Pump assembly

Abstract

The invention relates to a pump assembly (1), in particular a magnetic clutch pump assembly, comprising an inner chamber (11) formed by a pump housing (2) of the pump assembly (1), a slotted pot (10) which hermetically seals off a chamber (12) enclosed by the slotted pot from the inner chamber (11) formed by the pump housing (2), a connection flange (27), which is formed on the slotted pot (10), for securing the slotted pot to the pump housing (2) or to a component paired with the pump housing (2), in particular a housing cover (4), an impeller shaft (13) which can be rotated about a rotational axis (A), an impeller (16) mounted on one end of the impeller shaft (13), an inner rotor (17) mounted on the other end of the impeller shaft (13), and an outer rotor (24) which interacts with the inner rotor (17). The connection flange (27) has a tarnish protection (35). To be published with figure 1.

Description

[0001] KSB SE & Co. KGaA 67227 Frankenthal

[0002] Description

[0003] Pump arrangement

[0004] The invention relates to a pump arrangement, in particular a magnetic coupling pump arrangement, with an interior space formed by a pump housing of the pump arrangement, a containment shell which hermetically seals a chamber enclosed by it from the interior space formed by the pump housing, a connecting flange formed on the containment shell for fastening to the pump housing or to a component associated with the pump housing, in particular a housing cover, an impeller shaft which can be driven to rotate about an axis of rotation, an impeller arranged at one end of the impeller shaft, an inner rotor arranged at the other end of the impeller shaft and an outer rotor which interacts with the inner rotor.

[0005] A magnetic drive pump, also known as a magnetically coupled pump or magnetically coupled pump, is a centrifugal pump in which the required drive power of the pump is transmitted magnetically. Unlike conventional pumps, which have a direct mechanical connection between the motor and pump, a magnetically coupled pump uses a magnetic coupling to transmit the motion from the motor to the pump.

[0006] The magnetic coupling consists of two magnetic rotor assemblies separated by a housing. One rotor assembly is connected to the motor, while the other rotor assembly is connected to the pump. The two rotor assemblies are equipped with magnets that attract each other, thus transmitting the rotary motion. The magnetic field allows the two rotor assemblies to rotate together without any mechanical connection. The advantage of a magnetic coupling pump is that it creates a completely static seal with the pumped medium. Since there is no direct mechanical connection between the pump shaft and the motor shaft, liquids or gases cannot escape into the environment through potential leaks at dynamically sealed points. This makes magnetic coupling pumps ideal for use in demanding applications where high reliability and chemical resistance are required.

[0007] Such a pump arrangement is known from DE 10 2004 003 400 A1, which, to expand the application range, features a drive rotor designed as a common part for external drive elements. However, this only allows an expansion of the application range to a certain extent. Beyond a certain size, an adjustment of the rotor size is unavoidable.

[0008] EP 0814268 A1 discloses a modular kit for the production of pumps, which is intended to offer the possibility of producing pumps from a small number of components according to application requirements. However, the proposed solution only allows the replacement of components assigned to a single size.

[0009] DE 10 2014 214 929 A1 describes a magnetic drive pump that uses two stationary mechanical seals. This eliminates vibrations from the stationary spring elements, increasing the service life and sealing effectiveness of the mechanical seal.

[0010] DE 10 2013 208 460 A1 shows a positioning of an axial bearing arrangement in a magnetic coupling pump in which the lubrication of the bearing arrangement is improved and the acting radial bearing forces are reduced.

[0011] DE 10 2013 007 849 A1 discloses an auxiliary impeller mounted on the inner rotor of a magnetic coupling pump. During operation, this creates a forced circulation of a lubricant flow, which in particular lubricates the bearing assembly and also dissipates the heat generated by eddy current losses from the containment shell area. A rolling bearing failure on the outer rotor of the magnetic coupling can lead to a perforation of the containment shell, thus causing significant damage to the pump assembly.

