Systems and apparatuses include a primary hydraulic pump including a primary displacement actuator and a primary pressure port, a primary load sense system fluidly coupled to the primary displacement actuator, a secondary hydraulic pump including a secondary displacement actuator and a secondary pressure port, a secondary load sense system fluidly coupled to the secondary displacement actuator, and a crossover pressure controller coupled between the primary pressure port and the secondary pressure port and including: a selectively energizable crossover pressure solenoid, and a crossover pressure spool movable by the crossover pressure solenoid between a combined pressure position providing fluid communication between the primary pressure port and the secondary pressure port, and a separate pressure position inhibiting fluid communication between the primary pressure port and the secondary pressure port.

A hydraulic system for recovering hydraulic energy, the hydraulic system made of at least: a first actuator for generating hydraulic energy and providing fluid under pressure; a tank line for receiving the fluid under pressure drained from the first actuator; a second actuator driven by the fluid under pressure drained from the first actuator; a recovery line for supplying the fluid under pressure drained from the first actuator. The system further includes a pressure compensating valve which controls flow of fluid in the tank line and maintains a fluid pressure differential across a first directional control valve. The first pressure compensating valve is provided with a first fluid pressure sensing line in communication with the recovery line and a second fluid pressure sensing line in communication with the first actuator.

A working machine includes a prime mover, a hydraulic pump driven by power of the prime mover, a cooler including a cooling fan rotated by either the power of the prime mover or hydraulic fluid delivered from the hydraulic pump, and a controller configured or programmed to perform a reduction control for reducing a target fan rotation speed that is a target rotation speed of the cooling fan in response to reduction of an actual prime mover rotation speed that is an actual rotation speed of the prime mover, and to perform, after the reduction control, a restoration control for restoring the target fan rotation speed. The controller is configured or programmed to make a difference between a reduction rate of the target fan rotation speed in the reduction control and an increase rate of the target fan rotation speed in the restoration control.

A hydraulic system for a work vehicle has a first hydraulic circuit at a first nominal pressure and a second hydraulic circuit at a second nominal pressure different than the first nominal pressure. A dual-chamber hydraulic reservoir includes a first tank associated with the first hydraulic circuit and defining a first opening and a second tank associated with the second hydraulic circuit and defining a second opening. An exchange system has a particulate filter disposed within an exchange path between the first opening of the first tank and the second opening of the second tank. The exchange system is configured to resupply the first tank with hydraulic fluid from the second tank.

Systems and apparatuses include a primary hydraulic pump including a primary displacement actuator and a primary pressure port, a primary load sense system fluidly coupled to the primary displacement actuator, a secondary hydraulic pump including a secondary displacement actuator and a secondary pressure port, a secondary load sense system fluidly coupled to the secondary displacement actuator, and a crossover pressure controller coupled between the primary pressure port and the secondary pressure port and including: a selectively energizable crossover pressure solenoid, and a crossover pressure spool movable by the crossover pressure solenoid between a combined pressure position providing fluid communication between the primary pressure port and the secondary pressure port, and a separate pressure position inhibiting fluid communication between the primary pressure port and the secondary pressure port.

A working machine includes a prime mover, a hydraulic pump driven by power of the prime mover, a cooler including a cooling fan rotated by either the power of the prime mover or hydraulic fluid delivered from the hydraulic pump, and a controller configured or programmed to perform a reduction control for reducing a target fan rotation speed that is a target rotation speed of the cooling fan in response to reduction of an actual prime mover rotation speed that is an actual rotation speed of the prime mover, and to perform, after the reduction control, a restoration control for restoring the target fan rotation speed. The controller is configured or programmed to make a difference between a reduction rate of the target fan rotation speed in the reduction control and an increase rate of the target fan rotation speed in the restoration control.

A device for maintaining a hydraulic supply of a utility vehicle includes a hydraulic pump, which is adjustable in terms of its delivery volume via a pressure control inlet, for feeding hydraulic fluid to a hydraulic circuit, a pressure accumulator that can be charged from the hydraulic circuit via a check valve, a pressure connection between the hydraulic circuit and the pressure control inlet of the hydraulic pump being producible via a sensor line by means of a charging valve, and a supply connection between the pressure accumulator and the hydraulic circuit being producible by means of a discharging valve, by virtue of the check valve being bypassed.

A controller for hydraulic system of a work machine is provided. The controller is configured to perform a worktool disconnect routine to reduce pressure in a first worktool line and a second worktool line of the hydraulic system. The hydraulic system comprises a spool valve, a first worktool port connected to the spool valve by the first worktool line, a second worktool port connected to the spool valve by the second worktool line, a high pressure flow source of hydraulic fluid connected to the spool valve by a high pressure line and a low pressure tank line connected to the spool valve, the low pressure tank line at a lower pressure than a pressure of the high pressure line. When performing the worktool disconnect routine the controller is configured to: check that a power source of the work machine is operating, instruct the high pressure flow source of hydraulic fluid to provide no flow of hydraulic fluid in the high pressure line to the spool valve, instruct the spool valve to move to a first position wherein the first worktool port is connected to the low pressure tank line and the second worktool port is connected to the high pressure flow source in order to reduce a pressure in the first worktool line, and instruct the spool valve to move to a second position wherein the second worktool port is connected to the low pressure tank line and the first worktool port is connected to the high pressure flow source in order to reduce a pressure in the second worktool line.

A machine comprises a frame, a plurality of ground engaging units, a plurality of moveable legs, and a hydraulic system. A first ground engaging unit and a second ground engaging unit connect a first leg and a second leg, respectively, with the frame. The hydraulic system controls heights of the plurality of moveable legs. The hydraulic system comprises a fluid circuit to control fluid between the first and second legs, a load holding valve to control fluid flow into the fluid circuit, and first and second relief valves to control flow of fluid between the first and second legs in opposite directions. A method for controlling slope of a construction machine comprises activating a relief valve connecting right and left lifting cylinders to control flow of hydraulic fluid between the lifting cylinders to control retraction of one of the lifting cylinders from retracting.

A hydraulic system for a work vehicle has a first hydraulic circuit at a first nominal pressure and a second hydraulic circuit at a second nominal pressure different than the first nominal pressure. A dual-chamber hydraulic reservoir includes a first tank associated with the first hydraulic circuit and defining a first opening and a second tank associated with the second hydraulic circuit and defining a second opening. An exchange system has a particulate filter disposed within an exchange path between the first opening of the first tank and the second opening of the second tank. The exchange system is configured to resupply the first tank with hydraulic fluid from the second tank.