A fan and a motor drive device thereof are provided. The motor drive device is configured to drive a motor and includes a control management unit and a voltage converter. The control management unit classifies target rotation speed signals provided by an ECU into multiple rotation speed ranges, each corresponding to a specific output duty ratio. The control management unit receives a target rotation speed signal transmitted from the ECU in a real-time manner, and output a voltage regulating signal, which is a pulse width modulation signal having a duty ratio corresponding to one of the rotation speed ranges in which the target rotation speed signal transmitted from the ECU falls. The voltage converter is connected between a power source and the motor, and is configured to regulate a voltage outputted to the motor in response to the voltage regulating signal having the specific duty ratio outputted from the control management unit, to regulate a rotation speed of the motor.

A vehicle radiator air intake screen maintenance system comprising a radiator fan, a fan motor; and a processor operable to control the rotational speed and direction of the radiator fan to: periodically implement a drop cycle whereby a radiator cooling air flow generated by the fan rotating in a forward direction is slowed such debris collected on a radiator air intake screen of the vehicle is caused to fall off due to gravitational force; and periodically implement a full reverse cycle where a rotational direction of the fan is reversed and an expulsion air flow is generated whereby debris collected on vehicle radiator and the air intake screen will be blown off, whereafter reverse rotation of the fan is stopped and the fan is returned to the full forward operating speed and direction.

A fan clutch, in particular for a fan of a cooling system of a motor vehicle having a housing and an annular flange for connecting the fan, wherein the flange is arranged centrally around a housing axis, wherein the flange forms a flat flange-ring plane substantially perpendicular to the housing axis and has a flange-ring inner side and a flange-ring outer side which bound the flange-ring plane, wherein the flange is contorted in the flange-ring plane in certain areas in a direction substantially parallel to the housing axis.

A fluid friction clutch with a housing, a clutch plate and a reservoir that are disposed in the housing, a supply pump element rotatably coupled to the clutch plate, a supply conduit and a valve. The clutch plate and the housing form a working chamber. The supply conduit couples the reservoir to an inlet side of the working chamber. The supply pump element has a pump inlet and a pump outlet that are spaced circumferentially apart from one another about a rotational axis of the clutch plate. The pump outlet is coupled in fluid communication with the supply conduit. The valve has a valve element that is movable between a first or extended position and a second or retracted position. Placement of the valve element in the first position at least partly blocks fluid flow to the pump outlet.

Two cooling fans acting on different heat exchangers may be driven via parallel circuits from a variable displacement hydraulic pump. At least one of the circuits includes a two position valve operable by a control system to vary the flow resistance of the circuit to share the flow between the two fan motors responsive to the relative heat load on the heat exchangers. The pump displacement is controlled to provide a constant hydraulic output pressure irrespective of the operational state of the or each valve assembly.

Power systems and enclosures having a configurable cooling air flow are disclosed. The power system includes an enclosure; an air inlet location, a first air outlet location, a second air outlet location, a fan assembly, and one or more relocatable covers to obstruct the first and second air outlet locations. The air inlet location may be at a first location on an exterior of the enclosure to permit intake of air from the exterior of the enclosure to an interior of the enclosure. The first air outlet location may be at a second location on the exterior of the enclosure to expel air taken in through the air inlet location, while the second air outlet location at a third location on the exterior of the enclosure to expel air taken in through the air inlet location.

Power systems and enclosures having a configurable cooling air flow are disclosed. The power system includes an enclosure; an air inlet location, a first air outlet location, a second air outlet location, a fan assembly, and one or more relocatable covers to obstruct the first and second air outlet locations. The air inlet location may be at a first location on an exterior of the enclosure to permit intake of air from the exterior of the enclosure to an interior of the enclosure. The first air outlet location may be at a second location on the exterior of the enclosure to expel air taken in through the air inlet location, while the second air outlet location at a third location on the exterior of the enclosure to expel air taken in through the air inlet location.

A multiplane fan cooling system and method is disclosed for a cooling system with first, second and intake planes; a first fan and heat exchanger on the first plane, a second fan and heat exchanger on the second plane, and a shared air cavity bounded at least partially by these three planes. Each fan pulls air into the shared air cavity through the intake plane and across its associated heat exchanger. The first fan cools the first heat exchanger, and counteracts the second fan from drawing air into the shared air cavity through the first heat exchanger. The second fan cools the second heat exchanger. The second fan can be activated to counteract the first fan from drawing air into the shared air cavity through the second heat exchanger. All the air in the shared air cavity can be available to each of the fans.

A multiplane fan cooling system and method is disclosed for a cooling system with first, second and intake planes; a first fan and heat exchanger on the first plane, a second fan and heat exchanger on the second plane, and a shared air cavity bounded at least partially by these three planes. Each fan pulls air into the shared air cavity through the intake plane and across its associated heat exchanger. The first fan cools the first heat exchanger, and counteracts the second fan from drawing air into the shared air cavity through the first heat exchanger. The second fan cools the second heat exchanger. The second fan can be activated to counteract the first fan from drawing air into the shared air cavity through the second heat exchanger. All the air in the shared air cavity can be available to each of the fans.

A hydraulic drive fan control device is provided with a variable displacement hydraulic pump, a hydraulic motor, a hydraulic drive fan that is driven by the hydraulic motor, a flow amount control valve, a rotational speed detector that detects a rotational speed of an engine, and a controller. The controller outputs a first valve control signal to the flow amount control valve and outputs a first pump control signal to the hydraulic pump to rotate the hydraulic drive fan at a first rotational speed, and outputs a second valve control signal to the flow amount control valve and outputs a second pump control signal to the hydraulic pump, thereby stopping the rotation of the hydraulic drive fan.