Abstract: A wind power generator is provided with a drive unit, a clutch hydraulic source, and a clutch control portion. The drive unit has a hydraulic clutch mechanism configured to perform switching between transmission and non-transmission of rotary power from an output shaft to a pinion. The clutch hydraulic source supplies a hydraulic pressure to the clutch mechanism. The clutch control portion controls a hydraulic pressure supplied from the clutch hydraulic source to the clutch mechanism.

Abstract: A fuel grasping device in a nuclear reactor has a telescopic tube including a plurality of tubular members combined with each other to enable a telescopic motion, a fuel gripper arranged at a lower end of the telescopic tube to grasp the fuel assembly for the nuclear reactor, and a driver for winding up and down a rope to perform the telescopic motion vertically. Rotatable members are mounted on the tubular members. A pulling-out preventing projection is used at the joint position of the tubular members. A deceleration of the vertical velocity at the joint position of the tubular members is not necessary so that a time period for the vertical movement can be decreased.