Abstract: The present invention provides a controller for hydraulic apparatus (100). The controller is configured to determine (310) that an energy return criteria has been met by movement of a first movement component of a first hydraulic actuator. In response thereto, the controller is further configured to select (320) at least one among a plurality of energy control strategies based on at least one operational characteristic of the hydraulic apparatus, and to control (330) the hydraulic apparatus to implement the energy control strategy during movement of the first movable component in such a way as to meet the energy return criteria. The plurality of energy control strategies comprises a first energy control strategy and a second energy control strategy. The at least one operational characteristic of the hydraulic apparatus comprises an indication of an expected energy recovery of one or more of the energy control strategies.

Abstract: A load-controlled hydraulic supply for a utility vehicle includes a variable-displacement pump supplied with hydraulic fluid from a hydraulic reservoir. The variable-displacement pump has a mechanically actuable control slide for changing a volume flow delivered. An electrical actuator is configured to actuate the control slide. A controller is configured to control the electrical actuator in accordance with a determined load requirement on a consumer side.

Abstract: A fluid end includes a housing having a bore extending toward a cavity and a wear sleeve positioned within the bore. The fluid end also includes a plunger positioned within a plunger bore extending through the wear sleeve, the plunger reciprocating within the plunger bore. The fluid end further includes a wear sleeve retainer coupled to the housing and positioned to block axial movement of the wear sleeve, the wear sleeve retainer having external threads along a body that engage internal threads formed in the housing. The fluid end also includes an anti-rotation system, coupled to the housing, the anti-rotation system engaging the wear sleeve retainer to block rotation of the wear sleeve retainer in at least one direction. The fluid end further includes a packing nut coupled to the wear sleeve retainer.

Abstract: The present disclosure relates to a piston assembly, the piston assembly comprising a cylinder extending along an axis and having an open axial end, a cap assembly closing the cylinder at its open axial end, wherein the cap assembly comprises an insertion portion received in the cylinder at its open axial end, and a piston axially movably disposed within the cylinder and partially received in the insertion portion of the cap assembly. The present disclosure further relates to a variable displacement hydraulic unit including said piston assembly.

Abstract: Disclosed are a method and a device for detecting a position of a piston rod, a hydraulic cylinder and a working machine. The method includes: acquiring a target image at a target position; obtaining a pixel information corresponding to the target image; comparing the pixel information with a pixel database of the piston rod, a full-stroke pixel information of the piston rod and a relationship between the full-stroke pixel information of the piston rod and a displacement of the piston rod are stored in the pixel database of the piston rod, and the full-stroke pixel information at least comprises the pixel information within a range in which the piston rod is configured to move relative to the target position; and determining a position information of the piston rod based on a comparison result.

Abstract: The hydraulic drive system includes a hydraulic pump, a plurality of variable displacement actuators, and a control unit. The hydraulic pump discharges a hydraulic fluid. The variable displacement actuators each receive a pressure of the hydraulic fluid discharged from the hydraulic pump to operate corresponding one of a plurality of drive parts. The control unit controls displacement varying parts of the variable displacement actuators. The control unit controls the displacement varying parts of the variable displacement actuators, based on sensed pressures in fluid inflow parts of the variable displacement actuators in operation, such that the pressures in the fluid inflow parts of the variable displacement actuators in operation approach a common target pressure.

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.