Drive unit for an electrically driven vehicle

Patent metadata

Field	Value
Publication number	US-12160145-B2
Application number	US-202117926848-A
Country	US
Kind code	B2
Filing date	May 26, 2021
Priority date	May 29, 2020
Publication date	Dec 3, 2024
Grant date	Dec 3, 2024

Abstract

A drive unit for an electrically driven vehicle with an inverter module, an electric machine a stator which is controllable by the inverter module. The rotor of the electric machine rotationally drivingly communicates with at least one shaft of the drive unit, the shaft being rotatably supported in a respective associated housing by a bearing arrangement. The housing and the inverter module are grounded. Further, the drive unit has a grounded, low-impedance electrical connection between the shaft and the inverter module so that, when a potential difference occurs between the shaft and the inverter module, a short circuit is produced. Low-impedance potential equalizer is provided between the shaft and the associated housing. It is provided that the shaft is formed as a rotor shaft or as a transmission shaft, the bearing arrangement has two bearings spaced apart axially from one another, and the potential equalizer is formed axially between the two bearings.

First claim

The invention claimed is:

1. A unit for an electrically driven vehicle comprising:
an inverter module,
an electric machine with a rotor and with a stator which is controllable by the inverter module, wherein the rotor rotationally drivingly communicates with at least one shaft of the drive unit, and wherein the shaft is rotatably supported in a respective associated housing by a bearing arrangement, and
wherein the housing and the inverter module are grounded, and
wherein the drive unit has a grounded, low-impedance electrical connection between the shaft of the drive unit and the inverter module so that, when a potential difference occurs between the shaft and the inverter module, a short circuit is produced, wherein low-impedance potential equalizing means are provided between the shaft and the associated housing, and
wherein the shaft is formed as a rotor shaft or as a transmission shaft,
wherein the bearing arrangement has two bearings spaced apart axially from one another, and
wherein the potential equalizing means are formed axially between the two bearings, and
wherein the rotor comprises an electromagnetically active rotor component which is secured to the rotor shaft and which is formed axially between the two bearings, and wherein the potential equalizing means are arranged axially within the extension of the active rotor component.

2. The drive unit according to claim 1 , wherein the potential equalizing means are formed substantially midway between the two bearings.

3. The drive unit according to claim 1 , wherein the potential equalizing means are formed as a sliding ring arrangement or slip ring arrangement with two rings in mutual contact with one another, wherein one of the rings is arranged on the rotor shaft or transmission shaft, and the other ring is arranged on a conductive element which is secured to and electrically connected with the respective associated housing.

4. The drive unit according to claim 3 , wherein the potential equalizing means are arranged radially inside of the rotor shaft or the transmission shaft, wherein the rotor shaft or the transmission shaft is constructed as a hollow shaft, and wherein the conductive element is secured axially at the end side to the adjacent or associated housing and extends axially inside of the hollow shaft.

Assignees

• Zahnradfabrik Friedrichshafen

Inventors

• Wesa Matthias
• Jung Andreas

Classifications

• H02K11/00

  Structural association of dynamo-electric machines with electric components or with devices for shielding, monitoring or protection (casings, enclosures or supports H02K5/00) · CPC title

• H02K11/0141

  Shields associated with casings, enclosures or brackets · CPC title

• H02K7/003

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

• H02K5/1732

  radially supporting the rotary shaft at both ends of the rotor (H02K5/1737 takes precedence) · CPC title

• H02K11/40 Primary

  Structural association with grounding devices · CPC title