WO2019154571A1

WO2019154571A1 - Progressive cavity pump

Info

Publication number: WO2019154571A1
Application number: PCT/EP2019/050258
Authority: WO
Inventors: Dirk Overmeier; Peter McGarian
Original assignee: Seepex Gmbh
Priority date: 2018-02-06
Filing date: 2019-01-07
Publication date: 2019-08-15
Also published as: DE102018102640A1; EP3749861A1; EP3749861B1

Abstract

The invention relates to a progressive cavity pump, comprising at least a stator (1), a rotor (2), which rotates in the stator, a drive (3) for the rotor, a pump housing (4), which is connected to the stator (1) and which has at least one inlet or outlet opening (6) for the medium to be pumped, a connection housing (14), which is arranged between the pump housing (4) and the drive (3) and which is open or is to be opened, a connection shaft (9), which is detachably connected to the drive (3) and which is at least partly arranged in the connection housing (14). The connection shaft (9) is sealed by means of a (preferably single-acting) slide ring seal (13) in order to separate the pump housing (4) liquid-tight from the surroundings or from the connection housing. The slide ring seal (13) has a seal housing (18), which is fastened to the pump housing (4) and/or the connection housing (14), a slide ring (19), which is fastened to the connection shaft (9) for conjoint rotation and rotates in the seal housing (18), and a stationary counter ring (20), which is fastened to the seal housing (18). The pump is characterized in that the seal housing (18) is designed as a divided seal housing and comprises a main housing (18a), which in the assembled state surrounds the slide ring (19) and is fastened to the pump housing (4) and/or the connection housing (14), and a housing cover (18b), which bears the counter ring (20) and is detachably fastened to the main housing (18a) and can be separated therefrom.

Description

Cavity Pump

Description:

The invention relates to an eccentric screw pump having at least one stator, a rotor rotating in the stator, a drive for the rotor, a pump housing (eg, suction housing) connected to the stator (eg suction side), which has at least one inlet or outlet Having outlet for the medium to be conveyed, arranged between the pump housing and drive, open or openable connection housing, a detachably connected to the drive connection shaft which is at least partially disposed in the connection housing, wherein the connecting shaft (for liquid-tight separation of the pump housing from the environment or with respect to the open or to be opened connecting housing) is sealed with a mechanical seal, wherein the mechanical seal a fixed to the pump housing and / or the connecting housing seal housing, a rotationally fixed on the

Has shaft mounted and rotating in the seal housing slip ring and fixed to the seal housing, stationary mating ring.

Such an eccentric screw pump is a pump from the group of rotary displacement pumps, which are used to convey a wide variety of media and in particular highly viscous liquids in various industrial sectors. The liquids to be delivered can be z. B. also contain solids. The stator is preferably made of elastic or elastomeric material and is usually surrounded by a one-piece or multi-part stator shell or stator housing. Alternatively, but also stators made of other material, eg. B. detected from metal. The suction side connected to the stator pump housing is generally referred to as a suction housing and the pressure side connected to the stator housing z. B. as a discharge nozzle. In principle, however, it is also possible to operate such a pump in the opposite direction of conveyance, so that the suction housing (as pump housing) would then be arranged on the pressure side. The designation of the pump housing as a suction housing is therefore independent of the actual conveying direction within the scope of the invention. It is the housing arranged between the stator and the drive. The rotating and at the same time the eccentricity ensuring connection between the drive or the connecting shaft on the one hand and the rotor on the other hand via a arranged in the pump housing coupling rod z. B. is connected via a drive-side joint with the connecting shaft and a rotor-side joint with the rotor. Alternatively, the eccentricity but also by other measures (ie without joints) realize, for. B. by a flexible / flexible elastic coupling rod. Coupling rod thus means an element which ensures the eccentricity of the rotor and the eccentric

