torque transmission chamber 6 while when the actuator 10 6 is turned on the armature 9 6 b is sucked to the actuator 10 6 side and hence the leaf spring 9 6 a is brought into pressure contact with the partition plate 4 whereby the oil supply adjustment hole 8 is closed and the supply of the oil to the torque transmission chamber is stopped in case of the external control type fan coupling device shown in fig6 by adopting the linear solenoid type actuator 10 6 having no operating shaft in the same manner as the fan coupling device shown in fig2 and fig4 it is possible to enhance the fan rotation response further since the lead line 13 for supplying electricity can be wired in the inside of the rotary shaft body drive shaft 1 compared to the system in which the lead line 13 is wired through the casing 2 1 and the cover 2 2 of the hermetic housing 2 it is possible to obtain advantageous effects including an advantageous effect that a centrifugal force which acts on the lead line 13 is small and hence there is no possibility of the occurrence of disconnection whereby the elevation of the electric resistance attributed to the generation of heat by the fan coupling device can be reduced as the layout arrangement of the primary.