Hydraulic Pressurizing Medium Supply Assembly for a Mobile Work Machine, and Method

Abstract

A hydraulic pressurizing medium supply assembly has an adjustable axial piston machine. An actuating cylinder is controlled by way of a pilot valve. The pilot valve is actuated by a control installation. The control installation, as input variables, has an actual pressure and/or an actual swivel angle of the adjustable axial piston machine. One or a plurality of the input variables are compared with a matching nominal value and a control value is emitted, or in each case a control value is emitted. The controlling of the input variables is part of a first closed-loop control circuit. An underlying second closed-loop control circuit has an input variable which is based on the control variable or the control variables and serves as a nominal variable. A further input variable of the second closed-loop control circuit is an actual delivery-volume adjustment rate of the axial piston machine.

Claims

1. A hydraulic pressurizing medium supply assembly for an open hydraulic circuit, comprising: a hydro machine; an adjusting mechanism including (i) an actuating cylinder having a set piston configured to adjust a delivery volume of the hydro machine, and (ii) a pilot valve electrically actuatable in a proportional manner, wherein an inflow to and/or an outflow from a control chamber of the actuating cylinder that is limited by the set piston is configured for control via the pilot valve in order for an actuation of the set piston to be impinged with pressurizing medium; and an electronic control which, as input variables, has at least a nominal outlet pressure of the hydro machine and/or a nominal delivery volume or a nominal swivel angle of the hydro machine, and which, as an output variable, has a control variable for the pilot valve, wherein the electronic control has a first closed-loop control circuit for an actual outlet pressure of the hydro machine and/or for an actual delivery volume or an actual swivel angle of the hydro machine, wherein the electronic control, so as to underlie the first closed-loop control circuit, has a second closed-loop control circuit for a delivery-volume adjustment rate or a swivel-angle adjustment rate of the hydro machine, wherein the second closed-loop control circuit, as an input variable, having an actual delivery-volume adjustment rate or an actual swivel-angle adjustment rate of the hydro machine, and, as an output variable, having the control variable for the pilot valve, and wherein the second closed-loop control circuit is supplied a control value from the first closed-loop control circuit in the form of a nominal delivery-volume adjustment rate or a nominal swivel-angle adjustment rate.

2. The hydraulic pressurizing medium supply assembly according to claim 1, wherein: the first closed-loop control circuit is configured for an actual torque of the hydro machine, and a nominal torque and the actual torque are included as the input variables for the electronic control.

3. The hydraulic pressurizing medium supply assembly according to claim 2, wherein: the first closed-loop control circuit emits in each case one control variable for the actual outlet pressure of the hydro machine and/or for the actual delivery volume or the actual swivel angle of the hydro machine and/or for the actual torque of the hydro machine, and the electronic control has an alternating control including a minimum value generator for the emitted control variables.

4. The hydraulic pressurizing medium supply assembly according to claim 3, wherein: the first closed-loop control circuit for the actual outlet pressure of the hydro machine and/or for the actual delivery volume or the actual swivel angle of the hydro machine and/or for the actual torque of the hydro machine includes a further controller having an I-proportion, and the I-proportion, in a case of an inactive controller having the I-proportion or inactive controllers having the I-proportion, is frozen or partially or completely reduced.

5. The hydraulic pressurizing medium supply assembly according to claim 1, wherein a nominal pressure gradient is included as one of the input variables for controlling the actual outlet pressure in the first closed-loop control circuit.

6. The hydraulic pressurizing medium supply assembly according to claim 5, wherein the nominal pressure gradient is adjustable for adapting control dynamics of the hydraulic pressurizing medium supply assembly.

7. The hydraulic pressurizing medium supply assembly according to claim 5, wherein the nominal pressure gradient limits variation of the nominal outlet pressure.

8. The hydraulic pressurizing medium supply assembly according to claim 1, wherein a delivery-volume adjustment rate target or a swivel-angle adjustment rate target is included as one of the input variables for the electronic control that is adjustable for adapting control dynamics of the hydraulic pressurizing medium supply assembly.

