Multiple displacement pump

Abstract

Known multi-displacement pumps are designed to be actuated either pneumatically or electrically. The present invention proposes an arrangement that allows for the production of such a pump from largely identical parts or the conversion of such a pump from one drive type to the other with minimal effort. For this purpose, the displacement elements are connected via a connecting element that can be extended through a cover of the fluid chambers, so that a mechanical actuator can be optionally attached, which can be connected to an electric drive or to a control valve.

Description

[0001] The present invention relates to a multi-displacement pump with a pump housing comprising a first outer cover and a second outer cover 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, and wherein the displacement elements of the at least two fluid chambers can be connected to at least one stroke rod in a force-fit and detachable manner via at least one connecting element, wherein the at least one stroke rod can extend the at least one connecting element through a first opening in the adjacent first cover.wherein the propellant chambers are operatively connected to a pneumatic drive via pneumatic access openings in the covers and the at least one connecting element can be extended by means of the at least one lifting rod in such a way that the drive can be removed.

[0002] Such a mechanical multi-displacement pump is already known from CH 717057 A1, and a corresponding pneumatic displacement pump from DE 197 38 779 A1. Further reference should be made to US 2,918,878 A, AT 34296 B, US 2023 / 184235 A1, US 5,558,506 A1 and EP 3 115 607 A1.

[0003] Furthermore, DE 10 2021 104 548 A1 is 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 out of the fluid chambers on one side and actuates a control valve with its free end. This control valve regulates the alternating flow of propellant into propellant chambers within the fluid chambers.

[0004] Double diaphragm pumps are generally displacement pumps. They contain two diaphragms rotating in parallel, each housed in a separate chamber. The diaphragms are clamped at their outer diameter. Each chamber has an inlet and an outlet, with a check valve located before and after each outlet. Axial movement of the diaphragms increases the volume of the first chamber while simultaneously decreasing the volume of the second. This change in volume draws in the fluid and then displaces it. Due to the synchronous movement of the diaphragms, one diaphragm is in the suction stroke while the other is in the pumping stroke. Double diaphragm pumps are available with two different drive types: pneumatic and electric.

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

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

[0007] In general, the principles of double diaphragm pumps can be extended to the multi-displacement pump discussed here. For the purposes of this discussion, the term "multi-displacement pump" also refers to pumps that do not necessarily have only two diaphragms, but two or more, and these do not necessarily have to be diaphragms; they can also be other displacers, such as pistons.

[0008] While the aforementioned pumps based on the peripheral flow principle are very compact, which can be helpful in everyday use, they are inflexible and cannot be adapted to external circumstances. In particular, the pump drive cannot be modified. If, for example, an electrical drive is prohibited in a specific environment, such as for explosion protection reasons, these pumps can no longer be used. Conversely, this also 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 present invention aims to create a multi-displacement pump that is as variable as possible and adaptable to different application environments.

[0010] This is achieved by a multi-displacement pump according to the features of independent claim 1. Useful embodiments of such multi-displacement pumps can be found in the subsequent dependent claims.

[0011] One possible embodiment is a multi-displacement pump with a pump housing comprising two outer covers and at least one intermediate piece located between the covers. At least two fluid chambers are formed between the covers and the intermediate piece. These fluid chambers are divided into at least one propellant chamber and one media chamber by means of at least one displacement element. The displacement elements of the at least two fluid chambers are connected to at least one stroke rod via at least one connecting element in a force-fit and preferably detachable manner. Such a multi-displacement pump can further provide that the at least one stroke rod and the at least one connecting element extend through a first opening in an adjacent first cover. The stroke rod is force-fitted to a first mechanical actuator by means of detachable connecting elements.

[0012] The pump unit and the drive unit are considered separately. Combined, they form a functional pump. The unique feature is that the pump unit is designed for different drive types. Due to the positive-locking but detachable connection between the connecting rod and the drive, the drive can be removed from the multi-displacement pump and a different drive attached. Either a pneumatic or an electric drive unit can be adapted laterally. In particular, the connecting element can be designed to accommodate both an electric drive and a mechanically actuated control valve. The changeover should require only a few assembly steps. Minor modifications to the pump unit are possible. This flexibility allows the user to choose their preferred drive type and quickly convert the pump accordingly.