[0012] Previous solutions for damage control sometimes involve using additional adapter pieces as tarnish protection or attaching tarnish protection to housing components. This involves considerable assembly effort and results in additional sealing points, which in turn can represent a weak point.

[0013] The object of the invention is to provide a pump assembly, in particular a magnetic drive pump assembly, with a start-up protection device that can be implemented without additional assembly effort and without additional sealing points. The start-up protection device should be able to effectively prevent the containment shell from breaking through or grinding through in the event of rolling bearing failure. Furthermore, the start-up protection device should be characterized by a compact and integrated design. The start-up protection device should be easy and cost-effective to implement.

[0014] This object is achieved according to the invention by a pump arrangement, in particular a magnetic coupling pump arrangement, according to the features of claim 1. Preferred variants can be found in the independent main claims, the subclaims, the description and the drawings.

[0015] According to the invention, the connection flange of the containment shell has a start-up protection.

[0016] The start-up protection is preferably an integral and compact component of the connecting flange.

[0017] Ideally, the containment shell, connecting flange, and tarnish protection are formed into a single-piece structure. This single-piece structure creates a single component, significantly reducing assembly effort and eliminating additional sealing points. Advantageously, the tarnish protection, connecting flange, and containment shell are manufactured additively, resulting in a cohesive joint formed by a single additive manufacturing process. This eliminates the need for a separate, conventional welding and / or adhesive bond. In this case, the tarnish protection, connecting flange, and containment shell are designed and manufactured as a single-piece structure from the outset. This means that the tarnish protection, connecting flange, and containment shell are already connected to one another in their final shape and position.

[0018] In a generative manufacturing process, such as selective laser melting, the containment shell, the connecting flange, and the tarnish protection are built up layer by layer. The tarnish protection, the connecting flange, and the containment shell are printed as a single structure. The tarnish protection, the connecting flange, and the containment shell are thus already connected to each other during the printing process, forming a single-piece structure.

[0019] In contrast to processes such as welding, gluing, or other joining techniques, the one-piece design refers to the fact that the tarnish protection, the connecting flange, and the containment shell are designed and manufactured from the outset as a coherent component and a single unit. In a one-piece design, the containment shell, the connecting flange, and the tarnish protection are not separated or separate, but form a continuous, undivided structure.

[0020] For example, the containment shell with the connecting flange and the starter guard form a monolithic construction. The term "monolithic" refers to the fact that the starter guard, the connecting flange, and the containment shell are made from a single piece, without the need to assemble them as separate parts. The term "monolithic" emphasizes the uniformity and integrity of the one-piece structure, which is designed and manufactured as a continuous unit. For example, the starter guard is designed as an essentially cylindrical structure. This cylindrical structure can engage a gap in the outer rotor without contact and support the outer rotor in the event of damage, thus preventing mechanical damage to the containment shell in the coupling area.

[0021] A cylindrical structure is a geometric shape that exhibits the properties of a cylinder. A cylinder consists of two parallel circular surfaces connected by a curved, straight, or slightly inclined side surface. The parallel circular surfaces are called the bases of the cylinder, while the curved side surface forms the cylinder's mantle. The bases of a cylinder are circles of equal radius, while the distance between the bases is called the cylinder's height. The height of the cylinder is the perpendicular distance between the two bases.

[0022] In order to use as little material as possible for the necessary support structures when manufacturing the containment shell using an additive process, in particular selective laser melting, the connecting flange has initial recesses.

[0023] For the same reason, the tarnish protection preferably has second recesses in the form of pointed arches.

[0024] A pointed arch is a specific type of arch. It is characterized by its tapered shape, with the top of the arch having a sharper point than other arch shapes such as the round arch.

