EP3961039A1 - Pump for conveying a fluid - Google Patents

Abstract

The invention relates to a pump for conveying a fluid, comprising a casing (4) and a pump shaft (2) arranged in the interior of the casing (4) and rotatable about an axis (A) with an impeller ( 34) for acting on the fluid, the pump (1) further having a pump inlet (7) for supplying the fluid to the interior space and a pump outlet (6) for removing the fluid from the interior space, wherein one end of the casing housing (4) is closed with a cover (5, 51, 52), and the pump (1) comprises a clamping assembly (10) for securing the cover (5, 51, 52) to the casing (4), the clamping assembly (10) a Clamping element (11) and a clamping means (12) that can be arranged in a bore (13) of the clamping element (11), the clamping element (11) comprising a first contact surface (111) and a second contact surface (112). The clamping means (12) is arranged so that it can be moved relative to the clamping element (11) along a clamping axis (X) in such a way that the clamping element (11), through interaction with the clamping means (12), when the cover is installed between the jacket housing (4) and the Cover (5, 51, 52) is clamped, with a clamping force being exerted on the cover from the jacket housing (4) via the first contact surface (111) to the second contact surface (112) in the installed state, so that the cover (5, 51, 52 ) is secured in the installed state by the clamping force on the casing (4).

Description

The invention relates to a pump with a casing according to the preamble of the independent claim.

Multistage pumps for pumping a fluid are used in many different industries, especially for applications where high pressure is to be generated. Important branches of industry in which multistage pumps are used are e.g. the oil and gas processing industry, the power generation industry, the chemical industry, the clean and waste water industry or the pulp and paper industry.

In the oil and gas processing industry, multi-stage pumps are designed eg for pumping hydrocarbon fluids, eg for recovering the crude oil from the oil field or for transporting the oil/gas through pipelines or within refineries. Another application is the injection of a process liquid, in most cases water and especially seawater, into an oil reservoir. For such applications, these pumps are designed as (water) injection pumps that pump seawater under high pressure into a borehole that leads to an underground area of an oil deposit.

For other applications, a multi-stage pump can be designed as a boiler feed pump for a power plant or as a booster pump, e.g. in a reverse osmosis process for water desalination, to name just a few examples.

A multi-stage pump consists of several stages, each with an impeller, with all the impellers being arranged one after the other on a common pump shaft. The pump shaft is driven for rotation around an axis, e.g. by an electric motor, so that all impellers rotate together around the axis.

Several designs are known for multi-stage pumps. A multistage pump can be designed as a vertical pump, i.e. the pump shaft extends in the vertical direction during operation of the pump, the vertical direction being the direction of gravity. A multistage pump can be configured as a horizontal pump, i.e. the pump shaft extends in the horizontal direction during operation of the pump, with the vertical direction being the direction of gravity. In addition, a multi-stage pump can be designed as a radially divided pump or as an axially divided pump. Further embodiments of multi-stage pumps are e.g. sectional or shell pumps.

Link pumps consist of several stage casings, which are arranged one behind the other in the axial direction defined by the axis of the pump shaft. The stage casings are fixed to one another with the aid of tie rods which extend through all the stage casings. The majority of stage casings consist of a suction casing on the inlet side of the pump and a discharge casing on the outlet side of the pump. All stage housings together form the housing of the multi-stage pump.

Casing pumps also consist of a large number of stage casings, similar to a segment pump. However, the stage casings are located within an outer casing (casing) that surrounds the stage casings, making this type of multi-stage Pump is a double casing pump. The jacket housing is closed at its axial ends by a cover, ie a suction cover or a pressure cover. It is also possible for the stage casings to be configured so that together they form a cartridge which can be removed in its entirety from the casing.

In order to close the jacket housing with the cover at the axial end, the jacket housing and cover are connected by means of a screw connection (or a bolt connection). In this case, the cover and the jacket housing have corresponding bores in order to connect them to one another via a large number of screws and thus to close the jacket housing with the cover. In the operating state of the pump, the cover and thus the screw connection are subject to high loads, since high pressure is built up inside the jacket housing, which therefore also acts on the cover and the screw connection. In addition, if the pump malfunctions, an upward hydraulic axial thrust can act on the cover. The pressure must be absorbed directly by the screw connection. This has a negative effect on the sealing behavior of the cover/jacket housing connection. The loads are transmitted exclusively via the screws of the screw connection, which can result in deformations that then have a correspondingly negative effect on the sealing behavior. This is then a possible cause of a leaking jacket housing. This can be a problem with subsea pumps in particular, as these are additionally stressed by the water pressure.

