Multi-mode electromechanical variable transmission

• US 10,160,438 B2
• Filed: 02/09/2018
• Issued: 12/25/2018
• Est. Priority Date: 02/17/2015
• Status: Expired due to Fees

• Current Assignee: Oshkosh Corporation
• Original Assignee: Oshkosh Corporation
• Inventors: Shukla, Deepak, Kotloski, Andrew
• Primary Examiner(s): Scott, Jacob S.
• Application Number:
  US15/892,848
• Publication Number:
  US 20180162351A1
• Time in Patent Office: 319 Days
• Field of Search: None
• CPC Class Codes: B60K 2006/268 Electric drive motor starts the engine, i.e. used as starter motor
• CPC Class Codes: B60K 2006/381 characterized by driveline brakes shift brakes in transmission B60K6/54
• CPC Class Codes: B60K 6/365 with the gears having orbital motion
• CPC Class Codes: B60K 6/387 Actuated clutches, i.e. clutches engaged or disengaged by electric, hydraulic or mechanical actuating means
• CPC Class Codes: B60K 6/445 Differential gearing distribution type
• CPC Class Codes: B60W 10/02 including control of driveline clutches
• CPC Class Codes: B60W 10/08 including control of electric propulsion units, e.g. motors or generators
• CPC Class Codes: B60W 10/105 of electric type
• CPC Class Codes: B60W 20/10 Controlling the power contribution of each of the prime movers to meet required power demand
• CPC Class Codes: B60W 20/30 Control strategies involving selection of transmission gear ratio control of change speed gearings, together with other vehicle sub-units B60W10/10; HEV transmission gearing B60K6/36; gearings and control thereof F16H
• CPC Class Codes: B60W 2510/0638 Engine speed
• CPC Class Codes: B60W 30/182 Selecting between different operative modes, e.g. comfort and performance modes
• CPC Class Codes: B60W 30/19 Improvement of gear change, e.g. by synchronisation or smoothing gear shift
• CPC Class Codes: F16H 2037/0873 with switching, e.g. to change ranges
• CPC Class Codes: F16H 2037/101 Power split variators with one differential at each end of the CVT
• CPC Class Codes: F16H 2200/2007 with two sets of orbital gears
• CPC Class Codes: F16H 2200/2043 with five engaging means
• CPC Class Codes: F16H 3/727 with at least two dynamo electric machines for creating an electric power path inside the gearing, e.g. using generator and motor for a variable power torque path special adapted for a hybrid electric vehicle B60K6/20
• CPC Class Codes: F16H 3/728 with means to change ratio in the mechanical gearing
• CPC Class Codes: Y02T 10/62 Hybrid vehicles
• CPC Class Codes: Y10S 903/917 : with transmission for changing gear ratio
• CPC Class Codes: Y10S 903/93 : Conjoint control of different elements

Abstract

A vehicle includes a drive axle, a multi-mode transmission, and a controller coupled to the multi-mode transmission. The multi-mode transmission includes a first gear set having a first planetary gear carrier and a second gear set having a second planetary gear carrier, a first motor/generator coupled to the first gear set, a second motor/generator coupled to the second gear set and selectively coupled to a connecting shaft, a brake positioned to selectively limit a rotational movement of a ring gear of the second gear set when engaged, a first clutch selectively rotationally coupling the first gear set and the second gear set to the drive axle when engaged, and a second clutch selectively rotationally coupling the second motor/generator to the connecting shaft when engaged. The controller is configured to engage the brake and the clutches to selectively reconfigure the multi-mode transmission to an intermediate shift mode of operation.

Claims

1. A vehicle, comprising:

a drive axle;

a multi-mode transmission including;

a first gear set having a first planetary gear carrier and a second gear set having a second planetary gear carrier;

a first motor/generator coupled to the first gear set;

a second motor/generator coupled to the second gear set and selectively coupled to a connecting shaft;

a brake positioned to selectively limit a rotational movement of a ring gear of the second gear set when engaged;

a first clutch selectively rotationally coupling the first gear set and the second gear set to the drive axle when engaged; and

a second clutch selectively rotationally coupling the second motor/generator to the connecting shaft when engaged; and

a controller coupled to the multi-mode transmission and configured to engage the second clutch, the brake, and the first clutch to selectively reconfigure the multi-mode transmission to an intermediate shift mode of operation.

2. The vehicle of claim 1, wherein the controller is configured to selectively transition the multi-mode transmission into the intermediate shift mode of operation in response to the second motor/generator having a rotational speed that is substantially equal to a rotational speed of the connecting shaft.

3. The vehicle of claim 1, wherein the controller is configured to selectively transition the multi-mode transmission into the intermediate shift mode of operation in response to the difference between a rotational speed of the second motor/generator and a rotational speed of the connecting shaft falling below a threshold level.

