Abstract: A power distribution transmission unit (1) having a hydrostatic power branch (2) and a mechanical power branch (3) connected by a connection system (8). The connection system (8) at least partially damps transfer of oscillations between the power branches. The power flow can be passed between the power branches, via a connecting shaft (22) that compensates axial offset between a hydrostat shaft (18) of the hydrostatic power branch (2) and a shaft (20) of the mechanical power branch (3). The connecting shaft (22) is a hollow shaft and a spring device (27), elastically prestressing the hydrostat shaft (18), is arranged within the connecting shaft. The tooth profiles (23, 25) of the connecting shaft (22) are formed as curved outer teeth which engage in tooth profiles (24 and 26) of the hydrostat shaft (18) of the hydrostatic power branch (2) and of the shaft (20) of the mechanical power branch (3), in each case made as inner teeth.

Abstract: A slave cylinder (50) for a vibration-damped hydraulic force transmission system, particularly a hydraulic clutch actuating system for motor vehicles is disclosed, comprising a cylinder housing (52), a piston (56) received therein to be longitudinally displaceable and a pressure chamber (60) which is bounded by the cylinder housing and the piston and which can be selectably acted on by a pressure medium, by way of a pressure connection (66) provided in the cylinder housing, in order to displace the piston in the cylinder housing. An insert member (68) which is inserted in the pressure chamber and secured in the pressure connection and which is equipped with a device (70) for reducing pressure pulses, the device being constantly open to the pressure medium, is additionally provided. As a result, the vibration-damping measures or means are integrated in the slave cylinder in a particularly economic and space-saving manner.

Abstract: The invention relates to a method and a device for damping the displacement of construction machines, in particular wheel loaders, comprising working equipment that is driven by means of a hydraulic cylinder, a hydraulic source, a controlled valve for supplying the hydraulic cylinder with hydraulic fluid, a regulator unit comprising control software, in addition to an acceleration sensor.

Abstract: A reservoir device is provided, which prevents water from flooding in an accumulation tank and improves on-vehicle installation capability. The reservoir device 10 includes a catch tank 13 connected to an airspace “A” formed above an oil surface of working oil accumulated in an accumulation tank 12, which has a bottom surface formed with an external-air communication aperture 32. Liquid entering from the external-air communication aperture 32 is allowed, to be accumulated in the catch tank 13 once, and then is suitably discharged through the external-air communication aperture 32. This precludes the accumulation tank 12 from flooding with water and improves on-vehicle installation capability.

Abstract: A hydraulic ride control system for a working vehicle such as a wheel loader is provided with boom cylinders, an actuator control valve for controlling a pressure in bottom pressure chambers of the boom cylinders, an accumulator connected to the bottom pressure chambers of the boom cylinders via a connection line, an opening control valve having a pilot chamber to selectively communicating or cutting off the connection line depending on a pressure in the pilot chamber, and a selector unit for selectively feeding a pressure to or draining a pressure from the pilot chamber. The selector unit comprises a controller for variably controlling an opening of the opening control valve.

Abstract: A device for reducing hydraulic-fluid oscillation in a hydraulic system, in particular in a hydraulic system of an aircraft, wherein the hydraulic system comprises a pump that is driven by a drive, which pump conveys a fluid to a hydraulic line by pressure pulsation. The device comprises an actuator, arranged in the hydraulic line for generating pressure pulsation that compensates for the pressure pulsation of the pump.

Abstract: Disclosed is a hydraulic control arrangement for damping wagging vibrations, wherein during operation a hydraulic cylinder of a lifting equipment can be connected to a hydraulic accumulator via a damping valve arrangement. The damping valve arrangement comprises a nozzle valve arrangement with two different nozzle cross-sections, the larger of which is active when filling the hydraulic accumulator and the smaller of which is active during adaptation of the hydraulic accumulator to the load pressure of the hydraulic cylinder.

