GB2533224A

GB2533224A - A hydraulic arrangement for a work machine and a process for a hydraulic arrangement

Info

Publication number: GB2533224A
Application number: GB1521845.6A
Authority: GB
Inventors: Szeles Botond
Original assignee: Robert Bosch GmbH
Current assignee: Robert Bosch GmbH
Priority date: 2014-12-11
Filing date: 2015-12-11
Publication date: 2016-06-15
Anticipated expiration: 2035-12-11
Also published as: CN105697474A; GB2533224B; CN105697474B; GB201521845D0

Abstract

A hydraulic arrangement for a work machine and a process for a hydraulic arrangement comprising a first hydraulic consumer 2, in the form of a motor, for a slewing gear of a work machine, such as excavator, and a second hydraulic consumer 4, in the form of a cylinder, for an arm of the work machine. When the slewing gear is braked and when the arm is lowered, a flywheel 10 can be driven by a pivotable hydraulic machine 6 to recover the energy and as both consumer units are in active communication with the flywheel the energy can be recovered simultaneously. The arrangement is configured in such a way that the energy stored in the flywheel 10 is then usable to drive movement of the arm through the action of machine pivotable hydraulic machine 6 but is not useable for the slewing gear.

Description

A hydraulic arrangement for a work machine and a process for a hydraulic arrangement

Description

The invention starts with a hydraulic arrangement having a flywheel for storing energy according to the precharacterising clause of Claim 1. The invention moreover starts with a process for recovering energy for a hydraulic arrangement of this type.

A hydraulic arrangement of this type is known from publication CU 1382920 Al. In this, a flywheel is provided 15 for the storage of energy.

Publication RU 2 237 135 Cl discloses a further embodiment of a hydraulic arrangement with a flywheel. In this, a hydraulic motor can be driven by consumers and in turn drives a flywheel. The flywheel can be used to drive a hydraulic pump as a pressurising-medium source.

The known solutions are disadvantageous in that they are technically complex in design.

By contrast, the object on which the invention is based is to provide a hydraulic arrangement which eliminates the said disadvantages. The object on which the invention is based is moreover to provide a simple process for recovering energy for a hydraulic arrangement of this type.

The object is achieved according to the features of Claim 1 with regard to the hydraulic arrangement and according to the features of Claim 14 with regard to the process.

Other advantageous further developments of the invention are the subject matter of further subclaims.

According to the invention, a hydraulic arrangement for a work machine, in particular for an excavator, is provided. This has a first hydraulic consumer and at least one second hydraulic consumer. A flywheel or a flywheel mass is provided to store recovered energy at least of the first consumer, in particular when the first consumer is braked. The recovered energy stored by the flywheel is advantageously used only for the at least one second consumer and not for the first consumer.

This solution is advantageous in that the arrangement is designed in such a way that the recovered energy is not used for the first and the second consumer, thereby reducing the technical complexity of the device.

The first consumer is preferably a hydraulic machine for a slewing gear of the excavator. Energy can be easily recovered for example upon fluidic braking of the slewing gear. The second consumer is preferably a hydraulic cylinder for an arm of the excavator, whereby the energy can be recovered upon a lowering action. The recovered energy is then advantageously reused to raise the arm. The energy input for raising the arm is normally greater than an energy input for rotating the slewing gear, whereby the energy recovered from the slewing gear is advantageously used for the arm and cannot be reused for the slewing gear, which reduces the technical complexity of the device by comparison with the prior art, as already explained above.

In a further design of the invention, a hydraulic machine is provided which is mechanically connected to the flywheel, whereby recovered energy can be supplied to the flywheel by way of the hydraulic machine and reused energy can be provided by the flywheel to drive the hydraulic machine. The hydraulic machine is therefore preferably usable as a hydraulic motor and as a hydraulic pump. In a further design, the hydraulic machine is pivotable, whereby a braking pressure for the first and/or for the second consumer is for example adjustable. The hydraulic machine is furthermore advantageously continuously pivotable to adjust a delivery rate and an intake rate proportionally.

