Abstract: A hydraulic system includes a hydraulic mechanism that includes a first and a second chamber. The hydraulic system includes a control valve fluidly connected to the first chamber and a pressure sensor that is configured to measure the fluid pressure in the first chamber. The hydraulic system includes a processing unit connected to the control valve. The processing unit is configured to control a hydraulic fluid flow rate to and from the first chamber of the hydraulic mechanism via the control valve to provide a shock absorption response. The hydraulic fluid flow rate is based at least in part on a pressure measurement received from the pressure sensor. The shock absorption response is based on a simulated hydraulic accumulator.

Abstract: The present disclosure relates to a fork movement control device. A fork movement control device according to an exemplary embodiment of the present disclosure may control and simultaneously move two forks by manipulating a single lever.

Abstract: A hydraulic system includes a first hydraulic device to be operated by an operation fluid, a second hydraulic device, the second hydraulic device being configured to be operated by the operation fluid, a first control valve to control the first hydraulic device, a second control valve disposed on a downstream side of the first control valve and configured to control the second hydraulic device, a communication tube connecting the first hydraulic device to the first control valve, the communication tube being configured to supply a return fluid that returns from the first hydraulic device to the first control valve, a supply fluid tube connecting the first control valve to the second control valve and being configured to supply the return fluid to the second control valve, and a connection fluid tube disposed on the first control valve, the connection fluid tube connecting the communication tube to the supply fluid tube.

Abstract: There is provided a work machine that can limit operation of a work device by MC, and improves the responsiveness of a hydraulic actuator to operation of an operation device by an operator, and ensures operability equivalent to that of a work machine that does not have MC functions, and allows the hydraulic actuator for which the operation device is not being operated to automatically operate in either direction of the operation directions thereof. For this purpose, a drive system includes a selector valve 203a disposed between a secondary port 134a of an operation device 45a and a flow control valve 15a and between a proportional solenoid valve 54a and the flow control valve 15a and a selector valve 203b disposed between a secondary port 134b of the operation device 45a and the flow control valve 15a and between a proportional solenoid valve 54b and the flow control valve 15a.

Abstract: An accumulator includes a housing, a flexible bladder and a support. The housing includes a chamber having a defined volume and a passage extending through the housing. The flexible bladder is positioned within the chamber and contains a compressible gas. The bladder being operable in an expanded condition and a partially collapsed condition. The support is positioned in the chamber and engages the flexible bladder when the flexible bladder is in the expanded condition. Liquid is positioned in the chamber and in contact with the flexible bladder. A volume of the liquid within the chamber is at a minimum when the flexible bladder is in the expanded condition. The volume of liquid within the chamber increases as a pressure of the liquid increases to compress the gas and operate the flexible bladder in the partially collapsed condition.

Abstract: The subject matter of this specification can be embodied in, among other things, a rotary actuator that includes a first rotary actuator assembly having a first housing, a first mounting assembly radially projecting from a first longitudinal end of the first housing and defining a first axial aperture, and a first output shaft extending into the first axial aperture, a second rotary actuator assembly having a second housing, a second mounting assembly radially projecting from a second longitudinal end of the second housing and defining a second axial aperture, and a second output shaft extending into the second axial aperture, and a bearing assembly having an outer surface in contact with at least one of the first mounting assembly and the second mounting assembly, and an inner surface in contact with at least one of the first rotor assembly and the second rotor assembly.

Abstract: A pedal force simulator device includes: a pressure piston actuatable by a brake pedal and axially moveably mounted in a housing; and at least two disk spring stacks connected in series, each disk spring stack having at least two disk springs, at least two of the disk spring stacks having different spring constants, and the disk spring stacks being situated in the housing between an end face of the pressure piston and an axial stop of the housing. At least one of the disk spring stacks includes an axial receiving recess, in which a spring element, which can be elastically deformed by the pressure piston, is situated, one end of the spring element being supported on the pressure piston and the other end being supported on one of the disk spring stacks.

