EP2143959A1 - Pump power unit and method for modular construction of a pump power unit - Google Patents

Abstract

The assembly comprising a pump (6) with a number of pump stages (10). A clamping element (12) e.g. tightening strap, and a cable rail (14), whose axial lengths depend on the number of pump stages, have no connection configuration on one of axial ends of the components, where the connection configuration is limited to the axial ends. The clamping element and the cable rail are connected to a connection element (20), which is coupled and/or connected to adjacent parts of the assembly, in a friction fit and/or positive fit manner. An independent claim is also included for a method for modular construction of a pump assembly.

Description

The invention relates to a pump unit and a method for modular construction of a pump unit.

There are pump units, in particular multi-stage pump units known, in which, depending on the desired performance of the pump unit different numbers of pump stages are juxtaposed. The individual pump stages are preferably formed identically and are held together by suitable connecting means, such as tensioning straps.

Even if the individual pump stages are of identical design, certain components must be adjusted in their length to the total number of pump stages used. This is firstly the shaft which drives the impellers of the pump stages and extends through the entire pump and is coupled at one end to a motor shaft. On the other hand, these are the clamping bands, which hold the individual pump stages, and possibly a cable guide, which is arranged on the outside of the pump unit to guide the connection cable from the drive motor, which is arranged at the lower end of the pump unit, to the upper end. These components must therefore be manufactured and provided in different lengths in order to build pump units with different numbers of pump stages.

In view of this, it is an object of the invention to improve the construction of such pump units to the effect that pump units with different numbers of pump stages can be constructed with a reduced number of items to be specially adapted.

This object is achieved by a pump unit having the features specified in claim 1 and by a method for modular construction of a pump unit with the features specified in claim 16.

The pump unit according to the invention has a pump with one or more pump stages. It is inventively provided that different numbers of identical pump stages can be put together to build a pump unit with a desired number of pump stages. The pump unit according to the invention therefore has a modular structure. The individual pump stages are coupled to a drive motor.

In order to reduce the number of required individual parts, which are required for such a modular structure for the realization of pumps with different numbers of pump stages, according to the invention a special construction of individual components of the pump unit is provided. These are the length-dependent components whose length depends on the number of pump stages used, ie in particular the shaft, possible clamping elements and / or possibly a required cable management. According to the invention, at least one of these components, the axial length of which depends on the number of pump stages, is formed on at least one of its axial ends in such a way that no connection configuration formed in the component itself and limited to the axial end is provided at this axial end. That is, the components should be so be formed so that at least one axial end need not have a special geometric configuration, which makes it possible to connect or couple this axial end with other components. This makes it possible to cut this component from a longer component in the desired length. For example, if a shorter shaft is needed, it can be sawn off a longer shaft or longer bar stock. Accordingly, a clamping element can be shortened as needed. These components do not have, as for example a conventional shaft, on the axial end positive locking elements for coupling with a motor shaft or as a clamping element hooks for hooking into adjacent pump components. Instead of such a special connection configuration at the axial end of the components themselves, it is provided according to the invention to connect the axial end with an additional connection element. In this case, this connection should be non-positive and / or positive, preferably no additional special fasteners or connection techniques are to be used. The connecting element in turn is coupled to adjacent parts of the pump unit and / or connected or provided for coupling with adjacent parts of the pump unit. That is, the connection element has the special connection configuration, for example in the form of a coupling, for connection to a motor shaft.

The inventively proposed construction of the length-dependent components has the advantage that a pump unit with a certain number of pump stages can not only be manufactured industrially, but also, for example, can be assembled by a local dealer in the desired configuration. No elaborate storage is required, which holds the length-dependent components in all possibly required lengths. Rather, these elements can be provided in a maximum length or possibly also as "endless material", of which then the required Length cut to length, for example, cut or sawn off. The length results from the number of pump stages. The cut-to-length component is then positively and / or positively connected to an axial end or to both axial ends with corresponding connection elements, in order then to be able to connect to the adjacent pump parts by means of the connection elements. The connection with the connection elements does not require a special design of the axial ends of the length-dependent components themselves, so that a complex processing of these ends, for example, an introduction of a groove for a key o. Ä. Can be omitted.

According to a first preferred embodiment, the component or the length-dependent component is a tensioning element, preferably a tensioning band, which holds the pump of the pump unit together in the axial direction. Such a clamping element or strap extends over the length of the pump, ie on the outside of the successive or juxtaposed pump stages along the first to the last pump stage and is connected there to adjacent components of the pump. These adjacent components are the end portions of the pump, for example, the discharge port at the discharge end and a connecting element at the opposite end, which has the suction openings of the pump and is provided for connection to a drive motor. Such a clamping element may be formed for example as a long threaded rod, which can be easily cut to the desired length. In this case, such a threaded rod just does not have a connection configuration restricted to the axial end, but the thread preferably extends over the entire length or at least over a length of the threaded rod which extends beyond the end region. The connection elements can then be screwed to the axial ends.

