Stator cooling for electric machines

Patent metadata

Field	Value
Publication number	US-12166381-B2
Application number	US-202117494900-A
Country	US
Kind code	B2
Filing date	Oct 6, 2021
Priority date	Dec 30, 2020
Publication date	Dec 10, 2024
Grant date	Dec 10, 2024

Abstract

A stator can comprise a stator body comprising an inner cooling duct, and an outer cooling duct, wherein the inner cooling duct is located closer to a center axis of the stator body than the outer cooling duct, a first endplate received at a first end of the stator body, the first endplate comprising an inlet jacket circumferentially located within the first endplate, an inlet finger fluidly connected to the inlet jacket, and a drainage jacket circumferentially located within the first endplate, a second endplate received at a second end of the stator body, the second endplate comprising an outlet jacket circumstantially located within the second endplate, and an outlet finger fluidly connected to the outlet jacket, wherein the inner cooling duct fluidly connects the inlet jacket to the outlet finger, and wherein the outer cooling duct fluidly connects to the outlet jacket to the drainage jacket.

First claim

What is claimed is:

1. A stator, comprising:
a stator body, comprising:
an inner cooling duct parallel to a center axis of the stator body, and
an outer cooling duct parallel to the center axis of the stator body, wherein the inner cooling duct is located closer to the center axis of the stator body than the outer cooling duct;

a first endplate received at a first end of the stator body, the first endplate comprising:
an inlet jacket having a first circumferential path located within the first endplate,
an array of inlet fingers fluidly connected to the inlet jacket, wherein the first circumferential path is normal to the center axis of the stator body and is fluidly connected to the array of inlet fingers, and
a drainage jacket having a second circumferential path located within the first endplate, wherein the second circumferential path is normal to the center axis of the stator body;

a second endplate received at a second end of the stator body, the second endplate comprising:
an outlet jacket having a third circumferential path located within the second endplate, and
an array of outlet fingers fluidly connected to the outlet jacket, wherein the third circumferential path is normal to the center axis of the stator body and is fluidly connected to the array of outlet fingers;

wherein the inner cooling duct fluidly connects the inlet jacket to the outlet fingers, and wherein the outer cooling duct fluidly connects the outlet jacket to the drainage jacket.

2. The stator of claim 1 , further comprising:
an oil inlet received in the stator body and fluidly connected to the inlet jacket; and
an oil drain received in the stator body and fluidly connected to the drainage jacket.

3. The stator of claim 2 , wherein the oil inlet and the oil drain are fluidly connected to a transmission oiling system.

4. The stator of claim 1 , wherein the first endplate and the second endplate comprise stamped endplates.

5. The stator of claim 1 , wherein copper windings of the stator are received between each inlet finger of the array of inlet fingers.

6. The stator of claim 1 , wherein the inner cooling duct is one of an array of inner cooling ducts, and wherein the array of inner cooling ducts is circumferentially located around the stator.

7. The stator of claim 1 , wherein the outer cooling duct is one of an array of outer cooling ducts, and wherein the array of outer cooling ducts is circumferentially located around the stator.

8. The stator of claim 1 , wherein the first endplate is removably attached to the stator body of the stator.

9. The stator of claim 1 , wherein the second endplate is removably attached to the stator body of the stator.

10. The stator of claim 1 , wherein the inlet jacket and inlet fingers are located on a non-driving-end of the stator, and wherein the outlet jacket is located on a driving end of the stator.

11. A stator assembly, comprising:
a stator body, wherein the stator body comprises:
an array of inner cooling ducts parallel to a center axis of the stator body, circumferentially located around the stator body, and fluidly connecting a first end of the stator body to a second end of the stator body, and
an array of outer cooling ducts parallel to the center axis of the stator body, circumferentially located around the stator body, and fluidly connecting the second end of the stator body to the first end of the stator body, wherein the array of outer cooling ducts is located closer to an outer surface of the stator body than the array of inner cooling ducts;

a first stator endplate located at the first end of the stator body, wherein the first stator endplate comprises:
an inlet jacket having a first circumferential path located at the first end of the stator body, and
an array of inlet fingers fluidly connected to the inlet jacket and fluidly connected to the array of inner cooling ducts, wherein the first circumferential path is normal to the center axis of the stator body and is fluidly connected to the array of inlet fingers; and

a second stator endplate located at the second end of the stator body, wherein the second stator endplate comprises:
an outlet jacket having a second circumferential path located at the second end of the stator body, wherein the second circumferential path is normal to the center axis of the stator body, and
an array of outlet fingers fluidly connected to a drainage jacket having a third circumferential path located within the first stator endplate, and fluidly connected to the array of outer cooling ducts, wherein the third circumferential path is normal to the center axis of the stator body and is fluidly connected to the array of outlet fingers.

12. The stator assembly of claim 11 , further comprising:
an oil inlet received in a top side of the stator body and fluidly connected to the inlet jacket; and
an oil outlet received in a bottom side of the stator body, wherein the bottom side is opposite the top side, and wherein the oil outlet is fluidly connected to the drainage jacket.

13. The stator assembly of claim 12 , wherein the oil inlet is fluidly connected to an outlet of a transmission oil system, and wherein the oil outlet is fluidly connected to an oil inlet of the transmission oil system.

14. The stator assembly of claim 11 , wherein the array of outer cooling ducts comprises rectangular ducts.

15. The stator assembly of claim 11 , wherein the array of inner cooling ducts comprises cylindrical ducts.

16. The stator assembly of claim 11 , wherein the stator body further comprises:
an array of copper windings received between fingers of the array of inlet fingers and fingers of the array of outlet fingers.

17. The stator assembly of claim 11 , wherein the first stator endplate and the second stator endplate are each formed by a stamping process.

18. A method for cooling a stator, comprising:
directing coolant from a coolant reservoir to a coolant inlet at a first end of the stator;
directing at least some of the coolant from the coolant inlet to an inlet jacket having a first circumferential path located at the first end of the stator;
directing at least some of the coolant from the inlet jacket to an array of inlet fingers, wherein the first circumferential path is normal to a center axis of the stator and is fluidly connected to the array of inlet fingers;
directing at least some of the coolant from the inlet fingers to an inner cooling duct spanning from the first end of the stator to a second end of the stator, wherein the inner cooling duct is parallel to the center axis of the stator;
directing at least some of the coolant from the inner cooling duct to an array of outlet fingers;
directing at least some of the coolant from the outlet fingers to an outlet jacket having a second circumferential path located at the second end of the stator, wherein the second circumferential path is normal to the center axis of the stator;
directing at least some of the coolant from the outlet jacket to an outer cooling duct spanning from the second end of the stator to the first end of the stator, wherein the outer cooling duct is parallel to the center axis of the stator;
directing at least some of the coolant from the outer cooling duct to a drainage jacket having a third circumferential path located at the first end of the stator, wherein the third circumferential path is normal to the center axis of the stator and is fluidly connected to the array of outlet fingers; and
directing at least some of the coolant from the drainage jacket to an oil drain at the first end of

Assignees

• Volvo Car Corp

Inventors

• Andersson Johan
• Brunberg Johan

Classifications

• H02K5/203

  specially adapted for liquids, e.g. cooling jackets · CPC title

• H02K9/19

  for machines with closed casing and closed-circuit cooling using a liquid cooling medium, e.g. oil · CPC title

• H02K1/20 Primary

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