EP2128446B1 - Hydraulic unit - Google Patents

Description

The invention / innovation relates to a hydraulic unit for providing a pressurized hydraulic fluid for driving a coupled hydraulic actuator, with a motor arranged in a pressurized motor housing, arranged in a storage housing hydraulic accumulator, arranged in a pump housing hydraulic pump and a hydraulic block, wherein at least the motor housing, pump housing and the hydraulic block form a uniform manageable rigid module and the hydraulic fluid flowing around in the module passes through all elements of the module in the longitudinal direction (circulation system) in certain areas.

Hydraulic units are known from the prior art. WO 2006/056256 A2 teaches a hydraulic power unit, which uses an electric motor and a pump operated via this for generating pressure to a pressurized hydraulic fluid at an output. The hydraulic fluid drawn in by the pump is provided with a storage space with a variable compensation volume, in which the hydraulic fluid is stored gas-free.

Furthermore, a compact design of the hydraulic unit is known from the prior art, which provides that arranged in a housing of the unit of the electric motor and the pump and the housing surrounded by the interior space forms the storage space for the hydraulic fluid.

The invention / innovation is the object of developing a hydraulic unit with the features of the preamble of claim 1 such that it can be realized in a compact design, controlled by the simplest control and regulated (without electric valves) can be and has good operating characteristics such as high rigidity, overload safety and low noise emission. It is another object of the invention to have both good adaptability to, for example, extreme cold, ways and speeds as well as a high degree of flexibility.

This object is solved by the characterizing features of claim 1. Advantageous development of the invention will become apparent from the dependent claims 2-40.

As the core of the invention, it is considered that the hydraulic pump and the hydraulic block form a functional unit, the hydraulic block is provided with a plurality of hydraulic connection elements and a flange arranged in the pump housing delivery chamber is covered by the hydraulic block on the opposite side of the motor housing. In particular, the arrangement of the hydraulic pump immediately adjacent to the hydraulic block allows both a manufacturing technology easy to implement, as well as reliably operable in operation functional unit. The integration of the delivery chamber of the pump final "lid" to the hydraulic block, the dimensioning of the entire hydraulic unit is reduced. Parts of the pump components are assigned to the hydraulic unit. Both in the pump housing, as well as in the hydraulic block valves can be integrated. The hydraulic connection elements serve as an interface of the hydraulic unit to the connecting lines of the hydraulic actuators to be driven,

The hydraulic accumulator can be part of the uniform, manageable rigid module, thus reducing the dimensioning of the entire unit.

The hydraulic fluid flowing through all the elements of the module in the longitudinal direction is preferably guided in one circulation. This can be the Hydraulic fluid also be assigned a cooling function in addition to the power transmission function.

In particular in the pump housing, hydraulic elements such as pressure relief valves, suction valves or pilot operated check valves may be integrally employed and assisted by the shape and shape of the channels in the pump housing (e.g., channeling and / or concentration of hydraulic fluid in the area of the valves used).

Furthermore, the immediate vicinity of the hydraulic block to the pump (integration) achieves design advantages, it can be ensured directly from the delivery chamber of the pump via shortest connections to the hydraulic connection elements and optionally between these intermediate overload valves / pressure relief valves a safe, reliable and energy-saving operation of the hydraulic unit ,

It is advantageous if circumferential elements of the hydraulic pump protrude into the region of the hydraulic block via the flange surface arranged between the pump housing and the hydraulic block in the delivery chamber. For example, shaft elements (pinion shaft) of the pump can be mounted at least in regions in a corresponding recess of the hydraulic block. By such measures, the dimensioning of the entire hydraulic unit is further reduced. This effect is further promoted by the fact that the rotating elements of the hydraulic pump are guided in the region of the hydraulic block. Such a guide can positively affect both the storage and optionally other functions of the pump shaft to elements of the hydraulic block, for example, the pump shaft is formed as a hollow shaft, which in a continuing, preferably hydraulic fluid leading channel of the hydraulic block continues.