9. The hydraulic pressurizing medium supply assembly according to claim 8, wherein: the delivery-volume adjustment rate target or the swivel-angle adjustment rate is supplied to a control element which, as a further input variable, has the control value of the first closed-loop control circuit in the form of the nominal delivery-volume adjustment rate or the nominal swivel-angle adjustment rate, and the control element, as an output variable, emits a final nominal delivery-volume adjustment rate for the second closed-loop control circuit that is limited by the delivery-volume adjustment rate target.

10. The hydraulic pressurizing medium supply assembly according to claim 1, wherein: a highest actual load pressure of consumers which are supplied by the hydraulic pressurizing medium supply assembly is detected as an actual load sensing pressure and is supplied as one of the input variables to the electronic control, a nominal pressure differential is included as one of the input variables for the electronic control, wherein a nominal pressure for the electronic control which is included as one of the input variables for the first closed-loop control circuit is determined from the actual load sensing pressure and the nominal pressure differential, and/or wherein actual load sensing pressures of part of the consumers or of all consumers are detected, and wherein generating a maximum value or prioritizing the actual load sensing pressures takes place in the electronic control.

11. The hydraulic pressurizing medium supply assembly according to claim 1, wherein a filter is included for at least one of the input variables, or for part of the input variables, or for all input variables of the electronic control.

12. The hydraulic pressurizing medium supply assembly according to claim 1, wherein: a, or a respective, amplification factor for the first closed-loop control circuit is included for controlling the actual outlet pressure of the hydro machine and/or for controlling the actual delivery volume of the hydro machine and/or for controlling an actual torque of the hydro machine, and the amplification factor is a function of an actual temperature and/or of an actual rotating speed of the hydro machine and/or of the actual outlet pressure of the hydro machine and/or of a nominal pressure gradient of the hydro machine.

13. The hydraulic pressurizing medium supply assembly according to claim 1, wherein a neutral current of the pilot valve is pre-controlled.

14. The hydraulic pressurizing medium supply assembly according to claim 1, wherein: a valve slide of the pilot valve is actuated in such a manner that the valve slide temporarily or continually carries out an axial oscillating movement, and a frequency and an amplitude of the axial oscillating movement is controllable as a function of the actual outlet pressure.

15. A method of operating a hydraulic pressurizing medium supply assembly, comprising: controlling a pilot valve by way of a first closed-loop control circuit and a second closed-loop control circuit, wherein the hydraulic pressurizing medium supply assembly includes: a hydro machine; an adjusting mechanism including (i) an actuating cylinder having a set piston configured to adjust a delivery volume of the hydro machine, and (ii) the pilot valve electrically actuatable in a proportional manner, wherein an inflow to and/or an outflow from a control chamber of the actuating cylinder that is limited by the set piston is configured for control via the pilot valve in order for an actuation of the set piston to be impinged with pressurizing medium; and an electronic control which, as input variables, has at least a nominal outlet pressure of the hydro machine and/or a nominal delivery volume or a nominal swivel angle of the hydro machine, and which, as an output variable, has a control variable for the pilot valve, wherein the electronic control has the first closed-loop control circuit for an actual outlet pressure of the hydro machine and/or for an actual delivery volume or an actual swivel angle of the hydro machine, wherein the electronic control, so as to underlie the first closed-loop control circuit, has the second closed-loop control circuit for a delivery-volume adjustment rate or a swivel-angle adjustment rate of the hydro machine, wherein the second closed-loop control circuit, as an input variable, having an actual delivery-volume adjustment rate or an actual swivel-angle adjustment rate of the hydro machine, and, as an output variable, having the control variable for the pilot valve, and wherein the second closed-loop control circuit is supplied a control value from the first closed-loop control circuit in the form of a nominal delivery-volume adjustment rate or a nominal swivel-angle adjustment rate.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0042] Preferred exemplary embodiments of the disclosure will be explained in more detail hereunder by means of schematic drawings in which:

