Inertia assisted engine cranking

• US 8,833,324 B2
• Filed: 10/01/2010
• Issued: 09/16/2014
• Est. Priority Date: 10/01/2010
• Status: Active Grant

• Current Assignee: Cummins Incorporated
• Original Assignee: Cummins Incorporated
• Inventors: O'Brien, John P., Barnes, David M.
• Primary Examiner(s): Vo, Hieu T
• Assistant Examiner(s): Castro, Arnold
• Application Number:
  US12/924,585
• Publication Number:
  US 20120080002A1
• Time in Patent Office: 1,446 Days
• Field of Search: 123/179.22, 123/198.R, 123/179.3, 701/113
• US Class Current: 123/179.22
• CPC Class Codes: B60K 2006/268 Electric drive motor starts the engine, i.e. used as starter motor
• CPC Class Codes: B60K 2025/005 driven by electric motors forming part of the propulsion unit
• CPC Class Codes: B60K 2025/022 by a mechanical transmission
• CPC Class Codes: B60K 25/00 Auxiliary drives B60K16/00 takes precedence; arrangements of tyre-inflating pumps mounted on vehicles B60C23/10; driving tyre-inflating pumps B60C; driving engine auxiliaries F02B
• CPC Class Codes: B60K 6/48 Parallel type
• CPC Class Codes: F02N 11/00 Starting of engines by means of electric motors
• CPC Class Codes: F02N 11/003 said electric motor being also used as a drive for auxiliaries, e.g. for driving transmission pumps or fuel pumps during engine stop
• CPC Class Codes: F02N 11/006 using a plurality of electric motors
• CPC Class Codes: F02N 5/04 of inertia type
• CPC Class Codes: Y02T 10/62 Hybrid vehicles

Abstract

An inertia assisted engine starting apparatus and method are disclosed. The apparatus includes an internal combustion engine and an accessory drive system including an accessory. The accessory includes a rotatable member. An electric motor is selectively rotationally coupled to the accessory drive system. A mechanical coupling device selectively transfers rotational kinetic energy from the accessory drive system to start the internal combustion engine.

Claims

1. An apparatus, comprising:

an internal combustion engine including a crankshaft;

an accessory drive system including an accessory, the accessory including a rotatable member;

a motor configured to selectively drive the accessory drive system effective to rotate the rotatable member;

a mechanical coupling device configured to selectively transfer rotational kinetic energy from the accessory drive system to the crankshaft; and

a controller operatively coupled with the mechanical coupling device and the motor;

wherein the controller is configured to;

couple the accessory drive system to the crankshaft;

evaluate whether there is sufficient kinetic energy stored by the accessory drive system to start the engine; and

if there is not sufficient kinetic energy stored by the accessory drive system to start the engine, control operation of the motor to increase torque provided to the crankshaft to start the engine;

wherein the controller is operable to start the engine either solely with stored kinetic energy of the accessory drive system or with stored kinetic energy of the accessory drive system in combination with torque from operation of the motor.

2. The apparatus of claim 1, wherein the accessory is selected from the accessories consisting of:

a coolant pump, a cooling fan, a compressor, and an engine alternator.

3. The apparatus of claim 1, wherein the electric motor provides further rotational kinetic energy concurrent with one or more accessories to start the internal combustion engine.

4. The apparatus of claim 1, further comprising a second electric motor to selectively provide rotational mechanical power to at least one of the accessory drive system and the internal combustion engine.

5. The apparatus of claim 1, further comprising an electric energy storage device to selectively provide electric power to the electric motor and wherein the electric motor is structured to selectively generate electric energy for storage by the electric energy storage device.

6. The apparatus of claim 5, wherein the electric motor is an asynchronous direct motor generator.

7. The apparatus of claim 1, wherein the internal combustion engine further comprises a diesel engine.

8. A method, comprising:

determining the rotational speed of at least one of an accessory drive system and an electric motor;

determining whether the rotational speed exceeds a predetermined speed;

in response to the rotational speed exceeding a predetermined speed, coupling the accessory drive to an internal combustion engine;

in response to the coupling, evaluating whether the kinetic energy is sufficient to start the engine and, if the kinetic energy is not sufficient to start the engine, operating the motor to increase the energy provided to start the engine;

wherein the engine is started either with kinetic energy without energy from operation of the motor, or with kinetic energy in combination with energy from operation of the motor.

9. The method of claim 8, further comprising rotating at least one of the accessory drive system and the electric motor to obtain the predetermined speed.

10. The method of claim 8, further comprising transferring the kinetic energy in the electric motor to the internal combustion engine to start the internal combustion engine.

11. The method of claim 8, further comprising providing additional torque to start the internal combustion engine in the case of a cold start.

12. The method of claim 8, wherein the internal combustion engine at least partially powers the accessory drive system once the internal combustion engine is started.

13. The method of claim 8, further comprising selectively producing and storing electric energy from the electric motor.

14. A method, comprising:

operating a vehicle power system including an internal combustion engine, an electric motor, and a device, the device selected from the devices consisting of;

a fan, a pump, a compressor, and an engine alternator;

powering the device with the electric motor;

storing kinetic energy in at least one of the electric motor and the device;

transferring the kinetic energy to the engine; and

evaluating whether the kinetic energy is sufficient to start the engine; and

if the kinetic energy is not sufficient to start the engine, operating the motor to increase the energy provided to start the engine;

wherein the engine is started either with kinetic energy without energy from operation of the motor, or with kinetic energy in combination with energy from operation of the motor.

15. The method of claim 14, wherein transferring at least a portion of the kinetic energy to start an internal combustion engine further comprises engaging a clutch.

16. The method of claim 14, further comprising controlling motor torque to smooth clutch engagement.

17. The method of claim 14, further comprising providing additional torque to start the internal combustion engine.

18. The method of claim 14, further comprising at least partially powering the device with the engine after engine startup.

19. An apparatus, comprising:

an internal combustion engine;

an accessory drive system including one or more accessories each including a rotatable member for storing rotational kinetic energy;

means for driving the accessory drive system;

means for transferring the kinetic energy to start the internal combustion engine;

a controller operatively coupled with the means for driving the accessory drive system and the means for transferring the rotational kinetic energy;

wherein the controller is configured to;

control the means for transferring the kinetic energy to provide stored rotational kinetic energy to turn the engine;

evaluate whether there is sufficient stored rotational kinetic energy to start the engine; and

if there is not sufficient stored rotational kinetic energy to start the engine, control operation of the means for driving the accessory system to increase torque provided to the crankshaft to start the engine;

wherein the controller is operable to start the engine either with stored rotational kinetic energy or with a combination of stored rotational kinetic energy and energy from operation of the means for driving the accessory drive system.

20. The apparatus of claim 19, wherein means for driving the accessory drive system provides rotational kinetic energy concurrent with the rotational kinetic energy from the one or more accessories to start the internal combustion engine.

21. The apparatus of claim 19, wherein means for storing rotational kinetic energy includes at least one of:

a coolant pump, a cooling fan, a compressor, and an electric motor.

22. The apparatus of claim 19, wherein the means for driving the accessory drive system further comprises a selective motor/generator and an electric energy storage device.

23. The apparatus of claim 19, wherein the internal combustion engine is further equipped with means for a start/stop function.

24. The apparatus of claim 19, further comprising a means for starting under a cold start condition.

25. The apparatus of claim 19, further comprising a means to determine if a rotational speed exceeds a predetermined speed.