In the sense of an additional function, it may be provided that the peripheral elements arranged in the pump housing, cooperating therewith, valve elements arranged in the pump housing and the valve elements of the hydraulic block form a coherent integrated hydraulic functional unit. For example, the surface of the hydraulic block facing the pump does not only have a function concluding the delivery chamber, but also has further recesses influencing the function of the pump and / or the hydraulic fluid management, control and / or regulation. In particular, the fact that there is a connection to the pump directly from the valve elements of the hydraulic block, both a structurally simple, and low-maintenance and thus a reliable hydraulic unit is provided, for example, the sealed areas can be reduced to a minimum (only static seals).

Preferably, the pump is designed such that it is operable in four-quadrant mode and thereby allows a promotion of the hydraulic fluid in two directions (forward / backward). This also makes it possible, for example, not only to use the hydraulic unit as a medium providing hydraulic pressure, but also to tap from this electrical energy when the hydraulic unit is acted upon by a hydraulic pressure (energy return - 2, and 4 th quadrant).

Advantageously, the pump is designed as a gear pump. This includes, for example, an external gear, internal gear or gerotor pump. Vane pumps, screw pumps, rotary lobe pumps or rotary vane pumps can also be used in conjunction with the hydraulic unit. Such pumps have the advantage that they are a relative ensure uniform delivery of the pump medium and the conveying direction is reversible with the direction of rotation.

As drive modes for the motor are preferably called controlled or unregulated electrical asynchronous or synchronous motors. Generally, under oil designs are preferred which ensure intensive cooling, build compact and achieve a low mass moment of inertia.

To increase the versatility of the system, it is advantageous if between the pump housing of the (first) hydraulic pump and the motor driving the pump, a further hydraulic pump is arranged, which is also driven by the motor. Alternatively or additionally, the further hydraulic pump can be arranged between the motor and the hydraulic accumulator and / or between the first pump and the hydraulic block and can likewise be driven via the motor driving the first hydraulic pump. By means of the further hydraulic pump higher pressures for the hydraulic medium can be generated. For example, in the case of driving a pressing or punching machine, it is advantageous for fast linear movements of the pressing or punching machine to use the pump power of the first pump and for the forming and / or shear phases of the pressing / punching machine, the pump power (especially at high Press) the other hydraulic pump to use. Depending on the application, it may be advantageous to operate these two hydraulic pumps either to achieve high pressures in series or when the high pressures should not be crucial to switch the first and the other hydraulic pump in a parallel operative connection, so that larger delivery volumes can be achieved , Furthermore, a hydraulic pump can be designed as a radial piston pump and arranged both on the pump and preferably on the storage side of the engine. Since this has a favorable efficiency and reaches high load pressures at a smaller flow rate, it is suitable for the above-described Forming and / or shear phases. Consequently, the radial piston pump can serve primarily as a second higher pressure level. In order to be able to use the full drive power for the high pressures, the delivery of the low-pressure pump is automatically switched to pressureless circulation.

When two internal gear pumps interact in series between the hydraulic block and the electric motor, normal delivery and high pressure are achieved.

The leak hydraulic fluid occurring during operation of the hydraulic unit is preferably returned directly to the housing in the hydraulic system of the hydraulic unit. Thus, it is contemplated that the hydraulic fluid exiting from one or more pressure relief valves and / or other hydraulic elements (e.g., pilot operated check valves) may be internally fed directly into the hydraulic system of the hydraulic unit. This pressure limiting valve and / or hydraulic element is preferably arranged in the region of the hydraulic block and is operatively connected to channels arranged in the region of the pressure limiting valve and / or hydraulic element, which purposefully recirculate the escaping hydraulic fluid into the hydraulic system of the hydraulic unit. This can also be used for one circulation to maintain the cooling.

According to a further embodiment, a hydraulic return flow channel is formed in the central region of the at least one hydraulic pump, which connects the outlet of the pressure limiting valve with the hydraulic reservoir passing through the engine and hydraulic accumulator. Such a hydraulic return flow channel is preferably operatively connected directly or indirectly to the pressure limiting valve and / or hydraulic element. Preferably, the shaft of the motor and / or the shaft of the pump as Hollow shaft formed and forms a part of the return channel (circulation channel) for the hydraulic fluid to return them to the hydraulic accumulator. As a result, in the course of circulation, a flow of the motor between stator and rotor takes place. By such a design of the circulation, both the dimensioning of the entire hydraulic unit can be reduced, as well as a cooling function are taken over by the flowing back through the return flow in the hydraulic fluid, as this when flowing through the motor and / or pump hollow shaft to just this place, but especially at the stator and rotor of the engine can dissipate heat energy.