Proceeding from this prior art, it is the object of the invention to provide a pump with a jacketed housing which avoids the disadvantageous effects known from the prior art, in particular enables a more compact and assembly-friendly solution/construction compared to a conventional screw connection, and is particularly suitable for absorbing an axial thrust in the event of an accident.

This object is solved by a pump having the features of the independent claim.

The dependent claims relate to particularly advantageous embodiments of the invention.

The invention relates to a pump for conveying a fluid, comprising a casing and a pump shaft which is arranged in an interior space of the casing and can be rotated about an axis. The pump shaft includes an impeller arranged non-rotatably thereto for acting on the fluid, the pump further having a pump inlet for supplying the fluid to the interior space and a pump outlet for discharging the fluid from the interior space. One end, in particular an axial end, of the casing is closed with a cover. In addition, the pump comprises a clamping arrangement for securing the cover on the casing, the clamping arrangement comprising a clamping element and a clamping means which can be arranged in a bore of the clamping element. Here, the tensioning element comprises a first contact surface and a second contact surface.

With the clamping arrangement according to the invention, the cover can be secured in the direction of the axis, in particular in the event of a malfunction, in that a hydraulic, upward thrust is directed via the clamping element into the jacket housing. In principle, however, the cover can also be connected to the casing via the clamping arrangement, in particular can be fastened to the casing (for example in order to close the casing with the cover).

The pump according to the invention is characterized in that the clamping means is arranged so that it can be moved relative to the clamping element along a clamping axis in such a way that the clamping element clamps between the jacket housing and the cover by interacting with the clamping means (arranged in the bore of the clamping element) when the cover is in the installed state is, being in the installed state a clamping force is exerted on the cover by the jacket housing via the first contact surface to the second contact surface (or in the installed state the clamping force is also exerted on the jacket housing by the cover via the second contact surface to the first contact surface), so that the cover is clamped in the installed state by the clamping force on Casing secured (particularly secured in a direction of the axis) is. In this way, in the event of a pump malfunction, the cover can be secured in the direction of the resulting hydraulic thrust.

The installed state is therefore the state in which the cover is fastened to the jacket housing, with the clamping force being generated in particular by the fact that the clamping element is clamped between the cover and the jacket housing.

Since the clamping element is clamped between the casing and the cover when the cover is installed, (operating) loads are no longer transmitted (exclusively) via screw connections, but rather via the clamping element, which is preferably clamped in a non-positive and positive manner. In this case, there is a favorable flow of forces from the cover to the casing via the clamping element.

In particular, the pump according to the invention with the clamping arrangement according to the invention means that pressure on the cover and the resulting forces do not have to be absorbed by a screw connection, but are largely conducted into the jacket housing via the clamping element, which leads to a considerable relief of the clamping means .. The clamping device is only loaded with a small proportion of the forces and moments to be transmitted. In contrast to the prior art, the clamping device is not the main stressed component. The clamping device fixes the clamping element (after a clamping process) in its position (in the installed state). In comparison to the state of the art, the clamping means can thus be made significantly smaller (shorter and/or smaller in diameter clamping means).

It is a particularly preferred embodiment of the invention when the pump comprises a plurality of clamping assemblies. In particular, at least two clamping arrangements can be understood as the multiplicity of clamping arrangements. However, for example, 20 (or some other plurality of) clamping assemblies could be used. In practice, both axial ends of the pump can also be closed with a cover. The suction side with a suction cover and the pressure side with a pressure cover. The suction cover is preferably attached with a first plurality of clamping arrangements and the pressure cover with a second plurality of clamping arrangements.

In an embodiment of the invention, the clamping arrangement can further comprise a holding element which, when installed, is arranged between the clamping element and the jacket housing in such a way that the clamping force is exerted (or transmitted) from the jacket housing to the first contact surface via the holding element when installed. Alternatively, the retaining element can be arranged between the clamping element and the cover in the installed state such that the clamping force is exerted on the cover by the retaining element via the second contact surface in the installed state. The holding element can, among other things, simplify the attachment of the clamping arrangement to the cover and casing.

In particular, the holding element can include a clamping bore. In the installed state, the clamping means is arranged in the clamping bore in such a way that the clamping element is clamped between the casing and the cover via the retaining element. The clamping means is therefore arranged here both in the bore of the clamping means and in the clamping bore of the holding element. When the tensioning element is tensioned in the installed state with the tensioning means, the tensioning element is arranged relative to the retaining element (guided to the retaining element) in such a way that it is tensioned via the retaining element.

