Noise optimization system for cooling a drive of a centrifugal pump

Abstract

The present invention relates to a system (1) for driving a centrifugal pump (2), wherein the system (1) has at least one cooling assembly (6, 23) comprising cooling ribs (7). The cooling ribs (7) are arranged in rows at intervals from each other. At least a portion of the cooling ribs (7) has a lower region (11) and an upper region (12) having a height (H), the upper region forming a height profile (13), wherein the upper region (12) has a notch (14) for forming the height profile (13). Each notch (14) forms a geometry having a width (B) and a depth (T).

Description

Technical Field

[0001] The present invention relates to a system for driving a centrifugal pump, wherein the electric motor has at least one cooling assembly comprising cooling ribs arranged in rows at intervals from each other. Background Technology

[0002] Centrifugal pumps typically consist of a drive system, which usually includes one or more electric motors and power electronics for speed regulation via frequency conversion. Here, it is precisely the electric motor and its associated motor electronics that require adequate cooling during operation.

[0003] An electric motor consists of a rotor that is torsionally connected to a motor shaft, a stator with a wound stator assembly, a stator housing with cooling ribs on the outer side, two bearing end caps with rolling or sliding bearings on both sides, and a fan wheel that is torsionally connected to the shaft end opposite to the drive side. The fan wheel can be surrounded by a fan shroud that is securely connected to the stator housing.

[0004] DE 10 2021 000 933 A1 discloses a pump comprising a drive motor, at least one electronic device housing, and at least one cooling body for discharging heat from the electronic device housing, wherein an intermediate element for thermally decoupling the cooling body from the motor housing is introduced between the cooling body and the motor housing of the drive motor.

[0005] DE 10 2021 108 359 A1 describes an electric motor with a cooling assembly for driving a centrifugal pump. The cooling assembly includes a fan wheel and a shroud, wherein the shroud encloses a space. Guiding elements are arranged in the space.

[0006] DE 10 2021 005 031 A1 discloses a heating circulation pump having at least one electronic device housing for pump electronics, wherein the electronic device housing is assembled from at least two housing components having an integrated cooling body, and at least one sealing element is placed in the connection gap between the at least two housing components.

[0007] Centrifugal pumps, and therefore the electric motors used to drive them, are also used in some noise-sensitive areas, such as hospitals, kindergartens and schools, as well as private homes. One application area here is fluid transport in heating or cooling systems. Here, it is desirable and desirable to keep the noise or sound pressure level of the motors and pumps as low as possible.

[0008] In some pump series, centrifugal pumps have been implemented with noise optimization. To achieve even lower sound pressure levels, components adjacent to the pump (such as cooling assemblies) must also be prioritized for optimization. At certain frequencies, for example, the ends of the cooling fins of the cooling assembly may move and emit corresponding sound waves.

[0009] The structure of the cooling fins in a cooling assembly can be prone to resonance, especially if it is not stably mounted or adequately damped. If the frequency of the excitation force of the motor, power electronics, or pump coincides with the inherent resonant frequency of the cooling fins, the vibration will be amplified, potentially leading to loud noise.

[0010] In addition, the cooling components are equipped with fans that draw air through the cooling fins to expel heat. If these fans are not properly balanced, or if they are worn, they may produce additional vibrations. Vibrations can also be caused by uneven rotation of the fan blades and can be perceived as a humming or buzzing sound. Summary of the Invention

[0011] The objective of this invention is to provide a system for driving a centrifugal pump with a cooling assembly, which can operate with particularly low noise and at low sound pressure levels. The cooling assembly should reliably remove heat generated during system operation and during the transport of hot fluids. Furthermore, the cooling assembly is characterized by a compact structural form. The cooling assembly should be simple and cost-effective to implement.

[0012] This task is solved according to the invention by a system for driving a centrifugal pump having the features of claim 1. Preferred variations can be found in the parallel main claims, dependent claims, description, and drawings.

[0013] According to the invention, at least a portion of the cooling rib has a lower region and an upper region with height, the upper region forming a height profile for noise reduction, wherein the upper region has a notch for forming the height profile, and each notch forms a geometry having a width and a depth.

[0014] For example, the system consists of an electric motor and power electronics used to drive a centrifugal pump.

[0015] Cooling components can be arranged, for example, between the pump housing of the centrifugal pump and the electric motor.

[0016] In another variation of the invention, the cooling assembly may be arranged between the electric motor and the housing or power electronics housing for regulating the electric motor.

[0017] The cooling assembly according to the invention has a plurality of cooling ribs. For example, the cooling ribs are arranged in rows that are spaced apart from each other.

[0018] Preferably, the cooling ribs are oriented and arranged parallel to each other.

[0019] For example, the cooling ribs are constructed as flat cuboids standing upright on the substrate.

[0020] The substrate is constructed of, for example, a thermally conductive material and is preferably in contact with an electric motor and / or a power electronic device.

[0021] In one variation of the invention, the substrate has a height corresponding to the thickness of the cooling ribs.

[0022] The lower region of the cooling ribs is, for example, more than 60%, preferably more than 70%, and especially more than 80% of the total height of the cooling ribs.

[0023] The upper region of the cooling rib is, for example, less than 40% of the total height of the cooling rib, preferably less than 30%, and especially less than 20%.

[0024] For example, the upper region is more than 10% higher than the lower region, preferably more than 15%, especially more than 20%, and / or less than 50%, preferably less than 40%, especially less than 30%.

[0025] In one variation of the invention, the spacing between the cooling ribs is greater than three times the thickness of the cooling ribs, preferably greater than four times the thickness, especially greater than five times the thickness, and / or less than eight times the thickness of the cooling ribs, preferably less than seven times the thickness, especially less than six times the thickness.