A particularly advantageous embodiment of the hydraulic unit according to the invention is formed in that the return flow channel formed by the shaft of the motor is aligned coaxially with the hydraulic return flow of the pump. Such a linear hydraulic fluid guide simplifies the overall construction, reduces the resistances acting on the hydraulic fluid and promotes or allows the hydraulic fluid circulation

For example, the return flow channel formed by the shaft of the engine immediately continues with the volume of the hydraulic accumulator.

In a further development of the invention, the opposing flanges of the pump housing are aligned parallel to each other. In particular, if these flanges are aligned parallel to each other and / or have a coordinated coupling surface, it is possible, in the manner of a modular system, one, two or more pump housing together and thus designed depending on the application, the performance of the hydraulic unit targeted.

In addition, it has proved to be advantageous if the axes of rotation of the rotating elements of at least one hydraulic pump and the electric motor are arranged substantially coaxially with each other. This feature also allows a simple and constructed in the manner of a modular design composition of the hydraulic pump with the electric motor.

Further, it is provided to connect the drive motor with the pump driving shaft by means of a coupling element, such as a cross slide. Such a coupling element may be formed depending on the combination of different motors and different pumps as a specific combination part, so that at the interfaces of the engine and the pump relatively simple held, the respective component conditions corresponding configurations of the interfaces can be implemented. Thus, in a first combination case of a first motor with a first pump, a first coupling element for connecting the two elements can be used and in a second combination case in the combination of a second motor with again the first pump, a second coupling element can be used. Such a composition of the individual hydraulic units with such coupling elements increases the flexibility and simplifies the overall construction in particular when providing a plurality of different power gradations (motor-pump combination). In combination with the central hydraulic fluid return, the coupling element has corresponding recesses and / or openings. In addition, such a coupling compensates for a possible axial offset due to manufacturing tolerances.

Furthermore, it may be provided to arrange the connecting flange passing through hydraulic fluid carrying elements substantially symmetrical to the motor axis.

It is also advantageous if the hydraulic block, the pump housing, the motor housing and the storage housing are formed substantially rotationally symmetrical and are arranged coaxially or axially parallel to each other.

In order to simplify the anchoring of the hydraulic unit with the environment, for example with a support element and / or a robot arm, it is advantageous if the pump housing and / or the motor housing in each case with at least one region beyond the outer diameter of the pump housing or the motor housing final pump flange respectively motor flange area is provided. The pump flange region and the motor flange region advantageously have at least one mounting flange arranged in a coplanar plane, on which the essentially cylindrical hydraulic unit can be reliably and statically mounted on a flat surface.

The hydraulic accumulator used is preferably a bladder accumulator or a piston accumulator which has an air or gas bias directed against the hydraulic reservoir. Alternatively or additionally, the bladder accumulator or piston accumulator can also be preloaded with a different preloading element (for example a spring). In particular, the use of a bladder accumulator having at least one air or gas bias directed against the hydraulic reservoir has the advantage that by controlling and regulating the air or gas bias (e.g., from a pneumatic network), the operation of the hydraulic unit can be selectively influenced.

The flexibility and simplicity of the hydraulic unit can be further positively influenced by a terminal adapter with hydraulic connection elements can be attached to the hydraulic block. Furthermore, a cover housing element can be attached to the hydraulic block, which covers at least one valve element. Depending on the type and dimensions of the connected Hydraulic connections of the hydraulic lines to the hydraulic unit and / or depending on the required volume flows, various modular attachment to the hydraulic block connection adapter can be arranged on the hydraulic block. The hydraulic connection elements of the hydraulic block are then formed by the hydraulic connection elements of the connection adapter. Actuators can be directly connected with suitable flanges, so that the hydraulic unit forms a unit with the actuator.

Advantageously, the hydraulic unit is designed in such a way that no outwardly acting seals are arranged on moving parts. This is achieved inter alia by the encapsulated, guided in the manner of a circulation hydraulic fluid.

A further advantageous measure is to provide at least one suction valve for volume compensation for thermal processes and possibly leakage in the hydraulic unit.