Abstract: A system for charging and discharging at least one hydraulic accumulator (10) can be connected to a valve control device (12). The valve control device (12) has at least one logic valve (14). A shuttle valve (16) and a hydraulically operated switching valve (18) are also provided. The valves (14, 16, 18) are interconnected such that the hydraulically actuatable switching valve (18) compares the accumulator pressure (pA) to a minimum accumulator pressure (pA0) that can be adjusted via the control pressure setting of this switching valve (18).

Abstract: The present invention is a reversible pump-turbine installation positioned in a vertical borehole instead of in a conventional underground powerhouse or deep concrete powerhouse. The required plant cavitation coefficient may be achieved by simply boring a vertical borehole to the required depth rather than routing the water flow to and from a deeply buried powerhouse. A pneumatically controlled pressure relief valve may be incorporated into this invention.

Abstract: The invention relates to an accumulator module for a hydromechanical spring-loaded drive, wherein the spring-loaded drive is provided to actuate a high-voltage power switch (12), and wherein the accumulator module contains a pressure-tight housing (1), an accumulator piston (2) which protrudes into the housing (1) and is axially moveable in the housing (1), and a sealing cover (4) which seals the housing in an pressure-tight manner. In addition, at least one connecting channel (5, 6) is provided, which is introduced into the housing (1) for transporting a highly pressurised fluid present between the inner wall (7) of the housing and the head (3) of the accumulator piston to a high-pressure channel (11) of the spring-loaded drive, which channel is outside the housing. In order to increase the service life of the accumulator module, at least one pressure relief groove (8) is circumferentially applied to the head (3) of the accumulator piston.

Abstract: A hydraulic drive system of a construction machine includes: a boom control valve connected to a boom cylinder by a boom raising supply line and a boom lowering supply line; a pump that sucks hydraulic oil through a suction line, and delivers the hydraulic oil through a delivery line; a regenerative valve that brings the boom raising supply line and the suction line into communication with each other through a regenerative line when a boom lowering operation is performed; and a controller that controls an accumulator switching valve. The controller: switches the accumulator switching valve to a pressure accumulation position when a pressure accumulation condition is satisfied; switches the accumulator switching valve to a pressure release position when a pressure release condition is satisfied; and switches the accumulator switching valve to a neutral position when neither the pressure accumulation condition nor the pressure release condition is satisfied.

Abstract: A hydraulic system includes a hydraulic pump to output an operation fluid, first and second hydraulic devices to be operated by the operation fluid, first and second control valves to control the first and second hydraulic device, respectively, first and second communication tubes connecting the first hydraulic device to the first control valve, a supply fluid tube connecting the first control valve to the second control valve, the supply fluid tube being configured to supply the return fluid to the second control valve, first and second connection fluid tubes disposed on the first control valve, a discharge fluid tube connected to the first control valve, first and second branching fluid tubes branched from the first and second connection fluid tubes, respectively, first and second throttles disposed on the first and second branching fluid tubes, respectively, the second throttle being smaller than the first throttle.

Abstract: A series hydraulic hybrid system for a vehicle may have: a hydraulic circuit with a first hydraulic displacement unit in fluid communication with a second hydraulic displacement unit, a hydraulic actuator, and a hydraulic accumulator assembly. The hydraulic accumulator assembly is selectively in fluid communication with the hydraulic circuit via at least one controllable circuit valve. The hydraulic accumulator assembly is selectively in fluid communication with the hydraulic actuator via at least one controllable actuator valve, such that the hydraulic accumulator assembly is configured to be selectively fluidly connected with and to be selectively fluidly disconnected from the hydraulic actuator via the at least one actuator valve independently of a control position of the at least one circuit valve. A method of operating the system is also described.