[0013] The pump unit is based on the central flow principle. The inlet, outlet, and check valves are located in the intermediate section. The displacement elements can either operate independently or are mechanically connected via connecting elements. The pump unit can be completely sealed on one side by a second cover. On the opposite side, the lifting rod protrudes. This rod is used to connect the drive unit to at least one connecting element. For emptying the pump unit, the media chambers can have drain holes located at the lowest point, which are sealed during operation.

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

[0015] It is advantageous if the first opening of the first cover, preferably after the removal of at least one lifting rod, is sealable against the propellant. Such a seal ensures that if the externally extending lifting rod is removed, the propellant cannot escape from the propellant chamber. In principle, with a pneumatic drive, it is also possible to omit the lifting rod and connect the two displacement elements via the connecting element, otherwise acting solely on the pressure exerted on the propellant chambers. Accordingly, the covers can be equipped with sealable pneumatic access openings for connection to a pneumatic drive. Such access openings can be designed, in particular, to provide a very simple, possibly standardized, connection to a propellant source, such as a compressed air connection.

[0016] Besides connecting the housing of the mechanical actuator to the first cover, this can also be achieved by forming the first cover and the housing of the mechanical actuator as a single unit. In such a case, the cover can be detached with one drive unit, and another cover with a different drive unit can be attached. It is also possible, if necessary, to provide no through-hole in the cover if the lifting rod does not need to pass through it.

[0017] Regarding the connection options for an externally extending lifting rod, one possibility is that the mechanical actuator is a control valve, which is actuated by the lifting rod depending on the deflection position of the displacement elements. While the displacement of the displacement elements is caused by the propellant, the control valve is actuated by the lifting rod when an end position is reached, thus generating the counter-stroke and refilling the affected propellant chamber after it has been completely emptied, or vice versa.

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

[0019] One possibility for an electric drive is that the mechanical actuator includes an electric drive with alternating direction of rotation that interacts with the lifting rod, preferably an electric motor which interacts with a ball screw or a thread, which are optionally assigned to the lifting rod.

[0020] Another possibility is that the mechanical actuator includes an eccentric mounted on a rotary axis connected directly to an electric motor or via an intermediate gearbox, which is enclosed by a rotary bearing which in turn is pivotably mounted at one end of the lifting rod.

[0021] It is also possible for the mechanical actuator to include an eccentric mounted on a rotary axis connected directly to an electric motor or via a gearbox. This eccentric actuates a plunger, preferably spring-loaded, which in turn is formed by the lifting rod. To limit the stroke, the plunger can be disengaged against a stop as it moves towards the eccentric. In this case, the eccentric will not be in continuous contact with the plunger, and the conveying capacity will be limited.

[0022] Another embodiment provides that the lifting rod is connected to the armature of a traction magnet, which is spring-mounted relative to a stationary yoke and can be electromagnetically actuated by energizing an excitation coil associated with the yoke. While in this embodiment half of the movement is achieved mechanically by a spring, thus allowing a defined rest position, another variant provides that the lifting rod is connected to the armature of a traction magnet, which is movable back and forth between two opposing yokes and can be electromagnetically actuated by alternately energizing excitation coils associated with the yokes. Here, movement of the displacement elements occurs only as a result of energizing the excitation coils.

[0023] It is particularly advantageous to provide a tubular connecting element with the lifting rod passing through it. The lifting rod has stop elements on both sides adjacent to the end faces of the connecting element, against which the connecting element abuts during longitudinal displacement of the lifting rod. This solution can be especially advantageous for diaphragm pumps. It has been observed that these pumps are subject to particularly high wear when fastened with conventional connecting elements under tensile stress. Furthermore, when connecting the displacement elements with a tubular connecting element and passing a lifting rod through it, which has stop elements on both sides of the connecting element, the connecting element, and consequently the displacement elements connected in this way, can be displaced during any movement.The use of membranes results in a particularly gentle actuation of the membranes.

[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 can be guided through the connecting element and the corresponding connection openings of the at least one participating displacement element without the end-face stop element and then fixed in place by means of the connecting means, in particular by means of a screw connection. The second stop element can be attached in various ways: firstly, in the case of a multi-part lifting rod, it can be inserted between two elements, or it can be attached to the lifting rod by friction or form-fitting, by shrinking, or by welding.

