A fluid friction clutch may include a rotatably mounted shaft, a drive disk arranged on the shaft in a rotationally fixed manner, a driven body rotatably arranged on the shaft, and a ring-shaped transfer region disposed between the drive disk and the driven body. The transfer region may be configured to receive a viscous fluid via which the drive disk is couplable to the driven body for transferring a torque. The transfer region may be defined by a ring-shaped first groove profile of the drive disk and a ring-shaped second groove profile of the driven body that engage one another axially. The clutch may also include a storage chamber fluidically connected to the transfer region via an inflow path and via a return path. The return path may include a first retaining body and a second retaining body arranged radially offset relative to one another by an arc angle.

A parallel hybrid vehicle includes: an engine serving as a drive source for travel of the parallel hybrid vehicle; an electric motor serving as a drive source for travel of the parallel hybrid vehicle; and a water pump that causes a cooling liquid to circulate in a cooling path. The water pump is connected to the engine to receive power from the engine and is connected to the electric motor to receive power from the electric motor.

A cooling control system for a working machine includes a fan, a housing to which the fan is attached, a prime mover having an output shall, a rotor to be rotated by a rotating power of the output shaft and to be rotated with the housing by a fluid introduced to a gap formed between the housing and the rotor, a fluid setting circuit to set an introduction amount of the fluid introduced to the gap, and a control device to control the fluid setting circuit to control the fan. The control device includes a setting circuit to set a target rotation speed of the fan based on a responsiveness of an actual rotation speed of the fan at time of changing of the target rotation speed of the fan.

A clutch device for a clutch system has an input member that rotates at a first speed. A friction drive system is disposed between the input member and an output member. The clutch device is selectively movable by a fluid actuator assembly, between an engaged position in which the friction drive system drives the output member to rotate at the first speed, and a disengaged position in which a viscous drive system rotates the output member at a second speed slower than the first speed. A variable viscous fluid supply assembly includes a viscous fluid storage chamber, a valve, and a valve actuator that selectively drives the valve to move between an open position and a closed position to control an amount of viscous fluid available to the viscous drive system, thereby varying the second speed.

A fluid friction clutch may include a rotatably mounted shaft, a drive disk arranged on the shaft in a rotationally fixed manner, a driven body rotatably arranged on the shaft, and a ring-shaped transfer region disposed between the drive disk and the driven body. The transfer region may be configured to receive a viscous fluid via which the drive disk is couplable to the driven body for transferring a torque. The transfer region may be defined by a ring-shaped first groove profile of the drive disk and a ring-shaped second groove profile of the driven body that engage one another axially. The clutch may also include a storage chamber fluidically connected to the transfer region via an inflow path and via a return path. The return path may include a first retaining body and a second retaining body arranged radially offset relative to one another by an arc angle.

A control device for a dutch, which is provided between an operating machine and a drive shaft of an engine, controls the operation of a valve member for opening and closing an oil supply hole through which an oil reservoir chamber and a torque transmission chamber communicate. The control device refers to a target rotational speed of a rotational solid of the operating machine and to the acquired rotational speed of the rotational solid of the operating machine, calculates a proportional manipulated variable based on the deviation between the angular acceleration of the rotational solid and a target angular acceleration, and controls the operation of the valve member on the basis of this calculated proportional manipulated variable.

Provided is a fluid fan clutch with excellent cooling performance capable of effectively preventing, by very simple means, a decrease in the volume of air due to backflow of cooling fan air occurring when the fan clutch is activated. The fluid fan clutch has a structure with a fan removably fixed to a housing composed of a front-side housing component (cover) and a back-side housing component (case), wherein projecting parts for preventing backflow of fan air are arranged on the back-side housing component so as to be shifted in the circumferential direction with respect to fixing projections of the front-side housing component.

A method, system, and apparatus are provided for optimizing control of the rotational speed of a fan in a vehicle so as to reduce the aerodynamic drag of a vehicle in a given operating parameter, and accordingly, to improve fuel efficiency of operation of the vehicle. Certain exemplary embodiments include determining an optimized speed of rotation of a cooling fan of the vehicle for reducing overall fuel demand in given operating conditions, and controlling rotation speed of the fan at the optimized speed in order to minimize fueling demand of a prime mover of the vehicle.

A parallel hybrid vehicle includes: an engine serving as a drive source for travel of the parallel hybrid vehicle; an electric motor serving as a drive source for travel of the parallel hybrid vehicle; and a water pump that causes a cooling liquid to circulate in a cooling path. The water pump is connected to the engine to receive power from the engine and is connected to the electric motor to receive power from the electric motor.

An external control type fan clutch device has an electromagnet fixed to a rotating shaft. The electromagnet is energized to activate a valve member formed of a plate spring and an armature and provided to a drive disk or a sealed housing to externally control opening and closing an oil circulating flow passage (oil supply port). The valve member is structured so that the armature attached to the plate spring of the valve member is divided into a plurality of pieces in the direction from the base end side to the oscillating end side of the plate spring to provide a plurality of bend points of the plate spring.