PURPOSE: To linearly control the function by adjusting the oil quantity with a pump mechanism operated by the partition plate discharge hole of the torque transmission chamber side, multiple dams of a partition plate, and the difference of the revolving speed of a rotary shaft body and a sealed case according to the outside temperature.

CONSTITUTION: When the outside temperature is the preset temperature or below, the oil of the torque transmission chamber 4 side is pumped by dams 11n of a partition plate 5, it is fed into a flow passage 12 from the outermost discharge hole 50 and a through hole 80 by a pump mechanism 15 and discharged to an oil sump chamber 6, and no torque is transmitted. When the outside temperature reaches the preset temperature, a valve member 8 is rotated by the deformation of a temperature-sensitive body 10, a feed hole 14 is communicated with a through hole 13, oil flows into the torque transmission chamber 4, the discharge hole 50 is closed, a discharge hole 51 is communicated with a through hole 81, the oil on the center side from the dams 11n is discharged to the oil pump chamber 6 by the suction of the pump mechanism 15 and the pumping of the dams 11n, the oil quantity in the torque transmission chamber is maintained by the dams 11n, and torque is transmitted. When the temperature further rises, the oil quantity in the torque transmission chamber 4 is increased, and the rotation of a fan is increased by the increase of the torque transmission. The function can be linearly controlled.