Transmission fluid warm-up system and method

Patent metadata

Field	Value
Publication number	US-9441725-B2
Application number	US-201414558135-A
Country	US
Kind code	B2
Filing date	Dec 2, 2014
Priority date	Dec 2, 2014
Publication date	Sep 13, 2016
Grant date	Sep 13, 2016

Abstract

A vehicle includes a transmission having gears lubricated by oil and a variable voltage converter (VVC). The VVC includes an inductor arranged such that the oil contacts the inductor. The vehicle also includes at least one controller configured to operate the VVC to output a desired power. The controller, in response to a temperature of the oil being less than a threshold, alters a voltage and current of the VVC while maintaining the desired power to increase heat output by the inductor.

First claim

What is claimed is:

1. A vehicle comprising:
a transmission including gears lubricated by oil;
a variable voltage converter (VVC) including an inductor arranged such that the oil contacts the inductor; and
at least one controller configured to operate the VVC to output a desired power, and in response to a temperature of the oil being less than a threshold, alter a voltage and current of the VVC while maintaining the desired power to increase heat output by the inductor.

2. The vehicle of claim 1 wherein the transmission further includes a housing and wherein the inductor is mounted within the housing.

3. The vehicle of claim 2 wherein the transmission further includes nozzles for spraying the oil directly on the inductor.

4. The vehicle of claim 1 further comprising:
a power electronics housing attached to the transmission, wherein the inductor is mounted within the power electronics housing; and
fluid lines connected to the inductor and configured to circulate oil between the inductor and the transmission.

5. The vehicle of claim 1 wherein, in response to a temperature of the oil being less than a threshold, the controller is further configured to increase the voltage and proportionally decrease the current while maintaining the desired power to increase heat output by the inductor.

6. The vehicle of claim 1 further comprising a transmission shaft coupled to at least one of the gears, and wherein the controller is further configured to receive a signal indicating a speed of the shaft and in response to the speed being greater than a threshold speed, operate the VVC to increase heat output by the inductor.

7. The vehicle of claim 1 wherein the controller is further configured to receive a signal indicating a driver torque request and in response, operate the VVC to increase heat output by the inductor if the driver torque request is below a threshold value.

8. A vehicle comprising:
a transmission including gears lubricated by oil;
a battery;
a variable voltage converter electrically connected to the battery and including an inductor arranged to contact the oil; and
at least one controller configured to receive a signal indicative of an oil temperature, and reverse a polarity of a battery current if the oil temperature is below a threshold value to increase heat output by the inductor to heat the oil.

9. The vehicle of claim 8 wherein the controller is further configured to reverse the polarity of the battery current if the oil temperature is below the threshold value and a tip-in event, tip-out event or a terminal voltage event has occurred.

10. The vehicle of claim 8 wherein the controller is further configured to reverse the polarity of the battery current if the oil temperature is below the threshold value and a tip-in event or a tip-out event has occurred.

11. The vehicle of claim 10 wherein the controller is further configured to reverse the polarity of the battery at a first slew rate for the tip-in event and at a second slew rate for the tip-out event.

12. The vehicle of claim 11 wherein the first slew rate is greater than the second slew rate.

13. The vehicle of claim 8 wherein the inductor is mounted within the transmission.

14. The vehicle of claim 13 wherein the transmission further includes nozzles for spraying the oil directly on the inductor.

15. A method for heating a transmission of a hybrid vehicle, the vehicle including a variable voltage converter (VVC) having an inductor in contact with transmission oil, the method comprising:
operating the VVC to output a desired power, and in response to a temperature of the oil being less than a threshold, alter a voltage and current of the VVC while maintaining the desired power to increase heat output by the inductor.

16. The method of claim 15 wherein the inductor is mounted within the transmission.

17. The method of claim 16 further comprising splashing the oil onto the inductor by rotating gears within the transmission.

18. The method of claim 16 further comprising spraying oil directly on the inductor with a nozzle.

19. The method of claim 15 further comprising increasing the voltage and proportionally decreasing the current while maintaining the desired power to increase heat output by the inductor if the temperature of the oil is less than the threshold.

20. The method of claim 15 further comprising receiving a signal indicative of a transmission shaft speed and wherein the operating is commenced in response to the shaft speed being above a threshold speed.

Assignees

• Ford Global Tech Llc

Inventors

• Dobbins Brandon
• Kozarekar Shailesh Shrikant
• Layden Kevin

Classifications

• F16H57/0457

  Splash lubrication · CPC title

• B60K6/445

  Differential gearing distribution type · CPC title

• F16H57/0413 Primary

  Controlled cooling or heating of lubricant; Temperature control therefor · CPC title

• F16H57/042

  Guidance of lubricant · CPC title

• B60Y2306/03

  Lubrication · CPC title