EP2676036B1 - Pressure-accumulator-free hydraulic drive arrangement for and comprising a consumer, in particular for presses, and method for operating a pressure-accumulator-free hydraulic drive arrangement of said type - Google Patents

Description

The invention relates to an accumulatorless hydraulic drive arrangement for and with a consumer, in particular for presses with the features of the preamble of claim 1 and a method for operating such accumulatorless hydraulic drive assembly with the features of the preamble of claim 17. Accordingly, the invention of a pressure accumulatorless hydraulic drive assembly with working piston, additional rapid traction piston and ring-like return piston, especially when the accumulatorless hydraulic drive assembly for and with a consumer, in particular for pressing, a double-acting, a working piston, a piston rod and a cylinder chamber comprising piston / cylinder unit, in the the reversibly movable working piston, the cylinder chamber on the one hand in a first piston chamber and a second piston chamber complementing the first piston chamber and on the other hand, in an annular space surrounding the piston rod divided. A first pressure line supplies the first piston space, a second pressure line supplies the second piston space and a third pressure line supplies the annular space with pressure medium which is conveyed by at least one variable-speed and / or rotationally variable driven pump.

TECHNOLOGICAL BACKGROUND

Variable speed hydraulic drives for large cylinders are roughly equivalent to WO 2010/020427 executed. There two separate pump drive arrangements for the working stroke on the one hand and the return stroke on the other hand are provided to save large-volume pressure accumulator. The hydraulic cylinder may be equipped with an additional rapid traverse piston chamber. The first pump first conveys exclusively in the relatively small-area rapid traverse cylinder. The working piston is filled with pressureless hydraulic oil through an open filling valve. To build up a significant pressing force, the filling valve is closed. By actuating a switching valve, the large piston chamber is now also connected to the first pump. Thus, a high power can be generated at low speed. Plants according to this circuit concept have been implemented many times and prove themselves in practice.

The disadvantage is the high construction costs for the two motor pump stations. Especially with large consumers, the inverter controls and power supplies used for the motor drive are quite expensive.

The large directional control valves for switching the pump delivery flow from rapid traverse piston to the large piston surface are also expensive.

PRESENTATION OF THE INVENTION

The object of the invention is to develop the aforementioned variable-speed drive so that only a single electric motor and the corresponding also only a single inverter is required. Another goal is to reduce the number of switchable valves to reduce construction and maintenance costs.

To solve the problem, a druckspeicheriose hydraulic drive assembly for and with a consumer, in particular for presses with the features of claim 1 and a method having the features of claim 17 is proposed. Accordingly, the invention is based on the WO2010 / 020427 to provide on the concept, in a pressure accumulatorless hydraulic drive assembly with working piston, additional rapid traverse piston and ringlike Rückholkolben a Drehrichtungsvariable pump assembly of a variable speed motor with at least two pumps and the three cylinder (or piston) spaces via three pressure lines individually and directly with the pump to connect such that in both directions a rapid traverse takes place.

Although it is known per se to drive in hydraulic drive arrangements two pumps with a single motor ( CH PS 481 750 . DE 103 29 067 A1 . DE19715157 A1 . JP 08014108 A or WO 02/04820 A1 ), These drive assemblies usually a pressure accumulator, as described DE 103 29 067 A1 , need or act on the same piston surface, as after the DE 103 29 067 A1 . DE19715157 A1 or JP 08014108 A WO 02/04820 A1 , Or the two pumps are designed for different delivery rates or pressures to drive a differential piston, so a double-acting piston with different sized piston surfaces, as in the DE 103 29 067 A1 . DE19715157 A1 or WO 02/04820 A1 , Or the pumps drive completely different systems on the same press, as with the CH PS 481 750 , All of these drive arrangements require at least one fluid switching valve and / or very large presses, ie with very large-volume piston extremely large-sized pumps and / a lot of time for long strokes.

