The disclosure relates to a hydraulic driving system and a driving method for barring. The driving system comprises: three or more main drive hydraulic cylinders, which are divided into two groups to provide pulling and pushing forces to a driven impeller, each main drive hydraulic cylinder including a cylinder body and a piston rod which divides the cylinder body into a rod cavity and a godless cavity, wherein an oil line for the rod cavity and an oil line for the godless cavity of each main drive hydraulic cylinder are controlled by one control valve module; and a control device, which controls the control valve module according to wind and/or load signals, to simultaneously convert flow directions of hydraulic oil in the oil line for the rod cavity and the oil line for the godless cavity of at least one of the three or more main drive hydraulic cylinders.

A solenoid flow control valve includes: an inlet passage that allows an inlet port to communicate with a pilot pressure chamber; an outlet passage that allows the pilot pressure chamber to communicate with an outlet port; a fixed restrictor provided on the outlet passage; a pilot spool that closes the inlet passage when a solenoid is in a non-excitation state, whereas when solenoid is in an excitation state, opens inlet passage at an opening degree corresponding to an input current value to generate a pilot pressure corresponding to the input current value in pilot pressure chamber, the pilot spool opening a bypass passage when input current value is less and closes bypass passage when input current value is greater than or equal to the predetermined value; and a main spool that controls a flow rate from inlet to outlet port in accordance with the pilot pressure chamber's pilot pressure.

An excavator includes a lower travelling body; an upper turning body mounted on the lower travelling body; an engine installed in the upper turning body; a hydraulic pump connected to the engine; a hydraulic actuator driven by hydraulic oil discharged by the hydraulic pump to move a work element; a first control valve configured to control a flow rate of the hydraulic oil flowing from the hydraulic pump to the hydraulic actuator; a second control valve configured to control a flow rate of the hydraulic oil flowing from the hydraulic actuator to a hydraulic oil tank; and a control device configured to control opening and closing of the second control valve.

An excavator includes a lower travelling body; an upper turning body mounted on the lower travelling body; an engine installed in the upper turning body; a hydraulic pump connected to the engine; a hydraulic actuator driven by hydraulic oil discharged by the hydraulic pump to move a work element; a first control valve configured to control a flow rate of the hydraulic oil flowing from the hydraulic pump to the hydraulic actuator; a second control valve configured to control a flow rate of the hydraulic oil flowing from the hydraulic actuator to a hydraulic oil tank; and a control device configured to control opening and closing of the second control valve.

Provided are an energy regeneration device which can regenerate energy of a working fluid discharged from an actuator while controlling a flow rate of the working fluid, and a work machine including the foregoing device. The regeneration device (100) includes a boom cylinder (20), an inertial fluid container (102), an oil tank (110), an accumulator (105), a low-pressure-side opening/closing device (103), and a high-pressure-side opening/closing device (104). A calculation unit (151) calculates a duty ratio for opening/closing the low-pressure-side opening/closing device (103) and the high-pressure-side opening/closing device (104) in accordance with a desired flow rate of a working fluid discharged from the boom cylinder (20). A regeneration control unit (153) selects alternately the low-pressure-side opening/closing device (103) and the high-pressure-side opening/closing device (104) as a destination with which the inertial fluid container (102) communicates in accordance with the calculated duty ratio, and supplies a discharged working fluid to an accumulator (105).

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), and first and second control valves (700, 800). A net load (90) is supported by a first chamber (116, 118) of the hydraulic cylinder, and a second chamber (118, 116) of the hydraulic cylinder 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 control valve may apply a holding pressure and thereby hold the first counter-balance valve closed and the second counter-balance valve open.

An apparatus for recuperating hydraulic energy in a working machine includes at least one first differential cylinder piston device with a differential cylinder and separate rod and bottom sides, and at least one hydraulic accumulator which is hydraulically connectable with the differential cylinder piston device. The potential energy of the differential cylinder piston device retracting under pressing load is at least partly storable in the hydraulic accumulator. The rod and bottom sides are connectable with each other via at least one brake valve for recirculating hydraulic fluid from the bottom side into the rod side.

An apparatus for recuperating hydraulic energy in a working machine includes at least one first differential cylinder piston device with a differential cylinder and separate rod and bottom sides, and at least one hydraulic accumulator which is hydraulically connectable with the differential cylinder piston device. The potential energy of the differential cylinder piston device retracting under pressing load is at least partly storable in the hydraulic accumulator. The rod and bottom sides are connectable with each other via at least one brake valve for recirculating hydraulic fluid from the bottom side into the rod side.

A valve body of a speed controller includes a main body that extends along a first axis and a mounting portion that projects from a side of the main body along a second axis that intersects the first axis orthogonally. A first port, a needle valve, and a check valve are disposed in the main body. The mounting portion, which is a portion to be mounted on a cylinder portion, includes a second port formed therein. A position at which the mounting portion is disposed on the side of the main body is away from the first axis in a direction of a third axis that orthogonally intersects the first axis and the second axis.

A valve body of a speed controller includes a main body that extends along a first axis and a mounting portion that projects from a side of the main body along a second axis that intersects the first axis orthogonally. A first port, a needle valve, and a check valve are disposed in the main body. The mounting portion, which is a portion to be mounted on a cylinder portion, includes a second port formed therein. A position at which the mounting portion is disposed on the side of the main body is away from the first axis in a direction of a third axis that orthogonally intersects the first axis and the second axis.