EP2553269B1 - Double diaphragm pump - Google Patents

Description

The present invention relates to a diaphragm pump having at least one membrane.

In membrane pumps, the membrane limits a delivery chamber into which a supply line and an outlet line open. As a rule, non-return valves are arranged in the supply and discharge lines in such a way that, by moving the membrane back and forth, the conveying medium can first be sucked into the conveying space via the feed line and then be forced out of the conveying space via the outlet line.

So that a continuous pumping is possible, usually two diaphragm pumps are connected in parallel, wherein one sucks the fluid and the other presses out the pumped fluid from its pumping chamber in the same time.

Double diaphragm pumps are also known in which the diaphragms, which are usually designed as disc diaphragms, are adjusted by means of a common piston-cylinder system or by means of an electric drive. In rooms in which explosive gases may occur, no electric pumps may be operated or the strict requirements of explosion protection must be taken into account. Here, pneumatic pumps are generally used, in which a piston which is mechanically connected to the membranes, by means of compressed air in a cylinder is moved back and forth. The compressed air is switched by means of a main valve such that the two working spaces are alternately filled with compressed air. Such a pump is out of the US 4,818,191 known. The separate from the pump room from the membranes chambers are connected by channels with the environment, so that in case of leakage, the fluid can escape from the pump and does not hinder the movement of the membranes. A disadvantage of this pump is that the membranes are exposed to a high differential pressure load due to the high pressure in the delivery chamber and the pressure prevailing behind the membrane ambient pressure, resulting in rapid wear of the membranes.

A further developed pneumatically driven double diaphragm pump is from the WO2009 / 024619 known. In this pump, the compressed air driving the piston is simultaneously directed into the space behind the membrane. At the same time, the membrane is supported by a plate, which, however, only fully supports the membrane in one dead center. The disadvantage of this pump is that in case of a defect of the membrane, the fluid enters the pneumatic and the valves and thus the entire pump is out of action. The pump can then be repaired, if at all, only with great effort.

A double-chamber diaphragm pump without driven piston is out of the DE 32 06 242 known. A disadvantage of this pump are the large spaces that must be filled after reaching dead center with compressed air, so that the membrane can be moved in the other direction. This requires a lot of compressed air, which increases the maintenance costs of the pump. A similarly constructed pump with the same disadvantages is from the CA 1172904 , of the WO97 / 10902 and the US 5,368,452 known. Even with the pump known from WO2009 / 024619, a disproportionate amount of compressed air is required for the operation of the pump. Also, these pumps are not pressure-translated, so that the delivery pressure is always below the feed pressure.

Out EP 247 459 is a portable pressure-generating apparatus known which serves for connection to diaphragm pumps. The apparatus generates by means of a hydraulic medium, a pressure or negative pressure for adjusting the diaphragm in the diaphragm pumps.

Out DE 84 33 622 . DE 31 50 976 and WO97 / 10902 each double diaphragm pumps are previously known, in which the membrane are connected to each other by means of a piston rod, wherein the adjustment of the diaphragm mittesl adjustment of the piston rod takes place.

Object of the present invention is to provide a diaphragm pump, in which the membranes have a long service life and are subjected to low differential pressures and has a good efficiency.

This object is achieved with a diaphragm pump having the features of claim 1. Advantageous embodiments of the diaphragm pump according to claim 1 result from the features of the subclaims.

The invention is based on the idea that the diaphragm pump has a first piston-cylinder system whose piston drives at least one hydraulic cylinder. The piston can thereby by means of a fluid, e.g. Compressed air or a liquid medium driven, i. be moved back and forth. As a result, the at least one hydraulic piston is also moved back and forth. The hydraulic piston is in turn arranged in a cylinder and divides this into two working spaces, a first and a second working space. At least one first working space is filled with a hydraulic medium which acts on the membrane of the diaphragm pump.

The diaphragm pump is designed as a double diaphragm pump, so that in each case the two membranes promote alternately. Advantageously, the first working space is limited in each case by the hydraulic piston and the membrane. However, it is also possible that the working space is connected via a connecting line with the space separated from the diaphragm by the pumping chamber, and thus the hydraulic medium moved by the hydraulic piston acts on the diaphragm and adjusts it.