Particularly preferred is the formation of the clamping element as a clamping band, for example as a sheet metal strip made of stainless steel. Such a material may be provided in a large length, for example rolled up, and then cut to the desired length, depending on which number of pump stages is to be held together. These tension straps then do not have, as in conventional configuration, hooks or threaded portions fixedly formed at their axial ends for connection to adjacent pump parts, but are connected there to a connection element having a specific geometric configuration for connection to adjacent pump parts.

Preferably, the clamping element is positively connected to at least one axial end with a connection element, which has connecting means, in particular a hook and / or a thread, which fix the clamping element to the pump. The clamping element is designed so that it just does not have a special connection configuration at the axial end. Rather, it can be cut to a desired level from a longer component without the resulting axial end having to be specially machined to give it a terminal configuration. Rather, this axial end is then positively and / or positively connected to the connection element, which has this connection configuration. This connection configuration may be formed in a known manner as a hook or thread to attach the strap to the pump.

According to a special embodiment, the clamping element is connected to at least one axial end in a form-fitting manner with a connecting element, wherein the connecting element is integrated into the pump. This means that at least one of the connection elements can be an integral part of another component of the pump, for example one Connecting piece between the pump stages and a drive motor. Thus, the number of required components can be reduced, since at least at one axial end of the clamping element can be dispensed with a separate connection element. At the same time no special connection geometry must be formed on the strap at this end. Instead, a receptacle is formed on a component of the pump, for example, the connecting piece, in which the clamping band can be fixed in a form-fitting manner. The receptacle corresponds to the recording, as it is also formed in a separate connection element for positive connection.

Preferably, the tension member is provided with a longitudinally repeating array of engagement members which are engageable or engageable with corresponding engagement members on the engagement member. In this case, the engagement elements are preferably repeated at certain intervals, which correspond to the length of a pump stage. This ensures that when the clamping element is cut to a length which corresponds to a specific number of pump stages, exactly at the axial end a matching engagement element is located, which can engage with a corresponding engagement element on the connection element. Such engagement elements may be, for example, holes or protrusions which are arranged distributed in defined intervals at intervals over the length of the clamping element in the clamping element. On the connecting element corresponding recesses or projections may be formed, which can engage with these holes or projections on the clamping element.

Particularly preferably, the engagement elements on the clamping element in the form of repeating in the axial direction changes of Width of the clamping element formed. This means that the clamping element has on its outer contour a wave or zigzag shape, so that in the longitudinal direction of the clamping element undercuts or shoulders are formed, which can be engaged behind by engagement elements on the connection element. Particularly preferably, the clamping element is designed as a flat strap whose side edges are wavy or zigzag contoured. Alternatively, for example, one or two toothed side edge (s) or the formation of individual regularly spaced recesses or projections on one side edge or both side edges would be conceivable.

The connecting element correspondingly preferably has a receptacle for the clamping element, which tapers in its width to an axial end in such a way that it engages behind the clamping element in a region of reduced width. That is, the receptacle for the clamping element in the connecting element has a smaller axial width at the end facing the clamping element. Preferably, this is an axial width which corresponds to the width of the clamping element at its narrowest point. Starting from this narrowing of the width at the axial end, the receptacle expands preferably in the axial direction facing away from the clamping element, so that a region of the clamping element with a greater width can be accommodated there. Thus, the receptacle of the connecting element engages around the width-extended region of the clamping element.

According to a second preferred embodiment of the invention, the component, ie the length-dependent component is a shaft of the pump which drives the impeller or wheels, wherein the shaft is frictionally provided at one longitudinal end with a coupling which forms a connection element. The frictional connection with the coupling has the advantage that in the shaft itself no positive locking elements must be formed at the axial end. The frictional connection can be made on a smooth shaft, so that it can be cut to length in the desired length of a rod or pipe material. The coupling is preferably used for connection to the axial end of a motor shaft of the motor attached to the pump, the motor and pump forming the pump unit according to the invention.

The coupling preferably has a force-locking element on one axial side and a positive-locking element on an opposite axial side. The traction element is used for frictional connection with the pump shaft, as described above. The form-locking element is used for connection to the axial end of the motor shaft. The interlocking element can be formed, for example, as an internal toothing in a receiving opening at the axial end of the coupling, in which engages a toothed end of the motor shaft, so that a positive connection between the motor shaft and coupling for torque transmission is created.

