A fluid friction clutch with a housing, a clutch plate and a reservoir that are disposed in the housing, a supply pump element rotatably coupled to the clutch plate, a supply conduit and a valve. The clutch plate and the housing form a working chamber. The supply conduit couples the reservoir to an inlet side of the working chamber. The supply pump element has a pump inlet and a pump outlet that are spaced circumferentially apart from one another about a rotational axis of the clutch plate. The pump outlet is coupled in fluid communication with the supply conduit. The valve has a valve element that is movable between a first or extended position and a second or retracted position. Placement of the valve element in the first position at least partly blocks fluid flow to the pump outlet.

Disclosed is a viscous coupling that has a housing that carries ribs that are arranged concentrically about a central axis. A rotor is provided that can rotate relative to the housing about the central axis in a predetermined direction. The rotor also carries ribs, and the ribs of the housing and the rotor are arranged in a working chamber surrounded by the housing. Also provided is a fluid reservoir. A fluid discharge line leads from the working chamber to the fluid reservoir. A wiper is moveably arranged between the housing and the rotor and scrapes fluid from the rotor and feeds it to the fluid discharge line. A stop is provided for the wiper and is arranged next to the rotor.

A viscous clutch includes an input member rotatable about an axis of rotation, an output member selectively rotatable about the axis of rotation, a working chamber bounded by the input member and the output member, a reservoir, a release bore that fluidically connects the reservoir to the working chamber, a leading wiper that extends into the working chamber, a leading pump bore positioned adjacent to the leading wiper that fluidically connects the working chamber to the reservoir, a trailing wiper that extends into the working chamber, and a trailing pump bore positioned adjacent to the trailing wiper and downstream of the leading pump bore that fluidically connects the working chamber to the reservoir. The trailing wiper has a width that is greater than a width of the leading wiper.

A viscous clutch includes an input member rotatable about an axis of rotation, an output member selectively rotatable about the axis of rotation, a working chamber bounded by the input member and the output member, a reservoir, a release bore that fluidically connects the reservoir to the working chamber, a leading wiper that extends into the working chamber, a leading pump bore positioned adjacent to the leading wiper that fluidically connects the working chamber to the reservoir, a trailing wiper that extends into the working chamber, and a trailing pump bore positioned adjacent to the trailing wiper and downstream of the leading pump bore that fluidically connects the working chamber to the reservoir. The trailing wiper has a width that is greater than a width of the leading wiper.

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.

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.

A cooling control system includes a prime mover, a fan to be rotated under rotational power of an output shaft of the prime mover, a housing to which the fan is attached, a rotor to be rotated under rotational power of the prime mover, the rotor and the housing, under the agency of a fluid, rotating together, a fluid setting circuit to determine an injection quantity of the fluid to be introduced into the gap, a fan rotation detection device to detect a fan actual rotation speed, a target rotation obtaining circuit to obtain a fan target rotation speed. The integral controlling circuit does not execute the integral control with a difference between the fan actual rotation speed and a fan target rotation speed being greater than or equal to a threshold, and executes the integral control with the difference being less than the threshold.

A viscous clutch includes an input member, an output member, a working chamber defined between the input member and the output member, a reservoir to hold a supply of a shear fluid, a valve that controls a flow of the shear fluid between the reservoir and the working chamber along a fluid circuit that fluidically connects the reservoir and the working chamber, a bearing, and an electromagnetic coil supported by the bearing. The electromagnetic coil includes a coil housing and a winding that forms multiple turns within an interior volume of the coil housing, wherein the coil housing has a stepped configuration to at least partially accommodate the bearing within a first step. Selective energization of the electromagnetic coil actuates the valve.

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.

A viscous clutch (20) includes an input member (26), an output member (24), a working chamber (30) defined between the input member and the output member, a reservoir (28) to hold a supply of a shear fluid, a valve (32) that controls a flow of the shear fluid between the reservoir and the working chamber along a fluid circuit that fluidically connects the reservoir and the working chamber, a bearing (48), and an electromagnetic coil (34) supported by the bearing. The electromagnetic coil includes a coil housing (34-1) and a winding (34-2) that forms multiple turns within an interior volume (34-3) of the coil housing, wherein the coil housing has a stepped configuration to at least partially accommodate the bearing within a first step (34-4). Selective energization of the electromagnetic coil actuates the valve.