Multiple displacement pump

Abstract

Known multiple-displacement pumps are designed to be operated either with a pneumatic or an electric drive. The present invention proposes an arrangement that allows such a pump to be manufactured from largely identical parts or to be converted from one drive type to the other with minimal effort. For this purpose, the displacement elements can be connected via a connecting means that can be extended through a cover of the fluid chambers, allowing a mechanical actuator to be optionally attached, which can be connected to an electric drive or to a control valve.

Description

[0001] The present invention relates to a multiple displacement pump with a pump housing which comprises two external covers and at least one intermediate piece received between the covers, wherein at least two fluid chambers are formed between the covers and the at least one intermediate piece, which are divided into at least one propellant chamber and one media chamber by means of at least one displacement element each, and wherein the displacement elements of the at least two fluid chambers are non-positively and detachably connected to at least one lifting rod via at least one connecting element, wherein the at least one lifting rod can extend the at least one connecting element through a first passage of an adjacent first cover.

[0002] Such a multiple displacement pump is already known from US 2,918,878 A. Reference is also made to AT 34296 B and CH 717057 A1.

[0003] Furthermore, DE 10 2021 104 548 A1 is already known from the prior art. This relates to a pneumatically operated double diaphragm pump whose diaphragms are coupled to each other by means of a connecting element. The connecting element extends through an intermediate piece that separates two fluid chambers in which the diaphragms displace a fluid. The connecting element extends outward from the fluid chambers on one side and actuates a control valve with a free end, which controls the alternating outflow and inflow of propellant into propellant chambers within the fluid chambers.

[0004] Double diaphragm pumps generally operate on the positive displacement principle. They contain two synchronized diaphragms located in separate chambers. The diaphragms are clamped at their outer diameter. Each chamber has an inlet and an outlet channel. A check valve is located upstream and downstream of each chamber. The axial movement of the diaphragms increases the volume of the first media chamber while reducing the volume of the second media chamber. This change in volume draws in the medium and then displaces it. Due to the synchronized stroke, one diaphragm is on the suction stroke, while the other is on the pumping stroke. Double diaphragm pumps are available with two different drive types: pneumatic and electric.

[0005] The majority of double diaphragm pumps operate according to the peripheral flow principle. This design differs from the central flow design in the placement of the drive unit. In the peripheral flow design, the drive unit is located centrally between the two diaphragms, while the fluid side is on the outside. In the central flow design, the drive unit is mounted on the outside and the fluid side is on the inside.

[0006] Double diaphragm pumps based on the peripheral flow principle are known from US 11,655,810 B2, US 11,174,854 B2 and US 11,434,892 B2, in which the drive between the two diaphragms acts on a spindle which connects the diaphragms to each other as a connecting element.

[0007] In general, the principles of double-diaphragm pumps can be extended to the multiple-displacement pump discussed here. In this context, multiple-displacement pumps also refer to pumps that do not necessarily have just two diaphragms, but rather two or more. These do not necessarily have to be diaphragms; they can also be other displacement devices, such as pistons.

[0008] Although the aforementioned pumps based on the peripheral flow principle are particularly compact, which can be helpful in everyday use, they are inflexible and cannot be adapted to external conditions. In particular, the pump drive cannot be adapted. If, for example, an electric drive must be dispensed with in a particular environment, for example for explosion protection reasons, these pumps can no longer be used. Conversely, this applies to the pump according to DE 10 2021 104 548 A1 if it is used in an environment where no compressed air is available.

[0009] Against this background, the object of the present invention is to create a multiple displacement pump which is as variable as possible and can be adapted to different application environments.

[0010] This is achieved by a multiple displacement pump according to the features of claims 1 and 19. Useful embodiments of such multiple displacement pumps can be found in the respective subsequent dependent claims.

[0011] In this respect, a multiple displacement pump is provided with a pump housing which comprises two external covers and at least one intermediate piece received between the covers, wherein at least two fluid chambers are formed between the covers and the at least one intermediate piece, which are each divided into at least one propellant chamber and one media chamber by means of at least one displacement element, and wherein the displacement elements of the at least two fluid chambers are non-positively and preferably releasably connected to at least one lifting rod via at least one connecting element. Such a multiple displacement pump is characterized according to the invention in that the at least one lifting rod extends the at least one connecting element through a first passage of an adjacent first cover, wherein the lifting rod is non-positively connected to a first mechanical actuator by means of releasable connecting means.

[0012] According to the invention, the pump unit and the drive unit are considered separately. In combination, a functional pump is formed. The special feature is that the pump unit is designed for different drive types. Due to the non-positive but detachable connection between the connecting rod and the drive, the drive can be removed from the multiple displacement pump and a different drive attached to it. Either a pneumatic or an electric drive unit can be adapted to the side. In particular, the connecting means can be designed so that both an electric drive and a mechanically operated control valve can be connected to it. The change should be possible with just a few assembly steps. Minor modifications to the pump unit are not excluded. This option allows the user to decide which drive they prefer and convert the pump accordingly within a short time.