[0043] FIG. 1 in a schematic illustration shows a hydraulic pressurizing medium supply assembly according to a first exemplary embodiment;

[0044] FIG. 2 in a schematic illustration shows a control for the pressurizing medium supply assembly from FIG. 1;

[0045] FIG. 3 in a schematic illustration shows a control for the pressurizing medium supply assembly from FIG. 1, according to a further exemplary embodiment;

[0046] FIGS. 4 and 5 in a schematic illustration show in each case a determination of amplification factors of a controller according to one exemplary embodiment;

[0047] FIGS. 6a and 6b show a crawler excavator, and in a schematic illustration a pressurizing medium supply assembly for a crawler excavator;

[0048] FIGS. 7a and 7b show a telehoist load lugger, and in a schematic illustration a pressurizing medium supply assembly for a telehoist load lugger;

[0049] FIGS. 8a and 8b show a compact excavator, and in a schematic illustration a pressurizing medium supply assembly for a compact excavator; and

[0050] FIGS. 9a and 9b show a cooling/ventilating system, and in a schematic illustration a pressurizing medium supply assembly for a cooling/ventilating system.

DETAILED DESCRIPTION

[0051] Shown according to FIG. 1 is a hydraulic pressurizing medium supply assembly 1 which has a hydro machine in the form of an axial piston machine 2. Said axial piston machine 2 has a swivel cradle for adjusting a delivery volume. The axial piston machine 2 can be used as a pump as well as a motor. The axial piston machine 2 is driven by a drive unit 4 which can be, for example, an internal combustion engine such as, for example, a diesel engine, or an electric motor. The axial piston machine 2 is connected to the drive unit 4 by way of a drive shaft 6. A rotating speed 8 of the drive shaft 6 can be detected by way of means not illustrated, for example by way of a rotating speed sensor, and be supplied to a control of the pressurizing medium supply assembly 1. An adjusting mechanism 12 is provided for the axial piston machine 2. Said adjusting mechanism 12 has a pilot valve 14. The valve slide of said pilot valve 14 is electrically actuatable in a proportional manner by way of an actuator 16. To this end, the actuator 16 is supplied a control variable 18 by a control 20. The valve slide of the pilot valve 14 in the direction of an initial position is impinged with a spring force of a valve spring 22. The spring force acts counter to the actuating force of the actuator 16.

[0052] The axial piston machine 2 at the outlet side is connected to a pressure line 24 which in turn is connected to a main control valve 26 or a valve block. The supply of pressurizing medium between the axial piston machine 2 and one or a plurality of consumers can be controlled by way of said main control valve 26. A control line 28 which is connected to a pressure connector P of the pilot valve 14 branches off from the pressure line 24. The control line 28 is configured, for example, in a housing of the axial piston machine 2. The pilot valve 14 furthermore has a tank connector T which by way of a tank line 30 is connected to a tank. The pilot valve 14 moreover has an operation connector A which is connected to a control chamber 32 of an actuating cylinder 34. The control chamber 32 herein is delimited by a set piston 36 of the actuating cylinder. A swash plate of the axial piston machine 2 can in this instance be adjusted by way of the set piston 36. A displacement path of the set piston 36 is detected by way of a displacement transducer 38. Alternatively or additionally, a swivel angle of the swivel cradle of the axial piston machine 2 is detected on a pivot axle of the swivel cradle by way of a rotary magnetic sensor. The actual delivery volume or the actual displacement volume of the axial piston machine 2 can in this instance be determined by way of the detected path. The actual delivery volume 40 is then reported to the control 20. The pressure connector P in the initial position of the valve slide of the pilot valve 14 is connected to the operation connector A, and the tank connector T is blocked. When the valve slide is impinged with the actuating force of the actuator 16, the valve slide, proceeding from the initial position thereof, is moved in the direction of switched positions in which the pressure connector P is blocked and the operation connector A is connected to the tank connector T. The set piston 36 in the initial position of the valve slide of the pilot valve 14 is thus impinged with pressurizing medium from the pressure line 24. Furthermore provided in the adjusting mechanism 12 is a cylinder 42. The latter has a set piston 44 which engages on the swash plate of the axial piston machine 2. The set piston 44 delimits a control chamber 46 which is connected to the pressure line 24. The set piston 44 by way of pressurizing medium of the control chamber 46 and by way of the spring force of a spring 48 is impinged in such a manner that said set piston 44 loads the swash plate in the direction of increasing the delivery volume.

