Centrifugal pump casing
The introduction of domes on centrifugal pump housings provides a standardized interface for secure support, allowing multiple designs to be produced on a single line, addressing the issue of multiple workpiece carriers and assembly instability.
Patent Information
- Authority / Receiving Office
- EP · EP
- Patent Type
- Applications
- Current Assignee / Owner
- WILO SE
- Filing Date
- 2025-11-25
- Publication Date
- 2026-06-24
AI Technical Summary
The current manufacturing process for centrifugal pumps is hindered by the need for multiple workpiece carriers due to varying pump designs, leading to increased setup times and costs, as well as instability during assembly.
Centrifugal pump housings with three domes on their outer side, providing defined force-bearing points that allow for standardized support on a single workpiece carrier, ensuring secure positioning and force absorption across different series, sizes, and designs.
Enables the production of various centrifugal pump designs on a single production line without changeovers, improving assembly stability and reducing setup times and costs.
Smart Images
Figure IMGAF001_ABST
Abstract
Description
[0001] The invention relates to a centrifugal pump housing of an inline centrifugal pump comprising a first housing part enclosing a suction channel, to which a first connection nozzle with a suction opening leading into the suction channel is integrally formed, a second housing part at least partially enclosing a spiral pump chamber for receiving an impeller, and a third housing part enclosing a pressure channel, to which a second connection nozzle with a pressure opening leading out of the pressure channel is integrally formed, wherein the first housing part is shaped such that the suction channel opens coaxially to the axis of rotation of the impeller into the pump chamber, and the second housing part carries a suction mouth or suction neck seal surrounding the opening of the suction channel into the pump chamber for sealing the impeller, the second housing part transitions into the third housing part such that the pump chamber transitions tangentially into the suction channel, and the third housing part is shaped such thatthat the pressure opening is coaxial with the suction opening on an inline axis, and wherein the first, second and third housing parts merge seamlessly into one another.
[0002] Centrifugal pump units of the type described are well known. They are predominantly used with electrically driven centrifugal pumps for liquids and are designed for installation within a pipeline, such that the hydraulic-mechanical connections between the centrifugal pump and the pipeline lie on an axis that coincides with the axis of the pipeline. This is colloquially referred to as "inline," and a corresponding centrifugal pump is called an "inline centrifugal pump." In this description, said axis will be referred to as the "inline axis."
[0003] Inline centrifugal pumps are used in a wide variety of applications, such as heating, cooling, and air conditioning (HVAC) systems, for drinking water or process water circulation, in pressure boosting systems, and for pumping chemical liquids. To accommodate these diverse applications and varying pipe diameters and connections, inline centrifugal pumps are available in different performance classes and with pump housings in a wide range of sizes, designs (especially regarding connection nozzles), and materials. The connection nozzles can be, for example, threaded nozzles that are tightened to the pipe with a union nut.It is also common to use connection fittings in the form of radial flanges, which are screwed to counter flanges on the pipeline via several threaded screws arranged in a circle.
[0004] The material of the pump housing is usually selected depending on the pumped medium. Typically, a metal is used, such as brass or a brass alloy (red brass) or stainless steel (precision stainless steel casting), although cast iron (gray cast iron) is used for most applications. Metal pump housings are usually cast. However, it is also possible to manufacture pump housings layer by layer using a 3D printing process, for example, selective laser sintering (SLS). It is also known to produce pump housings from plastic using injection molding.
[0005] The foregoing illustrates that, as a result of combining various criteria and possibilities, particularly the desired pump performance, the pump casing material, the pipe connections, the impeller size and design, and the manufacturing process, a pump manufacturer often produces several hundred different pump casings within the same pump series or at least across multiple pump series, and processes them on one or more production lines. Among other things, the suction neck or suction inlet seal is installed in the pump casing, and possibly also an axial bearing for the impeller. Both are positively engaged by pressing them into a corresponding receptacle for the suction neck or suction inlet seal or for the axial bearing within the pump chamber.