[0025] The pointed arch is often associated with Gothic architecture and was a prominent feature of many Gothic cathedrals and churches. The pointed arch offers the advantage of a larger span at the same height, or greater load transfer with the same span. This ideal force dissipation corresponds to ideal heat dissipation, which is particularly advantageous for the additive manufacturing of tarnish protection. The design of the tarnish protection using a geometry optimized for temperature dissipation and load transfer in the design of recesses in the shape of the Gothic arch or the pointed arch enables ideal temperature dissipation and thus reduces the required use of metal powder during additive manufacturing, which in turn has a beneficial effect on the overall manufacturing costs. The ratio of web width, opening and opening height of the pointed arch can be adapted to the mass of the connecting flange.

[0026] Advantageously, the tarnish protection also has third recesses in the shape of diamonds.

[0027] A rhombus, also called a rhombus, is a geometric shape with specific characteristics. It is a quadrilateral in which all sides are equal length, but no right angles exist. All four sides of the rhombus are equal length, the opposite sides are parallel to each other, and the opposite angles are equal, but they are not right angles.

[0028] The diamond-shaped recesses further reduce the mass of the tarnish protection.

[0029] Ideally, the tarnish guard itself serves as a support structure for the flange during the manufacturing process and has as small annular support structure area as possible at the free end of the tarnish guard for the support structure. The support structure is created during the manufacturing process and removed afterwards, leaving only the support structure area. The support structure area is as small as possible to minimize the amount of support material required when using selective laser melting.

[0030] The annular anti-rotation device can have at least one chamfer that engages, for example, in a recess and / or groove of the outer rotor, without contact in the event of damage. The chamfer allows for a particularly delicate engagement and, if necessary, support of the outer rotor. A corresponding chamfer can also be provided on the connecting flange.

[0031] In a particularly advantageous variant of the invention, the containment shell has reinforcements which stiffen it in the area of ​​the start-up protection.

[0032] The reinforcements are, for example, flat, plate-like elements that are generatively integrated along the structure of the connecting flange at the transition to the start-up protection to increase its rigidity, strength, and stability. The reinforcements can have various shapes and sizes depending on the load specifications of the pump assembly and can be rectangular, square, circular, or other geometric shapes.

[0033] For example, the reinforcements also serve as a support structure during the manufacturing process and form a transition from the containment shell via the start-up protection to the connecting flange.

[0034] According to the invention, a pump arrangement, in particular the one-piece structure of the containment shell with connecting flange and start-up protection, is produced by a method in which the containment shell with connecting flange is produced by selective exposure of energetic radiation to powder layers applied in layers.

[0035] Selective laser melting (SLM) is an additive manufacturing process used to produce the tarnish guard, the connecting flange, and the containment shell as a one-piece structure from metal powder, particularly cast material powder. It is a form of 3D printing that uses a high-power laser to selectively melt the powder and build up the containment shell, the connecting flange, and the tarnish guard layer by layer.

[0036] The containment shell with the connecting flange and tarnish protection is built layer by layer by applying a thin layer of powder to a build platform. The laser beam is then directed at the selected areas, where it melts the metal powder and bonds it into a solid layer. A new layer is then applied, and the process is repeated until the containment shell with the connecting flange and tarnish protection is created.

[0037] Preferably, a high-power laser, such as a fiber laser or a CO2 laser, is used. The laser beam is precisely controlled to melt and fuse the metal powder. The laser parameters, such as power, intensity, and speed, are adjusted according to the requirements of the process and the selected metallic material, which has properties comparable to a conventional cast material. For example, the laser parameters can also be partially adjusted to achieve defined and desired microstructures.

[0038] After laser melting, the tarnish protection and the containment shell with the connecting flange can possibly be reworked in order to achieve, for example, the flat support structure surfaces described above.

[0039] Ideally, the second recesses in the form of pointed arches and the third recesses in the form of diamonds in combination with the reinforcements are designed in such a way that there is sufficient metallic mass to dissipate the heat during the selective laser melting process, but at the same time the implementation of the recesses does not result in too much metallic mass, which in turn would require a large amount of heat dissipation.

[0040] The depth and width of the start-up protection are designed in such a way that the start-up protection is sufficiently stable to protect the containment shell.