[0053] Furthermore provided is a pressure sensor 50 by way of which the pressure in the pressure line 24 is detected and reported to the control 20, wherein the pressure is an actual outlet pressure 52. Moreover provided is a pressure sensor 54 which detects the highest actual load pressure (actual LS pressure) 56, the latter being transmitted to the control 20.

[0054] A control 57 by way of a CAN interface 58 is connected to the control 20, in particular for transmitting the actual rotating speed to the control 20. It is also conceivable for the actual rotating speed 8 to be supplied directly to the control 20.

[0055] The position of the swash plate of the axial piston machine 2 in the use of the pressurizing medium supply assembly 1 is controlled by way of the pilot valve 14 and the set piston 36. A conveyed volumetric flow of the axial piston machine 2 is proportional to the position of the swash plate. The adjusting piston 44 pre-loaded by the spring 48, or the counter piston, is at all times impinged by the actual outlet pressure or the pump pressure. In a non-rotating axial piston machine 2 and an adjusting mechanism 12 without pressure the swash plate by the spring 48 is kept in a position of +100 percent. In a driven axial piston machine 2 and a non-energized actuator 16 of the pilot valve 14, the swash plate pivots to a zero-stroke pressure, since the set piston 36 is impinged with pressurizing medium of the pressure line 24. An equilibrium between an actual outlet pressure at the set piston 36 and the spring force of the spring 48 is established at a predetermined pressure or pressure range, for example between 8 to 12 bar. Said zero-stroke operation is assumed, for example, in the event of de-energized electronics or a de-energized control 20. The actuation of the pilot valve 14 takes place by way of the control 20, the latter being, for example, preferably digital electronics, alternatively analog electronics. The control 20 processes the required control signals, as is explained in more detail hereunder.

[0056] FIG. 2 schematically shows a functioning mode of the control 20. The latter has a first closed-loop control circuit 60 and a second closed-loop control circuit 62. The first closed-loop control circuit 60 has a controller 64 for a swivel angle of the swash plate of the axial piston machine 2 from FIG. 1, a controller 66 for the outlet pressure of the axial piston machine 2, and a controller 68 for a torque of the axial piston machine 2. The controller 64 as input variables has a nominal delivery volume 70 and the actual delivery volume 40. A control variable 72 is provided as an output variable. The controller 66 as input variables has a nominal outlet pressure 74 and the actual outlet pressure 52. A control variable 75 is provided as an output variable. The controller 68 as input variables has an actual torque 76 or a nominal torque. The actual torque which in turn is able to be determined by means of a characteristics map by way of the actual rotating speed 8 is provided as a further input variable. A control variable 78 is provided as an output variable for the controller 68. In the respective controllers 64 to 68, the input variables are in each case supplied to a control element in the form of a PID controller.

[0057] The control variables 72, 75 and 78 are supplied to a minimum value generator 80. The latter ensures that only the controller 72, 75 or 78 assigned to the desired operating point is automatically active. Either the outlet pressure, the torque, or the delivery volume herein is precisely controlled, wherein the respective two other variables are below a predefined nominal value. An output signal of the minimum value generator 80 in this instance is a nominal value in the form of a delivery-volume adjustment rate or a nominal delivery-volume adjustment rate 82.