In practice, the retaining element can also include an additional bore. In the installed state, a holding means is in the additional bore arranged that the holding element is attached to the casing housing or the lid. The holding means can be a screw, a pin or a bolt, for example, which is stretched/turned into the additional bore in order to arrange the holding element on the casing or the cover. In this way, both the fastening of the cover (the transfer to the installed state) is made easier and a more stable clamping arrangement is made possible.

In a particularly preferred embodiment, the clamping element can be designed as a wedge-shaped clamping element, in which case the first contact surface can be a first conical contact surface and the second contact surface can be a second annular (or ring segment-shaped) contact surface. In particular, annular can be understood to mean that the contact surface corresponds to the surface of a ring cutout/ring segment.

In order to simplify the arrangement of the clamping arrangement, the jacket housing or the cover can comprise a bulge in which the clamping arrangement is clamped/is arranged in the installed state between the jacket housing and the cover. If the pump comprises the multiplicity of clamping arrangements, the cover or the jacket housing preferably comprises a multiplicity of bulges or a groove in which the clamping arrangements are braced in the installed state between the jacket housing and the cover.

The cover does not have to be attached to the jacket housing solely by the clamping force of the clamping arrangement. In order to enable better attachment of the cover to the casing, the casing may comprise a projection, the cover being arranged on a projection such that the cover is supported by the projection in an axial direction of the axis. While the cap is supported in the axial direction by the protrusion, the cap is supported in a direction opposite to the axial direction by the clamp assembly, specifically, a plurality of clamp assemblies. so that the lid is fixed in the axial direction and the direction opposite to the axial direction. For this purpose, the cover can in particular comprise a shoulder, with which the cover is then arranged on the projection. Both the projection and the shoulder can be circumferential, so that the projection extends along an inner circumference of the casing and the shoulder extends along an, in particular outer, circumference of the cover.

Alternatively, a plurality of clamping arrangements could also be arranged on both sides of the cover (with respect to the axis or the axial direction) in order to fasten the cover in the axial direction and in the direction opposite to the axial direction (and thus the cover in the installed state to fix). In this case, both sides therefore refers to a side of the cover facing the interior and the opposite side of the cover, which is directed outwards.

The tensioning arrangement functions in particular as a thrust transmission device which transmits an upward hydraulic axial thrust (hydraulic axial thrust which pulls the cover towards the interior in the event of a fault) from the cover to the jacket housing in the event of a fault (of the pump).

As already mentioned above, the pump particularly preferably comprises the plurality of clamping arrangements. The clamping arrangements are designed in particular as ring part segments. In the installed state, these annular part segments can be arranged at a uniform distance from one another along the circumference of the cover. The ring part segments can be arranged in the bulges or in the circumferential groove.

In practice, the clamping means can be designed as a clamping screw. The clamping screw is placed in the bore of the clamping element. The bore includes a thread corresponding to a screw thread of the clamping screw, so that the clamping screw is arranged to be movable along the bracing axis by rotation in the bore (about the bracing axis) in such a way that the clamping element can be clamped by interacting with the clamping screw in the installed state of the cover between the jacket housing and the cover. Since the clamping screw moves relative to the clamping element as a result of the rotation, the clamping element can therefore be clamped between the cover and the jacket housing. The tightening takes place, for example, by pressing one end of the screw against a surface of the cover (or the casing), as a result of which a force necessary for tightening is transmitted to the tightening element. Alternatively, the force required for clamping can be exerted on the clamping element by arranging the clamping screw in the clamping bore of the holding element and guiding the clamping element to the holding element by rotating the clamping screw and thus clamping it with the holding element.

Thread settling as a result of relaxation, which generally occurs in the most heavily loaded screw connections of the prior art, is no longer relevant due to the arrangement according to the invention. The clamping means can also be designed as a clamping pin or clamping bolt.

In a particularly preferred embodiment, the clamping element is designed as a ring wedge (wedge-shaped clamping element adapted to the round shape of the cover), especially when the clamping arrangement is designed as a ring part segment and the clamping screw is guided through the bore of the ring wedge. As already mentioned, the pump preferably includes a large number of clamping arrangements, so that the ring wedges are clamped in the radial and axial direction in the bulges or the (ring) groove by means of the clamping screws and thus fasten the cover. In the groove/bulges, the cover preferably includes planar contact surfaces against which the clamping elements can rest with a wedge surface (or rest in the installed state).