[0041] According to the invention, a pump assembly with a start-up protection device is used to protect against the destruction of the containment shell and the resulting leakage of medium into the environment. Further features and advantages of the invention will become apparent from the description of exemplary embodiments with reference to the drawings and from the drawings themselves.

[0042] It shows:

[0043] Fig. 1 shows the longitudinal section through a magnetic coupling pump arrangement,

[0044] Fig. 2 is a perspective view of a containment shell according to the invention with connecting flange and start-up protection in a one-piece design,

[0045] Fig. 3 a detailed view of the recesses of the tarnish protection in the form of pointed arches,

[0046] Fig. 4 shows the arrangement of the outer rotor, the main body of the containment shell and part of the start-up protection

[0047] Fig. 5 is a perspective view of a one-piece can according to the invention with connecting flange and start-up protection in the version for small cans,

[0048] Figure 1 shows an example of a pump assembly 1 in the form of a magnetic coupling pump assembly, as is known from the prior art. The pump assembly 1 has a multi-part pump housing 2 of a centrifugal pump, which comprises a hydraulic housing 3 designed as a spiral housing, a housing cover 4, a bearing support lantern 5, a bearing support 6, and a bearing cover 7.

[0049] The hydraulic housing 3 has an inlet opening 8 for sucking in a pumped medium and an outlet opening 9 for expelling the pumped medium. The housing cover 4 is arranged on the side of the hydraulic housing 3 opposite the inlet opening 8. The bearing support lantern 5 is fastened to the side of the housing cover 4 facing away from the hydraulic housing 3. The bearing support 6 is attached to the side of the bearing support lantern 5 opposite the housing cover 4. The bearing cover 7 is in turn fastened to the side of the bearing support 6 facing away from the bearing support lantern 5.

[0050] A containment shell 10 is attached to the side of the housing cover 4 facing away from the hydraulic housing 3 and extends at least partially through an interior space 11 defined by the pump housing 2, in particular by the housing cover 4, by the bearing support lantern 5, and by the bearing support 6. The containment shell 10 hermetically seals a chamber 12 enclosed by it from the interior space 11.

[0051] An impeller shaft 13 rotatable about a rotation axis A extends from a flow chamber 14 defined by the hydraulic housing 3 and the housing cover 4 through an opening 15 provided in the housing cover 4 into the chamber 12.

[0052] An impeller 16 is attached to one end of the impeller shaft 13 located within the flow chamber 14. An inner rotor 17 is arranged within the chamber 12 at the opposite end of the shaft. The inner rotor 17 is equipped with several magnets 18, which are arranged on the side of the inner rotor 17 facing the containment shell 10.

[0053] Between the impeller 16 and the inner rotor 17 there is arranged a bearing arrangement 19 which is operatively connected to the impeller shaft 13 which can be driven to rotate about the axis of rotation A.

[0054] A drive motor (not shown), preferably an electric motor, drives a drive shaft 20. The drive shaft 20, which can be driven rotatably about the axis of rotation A, is arranged essentially coaxially with the impeller shaft 13. The drive shaft 20 extends through the bearing cover 7 and the bearing bracket 6 and is mounted in two ball bearings 21, 22 accommodated in the bearing bracket 6. An outer rotor 24 carrying a plurality of magnets 23 is arranged at the free end of the drive shaft 20. The magnets 23 are arranged on the side of the outer rotor 24 facing the containment shell 10. The outer rotor 24 extends at least partially over the containment shell 10 and interacts with the inner rotor 17 in such a way that the rotating outer rotor 24 also sets the inner rotor 17 and thus the impeller shaft 13 and the impeller 16 in a rotational movement by means of magnetic forces.

[0055] The containment shell 10, shown in perspective in Fig. 2, is intended for installation in the pump assembly 1 shown in Fig. 1 as an example of various magnetic coupling pump assemblies. The containment shell 10 has a substantially cylindrical base body 25 with a central longitudinal axis B arranged substantially coaxially to the axis of rotation A according to Fig. 1. The base body 25 is open on one side and closed on the side opposite the open side by means of a substantially curved base 26. Arranged on the open side is an annular connecting flange 27 which is formed integrally with the base body 25.

