Eccentric screw pump

Abstract

Eccentric screw pump with at least - a stator (1), - a rotor (2) rotating in the stator (1), - a drive (3) for the rotor (2), - a pump housing (4) connected to the stator (1), which has at least one inlet or outlet opening (6) for a medium to be pumped, - a connecting shaft (9) connected to the drive (3), - a coupling rod (10) arranged in the pump housing (4), which is detachably connected to the connecting shaft (9) at a separation point, wherein the rotor (2), coupling rod (10) and connecting shaft (9) form a rotating unit during operation of the progressive cavity pump, characterized in that the drive (3) is displaceable in the axial direction (A) to expose the separation point, wherein the drive (3) with the rotating unit connected to it is displaceable in the axial direction (A) such that the separation point can be pulled out of the pump housing (4) in the direction of the drive (3) and the rotating unit can be separated at the separation point.

Description

[0001] The invention relates to an eccentric screw pump with at least - a stator, - a rotor rotating in the stator, - a drive for the rotor, - a pump housing (e.g. suction housing) connected to the stator (e.g. suction side or drive side), which has at least one inlet opening (or outlet opening) for the medium to be pumped, - a connecting shaft (detachably) connected to the drive, - a coupling rod arranged in the pump housing, which is detachably connected to the connecting shaft at a separation point, whereby the rotor, coupling rod and connecting shaft form a rotating unit during operation.

[0002] Such an eccentric screw pump is a pump from the group of rotating positive displacement pumps, which are used to pump a wide variety of media, especially highly viscous liquids, in a wide range of industries. The liquids to be pumped may also contain solids, for example.

[0003] The stator is preferably made of elastic (e.g. elastomer) material and is generally surrounded by a one-piece or multi-piece stator shell or stator housing. Alternatively, stators made of other materials, e.g. metal, are also included. The pump housing connected to the stator on the suction side is generally referred to as the suction housing, and the housing connected to the stator on the pressure side is referred to, for example, as the pressure port. In principle, it is also possible to operate such a pump in the opposite direction of flow, so that the suction housing (as the pump housing) would then be arranged on the pressure side. In the context of the invention, the designation of the pump housing as the suction housing is therefore independent of the actual direction of flow. It is the housing arranged between the stator and the drive. The rotating connection between the drive and the drive, which also ensures eccentricity, is formed by the drive and the pump housing.The connection between the connecting shaft on the one hand and the rotor on the other hand is achieved via a coupling rod arranged in the pump housing, which is connected to the connecting shaft, for example, via a drive-side joint, and to the rotor, via a rotor-side joint. Alternatively, the eccentricity can also be achieved by other measures (i.e. without joints), e.g. by a flexible / elastic coupling rod. A coupling rod therefore means an element that ensures the eccentricity of the rotor or enables the eccentric movement between the rotating connecting shaft and the rotor. In principle, this coupling rod can also be formed integrally with the rotor; however, the coupling rod is detachably connected to the connecting shaft at a separation point, which can be formed, for example, by the drive-side joint.In principle, however, designs are also covered in which a separation point is provided in addition to the drive-side joint. The connecting shaft is also referred to as a plug-in shaft. It can be connected directly to the drive's output shaft and serve as a connecting piece between the drive's output shaft and the pump's power transmission components. Alternatively, the connecting shaft can also be connected to the drive or the drive's output shaft via a coupling.

[0004] A connecting housing, also known as a "lantern" in practice, is usually arranged between the pump casing (suction casing) and the drive. This serves, for example, to hold or fasten and support the pump casing on the one hand and the drive on the other, so that this connecting housing or lantern is fastened, for example, to a pump base (e.g. a baseplate or foundation) and supports and carries the drive and the pump casing. Suspended arrangements are also possible. The connecting housing can also be a bearing block that is fastened to the pump base (e.g. baseplate or foundation). The bearing block serves to absorb axial and radial forces, and the pump casing on the one hand and the drive on the other can each be fastened and supported on the pump base (baseplate or foundation).In such embodiments with a bearing block, the connecting shaft can be connected to the drive via an interposed (flexible) coupling (for torque absorption). As a rule, it is expedient for the connecting housing to be designed as an open or at least as an openable connecting housing, which is consequently accessible from the outside through an opening (e.g., on the side or top). The connecting shaft is arranged (at least in part) in this connecting housing. In addition, it is generally provided that the connecting shaft is sealed with a shaft seal (e.g., arranged in the connecting housing and attached to it) to create a liquid-tight separation of the pump housing (from the environment or from the connecting housing). Such a shaft seal can be a mechanical seal or a stuffing box packing.

