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 rotor arm configured for rotary movement, an arcuate-shaped first piston disposed in said housing for reciprocal movement in the arcuate chamber, where a seal, the cavity, and the piston define a pressure chamber that includes part or all of the arcuate chamber, and a portion of the piston contacts the rotor arm, and a rotor assembly rotatably surrounding said housing and having a rotary output tube about the axis, wherein the rotor arm extends radially outward to the rotary output tube and the rotor arm is coupled to the rotary output tube.

Abstract: The subject matter of this specification can be embodied in, among other things, a rotary actuator that includes a housing defining a first arcuate chamber portion and comprising a first cavity, a first open end, a first seal carrier assembly defining a second arcuate chamber portion and comprising a second cavity in fluid communication with the first cavity, a first piston seal, a second open end, and a third open end opposite the second open end, a first face seal in sealing contact with the housing proximal to the first open end and the second open end, a rotary output assembly, and an arcuate-shaped first piston disposed in said housing for reciprocal movement in the first arcuate chamber portion and in the second arcuate chamber portion.

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 rotor arm configured for rotary movement, an arcuate-shaped first piston disposed in said housing for reciprocal movement in the arcuate chamber, where a seal, the cavity, and the piston define a pressure chamber that includes part or all of the arcuate chamber, and a portion of the piston contacts the rotor arm, and a rotor assembly rotatably surrounding said housing and having a rotary output tube about the axis, wherein the rotor arm extends radially outward to the rotary output tube and the rotor arm is coupled to the rotary output tube.

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, an articulated joint includes a first rotary actuator having a first housing defining a first arcuate chamber comprising a first cavity, and an arcuate-shaped first piston having a first radius of curvature and disposed in said first housing for reciprocal movement in the first arcuate chamber, a second rotary actuator having a second housing defining a second arcuate chamber comprising a second cavity, and an arcuate-shaped second piston having a second radius of curvature and disposed in said second housing for reciprocal movement in the second arcuate chamber, wherein a first radial side of the first piston relative to the first radius of curvature is in bearing contact with a first radial side of the second piston relative to the second radius of curvature at a contact point between the first axis and the second axis.

Abstract: The subject matter of this specification can be embodied in, among other things, a rotary actuator that includes a housing defining a first arcuate chamber portion and comprising a first cavity, a first open end, a first seal carrier assembly defining a second arcuate chamber portion and comprising a second cavity in fluid communication with the first cavity, a first piston seal, a second open end, and a third open end opposite the second open end, a first face seal in sealing contact with the housing proximal to the first open end and the second open end, a rotary output assembly, and an arcuate-shaped first piston disposed in said housing for reciprocal movement in the first arcuate chamber portion and in the second arcuate chamber portion.

Abstract: The subject matter of this specification can be embodied in, among other things, an articulated joint includes a first rotary actuator having a first housing defining a first arcuate chamber comprising a first cavity, and an arcuate-shaped first piston having a first radius of curvature and disposed in said first housing for reciprocal movement in the first arcuate chamber, a second rotary actuator having a second housing defining a second arcuate chamber comprising a second cavity, and an arcuate-shaped second piston having a second radius of curvature and disposed in said second housing for reciprocal movement in the second arcuate chamber, wherein a first radial side of the first piston relative to the first radius of curvature is in bearing contact with a first radial side of the second piston relative to the second radius of curvature at a contact point between the first axis and the second axis.

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: A trim system for controlling an equivalence ratio in a fuel system is provided. The fuel system includes an air duct, a mixer disposed in the air duct, and a converter. The mixer has a reference pressure port and an air valve vacuum port. The converter has an outlet port and a bias port. The trim system comprises the mixer, the converter, a balance line, one or more orifices, and first and second trim valves. The outlet port is operably coupled to the mixer to deliver vaporized fuel to the mixer. The balance line is operably coupled to the reference pressure port, the bias port, and the air valve vacuum port. The balance line provides pressure to the bias port. The first and second trim valves are disposed in the balance line and operable such that the equivalence ratio in the fuel system is controlled.

Abstract: A high recovery sonic gas valve design with the inlet flow entering transverse and orthogonal to the outlet flow is presented. The configuration cancels the effects of the inlet flow entering orthogonal to the axis of the nozzle and diffuser. The inlet passage is curved in a manner to let the flow enter along the centerline of the nozzle and diffuser. The nozzle is contoured and provides upstream flow impedance. The diffuser is contoured with the area gradient varying from a low positive value at the nozzle throat then to a maximum value and finally dropping off significantly to near zero prior to the nozzle exit. The diffuser is nearly cylindrical and may extend past the valve outlet flange and protrude into adjacent piping.

Abstract: A fluid metering valve includes a gear rack which is slidable on a valve stem in which a spring counteracts the force of an actuator to maintain a constant load on the gear mechanism to prevent backlash. Corresponding stop mechanisms between the gear and the shaft of a rotary actuator come into engagement with each other near a fully closed position of the fluid metering valve for zero calibration purposes upon power loss to the actuator. A single valve member and a single actuator of the fluid metering valve provides for both a shut-off function and a metering function.