The shaft preferably has a constant cross section over its length. It is thus possible to cut off the shaft arbitrarily from a rod material, depending on the number of pump stages provided. A special geometric configuration of the axial end is, as described above, not required.

More preferably, the impellers of the pump are non-rotatably fixed non-rotatably on the shaft. Thus, no machining steps on the shaft itself are required for attachment of the wheels. Rather, the wheels can be clamped to a shaft, which preferably has a constant cross section over the entire length, at the desired location.

For this purpose, the wheels preferably have a hub with a conical inner circumference and a clamping cone with a corresponding conical outer periphery, wherein the clamping cone is slotted, has an axial through hole through which the shaft extends, and is clamped by a clamping element against the conical periphery of the hub. The tensioning element may for example be a screw which is in engagement with a thread on the outer circumference of the clamping cone. The screw or nut preferably engages on the axial end of the clamping cone, which has the smallest diameter. The arrangement is such that this end preferably extends beyond the axial end of the hub, so that the screw can be supported against the axial end of the hub. By rotation of the screw, the clamping cone can then be pulled further into the interior of the hub, wherein due to the conical configuration of inner diameter of the hub and conical outer periphery of the clamping cone of the clamping cone is reduced in diameter by reducing the width of the slot. In this way, the clamping cone and with it the hub and thus also the impeller is clamped onto the shaft.

The traction element of the coupling is preferably designed such that the coupling has at one axial end a receptacle with conical inner circumference and a clamping cone with a corresponding conical outer circumference, wherein the clamping cone is slotted, having an axial through hole through which the shaft extends, and through a clamping element is clamped against the conical inner periphery of the receptacle. Also, this clamping element, as described above with reference to the clamping connection for the impeller, be a clamping screw. The attachment to the shaft corresponds to the preceding description, wherein the function of the hub is taken over by the clutch. The clamping screw can also instead of the clamping cone itself to a thread on the Clutch attack, which is preferably arranged at the axial end of the clamping cone receiving conical opening. By the clamping screw, which z. B. can be configured as a union nut, then the clamping cone can be pressed into this conical opening. In this case, the clamping cone decreases in diameter, wherein the slot is reduced in width. In this way, the clamping cone with the surrounding coupling is clamped firmly on the shaft.

According to a third preferred embodiment, the component, i. H. the length-dependent component a extending in the axial direction of the cable rail. Such a cable rail is arranged along the length of the pump to guide the electrical connection cable for the drive motor from one axial end of the pump to the opposite axial end of the pump. This is particularly necessary if the pump is designed as a submersible pump in which the motor is arranged on the underside of the pump, while the cable must be led out of the borehole upwards. The length of such a cable rail is dependent on the length of the pump, which in turn depends on the number of pump stages used.

Preferably, the cable rail has a constant cross section over its entire axial length and engages at least one axial end in a connection element which fixes the cable rail on the outer circumference of the pump. In this case, the cable rail is preferably connected in a form-fitting manner with the connection element. The connection element in this case has fastening elements for attachment to the pump, for example holes, through which screws can be guided in order to screw the connection element to the pump. The positive connection of the cable rail with the connection elements is preferably carried out in such a way that at each End of the cable rail, a connection element is arranged, wherein each connection element has a contact surface, which comes into contact with an end face of the connection rail. Thus, the cable rail is limited by the two connecting elements in their axial mobility, ie fixed in the axial direction. Furthermore, the connection element is preferably designed such that it engages around the cable rail in the region of the axial end on the outside, so that the cable rail is also held in a transverse direction, ie transversely to its longitudinal axis in the connection element. In the second transverse direction normal to the longitudinal axis, the cable rail can be fixed by the connection element in such a way that the cable rail between the connection element and outer circumference of the pump is fixed when fastening the connection element.

If the cable rail has a constant cross section over its length, it is possible to cut off the cable rail from a long component to the cross section of the cable rail in the desired length. The long component is preferably a long profile in the form of the cable rail from which the cable rail is cut off.

It is to be understood that the length-dependent component may not only be either a tensioning element, a shaft or a cable rail, but instead two, but preferably all three components, ie shaft, clamping element and cable rail formed in the pump unit according to the invention in the manner described above could be. If the above-described force and / or form-locking connections is mentioned, then it is to be understood that these compounds can optionally be additionally glued. Gluing is a bonding process that can not only be used on an industrial scale, but can also be done on site during assembly of the pump unit.

The invention further relates to a method for modular construction of a pump unit with a single or multi-stage pump. In this case, the pump unit preferably corresponds to the preceding description.