Movement between the rotating connecting shaft and the rotor allows. Basically, it is also within the scope of the invention that this coupling rod is formed integrally with the connecting shaft and / or is formed integrally with the rotor. The connecting shaft is also referred to as a stub shaft, it is usually connected directly to the output shaft of the drive and serves as a connecting piece between the output shaft of the drive and the power transmission parts of the pump. The connection housing arranged between the pump housing (suction housing) and the drive is also referred to in practice as a "lantern". This serves z. B. the recording or attachment and support of the pump housing on the one hand and the drive on the other hand, so that this connection housing or the lantern z. B. is mounted on a base plate or directly on a foundation and the drive and the pump housing is supported and carries. Also, hanging arrangements are feasible. In this case, this connection housing is designed as an open or at least as an openable connection housing, which is thus accessible through an opening from the outside. Preferably, the connection housing is a separate housing from the pump housing, so that z. B. the pump housing is fastened by means of screws or the like to the connection housing. In principle, however, the invention also covers embodiments in which the pump housing and connecting housing are formed in one piece and consequently inseparable from each other. For the operation of the eccentric screw pump, this is usually installed in a (pipe) pipe system, so that z. B. to the suction housing (ie, the inlet or outlet), a suction line and to the discharge nozzle of the pump, a pressure line are connected.

The stator of the eccentric screw pump can be used as a longitudinally divided stator of at least two Statorteilschalen, z. B. stator half shells. Furthermore, the stator can be exchangeable separately from the stator jacket and consequently not fixed and in particular not materially connected to the stator jacket. This makes it possible to replace the elastomeric stator separately from the stator jacket and without a costly disassembly of the pump is necessary. The stator jacket consists z. B. from at least two sheath segments, which form a stator clamping device as clamping segments, with which the stator in the radial direction against the rotor can be tensioned. In this case, the stator jacket of z. B. three sheath segments or four sheath segments, the

Form Statorspannvorrichtung. An eccentric screw pump of this kind is z. B. from WO 2009/024279 A1 or DE 10 2014 112 550 B4 known.

By the way, an eccentric screw pump with rotor separation is known from EP 2 428 680 B1. The rotor is detachably connected to the coupling joint or a joint part of the coupling joint without dismantling the coupling joint. Such pumps with rotor separation are also included in preferred development of the invention.

For liquid-tight separation of the pump housing from the environment or against the open or openable

Connecting housing, the connecting shaft is sealed with a (preferably single-acting) mechanical seal. Such a mechanical seal is subject to wear, so that it must be replaced or repaired as a wear part if necessary. For this purpose, it is usually necessary in the known from practice eccentric screw pumps, the pump housing (suction housing) and optionally to the input or

Disconnect outlet opening of the pump housing connected suction line. Only then can the mechanical seal be dismantled. Also, the assembly of the mechanical seal or a new mechanical seal with mechanical seal housing is possible only with disassembled pig housing and dismantled suction, otherwise damage to the stationary counter-ring of the mechanical seal are to be feared when inserting the stub shaft through the mechanical seal housing damage. In this respect, there is a need to simplify the replacement or maintenance of the mechanical seal of such an eccentric screw pump. - This is where the invention starts.

The invention has for its object to provide an eccentric screw pump of the type described above, which is characterized by a simple design by optimized maintenance and repair options, especially in the field of mechanical seal.

To solve this problem, the invention teaches a generic eccentric screw pump with mechanical seal of the type described above, that the seal housing of the mechanical seal as (axially) split seal housing is formed and on the one hand in the assembled state surrounding the seal ring and attached to the pump housing and / or the connecting housing basic housing and on the other hand has a housing cover supporting the counter ring, which is releasably secured (together with the mating ring) to the base housing, so that the housing cover is separable from the base housing together with the mating ring and refastenable. The seal housing is thus formed divided in such a way that the connecting shaft with the attached slide ring (without the mating ring) can be pulled out of the seal housing. The mechanical seal is a preferably single-acting mechanical seal,

d. H. is formed with a single sealing surface which is formed between a single sliding ring and a single mating ring. Single-acting sliding ring seal thus means in the context of the invention, a mechanical seal with a single seal ring-counter-ring pair.