Abstract: A travel jolt minimizing assembly for use in association with an articulated loader steering environment having a orbitrol pump, and a flow amplifier coupled to the orbitrol pump through a left orbitrol signal and a right orbitrol signal, and a steering cylinder coupled to the flow amplifier. The travel jolt minimizing assembly includes a system for temporarily diverting the left orbitrol signal within a predetermined degrees of a full articulation in a left direction and a system for temporarily diverting the right orbitrol signal within a predetermined degrees of a full articulation in a right direction. The invention further includes a response cushion assembly which minimizes jolts which occur upon a rapid change in direction.

Abstract: A hydraulic steering system has a steering linkage and an actuator actuating the steering linkage. Pressurized hydraulic fluid can be fed to the actuator and removed from the actuator through a return pipe. A device installed into the return pipe counteracts volume flow pulsations by damming up the hydraulic fluid return flow. The device dams up the hydraulic fluid only in the event of an occurrence of a volume flow pulsation.

Abstract: The invention concerns a vibration-decoupling device for a hydraulic circuit and in particular concerns a vibration-decoupling device for a hydraulic circuit used in an agricultural vehicle. The device has a fluid transfer element (3) able to be connected at one end (4) to a high pressure outlet of a hydraulic pump (1) and to transport fluid expelled from the pump. The another end (5) of the fluid transfer element (3) is moveably connected with a fixed element (11) such as a gear assembly housing so that the fluid can be passed to a hydraulic consumer. A support element (9) is moveably connected with the fixed element (11) and the fluid transfer element (3) and acts so that a force is exerted on the fluid transfer element (3) in one direction while the other end (5) of the fluid transfer element (3) and the fixed element (11) remain securely connected together.

Abstract: A travel vibration suppressing device 20 is structured such that a directional control valve 30 for a bucket, a directional control valve 29 for a boom, a ride control valve 31 and a boom speed increasing valve 33 are integrally arranged in a laminated manner by an internal piping. The ride control valve 31 communicates or cuts off a bottom chamber 11a of a boom cylinder 11 and an accumulator 27. The boom speed increasing valve 33 supplies a discharge pressure of a hydraulic pump 21 to the bottom chamber 11a or a head chamber 11b or connects the to the bottom chamber 11a or the head chamber 11b to a tank 23.

Abstract: A hydraulic power output unit can be used in a hydraulic hybrid drive system for propelling a vehicle. The hydraulic power output unit includes a housing having an input shaft that extends within the housing and is adapted to be rotatably driven by a source of rotational power. A hydraulic pump is rotatably driven by the input driveshaft to pump hydraulic fluid. A vibration damper is provided within the housing for dampening vibrations in the input shaft.

Abstract: A transmission device (10) having at least one form-fitting shifting element (12) which is hydraulically actuated via a hydraulic system (11) with hydraulic pressure (p—12), in the area of a piston chamber, via a feed line (20) that conveys hydraulic fluid, to shift from a disengaged to and engaged operating state. A non-return valve device (27) is arranged upstream of the form-fit shifting element (12).

Abstract: A valve arrangement for vibration decoupling has a housing, in which two valve bodies are accommodated, a first of which is biased by a spring in a reference direction towards a stop integral with the housing and has a through-path for fluid. The other housing is biased by a spring in an opposite direction towards a valve seat on the first valve body and lifts away from the latter in the event of a volume flow in the reference direction, so as to open the through-path for fluid. A further through-path for fluid is provided between the first valve body and the housing, wherein a further valve seat is formed on the stop integral with the housing, towards which further valve seat the first valve body is biased by a spring and lifts away from the valve seat in the event of a volume flow in the opposite direction.

Abstract: A damper valve includes first and second chambers separated by a partition wall, hydraulic oil flowing from the first chamber to the second chamber via a supply path, and returning to the first chamber from the second chamber via a return path. A valve plate that is elastically deformable is urged toward a valve seat formed in the return path. The valve plate produces an elasticity restoring force so as to establish a balance between an urging force provided by an urging member and a reaction force provided by the valve plate, and is in line-contact with the valve seat when keeping the balance. The valve seat or the valve plate is formed into a conical tapered shape centered around the predetermined axis so that when the valve plate is abutted against the valve seat, an annular oil chamber is formed between the valve seat and the valve plate.