[0005] Some essential components of a progressing cavity pump are subject to considerable wear during operation, so they must be replaced regularly as wear parts. In addition to the stator and rotor, this particularly applies to the shaft seal located on or near the connecting shaft, which, as a wear part, must be replaced or repaired as needed. In addition, maintenance work may also be required on the joints, such as the drive-side joint.

[0006] Solutions for simplifying maintenance work and replacing wear parts are known in a wide variety of variants for progressing cavity pumps. WO 2010 / 012993 A2 describes the possibility of exposing the area of ​​the rotor-side joint of the coupling rod by designing the stator-side or rotor-side housing nozzle of the pump housing so that it can be removed. For this purpose, a nozzle section of this housing nozzle can be detached from the pump housing and pushed onto the stator in an axial direction or parallel to the axis, thus exposing the rotor-side area of ​​the coupling rod.

[0007] The older, unpublished German patent application DE 10 2016 121 582 A describes a variant in which the drive-side housing nozzle can be removed in such a way that the drive-side joint can be exposed for maintenance or disassembly. For this purpose, the drive-side housing nozzle of the pump housing can be removed in such a way that the drive-side joint is exposed, for example, by the drive-side housing nozzle having a fixed nozzle section and a nozzle section that is axially displaceable relative to it. The connecting housing can be pivoted about a vertical axis of rotation without the pump housing itself having to be removed, because pushing back the second nozzle section creates sufficient space to pivot the connecting housing, so that the connecting shaft can then be removed from the connecting housing for maintenance purposes (cf. DE 10 2016 121 582 A).

[0008] Eccentric screw pumps are also known, for example, from DE 20 2016 008 445 U1, WO 2010 / 012993 A2 and DE 10 2015 007 521 A1.

[0009] Overall, there is a practical need to simplify maintenance and repair work. This is where the invention comes in.

[0010] Furthermore, DE 297 19 605 U1 discloses a fan assembly with a fan housing for accommodating an impeller driven by a drive motor. A linear guide device is arranged on the fan housing for moving the impeller out of and into the fan housing. The drive motor, connected to the impeller via a drive shaft, is slidably guided along the linear guide device. This is intended to make it possible to move the impeller out of the fan housing so that it can be inspected.

[0011] Finally, DD 222 380 A1 describes a common base plate for working and driving machines, especially for centrifugal pumps. The base plate is provided with slots onto which slotted slide rails are screwed.

[0012] The invention is based on the object of creating an eccentric screw pump of the type described above which, while being structurally simple and economical, is characterized by improved maintenance and repair options, particularly in the area of ​​the connecting shaft and its shaft seal.

[0013] To achieve this object, the invention teaches an eccentric screw pump having the features of claim 1. It is provided that the drive (with the rotating unit) can be displaced by a predetermined amount in the axial direction to expose the separation point (between coupling rod and connecting shaft).

[0014] Whereas previously, in order to improve maintenance and repair measures, access was generally provided from the stator side, e.g. by dismantling the stator, or the pump housing itself was structurally modified, e.g. to simplify access to the joints on the coupling rod, the invention implements a displacement system for the drive of the eccentric screw pump in order to create access to the drive-side joint and / or the connecting shaft and / or the shaft seal provided for the connecting shaft. For this purpose, the drive with the rotating unit connected to it can be displaced in the axial direction in such a way that the separation point (between the coupling rod and the connecting shaft) can be pulled out of the pump housing towards the drive, so that after the axial displacement of the drive, the rotating unit can be separated at the separation point, e.g. between the connecting shaft and the coupling rod.This means that no housing modifications are necessary, so that the eccentric screw pump according to the invention can be implemented with any conventional housing type and any conventional stator. The invention enables easy maintenance, particularly in pumps in which the rotating unit cannot be displaced toward the stator. For example, solutions with a longitudinally split stator are known in practice, which allow for easy disassembly of the stator and thus displacement of the rotating unit toward the stator. However, the invention can preferably be implemented in embodiments in which this possibility of disassembling the stator does not exist.