The flow and return of a hydraulic actuator can be accomplished by only a reversal of the pump rotation of the hydraulic unit. Thus, a forward and reverse flow can be realized without the use of electromagnetic directional control valves. Conveniently, the hydraulic unit is a closed to the atmosphere system and makes it possible to adjust the pressure of different sizes variable. This prevents re-suction (from the atmosphere) and effectively excludes the absorption of air, moisture and foaming harmful to the operation of hydraulic systems.

In an embodiment of the invention, the hydraulic actuators perform linear and / or rotary movements. Furthermore, the unit for decentralized drives can be provided and position independent, stationary and in particular mobile operation with high accelerations (eg mounting on a robot).

Fig. 1:

eine perspektivische Darstellung der Hydraulikeinheit;

Fig. 2:

eine schematische, mittige Längsschnittdarstellung gem. Fig. 1;

Fig. 3:

eine schematische Vollschnittdarstellung gem. Schnittlinie IV-IV aus Fig. 1;

Fig. 4:

eine perspektivische Vollschnittdarstellung gem. Schnittlinie V-V aus Fig. 1;

Fig. 5:

eine schematische Vollschnittdarstellung gem. Schnittlinie VI-VI aus Fig. 1;

Fig. 6:

einen Schaltplan einer einen Aktuator mit einseitiger Kolbenstange betreibenden Hydraulikeinheit in 2-Stufenausführung mit unterschiedlichen Volumenströmen und unterschiedlichen Drücken;

Fig. 7:

einen Schaltplan einer einen Aktuator mit durchgehender Kolbenstange (Gleichgangzylinder) betreibenden Hydraulikeinheit;

Fig. 8:

einen Schaltplan einer einen Aktuator mit einseitiger Kolbenstange betreibenden Hydraulikeinheit mit druckgesteuertem 2-Wege-Ventil;

Fig. 9

einen Schaltplan einer einen Aktuator mit einseitiger Kolbenstange betreibenden Hydraulikeinheit mit einem entsperrbaren Rückschlagventil.

The invention is explained in more detail with reference to embodiments in the drawing figures. These show

Fig. 1:

a perspective view of the hydraulic unit;

Fig. 2:

a schematic, longitudinal longitudinal view in accordance with. Fig. 1 ;

3:

a schematic full sectional view acc. Section IV-IV off Fig. 1 ;

4:

a perspective full-sectional view acc. Cut line VV off Fig. 1 ;

Fig. 5:

a schematic full sectional view acc. Section line VI-VI off Fig. 1 ;

Fig. 6:

a circuit diagram of an actuator with a one-sided piston rod operating hydraulic unit in 2-stage design with different flow rates and different pressures;

Fig. 7:

a circuit diagram of an actuator with a continuous piston rod (Gleichgangzylinder) operating hydraulic unit;

Fig. 8:

a circuit diagram of an actuator with a one-sided piston rod operating hydraulic unit with pressure-controlled 2-way valve;

Fig. 9

a circuit diagram of an actuator with a one-sided piston rod operating hydraulic unit with a pilot operated check valve.

In the Fig. 1 illustrated hydraulic unit 1 is (not shown) for driving a coupled hydraulic actuator driven by a arranged in a motor housing 2 electric motor 3. At a first end of the motor housing 2, a storage housing 4 is flanged with a hydraulic accumulator 5 arranged therein. At the hydraulic accumulator 5 opposite end face of the motor 3 is arranged in a pump housing 6 hydraulic pump 7 and on the pump housing 5, a hydraulic block 8 is attached. About arranged on the hydraulic block 8 hydraulic connection elements 9 (interfaces) hydraulic actuators are connected.

As shown, the motor housing 2, the pump housing 6, the hydraulic block 8 and the storage housing 4 form a uniformly hand-held rigid module 30, wherein the hydraulic fluid flowing around in the module 30 passes through all the elements of the module 30 in the longitudinal direction. By juxtaposing the hydraulic pump 7 and the hydraulic block 8, a functional unit is formed. The arranged in the pump housing 6 delivery chamber 10 is covered on the motor housing 2 opposite side by the hydraulic block 8. As can be seen in the illustrated embodiment, the hydraulic accumulator 5 is part of the uniformly manageable rigid module 30th