In practice, the pump can be designed as a multi-stage pump. The multistage pump comprises a plurality of stages arranged in series with respect to the axis, the plurality of stages comprising at least a first stage and a last stage, each stage having a stage casing and an impeller for acting on the fluid, and each impeller is non-rotatably attached to the pump shaft. In particular, the pump can also be a submersible pump and/or a multiphase pump. The pump is particularly preferably a barrel pump.

The invention is explained in more detail below using exemplary embodiments with reference to the drawing.

Fig. 1a

eine schematische Querschnittsansicht einer erfindungsgemässen Ausführung einer mehrstufigen Pumpe in einem Schnitt entlang einer Achse;

Fig. 1b

die Ausführung gemäss Fig. 1a in einem Querschnitt senkrecht zur axialen Richtung entlang der Schnittlinie II-II in Fig. 1a;

Fig. 2a

eine schematische Querschnittsansicht einer erfindungsgemässen Spannanordnung mit einem Halteelement und einer Spannbohrung;

Fig. 2b

eine schematische Querschnittsansicht einer erfindungsgemässen Ausführung;

Fig. 2c

eine schematische Querschnittsansicht einer erfindungsgemässen Spannanordnung mit einem Halteelement;

Fig. 3a

eine schematische dreidimensionale Ansicht einer erfindungsgemässen Spannanordnung mit einem Halteelement und einer Spannbohrung;

Fig. 3b

eine weitere schematische dreidimensionale Ansicht der erfindungsgemässen Spannanordnung gemäss Fig. 3a;

Fig. 4a

eine schematische Querschnittsansicht eines Ausschnittes einer erfindungsgemässen Ausführung einer mehrstufigen Pumpe in einem Schnitt entlang einer Achse;

Fig. 4a

eine schematische Querschnittsansicht eines Teilausschnittes von Fig. 4a.

The drawings show:

Fig. 1a

a schematic cross-sectional view of an embodiment of a multi-stage pump according to the invention in a section along one axis;

Fig. 1b

the execution according to Fig. 1a in a cross section perpendicular to the axial direction along line II-II in Fig. 1a ;

Figure 2a

a schematic cross-sectional view of a clamping arrangement according to the invention with a holding element and a clamping bore;

Figure 2b

a schematic cross-sectional view of an embodiment according to the invention;

Figure 2c

a schematic cross-sectional view of a clamping arrangement according to the invention with a holding element;

Figure 3a

a schematic three-dimensional view of a clamping arrangement according to the invention with a holding element and a clamping bore;

Figure 3b

a further schematic three-dimensional view of the clamping arrangement according to the invention Figure 3a ;

Figure 4a

a schematic cross-sectional view of a detail of an embodiment of a multi-stage pump according to the invention in a section along one axis;

Figure 4a

a schematic cross-sectional view of a portion of FIG Figure 4a .

Fig. 1a shows a schematic cross-section of an embodiment of a multi-stage pump according to the invention, which is denoted in its entirety by the reference number 1. The multi-stage pump 1 is designed as a centrifugal pump for conveying a liquid from a pump inlet 7 to a pump outlet 6 .

In the following description of a preferred embodiment of the multistage pump 1 according to the invention, a configuration is discussed as an example in which the multistage pump 1 is designed as a horizontal casing pump with a multistage casing, i.e. as a double casing pump. The multi-stage pump can, for example, be designed as pump 1 of pump type BB5.

It goes without saying that the invention is not limited to such embodiments. The multistage pump can be designed, for example, as a vertical multiphase pump.

The multi-stage pump 1 consists of a jacket housing 4 and several stages 3, each of which has an impeller 34 for applying the liquid. All impellers 34 are arranged one after the other on a pump shaft 2 which is designed for rotation about an axis A. The pump shaft 2 runs centrally through the casing 4 and is supported by radial bearings (not shown) and at least one thrust bearing (not shown). In addition, shaft seals (not shown), e.g. mechanical seals, in a manner known in the art. The shaft seals prevent the liquid from escaping along the pump shaft 2 from an interior 8 of the casing 4 to the outside.

The axis A defines an axial direction (as well as a direction opposite to the axial direction), the axis A being defined by the longitudinal axis of the pump shaft 2, i.e. the axis of rotation about which the pump shaft 2 rotates during operation. A direction perpendicular to the axis A is referred to as "radial direction". The term "axial" or "axial" is used with the general meaning "in the axial direction" or "relative to the axial direction". In an analogous manner, the term "radial" or "radial" is used with the common meaning "in the radial direction" or "in relation to the radial direction".

