An open center (OC)-open center load sense (OCLS) conversion valve and hydraulic circuits therewith configured to control flow from a hydraulic pump to multiple hydraulic functions. The conversion valve includes cartridge, load sense, pump, first function supply, first function return, and downstream ports. When an OC cartridge is inserted in the cartridge port, regardless of load sense, the pump and first function supply ports are connected and the first function return and downstream ports are connected. When an OCLS cartridge is inserted in the cartridge port and load sense is detected, the pump and first function supply ports are connected and the first function return and downstream ports are connected. When an OCLS cartridge is inserted in the cartridge port and load sense is not detected, the pump, first function return and downstream ports are connected.

A hydraulic system for a machine includes a first pump, an implement pump, a control valve, and an auxiliary circuit. The first pump is configured to supply a first fluid flow to a first circuit, such as a steering circuit. The implement pump is configured to supply a second fluid flow to an implement circuit to actuate a primary implement function. The auxiliary circuit is configured to deliver fluid flow to actuate an auxiliary implement function. The auxiliary circuit is fluidly coupled to the implement circuit. The auxiliary circuit is also coupled to the first circuit by the control valve. The control valve is located downstream, in the direction of fluid flow, of the implement pump and the first pump. The control valve is configured to allow at least a portion of the first fluid flow to enter the auxiliary circuit and be delivered to the auxiliary implement function.

An open center (OC)-open center load sense (OCLS) conversion valve and hydraulic circuits therewith configured to control flow from a hydraulic pump to multiple hydraulic functions. The conversion valve includes cartridge, load sense, pump, first function supply, first function return, and downstream ports. When an OC cartridge is inserted in the cartridge port, regardless of load sense, the pump and first function supply ports are connected and the first function return and downstream ports are connected. When an OCLS cartridge is inserted in the cartridge port and load sense is detected, the pump and first function supply ports are connected and the first function return and downstream ports are connected. When an OCLS cartridge is inserted in the cartridge port and load sense is not detected, the pump, first function return and downstream ports are connected.

An open center (OC)-open center load sense (OCLS) conversion valve and hydraulic circuits therewith configured to control flow from a hydraulic pump to multiple hydraulic functions. The conversion valve includes cartridge, load sense, pump, first function supply, first function return, and downstream ports. When an OC cartridge is inserted in the cartridge port, regardless of load sense, the pump and first function supply ports are connected and the first function return and downstream ports are connected. When an OCLS cartridge is inserted in the cartridge port and load sense is detected, the pump and first function supply ports are connected and the first function return and downstream ports are connected. When an OCLS cartridge is inserted in the cartridge port and load sense is not detected, the pump, first function return and downstream ports are connected.

A hydraulic drive device for an industrial vehicle includes a variable displacement pump, a displacement control valve, a power steering cylinder, a power steering valve, a loading cylinder, a loading valve, a hydraulic oil passage, and a pilot line. The displacement control valve controls the variable displacement pump to increase displacement of the variable displacement pump when differential pressure between discharge pressure of hydraulic oil discharged from the variable displacement pump and pilot pressure generated in the pilot line is smaller than a predetermined set pressure. A spool of the loading valve is provided with a groove portion that forms a communication passage that makes communication between the hydraulic oil passage and the pilot line at a neutral position of the loading valve when the power steering valve is located in a neutral position.

A hydraulic drive device for an industrial vehicle includes a variable displacement pump, a displacement control valve, a power steering cylinder, a power steering valve, a loading cylinder, a loading valve, a hydraulic oil passage, and a pilot line. The displacement control valve controls the variable displacement pump to increase displacement of the variable displacement pump when differential pressure between discharge pressure of hydraulic oil discharged from the variable displacement pump and pilot pressure generated in the pilot line is smaller than a predetermined set pressure. A spool of the loading valve is provided with a groove portion that forms a communication passage that makes communication between the hydraulic oil passage and the pilot line at a neutral position of the loading valve when the power steering valve is located in a neutral position.

Disclosed embodiments include steering circuits utilizing a controllable cross-feed loop between left and right drive motor sides of an articulated power machine to reduce skidding caused by a turning operation in which an articulation actuator changes an articulation joint angle between a front frame member and a rear frame member of the power machine.

A hydraulic valve assembly for a work vehicle includes a fan and brake function module. A first pump supplies hydraulic pressure to a fan circuit and to first and second service brake circuits of the vehicle. A second pump supplies hydraulic pressure to a steering and work function module that in turn supplies hydraulic pressure to a steering circuit and a work function circuit of the vehicle. The hydraulic valve assembly may also include a work control module and an auxiliary module. The modules of the hydraulic valve assembly are separably connected together via interface surfaces.

A work vehicle includes a bypass passage formed in an operational valve of a dump cylinder and configured to feed pressure oil from a hydraulic pump to a power steering device when the operational valve is under a neutral state and an oil feeding passage equipped with an orifice, the orifice-equipped oil feeding passage being configured to feed the pressure oil from the hydraulic pump to a rod side oil chamber of the dump cylinder when the operational valve is under the neutral state.

A work vehicle includes a bypass passage formed in an operational valve of a dump cylinder and configured to feed pressure oil from a hydraulic pump to a power steering device when the operational valve is under a neutral state and an oil feeding passage equipped with an orifice, the orifice-equipped oil feeding passage being configured to feed the pressure oil from the hydraulic pump to a rod side oil chamber of the dump cylinder when the operational valve is under the neutral state.