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

A control system for controlling a work machine including a working unit including elements and actuators that drives the elements includes: a first hydraulic pump and a second hydraulic pump each of which supplies operating oil to at least one of the actuators; and a control device that calculates a distribution flow rate of operating oil distributed to each of the actuators based on an operating state of the working unit and switches, based on the calculated distribution flow rate, between a first state in which the operating oil supplied from both the first hydraulic pump and the second hydraulic pump is supplied to the actuators and a second state in which the actuator to which the operating oil is supplied from the first hydraulic pump is different from the actuator to which the operating oil is supplied from the second hydraulic pump.

A shovel may be provided with a main pump, hydraulic actuators including a swing hydraulic motor, a control valve that controls a flow of a working oil between the main pump and the hydraulic actuators, and an accumulator part that releases the working oil between the main pump and the control valve, and between the swing hydraulic motor and the control valve. The accumulator part may release the working oil at an upstream of the main pump.

Disclosed is an exemplary hydraulic system including a first fluid circuit and a first pump fluidly connected to the first fluid circuit. The first pump configured to produce a fluid output at a first flow rate when operated at a selected speed. The hydraulic system further includes a second fluid circuit and a second pump selectively fluidly connectable to the first fluid circuit and the second fluid circuit. The second pump configured to produce a fluid output at a second flow rate when operated at the selected speed, with the second flow rate being greater than the first flow rate of the first pump. A first valve fluidly connects the second pump to the first fluid circuit when the first valve is arranged in an open position, and fluidly connects the second pump to second fluid circuit when the first valve is arranged in a closed position.

A control system includes: first and second hydraulic pumps; an opening/closing device provided in a passage connecting the first and second hydraulic pumps and configured to open and close the passage; a control device controlling the opening/closing device to switch between connected and unconnected states of the first and second hydraulic pumps; a first hydraulic cylinder to which hydraulic fluid from the first hydraulic pump is supplied in the unconnected state; and a second hydraulic cylinder to which hydraulic fluid from the second hydraulic pump is supplied in the unconnected state. The control device controls the opening/closing device to be in the connected state when distributed flow rates of the hydraulic cylinders are a predetermined supply flow rate or lower and a difference between a pressure in a rod-side space and a pressure in a cap-side space of the hydraulic cylinder is a defined value or smaller.

A hydraulic system and method of controlling such on a machine is disclosed. The hydraulic system may comprise a primary hydraulic circuit that includes a first load sense controlled pump, a secondary hydraulic circuit that includes a second load sense controlled pump, a flow sharing valve, and a load sense arrangement. The load sense arrangement may include a main resolver configured to select a higher pressure signal between the primary and secondary hydraulic circuits, and a load sense valve having an open position at which pressure signal flow between the primary hydraulic circuit and the main resolver is allowed, and a closed position at which pressure signal flow between the primary hydraulic circuit and the main resolver is blocked. In an embodiment, when the load sense valve is in the closed position, the second load sense controlled pump may be controlled only by the secondary hydraulic circuit.

An oil supply system may include a first hydraulic pump pumping oil to a low pressure portion through a first main line, a second hydraulic pump pumping oil to a high pressure portion through a second main line, first and second check valves that are respectively disposed at one side of the first and second main lines, a first convert valve supply the oil flowing the second main line to the low pressure portion depending on the pressure of oil that is transferred from a front side of the first check valve of the first main line, and a second convert valve supplying oil flowing the first main line to the high pressure portion depending on the pressure of oil that is transferred from a front side of the second check valve of the second main line.

A hydraulic drive device for a molding machine includes at least one motor, such as an electric motor, at least one first hydraulic pump which can be driven by the at least one motor, and at least one flywheel. At least one second hydraulic pump is connected, or can be connected, with the at least one flywheel, and a hydraulic connection conduct is provided between the first hydraulic pump and the second hydraulic pump.

Provided is construction machinery that is capable of greatly reducing the amount of fuel consumption by making effective use of recovered energy. The construction machinery has a first hydraulic pump 3 for discharging hydraulic oil for driving an actuator 6, a second hydraulic pump 9, a second prime mover 7 for driving the second hydraulic pump 9, energy storage device 8 for storing energy for driving the second prime mover 7, and a hydraulic oil supply circuit 10 including a hydraulic oil switching section 11c that accepts the hydraulic oil discharged from the first hydraulic pump and the hydraulic oil discharged from the second hydraulic pump and supplies either the mixture of the accepted hydraulic oils or a selected one of the accepted hydraulic oils to the actuator 6. The construction machinery includes a control device 20 that, when the drive efficiency of the second hydraulic pump 9 and/or the amount of energy stored in the energy storage device 8 is higher than a preselected setting value, outputs a switch command to the hydraulic oil switching section 11c and outputs a drive command to the second prime mover 7.

The present invention provides a controller for hydraulic apparatus (100). The controller is configured to determine (310) that an energy return criteria has been met by movement of a first movement component of a first hydraulic actuator. In response thereto, the controller is further configured to select (320) at least one among a plurality of energy control strategies based on at least one operational characteristic of the hydraulic apparatus, and to control (330) the hydraulic apparatus to implement the energy control strategy during movement of the first movable component in such a way as to meet the energy return criteria. The plurality of energy control strategies comprises a first energy control strategy and a second energy control strategy. The at least one operational characteristic of the hydraulic apparatus comprises an indication of an expected energy recovery of one or more of the energy control strategies. The first energy control strategy comprises transferring energy from the first hydraulic actuator, via a hydraulic machine, to an energy consumer in torque connection with the hydraulic machine. The second energy control strategy comprises transferring energy from the first hydraulic actuator to a low-pressure reservoir of hydraulic fluid in the hydraulic circuit.