The first piston of the first piston-cylinder system is advantageously driven by compressed air, so that the diaphragm pump can also be used in explosion-proof rooms.

Due to the freely selectable surfaces of the first piston and hydraulic piston, any desired pressure ratio between the driving pneumatic pressure and the delivery pressure of the pump can be adjusted.

Regardless of the delivery pressure of the diaphragm pump, the diaphragms are exposed to a maximum of one differential pressure load (maximum suction power) of one bar, which advantageously results in a long service life of the diaphragms.

Advantageously, as the hydraulic medium, an inert liquid is selected for the conveyed medium, so that in the event of a defect in the membrane, the fluid being conveyed is not contaminated. If the fluid enters the first working space in the event of a malfunction, this will not affect the pump.

Advantageously, the second working spaces of the hydraulically acting piston-cylinder systems are interconnected so that they function as damping members by pumping the medium in these work spaces, which is advantageously the same inert hydraulic medium as in the first work spaces, back and forth.

If the pump is designed as a double diaphragm pump, the membranes are connected to each other by means of a connecting element, which synchronizes the movement of the membranes. This connecting element is not used to drive the membranes. Advantageously, the connecting element at its ends in each case a thread with which it is screwed into the membranes. The screwing can be done directly in the material, in particular rubber, or in an inset in the membrane threaded bushing. Since the connecting element does not transmit large forces, it is usually possible to dispense with a threaded bushing.

A small construction is advantageously achieved when the driving first piston-cylinder system between the hydraulically acting piston-cylinder systems is arranged. The first piston is rigidly connected by means of piston rods with the two hydraulic pistons, whereby they are adjusted synchronously with him. The connecting element of the membranes can advantageously pass through the tubular piston rods and is mounted in these displaceable. At the same time, the connecting element passes through the hydraulic pistons, with correspondingly arranged seals preventing hydraulic fluid from passing from one working space to the other through the piston rods.

Advantageously, the diaphragm pump has at least one device for monitoring the quantity of hydraulic medium present in one and / or several working chambers of the hydraulically acting piston-cylinder systems and / or in their connecting line. If hydraulic medium escapes and is sucked out of a storage container, this is detected by the device and the pump stopped and / or sent an error signal to a higher-level control system.

The first piston of the first piston-cylinder system reciprocating fluid, in particular compressed air, is guided by a main valve, which is controlled in particular by the movement of the first piston, alternately into the first and second working space of the first piston-cylinder system.

In the working spaces axially or frontally bounding walls of the first piston-cylinder system are each of the first piston before or upon reaching the respective dead center or switching point mechanically operated changeover valves, in particular 3/2-way valves arranged. The switching valves control the main valve switching compressed air. Advantageously unregulated compressed air is used, ie compressed air, which is provided by an external compressed air source available. This pressure is usually higher than the pressure with which the diaphragm pumps are operated according to the prior art. This ensures that the diaphragm pump according to the invention safely switches. This is with diaphragm pumps according to the state of the art, in which the main valve only has an input for regulated air, often not given, because the regulated pressure to the first piston-cylinder system is often very low.

The first piston mechanically actuates the valve actuators of the change-over valves, the change-over valves being designed in particular as a cartridge valve, i. from the outside in the respective frontally limiting wall of the first piston-cylinder system can be used, in particular screwed, are. This results in a particularly favorable structure, since the valves can be replaced without opening the delivery chambers.

The main valve is advantageously arranged outside of the housing of the diaphragm pump, so that the main valve can be easily cleaned, repaired or replaced.

Advantageously, the main valve is designed as a 4/2-way valve or as a 5/2-way valve. That the valve control element of the main valve moves alternately back and forth between two end positions. It thus has only two defined positions in the form of end positions. On the way from one end position to the other end position, that is, during the movement, the two working chambers of the first piston-cylinder system are connected to each other via the valve control element of the main valve and thus the receiving working space with the compressed in a central region between the end positions Compressed air from the transferring working space prefilled. Thereafter, the working space, which was pre-filled, filled with regulated air on. The other working space is connected to the valve outlet, so that the remaining working air from the working space can relax via muffler. This results in a better efficiency of the diaphragm pump according to the invention, since less compressed air is required for the operation of the pump.

