Output Split Electrically-Variable Transmission with Electric Propulsion Using One or Two Motors

• US 20090082171A1
• Filed: 09/10/2007
• Published: 03/26/2009
• Est. Priority Date: 09/10/2007
• Status: Active Grant

• Current Assignee: GM Global Technology Operations LLC (General Motors Company)
• Original Assignee: GM Global Technology Operations Incorporated (Motors Liquidation Co. GUC Trust)
• Inventors: Conlon, Brendan M., Holmes, Alan G., Savagian, Peter J., Harpster, Michael O. JR.
• Granted Patent: US 7,867,124 B2
• Time in Patent Office: Days
• US Class Current: 477/5
• CPC Class Codes: B60K 6/365 with the gears having orbital motion
• CPC Class Codes: B60K 6/442 Series-parallel switching type
• CPC Class Codes: B60K 6/445 Differential gearing distribution type
• CPC Class Codes: B60L 2240/423 Torque
• CPC Class Codes: B60L 2240/441 Speed
• CPC Class Codes: B60W 10/08 including control of electric propulsion units, e.g. motors or generators
• CPC Class Codes: B60W 10/10 including control of change-speed gearings
• CPC Class Codes: B60W 20/00 Control systems specially adapted for hybrid vehicles hybrid vehicle design, B60K6/00; electric vehicles B60L
• 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 2510/10 Change speed gearings
• CPC Class Codes: B60W 2520/10 Longitudinal speed
• CPC Class Codes: B60W 2710/0644 Engine speed
• CPC Class Codes: B60W 2710/08 Electric propulsion units
• CPC Class Codes: B60W 2710/083 Torque
• CPC Class Codes: F16H 2037/088 Power split variators with summing differentials, with the input of the CVT connected or connectable to the input shaft
• CPC Class Codes: F16H 2200/2005 with one sets of orbital gears
• CPC Class Codes: F16H 2200/2035 with two engaging means
• CPC Class Codes: F16H 2200/2038 with three engaging means
• CPC Class Codes: F16H 2200/2041 with four engaging means
• 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: Y02T 10/64 : Electric machine technologies in electromobility
• CPC Class Codes: Y10S 903/91 : Orbital, e.g. planetary gears
• CPC Class Codes: Y10S 903/913 : One way
• CPC Class Codes: Y10S 903/917 : with transmission for changing gear ratio

Abstract

An electrically-variable transmission is provided with input member and output member, first and second motor/generators, a first planetary gear set and a final drive gearset. Two or three torque-transmitting mechanisms that are selectively engagable alone or in different combinations to establish at least one forward electric-only operating mode including a series mode, an output split mode, and at least one neutral mode including a purely neutral mode and a neutral battery charge mode. The transmission optionally includes a one-way clutch selected from the group of friction clutch and dog clutch, or is a lockable one-way clutch, for enabling low loss forward operation, regenerative braking functionality, and/or reverse vehicle operation.

Claims

9-1. The EVT of claim 1, wherein said planetary gear set includes a sun gear member, a ring gear member, and a carrier member, said sun gear member being continuously connected to said second motor/generator, said ring gear member being selectively connectible to said first motor/generator through said second torque-transmitting mechanism and selectively connectible to said stationary member through said first torque-transmitting mechanism, and said carrier member is continuously connected to said output member.

10. A hybrid powertrain having an electrically-variable transmission (EVT), the hybrid powertrain comprising:

an engine;

an input member;

an output member;

a stationary member;

first and second motor/generators;

an energy storage device operatively connected to each of said first and said second motor/generators for providing power to and receiving power from said first and second motor/generators, wherein said energy storage device is configured to be operatively connectable with an offboard power supply for recharging said energy storage device; and

a first planetary gear set representable by a first three-node lever of a lever diagram having a first node, a second node, and a third node;

wherein said first motor/generator and said input member are selectively connectable with said third node, said second motor/generator is continuously connected with said first node, and said second node is continuously connected for common rotation with said output member;

a first torque-transmitting mechanism selectively engagable to connect said third node to said stationary member; and

a second torque-transmitting mechanism selectively engagable to connect said first motor/generator with said third node;

wherein engagement of selected ones of said first and said second torque-transmitting mechanisms alone or in different combinations establishes at least one forward electric-only mode, a series mode, an output split mode, and at least one neutral mode.

11. The hybrid powertrain of claim 10, wherein said EVT is operable for transitioning from said output split mode to said at least one forward electric-only mode via synchronous shift to an appropriate speed ratio of said EVT and engagement of said first torque-transmitting mechanism, said at least one forward electric-only mode being a one motor electric-only mode.