[0058] The latter in this instance is an input variable for the second underlying closed-loop control circuit 62. The derivation of the actual delivery volume 40 is a further input variable of the second closed-loop control circuit 62, said further input variables in this instance being an actual delivery-volume adjustment rate 84. The input variables 82 and 84 for the second closed-loop control circuit 62 are then supplied to a control element in the form of a PID element 86. The latter then emits the control variable 18 for the pilot valve 14 from FIG. 1.

[0059] According to FIG. 3, a further embodiment for the control 20 from FIG. 1 is shown. Said further embodiment has a controller 88 for the delivery volume of the axial piston machine 2, cf also FIG. 1. Furthermore provided are a controller 90 for the outlet pressure of the axial piston machine 2 and a controller 92 for the torque of the axial piston machine 2. This forms part of a first closed-loop control circuit 94. Furthermore provided so as to underlie the first closed-loop control circuit is a second closed-loop control circuit 96 for the delivery-volume adjustment rate of the axial piston machine 2.

[0060] The controller 88 has a control element 98 in the form of a P-element. The nominal delivery volume 70 and the actual delivery volume 40 are provided as input variables. The actual delivery volume 40 is supplied to the control element 98 by way of a filter in the form of a PT1 filter. The control variable 72 is provided as the output variable at the output side of the controller 88, said control variable 72 being supplied to the minimum value generator 80.

[0061] The controller 90 as input variables has the actual outlet pressure 52, the actual LS pressure 56, a nominal pressure differential 100 and a nominal pressure gradient 102. The actual LS pressure 56 and the nominal pressure differential 100 by way of a summing element 104 are linked so as to form a nominal outlet pressure. The nominal outlet pressure is then supplied to a control element 106 in the form of an inverted PT1 element which estimates a predicted signal profile. The nominal outlet pressure is then furthermore supplied to a control element 108 which has the nominal pressure gradient 102 as a further input variable. The nominal pressure gradient 102 then predefines the maximum potential gradient which is to be provided. The nominal outlet pressure by way of the control element 108 is then influenced by the predefined nominal pressure gradient 102 in such a manner that the dynamic characteristic of the pressurizing medium supply assembly 1 from FIG. 1 can be controlled by the nominal pressure gradient 102. For example, the influence can be such that the higher the nominal pressure gradient 102 the more rapidly the swash plate of the axial piston machine 2 is able to be adjusted. It conversely applies in this instance that the smaller the nominal pressure gradient the slower the swash plate of the axial piston machine 2 is adjusted. After the control element 108, the nominal outlet pressure is then supplied to a control element 110 in the form of a PID element. The actual outlet pressure 52 is then provided as a further input variable for the control element 110. The control variable 75 which is supplied to the minimum value generator 80 results as the output variable of the control element 110.

[0062] The actual LS pressure 56 of the controller 90 prior to the summing element 104 is supplied to a filter 112 which is a variable PT1 filter. The same applies to the actual outlet pressure which prior to the control element 110 is likewise supplied to a filter 114 in the form of a variable PT1 filter. The filters 112 and 114 have variable, in particular pressure-dependent, filter coefficients, as is explained in more detail above.

[0063] The controller 92 as input variables has the actual rotating speed 8, the actual delivery volume 40, the actual outlet pressure 52, and a nominal torque 116. The input variables are supplied to a control element 118 in the form of a P-element. The control variable 78 which is supplied to the minimum value generator 80 is provided as an output variable for the control element 118. A control element 120 which, as in the case of the control element 106, is an inverted PT1 filter, is provided for the control variable 78 after the control element 118. Furthermore, the actual rotating speed, the actual delivery volume 40, and the actual outlet pressure 8, prior to being supplied to the control element 118, are supplied to a control element 122. The latter serves for calculating an actual torque 124 based on the actual rotating speed 8, on the actual delivery volume 40, and the actual outlet pressure 8. The calculation is performed by means of a characteristics map of the control element 122. The characteristics map is a function of the actual outlet pressure 52 which is supplied to the control element 122. The actual delivery volume 40 is furthermore supplied to the control element 122. The characteristics map in this instance can alternatively or additionally be a function of the actual delivery volume 40. In other words, the actual torque 124 is formed from the actual rotating speed 8 and from the actual outlet pressure 52 and/or from the actual delivery volume 40. The actual torque 124, prior to reaching the control element 118, is then subsequently supplied to a filter 126 in the form of a PT1 element.

