EP3181908A1 - Multi-stage centrifugal pump having tension anchors made of sheet metal - Google Patents

Abstract

The multi-stage centrifugal pump has a foot part (2) and a head part (9), between which pump stages are incorporated. Head part (9) and foot part (2) are connected by tie rods (11) which are fixed at one end to the head part (9) with the other end at the foot part (2). The tie rods (11) have at one end a thread (14), with which they are braced on the head part (9). The tie rods (11) are formed from sheet metal and have at the other end a recess (16), with which they are at least in the pulling direction (22) positively fixed to the foot part (2).

Description

The invention relates to a multi-stage centrifugal pump with the features specified in the preamble of claim 1.

Such centrifugal pumps are known in numerous design variants, in this context, reference is made in particular to the Grundfos CR series, which is available in different sizes on the market. Common to all these pumps is that they have a foot part, with which they stand in operation on the ground or a foundation provided for this purpose, and a head part, which is designed as a motor chair or is provided for receiving a motor chair, via which a drive motor for the Pump is connectable. In other words, these are pumps in which the actual centrifugal pump and the drive motor essentially form independent units, which are coupled to one another in the area of the motorized chair. Normally standard motors are used which are not specially designed for these pumps, but which can also be used in other drive applications. This centrifugal pump must therefore be structurally designed so that it can accommodate floor mounted the drive motor mounted on the head part and its reaction forces. The centrifugal pumps are designed in series, the head and foot parts match each, but differ in the number of interposed pump stages.

In known centrifugal pumps of this type, the pump stages between the headboard and footboard are incorporated, with the headboard and footboard connected by tie rods that give the pump the mechanical cohesion. For this purpose, four generally distributed symmetrically around the circumference of the pump stages tie rods are provided, which are formed from round material and are provided at the ends with an external thread. These tie rods are either fixed in threaded holes of the foot or fastened there by nuts, the headboard side, the free ends of the tie rods are guided through corresponding holes in the head and nuts are set there. About this tie rods thus integrated between the headboard and footboard pump stages are clamped together, whereby the entire structure gets its stability.

A disadvantage of multi-stage centrifugal pumps of this type is that the tie rods are quite expensive to assemble. So they must first be screwed in the foot, after which the connection is made with the head part and finally the headboard side nuts are placed and tightened with the required torque. Moreover, these helical tie rods are expensive and heavy. They are clearly projecting laterally relative to the cylindrical pump body, so that they always form attack surfaces on which it is easy to get caught with a tool or other objects. Due to the lateral projection on the pump body bending moments on the headboard and foot are also effective, which can lead to undesirable deformations.

Against this background, the invention has for its object to improve a multi-stage centrifugal pump of the type mentioned in terms of tie rods and their attachment.

This object is achieved according to the invention by a multi-stage centrifugal pump having the features specified in claim 1. Advantageous embodiments of the invention are described in the subclaims, the following description and the drawing. In this case, the features specified in the subclaims and the description in each case but also in a suitable combination, the inventive solution according to claim 1 further develop.

The multi-stage centrifugal pump according to the invention has a foot part and a head part, between which pump stages are incorporated. Headboard and footboard are connected together by tie rods which are fixed at one end to the headboard and at the other end to the footboard, the tie rods being threaded at one end with which they are braced at the headboard or at the footboard. According to the invention, the tie rods are at least partially formed from sheet metal and have at least at the other end, ie at the non-threaded end at least one recess in the sheet, with which they are fixed at least in the pulling direction positively on the foot or on the headboard.

In principle, it does not matter whether the form-fitting connection by means of the recess Fußteilseitig and the screw headboard side or vice versa, since the head part, however, is more accessible, it is usually easier to provide the screw headboard side.

It should be noted that the centrifugal pumps of the type in question here have a foot, with which they stand up on the ground or a foundation, that is, a component that carries the entire pump and the motor connected thereto.

