A fluid powered rotary actuator having a first member which is pivotally connected to a second member and which is includes at least one toroidal shaped spear or piston which acts within a correspondingly shaped toroidal shaped cylinder to move the first member relative to the second member. Each toroidal shaped spear or piston and cylinder assembly includes seals mounted within a seal carrier and the configuration allows movement of the seals relative to the or each cylinder. This configuration allows the seals to continue to provide a leak resistant hydraulic seal between each toroidal shaped spear or piston and its associated cylinder even in cases where the toroidal shaped spears or pistons deflect relative to their associated cylinders. The cylinders are also mounted to the first or second members in a manner designed to reduce the chance of tensile cracking due to deflection of the cylinders.

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.

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.

A rotary joint, including: a hydraulic follow-up mechanism and a rotary transmission mechanism. The hydraulic follow-up mechanism includes a cylinder body, a valve sleeve, a valve core, a valve body, a left end cover and a right end cover. The rotary transmission mechanism includes a tray, a stabilizing ring, a follow-up disk, a torque transfer disk and a stable supporting wheel mechanism. The left end cover and the right end cover are arranged at the left and right ends of the cylinder body, respectively. The valve body is concentrically mounted in a cylindrical hollow chamber of the cylinder body. The output shaft at the right end of the valve body projects out of the right end cover. The right end of the valve core is provided with a valve core torque transfer shaft extending rightwards through the right end of the valve body.

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.

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.

In the integrated hydraulic rotary actuator according to the present invention, a valve, a sensor, a controller, and a driving unit for controlling the rotary actuator are integrated, so wires connecting them are not exposed to the outside. Accordingly, it is possible to prevent damage due to interference in operation and maintenance is easy. Further, since it is integrated, including a controller, when the actuator according to the present invention is used, connecting with other parts is easy and interference can be reduced. Therefore, it is easy to design and manufacture a resultant product.

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.

A dual directional actuator may be linked to another actuator, device, object, or joint (e.g., a robotic limb or the like). A linkage mechanism may securely couple the actuator to the other actuator, device, object, or joint. Additionally, a piston axle bridge may couple the piston of the actuator to an internal or external axle. The dual directional actuator may be coupled to manifolds with integrated tee fittings to eliminate hoses external to a joint comprising one or more dual directional actuators.

A powertrain has a continuously variable transmission including a shaft rotatable about an axis. The CVT further comprises a variator assembly that includes a pulley supported on the shaft. The pulley has a movable sheave with a ramp surface. The movable sheave is axially movable on the shaft. The variator assembly also includes an endless rotatable device frictionally engaged with the movable sheave. An actuator mechanism includes a wedge component supported on the shaft. The wedge component has a wedge surface that automatically engages the ramp surface when torque on the shaft is in a first direction. The wedge surface applies a wedge force on the ramp surface. The actuator mechanism further includes an actuator that is operatively connected to the movable sheave and is activatable to apply a force on the movable sheave.