Automatic two-mode high reduction power transmission system

Patent metadata

Field	Value
Publication number	US-10519920-B2
Application number	US-201815873622-A
Country	US
Kind code	B2
Filing date	Jan 17, 2018
Priority date	Jan 17, 2018
Publication date	Dec 31, 2019
Grant date	Dec 31, 2019

Abstract

An automatic two-mode high reduction power transmission system. A power transmission system includes a first device that delivers a first input and receives a second output. A second device delivers a second input and receives a first output. A power transmission has two planetary gear sets and operates in a first mode at a first speed ratio, where the first input is received from the first device and in response, the first output is delivered to the second device. The power transmission operates in a second mode at a second speed ratio that is different than the first speed ratio, where the second input is received from the second device and in response, the second output is delivered to the first device. A pair of freewheel mechanisms automatically couple one of the first or second devices with the power transmission to provide the two modes.

First claim

What is claimed is:

1. A power transmission system comprising:
a first device configured to deliver a first input and to receive a second output;
a second device configured to deliver a second input and to receive a first output;
a power transmission having first and second planetary gear sets and configured to:
operate in a first mode having a first speed ratio, wherein the first input is received from the first device and, in response, the first output is delivered to the second device; and
operate in a second mode having a second speed ratio different than the first speed ratio, wherein the second input is received from the second device and, in response, the second output is delivered to the first device; and

first and second freewheel mechanisms each configured to automatically couple one of the first or second devices with the power transmission.

2. The system of claim 1 , wherein the first device and the power transmission are configured as a unit that mounts on the second device.

3. The system of claim 2 , wherein the first device comprises an electrical machine configured to operate in a motor mode and in a generator mode, and wherein the second device comprises an internal combustion engine.

4. The system of claim 1 , comprising:
a sun gear disposed in the first planetary gear set and coupled directly with the first device; and
a ring gear disposed in the second planetary gear set and couplable with the second device through one of the first or second freewheel mechanisms.

5. The system of claim 1 , comprising:
a sun gear disposed in the first planetary gear set and coupled directly with the first device;
a first ring gear;
a first set of planet gears that mesh with the sun gear and with the first ring gear;
a second ring gear; and
a second set of planet gears that mesh with the second ring gear;
wherein the first and second sets of planet gears are configured as stepped pinion gears where each stepped pinion gear has a first pinion meshing with the first ring gear and a second pinion meshing with the second ring gear, the first pinion fixed with the second pinion, and the first pinion larger in size than the second pinion.

6. The system of claim 5 , comprising: a carrier carrying the stepped pinion gears, wherein the first freewheel mechanism is configured to control coupling between the second device and the carrier and the second freewheel mechanism is configured to control coupling between the second device and the second ring gear.

7. The system of claim 6 , wherein the first input device is connected, directly, to the sun gear.

8. The system of claim 7 , wherein the second planetary gear set does not include a sun gear.

9. The system of claim 8 , wherein the first device comprises an electrical machine configured to operate in a motor mode, and in a generator mode and wherein the second device comprises an internal combustion engine.

10. The system of claim 9 , wherein the electrical machine is configured to start the engine when operating in the motor mode by supplying the first input to the power transmission, wherein the first freewheel mechanism is disengaged to freewheel without transmitting torque, and the second freewheel mechanism is engaged to transmit torque from the second ring gear to the engine.

11. The system of claim 10 , wherein the electrical machine is configured to generate electric power when operating in the generator mode while the engine supplies the second input to the power transmission wherein the first freewheel mechanism is engaged and transmitting torque from the engine to the carrier, and the second freewheel mechanism is disengaged to freewheel without transmitting torque.

12. A power transmission system comprising:
a first device configured to deliver a first input and to receive a second output;
a second device configured to deliver a second input and to receive a first output;
a first planetary gear set connected, directly, to the first device;
a second planetary gear set connected with the second device;
a first freewheel mechanism connected between the second device and at least one of the first planetary gear set or the second planetary gear set; and
a second freewheel device connected between the second device and the second planetary gear set;
wherein the power transmission system is configured to:
operate in a first mode having a first speed ratio, wherein the first device delivers a first input through a first power flow that results in a first output supplied to the second device, the first power flow directed through the first planetary gear set, the second planetary gear set, and the second freewheel mechanism; and
operate in a second mode having a second speed ratio different than the first speed ratio, wherein the second device delivers a second input through a second power flow that results in a second output supplied to the first device, the second power flow directed through the first freewheel mechanism, the first planetary gear set and the second planetary gear set.

13. The system of claim 12 , comprising:
a sun gear disposed in the first planetary gear set and coupled directly with the first device; and
a ring gear disposed in the second planetary gear set and couplable with the second device through the second freewheel mechanism.

14. The system of claim 12 , comprising:
a sun gear disposed in the first planetary gear set and coupled directly with the first device;
a first ring gear in the first planetary gear set;
a first set of planet gears that mesh with the sun gear and with the first ring gear;
a ring gear disposed in the second planetary gear set and couplable with the second device through the second freewheel mechanism;
a second ring gear in the second planetary gear set; and
a second set of planet gears that mesh with the second ring gear;
wherein the first and second sets of planet gears are configured as stepped pinion gears where each stepped pinion gear has a first pinion meshing with the first ring gear and a second pinion meshing with the second ring gear, the first pinion fixed with the second pinion, and the first pinion larger in size than the second pinion.

15. The system of claim 14 , comprising: a carrier carrying the stepped pinion gears, wherein the first freewheel mechanism is configured to control coupling between the second device and the carrier and the second freewheel mechanism is configured to control coupling between the second device and the second ring gear.

16. The system of claim 15 , wherein the second planetary gear set does not include a sun gear.

17. The system of claim 16 , wherein the first device comprises an electrical machine configured to operate in a motor mode and in a generator mode and wherein the second device comprises an internal combustion engine.

18. The system of claim 17 , wherein the electrical machine is configured to start the engine when operating in the motor mode to supply the first input to the power transmission wherein the first freewheel mechanism is disengaged to freewheel without transmitting torque, and the second freewheel mechanism is engaged and transmitting torque from the second ring gear to the engine.

19. The system of claim 18 , wherein the electrical machine is configured to generate electric power when operating in the generator mode while the engine supplies the second input to the power transmission wherein the first freewheel mechanism is engaged and transmitting torque from the engine to the carrier, and the second freewheel mechanism is disenga

Assignees

• Deere & Co

Inventors

• Patil Mahendra S
• Turner Christopher D
• Panse Prasad M
• Jagtap Pranav

Classifications

• F16H2200/2005

  with one sets of orbital gears · CPC title

• F02N15/046 Primary

  of the planetary type · CPC title

• F02N15/023

  of the overrunning type · CPC title

• F02N15/02

  Gearing between starting-engines and started engines; Engagement or disengagement thereof · CPC title

• F02N11/04

  the motors being associated with current generators · CPC title