A hydraulic machine. A boom actuator includes a large chamber and a small chamber. A recovery unit receives fluid discharged from the large chamber and then recovers energy. A recovery line connects the large chamber and the recovery unit. An accumulator is connected to a first point on the recovery line. A discharge valve is disposed on the recovery line between the first point and the recovery unit. A first sensor measures a pressure in the accumulator. A controller controls opening and closing of the discharge valve. The controller performs anti-bouncing control of: determining a target pressure in the accumulator corresponding to a load pressure applied to fluid in the large chamber by a load according to a predetermined correspondence; and controlling the opening and closing of the discharge valve such that the pressure in the accumulator measured by the first sensor reaches the target pressure.

A hydraulic machine. A high pressure line allows working fluid to flow into a hydraulic motor. A low pressure line allows working fluid to flow out of the hydraulic motor. High pressure line valves open and close the high pressure line. Low pressure line valves open and close the low pressure line. An operator input device inputs a command to control movement of the hydraulic motor. A control unit controls the high pressure line valves and the low pressure line valves to be opened and closed by receiving the command from the operator input device. The control unit controls the high pressure line valves to have a normalized flow factor K.sub.vHP, and controls the low pressure line valves to have a normalized flow factor K.sub.vLP, where K.sub.vLP<K.sub.vHP when a normalized flow factor K.sub.vcmd corresponding to the command is 0<K.sub.vcmd<1.

A telescopic actuator includes a first segment having a first hollow cavity, a second segment having a second hollow cavity, a third segment having a third hollow cavity, and a first port and a second port. The second segment is slidably connected to the first segment through the first hollow cavity, and the third segment is slidably connected to the second segment through the second hollow cavity, the second hollow cavity being insulated from the first hollow cavity and communicating with the third hollow cavity. The first port is configured to flow fluid into and out of the first hollow cavity, and the second port is configured to flow fluid into and out of the second hollow cavity and the third hollow cavity. Embodiments described herein also include a motion simulating apparatus and an actuating system incorporating the telescopic actuator.

A hood lifting mechanism according to various implementations includes a housing and a piston. A distal end of the piston is urged away from a distal end of the housing to lift a hood upwardly away from a vehicle body in response to the vehicle hitting a pedestrian. To prevent the piston from rattling or moving within the housing while in a stored position, a portion of the piston and a portion of the housing form an interference fit in the stored position. A gas generator in fluid communication with a proximal end of the housing provides sufficient force to overcome the interference fit and urge the distal end of the piston out of the housing.

In a method for operating a hydraulic device for providing a supply to hydraulic consumers (V) on a plastics injection moulding machine, provision is made of a pump (10) with a volumetric delivery characteristic that results in cyclic pulsations and of a servomotor (11) with multiple poles that result in cyclic pulsations. The pressure at the hydraulic consumer (V) is detected and is input as an actual value into a pressure regulator (13) that readjusts the servomotor (11), on the basis of a predefined pressure profile, to a pressure setpoint value at the hydraulic consumer (V). The cyclic pressure pulsation is minimized in that, by means of a rotational angle sensor (20), the rotational angle (φ) of the pump (10) and/or of the servomotor (11) is detected and correlated with the cyclic pulsations, and in that, from this, a corrective value or a corrective function is determined and is transmitted to the pressure regulator (13) with control subordinate to the regulation of the pressure setpoint value. Alternatively or in addition, this is achieved in the case of a hydraulic device also in that, as corrective means for the pressure regulation, said means being subordinate to the consideration of the pulsations, the number of components of the pump (10) that result in the cyclic pulsations and the number of components of the servomotor (11) that generate cyclic pulsations are equal, or one is a multiple of the other.

There is provided a control module for a hydraulic system. The module comprises a tank and a plurality of valves. The tank is configured to store hydraulic fluid and is substantially cylindrical. The plurality of valves fluidly connect with the tank and are configured to control distribution of hydraulic fluid from the tank to one or more components of the system. The plurality of valves are spaced around a circumference of the tank. One or more passages fluidly connect the tank with at least one of the plurality of valves and/or a first of the plurality of valves with a second of the plurality of valves.

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.

The present disclosure discloses a reducing noise double-channel oil pump including a pump body. The pump body connects an oil box and an actuator. Parallel distributed a small and a big flow oil channels are located between the oil box and the actuator. The small flow oil channel connects a first twin pump and first one-way valves. The big flow oil channel connects a second twin pump and second one-way valves. The pump body also disposes a reducing noise oil channel. A connection of the reducing noise oil channel and the big flow oil channel locates a one-way controlled valve. Another end of the reducing noise oil channel connects an oil pressure feedback oil way. A connection of the reducing noise oil channel and the oil pressure feedback oil way locates an oil pressure driving mechanism. The middle of the reducing noise oil channel connects an unloading oil way.

An electrohydraulic control circuit for driving a hydraulically actuated actuating element (5, 6), by means of which a segment (5.3) of a manipulator, in particular of a large manipulator for truck-mounted concrete pumps, can be adjusted in terms of its orientation, wherein there are provided an electrically driven first valve (2.4), which is connected to hydraulic working lines of the actuating element (5.6) for the drive thereof, and leak-free check valves (2.5, 2.6) provided in the working lines of the actuating element (5.6), which valves are arranged on the actuating element (5.6) or on the segment (5.3) associated with this actuating element (5.6) and can be released for the normal operation of the actuating element (5.6), wherein the release of the check valves (2.5, 2.6) is driven by an electronic control unit (ECU) separate from the first valve (2.4) and the check valves (2.5, 2.6).

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.