Abstract: The invention provides a hydraulic inerter mechanism, including: a hydraulic cylinder; a hydraulic motor connected to the hydraulic cylinder, with an output shaft thereon for converting the motion of the hydraulic cylinder from rectilinear motion to rotary motion; and an inertia body disposed on the output shaft. In operation, an external force applied to the inerter mechanism causes displacement of the piston, thereby pushing working fluid inside the hydraulic cylinder to generate a pressure difference between an inlet and an outlet of a hydraulic motor. The differential pressure consequently drives the hydraulic motor to rotate, and then the output shaft further drives the inertia body to rotate, thereby attaining inerter characteristics.

Abstract: A hydraulic system for a suspension system is disclosed. The system has a hydraulic cylinder, a hydraulic tank, a conveying means, a hydraulic accumulator, a control device, a load holding device disposed between the hydraulic accumulator and the hydraulic cylinder, and an on-off valve disposed between the hydraulic accumulator and the control device. In order to provide a suspension function for the hydraulic cylinder while simultaneously ensuring safeguarding of the hydraulic cylinder and of the hydraulic accumulator against a pressure drop in the case of a tube break, the present invention provides a system that controls the on-off valve and the load holding device synchronously through a control pressure device, such that when the suspension function is activated the load holding device is opened and the on-off valve is closed.

Abstract: An improved hydraulic arrangement is provided for a spring support system. The arrangement comprises a hydraulic cylinder, a hydraulic reservoir, a hydraulic fluid feeder, a hydraulic accumulator, a first control valve between the hydraulic cylinder and the accumulator, a second control valve between the hydraulic cylinder and the hydraulic reservoir as well as an automatic shut-off valve and a controller with a lifting position, a lowering position and a neutral position for the hydraulic cylinder. In order to prevent different pressure loads between the accumulator and the hydraulic cylinder, it is suggested to equalize the pressure between the accumulator and the hydraulic cylinder, without impairing the spring support system or the automatic shut-off valve. Accordingly, the accumulator is suitably connected to a non-return valve and to a flow restrictor or orifice.

Abstract: A method of operating a work machine includes moving a work implement via a first actuator having a range of motion, and ameliorating an end of stroke effect on a second actuator if an end of stroke condition of the first actuator is sensed. A work machine includes an electronic controller having software control logic for sensing a stroke condition of an actuator in a work implement system, and for ameliorating an end of stroke effect on a hydraulic actuator of the work implement system if an end of stroke condition of a first actuator is sensed.

Abstract: In an air servo cylinder formed by integrally combining an air cylinder, servo valves, and a controller via a manifold block, there are provided, in the manifold block, air discharge flow paths for releasing, to the outside, compressed air discharged associated with operations of the servo valves. In each of the air discharge flow paths, a silencer for reducing exhaust noise is incorporated so as not to protrude from the manifold block to the outside.

Abstract: What is disclosed is a hydraulic control system for controlling a hydraulic consumer actuating a working tool of a mobile equipment that is provided with oscillation damping means for attenuating oscillations during braking of the working tool. In accordance with the invention, the oscillation damping means comprise two pilot-controlled shut-off valves arranged in opposite directions, that are positioned in a connecting line between a pressure medium supply and a pressure medium drain. The shut-off valves are subjected to the pressure in the drain and in the delivery, respectively, in the opening direction, and also to this pressure and to the force of a spring in the closing direction. Following a predetermined initial stroke of a regulator of the control system, the pressure acting on the drain-side shut-off valve in the closing direction may be reduced, so that the latter is opened by the pressure in the drain, and the connecting line between delivery and return is opened.

Abstract: A hydraulic arrangement is described comprising a lifting cylinder 10 for a lifting arm 12 pivotably mounted on a vehicle. A hose 22 selectively connects a working chamber 10a of the lifting cylinder 10 to a supply 16 and a return 18 line to raise and lower the lifting arm, respectively. A safety check valve 46 is connected between the hose 22 and the working chamber 10a to maintain the working chamber under pressure and avoid collapse of the lifting arm 12 in the event of rupturing of the hose 22. An accumulator 70 is connectable to the working chamber 10 of the lifting cylinder 10 by way of the safety check valve 46 to provide ride control. A solenoid 50 overrides the operation of the safety check valve 46 while the hose 22 is isolated from both the supply 16 and the return 18 line to allow fluid to flow in both directions between the accumulator 70 and the working chamber 10a to cause the lifting cylinder to act as a spring supporting the weight of the lifting arm.

