| 摘要 |
PURPOSE:To avoid any entrainment at the time of start of an engine without increasing an axial length by providing a communication passage for a pump port and an inner circumferential reservoir at the opposite surface of a pump projection of a division plate, and another communication passage for an operational chamber and an outer peripheral reservoir on the opposite side of the pump projection of the division plate, respectively. CONSTITUTION:Since an amount of viscous fluid in torque transmitting portions 29, 30 is small at the time of start of an engine, a transmission torque from a rotor 12 to a housing 13 is very small and a fan is rotated at a very low speed. With the rotation of the rotor 12, fluid in an operation chamber 17 is supplied from a pump port 22 and a communication passage 23 to an inner circumferential reservoir 18, and fluid in an outer peripheral reservoir 19 is supplied from the operation chamber 17 to the reservoir 18. A temperature sensing member 27 senses an increase in water temperature of an engine. When the temperature is not high, only a supply port 24 is opened with a little rotation of a valve 26 so that fluid is supplied from the reservoir 18 only to the torque transmitting portion 29 at a low rotational speed of the fan. Meanwhile, a supply port 25 is opened with an increase in water temperature so that the fluid is supplied also to the torque transmitting portion 30, thereby increasing the rotational speed of the fan. |