According to the invention, the tie rods are at least partially formed from sheet metal, preferably up to the threaded portion at one end completely made of sheet metal. The tie rods should as far as possible be formed of sheet metal, that is, the threaded portion should be formed as short as necessary. The sheet metal part should thus bridge the entire area between the headboard and footboard or end immediately before the head or footboard, where then joins the threaded portion. Such tie rods formed from sheet metal can be produced inexpensively, for example by laser cutting or punching, which is particularly advantageous in large quantities. The connection is made on one side form-fitting manner by means of the at least one recess, either on the foot part or on the head part, preferably on the foot part, so that the thread is arranged headboard side and bolted there with a nut. The extensive design of the tie rods made of sheet metal also has the advantage that they can be adapted to the outer contour of the pump stages, whereby the radial size in the pump stages can be significantly reduced. As a result, the known in constructions according to the prior art torque loads of the head and foot can be significantly reduced. In addition, the design of the tie rods made of sheet metal also allows a much more aesthetically pleasing design than was the case in the prior art, in which the clamping bolts protrude externally body-like radially. The dimensioning of the tie rods depends on the forces to be absorbed and the tensile strength of the material used. However, they should advantageously be at least dimensioned so that an inherent stability of the tie rods is given. This can also be supported, for example, by the fact that the tie rods have a curvature adapted to the curvature of the pump body, ie are bent around their longitudinal axis. Such a curvature makes it possible to apply the tie rods practically without any spacing to the pump body formed in the region of the pump stages, so that these, which is particularly advantageous, have the same temperature level as the pump body.

The determination of the end formed of sheet metal is carried out according to the invention by means of at least one recess into which engages a correspondingly provided on the foot or head part projection. If the recess is completely within the sheet, a peg-like or hook-like projection is provided on the foot or head part side, in order to obtain a positive connection in the pulling direction. Such a pin may, for example, lie within an anchor recess of the foot part or be formed at a suitable location on the foot part.

As an anchor recess, the recesses are referred to below, which are provided for the positive fixing, ie for anchoring the end formed of sheet metal of a tie rod and are determined. In contrast to the recesses in the end formed of sheet metal of a tie rod hereinafter referred to only as recesses. It may be either recesses in the form of holes within the sheet or lateral recesses. Finally, the recesses in the head part are referred to below as hole recesses in which the headboard ends of the tie rods are fixed. These may be holes, holes or laterally open recesses.

It is particularly advantageous if, according to an embodiment of the invention, the tie rods each have a recess on at least one longitudinal side. Then, a positive fixing in the head or foot part can be done by designing a corresponding anchor recess, which has an area in which the tie rod is inserted and has another area at which a counter part engages in this recess. This state can be achieved, for example, by pivoting, transverse shifting or turning.

It is particularly advantageous if lateral recesses are provided on both longitudinal sides of the tie rod, preferably on same height, then there is a particularly uniform force in the tie rod.

In principle, it is conceivable to also form the threaded end of the tie rod made of sheet metal, in which further material is applied to the sheet metal body either by folding or by applying, in which then a thread is cut or stamped. Advantageously, however, according to a development of the invention, it is provided to provide the tie rods at their threaded end with a threaded bolt, which is connected to the formed part of the tie rod by welding.

In order to fix the threaded end of the tie rod in the headboard or footboard, according to the invention, there are provided hole recesses through which the threaded ends of the tie rods are guided and fixed and braced there by means of a respective nut. This attachment is advantageously headboard side, wherein the head part is advantageously designed as a motor chair. It is then the same component which not only closes the pump steps upwards, but at the same time also forms the motor mount. The hole recesses may be laterally open, so that it is not necessary to put the threaded ends of the tie rods through them, but that they can be inserted, for example, from the side. This facilitates in particular the automated assembly.

Advantageously, the part of the pump clamped between the foot part and the head part has a cylindrical section, for example formed by a tube which forms the return channel from the pressure side back to the foot part. According to one embodiment of the invention, it is provided to adapt the parts of the tie rods formed from sheet metal to the curvature of this cylindrical portion, that is to their Deform longitudinal axis. Such deformation makes it possible to apply the tie rods almost flush to this cylindrical portion, if desired. Alternatively, the tie rods can also be arranged at a distance, even with this arrangement, a technically and optically advantageous design may result.