[0013] The pump unit is constructed according to the central flow principle. The inlet and outlet, as well as the check valves, are located in the intermediate piece. The displacement elements can either operate individually or be mechanically connected to one another via connecting elements. On one side, the pump unit can be completely closed by a second cover. The lifting rod then protrudes outward on the opposite side. This is used to couple the drive unit with at least one connecting element. To empty the pump unit, the media chambers can have drain holes located at the lowest point and closed during operation.

[0014] With some advantage, it can be provided that the first mechanical actuator is detachably connected to the first cover on its outer side facing away from the first fluid chamber. This allows the drive to be replaced, but after replacement, it is reconnected to the pump housing, so that in the event of transport, a unit is created that can be moved as a whole.

[0015] In this case, it is expedient if the first passage of the first cover can be closed in a propellant-tight manner, preferably after removal of at least one lifting rod. Such a closure ensures that if the outwardly extending lifting rod is removed, the propellant cannot escape from the propellant chamber. In principle, with a pneumatic drive, it is also possible to dispense with the lifting rod and connect the two displacement elements via the connecting element, but otherwise only drive them based on the pressure on the propellant chambers. Accordingly, pneumatic access openings that can be closed in a propellant-tight manner for connection to a pneumatic drive can be assigned to the covers. Such access openings can in particular be designed such that they have a particularly simple, possibly standardized connection to a propellant source, for example a compressed air connection.

[0016] In addition to connecting a housing of the mechanical actuator to the first cover, this can also be achieved by forming the first cover integrally with a housing of the mechanical actuator. In such a case, the cover can be released using one drive and reattached using another drive. If necessary, it can also be provided that no through-opening is provided in the cover if the lifting rod does not need to pass through it.

[0017] Regarding the connection options for an outwardly extending lifting rod, a first possibility is for the mechanical actuator to be a control valve, which is actuated by the lifting rod depending on the deflection position of the displacement elements. While the displacement elements are deflected by the propellant, the control valve is actuated by the lifting rod when an end position is reached, thus generating the counterstroke and refilling the affected propellant chamber after it has been completely emptied, or emptied again after it has been completely filled.

[0018] In the case of mechanical designs, particularly those based on electric drives, however, the displacement elements are actuated in the opposite direction, thereby alternately displacing the medium to be pumped from the two fluid chambers. A propellant can still be provided to support the displacement elements. This is particularly relevant for diaphragms. In such a case, the propellant chambers are fluidically connected to one another and can thus communicate with each other, i.e., exchange the propellant during the actuation of the displacement elements.

[0019] A first possibility of an electric drive can be that the mechanical actuator comprises an electric drive with alternating direction of rotation that interacts with the lifting rod, preferably an electric motor that interacts with a ball screw or a thread that is optionally assigned to the lifting rod.

[0020] Another possibility is that the mechanical actuator comprises an eccentric mounted on a rotary axis connected to an electric motor directly or with the interposition of a gear, which is enclosed by a rotary bearing, which in turn is pivotally mounted at one end of the lifting rod.

[0021] It can also be provided that the mechanical actuator comprises an eccentric mounted on a rotary axis connected to an electric motor directly or via a gear mechanism. This eccentric actuates a preferably spring-loaded plunger, which in turn is formed by the lifting rod. To limit the stroke, the plunger can disengage toward the eccentric against a stop. In this case, the eccentric will not be in continuous contact with the plunger, and the conveying capacity will be limited.

[0022] A further embodiment can provide that the lifting rod is connected to an armature of a pulling magnet, which is spring-mounted relative to a fixed yoke and can be electromagnetically actuated by energizing an excitation coil assigned to the yoke. While in this embodiment half of the movement is carried out mechanically by a spring and a defined rest position can thus be established, in a further variant it can also be provided that the lifting rod is connected to an armature of a pulling magnet, which can move back and forth between two opposing yokes and can be electromagnetically actuated by alternately energizing excitation coils assigned to the yokes. Here, movement of the displacement elements occurs only due to energization of the excitation coils.

[0023] It can be particularly advantageous for the connecting element to be tubular and for the lifting rod to be guided through the connecting element, the lifting rod having stop elements on both sides adjacent to the end faces of the connecting element, against which the connecting element strikes when the lifting rod is displaced longitudinally. This solution can be of particular interest for diaphragm pumps. It has been found that these are subject to particularly great wear when attached using known connecting elements when subjected to tensile stress. Even when the displacement elements are connected using a tubular connecting element and a lifting rod is passed through which has stop elements on both sides of the connecting element, the connecting element and thus also the displacement elements connected in this way can be pushed during each movement.The use of membranes results in particularly gentle operation.

