A rotary actuator where a thrust bearing ring is positioned at an inside of a tube assembly accommodating oil, thereby reducing abrasion and damage caused by rolling friction and improving rotary power of an axle load by increasing hydraulic pressure of a piston. The rotary actuator includes the tube assembly, a piston, an axle load assembly, and a thrust bearing ring. The tube assembly is provided with a tube spiral portion where a spiral is formed at an inner circumference surface, and is formed of a first passage where oil flows into and out and a second passage spaced apart from the first passage by a fixed distance.

Systems, assemblies, and methods can involve a retainer assembly adapted to interface with a sensor rod of an in-cylinder position sensor assembly of a fluid cylinder. The retainer assembly can comprise an annular body that defines a bore extending from a first end of the annular body to a second end of the annular body opposite the first end; a sleeve disposed in the bore at an inner wall of the annular body; and one or more magnets fixedly provided between the annular body and the sleeve in a radial direction of the annular body. Each of the one or more magnets may be fixedly molded in place between the annular body and the sleeve in the radial direction of the annular body.

A vehicle lift includes a hydraulic cylinder having a component that rotates as the cylinder lengthens and shortens. A sensor measures the rotation or rotational position of the rotating component, and the sensor's output is used by a controller to control the vehicle lift. In some embodiments, the vehicle lift includes a scissor or parallelogram mechanism, while others are column lifts. In some embodiments, the controller uses the sensor's output to manage the limits of travel of the vehicle lift, and in others, the controller uses it to coordinate lift operations with other lifts.

A modular actuator assembly which can be used for partial stroke testing of a valve, the assembly having a force module and a tandem piston module. The force module has a primary piston and piston rod interconnected to a shaft which is movably mounted therein. The tandem piston module is connected to the force module and has a tandem piston and piston rod. An indicator plate is connected to the piston rod and is selectively positionable on the tandem piston rod. The tandem piston rod extends into the force module and acts as a pneumatically engaged hard stop for preventing spurious travel of the primary piston and hence spurious valve travel.

A system for measuring the position of a rod element as, for example, a hydraulically or pneumatically operated piston rod. Unlike the prior art, the system according to the present invention employs a measuring principle that does not require preparatory treatment of the rod element as is required in the known solutions. The system employs direct time of flight measurements with the aid of acoustic surface waves that are introduced into the rod element. The instrument is retrofittable on existing cylinders without any modification/reconstruction thereof. An EMAT principle is employed to introduce the surface waves into the measurement in a non-contact manner.

The invention relates to a master brake cylinder arrangement with actuation detection for a motor vehicle braking system, having at least one piston arrangement with a piston, which is movably guided in a cylinder bore in a cylinder housing, said piston with the cylinder bore defining a pressure chamber which is fluidically coupled to a hydraulic brake circuit. During a forward stroke, the piston can be moved from a start position into a possible actuation piston along a movement axis, which coincides essentially with a longitudinal axis of the cylinder bore, and during a return stroke, said piston is moved from an actuation position into a start position. The piston is associated with a coupling element which is coupled to a position detecting rod for common movement therewith, said position detecting rod being moved essentially parallel to the first cylinder bore, the position of the position detecting rod can be detected by means of a position detecting sensor placed on the cylinder housing. According to the invention, in order to save space, the coupling element can be locked relative to the piston for a common lift movement therewith and after exceeding a predetermined path of the lift movement, the piston can be moved further relative to the coupling element.

A master brake cylinder arrangement includes at least one piston arrangement with a piston movably guided in a receiving bore in a master brake cylinder housing. The piston, together with the receiving bore, delimits a pressure chamber which is in fluid connection with a hydraulic brake circuit and may be moved along a movement axis between an initial position and an actuation position. A position detecting device detects movement of the piston caused by actuation is provided within the receiving bore. The position detecting device has a sensor element, which is movable as a function of a piston movement, and a position detecting sensor, which is arranged fixed on the master brake cylinder housing. The sensor element is received and guided in the master brake cylinder housing independently of the piston and is capable of interacting with the piston for deflection as a function of the piston movement.

A master brake cylinder arrangement includes at least one piston arrangement with a piston movably guided in a receiving bore in a master brake cylinder housing. The piston, together with the receiving bore, delimits a pressure chamber which is in fluid connection with a hydraulic brake circuit and may be moved along a movement axis between an initial position and an actuation position. A position detecting device detects movement of the piston caused by actuation is provided within the receiving bore. The position detecting device has a sensor element, which is movable as a function of a piston movement, and a position detecting sensor, which is arranged fixed on the master brake cylinder housing. The sensor element is received and guided in the master brake cylinder housing independently of the piston and is capable of interacting with the piston for deflection as a function of the piston movement.

A fluid pressure cylinder comprises a rod insertion hole formed in a piston member, an auxiliary rod provided to a head side wall member so as to be inserted into the rod insertion hole, an open/shut valve mechanism for detection, and a fluid passage that is opened and shut by the open/shut valve mechanism. The open/shut valve mechanism includes a valve body reception hole formed in the auxiliary rod, a valve body that is movably held in the valve body reception hole and that has a recessed engagement portion on its external peripheral portion, and a spherical body mounted on the auxiliary rod so as to engage with the recessed engagement portion; when the piston member has reached a set shifting position, the valve body is changed over to the closed position or to the opened position due to cooperation between the spherical body, the recessed engagement portion, and the inner peripheral wall portion of the rod insertion hole.

The present invention makes a rotary movement smooth, the rotary movement allowing direct detection of the movement of an output member of a rotary clamp. In a clamp, an output member is accommodated in a cylinder hole. A first valve chamber, to which compressed air is supplied, is provided between a lower wall of a housing and the output member. A second valve chamber is a hollowed out portion of the output member so as to be provided open toward the first valve chamber. A valve rod is inserted into the second valve chamber from the lower wall. A valve rod passage that allows the second valve chamber to communicate with outside air is provided in the valve rod, and a seal section is provided in a peripheral gap where the valve rod and the second valve chamber move relatively to one another. The gap is formed so that, as the valve rod and the second valve chamber are in relative movement, there is a region which is sealed by the seal section against movement of the compressed air through the gap between the valve rod and the second seal chamber and the there is a region which is open from the seal.