The first and the at least one second consumer are advantageously in active communication with the flywheel in such a way that the energy can be simultaneously recovered from the first consumer and the at least one second consumer. For example, the hydraulic machine can be driven by both consumers for this. The hydraulic machine is then connected to the first consumer in such a way that it cannot deliver pressurising medium back to this. The at least one second consumer can be driven by the hydraulic machine by way of the flywheel to reuse the energy.

So that a pressure equalisation can take place when the hydraulic machine is simultaneously driven by the consumers, a throttle valve is arranged fluidically between the first consumer and the hydraulic machine and a further throttle valve is arranged fluidically between the at least one second consumer and the hydraulic machine. The respective throttle valve enables a flow cross-section between the hydraulic machine and the respective consumer to be adjusted proportionally, in particular during the recovery of the energy. Therefore, with reference to the first consumer, when a throttle valve is arranged between this and the hydraulic machine, an uptake of the quantity of energy produced when braking a beam of the excavator is conducted from an open hydraulic circuit or slewing-gear circuit by way of the throttle valve (throttle control) to the hydraulic machine and stored temporarily by the flywheel or by a flywheel-mass energy store. It is alternatively conceivable to provide only one throttle valve to equalise the different pressure levels of the consumers.

In an alternative embodiment, the hydraulic machine can be driven solely by the at least one second consumer for the purpose of recovering the energy and this second consumer can in turn be driven by the hydraulic machine. In addition, a second hydraulic machine is connected to the flywheel which can then be driven by the first consumer. This can preferably not drive the first consumer, whereby it can be of a technically simple design as a hydraulic motor. The quantity of energy produced when the beam of the excavator is braked can therefore be taken from the open slewing gear circuit by the second hydraulic machine, the delivery rate of which can preferably be adjusted proportionally to the rotational speed of the beam. As a result of the arrangement of two hydraulic machines, with simultaneous recovery of energy from the slewing gear and from the arm, or from the first consumer and the second consumer, there is no need for a throttling action. It is for example furthermore possible to also recover the energy from the slewing gear when the arm is raised.

In a further design of the invention, the pressurising medium can be returned from the second hydraulic machine on the output side to a low-pressure side of the first consumer. Non-return valves can be provided for this. For example both pressure sides of the first consumer are each connected to an output side of the second hydraulic machine by way of a non-return valve which opens in the direction of the consumer.

As already mentioned above, a technically simple feature of the device is that the second hydraulic machine is usable solely as a hydraulic motor. A further technically simple feature of the device is that the second hydraulic machine can be a constant machine. It is alternatively conceivable that this can be designed to be pivotable.

The hydraulic cylinder is advantageously a differential cylinder whereof the pressure chambers can be connected by way of a connecting valve. It is therefore possible to adjust a pressure level in the hydraulic cylinder when recovering the energy. For example, it is possible to continuously adjust a flow cross-section of a pressurising-medium flow path between the pressure chambers by means of the connecting valve. The hydraulic cylinder preferably has a piston which separates a cylinder chamber from an annular chamber penetrated by a piston rod. When the arm is lowered, the piston is preferably moved in a direction which reduces the size of the cylinder chamber, whereupon the connecting valve can then be opened so that pressurising medium can flow from the cylinder chamber to the annular chamber, whereby only an area which is equivalent to the cross-sectional area of the piston rod bears against the piston, and the pressure in the cylinder chamber is thereby increased. The pressurising-medium connection between the pressure chambers can be adjusted according to the pressure in the cylinder chamber to in turn adjust a pressure in the annular chamber without having to provide a pressure sensor for the annular chamber.

A pressure sensor is preferably arranged on sides of the cylinder chamber of the hydraulic cylinder for the purpose of pressure measurement. It is possible to determine a lowering speed of the hydraulic cylinder (throttle control) depending on the measurement determined by the pressure sensor and depending on a movement of an actuating element (joystick). With this, the hydraulic machine which is connected to the flywheel can be adjusted accordingly.

