A hydraulic system for construction machinery is capable of suppressing irregularity in the operation of the front structure not intended by the operator, and includes a regeneration motor adapted to be driven by return fluid from a bottom port of a boom cylinder; a regeneration electric motor converting rotary power into electric energy; return fluid control valves controlling the flow of the return fluid according to a pilot pressure related to an operation of a boom control lever; and a malfunction prevention device adapted to be activated by pressure fluctuation caused by malfunction of a solenoid valve for the return fluid control valve that interrupts the delivery of a pilot secondary pressure from the solenoid valve to the corresponding return fluid control valve.

The present invention relates to a hydraulic system for a hydraulically actuable work machine that comprises a switching valve block having a plurality of valve block inputs for a respective connection to a pressure output of one or more hydraulic fluid pumps; having a plurality of valve block outputs for outputting a pressurized hydraulic fluid; and having at least one valve that is arranged between valve block inputs and valve block outputs and that is adapted to selectively produce a fluid connection between a first valve block input and a first valve block output or between the first valve block input and a second valve block output; a plurality of pressure sources, preferably a plurality of separately controllable pressure sources of which each one is connected to a respective valve block input; and a plurality of hydraulic consumers of which each one is connected to a respective valve block output. The system is characterized in that the first valve block output furthermore already has a fixed fluid connection, preferably a fixed exclusive fluid connection, to a second valve block input and in that the steering is connected to the first valve block output.

An online method for reconfiguring pressure and position sensors in a hydraulic system is disclosed. In one step, a sensor drift condition, a recalibration request, or an unisolated fault condition is detected. In another step, a system pressure sensor or another sensor, such as a load-sense pressure sensor, is verified as a trusted master reference sensor. Another step includes measuring and recording a first pressure reading at the master reference sensor and first voltage readings associated with first, second, third, and fourth pressure slave sensors at a first pump pressure set point. Another step includes, repeating the previous step at a second pump pressure set point. A new gain and offset for each of the first, second, third, and fourth pressure sensors can be calculated based on a comparison of the recoded first and second pressure readings and the recorded first and second voltage readings.

A hydraulic cylinder assembly includes a hydraulic cylinder, a motor for driving an adjustable pump, the pump, and a pivot angle control system for the pump. The pivot angle control system has at least one adjustment piston for adjusting the pump and an electrically controllable valve for controlling the adjustment piston. At least one conveying direction of the pump and thus a movement of the hydraulic cylinder is controllable via the pivot angle control system. The hydraulic cylinder assembly further includes an electrical control unit for operating at least the motor and the valve and an uninterruptible power supply, configured such that, in the event of a failure of a power supply for the control unit, at least the control unit can be supplied with electrical power from the uninterruptible power supply.