Gear system for electric vehicle

Patent metadata

Field	Value
Publication number	US-11031851-B2
Application number	US-201615372818-A
Country	US
Kind code	B2
Filing date	Dec 8, 2016
Priority date	May 27, 2010
Publication date	Jun 8, 2021
Grant date	Jun 8, 2021

Abstract

A power transmission device for a vehicle is comprised of a motor including a rotor shaft and a stator having an electromagnetic coil; an inverter configured to generate an alternating current, the inverter being connected with the coil to controllably rotate the rotor shaft relative to the stator; a gear set including an input shaft coupled with and rotated by the rotor shaft, an output shaft and gears so meshed as to transmit torque of the input shaft to the output shaft; and a grounding path electrically connecting a part of the gear set with a body of the vehicle, the part being so disposed as to have the input shaft electrically interposed between the part and the rotor shaft.

First claim

The invention claimed is:

1. A gear system for a vehicle used in combination with an inverter and a motor electrically connected to and driven by the inverter, comprising:
a gear casing spatially separate from a housing of the motor;
a gear set confined in the gear casing, the gear set including an input shaft coupled with and rotated by the motor, an output shaft, meshed gears, and one or more counter shafts driven only by the meshed gears to mediate transmission of torque from the input shaft to the output shaft;
a spline coupling drivingly interposed between a rotor shaft of the motor and the input shaft, the spline coupling functioning as a resistor; and
a grounding path electrically connecting a connection point on the one or more counter shafts with a body of the vehicle, the connection point being positioned such that at least one engagement among the meshed gears is interposed between the input shaft and the connection point,
wherein the grounding path functions as a resistor for attenuating radio noise flowing from the inverter beyond the connection point toward the output shaft.

2. The gear system of claim 1 , further comprising:
a brush in slidable contact with one selected from the group consisting of the input shaft, the one or more counter shafts, or the output shaft, and connected with the grounding path so as to electrically connect the connection point of the one or more counter shafts of the gear set with the body of the vehicle.

3. The gear system of claim 2 , wherein the gear casing is electrically connected with the grounding path; and
the gear system further comprises a lead line electrically connected with the brush and the gear casing.

4. The gear system of claim 2 , further comprising:
an oil seal intervening between the gear set and the brush.

5. The gear system of claim 4 , further comprising:
a brush chamber housing the brush; and
a breather communicating with the brush chamber and an outside of the brush chamber.

6. The gear system of claim 1 , wherein the connection point is an end portion of any of the one or more counter shafts.

7. The gear system of claim 1 , wherein the gear casing is isolated from the housing of the motor.

8. The gear system of claim 4 , wherein the oil seal seals oil within the gear casing.

9. The gear system of claim 1 , further comprising:
a cover attached to the gear casing,
wherein the one or more counter shafts are entirely disposed within the gear casing and the cover.

10. The gear system of claim 5 , further comprising:
a cover attached to the gear casing,
wherein the brush chamber is enclosed by the gear casing and the cover.

11. The gear system of claim 2 , further comprising:
a cover attached to the gear casing,
wherein the gear casing and the cover define a brush chamber in which a brush case is provided, and
wherein the brush case is attached to the gear casing and houses the brush.

12. The gear system of claim 11 , further comprising a brush spring having one end connected to an interior of the brush case and another end connected to the brush.

13. The gear system of claim 11 , wherein the brush case is made of an electrically non-conductive material.

14. The gear system of claim 1 , wherein the gear set and the motor are not within a same case.

Assignees

• Nissan Motor

Inventors

• Okada Tomohiro
• Oikawa Naoaki
• Saruwatari Takahiro
• Ikeda Tatsuhiko
• Nakayama Ken
• Soeda Kazuhiko
• Inada Akinori

Classifications

• Y02T10/70

  Energy storage systems for electromobility, e.g. batteries · CPC title

• Y02T10/72

  Electric energy management in electromobility · CPC title

• F16H57/02

  Gearboxes; Mounting gearing therein · CPC title

• F16H2057/02034

  Gearboxes combined or connected with electric machines · CPC title

• F16H3/091

  including a single countershaft · CPC title