[0015] In a generally known manner, the coupling rod is preferably connected to the connecting shaft via a drive-side joint. In such an embodiment, the drive-side joint (as the separation point) can be pulled out of the pump housing as the drive (with the rotating unit) is moved. At the same time, moving the drive creates sufficient space to expose the drive-side joint so that it can be separated or disassembled outside the pump housing. This simplifies maintenance work on the drive-side joint itself. Of particular importance, however, is the fact that once the joint has been disassembled, the connecting shaft can be easily removed and, for example, the shaft seal can be replaced.

[0016] A connecting housing is generally arranged between the pump housing and the drive, with the connecting shaft preferably being arranged completely or partially in this connecting housing. The connecting housing can be designed as an open connecting housing. The invention now proposes that the drive, together with the connecting housing (and the rotating unit) (which is fastened thereto, for example), can be displaced in the axial direction. In practice, the connecting housing is connected to a connecting flange of the pump housing, for example, with the end facing away from the output, or screwed to this. For maintenance purposes, this connection between the connecting housing and the pump housing can be released, and the drive, with the connecting housing fastened thereto and the rotating unit also connected to the drive, can then be displaced in the axial direction (away from the pump housing).This not only pulls the drive-side joint out of the pump housing, but also creates a free space between the pump housing (or its drive-side connection flange) on the one hand and the (displaced) connecting housing. The coupling joint (or another separation point) of the rotating unit is now located in this free space. After separating or dismantling the drive-side joint or another separation point, it is particularly possible to carry out maintenance work in the area of ​​the connecting shaft or the shaft seal of the connecting shaft. This is because the connecting shaft is equipped with a shaft seal to create a liquid-tight separation of the pump housing (from the environment or from the connecting housing). This seal is located, for example, in the connecting housing and fastened to the connecting housing. This can be a mechanical seal, for example, or alternatively a stuffing box packing.Such a shaft seal is a wearing part and according to the invention, by moving the drive (with the connecting shaft) and the subsequent joint separation, the area of ​​the connecting shaft and / or the shaft seal is freed up so that, for example, the shaft seal and / or the connecting shaft can be replaced. To do this, the connecting housing is first accessed via the opening facing the pump housing. Furthermore, the connecting housing can also be an open housing (when assembled) or one that can be opened, so that the connecting housing can also have one or more lateral or top openings for maintenance work. To replace the connecting shaft and / or the mechanical seal, however, the rotating unit must first be separated, e.g.the disassembly of the drive-side coupling joint is necessary, so that according to the invention the displacement of the drive system is important.

[0017] In principle, it is within the scope of the invention to design the displacement path of the drive or drive system so large that not only the possibility of joint separation exists, but also that the connecting shaft can be removed via the front opening of the connecting housing, so that the displacement path should at least correspond to the length of the connecting shaft.

[0018] However, in a modified embodiment, it is also possible for the drive, after being displaced in the axial direction, to also be pivotable about a vertical axis - relative to the base area of ​​the pump - preferably through a pivot angle of at least 10°, particularly preferably through a pivot angle of at least 30° or possibly even approximately 45° or more. Such pivoting of the drive (optionally with the connecting housing connected to it) has the advantage that the front opening of the connecting housing is easily accessible, allowing the connecting shaft and / or the shaft seal to be easily replaced or repaired. In such an embodiment with a pivotable drive, it is also possible to work with a relatively short displacement path, since the displacement path only needs to be long enough to disassemble the drive-side joint and pivot the drive.

[0019] The invention initially encompasses embodiments in which the connecting housing is designed as a so-called "lantern." This refers to a connecting housing that supports the pump housing on the one hand and the drive on the other, and in particular carries the drive, so that the drive itself is not directly attached to the pump base (e.g., a baseplate or foundation). Such a connecting housing is generally connected (e.g., screwed) directly to the drive or drive housing using connecting means, e.g., screws, so that, according to the invention, the drive with the connecting housing (and the rotating unit) attached to it can be displaced in the axial direction.

[0020] The invention also relates to embodiments in which the connecting housing is designed as a (simple) bearing block. A bearing block is a connecting housing that absorbs axial and radial forces and is also connected to the drive-side connection flange of the pump housing via a front-end opening, although the drive is not attached to this bearing block in a load-bearing manner. Rather, in such embodiments, it is generally provided that the connecting shaft is connected to the drive via an interposed (elastic) coupling that absorbs the torque. In such an embodiment, it is also provided that, in order to expose a separation point (e.g., a drive-side joint) and for the purposes of servicing the connecting shaft and / or the shaft seal, the drive is displaceable with the connecting housing / bearing block, specifically in a connected state.