The use of such a mechanical seal with split seal housing allows disassembly and consequently the replacement or maintenance of the mechanical seal without costly further disassembly of the pump and in particular without disassembly of the piping or the pump housing. Because according to the invention it is possible first to separate the second divided mechanical seal housing through the open or open connection housing by the housing cover is released from the basic housing. Subsequently, at least the connecting shaft can be pulled out of the connecting housing with the sliding ring arranged on the connecting shaft in the axial direction (without the counter ring, which is fastened to the housing cover). For this purpose, access to the pump housing from the stator side is preferably made possible. This will be discussed below. The housing cover (with the mating ring attached thereto) can be removed directly from the open or open connection housing and in this way can all parts of the mechanical seal to wait or exchange, preferably without disassembly of the pump housing and the connected piping system and without disassembly of the drive. The two-part mechanical seal housing according to the invention also leads to advantages in the subsequent assembly, because the connecting shaft (stub shaft) with the attached sliding ring can be threaded into the mechanical seal housing, namely in the stationary base housing, without the risk of damage to the mating ring, since this

Counter ring remains detached during assembly of the basic housing. Only after insertion (and centering) of the connecting shaft and preferably after plugging or insertion of the connecting shaft on or in the output shaft of the drive, the housing cover is fixed to the stationary counter ring on the base housing, so that before threading the connecting shaft no danger Damage exists. Overall, with the inventive design maintenance work on the mechanical seal on the eccentric screw pump easily and quickly perform, so that a particularly economical operation of the pump is possible.

Particularly preferably, the inventive design, the rotating unit or a part of the rotating unit, which consists of at least the connecting shaft and preferably also arranged between the rotor and connecting shaft coupling rod (possibly with joints), is uniform in the course of maintenance in the axial Remove the direction from the pump housing after the housing cover of the seal housing has been removed from the basic housing. In the context of the invention, the rotating unit is preferably understood to mean the unit which rotates during operation and which can be separated from the drive as a whole and consists at least of the connecting shaft, the coupling rod (possibly with joints) and the rotor. However, it is within the scope of the invention to first separate the rotor from the coupling rod and then extract the remaining part of the rotating unit (connecting shaft and coupling rod) in the manner described in the suction housing. It is not necessary to dismantle the sow housing or the suction line. Preferably, the rotating unit (with sliding ring) or arranged in the suction housing part of the rotating unit can be

(For example, without rotor) pull out in the axial direction through the housing opening facing the stator of the pump housing.

For this purpose, it is expedient to create sufficient space for the dismantling described on the stator side of the suction housing. This succeeds z. Example, characterized in that the stator connected to the stator stator is removed altogether, so that subsequently the rotating unit or the described part of the rotating unit can be pulled out of the pump housing.

Preferably, this can be realized in those embodiments in which the stator of the pump can be removed without the drive and the suction housing and the suction line must be removed. In this case, if necessary, the pressure line or the discharge nozzle must be removed to disassemble the stator and then can perform the described maintenance of the mechanical seal over the suction housing in the manner described. Although some dismantling work in the area of the pressure housing or pressure lines are required, this option is interesting, z. B. if the dismantling of suction line (eg funnel in funnel pumps) or drive would be much more expensive than the dismantling of the pressure line.

Particularly preferably, the invention can be implemented in such embodiments, in which the stator of the pump can be removed without the drive and without the pressure line and without the suction line and the suction housing must be removed. For this purpose, various practical solutions are known. In such solutions, the mechanical seal can now be maintained or changed in the manner described, without any part of the

Piping system must be dismantled. In such embodiments, the invention is particularly advantageous.

Particularly preferably, the invention is realized in a progressive cavity pump with longitudinally divided stator, the z. B. of several (elastic) Statorteilschalen, z. B. Statorhalbschalen and / or multiple shell segments (as Statorspannvorrichtung). Because in such an embodiment, there is the particularly simple way to dismantle or partially disassemble only the stator and thus one obtains on the stator housing opening of the pump housing (sow housing) access to the rotating unit, which now completely pulled out (after separation of the seal housing) can be. In principle, it is possible to completely pull out the entire rotating unit, including the rotor. In a preferred embodiment, however, a first separation of the rotor from the rotating unit or the remaining part of the rotating unit, so that then the remaining part of the rotating unit (connecting shaft and coupling rod, possibly with joints) can be uniformly pulled out of the pump housing. This succeeds z. B. in that the rotor-side coupling joint is separated and thus the rotor is removed from the coupling rod. The invention can be implemented particularly preferably in progressing cavity pumps with rotor separation (eg, in accordance with EP 2 428 680 B1). In this case, the rotor is detachably connected without dismantling the rotor-side coupling joint to the rotor-side coupling joint by a separation point separate from the joint is realized. The rotor can thus be separated without joint separation of the rotating unit and as a rotating unit, the connecting shaft remains with the coupling rod including both joints and the so-called rotor head, which is separable from the rotor. This is shown in the figure description.