All impellers 34 are mounted on the pump shaft 2 in a torque-proof manner. The pump shaft 2 is driven by a drive unit (not shown), for example an electric motor. in the in Fig. 1a In the embodiment shown, the drive unit is arranged outside the casing 4 and is coupled to the pump shaft 2 in a known manner. In other embodiments, the drive unit can be arranged inside the casing 4 .

Fig. 1a 1 shows the multi-stage pump 1 in a schematic cross-sectional view in a section along the axis A. For a better understanding, FIG Fig. 1b the multistage pump 1 in a cross section perpendicular to the axis A along the section line II-II in 1 a.

The jacket housing 4 is closed by a cover, in particular two covers. In the embodiment according to Fig. 1a the jacket housing is closed at its first axial end by a suction cover 51 and at its second axial end by a pressure cover 52. The suction cover 51 and the pressure cover 52 are each connected via a clamping arrangement 10 according to the invention, which is located in a bulge 18 is arranged, connected to the jacket housing 4. In this case, the suction cover 51 and the pressure cover 52 are supported by a projection 20, the suction cover 51 and the pressure cover 52 being secured by the clamping arrangements 10 on the jacket housing. The pump is therefore in an installed state.

The pump shaft 2 runs centrally both through the suction cover 51 and through the pressure cover 52. The jacket housing 4 is clamped between the suction cover 51 and the pressure cover 52. The jacket housing 4 is tubular and extends coaxially to the pump shaft 2 from the first axial end to the second axial end. In addition, the jacket housing 4 is designed to accommodate the multiple stages 3 so that the multiple stages 3 are enclosed by the jacket housing 2 .

Of course, the casing does not have to be closed with two covers. One axial end of the pump can also be part of the casing so that only the other axial end is closed with a cover.

The multistage pump 1 has the plurality of stages 3 including at least a first stage 31 and a last stage 33 . The plurality of stages 3 may further include one or more intermediate stage(s) 32 . All intermediate stages 32 are arranged between the first stage 31 and the last stage 33 with respect to the axis A. All stages 31, 32, 33 are arranged one behind the other in the interior 8 of the casing 4, so that the casing 4 encloses all the steps 31, 32, 33. The first stage 31 is located next to the pump inlet 7 near the suction cap 51 and receives the low pressure liquid from the pump inlet 7. The last stage 33 is located next to the outlet cap 52 and discharges the high pressure liquid through the pump outlet 6. The flow of liquid through the multistage pump 1 is measured in Fig. 1a indicated by the solid line arrows without reference number.

in the in Fig. 1a In the illustrated embodiment, the multistage pump 1 consists of three intermediate stages 32, so the multistage pump 1 has five stages 31, 32, 33. It should be understood that the number of five stages 31, 32, 33 is only an example. In other embodiments, the multi-stage pump may include fewer than five stages, eg only two stages, ie there is no intermediate stage. In still other embodiments, the multi-stage pump may include more than five stages, eg, eight stages.

Each stage 31, 32, 33 of the plurality of stages 3 consists of a stage casing 30, an impeller 34 for impinging the liquid, and a diffuser 9 configured to surround the impeller 34 and receive the impeller 34 liquid. The diffuser 9 of the last stage 33 is configured to form the stage casing 30 of the last stage 33 at the same time.

The stage casings 30 are arranged in series with respect to the A axis. The stage casing 30 of the first stage 31 rests against a stationary part 41 of the multi-stage pump 1, the stationary part 41 being stationary in relation to the shell casing 4. Each of the subsequent stage casing 30 abuts the preceding stage casing 30 in each case. The entirety of the stage housings 30 thus forms an inner pump housing, which is also referred to as a cartridge.

The stage housings 30 are fixed to one another by a large number of tie rods 42 . Each tie rod 43 extends along axis A parallel to the pump shaft 2 and through all of the stage cases 30. The tie rods 42 are tensioned by means of tensioners 43 in a manner known in the art.

All of the impellers 34 are formed as centrifugal impellers 34 having a plurality of impeller blades that redirect fluid flow from a generally axial direction to the radial direction.

All diffusers 9 are configured as radial diffusers 9 and arranged in such a way that they enclose the respective impeller 34 radially outwards. A plurality of guide passages 91 are provided after each diffuser 9 of the first stage 31 and all intermediate stages 32 to redirect the generally radial flow of fluid to the axial direction and direct the fluid from the respective diffuser 9 to the suction side of the impeller 34 of the next stage guide. Preferably, the guide channels 91 are delimited by guide vanes, which can be curved to gently deflect the fluid. The diffuser 9 of the last stage 33 is configured to direct the liquid to the pump outlet 6 .

