Hydraulic switching element arrangement

Abstract

Hydraulic switching element arrangement for fluidically actuating at least one consumer of a motor vehicle, preferably a transmission comprising several gears, in particular a dual-clutch transmission, with at least one pump (14, 16), at least two hydraulic actuating elements (12a, 12b, 12c, 12d, 12e, 12f) for actuating the at least one consumer and at least one valve arrangement for connecting one of the actuating elements (12a, 12b, 12c, 12d, 12e, 12f) to the pump (14, 16), wherein the pump (14, 16) is a reversing pump and comprises a first delivery direction and a second delivery direction opposite to the first delivery direction, wherein the at least two hydraulic actuating elements (12a, 12b, 12c, 12d, 12e, 12f) are each actuable in a first actuating direction and in a second actuating direction opposite to the first actuating direction for actuating the at least one consumer, the direction of actuation of the actuating elements can be determined by the valve arrangement, wherein the actuating element (12a, 12b, 12c, 12d, 12e, 12f) to be actuated can be determined by the first delivery direction and second delivery direction of the pump (14, 16), characterized in that two pumps (14, 16), at least two valve arrangements and at least four actuating elements (12a, 12b, 12c, 12d, 12e, 12f) are provided.

Description

[0001] The invention relates to a hydraulic switching element arrangement for at least one consumer of a motor vehicle, preferably a transmission, in particular for dual-clutch transmissions.

[0002] When operating transmission shifting elements, high speed and low force are typically required at the beginning of the movement sequence to approach a shift actuation position, and high force and low speed are required once this position, such as the synchronization point, is reached. To meet these different requirements, the drives must be designed for maximum performance. For hydraulic actuation, a relatively large pump with a correspondingly powerful drive, such as an electric motor, must be provided.

[0003] From the publications DE 10 2014 215 516 A1 and DE 10 2010 001 069 A1, hydraulic switching element arrangements for fluidically actuating at least one consumer of a motor vehicle with at least one reversing pump, at least two hydraulic actuating elements for actuating the at least one consumer and at least one valve arrangement for connecting one of the actuating elements to the reversing pump are already known, wherein the at least two hydraulic actuating elements can each be actuated in a first actuating direction and in a second actuating direction opposite to the first actuating direction, wherein the actuating direction of the actuating elements can be determined by the valve arrangement and wherein the actuating element to be actuated can be determined by the first delivery direction and second delivery direction of the reversing pump.

[0004] However, these known hydraulic switching element arrangements are not optimally designed in terms of energy.

[0005] It is therefore an object of the invention to provide a hydraulic switching element arrangement with high dynamics and application, which has an optimized power consumption.

[0006] The object is achieved according to the invention by a hydraulic switching element arrangement having the features of claim 1. Preferred embodiments of the invention are specified in the subclaims, which may each individually or in combination represent an aspect of the invention.

[0007] The invention relates to a hydraulic switching element arrangement for fluidically actuating at least one consumer of a motor vehicle, preferably a transmission comprising a plurality of gears, in particular a dual-clutch transmission, comprising at least one pump, at least two hydraulic actuating elements for actuating the at least one consumer, and at least one valve arrangement for connecting one of the actuating elements to the pump, wherein the pump is a reversing pump and comprises a first conveying direction and a second conveying direction opposite to the first conveying direction, wherein the at least two hydraulic actuating elements are each actuable in a first actuating direction and in a second actuating direction opposite to the first actuating direction for actuating the at least one consumer, wherein the actuating direction of the actuating elements can be determined by the valve arrangement,wherein the actuating element to be actuated can be determined by the first delivery direction and the second delivery direction of the pump, wherein two pumps, at least two valve arrangements, and at least four actuating elements are provided. With two pumps, two shifting elements of a partial transmission can always be actuated independently at the same time. In this way, the disengagement and engagement of the different gears of the transmission can occur at overlapping times. For example, with two shifting elements per partial transmission, one shifting element from each partial transmission can be connected to each pump via the actuating elements. This can be achieved, for example, byEach pump, each with a valve arrangement and at least two actuating elements, forms its own switching element circuit. The resulting two switching element circuits cannot be interconnected. The actuating elements allow the switching elements of the sub-transmissions to be switched simultaneously and independently of one another.

