Abstract: A digging machine such as a face shovel is controlled in an automated dumping sequence in which the bucket is pivoted to a first angular orientation before opening and, optionally, re-orienting to a second, slightly more forwardly inclined angular orientation. The first orientation may relieve the front part of the bucket from the load while the second orientation is selected to discharge the load at an optimal trajectory. The bucket may move to a third angular orientation before closing the front part against gravity.

Abstract: A closed-loop hydraulic circuit associated with a swing mechanism of a machine is controlled to obtain both a pressure control during acceleration and deceleration of the swing mechanism and a velocity control during coasting. In this manner, a system pressure in closed-loop hydraulic circuit is maintained below a maximum allowable pressure during acceleration and deceleration, and the swing mechanism can be rotated at a desired constant speed during coasting. This is achieved by controlling a hydraulic actuator adjusting the displacement of a variable displacement pump in different control modes, depending on a comparison between a desired displacement of the pump and an actual displacement of the same.

Abstract: A digging machine (1) such as a face shovel is controlled in an automated dumping sequence in which the bucket (10, 10?) is pivoted to a first angular orientation before opening and, optionally, re-orienting to a second, slightly more forwardly inclined angular orientation. The first orientation may relieve the front part (20) of the bucket from the load while the second orientation is selected to discharge the load at an optimal trajectory. The bucket may move to a third angular orientation before closing the front part (20) against gravity.

Abstract: A closed-loop hydraulic circuit associated with a swing mechanism of a machine is controlled to obtain both a pressure control during acceleration and deceleration of the swing mechanism and a velocity control during coasting. In this manner, a system pressure in closed-loop hydraulic circuit is maintained below a maximum allowable pressure during acceleration and deceleration, and the swing mechanism can be rotated at a desired constant speed during coasting. This is achieved by controlling a hydraulic actuator adjusting the displacement of a variable displacement pump in different control modes, depending on a comparison between a desired displacement of the pump and an actual displacement of the same.

Abstract: A hydraulic control system may include a closed loop hydraulic circuit with at least one hydraulic motor. A plurality of variable displacement pumps may be fluidly connected in parallel in the closed loop hydraulic circuit. A plurality of hydraulic actuators may be configured to adjust the displacement of the variable displacement pumps. A pilot valve assembly may be configured to supply the hydraulic actuators with hydraulic fluid having a pilot pressure corresponding to a desired displacement of the variable displacement pumps. A pressure regulating device may be configured to limit the pilot pressure of the hydraulic fluid supplied to the hydraulic actuators when a working pressure in the closed loop hydraulic circuit reaches a maximum allowable working pressure.

Abstract: The invention relates to an system for supplying a hydraulic circuit with hydraulic fluid. The system includes a working reservoir and an auxiliary reservoir connected to the working reservoir by a hydraulic line. An air pump has an inlet connected to a suction line that opens into a liquid-free portion of the auxiliary reservoir so that a negative pressure can be built up in the auxiliary reservoir relative to the atmospheric ambient pressure. The air pump inlet is also connected to a control line, which comprises a control opening which is covered by the hydraulic fluid in the working reservoir, at least before the air pump is started up.

Abstract: A hydraulic control system may include a closed loop hydraulic circuit with at least one hydraulic motor. A plurality of variable displacement pumps may be fluidly connected in parallel in the closed loop hydraulic circuit. A plurality of hydraulic actuators may be configured to adjust the displacement of the variable displacement pumps. A pilot valve assembly may be configured to supply the hydraulic actuators with hydraulic fluid having a pilot pressure corresponding to a desired displacement of the variable displacement pumps. A pressure regulating device may be configured to limit the pilot pressure of the hydraulic fluid supplied to the hydraulic actuators when a working pressure in the closed loop hydraulic circuit reaches a maximum allowable working pressure.

Abstract: The present disclosure relates to a hydraulic mining shovel. The shovel may comprise a main frame, a power module and a counterweight module. The shovel may further comprise a first exhaust aftertreatment module and a second exhaust aftertreatment module, each being mounted onto the counterweight module and each including a reductant tank and pump unit and a selective catalytic reduction unit. The first exhaust aftertreatment module and the second exhaust aftertreatment module may be configured and arranged substantially mirror-symmetrically at opposing sides of the counterweight module with respect to a central longitudinal axis of the main frame.

Abstract: The invention relates to an system for supplying a hydraulic circuit with hydraulic fluid. The system includes a working reservoir and an auxiliary reservoir connected to the working reservoir by a hydraulic line. An air pump has an inlet connected to a suction line that opens into a liquid-free portion of the auxiliary reservoir so that a negative pressure can be built up in the auxiliary reservoir relative to the atmospheric ambient pressure. The air pump inlet is also connected to a control line, which comprises a control opening which is covered by the hydraulic fluid in the working reservoir, at least before the air pump is started up.

Abstract: The invention relates to an system for supplying a hydraulic circuit with hydraulic fluid. The system includes a working reservoir and an auxiliary reservoir connected to the working reservoir by a hydraulic line. An air pump has an inlet connected to a suction line that opens into a liquid-free portion of the auxiliary reservoir so that a negative pressure can be built up in the auxiliary reservoir relative to the atmospheric ambient pressure. The air pump inlet is also connected to a control line, which comprises a control opening which is covered by the hydraulic fluid in the working reservoir, at least before the air pump is started up.