Advantageously, the main valve has an input for unregulated compressed air of an external compressed air source, wherein the main valve itself may have a pressure control device for generating regulated compressed air of a certain pressure. About a displaceably arranged in the housing of the main valve valve control element, which is controlled by the switching valves controlled by the compressed air, in particular the unregulated Compressed air is adjusted, the regulated compressed air is passed alternately into the working chambers of the first piston-cylinder system.

So that the remaining working space in the dead centers of the first piston is as small as possible, the axial cylinder walls of the cylinder of the first piston-cylinder system can be advantageously adapted to the shape of the axial walls of the first piston. A planar design of the walls is to be preferred here.

The switching valves may advantageously have throttles, so that the forced out of the respective working space air is braked by the throttle and this advantageously leads to a slowed movement of the valve control element of the main valve from the central region, whereby the phase of pressure equalization between the prestressed and soon To be emptied work space and the next to be filled work space is as long as possible. The throttle at the beginning of the movement of the pneumatic piston is not so strong, so that the valve control element of the main valve is moved at high speed from its end position in the direction of the central region in which the working spaces of the pneumatic cylinder are short-circuited.

Each delivery chamber can advantageously be connected via a respective feed channel to a common supply line and / or via an outlet channel to a common pressure line, wherein the supply line and / or the pressure line is floatingly mounted on at least one connection region of the pump housing. This advantageously ensures that no mutually occurring stresses occur at the joints mechanical fatigue. Valves, in particular non-return valves, are respectively arranged in the feed channels and in the outlet channels.

It is of course possible that by means of the first piston-cylinder system, which is in particular pneumatically driven by compressed air, a plurality of mutually parallel hydraulic piston can be driven. As a result, by means of a pneumatic drive more than two membranes, In particular, a multiple of two are driven or adjusted for sucking and pressing.

Hereinafter, a possible embodiment of the diaphragm pump, which is designed as a double diaphragm pump, explained in more detail with reference to drawings.

Fig. 1:

Perspektivische Ansicht der erfindungsgemäßen Membranpumpe in Form einer Doppelmembranpumpe;

Fig. 2:

geschnittene Darstellung der Membranpumpe gemäß Fig. 1;

Fig. 3:

Querschnittsdarstellung durch die Doppelmembranpumpe gemäß der Figuren 1 und 2;

Fig. 4:

Teilausschnitt aus der Figur 3;

Fig. 5:

Pneumatikplan für eine erfindungsgemäße Membranpumpe mit einem 5/2-Wegeventil als Hauptventil;

Fig. 6:

Pneumatikplan für eine erfindungsgemäße Membranpumpe mit 4/2-Wegeventil als Hauptventil.

Show it:

Fig. 1:

Perspective view of the diaphragm pump according to the invention in the form of a double diaphragm pump;

Fig. 2:

Sectional view of the diaphragm pump according to Fig. 1 ;

3:

Cross-sectional view through the double diaphragm pump according to the Figures 1 and 2 ;

4:

Part of the FIG. 3 ;

Fig. 5:

Pneumatic plan for a diaphragm pump according to the invention with a 5/2-way valve as the main valve;

Fig. 6:

Pneumatic plan for a diaphragm pump according to the invention with 4/2-way valve as the main valve.

The Figures 1 and 2 show a perspective view of the diaphragm pump according to the invention in the form of a double diaphragm pump.

The double-diaphragm pump has a housing cover 19 and a housing part 11 accommodating the cylinder 10 of the hydraulically acting piston-cylinder system 9, 10. The housing part 11 is, as in FIG. 2 fastened by means of coaxial screws 11a attached to the axial cylinder wall 3 of the first piston-cylinder system. From the housing cover 19 and the housing part 11 is at 22 (s. FIG. 3 and 4 ) the membrane M is clamped. Housing cover 19 and housing part 11 are connected to each other by means of screws 19a and hold the membrane M in position. The housing cover 19 forms below and above each a receptacle for a Check valve 24. The check valves 23, 24 are inserted into the corresponding recesses of the housing cover 19 before the housing flanges 25, 27 are screwed onto the housing cover 19. Additional seals prevent fluid from passing around the housing of the check valves 23, 24. The axial walls 3 of the first piston-cylinder system are held by spacers 7 at a distance and connected to each other by means of screws 6. Between the walls 3 is also pressure-tight, the cylindrical wall sleeve 2, which forms the cylinder, arranged, with additional seals to ensure the tightness. The screws 6 have a screw head 6a and at its end a thread 6b, with which they are screwed to the one axial wall 3.