For the positive integration of the ends of the tie rods anchor recesses are preferably provided in the foot part, each having an insertion part and a holding part. The insertion part is designed so that a sheet metal formed end of a tie rod can be passed through this insertion part and indeed so far until the recesses lie on the longitudinal sides within these Ankerausnehmungen. Then, by moving or pivoting a tie rod can be transferred with its blechteilseitigen end of the insertion part of an anchor recess in the holding part, in which the tie rod is held positively at least in the direction of its longitudinal axis and in which the surrounding the anchor recesses material laterally into the recesses of the blechteilseitigen end engages the tie rod. In this case, the transfer from the insertion part in the holding part can advantageously be carried out by radial displacement or in a simple manner by pivoting, as will be described in detail below.

Advantageously, the anchor recesses are designed so that the holding parts radially outwardly adjoin the insertion parts, so that the cylindrical portion of the surrounding pump stages secure the ends of the tie rods, which lie in the Halteilen the Ankerausnehmungen, positively, so that they no longer in reach the area of the insertion parts, in which they can be pushed through for assembly or disassembly purposes.

It is particularly advantageous if the anchor recesses are arranged in a circle around the longitudinal center axis of the pump, preferably in the foot part, and their insertion parts are covered by a component of the pump, for example a pump stage or the circumferential jacket, for positive fixing of the tie rod located in the holding part. The tie rods are advantageously arranged symmetrically about the longitudinal center and axis of rotation of the pump around, there may be provided three, four or more tie rods.

It is particularly advantageous in terms of construction if the anchor recesses are arranged in an axial wall, preferably of the foot part. In this arrangement, the actual foot can consist of a plate, for example, made of cast iron and an upwardly adjoining part either also made of cast, so be designed as a one-piece component with the plate or possibly also as a sheet metal construction.

According to an alternative embodiment of the invention, the insertion parts of the anchor recesses are arranged in a radial wall and the holding parts of the anchor recesses in an axial wall, preferably of the foot part. Such an arrangement has the advantage that the tie rods can be inserted from the side and fixed in a form-fitting manner, for example by pivoting. This results in a very simple and reliable installation. In this case, the holding parts of the anchor recesses may alternatively be provided in a corresponding recess or recess in the radial wall, typically in its peripheral side.

Advantageously, both the head part and the foot part are formed as a metallic casting, wherein the foot part for setting up the pump on a foundation, typically on the ground, formed is and the head part for receiving an electric motor driving the pump is formed. These components can then be used for a whole series of pumps, wherein only the tie rods and the incorporated therebetween pump stages or the surrounding the return channel forming pipe must be adjusted according to the number of pump stage. The pump is advantageously designed as an in-line pump and has a suction port and a pressure port in the foot part, wherein the pump stages are surrounded by an annular channel through which the last pump stage is connected to the pressure port in the foot and the outer channel wall either adjacent or Preferably, the tie rods are arranged at a small distance. In this case, the foot part can be formed with its suction and pressure connection as a casting, but it can also be constructed, for example, only the actual foot part forming plate made of cast iron and the rest of the foot part of sheet metal.

It is particularly advantageous if the tie rods are formed except for the threaded end portion of sheet metal, so the sheet metal part of the tie rod extends from the foot to the head or right up to it. As a result, on the one hand a cost-effective production and on the other a visually and technically preferable construction feasible, in which the tie rods lie almost flush with the otherwise there cylindrical pump body. It when the tie rods are integrally formed and in particular also intrinsically stable, since then they are relatively easily einliederbar in largely automated assembly processes is particularly advantageous.

