Compacting vehicle, wherein a travel drive and a vibration unit are supplied with pressure fluid from a common supply point

Abstract

The invention relates to a compacting vehicle (10) having at least one roller (20) for dynamically compacting a ground (11), wherein the compacting vehicle (10) has a travel drive connection to at least one first hydraulic machine (21), and wherein at least one roller (20) is assigned a vibration unit (30), which has a drive connection to an associated second hydraulic machine (31). According to the invention, the at least one first, the at least one second and a third hydraulic machine (21; 31; 41) are each connected, on the high pressure side, to a common supply point (50) and, on the low pressure side, to a common tank, such that they form an open hydraulic circuit; the mentioned connections to the supply point can each be continuously opened such that a high pressure in the at least one first, in the at least one second and in the third hydraulic machine (21; 31; 41) is substantially equal to the pressure at the supply point (50), the at least one first; the at least one second and the third hydraulic machine (21; 31; 41) each have an adjustable displacement volume; and the displacement volume of the at least one second hydraulic machine (31) can be set such that the desired vibration intensity (81) results while the mentioned connections to the supply point (50) are open. (Figure 1)

Description

[0001] The invention relates to a compaction vehicle according to the preamble of claim 1.

[0002] EP 1342849 B1 discloses a compaction vehicle in the form of a road roller. The compaction vehicle has two circular cylindrical rollers that roll over a subsoil to smooth it. At least one of the rollers can be equipped with a vibration unit to improve subsoil compaction.

[0003] Another compaction vehicle is known from DE 10 2010 056 531 A1, which shows the motors that drive the roller and the vibration unit. A hydraulic motor is specified as a possible embodiment of the aforementioned motors.

[0004] Another compaction vehicle is known from DE 10 2013 227 007.

[0005] A wide variety of such compaction vehicles are known from the prior art, and these can comprise up to six hydraulic motors. It would now be obvious to supply all of these hydraulic motors with pressurized fluid in an open hydraulic circuit using a common pump, with the direction of rotation and speed of each hydraulic motor being controlled by an assigned valve. However, the throttling losses arising in such valves are very high. For this reason, the hydraulic motors are usually operated in a closed hydraulic circuit, with the speed and direction of rotation being adjusted by adjusting the displacement of the respective hydraulic machines. However, it is not possible to connect an unlimited number of hydraulic motors to a common pump in a closed hydraulic circuit.Typically, a maximum of two hydraulic motors can be connected to a common pump, and only if the two hydraulic motors are subject to comparable loads. Accordingly, a compaction vehicle constructed in this way has several pumps, each operated by a few associated hydraulic motors in a closed hydraulic circuit.

[0006] The invention seeks to create a compaction vehicle with a hydraulic drive, allowing any configuration of hydraulic motors or first and second hydraulic machines. Ideally, only a single pump or third hydraulic machine should be used to supply all hydraulic motors or first and second hydraulic machines with pressurized fluid. Valves and the associated throttling losses in the primary energy transmission from the third hydraulic machine to the first or second hydraulic machines should be eliminated as completely as possible.

[0007] According to claim 1, it is proposed that the at least one first, the at least one second and the third hydraulic machines are each connected on the high-pressure side to a common supply point and on the low-pressure side to a common tank, so that they form an open hydraulic circuit, wherein the said connection to the supply point can be continuously released in such a way that a high pressure in the at least one first, in the at least one second and in the third hydraulic machines is substantially equal to the pressure at the supply point, wherein the at least one first, the at least one second and the third hydraulic machines each have an adjustable displacement volume, wherein a displacement volume of the at least one second hydraulic machine is adjustable in such a way that the desired vibration intensity is achieved while the said connections to the supply point are released.

[0008] The vibration unit preferably comprises at least one mass rotatable relative to a rotational axis, the center of gravity of which is arranged away from said rotational axis, wherein the at least one mass is connected to an associated second hydraulic machine for rotational drive. Preferably, several masses are provided, the eccentricity and direction of rotation of which are coordinated to produce an oscillating acceleration force that is oriented substantially perpendicular to the ground. The vibration unit is preferably arranged inside the respective roller.