In the drawing figure 2, the hydraulic unit 1 is shown in longitudinal section. It can be seen in particular that the hydraulic fluid in the longitudinal direction of all elements 3, 5, 7, 8 of the module 30 in its longitudinal direction flowed through in a circular manner. This can be used, inter alia, that leak hydraulic fluid gehäuseintem is traceable directly into the hydraulic system of the hydraulic unit 1. In addition, the exiting from the pressure relief valves 11 hydraulic fluid gehäuseintem be returned directly into the hydraulic system of the hydraulic unit 1. This can be achieved, in particular, by means of a hydraulic return flow channel 12 which is arranged in the central region Z of the hydraulic pump 7, whereby the latter connects the outlet 13 of a pressure limiting valve 11 and / or a pilot operated check valve (not shown) with a hydraulic reservoir passing through the motor 3. The hydraulic reservoir is formed, in particular, by the volume area penetrated by the hydraulic fluid, wherein the largest hydraulic reservoir volume can be found in the region of the hydraulic accumulator 5. As especially in the sectional view of the FIG. 2 can be seen, the motor 3 has a hollow shaft 14, which is used as reflux channel 12 for the hydraulic fluid to the hydraulic accumulator 5. In connection with the hollow shaft 14, it is advantageous, as shown, to connect coaxially with the Hydraulikrückflußkanal 12 (hollow shaft 15) of the hydraulic pump 7. The hydraulic return passage 12 with its hollow shafts 14, 15 is directly connected to the volume of the hydraulic accumulator 5.

Especially for the hydraulic fluid return, it is advantageous if the axes of rotation of the rotating elements of the hydraulic pump 7 and the electric motor 3 are arranged coaxially with each other. If the two hollow shafts 14, 15 of the motor 3 and the hydraulic pump 7 are aligned coaxially with each other, they can be coupled together by a connecting sleeve 16 in such a way that the circulation of the hydraulic fluid is not disturbed.

In the illustrated embodiment, the hydraulic accumulator 5 comprises a bladder accumulator, which at its end remote from the motor 3 end 17 with a can be operated against the hydraulic reservoir directed air or gas bias and / or spring element bias. Furthermore, in particular from the sectional view ( Fig. 2 ) can be seen that on the moving parts (hollow shafts 14, 15 and bearing elements of the motor 3 and the hydraulic accumulator 5) no outwardly acting seals are arranged.

For the formation of a functional unit of the hydraulic block 8 and the hydraulic pump 7, it is advantageous if the pump housing 6 is wholly or partially provided with hydraulic elements (valves, channels). Because in Fig. 2 In some cases the (hidden) elements lying behind the cut surfaces are shown visually (dot-dash line S), the connecting channels 18 arranged in the region of the connection surface of the hydraulic block 8 and the hydraulic pump 7 as well as parts of the delivery chambers 10 of the hydraulic pump 7 are visible. The connecting channels 18 and parts of the delivery chamber 10 are thus incorporated as hydraulic elements in the pump housing 6. In the course of this integrated construction of the hydraulic pump 7 and the hydraulic block 8, it is expedient to allow circulating elements of the hydraulic pump 7, such as the pinion shaft 19, to protrude into the area of the hydraulic block 8 via flange surfaces arranged between the pump housing 6 and the hydraulic block 8. In these protruding areas, the pinion shaft 19 is thus guided in the hydraulic block 8. By providing a hollow shaft 15 for the pinion shaft 19 of the hydraulic pump 7, the pinion shaft 19 in addition to its wave function also advantageously cooperate with arranged in the pump housing 6 valve elements and / or valve elements of the hydraulic block 8 and form a contiguous integrated hydraulic functional unit.

In drawing figure 3, the hydraulic block 8 is shown cut, it is easy to see how the pressure relief valve 11 is disposed within the hydraulic block 8 and how the outgoing from the pump connecting channels 18th and the central hydraulic fluid return passage 12 leads from the hydraulic block 8 to the hollow shafts 14, 15. In addition, 8 additional attachments 21, 22 can be seen on the hydraulic block. The hydraulic block 8 is viewed from the side view in cross-section T-shaped. A cover housing element 21 can be attached to the hydraulic block 8 in such a way that it at least partially covers the hydraulic block 8 as well as optionally valves 11 connected to the hydraulic block 8 and projecting beyond its contour. The hydraulic connection elements 9 associated with the hydraulic block 8 are arranged in the illustrated embodiment on the connection adapter 22 and connected by means of channels to the hydraulic block 8. Thus, the connection adapter 22 serves as an adapter to the different connection options due to different connection line connections of the actuators used in each case (line diameter, terminal locking mechanism). By Abdeckgehäuseelement 21 and / or the terminal adapter 22, it is possible to keep the hydraulic block 8 manufacturing technology simple and to run it as a series part. The application-specific interfaces can be assigned to the modular adapters 22 which can be attached to the hydraulic block 8.

