Electric axle

Patent metadata

Field	Value
Publication number	US-12584549-B2
Application number	US-202418784614-A
Country	US
Kind code	B2
Filing date	Jul 25, 2024
Priority date	Jul 26, 2023
Publication date	Mar 24, 2026
Grant date	Mar 24, 2026

Abstract

Methods and systems are provided for an electric axle. The electric axle system includes, in one example, a first electric machine and a planetary reduction differential configured to receive mechanical power from the first electric machine. The planetary reduction differential includes a first planetary gear set directly rotationally coupled to a second planetary gear set. In the electric axle system, a sun gear in the first planetary gear set is directly coupled to an input shaft of the planetary reduction differential.

First claim

The invention claimed is:

1 . An electric axle system, comprising:
a first electric machine; a planetary reduction differential configured to receive mechanical power from the first electric machine; a Ravigneaux three-speed mode planetary gear set rotationally coupled and positioned coaxial to the planetary reduction differential; and a mode clutch configured to:
ground a carrier or a ring gear in the Ravigneaux three-speed mode planetary gear set, in a first mode;
ground a second sun gear in the Ravigneaux three-speed mode planetary gear set, in a second mode; and
rotationally couple the carrier or the ring gear to the second sun gear in the Ravigneaux three-speed mode planetary gear set, in a third mode;
wherein a first sun gear in the Ravigneaux three-speed mode planetary gear set is rotationally coupled to the first electric machine; wherein the planetary reduction differential includes a first planetary gear set directly rotationally coupled to a second planetary gear set; wherein a sun gear in the first planetary gear set is directly coupled to an input shaft of the planetary reduction differential; and wherein a carrier in the first planetary gear set is directly coupled to an output shaft.

2 . The electric axle system of claim 1 , wherein:
the first planetary gear set is a simple planetary gear set and the second planetary gear set is a simple planetary gear set; and/or the first and second planetary gear sets have an identical ring gear to sun gear ratio.

3 . The electric axle system of claim 2 , wherein:
a ring gear in the second planetary gear set is directly coupled to an output shaft; a ring gear in the first planetary gear set is directly rotationally coupled to a sun gear in the second planetary gear set; and a carrier in the second simple planetary gear set is grounded.

4 . The electric axle system of claim 1 , wherein:
the first planetary gear set is a simple planetary gear set and the second planetary gear set is a meshed planet compound planetary gear set; and a ring gear in the second planetary gear set is grounded.

5 . The electric axle system of claim 4 , wherein:
a sun gear in the second planetary gear set is directly coupled to an output shaft; and a ring gear in the first planetary gear set is directly rotationally coupled to a carrier in the second planetary gear set.

6 . The electric axle system of claim 4 , wherein:
a carrier in the second planetary gear set is directly coupled to an output shaft; and a ring gear in the first planetary gear set is directly rotationally coupled to a sun gear in the second planetary gear set.

7 . The electric axle system of claim 1 , wherein:
the first planetary gear set is a meshed planet compound planetary gear set and the second planetary gear set is a meshed planet compound planetary gear set; and a ring gear in the second planetary gear set is grounded.

8 . The electric axle system of claim 7 , wherein:
a sun gear in the second planetary gear set is directly coupled to an output shaft; and a ring gear in the first planetary gear set is directly rotationally coupled to a carrier in the second planetary gear set.

9 . The electric axle system of claim 7 , wherein:
a carrier in the second planetary gear set is directly coupled to an output shaft; and a ring gear in the first planetary gear set is directly rotationally coupled to a sun gear in the second planetary gear set.

10 . The electric axle system of claim 1 , wherein the first electric machine is positioned coaxial, parallel, or transverse, to the planetary reduction differential.

11 . The electric axle system of claim 1 , further comprising a second electric machine rotationally coupled to the planetary reduction differential.

12 . A method for operation of an electric axle, comprising:
operating a first electric machine to deliver mechanical power to a planetary reduction differential; and operating a mode clutch in a Ravigneaux three-speed mode planetary gear set that is rotationally coupled to the planetary reduction differential to shift the Ravigneaux three-speed mode planetary gear set between two operating modes included in a set of three operating modes; wherein the electric axle includes:
the first electric machine; and
the planetary reduction differential that is configured to receive mechanical power from the first electric machine;
wherein the planetary reduction differential comprises a first planetary gear set directly rotationally coupled to a second planetary gear set; wherein a sun gear in the first planetary gear set is directly coupled to an input shaft of the planetary reduction differential; and wherein a carrier in the first planetary gear set is directly coupled to an output shaft.

13 . The method of claim 12 , further comprising operating a second electric machine to deliver mechanical power to the planetary reduction differential.

14 . An electric axle, comprising:
an electric machine; a planetary reduction differential configured to receive mechanical power from the electric machine; a Ravigneaux three-speed mode planetary gear set rotationally coupled and positioned coaxial to the planetary reduction differential; and a mode clutch configured to selectively transition the Ravigneaux three-speed mode planetary gear set between two of three modes; wherein the mode clutch is configured to:
in a first mode, ground a carrier or a ring gear in the Ravigneaux three-speed mode planetary gear set;
in a second mode, ground a second sun gear in the Ravigneaux three-speed mode planetary gear set; and
in a third mode, rotationally couple the carrier or the ring gear to the second sun gear in the Ravigneaux three-speed mode planetary gear set;
wherein the planetary reduction differential includes a first planetary gear set directly rotationally coupled to a second planetary gear set; wherein a sun gear in the first planetary gear set is directly coupled to an input shaft of the planetary reduction differential; wherein a carrier in the first planetary gear set is directly coupled to an output shaft; wherein a ring gear in the second planetary gear set is directly coupled to an output shaft; wherein a ring gear in the first planetary gear set is directly rotationally coupled to a sun gear in the second planetary gear set; and wherein a carrier in the second planetary gear set is grounded.

15 . The electric axle of claim 14 , wherein a ring gear or a carrier in the Ravigneaux three-speed mode planetary gear set is coupled to the planetary reduction differential input shaft.

Assignees

• Dana Heavy Vehicle Sys Group

Inventors

• Waltz William F
• David Jeffrey M

Classifications

• F16H2200/2023

  using a Ravigneaux set with 4 connections · CPC title

• F16H2200/2005

  with one sets of orbital gears · CPC title

• F16H2200/0034

  the gear ratios comprising two forward speeds · CPC title

• F16H2200/0021

  specially adapted for electric vehicles · CPC title

• F16H2048/106

  characterised by two sun gears · CPC title