[0021] With regard to the possible constructive variants for realizing the displaceability and / or pivotability of the different embodiments, reference is made to the description of the figures.

[0022] It is possible for the connecting housing (in the lantern design) with the drive mounted thereon to be mounted displaceably and, if necessary, pivotably on the pump base or, alternatively, suspended from a support structure. Such a suspended arrangement is possible, for example, with hopper pumps, in which the connecting housing is mounted suspended and axially displaceable on a silo or similar structure, thus hanging below the silo. The drive itself is flanged to the connecting housing and thus displaceable with the connecting housing.

[0023] Alternatively, embodiments are provided in which the drive is not supported on the connecting housing, but is attached together with the connecting housing to a common support, which in turn is arranged displaceably (and optionally pivotably) on a stationary pump base or suspended from a support device (e.g., on a hopper or silo). This embodiment particularly relates to variants in which the connecting housing is designed as a bearing support.

[0024] In a structurally simple variant, it is possible for the connecting housing (or the drive) to be guided on a guide plate which has at least one guide slot extending in the axial direction, into which a guide pin arranged on the connecting housing or the drive (secured against rotation) engages so as to be displaceable in the axial direction. Such a pin can, for example, be arranged on an adapter plate which is fastened to the connecting housing (or the drive), so that the adapter plate (with the connecting housing attached to it) can be displaced relative to the guide plate, which is, for example, fixedly fastened to the pump base. In such an embodiment with a guide slot, it can be expedient to achieve pivotability if an opening is connected to the end of the guide slot, which allows rotation of the connecting housing (or the drive). The pin can, for example,be designed in such a way that it is only displaceable and not rotatable within the guide slot and, in contrast, the opening is then widened so that pivoting is possible within the end opening after the end of the displacement path.

[0025] In an alternative embodiment, the displacement of the connecting housing and / or the drive can also be achieved with one or, preferably, several linear guides. For details, please refer to the description of the figures.

[0026] Optionally, it is also provided that a support is attached to the pump housing or to the pump base, which supports the coupling rod against sinking at the separation point during the separation.

[0027] Overall, the invention provides a displacement system for the drive of the eccentric screw pump for the purpose of disassembling, for example, the drive-side joint and the shaft seal, wherein the drive is displaced axially relative to the pump housing and away from the pump housing, as it were "backwards", and then rotated if necessary. Displacement mechanisms of various designs can be used, e.g. roller systems, linear guides and / or a carriage on which the drive is attached. In the case of hopper pumps of silo design, the drive can also be installed suspended in a device. The fixing and alignment of the drive for pump operation can be achieved using additional adjusting or fastening screws. Furthermore, aids for disassembly and assembly can be integrated, e.g. screws and / or spindles for applying the axial forces for displacing the rotating unit.This simplifies the disassembly of the mechanical seal and / or servicing the drive-side joint. Lifting equipment may be unnecessary during maintenance work. This also reduces the risk of injury, as even with large pumps, this maintenance work can be performed safely by one person.

[0028] The invention will be explained in more detail below with reference to drawings which merely represent exemplary embodiments. Fig. 1C shows an eccentric screw pump according to the invention in a simplified side view in different mounting positions, Fig. 2 the object after Fig. 2 in a plan view in another assembly position, Fig. 3 a base plate of the eccentric screw pump according to Fig. 1A in a top view, Fig. 4 a modified embodiment of the invention corresponding to a functional position according to Fig. 1C, Fig. 5 the object after Fig. 4 in a top view in a further functional position (according to Fig. 2), Fig. 6 a modified embodiment of the article according to Fig. 1C, Fig. 7 a further modification of the object according to Fig. 6, Fig. 8 another embodiment of an eccentric screw pump (section) and Fig. 9 the embodiment according to Fig. 1A to 1C in modified version.