[0056] The connecting flange 27 has a plurality of mounting openings 28 extending parallel to the central longitudinal axis B.

[0057] The base 26 is formed by a substantially spherical segment-shaped dome region 29 and an outer rim region 30 forming the transition region between the base body 25 and the dome region 29.

[0058] The base body 25 has an outer surface 31 with a plurality of elevations 32. The outer surface 31 is essentially wave-shaped, each with a plurality of wave peaks and wave troughs. The elevations 32 are screw- or spindle-shaped. Hollow spaces (not shown) are provided in the elevations 32. The hollow spaces can detect damage to the containment shell 10 before a break occurs during pump operation using sensor monitoring and a control module, and can transfer the pump assembly 1 to a secure state.

[0059] In the illustrated embodiment, the connecting flange 27 has twelve cylindrical sleeves 33 that define the mounting openings 28. Screws 34, shown in Fig. 1, extend through the sleeves 33 or mounting openings 28 for fastening the containment shell 10 to the housing cover 4.

[0060] A tarnish guard 35, which prevents the outer rotor 24 from touching the outer surface 31 or the elevations 32 of the base body 25, is designed as a sleeve-like or hollow-cylindrical structure and extends from the connecting flange 27 coaxially to the central longitudinal axis B of the containment shell 10, i.e., in the axial direction, at least partially over the base body 25 with a defined radial distance. The base 26 and base body 25 with the elevations 32, as well as the connecting flange 27 and tarnish guard 35, together form a one-piece structure. The one-piece structure is produced by additive manufacturing.

[0061] The stability and flexural rigidity of the connecting flange 27 and the anti-tarnish protection 35 are achieved by first reinforcements 36 in combination with an annular collar 37. First recesses 38 are arranged between them. The cylindrical sleeves 33 are fixed by the annular collar 37. This increases the rigidity and reduces the area to be supported, which is necessary for the required support structure during the manufacture of the containment shell 10.

[0062] The tarnish protection 35 comprises, at its free end 39 facing away from the connecting flange 27, a thrust ring 40 with a thrust surface 41 facing the base body 25. The thrust ring 40 is connected to the area of ​​the connecting flange 27 via a sleeve-like connecting element 42. The tarnish protection 35 has, particularly in the area of ​​the connecting element 42, recesses in the shape of pointed arches, referred to as second recesses 43 in the further course of the description of the figures, and recesses in the shape of diamonds, referred to as third recesses 44 in the further course of the description of the figures.

[0063] Second and third recesses 43, 44, in combination with reinforcements 36, are designed to provide sufficient metallic mass to dissipate heat during the selective laser melting process, creating a self-supporting structure and simultaneously ensuring sufficient rigidity of the assembly. Fig. 3 shows a detailed view of the containment shell 10, in particular the tarnish protection 35, with the second recesses 43 in the shape of pointed arches and the third recesses 44 in the shape of diamonds.

[0064] Starting from the reinforcements 36, which form the transition from the connecting flange 27 to the tarnish protection 35, in particular to the connecting element 42, in the direction of the free end 39, the second recesses 43 are delimited by the thrust ring 40 on the side opposite the pointed arch. Between each pointed arch of the second recess 43, the third, diamond-shaped recesses 44 are provided to reduce material usage. An angle a of essentially 60° is defined from the beginning of the pointed arch to the center of the sides of the recess 43. This advantageous structure for force conduction is also very advantageous for heat dissipation, which must be given particular importance in the selective laser melting manufacturing process.