In the perspective sectional view of the drawing figure 4 gem. the section line VV of FIG. 1 is the zahnringpumpenartige structure of the hydraulic pump 7 of the illustrated embodiment recognizable. Preferably, an internal gear pump is used, since in this the axis of rotation of the central element (pinion shaft 19) remains concentric relative to the pump housing 6 and in particular the hydraulic block 8 and thus finally a linear hydraulic return passage 12 can be formed by the hollow shaft 15 of the hydraulic pump 7.

From the drawing figure 5, the motor 3 and the hydraulic pump 7 connecting coupling element 23 can be seen. This is a Cross slide 24, which compensates both manufacturing tolerances of the two connection partners, as well as in the sense of modular design allows different motor-pump combinations.

The in the FIGS. 6 and 7 shown schematic diagrams put in the first hydraulic pump 7, a hydraulic fluid both forward and backward promoting hydraulic pump 7, which is operable in four-quadrant mode, based. Thus, the actuator can be provided with a one-sided (25) or continuous (26) piston rod. In the embodiment shown in Figure 7, the cylinder 25 is shown with one-sided piston rod, for example, the pressing cylinder of a punching tool. For the thereby necessary high pressures between the engine 3 and the hydraulic accumulator 5, a further hydraulic pump 27 is arranged, which is also driven via the first hydraulic pump 5 driving motor 3. This further hydraulic pump 27 may be formed as a radial piston pump and thereby delivers the higher pressure than the hydraulic block 8 facing the first hydraulic pump 7. To use the second radial piston pump 27 as the second higher pressure level, it is set with the first hydraulic pump 7 in parallel. In particular, by the corresponding use and arrangement of a pressure-controlled 2-way valve, the hydraulic pumps 7, 27 are set in operative connection, that when exceeding the low pressure, the promotion of the low-pressure pump 7 is automatically pressureless circulation, so that the drive power of the engine. 3 concentrated on the high-pressure pump 27.

The embodiment shown in Figure 7 represents the basic design for the operation of a co-axial cylinder. In this flow and return volume are equal and thus also the forward and return speeds of the connected actuator 26. actuators with one-sided piston rod (reference numeral 25 in Fig. 6 ) have different Flow and return volumes. Although the speeds for such cylinders are also the same after this circuit, but during the flow, the missing volume is sucked in via a check valve in the function as Nachsaugventil 31 and the excess volume flows through a pressure relief valve 11 during the return.

In drawing figures 8 and 9 actuators are shown with one-sided piston rod and different flow and return speed. In drawing figure 8, the excess oil flows through a pressure-controlled 2-way valve and at FIG. 9 via a pilot operated check valve without pressure.

The hydraulic block 8, the pump housing 6, the motor housing 2 and the storage housing 4 are formed substantially rotationally symmetrical and coaxial with each other, see. Fig. 1 , In this case, the pump housing 6 and the motor housing 2 each have at least one pump flange region 28 or motor flange region 29 projecting in regions beyond the outer diameter of the pump housing 6 or the motor housing 2. These flanges 28, 29 are used to mount the hydraulic unit 1 to other elements. For example, the hydraulic unit 1 can be mounted on a robot arm in a simple manner via such flanges. For mounting on flat surfaces, it is advantageous if the pump flange region 28 and the motor flange region 29 are designed as mounting flanges 28, 29 arranged in a coplanar plane.