[0025] If, however, the lifting rod is omitted, for example in a pneumatic system, the tubular connecting element can be provided so that, after the lifting rod is removed, it can be detachably closed at least at one position, preferably at both ends. 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., that they cannot exchange propellant or even mix propellant with the medium. This is achieved particularly well if the connecting element is sealed at both ends and either filled with material or sealed with a gasket.

[0026] While it is initially possible for the electrical 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 create a form-fit and / or force-fit connection between a mechanical connection of the mechanical actuator and the lifting rod, which may in particular be screw connectors, a bayonet fitting or a quick coupling.

[0027] It has already been pointed out that in the case of a purely electrically operated multi-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 each fluid chamber is assigned a second, parallel displacement element with the formation of an intermediate space, preferably with an insert placed between them, wherein the intermediate space is filled with a support fluid.

[0028] According to the invention, a multi-displacement pump is provided in the present case with a pump housing comprising two outer 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 each other and / or separately via at least one connecting element in a force-fit manner, and preferably detachably, to at least one stroke rod, wherein the at least one connecting element can be extended by means of the at least one stroke rod and the propellant chambers are operatively connected to a pneumatic drive via pneumatic access openings in the covers.

[0029] It is provided that a pressure transmission unit with a further fluid chamber is assigned to a first cover adjacent to the connecting means, wherein the connecting element is extended by means of a lifting rod by means of the connecting means and the lifting rod connects the connecting element to a further displacement element received in the further fluid chamber and wherein a first sub-chamber of the pressure transmission unit is fluidly connected to the first propellant chamber and a second sub-chamber of the pressure transmission unit is fluidly connected to the second propellant chamber.

[0030] In a pneumatically driven pump operating according to the principle described above, the achievable delivery pressure is approximately equal to the inlet pressure of the propellant. To achieve a higher delivery pressure than the inlet pressure of the propellant, a pressure intensifier is used. This is achieved with a pressure intensifier unit, which includes an additional displacement element. This element can be alternately pressurized on both sides with propellant, for example, compressed air. The propellant can enter the chambers of the pressure intensifier unit via connecting channels. A pneumatic drive unit controls or regulates the flow of propellant and can be flanged to the side. This increases the effective area of ​​the propellant, while the area of ​​the pumped medium remains constant. The connecting element is rigidly connected to both displacement elements of the multi-displacement pump and to the pressure intensifier unit.

[0031] In principle, this can be the same multi-displacement pump as in the case described at the beginning, except that pneumatic operation without a lifting rod is provided, whereas in the version described above, mechanical operation or pneumatic operation with a lifting rod is provided.

[0032] In such a multi-displacement pump, the diaphragm movement is pneumatically implemented. It includes a compressed air connection through which compressed air is directed to a control valve. This control valve alternately directs the flow of propellant into the propellant chamber behind the displacement elements. The incoming propellant builds up pressure there, moving the displacement element axially. This causes the displacement element to perform a pumping stroke. Once the stroke is complete, the control valve is actuated and then switches the flow of propellant to the second displacement element. This results in a stroke in the opposite direction.

[0033] Accordingly, in this variant it can also be provided that a first cover has a first opening for receiving a lifting rod, whereby in this embodiment the first opening is now sealed to prevent the passage of propellant from entering.

[0034] Furthermore, the first cover can also be formed in one piece with the housing of the pneumatic actuator.

[0035] Further developing the aforementioned features, several parallel pressure transmission 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 therefore possible to use multiple pressure transmission units and mount them on the side of the first or second cover. The pressure transmission unit can, in particular, be designed with an additional diaphragm or piston.

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

[0037] The intermediate piece between the chambers of the multi-displacement pump serves to separate the fluid chambers and, if present, accommodates the connecting element. Preferably, the intermediate piece has either a common suction line and a common discharge line, or two separate suction lines and two separate discharge lines for the media chambers of the adjacent fluid chambers, wherein the suction lines and the discharge lines are each shut off from the media chambers by means of valves that close in the same direction, preferably ball valves. Depending on the application, separate suction and discharge lines can enable the metering of several fluids, while common suction and discharge lines allow only a single, combined pumping operation.