Advantageously, the foot part has a cup-shaped structure, wherein the anchor recesses are then advantageously arranged where the pot bottom merges into the pot wall. It may then be provided, for example, the insertion part of the anchor recesses in the wall and the holding part in the ground. The anchor recess then extends into two areas. If the foot part is fluid-conducting and for this reason the inner side of the pot wall can not be provided with anchor recesses, the pot base can protrude radially beyond the pot wall, in order accordingly to arrange anchor recesses on the outside.

Fig. 1

in stark vereinfachter perspektivischer Darstellung ein erstes Ausführungsbeispiel einer Kreiselpumpe gemäß der Erfindung,

Fig. 2

die Kreiselpumpe nach Fig. 1 in Explosionsdarstellung,

Fig. 3

das Fußteil der Pumpe nach Fig. 1 von unten mit festgelegtem Zuganker,

Fig. 4

die Anordnung gemäß Fig. 3 schräg von oben,

Fig. 5

ein anderes Ausführungsbeispiel der Kreiselpumpe in Darstellung nach Fig. 1,

Fig. 6

die Pumpe nach Fig. 5 mit Fußteil im Teilschnitt und einem Zuganker in Einführstellung,

Fig. 7

die Pumpe gemäß Fig. 5 in Explosionsdarstellung,

Fig. 8

das Fußteil der Pumpe gemäß der Pumpe nach Fig. 5 in perspektivischer Ansicht schräg von vorne und oben,

Fig. 9

das Fußteil gemäß Fig. 8 in um 90° gedrehter Ansicht gegenüber Fig. 8,

Fig. 10

das Fußteil gemäß Fig. 8 in perspektivischer Ansicht von unten und

Fig. 11

zur Verdeutlichung des konstruktiven Aufbaus in Seitenansicht eine vergleichbar aufgebaute Kreiselpumpe im Längsschnitt mit angeschlossenem Elektromotor.

The invention is explained in more detail with reference to exemplary embodiment illustrated in the drawings. Show it:

Fig. 1

in a greatly simplified perspective view of a first embodiment of a centrifugal pump according to the invention,

Fig. 2

the centrifugal pump after Fig. 1 in exploded view,

Fig. 3

the foot part of the pump after Fig. 1 from below with fixed tie rod,

Fig. 4

the arrangement according to Fig. 3 diagonally from above,

Fig. 5

another embodiment of the centrifugal pump in illustration after Fig. 1 .

Fig. 6

the pump after Fig. 5 with foot part in partial section and a tie rod in insertion position,

Fig. 7

the pump according to Fig. 5 in exploded view,

Fig. 8

the foot part of the pump according to the pump Fig. 5 in perspective view obliquely from the front and top,

Fig. 9

the foot part according to Fig. 8 in 90 ° rotated view opposite Fig. 8 .

Fig. 10

the foot part according to Fig. 8 in perspective view from below and

Fig. 11

to illustrate the structural design in side view of a comparably constructed centrifugal pump in longitudinal section with connected electric motor.

In the case of Fig. 1 The illustrated centrifugal pump 1 is a multi-stage centrifugal pump of the inline type (see also Fig. 11 ). It has a foot part 2, which is provided with its underside for placement on the floor or a corresponding foundation. The foot part 2 has substantially the shape of a rectangular plate which has four mounting recesses 3 at its corners, with which the foot part 2 can be screwed to the foundation, guided in the corresponding head screws through these recesses 3 and anchored in the foundation. The foot part 2 has a circular receptacle 4, which is provided for receiving a suction port 5 and a pressure port 6 exhibiting component which receives it upwardly subsequent pump stages, which are closed at the top by a cover part 7. Between the cover part 7 and the suction and pressure connection 5, 6 receiving component, a cylindrical pipe section 8 is arranged, which surrounds the pump stages at a distance and forms an annular channel through which the exiting at the end of the last pump stage liquid is led to the pressure port 6. At the top, the pump is closed by a head part 9, which at the same time forms a motor chair for an electric motor which can be flanged there.