Advantages are also realized with the invention in such pumps, in which the assembly or disassembly of the suction line of the suction housing is associated with great effort, eg. B. funnel pumps, which are optionally mounted under silos. In funnel pumps, the inlet or outlet opening is formed by a funnel and possibly additional conveyors are arranged in the suction housing, for. B. on the coupling rod.

Although mechanical seals with split seal housing are known in practice, but only in the embodiment as a double-acting or multi-acting mechanical seal, which is particularly realized as a so-called "back to back solution", in a housing at both ends in each case a sliding ring and an associated Having mating ring. In such double-acting mechanical seals, an opening of the housing via a removable cover is required solely for reasons of mounting the seal. The inventive concept, which serves the simple replacement of the seal without disassembly of the sow housing, can not be realized with such a double-acting mechanical seals with removable housing cover. The invention therefore preferably relates to single-acting mechanical seals.

The basic housing of the (single-acting) mechanical seal according to the invention is preferably formed as a hollow cylinder. The housing cover is also preferably hollow cylindrical or annular, so that it has a central opening through which the connecting shaft can be passed. On the housing cover of the mating ring is rotatably secured, preferably inserted with the interposition of a seal in the mating ring. The housing cover is preferably detachable with (positive and / or non-positive) fastening means on the

Basic housing attached. It may be z. B. to act screws and / or locking means and / or clamping means.

The drive of an eccentric screw pump generally has an output shaft, at the pump-side output end of the connecting shaft is releasably secured with its drive end shaft end. The output shaft of the drive thus protrudes into the connecting housing, so that the connecting shaft is coupled within the connecting housing with the output shaft of the drive. In the mechanical seal according to the invention with two-part housing is now provided in a preferred embodiment, that the output end (the output shaft) of the basic housing of the mechanical seal (in the assembled state) is spaced such that the housing cover of the mechanical seal housing in disassembled state of the connecting shaft between the output end (the Output shaft) and basic housing can be removed from the connection housing. This can be z. B. realize that the housing cover, preferably including the mating ring attached thereto, has a length or overall length L in the axial direction, which is less than the axial distance A between the output end of the drive shaft and the base housing of the mechanical seal. Consequently, after the connecting shaft is pulled out of the connecting housing, the housing cover with the mating ring attached thereto can be guided between the stationary housing and the output shaft and out of the connecting housing z. B. for the purpose of replacement. In principle, however, the invention also alternatively embraces embodiments in which the described axial distance A is less than the overall length L described. Because there is also the possibility of the counter ring of the mechanical seal before the radial removal from the connecting housing before from the housing cover

so that it can be removed from the connector housing separately and without the housing cover, and then replaced.

The invention also provides a mechanical seal for an eccentric screw pump of the type described. The inventive (single-acting) mechanical seal with the split seal housing is therefore also provided independently under protection.

In addition, the invention relates to a method for maintenance (or inspection) and / or replacement of a mechanical seal of an eccentric screw pump of the type described. In this method, the housing cover is first disengaged (for disassembly) of the basic housing, through the (frontally) open or open connection housing through. Subsequently, at least the connecting shaft with the sliding ring arranged on the connecting shaft is removed from the connecting housing in the axial direction and particularly preferably through the pump housing from the frontal opening. In a preferred embodiment, the already described rotating unit of the eccentric screw pump (including the connecting shaft), possibly after prior separation of the rotor, in the axial direction through the pump housing, for. B. after the stator has been removed, for. B. in a pump with longitudinally divided stator. The method according to the invention also relates to the assembly of the connecting shaft or of the rotating unit (for example after replacement of the sliding ring and / or the counter ring). For this purpose, the connecting shaft or the rotating unit is first inserted (through the frontal opening) in the connecting housing while the connecting shaft inserted through the base housing and the housing cover solved by it and z. B. plugged onto the output shaft of the drive or plugged into this. Only then is the housing cover fastened to the basic housing. These

In particular, the procedure has the great advantage that damage to the mechanical seal or the mating ring on the housing cover is avoided, since it is not firmly mounted, but (temporarily) loosely arranged in the connecting housing.