The WO 2008/082463 A1 discloses a pressure accumulator-free hydraulic drive assembly for and with a consumer, in particular for pressing, with a double-acting, at least one reversibly movable piston, at least one reversibly movable rapid traverse piston, at least one piston rod and at least one cylinder chamber comprising piston / cylinder unit, wherein the at least one cylinder chamber or the cylinder chambers comprise at least one first piston chamber, which acts on the working piston with fluid pressure, at least one second piston chamber which supplements the first piston chamber, and which comprises / surround the rapid traverse piston with fluid pressure, and at least one annular space surrounding the piston rod, with the piston chambers with a pressure medium supplying pressure lines, with a pump assembly which comprises at least two speed and Drehrichtungsvariabel driven pumps and at least one with the piston / cylinder unit and the pump assembly hydraul Isch connected or connectable pressure medium tank. According to a first embodiment of the invention, in a pressure accumulator-free hydraulic drive arrangement is provided that at least one pump assembly, a first variable speed and / or rotationally variable driven pump and a second speed and / or direction variable variable driven pump and both pumps together driving speed and / or direction variable drive includes. In at least one tank hydraulically connected or connectable to the piston / cylinder unit and the pump arrangement, the pressure medium can be stored substantially without pressure. The first pump is connected via a first pressure line to the first piston chamber or connectable. The second pump is connected on the one hand via a second pressure line to the second piston chamber and on the other hand via the third pressure line to the annular space or connectable. The common drive can be an electric motor. This could u. A. be a (permanent-field) servomotor as well as a standard asynchronous motor with a corresponding 4-quadrant inverter.

• Eine Motor-Umrichter-Kombination entfällt vollständig
• Bei einer Ausführung mit erhöhtem Sicherheitsniveau entfällt auch eine Bremse
• Ein vor dem Arbeitskolben angeordnetes Schaltventil für ein Umleiten des Druckfluids kann entfallen.
• Die Regelalgorithmen für den Umrichter eines elektrische Antriebsmotor werden einfacher, weil nicht mehr zwei Motor-Pumpen-Kombinationen gegeneinander wirken.
• Die neuen Einheiten können kostengünstig kombiniert werden.

By the invention are compared to in the WO 2010/020427 described solution from which the invention proceeds, u. A. achieves the following advantages:

• A motor-inverter combination is completely eliminated
• In a version with increased safety level also eliminates a brake
• A valve disposed in front of the working piston switching valve for redirecting the pressurized fluid can be omitted.
• The control algorithms for the inverter of an electric drive motor are easier because no more two motor-pump combinations work against each other.
• The new units can be combined cost-effectively.

The first pump and / or the second pump preferably has an adjustable delivery volume in favor of a variable operation, in particular if an external adjusting device is provided, which can respond to hydraulic or electrical control variables of an external control, such as in an inverter.

The first piston chamber can be connected to the tank via a supply line having a filling valve or can be connected in order to accelerate the filling of the working cylinder with working fluid in a rapid traverse phase.

If a rapid traverse piston is arranged in the first piston chamber and the ratio of the rapid traction piston surface to the annular chamber surface is approximately the same, the operation, in particular the control of the pumps, is comparatively simple.

If at least one further, the first pump assembly corresponding further pump assembly is provided which act in parallel to the piston / cylinder unit in the same direction with the first pump assembly, thereby particularly large-volume piston / cylinder units can be operated.

If the first, the second and / or the third pressure line switching valve-free, in particular free of safety-related switching valves is operable or, thereby u. A. Prevents or reduces impacts in the hydraulic system.

If the pump arrangement comprises a third pump which can be driven in a variable speed and / or direction of rotation, which is drivable together with the other two pumps by the common drive, the three pressure lines being assigned to each of the three pumps, thereby controlling the piston / cylinder unit, simplified.

If a first piston, in particular the working piston, is effective on one side and at least one, preferably double effective piston / cylinder unit, if desired, by a double-acting piston / cylinder auxiliary unit in rapid traverse forward and zurückbewegbar and at least one of the piston chambers, in particular the second piston chamber and the annulus in the at least one double effective piston / cylinder unit or auxiliary unit are provided, characterized z. As the operation of even larger working piston possible and / or achieved greater structural flexibility.

If the at least one converter is connected or connectable to a pressure sensor associated with the working piston and / or to a displacement encoder associated with the working piston, and the at least one converter has a comparatively high safety level, in particular category 3 according to the guideline DIN EN 954-1 or Performance Level d in accordance with ISO 13849. Highest safety requirements (eg category 4 according to guideline DIN EN 954-1 or performance level e according to ISO 13849) can be achieved by combining it with other elements, such as a brake included in the pump arrangement.

