Viscous fan drive control with integrated speed sensor.

摘要

A viscous fluid fan clutch (10) with an input member (42) in a working chamber (100) of an output housing (60) has the supply of viscous fluid to the chamber (100) controlled by a valve (196) in dependence of rotational speed measured by a sensor (166) mounted on a non-rotating part (122). The valve (196) may be actuated by an electro-magnetic coil (174) attracting a rotating part (152) into sliding friction contact with a surface (190) of the non-rotating part (122).