[0024] In such a case, it can also be provided that at least one end-face stop element of the lifting rod is detachably connected to the lifting rod, preferably by means of a screw connection. This simplifies the installation of the lifting rod, which, without the end-face stop element, can be guided through the connecting element and the corresponding connection openings of the at least one displacement element involved and can then be fixed using the connecting means, in particular by means of a screw connection. The second stop element can be fastened in various ways; on the one hand, in the case of a multi-part lifting rod, it can be inserted between two elements, or it can be fastened to the lifting rod in a force-fitting or form-fitting manner, by shrinking or by welding.

[0025] If, however, the lifting rod is omitted, for example, in pneumatic operation, the tubular connecting element can be releasably closed at least at one position, preferably at both ends, after the lifting rod has been removed. In particular, it must be ensured that the chambers located on either side of the connecting element cannot communicate with each other across the connecting element, i.e., cannot exchange propellant with each other or even mix propellant with the medium. This is particularly effective if the connecting element is sealed at both ends and is either filled with material or sealed.

[0026] While it is initially possible for the electric drive means to act directly on the end of the lifting rod pointing away from the displacement elements, it can also be provided that the connecting means are designed to produce a positive and / or non-positive connection between a mechanical connection of the mechanical actuator and the lifting rod, which can in particular be screw connectors, a bayonet lock or a quick coupling.

[0027] It has already been pointed out that in the case of a purely electrically operated multiple displacement pump, it is possible for the propellant chambers of the fluid chambers to be fluidically connected to one another. In such a case, it can additionally be provided that a second, parallel displacement element is assigned to each of the fluid chambers, forming an intermediate space, preferably with an insert interposed therebetween, wherein the intermediate space is filled with a support fluid.

[0028] Further provided according to the invention is a multiple displacement pump with a pump housing which comprises two external covers and at least one intermediate piece received between the covers, wherein at least two fluid chambers are formed between the covers and the at least one intermediate piece, which are divided into at least one propellant chamber and one media chamber by means of at least one displacement element each, and wherein the displacement elements of the at least two fluid chambers can be connected to one another and / or separately via at least one connecting element in a force-fitting manner, and preferably detachably, to at least one lifting rod, wherein the at least one connecting element can be extended by means of the at least one lifting rod and the propellant chambers are operatively connected to a pneumatic drive via pneumatic access openings in the covers.

[0029] In principle, this can be the same multiple displacement pump as in the case described above, with only pneumatic operation without a lifting rod being provided, whereas in the embodiment described above, mechanical operation or pneumatic operation with a lifting rod is provided.

[0030] Such a multiple-displacement pump pneumatically implements the diaphragm movement. It contains a compressed air connection through which compressed air is fed to a control valve. This control valve controls the flow of propellant alternately into the propellant chamber behind the displacement elements. The inflowing propellant builds up pressure there and moves the displacement element axially. This then performs a pumping stroke. Once the stroke is complete, the control valve is actuated and then switches the propellant flow behind the second displacement element. This results in a stroke in the opposite direction.

[0031] Accordingly, in this variant it can also be provided that a first cover has a first passage for receiving a lifting rod, wherein in this embodiment the first passage is now sealed in a propellant-tight manner.

[0032] Furthermore, the first cover can also be formed in one piece with a housing of the pneumatic actuator.

[0033] In a further specific embodiment, it can be provided that a pressure booster unit with a further fluid chamber is assigned to a first cover adjacent to the connecting means, wherein the connecting element is extended by a lifting rod with the aid of the connecting means and the lifting rod connects the connecting element to a further displacement element accommodated in the further fluid chamber and wherein a first sub-chamber of the pressure booster unit is fluidly connected to the first propellant chamber and a second sub-chamber of the pressure booster unit is fluidly connected to the second propellant chamber.

[0034] In a pneumatically driven pump that operates according to the principle described above, the achievable discharge pressure is approximately equal to the inlet pressure of the propellant. To achieve a higher discharge pressure than the inlet pressure of the propellant, a pressure booster can be used. For this purpose, a pressure booster unit can be used, which comprises an additional displacement element. This can be alternately pressurized on both sides with propellant, for example compressed air. The propellant can reach the chambers of the pressure booster unit through connecting channels. A pneumatic drive unit controls or regulates the propellant flow and can be flanged on the side. This increases the effective area of the propellant, while that of the medium to be pumped remains constant. The connecting element is firmly connected to both displacement elements of the multiple displacement pump and to the pressure booster unit.

[0035] In a further development of this feature, several parallel pressure booster units can be provided, the first sub-chambers of which are fluidly connected to the first propellant chamber and the second sub-chambers of which are fluidly connected to the second propellant chamber. It is thus possible to use several pressure booster units and install them on the side of the first or second cover. The pressure booster unit can, in particular, be designed with an additional diaphragm or with an additional piston.

[0036] In this embodiment, the connecting element can also be tubular and have a passage along its longitudinal extension for receiving the lifting rod. The tubular connecting element can then preferably have a releasable closure at least at one position, preferably at both ends.

