Abstract: In a rotation device using a hydraulic actuator, a rotation angle range is increased. A placement member rotatably coupled to a rotary member has a projecting part on an upper face. A hydraulic actuator is arranged on a projecting face of the projecting part; the actuator and the rotary member coupled with a wire material. The projecting part is formed such that it becomes higher from a leading edge on the side of the rotary member to an intermediate portion in the longitudinal direction, and becomes lower from the intermediate portion to a trailing edge. Thereby, when fluid is supplied to the actuator and shortens the actuator length, a tip of the actuator moves along the projecting face of the projecting part, and is located high, separated from the upper face of the placement member such that the rotation angle range of the rotary member becomes large.

Abstract: In a rotation device using a hydraulic actuator, a rotation angle range is increased. A placement member rotatable coupled to a rotary member has a projecting part on an upper face, A hydraulic actuator is arranged on a projecting face of the projecting part; the actuator and the rotary member coupled with a wire material. The projecting part is formed such that it becomes higher from a leading edge on the side of the rotary member to an intermediate portion in the longitudinal direction, and becomes lower from the intermediate portion to a trailing edge. Thereby, when fluid is supplied to the actuator and shortens the actuator length, a tip of the actuator moves along the projecting face of the projecting part, and is located high, separated from the upper face of the placement member such that the rotation angle range of the rotary member becomes large.

Abstract: A fluid pressure-type actuator is stably operable for a longer period of time than that of a conventional actuator. The actuator 1 is formed with a non-rubber bag body 5 covered with a covering body 2 that is expandable and contractable. The bag body 5 is constructed so that both a longitudinal dimension and an outer diameter thereof when inflated to the maximum extent are larger than an inner longitudinal dimension and inner diameter of the covering body 2 when the covering body 2 is expanded to the maximum extent. The covering body 2 is constructed so as to have a constricting force against a pressing force caused by inflating the bag body 5 when the covering body 2 is expanded to the maximum extent. If fluid is supplied to the actuator 1, because the bag body 5 is restrained with the covering body 2 before inflated to the maximum extent, an explosion of the bag body 5 is prevented.