At least one supply unit in the form of a hydraulic machine is advantageously provided to supply pressurised medium to the consumers. The supply unit is preferably controlled in such a way that, when the energy is returned to the second consumer, a power output of the at least one supply unit is preferably dependent on the energy returned and can preferably be reduced by the amount of the returned energy. The supply unit can be driven for example by way of an electrical drive or an internal combustion engine. A further second supply unit in the form of a hydraulic machine is preferably provided, which can be driven together with the first supply unit in technically simple manner, for example by way of a common drive shaft. In technically simple manner, the supply units are furthermore not continuously pivotable. It is conceivable that the first supply unit is provided for the second consumer and the second supply unit is provided for the first consumer.

In a further design of the invention, the supply unit or supply units are hydraulic pumps which are proportionally adjustable.

A flow cross-section between a supply unit or both supply units and the second consumer, in particular during the supply of returned energy to the second consumer, can be reduced for example by a throttle element or by a plurality of throttle elements. It is therefore possible not only to reduce the power output of the supply unit or supply units when the energy is returned by the flywheel, but it is also possible to reduce a flow cross-section.

A pivoting-angle sensor and/or a rotational-speed sensor is preferably associated with the hydraulic machine used to return the energy in order to determine an actual delivery rate of the hydraulic machine. It is furthermore possible to provide a rotational-speed sensor for the supply unit or a common rotational-speed sensor or a respective rotational-speed sensor for both supply units. It is moreover possible to provide a pivoting-angle sensor for the supply unit or a respective pivoting-angle sensor for both supply units. It is therefore also possible to determine the actual delivery rate of the supply unit or the supply units.

In a further design of the invention, means can be provided on one hand to use a volume flow of a pressurising medium of the first and/or second consumer when recovering the energy to drive the flywheel and on the other hand to discharge it to a tank, in particular by way of a valve. Therefore, when storing the available energy from the individual consumers, the volume flow of the pressurising medium can be divided according to the system status so that the pressurising medium can be delivered both to the hydraulic machine and, particularly by way of a control block, to the tank.

The flywheel is preferably mechanically coupled to the hydraulic machine or to both hydraulic machines by way of a gear, whereby a particular rotational-speed transmission ratio is possible. If two hydraulic machines are provided to recover energy, the second hydraulic machine is preferably connected to the first hydraulic machine by way of a through-drive, whereby the hydraulic machines can be connected to the flywheel mechanically in series. It is alternatively possible for the hydraulic machines to also be connected to the flywheel mechanically in parallel, for example by way of a transfer gearbox.

A valve block is advantageously arranged between the second hydraulic machine and the first consumer, whereby a higher-20 pressure side can be connected to the second hydraulic machine in the event of an activation/actuation.

In a process according to the invention for recovering energy in a hydraulic arrangement according to one of the aspects above, during a braking procedure, pressurising medium is preferably delivered unthrottled from one or from both consumers to the hydraulic machine used as a hydraulic motor, in which case corresponding throttle valves are opened. Alternatively or additionally, when the pressurising medium is fed back, this can flow substantially unthrottled from the hydraulic machine used as a hydraulic pump into the hydraulic cylinder of the arm in that the corresponding valve or the corresponding valves is/are opened. The speed of the arm can be determined by the rotational speed and/or by the pivoting angle of the hydraulic machine.

When the arm is lowered, the connecting valve for the pressure chambers of the hydraulic cylinder can be completely or partially opened as required.

A required speed of the individual consumers can be determined without direct position or speed measurement on the basis of a request by the driver, i.e. from the extent of a movement of a corresponding actuating element.

A plurality of exemplary embodiments of an arrangement according to the invention are illustrated in the drawings. The invention is now explained in more detail with reference to the figures of these drawings, which show Figure 1 a hydraulic circuit diagram of a first exemplary embodiment, Figure 2 a hydraulic circuit diagram of a second exemplary embodiment, Figures 3a and 3b a respective hydraulic circuit diagram of a third and a fourth exemplary embodiment Figure 4 a hydraulic circuit diagram of a fifth exemplary embodiment and Figure 5 a schematic view of the arrangement according to a sixth exemplary embodiment.