[0064] Furthermore, the actual delivery volume 40, prior to being supplied to the control element 98, is supplied to a filter 99 in the form of a PT1 element.

[0065] The minimum value generator 80 from the control variables 72, 75 and 78 forms the nominal delivery-volume adjustment rate 82. The latter is supplied to a control element 128. The dynamic characteristic of the pressurizing medium supply assembly 1 can be influenced by said control element 128. To this end, a delivery-volume adjustment rate target 130, which is adjustable, is provided as a further input variable for the control element 128. For example, the nominal delivery-volume adjustment rate 82 which is emitted from the minimum value generator 80 can be limited and/or influenced in such a manner by way of the delivery-volume adjustment rate target 130 that the greater the variable 130 the faster the swash plate of the axial piston machine 2 can be pivoted and vice versa. The dynamic characteristic of the pressurizing medium supply assembly 1 can thus be influenced by adjusting the delivery-volume adjustment rate target 130 and/or by adjusting the nominal pressure gradient 102. On account thereof, the pressurizing medium supply assembly 1 can be adapted in a simple and cost-effective manner to different work machines and/or to different application conditions and/or to different specific applications, for example.

[0066] After the control element 128, the final nominal delivery-volume adjustment rate 132 as an input variable is supplied to the second closed-loop control circuit 96. The latter has a control element 134 in the form of a PI-element. The actual delivery-volume adjustment rate 84 is provided as a further input variable for the control element 134. Said actual delivery-volume adjustment rate 84 is based on the actual delivery volume 40 which is derived in a control element 136. Thereafter, the derivation, thus the actual delivery-volume adjustment rate, is supplied to a filter 138 in the form of a PT1 filter. Prior to the actual variable 84 being supplied to the control element 134, a control element 140 in the form of an inverted PT1 filter is subsequently provided. The control element 134 of the second closed-loop control circuit 96 has the control variable 18 as the output variable for the pilot valve 14 from FIG. 1. Said control variable 18 is supplied to a summing element 142. A preliminary control value 144 is provided as a further input variable for the summing element 142. Said preliminary control value 144 is an output variable of a control element 150 which has the actual outlet pressure 52 as the input variable. The preliminary control value 144 is then determined based on the actual outlet pressure 52. The summing element 142 then links the control variable 18 and the preliminary control value 144, a neutral current of the pilot valve being pre-controlled therewith. A pressure-dependent target of a neutral signal value for the pilot valve 14 from FIG. 1 is thus established. This has the advantage that the control 20 is relieved in terms of said control task. A final control variable 146 for the pilot valve 14 is then provided as an output variable of the summing element 142.

