Abstract: A hydraulic lifting column comprising a base structure, a head structure and a lifting structure. The lifting structure comprising a hydraulic power unit and hydraulic linear actuators extending between the base structure and the head structure, the hydraulic power unit acting on the hydraulic linear actuators. The lifting structure comprising four linear actuator units with a mutually parallel, vertically oriented working direction. Each linear actuator unit comprising a double cylinder having two-cylinder bores arranged next to one another and two piston structures with piston rods oriented parallel to one another and extendable in opposite directions from the double cylinder. The four lower piston rods are connected to the base structure at the corners of a first quadrilateral and the four upper piston rods are connected to the head structure at the corners of a second quadrilateral.

Abstract: A hydraulic circuit for a pair of cylinders of an articulation system includes a pump, a reservoir, a directional control valve (DCV), a pair of actuator valves (AVs) and an articulation charge circuit (ACC). The DCV is fluidly coupled to the pump, the reservoir and the pair of cylinders via a supply line, a fluid return line and a pair of cylinder supply lines (CSLs) respectively. Each CSL has a load check valve (LCV) therein. The AVs are fluidly coupled with the DCV and the pump via a pilot supply line (PSL) for actuating movement of the DCV. The ACC, associated with the PSL and each cylinder supply line downstream of the associated LCV, charges a corresponding CSL with fluid from the PSL for increasing a pressure in the corresponding CSL when the pressure in the corresponding CSL falls below the pressure of fluid associated with the PSL.

Abstract: The invention discloses a paired air pressure energy storage device, an inspection method and a balance detection mechanism thereof. The paired air pressure energy storage device includes an inner body and an outer body sleeved outside the inner body. The inner body is filled with a first gas. A cavity formed between the outer body and the inner body is filled with a second gas. There is a gas energy pressure difference between the first gas and the second gas. The gas energy pressure difference is relative pressure gas energy. The invention can store two gases with different pressure intensities, has a simple structure, is convenient for transportation, and is favorable for effective energy storage and long-term storage of gases.

Abstract: A reciprocating pump is disclosed. The reciprocating pump may comprise a power end, and a fluid end operatively connected to the power end. The fluid end may include a plunger, a cylinder configured to operatively engage the plunger, and an end block. The plunger, the cylinder, and the end block of the fluid end may each be fabricated from a high toughness martensitic stainless steel composition comprising between 11.50% and 17.00% by weight chromium, between 3.50% and 6.00% by weight nickel, between 0.30% and 1.50% by weight molybdenum, between 0.01% and 0.20% by weight vanadium, and iron.

Abstract: A cylinder protection device for a cylinder of a machine includes a cylindrical body. The cylinder protection device includes a first portion having a first surface and a second surface. The first and second surfaces are disposed between a first end and a second end of the first portion. The first and second surfaces are inclined relative to each other. Further, the first and second surfaces intersect at a first upper edge of the first portion. The cylinder protection device also includes a second portion disposed on the cylindrical body and connected to the second end of the first portion. The second portion includes a third surface and a fourth surface inclined relative to each other. Further, the third and fourth surfaces intersect at a second upper edge of the second portion. The second upper edge is inclined relative to the first upper edge of the first portion.

Abstract: A hydraulic drive device for a cargo vehicle includes a hydraulic cylinder supplying and discharging of hydraulic oil, an operation member that operates the hydraulic cylinder, a hydraulic pump, a lowering oil path connecting the hydraulic cylinder and the hydraulic pump, an operation valve disposed in the lowering oil path, a bypass oil path that branches off from the lowering oil path, a bypass flow rate control valve disposed in the bypass oil path and that controls a bypass flow rate, and a resistance element that is disposed closer to the hydraulic cylinder than the operation valve in the lowering oil path and that increases a fluid resistance. A pilot flow path of the bypass flow rate control valve is connected to a part of the lowering oil path between the hydraulic cylinder and the resistance element.