4. The vehicle of claim 1, wherein the connecting shaft is coupled to the drive axle through a fixed ratio when the multi-mode transmission is selectively reconfigured into the intermediate shift mode of operation.

5. The vehicle of claim 1, wherein the controller is configured to:

engage the brake and the first clutch to selectively reconfigure the multi-mode transmission into a mid range mode of operation.

6. The vehicle of claim 5, wherein the controller is configured to:

disengage the brake to selectively reconfigure the multi-mode transmission into a high range mode of operation from the intermediate shift mode of operation and thereby complete a transition between the mid range mode of operation and the high range mode of operation.

7. The vehicle of claim 1, further comprising an engine coupled to the connecting shaft and configured to provide a rotational input to the multi-mode transmission.

8. The vehicle of claim 1, wherein the first motor/generator and the second motor/generator are each configured to receive stored energy from an energy storage device and provide a mechanical energy output such that the multi-mode transmission is configured to drive the drive axle without receiving a mechanical energy input from an engine.

9. The vehicle of claim 1, wherein the controller is configured to automatically transition the multi-mode transmission out of the intermediate shift mode of operation in response to at least one of an elapsed shift time, a traveled shift distance, a change in a speed of the connecting shaft, and a request.

10. The vehicle of claim 1, wherein the first planetary gear carrier and the second planetary gear carrier are rotatably coupled, and wherein the first clutch is configured to selectively rotationally couple the first planetary gear carrier and the second planetary gear carrier to the drive axle when engaged.

11. A drive system for a vehicle, comprising:

a first gear set including a first sun gear, a first ring gear, a first plurality of planetary gears coupling the first sun gear to the first ring gear, and a first carrier rotationally supporting the first plurality of planetary gears;

a second gear set including a second sun gear, a second ring gear, a second plurality of planetary gears coupling the second sun gear to the second ring gear, and a second carrier rotationally supporting the second plurality of planetary gears;

a first electrical machine coupled to the first gear set;

a second electrical machine coupled to the second gear set;

a connecting shaft coupled to the first gear set;

a brake positioned to selectively limit a rotational movement of the second gear set when engaged;

a first clutch selectively rotationally coupling the first carrier and the second carrier to a driveshaft output of the vehicle when engaged; and

a second clutch selectively rotationally coupling the second electrical machine to the connecting shaft when engaged,

wherein the drive system is selectively reconfigurable into an intermediate shift mode of operation, in which the brake, the first clutch, and the second clutch are engaged.

12. The drive system of claim 11, wherein the drive system is transitioned from the intermediate shift mode of operation in response to at least one of an elapsed shift time, a traveled shift distance, a change in a speed of the connecting shaft, and a request.

13. The drive system of claim 12, wherein the connecting shaft is coupled to an engine, wherein the drive system is transitioned from the intermediate shift mode of operation and into a first mode of operation by disengaging the second clutch in response to the engine falling below a first threshold speed, and wherein the drive system is transitioned from the intermediate shift mode of operation and into a second mode of operation by disengaging the brake in response to the engine exceeding a second threshold speed.

14. The drive system of claim 11, wherein the second clutch is disengaged to transition from the intermediate shift mode of operation to a first mode of operation, and wherein the brake is disengaged to transition from the intermediate shift mode of operation to a second mode of operation.

15. The drive system of claim 11, wherein the connecting shaft is coupled to an engine and configured to receive a rotational input from the engine.

16. The drive system of claim 11, wherein the first electrical machine and the second electrical machine are each configured to receive stored energy from an energy storage device and provide a mechanical energy output such that the drive system is configured to drive the driveshaft output without receiving a mechanical energy input from an engine.

17. The drive system of claim 11, wherein the drive system is transitioned into the intermediate shift mode of operation in response to the second electrical machine having a rotational speed that is substantially equal to a rotational speed of the connecting shaft.

18. The drive system of claim 11, wherein the drive system is transitioned into the intermediate shift mode of operation in response to the difference between a rotational speed of the second electrical machine and a rotational speed of the connecting shaft falling below a threshold level.

19. The drive system of claim 11, wherein the connecting shaft is coupled to the driveshaft output of the vehicle through a fixed ratio when the drive system is selectively reconfigured into the intermediate shift mode of operation.

20. A method of operating a multi-mode transmission of a vehicle, the method comprising:

engaging a brake and first clutch of the multi-mode transmission to configure the multi-mode transmission into a first mode of operation whereby a first electromagnetic device is coupled to a connecting shaft, the first clutch coupling a first planetary gear set and a second planetary gear set to a driveshaft output of the vehicle when engaged;

engaging a second clutch of the multi-mode transmission to couple the connecting shaft and a second electromagnetic device, thereby configuring the multi-mode transmission into an intermediate shift mode; and

at least one of (i) disengaging the brake to complete a reconfiguration of the multi-mode transmission into a second mode of operation and (ii) disengaging the second clutch to revert the multi-mode transmission into the first mode of operation from the intermediate shift mode.