Abstract: A working machine comprises an operation member for operating a hydraulic device via a control valve. An oscillation calculator acquires a specific value corresponding to a feature representing oscillation of the operation member when the feature appears in variation of an control signal output according to an operation amount of the operation member within one of a sequence of predetermined periods, and calculates an evaluation value representing a degree of oscillation of the operation member by adding up the specific value or values obtained within one or more of the predetermined periods. A control signal generator generates a control signal for controlling the control valve based on the operation signal. The control signal generator decreases a value of the control signal per a unit value of the operation signal as the evaluation value gradually increases with the elapse of one or more of the sequence of the predetermined periods.

Abstract: A hydraulic tank has an elastically deformable membrane defining a variable compensation chamber within the tank. The membrane has a fixed perimeter portion and a thrusting portion. A perimeter inlet portion is arranged between the perimeter fixing portion and the thrusting portion. In the condition of minimum expansion of the compensation chamber, the thrusting portion is completely arranged between the perimeter inlet portion of the membrane and a wall of the tank.

Abstract: A head unit device for controlling motion of an object includes shear thickening fluid (STF) and a chamber configured to contain a portion of the STF. The chamber further includes a piston compartment and an auxiliary compartment. The head unit device further includes an auxiliary bypass configured within the chamber, and a piston housed at least partially radially within the piston compartment. The chamber further includes a set of fluid flow sensors and a set of fluid manipulation emitters to control the auxiliary bypass to adjust the STF flow between the piston compartment and the auxiliary compartment to cause selection of one of a first range of shear rates or a second range of shear rates for the STF within the piston compartment.

Abstract: An aircraft assembly having: a first part; a second part, the second part being movably mounted with respect to the first part; an electro-hydraulic actuator coupled between the second part and a first anchor point, the actuator comprising a cylinder defining a bore and a piston and rod assembly slidably mounted within the bore and an active chamber within which an increase in fluid pressure causes the actuator to change during a first phase between first and second extension states to move the second part relative to the first part. The electro-hydraulic actuator further includes a hydraulic fluid supply circuit comprising a piezo-electric pump operable to supply pressurised fluid to the active chamber to change the actuator between first and second extension states.

Abstract: A method for operating a hydraulic valve of a hydraulic device of a motor vehicle transmission device, wherein an actuating current of the hydraulic valve is superposed with a modulation alternating current in order to adjust a shaking vibration of the hydraulic valve by a control device, wherein a deviation between an actual pressure resulting from the actuating current and a setpoint pressure determined as a function of the actuating current is determined for the hydraulic device by means of an electronic computing device, and an amplitude and/or a frequency of the modulation alternating current is increased as compared to a starting value equalizing a hysteresis of the actual pressure relative to the setpoint pressure, as a function of a tolerance range being exceeded by the determined deviation.

Abstract: A piston of a cylinder of an internal combustion engine includes: a piston skirt; a grooved ring belt on a first axial side of the piston skirt, the ring belt grooves being limited by, and separated from one another by, ring lands, the ring grooves for receiving a piston ring; and an oil collection channel between the piston skirt and the ring belt. The oil collection channel has a greater depth than in the circumferential position of a coupling side of the piston and/or in the circumferential position of a coupling opposite side of the piston. The oil collection channel has a gradient, the gradient emanating from an axial depth in a region of the coupling side and/or of the coupling opposite side in the direction of the axial depth in the region of the pressure side and/or of the pressure opposite side.

Abstract: A renewable energy and waste heat harvesting system is disclosed. The system includes an accumulator unit having a high pressure accumulator and a low pressure accumulator. At least one piston is mounted for reciprocation in the high pressure accumulator. The accumulator unit is configured to receive, store, and transfer energy from the hydraulic fluid to the energy storage media. The system collects energy from a renewable energy source and transfers the collected energy using the pressurized hydraulic fluid. The system further includes one or more rotational directional control valves, in which at least one rotational directional control valve is positioned on each side of the accumulator unit. Each rotational directional control valve includes multiple ports. The system also includes one or more variable displacement hydraulic rotational units. At least one variable displacement hydraulic rotational unit is positioned adjacent each of the rotational directional control valves.