[0008] The pump can be driven by a pump drive, in particular an electric motor. The pump and the pump drive together can form a pump actuator. By designing the pump as a reversing pump, the pump can have a first delivery direction and a second delivery direction for the working fluid, for example hydraulic oil, engine oil, machine oil or gear oil. The first delivery direction or the second delivery direction of the pump can be set by the direction of rotation of the pump drive. The pump can preferably be a fluid pump that can be operated in opposite delivery directions. The fluid pump can in particular be a hydraulic pump. The hydraulic pump is preferably designed as a positive displacement pump. The hydraulic pump can be designed as a vane pump, gear pump or piston pump.

[0009] The at least two actuating elements can actuate the at least one consumer, for example a transmission with multiple gears, wherein the actuating elements can each actuate one gear of the transmission or preferably two gears. Preferably, each actuating element can actuate a gear rail of the transmission with which two gears can be actuated. In particular, the transmission can, for example, have shift elements that can be actuated by the actuating elements in order to engage or disengage a gear. The actuating elements can, for example, be designed as levers or hydraulic cylinders and can be actuated by the working pressure of the working fluid. In this case, for example, the pump can actuate one of the actuating elements in the first delivery direction in order to actuate the transmission, and in the second delivery direction the pump can actuate another actuating element.The actuation direction of the actuating element to be actuated can be selected using the valve arrangement. The actuating element to be actuated can be selected using the pump's first flow direction and the pump's second flow direction.

[0010] The valve arrangement can either be a single valve that connects multiple actuating elements to the pump, or it can comprise multiple valves that, through different switching positions, connect the selected actuating element to the pump or disconnect it from the pump's hydraulic circuit. In a configuration with multiple valves, the valve arrangement can use either identical valves or different valves. In particular, the valve arrangement can select an actuating direction of the selected actuating element.

[0011] Such a design makes it possible to provide a hydraulic switching element arrangement with high dynamics and application, which has an optimized power consumption.

[0012] It is preferred that the actuating elements are differential area switching elements, preferably differential area gear switching elements, in particular double-acting hydraulic cylinders, with different hydraulic effective areas.

[0013] The term "double-acting hydraulic cylinder" describes a hydraulic cylinder that comprises a piston with two opposing piston surfaces that can be pressurized with hydraulic fluid. This allows the hydraulic cylinder to have two active directions of movement.

[0014] The term "different hydraulic active surfaces" describes the fact that the hydraulic cylinder can be designed as a differential cylinder. A differential cylinder can have a piston rod on only one side of the piston surface. This allows the differential cylinder to have two different sized active surfaces. One active surface can be on the piston side, which can act completely, and the other can be the rod-side surface, where only the annular surface can act. Due to the different active surfaces, the differential cylinder can extend and retract at two different speeds.

[0015] In particular, the hydraulic cylinder can be actuated such that, in a first switching position of the valve arrangement, the working fluid is delivered to the surface of the piston side, and in a second switching position of the valve arrangement, the working fluid can be delivered to both surfaces, whereby the piston can move in both directions of movement in the hydraulic cylinder. By actuating the hydraulic cylinder in the second switching position, the unequal effective area ratio can be compensated, so that the hydraulic cylinder can be actuated like a synchronous cylinder to enable an equal volume of working fluid flowing in and out, thus enabling retraction and extension at the same speed.