[0009] A continuously releasable connection should be understood, on the one hand, as a connection that is permanently open and most preferably has a constant, low flow resistance. However, the continuously releasable connection can also be formed by a switching valve that has at least two discrete switching positions, with the connection having a constant, low flow resistance in each switching position. There can be a switching position that is designed as a blocking position so that the associated hydraulic machine is hydraulically clamped in a rotationally fixed manner. The switching valve can, for example, be used to reverse the direction of rotation of the associated hydraulic machine without the hydraulic machine having to be adjustable beyond a displacement volume of zero. There should precisely be no continuously adjustable valve, as is otherwise usual with a hydraulic motor in an open circuit.

[0010] The supply point is preferably a space filled with pressurized fluid, with essentially the same pressure prevailing throughout the entire space. The supply point is preferably formed by an elongated line. The supply point is preferably not a small, point-like location, but rather has a spatial extension.

[0011] A hydraulic machine is understood to be a machine that converts hydraulic power into mechanical power in the form of rotary motion and vice versa. The hydraulic machines mentioned are preferably axial piston machines. The at least one first and / or the at least one second hydraulic machine and the third hydraulic machine are preferably designed with a bent-axis design. This means that all hydraulic machines can be designed such that they are adjustable beyond zero displacement. The bent-axis design otherwise preferred for hydraulic motors is not preferred for this very reason. The open hydraulic circuit mentioned is preferably operated with a liquid pressurized fluid, with hydraulic oil being used most preferably.

[0012] Advantageous further developments and improvements of the invention are specified in the dependent claims.

[0013] It can be provided that the direction of rotation of the at least one first hydraulic machine can be reversed by adjusting the respective displacement volume, while the flow direction of the respective first hydraulic machine remains constant. The displacement volume of the at least one first hydraulic machine can therefore be adjusted beyond zero displacement volume. This allows the direction of travel of the compaction vehicle to be reversed while the vibration drive continues to run unchanged. The back and forth movement of the compaction vehicle, which is frequently encountered when compacting a road surface while the vibration unit continues to run, can therefore be carried out without problems. The change in direction of travel can take place very smoothly. The direction of rotation of the at least one second hydraulic machine can also be reversible by adjusting the displacement volume.Depending on the design of the vibration unit, different vibration properties can be achieved.

[0014] It can be provided that the supply point is connected to a hydraulic accumulator. For the controllability of the entire hydraulic drive, it is particularly advantageous if the pressure at the supply point essentially remains constant at a predetermined value. This predetermined value can change if the desired operating state changes, i.e. it is only temporarily constant as long as the desired operating state does not change. As will be explained below, this pressure value is preferably set by adjusting the displacement volume of the third hydraulic machine. However, this control reacts comparatively sluggishly if the pressure at the supply point changes abruptly due to rapidly changing external loads on the at least one first or the at least one second hydraulic machine.The hydraulic accumulator can mitigate such sudden changes in pressure at the supply point so that the pressure control by the third hydraulic machine operates sufficiently quickly. The filling and discharging speed of the hydraulic accumulator is preferably adjusted so that the entire compaction vehicle has optimally low energy consumption. A valve unit can be assigned to the hydraulic accumulator, which controls the exchange of pressurized fluid between the supply point and the hydraulic accumulator depending on the pressure at the supply point. This is intended, in particular, to prevent the hydraulic accumulator from becoming overfilled. Furthermore, it is intended to prevent an empty hydraulic accumulator from disrupting the function of the hydraulic drive.

[0015] Two or more rollers may be provided, each connected to its own first hydraulic machine for rotational drive, with all first and second hydraulic machines connected to the same supply point and the same tank. Each roller is preferably assigned a separate first hydraulic machine. Each roller is preferably assigned its own vibration unit with its own second hydraulic machine. In this case, the present invention is particularly useful because, compared to a conventional compaction vehicle, a particularly large number of pumps or third hydraulic machines can be dispensed with.