Optionally, the invention proposes to remove the rotating unit during disassembly with a (specially designed for this purpose) mounting tool from the pump housing and / or introduce during assembly in the pump housing. Such an assembly tool has at least one plate-shaped or cup-shaped receptacle for the rotating unit and a handle attached thereto. Details of this are described by way of example in the description of the figures. Such an assembly tool according to the invention is also provided separately under protection.

In the following the invention will be explained in more detail with reference to drawings showing only one exemplary embodiment. Show it:

1 shows an eccentric screw pump in a simplified side view,

2 is an enlarged detail of the article of FIG. 1 (in the assembled state),

3 shows the object according to FIG. 2 during disassembly, FIG.

Fig. 4 shows the object of Fig. 3 in a further functional position during disassembly and

5 shows an assembly tool for an eccentric screw pump according to the invention or for carrying out a method according to the invention (in a perspective view). In Fig. 1, an eccentric screw pump is simplified, which has in its basic structure a stator 1, a rotor 2 rotating in the stator 1 and a drive 3 for the rotor 2. For example, on the suction side of the stator 1, a pump housing 4 is connected, which is referred to as a suction housing 4. A pressure part connected to the stator 1 housing part is referred to, for example, as a connecting piece or discharge nozzle 5. The pump housing 4 has an inlet opening (or depending on the operating direction outlet opening) 6, on the z. B. is supplied to the medium to be conveyed, which is funded by the pump housing 4 via the stator / rotor to the pressure nozzle 5. For this purpose, the pump housing 4 has a stator (frontal) housing opening 7, through which the medium from the pump housing 4 enters the stator 1. The drive 3 is equipped with an output shaft 8, which is connected to a connecting shaft 9. This connecting shaft 9 is formed in the embodiment as a plug-in shaft. The rotor 2 is connected in the embodiment via a coupling rod 10 with the connecting shaft 9, wherein the coupling rod 10 is connected via a drive-side joint 11 with the connecting shaft 9 and a rotor-side joint 12 with the rotor 2, wherein the coupling rod 10 and the joints 11, 12 the eccentric movement of the rotor 2 or rotor end is made possible. Basically, however, it is also possible to work with embodiments without joints or coupling rod by z. B. the coupling rod or the rotor-side end (as a coupling rod) is elastic. Such an embodiment is not shown. Between the pump housing 4 and the drive 3, a connection housing 14 is arranged, which is also referred to as a lantern.

This connection housing 14 is open, in the embodiment laterally open, d. H. it has lateral openings. Basically, however, there is also the possibility that these (lateral, upper and / or lower) openings are closable, so that the connection housing can also be designed as a closed, but openable housing. For fluid-tight separation of the pump housing 4 against the environment or against the drive, the connecting shaft 9 is sealed with a shaft seal, which is designed as a mechanical seal 13, as a single-acting mechanical seal 13. This mechanical seal 13, which is of particular importance according to the invention, is in Described in more detail below. In any case, in the illustrated embodiment, the coupling rod 10 (substantially) within the pump housing 4 is arranged, while the connecting shaft 9 (substantially) within the connection housing 14 is arranged. The mechanical seal 13 is (substantially) disposed within the connecting housing 14.

In the exemplary embodiment illustrated in FIG. 1, the stator 1 is designed as a longitudinally-divided stator and, in the exemplary embodiment, it consists of two stator half-shells 1 a, 1 b which are merely indicated. Longitudinal means, along the stator longitudinal axis or parallel to this. The stator is at least partially surrounded by a stator jacket 15, which is formed in the embodiment as a longitudinally divided jacket and a plurality of shroud segments 16 which serve as a clamping segment and form a Statorspannvorrichtung. Details are not shown, they are z. B. from DE 10 2014 112 550 B4 or WO 2009/024279 A1. However, the invention can also be realized with other stator designs.

