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 enclosed by the slotted pot from the inner chamber (11) formed by the pump housing (2), an impeller shaft (20) which can be rotated about a rotational axis (A), an impeller (23) mounted on one end of the impeller shaft (20), an inner rotor (17) mounted on the other end of the impeller shaft (20), and an outer rotor (38) which interacts with the inner rotor (24). A connection flange (27) for securing the slotted pot (10) to the pump housing (2) or a component paired with the pump housing (2) is formed on the open end of the slotted pot (10).

Description

[0001] Description

[0002] Pump arrangement

[0003] 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, 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.

[0004] 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.

[0005] 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 rotational motion. The magnetic field allows the two rotor assemblies to rotate together without any mechanical connection.

[0006] The advantage of a magnetic drive 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 drive 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 arranged on the inner rotor of a magnetic drive 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. In previously known magnetic drive pumps, the containment shell is usually welded to a type of flange in order to attach the containment shell to a region of the pump housing. Such a welded joint generally has a different microstructure than the containment shell and / or the flange and can therefore represent a weak point in the sense of a predetermined breaking point during operation of the magnetic drive pump. Welded joints are costly, complex, and difficult to inspect.

[0012] The object of the invention is to provide a pump assembly, in particular a magnetically coupled pump assembly, that does not have the previously described weak point in the containment shell. The containment shell should be able to permanently hermetically seal the pump assembly. Furthermore, the containment shell should be characterized by a compact design. The design of the containment shell should facilitate the replacement of spare parts. The containment shell should be simple and cost-effective to implement.

[0013] 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.

[0014] According to the invention, a connecting flange for fastening the containment shell to the pump housing or a component associated with the pump housing, for example a housing cover, is formed at the open end of the containment shell.

[0015] The connecting flange is designed, for example, as an extension or thickening of the containment shell, which protrudes beyond the cylindrical dimensions of the containment shell.

[0016] At the same time, the connection flange can preferably function as a connecting piece that connects the containment shell to the pump housing or a component associated with the housing, in particular the housing cover. The connection flange offers increased strength and stability and ensures a secure connection of the containment shell to the housing or housing cover. The connection flange also serves, for example, as a supporting element that provides additional stability or reinforcement for the containment shell, thus relieving stress on the seal. The special design of the connection flange protects the containment shell from deformation and / or breakage.

[0017] In addition, the connecting flange preferably also fulfils a specific function, such as accommodating fastening elements for mounting and / or dismounting the containment shell on the housing.

[0018] Ideally, the connecting flange is formed with the containment shell in a one-piece structure.

[0019] Advantageously, the connecting flange and containment shell are manufactured additively and thus formed together as a single, integral part through a generative manufacturing process. This eliminates the need for a separate welded joint, which would otherwise be required. In this case, the collar and containment shell are designed and manufactured as a single-piece structure from the outset. This means that the connecting flange and containment shell are already connected to each other in their final shape and position.

[0020] In the case of a generative manufacturing process, such as selective laser melting, the connecting flange and the containment shell are built up layer by layer. The connecting flange and the containment shell are printed as a single structure. The connecting flange and the containment shell are thus already connected to each other during the "printing process," forming a single-piece structure.

[0021] In contrast to processes such as welding, gluing, or other joining techniques, the one-piece design means that the connecting flange and the containment shell are designed and manufactured from the outset as a cohesive component and as a single unit. In a one-piece structure, the connecting flange and the containment shell are not separated or separate, but form a continuous, undivided structure. This offers the possibility, in a special design of the containment shell, of integrating connecting channels between the containment shell, in particular the base body of the containment shell, and the connecting flange. The outer surface of the base body is provided with a multitude of elevations, with cavities provided in the elevations that extend into the connecting flange.The internal pressure of the cavities can be monitored for pressure changes in order to prevent possible destruction of the containment shell and thus leakage of the pumped medium.

[0022] For example, the connecting flange and containment shell form a monolithic structure. The term "monolithic" refers to the fact that the collar and containment shell are made from a single piece, without the need to assemble them as separate parts. The term "monolithic" emphasizes the unity and integrity of the one-piece structure, which is designed and manufactured as a continuous unit.