[0006] For this assembly process, the centrifugal pump housing is placed in a workpiece carrier with the pump chamber open at the top, i.e., with a horizontal inline axis, and held by the carrier in such a way that the suction channel opening is accessible. During the pressing process, the pump housing is pressed against the workpiece carrier, which absorbs the force. Later in the production line, the electric motor is mounted to the centrifugal pump housing. The electric motor has an approximately square motor flange, which is placed onto a corresponding mounting flange on the pump housing so that their bores align. The weight of the electric motor, possibly including an electronic module already mounted on it, thus rests on the pump housing during motor assembly.Alternatively, the electronic module, containing the electronics for controlling the electric motor or centrifugal pump, is mounted to the motor housing after the motor has been installed. For many centrifugal pump models, this is done on an axial end face of the electric motor. It should be noted that some electronic modules protrude laterally beyond the motor housing, which shifts the center of gravity of the entire assembly. For all assembly operations, the centrifugal pump housing must be held securely and without tilting in the respective workpiece carrier.
[0007] Currently, there are many different workpiece carrier systems. The various series, sizes, and designs necessitate a multitude of different workpiece carriers, as these must be adapted to the size and design of the centrifugal pump housing to ensure the required positional stability and resistance to tipping. This results in frequent changeovers on the production line and incompatibility between the production systems. Consequently, there are additional time and costs associated with setup times and line equipment.
[0008] It is therefore an object of the present invention to provide centrifugal pump housings for a wide variety of centrifugal pump designs, which simplifies the manufacturing process of the centrifugal pumps containing the centrifugal pump housings, in particular reduces the time and physical effort required to equip the corresponding production line in preparation for connecting a centrifugal pump housing with the other components of the centrifugal pump, and at the same time ensures simple and safe assembly of the centrifugal pump.
[0009] This problem is solved by centrifugal pump housings with the features of claim 1. Advantageous further developments are specified in the dependent claims and are explained below.
[0010] According to the invention, a centrifugal pump housing of the type mentioned in the introduction is further developed by having three domes molded onto the outer side of the centrifugal pump housing facing away from the pump chamber, which rise parallel to the axis of rotation of the impeller, have an outer contour which is intended to be at least partially encompassed by a corresponding dome receptacle of a tool carrier, and have a flat end face forming a support surface for force absorption, wherein the support surfaces of all three domes are parallel to each other and form vertices of a triangle which encloses the impeller axis.
[0011] The core idea of the invention is therefore to provide defined force-bearing points or surfaces on the pump housing, with which the centrifugal pump housing is supported on the workpiece carrier of the production line, across different series, sizes, and designs, so that centrifugal pump housings of various series, sizes, and designs can be held in the same workpiece carriers. The invention therefore also relates to a group comprising at least one first and one second centrifugal pump housing according to the invention, which differ in design.
[0012] The force-bearing points are provided by the end faces of the domes, which form protrusions on the pump housing. Together, the domes create a mechanical interface to the workpiece carrier, providing a standardized interface for use with pump housings of different series, sizes, and designs. This allows for the use of the same interface for different pump housing sizes, variants, and configurations. This interface enables the orientation of the pump housing and the absorption of forces during the machining process along the production line. The domes ensure the secure positioning of the pump housing during manufacturing in all coordinate directions, including rotation. The support surfaces of the domes are designed to reliably absorb the forces and torques occurring during the process.This interface is used for the complete assembly of the centrifugal pump. This allows a large number of centrifugal pump and pump housing variants to be produced on a single production line without any changeover procedures.
[0013] The distinction between the first and second centrifugal pump housing can lie in at least one of the following characteristics: the material from which they are manufactured, in particular cast, the shape and / or size of the first and / or second connection nozzle, the shape and / or size of the first, second or third housing part, the distance between the first and second connection nozzle, the diameter and / or arrangement of the suction mouth or suction neck seal, wherein at least the support surfaces and outer contour of the domes of the first centrifugal pump housing are identical to those of the second centrifugal pump housing in terms of their size, shape and position relative to each other.
[0014] Preferably, the first dome of the three domes rises on the left side and the second dome of the three domes on the right side of the first housing section, where "left side" and "right side" refer to the inline axis. This ensures that the force-bearing points, or support surfaces, are located as far as possible from the center of the pump housing and the motor axis, and that the triangle formed by the domes is as large as possible. In this context, the center of the pump housing is defined as any geometric locus of the intersection of the pump housing's surface with an axial plane encompassing the inline axis and the impeller axis.