The object of the method is that at least one of those components of the pump unit whose length depends on the number of pump stages, d. H. The length of the pump depends on its length is not specifically made for a certain number of pump stages. Instead, this length-dependent component is tailored to the desired length before mounting the pump, depending on the currently desired number of pump stages. This makes it possible to mount pumps with the desired number of pump stages on demand, without having to provide special, length-dependent components for every feasible number of pump stages. Instead, it is sufficient to maintain the longest version of the particular component that could be used and, if necessary, shorten this component if fewer pump stages are to be used. Alternatively, the components can also be provided as a long material. Thus, in particular, a strap, for example, be supplied as a sheet metal strip from a roll.

For assembly, the component is thus cut or cut in the desired length of a universal component. Subsequently, it is connected at its axial end with a connecting element, which in turn has a special connection configuration, which serves for connection or coupling with adjacent parts of the pump unit. The connection of the axial end of the length-dependent component with the connection element is preferably non-positive and / or positive. Regarding the details of the procedure is based on the above Description of the pump unit referenced, which also show the details of the procedure.

Fig. 1

eine Gesamtansicht eines erfindungsgemäßen Pumpenaggregates,

Fig. 2

die Ansicht eines Spannbandes des Pumpenaggregates gemäß Fig. 1,

Fig. 3

eine Explosionsansicht des Spannbandes gemäß Fig. 2,

Fig. 4

eine Ansicht des Spannbandes gemäß Figuren 2 und 3 ohne Anschlusselemente,

Fig. 5

eine Seitenansicht des Anschlusselementes in Fig. 2 und 3,

Fig. 6

eine axiale Draufsicht auf das Anschlusselement gemäß Fig. 5,

Fig. 7

eine Schnittansicht einer Kupplung,

Fig. 8

eine perspektivische Explosionsansicht der Kupplung,

Fig. 9

eine Schnittansicht eines Laufrades des Pumpenaggregates gemäß Fig. 1,

Fig. 10

eine perspektivische Explosionsansicht einer Kabelführung des Pumpenaggregates gemäß Fig. 1,

Fig. 11

die Kabelführung gemäß Fig. 10 im zusammengesetzten Zustand,

Fig. 12

eine Detailansicht des in Fig. 1 gezeigten Zwischenstückes,

Fig. 13

eine alternative Ausführungsform eines Anschlusselementes,

Fig. 14

eine alternative Ausführungsform des Spannbandes mit Anschlusselementen in perspektivischer Explosionsdarstellung und

Fig. 15

die Bauteile gemäß Fig. 14 in zusammengefügter Form.

The invention will now be described by way of example with reference to the accompanying drawings. In these shows:

Fig. 1

an overall view of a pump unit according to the invention,

Fig. 2

the view of a clamping band of the pump unit according to Fig. 1 .

Fig. 3

an exploded view of the strap according to Fig. 2 .

Fig. 4

a view of the strap according to FIGS. 2 and 3 without connection elements,

Fig. 5

a side view of the connection element in FIGS. 2 and 3 .

Fig. 6

an axial plan view of the connecting element according to Fig. 5 .

Fig. 7

a sectional view of a coupling,

Fig. 8

an exploded perspective view of the coupling,

Fig. 9

a sectional view of an impeller of the pump unit according to Fig. 1 .

Fig. 10

an exploded perspective view of a cable guide of the pump unit according to Fig. 1 .

Fig. 11

the cable routing according to Fig. 10 in the assembled state,

Fig. 12

a detailed view of the in Fig. 1 shown intermediate piece,

Fig. 13

an alternative embodiment of a connection element,

Fig. 14

an alternative embodiment of the tension band with connection elements in a perspective exploded view and

Fig. 15

the components according to Fig. 14 in assembled form.

This in Fig. 1 The pump unit shown is designed as a submersible pump unit and has at a lower end in use a drive motor 2, to which an axial intermediate piece 4 is attached, which serves to connect the pump 6 to the drive motor 2. At the axial end opposite the connecting piece 4, the pump 6 has a connecting piece 8 in which the discharge nozzle of the pump is formed. Between the intermediate piece 4 and the connecting piece 8, a plurality of pump stages 10 is arranged. To hold the pump 6, clamping elements in the form of clamping bands 12 are provided, which are fixed with its one axial end to the intermediate piece 4 and with the opposite axial end to the connecting piece 8 and both braced against each other, so that the individual pump stages 10 pressed together and between Connector 8 and spacer 4 are kept clamped. On the outer circumference of the pump 6 extends in the axial direction beyond a cable guide 14, in which the connecting cable is guided by the drive motor 2 to the opposite axial end of the pump unit.

Depending on the desired power or delivery height of the pump unit different numbers of pump stages 10 are set to one another. In order to make this possible, differently long shafts, by means of which the impellers of the individual pump stages 10 are driven, and differently long clamping bands and cable guides 14 of different lengths, are required inside.