The accumulatorless hydraulic drive assembly for a consumer, in particular for presses, is operated in one embodiment such that in a double-acting, a piston, a piston rod and a cylinder chamber comprehensive piston / cylinder unit of the working piston, the cylinder chamber on the one hand into a first piston chamber and dividing a second piston chamber, which supplements the first piston chamber, and the annular piston chamber, by reversing the first piston chamber via a first pressure line, the second piston chamber via a second pressure line and the annular space via a third pressure line with a pressure medium in that a first and a second pump which can be driven in variable speed and / or direction of rotation are driven jointly by a drive which is variable in speed and / or direction of rotation, that the pressure means in one with the at least one piston / cylinder unit and the pump penanordnung hydraulically connected or connectable tank is stored, that the second pump in a first rotational direction of the common drive a working fluid under extension of the piston rod at rapid traverse via the second pressure line in the second piston chamber and pumps via the third pressure line sucks from the annulus and the first pump Working fluid via the first pressure line in the first piston chamber fills and that the time pump sucks in a second direction of rotation of the common drive by retrieving the piston rod at high speed, the working fluid from the second piston chamber and pumped into the annulus while working fluid from the first piston chamber flows back into the tank.

• das Verhältnis der Eilgangkolbenfläche F2 zu der Arbeitskolbenfläche F1 und/oder zu der Ringraumfläche F3 vorzugsweise kleiner oder gleich 1 ist und/oder
• dem Antrieb der Pumpenanordnung eine Antriebswelle zugeordnet ist, über die die erste Pumpe und die zweite Pumpe gemeinsam antreibbar sind und/oder
• mindestens eine weitere, der ersten Pumpenanordnung entsprechende Pumpenanordnung vorgesehen ist, die in Parallelschaltung auf die Kolben/Zylinder-Einheit gleichsinnig mit der ersten Pumpenanordnung einwirken und/oder
• die erste D1, die zweite D2 und/oder die dritte D3 Druckleitung über Rückschlagventile mit dem Tank verbindbar sind.

As further advantageous, it has been found that:

• the ratio of the Eilgangkolbenfläche F2 to the working piston surface F1 and / or to the annular space F3 is preferably less than or equal to 1 and / or
• the drive of the pump assembly is associated with a drive shaft, via which the first pump and the second pump are jointly driven and / or
• at least one further, the first pump assembly corresponding pump assembly is provided which act in parallel with the piston / cylinder unit in the same direction with the first pump assembly and / or
• the first D1, the second D2 and / or the third D3 pressure line via check valves to the tank are connectable.

The above-mentioned and the claimed components to be used according to the invention described in the exemplary embodiments are not subject to special conditions of size, shape, material selection and technical design, so that the selection criteria known in the field of application can be used without restriction.

Further details, features and advantages of the subject matter of the invention will become apparent from the subclaims, as well as from the following description of the accompanying drawings and table, in which - by way of example - an embodiment of a pressure accumulator hydraulic drive arrangement are shown. Also, individual features of the claims or the embodiments can with other features of other claims and embodiments.

BRIEF DESCRIPTION

Fig. 1A

eine druckspeicherlose hydraulische Antriebsanordnung als Blockschaltbild;

Fig. 1B

eine zu Fig.1A alternative druckspeicherlose hydraulische Antriebsanordnung mit Bremse als Blockschaltbild;

Fig. 2A

eine modular aufgebaute druckspeicherlose hydraulische Antriebsanordnung für Großanlagen als Blockschaltbild;

Fig. 2B

von der modularen Antriebsanordnung nach Fig. 2A ein Einzelmodul;

Fig.3

eine dritte Ausführung einer druckspeicherlosen hydraulischen Antriebsanordnung für Großanlagen als Blockschaltbild

Fig.4

eine vierte Ausführung einer druckspeicherlosen hydraulischen Antriebsanordnung für Großanlagen als Blockschaltbild sowie

Fig.5

eine fünfte Ausführung einer druckspeicherlosen hydraulischen Antriebsanordnung für Großanlagen als Blockschaltbild.

In the drawing show:

Fig. 1A

an accumulatorless hydraulic drive assembly as a block diagram;

Fig. 1B

one too 1A alternative accumulatorless hydraulic drive assembly with brake as a block diagram;

Fig. 2A

a modular built pressure accumulatorless hydraulic drive assembly for large plants as a block diagram;

Fig. 2B

from the modular drive arrangement Fig. 2A a single module;

Figure 3

a third embodiment of an accumulatorless hydraulic drive assembly for large plants as a block diagram

Figure 4

a fourth embodiment of a pressure accumulator-free hydraulic drive assembly for large plants as a block diagram and

Figure 5

a fifth embodiment of a pressure accumulator hydraulic drive arrangement for large plants as a block diagram.