Abstract: A system is used with a boom pivoted on a frame about a horizontal pivot axis between raised and lowered positions by a first fluid ram joining the frame and the boom. A releasable locking mechanism locks the boom relative to the frame to prevent pivotal movement of the boom about its horizontal pivot axis. A second fluid ram is disposed between the frame and the boom, the second fluid ram compressed between the frame and the boom when the boom is adjacent the raised position, but prior to the boom achieving a latched position substantially coinciding with the raised position. A fluid circuit of the second fluid ram has two selectable pressure levels. The first level substantially prevents the boom from achieving the latched position, the second level permits the boom to achieve the latched position while providing fluid cushioning to dissipate impact forces between the boom and frame.

Abstract: What is disclosed is a hydraulic control arrangement for a mobile equipment, such as for a backhoe loader or a wheel loader, wherein a working tool of the equipment is adapted to be actuated by means of a hydraulic cylinder whose pressure chambers may jointly be connected with a hydraulic accumulator 14 for attenuating pitching oscillations of the working tool.

Abstract: A control system for a trimmer head assembly includes a first arm including a first mowing device, a first cylinder connected to the first arm, a source of fluid in selective communication with the first cylinder via a fluid line, and an accumulator in selective communication with the first cylinder when the first cylinder is not in communication with the source of fluid. The accumulator is adapted to receive fluid from the first cylinder when an external force is applied to the first arm and to deliver fluid to the first cylinder when the external force has been removed from the first arm.

Abstract: A hydraulic actuation apparatus for a motor vehicle clutch includes a master cylinder, a slave cylinder, a hydraulic line forming a main fluid channel connecting the master cylinder to the slave cylinder to form a pressure space, and a damping member arranged in the pressure space for attenuating pressure pulses. The damping member includes a connection channel connected to the main fluid channel and a fluid guide directing fluid from the main fluid channel into the connection channel. The damping member or other hydraulic operating component is preferably formed integrally with the hydraulic line, and is preferably injection molded plastic.

Abstract: A hydraulic arrangement is provided for a spring support system. The hydraulic circuit arrangement includes a hydraulic cylinder, a hydraulic tank, a hydraulic conveying device, a hydraulic accumulator, a first selector valve arranged between the hydraulic accumulator and the hydraulic cylinder, a control implement with at least three switch positions, that include a lifting position, a lowering position and a neutral position for the hydraulic cylinder and a pipe break safety arrangement arranged between the control implement and the hydraulic cylinder. In order to permit the opening of the pipe break safety arrangement, a first control pressure line extends between the pipe break safety arrangement and a conveying device and first switching devices are arranged in the first control pressure line so that a control pressure can be applied to the first control pressure line by switching the first switching devices and the pipe break safety arrangement can be controlled to open.

Abstract: A system for reducing oscillating movement of a boom assembly about a fore-and-aft aligned axis defined by a pivotal connection of a suspension arrangement independent of a carrier frame is provided. The system includes an accumulator, a cylinder actuator mechanically interconnected between the carrier frame and the boom assembly, and a metered orifice connected in fluid communication to restrict a fluid flow between the accumulator and the cylinder actuator. In response to rotation of the boom assembly in a first direction relative to the carrier frame, the system creates a force resisting the rotation of the boom assembly in the first direction. Thereby, the system deadens oscillating pivotal movement of the boom assembly relative to the carrier frame and exerts a biasing force to assist in returning and/or maintaining the boom assembly at a generally horizontal alignment.