According to the invention a modular system is now provided according to which these three mentioned length-dependent components, shaft, straps 12 and cable guide 14, not in different lengths for different numbers of pump stages 10 must be kept, but in a simple manner in the desired length individually before mounting the pump unit can be manufactured or provided. It is thus possible to provide only one universal component of great length of each of these three components, from which then the desired length for the respective pump to be mounted can be cut off or cut to length.

Based on FIGS. 2 to 4 First, the embodiment of the straps will be explained. The actual strap 12 is formed as a simple band member made of sheet metal and has no special final configuration. This means that at the axial ends 18, no connection configurations for attachment to the connecting piece 8 or the intermediate piece 4 are formed on the clamping band 12 itself. Rather, this connection configuration is laid in two connection elements 20 and 22, which are connected to the axial ends 18 of the tension band 12. The connecting element 20 has a threaded rod, with which it can be screwed to the connecting piece 8. The connecting element 22 has a hook with which it can engage in a recess on an intermediate piece 4. Via a nut on the thread of the connecting element 20, the clamping band 12 can then be tensioned on the pump 6.

It should be understood, however, that the bracing by means of a screw can alternatively be done on the intermediate piece 4. Then, the clamping element can be fixed directly to the connector 8 accordingly.

Based on FIGS. 14 and 15 an alternative embodiment of strap 12 'and connecting elements 20' and 22 'is shown. In this case, the clamping band 12 'is also formed as existing stainless steel sheet metal strip, which is cut to length depending on the required length. The sheet-metal strip has a plurality of rectangular recesses 65, which are each arranged at the same distance A from one another in the longitudinal direction of the strip. The distance A of two recesses 65 corresponds to the axial length of a pump stage 10. At the connection elements 20 'and 22', which moreover in their function and arrangement correspond to the connecting elements 20 and 22 are for positive connection with the clamping band 12 'hook-like elements 66th provided in the form of formations 66, which are intended for engagement in the clamping band 12 'and in the joined state ( Fig. 15 ) enforce the recesses 65 and reach behind. In the assembled state of the pump, that is, when the connecting pieces 20 'and 22' tensile forces act, which clamp the pump stages 10, these formations 66 are positively connected to the clamping band 12 '. The hook-like elements 66 are therefore each open in the direction in which the tensile forces are applied and formed closed in the opposite direction.

The FIGS. 12 and 13 moreover show alternative embodiments of connection elements 20 and 22. Thus, according to Fig. 12 as well as in Fig. 1 shown, the connecting element 22 are integrated directly in the form of a receptacle 24 in the connecting or intermediate piece 4. In this case, the receptacle 24 is corresponding to the following Configuration configured. The receptacle 24 makes it possible for the tensioning strap 12 to be fixed directly to the intermediate piece 4 in a form-fitting manner without this having to have a special connection configuration provided at the end. The intermediate piece 4 is preferably composed in two parts of two parts 4a and 4b. Preferably, the part 4a of the intermediate piece 4 is made as a metal powder injection molded part. This makes it very easy to form, in particular, the complex geometry of the receptacle 24 directly in the intermediate piece 4. The part 4b of the intermediate piece is preferably formed as a conventional metal casting. Both parts 4a and 4b are then welded together. However, it is also conceivable to form the intermediate piece 4 as a one-piece component, for example as a cast part.

Instead of providing the fitting 20 with a screw as described above and in FIG FIGS. 2 and 3 is shown, it is also possible to provide in the fitting 20 a receptacle 23 for a conventional hex nut, as in Fig. 13 shown. Thus, in the recess 23, a hex nut can be used, in which then a screw 25 can be screwed to string the connection element 20 in the manner described above. This is also in Fig. 1 shown. Also in Fig. 13 shown connecting element 20 may preferably be manufactured as a metal powder injection molded part. In this case, the complex geometry of the receptacle 24 can be well formed. In the configuration according to FIGS. 12 and 13 the receptacles 24 are formed on the outside of the pump, that is open to the outside. Otherwise, the design of the receptacle 24 corresponds to the below with reference to FIGS. 5 and 6 described embodiment of the recording, only that in FIGS. 5 and 6 the receptacles 24 on the connection elements 20, 22 in the radial direction facing the inside, as well as in Fig. 2 and 4 can be seen.