The suction and pressure connection 5, 6 having component, the adjoining pump stages, the surrounding pipe section 8 and the cover part 7 are clamped between the foot part 2 and the head part 9 positive and non-positive, by four symmetrically about the longitudinal These tie rods 11 are made of sheet metal and have an elongated narrow shape, they are bent about their longitudinal axis, corresponding to the curvature of the pipe section 8, so that they like Fig. 1 it can be seen that they continue to the outside. The tie rods 11 have a lower end 12, which is also formed of sheet metal and an upper end 13, which is formed by an externally threaded pin 14 which is firmly connected by welding to the upper end of the formed part of the tie rod 11 is. Towards the lower end 12, the sheet metal section 15 is provided with two recesses 16 on its longitudinal side, which are arranged at the same height, the underside of which is recessed 90 ° inwards and their upper side tapers obliquely to the outer edge of the sheet metal section 15. For anchoring these lower ends 12 of the tie rod 11 four anchor holes 18 are provided in the foot part 2, namely at the edge of the receptacle 4, in the axial wall 17, whose contour is best in Fig. 4 is recognizable.

Each anchor recess has an insertion part 19 and a holding part 20, which are matched to the lower end 12 of a tie rod. Thus, the insertion part 19 is dimensioned so that it corresponds to the cross-sectional area of the sheet metal section 15, that is, a tie rod 11 with its lower end 12 from above into the insertion part 19 can be inserted and passed. This lower end 12 is inserted so far into the insertion part 19 until the recesses 16 are arranged at the height of the anchor recess 18, then the tie rod 11 is displaced radially outwardly in the anchor recess 18, so that the comparatively narrow web part 21, which is between the Recesses 16 is formed in the sheet metal section 15, in the holding part 20 of the anchor recess 18 passes, whereby the tie rod 11 is positively fixed in the pulling direction 22 in the foot part 2. In this case, the holding part 20 of the armature recess 18, which is arranged in the axial wall 17 of the receptacle 4, in the radial wall 23 of the receptacle 4 according to the obliquely upward expiring recesses 16, so that the tie rod in this position outside of the actual recording 4, namely radially offset thereto is arranged.

The receptacle 4, which is provided in terms of their dimensions for receiving the suction and pressure port 5, 6 receiving component, this component after incorporation of the tie rods 11 still record, but with the effect that by incorporating the component in the recording 4, the insertion parts 9 of the anchor recesses 18 closed and thus the lower ends 12 of the tie rods 11 are positively fixed within the foot part 2.

Once the tie rods 11 are positively fixed within the foot part 2, the remaining pump parts, in particular the pump stages, the pipe section 8 and the cover part 7 can be incorporated, after which the head part 9 is placed from above. In this case, the upper ends 13, so the threaded bolts 14 pass through hole recesses 24 in the head part 9, which are arranged in alignment with the arranged in the foot part 2 Ankerausnehmungen 8, so that after placement of the head part protruding through the hole recesses 24 pin 14 below Intermediate washers provided with nuts 25 and braced. This gives the entire centrifugal pump 1 a closed and stable structure, wherein, as in particular from Fig. 1 it can be seen, the tie rods 11 rest in only a small distance to the otherwise cylindrical pump body, so that a total of a slim outer contour arises practically without projections in the radial direction.

When using the Fig. 5-10 embodiment shown are incorporated into the foot 2a of the suction port 5 and the pressure port 6. There, the pipe section 8, which defines the annular channel to the outside, between the foot part 2a and the head part 9a. The structure in detail arises in particular from Fig. 7 , In this construction, the head and foot parts 9a, 2a made of castings are not lined with stainless steel sheet as in the above-described embodiment, but form parts of the flow channels. The basic structure is similar, but the receptacle 4a is formed closed, that is without recess on the inside. This is necessary to ensure the tightness relative to the pipe section 8. Here, the receptacle 4a surrounding anchor recesses 18a are provided, which are arranged on the outside of the receptacle 4a and having a radial insertion part 19a and an axial holding part 20a. The radial insertion part 19a of an armature recess 18a lies in a radial wall 23a, which surrounds the receptacle 4a at a distance and receives the pressure and the suction connection 5, 6. This radial wall 23a is stepped at its upper end in an axial wall 17a, which is not part of the receptacle 4a, but forms an outer shoulder.