DETAILED DESCRIPTION OF EMBODIMENTS

Out FIGS. 1A, 1B is a double-acting, a piston 21, a piston rod 22 and a cylinder chamber comprising piston / cylinder unit 20 can be seen, in the reversibly movable piston 21, the cylinder chamber on the one hand in a first piston chamber 23A (or working cylinder) and a first piston chamber a so-called rapid traction piston 21A receiving second piston chamber 23B (or rapid traverse cylinder) and on the other hand in a piston rod 22 surrounding annular space 23C (or Rückholzylinder ). The rapid traction piston 21A may be oriented in a direction opposite to the piston rod, as shown, or (not shown) in a direction similar to the piston rod. The piston / cylinder unit 20 is connected to a first pressure line D1 supplying the first piston chamber 23A with a pressure medium, a second pressure line D2 supplying pressure fluid to the second piston chamber 23B, and a third pressure line D3 supplying the annular space 23C with pressure medium.

A single, designed as a servomotor drive 33 drives a double pump in the form of two, in particular variable speed pumps 31, 32 on a single drive shaft 33A. Both pumps are preferably equipped with a device for adjusting their delivery volume. The adjustment can be done purely by pumping means by a control device that changes the flow rate, for example, the current pressure following. Pumps with adjusting devices of this type are available on the market. Alternatively, according to Figure 1A , an adjusting device 39A, 39B, 39C are used, which can respond to hydraulic or electrical control variables of an external control, such as in an inverter 35. Thus, the pump flow rate can be adjusted in proportion to an input signal from "zero" to the maximum flow. Such an adjusting device is produced, for example, by BoschRexroth under the name "HS4" for the axial piston pumps of the A4 series.

The servo motor closest to the pump 32 is connected on its one side with the serving as Rückholzylinder annular space 23 C and on the other side with the piston space 23 B serving as a rapid traverse cylinder. Both piston surfaces F3 and F2 are approximately equal. The (first) pump 31 is on its one side with a tank 40, on the other side with the cylinder serving as a working piston chamber 23 A fluidly connected. In addition, the piston chamber 23A is equipped with a filling valve 34 to fill the piston chamber automatically very quickly when it increases. The displacement sensor 36 installed on the piston rod 22 reports the current piston position to a converter 35 supplying the drive 33 with electrical voltage.

For all conceivable embodiments applies that the drive at least one mechanical transmission for the torque transmission to at least one of the pumps and / or at least one additional pump of the same drive train can be advantageously assigned, in particular to use motors with relatively higher speeds compared to the pump can , It is also helpful if the pump arrangement comprises a brake, in particular in order to favor a switching valveless operation.

The at least one inverter 35 may be connected to a working piston 21 associated pressure sensor and / or a working piston 21 encoder 36 or connect bar and / or have a relatively high level of security, especially category 3 according to the directive DIN EN 954-1 or Performance Level d in accordance with ISO 13849. Combination with other elements, such as a brake included in the pump arrangement, also requires the highest safety requirements (eg Category 4 according to the guideline DIN EN 954-1 or Performance Level e according to ISO 13849) reachable.

The following procedure is possible:

To extend the provided on the piston 21 piston rod 22 at rapid speed promotes rotation of the servomotor M, the (second) pump 32 oil in the piston chamber 23B of the relatively small-area rapid traverse piston 21 A. At the same time, the pump sucks oil from the annular space 23C. The filling valve 34 is open so that the oil flow required to fill the piston chamber 23A serving as the working cylinder can be sucked from the tank 40. The first Pump 31 is z. B. by the common shaft 33 A to the pump 32 by the servo motor M at the same speed as the pump 32 driven. The delivery flow is preferably set to the maximum via the adjusting device of each pump, so that the pump delivery flow supplements that through the filling valve. This happens at comparatively low pump pressure.

To switch to working speed , the filling valve 34, for example, closed from a certain pressure, the pump 31 fills the large (first) piston chamber 23A now alone. The delivery volume of the pump 32 is thereby withdrawn, optionally pressure-dependent or with the aid of an active, preferably via the inverter 35 controlled adjustment to a predetermined value, approximately corresponding to the area ratio of the two piston surfaces F1 and F2. For example, if F1 is ten times greater than F2, the flow rate is reduced to about 1/10 of the volume flow delivered during rapid traverse.