[0016] It can be provided that the supply point is connected to a pressure sensor, whereby the displacement volume of at least one second hydraulic machine can be adjusted depending on the pressure measured by the pressure sensor and the desired vibration intensity. The corresponding relationship is preferably stored in a characteristic map. The adjustment preferably takes place in the form of a control or pilot control. This eliminates the need for expensive controllers. The achievable positioning accuracy is often sufficient for a vibration unit.

[0017] It can be provided that the supply point is connected to a pressure sensor, whereby the displacement volume of the third hydraulic machine can be adjusted depending on the pressure measured by the pressure sensor. In a conventional hydraulic drive, a pressure control system operating with a hydraulic pressure regulator would be preferred at this point, as this has proven itself and is very reliable. The hydraulic pressure control system can also cope well with the strong pressure fluctuations often encountered in a hydraulic drive. Nevertheless, within the scope of the present invention, electronic pressure control is preferred, even though this requires a high level of computing power to be installed in the control device in order to achieve a control quality comparable to that of conventional hydraulic pressure control.As can be seen from the method explained below, the setpoint of this control system should be very flexibly adapted to the current operating conditions of the compaction vehicle. This is much easier to achieve with electronic pressure control than with hydraulic pressure control. Furthermore, the proposed pressure sensor can be used in the adjustment of the at least one first and at least one second hydraulic machine, whereby this represents a preferred embodiment of the invention. The single pressure sensor can thus be used for three different purposes.

[0018] A first control loop can be provided, the actual value of which is the pressure measured by the pressure sensor, and the manipulated variable of which is the displacement volume of the third hydraulic machine. Subsequently, the pressure at the supply point is regulated to a value specified by a target value. This pressure is thus no longer dependent on the driving resistance that the compaction vehicle must overcome during travel. It is also not dependent on the set vibration intensity or the drive torque of the at least one second hydraulic machine.

[0019] The corresponding target value is preferably selected such that the desired speed can be achieved at the at least one first hydraulic machine, wherein said speed determines the travel speed of the compaction vehicle. The aim is to keep the pressure at the supply point as low as possible in order to save energy. The speed of the at least one first hydraulic machine is preferably measured at least indirectly using a first speed sensor. It should be noted that all rollers typically rotate at the same peripheral speed, which is equal to the travel speed of the compaction vehicle. Accordingly, a single first speed sensor is normally sufficient. If slippage on the rollers is to be feared, several first speed sensors are preferably used to detect this slippage.The speed of the third hydraulic machine is preferably measured with a third speed sensor, the corresponding measured value being taken into account in the said control, in particular when determining the setpoint of the first control loop.

[0020] Protection is accordingly claimed for a method wherein a target value of the first control loop is selected depending on the desired travel speed of the compaction vehicle and / or depending on the desired vibration intensity. With regard to the travel speed, for example, the drive torque of the rollers required to achieve the travel speed can be determined. The maximum displacement volume of the first hydraulic machine in turn determines the minimum required pressure at the supply point. A similar procedure can be used with regard to the vibration intensity. The highest of the pressures determined in this way is decisive for determining the target value. The setting of the target value of the first control loop preferably takes place in the form of a control system, i.e. without feedback.

[0021] It can be provided that at least one second hydraulic machine is assigned a second speed sensor, by means of which a speed of the respective second hydraulic machine can be measured, wherein a second control loop is provided, the actual variable of which is a measured value of the second speed sensor, the manipulated variable of which is the displacement volume of the respective second hydraulic machine. This allows the vibration intensity to be adjusted very precisely. With changing substrates with different damping behavior, the vibration intensity does not fluctuate substantially. The target variable of the second control loop corresponds to the speed desired on the respective second hydraulic motor. This, in turn, is proportional to the desired vibration intensity. The second control loop is preferably combined with the characteristic map explained above, which then operates as a so-called feedforward control.

[0022] The supply point may be formed by a line that extends at least 50% of the compaction vehicle's length in the direction of travel. This allows all hydraulic machines of the compaction vehicle to be easily connected to the supply point. It is understood that the free cross-sectional area of ​​said line is preferably selected to be large enough to ensure essentially the same pressure at all points along the line.