In the cylinder 2, 3 of the first piston-cylinder system, the first piston 1 is arranged, which is formed by two discs 1a, 1b and the working spaces A and B separated from each other. The discs 1a, 1b are screwed together by means of the screws 4. The cylindrical wall 2 has on its outer side ribs for absorbing heat from the ambient air to prevent icing of the diaphragm pump. The axial walls 3 also have recesses 3b, which also serve better heat conduction and for stiffening and material savings. The piston 1 has a circumferential seal 1 c, which bears sealingly against the inner wall of the cylinder 2.

During assembly of the piston 1, the piston stands 8a, 8b are previously pushed through the bores 1d until the collars 8c engage in the corresponding recesses 1e of the piston discs 1a, 1b. By assembling the piston discs 1a, 1b, the piston rods 8a, 8b are positively secured to the piston 1.

The piston rods 8a, 8b pass through the bores 3a of the axial walls 3, wherein seals 56 ensure that no compressed air from the working chambers A, B enters the hydraulic chambers H ₂ . With their ends 8 d, the piston rods 8 a, 8 b are sealingly connected to the hydraulic piston by means of screws 60. The piston rods 8a, 8b are tubes formed, in which the connecting element 5 rests displaceable in the form of a rod. The connecting element 5 is screwed with its outer thread having ends 5a in the diaphragm plate 20. The diaphragm plate 20 is formed in the membrane M _i in the center 21.

The hydraulic pistons 9 each have a circumferential seal 12, which abut sealingly on the inner wall of the cylinder wall 10 and the two working spaces H ₁ , H ₂ separate from each other. The two hydraulic chambers H _{2 of} the two hydraulic piston-cylinder systems are connected to each other via the connecting channels 16, 17 and 18. In the hydraulic piston 9 each differential pressure valves 13 are arranged. If when working the pump, the differential pressure between the working spaces H ₁ and H ₂ exceed a certain value, opens the differential pressure valve 13 and the differential pressure can be lowered to a predetermined value. The connecting channel 16, 17, 18 can be connected by means of a further connection line, not shown, with a storage container and / or a sensor. If there is now an inflow or outflow of hydraulic medium on the reservoir or the connecting line, this may mean a breakage of the membrane, whereupon a fault signal can be sent to a higher-level control and / or the membrane pump is automatically stopped. This can be done, for example, by the positively controlled closing of the supply line supplying the pump with compressed air.

The feed channels 28 are connected to one another by means of the feed line 36, wherein the feed line 36 forms with its one end 41 the delivery medium inlet of the pump. The other end of the pipe 36 formed as a supply line is closed by means of a screwed plug 34. The supply line 36 is located with its areas 36a floating in the housing flanges 27, wherein seals 39 provide the necessary tightness. The housing flanges 27 have an annular space 40 comprising the regions 36a, which is formed by a circumferential groove. In the region 36a, the supply line 36 has window-like openings 38, through which the pumped medium passes from the interior 37 of the supply line 36 into the annular space 40 and from there into the feed channel 28.

The outlet channels 26 are connected to each other by means of the pressure line 29, wherein the pressure line 29 forms with its one end 33 the delivery medium outlet of the pump. The other end of the pipe formed as a pressure line 29 is closed by means of a screwed plug 34. The pressure line 29 is located with its areas 29a floating in the housing flanges 25, wherein seals 39 provide the necessary tightness. The housing flanges 25 have an annular space 32 comprising the regions 29a, which is formed by a circumferential groove. In the regions 29 a, the pressure line 29 has window-like openings 31, through which the conveying medium can pass from the annular space 32 into the interior space 30 of the pressure line 29.

In the axial walls 3 switching valves 14 are arranged, which extend with an extension 15 of its valve control members in the working spaces A, B. If the piston 1 reaches its dead center, the respective changeover valve is actuated, whereby compressed air, not shown, is passed to the main valve 50, and the main valve in turn switches.

The main valve 50 is disposed on the outside of the pump housing, so that a good heat exchange with the ambient air can take place, whereby the risk of icing is reduced.