[0015] Preferably, a third dome of the three domes rises in the area between the first housing part and the second connection nozzle. Here too, this intermediate area is meant in relation to the inline axis. The triangle spanned by the domes thus has a maximum size and further ensures that both the center of gravity of the centrifugal pump housing, considered on its own, and the center of gravity of the subsequent assembly stages in the manufacturing process, in which the pump housing is mechanically connected (only) to an electric motor or to an electric motor and an electronic module for regulating and / or controlling the electric motor or the centrifugal pump, are optimally positioned.is located within the triangle, so that the pump housing cannot tilt to one side when pressing in the suction neck or suction mouth seal, when mounting the electric motor on the pump housing, or when mounting the electronic module on the axial end face of the motor housing of the electronic module.
[0016] In one design variant, the first and second domes can be positioned at the same height relative to the inline axis. In other words, the first and second domes are then symmetrically aligned with the center of the pump housing in a common horizontal plane that is parallel to the impeller axis and perpendicular to the inline axis. Such an arrangement is advantageous because the first housing section is also symmetrical. The symmetrical arrangement of the first and second domes improves the aesthetics.
[0017] Furthermore, it is advantageous if the support surfaces of the three domes lie in a common radial plane that runs perpendicular to the impeller axis. In other words, the three domes terminate flush with each other. On the one hand, this simplifies the manufacturing of the workpiece carrier because the dome mounts can all be the same height and therefore do not need to be differentiated. Additionally, the radial plane can serve as a measuring or reference plane for measuring the pump housing and checking compliance with tolerances. Alternatively, the domes can have different heights; in particular, one or two domes can be lower than the others, so that the end face(s) of these lower domes are closer to the outer contour of the pump housing. This saves material and creates more clearance around the pump housing.
[0018] The outer contour of the domes, facing away from the inline axis, can be rounded, i.e., free of corners. This is advantageous for casting with expendable cores. In cross-section, the outer contour can, for example, form a circular or elliptical segment. This simplifies the insertion of the pump housing into the workpiece carrier or its dome receptacles.
[0019] Advantageously, the cross-section of the domes can increase from the support surface towards their base located on the second housing part, for example, linearly or quadratically. In particular, the domes can be conical or stump-shaped, at least in sections. In other words, the cross-section of the domes widens towards the base or the second housing part, and narrows in the opposite direction. This results in good static force transmission while simultaneously reducing the amount of material required for the domes compared to a constant cross-section. Furthermore, this achieves self-centering of the domes in the dome receptacles, as the domes essentially slide into the receptacles on their own, initially with some play, but ultimately in a stable, positive fit.
[0020] It is particularly advantageous if the support surface of the third dome lies beyond an axial plane encompassing the impeller axis and the inline axis. Thus, the support surface of the third dome is not located in the center of the pump housing. This is beneficial when the pump housing is manufactured by casting using two half-shells whose parting line lies in the center of the pump housing being produced. This results in a casting-related burr along the center of the pump housing's outer contour, which would also be present on the support surface of the third dome. By shifting the support surface of the third dome to the right or left side of the inline axis, this unevenness on the support surface of the third dome is prevented.
[0021] It is also advantageous if the support surface of the third dome lies on the same side of the axial plane or pump housing as the tangential transition from the pump chamber to the pressure channel, where this transition results in an additional amount of material. Simply put, the third housing section rests predominantly on the pump housing half with the tangential transition, making the weight of this half greater than the weight of the other half. Consequently, the center of gravity of the pump housing is also shifted from the center to the half with the tangential transition. Positioning the support surface of the third dome on precisely this half of the pump housing ensures that the center of gravity lies as far inward as possible within the triangle formed by the domes.
[0022] In one design variant, the third dome can seamlessly transition into a rib extending from the second connection nozzle to the first housing section. This mechanically stabilizes the third dome and gives it an overall elongated shape. Such a rib serves both to reinforce the housing statically and to ensure good material distribution during casting, as the cavity forming the rib facilitates the distribution of the casting material. The rib can lie in the axial plane encompassing the inline axle and the impeller axle. Furthermore, the rib can be used as an information carrier by incorporating numbers and letters into it or by applying a label. The off-center positioning of the third dome's support surface in this case also has the advantage that one of the rib's side surfaces remains unobstructed, i.e., unaffected by the presence of the third dome.
[0023] Ideally, the third dome transitions seamlessly into the rib without any undercut. In other words, the dimensions of the third dome are such that its height and width do not decrease as it approaches the rib. This means that, in the direction of demolding of the mold half-shell forming the third dome, there is no volume between the third dome and the rib that would need to be filled by a further mold, as this would complicate the casting process for the pump housing.