Figure 1 shows a hydraulic arrangement 1 for an excavator. This has a first consumer 2 in the form of a hydraulic machine for a slewing gear of the excavator and a second consumer 4, which has two hydraulic cylinders for an arm of the excavator. To recover energy, both consumers 2, 4 are fluidically connected to a hydraulic machine 6, which is mechanically coupled to a flywheel 10 by way of a gear 8. The flywheel 10 can be driven by way of the hydraulic machine 6 on the one hand and the flywheel 10 can drive the hydraulic machine 6 on the other in order to reuse recovered energy for the second consumer 4. To supply pressurising medium to the consumers 2 and 4, two supply units 12 and 14 are provided, which are designed as pivotable hydraulic pumps. These can be driven by a drive unit 16 by way of a common drive shaft. In addition to the consumers 2 and 4, two further consumers 18 and 20, each in the form of a hydraulic cylinder, are provided. The consumers 2, 4, 18 and 20 are connected to the supply units 12, 14 by way of a valve block 21.

The first consumer 2 is preferably used in an open hydraulic circuit. The hydraulic machine 22 of the consumer 2 has a first pressure side 24 and a second pressure side 26. These can be alternately connected by way of the valve block 21 either to one of the supply units 12, 14 or both supply units 12, 14 or a tank 28. The first pressure side 24 can be connected to the second pressure side 26 by way of a first pressure-limiting valve 30. The second pressure side 26 can then be connected to the first pressure side 24 by way of a further second pressure-limiting valve 32. To measure the rotational speed of the hydraulic machine 22, a rotational-speed sensor 34 is provided, which can also be used to detect the rotational direction. In addition, the first pressure side 24 is connected to the valve block 21 by way of a non-return valve 36, which opens towards the pressure side 24, and the second pressure side 26 is connected to a non-return valve 38 which opens towards the pressure side 26. When the first consumer 2, and therefore the slowing gear, is braked, pressurising medium is taken from the first pressure side by way of a first non-return valve 40 or from the second pressure side 26 by way of a second non-return valve 42. A respective non-return valve 40 and 42 opens here in the pressurising-medium flow direction towards the hydraulic machine 6. Downstream of the non-return valves 40 and 42, a common throttle valve 44 is provided by means of which a flow cross-section in the flow path between the non-return valves 40 and 42 and the hydraulic machine 6 is continuously adjustable.

The throttle valve 44 has an input connection E to which the non-return valves 40 and 42 are connected and an output connection A which is connected on the input side to the hydraulic machine 6. An input-side pressure of the throttle valve 44 is measured by a pressure sensor 46. A valve slide of the throttle valve 44 can be acted upon by an actuating force in the direction of closing positions by way of a spring force of a valve spring and, conversely, in the direction of opening positions by an actuator. The actuator is controlled by an electronic control unit (ECU) 48.

The second consumer 4 has a first hydraulic cylinder 50 and a second hydraulic cylinder 52. These are arranged fluidically parallel to one another. Each hydraulic cylinder 50, 52 has a piston 54 which each separate a cylinder chamber 56 from an annular chamber 60 penetrated by a piston rod 58. The cylinder chambers 56 can be connected to the annular chambers 60 by way of a connecting valve 62. This is designed according to the throttle valve 44 and has an input connection E, which is connected to the cylinder chambers 56, and an output connection A, which is connected to the annular chambers 60. The connecting valve 62 is connected to a pressurising-medium flow path 64 between the cylinder chambers 56 and the hydraulic machine 6 by way of a non-return valve 66 which opens towards the connecting valve 62. By way of the connecting valve 62, the cylinder chambers 56 can be connected to the annular chambers 60 in throttled manner, or if required also in unthrottled manner, in particular when the arm is lowered and therefore when the cylinder chambers are reduced in size, whereupon a pressure in the cylinder chambers 56 increases in the event of a throttling effect. The connecting valve 62 is therefore preferably always opened when the arm is lowered. A pressure in the cylinder chambers 56 can be measured by way of a pressure sensor 68.