Abstract: The invention relates to a system for energy storage and recovery, comprising: at least one compressed-air tank, at least one pressurized-water tank in communication with the compressed-air tank, at least one turbine in effective communication with the at least one pressurized-water tank, a generator for generating electrical energy, a high-pressure pump for pumping water from a water reservoir into the pressurized-water tank. According to one aspect of the invention, the turbine in effective communication with the at least one pressurized-water tank is a reaction turbine, which is connected in series with a constant pressure turbine in such a manner that a drive shaft of the reaction turbine is connected to a drive shaft of the constant pressure turbine and a drive shaft of the generator, and the constant pressure turbine is arranged between the reaction turbine and the generator, wherein the generator includes an interface for connection to a public power grid.

Abstract: A hydraulic system includes an engine; at least one hydraulic pump operatively coupled to the engine for transfer of mechanical power therebetween; and a controller operatively coupled to the engine and the at least one hydraulic pump. The controller is configured to determine a lug speed error as a difference between a target lug speed value and a speed of the engine, set at least one closed-loop gain to a non-zero value when the speed of the engine is less than the target lug speed value, and generate a pump control signal by scaling the lug speed error by the at least one closed-loop gain.

Abstract: The invention relates to a hydraulic machine, in particular to a hydraulic motor with two working lines, from one of which a high pressure line and from the other one a low pressure line is branched off. An electronic control unit and a servo displacement unit are provided to control the displacement of the displacement volume of a drive mechanism of the hydraulic machine, wherein the displacement volume can be determinated by the displacement of a servo piston within the servo displacement unit. For this, the servo piston can be loaded at least on one side via a servo pressure line with hydraulic fluid under servo pressure, wherein the servo pressure level can be adjusted by a control spool arranged moveable within a control valve. For this, hydraulic fluid from the low pressure line or, perhaps, from the high pressure line is guidable via the control valve to the servo pressure line if a suitable control signal is available at a switching valve.

Abstract: A piston for use in an internal combustion engine having a pressure side and counterpressure side. The piston includes a piston skirt having skirt wall sections and box walls connecting the skirt wall sections. A spacing between the box walls on the pressure side is 35%-51% of the piston diameter and on the counterpressure side is 26%-39% of the piston diameter. Reduced angles of the extraction angle slopes on the pressure and counterpressure sides as well as larger free spaces are achieved which provides for lower piston mass and greater distribution of stresses in the box region of the piston.

Abstract: A hydraulic-pneumatic energy storage and recovery system, which comprises first and second sealed containers within each of which a volume of liquid is introducible and from which the introduced liquid is pneumatically propellable; a turbine interposed between the first and second containers and coupled with a generator, to produce power when caused to be rotated by the pneumatically propelled liquid; and collection-delivery apparatus located externally to the first and second containers, for collecting energy-depleted liquid gravitating from the turbine and for delivering the collected liquid to one of the first and second containers, to be used in subsequent energy recovery cycles.

Abstract: Embodiments of the inventive concept include a manufactured pressure vessel including pressure cells having an impermeable layer containing porous material in which air can permeate, and a big mass layer disposed atop the pressure vessel to pressurize the air within the pressure vessel. The impermeable layer can include rubber from recycled vehicle tires. The big mass layer can have a total weight of between one (1) million and one (1) billion tonnes, or more. The big mass layer can include a remediated upper surface. The pressure vessel can include an interface section through which the air can enter and exit the pressure vessel. Pressure lines can be coupled to the interface section. A turbine center can be coupled to the pressure lines to generate electricity in response to pressurized air received through the pressure lines, or to pump air through the pressure lines into the pressure vessel to pressurize the pressure vessel.

Abstract: There is provided a shoe for a compressor with improved seizure resistance. The shoe for the compressor includes: a first sliding face that slides on a piston; a second sliding face that slides on a swash plate; and a recess formed in the second sliding face. In a section along a height direction and scaled up 1000 times in the height direction and 10 times in a radial direction, a connecting portion between the second sliding face and the recess 53 is formed in a rounded shape with a radius R2 larger than 5 mm.