[0024] Corresponding to the third dome, the first and second domes can additionally or alternatively be integrally integrated into the first housing part. This mechanically stabilizes the first and second domes against the first housing part and gives them an overall elongated shape. Here, too, the integral transition into the first housing part can be designed to be free of any undercut. In other words, the dimensions of the first and second domes are such that they do not decrease in height or width towards the first housing part. This means that, in the direction of demolding of the first half-shell of the mold forming the first dome and in the direction of demolding of the second half-shell of the mold forming the second dome, there is no volume between the first dome and the first housing part, or between the second dome and the first housing part, that would require further molding.In the case of casting the pump housing, demolding the mold, or rather the half-shells, is thus simplified.
[0025] It can also be provided that the first and second domes widen towards the first housing part, which also simplifies the demolding of the mold or the half-shells. Likewise, the third dome can widen towards the rib.
[0026] As mentioned previously, the centrifugal pump housing is ideally manufactured by casting. Suitable casting materials include gray cast iron, red brass, or stainless steel investment casting. However, the centrifugal pump housing can also be manufactured layer by layer using a 3D printing process from metal or plastic, or injection molded from plastic.
[0027] The invention further relates to a centrifugal pump assembly comprising a centrifugal pump housing according to the invention. The centrifugal pump assembly is preferably a wet rotor pump, ideally for use as a heating, coolant, or drinking water pump.
[0028] Further features, advantages, and properties of the invention are explained in more detail below with reference to exemplary embodiments and the accompanying figures. In the figures, identical reference numerals or symbols denote identical or at least functionally equivalent components, parts, areas, or directions.
[0029] It should be noted that, within the context of this description, the terms "exhibit," "comprise," or "include" in no way exclude the presence of other characteristics. Furthermore, the use of the indefinite article for an object does not preclude its plural form.
[0030] Features of one embodiment of the invention may also be present in another embodiment, unless this is technically impossible. Furthermore, described process features may be present in one of the devices described herein, and described device features may be present in the method described herein.
[0031] They show: Fig. 1a and 1b : a group of four centrifugal pump housings with a uniform mechanical interface according to the invention for their integration into a workpiece carrier of a production line Fig. 2 : the third centrifugal pump housing with a triangle drawn on it. Fig. 3 : schematic representation of two centrifugal pumps according to the invention in mounting position on identical workpiece carriers
[0032] Figure 1a and 1bThe drawings, distributed across two sheets, show four centrifugal pump housings 1a, 1b, 1c, 1d of inline centrifugal pumps 100, each with a different design. They differ in their size and in the type of their hydraulic connections 3, 7. The first, third, and fourth centrifugal pump housings 1a, 1c, 1d have flanged connections, while the second centrifugal pump housing 1b has threaded connections. The centrifugal pump housings 1a, 1b, 1c, 1d are each shown from the front, looking towards the pump or impeller axis 20, so that an electric motor 23 driving the centrifugal pump 100 is located on the non-visible rear side of each centrifugal pump housing 1. The centrifugal pump housings 1a, 1b, 1c, 1d are collectively referenced by the reference numeral 1.
[0033] The centrifugal pump housings 1 have in common that they comprise a first housing part 2 enclosing a suction channel, to which a first connection nozzle 3 with a suction opening 4 leading into the suction channel is integrally formed; a second housing part 5 at least partially enclosing a spiral-shaped pump chamber for receiving an impeller 17; and a third housing part 6 enclosing a pressure channel, to which a second connection nozzle 7 with a pressure opening 8 leading out of the pressure channel is integrally formed, wherein the first, second, and third housing parts 2, 5, 6 are integrally joined to one another. The first housing part 2 is shaped such that the suction channel opens into the pump chamber coaxially with the axis of rotation 20 of the impeller 17, and the second housing part 5 carries a suction mouth or suction neck seal 18 surrounding the opening of the suction channel into the pump chamber for sealing the impeller 17.The second housing part 5 transitions into the third housing part 6 in such a way that the pump chamber merges tangentially into the suction channel. The third housing part 6 is shaped such that the pressure port 8 lies coaxially with the suction port on an inline axis 10, allowing the centrifugal pump housings 1 to be mounted in a pipeline. The second housing part 5 has a mounting flange 9 to which a motor flange 25 of the electric motor 23 is mounted by means of screws 26.