Abstract: A cylinder device includes: a first piston (8) inserted in a first cylinder hole (4) so as to be movable in an axial direction, a piston rod (7) being hermetically inserted in the first piston (8), the first piston (8) being fixed to the piston rod (7); a second piston (10, 37) inserted in a second cylinder hole (5) so as to be movable in the axial direction, the piston rod (7) being inserted in the second piston (10, 37); and a partition wall (13) dividing a cylinder hole (6) into the first cylinder hole (4) and the second cylinder hole (5), the partition wall (13) being movable in the axial direction.

Abstract: A servo regulator includes servo piston, a first pressure chamber and a second pressure chamber, a spool, a biasing member provided on an outer periphery of the spool and configured to bias the spool, a first support portion configured to support one end portion of the biasing member when the spool is moved to a first direction where the pressure in the first pressure chamber is raised, and a second support portion configured to support other end portion of the biasing member when the spool is moved to a second direction where the pressure in the second pressure chamber is raised, wherein at least one of the first support portion and the second support portion is detachably provided on the spool.

Abstract: To achieve the improvement of recovery efficiency from a rod end oil chamber to a head end oil chamber during extending operation of a stick cylinder, and at the same time, to prevent an operation speed of the stick cylinder from being impaired when recovery is impossible, as well as to achieve the reduction of the number of parts, in a construction machine equipped with a stick. It is configured such that a first region Y1 at which a discharge valve passage 14g is opened while being throttled and a second region Y2 at which the discharge valve passage 14g is wider opened than at the first region Y1 are provided, in an operating position of a stick control valve 14 during extending operation of the stick cylinder, and if recovery from the rod end oil chamber 9b to the head end oil chamber 9a during extending operation of the stick cylinder 9 is possible, the stick control valve 14 is caused to be positioned at the first region Y1, and if the recovery is impossible, positioned at the region Y2.

Abstract: A slewing-type work machine includes a slewing state determination section which determines whether or not slewing motion of an upper slewing body is in a deceleration state, and a capacity control section which controls a motor capacity. The capacity control section sets the motor capacity to a capacity set for a combined operation during a performance of the combined operation in which an operation for slewing the upper slewing body and an operation for actuating an attachment are performed simultaneously, while setting the motor capacity to a preset default capacity even during the performance of the combined operation when the slewing state determination section determines that the slewing motion of the upper slewing body is in the deceleration state.

Abstract: Disclosed embodiments include hydraulic systems which provide power to lift, tilt and auxiliary (e.g., implement) functions, including high-flow auxiliary functions, with increased efficiency. Disclosed embodiments incorporate a single variable displacement pump that supplies pressurized fluid to a main control valve (e.g., for lift, tilt, and auxiliary functions) and a bypass circuit. The main control valve supplies fluid to control lift, tilt, and auxiliary flow for implements. The bypass circuit combines flow with the output of the auxiliary section of the main control valve to optionally provide high-flow for selected implements. The single variable displacement pump can then be set to different output flow levels, with the bypass circuit functioning differently under different conditions to optimize hydraulic flow to carryout various tasks under various conditions.

Abstract: A flushing module for hydraulic drives, in particular for self-contained drives, for cleaning and/or replacing hydraulic medium. The flushing module has a pump and at least one shutoff valve and a housing. The flushing module is portable.

Abstract: A hydraulic system includes a hydraulic pump, an output fluid tube connected to the hydraulic pump, an operation fluid tube connected to a hydraulic device, an unload valve connected to the output fluid tube, and having: a supply position in which the operation fluid in the output fluid tube is supplied to the operation fluid tube; and a restrain position in which supply of the operation fluid to the operation fluid tube is restrained, an operation valve connected to the output fluid tube, a control fluid tube connecting the operation valve and the hydraulic device, a warmup fluid tube connecting the control fluid tube and the operation fluid tube, and a check valve provided in the warm-up fluid tube and being for allowing the operation fluid to flow from the control fluid tube side toward the operation fluid tube, and for blocking the operation fluid from flowing side from the operation fluid tube toward the control fluid tube.