[0023] Preferably, the connecting flange is designed as an annular element. An annular element refers to a structure that has the shape of a closed loop.

[0024] Ideally, the connection flange is attached to the housing or a component associated with the housing, such as the pump housing cover. This secures the containment shell in its position between the inner and outer rotors, ensuring it is securely and permanently positioned.

[0025] For example, the connecting flange has at least four, preferably at least eight, in particular at least twelve cylindrical sleeves. In this design, the sleeves serve as mounting holes for accommodating fastening elements, such as screws, whose flat surface ensures a very precise attachment to the housing or housing cover.

[0026] In an advantageous variant of the invention, the connecting flange has a projection that interacts with a sealing element and with a groove in the housing or in the housing cover. The projection extends from the connecting flange in the axial direction towards the housing or a component assigned to the housing, for example the housing cover. The sealing element is preferably designed as a graphite sealing ring, which is pressed into the groove of the housing cover by the projection of the connecting flange. Alternative seals can include, for example, PTFE, EPDM, etc. This allows the containment shell to be hermetically sealed, particularly in the area of ​​attachment to the housing or a component assigned to the housing, even under challenging pressure and / or temperature conditions.

[0027] Ideally, the connecting flange is not produced as a solid material, but rather has a beneficial structure consisting of a multitude of supporting elements. These elements are designed, for example, as ribs and / or webs.

[0028] A rib and / or web is a structural element used to increase the rigidity and strength of the connecting flange. The reinforcing ribs or webs serve to increase the flexural rigidity of the connecting flange. This reduces the flexibility and deflection of the connecting flange, resulting in increased structural integrity and improved load-bearing capacity. Furthermore, a self-supporting geometry is achieved, enabling support-free manufacturing using selective laser melting, which can significantly save material in the manufacture of the containment shell.

[0029] Alternatively or additionally, the connecting flange has plate-shaped reinforcement structures.

[0030] Plate-shaped reinforcement structures are flat, plate-like elements that are generatively integrated along the structure of the connecting flange to increase its rigidity, strength, and stability. The plate-shaped reinforcement structures can have various shapes and sizes depending on the load specification of the pump assembly and can be rectangular, square, circular, or designed in other geometric shapes. For example, the collar has a plurality of recesses in the form of chamfers, which are preferably arranged next to and around the ribs, webs, and plate-shaped reinforcement structures. The recesses, in combination with the ribs, webs, and plate-shaped reinforcement structures, form a static and structural structure that is optimized for minimum mass while simultaneously providing maximum flexural rigidity.

[0031] In an advantageous variant, the connecting flange has at least one 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. In an advantageous variant, the surface is as small as possible to minimize the amount of support material required when using selective laser melting. This annular support structure surface forms, for example, the outer edge of the connecting flange.

[0032] Ideally, the annular support structure is hollow-cylindrical up to the height of the collar. The support structure extends essentially coaxially to the base body of the containment shell and is assembled together with the containment shell structures, starting from a base plate or build platform of the 3D printer.

[0033] Additionally, the connecting flange can also have two and / or three and / or four radially spaced annular support structure surfaces. The annular support structure surfaces can be interrupted by the sleeves of the fastening elements, with the sleeves being advantageously supported in their arrangement and strength by the annular support structures. In this respect, the ribs, webs, and plate-shaped reinforcement structures originate from and / or terminate at the annular support structure surfaces.

[0034] In an advantageous variant of the invention, the connecting flange and the containment shell are formed from a metallic material that has comparable properties to a conventional cast material. According to the invention, a pump assembly, in particular the one-piece structure of the connecting flange and the containment shell, is manufactured using a method in which the containment shell with the connecting flange is produced by selectively applying energetic radiation by melting powder layers.

[0035] Selective laser melting (SLM) is an additive manufacturing process used to produce the connecting flange and the containment shell as a one-piece structure from metal powder. In its finished state, the material preferably exhibits the properties of a cast material. It is a form of 3D printing in which a high-power laser is used to selectively melt the powder and build up the containment shell and connecting flange layer by layer.