The positioning is done in the usual way by stopping the servomotor M.

To decompress the direction of rotation of the servomotor is reversed. The pressurized oil drives the servomotor, which now acts as a generator. The resulting electrical energy is supplied to the DC link of the inverter and can optionally be fed back into the electrical network. The procedure corresponds in principle to that in WO 2010/020427 described. Method.

For the upward movement of the filling valve 34 is opened, the reversed pump 32 now promotes in the (lower) annular space 23 C of the piston / cylinder unit 20, so that the piston rod 22 retracts at rapid traverse speed. In addition, the pump sucks the oil 32 from the Eilgangkolbenraum 23B. The pump 31 is preferably operated at full flow to assist the possibly switchable Füllverntil when emptying the cylinder.

Both pumps and motors and converters are limited in their actual available nominal size. For large cylinders, this may not be sufficient. In such cases, two or more of the drives can be combined into one unit and preferably the two motors are operated in synchronism according to the system master-slave. FIG. 2A shows an example of a double module. Thus, regardless of the size of the system always the same components can be used, which simplifies commissioning and spare parts inventory.

An alternative embodiment according to FIG. 3 shows the use of a triple pump. The three pumps 31, 32, 43 are driven together by the drive 33 via the common drive shaft 33A and are connected on the one hand to the tank 40 and on the other hand to one of the pressure lines D1, D2 and D3 respectively and thus supply the first and second piston chambers 23A separately , 23B and the annular space 23C in the same operating sense as above FIGS. 1 to 3 described. This allows more flexibility in the press design. Also increases the number of usable pumps, because versions can be used that can not build pressure on both ports. The piston surfaces F2 and F3 can then be quite different from each other.

In the further alternative embodiment according to FIG. 4 the working piston 21 is effective on one side and at least one (in the drawing two) double-acting piston / cylinder auxiliary units 24A, 24B via a bridge member 25 in rapid traverse forward and zurückbewegbar. The second piston space 23B and the annular space 23C are provided in the double-acting piston / cylinder auxiliary units 24A, 24B. Thus, extremely large-scale working piston 21 can be actuated by a single or a few drive modules, each with only one drive 33.

In the further alternative embodiment according to FIG. 5 the working piston 21 is effective on one side and by at least one (in the drawing two) double-acting piston / cylinder auxiliary units 24A, 24B via a bridge member 25th in rapid traverse forward and zurückbewegbar. Instead of the displacer 21 B after Figure 4 is after Fig. 5 provided in the second piston chamber only an opening for substantially unpressurized subsequent flow of fluid, when the trailer for the rapid traverse load is correspondingly large. The same goal can in the embodiments according to Fig. 1A to 3 be achieved when the displacer 21 B are replaced by such openings.

Thus, by the invention - even free of valves under fluid pressure - extremely large-scale working piston 21 are actuated by a single or a few drive modules, each with only one drive 33. LIST OF REFERENCE NUMBERS 10 drive arrangement 34 filling valve 20 Piston / cylinder unit 35 inverter 20A-C hydraulic subunits 35A, B inverter 21 working piston 36 encoder 21A Eilgangkolben 36A, B encoder 21 B displacer 37 transmission 22 piston rod 37A, B transmission 22A, B piston rod 38 brake 23A first piston chamber or working cylinder 39A adjustment 39B adjustment 23B second piston chamber or rapid traverse cylinder 39C adjustment 39D adjustment 23C Annulus or backwood cylinder 40 Pressure medium tank 24A Piston / cylinder auxiliary unit 43 third pump 24B Piston / cylinder auxiliary unit 25 bridge member D1 first pressure line 30 pump assembly D1A, B first pressure line 30A pump assembly D2 second pressure line 30B pump assembly D2A, B second pressure line 31 first pump D3 third pressure line 31A, B first pump D3A, B third pressure line 32 second pump F2 Eilgangkolbenfläche 32A, B second pump F1 Working piston area 33 drive F3 Annulus area 33 ', 33 " drive 33A drive shaft

Claims (20)