The cylinder chambers 56 are furthermore connected to the valve block 21 by way of a connecting line 73 and the annular chambers 60 are furthermore connected to the valve block 21 by way of a connecting line 75.

Arranged in the pressurising-medium flow path 64 is a throttle valve 70 which is designed according to the throttle valve 44. This has an input connection E which is connected to the cylinder chambers 56 and an output connection A which is connected to the hydraulic machine 6.

The connecting valve 62 branches off between the throttle valve 70 and the cylinder chambers 56. Both the connecting valve 62 and the throttle valve 70 can likewise be controlled by way of the ECU 48. A pressure on the output side of the throttle valve 70 can be detected by way of a pressure sensor 72. The output sides A of the throttle valves 44 and 70 are connected to one another and attached to a working connection X of the hydraulic machine 6.

In addition to the working connection X, the hydraulic machine 6 has a tank connection T which is connected to the tank 28. The hydraulic machine 6 can be used as a hydraulic pump and hydraulic motor. It is continuously pivotable, whereby a delivery volume can be adjusted in pump mode and an intake volume can be adjusted in motor mode. The working connection X of the hydraulic machine 6 is moreover connected to the tank 28 by way of a non-return valve 77, which opens in the pressurising-medium flow direction away 10 from the tank 28.

The adjustment of the supply units 12, 14 and the hydraulic machine 6 takes place by way of the ECU 48. The valve block 21 can likewise be controlled by way of the ECU 48. The sensors 46, 68 and 72 are furthermore connected to the ECU 48. In addition, a rotational-speed sensor 74 is provided for the hydraulic machine 6 and a rotational-speed sensor 76 is provided for the supply units 12, 14. A respective pivoting-angle sensor 78, 80 and 82 is moreover associated with the hydraulic machine 6 and the supply units 12, 14. The sensors 74 to 82 are likewise connected to the ECU 48. To control the consumers 2, 4, 18 and 20, actuating elements 84 in the form of joysticks are provided, which are connected to the ECU 48.

As the slewing gear, i.e. the first consumer 2, is braked, the throttle valve 44 is opened. The hydraulic machine 6 is then driven as a hydraulic motor. The pivoting angle of the hydraulic machine 6 is adjusted here in such a way that the entire volume flow can be taken from the first consumer 2 and possibly also from the arm, i.e. the second consumer 4. A braking force is determined by a counterpressure. The hydraulic machine 6 then in turn drives the flywheel 10 by way of the gear 6. So that pressurising medium can flow from the second consumer 4 to the hydraulic machine 6 when the arm is lowered, the throttle valve 70 is likewise opened here. An opening cross-section of the throttle valves 44 and 70 is selected here so that the pressure level of the consumers 2 and 4 on the output side of the throttle valves 44 and 70 are equalised. The pressure sensor 68 together with a movement of at least one of the actuating elements 84 (throttle control) indicates how quickly the arm of the second consumer 4 is to be lowered. The hydraulic machine 6 is adjusted accordingly.

To feed pressurising medium back into the cylinder chambers 56 of the consumer 4, the hydraulic machine 6 acting as a hydraulic pump delivers pressurising medium from the tank 28 by way of the open valve 70. An extension speed of the arm is determined by the rotational speed and the pivoting angle of the hydraulic machine 6 when the valve 70 is fully open.

In contrast to Figure 1, a hydraulic machine in the form of a hydraulic motor 86 is additionally provided according to Figure 2. The throttle valve 44 is then no longer connected to the hydraulic machine 6 on the output side, but to the hydraulic motor 66 by way of a connection line 88. The hydraulic motor 86, which is adjustable in terms of its intake volume, has an input connection E, which is connected to the connection line 88, and an output connection A, which is connected to an output line 90. The output line 90 leads between the non-return valves 36 and 38 to feed pressurising medium to a pressure side 24 or 26 which has a low-pressure. The hydraulic motor 66 is connected to the hydraulic machine 6 by way of a through-drive 92. The connection line 88 is moreover connected to the tank 28 by way of a non-return valve 93, with the non-return valve closing in the flow direction away from the tank 28.