[0036] The containment shell with the connecting flange is built layer by layer by applying a thin layer of powder to the 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 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 material. For example, the laser parameters can also be partially adjusted to achieve defined and desired microstructures.

[0038] After laser melting, the containment shell with the connecting flange can be reworked if necessary, for example, to achieve flat surfaces on the projection and / or sleeves or to remove the support structures. Ideally, the recesses, in combination with the ribs, webs, and plate-shaped reinforcement structures, are designed to provide sufficient metallic mass to dissipate heat during the selective laser melting process, while at the same time, the implementation of the recesses prevents excessive metallic mass, which would in turn result in excessive heat dissipation.

[0039] The height of the flange is designed so that the connecting flange is sufficiently rigid so as not to deform and to be able to ensure tightness with a sealing element.

[0040] The containment shell has a base body whose outer surface is provided with a plurality of elevations, wherein cavities are provided in the elevations which extend into the connecting flange.

[0041] According to the invention, the pump arrangement with a one-piece structure of the containment shell and the connecting flange is used for the hermetically sealed conveyance of fluids.

[0042] Further features and advantages of the invention will become apparent from the description of embodiments with reference to the drawings and from the drawings themselves.

[0043] It shows:

[0044] Fig. 1 shows the longitudinal section through a magnetic coupling pump arrangement,

[0045] Fig. 2 a perspective view of the containment shell with formed collar,

[0046] Fig. 3 a detailed section through a collar,

[0047] Fig. 4 shows a detailed section through a collar with two annular support structures, Fig. 5 shows a plan view of a collar with two annular support structures.

[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 attached 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 attached 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 drive 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. An annular connecting flange 27, which is formed integrally with the base body 25, is arranged on the open side. The connecting flange 27 has a plurality of openings 28 extending parallel to the central longitudinal axis B, through which openings the screws 34 shown in Fig. 1 can be pushed and screwed into corresponding threaded holes in the housing cover 4 according to Fig. 1.

[0056] 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.

[0057] 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.

[0058] In the illustrated embodiment, the connecting flange 27 has twelve cylindrical sleeves 33 that define the openings 28. The screws 34 shown in Fig. 1 extend through the sleeves 33 or openings 28 for fastening the containment shell 10 to the housing cover 4.

[0059] Plate-shaped reinforcement structures 35 are arranged at the transition between the containment shell 10, in particular the base body 25, and the connecting flange 27. The plate-shaped reinforcement structures 35 stiffen the design of the connecting flange 27 and simultaneously serve as a support structure during the construction of the containment shell 10 with the connecting flange 27 during the selective laser melting process. Furthermore, the plate-shaped reinforcement structures 35 dissipate the heat generated during the melting of the metallic powder used to construct the connecting flange 27 to the base body 25 and the support structure required during production. In the region of the connecting flange 27, the containment shell 10 has an annular first collar 36 with a plurality of ribs 37 and webs 38.

[0060] The stability and flexural rigidity of the connecting flange 27 are achieved by the combination of the first collar with the ribs 37 and the webs 38. Recesses 39 are formed between them, reducing the required material usage and minimizing the support structure area 40 required for selective laser melting. The cylindrical sleeves 33 are secured by the first collar 36.

[0061] The support structure, not shown in the figures, is created during the manufacturing process. After the containment shell 10 is completed using the selective laser melting process, the support structure is removed again, leaving only the support structure surface 40.

[0062] The connecting flange 27 and the containment shell 10 form a continuous, undivided structure, which offers the possibility of integrating connecting channels 41 between the containment shell 10, in particular the base body 25 of the containment shell 10, and the connecting flange 27.

[0063] Fig. 3 shows a detailed section through a connecting flange 27. The connecting flange 27 comprises an axial projection 42, which cooperates with a sealing element and with a groove (not shown) in the housing cover 4 in order to realize the hermetically sealed design of the containment shell 10 also at the connection points.