The tie rods 11 themselves are designed exactly as in the previously described embodiment. They will be here, however, as in particular Fig. 6 can be seen, obliquely from the outside and up through the insertion part 19a, so the Ankerausnehmungsteil inserted in the radial wall 23a until the recesses 16 and the web 21 of the tie rods 11 are arranged at the level of the holding parts 20a of the anchor recesses 18a. Then, the tie rod 11 is pivoted obliquely upward until it rests parallel to the pipe section 8 at a distance and the threaded bolt 14 engages in the laterally open hole recess 24a, with respect to the upper end, he as in the previous embodiment under inclusion of a Washer screwed with a nut 25 and thus fixed. With the pivoting of the tie rod 11, approximately to a tangential to the upper edge of the foot part 2a extending axis, the narrow sheet metal portion 21 passes between the recesses 16 in the region of the holding part 20a of the anchor recess 18a in the axial wall 17a, whereby the parts of the projecting parts of the Sheet metal section 15 received a positive connection in the pulling direction 22 and in the opposite direction. The tie rod 11 is held in this position by the threaded bolt 14 defined by the nut 25, with which the upper end 14 of the tie rod 11 is fastened to the head part 9a.

The holding part 20a of an anchor recess 18a is provided in the above-described embodiment in the axial wall 17a, but it can also be provided this part of the anchor recess 18a in the radial wall 23a, if this dimensioned accordingly and one matched to the lower end 12 of the tie rod 11 that is, in the form of corresponding recess or recess.

The main advantage of the above-described arrangement is that the pump can be constructed almost completely starting from the foot part 2a to the head part 9a, after which the tie rods 11 are finally inserted into the anchor recesses 18a and secured there in a form-fitting manner by pivoting. The corresponding tensile stress between the foot 2a and the head part 9a is then applied by tightening the nut 25 with the intended torque. This design is therefore particularly advantageous for at least partially automated assembly.

Based on Fig. 11 is the basic structure of such a centrifugal pump with drive, which, as the break line in horizontal Direction clarified, stands for multi-stage centrifugal pumps with virtually any number of pump stages. To drive the centrifugal pump is mounted on the head part 9a, which is formed at the upper end as a motor chair, a drive motor 26 in the form of an electric motor whose shaft 27 is rotatably connected to a shaft 28 of the centrifugal pump 1 by a coupling. On the drive shaft 28 of the centrifugal centrifugal impellers 29 are rotatably arranged according to the number of stages, which together with housing-fixed nozzles 30 form the pump stages.

The delivery fluid will flow over the (in Fig. 11 not visible) suction connection 5 led to the suction port of the lowest pump stage and passes from there pump stage to pump stage with pressure increase upwards, where it exits within the head part 9a and is passed via an annular channel 31 back down to the foot part and there to the pressure port 6.

LIST OF REFERENCE NUMBERS

1

rotary pump

2, 2a

the foot part

3

fixing recesses

4, 4a

admission

5

suction

6

pressure connection

7

the lid part

8th

pipe section

9, 9a

the headboard

10

Rotary axis, longitudinal central axis

11

tie rods

12

lower end of 11

13

upper end of 11

14

threaded bolt

15

sheet metal section

16

recesses

17, 17a

axial wall of 4

18, 18a

anchor recess

19, 19a

the introductory part of 18

20, 20a

the holding part of 18

21

Bridge part of 11

22

tensile direction

23, 23a

radial wall of 4

24, 24a

Lochausnehmungen

25

mother

26

electric motor

27

motor shaft

28

pump shaft

29

impellers

30

nozzles

Claims (16)

