Differential carrier temperature sensing method

• US 9,976,644 B2
• Filed: 04/04/2017
• Issued: 05/22/2018
• Est. Priority Date: 03/11/2013
• Status: Active Grant

• Current Assignee: Dana Automotive Systems Group, LLC (Dana, Inc.)
• Original Assignee: Dana Automotive Systems Group, LLC (Dana, Inc.)
• Inventors: Beesley, Peter A., Paielli, Perry M.
• Primary Examiner(s): Verbitsky, Gail Kaplan
• Application Number:
  US15/478,497
• Publication Number:
  US 20170204959A1
• Time in Patent Office: 413 Days
• Field of Search: 374144, 374145, 374147, 374148, 374208, 374137, 374153, 475220, 475230
• CPC Class Codes: F16H 57/01 Monitoring wear or stress of gearing elements, e.g. for triggering maintenance
• CPC Class Codes: F16H 57/0405 Monitoring quality of lubricant or hydraulic fluids
• CPC Class Codes: F16H 59/72 dependent on oil characteristics, e.g. temperature, viscosity
• CPC Class Codes: F16H 61/0006 Electronic control units for transmission control, e.g. connectors, casings or circuit boards
• CPC Class Codes: G01K 7/427 Temperature calculation based on spatial modeling, e.g. spatial inter- or extrapolation
• CPC Class Codes: G01N 25/72 Investigating presence of flaws
• CPC Class Codes: H05K 7/20854 Heat transfer by conduction from internal heat source to heat radiating structure H05K7/20863 takes precedence

Abstract

A method of sensing an internal temperature of a differential carrier includes providing a differential carrier temperature sensing package with an electronic circuit board having a first temperature sensor that is in thermally conductive contact with a thermal conductor, where the thermal resistance of the package and thermal conductor is given and known as R_ENC. The package is extended through an opening in a differential carrier that has a fluid in it. The first temperature sensor senses a differential fluid temperature T_SNS. The electronic circuit board further has a second temperature sensor, whereby the thermal resistance of the circuit board is a given known resistance R_PCB. The second temperature sensor senses an internal package temperature T_PCB within the package. Consequently, an internal temperature of the differential is calculated from the equation:
T_INT=T_SNS(1 R_ENC/R_PCB)−T_PCB(R_ENC/R_PCB).

Claims

1. A method of determining an internal differential carrier temperature T_INT, comprising:

measuring a temperature T_SNS of a fluid within a differential carrier;

measuring an internal temperature T_PCB of an electronic circuit board disposed within a package housing of a temperature sensing package;

utilizing a known housing plus thermal conductor thermal resistance R_ENC of a thermal conductor disposed within the package housing; and

utilizing a known thermal conductor resistance of the package housing at the electronic circuit board R_PCB disposed within the package housing of the temperature sensing package, wherein an internal differential carrier temperature T_INT is calculated by way of the equation;

T_INT=T_SNS(1 R_ENC/R_PCB)−

T_PCB(R_ENC/R_PCB) wherein the internal differential carrier temperature Tint is to be used to monitor and control a vehicle within which the differential carrier resides.

2. The method of determining an internal differential carrier temperature of claim 1, wherein thermal energy is conducted from the interior of the differential carrier to the electronic circuit board of the temperature sensing package when the temperature inside the differential carrier is higher than the temperature outside the differential carrier.

3. The method of determining an internal differential carrier temperature of claim 1, wherein thermal energy is conducted from the electronic circuit board of the temperature sensing package to the interior of the differential carrier when the temperature outside the differential carrier is higher than the temperature inside the differential carrier.