LIST OF REFERENCE NUMBERS

1

hydraulic unit

2

motor housing

3

engine

4

storage Enclosures

5

hydraulic accumulator

6

pump housing

7

hydraulic pump

8th

hydraulic block

9

Hydraulic connection element

10

delivery chamber

11

Pressure relief valve

12

Hydraulikrückflußkanal

13

Output v. 11

14

Hollow shaft v. 3

15

Hollow shaft v. 7

16

connecting sleeve

17

End of v. 5

18

connecting channel

19

pinion shaft

21

Abdeckgehäuseelement

22

connection adapter

23

coupling member

24

cross slide

25

Einwegezylinder

26

Two-way cylinder

27

Hydraulic pump (further)

28

Pumpenflanschbereich

29

Motorflanschbereich

30

module

31

cavitation valve

Z

Central area

Claims (15)

1. Hydraulic unit (1) for providing a pressurized hydraulic liquid for driving a coupled hydraulic actuator, having a motor (3) which is arranged in a motor housing (2), a hydraulic accumulator (5) which is arranged in an accumulator housing (4), a hydraulic pump (7) which is arranged in a pump housing (6), and a hydraulic block (8), at least the motor housing (2), the pump housing (6) and the hydraulic block (8) forming a rigid module (30) which can be handled as one unit, and the hydraulic liquid which flows around in the module (30) permeating all elements of the module (30) in regions in the longitudinal direction, the hydraulic pump (7) and the hydraulic block (8) forming one functional unit, and the hydraulic block (8) being provided with a plurality of hydraulic connector elements (9), characterized in that, by way of a flange, the hydraulic block covers a delivery chamber (10) which is arranged in the pump housing (6) on the side which lies opposite the motor housing (2).
2. Hydraulic unit according to Claim 1, characterized in that the hydraulic accumulator (5) is a constituent part of the rigid module (30) which can be handled as one unit.
3. Hydraulic unit according to Claim 1 or 2, characterized in that the hydraulic liquid which flows through all elements of the module (30) in the longitudinal direction is guided in circulation.
4. Hydraulic unit according to one of the preceding claims, characterized in that the hydraulic pump (7) is a pump (7) which can be operated in the four-quadrant mode and permits a delivery of hydraulic liquid in two directions, namely the forward and reverse direction.
5. Hydraulic unit according to one of the preceding claims, characterized in that a further hydraulic pump (27) which can likewise be driven via the motor (3) is arranged between the pump housing (6) of the (first) hydraulic pump (7) and the motor (3) which drives the hydraulic pump (7).
6. Hydraulic unit according to one of the preceding claims, characterized in that a further hydraulic pump which can likewise be driven via the motor (3) is arranged between the pump housing (6) of the (first) hydraulic pump (7) and the hydraulic block (8).
7. Hydraulic unit according to one of the preceding claims, characterized in that a further hydraulic pump (27) which can likewise be driven via the motor (3) which drives the first hydraulic pump (7) is arranged between the motor (3) and the hydraulic accumulator (5).
8. Hydraulic unit according to one of Claims 5 to 7, characterized in that the first and the further hydraulic pump (7, 27) can be operated in a series connection in order to achieve high pressures.
9. Hydraulic unit according to one of Claims 5 to 8, characterized in that the hydraulic pumps (7, 27) are operatively connected in such a way that, if the low pressure is exceeded, the delivery of the low pressure pump (7) changes over automatically to circulation.
10. Hydraulic unit according to one of the preceding claims, characterized in that a hydraulic return flow channel (12) is formed in the central region (Z) of the at least one hydraulic pump (7), which hydraulic return flow channel (12) connects the outlet of at least one pressure limiting valve (11) and/or a check valve which can be unlocked to a hydraulic reservoir which permeates the motor (3).
11. Hydraulic unit according to one of the preceding claims, characterized in that the shaft of the motor (3) is configured as a hollow shaft (14) and forms a return flow channel (12) for the hydraulic liquid to the hydraulic accumulator (5).
12. Hydraulic unit according to one of the preceding claims, characterized in that the hydraulic accumulator (5) is a bladder accumulator or piston accumulator which has an air or gas prestressing means and/or spring element prestressing means which is directed counter to the hydraulic reservoir.
13. Hydraulic unit according to one of the preceding claims, characterized in that the housing of the hydraulic block (8) consists of a middle valve flange (21) and at least one connector flange (20) which is attached to it.
14. Hydraulic unit according to one of the preceding claims, characterized in that no seals which act towards the outside are arranged on moving parts.
15. Hydraulic unit according to one of the preceding claims, characterized in that a forward and return movement of a hydraulic actuator can be carried out by way of a reversal of the pump rotational direction.

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