Abstract: A viscous fluid shear device having a housing, a rotor, which is rotatable in the housing, and a wiper that is coupled to the housing. The housing defines a scavenge conduit and a nozzle. Viscous fluid that clings to the circumference of the rotor during operation of the viscous fluid shear device is driven through the nozzle and directed by the wiper into the scavenge conduit.

Abstract: A viscous fluid shear device having a housing, a rotor, which is rotatable in the housing, and a wiper that is coupled to the housing. The housing defines a scavenge conduit and a nozzle. Viscous fluid that clings to the circumference of the rotor during operation of the viscous fluid shear device is driven through the nozzle and directed by the wiper into the scavenge conduit.

Abstract: A biased spool valve restrictor member for positioning in the scavenge channel in a viscous fluid fan drive where it can restrict the flow of scavenge pump-out at low fan speed, and thereby improving the ability of the fan drive to engage at such speeds.

Abstract: A viscous fan drive including a fluid valve activated by a bimetal member, and including a clutch disk member and fluid reservoir rotatable at input speed. The fluid reservoir is contained in a reservoir chamber member positioned on the clutch disk member. The bimetal coil member controls the operation of a valve member which in turn controls the passage of fluid into the working chamber for operation of a cooling fan.

Abstract: A viscous fan drive including a fluid valve activated by a bimetal strip member, and including a clutch disk member and fluid reservoir rotatable at input speed. The fluid reservoir is contained in a reservoir chamber member positioned on the clutch disk member. The bimetal strip member controls the operation of a valve member which in turn controls the passage of fluid into the working chamber for operation of a cooling fan.

Abstract: A viscous fan drive including a fluid valve activated by a bimetal member, and including a clutch disk member and fluid reservoir rotatable at input speed. The fluid reservoir is contained in a reservoir chamber member positioned on the clutch disk member. The bimetal member controls the operation of a valve member in the housing which in turn controls the passage of fluid from a scavenge passageway into the fluid chamber and working chamber for operation of a cooling fan.

Abstract: A viscous fan drive having improved pumping efficiency from removing fluid from a fluid operating chamber to a fluid reservoir chamber is achieved by providing a wiper element that is located within the radial clearance between the clutch and the housing that effectively seals leakage paths leading (upstream) and trailing the wiper. The wiper element includes a radial tang that is positioned within a corresponding slot of the cover wall. The wiper element also has a pair of spaced apart arms extending from the radial tang portion each having a radial outer surface that has a similar radius as the cover wall and a radial inner surface has a similar radius as the clutch. The wiper element also preferably includes details designed to seal the radial inner surface to the outer periphery of the clutch during fan drive operation and a locating detail to aid in assembly.

Abstract: A viscous fan drive having improved pumping efficiency from removing fluid from a fluid operating chamber to a fluid reservoir chamber is achieved by providing a wiper element that is located within the radial clearance between the clutch and the housing that effectively seals leakage paths leading (upstream) and trailing the wiper. The wiper element includes a radial tang that is positioned within a corresponding slot of the cover wall. The wiper element also has a pair of spaced apart arms extending from the radial tang portion each having a radial outer surface that has a similar radius as the cover wall and a radial inner surface has a similar radius as the clutch. The wiper element also preferably includes details designed to seal the radial inner surface to the outer periphery of the clutch during fan drive operation and a locating detail to aid in assembly.

Abstract: A viscous fan drive having improved pumping efficiency from removing fluid from a fluid operating chamber to a fluid reservoir chamber is achieved by providing a wiper element that is located within the radial clearance between the clutch and the housing that effectively seals leakage paths leading (upstream) and trailing the wiper. The wiper element includes a radial tang that is positioned within a corresponding slot of the cover wall. The wiper element also has a pair of spaced apart arms extending from the radial tang portion each having a radial outer surface that has a similar radius as the cover wall and a radial inner surface has a similar radius as the clutch. The wiper element also preferably includes details designed to seal the radial inner surface to the outer periphery of the clutch during fan drive operation and a locating detail to aid in assembly.

Abstract: A viscous fan drive in which the output drive to the fan is controlled by the movement of viscous fluid from a fluid reservoir and into the operating and working chamber of the coupling during normal operation. The input-coupling assembly and cover member are formed with a unique combination of continuous and non-continuous radially extending lands and grooves designed to distribute the viscous fluid in a continuous film throughout the shear zone so as to maximize output fan speed at a given input speed. An armature-venting feature is designed to simplify the opening and closing of the valve disk in an electronic version of the viscous fan drive depending upon the desired operating condition.

Abstract: An electronically-controlled viscous coupling is coupled to a water pump to control the coolant flow rate of engine coolant to an engine at a given engine speed to maximize fuel economy and minimize emissions. The viscous coupling has a stationary electrical coil that, when excited by electrical current, induces the driven disk to flex away from an input disk within the viscous, thereby increasing the size of the shear area, thereby decreasing the amount of torque produced to drive the water pump shaft and impellers that control the coolant flow rate. A carrier coupled to the back of the driven disk maximizes the amount of flex allowed to the driven disk, thereby assuring a maximum decrease in rotational speed of the impellers at a given engine speed and ensuring that the driven disk does not contact the stationary coil.

Abstract: An electronically-controlled viscous coupling is coupled to a water pump to control the coolant flow rate of engine coolant to an engine at a given engine speed to maximize fuel economy and minimize emissions. The viscous coupling has a stationary electrical coil that, when excited by electrical current, induces the driven disk to flex away from an input disk within the viscous, thereby increasing the size of the shear area, thereby decreasing the amount of torque produced to drive the water pump shaft and impellers that control the coolant flow rate. A carrier coupled to the back of the driven disk maximizes the amount of flex allowed to the driven disk, thereby assuring a maximum decrease in rotational speed of the impellers at a given engine speed and ensuring that the driven disk does not contact the stationary coil.