[0023] It can be provided that the at least one first hydraulic machine, the at least one second hydraulic machine, and / or the third hydraulic machine each comprise an actuating device configured to adjust the displacement volume of the respective hydraulic machine substantially proportional to an actuating signal. Said actuating device preferably operates hydraulically. It preferably comprises an actuating cylinder, a control valve, and a position sensor. Preferably, it comprises a fourth control loop, which, using the aforementioned components, adjusts the displacement volume to a target value predetermined by the actuating signal.

[0024] It can be provided that at least one first hydraulic machine is assigned a third control loop, the actual variable of which is the speed of the respective first hydraulic machine, the manipulated variable of which is the displacement volume of the respective first hydraulic machine. If several first hydraulic machines are provided, their displacement volumes are set either equally or in a fixed, predetermined ratio. Thus, in this case too, only a single third control loop is provided. This allows the travel speed to be set particularly precisely. Alternatively, it is conceivable to set the displacement volume of at least one first hydraulic machine by means of a further characteristic map which has the desired travel speed and the measured value of the pressure sensor at the supply point as input variables.

[0025] It is understood that the features mentioned above and those to be explained below can be used not only in the combination specified in each case, but also in other combinations or on their own, without departing from the scope of the present invention.

[0026] The invention is explained in more detail below with reference to the accompanying drawings. It shows: Fig. 1 shows a roughly schematic side view of a compaction vehicle according to the invention; Fig. 2 shows a circuit diagram of the hydraulic drive of the compaction vehicle according to Fig. 1 ; Fig. 3 in Fig. 2 missing control of the second hydraulic machine; and Fig. 4 an alternative connection of the second hydraulic machine to the supply point and the tank.

[0027] Fig. 1 shows a roughly schematic side view of a compaction vehicle 10 according to the invention. The present compaction vehicle 10 is designed in the form of a road roller, with which a subsoil 11 in the form of a freshly asphalted road can be smoothed. The compaction vehicle 10 has two rotatable, circular-cylindrical rollers 20, which roll on the subsoil to smooth it. In this case, only the front roller 20 is driven by a first hydraulic machine 21. It should be noted that Fig. 1 shows an extraordinarily simple embodiment of a compaction vehicle according to the invention. However, the present invention saves particularly significant costs when many first and second hydraulic machines 21; 31 are used, for example, when all rollers 20 are driven and simultaneously equipped with a vibration unit 30. The compaction vehicle can also have more than two rollers 20.

[0028] In this case, only the rear roller 20 is equipped with a vibration unit 30. The vibration unit 30 is intended to exert a pulsating force perpendicular to the subsoil 11 on the associated roller 20, so that the subsoil 11 is more effectively compacted. For this purpose, for example, a rotatably mounted mass 33 can be used, the center of gravity of which is arranged off the axis of rotation or eccentrically. This mass 33 is connected to a second associated hydraulic machine 31 for rotational drive.

[0029] It should also be noted that the supply point 50 is in the form of a line 54, which extends over at least 50% of the length of the compaction vehicle 10 in the direction of travel 15. This allows all Fig. 2 and 3 shown connections to the first and second hydraulic machines 21; 31 are established. Nevertheless, the pressure in line 54 is essentially the same everywhere.

[0030] Fig. 2 shows a circuit diagram of the hydraulic drive of the compaction vehicle 10 according to Fig. 1 The hydraulic drive comprises a supply point 50 in the form of an elongated line 54. The first, second, and third hydraulic machines 21; 31; 41 are connected to this line by their high-pressure sides, providing a permanently open, low-resistance fluid exchange connection. No valves, throttles, or the like are installed in this connection, so that the high pressure in said hydraulic machines 21; 31; 41 is essentially equal to the pressure at the supply point 50. The first, second, and third hydraulic machines 21; 31; 41 are each designed as axial piston machines with adjustable displacement. The first and second axial piston machines 21; 31 are preferably designed as swashplates, and are operated as motors for most of their operating time. They are preferably adjustable beyond zero displacement.The third hydraulic machine 41 is preferably designed as a swash plate, and is operated predominantly as a pump. All hydraulic machines 21; 31; 41 are equipped with an actuating device 13 configured to adjust the displacement volume of the respective hydraulic machine 21; 31; 41 essentially proportionally to an associated actuating signal 14. Accordingly, no hydraulic pressure and / or power control takes place on the hydraulic machine 21; 31; 41 itself. Instead, the hydraulic drive is controlled as described below, preferably using an electronic control device.

