Abstract: A rotary actuator, including a manifold block and a rotor assembly that includes a rotor shaft and a plurality of arcuate pistons attached to the rotor shaft, each arcuate piston curving at a set radial distance from the rotor shaft, and each piston attached to the rotor shaft via a crank arm. A pressure chamber assembly coupled to the manifold block defines a plurality of piston pressure chambers that receive and at least partially enclose each arcuate piston, including a plurality of gland seals disposed adjacent the entrance of each piston pressure chamber to create a seal between the inner surface of the pressure chamber and the outer surface of the arcuate piston. Each gland seal includes an inner seal that engages the piston surface of the arcuate piston, and plural outer seals that engage the inner surface of the piston pressure chamber, forming a hydraulic seal.

Abstract: A rotary actuator, including a manifold block and a rotor assembly that includes a rotor shaft and a plurality of arcuate pistons attached to the rotor shaft, each arcuate piston curving at a set radial distance from the rotor shaft, and each piston attached to the rotor shaft via a crank arm. A pressure chamber assembly coupled to the manifold block defines a plurality of piston pressure chambers that receive and at least partially enclose each arcuate piston, including a plurality of gland seals disposed adjacent the entrance of each piston pressure chamber to create a seal between the inner surface of the pressure chamber and the outer surface of the arcuate piston. Each gland seal includes an inner seal that engages the piston surface of the arcuate piston, and plural outer seals that engage the inner surface of the piston pressure chamber, forming a hydraulic seal.