[0067] It is conceivable that a control element which is not illustrated and which has the control variable 146 as the input variable is disposed downstream of the summing element 142. Said control variable 146 is superimposed with a low-frequency signal by the control element, so that the valve slide of the pilot valve 14 is continually in axial oscillating movement so as to avoid seizing of the valve slide. The final control variable for the pilot valve 14 is in this instance provided as the output variable of the control element. The superimposition by the low-frequency signal can be referred to as dithering. The object of dithering is to reduce the hysteresis of the pilot valve 14 in that a minor movement of the valve slide is maintained. The movement herein must not become excessively large so as to avoid effects on the system (for example, the pilot valve 14 oscillates excessively such that said oscillation is reflected in the swivel angle or the pressure). The dithering (frequency and amplitude) is optimized in such a manner that the hysteresis is minimized and the system is not excited. The smaller the frequency and the larger the amplitude the better the valve slide can be kept in movement. However, a small frequency leads to a large periodic duration of the superimposed sinus signal. The problem that said period may run so as to be specifically counter to the nominal signal is created on account thereof. A delayed reaction is obtained when the superimposed dithering runs in the direction other than the nominal signal, which can be disadvantageous in terms of controlling the pump. There is however the possibility for the dithering frequency to be increased and/or the amplitude to be reduced at comparatively high pressures, since better lubrication takes place by virtue of the pressure and the hysteresis of the pilot valve 14 decreases. The influence of out-of-phase dithering is also reduced on account thereof, and the control dynamic characteristic is enhanced.

[0068] FIG. 4 schematically shows a control parameter for the control 20 which is dependent on the operating point. Said control parameter in an exemplary manner is an amplification factor Kp of the controller 90 for the outlet pressure of the axial piston machine 2. The amplification factor Kp is supplied to the control 20 by way of the control element 110, for example. According to FIG. 4, the amplification factor Kp as a function of a temperature 154 of a pressurizing medium of the pressurizing medium supply assembly 1 can be calculated by way of a control element 152. The temperature is detected from the pressurizing medium in the pressure line 24 by way of a sensor, for example. The amplification factor Kp in this instance is determined by way of a characteristics map, for example. Alternatively or additionally, the amplification factor by way of a control element 156 can be a function of the actual rotating speed 8. The amplification factor Kp herein is likewise determined by way of a characteristics map. Alternatively or additionally, a control element 158 by way of which the amplification factor Kp is able to be determined by way of the actual outlet pressure 52 is provided, wherein this can likewise take place by way of a characteristics map. Alternatively or additionally, the amplification factor Kp based on the nominal pressure gradient 102 can furthermore be determined by way of a control element 160. The nominal pressure gradient 102 herein can be derived from the nominal outlet pressure 74 by way of a control element 162. If the amplification factor Kp is determined by way of a plurality of control elements 152, 156, 158, 160, said amplification factor Kp can be linked by way of a respective control element 164 at the outlet side and then be finally emitted as an output variable of the control element 164.

[0069] According to FIG. 5, the amplification factor Kp, alternatively or additionally to the control elements 152, 156, 158, 160 shown in FIG. 4, can be determined by way of the actual outlet pressure 52. To this end, a control element 166 in which the amplification factor Kp in this instance based on the actual outlet pressure 52 is determined by way of a characteristics map. In this case, the amplification factor Kp increases the higher the actual outlet pressure. The amplification factor Kp, alternatively or additionally to the controller 90, can also be used for the controller 88 and/or 92.

[0070] It is also conceivable that a temporal adaptation of the running times of at least one signal, or of part of the signals, or of all signals of the closed-loop control circuits 94 and 96 from FIG. 3 is provided, wherein a phasing of the signal or signals is in particular adaptable. This can take place by way of the control element 106 and/or 120, for example.

[0071] The preliminary control value 144 in the control element 150 can preferably be determined based on a model while taking into consideration flow forces at the pilot valve 14 and/or a magnet characteristic of the actuator 16 and/or of a control edge characteristic of the valve slide of the pilot valve 14 and/or a spring stiffness of the valve spring 22.