[0037] Between the chambers of the multiple displacement pump, the intermediate piece serves to separate the fluid chambers and, if present, accommodates the connecting element. Preferably, the intermediate piece further comprises either a common suction line and a common pressure line, or two separate suction lines and two separate pressure lines for the media chambers of the respective adjacent fluid chambers, wherein the suction lines and the pressure lines are each blocked off from the media chambers by means of valves that block in the same direction, preferably ball valves. Depending on the application, separate suction and pressure lines can enable metering of several fluids, while shared suction and pressure lines can only enable joint delivery.

[0038] Furthermore, it can be provided that the intermediate piece has a through-opening through which a connecting means can be passed, connecting several displacement elements to one another and to the at least one lifting rod. In this case, it can additionally be provided that this through-opening is closable, which is particularly important for the possibility of equipping the multiple displacement pump with separate drives for the different displacement elements. To prevent fluid exchange between the fluid chambers, it must be ensured that the through-opening is sealed in a media-tight manner if no connecting element is used to connect several displacement elements to one another.

[0039] By using two separate drives for each of the displacement elements, the fluid chambers can flow through at different speeds, allowing two different fluids to be pumped with different throughputs. Mixtures in predetermined ratios can be created depending on the conveying speeds. This is also possible using an insert which is placed in the propellant chamber on one side of the fluid chamber, as this makes it possible to change the chamber volume using an insert. For this purpose, an axially adjustable stop is installed. During the suction stroke, the striking reduces the suction volume, which also reduces the pump volume. Different quantities can be pumped into adjacent fluid chambers, especially when the displacement elements, preferably diaphragms, are firmly connected to one another by a connecting element, whereby the central stroke remains constant.

[0040] Finally, it can be provided that the intermediate piece and / or the cover and / or the housing of the at least one mechanical actuator have a support foot on at least one side pointing away from the intermediate piece. This is particularly helpful when the displacement elements are connected to one another by means of a connecting element, and the connecting element is extended outwardly to form a drive. Due to the resulting asymmetry, a support foot ensures that the multiple displacement pump is not prone to tipping.

[0041] The invention described above is explained in more detail below using an exemplary embodiment.

[0042] It shows Figure 1a a multiple displacement pump according to the invention with an extended lifting rod and two connected membranes in a schematic representation, Figure 1b the multiple displacement pump according to Figure 1awith a lifting rod guided through the connecting element in a schematic representation, Figure 2 the multiple displacement pump according to Figure 1awith an insert for one-sided reduction of the delivery capacity in a schematic representation, Figure 3a a multiple displacement pump with a pressure intensifier unit with an additional diaphragm in a schematic representation, Figure 3b a multiple displacement pump with a double pressure intensifier unit with two additional diaphragms in a schematic representation, Figure 3c a multiple displacement pump with a pressure intensifier unit with an additional piston in a schematic representation, Figure 4a a multiple displacement pump with a mechanical actuator in the form of an electric motor with a recirculating ball screw in a schematic representation, Figure 4b a multiple displacement pump with a double-sided mechanical actuator in the form of an electric motor with a recirculating ball screw in a schematic representation, Figure 4c a multiple displacement pump with a mechanical actuator in the form of an electric motor with a thread in a schematic representation,Figure 5a a multiple displacement pump with a mechanical actuator in the form of an eccentric and an articulated lifting rod in a schematic side view, Figure 5b the multiple displacement pump according to , Figure 5a in a plan view, Figure 5c a multiple displacement pump with a mechanical actuator in the form of an eccentric for acting on a tappet formed by the lifting rod in a schematic representation, Figure 6a a multiple displacement pump with a mechanical actuator in the form of a pull magnet with spring return in a schematic representation of a first stroke, Figure 6b the multiple displacement pump according to Figure 6ain a schematic representation of a second stroke, Figure 6c a multiple displacement pump with two mechanical actuators in the form of pull magnets with spring return in a schematic representation, Figure 6d a multiple displacement pump with two mechanical actuators in the form of pull magnets with opposing and oppositely acting yokes in a schematic representation, Figure 7a the multiple displacement pump according to Figure 1a with media connection of the propellant chambers in schematic representation, Figure 7b the multiple displacement pump according to Figure 7a with unconnected displacement elements in schematic representation, Figure 8a the multiple displacement pump according to Figure 1a with inserts in the fluid chambers and a second displacement element forming an intermediate space in a schematic representation, and Figure 8b the multiple displacement pump according to Figure 8a with unconnected displacement elements in schematic representation.

[0043] Figure 1a shows a multiple displacement pump 1, which is made of a first cover 2 and a second cover 3, as well as an intermediate piece 4 between the covers 2 and 3. The covers 2 and 3, together with the intermediate piece 4, form a fluid chamber 5 and 8, respectively, wherein in the illustration of the other figures, the fluid chamber shown on the left is referred to as the first fluid chamber 5 and the fluid chamber shown on the right is referred to as the second fluid chamber 8.