The hydraulic motor 86 can now be driven in particular when the slewing gear is braked. The hydraulic machine 6 on the other hand is driven by the arm and can extend this latter. As a result of the arrangement of the hydraulic motor 86, as the energy is simultaneously recovered from the slewing gear and from the arm, this can take place without throttling by the throttle valves 44, 74. It is conceivable here to save on the throttle valve 44 and/or the throttle valve 70.

In contrast to Figure 2, a hydraulic motor 94, which is designed as a constant motor, is provided according to Figure 3a to recover energy of the first consumer. A pressure sensor 96 is moreover provided between the hydraulic motor 94 and the throttle valve 44.

The pressure-limiting valves 30 and 32 are connected on the output side between the non-return valves 36 and 38 by way of a connecting line 98. A feed pump 100 is moreover provided, which can deliver pressurising medium from the tank 28 into the output line 90. On the output side of the feed pump 100, this is connected to the tank 28 by way of a non-return valve 102, with the non-return valve closing in the pressurising-medium flow direction away from the tank 28.

In contrast to Figure 3a, the hydraulic motor 94 is replaced by a pivotable hydraulic motor 104 according to Figure 3b.

In Figure 4, the hydraulic machine 6 and the hydraulic motor 104 are arranged mechanically parallel. The gear 8 is designed accordingly for this. Conversely, in the embodiments of Figures 2 to 3b, the machines for recovering the energy are arranged mechanically in series.

According to Figure 5, the flywheel 10, which is connected by way of the gear 8 to the hydraulic machine 6 and the hydraulic motor 94 or 104, is illustrated schematically. A first valve block 106 is arranged between the first consumer 2 and the hydraulic machine 94 or 104 and a second valve block 108 is arranged between the second consumer 4 and the hydraulic machine 6.

A hydraulic arrangement is disclosed, which has a first hydraulic machine for a slewing gear of an excavator and a second hydraulic machine for an arm of the excavator. As the slewing gear is braked and as the arm is lowered, a flywheel for recovering the energy can be driven by corresponding means. The arrangement here is designed in such a way that the energy stored in the flywheel is usable for the arm and not for the slewing gear.

List of reference numerals 1 Arrangement 2 First consumer 4 Second consumer 6 Hydraulic machine 8 Gear Flywheel 12 Supply unit 14 Supply unit 16 Drive unit 18 Consumer Consumer 21 Valve block 22 Hydraulic machine 24 First pressure side 26 Second pressure side 28 Tank Pressure-limiting valve 32 Pressure-limiting valve 34 Rotational-speed sensor 36 Non-return valve 38 Non-return valve Non-return valve 42 Non-return valve 44 Throttle valve 46 Pressure sensor 48 Electronic control unit First hydraulic cylinder 52 Second hydraulic cylinder 54 Piston 56 Cylinder chamber 58 Piston rod Annular chamber 62 Connecting valve 64 Pressurising-medium flow path 66 Non-return valve 68 Pressure sensor Throttle valve 72 Pressure sensor 73 Connecting line 74 Rotational-speed sensor 75 Connecting line 76 Rotational-speed sensor 77 Non-return valve 78 Pivoting-angle sensor Pivoting-angle sensor 82 Pivoting-angle sensor 84 Actuating elements 86 Hydraulic motor 88 Connection line Output line 92 Through-drive 93 Non-return valve 94 Hydraulic motor 96 Pressure sensor 98 Connecting line 100 Feed pump 102 Non-return valve 104 Hydraulic motor 106 First valve block 108 Second valve block E Input connection A Output connection X Working connection Tank connection

