HYBRID VEHICLE POWERTRAIN COOLING SYSTEM

• US 20120173063A1
• Filed: 08/18/2011
• Published: 07/05/2012
• Est. Priority Date: 12/31/2010
• Status: Active Grant

• Current Assignee: Cummins Incorporated
• Original Assignee: Cummins Incorporated
• Inventors: Madurai Kumar, Mahesh, Andreae, Morgan M.
• Granted Patent: US 9,096,207 B2
• Time in Patent Office: Days
• US Class Current: 701/22
• CPC Class Codes: B60K 6/48 Parallel type
• CPC Class Codes: B60W 10/02 including control of driveline clutches
• 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 10/26 for electrical energy, e.g. batteries or capacitors
• 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 2710/0688 Engine temperature
• CPC Class Codes: F01P 2005/105 Using two or more pumps
• CPC Class Codes: F01P 2005/125 Driving auxiliary pumps electrically
• CPC Class Codes: F01P 2050/24 Hybrid vehicles
• CPC Class Codes: Y02T 10/62 Hybrid vehicles

Abstract

Some exemplary embodiments include a hybrid vehicle cooling system comprising a closed loop coolant flowpath including a valve operable to direct coolant flow to an internal combustion engine or to an internal combustion engine bypass, a thermostat operable to direct coolant flow from the internal combustion engine or the internal combustion engine bypass to a radiator or a radiator bypass, a plurality of hybrid powertrain components positioned in parallel to receive coolant flow from the radiator or the radiator bypass, a mechanically driven coolant pump operable to pump coolant through the closed loop coolant flowpath, and an electrically driven coolant pump operable to pump coolant through the closed loop coolant flowpath. Additional exemplary embodiments include methods of operation and/or control of hybrid vehicle cooling systems.

Claims

1. A hybrid vehicle cooling system comprising:

a closed loop coolant flowpath including

at least one valve operable to direct coolant flow to an internal combustion engine or to an internal combustion engine bypass,

a thermostat operable to direct coolant flow from the internal combustion engine or the internal combustion engine bypass to a radiator or a radiator bypass,

a plurality of hybrid powertrain components positioned in parallel to receive coolant flow from the radiator or the radiator bypass;

a mechanically driven coolant pump operable to pump coolant through the closed loop coolant flowpath; and

an electrically driven coolant pump operable to pump coolant through the closed loop coolant flowpath.

2. A hybrid vehicle cooling system according to claim 1 comprising a controller configured to control the system to operate in a first mode wherein the engine is on, the mechanically driven coolant pump operates to pump coolant through the closed loop coolant flowpath up to a threshold coolant flow rate, and the mechanically driven coolant pump and the electrically driven coolant pump operate to pump coolant through the closed loop coolant flowpath above the threshold coolant flow rate.

3. A hybrid vehicle cooling system according to claim 2 comprising a controller configured to control the system to operate in a second mode wherein the engine is off, the mechanically driven coolant pump is off, the at least one valve directs coolant flow to the internal combustion engine bypass, and the electrically driven coolant pump operates to pump coolant through the closed loop coolant flowpath.

4. A hybrid vehicle cooling system according to claim 3 comprising a controller operable to control the system to operate in a third mode wherein one or more of the plurality of hybrid powertrain components is controlled to heat the coolant effective to heat the engine.

5. A hybrid vehicle cooling system according to claim 1 wherein the flowpath connects the engine or engine bypass in series with the plurality of hybrid powertrain components.

6. A hybrid vehicle cooling system according to claim 1 wherein the plurality of hybrid powertrain components include a motor/generator, a clutch, and power electronics.

7. A hybrid vehicle cooling system according to claim 1 wherein the mechanically driven coolant pump and the electrically driven coolant pump are positioned in series in the coolant flow path intermediate the engine and the plurality of hybrid powertrain components.

8. A hybrid vehicle cooling system according to claim 1 comprising a plurality of valves operable to direct coolant flow from the radiator or the radiator bypass to corresponding ones of the plurality of hybrid powertrain components or a hybrid powertrain component bypass.

9. A hybrid vehicle cooling system according to claim 1 wherein the system has a required peak coolant flow rate and the maximum coolant flow rate provided by the mechanically driven coolant flow pump is less than the required peak coolant flow rate.

10. A hybrid vehicle cooling system according to claim 1 wherein

the mechanically driven coolant pump is operable to pump coolant through the engine and the electrically driven coolant pump is operable to pump coolant through the engine or the engine bypass.

11. A hybrid vehicle cooling system according to claim 1 wherein coolant flow proceeds in series from the mechanically driven coolant pump or the electrically driven coolant pump to the engine or engine bypass to the radiator or radiator bypass to the plurality of hybrid powertrain components to the mechanically driven coolant pump or the electrically driven coolant pump.

12. A hybrid vehicle system comprising:

an internal combustion engine;

an electric machine;

power electronics operable to provide power to the electric machine;

a coolant flowpath in thermal communication with the internal combustion engine, the electric machine, and the power electronics; and

a controller operable to control the electric machine and the power electronics to provide power to the electric machine;

wherein the controller is operable to selectively increase the temperature of the internal combustion engine by controlling at least one of the electric machine and the power electronics to provide increased heat to the coolant.

13. A hybrid vehicle cooling system according to claim 12 wherein the controller is operable to selectively operate an electrical coolant pump to increase coolant flow rate provided by an mechanical coolant pump driven by the internal combustion engine.

14. A hybrid vehicle cooling system according to claim 12 wherein the controller is operable to selectively direct coolant to bypass the internal combustion engine.

15. A hybrid vehicle cooling system according to claim 12 wherein coolant flow to the electric machine and the power electronics is in parallel.

16. A hybrid vehicle cooling system according to claim 12 comprising a radiator wherein the coolant flowpath is routed in series through the engine, the radiator and at least one of the electric machine and the power electronics.

17. A hybrid vehicle cooling system according to claim 12 wherein the electric machine comprises a motor/generator.

18. A method comprising:

pumping coolant through a closed loop flowpath in thermal communication with an internal combustion engine, an electric motor, and power electronics;

determining a engine temperate condition; and

controlling operation of the electric motor or the power electronics to increase heat transfer to the coolant effective to heat the engine based upon the engine temperate condition.

19. A method according to claim 18 wherein the controlling operation of the electric motor or the power electronics to increase heat transfer to the coolant effective to heat the engine includes controlling the electric motor or the power electronics to operate at reduced efficiency.

20. A method according to claim 18 comprising operating the engine, pumping coolant through the closed loop flowpath with an engine driven coolant pump up to a threshold coolant flow rate, and pumping coolant through the closed loop flowpath with the engine driven coolant pump in combination with an additional coolant pump above the threshold coolant flow rate.

21. A method according to claim 18 comprising controlling a valve to selectively direct coolant flow through the engine or through an engine bypass.

22. A method according to claim 18 comprising pumping coolant through the closed loop flowpath with an electrically driven coolant pump and directing coolant to bypass the engine while the engine is off.

23. A method according to claim 18 comprising selectively cooling the coolant by transferring heat from the coolant with a radiator.