The clamping band 12 is formed as a curved sheet metal strip. The curvature is adapted to the curvature of the outer circumference of the pump 6. The sheet metal strip has a lengthwise repeating change in width. That is, portions of small width B ₁ and portions of larger width B ₂ are repeated. The repetitive section A corresponds to the length of a module, ie the length of a pump stage 10. Due to the repetitive change in width of the tension band 12 this has the form of adjoining trapezoidal sections, ie, starting from a region with a small width widens the width of the clamping band up to the width B ₂ and from there, the width decreases again to the width B ₁ , etc. This results in a zigzag-shaped side contour of the tension band 12. This contour forms engagement elements which repeat at the distance A over the length of the tension band 12. By means of these engagement elements, the tension band 12 can be fastened in a form-fitting manner to the connection elements 20 and 22. Depending on the length of the pump 6, ie the number of pump stages 10, the clamping band 12 can be cut to a length of a suitable length with a multiple of the repetition distance A. The tension band is cut so that it ends at the axial ends 18 in the region of its greater width B ₂ . Thus, the width of the clamping band decreases starting from the axial ends 18, so that spaced from the axial ends 18 regions of small width B ₁ , ie constrictions are given in width. Thus, the axial ends 18 can be engaged in the form-fitting manner in the width, as based on the FIGS. 5 and 6 will be explained in more detail.

Based on FIGS. 5 and 6 the connection of the connecting element 22 is described in more detail with the strap 12. It should be understood that the connection of the connecting element 20 takes place at the opposite end of the clamping band 12 in the same manner. The connection elements 20 and 22 differ only in that the connection element 22 has a hook for connection to the pump and the connecting element 20 has a threaded pin.

On the connection element 22 (corresponding to the connection element 20), a receptacle 24 is formed, which has two obliquely extending side edges 26, so that a total of a trapezoidal or conical receptacle 24 is created, which has its smallest width at the axial end 28 of the connecting element 22 has. The receptacle 24 is to the inside, d. H. opened to the pump stages 10 side facing out, on the outside, it has a closed outer wall 27.

In the Fig. 1 . 12 and 13 embodiments shown are designed exactly the opposite. There, the receptacle 24 is formed open to the outside and the inside is closed.

Furthermore, the receptacle 24 has a groove 29 in the side walls 26 and the bottom edge connecting the side walls 26, ie the edge facing away from the axial end 28. The receptacle 24 is configured such that the axial end 18 of the tension band 12 can be inserted into it so that the area of the tension band with the smallest width B ₁ comes to lie in the region of the axial end 28 between the side edges 26 of the receptacle 24. The region of greater width of the tension band B ₂ is spaced from the axial end 28 in the receptacle 24. The smallest distance between the side edges 26 is smaller than the largest width B _{2 of} the tension band 12. Thus, the side edges 26, the axial end of the tension band 12 behind - or embrace. In this way, a fixation in the axial direction is achieved. By the circumferential groove 29 is also ensured that in the tensioned state, the connecting element 22 can not slip from the clamping band 12 in the radial direction relative to the longitudinal axis X of the pump. The strap 12 engages with its side edge in the Groove 29 a. For this purpose, the groove has a width which is slightly larger than the material thickness of the clamping band 12. It is thus created a secure in all directions positive connection between the connecting element 22 and the clamping band 12.

Based on FIGS. 7 and 8 the design of the shaft 30 and its connection with a coupling 32 is described in more detail. The shaft 30 is formed as a simple round rod and has at its axial end 34 no special geometric connection configuration for positive connection with the coupling 32. Thus, the shaft 30 can be easily cut or sawed off from a long material, and there is no further processing of the axial end 34, for example, for introducing a groove o. Ä. Required. Instead, the coupling 32 is merely fixed non-positively on the axial end 34 of the shaft 30. The coupling 32 thus forms a connection element for connection to other parts of the pump. In this case, this is an output shaft, not shown here, of a drive motor.

For coupling with the output shaft of the drive motor, the coupling 32 at one axial end a receiving opening 36 with an internal toothing, in which a correspondingly toothed axial end of the output shaft of the drive motor can intervene. The receiving opening 36 thus forms a positive locking element at a first axial end of the coupling 32. The opposite axial end 32 is formed for purely frictional connection with the shaft 30.

For this purpose, a conical receiving opening 38 is formed at this axial end. The conical receiving opening 38 has a conical inner contour and, like the receiving opening 36, is located concentrically to the longitudinal axis of the axis X. The conical receiving opening 38 tapers towards the interior of the coupling 32. In the conical receiving opening 38, a clamping cone 40 is inserted. The clamping cone 40 has a conical Outer contour, which corresponds to the conical inner contour of the receiving opening 38, ie in particular both have the same pitch relative to the longitudinal axis X. The clamping cone 40 has in its interior a cylindrical through hole 42 into which the shaft 30 is inserted. In addition, the clamping cone 40 is formed slotted, ie, it has a slot 44 which extends in the radial direction from the through hole 42 to the outer periphery and is open to both the through hole 42 and the outer periphery. The slot 44 allows that when the clamping cone 40 is pressed into the receiving opening 38, can be compressed, so that the inner diameter of the through hole 42 is reduced and the clamping cone 40 is pressed onto the peripheral wall of the shaft 30 and generates a frictional connection there ,

At the same time a frictional connection between clamping cone 40 and clutch 32 is created by the pressure between clamping cone 40 and the inner wall of the conical receiving opening 38.

