Electric drive unit having a cooling sleeve

Patent metadata

Field	Value
Publication number	US-10944305-B2
Application number	US-201716334864-A
Country	US
Kind code	B2
Filing date	Aug 9, 2017
Priority date	Sep 21, 2016
Publication date	Mar 9, 2021
Grant date	Mar 9, 2021

Abstract

An electric drive unit with an electric machine arranged in a motor housing. The electric machine has a rotor and a stator. A transmission is arranged in a transmission housing and driven by the electric machine. A cooling sleeve is provided, which forms a radially outward facing hollow space for a coolant by virtue of a spiral-shaped circumferential web between itself and the surrounding motor housing. Furthermore the cooling sleeve has a holding web which is designed to be clamped between two motor housing components.

First claim

The invention claimed is:

1. An electric drive unit comprising an electric machine arranged in a motor housing
the electric machine having a rotor and a stator,
a transmission being arranged in a transmission housing and driven by the electric machine,
a cooling sleeve forming a hollow space for a coolant between the cooling sleeve and the surrounding motor housing by virtue of a spiral-shaped circumferential web extending radially outward is provided,
the cooling sleeve has a holding web that extends radially outward further than the spiral-shaped circumferential web and is clamped between first and second motor housing components such that the first and the second motor housing components are completely axially spaced from each other by the holding web,
an annular third motor housing component that radially encircles the cooling sleeve, comprising a first flange and a second flange arranged at axially opposite ends of the third motor housing component,
the first and the second flanges of the third motor housing component extend radially outward therefrom,
the first flange of the third motor housing component is fixed to the first motor housing component and the second flange of the third motor housing component is fixed to the second motor housing component and to the holding web of the cooling sleeve.

2. The electric drive unit according to claim 1 , wherein the holding web of the cooling sleeve is arranged in an axially central area of the cooling sleeve.

3. The electric drive unit according to claim 1 , wherein the holding web has an opening, which facilitates a flow of coolant in the hollow space from one axial side of the holding web to the other axial side of the holding web.

4. The electric drive unit according to claim 1 , wherein the first and the second motor housing components and the holding web of the cooling sleeve are connected in a screwed joint by screws that extend from one of the first and the second housing components through holes in the holding web to the other of the first and the second housing components.

5. The electric drive unit according to claim 1 , wherein the first and the second motor housing components the holding web of the cooling sleeve, and the transmission housing are connected to each other in a single screwed joint by screws that extend from the first housing component through the holding web and the second housing component to the transmission housing.

6. The electric drive unit according to claim 1 , wherein the spiral-shaped circumferential web is formed on the cooling sleeve and extends outwards from a radially outer side of the cooling sleeve.

7. The electric drive unit according to claim 1 , wherein the spiral-shaped web is formed on the first and the second motor housing components and extends radially inward from a radially inner side thereof, the spiral-shaped web contacts and forms a seal against an outside of the cooling sleeve.

8. A cooling sleeve for an electric drive unit which surrounds a stator of an electric machine in such manner that heat from the stator is transferrable to the cooling sleeve,
a radially outer surface of the cooling sleeve has a spiral-shaped web that surrounds the cooling sleeve,
the spiral-shaped web together with a motor housing of the electric drive unit that surrounds the cooling sleeve forms a hollow space into which cooling liquid can be introduced,
the motor housing having a first housing component that encloses an axial end of the electric machine and a second housing component that encloses an opposite axial end of the electric machine,
the cooling sleeve has a radially extending holding web, the first housing component mates with a first axial side of the holding web and the second housing component mates with a second axial side of the holding web such that the cooling sleeve is connected to the motor housing, and the first and the second housing components are axially separated from one another by the holding web,
the electric drive unit has an annular third motor housing component that radially encircles the cooling sleeve, comprising a first flange and a second flange arranged at axially opposite ends of the third motor housing component, the first and the second flanges of the third motor housing component extend radially outward therefrom, the first flange of the third motor housing component is fixed to the first motor housing component and the second flange of the third motor housing component is fixed to the second motor housing component and to the holding web of the cooling sleeve.

9. The cooling sleeve according to claim 8 , wherein the holding web is arranged in an axially central area of the cooling sleeve.

10. The cooling sleeve according to claim 8 , wherein the holding web has an opening which enables the cooling liquid to flow along the hollow space between the first and the second axial sides of the holding web.

11. An electric drive unit comprising:
an electric machine having a rotor and a stator and being arranged in a motor housing, the motor housing comprising at least first and second housing components;
a transmission being driven by the electric machine and arranged in a transmission housing;
a cooling sleeve being connected to a radially outer surface of the stator such that a hollow space is formed radially between the motor housing and an outer surface of the cooling sleeve, the outer surface of the cooling sleeve having a spiral-shaped circumferential web extending radially outward therefrom, the spiral-shaped circumferential web facilitating a flow of coolant within the hollow space circumferentially around and axially along the cooling sleeve between the cooling sleeve and the motor housing, the cooling sleeve having a holding web that extends radially from the outer surface thereof and is clamped between the first and the second housing components by screws that extend from one of the first and the second housing components through holes in the holding web to the other of the first and the second housing components to form a screwed connection; and
an annular third motor housing component that radially encircles the cooling sleeve, comprising a first flange and a second flange arranged at axially opposite ends of the third motor housing component, the first and the second flanges of the third motor housing component extend radially outward therefrom, the first flange of the third motor housing component is fixed to the first motor housing component and the second flange of the third motor housing component is fixed to the second motor housing component and to the holding web of the cooling sleeve.

Assignees

• Zahnradfabrik Friedrichshafen

Inventors

• Banerjee Alexander
• Höring Gerhard

Classifications

• H02K9/19

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

• H02K7/006 Primary

  Structural association of a motor or generator with the drive train of a motor vehicle · CPC title

• H02K5/203

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

• H02K7/116 Primary

  with gears · CPC title

• H02K2213/12

  Machines characterised by the modularity of some components · CPC title