[0044] A first displacement element 11 is arranged in the first fluid chamber 5 and a second displacement element 12 is arranged in the second fluid chamber 8 such that the fluid chambers 5 and 8 are each divided into a media chamber 7 and 10 and a propellant chamber 6 and 9. A medium to be pumped is passed through the media chambers 7 and 10, whereby the lines required for this are contained in the intermediate piece 4. Since this is not important, they are not shown in the following. Membranes are always shown as displacement elements 11 and 12 in the following figures, but this should only be understood as representative. Other displacement elements, in particular pistons, can equally well be used within the scope of the present invention.

[0045] The multiple displacement pump 1 has a through-opening 38 in the intermediate piece 4, through which a connecting element 13 is passed, connecting the two displacement elements 11 and 12 to one another. Due to this mechanical connection, the displacement elements 11 and 12 inevitably move in synchronization. A lifting rod 14 is assigned to the connecting element 13 via a connecting means 15, such as a screw connection, a bayonet lock, or the like. This lifting rod 14 extends outward through the first cover 2. There, it is possible to engage the lifting rod 14 with a mechanical actuator in order to move the displacement elements 11 and 12, or conversely, to have a flow valve actuated by the lifting rod 14.Due to this design, the multiple displacement pump 1 is very variable and versatile and can be adapted, particularly after production, with regard to its drive and other functional elements.

[0046] If the lifting rod 14 is omitted and a first passage 16 of the first cover 2 is closed, the multiple displacement pump can be converted to pneumatic operation, for example. While the displacement elements 11 and 12 can remain coupled, pneumatic access openings 18 in the covers 2 and 3, which can also be arranged in the intermediate piece 4, are opened and connected to a control valve. By alternately actuating the valve, the displacement elements 11 and 12 are then no longer actuated mechanically from the outside, but rather by a propellant, which can be pumped alternately from the first propellant chamber 5 into the second propellant chamber 8 and vice versa. Separate control of the propellant chambers 5 and 8 is also possible.However, it is also useful in this case to pass the lifting rod 14 through the first cover 2 in order to actuate the control valve in the end positions via the lifting rod 14.

[0047] Figure 1b shows a variant of the Figure 1a , wherein the lifting rod 14 is formed concentrically with the connecting element 13. The connecting element 13 is received between two stop elements 39 and 40 and is also moved in a through-opening 38 of the intermediate piece 4, since it is selected to be long enough to connect the two displacement elements 11 and 12. Sealing is also provided here in such a way that a medium conveyed in the media chambers 7 and 10 cannot switch between the media chambers 7 and 10 through the through-opening 38.

[0048] The connecting element 13, which in this context is tubular, engages around the lifting rod 14, so that in both directions of movement the lifting rod 14 only pushes, but not pulls, the connecting element 13 and thus the displacement elements 11 and 12. There is therefore no flat, frictional connection between the lifting rod 14 and the connecting element 13; rather, the lifting rod 14 can slide in the connecting element 13 between the stop elements 39 and 40, with the lifting rod 14 being mounted with as little play as possible relative to the connecting element 13 when assembled. Especially in the case of diaphragms, it is particularly advantageous if they are only subjected to compressive and not tensile stress in order to increase their durability.

[0049] While a central stop element 40 can be permanently attached to the lifting rod 14 by welding, joining, shrinking, and the like, a front-end stop element 39 is detachably connected to an end of the lifting rod 14, for example by screwing, so that the lifting rod 14 can be pulled out through the tubular connecting element 13 as needed. The ends of the connecting element 13 that remain open can then be sealed in a media-tight manner when the lifting rod 14 is no longer to be used. At the free end of the lifting rod 14, i.e., opposite the front-end stop element 39, a connecting means 43 is attached to establish a connection to a mechanical actuator, such as a drive motor or one of the drives shown below. This allows switching between different drives and drive types, mechanical, electrical, pneumatic, or hydraulic.Likewise, the tubular connecting means 13 can also be attached to only one displacement element 11 or 12, so that the stop elements 39 and 40 are located directly on either side of the displacement element 11 or 12. Such configurations are shown below and can be used when multiple drives are used for the individual displacement elements 11 and 12, particularly for dosing purposes.

[0050] For the sake of simplicity, the lifting rod 14 and the at least one connecting element 13 are shown below as one part together with any connecting means 15 or 43.

[0051] Figure 2First, it shows a multiple displacement pump 1, in which a first displacement element 11 is moved by the lifting rod 14 and the connecting element 13. The first displacement element 11 can utilize the size of its fluid chamber, while a second displacement element 12 runs against a diaphragm stop 34 inserted into the fluid chamber there. This allows a variable ratio between the flow rate in the two fluid chambers to be set, which is particularly advantageous for use as a metering pump.

