A hydraulic system (600) and method for reducing boom dynamics of a boom (30), while providing counter-balance valve protection, includes a hydraulic actuator (110), first and second counter-balance valves (300, 400), first and second control valves (700, 800), and first and second blocking valves (350, 450). A net load (90) is supported by a first chamber (116, 118) of the hydraulic actuator, and a second chamber (118, 116) of the hydraulic actuator may receive fluctuating hydraulic fluid flow from the second control valve to produce a vibratory response (950) that counters environmental vibrations (960) on the boom. The first blocking valve prevents the fluctuating hydraulic fluid flow from opening the first counter-balance valve. The first blocking valve may drain leakage from the first counter-balance valve.

The present invention discloses a method for calculating a pressure loss of a series R-type automobile vibration damper. The automobile vibration damper includes a frame, a spring, an axle, a hydraulic cylinder, an upper oil tank, a piston, a lower oil tank, and a resistance adjustment section. The resistance adjustment section is composed of 4 capillaries connected in series and solenoid valves. The four capillaries are all coiled into an M shape. The 4 capillaries are R8, R4, R2, and R1 and are connected in parallel with solenoid valves V.sub.R8, V.sub.R4, V.sub.R2, V.sub.R1, respectively. Due to the viscous effect of oily liquid in the cylinder, when the oily liquid flows through the resistance adjustment section, the damping can be adjusted by adjusting the configurations SR, of the solenoid valves V.sub.R8, V.sub.R4, V.sub.R2, and V.sub.R1. The present invention provides a method for calculating a pressure loss of an R-type automobile vibration damper, and achieves the purpose of reducing uncertainties of a control model, which provides a theoretical basis for improving the control quality of the vibration damper.

The invention relates to a valve, which is characterized in that between a neutral position (38) of a control spool (STS) and one of its end positions (34, 42) a regeneration position (36) is provided, in which two utility ports (A, B) are interconnected in a fluid-conveying manner, or a floating position (40) is provided, in which these utility ports (A, B) are interconnected in a fluid-conveying manner. The invention relates to a further valve, which is characterized in that by a further motion of the control spool (STS) in the same direction, as that, in which a fluid connection is established between the utility ports (A, B) starting from the neutral position (38), this fluid connection is interrupted.

A system for compensating for drift or movement of a hydraulic actuator connected to a machine's boom or similar elongate member that is caused, at least in part, by damping of mass-induced vibration. The system comprises a processing unit and a plurality of sensors operable to collect data from a control valve connected to an actuator's load holding chamber and to calculate additional volume present therein due to vibration damping. Using the calculated additional volume, the processing unit determines a hydraulic fluid flow rate appropriate to substantially reduce or eliminate the additional volume. The processing unit combines this flow rate with the hydraulic fluid flow rate necessary to cause operation of the actuator in response to the machine's operator input, and provides signals to the control valve causing actuation of the valve to output hydraulic fluid to the actuator at a rate equal to the combined flow rates.

Method and apparatus for improving the performance, response, and durability of an electro-hydraulic active suspension system. The noise caused by hydraulic flow ripple is reduced and system response is improved.

A hydraulic system (600) and method for reducing boom dynamics of a boom (30), while providing counter-balance valve protection, includes a hydraulic cylinder (110), first and second counter-balance valves (300, 400), first and second control valves (700, 800), and a selection valve set (850). The selection valve set is adapted to self-configure to a first configuration and to a second configuration when a net load (90) is supported by a first chamber (116, 118) and a second chamber (118, 116) of the hydraulic cylinder, respectively. When the selection valve set is enabled in the first and second configurations, the second and first control valve may fluctuate hydraulic fluid flow to the second and first chamber, respectively, to produce a vibratory response (950) that counters environmental vibrations (960) of the boom. When the selection valve set is not enabled, the first and second counter-balance valves are adapted to provide the hydraulic cylinder with conventional counter-balance valve protection.

The present invention concerns an attenuation device (1) of the fluid flow pulsation along a duct of a hydraulic circuit connected with a hydraulic machine, comprising at least an attenuation module (3) passed through by a pass-through duct (5) configured to be placed in fluid communication with said duct of said hydraulic circuit. In particular, in said attenuation module (3) a first duct (7) is obtained having an opened first end (70) in fluid communication with said pass-through duct (5), and a closed second end, said first duct (7) extending along a curved line comprising a plurality of curved sections, said first duct (7) being adapted to attenuate the pulsation of said fluid flow along said duct of said hydraulic circuit to reduce the vibrations generated by said pulsation of said fluid flow.

A ram air turbine (RAT) actuator piston can include a body defining a piston structure having an inner cavity. The piston can include one or more damping holes axially defined through the body to the inner cavity and a lock rod hole defined axially through the body to the inner cavity. The lock rod hole can have a larger flow area than one or more of the one or more damping holes. The lock rod hole can be configured to receive a lock rod of a RAT actuator to at least partially block flow through the lock rod hole when the lock rod is in a locked position. The one or more damping holes can be configured to allow flow through the damping holes in the locked position to allow the RAT actuator piston to move within the RAT actuator in the locked position to dissipate vibratory loads.

A transmission system (10) includes a first piston (12), a second piston (14) and a modulator piston (16). The first piston (12) receives an input force (F.sub.IN), the second piston (14) transmits an output force (F.sub.OUT), and the modulator piston (16) transmits a modulating force (F.sub.ACT>which modulates the input force (F.sub.IN) received by the second piston (14) to implement tremor cancellation and force and/or provide variable motion scaling.

A damping device, particularly for damping or avoiding pressure surges such as pulses, in hydraulic supply circuits, preferably in the form of a silencer, includes a damping housing that surrounds a damping chamber (19), has at least one fluid inlet (11), has at least one fluid outlet (13) and has a fluid receiving chamber (19) extending between the fluid inlet (11) and the fluid outlet (13). During operation of the device, a fluid flow crosses the damping chamber (19) in a through-flow direction (15), coming from the fluid inlet (11) in the direction of the fluid outlet (13). At least parts of the fluid receiving chamber (19) extend in at least one extension direction transversely with respect to the through-flow direction (15). The fluid receiving chamber (19) immediately adjoins the fluid inlet (11) and the fluid outlet (13) and is delimited by at least one yielding wall part (4).