A vented pressurized gas-powered actuator includes a housing having a central longitudinal axis and an inner surface. The inner surface has a constant radius between first and second planes extending perpendicular to the axis. At least one vent groove extends from the inner surface in a direction away from the axis. The at least one groove has a first end intersecting the first plane.

A cylinder has a piston part, a cylinder part, and a pipe section connected to the piston or cylinder parts. A portion of the pipe section encloses a pressure compartment which receives a fluid to apply a pressure on a pressure surface so the piston part is displaced in a first stroke direction. A first return pressure compartment receives a fluid to apply a pressure on a first return pressure surface so that the piston part is displaced in a second return stroke direction. The first return pressure compartment is positioned on the outside of the pipe section, and the area of the first return pressure surface is substantially equal to the area of the return pressure surface so that a volume-neutral operation of the cylinder is provided. Also described is a hydraulic system, an excavator comprising the cylinder and a procedure for operation of the cylinder.

A hydraulic system for operating a hydraulic fall-back support of a work machine including at least one hydraulic fall-back support cylinder for tracking and limiting movements of a boom of the work machine and a hydraulic pump by means of which the fall-back support cylinder and at least one further hydraulic consumer can be supplied with hydraulic fluid. A stop valve having a blocking position and a passage position is connected between the hydraulic pump and the fall-back support cylinder, by means of which the stop valve and a load-bearing cylinder space of the fall-back support cylinder is blockable and a hydraulic store connected to the load-bearing cylinder space is provided between the stop valve and the fall-back support cylinder.

An object is to provide a cylinder device which can be used successfully over a long period of time. The cylinder device includes a cylinder, a piston, an external cylinder, a tank and first piping. The piston is slidably inserted into the cylinder. The piston divides an interior of the cylinder into a rod-side chamber and a piston-side chamber. The external cylinder is disposed outside the cylinder and covers the cylinder. The tank is formed in a space between the cylinder and the external cylinder and stores an operating fluid. The first piping constitutes part of a first passage through which passes the operating fluid supplied to and discharged from the rod-side chamber or the piston-side chamber. The first piping has two ends one of which has a larger outer diameter than the other end. The first piping is disposed in the tank.

A hydraulic cylinder enclosing a cavity, the cylinder containing a thru hole, an inner cylinder surface, and a longitudinal axis, and a piston within the cavity and movable relative to the cylinder in parallel to the longitudinal axis between a first and second positions. The piston includes a rod extending through the thru hole, the piston attached to the rod and in sealed engagement with the inner cylinder surface, and dividing the cavity into low and high pressure cavities, and each of the low and high pressure cavities containing a hydraulic fluid. The hydraulic cylinder further including a flexible bladder within the high pressure cavity containing a gas and preventing the gas from mixing with hydraulic fluid in the high pressure cavity. The flexible bladder is attached to an end of the cylinder, and is expandable within the high pressure cavity so that when the piston is in the first position, the flexible bladder and the gas are compressed, and as the piston moves toward the second position, the flexible bladder and the gas fill at least a portion of the high pressure cavity.

A hydraulic unit for generating brake pressure for a hydraulic brake system, comprising a housing which is produced from a cast blank, wherein the cast blank has at least one receiving cavity which is provided for machining to form a receiving profile for sealingly receiving a connecting piece, which is connected to a fluid container and can be plugged into the receiving profile along a plug-in axis, wherein the housing comprises at least one piston bore for receiving at least one piston, which is driven along a piston bore axis into the cast blank.

Implementations are disclosed herein that relate to a cylinder occupying structure. An example provides a cylinder system comprising a mechanical cylinder including an internal space in which a fluid is introduced, and a piston configured for reciprocating motion in the internal space, and a cylinder occupying structure including an insertion rod acting as a second piston, wherein the insertion rod is variably inserted into, and retracted from, the internal space of the cylinder in correspondence with the reciprocating motion of the piston and where parts of the insertion rod and the piston may surround the combustion space, and where fluid compression and fluid combustion is conducted within separate spaces.

There are provided a piston rod having one end portion attached to a marine vessel propulsion machine main body; an inner cylinder; an inner piston mounted in the other end portion of the piston rod, dividing a space in the inner cylinder into a fourth chamber and a fifth chamber; an outer cylinder accommodating the inner cylinder therein; a cap covering an opening portion of one end portion of the outer cylinder; and an outer piston dividing a space in the outer cylinder into a second chamber and a first chamber, is formed with a through hole that allows the fourth chamber and the second chamber to communicate with each other, comes into contact with the cap to divide the third space into an inner space on a more inner side than the through hole and an outer space on a more outer side than the inner space.

There are provided a bar-shaped piston rod having one end portion attached to a marine vessel propulsion machine main body; an inner cylinder; an inner piston mounted in the other end portion of the piston rod, is accommodated in the inner cylinder, and divides a space in the inner cylinder into a fourth chamber on the one end portion side and a fifth chamber on the other end portion side; an outer cylinder accommodating the inner cylinder therein; and an outer piston covering an opening portion of one end portion of the inner cylinder in a state where the piston rod is exposed, divides a space in the outer cylinder into a second chamber on one end portion side and a first chamber on the other end portion side, and is formed with a through hole that allows the fourth chamber and the second chamber to communicate with each other.

State of art techniques utilize active systems for stronger suction in surface crawlers while the passive approaches have limitation in providing consistent grip while moving across curved surfaces or dents. Embodiments herein provide an autonomous surface crawling robot for crawling over surfaces using electro-mechanical assembly for creating strong suction force and enabling the robot to smoothly crawl over flat surfaces, horizontal/vertical/inclined surfaces, curved surfaces, and surfaces with dents. Battery powered motors are used for only mobilization, while mechanical assembly generates suction to provide consistent grip across different type of surfaces. A dual flexible cam profile assembly including a cam profile and a guide rail generates required suction and addresses the technical challenge of maintaining suction across varying surfaces without using external power for suction generation. The dual flexible cam profile provides a robust, less prone to error or slippage type passive crawler mechanism, with consistent grip across uneven the surface.