[0064] The effective height X of the connecting flange 27 is the value that defines the rigidity of the connecting flange 27. The effective height X is reduced by the height of the recesses 39. This reduces the mass of the connecting flange 27 and also the amount of metal powder required, as well as the cost-intensive construction time for SLM (SLM Selective Laser Melting). The ribs 37 and webs 38 and plate-shaped reinforcing structures 35 form intersecting first chamfers 43 and second chamfers 44, visible in the sectional view, which delimit the recesses 39. This reduces the support depth Z required for otherwise conventional mounting flanges to the support depth Y, which corresponds to the width of the annular support structure surface 40.

[0065] Fig. 4 essentially corresponds to Fig. 3 and shows a detailed section through another embodiment of the connecting flange 27. For higher pressures within the containment shell 10, it is necessary to make the connecting flange 27 thicker in the axial direction. To ensure that material can still be saved during production using selective laser melting for the required support structure, the connecting flange 27 has, in addition to the first annular collar 36, a second annular collar 45 arranged radially spaced from the first collar 36. The second collar 45 has a support structure surface 46.

[0066] Fig. 5 shows a plan view of a connecting flange 27 with the first collar 36 and the second collar 45. At the transition of the containment shell 10, in particular the base body 25, to the connecting flange 27, the plate-shaped reinforcement structures 35 are designed with a 45° chamfer.

[0067] The stability and flexural rigidity of the connecting flange 27 are achieved, in addition to the plate-shaped reinforcement structures 35, by the combination of the first collar 36 with the ribs 37 and the webs 38. The recesses 39 are arranged between them. The cylindrical sleeves 33 are fixed by the first collar 36 and the second collar 45.

Claims

Patent claims Pump arrangement 1. Pump arrangement (1), in particular a 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 enclosed by it from the interior space (11) formed by the pump housing (2), an impeller shaft (20) which can be driven to rotate about an axis of rotation (A), an impeller (23) arranged at one end of the impeller shaft (20), an inner rotor (24) arranged at the other end of the impeller shaft (20) and an outer rotor (38) which interacts with the inner rotor (24), characterized in that a connecting flange (27) for fastening the containment shell (10) to the pump housing (2) or to a component assigned to the pump housing (2) is formed at the open end of the containment shell (10).

2. Pump arrangement according to claim 1, characterized in that the connecting flange (27) is formed with the containment shell (10) in a one-piece structure.

3. Pump arrangement according to claim 1 or 2, characterized in that the connecting flange (27) is designed as an annular element.

4. Pump arrangement according to one of claims 1 to 3, characterized in that the connecting flange (27) has a projection (41) which cooperates with a sealing element and with a groove of a housing cover (4).

5. Pump arrangement according to one of claims 1 to 4, characterized in that the connecting flange (27) has a plurality of ribs (37) and / or webs (38).

6. Pump arrangement according to one of claims 1 to 5, characterized in that the connecting flange (27) has plate-shaped reinforcing structures (35).

7. Pump arrangement according to one of claims 1 to 6, characterized in that the connecting flange (27) has a plurality of recesses (39).

8. Pump arrangement according to one of claims 1 to 7, characterized in that the connecting flange (27) has at least one annular support structure surface (40).

9. Pump arrangement according to one of claims 1 to 8, characterized in that the connecting flange (27) has at least four, preferably at least eight, in particular at least twelve cylindrical sleeves (16).

10. Pump arrangement according to one of claims 1 to 9, characterized in that the connecting flange (27) and the containment shell (10) are formed from a metallic material.

11. Pump arrangement according to one of claims 1 to 10, characterized in that the containment shell (10) has a base body (25) whose outer circumferential surface (31) is provided with a plurality of elevations (32), wherein hollow spaces are provided in the elevations (32) which extend into the connecting flange.

12. Method for producing a pump arrangement (1), characterized in that the one-piece structure of the connecting flange (27) and the containment shell (10) is produced by selective exposure to energetic radiation by melting powder layers.

13. Use of a pump arrangement (1) with a one-piece structure of the containment shell (10) and the connecting flange (27) for the hermetically sealed conveyance of fluids.

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