Fan variable immersion system

摘要

A fan system includes a rotatable axial flow fan unit, a fan shroud unit adjacent to the fan unit and capable of surrounding at least a portion of an outer periphery of the fan unit; and an actuator coupled to one of the units and operable to move said one of the units with respect to the other of the units, thereby varying immersion of the fan unit within the shroud unit. The actuator may be coupled to the shroud unit and is operable to move the shroud unit with respect to the fan unit. A control unit controls the actuator to vary fan immersion as a function of sensed parameter signals, and thereby maximizes fan efficiency.