[0016] The pistons in the hydraulic cylinder can be displaced from two opposite sides by a working fluid. Each side of the piston can form its own pressure chamber in conjunction with the hydraulic cylinder. In particular, each hydraulic cylinder can have two connections, with a first connection actuating the actuating element in the first actuating direction and a second connection actuating the actuating element in the second actuating direction, so that the double-acting hydraulic cylinder can be moved in both the first and second actuating directions. The actuating direction of the hydraulic cylinder to be actuated can be selected using the valve arrangement, and the actuating element to be actuated can be selected using the pump's delivery direction.In a first switching position of the valve arrangement, the working fluid can be delivered to the surface of the piston side, and in a second switching position of the valve arrangement, the working fluid can be delivered to both surfaces, whereby the piston can move in both directions of movement in the hydraulic cylinder. Furthermore, for example, when the pump is actuated in the first delivery direction, a gearbox can be actuated by the selected double-acting hydraulic cylinder, while when the pump is actuated in the second delivery direction, the pump transfers the working fluid to another hydraulic cylinder. Due to the valve arrangement, the actuated hydraulic cylinder can transfer working fluid from the hydraulic cylinder to a reservoir via the valve arrangement.

[0017] Preferably, the ratio of the effective areas of the actuating elements is 1:5, preferably 1:3, in particular 1:2. This allows a hydraulic switching element arrangement with high dynamics to be provided.

[0018] In a preferred embodiment, the valve arrangement comprises at least one directional control valve. The use of a directional control valve makes it easy to select the actuating element to be used. In particular, for example, with two actuating elements, the at least one directional control valve can comprise at least four switching positions in order to connect one actuating element to the pump and to determine the direction of movement of the respective actuating element. The directional control valve can preferably provide two switching positions for each actuating element in order to be able to determine a direction of movement of the actuating element connected to the pump. Furthermore, the directional control valve can also comprise a fifth switching position in order to disconnect both actuating elements from the pump.In particular, the valve arrangement can, for example, also have a plurality of directional control valves, wherein, in the case of two actuating elements, one directional control valve is assigned to each actuating element. The directional control valves can have two switching positions: a first switching position for connecting the actuating element to the pump in the first actuating direction and a second switching position for connecting the actuating element to the pump in the second actuating direction. Furthermore, the directional control valves can also comprise a third switching position in order to separate the respective actuating element from the pump. The at least one directional control valve of the valve arrangement can comprise an elastic element in order to assume an initial position. The elastic element can be a compression spring which, for example, holds the directional control valve in a first switching position. When confirmed in a second switching position, the elastic element can be compressed.A return to the first switching position can then be achieved with the help of the elastic element. This saves the energy required to actuate the directional control valve, since a return to the first switching position can be achieved passively with the help of the elastic element. The elastic element can also be designed as a tension spring or disc spring. Furthermore, the directional control valve can be switched from a first switching position to a second switching position electrically or magnetically.

[0019] The pump is preferably a reversible variable displacement pump. The displacement of the reversible variable displacement pump is adjusted load-dependently without additional active control elements. The term active control elements refers to electrical or electronic components that can change the displacement of the reversible variable displacement pump. The displacement can be adjusted using one lifting cylinder connected to the first discharge direction outlet of the pump and one lifting cylinder connected to the second discharge direction outlet of the pump. In this way, the displacement of the pump can be adjusted regardless of the direction in which pressure is being built up.

[0020] Preferably, at least one actuating element can be actuated via a switching logic both by a first pump and by a second pump different from the first pump. For example, in a dual transmission, a first sub-transmission can comprise two switching elements and a second sub-transmission can comprise three switching elements. By using two pumps, two switching element circuits can again be formed, whereby any two switching elements on a sub-transmission can be actuated simultaneously. For example, the two switching element circuits can be connected via the switching logic to the third switching element of the sub-transmission with three switching elements. The third switching element of the sub-transmission can thus be actuated via an actuating element either by the first pump of the first switching element circuit or by the second pump of the second switching element circuit.In this way, a gear can be disengaged on this sub-transmission while another gear can be engaged at the same time. The shift logic can be a rotary valve, an OR valve, a check valve, or a directional control valve with different shift positions. For example, if both sub-transmissions each have three shift elements, an element can be arranged on the second sub-transmission parallel to the third shift element with the same circuitry to enable actuation by both the first shift element circuit and the second shift element circuit.