As in Fig. 1b As can be seen, this embodiment of the multi-stage pump 1 comprises a large number of clamping arrangements 10, namely three clamping arrangements 10 per cover 5, 51, 52, each clamping arrangement 10 being arranged in a bulge 18 of the cover 5 (suction cover 51 and/or pressure cover 52). is.

These clamping arrangements 10 are arranged at a uniform distance from one another along a circumference of the cover 5 .

Figure 2a shows a schematic cross-sectional view of the clamping arrangement 10 according to the invention with a holding element 14 and a clamping bore 16 in the installed state.

The clamping arrangement 10 comprises a clamping element 11 and a clamping means 12 arranged in a bore 13 of the clamping element 11. The clamping means 12 is designed as a clamping screw 12 and the clamping element 11 is designed as a wedge-shaped clamping element 11, the first contact surface 111 being a first conical contact surface 111 and the second abutment surface 112 is a second annular abutment surface 112 .

In the installed state, the clamping screw 12 is arranged in the clamping bore 16 of the holding element 14 in such a way that the clamping element 11 can be Retaining element 14 is braced between the jacket housing 5 and the cover 4 . For this purpose, the clamping screw 12 is arranged both in the bore 13 of the clamping means 11 and in the clamping bore 16 of the holding element 14 .

The retaining element 14 also includes an additional bore 17. A retaining means 15, which is designed as a bolt 15, is arranged in the additional bore 17 in such a way that the retaining element 14 is fastened to the casing 4.

The cover 5 comprises the bulge 18 or a groove 18 in which the clamping element 11 is (at least partially) arranged.

In order to enable a better attachment of the cover 5 to the casing 4, the casing 4 comprises a projection 20, the cover 5 being arranged with its shoulder 22 on the projection 20 such that the cover 5 is supported by the projection 20 in the axial direction is. While the cap 5 is supported in the axial direction of the axis A by the projection 20, the cap is supported in a direction opposite to the axial direction by the clamp assembly 10, specifically a plurality of clamp assemblies, so that the cap 5 is supported in the axial direction and secured in the direction opposite to the axial direction (so it is in the installed state).

When attaching the clamping arrangement 10 to the pump 1 (i.e. when transferring to the installed state), the clamping arrangement 10 with the holding element 14, with the clamping screw 12 already being arranged in the bore 13 and clamping bore 16, is brought up to the cover 5 and the jacket housing 4 . In doing so, the clamping element 11 is inserted into the bulge 18 . Then the bolt 15 is inserted through the additional bore 17 into the casing 4 in order to fasten the holding element 14 . Then the clamping element 11 is clamped by rotating the clamping screw 12 in the bore 13 . The bore 13 includes a thread corresponding to the clamping screw 12 (not shown), so that the Clamping screw 12 rotates in the bore 13 about a bracing axis X. Here, the clamping element 11 moves in the direction of the holding element 14 so that the clamping element 11 is clamped by interaction with the clamping screw 14 via the holding element 14 between the cover 5 and the casing 4 .

In the installed state, a clamping force is therefore exerted by the casing 4 on the retaining element 14 via the first contact surface 111 to the second contact surface 112 on the cover 5 (or from the cover 5 via the second contact surface 112 to the first contact surface 111 via the retaining element 14 on the casing 4 ).

Figure 2b shows a schematic cross-sectional view of an embodiment of the clamping arrangement 10 according to the invention in the installed state.

The structure is basically analogous to the structure according to the embodiment Figure 2a , However, the clamping arrangement 10 comprises only the clamping element 11 and the clamping means 12, which is designed as a clamping screw 12.

When attaching the clamping arrangement 10 to the pump 1 (ie when transferring to the installed state), the clamping arrangement 10 is brought up to the cover 5 and the jacket housing 4 . In doing so, the clamping element 11 is inserted into the bulge 18 . For this purpose, the bulge 18 can comprise a "larger part" in order to be able to insert the clamping element 11 and a smaller part for fastening, so that the bulge 18 and the clamping element 11 work together like a bayonet lock.

Then the clamping element 11 is clamped by rotating the clamping screw 12 in the bore 13 . The bore 13 includes a thread (not shown) that corresponds to the clamping screw 12 , so that the clamping screw 12 rotates about the clamping axis X in the bore 13 . Here, the clamping element 11 moves along the clamping axis X in the direction of the screw head 120 of the clamping screw 12, so that the Clamping element 11 is clamped by interacting with the clamping screw 12 between the cover 5 and the jacket housing 4 , in that the end of the clamping screw 12 opposite the screw head 120 is supported on a surface of the cover 5 .