1. A hydraulic drive arrangement (10), without a pressure chamber, for and with a consumer, in particular for presses,
   with one dual-action piston/cylinder unit (20) comprising at least one fast-speed piston (21A) that is movable in the reverse direction, at least one piston rod (22, 22A, 22B), and at least one cylinder space, in which piston/cylinder unit (20) the at least one cylinder space or the cylinder spaces comprises/comprise at least one first piston space (23A) that subjects the at least one working piston (21) to fluidic pressure, at least one second piston space (23B) that supplements the first piston space (23A) and that subjects the fast-speed piston (21A) to fluidic pressure, and at least one annular space (23C) that encloses one of the piston rods (22, 22A, 22B),
   with pressure lines (D1, ...) that supply pressure means to the piston spaces,
   with a pump arrangement (30; 30A, 30B) that comprises at least two pumps that are driven with variable speed and variable direction of rotation, and
   with at least one pressure-means tank (40) that is hydraulically connected or connectable to the piston/cylinder unit (20; 20A, 20B, 20C) and to the pump arrangement (30; 30A, 30B),
   characterised in that
   one or further pump arrangement/s (30, 30A, 30B) in each case comprises at least one first and one second pump (31, 32), and if applicable at least one further pump (43), and a variable-speed drive (33) that jointly drives the two or several pumps (31, 32, 43),
   the first pump (31) by way of a first pressure line (D1) is connected or connectable preferably only to one, namely to the first, piston space (23A),
   the second pump (32) by way of a second pressure line (D2) is connected or connectable preferably only to one, namely to the supplementary (second), piston space (23B),
   the second (32) or a third (43) pump by way of a third pressure line (D3), through which a medium flows in the opposite direction relative to the medium in the second pressure line (D2), is preferably connected or connectable only to one annular space, namely the annular space (23C), so that the hydraulic drive arrangement (10) is operable by means of a sole single-motor drive train not only in both movement directions at fast speed, but also achieves high operating pressures at work speed.
2. The arrangement according to claim 1, characterised in that the at least one working piston (21) is a dual-action piston that divides the cylinder space into the first piston space (23A) on the one hand, and into the annular space (23C) that encloses the piston rod (22) on the other hand.
3. The arrangement according to claim 1 or 2, characterised in that the second piston space (23B), which supplements the first piston space (23A), is opposite the annular space (23C) relative to the working piston (21).
4. The arrangement according to any one of claims 1 to 3, characterised in that the dual-action piston/cylinder unit (20) comprises at least two hydraulic subordinate units (20A, 20B, 20C) that are arranged in a suspended position and that are operatively interconnected by a bridging element (25), at least one of which hydraulic subordinate units (20A, 20B, 20C) comprises the at least one working piston (21) that is movable in the reverse direction, and at least one other of the hydraulic subordinate units (20A, 20B, 20C) comprises the at least one fast-speed piston (21A) that is movable in the reverse direction.
5. The arrangement according to any one of claims 1 to 4, characterised in that the at least one working piston (21) and/or the at least one fast-speed piston (21A) carry/carries a displacement piston (21B) forming an annular space, and this annular space serves as the first or the second piston space (23A or 23B).
6. The arrangement according to claim 4 or 5, characterised in that the at least one hydraulic subordinate unit (20A, 20B) that comprises the at least one fast-speed piston (21A) that is movable in the reverse direction is of a dual-action design.
7. The arrangement according to claim 4, in which the at least one hydraulic subordinate unit (20A, 20B) that comprises the at least one fast-speed piston (21A) that is movable in the reverse direction is of a dual-action design, characterised in that the annular space (23C) is arranged on the underside of the fast-speed piston (21A) and the effectiveness for the downwards movement of the dual-action piston/cylinder unit (20) is achieved by replacement of the supplementary piston space by an opening that is not subjected to load by the pressure means.
8. The arrangement according to any one of claims 4 to 7, characterised in that the annular space (23C) is arranged at the bottom of the fast-speed piston (21A).
9. The arrangement according to any one of claims 4 to 6 or 8, characterised in that the supplementary (second) piston space (23B) is arranged at the top of the fast-speed piston (21A).
10. The arrangement according to any one of claims 1 to 9, characterised in that the first pump (31) and/or the second pump (32) and/or a further pump of the same drive train comprise/comprises an adjustable conveyance volume, in particular if an external adjusting device (39A, 39B, 39C) is provided that can react to hydraulic or electrical control variables of an external control system in the same manner as in a converter (35).
11. The arrangement according to any one of claims 1 to 10, characterised in that the first piston space (23A) is connected or connectable, by way of a supply line comprising a filling valve (34), to a tank, in particular to the tank (40), wherein if applicable the filling valve (34) replaces the supplementary second piston space and the second pressure line (D2).