[0052] Figures 3a, 3b and 3c show various multiple displacement pumps 1 that operate with a pressure booster. In order to achieve a higher discharge pressure than the inlet pressure, a pressure booster unit 31 is added to the structure described above. This can be achieved with an additional diaphragm 32, as in Figure 3a , or also via another piston 33 as in Figure 3c, which divide a further fluid chamber 35 into a first sub-chamber 36 and a second sub-chamber 37. The use of several pressure booster units 31 added in parallel is also possible, as in Figure 3b shown.

[0053] The pressure booster unit 31 is an additional element in which a further displacement element 32 or 33 is accommodated. This can be alternately pressurized with the propellant in both subchambers 36 and 37. The propellant, such as compressed air, can reach the propellant chambers of the pump unit through connecting channels 44. The pneumatic drive unit regulates the air flow and is flanged to the side, although this is not shown in the figures. This increases the effective area of the propellant, while that of the medium remains constant. The connecting element 13 is firmly connected to both displacement elements of the multiple displacement pump 1 and to the pressure booster unit 31.

[0054] The generation of the linear movement of the displacement elements 11 and 12 can, as shown in the Figures 4a and 4bshown, by means of a motor and a ball screw 20. For this purpose, an electric motor 19 is used, in which the rotating rotor ring is designed as a drive nut. The counterpart to this is the ball screw 20. This moves, depending on the direction of rotation of the rotor, translationally forwards or backwards. The force / movement is transmitted through a fixed connection to the connecting element 13. In the variant of the Figure 4b A spindle drive is used on each side to move the displacement elements 11 and 12. With such an arrangement, a connection between the displacement elements 11 and 12 is not necessary, and the lifting rods 14 are each connected to only one displacement element 11 or 12 via a connecting element 13. The two drive units can be controlled independently of each other.

[0055] The function of a Figure 4cshown screw drive is identical to that of the spindle drive according to Figures 4a and 4b . However, instead of a ball screw 20, a thread 21 is used to convert the rotary movement into a translational movement.

[0056] Another variant arises from the Figures 5a and 5b In this variant, an eccentric 22 is located on a drive shaft serving as a pivot bearing 23, which is connected to an electric motor. A gearbox can be located between the electric motor and the drive shaft. A rotatably mounted housing 45 with a further pivot bearing 46 for an axially guided lifting rod is located around this eccentric 22. The rotation of the drive shaft thus causes a linear forward or backward movement of the lifting rod 14.

[0057] Thematically similar is another variant according to Figure 5cHere, an eccentric 22 is firmly connected to the drive shaft of the electric motor, which serves as a pivot bearing 23. A gear can also be located between the electric motor and the drive shaft. A spring-loaded plunger 24 is permanently mounted on the eccentric. Rotation of the eccentric 22 pushes the plunger 24 inward, compressing the spring. Upon further rotation of the eccentric 22, the plunger 24 moves outward again due to the preload of the spring. The plunger 24 is connected to both displacement elements and transmits its movement to them.

[0058] With regard to Figures 6a and 6bThere, a connecting element is firmly connected to a movable armature 26 via a lifting rod 14. The armature 26 is spring-loaded on one side. A fixed excitation coil 28 is located next to the armature 26. Together, the components form a pulling magnet 25. When a voltage is applied to the excitation coil 28, a magnetic field is generated therein, which attracts the armature 26 towards a yoke 27, as shown in Figure 6b The spring 47 is thereby tensioned. When the voltage is switched off, the armature 26 is returned to its original position according to Figure 6a pressed.

[0059] In another variant according to Figure 6cA pull magnet 25 is used on each side. A displacement element 11 or 12 is connected to only one pull magnet 25. The strokes are executed by alternately energizing the left and right excitation coils 28. The spring 47 pushes the armatures 26 back to the starting position when the voltage is switched off. The two pull magnets 25 can be controlled independently of each other.

[0060] Furthermore, it is possible, as in Figure 6d It is shown to use two pull magnets 25 per side. The armature 26 is located between them. A continuous lifting rod 14 connects both armatures, as well as the displacement elements 11 and 12, via connecting elements 13. When voltage is applied, the outer excitation coil on the left side is energized simultaneously with the inner excitation coil on the right side, or the inner excitation coil on the left side is energized with the outer one on the right side.

[0061] When a pneumatic drive unit is used, a pressure is built up behind the displacer element 11, 12 which acts against it. The pressure of the medium prevails on the opposite side. The displacer element 11 or 12 is thus pressurised from both sides and permanently supported. When an electric drive unit is used, this pneumatic counterpressure is not present. The displacer element 11 or 12 is subjected to pressure on one side during operation. This one-sided pressure increases wear, particularly on diaphragms, and shortens their service life. This wear can be counteracted with hydraulic support. A liquid is poured into the propellant chambers 6 and 9 behind the diaphragms until the system is completely filled and vented. During operation, the propellant is alternately transported from one propellant chamber 6 to the other propellant chamber 9 and vice versa.The pressure on both sides of the diaphragm is virtually identical. Wear is reduced. A mechanical connection between the diaphragms is no longer required, but can be incorporated. Figure 7a shows this variant with a continuous connecting element 13 with lifting rod 14, with Figure 7b a connecting element 13 is connected to a lifting rod 14 only on the left side; on the right side, where the connecting element 13 is blindly closed, there is none.

