Abstract: A viscous clutch (10) is typically employed in a fan drive mechanism within a truck or automobile. A shaft (18), driven by the engine (12), rotates a clutch member (42) within the fan drive. The clutch member is arranged for fluid engagement with a body member (60) for the transmission of torque thereto when fluid is disposed in an operating chamber (100) defined by complementary shear surfaces in the clutch and body members (48,98), respectively. An actuator assembly (30) operates to displace a valving element (196) within the clutch to control the torque transmission therethrough and thus the speed of the output shaft and fan (34) thereof. The actuator is electrically powered by a generator (222) made up of an armature (224) carried by the body member and a plurality of field generating magnets carried by clutch member (42) for rotational interaction therebetween.

Abstract: A viscous clutch (10) is typically employed in a fan drive mechanism within a truck or automobile. A shaft (18), driven by the engine (12), rotates a clutch member (42) within the fan drive. The clutch member is arranged for fluid engagement with a body member (60) for the transmission of torque thereto when fluid is disposed in an operating chamber (100) defined by complimentary shear surfaces in the clutch and body members (48,98), respectively. An actuator assembly (30) operates to displace a valving element (196) within the clutch to control the torque transmission therethrough and thus the speed of the output shaft and fan (34) thereof. The actuator is electrically powered by a generator (222) made up of an armature (224) carried by the body member and a plurality of field generating magnets carried by clutch member (42) for rotational interaction therebetween.

Abstract: A fluid coupling device is disclosed of the type including an input coupling member (11) and an output coupling member (13). A valve plate (31) separates the device into a fluid operating chamber (33) and a fluid reservoir chamber (35). In a preferred embodiment, the valve plate defines an inlet port (53) and a discharge port (59), which are conventional, and, in accordance with the invention, a discharge port (55) is disposed adjacent a pumping element (57). Attached to the valve plate is a temperature-responsive bimetallic strip (63) having a closed position when the fluid temperature is below a predetermined maximum, such that the device operates in the engaged mode. When the fluid temperature rises above the predetermined maximum, the bimetallic strip (63) opens, permitting additional discharge flow through the port (55), causing the device to operate in the disengaged mode, and preventing overheating of the fluid and damage to the coupling device.