An external control type fluid coupling includes: a drive disk fixed to a rotary shaft; a housing rotatably supported by the rotary shaft and defining an internal space; a partition plate provided in the housing and partitioning the internal space into operation and storage chambers; a supply hole formed in the partition plate and supplying a fluid from the storage chamber to the operation chamber; a valve body provided in the housing and made of a magnetic material; and an electromagnet generating an attraction force between the electromagnet and the valve body so that the valve body is displaced to a closed state, in which the center of gravity of the valve body, rotatably connected to the housing, is set such that the valve body is rotated to a side on which the supply hole is opened by a centrifugal force acting with the rotation of the housing.

According to one aspect, a clutch mechanism includes a control member. The control member is adapted to receive motive power and includes a first dry clutch member and a first viscous clutch member. The clutch mechanism further includes an output member that includes a second dry clutch member and a second viscous clutch member. The first and second dry clutch members form a dry clutch and the first and second viscous clutch members form a viscous clutch. The clutch mechanism further includes an actuation arm coupled to at least one of the control and output members. The actuation arm is selectively controllable to effect relative movement of the control and output members such that one of the dry and viscous clutches is selectively engaged.

Power transmission systems including clutch arrangements and systems are adapted to be used in marine and other environments. Such power transmission systems may include clutch arrangements that provide more effective power transmission capabilities as well as greater durability and longer life. Slipping clutch arrangements may effectively vary the output speed of a clutch arrangement from the speed of the engine or other driver as desired for the particular application. Various clutch arrangements also provide for greater flexibility and drive options, lighter weight, and diverse types of capabilities.

The system includes: a driver; a rotating load configured to be driven into rotation by the driver; a controller, for controllably changing a rotation speed of the load; and a variable speed transmission, arranged between the driver and the load. The variable speed transmission includes a speed summing gear arrangement with a first input shaft, a second input shaft and an output shaft. The output shaft is drivingly coupled to the rotating load. The first input shaft is drivingly coupled to the driver. A continuous variable transmission device is mechanically coupled to the driver and to the second input shaft of the speed summing gear arrangement. The continuous variable transmission device is functionally coupled to the controller.

A viscous clutch (20) includes a housing assembly (28), a rotor assembly (26), a reservoir (38) to hold a supply of a shear fluid, a working chamber (40) operatively positioned between the housing assembly and the rotor assembly, and a fluid return bore (26-1B) that optionally extends radially through at least an outer diameter portion of the rotor assembly to the working chamber. Selective introduction of the shear fluid to the working chamber facilitates selective torque transmission between the housing assembly and the rotor assembly. The fluid return bore can form at least a portion of a fluid return path (50) from the working chamber to the reservoir.

A viscous clutch includes a shaft, a rotor disk, a housing having a base, a working chamber, a reservoir fluidically connected to the working chamber, a valve, an electromagnetic coil, and a flux guide that passes through the housing. The rotor disk includes a conductive portion made of a magnetic flux conductive material that forms a hub of the rotor disk that contacts the shaft and another portion. The base includes a hub with an axially-extending ring, and an armature of the valve is located radially outward of the axially-extending ring. The electromagnetic coil is located at an opposite side of the rotor disk from the reservoir. A magnetic flux circuit extends from the electromagnetic coil to the flux guide, then to the armature of the valve, then to the conductive portion of the rotor disk, then to the shaft, and then back to the electromagnetic coil.

This disclosure relates to a fluid friction clutch having a housing, a clutch disc which is arranged at one end of a shaft which is mounted within the housing, a working chamber which is configured between the housing and the clutch disc, a storage chamber for clutch fluid, and at least one feed duct which leads from the storage chamber to the working chamber. Moreover, a pressure relief device for discharging clutch fluid from the feed duct into the storage chamber is provided.

An internal combustion engine including a cooling liquid circuit, which is connected to a cylinder head and an engine block of the internal combustion engine and which includes a cooling liquid pump. The cooling liquid pump includes a drive shaft and is capable of conveying cooling liquid in the cooling liquid circuit. Further, the internal combustion engine includes a Visco clutch. The Visco clutch is arranged for the drive by the internal combustion engine. The Visco clutch includes a clutch fluid for torque transmission. At the output side, the Visco clutch is connected to the drive shaft of the cooling liquid pump. The drive shaft of the cooling liquid pump include at least one heat pipe. The heat pipe is in heat exchange with the clutch fluid as a heat source and the cooling liquid as a heat sink.

Outer plates have a doughnut-like disk shape and are attached to the inner circumferential surface of a case member. On the other hand, inner plates have a substantially arc shape and are swingably supported about a position at a distance from the center of rotation of a shaft. The inner plates are held at a first position, at which the interlocking area between the outer plates and the inner plates is small, by a tension coil spring when the relative rotational speed between the case member and the shaft is small, and, when the relative rotational speed between the case member and the shaft exceeds a predetermined value are pivotally moved toward the outer plates by the shearing force of a viscous fluid and held at a second position at which the interlocking area between the movable plates and the first plates is large.

A viscous clutch according to the present invention, which is composed of a main body having a fluid storage chamber of a concave shape formed at a central portion thereof and a cover having a concave fluid operation chamber formed at a central portion thereof, comprises: a fan housing in which the main body is stacked on an upper side of the cover so that an opening of the fluid operation chamber can be covered; a drive shaft which extends in a vertical direction and has a lower end inserted through a bottom plate of the main body; a rotor fixedly coupled to the lower end of the drive shaft so as to be rotatable in the fluid operation chamber; a rotary assembly integrally coupled to the main body so as to cover an opening of the fluid storage chamber; a coil core mounted on an upper surface of the rotary assembly and generating an electromagnetic force when an electric current is applied from the outside; and a valve assembly for opening or closing a fluid outlet according to whether or not an electric current is applied to the coil core.