| 摘要 |
In a tubular member (2), a hydraulic pressure expansion chamber (26) and a discharge passage (142) that provides communication between the hydraulic pressure expansion chamber and the outside and that has a valve seat (30) are formed. A valve element (52) is arranged on the valve seat in the discharge passage. When the tubular member rotates relative to the shaft member (1) from a state where the tubular member is stationary with respect to the shaft member, the valve element is displaced from a first position for maintaining a hydraulic pressure in the hydraulic pressure expansion chamber to a second position for discharging oil from the hydraulic pressure expansion chamber to the outside. |
