US 5,667,045 AGranted

Continuously variable fan drive clutch arrangement

AssigneeRockford Powertrain, Inc.

InventorGordon F. Cummings, III

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Abstract

A clutch mechanism for a cooling fan of a size capable of fitting into the limited envelope available in an over-the-road diesel tractor. A compact housing has a belt drive input and an output connected to the fan hub. A wet clutch is included within the housing lubricated by oil from the engine lubrication system. The housing includes an internal positive displacement booster pump cooperating with a controllable valve in the oil return line to the engine sump. When it is desired to operate the clutch, the valve is controllably closed to restrict flow from the clutch mechanism to the engine sump line. The positive displacement pump thereupon causes an increase in pressure in a pressure chamber in the housing, which acts on an internal piston to translate the clutch in a continuously variable manner between engaged and disengaged conditions.

Claims17

Dependent claims

A clutch arrangement for a cooling fan in a diesel driven vehicle, the clutch mechanism being of a size capable of fitting an envelope between a diesel engine and the cooling fan associated with a cooling radiator, the fan clutch arrangement comprising, in combination:

a compact housing having a belt drive input and an output connected to a fan hub;
a continuously variable wet clutch in the housing capable of a fully engaged position in which the input and hub are rotated at the same speed, a declutched position in which the output hub is stationary, and continuously variable positions therebetween in which the output hub is rotated at continuously variable speeds;
the housing having connections for an oil supply and an oil return connected in the path of engine oil flow from an oil pump to a sump;
a positive displacement booster pump in the housing having an inlet for receiving oil from the supply and for increasing the pressure of the oil in a pressure chamber in the housing located between the booster pump and the oil return, a piston in the housing adapted to be responsive to the pressure in the chamber for releasing and engaging the wet clutch between the fully engaged and declutched positions;
and
an electrically operable valve connected to the oil return for restricting the flow of oil to the sump and thereby controlling the pressure in the pressure chamber and the position of the clutch between the fully engaged and declutched positions.

3 more elements

A compact clutch arrangement for controlling the speed of a cooling fan associated with a radiator in a motor vehicle, the vehicle having an engine and engine sump, and the wet clutch comprising in combination:

a compact housing having a belt drive from the engine, serving as a power input;
a fan hub for connection to the fan;
a wet clutch having plates connected respectively to the housing and the fan hub for controllably varying the coupling between the drive and the fan between a fully engaged position in which the housing and fan hub are rotated at the same speed, a declutched position in which the fan hub is stationary, and continuously variable positions therebetween in which the fan hub is rotated at continuously variable speeds;
the housing having an oil input for receiving lubricating oil flow from the engine for lubrication of internal clutch parts and an outlet for returning lubricating oil to the engine sump;
a positive displacement pump in the housing and driven by the belt drive, the positive displacement pump being fluidically connected between the oil inlet and outlet;
a pressure chamber in the housing located between the positive displacement pump and the outlet, a pressure plate associated with the pressure chamber for operating the clutch as a function of pressure in the chamber;
and
a valve connected between the pressure chamber and the engine sump for controlling the pressure in the pressure chamber and thereby the state of engagement of the clutch.

5 more elements

Dependencies are inferred from the claim text.