[0021] It is preferred that the switching logic comprises at least one directional control valve or at least one check valve. When configured as a directional control valve, the directional control valve can comprise at least three switching positions. A first switching position for connecting the actuating element for actuating the third switching element of the sub-transmission with three switching elements to the first switching element circuit, a second switching position for separating the actuating element for actuating the third switching element from the first switching element circuit and the second switching element circuit, and a third switching position for connecting the actuating element for actuating the third switching element to the second switching element circuit. The directional control valve can be actuated electrically or magnetically. Furthermore, an elastic element can be arranged on the directional control valve for passively returning the directional control valve to an initial position.In a configuration with, for example, two check valves, a first check valve can prevent a transfer of working fluid from the first shift element circuit to the second shift element circuit upon actuation of the actuating element for actuating the third shift element of the sub-transmission with three shift elements through the first shift element circuit. When the actuating element for actuating the third shift element of the sub-transmission with three shift elements is actuated through the second shift element circuit, a second check valve can prevent a transfer of working fluid from the second shift element circuit to the first shift element circuit.In this way, an influence of the respective shift element circuit on the respective other shift element circuit when the third shift element of the sub-transmission with three shift elements is actuated can be avoided, for example, by additional working fluid in one shift element circuit. In particular, the shift logic can also comprise multiple directional control valves. For example, the shift logic can comprise two directional control valves, with one directional control valve each connecting the different shift element circuits to the actuating element for actuating the third shift element of the sub-transmission with three shift elements. The directional control valves can, for example, comprise two switching positions.A first switching position can, for example, enable an actuating element of a switching element circuit to be connected to the pump of the switching element circuit, and a second switching position can enable a connection of a switching element circuit to the actuating element for actuating the third switching element of the partial transmission with three switching elements.

[0022] In a preferred embodiment, the pump is connected to a reservoir for the working fluid or to a pressure accumulator via a dual-pressure valve. The dual-pressure valve can be designed as an AND valve and automatically connects the reservoir to the pump and the lifting cylinders. In particular, the low-pressure side of the pump and the lifting cylinders can be automatically connected to the reservoir via the dual-pressure valve. Furthermore, the pump can actuate other switching elements depending on the pressure direction without the need to switch active valves, and the fluid circuit cannot become overpressurized even under temperature fluctuations. In particular, the dual-pressure valve can connect the pump to the reservoir in such a way that pressure can always be built up on the side in the delivery direction, while the side opposite the delivery direction is connected to the reservoir.When using a pressure accumulator, the pressure accumulator can be designed in such a way that the pressure accumulator is just large enough to compensate for volume expansion of the working fluid under temperature fluctuations.

[0023] It is preferred that the at least one consumer comprises a first consumer and a second consumer. In this way, the hydraulic switching element arrangement can actuate different consumers with the aid of the actuating elements.

[0024] Preferably, the first consumer is a transmission comprising a plurality of gears and the second consumer is an additional element of the motor vehicle, in particular a second transmission or a parking brake.

[0025] The invention will be explained below by way of example with reference to the accompanying drawings using preferred embodiments, wherein the features presented below can represent an aspect of the invention both individually and in combination. They show: Fig. 1 a first embodiment of a hydraulic switching element arrangement, Fig. 2 a second embodiment of a hydraulic switching element arrangement, Fig. 3 a third embodiment of a hydraulic switching element arrangement, Fig. 4 a fourth embodiment of a hydraulic switching element arrangement, Fig. 5 a fifth embodiment of a hydraulic switching element arrangement, Fig. 6 a sixth embodiment of a hydraulic switching element arrangement, Fig. 7 a seventh embodiment of a hydraulic switching element arrangement, and Fig. 8 an eighth embodiment of a hydraulic switching element arrangement.

[0026] In the following drawings, the same reference symbols are used for the same components / terms.