[0029] The figures show a different design of an eccentric screw pump, each of which has a basic structure comprising a stator 1, a rotor 2 rotating in the stator 1, and a drive 3 for the rotor. At the end of the stator facing the drive, a pump housing 4 is connected to the stator 1, which is referred to as the suction housing 4 and is generally connected to the stator 1 on the suction side. On the opposite side (preferably the pressure side), a further housing part is connected to the stator 1, which is also referred to as a connection piece or pressure piece 5. The pump housing 4 has an inlet opening 6 (or outlet opening, depending on the direction of operation), through which, for example, the medium to be pumped is fed in. This medium is pumped from the pump housing 4 via the stator / rotor 1, 2 to the pressure piece 5. The drive 3 is connected to a connecting shaft 9, which is also referred to as a plug-in shaft and which, for example,is detachably connected to the output shaft (not shown) integrated into the drive 3. In the exemplary embodiment, the rotor 2 is connected to the connecting shaft 9 via a coupling rod 10, wherein the coupling rod 10 is connected to the connecting shaft 9 via a drive-side joint 11 and to the rotor 2 via a rotor-side joint 12, wherein the eccentric movement of the rotor 2 is enabled via the coupling rod 10 and the joints 11, 12. In principle, however, it is also possible to work with embodiments without joints, for example by designing the coupling rod or the rotor-side end (as a coupling rod) to be elastic. Such an embodiment is not shown.

[0030] During operation of the eccentric screw pump, the rotor 2, the coupling rod 10, and the connecting shaft 9 form a so-called "rotating unit." The coupling rod 10 is detachably connected to the connecting shaft 9 at a separation point. In the illustrated embodiment, this separation point is formed by the drive-side joint 11, because by disassembling this joint 11, the coupling rod 10 can be separated from the connecting shaft 9. This is necessary, for example, during maintenance work, especially when the connecting shaft 9 needs to be replaced.

[0031] According to the invention, it is now provided that the drive 3 with the rotating unit connected thereto is displaceable by a predetermined amount in the axial direction A in order to expose the aforementioned separation point, e.g., to expose the drive-side joint 11. Starting from the mounted position, the drive is displaceable by a predetermined amount in the direction away from the pump housing 4. Consequently, the drive 3 with the rotating unit connected thereto is displaceable in the axial direction A in such a way that the separation point (i.e., the joint 11) can be pulled out of the pump housing in the direction of the drive, and thus the rotating unit can be separated at the separation point, e.g., between the connecting shaft 9 and the coupling rod 10.

[0032] It should be noted that in the illustrated embodiments, a connecting housing 14, 14' is arranged between the pump housing 4 and the drive 3, wherein the connecting shaft 9 is arranged completely or partially in this connecting housing 14. It is provided that the drive 3 is displaced in the axial direction A together with this connecting housing 14, 14' during the displacement. In the assembled state of the pump, the connecting housing 14, 14' is connected to the drive-side housing flange 7 of the pump housing 4 or to the opening of the pump housing arranged therein (cf. Fig. 1A), which shows the assembled eccentric screw pump.

[0033] Starting from Fig. 1A, the connection between the connecting housing 14 and the housing flange 7 can first be released and then the drive 3 with the connected connecting housing 14 can be moved in the axial direction A, namely with the rotating unit, so that on the one hand a sufficient distance between the connecting housing 14 and the pump housing 4 is created and on the other hand the rotating unit is moved so far that the drive-side joint 11 comes out of the pump housing into the resulting free space between the pump housing 4 and the connecting housing 14 ( Fig. 1B).

[0034] It is important, among other things, that the connecting shaft 9 is sealed for the liquid-tight separation of the pump housing 4 from the environment or from the connecting housing 14, 14' with a shaft seal 13, which is arranged, for example, in the connecting housing 14, 14' and optionally fastened thereto. This shaft seal 13 can be designed, for example, as a mechanical seal or as a stuffing box packing. Such a shaft seal 13 is a wearing part that must be replaced if necessary. The same applies to the joint components. This replacement is now made significantly easier by the inventive design with a movable drive. Because Fig. 1B the drive-side joint 11 can now be disassembled ( Fig. 1C). Subsequently, the Fig. 1A to 1C, the possibility of displacing the drive with the connecting housing 14 attached thereto further in the axial direction, so that the axially nested joint components are pulled apart and it is possible to pivot the drive, specifically about a vertical axis relative to the base area of ​​the pump. Fig. Figure 2 shows this pivoted position, and it can be seen that this provides access to the connecting shaft 9 with the shaft seal 13 arranged thereon. It can thus be pulled axially out of the connecting housing 14 and separated from the drive 3, e.g., for replacement purposes. Optionally, the pivot angle can be limited by an end stop. Furthermore, the unit consisting of the drive 3 and the connecting housing 14 can be optionally fixed in the pivoted end position.