If the diaphragm plate 20 is adjusted by means of the hydraulic piston 9 in such a way that the delivery space F _{i is} reduced, the delivery medium located in the delivery space F _i is conveyed through the check valve 24 into the outlet channel 26. The check valve 23 is closed during this. If subsequently in the delivery space F _{i is increased} by returning the membrane M _i , then delivery medium 36 is sucked into the delivery space F _i via the now open non-return valve 23 from the supply line 36. During the suction phase, the check valve 24 is closed.

The FIG. 5 shows a pneumatic diagram of the diaphragm pump according to the FIGS. 1 to 4 , The operated with compressed air diaphragm pump has a compressed air inlet 43, which is advantageously arranged on the main valve 50. In or on the main valve 50, the pressure control device 45 may be arranged, which is connected by means of the connecting line 44 to the input 43.

The pressure regulator 45 may be a proportional valve having an adjustment mechanism, e.g. in the form of an adjusting screw, with which a spring for pressure adjustment can be biased. If an unregulated pressure of 7 bar is provided by the external compressed air source (not shown), the regulated pressure of the main valve 50 can be regulated by the pressure regulating device 45 via the connecting line. 5.5 bar are supplied.

The input 43 is connected via connecting lines 48, 49 with the switching valves 14 in connection. The switching valves are designed as 3/2-way valves and are connected by means of extending into the working spaces A, B extensions 15 of their valve control members. A spring presses the valve control members in the position shown, in which the control lines 52, 53 are not connected to the valve inlet or the connecting line 48, 49. Once the piston 1, the respective valve control member 15 is adjusted, the switching valve 14 is switched and the unregulated compressed air of the external pressure source switches the main valve 50 to.

The main valve 50 is designed as a 5/2-way valve. In the illustrated position, the regulated compressed air passes via the connecting line 57 into the working space A. The piston 1 is thus adjusted together with the hydraulic piston 9 to the right. By means of the hydraulic medium located in the hydraulic spaces H ₁ , the right-hand membrane (not shown ₎ is now adjusted to the right, which reduces its associated delivery space. The right membrane thus promotes. At the same time sucks in as well FIG. 5 not shown left membrane conveying medium from the supply line into its delivery chamber. When reaching the right dead center, the right switching valve 14 is connected via the extension 15, so that the main valve 50 is also switched. On the way to the left, the connection of the working space A with the connecting line 47 is first interrupted. Thereafter, the two work spaces are shorted together, so that the biased compressed air located in the working space B can relax into the working space A inside. For this purpose, a certain amount of time is available until finally the main valve 50 is complete has passed through and 47 regulated compressed air is passed through the connecting line in the working space B, whereby the piston 1 is now moved to the left. The remaining not yet relaxed compressed air in the pressure chamber B then relaxes via the valve outputs 51 via the muffler 35 into the environment.

The FIG. 6 shows an alternative embodiment in which the main valve 50 is formed as a 4/2-way valve. The main valve 50 is different from that in FIG FIG. 5 shown main valve only in that only one output 51 is provided.

LIST OF REFERENCE NUMBERS

A, B

Working space of the first piston-cylinder system

M ₁ , M ₂

membrane

1

First piston of the first piston-cylinder system

1a, 1b

piston discs

1c

poetry

1d

drilling

1e

Recess for collar 8c

2

Cylinders of the first piston-cylinder system

2a

Outer cooling fins of the cylinder 2

3

axial cylinder wall of the first piston-cylinder system

4

screw

5

connecting element

5a

Thread of the connecting element 5

6

connecting screw

7

spacer

8a, 8b

piston rod

8c

collar

9

hydraulic pistons

10

Cylinder of the hydraulically acting piston-cylinder system

11

housing part

12

poetry

13

Differential pressure _valve (p _H1 > p _H2 )

14

switching valve

15

Valve control member

16, 17, 18

Channel / link line

19

housing cover

20

diaphragm plate

21

Membrane region in which the diaphragm plate 20 is arranged

22

Clamping area of the membrane M _i

23

Check valve in the feed channel (only shown in left chamber)

24

Check valve in outlet channel (only shown in left chamber)

25

Housing flange with outlet channel 26 (outlet housing)

26

exhaust port

27

Housing flange with feed channel 28 (inlet housing)

