Patent ID: 8474416

Claim:
A hydraulically controlled fan drive system comprising: a housing assembly containing a hydraulic fluid; a pulley connected to said housing assembly for turning said housing assembly; a fan shaft rotatably mounted to said housing by a hydraulically actuated clutch; a piston slidably mounted with a piston housing for actuating said clutch; a pressure tube for delivering kinetically pressurized hydraulic fluid pressure within said housing assembly to said piston housing; a controllable valve for controlling the fluid pressure within said piston housing; a shaft rotationally supporting said housing and said pulley, said shaft having passages extending through said pulley; a base connected with said shaft for connecting said shaft with a structure, said base having coolant inlet and outlet; and an oil cooler connected with said base on a side of said base generally axially opposite of said pulley having oil inlet and outlets fluidly connected with respective said shaft passages, and said oil cooler having coolant inlets and outlets fluidly connected through said base with said base coolant inlets and outlets.