Abstract: A fan drive assembly including a cooling fan (11) and a fluid coupling device (13). The cooling fan includes a fan hub (17), a spider (15), and a plurality of fan blades (19). The coupling device has an output coupling assembly (21) including a body (23) and a cover (25). The body (23) includes preferably only three mounting portions (67), each being disposed immediately adjacent an outer periphery of the body. Each of the mounting portions (67) defines the necessary machining chucking surfaces (73), and a spider mounting surface (75) including a pilot surface (77) engaging the pilot diameter (79) of the spider (15). The body (23) includes cooling fins (61) covering substantially all of the rearward surface (59) of the body not covered by the mounting portions. The fan hub (17) also includes a rearwardly extending air dam portion (81), limiting localized radial air flow.

Abstract: A fan drive assembly including a cooling fan (11) and a fluid coupling device (13). The cooling fan includes a fan hub (17), a spider (15), and a plurality of fan blades (19). The coupling device has an output coupling assembly (21) including a body (23) and a cover (25). The body (23) includes preferably only three mounting portions (67), each being disposed immediately adjacent an outer periphery of the body. Each of the mounting portions (67) defines the necessary machining chucking surfaces (73), and a spider mounting surface (75) including a pilot surface (77) engaging the pilot diameter (79) of the spider (15). The body (23) includes cooling fins (61) covering substantially all of the rearward surface (59) of the body not covered by the mounting portions. The fan hub (17) also includes a rearwardly extending air dam portion (81), limiting localized radial air flow.

Abstract: A fan drive assembly including a cooling fan (11) and a fluid coupling device (13). The cooling fan includes a fan hub (17), a spider (15), and a plurality of fan blades (19). The coupling device has an output coupling assembly (21) including a body (23) and a cover (25). The body (23) includes preferably only three mounting portions (67), each being disposed immediately adjacent an outer periphery of the body. Each of the mounting portions (67) defines the necessary machining chucking surfaces (73), and a spider mounting surface (75) including a pilot surface (77) engaging the pilot diameter (79) of the spider (15). The body (23) includes cooling fins (61) covering substantially all of the rearward surface (59) of the body not covered by the mounting portions. The fan hub (17) also includes a rearwardly extending air dam portion (81), limiting localized radial air flow.

Abstract: A fan drive assembly including a cooling fan (11) and a fluid coupling device (13). The cooling fan includes a fan hub (17), a spider (15), and a plurality of fan blades (19). The coupling device has an output coupling assembly (21) including a body (23) and a cover (25). The body (23) includes preferably only three mounting portions (67), each being disposed immediately adjacent an outer periphery of the body. Each of the mounting portions (67) defines the necessary machining chucking surfaces (73), and a spider mounting surface (75) including a pilot surface (77) engaging the pilot diameter (79) of the spider (15). The body (23) includes cooling fins (61) covering substantially all of the rearward surface (59) of the body not covered by the mounting portions. The fan hub (17) also includes a rearwardly extending air dam portion (81), limiting localized radial air flow.

Abstract: A fan drive assembly including a cooling fan (11) and a fluid coupling device (13). The cooling fan includes a fan hub (17), a spider (15), and a plurality of fan blades (19). The coupling device has an output coupling assembly (21) including a body (23) and a cover (25). The body (23) includes preferably only three mounting portions (67), each being disposed immediately adjacent an outer periphery of the body. Each of the mounting portions (67) defines the necessary machining chucking surfaces (73), and a spider mounting surface (75) including a pilot surface (77) engaging the pilot diameter (79) of the spider (15). The body (23) includes cooling fins (61) covering substantially all of the rearward surface (59) of the body not covered by the mounting portions. The fan hub (17) also includes a rearwardly extending air dam portion (81), limiting localized radial air flow.

Abstract: A fluid coupling device (11) of the type including an input coupling member (35) having a cover member (49), which together define a reservoir (51) disposed within the input. The cover member (49) defines a fill port, through which flow is controlled by means of a valve arm (55). The input coupling (35) cooperates with a housing (41) and cover (43) (which comprise the output coupling) to define an operating chamber (47). Discharge fluid is pumped from the operating chamber through passages (63) and (65) to a passage (67) disposed approximately on the axis of rotation (A) of the coupling device. The passage (67) is defined by a cylindrical portion (69) which extends through an opening (71) in the cover member (49). Thus, discharge flow is communicated back into the reservoir (51) at the axis, and after the vehicle engine and fan drive have been shut down for a period of time, fluid does not bleed back from the reservoir into the operating chamber.

Abstract: A cooling system is disclosed in which a radiator (21) includes a coolant outflow tank (29) having separate compartments (39,41L,41R) in series with core portions (35,37L,37R) of the radiator. A temperature-responsive fan clutch (13) is adjacent the center core portion (35) and flow through that core portion is controlled by a thermostatic valve (49) which is operated between open (FIG. 3) and closed (FIG. 4) positions in response to the temperature of coolant flowing through one of the other (37L) core portions. With the thermostatic valve closed, and no flow through the center core portion, the temperature of air passing therethrough does not rise as it normally would with the vehicle stopped. Therefor, the fan clutch remains in the disengaged condition at a time when operation in the engaged condition would be both unnecessary and somewhat objectionable to the vehicle operator.