Abstract: A rotary actuator includes a housing, a rotor assembly rotatably journaled in said housing and including a rotary output shaft, a central actuation assembly including a central mounting point formed in an external surface of the rotary output shaft, said central mounting point proximal to the longitudinal midpoint of the rotary output shaft, a mounting assembly adapted for attachment to an external mounting connector of a mounting surface of an aircraft structural member, and an actuation arm removably attached at a proximal end to the central mounting point, said actuation arm adapted at a distal end for attachment to an external mounting feature of an aircraft assembly to be actuated.

Abstract: A rotary actuator includes a housing having an interior boundary that defines a central bore and has interior recesses, a chamber housing assembly disposed in the central bore and having an arcuate chamber, the arcuate chamber comprising a cavity, an exterior boundary of the chamber housing assembly having exterior recesses, each of the exterior recesses aligned with a respective one of the interior recesses, pins residing between the interior boundary and the exterior boundary, each of the pins mated to one of the exterior recesses and a corresponding one of the interior recesses to maintain an orientation of the chamber housing assembly with respect to the housing, a rotor assembly rotatably journaled in the chamber housing assembly and comprising a rotary output shaft and a rotor arm, and an arcuate-shaped piston disposed in the chamber housing assembly for reciprocal movement in the arcuate chamber.

Abstract: A rotary actuator includes a first housing defining a first arcuate chamber having a first cavity, a first fluid port in fluid communication with the first cavity, and an open end. A rotor assembly is rotatably journaled in the first housing and having a rotary output shaft and a first rotor arm extending radially outward from the rotary output shaft. An arcuate-shaped first piston is disposed in the first housing for reciprocal movement in the first arcuate chamber through the open end, wherein a first seal, the first cavity, and the first piston define a first pressure chamber, and a first portion of the first piston contacts the first rotor arm.

Abstract: A rotary actuator includes a first housing defining a first arcuate chamber having a first cavity, a first fluid port in fluid communication with the first cavity, and an open end. A rotor assembly is rotatably journaled in the first housing and having a rotary output shaft and a first rotor arm extending radially outward from the rotary output shaft. An arcuate-shaped first piston is disposed in the first housing for reciprocal movement in the first arcuate chamber through the open end, wherein a first seal, the first cavity, and the first piston define a first pressure chamber, and a first portion of the first piston contacts the first rotor arm.

Abstract: The subject matter of this specification can be embodied in, among other things, a rotary actuator that includes a housing defining an arcuate chamber comprising a cavity, a fluid port in fluid communication with the cavity, and an open end, the arcuate chamber following a portion of a first arc between a first end and a second proximal the open end, an arcuate-shaped piston disposed in said housing for reciprocal movement in the arcuate chamber through the open end, the arcuate-shaped piston following a portion of a second arc having a radius of curvature, wherein a seal, the cavity, and the piston define a pressure chamber, and a first bearing in contact with a first radial side of the piston relative to the radius of curvature at a contact point beyond the first arc.

Abstract: The subject matter of this specification can be embodied in, among other things, a seal assembly that includes a compressible seal slidably mounted on a central longitudinal shaft of a rotor assembly, the seal having a first lateral surface adapted for contacting a first end surface of a first stator and a first end surface of the second stator and a first end surface of a first longitudinal vane and a first end surface of a second longitudinal vane, a compression member slidably mounted on the shaft, and a locking piston slidably mounted on the shaft, the locking piston including an opening sized to receive the shaft, an end surface adapted to contact the compression member, a circumferential surface sized to be received in the bore of the housing, and a lateral surface adapted to receive actuation fluid.

Abstract: A rotary actuator includes a housing, a rotor assembly rotatably journaled in said housing and including a rotary output shaft, a central actuation assembly including a central mounting point formed in an external surface of the rotary output shaft, said central mounting point proximal to the longitudinal midpoint of the rotary output shaft, a mounting assembly adapted for attachment to an external mounting connector of a mounting surface of an aircraft structural member, and an actuation arm removably attached at a proximal end to the central mounting point, said actuation arm adapted at a distal end for attachment to an external mounting feature of an aircraft assembly to be actuated.