Abstract: A radial piston hydraulic motor comprising a box frame with a cam ring connected thereto, pistons in a piston frame and press rollers in the pistons, which press rollers can be pressed by means of the pressure of a hydraulic fluid, such as hydraulic oil, against an inner surface of the cam ring. The piston frame comprises connections between the interior space and passages, and a shutter valve is provided within each connection for controlling the hydraulic fluid flow through the connection between the passages and the interior space. The shutter valve is arranged to allow hydraulic fluid to flow from the passage into the interior space, when the pressure in the working pressure inlet passage, in the return passage and in the interior space is equal, i.e. the motor is in free-rotating state.

Abstract: A mechanism (100) for raising and lowering lifting arms (104) of a work vehicle includes an operating lever (111) that is secured at the column (103) of the steering wheel (102) of the work vehicle, a hydraulic arrangement and at least one linkage for operating the lifting arms (104). The hydraulic arrangement further includes a plurality of piston-cylinder pairs (105a-105b, 110a-110b, 115a-115b, 120a-120b, and 125a-125b) provided between the operating lever (111) and the linkage, for controlling the raising and lowering operation of the lifting arms (104). The operating lever (111) permits an effective and easy control of the raising and lowering operation of the lifting arms (104).

Abstract: The arrangement comprises a hydraulic machine with at least two operating cylinders, the hydraulic machine comprising a rotor part configured to be connected to the steered wheel and a stator part having main enclosures open in a receiving interface, and a pivot device that defines a pivot axis of the stator part and has main outer orifices linked to the main enclosures of the hydraulic machine in a connection interface. The arrangement further comprises a pilot line linked to a pilot chamber which has a pilot inlet in the receiving interface and the pilot line is formed in the pivot device and extends between an outer pilot orifice present in this device and a pilot opening located in the connection interface.

Abstract: A hydraulic system for a work vehicle that has a frame, a ground-engaging implement that moves the frame over a ground surface, and an attachment connected to the frame for movement with respect to the frame. The hydraulic system includes a pump that pumps hydraulic fluid, a first conduit fluidly connecting the pump and the attachment, a reservoir that contains hydraulic fluid, a second conduit fluidly connecting the pump to the reservoir, a fluid resistor fluidly connected with the second conduit, and a valve. The fluid resistor dissipates power from the work vehicle. The valve actuates between a first state in which the valve fluidly connects the pump to the first conduit such that hydraulic fluid is directed to the attachment, and a second state in which the valve fluidly connects the pump to the second conduit such that fluid is directed through the fluid resistor and into the reservoir.

Abstract: A hydraulic excavator (1) is provided with a controller (40) including an actuator control section (81) which, when an operation device (45, 46) is operated, controls at least one of a plurality of hydraulic actuators (5, 6, 7) in accordance with the velocities of the plurality of hydraulic actuators (5, 6, 7) and a predetermined condition. The controller (40) determines, based on a sensed value from a posture sensor (50), the direction of a load exerted on an arm cylinder (6) due to the weight of an arm (9), outputs, upon determining that the direction of the load is opposite to a driving direction of the arm cylinder (6), a second velocity Vamt2 to the actuator control section (81), and outputs, upon determining that the direction of the load is the same as the driving direction of the arm cylinder (6), a third velocity Vamt3 to the actuator control section (81).

Abstract: A hydraulic drive system for a work machine including a hydraulic energy recovery device that is configured to perform load sensing control and accumulates hydraulic fluid that returns from a hydraulic cylinder in operation of lowering a front work implement into an accumulator includes, in order to prevent, when operation other than operation of lowering the front work implement is to be performed, hydraulic energy accumulated in the accumulator from being consumed uselessly, a regeneration selector valve in a hydraulic line for regenerating the hydraulic fluid accumulated in the accumulator into a hydraulic fluid supply line of a main pump. The regeneration selector valve is controlled such that, only when saturation occurs with the main pump, flow from the accumulator to the hydraulic fluid supply line is permitted.

Abstract: A trajectory planning unit for providing a trajectory as a command variable for a control unit for position control of an actuator member of an actuator, wherein the trajectory planning unit is adapted to provide the trajectory on the basis of a target position curve and to limit the trajectory according to at least one limit value comprising a velocity limit value, an acceleration limit value, a braking acceleration limit value and/or a jerk limit value. The trajectory planning unit is adapted to provide the trajectory according to at least one specification value which can be specified, the specification value including an initial velocity value, a final velocity value, an initial acceleration value and/or a final acceleration value.

