Abstract: A fluid coupling device, includes a driving rotor, a driven rotor including an operation space, a valve unit supplying fluid stored in a storage space to the operation space and stopping supplying the fluid in accordance with a change in air temperature, and a pump portion for returning the fluid from the operation space to the storage space. A valve member of the valve unit is movable between a closed position and an open position, and includes an intermediate flow passage for keeping a predetermined amount of the fluid in the storage space and supplying the rest of the fluid to the opening when the valve member is in a predetermined position between the closed position and the open position.

Abstract: A viscous fluid coupling includes a housing rotatably supported to a drive shaft of an engine. An operation plate set in the housing divides a space of the housing into a reservoir and an operation chamber. The operation plate has a communication hole communicating the reservoir and the operation chamber. A rotor fixed to the drive shaft is disposed in the operation chamber. A valve mechanism installed to the operation plate to close and open the communication hole according to ambient temperature of the housing. A driven wheel fixed to the housing is located between the operation plate and the rotor. A torque transmitting section includes a first annular projection concentrically formed on the driven wheel and a plurality of second annular projections concentrically formed on the rotor. The first annular projections are overlappedly adjacent to the second annular projections so as to establish fluid coupling therebetween through the viscous fluid.

Abstract: A fluid coupling includes an operation plate for defining storage and working chambers in a housing and having a communicating hole for fluid communication between the two, a driven wheel arranged adjacent to the operation plate, a torque-transfer part for transmitting torque of a rotor to the housing, and a valve mechanism for opening and closing the communicating hole. An auxiliary chamber, which is arranged in the driven wheel, brings working fluid out of the communicating hole to the torque-transfer part. A positioning mechanism ensures circumferential positioning of the operation plate and the driven wheel.