[0035] The Fig. 1A to 1C and 2 show an embodiment in which the drive 3 is not only attached to the connecting housing 14 but is also supported, so that the drive 3 is consequently carried by the connecting housing 14 without being attached to the pump base 16. Such a connecting housing 14 is also referred to as a lantern. In this respect, in this embodiment, the drive 3 itself is not arranged directly displaceably on the pump base 16, but the connecting housing 14 is displaceably attached to the pump base 16 and the drive 3 is also displaced with the connecting housing 14. For this purpose, the connecting housing 14 is guided by an adapter plate 21 on a guide plate 18 which is fixedly attached to the pump base 16. This guide plate has (according to Fig. 3) has a guide slot 19 extending in the axial direction, into which a guide pin (not shown) arranged on the connecting housing 14 engages displaceably, preferably in such a way that no rotation or pivoting of the drive 3 is possible during the displacement. At the end, an opening 20 can be connected to the guide slot 19, which then allows rotation of the drive 3 or the connecting housing 14, in particular in order to Fig. 2. The design with the guide plate 18 is shown in Fig. 3 recognizable.

[0036] The Fig. 4 and Fig. 5 show a modified embodiment which, with regard to the displacement possibilities and the displacement construction, is similar to the embodiment according to the Fig. 1A to 1C or 2. However, it is an eccentric screw pump in the form of a funnel pump, i.e. the inlet opening 6 is formed by a funnel 6'. Furthermore, in Fig. 5 that in such a hopper pump, a conveying tool, e.g. a screw conveyor, is usually provided in the pump housing 4 to support the transport of the material from the pump housing into the area of ​​the stator. Furthermore, Fig. 5 that due to the housing dimensions a further pivoting of the drive 3 and the connecting housing 14 is necessary, i.e. the pivoting angle according to Fig. 5 is slightly larger than according to Fig. 2.

[0037] Fig. 6 shows - starting from the embodiment according to Fig. 4 and Fig. 5 - a variant in which, on the one hand, the displacement mechanism is modified and, on the other hand, pivoting of the drive 3 is omitted. It can again be seen that the drive 3 is supported on the connecting housing 14 and is carried by it without its own support on the pump base. The connecting housing 14 is displaceable via linear guides 22, in the exemplary embodiment two linear guide rails 22, with rollers 23 guided in the linear guide rails 22, which are connected to the connecting housing 14 via a carrier 24. The connecting housing 14 is consequently guided via the carrier 24 with the rollers 23 attached thereto in the linear guide rails 22, which are fixedly arranged on the pump base 16. Pivoting the drive 3 or connecting housing 14 is neither necessary nor intended in this embodiment.This is because the displacement path in the axial direction is dimensioned so large that the connecting shaft 9 can be removed via the front opening of the connecting housing 14 even without prior pivoting, i.e. the free space created between the pump housing 4 and the connecting housing 14 during the displacement is sufficient for dismantling the connecting shaft 9 and the shaft seal 13.

[0038] The same applies to the embodiment according to Fig. 7, which differs from the embodiment according to Fig. 6 in that the connecting housing 14 is not guided vertically on the pump base 16 via the support 24, but rather suspended from a support structure 17, which in the exemplary embodiment is formed by a silo. Consequently, the linear guide rails 22 are attached to the support structure 17 or to the silo in this embodiment.

[0039] While the Fig. 1 to 7 show embodiments in which the connecting housing 14 supports and carries the drive 3 as a “lantern”, Fig. 8 shows a modified embodiment of an eccentric screw pump in which the connecting housing 14' is designed as a bearing block 14'. The drive 3 is connected to the bearing block 14' via an interposed elastic coupling 15, but is not carried by the bearing block 14', but is independently supported on the pump base 16. In this embodiment, the displacement also takes place via the linear guide rails 22 and a carrier 24 with rollers 23, whereby not only the connecting housing 14' but also the drive 3 are directly attached to this carrier 24. For the purpose of maintenance work, the entire unit comprising the connecting housing 14', coupling 15, and drive 3 can be displaced together in the axial direction on the linear guide rails 22. Pivoting of the drive or the connecting housing 14' is also not provided for in this embodiment.

