Abstract
This paper describes design of a semi-rotary actuator of quarter-turn type for water hydraulic robotic arm that will be mounted on the deep submergence research vehicle. This actuator is vane-type, by which oscillating motion can be obtained directly. Also, the actuator is double vane-type that excessive force is not applied to bearings. Rotation angle of the actuator is 90 degrees. Metal components of the actuator is made of stainless steel. The bearings used are made of plastic. To reduce internal leakage and eliminate metal contact, plastic (UHMW-PE) plates are inserted between the sliding parts as seal material. To design the structure and dimension of the actuator, strength of the parts are analyzed by finite element method. The assembled actuator is driven by water hydraulic proportional valve. Smooth oscillating motion is obtained without any stick-slip. However, internal leakage is relatively large. Therefore, countermeasures to reduce the internal leakage are required.