[0031] The third hydraulic machine 41 is set in rotation by an associated drive motor 43. The drive motor 43 is preferably a diesel engine, although any other type of engine, in particular an electric motor, can be used. The drive motor 43 preferably runs with a fixed, predetermined direction of rotation. During the vast majority of operating times, the third hydraulic machine 41 pumps pressurized fluid from the tank 12 to the supply point 50, acting as a pump. Within the scope of the control according to the invention, however, it can also occur that pressurized fluid flows from the supply point 50 via the third hydraulic machine 41 to the tank, with the third hydraulic machine 41 acting as a motor and thus temporarily relieving the load on the drive motor 43.

[0032] The low-pressure sides of the first, second, and third hydraulic machines 21; 31; 41 are each connected to the tank 12, resulting in an open hydraulic circuit. These connections to the tank are also permanently open and low-resistance, and preferably no valves, throttles, or the like are arranged there. The entire hydraulic drive thus essentially operates entirely without valves, with the desired movement being achieved solely by adjusting the displacement volumes of the hydraulic machines 21; 31; 41.

[0033] In this case, however, a valve unit 52 is assigned to the supply point 50, which is connected between the supply point 50 and an optional hydraulic accumulator 51. The hydraulic accumulator 51 is used to compensate for peaks in power requirements, for example when accelerating the vibration drive (No. 30 in Fig. 1 ), so that they do not place excessive strain on the drive motor 43, which means that the latter does not have to be made excessively large. Furthermore, pressure peaks at the supply point 50 are absorbed by the hydraulic accumulator 51. The valve unit 52 initially adjusts a high pressure in the hydraulic accumulator 51 to a lower pressure at the supply point 50, so that the hydraulic accumulator 51 is discharged when it is sufficiently filled. It also causes the hydraulic accumulator 51 to be charged when the pressure inside it is lower than the pressure at the supply point 50. In this case, a predetermined charging volume flow is preferably not exceeded. The valve unit 52 can be of purely hydromechanical design. It is preferably electrically adjustable, being adjusted by the electronic control device 16.Preferably, the hydraulic accumulator 51 is provided with a pressure sensor (not shown) which is connected to the electronic control device 16 so that electronic control of the pressure in the hydraulic accumulator 51 can take place.

[0034] The first control circuit 60 regulates a pressure at the supply point 50 which is equal to the target value 63 of the first control circuit 60. This target value 63 is dependent on the desired driving speed of the compaction vehicle and the desired vibration intensity of the vibration drive (No. 30 in Fig. 1 ). In this case, the setpoint value 63 of the first control circuit 60 is preferably selected to be so small that the adjustment range of the first and second hydraulic machines 21; 31 is just sufficient to achieve the desired operating parameters (driving speed, vibration intensity).

[0035] The corresponding first controller 64 is embodied here as a PID controller, although a PI or I controller may also be used. The first controller 64 is preferably implemented by an electronic control device 16 comprising a programmable digital computer. The difference between the above-explained target variable 63 and the actual variable 61 is fed to the first controller 64, with a manipulated variable 62 present at its output, which forms the control signal 14 of the third hydraulic machine 41. The actual variable 61 of the first control loop 60 is the measured value of a pressure sensor 53 connected to the supply point 50.

[0036] Fig. 3 shows the Fig. 2 missing control of the second hydraulic machine 31. Fig. 2 and 3 together they show a uniform hydraulic drive. Fig. 3 shows the most complex control variant, in which a pre-control is carried out using a characteristic map 80, with the pre-control being superimposed on a closed-loop control with the second control loop 70. There are applications in which the pre-control alone, without the second control loop 70, results in sufficiently good system behavior. There are also applications in which the second control loop 70 alone, without the pre-control, results in sufficiently good system behavior.

