Magnetic Sensor Packaging for Transmissions

Abstract

Designs to package a magneto-elastic torque sensor in an automotive transmission for volume production applications are provided. A transfer case assembly includes a transfer case shaft having a magnetized region and a magnetic torque sensor, for detecting torque of the transfer case shaft, mounted on at least one bushing supporting the transfer case shaft. A drive axle assembly includes an axle housing, an input shaft having a magnetized region, and a magnetic torque sensor, for detecting torque of the input shaft, mounted to the axle housing.

What is claimed is: 
     
         1 . A transfer case assembly comprising:
 a transfer case shaft having a magnetized region; and   a magnetic torque sensor, for detecting torque of the transfer case shaft, mounted on at least one bushing supporting the transfer case shaft.   
     
     
         2 . The assembly of  claim 1  further comprising:
 a transfer case; 
 wherein the sensor is further mounted to the transfer case. 
 
     
     
         3 . The assembly of  claim 1  further comprising:
 an anti-rotation device connected to the sensor and configured to prevent rotation of the sensor in response to the transfer case shaft rotating. 
 
     
     
         4 . The assembly of  claim 1  wherein:
 the transfer case shaft includes one of a transfer case input shaft, a transfer case output shaft to rear wheels, a transfer case output shaft to front wheels, and a transfer case output shaft to power takeoff. 
 
     
     
         5 . The assembly of  claim 1  wherein:
 the sensor includes a sensor housing, wherein the sensor housing includes a channel running therethrough for conveying lubrication to areas adjacent the sensor. 
 
     
     
         6 . A transmission comprising:
 a transmission case;   a gear having a magnetized region, wherein the gear is one of an idler gear and a transfer gear; and   a magnetic torque sensor, for detecting torque transmitted by the gear, mounted to the transmission case.   
     
     
         7 . The transmission of  claim 6  wherein:
 the gear includes a plurality of pieces which together form the gear, wherein one of the pieces includes the magnetized region. 
 
     
     
         8 . A transmission comprising:
 a transmission case;   an idler shaft;   an idler gear and a transfer gear spaced apart from one another about different portions of the idler shaft;   wherein the idler shaft includes a magnetized region in a space between the idler gear and the transfer gear; and   a magnetic torque sensor, for detecting torque of the idler shaft, mounted on the transmission case adjacent to the magnetized region.