[0027] In Fig. 1 shows a hydraulic switching element arrangement 10. The hydraulic switching element arrangement 10 comprises four actuating elements 12a, 12b, 12c, and 12d. Two actuating elements 12a, 12c, and 12b, 12d are each assigned to a sub-transmission of a transmission for a motor vehicle. The actuating elements 12a, 12b are connected to a pump 14 via a valve arrangement, and the actuating elements 12c, 12d are connected to a pump 16 via a valve arrangement. The pumps 14, 16 are designed as reversible variable-displacement pumps and are each driven by a pump drive in the form of an electric motor. Depending on the direction of rotation of the pump drive, the pumps 14, 16 convey the working fluid, for example, hydraulic oil, in a first conveying direction or a second conveying direction opposite to the first conveying direction. Each actuating element 12a, 12b, 12c, 12d forms a shift rail.

[0028] By connecting the actuating elements 12a, 12b to the pump 14 and the actuating elements 12c, 12d to the pump 16, both switching elements of a partial transmission can be controlled simultaneously and independently of one another. The partial transmission assignment of the actuating elements 12a, 12b, 12c, 12d is marked with Roman numerals I and II. The pump 14 is connected in parallel with a reservoir 22 via a dual-pressure valve 18 such that pressure can always be built up in one direction and the other side is connected to the reservoir 22. The pump 16 is connected in parallel with a reservoir 22 via a dual-pressure valve 20 such that pressure can always be built up in one direction and the other side is connected to the reservoir 22. In addition, the fluid circuit can have an overpressure even under temperature fluctuations. The reservoir 22 can be the same reservoir for the working fluid in each case or two different reservoirs.

[0029] The actuating elements 12a, 12b, 12c, and 12d are designed as differential-area gear shifting elements in the form of double-acting hydraulic cylinders and have unequal areas on a piston. A smaller area is found on the rod side and a larger area on the piston side, which can act completely. The piston and the hydraulic cylinder form two pressure chambers, which can be enlarged or reduced by the piston in the actuating element. In a basic position, the actuating elements 12a, 12b, 12c, and 12d have an area ratio of 1:2.

[0030] In this embodiment, the valve arrangement comprises a separate directional control valve 24a, 24b, 24c, 24d for each actuating element 12a, 12b, 12c, 12d. The actuating elements 12a, 12b, 12c, 12d are each connected to the directional control valve 24a, 24b, 24c, 24d such that either the smaller surface or both surfaces of the actuating element 12a, 12b, 12c, 12d are connected to the pump 14, 16. This can be achieved using two switching positions of the directional control valves 24a, 24b, 24c, 24d. In a first switching position, one pressure chamber of the actuating element 12a, 12b, 12c, 12d is connected to the pump 14, 16, and the other pressure chamber is connected to a reservoir 22 for the working fluid. In the second switching position, both pressure chambers are connected to the pump 14, 16.In this way, the actuating elements 12a, 12b, 12c, 12d can each be moved in one direction or the other by the directional control valves 24a, 24b, 24c, 24d, depending on the valve position, in order to actuate the respective sub-gearbox. The first delivery direction or the second delivery direction of the pump 14, 16 determines which actuating element 12a, 12b, 12c, 12d is controlled.

[0031] The directional control valves 24a, 24b, 24c, 24d each have an elastic element in the form of a compression spring, which holds the directional control valve 24a, 24b, 24c, 24d in the first switching position or can transfer the directional control valve 24a, 24b, 24c, 24d from the second switching position to the first switching position.

[0032] Pumps 14, 16 are reversible variable-displacement pumps, each equipped with a lifting cylinder at the first discharge outlet and the second discharge outlet for adjusting the displacement of pumps 14, 16. The displacement is adjusted load-dependently without additional active control elements. As the load increases, the displacement decreases, and vice versa.

[0033] Pump 14, together with directional valves 24a, 24b, dual-pressure valve 18, and the two actuating elements 12a, 12b, forms a first switching element circuit. Pump 16, together with directional valves 24c, 24d, dual-pressure valve 20, and the two actuating elements 12c, 12d, forms a second switching element circuit. The two switching element circuits are not interconnected.

