The invention relates to a hydraulic cylinder comprising a body (1) having a wall (3) that defines a cylindrical cavity (2), with a cylindrical cavity axis (X), in which a piston (4) is movably mounted, said piston (4) separating said cylindrical cavity (2) into two tight chambers (5, 6) that are isolated from each other, the wall (3) of the body comprising at least two passages (7, 8) for introducing or discharging a fluid into each of said two chambers (5, 6). The cylinder also comprises two end walls (17, 18) and a rigid rod (32) which is secured to the piston (4) and coaxial with the cylindrical cavity (2), said rod (32) passing through a passage opening (20) provided in one of the two end walls (17, 18). The cylinder is characterised in that it comprises a position sensor (38) comprising a sensor head (39), a sensor rod (40) which is secured to the sensor head (39) and around which a magnet (41) is fitted, and a connector (42) connected to said sensor head (39).

The self-contained energy efficient hydraulic actuator system of the present invention includes a hydraulic cylinder, a servo motor that is configured to produce rated torque from zero RPM to maximum rated RPM with rotor speed/position feedback to a servo motor, a pump, and a solenoid valve that enables the hydraulic cylinder to maintain its position without the motor running. The system has the ability to hold a load in place without motor operation via the use of the solenoid valve, and therefore saves energy and extends the motor lifetime by minimizing the motor running time.

Provided is a fluid drive valve, which facilitates continuation of monitoring all the time, and which allows detection of leakage of an operation fluid from an actuator even when the actuator is operating. A pressure sensor is disposed on a pressure receiving surface, inside an actuator, on which pressure of an operation fluid acts. A pressure sensor is disposed on a non-pressure receiving surface, inside the actuator, on which pressure of the operation fluid does not act. In addition, a position sensor is disposed to detect the position of a valve stem.

Cylinder sensor assembly includes a sensor with pressure pipe extending from the first sensor axial face of a sensor body, an annular face seal adapted to be disposed between the first sensor axial face and an endcap external axial face, and a sensor retention assembly. The sensor retention assembly includes a plurality of fasteners and a retainer body having a retainer distal face, a plurality of through holes and an internal chamber with a radially-extending flange extending into the internal chamber with the internal chamber open to the retainer distal face. The sensor body is disposed within the internal chamber adjacent the radially-extending flange.

A sensor assembly (100, 300) for a vibratory conduit (130a, 330) is provided. The sensor assembly (100, 300) includes a sensor bracket (110, 310) having an outer surface (112, 312) substantially symmetric about an axis (S) and including a complementary portion (112c, 312c). The sensor assembly (100, 300) also includes a tube ring (120, 220, 320) having an outer surface (122, 222, 322) including a complementary portion (122c, 222c, 322c) affixed to the complementary portion (112c, 312c) of the sensor bracket (110, 310). The axis (S) of the sensor bracket (110, 310) is external of the vibratory conduit (130a, 330) when the tube ring (120, 220, 320) is affixed to the vibratory conduit (130a, 330).

A control loop for a double-acting pneumatic actuator is configured to generate two control signals, one for each of the two pneumatic chambers for the purpose of controlling the actuator position in view of operating constraints on the chamber pressures or the stiffness of the actuator. A numerical indicator of the stiffness may be computed in a variety of ways, for example, as the average of the two chamber pressures. In one embodiment a numerical indicator of stiffness is treated as an output of the system along with the position of the actuator. A multi-input multi-output control loop with position and pressure feedback may be used to simultaneously control the position and the stiffness of the actuator.

Working system for an application of force onto a workpiece, with a pneumatic actuator having an actuator housing designed to be fixed to a manipulator and a moveable element designed to couple an end effector and movably received on the actuator housing, and with a controller having a valve arrangement for a compressed air supply to the pneumatic actuator, has a position sensor system for determining a spatial position of the pneumatic actuator and for providing position-dependent electrical position sensor signals, and a processing system for processing the position sensor signals and for providing control signals to the valve arrangement, the processing system being designed for controlling a pneumatic supply to the pneumatic actuator as a function of the position sensor signals.

A pneumatic valve drive (1) for a valve (2), in particular for a vacuum valve, which has at least one pneumatic cylinder (3) with at least one piston (4) that is movably mounted in the pneumatic cylinder (3) and at least two cylinder cavities (5, 6) arranged on opposite sides of the piston (4). Each cylinder cavity (5, 6) is connected to at least one pressure source for applying pressure to each cylinder cavity (5, 6). One of the pressure sources is a constant pressure source (7) for applying a constant pressure to the cylinder cavity (5) arranged on one of the sides of the piston, and one of the other pressure sources is a regulated pressure source (8) for applying a variably regulatable pressure to the cylinder cavity (6) arranged on the opposite side of the piston (4).

An abnormality detecting system and an abnormality detecting method acquires a stroke of a piston as input from outside, calculates a travel time of the piston based on the results of sensing obtained by a first sensor and a second sensor, calculates a total travel distance of the piston using the number of operations and the stroke of the piston, and detects an abnormality of the actuator based on the travel time and the number of operations or the total travel distance of the piston.

A rotary drive device has a fluid-actuated rotary drive with a drive housing and a drive unit which is rotative relative thereto. The drive unit includes a drive shaft and a pivot piston, non-rotatably arranged thereon, separating two drive chambers from one another. For controlling the fluid-actuated rotary drive, a control valve arrangement including at least one electrically actuatable control valve is provided, which is attached to the drive housing and in this way is combined with the rotary drive to form a drive assembly that can be handled as a single unit. Furthermore, a robot arm is proposed, which has the rotary drive device as an arm joint connecting two arm members.