[0040] Finally, another option of the invention is exemplified in Fig. 9. It can be seen that a support 25 is provided on the pump base 16, which supports the rotating unit and in particular the coupling rod 10 against falling. Consequently, after the rotating unit has been pulled out of the pump housing 4 far enough that the joint 11 is exposed, the joint 11 can be separated without the coupling rod 10 then falling down. Such a support is according to Fig. 9, for example, is realized by a simple support plate with a suitable recess. It can also be used in the other embodiments.

Claims

[1] Eccentric screw pump with at least - a stator (1), - a rotor (2) rotating in the stator (1), - a drive (3) for the rotor (2), - a pump housing (4) connected to the stator (1) which has at least one inlet or outlet opening (6) for a medium to be pumped, - a connecting shaft (9) connected to the drive (3), - a coupling rod (10) arranged in the pump housing (4) which is detachably connected to the connecting shaft (9) at a separation point, wherein the rotor (2), coupling rod (10) and connecting shaft (9) form a rotating unit during operation of the eccentric screw pump, characterized bythat the drive (3) is displaceable in the axial direction (A) to expose the separation point, wherein the drive (3) with the rotating unit connected thereto is displaceable in the axial direction (A) such that the separation point can be pulled out of the pump housing (4) in the direction of the drive (3) and the rotating unit can be separated at the separation point. [2] Eccentric screw pump according to claim 1, characterized by that the separation point is arranged between the connecting shaft (9) and the coupling rod (10). [3] Eccentric screw pump according to claim 1 or 2, wherein the coupling rod (10) is connected to the connecting shaft (9) via a drive-side joint (11) to form a separation point, characterized by that the drive-side joint (11) can be pulled out of the pump housing (4) when the drive (3) is moved. [4] Eccentric screw pump according to one of claims 1 to 3, with a connecting housing (14, 14') arranged between the pump housing (4) and the drive (3), wherein preferably the connecting shaft (9) is arranged at least partially in the connecting housing (14, 14'), characterized by that the drive (3) is displaceable in the axial direction (A) together with the connecting housing (14, 14'). [5] Eccentric screw pump according to one of claims 1 to 4, wherein the connecting shaft (9) is sealed with a shaft seal (13), e.g. a mechanical seal or stuffing box packing, for the liquid-tight separation of the pump housing (4) from an environment or from the connecting housing (14), characterized bythat the shaft seal (13) is displaceable with the drive (3) and the connecting shaft (9) in the axial direction (A) and is replaceable at the separation point after the rotating unit has been separated, e.g. together with the connecting shaft (9). [6] Eccentric screw pump according to one of claims 1 to 5, characterized by that the drive (3) can be pivoted after being displaced in the axial direction (A) about a vertical axis - relative to the base area of the eccentric screw pump - preferably about a pivot angle of at least 10°, particularly preferably at least 30°. [7] Eccentric screw pump according to claim 6, characterized by that the drive (3) is pivotable together with the connecting housing (14) attached thereto, e.g. with the connecting housing (14) carrying the drive (3). [8] Eccentric screw pump according to one of claims 1 to 7, characterized bythat the connecting housing (14) with the drive (3) attached thereto is arranged displaceably and optionally pivotably on a pump base (16) or suspended from a support device (17). [9] Eccentric screw pump according to one of claims 1 to 7, characterized by that both the connecting housing (14') and the drive (3) are fastened to a common holder which is arranged displaceably and optionally pivotably on a stationary pump base (16) or suspended from a support device (17). [10] Eccentric screw pump according to one of claims 1 to 8, characterized bythat the drive (3) or the connecting housing (14, 14') is guided on a guide plate (18) which has at least one guide slot (19) extending in the axial direction (A), into which a guide pin arranged on the drive (3) or the connecting housing (14) engages displaceably, preferably displaceably and is secured against rotation. [11] Eccentric screw pump according to claim 10, characterized by that an opening (20) is connected to the end of the guide slot (19), which allows rotation of the drive (3) and / or the connecting housing (14). [12] Eccentric screw pump according to one of claims 1 to 11, characterized by that the drive (3) and / or the connecting housing (14, 14') are displaceable, e.g. rolling or sliding, by means of linear guides (22) on the pump base (16) or a support device (17). [13] Eccentric screw pump according to one of claims 1 to 12, characterized bythat a support (25) is attached to the pump housing (4) or the pump base (16), which supports the coupling rod (10) against sinking at the separation point during the separation.

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