Abstract: The cylinder device includes a first piston fitted in a first cylinder to be slidable, a piston rod connected to the first piston, and a stopper mechanism which operates when the first piston reaches a predetermined position on a first end portion side of one axial end of the first cylinder during an extension stroke or a compression stroke, in which the stopper mechanism includes a second cylinder provided on the first end portion side of the first cylinder and a second piston provided to be movable according to movement of the piston rod and able to fit into the second cylinder, and one end of the second piston on the first end portion side comes into contact with a rod flange part between a rod first outer diameter part of the piston rod and a rod second outer diameter part.

Abstract: A hydraulic system for a working machine includes first and second hydraulic actuators actuated by hydraulic fluid delivered by a hydraulic pump, a first flow rate controller to control a first supply flow rate of hydraulic fluid supplied to the first hydraulic actuator to match a first required flow rate, a second flow rate controller to control a second supply flow rate of hydraulic fluid supplied to the second hydraulic actuator to match a second required flow rate, and a special flow rate control system to, if a sum of the first and second required flow rates is greater than a maximum delivery flow rate of the hydraulic pump, reduce the first supply flow rate to allow the second supply flow rate to approach the second required flow rate.

Abstract: A patient handling apparatus includes a patient support surface, a base, and a hydraulic circuit. The hydraulic circuit includes a pump, a fluid reservoir, and a hydraulic cylinder operable to selectively raise or lower the patient support surface or the base. The hydraulic circuit controls flow of fluid between the cylinder and the fluid reservoir to thereby control the movement of the base or patient support surface. In addition, the hydraulic circuit may include a manual bypass circuit configured to bypass the pump in response to a manual input, which allows manual extension or retraction of the cylinder, for example, when the pump is not operational. The hydraulic circuit may also include a pump bypass circuit configured to bypass the pump to allow fluid to discharge from the cap end to the fluid reservoir for faster evacuation of fluid from the cylinder, thereby increasing retraction speed of the rod.

Abstract: A construction machine with a hydraulic system has a hydraulic control, which comprises a joystick, a hydraulic pressure source, and two hydraulic drives. Main control valves are controlled by a joystick. The construction machine comprises multiple components, and a hydraulic drive is assigned for moving these components. The hydraulic control comprises an electrically-actuatable priority proportional valve in the hydraulic connection of a drive. The priority valve is electrically connected to the electronic control unit and generates additional hydraulic resistance. The hydraulic control comprises sensors, on the components, for detection of the positions thereof. The detected sensor values are transferred to the control unit. At least one trajectory is stored in the control unit. A control mode can be activated, in which each priority valve is controlled using the current sensor values upon actuation of the joystick so that the stored trajectory is run by control of the drives.

Abstract: A working cylinder has a cylinder with a cylinder tube, and a piston unit, The cylinder has a coupling portion which has a closure part and cylinder tube end portion that has a threaded cylinder tube portion, a cylinder tube intermediate portion and a cylinder tube end. The closure part has an external thread and the threaded cylinder tube portion has an internal thread corresponding to the external thread. The external thread and the internal thread define a common threaded portion which is couples the closure part and the cylinder tube with a form fit. The cylinder tube end is connected to the closure part by a circumferential ring weld seam configured as a laser-produced ring weld seam and defines a sealing plane which is tight to pressure medium. In an operating state under load alleviation, the common threaded portion does not absorb an axial tensile force, and in the operating state under load, the ring weld seam and the common threaded portion each absorb an axial tensile force.

Abstract: A hydraulic excavator 1 includes an engine 16, a main hydraulic pump 17 driven by the engine 16, a plurality of hydraulic actuators driven with pressure oil discharged from the main hydraulic pump 17, a plurality of flow rate control valves adapted to control the flow rate of pressure oil to be supplied from the main hydraulic pump 17 to the respective hydraulic actuators, a pilot hydraulic pump 18 adapted to supply pressure oil for driving the flow rate control valves, and a controller 15 configured to control the discharge flow rate of the pilot hydraulic pump 18. The controller 15 controls the discharge flow rate of the pilot hydraulic pump 18 such that it becomes equal to the sum of requested pilot flow rates determined in accordance with control commands for the respective flow rate control valves and a preset standby flow rate.

Abstract: A fracturing pump spacer frame includes a hydraulic end connecting plate and a crosshead box connecting plate that are disposed spaced apart in parallel. The hydraulic end connecting plate and the crosshead box connecting plate are fastened by a support sleeve. The fracturing pump spacer frame further includes a leg. The hydraulic end connecting plate, the crosshead box connecting plate, the support sleeve, and the leg are integrally formed. The leg includes a first vertical supporting plate and a second vertical supporting plate that are vertically disposed and a first bottom supporting plate that is horizontally disposed. The first vertical supporting plate is located below the hydraulic end connecting plate. The second vertical supporting plate is located below the crosshead box connecting plate. Two sides of the first bottom supporting plate are respectively connected to lower ends of the first vertical supporting plate and the second vertical supporting plate.

