Kysor Industrial Corporation

Arthur E Elmer

A viscous fluid shear clutch comprises a two-part outer casing 14,15 and an inner clutch member 10 between which is defined a clearance gap into which viscous fluid may flow to provide an adjustable degree of coupling between the casing and the clutch members. Fluid is continually pumped out of the gap by a circumferential scoop pummp. The clutch may be assembled for reverse operation by indexing the casing parts relative to one another. The quantity of fluid in the gap may be controlled dependent on sensed temperature and sensed speed or sensed temperature alone. A thermo pressure valve provides a pressure force related to the sensed temperature; this relationship may be inverse for failsafe operation.

Viscous fluid shear clutches and control valves therefor

A viscous fluid shear clutch comprises a two-part outer casing 14,15 and an inner clutch member 10 between which is defined a clearance gap into which viscous fluid may flow to provide an adjustable degree of coupling between the casing and the clutch members. Fluid is continually pumped out of the gap by a circumferential scoop pump. The clutch may be assembled for reverse operation by indexing the casing parts relative to one another. The quantity of fluid in the gap may be controlled dependent on sensed temperature and sensed speed or sensed temperature alone. A thermo pressure valve provides a pressure force related to the sensed temperature; this relationship may be inverse for failsafe operation.

Viscous fluid clutches

A viscous fluid clutch for driving a cooling fan 18 from the crankshaft of an internal combustion engine includes an outer rotary casing 11, 12 connected to the fan and an inner rotary member 10 connected to the crankshaft coupling 9. The clearance gap between these two members is normally occupied by a viscous fluid and the drive is automatically adjusted by varying the quantity of fluid in the gap. A scoop pump 22 continuously pumps fluid from the gap inwards along passage 24 to a reservoir 20 via control valve 50, and the fluid returns to the clearance gap from the reservoir via a port 26. The valve 50 includes a piston 61, which is subject on one side of the pressure of the fluid supplied by the scoop pump 22, and hence to the relative speed of rotation between the crankshaft and the fan. In the other direction the piston 61 is subject to the fluid servo pressure in a conduit 48 derived from the sensed temperature of the engine coolant in duct 40.

Automatic thermal and speed controls for viscous fluid clutches

A viscous fluid transmission including a rotary casing adapted to receve a viscous fluid and a rotary element within the casing. The casing and the rotary element are connected respectively to two drive shafts. Means is provided for pumping the fluid from its normal position in the casing into a holding reservoir or other displaced zone so as to reduce the quantity of fluid in contact with the rotary element and hence the transmitted torque. Means is also provided for varying the pumping action to modify the quantity of fluid in the casing.

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Nailsworth, United Kingdom

Arthur E Elmer