[0038] Furthermore, the intermediate piece may have a through-opening through which a connecting element can be passed, linking several displacement elements to each other and to the at least one lifting rod. It may also be provided that this through-opening is closable, which is particularly important for the possibility of equipping the multi-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 to prevent media leakage when no connecting element is used to join several displacement elements.

[0039] By using two separate drives for each of the displacement elements, the fluid chambers can be traversed at different speeds, allowing two different fluids to be conveyed at different flow rates. Depending on the conveying speeds, mixtures in predetermined ratios can be created. This is also possible by using an insert that is placed in the propellant chamber of one of the fluid chambers. This allows the chamber volume to be changed by means of an insert. An axially adjustable stop is installed for this purpose. During the suction stroke, the stop reduces the suction volume, which also reduces the pumping volume. Especially when the displacement elements, preferably diaphragms, are rigidly connected to each other by a connecting element, thus ensuring a constant central stroke, different quantities can be conveyed in adjacent fluid chambers.

[0040] Finally, it may be provided that the intermediate piece and / or the covers 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 each other by means of a connecting element, and the connecting element is extended outwards to form a drive. Due to the resulting asymmetry, a support foot ensures that the multi-displacement pump does not tend to tip over.

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

[0042] They show Figure 1a a multi-displacement pump with an extended stroke rod and two connected diaphragms in schematic representation, Figure 1b the multi-displacement pump according to Figure 1awith a lifting rod passing through the connecting element in schematic representation, Figure 2 the multiple displacement pump according to Figure 1awith an insert for one-sided reduction of the delivery rate in schematic representation, Figure 3a; a multi-displacement pump with a pressure transmission unit with a further diaphragm in schematic representation, Figure 3b; a multi-displacement pump with a double pressure transmission unit with two further diaphragms in schematic representation, Figure 3c; a multi-displacement pump with a pressure transmission unit with a further piston in schematic representation, Figure 4a; a multi-displacement pump with a mechanical actuator in the form of an electric motor with ball screw in schematic representation, Figure 4b; a multi-displacement pump with a mechanical actuator on both sides in the form of an electric motor with ball screw in schematic representation, Figure 4c; a multi-displacement pump with a mechanical actuator in the form of an electric motor with thread in schematic representation,Figure 5a a multi-displacement pump with a mechanical actuator in the form of an eccentric and an articulated lifting rod in schematic side view, Figure 5b the multi-displacement pump according to , Figure 5a Figure 5c shows a multi-displacement pump with a mechanical actuator in the form of an eccentric for acting on a plunger formed by the lifting rod in a schematic representation; Figure 6a shows a multi-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 shows the multi-displacement pump according to Figure 6ain a schematic representation of a second stroke, Figure 6 a multi-displacement pump with two mechanical actuators in the form of pull magnets with spring return in a schematic representation, Figure 6 a multi-displacement pump with two mechanical actuators in the form of pull magnets with opposing and oppositely acting yokes in a schematic representation, Figure 7 the multi-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 8adie multiple displacement pump according to Figure 1a with inserts in the fluid chambers and each with a second displacement element forming an intermediate space in schematic representation, as well as Figure 8b the multiple displacement pump according to Figure 8a with unconnected displacement elements in schematic representation.

[0043] Figure 1a Figure 1 shows a multi-displacement pump 1, which consists 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, each form a fluid chamber 5 and 8, respectively, whereby in the illustration of the subsequent figures, the fluid chamber shown on the left is designated as the first fluid chamber 5 and the fluid chamber shown on the right as the second fluid chamber 8.

[0044] In the first fluid chamber 5, a first displacement element 11 and in the second fluid chamber 8, a second displacement element 12 are arranged such that 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, with the necessary lines contained in the intermediate piece 4. Since this is not essential, they are not shown in the following figures. In the subsequent figures, diaphragms are always depicted as displacement elements 11 and 12, but this is only meant to be representative. Other displacement elements, in particular pistons, can be used just as well.

[0045] The multi-displacement pump 1 has a through-opening 38 in the intermediate piece 4, through which a connecting element 13 is passed, which connects the two displacement elements 11 and 12 together.

