Drive unit having a rotor shaft

Patent metadata

Field	Value
Publication number	US-12549069-B2
Application number	US-202318310203-A
Country	US
Kind code	B2
Filing date	May 1, 2023
Priority date	May 1, 2023
Publication date	Feb 10, 2026
Grant date	Feb 10, 2026

Abstract

A drive unit includes a motor and a rotor shaft operably coupled with the motor. The rotor shaft has an inner surface that defines a hollow that extends axially from a first opening at a first end of the rotor shaft to a second opening at a second end of the rotor shaft and has a tapered portion that tapers radially inboard as the tapered portion of the inner surface extends axially away from the second end of the rotor shaft. The rotor shaft further defines a plurality of ports disposed axially between the tapered portion and the second end of the rotor shaft. The motor is configured to drive rotation of the rotor shaft, such that a fluid disposed within the hollow is propelled axially away from the first end of the rotor shaft and through the plurality of ports defined by the rotor shaft.

First claim

What is claimed is:

1 . A drive unit, comprising:
a motor; and a rotor shaft operably coupled with the motor, the rotor shaft having an inner surface that defines a hollow that extends axially from a first opening at a first end of the rotor shaft to a second opening at a second end of the rotor shaft and has a tapered portion that tapers radially inboard as the tapered portion of the inner surface extends axially away from the second end of the rotor shaft, the rotor shaft further defining a plurality of ports disposed axially between the tapered portion and the second end of the rotor shaft, wherein the motor is configured to drive rotation of the rotor shaft, such that a fluid disposed within the hollow is propelled axially away from the first end of the rotor shaft and through the plurality of ports defined by the rotor shaft, and wherein the rotor shaft comprises:
a first shaft component having a first end and a second end opposite the first end of the first shaft component and defining a first hollow, wherein the first end of the first shaft component is the first end of the rotor shaft and the first hollow defined by the first shaft component is a portion of the hollow defined by the rotor shaft; and
a second shaft component coupled to the first shaft component and having a first end and a second end opposite the first end of the second shaft component and defining a second hollow, wherein the second end of the second shaft component is the second end of the rotor shaft and the second hollow defined by the second shaft component is a portion of the hollow defined by the rotor shaft, and wherein the motor drives rotation of the first shaft component and the second shaft component.

2 . The drive unit of claim 1 , wherein the tapered portion of the inner surface of the rotor shaft is a portion of an inner surface of the first shaft component.

3 . The drive unit of claim 2 , wherein the tapered portion extends along a majority of the axial length of the first shaft component.

4 . The drive unit of claim 3 , wherein the tapered portion extends axially away from the first end of the first shaft component to a shelf of the inner surface of the first shaft component that extends radially outboard from the tapered portion.

5 . The drive unit of claim 4 , wherein the first end of the second shaft component abuts the shelf.

6 . The drive unit of claim 4 , wherein the second shaft component defines a plurality of inlets of the plurality of ports in the form of apertures defined wholly by the second shaft component.

7 . The drive unit of claim 2 , wherein the first shaft component further comprises:
a lip positioned between the first end of the first shaft component and the tapered portion of the inner surface of the first shaft component, wherein the lip extends radially inboard farther than the radially inboard-most portion of the tapered portion of the inner surface of the first shaft component.

8 . The drive unit of claim 2 , wherein the second shaft component includes an outer surface that is opposite an inner surface of the second shaft component, and a portion of the outer surface of the second shaft component is radially inboard of and axially aligned with a portion of the inner surface of the first shaft component, and the plurality of ports are defined at least partially by the outer surface of the second shaft component and extend from a corresponding plurality of inlets positioned within the first hollow to a corresponding plurality of outlets outside of the first hollow, such that the first hollow and an exterior environment of the rotor shaft are in fluid communication via the plurality of ports.

9 . The drive unit of claim 8 , wherein the second end of the first shaft component that defines the second opening of the first shaft component is welded to a portion of the outer surface of the second shaft component that extends between at least two adjacent ports of the plurality of ports to fix the second shaft component to the first shaft component.

10 . A method of circulating fluid within a fluid circuit of a drive unit, comprising the steps of:
actuating a motor of the drive unit to drive rotation of a rotor shaft that includes an inner surface that defines a hollow that extends axially from a first opening at a first end of the rotor shaft to a second opening at a second end of the rotor shaft and has a tapered portion that tapers radially inboard as the tapered portion of the inner surface extends axially away from the second end of the rotor shaft, wherein the tapered portion extends along a majority of the axial extent of the rotor shaft, the rotor shaft further defining a plurality of ports disposed axially between the tapered portion and the second end of the rotor shaft; and propelling fluid along the tapered portion of the inner surface of the rotor shaft axially away from the first end of the rotor shaft to the plurality of ports via rotation of the rotor shaft, such that the fluid within the hollow defined by the inner surface is circulated within a fluid circuit of the drive unit by flowing out of the hollow through the plurality of ports and subsequently back into the hollow through the first opening at the first end of the rotor shaft.

11 . The method of claim 10 , wherein the rotor shaft comprises:
a first shaft component having a first end and a second end opposite the first end of the first shaft component and defining a first hollow, wherein the first end of the first shaft component is the first end of the rotor shaft and the first hollow is a portion of the hollow defined by the rotor shaft; and a second shaft component having a first end and a second end opposite the first end of the second shaft component and defining a second hollow, wherein the second end of the second shaft component is the second end of the rotor shaft and the second hollow is a portion of the hollow defined by the rotor shaft, and wherein the tapered portion of the inner surface of the rotor shaft is a portion of the inner surface of the first shaft component, such that the step of propelling fluid along the tapered portion of the inner surface of the rotor shaft comprises:
propelling fluid along the tapered portion of the inner surface of the first shaft component axially away from the first end of the first shaft component.

12 . The method of claim 11 , wherein the first end of the second shaft component is disposed within the first hollow, and the portion of the second shaft component that is disposed within the first hollow at least partially defines a plurality of inlets of the corresponding plurality of ports defined by the rotor shaft, such that, in the step of propelling fluid along the tapered portion of the inner surface of the rotor shaft axially away from the first end of the rotor shaft to the plurality of ports via rotation of the rotor shaft, the fluid is propelled into the plurality of ports through the corresponding plurality of inlets at least partially defined by the portion of the second shaft component that is disposed within the first hollow.

13 . The method of claim 10 , wherein the flow rate of the fluid within the fluid circuit is dependent upon the rate of rotation of the rotor shaft.

14 . The method of claim 10 , wherein the drive unit does not include a secondary pump for propelling the fluid along the fluid circuit.

15 . A rotor shaft for an electric drive unit, comprising:
a first shaft component that extends axially from a first end to a second end opposite the first end, the first shaft component having an inner surface that defines a first hollow that extends

Assignees

• Schaeffler Technologies Ag

Inventors

• Linton Daniel
• Nelson Kyle

Classifications

• H02K7/003

  Couplings; Details of shafts (means for mounting rotors on shafts H02K1/28) · CPC title

• H02K1/22 Primary

  Rotating parts of the magnetic circuit · CPC title

• H02K1/32

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

• H02K9/19 Primary

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