Abstract: A hydraulic system of a vehicle includes a first pump for supplying at least one first hydraulic circuit and at least one second pump for supplying at least one second hydraulic circuit with hydraulic medium. The second pump supplies the first hydraulic circuit with hydraulic medium in an emergency mode or when an output pressure of the first pump fails.

Abstract: A method for operating a hydraulic consumer on an electrically actuated control valve includes providing the valve with an open valve position for establishing a connection between a valve inlet and a pilot line for influencing a pivot angle set on an axial piston pump and a system pressure which is present at the valve inlet and dependent on the pivot angle. Data regarding the current system pressure and the current pivot angle are detected and communicated to a control unit. The method includes determining an incorrect setting of the control valve if the control unit detects that a delivery volume flow of the axial piston pump is smaller than a value to be expected based on valve position, or the control unit detects that the system pressure present at the valve inlet is at a maximum without a delivery volume flow flowing in the direction of the hydraulic consumer.

Abstract: A hydraulic system of a vehicle includes a first pump for supplying at least one first hydraulic circuit and at least one second pump for supplying at least one second hydraulic circuit with hydraulic medium. The second pump supplies the first hydraulic circuit with hydraulic medium in an emergency mode or when an output pressure of the first pump fails.

Abstract: A method for operating a hydraulic consumer on an electrically actuated control valve includes providing the valve with an open valve position for establishing a connection between a valve inlet and a pilot line for influencing a pivot angle set on an axial piston pump and a system pressure which is present at the valve inlet and dependent on the pivot angle. Data regarding the current system pressure and the current pivot angle are detected and communicated to a control unit. The method includes determining an incorrect setting of the control valve if the control unit detects that a delivery volume flow of the axial piston pump is smaller than a value to be expected based on valve position, or the control unit detects that the system pressure present at the valve inlet is at a maximum without a delivery volume flow flowing in the direction of the hydraulic consumer.

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 directional control valve for activating a hydraulic load, comprising a housing with a pump connection for connecting to a pressure source, a tank connection for connecting to a hydraulic fluid reservoir and a first and second working connection for connecting to the hydraulic load, and a first and a second valve slide, which are held in the housing so as to be linearly movable in a displacement direction.

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: A hydraulic directional control valve for activating a hydraulic load, comprising a housing with a pump connection for connecting to a pressure source, a tank connection for connecting to a hydraulic fluid reservoir and a first and second working connection for connecting to the hydraulic load, and a first and a second valve slide, which are held in the housing so as to be linearly movable in a displacement direction.

Abstract: The invention concerns a system for supplying hydraulic fluid to a hydraulic system, with an operating reservoir that accepts the hydraulic fluid provided for the operation of the hydraulic system and an auxiliary reservoir connected to the operating reservoir over a hydraulic line for intermediate storage of hydraulic fluid withdrawn from the operating reservoir. According to the invention, an air pump is available that is connected on the one hand on its low pressure side to a suction line that ends in a fluid free area of the auxiliary reservoir, so that a negative pressure can be built up in the auxiliary reservoir as against the external atmospheric pressure, and that is connected, on the other hand, to a control line that is provided with a control opening that is covered by the hydraulic fluid in the operating reservoir at least before the air pump is put into operation.

Abstract: The invention concerns a system for supplying hydraulic fluid to a hydraulic system, with an operating reservoir that accepts the hydraulic fluid provided for the operation of the hydraulic system and an auxiliary reservoir connected to the operating reservoir over a hydraulic line for intermediate storage of hydraulic fluid withdrawn from the operating reservoir. According to the invention, an air pump is available that is connected on the one hand on its low pressure side to a suction line that ends in a fluid free area of the auxiliary reservoir, so that a negative pressure can be built up in the auxiliary reservoir as against the external atmospheric pressure, and that is connected, on the other hand, to a control line that is provided with a control opening that is covered by the hydraulic fluid in the operating reservoir at least before the air pump is put into operation.