[0037] The second control loop 70 comprises a second controller 74, which in this case is designed as a PID controller, although it can also be designed as a PI or I controller. The difference between the actual variable 71 and the target variable 73 is fed to its input. The actual variable 71 is formed from the measured value of the second speed sensor 32, i.e., the speed of the second hydraulic machine 31. The target variable 73 corresponds to the speed of the second hydraulic machine 31 at which the desired vibration intensity 81 is achieved. As already indicated, this control basically has an integral control behavior, whereby it subsequently reacts comparatively sluggishly to changes in the target variable 73. This problem can be remedied with feedforward control.

[0038] The pilot control comprises a characteristic map 80, which has as input variables the desired vibration intensity 81 and the measured value of the pressure sensor 53, i.e. the pressure at the supply point. As an output variable, the characteristic map 80 provides the displacement volume to be set at the second hydraulic machine 31, with which the desired vibration intensity 81 is achieved at the current pressure at the supply point. The characteristic map 80 preferably comprises a corresponding value table, from which intermediate values ​​are most preferably obtained by interpolation. This pilot control does not take into account, for example, that changing ambient temperatures also affect the required setting of the second hydraulic machine 31. This problem is counteracted by the second control loop 70.

[0039] The output variables of the characteristic map 80 and the second controller 74 are added, resulting in the control signal 14 for the second hydraulic machine 31. This is also referred to as a superposition of a feedforward control with a closed-loop control.

[0040] Fig. 4 shows an alternative connection of the second hydraulic machine 31 with the supply point 50 and the tank 12. In the embodiment according to Fig. 2 These connections were permanently open. The embodiment according to Fig. 4 is intended for cases in which the direction of rotation of the second hydraulic machine 31 is to be reversible, whereby in order to save costs no hydraulic machine adjustable beyond the displacement volume zero is to be used.

[0041] The second hydraulic machine 31 is therefore connected to a switching valve 34, which is designed as a 4 / 3-way valve. The switching valve 43 thus has four connections and three switching positions. These switching positions are discrete switching positions, with essentially no intermediate positions in which the opening cross-sections of the various connections change continuously.

[0042] The middle position is a locked position in which the respective second hydraulic machine 31 cannot move because it is hydraulically clamped. The connections to the tank 12 and the supply point 50 are blocked. In the Fig. 4 left position of the switching valve 34, the second hydraulic machine rotates clockwise, for example, whereby it is in the Fig. 4 right position of the switching valve 34 rotates counterclockwise. During the reversal of the direction of rotation, the displacement volume is preferably set to zero or almost zero on the second hydraulic machine 31, while the switching valve 34 is adjusted. In the two outer switching positions, the connections between the second hydraulic motor 31 and the tank 12 or the supply point 50 are thus continuously released. A continuous adjustment of the corresponding opening cross-sections preferably does not take place, while the vibration unit (No. 30 in Fig. 1 ) running.

[0043] It is understood that the first hydro machine (No. 21 in Fig. 2 ) can be connected in an analogous manner to the supply point 50 and the tank 12 using an analog switching valve. Reference symbol

[0044] 10Compaction vehicle 11Subsoil 12Tank 13Control device 14Control signal 15Direction of travel 16Electronic control device 20Roller 21First hydraulic machine 22First speed sensor 30Vibration unit 31Second hydraulic machine 32Second speed sensor 33Eccentric mass 34Switching valve 41third hydraulic machine 42third speed sensor 43drive motor 50Supply point 51Hydraulic accumulator 52Valve unit 53Pressure sensor 54Line 60First control loop 61Actual variable of the first control loop 62Manipulated variable of the first control loop 63Setpoint of the first control loop 64First controller 70Second control loop 71Actual variable of the second control loop 72Manipulated variable of the second control loop 73Setpoint of the second control loop 74Second controller 80Characteristic map 81Desired vibration intensity

