Abstract: A method for improving excavating operation characteristic and grading operation characteristic of an excavator is disclosed. A hydraulically controlled selector valve is added in a boom confluence control circuit of a hydraulic excavator, and a solenoid valve group is added in the boom confluence control circuit and the bucket/stick confluence control circuit. A controller sends a control signal to switch the solenoid valve group between a disconnected mode and a connected mode. The controller may send out a signal to disconnect the solenoid valve group, to restore a valve spool to a middle position, to restore a boom lifting confluence circuit, and to disconnect a bucket/stick swinging confluence circuit to perform a standard excavation mode. The controller may send out a signal to connect the solenoid valve group to disconnect a boom lifting confluence circuit and to increase a bucket/stick swinging confluence circuit to achieve a grading operation mode.

Abstract: A bicycle component control apparatus is configured to control at least one bicycle component. The bicycle component control apparatus basically comprises a user operating device, an electric actuating unit and a hydraulic unit. The electric actuating unit is controlled in response to operation of the user operating device. The hydraulic unit is fluidly connected to the at least one bicycle component so as to fluidly control the at least one bicycle component in response to actuation of the electric actuating unit.

Abstract: Low-pressure and high-pressure reciprocating and rotary applications use seal assemblies to prevent leakage. One embodiment of a seal assembly includes a major annular body having opposing spaced-apart annular lips extending from a heel portion with a bore extending through the heel portion. A first spring is disposed between the lips, biasing the lips apart. A minor annular body extends from one of the lips of the major annular body. The minor annular body has opposing spaced-apart walls that extend from a base region and form a pocket. A second spring is disposed in the pocket between the spaced-apart walls, biasing the walls apart. During actuator operation, pressurized fluid urges one wall of the minor annular body against a pump head surface to produce a face seal and one of the lips of the major annular body against a rod surface to produce a radial seal.

Abstract: A hydraulic machine includes oscillating radial cylinders close to an external shell of a crown or star of cylinder-piston groups. The pistons of the groups are made sliding on a crank shaft with throw or on interposed concentric elements, which create an alternative movement in the oscillating radial cylinders. The oscillating cylinders are placed in contact with a spherical oscillation surface made on a body or shell of the hydraulic machine. A passage of the hydraulic liquid to and from the oscillating radial cylinder, to create feeding and discharge of the cylinder, is formed through at least a flat lateral external surface on the side of the oscillating cylinder, parallel to an oscillation plane of the cylinders, to and from a feeding channel on a lateral body or cover of the hydraulic machine.

Abstract: The hydraulic temperature compensator has at least one longitudinally extensible hydraulic chamber and a gas-filled chamber which is at least partly enclosed by the hydraulic chamber, wherein the hydraulic chamber is subdivided into a first sub-chamber and a second sub-chamber which are hydraulically connected to each other by at least one throttle point and wherein the second sub-chamber adjoins the gas-filled chamber. The stroke transmitter has at least the hydraulic temperature compensator, a stroke actuator acting on the temperature compensator, and a further hydraulic chamber which is fluidically connected to the first sub-chamber of the hydraulic chamber of the temperature compensator, wherein the further hydraulic chamber is in fluidic connection with a displaceably mounted actuating element.

Abstract: A master cylinder having a primary piston and a secondary piston is described. The secondary piston is realized of plastic material; it is composed of a skirt and an end wall. The forward edge of the skirt is equipped with longitudinal slots intended to cooperate with the resupply seal to resupply the secondary pressure chamber and ensure operation in rest position whenever the brake circuit is in ESP mode. Supply occurs from the supply chamber, which is connected to the brake fluid reservoir.

Abstract: A first piston (10) is inserted in a housing (2) so as to be hermetically movable vertically. A second piston (20) is inserted in a cylindrical hole (14) of the first piston (10) so as to be hermetically movable axially, and has an output rod (26) projecting upward from the housing (2). A lock chamber (40) is formed below the first piston (10) and the second piston (20), and a release chamber (42) is formed above the first piston (10) and the second piston (20). A force multiplier (52) is arranged in the housing (2) so as to cause (i) a first force, with which a pressurized fluid supplied into the lock chamber (40) pushes the first piston (10) upward, to be transformed in a force-multiplying manner into a second force and (ii) the second force to be transmitted to the second piston (20). Further, a change-over mechanism (54) is arranged in the housing (2) so as to selectively couple the first piston (10) to the housing (2) or the second piston (20).