[0072] Shown according to FIG. 6a is a crawler excavator which according to FIG. 6b has a pressurizing medium supply assembly, see FIG. 1. Said crawler excavator has the axial piston machine 2 which is driven by the drive unit 4 in the form of a diesel engine. The supply of pressurizing medium to the hydro cylinders 168 and 170, to the hydro machines 172, 174 for moving the crawling excavator, and to a hydraulic auxiliary drive 176 is controlled by way of the main control valve 26. The crawler excavator herein has various input means 178 for an operator, said input means 178 being connected to a CAN bus 180. Pressure sensors 182, 184 are furthermore connected to the CAN bus 180. Said pressure sensors 182, 184 detect the actual outlet pressure of the axial piston machine 2. A safety valve is in each case provided at the inlet side of the hydro cylinders 168, 170, said safety valves safeguarding the hydro cylinders 168, 170 in the event of a breakage of an inlet line. Required input variables are detected by way of the control 20, as explained above, and the pilot valve 14 is in particular controlled by way of said control 20. Moreover, the main control valve 26 is controlled as a function of the signals of the input means 178 detected by way of the CAN bus 180.

[0073] FIG. 7a shows a telehandler having a the pressurizing medium supply assembly according to FIG. 7b. Said telehandler has two axial piston machines 2 and 186 which are driven by the drive unit 4 in the form of a diesel engine by way of a common drive shaft. Pilot valves of the axial piston machine 2, 186 are controlled by way of the control 20, as has been explained above. The axial piston machine 186 serves for supplying pressurizing medium to a wheel brake 188, to a steering system 190, and to a pilot fluid supply 192. The pilot fluid supply 192 is provided for the main control valve 26, or the main control valve block, respectively. The supply of pressurizing medium to hydro cylinders 168, 170, 194, 196 is controlled by way of said main control valve block. A hydro machine 198 used herein and the hydraulic auxiliary motor 176 are furthermore controlled by way of the main control valve 26. Input means 178 which by way of the CAN bus 180 are connected to the control 20, for example, are provided according to the exemplary embodiment in FIGS. 6a and 6b. A communication installation 200 is furthermore provided in order to communicate with a server and/or with a computer in a wireless manner, for example by radio or WiFi. For example, input variables for the control 20 can be adapted and/or a software can be upgraded or updated by way of the communication installation 200. Moreover, it is possible for data which includes information pertaining to a state of the pressurizing medium supply assembly 1 to be sent by way of the communication installation 200.

[0074] According to FIG. 8a, a compact excavator having a pressurizing medium supply assembly according to FIG. 8b is shown. The axial piston machine 2 which is driven by the drive unit 4 in the form of a diesel engine can be seen herein. Furthermore shown is the control 20 which is connected to a pressure sensor 202, for example, which detects the actual outlet pressure of the axial piston machine 2. The control 20 is moreover connected to a pressure sensor 204 which by way of the main control valve 26, or the main control block, respectively, detects the highest load pressure. The control 20 is furthermore connected to a displacement transducer 206 for the swivel angle of the swash plate of the axial piston machine 2. The pilot valve 14 is moreover connected to the control 20. Five hydro cylinders 208 are connected to the main control valve 26. Furthermore connected are the hydro machines 172, 174, and the hydraulic auxiliary motor 176. The pilot fluid supply 192 can optionally be provided. Input means 178 can hydraulically control the main control valve 26, for example, or be connected to the pressurizing medium supply assembly by way of the CAN bus 180.

[0075] The application potential of the pressurizing medium supply assembly 1 from FIG. 1 for a ventilation system is shown according to FIGS. 9a and 9b. According to FIG. 9a, the axial piston machine 2 which is driven by way of the drive unit 4, for example in the form of a diesel engine, is provided. The actual outlet pressure of the axial piston machine 2 is detected by way of the pressure sensor 50. A fan motor in the form of a hydro machine 210 is driven by way of the axial piston machine 2. Said hydro machine 210 in turn drives fan blades 212 in order for an air stream to be generated. Coolant of a cooling circuit is then cooled by way of the air stream. The pilot valve 14 can be controlled by way of the control 20. One or a plurality of temperatures detected by way of sensors can be supplied to the control 20 by way of the CAN bus 180, for example. The temperature can be, for example, a temperature of the coolant in a coolant line 214 and/or a temperature of the drive unit 4 and/or a temperature of the pressurizing medium. It is also conceivable for further input variables to be supplied to the control 20, as has been explained above.