Abstract: The invention relates to a swashplate (5) for a swashplate compressor (1) comprising a main swashplate body (8), which is made from a sintering material, and to a method for producing the swashplate (5).

Abstract: A bicycle telescopic apparatus includes a first tube, a second tube, an actuating member, and a hydraulic positioning structure. The first tube defines an axial direction. The second tube is telescopically received in the first tube in the axial direction. The actuating member is movable relative to the first tube in the axial direction of the first tube. The actuating member is configured to move the second tube relative to the first tube in the axial direction. The hydraulic positioning structure is configured to position the first tube and the second tube relative to each other in the axial direction.

Abstract: A mast assembly that includes a mast and a hydraulic circuit for moving the mast. The hydraulic circuit includes a primary hydraulic cylinder coupled to the mast to rotate the mast about a pivot axis and a secondary hydraulic cylinder extending from a rod end to a cap end that is fluidly coupled to the primary hydraulic cylinder. A directional valve is fluidly coupled between the primary hydraulic cylinder and secondary hydraulic cylinder to keep a pressure on the cap end of the secondary hydraulic cylinder greater than the pressure on the rod end of the secondary hydraulic cylinder during all operating conditions.

Abstract: A construction machine includes a bidirectionally tiltable type hydraulic pump 2, a hydraulic cylinder 1 having a cap chamber 1e and a rod chamber 1f, a first flow path 11 connecting the hydraulic pump 2 and the cap chamber 1e, a second flow path 12 connecting the hydraulic pump 2 and the rod chamber 1f, a discharge flow path 16 branched from the first flow path 11, a discharge valve 32 that is disposed in the discharge flow path 16 and controls a discharge rate of hydraulic working oil from the cap chamber 1e to the discharge flow path 16, an operation device 54 that instructs an action of the hydraulic cylinder 1, and a controller 56.

Abstract: A hydraulic steering unit (1) is described comprising a supply port arrangement having a pressure port (P) connected to a main flow path (5) and a tank port (T) connected to a tank flow path (6), a working port arrangement having a left working port (L) connected to a left working flow path (7) and a right working port (R) connected to a right working flow path (8), a bridge arrangement (14) of variable neutral open orifices, said bridge arrangement (14) comprising a first left orifice (A2L) connected to a main flow path (5) and to the left working flow path (7), a first right orifice (A2R) connected to a main flow path (5) and to the right working flow path (8), a second left orifice (A3L) connected to the left working flow path (7) and to the tank flow path (6), and a second right orifice (A3R) connected to the right working flow path (8) and to the tank flow path (6). Such a steering unit has a good steering behavior but can function as a closed-center solution.

Abstract: A hydraulic valve assembly for a work vehicle includes a fan and brake function module. A first pump supplies hydraulic pressure to a fan circuit and to first and second service brake circuits of the vehicle. A second pump supplies hydraulic pressure to a steering and work function module that in turn supplies hydraulic pressure to a steering circuit and a work function circuit of the vehicle. The hydraulic valve assembly may also include a work control module and an auxiliary module. The modules of the hydraulic valve assembly are separably connected together via interface surfaces.

Abstract: A fluid pressure circuit includes an HST circuit having a variable capacity fluid pressure pump configured to be driven by a mechanism to perform forward-reverse rotation, a fluid pressure motor configured to be driven by fluid discharged from the fluid pressure pump to perform forward-reverse rotation, a first line configured to connect a first port of the fluid pressure pump and a first port of the fluid pressure motor, and a second line configured to connect a second port of the fluid pressure pump and a second port of the fluid pressure motor; an accumulator connected in parallel with the fluid pressure pump; an accumulator pump configured to accumulate pressure fluid in the accumulator; and an accumulator switching valve configured to switch connection between the fluid pressure motor and the accumulator.