[0062] Finally, in another embodiment, an insert 29 and another diaphragm are mounted on each side. This creates an encapsulated space 30. A fluid, particularly compressed air or a liquid, is located in this space 30. When the pump is started up, the inner diaphragm is supported. The diaphragm movement is achieved by the propellant, which is conveyed back and forth through a connecting channel 44 between the first propellant chamber 6 and the second propellant chamber 9.

[0063] What is described above is a multiple displacement pump which is as variable as possible and can be adapted to different application environments. LIST OF REFERENCE SYMBOLS

[0064] 1Multiple displacement pump 2First cover 3Second cover 4Intermediate piece 5First fluid chamber 6First propellant chamber 7First media chamber 8Second fluid chamber 9Second propellant chamber 10Second media chamber 11First displacer element 12Second displacer element 13Connecting element 14Lifting rod 15Connecting element 16First feedthrough 17Second feedthrough 18Pneumatic access opening 19Electric motor 20Ball screw 21Thread 22Eccentric 23Pivot bearing 24Plunger 25Tension magnet 26Armature 27Yoke 28Excitation coil 29Insert 30Gap 31Pressure intensifier unit 32Further diaphragm 33Further piston 34Diaphragm stop 35Further fluid chamber 36First sub-chamber 37Second sub-chamber 38Access opening 39Front stop element 40Middle stop element 41Parallel displacement element 42Feedthrough 43Connecting element 44Connecting channel 45Housing 46Pivot bearing 47Spring

Claims

1. A multiple displacement pump with a pump housing comprising a first outer cover (2) and a second outer cover (3) and at least one intermediate piece (4) received between the covers (2, 3), wherein at least two fluid chambers (5, 8) are formed between the covers (2, 3) and the at least one intermediate piece (4), which are divided into at least one propellant chamber (6, 9) and one media chamber (7, 10) by means of at least one displacement element (11, 12), and wherein the displacement elements (11, 12) of the at least two fluid chambers (5, 8) are non-positively and detachably connected to at least one lifting rod (14) via at least one connecting element (13), wherein the at least one lifting rod (14) can extend the at least one connecting element (13) through a first passage (16) of the adjacent first cover (2), characterized in thatthe lifting rod (14) is connected to a first mechanical actuator by means of detachable connecting means (43) in such a force-locking but detachable manner that the drive can be removed and another drive can be attached thereto, namely either a pneumatic or an electric drive can be adapted.

2. Multiple displacement pump according to claim 1, characterized in that the first mechanical actuator is detachably connected to the first cover (2) on its outer side facing away from the first fluid chamber (5).

3. Multiple displacement pump according to one of claims 1 or 2, characterized in that the first passage (16) of the first cover (2) can be closed in a propellant-tight manner.

4. Multiple displacement pump according to claim 1, characterized in that the first cover (2) is formed in one piece with a housing of the first mechanical actuator.

5. Multiple displacement pump according to one of the preceding claims, characterized in thatthe covers (2, 3) are provided with propellant-tight, pneumatic access openings (18) for connection to a pneumatic drive.

6. Multiple displacement pump according to claim 5, characterized in that the first mechanical actuator is a control valve and this is actuated by the lifting rod (14) depending on the deflection position of the displacement elements (11, 12).

7. Multiple displacement pump according to one of claims 1 to 5, characterized in that the first mechanical actuator comprises an electric drive with alternating direction of rotation which interacts with the lifting rod (14).

8. Multiple displacement pump according to claim 7, characterized in that the first mechanical actuator comprises an electric motor (19) which cooperates with a ball screw (20) or a thread (21) which are optionally assigned to the lifting rod (14).

9. Multiple displacement pump according to one of claims 1 to 5, characterized in thatthe first mechanical actuator comprises an eccentric (22) mounted on a rotary axis connected to an electric motor directly or with the interposition of a gear, which eccentric is enclosed by a rotary bearing (23) which in turn is pivotally mounted at one end of the lifting rod (14).

10. Multiple displacement pump according to one of claims 1 to 5, characterized in that the first mechanical actuator comprises an eccentric (22) mounted on a rotary axis connected to an electric motor directly or with the interposition of a gear, which eccentric actuates a spring-loaded plunger (24) which in turn is formed by the lifting rod (14).

11. Multiple displacement pump according to claim 10, characterized in that the plunger (24) moves towards the eccentric (22) against a stop.

12. Multiple displacement pump according to one of claims 1 to 5, characterized in thatthe lifting rod (14) is connected to an armature (26) of a pulling magnet (25) which is resiliently mounted relative to a fixed yoke (27) and can be actuated electromagnetically by energizing an excitation coil (28) associated with the yoke (27).