Abstract: The subject matter of this specification can be embodied in, among other things, a multi-axis rotary actuator that includes a first rotary piston actuator configured to controllably actuate a first pivotal joint between a first linkage to a second linkage about a first axis, and a second rotary piston actuator configured to controllably actuate a second pivotal joint connecting the second linkage to a third linkage about a second axis.

Abstract: The subject matter of this specification can be embodied in, among other things, a fluid actuator including a housing defining a first chamber having a first cavity and a first open end, a first piston assembly including a tubular first piston defining a second chamber having a second cavity and a second open end, disposed in said first housing for reciprocal movement in the first chamber through the first open end, wherein a first seal, the first cavity, and the first piston define a first pressure chamber, and a second piston assembly having an second piston disposed in said first piston assembly for reciprocal movement in the second chamber through the second open end, wherein a second seal, the second cavity, and the second piston define a second pressure chamber, and a first portion of the second piston contacts a first end effector.

Abstract: The subject matter of this specification can be embodied in, among other things, a rotary vane actuator. A rotor assembly includes longitudinal vanes disposed radially on a central shaft, with each vane connected at their ends to a circular plates secured to the shaft. Each vane has an outer edge, wherein the shaft, a surface of each plate, and the vanes define interior pockets in the rotor assembly. A stator assembly includes two stator elements each having a first longitudinal edge and a second longitudinal edge.

Abstract: A rotary actuator includes a housing, a rotor assembly rotatably journaled in said housing and including a rotary output shaft, a central actuation assembly including a central mounting point formed in an external surface of the rotary output shaft, said central mounting point proximal to the longitudinal midpoint of the rotary output shaft, a mounting assembly adapted for attachment to an external mounting connector of a mounting surface of an aircraft structural member, and an actuation arm removably attached at a proximal end to the central mounting point, said actuation arm adapted at a distal end for attachment to an external mounting feature of an aircraft assembly to be actuated.

Abstract: A rotary actuator includes a housing having an interior boundary that defines a central bore and has interior recesses, a chamber housing assembly disposed in the central bore and having an arcuate chamber, the arcuate chamber comprising a cavity, an exterior boundary of the chamber housing assembly having exterior recesses, each of the exterior recesses aligned with a respective one of the interior recesses, pins residing between the interior boundary and the exterior boundary, each of the pins mated to one of the exterior recesses and a corresponding one of the interior recesses to maintain an orientation of the chamber housing assembly with respect to the housing, a rotor assembly rotatably journaled in the chamber housing assembly and comprising a rotary output shaft and a rotor arm, and an arcuate-shaped piston disposed in the chamber housing assembly for reciprocal movement in the arcuate chamber.

Abstract: A rotary actuator includes a housing defining an arcuate chamber including a cavity, a fluid port in fluid communication with the cavity, and an open end. A rotor assembly includes an output shaft and a rotor arm extending outward. An arcuate-shaped piston is disposed in said housing for reciprocal movement in the arcuate chamber through the open end, wherein a seal, the cavity, and the piston define a pressure chamber, and a portion of the piston contacts the first rotor arm. A central actuation assembly includes a central mounting point formed in an external surface of the output shaft, said central mounting point proximal to the longitudinal midpoint of the shaft, and an actuation arm removably attached at a proximal end to the central mounting point, said actuation arm adapted at a distal end for attachment to an external mounting feature of a member to be actuated.

Abstract: A rotary actuator includes a housing having an interior boundary that defines a central bore and has interior recesses, a chamber housing assembly disposed in the central bore and having an arcuate chamber, the arcuate chamber comprising a cavity, an exterior boundary of the chamber housing assembly having exterior recesses, each of the exterior recesses aligned with a respective one of the interior recesses, pins residing between the interior boundary and the exterior boundary, each of the pins mated to one of the exterior recesses and a corresponding one of the interior recesses to maintain an orientation of the chamber housing assembly with respect to the housing, a rotor assembly rotatably journaled in the chamber housing assembly and comprising a rotary output shaft and a rotor arm, and an arcuate-shaped piston disposed in the chamber housing assembly for reciprocal movement in the arcuate chamber.