Incidentally, it can be seen in the figures that, by way of example, an embodiment with the rotor separation (according to EP 2 428 680 B1) is realized. The rotor 2

can be separated from the coupling rod 10 without disassembly of the joint 12, because it is realized an additional separation point with the rotor head 17 shown in the figures. The rotor 2 is thus connected without disassembly of the coupling joint 12 releasably connected to the rotor head 17, which in turn is connected to the coupling joint 12. FIGS. 2 to 4 now show a functional position in which the rotor 2 has already been separated from the rotor head 17 and thus from the remaining part of the rotating unit.

The mechanical seal 13 has a seal housing 18 which is attached to the pump housing 4 and / or to the connection housing 14 by z. B. in the course of attachment of the pump housing 4 to the connection housing 14 between these two housings 4, 14 is clamped and projects into the interior of the connection housing 14. Furthermore, the mechanical seal 13 has a rotationally fixed on the shaft 9 and fixed in the seal housing 18 rotating seal ring 19 and attached to the seal housing 18, stationary mating ring 20. The sliding ring 19 is pressed by a spring element 21 against the counter-ring 20, and adjustable via a collar 22. Sliding ring 19, spring element 21 and collar 22 are usually arranged on a support sleeve 23, the z. B. formed as a rubber boot and non-positively, rotatably mounted on the connecting shaft 9 is attached. During operation rotatably connected to the connecting shaft 9 sliding ring 19 rotates relative to the stationary counter-ring 20, with frontally facing sealing surfaces 19 a, 20 a, which are oriented substantially perpendicular to the axis of rotation R.

According to the invention, the seal housing 18 is designed as a (axially) split seal housing. It has, on the one hand, a base housing 18a surrounding the sliding ring 19 in the mounted state and, on the other hand, a housing cover 18b carrying the counter ring 20. The

Base housing 18a is fixedly mounted on the connecting housing 14 and / or pump housing 4 and to this end, it has, for the embodiment, an outside circumferential collar 24 which is fixed between the pump housing 4 and the connecting housing 14. The housing cover 18b is releasably secured to the base housing 18a, e.g. Example by means of screws or other fastening means, so that the housing cover 18 b is separable from the base housing 18 a together with the mating ring 20 attached thereto. The base housing 18a is formed substantially hollow cylindrical. The housing cover 18b is annular and therefore has a central opening through which the connecting shaft 9 can be passed.

The inventive design allows easy maintenance or a simple replacement and reassembly of a mechanical seal. Reference is made to a comparative consideration of Figs. 2, 3 and 4. Fig. 2 shows first the eccentric screw pump in the assembled state, but with already separated rotor. To replace the mechanical seal 13 or parts of the sliding direction or to wait in other ways, the mechanical seal 13 should be removed from the connecting housing or pump housing. For this purpose, in the seal housing 18 according to the invention first of the housing cover 18b 18b removed from the base housing 18a and thus the mating ring 20 is separated from the sliding ring 19, because the mating ring 20 is rotatably connected to the housing cover 18b, z. B. with the interposition of a sealing ring 25 is pressed into the housing cover 18b. Subsequently, as shown in FIG. 4, the connecting shaft 9 can be pulled off the output shaft 8 in the axial direction and pulled out of the connecting housing 14 (after, of course, the connection between the connecting shaft 9 and the output shaft 8 has previously been released). It can be seen in Fig. 4 that with the connecting shaft 9 and the rotatably attached to the connecting shaft 9 part of the mechanical seal thirteenth

including the slide ring 19 are removed. It is interesting that the connecting shaft 9 can be removed with the attached slide ring 19 from the connection housing 14 without the pump housing 4 must be dismantled before. Even the suction pipe 26 connected to the opening 6 does not have to be disassembled.

Further, it is shown in Fig. 4 that not only the connecting shaft 9 is removed in the axial direction, but the rotating unit or the part of the rotating unit without rotor, the at least the connecting shaft 9 and in the embodiment, in addition, the coupling rod 10 with the mounted Joints 11, 12 comprises. This rotating unit can be pulled out of the pump housing 4 in the axial direction via the frontal opening 7, so that subsequently the part of the mechanical seal including the sliding ring 19 attached to the connecting shaft 9 is freely available for maintenance purposes. This succeeds particularly simple in the illustrated embodiment also because the stator 1 can be easily dismantled before, since it is a longitudinally divided stator. After disassembly or at least partial disassembly of the stator 1, the rotating unit can be easily pulled out in the manner described, without further disassembly of the pump or the components connected thereto is required. It is crucial that within the scope of the invention, an access via the frontal opening 7 of the pump housing 4 for the replacement of the mechanical seal is realized. This assumes that there is sufficient space available for removing the rotating unit. In the exemplary embodiment, this takes place via the longitudinally divided stator. However, the invention also includes embodiments in which the stator can be removed in other ways. If necessary, a disassembly of the pressure-side line system must be carried out beforehand.