Claims

Claims 1. A hydraulic arrangement for a work machine having a 5 first hydraulic consumer (2) and a second hydraulic consumer (4), wherein a flywheel (10) is provided, by means of which recovered energy at least of the first consumer (2) can be stored, characterised in that the arrangement is designed in such a way that the recovered energy is usable 10 for the at least one second consumer (4) and not for the first consumer (2).
2. An arrangement according to Claim 1, wherein the first consumer (2) is a hydraulic machine (22) for a slewing gear 15 of an excavator.
3. An arrangement according to Claim 2, wherein the energy of the slewing gear can be recovered when braking.
4. An arrangement according to one of Claims 1 to 3, wherein the second consumer (4) is a hydraulic cylinder (50) for an arm of the excavator.
5. An arrangement according to Claim 4, wherein the 25 recovered energy is used to raise the arm.
6. An arrangement according to one of the preceding claims, wherein a hydraulic machine (6) is connected to the flywheel (10) which is usable as a hydraulic motor and as a 30 hydraulic pump and is used to recover and reuse the energy.
7. An arrangement according to Claim 6, wherein the hydraulic machine (6) is pivotable.
8. An arrangement according to one of the preceding claims, wherein the first consumer (2) and the second consumer (4) are in active communication with the flywheel (10) in such a way that the energy can be recovered simultaneously from the first consumer (2) and the second consumer (4).
9. An arrangement according to one of Claims 6 to 8, wherein the hydraulic machine (6) can be driven in particular exclusively by the second consumer (4) and this can be driven by the hydraulic machine (6), and wherein a second hydraulic machine (86) is connected to the flywheel (10), which can be driven in particular exclusively by the first consumer (2), or wherein both consumers (2, 4) are fluidically connected to the hydraulic machine (6) and this can be driven by them.
10. An arrangement according to Claim 9, wherein a throttle valve (44) is arranged fluidically between the first consumer (2) and the hydraulic machine (6) and/or wherein a throttle valve is arranged fluidically between the second consumer (4) and the hydraulic machine (6), or wherein a throttle valve (44) is arranged fluidically between the first consumer (2) and the second hydraulic machine (86) and/or a throttle valve (70) is arranged fluidically between the second consumer (4) and the hydraulic machine (6).
11. An arrangement according to one of Claims 4 to 10, wherein the hydraulic cylinder (50) is a differential cylinder with a piston (54) which separates a cylinder chamber (56) from an annular chamber (60), wherein the chambers can be connected by way of a connecting valve (62).
12. An arrangement according to one of the preceding 5 claims, wherein at least one supply unit in the form of a hydraulic machine (12) is provided to supply pressuring medium to the consumers (2, 4) wherein, when the energy is returned to the second consumer (4), a power output of the at least one supply unit (12) is reduced depending on the 10 returned energy.
13. An arrangement according to Claim 10 or 11, wherein the flywheel (10) can be driven by the slewing gear (2) and by the arm (4) to recover energy by way of the common hydraulic machine (6) or by way of a respective hydraulic machine (6, 86), wherein the slewing gear (2) and the arm (4) are each connected by way of the proportionally adjustable throttle valve (44, 70) associated therewith to the common hydraulic machine (6) or their respective hydraulic machine (6, 86), and wherein the hydraulic machine (6) which is connected to the arm is pivotable and can be used as a hydraulic motor and as a hydraulic pump, and wherein the at least one supply unit is a hydraulic pump (12) which is provided as a main pressure source for the slewing gear (2) and the arm (4) and which is connected by way of a valve block (21) and/or by way of valves to the slewing gear (2) and the arm (4), wherein the arrangement is designed in such a way that the recovered energy is reused to drive the arm (4) and not to drive the slewing gear (2).
14. A process for recovering energy in a hydraulic arrangement according to one of the preceding claims, wherein, when the slewing gear (2) is braked, pressurising medium flows substantially unthrottled from one or from both consumers (2, 4) to the hydraulic machine used as a hydraulic motor (6), and/or wherein, when the energy is reused, pressurising medium flows substantially unthrottled from the hydraulic machine (6) used as a hydraulic pump into the hydraulic cylinder (50) of the arm (4), wherein a speed of the arm (4) can be determined by a rotational speed and/or a pivoting angle of the hydraulic machine (6).
15. A hydraulic arrangement as hereinbefore described with reference to and as shown in the accompanying drawings.
16. A process as hereinbefore described with reference 15 to and as shown in the accompanying drawings.