Viscous fluid coupling

摘要

A viscous fluid coupling which includes an input member having a rotatable shaft and a rotor secured to the shaft is disclosed. The viscous fluid coupling further comprises an output member rotatable disposed on the shaft and having a first chamber in which the rotor is disposed therein and a second chamber which is communicated to the first chamber through a passage, a torque transmitting mechanism for transmitting rotational torque from the input member to the output member through the viscous fluid and formed between an inner wall of the first chamber and an opposing surface of the rotor, a pumping mechanism pumping out the viscous fluid from the first chamber into the second chamber in accordance with the relative rotation between the input member and the output member and a valve device for opening and closing the passage according to an atmospheric temperature, wherein the torque transmitting mechanism is located in the diametrical direction so that amount of the viscous fluid in the torque transmitting mechanism varies when the shaft is rotated and based on the closing condition of the valve device.