In order to be able to press the clamping cone 40 into the receiving opening 38, the coupling 32 is provided with a thread 46 on its outer circumference at its axial end, to which the receiving opening 38 is opened. With this thread 46 enters a clamping screw in the form of a union nut 48 into engagement, which presses with its inner side against the end face of the clamping cone 40. Thus, the cap nut 48, when screwed onto the thread 46, presses the clamping cone 40 into the conical receiving opening 38, so that the conical outer surface of the clamping cone abuts against the conical inner surface of the receiving opening 38 and the clamping cone is compressed.

As in Fig. 9 are shown, the wheels 50 are preferably attached to the shaft 30 only frictionally. For this purpose, the wheels 50 have a hub 52 with a conical inner circumference, in which a Clamping cone 54 is inserted. The clamping cone 54 corresponds in its embodiment to the previously described clamping cone 40 of the coupling 32. In particular, the clamping cone 54 is also formed slotted. At its tapered end of the clamping cone 54 has an external thread on which a clamping screw or clamping nut 56 is screwed. The clamping nut 56 abuts against the axial end of the hub 52 and thus, when screwed onto the clamping cone 54, pulls the clamping cone 54 into the interior of the hub 52. Due to the conical configuration, the inner diameter of the clamping cone 54 decreases so that the shaft 30 in the clamping cone 54 and at the same time the clamping cone 54 in the hub 52 of the impeller 50 is clamped. This purely frictional attachment of the impeller 50 on a smooth shaft 30 has the advantage that the shaft 30 can be easily made from a round bar or pipe material without at the points where the clutch 32 or the wheels 50 are attached , positive engagement elements would have to be incorporated into the shaft. In this respect, it is possible to easily cut off the shaft 30 from a long material, in the desired length, which depends on the number of pump stages 10 used.

Based on FIGS. 10 and 11 Now, the third length-dependent component of the pump unit is described, namely the cable guide 14. The cable guide 14 is formed as a sheet metal profile with a substantially U-shaped cross-section. In this case, the cable guide 14 over the entire length has a constant cross-section. In particular, the axial ends 57 are in no way specially designed. The axial ends 57 are inserted into connection elements in the form of end pieces 58 which have a receptacle 60 adapted to the outer contour of the cable guide 14. Thus, the cable guide 14 can be held in a form-fitting manner in the end pieces 58. In particular, each end piece 58 at the rear end of the receptacle 60, ie at the the other end piece 58 side facing away, a contact shoulder 62 on which the end edge 57 of the cable guide 14 comes to rest. Thus, the cable guide 14 can be fixed in the axial direction between the two end pieces 58.

The end pieces 58 are also preferably made of sheet metal, such as stainless steel sheet and have holes 54, in which screws can be used to attach the end pieces 58 to the pump 6. In the example shown, both end pieces 58 are identical, but they could also be designed differently.

Characterized in that the cable guide 14 is also designed as a profile with a constant cross section without special connection configuration at their axial ends 57, it is possible to cut off the cable guide 14 from a long profile in the desired length.

It will be appreciated that in this preferred embodiment, all length-dependent elements, namely, the tension straps 12, shaft 30, and cable guide 14, are formed so as not to have a special connection configuration at their axial ends but to be cut off from a longer element of desired length can be. This makes it possible to easily manufacture pumps with different numbers of pump stages 10, without having to provide special shafts 30, straps 12 and / or cable guides 14 for each possible number of pump stages. Instead, these length-dependent elements can be cut to the desired length during assembly. After this trimming, it is not necessary, at the axial ends certain connection configurations, eg. B. to form a chip or to weld these axial ends with subsequent elements or connect in other complex manner. Instead, purely positive and / or positive connections are provided, so that an assembly in the "artisanal" Frame is possible. This makes it possible for such pumps of the desired length, ie with the desired number of pump stages 10, to be assembled very easily by the distributor, for example a dealer or wholesaler.