Claims

1. Compacting vehicle (10) having at least one roller (20) for dynamically compacting a substrate (11), wherein the compacting vehicle (10) has a travel drive connection to at least one first hydraulic machine (21), wherein at least one roller (20) is assigned a vibrating unit (30), which has a drive connection to an assigned second hydraulic machine (31), characterized in that the at least one first, the at least one second and a third hydraulic machine (21; 31; 41) are each connected on the high-pressure side to a common supply point (50) and on the low-pressure side to a tank (12) such that they form an open hydraulic circuit, wherein said connection to the supply point is in each case continuously releasable such that a high pressure in the at least one first, in the at least one second and in the third hydraulic machine (21; 31; 41) is substantially equal to the pressure at the supply point (50), wherein the at least one first, the at least one second and the third hydraulic machine (21; 31; 41) each have an adjustable displacement volume, wherein a displacement volume of the at least one second hydraulic machine (31) is adjustable in such a way that the desired vibrating strength (81) results, while said connections to the supply point (50) are released.

2. Compacting vehicle (10) according to Claim 1, wherein a displacement volume of the at least one first hydraulic machine (21) is adjustable in such a way that the desired driving speed results, and therefore the desired driving speed and vibrating strength can be achieved simultaneously.

3. Compacting vehicle (10) according to Claim 1 or 2, wherein a direction of rotation of the at least one first hydraulic machine (21) is reversible by adjustment of the displacement volume in question, with the throughflow direction of the relevant first hydraulic machine (21) in each case remaining the same.

4. Compacting vehicle (10) according to any one of the preceding claims, wherein the supply point (50) is connected to a hydraulic accumulator (51).

5. Compacting vehicle (10) according to any one of the preceding claims, wherein two or more rollers (20) are provided, which each have a rotary drive connection to a separate first hydraulic machine (21), wherein all of the first and all of the second hydraulic machines (21; 31) are connected to the same supply point (50) and to the same tank (12).

6. Compacting vehicle (10) according to any one of the preceding claims, wherein the supply point (50) is connected to a pressure sensor (53), wherein the displacement volume of at least one second hydraulic machine (31) is adjustable depending on the pressure measured with the pressure sensor (53) and depending on the desired vibrating strength (81).

7. Compacting vehicle (10) according to any one of the preceding claims, wherein the supply point (50) is connected to a pressure sensor (53), wherein the displacement volume of the third hydraulic machine (41) is adjustable depending on the pressure measured with the pressure sensor (53).

8. Compacting vehicle (10) according to Claim 7, wherein a first control circuit (60) is provided, the actual value (61) of which is the pressure measured with the pressure sensor (53), wherein the manipulated variable (62) thereof is the displacement volume of the third hydraulic machine (41).

9. Compacting vehicle (10) according to Claim 8, wherein at least one second hydraulic machine (31) is assigned a second rotational speed sensor (32), by means of which a rotational speed of the relevant second hydraulic machine (31) is measurable, wherein a second control circuit (70) is provided, the actual value (71) of which is a measured value of the second rotational speed sensor (32), wherein the manipulated variable (72) thereof is the displacement volume of the relevant second hydraulic machine (31).

10. Compacting vehicle (10) according to any one of the preceding claims, wherein the supply point (50) is formed by a line (54) which extends over at least 50% of the length of the compacting vehicle (10) in the direction of travel (15).

11. Compacting vehicle (10) according to any one of the preceding claims, wherein the at least one first hydraulic machine (21), the at least one second hydraulic machine (31) and / or the third hydraulic machine (41) in each case comprise / comprises an actuator device (13), which is designed to adjust the displacement volume of the relevant hydraulic machine (21; 31; 41) substantially proportionally to an actuating signal (14).

12. Compacting vehicle (10) according to any one of the preceding claims, wherein at least one first hydraulic machine (21) is assigned a third control circuit, the actual value of which is the rotational speed of the relevant first hydraulic machine (21), wherein the manipulated variable thereof is the displacement volume of the relevant first hydraulic machine (21).

13. Method, wherein a compacting vehicle (10) according to Claim 8 is used, wherein a setpoint value (63) of the first control circuit (60) is selected depending on the desired travel speed of the compacting vehicle (10) and / or depending on the desired vibrating strength (81).

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