[0046] Due to this mechanical connection, the displacement elements 11 and 12 necessarily move in unison. A connecting element 13 is linked to a connecting element 13 via a connecting element 15, such as a screw connection, a bayonet fitting, or the like. This connecting element 14 extends through the first cover 2 to the outside. A mechanical actuator can be attached to the connecting element 14 to move the displacement elements 11 and 12, or conversely, a flow valve can be actuated by the connecting element 14. Because of this design, the multi-displacement pump 1 is highly variable and versatile, and can be further modified even after manufacturing, particularly with regard to its drive system and other functional elements.

[0047] If the lifting rod 14 is omitted and the resulting opening 16 of the first cover 2 is closed, the multi-displacement pump can be converted to pneumatic operation. While the displacement elements 11 and 12 can remain coupled, pneumatic access ports 18 in the covers 2 and 3, which can also be located 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 actuated not mechanically from the outside, but by a propellant that can be alternately pumped from the first propellant chamber 5 to the second propellant chamber 8 and vice versa. Separate control of the propellant chambers 5 and 8 is also possible.However, passing the lifting rod 14 through the first cover 2 is also useful in this case in order to actuate the control valve via the lifting rod 14 in the end positions.

[0048] Figure 1b shows a variant of the Figure 1a 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 here in a through-opening 38 of the intermediate piece 4, as it is chosen to be long enough to connect the two displacement elements 11 and 12. A seal is also provided here such that a medium conveyed in the media chambers 7 and 10 cannot pass between the media chambers 7 and 10 through the through-opening 38.

[0049] The connecting element 13, which in this context is tubular, surrounds the lifting rod 14, so that in both directions of movement the lifting rod 14 acts only in a pushing, but not a pulling, manner on the connecting element 13 and thus on the displacement elements 11 and 12. Therefore, there is no flat, friction-fit connection between the lifting rod 14 and the connecting element 13; instead, the lifting rod 14 can slide within 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 in the assembled state. Particularly in the case of membranes, it is especially advantageous if they are subjected only to compression and not to tension, in order to increase their durability.

[0050] While a central stop element 40 can be permanently attached to the lifting rod 14 by welding, joining, shrinking, or similar methods, an end-face stop element 39 is detachably connected to an end face of the lifting rod 14, for example, by screws, 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 to prevent the media from entering the system when the lifting rod 14 is no longer needed. A connecting element 43 is attached to the free end of the lifting rod 14, i.e., opposite the end-face stop element 39, to establish a connection with a mechanical actuator, such as a drive motor or one of the drives described below. This allows for switching between different drives and drive types—mechanical, electrical, pneumatic, or hydraulic.The tubular connecting element 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, in particular, when several drives are used for the individual displacement elements 11 and 12 for the purpose of metering.

[0051] For the sake of simplicity, the lifting rod 14 and the at least one connecting element 13 are shown below together with any connecting means 15 or 43 as one part.

[0052] Figure 2Figure 1 shows a multi-displacement pump 1 in which a first displacement element 11 is moved by the stroke rod 14 and the connecting element 13. The first displacement element 11 can utilize the full size of its fluid chamber, while a second displacement element 12 runs against a diaphragm stop 34 inserted into its fluid chamber. This allows a variable ratio between the flow rates in the two fluid chambers to be set, which is particularly advantageous for use as a metering pump.

[0053] Figures 3a, 3b and 3c Figure 1 shows various multi-displacement positive displacement pumps 1, which operate with a pressure intensifier. In order to achieve a higher discharge pressure compared to the inlet pressure, a pressure intensifier unit 31 is added to the setup described above. This can be done with an additional diaphragm 32 as shown in Figure 1. 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 transmission units 31 added in parallel is also possible, as shown in Figure 3b shown.

[0054] The pressure transmission unit 31 is an additional element in which another displacement element 32 or 33 is housed. This element can be alternately pressurized with the propellant in both sub-chambers 36 and 37. The propellant, for example compressed air, can enter the propellant chambers of the pump unit via connecting channels 44. The pneumatic drive unit controls the air supply and is laterally flanged, although this is not shown in the illustrations. This increases the effective area of ​​the propellant, while that of the medium remains constant. The connecting element 13 is rigidly connected to both displacement elements of the multi-displacement pump 1 and to the pressure transmission unit 31.

