Dynamic Traction Control System

• US 20080004783A1
• Filed: 06/04/2007
• Published: 01/03/2008
• Est. Priority Date: 06/19/2006
• Status: Active Grant

• Current Assignee: Magna Powertrain Incorporated (Magna International Incorporated)
• Original Assignee: Magna Powertrain Incorporated (Magna International Incorporated)
• Inventors: Bansbach, Eric A., Mohan, Sankar K., Mizon, Richard, Vaughn, Brian, Kirkwood, Malcolm E.
• Granted Patent: US 7,491,145 B2
• Time in Patent Office: Days
• US Class Current: 701/67
• CPC Class Codes: B60K 23/0808 for varying torque distribution between driven axles, e.g. by transfer clutch
• CPC Class Codes: B60W 2510/105 Output torque

Abstract

A transfer case for a motor vehicle having an input shaft, a first output shaft, a second output shaft, a clutch, a transfer mechanism, a sensor portion and a magnetoelastic torque sensor. The clutch has a clutch pack and a thrust mechanism that is configured to exert an engagement force on the clutch pack. The clutch pack has a first portion, which is rotatably driven by either or both of the input shaft and the first output shaft, and a second portion that is supported for rotation relative to the first portion. The transfer mechanism couples the second portion of the clutch pack to the second output shaft. The sensor portion is coupled to the first or second output shaft and is at least partially formed of a magnetoelastic material. The magnetoelastic torque sensor is disposed about and radially in-line with the sensor portion.

Claims

1. A power transfer assembly for a motor vehicle, comprising:

a first shaft having a first sensor portion that is at least partially formed of a magnetoelastic material;

a second shaft having a second sensor portion that is at least partially formed of a magnetoelastic material;

a clutch disposed between said first and second shafts;

a clutch actuator for selectively actuating said clutch;

a first magnetoelastic torque sensor that is disposed about said first shaft in radial alignment with said first sensor portion;

a second magnetoelastic torque sensor disposed about said second shaft in radial alignment with said second sensor portion; and

a control system for controlling actuation of said clutch actuator based on signals from said first and second torque sensors.

2. The power transfer assembly of claim 1 wherein said magnetoelastic material of said first sensor portion is bonded to said first shaft.

3. The power transfer assembly of claim 2 wherein said magnetoelastic material of said second sensor portion is bonded to said second shaft.

4. A method for operating a transfer case in a motor vehicle, the method comprising:

providing a transfer case having a first shaft, a second shaft, a clutch disposed between said first and second shafts, and a power-operated clutch actuator for exerting a clutch engagement force on said clutch pack;

producing a first sensor signal that is representative of a magnitude of torque transmitted through said first shaft;

producing a second sensor signal that is representative of a magnitude of torque transmitted through said second shaft; and

operating said clutch actuator in response to said first and second sensor signals.

5. A transfer case for a motor vehicle, comprising:

an input shaft adapted to be coupled to an output of a transmission;

a first output shaft adapted to be coupled to a first driveline;

a second output shaft adapted to be coupled to a second driveline;

a clutch having a clutch pack and a thrust mechanism, said clutch pack disposed between said first and second output shafts, said thrust mechanism operable for exerting a clutch engagement force on said clutch pack;

a sensor portion coupled to one of said first and second output shafts, said sensor portion being at least partially formed of a magnetoelastic material; and

a magnetoelastic torque sensor that is disposed about a portion of said one of said first and second output shafts so as to be radially aligned with said sensor portion.

6. The transfer case of claim 5 wherein said one of the first and second output shafts includes a shaft member and wherein said magnetoelastic material of said sensor portion is bonded to said shaft member.