[0034] Furthermore, the centrifugal pump units 1 have three domes 11, 12, 13 molded onto the outer surface of the centrifugal pump housing 1, facing away from the pump chamber, which rise parallel to the axis of rotation 20 of the impeller. They have an outer contour 15 designed to be at least partially encompassed by a corresponding dome receptacle 22 of a workpiece carrier 19 on the production line 21. The domes 11, 12, 13 also have a flat end face forming a support surface 14 for force absorption, with the support surfaces 14 of all three domes 11, 12, 13 being parallel to each other. The centrifugal pump housings 1 are intended to be positioned in or on the workpiece carrier 19 with the support surfaces 14 of the domes 11, 12, 13, such that the centrifugal pump housings 1 are supported on the workpiece carrier 19 by the support surfaces 14. This is in Figure 3The impeller axis 20 is shown vertically in this case. The domes 11, 12, 13 form – figuratively speaking – the feet of the centrifugal pump housing 1. Together, the domes 11, 12, 13 form a uniform mechanical interface to the workpiece carrier 19, so that the four centrifugal pump housings 1a, 1b, 1c, 1d can alternatively be accommodated in the same workpiece carrier 19 and transported along the production line 21. Figure 3 Figure 1 shows two identical workpiece carriers 19 on the production line 21, with the left workpiece carrier 19 holding a centrifugal pump 100 with a pump housing 1b according to the second variant in Figure 1. Fig. 1a The right workpiece carrier 19 carries a centrifugal pump 100 with a pump housing 1c according to the third variant in Fig. 1a carries.
[0035] How Figure 2As illustrated, the support surfaces 14 of the three domes 11, 12, 13 form the vertices of a triangle that encloses the impeller axis 20. This triangle is chosen, based on the dome positions, to also encompass the center of gravity of each of the centrifugal pump housings 1a, 1b, 1c, 1d, both without a mounted electric motor 23 and with a mounted electric motor 23, as well as with a mounted electric motor 23 and an electronics housing 24. Although the center of gravity of the overall assembly shifts during the assembly of these components 23, 24 of the centrifugal pump 100 along the production line 21, it remains within the triangle. Thus, in each of the four configurations, the centrifugal pump housing 1 is held securely and without tilting in the workpiece carrier 19 during the assembly of the suction inlet or suction neck seal 18 and the aforementioned components 23, 24.Different workpiece carriers, which are individually adapted to the respective centrifugal pump housing 1a, 1b, 1c, 1d, can therefore be dispensed with, so that the production line 21 does not have to be retooled for the assembly of the different versions, i.e. it does not have to be equipped with individual workpiece carriers.
[0036] The standardized interface is such that a first dome 11 rises to the left and a second dome 12 to the right of the first housing part 2, extending from the second housing part 5. The terms "right" and "left" refer to the inline axis 10, or to an axial plane encompassing this inline axis 10 and the impeller axis 20, which divides the respective centrifugal pump housing 1a, 1b, 1c, 1d into a right and left housing half and defines its center. A third dome 13 rises from the third housing part 6 in the area between the first housing part 2 and the second connection port 7.
[0037] The first and second domes 11, 12 are at the same height relative to the inline axis 10. This height is marked by a dashed reference line BB, which connects all four centrifugal pump housings 1a, 1b, 1c, 1d. The third dome 13, in contrast, is located higher on the inline axis 10. In the Figure 1a and 1b A dashed reference line AA is drawn, connecting the third dome 13 of all centrifugal pump housings 1a, 1b, 1c, 1d.
[0038] The support surfaces 14 of the three domes 11, 12, 13 are shown hatched in the figures. They lie in a common radial plane that is perpendicular to the impeller axis 20 and parallel to the inline axis 10. The outer contour 15 of the domes 11, 12, 13, facing away from the inline axis 10, is rounded and, viewed in cross-section, forms a segment of a circle, more precisely a semicircle.
[0039] The support surface 14 of the third dome 13 is located off-center, i.e., beyond the axial plane encompassing the impeller axis 20 and the inline axis 10, and on the same side as the tangential transition of the pump chamber to the pressure channel. The tangential transition is recognizable by the lateral bulge of the second housing part, which is caused by the spiral shape of the pump chamber.