12. The arrangement according to any one of claims 1 to 11, characterised in that at least one control device designed as a converter (35) is provided for controlling the drive (33) and/or the conveyance volumes of the first and/or second pump (31, 32) and/or at least one further pump of the same drive train and/or of the filling valve (34) is provided.
13. The arrangement according to claim 12, characterised in that the at least one converter (35) is connected or connectable to a pressure sensor associated with the at least one working piston (21) and/or to a displacement sensor (36) associated with the at least one of the working pistons (21), and in that the at least one converter (35) provides a comparatively high level of safety, in particular category 3 according to the directive DIN EN 954-1 or to performance level d according to ISO 13849.
14. The arrangement according to any one of claims 1 to 13, characterised in that at least one mechanical gear arrangement (37) for torque transmission to at least one of the pumps (31, 32) and/or at least one further pump of the same drive train is associated with the drive (33).
15. The arrangement according to any one of claims 1 to 14, characterised in that the pump arrangement (30) comprises a brake (38).
16. The arrangement according to any one of claims 1 to 15, characterised in that the at least one working piston (21) is unilaterally active and movable to and fro at fast speed by at least one single-action or dual-action piston/cylinder auxiliary unit (24A, 24B, ...) and at least the annular space (23C) is provided in the at least one dual-action piston/cylinder auxiliary unit (24A, 24B, ...).
17. A method for operating a hydraulic drive arrangement, without a pressure chamber, for a consumer, in particular for presses,
    in which method in a dual-action piston/cylinder unit (20) comprising at least one movable working piston (21), at least one fast-speed piston (21A) that can be moved in reverse, at least one piston rod (22, 22A, 22B) and at least one cylinder space, the working piston is moved in reverse,
    in which method the at least one cylinder space or the cylinder spaces comprises/comprise at least one first piston space (23A) receiving the at least one working piston (21), at least one second piston space (23B) that supplements the first piston space (23A), and at least one annular space (23C) that encloses one of the piston rods (22, 22A, 22B), which annular space/s (23C) is/are subjected to fluid pressure by way of pressure lines (D1, ...),
    in which method the pressure means is stored in a tank (40) that is hydraulically connected or connectable to the at least one piston/cylinder unit (20) and to the pump arrangement (30),
    characterised in that
    at least one first and one second pump (31, 32) and if applicable at least one further pump (43) are together driven by a variable-speed drive (33),
    the first pump (31) by way of a first pressure line (D1) preferably pressurises only one, namely the first, piston space (23A), the second pump (32) by way of a second pressure line (D2) preferably pressurises only one, namely the supplementary (second), piston space (23B), and the second (32) or a third (43) pump by way of a third pressure line (D3) through which a medium flows in the opposite direction relative to the medium in the second pressure line, preferably pressurises only one annular space, namely the annular space (23C) with a pressure means, so that the hydraulic drive arrangement (10) is operable by means of a sole single-motor drive train not only in both movement directions at fast speed, but also achieves high operating pressures at work speed.
18. The method according to claim 17, characterised in that in a first direction of rotation of the joint drive (33) the second pump (32), by way of extending the piston rod (22, 22A, 22B) or extending the at least one working piston (21), pumps the working fluid at fast speed by way of the second pressure line (D2) into the second piston space (23B), and the second pump (32) or at least one further pump (43), by way of the third pressure line (D3), removes the working fluid by suction from the annular space (23C), and the first pump (31), by way of the first pressure line (D1), fills working fluid into the first piston space (23A), and
    in which method in a second direction of rotation of the joint drive (33) the second pump (32) or the at least one further pump (43) while withdrawing the piston rod (22) or the at least one working piston (21) at fast speed removes the working fluid by suction from the second piston space (23B) and pumps it into the annular space (23C) while working fluid flows from the first piston space (23A) back into the tank (40).
19. The method according to claim 17 or 18, characterised in that during downwards movement the first piston space (23A) is connected, by way of a supply line that comprises a filling valve (34), to a tank, in particular to the tank (40), so that the at least one working piston (21) at fast speed is in particular also entirely or partly lowered as a result of gravity, wherein if applicable the filling valve (34) connected to the tank replaces the supplementary second piston space and the second pressure line (D2).
20. The method according to any one of claims 17 to 19, characterised in that at least one of the pressure lines (D1, D2, D3) is operated without a switching valve, in particular at average pressures of the pressure means above 300 bar, and particularly preferably between 300 and 450 bar or higher.

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