This invention provides a linear actuator with a cylinder defining a cylinder axis. A piston is movable within the cylinder along the cylinder axis, and a piston rod extends axially from the piston for connection to a mechanism whereby in use, movement of the piston actuates the mechanism. A rotary output mechanism includes a rotary output element extending generally transversely from the cylinder and supported for rotation about an output axis generally normal to the cylinder axis. The rotary output mechanism is responsive to movement of the piston, and the rotary output element is adapted for operative engagement with an instrument mounted to the cylinder such that axial movement of the piston effects a corresponding rotational displacement of the rotary output element, whereby in use the instrument provides an output signal indicative of the position of the piston within the cylinder.

A drive system (1) which is designed in particular as a robot (1a) and which has a fluid-operated linear drive (2), on the drive unit (7) of which linear drive, which drive unit can be driven so as to perform a drive movement (8), there is mounted an electrically and fluidically operable working unit (3). The linear drive (2) is equipped with a control valve device (16) which can be actuated by means of an internal electronic control device (32) in order to move the drive unit (7). Two drive pressure sensor devices (113) and a travel measuring device (114) are connected to the internal electronic control device (32), such that a position-controlled operation of the drive unit (8) is possible. The drive system (1) furthermore includes a flexible electrical cable arrangement (97) and a flexible fluid hose arrangement (95), which are fixed to the drive unit (7) and which serve for the supply of electricity and fluid to the working unit (3).

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 sensor unit for a fluidic cylinder having a base carrier on which a circumferential seal is formed, so that an interior of the fluidic cylinder is sealable, and having a position sensor for detecting a position of the piston, and having a pressure sensor for detecting a pressure in the interior.

Disclosed are seal arrangements in a hydraulic device. The seal arrangement includes a seal channel defining a loop. A seal is seated within the seal channel. A coolant flow passage has a first part intersecting with the seal channel at a first point and a second part intersecting with the seal channel at a second point. The first part of the coolant flow passage is configured to provide hydraulic fluid to the seal channel such that, at the first point, a first portion of the hydraulic fluid flows in a first direction around the loop and a second portion of the hydraulic fluid flows in a second direction opposite to the first direction around the loop. At the second point, the first portion of hydraulic fluid and the second portion of hydraulic fluid are configured to flow into the second part of the coolant flow passage.

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.

A wheeled work vehicle includes: a transmission transmitting the rotational power of a traveling hydraulic motor to wheels; a traveling control valve having an interruption position that interrupts supply of hydraulic fluid from a hydraulic pump to the traveling hydraulic motor; a shift changeover valve that shifts the speed stage of the transmission by the position of the shift changeover valve being selectively switched; and a controller that controls the traveling control valve and the shift changeover valve. The controller switches the traveling control valve to the interruption position, then switches the position of the shift changeover valve such that the speed stage of the transmission is shifted to the low speed stage, and switches the traveling control valve from the interruption position to an original position side before the switching in a case where the controller shifts the transmission from the high speed stage to the low speed stage.

In a brake fluid pressure control apparatus, a sensing device is integrally fixed to a master piston. The sensing device including the body to be sensed, which may include a magnet, and a sensing body, which may include a sensor. The sensing bodying sensing an axial position of the master piston without relative movement, that is, without providing play. This arrangement improves the sensing precision of the sensing device. Since it is not necessary to provide a member separate from the master piston in order to retain the body to be sensed, it is possible to achieve downsizing of the brake fluid pressure control apparatus.

A hydraulic cylinder may include a housing and a rod extending from a working end positioned outside the housing through a rod end of the housing to a piston end positioned within the housing. The hydraulic cylinder may also include a piston arranged on the piston end of the rod and configured to articulate within the housing. The hydraulic cylinder may also include a cap end secured to the housing and having a pocket for receiving a sensor. The pocket may have a cylindrical sidewall. The cap end may include a bore extending therethrough and arranged generally tangential to the sidewall where the bore extends into the cap end, breaches the sidewall, and extends further passed the pocket. The hydraulic cylinder may also include a retention pin configured for placement in the bore and for an interference fit with the sensor when the sensor is arranged in the pocket.

A head unit system for controlling an object includes a head unit device that include shear thickening fluid (STF) and a chamber configured to contain the STF. The chamber further includes a set of gates between a front channel and a back channel. The set of gates includes a bypass opening set. The head unit device further includes a cupped piston housed at least partially radially within the chamber. The set of gates is configured to control flow of the STF between the front channel and the back channel to control movement of the object.