A dual pressure margin priority circuit and method for controlling flow from a pump to steering valve and low priority inlets. A steering pressure valve controls flow from pump to steering valve inlets, and provides a steering valve load sense pressure. A priority valve controls flow from pump to low priority inlets. A load sense cutoff valve has a first inlet receiving the steering valve load sense pressure. The load sense cutoff valve controls flow through the priority valve based on steering valve load sense pressure at the first cutoff valve inlet. The cutoff valve can include a second inlet coupled to tank, and a load sense input coupled to the steering valve load sense pressure. The cutoff valve can be a pressure limiter valve. The priority and steering pressure valves can be 2-way proportional flow spool valves with bias springs, and contributing and opposing load sense inputs.

A preselection valve is for a hydraulic valve assembly with a switching element, a pressure input line, a first pressure output line and a first load pressure line with a load pressure inlet and output. The switching element is switchable from neutral to a first switching position. The pressure input line is connected to the first pressure output line in the first position. The preselection valve has a second and third load pressure line and a load pressure increasing device. The second load pressure line branches off the pressure input line upstream of the switching element. The load pressure increasing device is connected to the third load pressure line, which connects the pressure increasing device to the first load pressure line. The second load pressure line is connected to the pressure increasing device in the first switching position and the second load pressure line is blocked in the neutral position.

A hydraulic system having a hydraulic pump, having a plurality of hydraulic loads and having a plurality of load-sensing valves for adjusting the pump performance of the hydraulic pump. An association unit is arranged between the hydraulic pump and the hydraulic loads and in a first switched state defines a first hydraulic path between the hydraulic pump and the hydraulic loads and in a second switched state defines a second hydraulic path between the hydraulic pump and the hydraulic loads. The system comprises a controller, which processes a state value of a hydraulic load as an input variable and which determines a control signal for the switched state of the association unit. The invention also relates to a method for controlling a hydraulic system.

A hydraulic system for controlling an implement on a work machine may include a hydraulic reservoir, a hydraulic pump in fluid communication with the reservoir, a central valve in fluid communication with the pump and configured for controlling the implement, a load sense pressure relief system, and a controller. The controller may be configured for controlling the central valve and the load sense pressure relief system and selecting between operating the hydraulic system at a first pressure and a second pressure based on a factor relating to implement position.

A hydraulic system for a work vehicle includes a first pump providing a first flow to a first circuit. A first pressure sensor measures a first pressure in the first circuit. A first swashplate angle sensor measures a first angle of a first swashplate of the first pump. A supplemental pump provides a supplemental flow to a supplemental circuit. A supplemental pressure sensor measures a supplemental pressure in the supplemental circuit. A supplemental valve adjusts the load sense signal provided to a supplemental load sensing compensator of the supplemental pump. A first valve selectively enables flow from the supplemental circuit to the first circuit when the supplemental pressure is equal to or greater than the first pressure. A controller determines to operate the supplemental pump in one of a standby condition and a use condition based in part on the first angle of the first swashplate.

A hydraulic system for a work vehicle includes a first pump with a first swashplate providing a first flow in a first circuit and a second pump with a second swashplate providing a second flow in a second circuit. A supplemental pump with a supplemental swashplate provides a supplemental flow to a supplemental circuit. A first valve selectively enables flow from the supplemental circuit to the first circuit. A second valve selectively enables flow from the supplemental circuit to the second circuit. A controller determines to operate the supplemental pump in one of a standby condition and a use condition based in part on a first angle of the first swashplate and a second angle of the second swashplate.

A hydraulic system for a work vehicle includes a first pump providing a first flow in a first circuit having a first pressure. A first load sense circuit connected to a first load sensing compensator of the first pump. The first load sense circuit having a first load sense pressure. A supplemental pump provides a supplemental flow to a supplemental circuit having a supplemental pressure. A supplemental load sense circuit connected to a supplemental load sensing compensator of the supplemental pump. A first supplemental valve selectively enables flow from the first load sense circuit to the supplemental load circuit based in part on a first pressure differential between the first pressure and the first load sense pressure. A first valve selectively enables flow from the supplemental circuit to the first circuit when the supplemental pressure is equal to or greater than the first pressure.

A preselection valve is for a hydraulic valve assembly with a switching element, a pressure input line, a first pressure output line and a first load pressure line with a load pressure inlet and output. The switching element is switchable from neutral to a first switching position. The pressure input line is connected to the first pressure output line in the first position. The preselection valve has a second and third load pressure line and a load pressure increasing device. The second load pressure line branches off the pressure input line upstream of the switching element. The load pressure increasing device is connected to the third load pressure line, which connects the pressure increasing device to the first load pressure line. The second load pressure line is connected to the pressure increasing device in the first switching position and the second load pressure line is blocked in the neutral position.

A hydraulic arrangement is disclosed for distributing a fluid in pressure coming from a source of fluid in pressure among hydraulic units of a work vehicle. The hydraulic arrangement includes a priority valve configured to divide the flow of the fluid source between a subset of the hydraulic units on the base of an equivalent load sensing signal derived from the hydraulic units. The hydraulic arrangement further includes by-pass means fluidly interposed between the source and the subset of the hydraulic units and configured to allow direct passage of fluid by-passing priority valve from the source to the subset of the hydraulic units according to a predefined condition.

An implement includes a mechanical coupling component configured to removably couple the implement to a support machine, a hydraulic fluid supply line configured to receive a supply flow of hydraulic fluid under pressure from a hydraulic system associated with the support machine, and a hydraulically-powered component configured to be actuated using the hydraulic fluid. The implement also includes a hydraulic fluid recovery system comprising a hydraulic fluid return line configured to fluidically couple to the hydraulic system associated with the support machine and provide a return flow of hydraulic fluid to the hydraulic system. A hydraulic fluid reservoir is configured to, when the hydraulic fluid return line is decoupled from the hydraulic system associated with the support machine, receive a portion of the hydraulic fluid from the hydraulic fluid return line when a fluid pressure in the hydraulic fluid return line increases to a pressure threshold.