Rotary actuator

Abstract

Disclosed is a rotary actuator utilizing magnetic screws which are stably rotatable at a great torque with little torque variation. The rotary actuator comprising (a) a closed hollow cylinder, a piston sliding within the cylinder, and a rotary shaft which rotates with the sliding of the piston, has (b) a first magnetic screw member which makes a linear motion in synchronism with the sliding of the piston, and is provided with a first spiral magnetized band, and (c) a rotary shaft rotatably supported in relation to the first magnetic screw member, and having a second magnetic screw provided with a second spiral magnetized band. (d) With the sliding of the piston, the second magnetic screw receives the magnetic force from the first magnetic screw to thereby rotate the rotating shaft.

Dependencies are inferred from the claim text.