In the installed state, the clamping force is therefore exerted from the casing 4 via the first contact surface 111 to the second contact surface 112 on the cover 5 (or from the cover 5 via the second contact surface 112 to the first contact surface 111 on the casing 4).

Figure 2c shows a schematic cross-sectional view of a clamping arrangement 10 according to the invention in the installed state with the holding element 14.

The structure is basically analogous to the structure according to the embodiment Figure 2a , However, the holding element 14 does not include a clamping bore for the clamping element 11. The clamping means 12 is also designed as a clamping screw 12.

When attaching the clamping arrangement 10 to the pump 1 (that is, when converting it to the installed state), the clamping element 11 with the clamping screw 12 is inserted into the bulge 18 . The holding element 14 is then brought to the corresponding point of the jacket housing 4 . Then the bolt 15 is inserted through the additional bore 17 into the casing 4 in order to fasten the holding element 14 . The clamping means 11 is clamped by rotating the clamping screw 12 in the bore 13 . The bore 13 includes the thread (not shown) that corresponds to the clamping screw 12 , so that the clamping screw 12 rotates in the bore 13 about the clamping axis X. Here, the clamping element 11 moves in the direction of the screw head 120, so that the clamping element 11 is clamped by interaction with the clamping screw 14 between the cover 5 and the jacket housing 4, in that the end of the clamping screw 12 opposite the screw head 120 is supported on a surface of the cover 5.

In the installed state, the clamping force is therefore exerted by the casing 4 on the retaining element 14 via the first contact surface 111 to the second contact surface 112 on the cover 5 (or from the cover 5 via the second contact surface 112 to the first contact surface 111 via the retaining element 14 on the casing 4 ).

Figure 3a shows a schematic three-dimensional view of a clamping arrangement 10 according to the invention with a holding element 14 and a clamping bore 16. Figure 3b shows a further schematic three-dimensional view of the clamping arrangement 10 according to the invention Figure 3a .

The clamping arrangement 10 is designed as a ring part segment 10 . The clamping element 11 is designed as an annular wedge 11 (wedge-shaped clamping elements 11 adapted to a round shape of the cover) and the clamping screw 12 is guided through the bore 13 of the annular wedge 11 . The first conical contact surface 111 rests on the holding element 14, while the second annular contact surface 112 is arranged on the cover (not shown) in the installed state.

This configuration is particularly preferred when a plurality of clamping assemblies 10 are used.

Figure 4a shows a schematic cross-sectional view of a detail of an embodiment according to the invention of a multi-stage pump 1 in a section along the axis A. Figure 4a shows a schematic cross-sectional view of a partial section of FIG Figure 4a .

The clamping arrangement 10 has a structure analogous to that of the clamping arrangement according to FIG Figure 2a on.

In order to enable better attachment of the cover 5 to the casing 4, the casing 4 also includes the projection 20 here, with the cover 5 having the shoulder 22 on the projection 20 is arranged that the lid 5 is supported by the projection 20 in the axial direction. While the lid 5 is supported in the axial direction of the axis A by the projection 20, the lid is supported in the direction opposite to the axial direction by the clamp assembly 10, specifically a plurality of clamp assemblies, so that the lid 5 is supported in the axial direction and the direction opposite to the axial direction is secured. In addition, the cover 5 is additionally fastened with a plurality of bolts 21 to a cartridge 60 of the pump (in particular to a suction housing of the cartridge 60).

The clamping arrangement 10 acts as a thrust transmission device which, in the event of a fault (of the pump), transmits the upward hydraulic axial thrust F (hydraulic axial thrust which, in the event of a fault, pulls the cover 5 in the direction of the interior 8) from the cover 5 to the jacket housing 4. Here, the force is transmitted along the arrow F through the tensioning element 11.

Due to the arrangement according to the invention, it can be avoided that (operating) loads are no longer transmitted via screw connections, but rather via the clamping element 11, which is preferably clamped in a non-positive and positive manner.

The clamping means 12 is only loaded with a small proportion of the forces and moments to be transmitted. In contrast to the prior art, the clamping means 12 is therefore not the main stressed component. The clamping means 12 fixes the clamping element 11 (after a clamping process) in its position (in the installed state between the cover and the casing). In comparison to the prior art, the clamping means 11 and all other screws, bolts or other fastening means used for the cover can thus be made significantly smaller (shorter and/or smaller diameter fastening means).