[0065] Fig. 4 shows a schematic illustration of how the outer rotor 24 and the containment shell 10, with the base body 25 and thrust ring 40, are arranged relative to one another. During operation, the free end of the outer rotor 24 rotates between the thrust ring 40 and the base body 25. The outer rotor 24 has a region 44 with a reduced outer diameter in the area of ​​the thrust ring 40. The axially adjacent region 45 has an outer diameter that essentially corresponds to the outer diameter of the thrust ring 40. This creates a radial recess 46 into which the thrust ring 40 engages.

[0066] The annular thrust ring 40 has a chamfer 47 at its free end, which makes the engagement particularly delicate and saves material for the support structure during production using selective laser melting. In the event of a brittle rolling bearing 20, 22, the outer rotor 24 can be supported by the thrust protection 40, thus preventing the containment shell 10 from breaking due to an unguided outer rotor 24.

[0067] Fig. 5 shows a perspective view of the one-piece structure of the containment shell 10 with tarnish protection 35 and connecting flange 27 in the design for small containment shells 10. Compared to the illustration in Fig. 2, the tarnish protection 35 tapers significantly and has additional, rib-like second reinforcements 48. To reduce the material used, the reinforcements 48 have additional openings called fourth recesses 49, which are diamond-shaped. In addition to the second recesses 43, this design variant features further, fifth recesses 50, which are designed as double pointed arches. The diamond-shaped recesses 49 here can also have any other shapes, e.g., circles, rectangles, etc.As shown in Figures 2 and 5, the free end 39 of the tarnish protection 35 has a support structure surface 51, which is an annular surface for a support structure required during manufacturing using an additive process. The support structure is created during the manufacturing process and subsequently removed, leaving only the support structure surface 51. The surface is as small as possible to minimize the amount of support material required when using selective laser melting. A further support structure surface 52 is provided on the collar 37.

Claims

Patent claims Pump arrangement 1. Pump arrangement (1 ), in particular magnetic coupling pump arrangement, with - an interior space (11) formed by a pump housing (2) of the pump arrangement (1), - a containment shell (10) which hermetically seals a chamber (12) enclosed by it from the interior space (11) formed by the pump housing (2), - a connecting flange (27) formed on the containment shell (10) for fastening to the pump housing (2) or to a component associated with the pump housing (2), in particular the housing cover (4), - an impeller shaft (13) rotatably driven about an axis of rotation (A), - an impeller (16) arranged at one end of the impeller shaft (13), - an inner rotor (17) arranged at the other end of the impeller shaft (13) and - an outer rotor (24) cooperating with the inner rotor (17), characterized in that the connecting flange (27) has a start-up protection (35).

2. Pump arrangement according to claim 1, characterized in that the connecting flange (27) has first recesses (38).

3. Pump arrangement according to claim 1 or 2, characterized in that the start-up protection (35) is designed as a substantially cylindrical structure.

4. Pump arrangement according to one of claims 1 to 3, characterized in that the start-up protection (35) has second recesses (43) in the form of pointed arches.

5. Pump arrangement according to one of claims 1 to 4, characterized in that the start-up protection (35) has third recesses (44) in the form of diamonds.

6. Pump arrangement according to one of claims 1 to 4, characterized in that the start-up protection (35) has at least one annular support structure surface (51, 52).

7. Pump arrangement according to claim 5, characterized in that the at least one annular start-up protection (51) has a chamfer (47).

8. Pump arrangement according to one of claims 1 to 6, characterized in that the start-up protection (35) has reinforcements (36, 48).

9. Pump arrangement according to one of claims 1 to 7, characterized in that the containment shell (10), the connecting flange (27) and the start-up protection (35) are designed as a one-piece structure.

10. Pump arrangement according to one of claims 1 to 8, characterized in that the start-up protection (35) is made of a metallic material.

11. A method for producing a pump arrangement (1), characterized in that the one-piece structure of the containment shell (10), the connecting flange (27) and the start-up protection (35) is produced by selective exposure of energetic radiation to powder layers applied in layers.

12. Use of a pump arrangement (1) with a start-up protection (35) as protection against destruction of the containment shell (10) and against leakage of medium into the environment.

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