A hydraulic-pump flow-rate calibration system includes: a variable capacitance type hydraulic pump that supplies an operating fluid to a hydraulic actuator; a regulator that changes the dispense flow rate of the hydraulic pump according to a flow rate command signal; a flow rate detection device that detects the flow rate of the operating fluid; a control device that outputs the flow rate command signal to the regulator to control the regulator; and a calibration device that calculates an actual measurement characteristic of the dispense flow rate for the flow rate command signal, and performs, on a preset reference characteristic, calibration based on the actual measurement characteristic. The actual measurement characteristic is calculated as a result of the flow rate of the operating fluid being detected by the flow rate detection device during output of a predetermined flow rate command signal from the control device to the regulator.

A turn-drive apparatus capable of securing high acceleration at the time of turning start with a reduced relief loss includes a hydraulic pump of a variable capacity type, a turning motor, a turning control device, a relief valve, and a flow rate control device that controls a pump flow rate. The flow rate control device calculates a relief-cut-control target pump flow rate on the basis of the sum of a minimum relief flow rate and a turning-speed flow rate, and inputs a pump capacity command to the variable capacity-type hydraulic pump based thereon. The flow rate control device makes the relief-cut-control target pump flow rate larger than the sum of the minimum relief flow rate and the turning-speed flow rate at the time of turning start.

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.

A refuse vehicle includes a chassis and a vehicle body. A variable displacement pump is positioned within the vehicle body and is configured to pump hydraulic fluid from a hydraulic fluid reservoir into a high pressure line of a hydraulic circuit. A lifting system on the vehicle includes at least one actuator in fluid communication with the variable displacement pump, which delivers pressurized hydraulic fluid from the hydraulic fluid reservoir to the actuator through the high pressure line to adjust a position of the actuator. A valve is positioned downstream of the variable displacement pump. In a first valve position, the valve restricts flow outward from the high pressure line. In a second valve position, the valve directs fluid from the high pressure line into a lower pressure line to reduce a hydraulic pressure within the high pressure line and adjust an output parameter of the variable displacement pump.

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.

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.

The invention refers to a hydraulic control system for controlling operation of a work attachment of a work machine, comprising a controller configured to output a work attachment control value controlling the operation of the work attachment, an operator input device configured to output a command signal depending on the amount of actuation of the operator input device for setting the work attachment control value, a save input device configured to generate a save command signal upon actuating the save input device and a mode select input device configured to select a first mode and a second mode, wherein the controller is configured to save a constant work attachment control value, wherein the constant work attachment control value is the work attachment control value as set by the command signal upon receiving the save command signal.

A hydraulic circuit for use on a construction machine includes a first valve, a second valve, and at least a third valve. The second and third valve each includes at least one inlet port connected to a first outlet port of the first valve. The first outlet port of each of the second and third valves are configured to reduce a first pressure to a second pressure and/or a third pressure downstream of the second valve and the third valve, respectively. The second valve and the third valve also include at least a second outlet port connected to a reservoir tank. A hydraulic motor is connected to the first outlet port of the second valve, which operates the hydraulic motor in a first direction. The hydraulic motor also is connected to the first outlet port of the third valve, which operates the hydraulic motor in a second direction.

The invention provides a hydraulic circuit for feeding an actuator (1) comprising first and second chambers (5, 6), the circuit comprising a slide valve (10) with a slide (16) that is movable between first and second extreme positions (18, 19) on either side of a stable central position (17) so that: in the central position, it connects the chambers (5, 6) of the actuator to a return port; in the first extreme position (18), it connects the first chamber (5) to a feed port and the second chamber to the return port; and in the second extreme position (19), it connects at least the second chamber (6) to the feed port. According to the invention, the hydraulic circuit includes pressure-maintaining means (20) for maintaining pressure in the first chamber of the actuator while the slide is passing through the central position on being moved from the first extreme position to the second extreme position.

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.