing oil through the first plurality of holes of the first plastic annular jet ring onto the first stator end-windings includes producing a first plurality of pressurized jets of the oil directly and orthogonally onto the first stator end-windings.

17. The method of claim 16 , wherein providing oil through the second plurality of holes of the second plastic annular jet ring onto the second stator end-windings includes producing a second plurality of pressurized jets of the oil directly and ort

Assignees

• Tesla Inc

Inventors

• Graves Scott Michael
• Bellemare Eric
• Hain Alexander

Classifications

• H02K9/193

  with provision for replenishing the cooling medium; with means for preventing leakage of the cooling medium · CPC title

• H02K1/20

  with channels or ducts for flow of cooling medium · CPC title

• B60Y2306/05

  Cooling · CPC title

• H02K15/165

  Balancing the rotors · CPC title

• H02K7/083

  radially supporting the rotary shaft at both ends of the rotor (H02K7/086, H02K7/09 take precedence) · CPC title