Method and apparatus to control motor cooling in an electro-mechanical transmission

• US 8,167,773 B2
• Filed: 10/15/2008
• Issued: 05/01/2012
• Est. Priority Date: 10/26/2007
• Status: Active Grant

• Current Assignee: Bayerische Motoren Werke AG, Daimler AG (Mercedes-Benz Group AG), Chrysler Group LLC (Stellantis NV)
• Original Assignee: Bayerische Motoren Werke AG, GM Global Technology Operations LLC (General Motors Company), Daimler AG (Mercedes-Benz Group AG), Chrysler LLC (Stellantis NV)
• Inventors: Kothari, Aniket, Sah, Jy-Jen F., Naqvi, Ali K, Gourlay, William Joseph
• Primary Examiner(s): Phan, Hau
• Assistant Examiner(s): Meyer, Jacob
• Application Number:
  US12/252,353
• Publication Number:
  US 20090107755A1
• Time in Patent Office: 1,294 Days
• Field of Search: 477/98, 180/65.265, 180/65.275, 180/65.285, 310/53, 184/104.1, 622/592
• US Class Current: 477/98
• CPC Class Codes: B60K 1/02 comprising more than one electric motor
• CPC Class Codes: B60K 2001/003 with means for cooling the electrical propulsion units
• CPC Class Codes: B60K 6/365 with the gears having orbital motion
• CPC Class Codes: B60K 6/445 Differential gearing distribution type
• CPC Class Codes: B60K 6/547 the transmission being a stepped gearing
• CPC Class Codes: B60L 2240/421 Speed
• CPC Class Codes: B60L 2240/423 Torque
• CPC Class Codes: B60L 2240/425 Temperature
• CPC Class Codes: B60L 2240/441 Speed
• CPC Class Codes: B60L 2240/445 Temperature
• CPC Class Codes: B60L 2240/485 Temperature
• 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 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 2050/0006 Digital architecture hierarchy
• CPC Class Codes: B60W 2510/0638 Engine speed
• CPC Class Codes: B60W 2510/0671 Engine manifold pressure
• CPC Class Codes: B60W 2510/0676 Engine temperature
• CPC Class Codes: B60W 2510/081 Speed
• CPC Class Codes: B60W 2510/087 : Temperature
• CPC Class Codes: B60W 2510/107 : Temperature
• CPC Class Codes: B60W 2510/244 : Charge state
• CPC Class Codes: B60W 2540/10 : Accelerator pedal position
• CPC Class Codes: B60W 2540/12 : Brake pedal position
• CPC Class Codes: B60W 2555/20 : Ambient conditions, e.g. wind or rain
• CPC Class Codes: B60W 2710/0666 : Engine torque
• CPC Class Codes: B60W 2710/083 : Torque
• CPC Class Codes: B60W 30/1843 : Overheating of driveline components B60W30/186 takes precedence
• CPC Class Codes: F16H 2037/104 : Power split variators with one end of the CVT connected or connectable to two or more differentials
• CPC Class Codes: F16H 2061/0037 : characterised by controlled fluid supply to lubrication circuits of the gearing see also lubrication control F16H57/0446
• CPC Class Codes: F16H 2200/201 : with three sets of orbital gears
• 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: F16H 59/72 : dependent on oil characteristics, e.g. temperature, viscosity
• CPC Class Codes: H02K 7/006 : Structural association of a motor or generator with the drive train of a motor vehicle
• CPC Class Codes: H02K 9/19 : for machines with closed casing and closed-circuit cooling using a liquid cooling medium, e.g. oil
• CPC Class Codes: Y02T 10/62 : Hybrid vehicles
• CPC Class Codes: Y02T 10/64 : Electric machine technologies in electromobility

Abstract

A method for controlling a powertrain including an transmission coupled to an engine and an electric machine and a hydraulic control system providing hydraulic flow to a cooling circuit of the electric machine, wherein the transmission is adapted to selectively transmit mechanical power to an output member, includes monitoring a temperature of the electric machine, determining a cooling flow requirement for the cooling circuit based upon the temperature of the electric machine, comparing the cooling flow requirement to a threshold cooling flow, and requesting active electric machine cooling of the electric machine based upon the comparing.

Claims

1. Method for controlling a powertrain comprising an electro-mechanical transmission mechanically-operatively coupled to an internal combustion engine and an electric machine and a hydraulic control system providing a first, base cooling flow to said electric machine and selectively providing a second, active cooling flow to said electric machine, said transmission adapted to selectively transmit mechanical power to an output member, said method comprising:

providing said base cooling flow to said electric machine through a first hydraulic circuit; and

selectively providing said active cooling flow to said electric machine through a second hydraulic circuit, comprising;

monitoring a temperature of said electric machine;

determining a cooling flow requirement for said electric machine based upon said temperature of said electric machine;

comparing said cooling flow requirement to said base cooling flow; and

providing said active cooling flow based upon said comparing.

2. The method of claim 1, further comprising:

monitoring flow requirements of other functions served by said hydraulic control system; and

wherein said providing said active cooling flow is further based upon said flow requirements of other functions.

3. The method of claim 2, further comprising:

monitoring an operating state of said engine; and

wherein said providing said active cooling flow is further based upon said operating state of said engine.

4. The method of claim 2, further comprising:

monitoring a hydraulic line pressure of said hydraulic control system; and

wherein said providing said active cooling flow is further based upon said hydraulic line pressure.