[0055] The generation of the linear motion of the displacement elements 11 and 12 can be, as in the Figures 4a and 4bThe force is generated by means of a motor and a ball screw 20. An electric motor 19 is used for this purpose, in which the rotating rotor ring serves as the drive nut. The counterpart to this is the ball screw 20. Depending on the direction of rotation of the rotor, this moves translationally forwards or backwards. The force / motion is transmitted via a fixed connection to the connecting element 13. In the variant of the Figure 4b In this arrangement, a spindle drive is used on each side to move the displacement elements 11 and 12. With this configuration, 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 by a connecting element 13. The two drive units can be controlled independently of each other.

[0056] The function of a in Figure 4cThe threaded drive shown 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 motion into a translational motion.

[0057] Another variant arises from the Figures 5a and 5b In this variant, an eccentric 22 is located on a drive shaft, which serves as a pivot bearing 23 and is connected to an electric motor. A gearbox may 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.

[0058] Another variant is thematically similar according to Figure 5cIn this arrangement, an eccentric 22 is rigidly connected to the drive shaft 23 of the electric motor, which serves as a pivot bearing. A gearbox can also be located between the electric motor and the drive shaft. A spring-loaded plunger 24 is permanently in contact with the eccentric. Rotation of the eccentric 22 pushes the plunger 24 inwards and compresses the spring. Further rotation of the eccentric 22 causes the plunger 24 to move outwards again due to the spring tension. The plunger 24 is connected to both displacement elements and transmits its movement to them.

[0059] With regard to Figures 6a and 6bA connecting element is rigidly connected to a movable armature 26 via a lifting rod 14. The armature 26 is spring-loaded on one side. A stationary excitation coil 28 is located next to the armature 26. Together, the components form a traction magnet 25. When a voltage is applied to the excitation coil 28, a magnetic field is generated within it, which attracts the armature 26 towards a yoke 27, as shown in Figure 6b shown. The spring 47 is tensioned. When the tension is switched off, the armature 26 is returned to its original position due to the spring force according to Figure 6a pressed.

[0060] In another variant according to Figure 6cA solenoid 25 is used on each side. A displacement element 11 or 12 is each connected to only one solenoid 25. The strokes are executed by alternately energizing the left and right excitation coils 28. The spring 47 pushes the armatures 26 back into the starting position when the voltage is switched off. The two solenoids 25 can be controlled independently of each other.

[0061] Furthermore, it is possible, as in Figure 6d The figure shows the use of two traction magnets 25 on each side. The armature 26 is located between them. A continuous pushrod 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 simultaneously energized with the inner excitation coil on the right side, or vice versa.

[0062] When using a pneumatic drive unit, pressure is generated behind the displacement element 11, 12, acting against it. On the opposite side, the pressure of the medium prevails. The displacement element 11 or 12 is thus pressurized from both sides and continuously supported. When using an electric drive unit, this pneumatic counter-pressure is absent. During operation, the displacement element 11 or 12 is subjected to pressure on one side only. This one-sided pressure increases wear, particularly on diaphragms, and shortens their service life. This wear can be counteracted by hydraulic assistance. For this purpose, a fluid is filled into the propellant chambers 6 and 9 behind the diaphragms until the system is completely filled and vented. During operation, the propellant is alternately transferred from one propellant chamber 6 to the other propellant chamber 9 and vice versa.The pressure on both sides of the diaphragm is almost identical. Wear is reduced. A mechanical connection between the diaphragms is no longer necessary, but can be included. Figure 7a This variant shows a continuous connecting element 13 with a lifting rod 14, at Figure 7b A connecting element 13 is only connected to a lifting rod 14 on the left side; on the right side, where the connecting element 13 is blindly closed, there is none.

[0063] Finally, in another embodiment, an insert 29 and another diaphragm are mounted on each side. This creates an encapsulated space 30. This space 30 contains a fluid, in particular compressed air or a liquid. When the pump is started up, the inner diaphragm is supported. The diaphragm movement is caused by the propellant, which is conveyed back and forth between the first propellant chamber 6 and the second propellant chamber 9 via a connecting channel 44.

