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 fan drive assembly includes a viscous coupling device (11), a radiator cooling fan (F), and a speed increasing mechanism (13), so that, at relatively low engine speeds, the fan (F) is driven at a speed ("overdrive") greater than the input speed to the coupling device (11), and at relatively higher engine speeds, the input torque is transmitted through the viscous coupling in the normal manner. In the subject embodiment, the speed increasing mechanism (13) is a planetary gear set, in which torque is transmitted from the input shaft (21) to the planet carrier (47), and in the overdrive condition, the sun gear (53) is grounded. The output of the planetary is the ring gear (59), which directly drives a housing (61) attached to both the housing (17) of the viscous coupling, as well as the cooling fan (F), thus effectively bypassing the viscous clutching action.

Abstract: A fluid coupling device is described of the type defining a fluid chamber divided by a valve plate (29) into a fluid operating chamber (31) and a fluid reservoir chamber (33). The valve plate defines a fluid inlet (55) and a discharge opening (51). Flow of fluid between the chambers (31) and (33) is controlled by a valve member (41) including first (57) and second (59) inlet covering portions, and a discharge covering portion (61). The valve member is controlled normally in response to external ambient air temperature, by means of a bimetal coil (43). When input speed to the coupling device becomes extremely high, slip speed increases, thus increasing the fluid temperature within the coupling. This additional heat causes the bimetal coil (43) to move the valve arm to a disengaged position (FIG. 4) in which the fluid inlet (55) is once again covered, and the discharge opening (51) is again uncovered, permitting the coupling device to operate in a disengaged mode.