5. The method of claim 2, wherein said providing said active cooling flow comprises:

selecting a flow management valve to an active electric machine cooling enabled position; and

selecting a pressure control solenoid position to an open position to allow flow to said second hydraulic circuit.

6. The method of claim 1, further comprising:

providing a second electric machine base cooling flow to a second electric machine through a third hydraulic circuit; and

selectively providing a second electric machine active cooling flow to said electric machine through a fourth hydraulic circuit, comprising;

monitoring a temperature of said second electric machine;

determining a cooling flow requirement for said second electric machine based upon said temperature of said second electric machine;

comparing said cooling flow requirement for said second electric machine to said second electric machine base cooling flow; and

providing said second electric machine active cooling flow based upon said comparing.

7. The method of claim 6, further comprising:

monitoring flow requirements of other functions served by said hydraulic control system; and

commanding activation of at least one of said active cooling flow to said electric machine and said second electric machine active cooling flow to said second electric machine based upon said comparing said cooling flow requirement to said base cooling flow, comparing said cooling flow requirement for said second electric machine to said second electric machine base cooling flow, said temperatures of said electric machines, and said flow requirements of other functions.

8. The method of claim 7, further comprising:

monitoring a hydraulic line pressure of said hydraulic control system; and

wherein commanding activation of at least one of said active cooling flow to said electric machine and said second electric machine active cooling flow to said second electric machine is further based upon said hydraulic line pressure.

9. The method of claim 7, further comprising:

monitoring a hydraulic line pressure of said hydraulic control system; and

modulating operation of functions served by said hydraulic control system based upon said monitoring said hydraulic line pressure.

10. The method of claim 7, further comprising:

monitoring a hydraulic line pressure of said hydraulic control system; and

modulating operation of an auxiliary hydraulic pump based upon said monitoring said hydraulic line pressure.

11. The method of claim 1, further comprising:

monitoring a hydraulic line pressure of said hydraulic control system; and

modulating operation of an auxiliary hydraulic pump based upon said monitoring said hydraulic line pressure.

12. Method for controlling a powertrain comprising an electro-mechanical transmission mechanically-operatively coupled to an internal combustion engine and first and second electric machines adapted to selectively transmit mechanical power to an output member, said method comprising:

providing a first base cooling flow to said first electric machine through a first hydraulic circuit;

providing a second base cooling flow to said second electric machine through a second hydraulic circuit;

selectively providing active cooling flows to each of said first and second electric machines through a first electric machine active cooling hydraulic circuit and a second electric machine active cooling hydraulic circuit, comprising;

monitoring temperatures of said first and second electric machines;

and

providing said active cooling flows to said first and second electric machines based upon said first base cooling flow, said second base cooling flow, said monitored temperatures, a power loss of a hydraulic pump, and an operational state of said powertrain.

13. Apparatus for controlling a powertrain comprising an electro-mechanical transmission mechanically-operatively coupled to an internal combustion engine and first and second electric machines adapted to selectively transmit mechanical power to an output member, said apparatus comprising:

said first and second electric machines; and

an active electric machine cooling control system;

monitoring temperatures of said first and second electric machines;

determining a base electric machine cooling flow for each of a first and second base cooling circuit providing a hydraulic flow to said first and second electric machines; and

commanding active cooling of said first and second electric machines through first and second active cooling circuits based upon said base electric machine cooling flows, said monitored temperatures, a power loss of a hydraulic pump, and an operational state of said powertrain.

14. The apparatus of claim 13, wherein said active electric machine cooling control system comprises:

a first hydraulic powertrain cooling module inputting said temperatures of said first and second electric machines and outputting cooling flow requirements of said first and second electric machines;

a second hydraulic powertrain cooling module inputting said cooling flow requirements of said first and second electric machines and outputting an active electric machine cooling request for each of the first and second electric machines; and

a hydraulic control command module inputting said active electric machine cooling requests, monitoring operation of a hydraulic control system selectively channeling said hydraulic flow, and selectively controlling said active cooling of said first and second electric machines.

15. The apparatus of claim 13, further comprising a hydraulic control system comprising:

a flow management valve selectively enabling said active cooling.

16. The apparatus of claim 15, wherein said hydraulic control system further comprises:

a pressure control solenoid selectively directing said active cooling to said first electric machine through said first active cooling circuit; and

a pressure control solenoid selectively directing said active cooling to said second electric machine through said second active cooling circuit.

17. Method for controlling a powertrain comprising an electro-mechanical transmission mechanically-operatively coupled to an internal combustion engine and first and second electric machines adapted to selectively transmit mechanical power to an output member, said method comprising:

monitoring temperatures of said first and second electric machines;

determining a base electric machine cooling flow for a base electric machine cooling circuit providing a hydraulic flow to said first and second electric machines; and

commanding active cooling of said first and second electric machines based upon base electric machine cooling flow, said monitored temperatures, a power loss of a hydraulic pump, and operational state of said powertrain, said commanding comprising;

determining a cooling flow requirement to said first and second electric machines based upon said monitored temperatures;

requesting active cooling of said first and second electric machines based upon said monitored temperatures and said base electric machine cooling flow;

determining prioritization among functions requiring hydraulic flow based upon said power loss of said hydraulic pump and said operational state of said powertrain; and

commanding active cooling of said first and second electric machines when said prioritization enables hydraulic flow to said first and second electric machines.