Patent ID: 6446774
Filing Date: 2002-09-10
Classification: B60W,F16D

Abstract:
A hydraulic coupling for use in a driveline apparatus for a motor vehicle to rotatively couple first and second rotary members, the hydraulic coupling comprising:a transfer clutch operatively connected between the first and second rotary members; a piston housing defining a piston chamber; a piston disposed in said piston chamber and actuable to engage said transfer clutch and rotatively couple the first and second rotary members; a hydraulic pump in fluid communication with a sump containing hydraulic fluid and providing a pumping action in response to relative rotation between the first and second rotary members; a first fluid flow path for supplying hydraulic fluid from said hydraulic pump to said piston chamber; a control valve located in fluid communication with said first flow path for regulating flow of hydraulic fluid into said piston chamber for actuating said piston; a second flow path for supplying hydraulic fluid from said control valve to a clutch chamber to cool said transfer clutch; a first temperature sensor for detecting the temperature of hydraulic fluid in said sump; a second temperature sensor for detecting the temperature of hydraulic fluid in said clutch chamber; a pressure sensor for detecting the pressure of fluid in said piston chamber; and an electronic traction control module controlling actuation of said control valve in response to sensor signals from said sensors.