Abstract: A hydraulic cylinder includes: a cylinder tube; a piston rod; a piston member; a rod inner passage provided within the piston rod, a rod inner passage being configured such that a first opening portion opens at an outer circumferential surface of the piston rod in the cylinder tube, and such that a second opening portion opens outside the cylinder tube; and a sensor part provided outside the cylinder tube, the sensor part being configured to detect that the working fluid is guided to the rod inner passage, the piston member is connected to the piston rod in a state in which one-side end surface is in contact with an annular step portion so as to block the first opening portion of the rod inner passage, the annular step portion being provided on the outer circumferential surface of the piston rod, and the sensor part is configured to detect that the working fluid is guided to the rod inner passage from a rod side chamber and a counter rod side chamber through a gap between the step portion and the piston membe

Abstract: A hydraulic work system can include a continuously variable displacement hydraulic pump that is powered by an engine and is in communication with a hydraulic actuator. A run-time displacement of the hydraulic pump for movement of the hydraulic actuator can be controlled based on a speed of the engine.

Abstract: The multi-temperature double-acting piston includes a peripheral sealing ring, a lower hot crown and/or an upper hot crown, and moves in translation in a cold cylinder of a heat engine which includes a lower cylinder head and an upper cylinder head, the piston including a central piston pin the lower piston rod of which passes through the lower cylinder head so as to be connected to a power transmission housed in a transmission casing, and the upper piston rod of which passes through the upper cylinder head so as to open out into a piston cooling and lubricating chamber, a lubricating-cooling gallery provided in the pin putting the chamber in communication with the casing via an internal piston volume.

Abstract: An intermittent flushing plunger packing assembly is described herein. The packing assembly includes a plurality of annular seals disposed about the plunger configured to reciprocate along a linear axis within the fluid bore of the pump, and an annular packing nut disposed circumferentially about the plunger and configured to retain the plurality of annular seals and adjust a combined height of the plurality of annular seals. A selected one of the plurality of annular seals proximate to the fluid cylinder of the pump has a flushing fluid chamber in fluid communication with a flushing fluid port coupled to a first one-way check valve allowing a pressurized flushing fluid to be introduced and retained within the flushing fluid chamber and creating a fluid barrier to prevent frac fluid in the fluid cylinder from bypassing the annular seals.

Abstract: A displacement pump is configured to mount to a drive housing. A reciprocating drive is connectable to a pump rod of the displacement pump and includes a connecting rod and a drive link that receives a head of the pump rod. A flange projects from a pump body of the pump and a ring projects from the pump body of the pump. A portion of the drive housing is received in a gap between the flange and the ring.

Abstract: A working cylinder has a cylinder tube has closure parts arranged at tube ends. The cylinder tube and the closure parts define a cylinder interior. The cylinder has a coupling section that has one of the closure parts, a cylinder tube end and a hollow adapter body. The closure part has an external thread and the adapter body has an internal thread that define a common threaded section constructed to releasably couple the closure part and the adapter body. The cylinder tube end is connected to the adapter body on a cylinder tube side thereof by a ring weld seam. The weld seam defines a sealing plane sealed with respect to a pressure media. The piston unit defines at least one working chamber inside the cylinder.

Abstract: A system for controlling a hydraulic supply on a mobile machine comprises electronic load sensing and is configured to predictively increase the pump supply pressure PSP following a determination that a hydraulic consumer is about to be actuated. The pump supply is increased irrespective of the reported hydraulic load at the time to meet a predicted hydraulic demand of consumer. The control system may revert to a load-sensing-based control of the pump supply after a given time period or in dependence on a predefined operational parameter being met. A corresponding method of controlling a hydraulic system on a mobile machine is also disclosed.

Abstract: A hydraulic control system for linear actuation that includes an electric motor connected to a hydraulic pump and a hydraulic cylinder connected to the pump by a first flow line. A pressure transducer, a pressure control valve, and a check valve are connected to the first flow line between the pump and the cylinder and a tank is connected to the pump by a second flow line and the cylinder by a return line. A control valve is connected between the first flow line and the return line.

Abstract: A supply device for an apparatus includes: a first flow path through which a fluid can flow; a first consumer which is arranged in the first flow path and can be supplied with the fluid via the first flow path; a pump which is arranged in the first flow path and by which the fluid can be pumped out of a reservoir through the first flow path; a throttle which is arranged in the first flow path upstream of the first consumer and downstream of the pump; a second flow path through which the fluid can flow and which is fluidically connected to the first flow path at a first connection point located in the first flow path upstream of the throttle and downstream of the pump; and a second consumer which is arranged in the second flow path and can be supplied with the fluid via the second flow path.

Abstract: A linear drive assembly configured for use within a power end assembly. The linear drive assembly is configured to interconnect a crankshaft and a pony rod and comprises a crosshead assembly attached to a connecting rod assembly. In one or more embodiments disclosed herein, the connecting rod assembly is configured to attach to opposite sides of the crosshead assembly so that no portion of the connecting rod assembly is disposed within an interior of a crosshead included in the crosshead assembly.

Abstract: A control system for a work machine includes a plurality of hydraulic pumps that discharge hydraulic oil, a hydraulic cylinder that moves a working equipment element, a plurality of flow rate control valves that are respectively connected to the hydraulic pumps and adjust a flow rate of the hydraulic oil supplied to the hydraulic cylinder, a plurality of supply flow paths respectively connected to the of flow rate control valves, a meter-in flow path that connects a collective part of the supply flow paths and an inlet of the hydraulic oil in the hydraulic cylinder, a plurality of discharge flow paths respectively connected to the flow rate control valves, a meter-out flow path that connects a collective part of the discharge flow paths and an outlet of the hydraulic oil in the hydraulic cylinder, and a throttle disposed in the meter-out flow path.