A hydraulic system for a vehicle includes a first hydraulic pump including a first displacement actuator and a first pressure port, a first load sense system fluidly coupled to the first displacement actuator, a second hydraulic pump including a second displacement actuator and a second pressure port, a second load sense system fluidly coupled to the second displacement actuator, and a crossover pressure controller coupled between the first pressure port and the second pressure port. The crossover pressure controller reconfigurable between (a) a combined pressure configuration providing fluid communication between the first pressure port and the second pressure port and (b) a separate pressure configuration inhibiting fluid communication between the first pressure port and the second pressure port. The crossover pressure controller is actuatable independent of the first load sense system and the second load sense system.

A pressure compensated load sense hydraulic system and method is disclosed where a first pressure compensated valve controls flow between a pump and a first function based on a highest function load; and a second pressure compensated valve controls flow between the pump and a second function based on the highest function load. First and second operator controls activate the first and second functions, respectively. When the first function is stalled and the second function is activated, the controller closes the first valve to remove the first function load from the load sense circuit and prevent flow to or from the first function. The controller can determine the first function is stalled when a timer exceeds an initialization period. When the controller closes the first valve, it can cycle the first valve between a shutoff period where the valve is closed, and a refresh period where the valve is opened.

A hydraulic system for a working machine is a load sensing (LS) system and includes a first hydraulic actuator and a first control valve for controlling the flow of hydraulic fluid from a pump to the first hydraulic actuator and for draining hydraulic fluid from the first hydraulic actuator, respectively and a second hydraulic actuator and a second control valve for controlling the flow of hydraulic fluid from the pump to the second hydraulic actuator and for draining hydraulic fluid from the second hydraulic actuator, respectively. The hydraulic system further includes a first hydraulic circuit for providing an LS pressure for the first actuator and a second hydraulic circuit for providing an LS pressure for the second actuator. At least one of the first and second hydraulic circuits includes an offset valve for changing the LS pressure before providing the LS pressure to the pump.

A multi-control hydraulic circuit supplies receivers with hydraulic fluid delivered by a pump with an output controlled by the pressure of a control line depending on a load pressure of the receivers, and delivers the hydraulic fluid at a regulated pressure. The hydraulic circuit consists of hydraulic modules each associated with a receiver having a distributor which regulates the variable output supplying the receiver via a pressure compensator connected at its inlet to the outlet of the variable choke of the distributor, and at its outlet. The plunger manages the connection between its inlet and its outlet. The pressure compensator has a fluid link equipped with a choke and connects the outlet to the control line, irrespective of the position of the plunger.

A valve block includes a plurality of control valve disks that form a first block part and a second block part. A supply pressure for the control valve disks of the first block part is limited by a common pressure-limiting valve. The common pressure-limiting valve is arranged such that a prevailing load pressure registered by the control valve disks does not exceed a specific value. The supply pressure for the control valve disks of the second block part is not limited.

The invention relates to a hydraulic valve device (1) including a high pressure connection (P) and a low pressure connection (T); at least one motor port connection (A) that is connectable to a motor port (A) on a hydraulic motor (M), preferably a hydraulic cylinder; a flow control valve (F), which is arranged between the high pressure connection (P) and the motor port connection (A) and which includes a flow opening (18) that is adjustable between a fully closed position and a fully open position; and a pressure regulator (R) that is arranged between the high pressure connection (P) and the flow regulating valve (F), wherein a regulator pressure (PR) that acts at a first connection point (3) between the pressure regulator (R) and the flow regulating valve (F) acts on the pressure regulator (R) via a first control conduit (4) to close the same. A second control conduit (5) including a first restrictor (6), is arranged to convey a load pressure (PL) that acts at the motor port connection (A) from a second connection point (7) positioned between the flow regulating valve (F) and the motor port connection (A) via the first restrictor (6) to a third connection point (8) at which a first control pressure (Pc) acts and which third connection point (8) is connected to the pressure regulator (R) to act on the same in the opening direction by means of said first control pressure (Pc), wherein the third connection point (8) is connected to the low pressure connection (T), via an adjustable second restrictor (9).

A load-controlled hydraulic supply for an attachment attached to an agricultural tractor includes a hydraulic high-pressure source providing a volume flow in a supply line, a pressure-compensated control valve including an actuation device for adjusting the volume flow in the supply line, a return line leading to a hydraulic reservoir, and a load-indicating line. The volume flow is adjusted based on pressure feedback prevailing at the load-indicating line.