Abstract: Cylinder unit of a high pressure pump for a fluid. Cylinder unit includes a cylinder formed by at least two concentric tubular components coupled by a shrink connection. A flange part with sealing system is detachably connected on one side of the cylinder, and sealing system has a movable plunger and a bearing bushing. A valve body is connected on other side of the cylinder. Bearing bushing and radially outermost component are arranged to bear against flange part to form an intermediate gap, a spring device has a distal portion supported on outermost component of the cylinder and a proximal portion on an outside of bearing bushing, and a valve body against which an other side of the cylinder bears are included. The tubular components have a metallic connection in a region of a surface bearing between the valve body and the cylinder.

Abstract: The present invention relates to a master cylinder assembly in a brake system and a piston stop. The master cylinder assembly comprises one or more piston assemblies. At least one of the piston assemblies comprises a piston (1), a piston stop (2) and a spring (3), wherein the piston stop (2) snaps into the piston (1), and the spring is retained between the piston (1) and the piston stop (2) and placed outside the piston stop (2). According to the present invention, on a circumferential wall of the piston stop (2) are provided deep slots (4) extending axially and running through the thickness of the circumferential wall, and these deep slots open towards one side of the piston stop where it snaps into the piston (1).

Abstract: An energy-recovery generation system for a handling and carrying electric vehicle, comprising a hoisting cylinder (9), wherein an output pipeline of the hoisting cylinder (9) is provided with a pressure sensor unit (1) and a directional valve (2); the directional valve (2) is under the control of the pressure sensor unit (1); a first outlet of the directional valve (2) is connected to a tank (5) through a way of a multi-way valve (4) with an operating handle; the pressure oil, flowing out from a second outlet of the directional valve (2), passes through a pump (7) having an oil suction port capable of bearing pressure or a motor, and then passes through the multi-way valve (4), to finally flow back to the tank (5); the pump (7) having an oil suction port capable of bearing pressure or the motor drives an electric motor (16) to output electric energy; an electric energy output end of the electric motor (16) is connected to an energy storage device (20) through a converter (21).

Abstract: A fluid-actuated rotary drive device is provided, with a housing (2) in which is formed a working chamber (3), in which is a swivel piston (18) able to swivel around a central axis (5). Also fitted or able to be fitted in the working chamber (3) is a space divider and stop unit (38), comprised of a space divider element (24) and at least one stop element (42) fixed to the former. The components of the space divider and stop unit (38) are fitted to one another by snap-in connection, so that the space divider and stop unit (38) is easy to handle during its installation in the working chamber (3).

Abstract: A vibrator has a hollow body with two end walls, a first piston slidably housed within the body, a first chamber defined therein and communicating with an inlet and bounded by a first active surface of the first piston, and a second chamber bounded by a second active surface of the piston, larger than and opposite the first active surface. The first piston slidingly houses a switch unit having at least one second piston and controlled by a fluid switch circuit having an inlet portion formed in the first piston and communicating with the first chamber. An outlet portion is formed in the first piston and communicates with the outlet. A switch portion, which is defined by the switch unit, communicates with the second chamber, and connects the second chamber to the inlet portion and to the outlet portion alternately as a function of the switch unit's axial position.

Abstract: A hydrostatic drive system includes a differential cylinder connected in a closed circuit to a high-pressure pump. A piston-side compression chamber and a piston-rod-side compression chamber of the differential cylinder are in communication with the high-pressure pump. The closed circuit includes a protection device having first and second protection valve devices that each includes a pressure relief valve and an anti-cavitation valve. The pressure relief valve of the first protection valve device is provided with an override device, by means of which the opening pressure of the pressure relief valve can be varied. When the high-pressure pump delivers into the piston-rod-side compression chamber, the pressure relief valve of the first protection valve device is adjusted by means of the override device to a reduced opening pressure and the differential volumetric flow flows out via the pressure relief valve to a low-pressure system.

Abstract: A pump including a cylinder body having first and second ends and a cylinder bore, a plug shaft including first and second ends and a plug shaft bore, wherein the first end of the plug shaft is fixed relative to the cylinder body, and wherein the second end of the plug shaft includes a stop, a first piston received within the cylinder bore to partially bound a first gas chamber and a hydraulic fluid chamber, the first piston being received over the plug shaft and axially moveable relative to the plug shaft, a socket shaft including first and second ends and a socket shaft bore, the socket shaft bore being configured to sealingly receive the plug shaft, a second piston received within the cylinder bore to partially bound a second gas chamber and the hydraulic fluid chamber, the second piston being connected to the socket shaft.