13. Multiple displacement pump according to one of claims 1 to 5, characterized in that the lifting rod (14) is connected to an armature (26) of a pulling magnet (25) which is movable back and forth between two opposing yokes (27) and can be electromagnetically actuated by alternately energizing excitation coils (28) associated with the yokes (27).

14. Multiple displacement pump according to one of the preceding claims, characterized in thatthe connecting element (13) is tubular and the lifting rod (14) is guided through the connecting element (13), wherein the lifting rod (14) has stop elements (39, 40) on both sides adjacent to the end faces of the connecting element (13), against which the connecting element (13) strikes during a longitudinal displacement of the lifting rod (14).

15. Multiple displacement pump according to claim 14, characterized in that at least one end-face stop element (39) of the lifting rod (14) is detachably connected to the lifting rod (14).

16. Multiple displacement pump according to claim 14, characterized in that the tubular connecting element (13) can be releasably closed at least in one position after removal of the lifting rod (14).

17. Multiple displacement pump according to one of the preceding claims, characterized in that the propellant chambers (6, 9) of the fluid chambers (5, 8) are fluidically connected to one another.

18. Multiple displacement pump according to claim 17, characterized in that a second, parallel displacement element (41) is assigned to each of the fluid chambers (5, 8) to form an intermediate space (30), the intermediate space (30) being filled with a supporting fluid.

19. A multiple displacement pump with a pump housing comprising a first outer cover (2) and a second outer cover (3) and at least one intermediate piece (4) received between the covers (2, 3), wherein at least two fluid chambers (5, 8) are formed between the covers (2, 3) and the at least one intermediate piece (4), which are divided into at least one propellant chamber (6, 9) and one media chamber (7, 10) by means of at least one displacement element (11, 12), and wherein the displacement elements (11, 12) of the at least two fluid chambers (5, 8) are non-positively and detachably connectable to at least one lifting rod (14) via at least one connecting element (13), wherein the at least one lifting rod (14) can extend the at least one connecting element (13) through a first passage (16) of the adjacent first cover (2), characterized in thatthe propellant chambers (6, 9) are operatively connected to a pneumatic drive via pneumatic access openings (18) in the covers (2, 3) and the at least one connecting element (13) can be extended by means of the at least one lifting rod (14) in such a way that the drive can be removed and another drive can be attached to it, wherein either a pneumatic or an electric drive can be adapted.

20. Multiple displacement pump according to claim 19, characterized in that a first cover (2) has a first passage (16) for receiving the lifting rod (14), wherein the first passage (16) is sealed in a propellant-tight manner.

21. Multiple displacement pump according to claim 19, characterized in that the first cover (2) is formed in one piece with a housing of the pneumatic drive.

22. Multiple displacement pump according to claim 19, characterized in thata pressure booster unit (31) with a further fluid chamber (35) is assigned to the first cover (2) adjacent to a connecting means (15), wherein the connecting element (13) is extended by a lifting rod (14) with the aid of connecting means (15), and the lifting rod (14) connects the connecting element (13) to a further displacement element (32, 33) accommodated in the further fluid chamber (35), and wherein a first sub-chamber (36) of the pressure booster unit (35) is fluidly connected to the first propellant chamber (6) and a second sub-chamber (37) of the pressure booster unit (35) is fluidly connected to the second propellant chamber (9).

23. Multiple displacement pump according to claim 22, characterized in that a plurality of parallel pressure booster units (35) are provided, the first sub-chambers (36) of which are fluidly connected to the first propellant chamber (6) and the second sub-chambers (37) of which are fluidly connected to the second propellant chamber (9).

24. Multiple displacement pump according to one of claims 22 or 23, characterized in that the displacement element (32, 33) of the one or more pressure booster units (35) is a further membrane (32) or a further piston (33).

25. Multiple displacement pump according to one of claims 19 to 24, characterized in that the connecting element (13) is tubular and has a passage (42) in the direction of a longitudinal extension for receiving the lifting rod (14).

26. Multiple displacement pump according to claim 25, characterized in that the tubular connecting element (13) has a releasable closure at least at one position.

27. Multiple displacement pump according to one of the preceding claims, characterized in thatthe intermediate piece (4) has either a common suction line and a common pressure line, or two separate suction lines and two separate pressure lines for the media chambers (7, 10) of the respectively adjacent fluid chambers (5, 8), wherein the suction lines and the pressure lines are each blocked off from the media chambers (7, 10) by means of valves which block in the same direction.

28. Multiple displacement pump according to one of the preceding claims, characterized in that the intermediate piece (4) has a through-opening (38) through which the connecting element (13), which connects a plurality of displacement elements (11, 12) to one another and to the at least one lifting rod (14), can be passed, wherein the through-opening (38) can be closed in a media-tight manner.

29. Multiple displacement pump according to one of the preceding claims, characterized in thatthe intermediate piece (4) and / or the covers (2, 3) and / or the housing of the at least one mechanical actuator have a support foot pointing away from the intermediate piece (4) on at least one side.

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