12. The hybrid powertrain of claim 10, further comprising a third torque-transmitting mechanism operable for establishing another of said at least one forward electric-only modes, said another of said electric-only modes being a two motor electric-only mode;

wherein said EVT includes a purely neutral mode in which said second motor/generator is disconnected from said output member by disengagement of said third torque transmitting mechanism, and further includes a neutral battery charge mode operable for charging said energy storage device upon engagement of said third torque transmitting mechanism to connect said first motor/generator to said engine and disengagement of said first and said second torque-transmitting mechanisms.

13. The hybrid powertrain of claim 10, wherein said first planetary gear set includes a sun gear member, a ring gear member, and a carrier member, said sun gear member being continuously connected to said second motor/generator, said ring gear member being selectively connectible to said first motor/generator through said second torque-transmitting mechanism and selectively connectible to said stationary member through said first torque-transmitting mechanism, and said carrier member is continuously connected to said output member.

14. The hybrid powertrain of claim 13, further comprising a one-way clutch, wherein said first torque-transmitting mechanism is selected from the group of friction clutch and dog clutch, and wherein said first torque-transmitting mechanism is positioned in parallel with said one-way clutch.

15. The hybrid powertrain of claim 13, wherein said first torque-transmitting mechanism is a lockable one-way clutch for enabling low loss forward operation, regenerative braking functionality, and reverse vehicle operation of the hybrid powertrain.

16. A hybrid powertrain comprising:

an engine;

an electrically-variable transmission having an input member and output member, said input member being selectively connectable to said engine;

a stationary member;

first and second motor/generators;

an energy storage device operatively connected to each of said first and said second motor/generators for providing power to and receiving power from said first and second motor/generators, wherein said energy storage device is configured to be operatively connectable with an offboard power supply for recharging said energy storage device;

a first planetary gear set representable by a first three-node lever of a lever diagram having a first node, a second node, and a third node;

a first torque-transmitting mechanism selectively engagable to connect said third node to said stationary member;

a second torque-transmitting mechanism selectively engagable to connect said first motor/generator with said third node;

a third torque-transmitting mechanism selectively engagable to connect said engine with said first motor/generator, wherein engagement of selected ones of said first, said second, and said third torque-transmitting mechanisms alone or in different combinations establishes six operating modes including a one-motor electric-only mode in which said engine is normally off, a series mode in which said engine is normally on, an output split mode, a neutral mode, a neutral battery charge mode, and a two-motor electric-only mode in which the engine is normally off;

wherein said first motor/generator and said input member are selectively connectable with said third node via said second torque-transmitting mechanism, said second motor/generator is continuously connected with said first node, and said second node is continuously connected for common rotation with said output member; and

wherein engagement of said first torque-transmitting mechanisms and disengagement of said second torque transmitting mechanism establishes an electric-only mode in which said input member does not rotate and said second motor/generator acts as a motor utilizing power from the recharged said energy storage device to provide driving torque at said output member.

17. The hybrid powertrain of claim 16, wherein said first planetary gear set includes a sun gear member, a ring gear member, and a carrier member, said sun gear member being continuously connected to said second motor/generator, said ring gear member being selectively connectible to said first motor/generator through said second torque-transmitting mechanism and selectively connectible to said stationary member through said first torque-transmitting mechanism, and said carrier member being continuously connected to said output member.

18. The hybrid powertrain of claim 17, wherein the hybrid powertrain is operable for starting said engine when said engine is disconnected from said first planetary gear set during said series mode, thereby providing an optimal transition from an engine-off to an engine-on condition.

19. The hybrid powertrain of claim 16, wherein said neutral mode describes a condition in which said second motor/generator is disconnected from said output member by disengagement of said third torque transmitting mechanism, and wherein said neutral battery charge mode operable for charging said energy storage device upon engagement of said third torque transmitting mechanism to connect said first motor/generator to said engine.

20. The hybrid powertrain of claim 16, further comprising a dog clutch, wherein said first torque-transmitting mechanism is a one-way clutch in parallel with said dog clutch for enabling low loss forward operation, regenerative braking functionality, and reverse vehicle operation of the hybrid powertrain.

21. The hybrid powertrain of claim 16, wherein said first torque-transmitting mechanism is a lockable one-way clutch for enabling low loss forward operation, regenerative braking functionality, and reverse vehicle operation of the hybrid powertrain.