Patent ID: 7419040

Claim:
An external control type fan-coupling device in which a seal device housing is constructed by a case of a nonmagnetic material supported through a bearing on a rotating shaft body fixedly attaching a drive disk to its tip, and a cover attached to the case; a partition plate fixedly attached to said cover for partitioning the interior of the seal device housing into an oil reservoir chamber and a torque transmitting chamber for internally mounting said drive disk; an oil circulating flow passage formed between said torque transmitting chamber and the oil reservoir chamber, and an oil supply adjusting hole formed in said partition plate; a valve member for opening and closing said oil supply adjusting hole is arranged within the oil reservoir chamber; a mechanism for controlling said oil circulating flow passage so as to be opened and closed by operating the valve member by an actuator; and the transmission of rotation torque from a drive side to a driven side is controlled by increasing and decreasing an effective contact area of oil in a torque transmitting clearance portion formed by the drive side and the driven side; wherein said actuator is attached to the cover of the seal device housing; a permanent magnet fixed to a stationary magnet support body and rotatably mounted relative to the shaft body via a second bearing, and an electromagnetic coil fixed to the case and opposed to said permanent magnet; a mechanism for operating the actuator by electric power generated in said electromagnetic coil attached to the cover of said seal device housing; and a non-contact type switch that can be energized to control said actuator.