Claims (15)

Pump for conveying a fluid, comprising a casing (4) and a pump shaft (2) arranged in the interior of the casing (4) and rotatable about an axis (A) with an impeller (34) arranged non-rotatably on the pump shaft (2) for action to the fluid, the pump (1) further having a pump inlet (7) for supplying the fluid to the interior (8) and a pump outlet (6) for discharging the fluid from the interior (8), wherein one end of the jacket housing ( 4) is closed with a cover (5, 51, 52), and the pump (1) comprises a clamping arrangement (10) for securing the cover (5, 51, 52) on the casing (4), the clamping arrangement (10 ) comprises a clamping element (11) and a clamping means (12) which can be arranged in a bore (13) of the clamping element (11), the clamping element (11) comprising a first contact surface (111) and a second contact surface (112),
characterized in that
the clamping means (12) is arranged so that it can be moved relative to the clamping element (11) along a clamping axis (X) in such a way that the clamping element (11), through interaction with the clamping means (12), when the cover (5, 51, 52) is in the installed state the jacket housing (4) and the cover (5, 51, 52) is clamped, wherein in the installed state a clamping force is transmitted from the jacket housing (4) via the first contact surface (111) to the second contact surface (112) on the cover (5, 51, 52) is exerted so that the cover (5, 51, 52) is secured in the installed state by the clamping force on the casing (4). Pump according to claim 1, wherein the clamping arrangement (10) comprises a holding element (14) which is arranged in the installed state between the clamping element (11) and the jacket housing (4) that the clamping force in the installed state of the Jacket housing (4) is exerted on the holding element (14) on the first contact surface (111). Pump according to Claim 1, in which the clamping arrangement (10) comprises a holding element (14) which, when installed, is arranged between the clamping element (11) and the cover (5, 51, 52) in such a way that the clamping force can be transferred from the holding element (14 ) is exerted on the cover (5, 51, 52) via the second contact surface (112). Pump according to claim 2 or 3, wherein the holding element (14) comprises a clamping bore (16) and the clamping means (12) is arranged in the clamping bore (16) in the installed state in such a way that the clamping element (12) via the holding element (14) between the jacket housing (4) and the cover (5, 51, 52) is braced. Pump according to claim 2, 3 or 4, wherein the holding element (14) comprises an additional bore (17) and in the installed state a holding means (15) of such a type in the additional bore (17) and a corresponding receptacle on the casing (4) or the cover ( 5, 51, 52) is arranged such that the holding element (14) is attached to the jacket housing (4) or the cover (5, 51, 52). Pump according to one of the preceding claims, wherein the clamping element (11) is a wedge-shaped clamping element (11) and the first abutment surface (111) is a first conical abutment surface (111) and the second abutment surface (112) is a second annular abutment surface (112). . Pump according to one of the preceding claims, wherein the casing (4) or the cover (5, 51, 52) comprises a bulge (18) in which the clamping arrangement (10) in the installed state between the casing (4) and the cover (5 , 51, 52) is tight. Pump according to one of the preceding claims, wherein the jacket housing (4) comprises a projection (20) and the cover is arranged on a projection (20) such that the cover (5, 51, 52) by the projection (20) in a is supported in the axial direction. Pump according to Claim 8, in which the cover (5, 51, 52) is arranged with a shoulder (22) on the projection (20) of the casing (4). A pump as claimed in any one of the preceding claims including a plurality of clamping assemblies (10). Pump according to claims 7 and 10, wherein the bulge (18) is designed as a circumferential groove (18) in which the clamping arrangements (10) are clamped in the installed state between the casing (4) and the cover (5, 51, 52). . Pump according to 10 or 11, the clamping arrangements (10) being arranged at a uniform distance from one another along a circumference of the cover (5, 51, 52) in the installed state. Pump according to one of the preceding claims, in which the clamping means (12) is a clamping screw (12) and the bore (13) comprises a thread which corresponds to the clamping screw (12), so that the clamping screw (12) can be rotated in the bore (13) is arranged to be movable about the bracing axis (X) along the bracing axis (X) in such a way that the clamping element (11) is held between the casing (4) and the Cover (5, 51, 52) is braced. A pump according to claim 5, wherein the retaining means (15) is a screw (15) or a bolt. Pump according to one of the preceding claims, configured as a multi-stage pump (1) comprising a plurality of stages (3) arranged in series with respect to the axis (A), the plurality of stages (3) including at least a first stage (31 ) and a final stage (33), each stage (3) having a stage casing (30) and an impeller (34) for acting on the fluid, each impeller (34) being non-rotatably mounted on the pump shaft (2).

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