Abstract: For controlling supply priorities, a hydraulic system includes several loads, a pump, and a tank. One load has a first-level supply priority, and optionally a second load has a second-level supply priority subordinate to the first level. A third load has a third-level supply priority subordinate to the second level. Each load can be connected to the pump by a separate supply line. The supply lines for the first and the optional second load are connected to the pump by a common load-pressure-controlled priority valve and the supply line for the third load is connected to the pump by an additional load-pressure-controlled priority valve. A first load-pressure line leading to the pump is connected to a load-pressure line of the third hydraulic load and to a second load-pressure line.

Abstract: A hydraulic arrangement for braking a trailer comprises a brake line connected between a brake system of a trailer and a trailer brake valve. The trailer brake valve is activated via a first control-pressure line which extends between the brake line and the trailer brake valve and via a second control-pressure line which extends between the trailer brake valve and a control-pressure source and acts in opposition to the pressure imposed on the trailer brake valve by the first control-pressure line. An adjustable pressure-reducing means for controlling the control pressure in the second control-pressure line is arranged in the second control-pressure line. It is proposed to design the control-pressure source as part of a hydraulic control of a brake system of a traction vehicle drawing the trailer and to force the pressure-reducing means mechanically into an open basic position by means of an adjustable prestressing force.

Abstract: A hydraulic system includes an engine driven adjustable hydraulic pump which supplies fluid to a hydraulic consumer, and an electronic control unit. The adjustable pump includes flow controller for controlling a pressure difference between the consumer and the adjustable pump to a pre-determined control pressure difference. The flow controller includes an actuator controlled by the control unit, through which the pressure difference can be controlled. The electronic control unit receives an engine speed signal and controls the actuator to control the pressure difference, in order to make power delivery of the adjustable pump conform to the operating conditions of a vehicle.

Abstract: The invention relates to a hitch system for an agricultural vehicle for lifting and lowering a load or an attachment. The hitch system further includes a hydraulic system with a double-action hydraulic cylinder, and an electronic control unit connected to the hydraulic system for controlling the hydraulic system and the pressurization of the hydraulic cylinder. The control unit controls a contact pressure for a working device as a function of a sensed load on the axle.

Abstract: A hydraulic arrangement for regulating a lifting mechanism (12) of an agricultural machine (10) is described. The hydraulic arrangement (16) comprises a hydraulic cylinder (24) having a chamber (50) capable of being acted upon by pressure, a proportionally adjustable inflow valve (22) which is connected on the outlet side via an inflow line (30) to the chamber (50) and which is connected on the inlet side to a hydraulic pump (18, 18?), a first outlet line (32) which makes a connection between the chamber (50) and a hydraulic tank (20), adjustment means (42, 44) for generating an adjustment signal for the hydraulic cylinder (24), and an electronic control unit (40).

Abstract: A hydraulic system for a mobile working machine includes a hydraulic pump, a steering valve, a steering actuator controlled by the steering valve, a first hydraulic line which extends between the hydraulic pump and the steering valve, and a hydraulic storage unit which is connected with the first hydraulic line via a second hydraulic line). So as to optimize a pressure state for the hydraulic system, a throttle connected in parallel with a check valve is located in the second hydraulic line. The check valve permits one-way fluid flow in a direction away from the hydraulic storage unit.

Abstract: The invention relates to an system for supplying a hydraulic circuit with hydraulic fluid. The system includes a working reservoir and an auxiliary reservoir connected to the working reservoir by a hydraulic line. An air pump has an inlet connected to a suction line that opens into a liquid-free portion of the auxiliary reservoir so that a negative pressure can be built up in the auxiliary reservoir relative to the atmospheric ambient pressure. The air pump inlet is also connected to a control line, which comprises a control opening which is covered by the hydraulic fluid in the working reservoir, at least before the air pump is started up.

Abstract: For controlling supply priorities, a hydraulic system includes several loads, a pump, and a tank. One load has a first-level supply priority, and optionally a second load has a second-level supply priority subordinate to the first level. A third load has a third-level supply priority subordinate to the second level. Each load can be connected to the pump by a separate supply line. The supply lines for the first and the optional second load are connected to the pump by a common load-pressure-controlled priority valve and the supply line for the third load is connected to the pump by an additional load-pressure-controlled priority valve. A first load-pressure line leading to the pump is connected to a load-pressure line of the third hydraulic load and to a second load-pressure line.

Abstract: A hydraulic system for an agricultural vehicle is proposed. The hydraulic system comprises a main hydraulic circuit, which is fed with hydraulic fluid by a main hydraulic pump, a variable displacement charge pump which supplies charge pressure to the main hydraulic pump, and a lubricating hydraulic circuits. In order to keep efficiency losses on the vehicle to a minimum, particularly at high engine speeds, part of the hydraulic fluid delivered by the charge pump can be diverted to the lubricating hydraulic circuit.

Abstract: A hydraulic circuit includes a control valve connected to a pump, a hydraulic reservoir, hydraulic work connections and a cylinder. A controllable check valve is connected between the work connections and the control valve. An overpressure safety device is connected between each work connection the corresponding check valve. In order to prevent sagging of a load on the cylinder, the overpressure safety device discharges hydraulic fluid between the check valve and the work connection to reduce an overpressure. The overpressure safety device includes an overpressure valve and a throttle connected downstream of this valve to throttle the flow of hydraulic fluid discharged through the overpressure safety device.