Accessory drive system and method for a hybrid vehicle with an electric variable transmission

• US 7,506,711 B2
• Filed: 01/17/2006
• Issued: 03/24/2009
• Est. Priority Date: 01/17/2006
• Status: Expired due to Fees

• Current Assignee: GM Global Technology Operations LLC (General Motors Company)
• Original Assignee: GM Global Technology Operations Incorporated (General Motors Company)
• Inventors: Usoro, Patrick B.
• Primary Examiner(s): VANAMAN, FRANK BENNETT
• Application Number:
  US11/333,620
• Publication Number:
  US 20070163818A1
• Time in Patent Office: 1,162 Days
• Field of Search: 180/65.2, 180/65.3, 180/65.4, 903/948, 123/198.F
• US Class Current: 180/65.23
• CPC Class Codes: B60K 1/02 comprising more than one electric motor
• CPC Class Codes: B60K 6/48 Parallel type
• CPC Class Codes: B60W 10/06 including control of combustion engines
• CPC Class Codes: B60W 10/08 including control of electric propulsion units, e.g. motors or generators
• CPC Class Codes: B60W 10/30 including control of auxiliary equipment, e.g. air-conditioning compressors or oil pumps
• 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 2510/10 Change speed gearings
• CPC Class Codes: Y02T 10/62 Hybrid vehicles

Abstract

An accessory drive system for a hybrid electric vehicle having an electric variable transmission. The apparatus includes an engine operatively connected to the electric variable transmission. The electric variable transmission includes a gear arrangement configured to selectively produce a plurality of speed ratios. The electric variable transmission also includes at least two motor/generators connected to the gear arrangement, and to a storage device. A drive pulley is connected to an output shaft of the engine. A plurality of driven pulleys are each connected to an accessory. A drive belt connectively couples the drive pulley and the plurality of driven pulleys. A controller is operatively connected to the engine and the motor/generators, and is configured to control the engine and the motor/generators to ensure the accessories are adequately powered.

Claims

1. An automotive accessory drive system for a hybrid electric vehicle comprising:

an engine;

an electric variable transmission operatively connected to the engine, said electric variable transmission including a gear arrangement and at least two motor-generators, said electric variable transmission being configured to selectively produce a plurality of speed ratios;

a drive pulley connected to an output shaft of said engine;

a plurality of driven pulleys each of which is connected to one of a plurality of accessories;

a drive belt connectively coupling said drive pulley and said plurality of driven pulleys and operable to transfer drive forces between said drive pulley and said plurality of driven pulleys;

a controller operatively connected to the engine and the electric variable transmission, said controller configured to ensure the plurality of accessories remain adequately powered by selecting a speed ratio adapted to ensure that the speed at which the accessories are driven does not fall below a predefined minimum speed;

wherein the engine includes a plurality of intake valves;

a plurality of exhaust valves; and

a crankshaft; and

wherein the controller is configurable to manipulate the intake valves and the exhaust valves when the accessories are being driven by power from the motor-generators through the engine crankshaft, in order to reduce crankshaft rotational resistance and engine pumping losses, and thereby improve the efficiency of the accessory drive system.

2. The automotive accessory drive system of claim 1, wherein the electric variable transmission includes a storage device operatively connected to the motor/generators, said storage device being configured to store energy from the motor/generators when excess power is being produced by the engine.

3. The automotive accessory drive system of claim 2, wherein the storage device is a battery operable to supply power to the motor/generators.

4. The automotive accessory drive system of claim 1, wherein the gear arrangement is a planetary gear arrangement.

5. The automotive accessory drive system of claim 1, wherein the motor/generators includes a first motor/generator and a second motor/generator.

6. An automotive accessory drive system for a hybrid electric vehicle comprising:

an engine;

an electric variable transmission operatively connected to said engine, said electric variable transmission including;

a gear arrangement configured to selectively produce a plurality of speed ratios;

at least two motor/generators connected to said gear arrangement; and

a storage device connected to said motor/generators;

a drive pulley connected to an output shaft of said engine;

a plurality of driven pulleys each of which is connected to one of a plurality of accessories;

a drive belt connectively coupling said drive pulley and said plurality of driven pulleys and operable to transfer drive forces between said drive pulley and said plurality of driven pulleys;

a controller operatively connected to the engine and the motor/generators, said controller configured to control the engine and the motor/generators to ensure said plurality of accessories are adequately powered without the need for individual motors for each accessory;

wherein the engine includes a plurality of intake valves;

a plurality of exhaust valves; and

a crankshaft; and

wherein the controller is configurable to manipulate the intake valves and the exhaust valves when the accessories are being driven by power from the motor-generators through the engine crankshaft, in order to reduce crankshaft rotational resistance and engine pumping losses, and thereby improve the efficiency of the accessory drive system.

7. The automotive accessory drive system of claim 6, wherein the gear arrangement is a planetary gear-set.

8. The automotive accessory drive system of claim 7, wherein the storage device is a battery operable to supply power to the motor/generator.

9. A method for operating an accessory drive system of a hybrid electric vehicle comprising:

providing an engine operatively connected to an electric variable transmission;

transferring energy from the electric variable transmission to a plurality of accessories;

establishing a predefined minimum speed at which all of said plurality of accessories must be driven in order to remain fully operational;

controlling the electric variable transmission to produce a speed ratio selected to ensure that the speed at which the accessories are driven does not fall below the predefined minimum speed; and

manipulating a plurality of intake valves and exhaust valves of the engine when the accessories are being driven by power from the electric variable transmission through an engine crankshaft, in order to reduce crankshaft rotational resistance and engine pumping losses, and thereby improve the efficiency of the accessory drive system.