Abstract: A rotary actuator includes a housing defining a first arcuate chamber comprising a cavity, a fluid port in fluid communication with the cavity, and an open end. A rotor assembly in the housing includes an output shaft and a rotor arm extending radially outward from the output shaft. An arcuate-shaped piston is disposed in the housing for movement in the arcuate chamber. The rotary actuator includes a fluid line is coupled to the fluid port, a high pressure fluid line, a low pressure fluid line, and a central pressure source coupled to the high pressure fluid line. A servo valve is positioned between the central pressure source and the hydraulic actuator and is controllable to selectively connect the fluid line to the high pressure fluid line and the low pressure fluid line to control movement of the hydraulic actuator.

Abstract: A rotary actuator includes a piston housing assembly including a cavity, a fluid port in cavity, and an open end. A rotor assembly is rotatably journaled in the piston housing assembly and includes a rotary output shaft, a rotor arm extending radially outward from the rotary output shaft, an arcuate-shaped piston disposed in said piston housing assembly for reciprocal movement in the piston housing assembly through the open end along a radius of curvature. A seal, the cavity, and the piston define a pressure chamber, and a portion of the piston connects to the rotor arm at an end portion.

Abstract: A rotary actuator includes a first housing defining a first arcuate chamber having a first cavity, a first fluid port in fluid communication with the first cavity, and an open end. A rotor assembly is rotatably journaled in the first housing and having a rotary output shaft and a first rotor arm extending radially outward from the rotary output shaft. An arcuate-shaped first piston is disposed in the first housing for reciprocal movement in the first arcuate chamber through the open end, wherein a first seal, the first cavity, and the first piston define a first pressure chamber, and a first portion of the first piston contacts the first rotor arm.

Abstract: A rotary actuator includes a housing defining an arcuate chamber including a cavity, a fluid port in fluid communication with the cavity, and an open end. A rotor assembly includes an output shaft and a rotor arm extending outward. An arcuate-shaped piston is disposed in said housing for reciprocal movement in the arcuate chamber through the open end, wherein a seal, the cavity, and the piston define a pressure chamber, and a portion of the piston contacts the first rotor arm. A central actuation assembly includes a central mounting point formed in an external surface of the output shaft, said central mounting point proximal to the longitudinal midpoint of the shaft, and an actuation arm removably attached at a proximal end to the central mounting point, said actuation arm adapted at a distal end for attachment to an external mounting feature of a member to be actuated.

Abstract: A rotary actuator includes a first housing defining a first arcuate chamber having a first cavity, a first fluid port in fluid communication with the first cavity, and an open end. A rotor assembly is rotatably journaled in the first housing and having a rotary output shaft and a first rotor arm extending radially outward from the rotary output shaft. An arcuate-shaped first piston is disposed in the first housing for reciprocal movement in the first arcuate chamber through the open end, wherein a first seal, the first cavity, and the first piston define a first pressure chamber, and a first portion of the first piston contacts the first rotor arm.

Abstract: A rotary actuator includes a housing defining an arcuate chamber including a cavity, a fluid port in fluid communication with the cavity, and an open end. A rotor assembly includes an output shaft and a rotor arm extending outward. An arcuate-shaped piston is disposed in said housing for reciprocal movement in the arcuate chamber through the open end, wherein a seal, the cavity, and the piston define a pressure chamber, and a portion of the piston contacts the first rotor arm. A central actuation assembly includes a central mounting point formed in an external surface of the output shaft, said central mounting point proximal to the longitudinal midpoint of the shaft, and an actuation arm removably attached at a proximal end to the central mounting point, said actuation arm adapted at a distal end for attachment to an external mounting feature of a member to be actuated.