Abstract: The present invention discloses a hydraulic cylinder suspension method for actively controlling shock-induced vibration when a hydraulic cylinder in a construction vehicle makes a sudden stop, the method comprising the steps of: determining whether the hydraulic cylinder makes a sudden stop; receiving a pressure signal; determining an operational direction of the hydraulic cylinder during a sudden stop of the hydraulic cylinder; and supplying hydraulic fluid to large and small chambers of the hydraulic cylinder or returning to a tank.

Abstract: A machine member driven by a hydraulic actuator may oscillate, or wag, when the hydraulic actuator decelerates or stops. The degree of oscillation is a function of the machine member's ability to track a deceleration command, which ability varies with changes in the position of the machine member and the load force acting thereon. To reduce the oscillation, a command that controls operation of the hydraulic actuator is filtered using a filter function that changes with the machine member's load. The load force exerted on the hydraulic actuator which in turn can be designated by fluid pressure that results from the hydraulic actuator. Preferably, the frequency of the filter function is varied inversely with the magnitude of the actuator load force.

Abstract: A control for a working apparatus having a boom arm. The apparatus includes a controller operable to receive signals from at least one pressure sensor. The at least one pressure sensor detects pressure of hydraulic fluid in at least one chamber of a control valve. The controller compares the signals from the at least one pressure sensor to parameters generated by testing the working apparatus. The controller predicts boom arm oscillations based on the comparison of the signals with the parameters, and generates a control signal in response to predicting the boom arm oscillations.

Abstract: A first fluid channel for operating an actuator and a second fluid channel for operating an actuator are connected to a boom cylinder, including a boom rod side line, a boom head side line. A first and second supply line and a first and second discharge line of each of the first and second fluid channels, respectively, are connected to first and second meter-in control valve and first and second meter-out control valves, respectively. When the boom operating lever is returned an operating position to a neutral position, a pressure vibration generated in each fluid channel for operating the actuators is detected, and respective meter-in control valves and meter-out control valves are controlled to dampen the pressure vibration in each fluid channel.

Abstract: A suspension device is for at least one drive part (10) that is to be cushioned. The drive part can be connected to an accumulator device (12) by a first valve unit (28) and to a tank connection (46) by a second valve unit (34) to transport fluid. The device is provided with a pressure compensation device (50), which when actuated compares the respective prevailing pressures in the drive part (10) and the accumulator device (12) to generate a common pressure level. This comparison permits the pressure level to be rapidly compensated in advance when the actual suspension is enabled in the form of the accumulator device, in such a way that the suspension pressure employed exactly matches the pressure of the respective drive part in the form of a hydraulic or working cylinder that prevails in the later as a result of the preceding load actuation operations.

Abstract: A hydraulic circuit for raising and lowering a load arm on a work machine is adapted to provide a ride control function which will cushion shocks through the load arm as the machine traverses rough terrain. The circuit includes a hydraulic ram that moves the load arm and a first hydraulic accumulator connected to a first chamber of a hydraulic ram. The accumulator provides a cushioning effect to the ram when the ride control function is engaged. The accumulator is located between a first control valve and a load hold valve of the circuit so that the load hold valve will hold the ram in position should there be any sudden pressure drop in or adjacent the accumulator. The accumulator can also be connected to a control surface of the load hold valve to simultaneously open the valve and cushion the ram. A second dedicated accumulator can also be introduced for this purpose if desired.

Abstract: Hydraulic systems generally comprise expansion hose lines and other damping elements which are provided with one or several serially connected hose chambers according to the generated pressure pulsation. The damping measures of the inventive hydraulic system are initiated according to the prevailing pressure during operation thereof. The aim of the invention is to keep the loss of pressure low and save a significant amount of energy during continuous operations. Said aim is achieved by a direct line connection between the source of pressure and the user, which bypasses the dampers. Said bypass line is blocked by a valve when the pressure in the system increases.

Abstract: A method of operating a hydraulic system of a loader arm carrying a working implement, the system having a ride improvement system and a selection valve connected to first and second chambers of a ram which operates the loader arm. A check valve assembly is provided, with the check valve assembly being responsive to pressure changes in the second chamber. The check valve assembly, when closed, prevents fluid from passing between the first chamber to the selection valve. Means are provided communicating the fluid pressure in the second chamber to the check valve, with the means responsive to pressure changes in the second chamber to open the check valve. The selection valve is operable to raise the loader arm with the system arranged to permit passage of fluid between the first chamber and the accumulator while permitting fluid to pass from the second chamber to a low pressure region.