LIST OF REFERENCE NUMBERS

2 - drive motor 4 - connecting piece 6 - pump 8th - connector 10 - pump stages 12, 12 ' - straps 14 - cable management 18 - axial 20, 20 ' - connecting element 22, 22 ' - connecting element 23 - admission 24 - admission 25 - screw 26 - side edges 27 - outer wall 28 - axial 29 - groove 30 - wave 32 - clutch 34 - axial 36 - receiving opening 38 - conical receiving opening 40 - clamping cone 42 - Through Hole 44 - slot 46 - thread 48 - Nut 50 - Wheel 52 - hub 54 - clamping cone 56 - locknut 57 - axial ends 58 - Tails 60 - admission 62 - contact shoulder 64 - holes 65 - Recesses in 12 ' 66 - hook-like elements X - longitudinal axis B ₁ , B ₂ - Width direction of the tension band 12 A - repeat distance

Claims (17)

Pump unit with a pump (6) with one or more pump stages (10), characterized in that at least one of the components (12, 30, 14) of the pump unit whose axial length depends on the number of pump stages (10), at least one its axial ends no in the component (12, 14, 30) itself formed, limited to the axial end connection configuration, but at this axial end force and / or positive connection with a connection element (20, 22, 32, 58) is connected, which with adjacent parts the pump unit is coupled and / or connected or provided for coupling with adjacent parts of the pump unit. Pump unit according to Claim 1, characterized in that the component is a tensioning element (12), preferably a tensioning band, which holds together the pump (6) of the pump unit in the axial direction (X). Pump unit according to claim 2, characterized in that the clamping element (12) at at least one axial end (18) is positively connected to a connecting element (20, 22), which connecting means, in particular a hook and / or a thread having, which the clamping element (20, 22) to the pump (6). Pump unit according to claim 2 or 3, characterized in that the clamping element (12) is connected to at least one axial end (18) positively connected to a connection element which is integrated in the pump. Pump unit according to claim 2 to 4, characterized in that the clamping element (12) is provided with a repeating over the length arrangement of engagement elements which are with corresponding engagement elements on the connection element (20, 22) in engagement or can engage. Pump unit according to claim 5, characterized in that the engagement elements on the clamping element (12 ') in the form of preferably rectangular recesses (65) are formed and that the corresponding engagement elements on the connecting elements (20', 22 ') by hook-like elements (66) are provided for positive engagement in the recesses (65). Pump unit according to claim 5, characterized in that the engagement elements on the clamping element (12) in the form of in the axial direction (X) repeating changes in the width (B ₁ , B ₂ ) of the clamping element (12) are formed. Pump unit according to claim 6, characterized in that the connecting element (20, 22) has a receptacle (24) for the clamping element (12), which tapers in its width to an axial end (28) such that it forms the clamping element (12). engages behind in a region of reduced width (B ₁ ). Pump unit according to one of the preceding claims, characterized in that the component is a shaft (30) of the pump (6) which drives the impeller or wheels (50), the shaft (30) being frictionally engaged with a coupling (32) at one longitudinal end ) connected is. Pump unit according to claim 9, characterized in that the coupling (32) is provided on one axial side with a force-locking element (38, 40) and on an opposite axial side with a positive-locking element (36). Pump unit according to claim 9 or 10, characterized in that the shaft (30) has a constant cross section over its length. Pump unit according to one of claims 9 to 11, characterized in that the one or more wheels (50) are non-rotatably fixed non-rotatably on the shaft (30). Pump unit according to one of claims 9 to 12, characterized in that the one or more wheels (50) have a hub (52) with a conical inner circumference and a clamping cone (50) with a corresponding conical outer periphery, wherein the clamping cone (50) is slotted, a axial through hole through which the shaft (30) extends, and by a clamping element (56) is clamped against the conical inner periphery of the hub (52). Pump unit according to one of claims 9 to 13, characterized in that the coupling (32) at one axial end has a receptacle (38) with conical inner circumference and a clamping cone (40) with a corresponding conical outer circumference, wherein the clamping cone (40) is slotted, an axial through hole (42) through which the shaft (30) extends, and is clamped by a clamping element (48) against the conical inner periphery of the receptacle (38). Pump unit according to one of the preceding claims, wherein the component is a in the axial direction (X) extending cable rail (14). Pump unit according to claim 14, characterized in that the cable rail (14) has a constant cross section over its entire axial length and engages at least one axial end (57) in a connection element (58), which the cable rail (14) on the outer circumference of the pump ( 6) fixed. Method for the modular construction of a pump unit with a single or multi-stage pump (6), characterized in that at least one of the components of the pump unit whose axial length (X) depends on the number of pump stages (10), in its length not specifically for a certain number of pump stages (10) is made, but cut to length for mounting in the desired length of a universal component and at least one axial end with a connection element (20, 22, 32, 58), which for connection or coupling with adjacent parts of the Pumpenaggregdtes serves, is positively and / or positively connected.

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