Patent ID: 8726854

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 connected 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 bracket shaft rotationally supporting said housing and said pulley, said bracket shaft having passages extending through said pulley; a base connected with said bracket shaft for connecting said bracket shaft with a structure; a coolant plate member connected to said base and having a first recessed portion, said coolant plate member having inlets and outlets for ingress and digress of a coolant from a remote cooler into said recessed portion; and an oil plate member juxtaposed between said coolant plate member and said bracket shaft and having a second recessed portion, said oil plate member having inlets and outlets fluidly connected with said bracket shaft passages; wherein oil circulated into and through said second recessed portion is cooled by coolant circulated into and through said first recessed portion.