4. A method of determining an internal differential carrier temperature, comprising:

providing a package housing comprising an upper portion and a lower portion connected together to form a sealed package housing, wherein the upper portion and the lower portion are in thermally conductive contact with an environment external to a differential carrier housing, wherein the lower portion is in thermally conductive contact with an outer surface of the differential carrier housing, wherein the lower portion of the package housing extends through an opening in the differential carrier housing, and wherein the lower portion of the package housing is in thermally conductive contact with a fluid within the differential carrier housing;

providing an electronic circuit attached to the upper portion within the package housing, and wherein the electronic circuit is in thermally conductive contact with the upper portion of the package housing;

providing a first temperature sensor disposed on the electronic circuit and in thermally conductive contact with a thermal conductor imbedded in and in thermally conductive contact with the lower portion of the package housing, wherein the lower portion of the package housing is in thermally conductive contact with the fluid within the differential carrier housing;

providing a second temperature sensor disposed on the electronic circuit;

measuring a temperature T_SNS of the fluid within the differential carrier and an internal temperature T_PCB of the electronic circuit board disposed within the package housing; and

utilizing a known package housing plus thermal conductor thermal resistance R_ENC of the thermal conductor disposed within the package housing, and a known thermal conductor resistance of the package housing at the electronic circuit board R_PCB, wherein an internal differential carrier temperature T_INT is determined by way of the equation T_INT=T_SNS(1−

R_ENC/R_PCB)−

T_PCB (R_ENC/R_PCB) wherein the internal differential carrier temperature Tint is to be used to monitor and control a vehicle within which the differential carrier resides.

5. A method of determining an internal differential carrier temperature, comprising:

providing a package housing comprising an upper portion and a lower portion connected together to form a sealed package housing, wherein the upper portion and the lower portion are in thermally conductive contact with an environment external to a differential carrier housing, wherein the lower portion of the package housing is in thermally conductive contact with an outer surface of the differential carrier housing, wherein the lower portion of the package housing is extends through an opening in the differential carrier housing, and wherein the lower portion of the package housing is in thermally conductive contact with a fluid within the differential carrier housing;

providing an electronic circuit attached to the upper portion of the package housing within the package housing, and wherein the electronic circuit is in thermally conductive contact with the upper portion of the package housing;

providing a thermal conductor imbedded in and in thermally conductive contact with the lower portion of the package housing, and wherein the lower portion of the package housing is in thermally conductive contact with the fluid within the differential carrier housing;

measuring a temperature T_SNS of the fluid within the differential carrier and an internal temperature T_PCB of an electronic circuit board disposed within the package housing; and

utilizing a known package housing plus thermal conductor thermal resistance R_ENC of the thermal conductor disposed within the package housing, and a known thermal conductor resistance of the package housing at the electronic circuit board R_PCB, wherein an internal differential carrier temperature T_INT is determined by way of the equation T_INT=T_SNS(1 R_ENC/R_PCB)−

T_PCB (R_ENC/R_PCB) wherein the internal differential carrier temperature Tint is to be used to monitor and control a vehicle within which the differential carrier resides.

6. The method of determining an internal differential carrier temperature of claim 5, wherein thermal energy is conducted from the interior of the differential carrier to the electronic circuit board of the temperature sensing package when the temperature inside the differential carrier is higher than the temperature outside the differential carrier.

7. The method of determining an internal differential carrier temperature of claim 5, wherein thermal energy is conducted from the electronic circuit board of the temperature sensing package to the interior of the differential carrier when the temperature outside the differential carrier is higher than the temperature inside the differential carrier.

8. A method of determining an internal differential carrier temperature T_INT, comprising:

measuring a temperature T_SNS of a fluid within a differential carrier;

measuring an internal temperature T_PCB of an electronic circuit board disposed within a package housing of a temperature sensing package;

utilizing a known housing plus thermal conductor thermal resistance R_ENC of a thermal conductor disposed within the package housing;

utilizing a known thermal conductor resistance of the package housing at an electronic circuit board R_PCB disposed within the package housing of the temperature sensing package; and

utilizing a known series dynamic thermal capacitance C_PCB1 and dynamic thermal resistance R_PCB1 of the package housing at an electronic circuit board disposed within the package housing of the temperature sensing package, wherein the electronic circuit board is in parallel with the base R_PCB, wherein an internal differential carrier temperature T_INT is calculated by way of the equation;

T_INT=T_SNS(1 R_ENC/R_PCB)−

T_PCB(R_ENC/R′

_PCB), wherein R′

_PCB=(R_PCB(sR_PCB1·

C_PCB1

     1))/(sC_PCB1(R_PCB R_PCB1

     1)) wherein the internal differential carrier temperature Tint is to be used to monitor and control a vehicle within which the differential carrier resides.