| 摘要 |
PURPOSE:To miniaturize the captioned device by providing a slit to one or both of wall surfaces facing to each other of cylinders and forming the slit in such a manner that the open-area becomes gradually larger as the position comes near the free end of the cylinder. CONSTITUTION:When a housing 31 is rotated by the driving power from an engine, the rotation of the housing 31 is transmitted from a cylinder 45 to a cylinder 47 by the shearing resistance of silicone oil and outputted from a rotary member 35. At this time, if the difference in the number of revolutions between the housing 35 and the rotary member 35 increases, both limiting quantity of this differential rotation and transmitting torque increase, while if the difference decreases both limiting quantity and transmitting torque decrease. Therefore, by moving the rotary member 35 through the operation of a shift fork 57 so as to change the overlapped quantity of the cylinders 45 and 47, the torque transmitting characteristics can be changed. At this time, owing to wedge-shaped slits 49, which are formed in the cylinder 45 on the housing (31) side, as the overlapping quantity L between the cylinder 45 and the cylinder 47 increases the effective operational area increases sharply. In other words, for the same stroke the adjustable range of the characteristics can be widened, compared with the conventional method. |