Multi-stage centrifugal pump with a foot part (2), with a head part (9) and with integrated pump stages therebetween, the head part (9) and foot part (2) being connected by tie rods (11) connected to one end (13) on the head part (9 ) and with the other end (12) are fixed to the foot part (2), wherein the tie rods (11) at one end (13) are provided with a thread, with which they on the head part (9) or on the foot part (2) are clamped, characterized in that the tie rods (11) are at least partially formed from sheet metal, at least at the other end (12) at least one recess (16) in the sheet metal, with which they at least in the pulling direction (22) form fit on the foot part (2 ) or on the head part (9) are fixed. Centrifugal pump according to claim 1, characterized in that the tie rods (11) each have at least one longitudinal side a recess (16). Centrifugal pump according to claim 1 or 2, characterized in that the tie rods (11) each have on both longitudinal sides, preferably at the same height recesses (16). Centrifugal pump according to one of the preceding claims, characterized in that the tie rods (11) have at their threaded end (13) a threaded bolt (14) which is connected by welding to the part (15) of the tie rod (11) formed from sheet metal is. Centrifugal pump according to one of the preceding claims, characterized in that preferably in the head part (9) Perforated holes (24) are provided, through which the threaded ends (13) of the tie rods (11) passed and fixed there by means of a respective nut (25) and braced, wherein the head part (9) is preferably designed as a motor chair. Centrifugal pump according to one of the preceding claims, characterized in that the pump (1) between the foot part (2) and the head part (9) has a cylindrical portion (8) and that the parts (15) of the tie rods (11) formed from sheet metal on an have the curvature of this cylindrical portion adapted curvature. Centrifugal pump according to one of the preceding claims, characterized in that preferably in the foot part (2) Ankerausnehmungen (18) are provided, each having an insertion part (19) and a holding part (20), wherein the insertion part (19) is formed so that an end (12) of a tie rod (11) is guided, and the holding part (20) is formed so that the end (12) of the tie rod (11) by preferably radial displacement and / or by pivoting at the level of its at least one recess ( 16) in the holding part (20) and the tie rod (11) is held positively at least in the direction (22) of its longitudinal axis. Centrifugal pump according to claim 7, characterized in that the anchor recesses (18) arranged in a circle around the longitudinal center axis (10) of the pump (1) preferably in the foot part (2) and their insertion parts (19) by a component of the pump (1) for positive fixing the tie rods (11) are covered. Centrifugal pump according to claim 8, characterized in that the holding parts (20) connect radially on the outside to the insertion parts (19) of the anchor recesses (18) and a cylindrical portion of the component, the ends (12) of the tie rods (11) form fit in the anchor recesses (18 ). Centrifugal pump according to one of the preceding claims, characterized in that the anchor recesses (18) in an axial wall (17) preferably of the foot part (2) are arranged. Centrifugal pump according to one of the preceding claims, characterized in that the insertion parts (19a) of the anchor recesses (18a) in a radial wall (23a) and the holding parts (20a) of the recesses (18a) in an axial or radial wall (23a) preferably of Foot part (2a) are arranged, Centrifugal pump according to one of the preceding claims, characterized in that the head part (9) and / or the foot part (2) is designed as a metallic casting, wherein the foot part (2) for setting up the pump (1) on a foundation, in particular the ground is formed and the head part (9) for receiving a pump (1) driving electric motor is formed. Centrifugal pump according to one of the preceding claims, characterized in that the pump (1) as inline pump with suction and pressure port (5, 6) in the foot part (2) is formed, the pump stages are surrounded by an annular channel through which the last pump stage with connected to the pressure port (6) is and at the outer channel wall, the tie rods (11) are preferably arranged spaced therefrom. Centrifugal pump according to one of the preceding claims, characterized in that the part (15) of a tie rod (11) formed from sheet metal extends from the foot part (2) to the head part (9) or directly in front of it. Centrifugal pump according to one of the preceding claims, characterized in that the foot part (2, 2a) has a cup-shaped structure and the anchor recesses (18, 18a) are arranged in the region in which the pot bottom merges into the pot wall. Centrifugal pump according to one of the preceding claims, characterized in that the tie rods (11) are integrally formed and preferably inherently stable.

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