[0034] Fig. 2 shows a hydraulic switching element arrangement 26. In contrast to the hydraulic switching element arrangement 10 from Fig. 1, the valve arrangement comprises directional control valves 28a, 28b, 28c, 28d with three switching positions. In a first switching position, one pressure chamber of the actuating element 12a, 12b, 12c, 12d is connected to the pump 14, 16, and the other pressure chamber is connected to a reservoir 22 for the working fluid. In the second switching position, the respective actuating element 12a, 12b, 12c, 12d is blocked and is therefore not connected to the pump 14, 16. In the third switching position, both pressure chambers are connected to the pump 14, 16.

[0035] In Fig. 3 shows a third embodiment of a hydraulic switching element arrangement 30. The valve arrangement of the hydraulic switching element arrangement 30 comprises two directional valves 32a, 32b. The directional valves 32a, 32b correspond to two directional valves 24a, 24b, 24c, 24d of the Fig. 1, which have been combined. In this way, the actuating element 12a or the actuating element 12b can be actuated with the directional control valve 32a, and the actuating element 12c or the actuating element 12d can be actuated with the directional control valve 32b. This is made possible by the fact that, thanks to the dual-pressure valve arrangement, pressure can only be built up to one actuating element 12a, 12b, 12c, 12d at a time by the pump 14, 16. The directional control valves 32a, 32b each have four switching positions in order to connect the actuating elements 12a, 12b, 12c, 12d to the pump 14, 16 in different ways.

[0036] Fig. 4 shows a fifth embodiment of a hydraulic shift element arrangement 34 for five shift rails, in which one sub-transmission has two shift elements and the other sub-transmission has three shift elements. Here, too, any two actuating elements 12a, 12b, 12c, 12d, 12e of a sub-transmission can be actuated simultaneously. Since only two pumps 14, 16 are provided, an actuating element 12e is actuated by both the one pump 14 and the other pump 16. For this purpose, the valve arrangement has two directional control valves 24f, 24g connected downstream of the pumps 14, 16. In this exemplary embodiment, the relationship applies that the pump direction determines the shift rail to be actuated and a directional control valve 24, 24b, 24c, 24d, 24e; the direction of movement of the shift rail is only partially determined, since the additional directional control valves 24f, 24g introduce a new degree of freedom.The actuating element 24e is therefore selected via the pump direction and optionally via the additional directional control valves 24f, 24g. The actuating direction is further determined via the directional control valves 24a, 24b, 24c, 24d, 24e on the actuating elements 12a, 12b, 12c, 12d, 12e. The two switching element circuits are connected to each other via the actuating element 24e.

[0037] In Fig. 5 shows a fifth embodiment of a hydraulic switching element arrangement 36. In the Fig. 5, the valve arrangement comprises directional control valves 28a, 28b, 28c, 28d, 28e for actuating the respective actuating elements 12a, 12b, 12c, 12d, 12e. The directional control valves 28a, 28b, 28c, 28d, 28e have three switching positions, the second switching position being a blocking position.

[0038] Fig. 6 shows a sixth embodiment of a hydraulic switching element arrangement 38. In the illustrated hydraulic switching element arrangement 36, the pump 14 is connected to the actuating element 12b or to the actuating element 12e with the aid of a switching logic 40. Furthermore, the pump 16 can be connected to the actuating element 12c or to the actuating element 12e with the switching logic. The switching logic 40 is depicted as a black box and can comprise at least one rotary valve, a directional control valve, an OR valve, or a check valve.

[0039] In Fig. Figure 7 shows a seventh embodiment of a hydraulic switching element arrangement 42. The connection of the additional switching element 12e is made possible by means of the check valves 12a, 12b.

[0040] Fig. Figure 8 shows an eighth embodiment of a hydraulic switching element arrangement 46. The hydraulic switching element arrangement 46 comprises a sixth actuating element 12f and a sixth directional control valve 28f. The actuating element 12f can be connected to the other pump outlet. With the aid of the check valves 44c, 44d, the actuating element 12f can be actuated by either the pump 14 or the pump 16.

[0041] In all the Fig. In the embodiments illustrated in Figures 1 to 8, the actuating elements can also actuate two different loads. For example, the load can comprise a first load and a second load, wherein the first load is a transmission comprising multiple gears and the second load is an additional element of the motor vehicle, in particular a second transmission or a parking brake.