In any case, disassembly of the pump housing and the suction-side lines is not required.

It is also advantageous that not only the sliding ring 19, but also the counter-ring 20 can be easily replaced by namely the housing cover 18b, on which the counter-ring 20 is fixed, is removed from the connection housing 14, but not on the suction housing, but about For this purpose, it is provided that the output end 8a of the output shaft 8 is spaced from the base housing 18a of the mechanical seal such that the housing cover 18b in the disassembled state of the connecting shaft between the output end 8a and the base housing 18a from the connection housing leaves. This is realized in that the housing cover 18b including the mating ring 20 attached thereto has a length L in the axial direction that is less than the axial distance A between the output end 8a and the (mounted) base housing 18a.

The inventive design of the split seal housing 18 has advantages not only in the described disassembly, but also in the subsequent required assembly. Because it is now possible to first insert the connecting shaft 9 or the entire rotating unit in the pump housing 4 and thereby the

Connecting shaft 9 hindurchzustecken through the base housing 18 a, without the risk that the arranged in the housing cover counter ring 20 is damaged. Because the connecting shaft 9 is inserted through this housing cover 18b or the mating ring 20 and plugged onto the output shaft 8 and inserted into this before the

Housing cover 18 b is attached to the base housing 18 a. This means that the housing cover 18b freely movable in the connection housing 14th

is arranged and is fixed only after the insertion of the connecting shaft 9 to the base housing 18a.

In the illustrated embodiment, assembly and disassembly can be implemented particularly easily with an additional assembly tool 27, which is shown in FIG. This mounting tool has on the one hand a receptacle 28 for the rotating unit and on the other hand on the receptacle 28 mounted handle 29. The receptacle 28 may be plate-shaped or cup-shaped and it is so dimensioned that it receives the rotating unit (here coupling rod and connecting shaft) substantially or almost over the entire length, so that the rotating unit despite the "unstable structure" (z B. with the joints) can be properly inserted from the rotor-side end into the pump housing 4, and indeed in the region of the output shaft 8 of the drive 3. The length of the receptacle 28 of the assembly tool 27 is at least so large that the coupling rod including fits the two joints so that the joints are supported and a stable arrangement is ensured. Consequently, the length of the receptacle of the assembly tool preferably corresponds at least to the length of rotor head 17, joint 12, coupling rod 10 and joint 11. Incidentally, it can be seen in FIG. 5 that the receptacle 28 is cup-shaped, so that it falls down the rotating unit guaranteed. This cup-shaped configuration can, for. B. arcuate in cross section, preferably circular, so that it has the shape of a (hollow) cylinder segment. Incidentally, it can be seen in FIG. 5 that the flange 30 of the receiving tool, to which the handle 29 on the one hand and the receptacle 28 are connected on the other hand, has a suitable receptacle or recess, eg. B. groove 31 which is formed in the embodiment U-shaped. In this recording or recess 31, the rotating unit, namely the rotor head 17 (positive fit) can be used, so that the

rotating unit is held securely. In this case, this receptacle / recess 31 is not only semicircular, but preferably U-shaped, so that even higher-built joint designs (eg, with collar protection) can be received in a practicable manner.