[0040] The centrifugal pump housings 1a, 1b, 1c, 1d also feature a rib 16 extending from the second connection port 7 to the first housing part 2, lying within the axial plane encompassing the inline axis 10 and the impeller axis 20. In the second, third, and fourth variants of the centrifugal pump housings 1b, 1c, 1d, this rib 16 extends all the way to the first housing part 2 and terminates on it. The third dome 13 merges seamlessly into the rib 16 without any loss of width or height. This ensures undercut-free demolding in the case of a cast centrifugal pump housing 1. Since the rib 16 is only connected to the third dome 13 on one side, its surface facing away from the third dome 13 can be used as a carrier for lettering, markings, or pump-specific information.
[0041] The first and second domes 11, 12 have an elongated cross-section radial to the impeller axis 20 and extend along the reference line BB to the first housing part 2, into which they merge seamlessly, widening slightly, without losing any width or height. Thus, demolding of a cast centrifugal pump housing 1 is also guaranteed without undercuts, with the demolding direction in this case being perpendicular to the aforementioned axial plane.
[0042] Together they form the in Figure 1a and 1bThe centrifugal pump housings 1a, 1b, 1c, 1d shown constitute a group comprising at least one first centrifugal pump housing 1a, 1b and one second centrifugal pump housing 1c, 1d, which differ structurally, namely in the shape and size of the first and second connection ports 3, 7, in the shape and size of the first, second and third housing parts 2, 5, 6, and in the distance between the first and second connection ports 3, 7. In contrast, the support surfaces 14 and the outer contour 15 of the domes 11, 12, 13 are identical in all centrifugal pump housings 1 shown with regard to their size, shape and position relative to each other. This ensures that identical workpiece carriers 19 can be used for centrifugal pump housings 1 with different designs, so that the production line 21 does not have to be retooled, i.e., equipped with different workpiece carriers 19, for the production of a different variant of the centrifugal pump housing 1.
[0043] It should be noted that the foregoing description is given merely as an example for illustrative purposes and in no way limits the scope of protection of the invention. Features of the invention that are indicated as "may," "exemplary," "preferred," "optional," "ideal," "advantageous," "if applicable," or "suitable" are to be considered purely optional and likewise do not limit the scope of protection, which is defined exclusively by the claims. Insofar as the foregoing description mentions elements, components, process steps, values, or information that have known, obvious, or foreseeable equivalents, these equivalents are also encompassed by the invention.Likewise, the invention includes any changes, alterations or modifications of embodiments which involve the replacement, addition, modification or omission of elements, components, process steps, values or information, as long as the basic idea of the invention is retained, regardless of whether the change, alteration or modification leads to an improvement or deterioration of an embodiment.
[0044] Although the foregoing description of the invention mentions a multitude of physical, intangible, or process-related features relating to one or more specific embodiments, these features can also be used in isolation from the specific embodiment, at least insofar as they do not necessarily require the presence of further features. Conversely, these features mentioned in relation to one or more specific embodiments can be combined arbitrarily with one another and with further disclosed or undisclosed features of illustrated or unillustrated embodiments, at least insofar as the features do not mutually exclude each other or lead to technical incompatibilities. Reference symbol list
[0045] 1 Centrifugal pump housing 1a-1d Different centrifugal pump housings 2 First housing part 3 First connection nozzle 4 Suction opening 5 Second housing part 6 Third housing part 7 Second connection nozzle 8 Discharge opening 9 Mounting flange 10 Inline shaft 11 First dome 12 Second dome 13 Third dome 14 Support surfaces 15 Outer contour 16 Rib 17 Impeller 18 Suction inlet or neck seal 19 Workpiece carrier 20 Impeller shaft 21 Production line 22 Dome mount 23 Electric motor 24 Electronics housing 25 Mounting flange 26 Screws 100 Centrifugal pump
Claims
1. Centrifugal pump housing (1) of an inline centrifugal pump (100) comprising: - a first housing part (2) enclosing a suction channel, to which a first connection nozzle (3) with a suction opening (4) leading into the suction channel is integrally formed; - a second housing part (5) at least partially enclosing a spiral pump chamber for receiving an impeller (17); and - a third housing part (6) enclosing a pressure channel, to which a second connection nozzle (7) with a pressure opening (8) leading out of the pressure channel is integrally formed, wherein the first housing part (2) is shaped such that the suction channel opens coaxially to the axis of rotation (20) of the impeller (17) into the pump chamber, and the second housing part (5) carries a suction mouth or suction neck seal (18) surrounding the opening of the suction channel into the pump chamber for sealing the impeller (17), the second housing part (5) being integrated into the third housing part (6) in such a way as to transitionsthat the pump chamber transitions tangentially into the suction channel, and the third housing part (6) is shaped such that the pressure opening (8) lies coaxially to the suction opening on an inline axis (10), and wherein the first, second and third housing parts (2, 5, 6) merge seamlessly into one another, , characterized by three domes (11, 12, 13) formed on the outer side of the centrifugal pump housing (1) facing away from the pump chamber, which rise parallel to the axis of rotation (20) of the impeller, have an outer contour (15) which is intended to be at least partially encompassed by a corresponding dome receptacle (22) of a workpiece carrier (19), and have a flat end face forming a support surface (14) for force absorption, wherein the support surfaces (14) of all three domes (11, 12, 13) are parallel to each other and form vertices of a triangle that encloses the impeller axis (20).
