Abstract: A fan drive system is provided having a housing connected with a pulley. A fan shaft is rotatably mounted to the housing by a clutch. A piston actuates the clutch. A pressure tube is provided for delivering pressure to the piston. A valve controls pressure against the piston. A fixed shaft rotatably supports the housing and the pulley and has passages extending through the pulley. A base connects the support shaft to a vehicle structure. An oil plate has inlets and outlets with the shaft passages. The oil plate circulates the hydraulic fluid. A coolant plate is juxtaposed between the oil plate and the structure supporting the support shaft. The coolant plate has inlets and outlets for coolant from a remote cooler.

Abstract: A fan drive system is provided having a housing connected with a pulley. A fan shaft is rotatably mounted to the housing by a clutch. A piston actuates the clutch. A pressure tube is provided for delivering pressure to the piston. A valve controls pressure against the piston. A fixed shaft rotatably supports the housing and the pulley and has passages extending through the pulley. A base connects the support shaft to a vehicle structure. An oil plate has inlets and outlets with the shaft passages. The oil plate circulates the hydraulic fluid. A coolant plate is juxtaposed between the oil plate and the structure supporting the support shaft. The coolant plate has inlets and outlets for coolant from a remote cooler.

Abstract: A fan drive system is provided having a housing connected with a pulley. A fan shaft is rotatably mounted to the housing by a clutch. A piston actuates the clutch. A pressure tube is provided for delivering pressure to the piston. A valve controls pressure against the piston. A fixed shaft rotatably supports the housing and the pulley and has passages extending through the pulley. A base connects the support shaft to a vehicle structure. An oil plate has inlets and outlets with the shaft passages. The oil plate circulates the hydraulic fluid. A coolant plate is juxtaposed between the oil plate and the structure supporting the support shaft. The coolant plate has inlets and outlets for coolant from a remote cooler.

Abstract: A fan drive system is provided having a housing connected with a pulley. A fan shaft is rotatably mounted to the housing by a clutch. A piston actuates the clutch. A pressure tube is provided for delivering pressure to the piston. A valve controls pressure against the piston. A fixed shaft rotatably supports the housing and the pulley and has passages extending through the pulley. A base connects the support shaft to a vehicle structure. An oil plate has inlets and outlets with the shaft passages. The oil plate circulates the hydraulic fluid. A coolant plate is juxtaposed between the oil plate and the structure supporting the support shaft. The coolant plate has inlets and outlets for coolant from a remote cooler.

Abstract: A feedback control logic system for commanding a particular air conditioning unit fan speed is driven by a pulse-width modulated signal from a control unit. The engine control unit decrements the pulse-width modulated signal to the air conditioning unit fan and allows the fan to run for a predetermined time. If a particular function, such as shutting off of an air conditioner pressure switch or other sensor, has not been achieved within the predetermined time, the engine control unit again decrements the pulse-width modulated signal.

Abstract: A fan penetration fixture consisting of a threaded shaft and a lock nut design. The fixture is designed to take the place of the fan clutch on a fan drive assembly in the vehicle being tested for a desired cooling system performance characteristic at each possible fan penetration. The threaded shaft portion of the fixture bolts to the fan hub. The desired fan is then bolted to the lock nut portion of the fixture. The lock nut can be positioned at any point along the threaded shaft to achieve a desired fan penetration.

Abstract: A fan penetration fixture consisting of a threaded shaft and a lock nut design. The fixture is designed to take the place of the fan clutch on a fan drive assembly in the vehicle being tested for a desired cooling system performance characteristic at each possible fan penetration. The threaded shaft portion of the fixture bolts to the fan hub. The desired fan is then bolted to the lock nut portion of the fixture. The lock nut can be positioned at any point along the threaded shaft to achieve a desired fan penetration.