Vehicle drive and method with electromechanical variable transmission

Patent metadata

Field	Value
Publication number	US-9821789-B2
Application number	US-201615186391-A
Country	US
Kind code	B2
Filing date	Jun 17, 2016
Priority date	Mar 14, 2013
Publication date	Nov 21, 2017
Grant date	Nov 21, 2017

Abstract

A vehicle drive includes a gear set, a first motor/generator coupled to a sun gear of the gear set, a second motor/generator selectively coupled to at least one of (a) a planetary gear carrier of the gear set and (b) a ring gear of the gear set, an engine coupled to the ring gear of the gear set and selectively coupled to the second motor/generator, and a clutch configured to selectively engage the second motor/generator to the engine. The first motor/generator and the second motor/generator are electrically coupled without an energy storage device configured to at least one of (a) provide electrical energy to the first motor/generator or the second motor/generator to power the first motor/generator or the second motor/generator and (b) be charged by electrical energy from the first motor/generator or the second motor/generator.

First claim

The invention claimed is:

1. A vehicle drive comprising:
a gear set comprising a sun gear, a ring gear, and planetary gears, the planetary gears coupling the sun gear to the ring gear, wherein the planetary gears are rotatably supported by a planetary gear carrier;
a first motor/generator coupled to the sun gear of the gear set;
a second motor/generator selectively coupled to at least one of (a) the planetary gear carrier of the gear set and (b) the ring gear of the gear set, wherein the second motor/generator is electrically coupled to the first motor/generator by an electrical power transmission system, wherein the first motor/generator and the second motor/generator are electrically coupled without an energy storage device configured to at least one of (a) provide electrical energy to the first motor/generator or the second motor/generator to power the first motor/generator or the second motor/generator and (b) be charged by electrical energy from the first motor/generator or the second motor/generator;
an engine coupled to the ring gear of the gear set and selectively coupled to the second motor/generator;
a clutch configured to selectively engage the second motor/generator to the engine.

2. The vehicle drive of claim 1 , wherein the first motor/generator generates all of the electrical energy required by the second motor/generator and the electrical energy required to offset power losses.

3. The vehicle drive of claim 2 , wherein the second motor/generator generates all of the electrical energy required by the first motor/generator and the electrical energy required to offset power losses.

4. The vehicle drive of claim 3 , wherein the second motor/generator generates the power required by the first motor/generator when a speed of the first motor/generator is less than a threshold speed.

5. The vehicle drive of claim 1 , wherein the clutch is configured to couple the second motor/generator to the engine and thereby change a configuration of the vehicle drive.

6. The vehicle drive of claim 5 , wherein, in a first configuration, the second motor/generator is coupled to an output of the gear set, and wherein, in a second configuration, the second motor/generator is coupled to the engine.

7. The vehicle drive of claim 6 , wherein the configuration changes when the speed of the second motor/generator is greater than a first threshold speed.

8. The vehicle drive of claim 6 , wherein the configuration changes when the difference of the speed of the second motor/generator in the first configuration and the speed of the second motor/generator in the second configuration is greater than a second threshold speed.

9. The vehicle drive of claim 8 , wherein the second threshold speed is a function of a fixed speed and a percentage of a throttle input.

10. The vehicle drive of claim 6 , wherein the configuration changes when the difference of the speed of the second motor/generator in the first configuration and the speed of the second motor/generator in the second configuration is less than a third threshold speed.

11. A vehicle drive comprising:
a gear set comprising a sun gear, a ring gear, and planetary gears, the planetary gears coupling the sun gear to the ring gear, wherein the planetary gears are rotatably supported by a planetary gear carrier;
a first motor/generator coupled to the sun gear of the gear set;
a second motor/generator selectively coupled to at least one of (a) the planetary gear carrier of the gear set and (b) the ring gear of the gear set, wherein the second motor/generator is electrically coupled to the first motor/generator by an electrical power transmission system, wherein the first motor/generator and the second motor/generator are electrically coupled without an energy storage device configured to at least one of (a) provide electrical energy to the first motor/generator or the second motor/generator to power the first motor/generator or the second motor/generator and (b) be charged by electrical energy from the first motor/generator or the second motor/generator;
an engine coupled to the ring gear of the gear set and selectively coupled to the second motor/generator; and
a controller including a processing circuit configured to:
operate the engine at a calculated speed;
operate one of the first motor/generator and the second motor/generator at a calculated torque; and
operate the other of the first motor/generator and the second motor/generator to maintain a voltage on the electrical power transmission system.

12. The vehicle drive of claim 11 , further comprising a clutch configured to selectively engage the second motor/generator to the engine, wherein the controller is configured to operate the clutch, wherein selectively engaging and disengaging the clutch changes a configuration of the vehicle drive.

13. The vehicle drive of claim 12 , wherein operating the engine at the calculated speed comprises:
determining a current configuration of the vehicle drive;
measuring current speeds of the vehicle, the engine, the first motor/generator, and the second motor/generator;
calculating a maximum power that can be provided at the current engine speed;
calculating a total power requested to be provided by a vehicle operator;
calculating a range of engine speeds that can provide the total power; and
operating the engine at an optimized speed, wherein the optimized speed is within the calculated range.

14. The vehicle drive of claim 12 , wherein operating one of the first motor/generator and the second motor/generator at the calculated torque comprises:
determining a current configuration of the vehicle drive;
measuring current speeds of the vehicle, the engine, the first motor/generator, and the second motor/generator;
calculating a total power requested to be provided;
calculating an electrical power from the motor/generators requested to be provided;
selecting the one of the first motor/generator and the second motor/generator to provide a required torque to produce the electrical power;
calculating the required torque for providing the electrical power; and
operating the selected motor/generator at the required torque.

15. The vehicle drive of claim 14 , wherein operating the other of the first motor/generator and the second motor/generator comprises:
determining the current configuration of the vehicle drive;
measuring current speeds of the vehicle, the engine, the first motor/generator, and the second motor/generator;
calculating the total power requested to be provided;
calculating the electrical power from the motor/generators requested to be provided;
selecting the other of the first motor/generator and the second motor/generator to maintain a voltage on the electrical power transmission system between the second motor/generator and the first motor/generator; and
operating the selected motor/generator to maintain the voltage on the electrical power transmission system.

16. The vehicle drive of claim 14 , wherein calculating the total power requested to be provided comprises:
calculating a maximum power deliverable to the vehicle drive at a current vehicle speed;
measuring a proportion of throttle input of the vehicle drive; and
calculating the total power requested to be provided by multiplying the maximum power deliverable and the proportion of throttle input.

17. The vehicle drive of claim 14 , wherein calculating the electrical power from the motor/generators requested to be provided comprises:
calculating a ratio of the electrical power from the motor/generators to the total power, wherein the ratio is a

Assignees

• Oshkosh Defense Llc

Inventors

• Shukla Deepak
• Zhang Rongjun
• Nasr Nader

Classifications

• B60W10/06

  including control of combustion engines · CPC title

• B60W20/10 Primary

  Controlling the power contribution of each of the prime movers to meet required power demand · CPC title

• B60W2510/08

  Electric propulsion units · CPC title

• B60K6/543

  the transmission being a continuously variable transmission · CPC title

• Y10S903/916

  with plurality of drive axles · CPC title