Claims

Sponsors:

1. eccentric screw with at least one stator (1), - a rotating rotor in the stator (2), a drive (3) for the rotor, one to the stator (1) pump housing (4), which at least one input or Outlet opening (6) for the medium to be conveyed, one between the pump housing (4) and drive (3) arranged, open or openable connection housing (14), a releasably connected to the drive (3) connecting shaft (9), at least is arranged in the connecting housing (14), wherein the connecting shaft (9) for liquid-tight separation of the pump housing (4) from the environment or against the connecting housing (14) with a mechanical seal (13) is sealed, wherein the mechanical seal (13) a seal housing (18) affixed to the pump housing (4) and / or the connecting housing (14), rotatably mounted on the connecting shaft (9) and rotatable in the seal housing (18) having a sliding ring (19) and a stationary counter-ring (20) fastened to the seal housing (18),

characterized in that the seal housing (18) is formed as a split seal housing and on the one hand in the assembled state surrounding the sliding ring (19) and on the pump housing (4) and / or the connecting housing (14) fixed to the base housing (18a) and on the other hand a counter ring (20) carrying the housing cover (18 b) which is releasably attached to the base housing (18 a) and separable therefrom, so that the connecting shaft (9) with the attached thereto slide ring (19) from the seal housing (18) can be pulled out ,

2. Eccentric screw pump according to claim 1, characterized in that the mechanical seal (13) is designed as a single-acting mechanical seal.

3. Eccentric screw pump according to claim 1 or 2, characterized in that the base housing (18a) is formed as a hollow cylinder and / or that the housing cover (18b) is formed as a hollow cylinder or annular with a central opening for the connecting shaft (9).

4. Eccentric screw pump according to one of claims 1 to 3, wherein the drive (3) has an output shaft (8), at the pump side

Output end (8a) the connecting shaft (9) is releasably secured with its drive end shaft end, characterized in that the output end (8a) from the base housing (18a) of the mechanical seal (13) is spaced such that the housing cover (18b) disassembled Condition of the connecting shaft (9) between the output end (8a) and the base housing (18a) can be removed from the connecting housing (14).

5. Eccentric screw pump according to claim 4, characterized in that the housing cover (18b), preferably including the attached thereto

Counter-ring (20), a length (L) in the axial direction, which is less than the axial distance (A) between the output end (8a) and the base housing (18a).

6. Eccentric screw pump according to one of claims 1 to 5, characterized in that the stator (1) as a longitudinally divided stator consists of a plurality of stator and / or that the stator (1) by a stator jacket (15) is surrounded, preferably as a longitudinally divided shell consists of several shell segments (16), which preferably form a Statorspannvorrichtung.

7. mechanical seal, in particular single-acting mechanical seal, for an eccentric screw pump according to one of claims 1 to 6, characterized in that the seal housing (18) as (axially) split seal housing is formed and on the one hand in the assembled state the sliding ring (19) surrounding and at The housing (18a) which can be fastened to the pump housing (4) and / or the connecting housing (14) and, on the other hand, has a housing cover (18b) carrying the counter-ring (20), which is detachably fastened to and separable from the housing (18a).

8. A method for maintenance and / or replacement of a mechanical seal (13) an eccentric screw pump according to one of claims 1 to 6, characterized in that for disassembly first through the open or open connection housing (14) through the housing cover (18b) of the basic housing (18a) is released and then at least the connecting shaft (9) with the on the connecting shaft (9) arranged slide ring (19) in the axial direction of the connecting housing (14) and preferably through the pump housing (4) is removed.

9. The method according to claim 8, characterized in that one of at least coupling rod (10) and connecting shaft (9) existing rotating unit of the eccentric screw pump is removed in the axial direction by the pump housing (4) throughout, for. B. by a stator facing the housing opening (7).

10. The method according to claim 8 or 9, characterized in that first the stator (1) dismantled and then the rotating unit through a stator (1) facing the housing opening (7) is removed from the pump housing (4).

11. The method according to any one of claims 8 to 10, characterized in that in the course of assembly, the connecting shaft (9) or the rotating unit first inserted into the pump housing (4) while the connecting shaft (9) through the base housing (18 a) and the detached housing cover (18 b) is inserted through it and z. B. is plugged or plugged into the output shaft and that subsequently the housing cover (18 b) is attached to the base housing (18 a).

12. The method according to any one of claims 8 to 11, characterized in that the rotating unit during disassembly with an assembly tool (27) removed from the pump housing and / or introduced during assembly in the pump housing (4), wherein the assembly tool at least a receptacle (28) for the rotating unit and an attached handle (29).

13. An assembly tool (4) for dismantling or mounting a rotating unit while performing a method according to any one of claims

8 to 12, with a z. B. plate-shaped receptacle (28) for the rotating unit and an attached handle (29).