Electric machine with improved dissipation of waste heat

Patent metadata

Field	Value
Publication number	US-10923984-B2
Application number	US-201916445555-A
Country	US
Kind code	B2
Filing date	Jun 19, 2019
Priority date	Jun 19, 2018
Publication date	Feb 16, 2021
Grant date	Feb 16, 2021

Abstract

An electric machine has a rotor on a rotor shaft. The rotor shaft is supported on bearings such that the rotor and the rotor shaft are rotatable around an axis of rotation. The rotor is surrounded radially on the outside by a stator, the stator by a casing. Covering elements are arranged at the axial ends of the rotor and stator, by which the rotor and the stator are enclosed with respect to the environment of the electric machine. One covering element is surrounded radially on the outside, and axially on the side facing away from the rotor and stator there, by an air guide element, the other covering element by an inner ring element. First and second cooling channels running axially are arranged in the casing or between the casing and stator. Rotor channels running axially are arranged in the rotor shaft and/or in the rotor.

First claim

The invention claimed is:

1. An electric machine, comprising:
a rotor shaft;
a rotor disposed on said rotor shaft and having a first axial end and a second axial end;
bearings supporting said rotor shaft such that said rotor together with said rotor shaft is rotatable around an axis of rotation;
a stator surrounding said rotor radially on an outside and having a first axial end and a second axial end;
a casing surrounding said stator radially on an outside;
covering elements, including a first covering element and a second covering element, disposed at said first axial end and said second axial end of said rotor and said stator, by means of said covering elements said rotor and said stator are enclosed with respect to an environment of the electric machine;
an air guide element surrounding said first covering element radially on an outside, and axially on a side facing away from said rotor and said stator;
an inner ring element surrounding said second covering element radially on an outside, and axially on a side facing away from said rotor and stator;
first cooling channels and second cooling channels running axially in said casing or between said casing and said stator;
rotor channels running axially and disposed in one of said rotor shaft or said rotor;
said casing having an air inlet radially on an outside, and via said air inlet a cooling air flow is fed to said first cooling channels; and
said first cooling channels configured to feed at least one part of the cooling air flow to said air guide element or to an interspace between said first covering element and said air guide element, said air guide element alone or in conjunction with said first covering element formed to deflect the at least one part of the cooling air flow radially to an inside, and is then fed via said rotor channels to said inner ring element or to an interspace between said second covering element and said inner ring element, said inner ring element alone or in conjunction with said second covering element formed to deflect the at least one part of the cooling air flow radially to an outside and is then fed to said second cooling channels, and said second cooling channels configured to route the at least one part of the cooling air flow axially through the electric machine, and finally escapes into the environment of the electric machine.

2. The electric machine according to claim 1 , wherein:
said casing has a square outer contour as viewed orthogonally to the axis of rotation, said first cooling channels are disposed in at least one side region of said square outer contour; and
said second cooling channels are disposed in corner regions of said square outer contour.

3. The electric machine according to claim 1 ,
further comprising an outer ring element surrounding said inner ring element radially on an outside at least over part of its periphery;
further comprising third cooling channels running axially and disposed in said casing or between said casing and said stator; and
wherein a further part of the cooling air flow is fed to said outer ring element or to an interspace between said casing and said outer ring element, and is deflected tangentially there and fed to said third cooling channels, and is finally routed by means of said third cooling channels axially through the electric machine, and then escapes into the environment of the electric machine.

4. The electric machine according to claim 3 , wherein said outer ring element extends over an angular range of approximately 180° or less as viewed from the axis of rotation.

5. The electric machine according to claim 1 , wherein at least one of said covering elements is fixed firmly to said rotor.

6. The electric machine according to claim 1 , wherein at least one of said air guide element or said inner ring element holds one of said bearings.

7. The electric machine according to claim 1 , wherein at least one of said air guide element or said inner ring element consist of aluminum or an aluminum alloy.

8. The electric machine according to claim 1 , wherein said casing has a top side and said air inlet is disposed on said top side of said casing.

9. The electric machine according to claim 1 , wherein said covering elements consist of aluminum, copper, an aluminum or copper alloy, or contain blocks of these materials.

10. The electric machine according to claim 1 , wherein:
said casing has a square outer contour as viewed orthogonally to the axis of rotation, and said first cooling channels are disposed in precisely one side region of said square outer contour; and
said second cooling channels are disposed in corner regions of said square outer contour.

11. The electric machine according to claim 4 , wherein said angular range is approximately 90° or less.

12. The electric machine according to claim 4 , wherein said angular range is approximately 45° or less.

13. A chassis of a railcar, the chassis comprising:
a frame;
a wheelset axle supported in said frame such that said wheelset axle is rotatable around a shaft axis;
a gearbox;
an electric machine fixed in said frame in front or in rear of said wheelset axle as viewed in a direction of travel of the chassis, said electric machine containing:
a rotor shaft acting on said wheelset axle via said gearbox;
a rotor disposed on said rotor shaft and having a first axial end and a second axial end;
bearings supporting said rotor shaft such that said rotor together with said rotor shaft is rotatable around an axis of rotation;
a stator surrounding said rotor radially on an outside and having a first axial end and a second axial end;
a casing surrounding said stator radially on an outside;
covering elements, including a first covering element and a second covering element, disposed at said first axial end and said second axial end of said rotor and said stator, by means of said covering elements said rotor and said stator are enclosed with respect to an environment of said electric machine;
an air guide element surrounding said first covering element radially on an outside, and axially on a side facing away from said rotor and said stator;
an inner ring element surrounding said second covering element radially on an outside, and axially on a side facing away from said rotor and stator;
first cooling channels and second cooling channels running axially in said casing or between said casing and said stator;
rotor channels running axially and disposed in at least one of said rotor shaft or said rotor;
said casing having an air inlet radially on an outside, and via said air inlet a cooling air flow being fed to said first cooling channels; and
said first cooling channels configured to feed at least one part of the cooling air flow to said air guide element or to an interspace between said first covering element and said air guide element, said air guide element alone or in conjunction with said first covering element formed to deflect the at least one part of the cooling air flow radially to an inside, and is then fed via said rotor channels to said inner ring element or to an interspace between said second covering element and said inner ring element, said inner ring element alone or in conjunction with said second covering element formed to deflect the at least one part of the cooling air flow radially to an outside and is then fed to said second cooling channels, and said second cooling channels configured to route the at least one part of the cooling air flow axially through the electric machine, and finally escapes into the environment of the electric machine.

14. The chassis according to claim 13 , wherein:
said casi

Assignees

• Siemens Mobility GmbH

Inventors

• Koerner Olaf
• Mucha Oana
• Wetzel Wolfgang

Classifications

• H02K5/161 Primary

  radially supporting the rotary shaft at both ends of the rotor (H02K5/165, H02K5/167, H02K5/173 take precedence) · CPC title

• H02K5/207

  with openings in the casing specially adapted for ambient air · CPC title

• H02K9/02 Primary

  by ambient air flowing through the machine · CPC title

• H02K1/32

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

• H02K1/20

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