2. Centrifugal pump housing (1) according to claim 1, characterized by the fact thatwith reference to the inline axis (10), a first dome (11) of the three domes (11, 12, 13) rises on the left and a second dome (12) of the three domes (11, 12, 13) rises on the right side of the first housing part (2).
3. Centrifugal pump housing (1) according to claim 1 or 2, characterized by the fact that When viewed along the inline axis (10), a third dome (13) of the three domes (11, 12, 13) rises in the area between the first housing part (2) and the second connection nozzle (7).
4. Centrifugal pump housing (1) according to claim 2, characterized by the fact that the first and second domes (11, 12), with respect to the inline axis (10), are at the same height.
5. Centrifugal pump housing (1) according to one of the preceding claims, characterized by the fact that the support surfaces (14) of the three domes (11, 12, 13) lie in a common radial plane that runs perpendicular to the wheel axis (20).
6. Centrifugal pump housing (1) according to one of the preceding claims, characterized by the fact thatthe outer contour (15) of the domes (11, 12, 13) facing away from the inline axis (20) is rounded, in particular forming a circular or elliptical segment when viewed in cross-section.
7. Centrifugal pump housing (1) according to one of the preceding claims, characterized by the fact that the cross-section of the domes (11, 12, 13) increases from the support surface (14) towards their base, in particular that the domes (11, 12, 13) are at least partially conical.
8. Centrifugal pump housing (1) at least according to claim 3, characterized by the fact that the support surface (14) of the third dome (13) lies beyond an axial plane encompassing the wheel axle (20) and the inline axle (10).
9. Centrifugal pump housing (1) at least according to claim 8, characterized by the fact that the support surface (14) of the third dome (13) lies on the same side of the axial plane as the tangential transition of the pump chamber to the pressure channel.
10. Centrifugal pump housing (1) at least according to claim 3, characterized by the fact thatthe third dome (13) merges in one piece into a rib (16), in particular without undercutting, wherein the rib extends from the second connecting stub (7) to the first housing part (2), and in particular lies within an axial plane which includes the inline axis (10) and the impeller axis (20).
11. Centrifugal pump housing (1) at least according to claim 2, characterized by the fact that the first and second domes (11, 12) merge seamlessly into the first housing part (2), in particular without undercutting.
12. Centrifugal pump housing (1) at least according to claim 2, characterized by the fact that the first and second domes (11, 12) become wider in the direction of the first housing part (2).
13. Group comprising at least one first centrifugal pump housing (1a, 1b) and one second centrifugal pump housing (1c, 1d) each according to one of the preceding claims, characterized by the fact that The first and second centrifugal pump housings (1a, 1b, 1c, 1d) differ in design.
14. Group according to claim 13, characterized by the fact that the first and second centrifugal pump housings (1a, 1b, 1c, 1d) differ in at least one of the following features: - the material from which they are manufactured, in particular cast, - the shape and / or size of the first and / or second connection nozzle (3, 7), - the shape and / or size of the first, second or third housing part (2, 5, 6), - the distance between the first and second connection nozzles (3, 7), - the diameter and / or arrangement of the suction mouth or suction neck seal, wherein at least the support surfaces (14) and outer contour (15) of the domes (11, 12, 13) of the first centrifugal pump housing (1) are identical in size, shape and position relative to each other to those of the second centrifugal pump housing (1).
15. Centrifugal pump assembly comprising a centrifugal pump housing (1) according to any one of claims 1 to 12.