[0042] Furthermore, up to eight gears can be shifted with four shift rails, for example, seven forward and one reverse. With five shift rails, a maximum of ten gears can be shifted. More shift rails can also be controlled, as is the case in Fig. 8 is shown. List of reference symbols 10 hydraulic switching element arrangement 12a, 12b, 12c, 12d, 12e, 12f Actuating elements 14 Pump 16 Pump 18 Dual pressure valve 20 dual-pressure valve 22 Reservoir 24a, 24b, 24c, 24d, 24e, 24f, 24g directional control valve 26 hydraulic switching element arrangement 28a, 28b, 28c, 28d, 28e, 28f directional control valve 30 hydraulic switching element arrangement 32a, 32b directional control valve 34 hydraulic switching element arrangement 36 hydraulic switching element arrangement 38 hydraulic switching element arrangement 40 switching logic 42 hydraulic switching element arrangement 44a, 44b, 44c, 44d check valve 46 hydraulic switching element arrangement

Claims

[1] Hydraulic switching element arrangement for the fluidic actuation of at least one consumer of a motor vehicle, preferably a transmission comprising a plurality of gears, in particular a dual-clutch transmission, with at least one pump (14, 16), at least two hydraulic actuating elements (12a, 12b, 12c, 12d, 12e, 12f) for actuating the at least one consumer and at least one valve arrangement for connecting one of the actuating elements (12a, 12b, 12c, 12d, 12e, 12f) to the pump (14, 16), wherein the pump (14, 16) is a reversing pump and comprises a first conveying direction and a second conveying direction opposite to the first conveying direction, wherein the at least two hydraulic actuating elements (12a, 12b, 12c, 12d, 12e, 12f) are each operable in a first actuating direction and in a second actuating direction opposite to the first actuating direction for actuating the at least one consumer, whereby the direction of actuation of the actuating elements can be determined by the valve arrangement, wherein the actuating element (12a, 12b, 12c, 12d, 12e, 12f) to be actuated can be determined by the first conveying direction and second conveying direction of the pump (14, 16), characterized by that two pumps (14, 16), at least two valve arrangements and at least four actuating elements (12a, 12b, 12c, 12d, 12e, 12f) are provided. [2] Hydraulic switching element arrangement according to claim 1, characterized by that the actuating elements (12a, 12b, 12c, 12d, 12e, 12f) are differential area switching elements, preferably differential area gear switching elements, in particular double-acting hydraulic cylinders with different hydraulic effective areas. [3] Hydraulic switching element arrangement according to claim 2, characterized bythat the ratio of the effective surfaces of the actuating elements (12a, 12b, 12c, 12d, 12e, 12f) is 1:5, preferably 1:3, in particular 1:

2. [4] Hydraulic switching element arrangement according to one of claims 1 to 3, characterized by that the valve arrangements comprise at least one directional control valve (24a, 24b, 24c, 24d, 24e, 24f, 24g, 28a, 28b, 28c, 28d, 28f, 32a, 32b). [5] Hydraulic switching element arrangement according to one of claims 1 to 4, characterized by that the pumps (14, 16) are reversible variable displacement pumps. [6] Hydraulic switching element arrangement according to one of claims 1 to 5, characterized by that at least one actuating element (12f, 12g) can be actuated via a switching logic (50) both by a first pump (14) and by a second pump (16) different from the first pump (14). [7] Hydraulic switching element arrangement according to claim 6, characterized bythat the switching logic (40) comprises at least one directional control valve (24f, 24g) or at least one check valve (44a, 44b, 44c, 44d). [8] Hydraulic switching element arrangement according to one of claims 1 to 7, characterized by that the pumps (14, 16) are connected via a two-pressure valve (18, 20) to a reservoir (22) for the working fluid or are connected to a pressure accumulator. [9] Hydraulic switching element arrangement according to one of claims 1 to 7, characterized by that the at least one consumer comprises a first consumer and a second consumer.

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