Abstract: A hydraulic control system for a work machine is disclosed. The hydraulic control system has a source of pressurized fluid and at least one actuator having a first and a second chamber. The hydraulic control system also has a first independent metering valve disposed between the source and the first chamber, and a second independent metering valve disposed between the reservoir and the second chamber. The first and second independent metering valves each have a valve element movable from a flow blocking to a flow passing position to facilitate movement of the at least one actuator. The hydraulic control system further has an accumulator and a third independent metering valve disposed in parallel with the first independent metering valve and between the accumulator and the first chamber. The third independent metering valve is configured to selectively communicate the accumulator with the first chamber to cushion movement of the at least one actuator.

Abstract: A method for controlling and modifying the drop rate of a header on an agricultural harvesting machine by providing a programmable electronic control unit capable of receiving operator input through an input device. The programmable electronic conrol unit generates output signals based on the operator input to raise and lower the header according to a corresponding output drop rate signal.

Abstract: A hydraulic arrangement is provided, including: a hydraulic cylinder that is provided with a first and a second chamber, a hydraulic reservoir, a hydraulic fluid feeder conveying hydraulic fluid, a hydraulic accumulator, a hydraulic line arranged between the hydraulic accumulator and the first chamber, a control valve arranged in the hydraulic line, a first supply line for the first chamber, a second supply line for the second chamber, and a controller with a lifting position, a lowering position, a neutral position, and a spring support position for controlling the hydraulic cylinder. The second supply line is fluidly connected to the hydraulic reservoir and the first and second supply lines are substantially prevented from being fluidly connected to the hydraulic fluid feeder when the controller is in the spring support position.

Abstract: A hydraulic control system including a source (11) of fluid having a pressure responsive means (15) and an actuator. A main control valve (21) has ports (27,29) communicating with the actuator ports by means of first (41) and second (43) conduits, and means to generate a load pressure (45). A pressure spike suppression valve (51) has ports connected across the conduits, the valve including a spool (65) moveable between a first position blocking communication between the ports, and a second position permitting communication. The valve (51) defines a spring chamber (67) including a spring (69) biasing the spool toward the first position. The valve defines a load signal passage (83) to communicate the load pressure to a chamber also to bias the spool toward the first position. The valve defines a pressure chamber (81) in communication with the source, fluid pressure therein biasing the spool toward the second position.

Abstract: In a hydraulic cylinder having a shock absorbing function, and capable of stopping as desired by an accumulator disposed within a cylinder rod. The accumulator includes an accumulator piston that divides the cylinder rod interior into first and second cylinder rod chambers, gas hermetically charged into the second cylinder rod chamber, and an accumulation port that is communicated with the first cylinder rod chamber and flows the operating oil from outside into the first cylinder rod chamber.

Abstract: A control device, in particular for working machines, such as wheel loaders, excavators or similar devices, includes at least one working tool (12), particularly a working shovel that can be actuated by at least one hydraulic working cylinder (10). The device has a control block for controlling the hydraulic fluid paths between the working cylinder (10), a hydraulic fluid supply (P) and a tank (T). The device also has at least one hydraulic accumulator (22) and a shut-off or stop valve (32). The shut-off valve has a controllable valve member (34) and is located between the working cylinder (10) and the accumulator (22). The valve member is connected in the transmission position for connecting the accumulator (22) in order to damp the motion of the working cylinder (10). A selector valve (26) that can be controlled by the control block (20) is connected in the feed line (24), blocking the line (24) in the non-actuated state.

Abstract: A system for damping the extension and retraction of a hydraulic cylinder of a work vehicle at the ends of the cylinder's stroke.