28

feed

29

pressure line

30

Interior of the pressure line 29

31

Passage opening in the wall of the pressure line 29

32

Annular space comprising the pressure line 29

33

Pump outlet for pumped medium

34

Plug with screw thread

Continuation of the list of reference numerals

35

Silencer for emanating the relaxing compressed air

36

feed

37

Interior of the supply line 36

38

Passage opening in the wall of the supply line 36

39

seals

40

Annular space comprising the supply line 36

41

Pump inlet for pumped medium

42

foot

43

Input for uncontrolled compressed air from an external compressed air source

44

connecting line

45

Pressure control device in the form of a proportional valve

46

Adjustment mechanism for regulated output pressure of the pressure regulator 46

47

Connecting line, supplies regulated compressed air to the main valve 50

48, 49

Connecting line for uncontrolled compressed air

50

main valve

51

Exits the main valve, which are connected to the mufflers 35

52, 53

Control line from the switching valve 14 to the main valve 50th

54, 55

Exit to the outside

56

poetry

57

Connecting line to the working space A

58

Connecting line to the working space B

66

Throttle in the switching valve 14th

Claims (19)

1. Diaphragm pump in which a fluid moves at least one first piston (1) of a first piston-cylinder system (1, 2, 3) backwards and forwards, wherein the first piston (1) is mechanically connected to at least one further hydraulic piston (9), and the hydraulic piston (9) drives at least one diaphragm (M₁, M₂) by means of a hydraulic medium, characterised in that the diaphragm pump is a double diaphragm pump having at least two diaphragms (M₁, M₂), wherein a hydraulic medium moves or drives the diaphragms (M₁, M₂), wherein the at least one hydraulic piston (9) moves the hydraulic medium, and in that the at least two diaphragms (M₁, M₂) are respectively interconnected mechanically by a connection element (5), in particular by a rod or a pipe.
2. Diaphragm pump according to Claim 1, characterised in that the connection element (5) is respectively connected by each of its ends (5a) to a diaphragm (M₁, M₂), in particular is screwed or pressed into said diaphragm.
3. Diaphragm pump according to either Claim 1 or 2, characterised in that one diaphragm (M₁, M₂) is arranged in a diaphragm chamber of a housing (11, 19) and it divides said diaphragm chamber into a conveying chamber (F₁, F₂) and a hydraulic chamber (H₁), wherein in particular the hydraulic chamber (H₁) is connected, in particular by a channel or a line, to the one first working chamber of the piston-cylinder system of a hydraulic piston (9), forms a part of the working chamber or is itself the working chamber.
4. Diaphragm pump according to any one of the preceding claims, characterised in that compressed air moves the first piston (1) of the first piston-cylinder system (1, 2, 3) backwards and forwards, a main valve (50), which is controlled in particular by the movement of the first piston (1), guiding the compressed air alternately into the first and second working chambers (A, B) of the first piston-cylinder system (1, 2, 3).
5. Diaphragm pump according to any one of the preceding claims, characterised in that the first piston-cylinder system (1, 2, 3) is arranged between two hydraulically acting piston-cylinder systems (9, 10), the first piston (1) being connected to the hydraulic pistons (9) by at least one piston rod (8a, 8b) which in particular engages or engage through the first piston (1) and/or is/are attached thereto.
6. Diaphragm pump according to Claim 5, characterised in that the connection element (5) is mounted in a freely displaceable manner with respect to the first piston (1) and to the hydraulic pistons (9), in particular is mounted displaceably in the piston rod (8a, 8b) and engages through the two hydraulic pistons (9), sealing elements being arranged in particular between the connection element (5) and the hydraulic pistons (9) and/or the piston rod (8a, 8b) such that hydraulic medium cannot pass from one hydraulic chamber (H₁, H₂) into the other hydraulic chamber along the connection element (5).
7. Diaphragm pump according to any one of the preceding claims, characterised in that the hydraulically acting piston-cylinder systems (9, 10) have in each case a first and a second working chamber (H₁, H₂), and in each case the first working chamber (H₁) is part of the hydraulic chamber, forms said hydraulic chamber or is connected thereto by a channel, and the second working chambers (H₂) are interconnected by a connection line (16, 17, 18), the second working chambers (H₂) in particular as well as the connection line (16, 17, 18) being filled with a hydraulic medium.
8. Diaphragm pump according to Claim 7, characterised in that the diaphragm pump has at least one means for monitoring the quantity of hydraulic medium in one and/or more working chambers (H₁, H₂) of the hydraulically acting piston-cylinder systems (9, 10) and/or in the connection line (16, 17, 18).
