Bearing current discharge assemblies for electric vehicles

Inventors: Sen Jiang Zhou (Troy, MI); David J. Varda (West Bloomfield, MI); Bradford E. Vorbeck (Clarkston, MI); Zachary Strand (Salem, OR); Timothy J. Reinhart (Lake Orion, MI)

Assignee: GM GLOBAL TECHNOLOGY OPERATIONS LLC

H02K5/1735 H02K5/225 H02K11/40

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Quick Facts

Patent No.: US 12695353
App. No.: 18/612,331
Granted: Jul 28, 2026
Kind: B2

External Links

USPTO Patent Center↗ Full Patent PDF↗

Abstract

A current discharge assembly for an electric machine in an electric vehicle, includes a rotor shaft defining a channel, a ground element positioned within the channel, and a connector positioned within the channel of the rotor shaft and extending circumferentially between the rotor shaft and the ground element. The connector is configured to electrically couple the rotor shaft to the ground element when the rotor shaft is rotating to allow current to flow from the rotor shaft to the ground element via the connector. Other example current discharge assemblies and methods for manufacturing current discharge assemblies are also disclosed.

Claims (36)

1 . A current discharge assembly for an electric machine in an electric vehicle, the current discharge assembly comprising:

a rotor shaft defining a channel;

a ground pipe extending into the channel and configured to provide a lubricant into the channel of the rotor shaft;

a connector positioned within the channel of the rotor shaft and extending circumferentially between the rotor shaft and the ground pipe, the connector configured to electrically couple the rotor shaft to the ground pipe when the rotor shaft is rotating to allow current to flow from the rotor shaft to the ground pipe via the connector:

a first plug and a second plug positioned in the channel between the ground pipe and the rotor shaft, the first plug positioned adjacent to a first side of the connector, the second plug positioned adjacent to a second side of the connector opposing the first side, and the first plug and the second plug configured to prevent the lubricant provided by the ground pipe from contacting the connector; and

a mounting bracket extending circumferentially along an outer diameter of the channel and positioned between the connector and the rotor shaft, wherein the connector, the first plug and the second plug are attached to the mounting bracket.

2 . The current discharge assembly of claim 1 , wherein the connector is a brush including a body and a plurality of bristles extending from the body.

3 . The current discharge assembly of claim 2 , wherein the plurality of bristles include carbon fiber.

4 . The current discharge assembly of claim 2 , wherein the plurality of bristles extend from the body towards the ground pipe and are configured to contact the ground pipe.

5 . The current discharge assembly of claim 2 , wherein the plurality of bristles extend from the body towards the rotor shaft and are configured to contact the rotor shaft.

6 . The current discharge assembly of claim 1 , wherein the connector is a bearing positioned between the rotor shaft and the ground pipe.

7 . The current discharge assembly of claim 6 , wherein the bearing is a roller bearing or a ball bearing.

8 . The current discharge assembly of claim 1 , wherein the connector includes a body and one or more spring loaded sticks configured to bias against one of the rotor shaft and the ground pipe.

9 . The current discharge assembly of claim 8 , wherein the one or more spring loaded sticks are configured to bias against the rotor shaft.

10 . The current discharge assembly of claim 8 , wherein the one or more spring loaded sticks are configured to bias against the ground pipe.

11 . A method for manufacturing a current discharge assembly for an electric machine in an electric vehicle, the electric machine including a rotor shaft defining a shaft channel, the method comprising:

providing a mounting bracket having a body defining a bracket channel extending therethrough;

cutting at least one slot into the body of the mounting bracket;

attaching a connector to the mounting bracket via the slot, the connector extending into the bracket channel;

inserting a ground pipe into the bracket channel of the mounting bracket to contact the connector extending into the bracket channel, the ground pipe providing a lubricant into the shaft channel of the rotor shaft;

inserting the ground pipe and the mounting bracket with the attached connector into the shaft channel of the rotor shaft so that the mounting bracket extends circumferentially along an outer diameter of the shaft channel, the mounting bracket is positioned between the connector and the rotor shaft, and the connector electrically couples the rotor shaft to the ground pipe when the rotor shaft is rotating to allow current to flow from the rotor shaft to the ground pipe via the connector; and

forming a first plug and a second plug between the ground pipe and the rotor shaft to prevent the lubricant provided by the ground pipe from contacting the connector, the first plug positioned adjacent to a first side of the connector, and the second plug positioned adjacent to a second side of the connector opposing the first side, wherein the first plug and the second plug are attached to the mounting bracket.

12 . The method of claim 11 , wherein attaching the connector to the mounting bracket via the slot includes pressing the connector into the slot.

13 . The method of claim 11 , wherein the connector is a brush having a plurality of bristles.

14 . A current discharge assembly for an electric machine in an electric vehicle, the current discharge assembly comprising:

a rotor shaft defining a channel;

a ground pipe extending into the channel and configured to provide a lubricant into the channel of the rotor shaft;

a mounting bracket extending circumferentially along an outer diameter of the ground pipe and positioned between the connector and the ground pipe, wherein the connector is attached to the mounting bracket, the mounting bracket having a tapering ring-shape with a diameter that increases from a first end of the mounting bracket to a second, opposing end of the mounting bracket.

15 . The current discharge assembly of claim 14 , wherein the mounting bracket includes a lip at the second end of the mounting bracket and one or more fingers extending from the first end of the mounting bracket.

16 . The current discharge assembly of claim 15 , wherein the one or more fingers are configured to contact and press against the ground pipe.

17 . The current discharge assembly of claim 16 , wherein the connector is a bearing positioned between the rotor shaft and the ground pipe.

18 . The current discharge assembly of claim 17 , wherein the bearing is a roller bearing or a ball bearing.

19 . The current discharge assembly of claim 14 , wherein the connector is a brush including a body and a plurality of carbon fiber bristles extending from the body.

20 . The current discharge assembly of claim 14 , wherein the connector includes a body and one or more spring loaded sticks configured to bias against one of the rotor shaft and the ground pipe.