Abstract: A hydraulic system includes a first output fluid tube connecting between a hydraulic pump to output operation fluid and a first operation valve to change a first pilot pressure of the operation fluid, a second output fluid tube connected between the hydraulic pump and a second operation valve to change a second pilot pressure of the operation fluid, a switching valve provided in the second output fluid tube, and a warm-up fluid tube connected between the first operation valve and the switching valve, wherein the switching valve is switched between a first position allowing the operation fluid to be drained through the first output fluid tube, the first operation valve, the warm-up fluid tube and the switching valve, and a second position allowing the operation fluid to be supplied through second output fluid tube to the second operation valve.

Abstract: An adjustable ride control circuit and method that includes a head valve that controls flow between a boom cylinder head intake and an accumulator, and a rod float valve that controls flow between a boom cylinder rod intake and tank, where the rod float valve is electronically adjustable and proportionally controls flow restriction. A controller controls ride control activation, and adjustment of the head and rod float valves. When ride control is activated, the head valve allows flow between the head intake and the accumulator, and the controller automatically adjusts the rod float valve. When ride control is deactivated, the head valve blocks flow between the head intake and the accumulator, and the rod float valve blocks flow between the rod intake and tank. An enable valve can control positioning of the head valve. A flow selector can select manual or automatic adjustment of the rod float valve.

Abstract: A hydraulic thruster system for providing an axial force. In one embodiment, the system comprises a pump, a motor for driving the pump, and a hydraulic thruster comprising: a cylinder comprising a plurality of cylinder pistons; a shaft comprising a plurality of shaft pistons; a plurality of first pressure chambers; and a plurality of second pressure chambers, wherein the plurality of shaft pistons are positioned inside the cylinder, between the cylinder pistons to form the plurality of first and a second pressure chambers, wherein the shaft further comprises a first fluid passage connected to the pump and to the first pressure chambers, and a second fluid passage connected to the pump and to the second pressure chambers, and wherein the pump may pump fluid into the first pressure chambers and suction fluid from the second pressure chambers providing an axial force between the shaft and the cylinder.

Abstract: A hydraulic pressure supply device includes: a hydraulic pump capable of changing a discharge capacity; an electric motor capable of changing a rotational frequency; a discharge capacity adjustment mechanism capable of adjusting the discharge capacity of the pump between a maximum and minimum discharge capacity; a pressure detector configured to detect pressure of an operating liquid discharged from the pump; a rotational frequency detector configured to detect the rotational frequency of the motor; and a controller configured to control operations of the motor and adjustment mechanism based on the rotational frequency, detected by the detector, to keep pressure of an actuator at arbitrary pressure, wherein, the controller controls the operation of the adjustment mechanism so the discharge capacity of the pump becomes a set lower limit discharge capacity. The set lower limit discharge capacity is set to be larger than the minimum discharge capacity and be adjustable by the controller.

Abstract: A rotary actuator, including a manifold block and a rotor assembly that includes a rotor shaft and a plurality of arcuate pistons attached to the rotor shaft, each arcuate piston curving at a set radial distance from the rotor shaft, and each piston attached to the rotor shaft via a crank arm. A pressure chamber assembly coupled to the manifold block defines a plurality of piston pressure chambers that receive and at least partially enclose each arcuate piston, including a plurality of gland seals disposed adjacent the entrance of each piston pressure chamber to create a seal between the inner surface of the pressure chamber and the outer surface of the arcuate piston. Each gland seal includes an inner seal that engages the piston surface of the arcuate piston, and plural outer seals that engage the inner surface of the piston pressure chamber, forming a hydraulic seal.

Abstract: Systems and methods are disclosed herein for fluid temperature-dependent control of engine speeds in a self-propelled work vehicle. An engine speed sensor generates signals representing an engine speed, and a temperature sensor generates signals representing a hydraulic fluid temperature. A controller receives the respective signals from the engine speed sensor and the temperature sensor. The controller is further configured, responsive to a startup command, to generate output signals preventing an increase in the engine speed to a target engine speed at least while the temperature of the hydraulic fluid is in a first temperature state. The controller may, e.g., automatically generate output signals for continuous and/or stepwise transitioning of the engine speed to the target engine speed, in accordance with a monitored temperature of the hydraulic fluid and corresponding temperature states.