[0064] The above description thus describes a multi-displacement pump which is as variable as possible and adaptable to different application environments. LIST OF REFERENCE SIGNS

[0065] 1 Multi-displacement pump 2 First cover 3 Second cover 4 Intermediate piece 5 First fluid chamber 6 First propellant chamber 7 First media chamber 8 Second fluid chamber 9 Second propellant chamber 10 Second media chamber 11 First displacement element 12 Second displacement element 13 Connecting element 14 Lifting rod 15 Connecting device 16 First bushing 17 Second bushing 18 Pneumatic access port 19 Electric motor 20 Ball screw 21 Thread 22 Eccentric 23 Rotary bearing 24 Plunger 25 Pull magnet 26 Armature 27 Yoke 28 Exciter coil 29 Insert 30 Intermediate space 31 Pressure transmission unit 32 Additional diaphragm 33 Additional piston 34 Diaphragm stop 35 Additional fluid chamber 36 First sub-chamber 37 Second sub-chamber 38 Through-hole 39 Front stop element 40 Middle stop element 41 Parallel displacement element 42 Feedthrough 43 Connecting element 44 Connecting channel 45 Housing 46 Swivel bearing 47 Spring

Claims

1. Multi-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 by means of at least one displacement element (11, 12) into at least one propellant chamber (6, 9) and one media chamber (7, 10), and wherein the displacement elements (11, 12) of the at least two fluid chambers (5, 8) can be frictionally and detachably connected to at least one stroke rod (14) via at least one connecting element (13), wherein the at least one stroke rod (14) can extend the at least one connecting element (13) through a first opening (16) of the adjacent first cover (2), wherein the propellant chambers (6, 9) via pneumatic access openings (18) in the covers (2,3) are operatively connected to a pneumatic drive 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, , characterized by the fact thata different drive can be attached to the connecting element (13), namely, either a pneumatic or an electric drive can be adapted, wherein the first cover (2), which is adjacent to connecting means (15), is associated with a pressure transmission unit (31) with a further fluid chamber (35), wherein the connecting element (13) is extended by means of the connecting means (15) by means of a lifting rod (14) and the lifting rod (14) connects the connecting element (13) with a further displacement element (32, 33) received in the further fluid chamber (35) and wherein a first sub-chamber (36) of the pressure transmission unit (31) is fluidly connected to the first propellant chamber (6) and a second sub-chamber (37) of the pressure transmission unit (31) is fluidly connected to the second propellant chamber (9).

2. Multi-displacement pump according to claim 1, characterized by the fact thata first cover (2) has a first opening (16) for receiving the lifting rod (14), wherein the first opening (16) is sealed in a propellant-tight manner.

3. Multi-displacement pump according to claim 1, characterized by the fact that the first cover (2) is formed in one piece with a housing of the pneumatic drive.

4. Multi-displacement pump according to one of the preceding claims, characterized by the fact that several parallel pressure transmission units (31) 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).

5. Multi-displacement pump according to one of the preceding claims, characterized by the fact that the displacement element (32, 33) of one or more pressure transmission units (31) is a further diaphragm (32) or a further piston (33).

6. Multi-displacement pump according to one of the preceding claims, characterized by the fact thatthe connecting element (13) is tubular and has a passage (42) in the direction of a longitudinal extension for receiving the lifting rod (14).

7. Multi-displacement pump according to claim 6, characterized by the fact that the tubular connecting element (13) has a releasable closure at least at one position.

8. Multi-displacement pump according to one of the preceding claims, characterized by the fact that the intermediate piece (4) either has 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 respective adjacent fluid chambers (5, 8), wherein the suction lines and the pressure lines are each shut off from the media chambers (7, 10) by means of valves shutting in the same direction.

9. Multi-displacement pump according to one of the preceding claims, characterized by the fact thatthe intermediate piece (4) has a through-opening (38) through which the connecting element (13), which connects several displacement elements (11, 12) to each other and to the at least one lifting rod (14), can be passed through, wherein the through-opening (38) can be closed in a media-tight manner.

10. Multi-displacement pump according to one of the preceding claims, characterized by the fact that the intermediate piece (4) and / or the covers (2, 3) and / or the housing of the at least one mechanical actuator shall have at least on one side a support foot pointing away from the intermediate piece (4).

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