External Control Type Fan-Coupling Device

An external-control-type fan coupling device being configured such that an inside of a hermetic housing which is formed of a non-magnetic casing which is supported on a rotary shaft body which mounts a drive disc on a distal end thereof by way of a bearing and a cover which is mounted on the casing is divided into an oil reservoir chamber and a torque transmission chamber which houses the drive disc therein by a partition plate which is mounted on the drive disc, the coupling device includes an oil circulation flow passage which is formed between the torque transmission chamber and the oil reservoir chamber and an oil supply adjustment hole which is formed in the partition plate, the coupling device includes a valve element which opens or closes the oil supply adjustment hole in the oil reservoir chamber, and an open/close control of the oil circulation flow passage is performed by operating the valve element using an actuator, and the rotational torque transmission from a drive side to a driven side is controlled by increasing or decreasing an effective contact area of oil in a torque transmission gap portion defined between the drive side and the driven side, wherein

• the coupling device adopts a method in which the actuator is arranged in the inside of the rotary shaft body, a control rod which is operated by the actuator penetrates the inside of the rotary shaft body in the axial direction so as to control the valve element, the coupling device includes a primary coil which is fixed to the outside and a secondary coil which is fixed to the rotary shaft body and faces the primary coil in an opposed manner, and the actuator which is mounted in the rotary shaft body is driven by an electric current induced to the secondary coil.