Abstract: An hydraulic system for a wheeled loader comprising a loader arm assembly which carries a working implement and which is connected to the body and which is movable between raised and lowered positions by means of a hydraulic ram means and in which a hydraulic accumulator is connected to the Hydraulic ram means wherein the loader arm assembly is connected at, or adjacent to, the rear end thereof to the body at, or adjacent to, the rear end thereof so that the loader arm assembly extends forwardly whereby, in a lowered position of the loader arm assembly, the working implement is disposed in front of the body wherein each chamber of the hydraulic ram means is connected to a selection valve means adapted to feed fluid under pressure to one chamber of the ram means and to receive fluid at a lower pressure from the other chamber of the ram means in order to raise the loader arm assembly or to feed fluid under pressure to said other chamber of the ram means and receive fluid at a lower pressure from said one chambe

Abstract: An anti-reaction valve device is configured to open such that a plunger and a sheet member move away from each other in association with first and second set difference pressures. Two anti-reaction valve devices are provided between two pipes fluidically connected to a hydraulically powered actuator such that directional relationship of connection of primary and secondary ports is reversed between the two anti-reaction valve devices so that a reaction of the actuator is inhibited quickly and reliably. A one-way valve is positioned between the secondary port and an open and close control chamber within which the plunger and the sheet member are movable into contact with and away from each other and serves to inhibit a back flow of a hydraulic fluid. The one-way valve is capable of inhibiting the plunger and the sheet member from moving away from each other undesirably, and hence malfunction of the anti-reaction valve devices.

Abstract: A pulsation dampening apparatus and a clutch master cylinder used for a hydraulic clutch operation system which has a hydraulic circuit. The apparatus has a housing which has a dampening chamber in the hydraulic circuit and a dampening assembly accommodated in the housing. The dampening assembly includes a working unit which dampens pulsations generated in the dampening chamber in the hydraulic circuit, an elastic retainer preloaded between the housing and the working unit to fasten the working unit into the housing by exerting a reaction force onto the working unit, and a force conversion mechanism which increases the reaction force of the elastic retainer in accordance with an urging force transmitted from the working unit to the elastic retainer.

Abstract: A hydro-pneumatic spring support arrangement, particularly for a vehicle axle with at least one hydraulic spring support cylinder arranged between vehicle chassis and vehicle axle, having a cylinder chamber and a rod end chamber each connected with at least one pressure accumulator and can be selectively connected by valve arrangements with a pressure source and a tank. To influence the ratio of the square of the spring rate to the axle loading and to make the spring rate conform to ballasting, vehicle, or operating conditions, the valve arrangement associated with the rod end chamber is provided with at least one first electromagnetic valve which connects the rod end chamber with the pressure source and is provided with a second electromagnetic valve which connects the rod end chamber with the tank. A pressure sensor is provided, particularly a rod end chamber pressure sensor, the signals of which are utilized for the control of the first and the second electromagnetic valves.

Abstract: A swing cushion system of a work machine includes a directional flow device having a directional control member, a control device coupled to the directional flow device that outputs a signal to the directional flow device to shift the directional control member to dissipate energy in the fluid.

Abstract: A hydraulic circuit for a hydraulic cylinder capable of executing and adjusting a shock absorbing function at the time of stopping the operation of a cylinder piston rod and releasing the function, comprises a damping control valve (v1) having a first switching position (v11) which blocks the connection of the accumulation port (22) with outside and performs supply and discharge or discharge and supply of the operating oil with respect to the first cylinder chamber (3) and the second cylinder chamber (4), a second switching position (v12) connecting at least the accumulation port (22) and the second cylinder chamber (4), and a third switching position (v13) connecting at least the accumulation port (22) and the first cylinder chamber (3).

Abstract: An operation mechanism for a variable displacement hydraulic pump. The hydraulic pump is disposed in a housing filled with fluid. A capacity regulating member is provided on the hydraulic pump in the housing for changing the discharge amount of the hydraulic pump. An operation member is operationally connected to the capacity regulating member. The operation member is to be manipulated outside the housing. A resistive device is interposed between the operation member and the capacity regulating member for making the motion of the capacity regulating member slow. The resistive device is an assembly unit comprising a casing, a piston slidably disposed in the casing, and fluid filled in the casing. The casing is fitted into the hole provided in the housing.