9. Diaphragm pump according to Claim 8, characterised in that the second working chambers (H₂) and connection line (16, 17, 18) connecting these together are connected to a storage tank containing a hydraulic medium by a further connection line, the system determining a discharge and/or supply of hydraulic medium through the further connecting connection line.
10. Diaphragm pump according to any one of the preceding claims, characterised in that at least the hydraulic medium located in the hydraulic chambers (H₁, H₂) is inert with respect to the conveyed medium and/or the changeover valves (14) have chokes (66).
11. Diaphragm pump according to any one of the preceding claims, characterised in that each conveying chamber (F₁, F₂) is connected by a respective feed channel (28) to a common feed line (36) and/or is connected by a respective outlet channel (26) to a common pressure line (29), the feed line (36) and/or the pressure line (29) being mounted in a floating manner in at least one connection region (25) of the pump housing and a respective valve (23, 24), in particular a check valve being arranged in particular in the feed channel (28) and in the outlet channel (25).
12. Diaphragm pump according to any one of the preceding claims, characterised in that the piston surface of the first piston (1), in particular of the pneumatic piston is greater than or equal to the piston surface of the hydraulic piston(s) (9), particularly in a specific ratio, in particular in a ratio of 1:1 to 1:40.
13. Diaphragm pump according to any one of the preceding claims, characterised in that hydraulic medium is exchanged from one to the other working chamber (H₁, H₂) of a hydraulically acting piston-cylinder system (9, 10) via a valve (13), in particular an excess pressure or vacuum valve, upon exceeding or falling below a particular pressure difference between the working chambers (M₁, M₂).
14. Diaphragm pump according to any one of the preceding claims, characterised in that arranged in the hydraulic piston (9) is an excess pressure or vacuum valve (13) which, in a normal case, blocks a connection channel, running axially through the hydraulic piston (9).
15. Diaphragm pump according to any one of the preceding claims, characterised in that the axial cylinder walls (3a) of the working chambers (A, B) of the first piston-cylinder system (1, 2, 3) are adapted to the shape of the axial walls (1c) of the first piston (1), in particular they are configured to be planar, such that the remaining working chamber is minimal in the dead centres of the piston (1).
16. Diaphragm pump according to any one of the preceding claims, characterised in that a respective changeover valve (14), in particular a 3/2-way valve which is mechanically actuated by the first piston (1) before or upon reaching the respective dead centre or switch-over point is arranged in the walls (3), defining axially and at the end face the working chambers (A, B), of the first piston-cylinder system (1, 2, 3), the changeover valves (14) controlling the compressed air, in particular unregulated compressed air, connecting the main valve (50), the piston (1) in particular mechanically actuating the valve actuators of the changeover valves (14), the changeover valves (14) being configured in particular as cartridge valves, i.e. they can be inserted, in particular screwed, from outside into the wall (3) respectively defining at the end face, of the first piston-cylinder system (1, 2, 3).
17. Diaphragm pump according to any one of the preceding claims, characterised in that the main valve (50) is a 5/2-way valve or a 4/2-way valve which interconnects the two working chambers (A, B) of the first piston-cylinder system (1, 2, 3) particularly in the changeover phase and thus the receiving working chamber (A, B) prefills with the compressed air from the transferring working chamber (B, A).
18. Diaphragm pump according to any one of the preceding claims, characterised in that the main valve (50) has an inlet (43) for unregulated compressed air of an external compressed air source, the main valve (50) itself having a pressure regulating means (45) for generating regulated compressed air of a particular pressure.
19. Diaphragm pump according to any one of the preceding claims, characterised in that the main valve (50) has a valve control member which is adjusted by the compressed air, in particular unregulated compressed air, controlled by the changeover valves (14), in particular the valve control member controlling the compressed air regulated by the pressure regulating means (45) and conducting it into the working chambers (A, B) of the first piston-cylinder system (1, 2, 3) in order to move the first piston (1).

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