[0026] For example, each cooling rib gradually narrows from the lower region towards the upper region. This means that the thickness decreases along the height of the cooling rib. This can be advantageous for demolding in cooling assemblies made by casting, where vibration reduction of the cooling ribs can also be achieved. This is particularly advantageous for noise reduction of the electric motor in the operation of centrifugal pumps.

[0027] According to the invention, the upper region of the cooling rib has a height profile. The height profile typically shows the variation of height along the length or direction of a segment, i.e., the length of the cooling rib in cooling assembly applications.

[0028] Height profiles are, for example, configured for passive noise reduction of electric motors used to drive centrifugal pumps. Here, the height profile configuration reduces the vibration of the cooling ribs or the vibration of the cooling ribs relative to each other and / or the sound pressure level caused by the vibration of the cooling ribs.

[0029] This can be achieved, for example, by means of notches in the upper region of the cooling ribs. Here, for example, the notches of the corresponding cooling ribs are arranged staggered from each other, within a row and / or relative to the next row, so that during the vibrational movement of the cooling ribs relative to each other, when sound pressure is generated, at least the paired portion is missing, thereby achieving passive noise reduction.

[0030] A notch may have a depth and a width.

[0031] In one variation of the invention, the depth and width of the notch can be constructed identically in all notches.

[0032] In another variation, the depth and width of the notch are implemented differently for each notch.

[0033] The arrangement of these notches, for example, creates the height profile of the upper region of the cooling ribs, thereby enabling passive noise reduction.

[0034] The height of the notch can be, for example, more than 50% of the height of the upper region, preferably more than 70%, and especially more than 90%.

[0035] In one variation of the invention, the width of the notch corresponds to the distance between the two notches.

[0036] In another variation of the invention, the width of the notch is greater than 1.5 times the distance between the two notches, especially greater than 2 times, especially greater than 2.5 times.

[0037] For example, more than three, preferably more than five, and especially more than seven notches are arranged in the cooling ribs of the cooling assembly.

[0038] For example, the high-profile is constructed periodically.

[0039] The term "periodicity" specifically refers to notches that form a height profile, arranged at regular intervals or in a periodic manner, or whose arrangement repeats. Notches used to construct a height profile are arranged at intervals or in cycles.

[0040] In one variation of the invention, the height profile has the same geometry in all cooling ribs of the cooling assembly.

[0041] In another variation of the invention, the height profile has the same geometry in every two cooling ribs of the cooling assembly, wherein the two shapes are arranged alternately with each other.

[0042] For example, at least one of the height profiles of the cooling component is constructed in a wavy and / or rectangular and / or triangular and / or trapezoidal and / or serrated shape.

[0043] In a variant of the invention, the height profiles of adjacent cooling ribs are constructed with phase shifts relative to each other, wherein, preferably, the height profiles of directly adjacent cooling ribs are constructed with phase shifts relative to each other.

[0044] Vibration of the cooling ribs can be reduced through each individually described embodiment, and especially in combinations of the described embodiments. For example, sound waves are canceled out by the embodiments of the cooling ribs. So-called air pumping caused by the movement of the cooling ribs relative to each other within the space is significantly reduced or even completely prevented, thereby eliminating sound and therefore noise.

[0045] For example, the phase of the height profile of adjacent cooling ribs is shifted by more than π / 8, preferably more than π / 6, especially more than π / 4, and / or less than 13π / 8, preferably less than 11π / 8, especially less than 9π / 8. This phase shift advantageously achieves passive noise reduction of the cooling assembly.

[0046] In one variant, the depth and width of the geometry are constructed identically in all notches.

[0047] In one alternative variation, the cooling ribs are at least partially constructed as corrugated plates erected on the substrate. This embodiment is advantageously suited for passive noise reduction of the cooling assembly.

[0048] For example, the cooling components are constructed in a manner that integrates them as part of the electric motor housing.

[0049] In one variant, the cooling assembly and the electric motor housing are constructed as a single piece.

[0050] In one alternative variation, the cooling assembly is inserted flush with the electric motor housing.

[0051] In another variation of the invention, the cooling assembly is connected to the power electronics. Here, for example, components of the power electronics can be connected to the cooling assembly flush with their surfaces.

[0052] In one alternative variation, the cooling components and power electronics are constructed as a single unit.

[0053] In one variant of the invention, the cooling assembly is constructed as a single piece.

[0054] In an alternative variation of the invention, the substrate of the cooling assembly is constructed in a cylindrical shape. For example, cooling fins are arranged in a star shape on the substrate, and / or arranged in a star shape and / or parallel to each other in a row. For example, this embodiment is advantageous in a one-piece embodiment of the cooling assembly and the electric motor housing.

[0055] In one variation of the invention, the rows of cooling ribs are constructed vertically on a cylindrical substrate. For example, these rows are oriented parallel to each other.

[0056] In one alternative variation, the rows of cooling ribs have a sinusoidal configuration.

[0057] For example, the cooling assembly may also include a fan for active cooling. Here, the highly contoured construction advantageously reduces noise development, thus allowing the electric motor used to drive the centrifugal pump to be used in noise-sensitive areas.

[0058] In one embodiment of the invention, a cooling assembly, particularly a one-piece structure of a cooling assembly, is manufactured by means of selectively applying energy radiation to a layer-by-layer coated powder layer to produce a cooling assembly having cooling ribs including notches for passive noise reduction.

[0059] Selective Laser Melting (SLM) is an additive manufacturing method used to create cooling ribs for cooling components in a one-piece structure from powders made of metal powders, particularly aluminum or copper alloys. It is a form of 3D printing in which a high-power laser is used to selectively melt the powder and build the substrate and cooling ribs layer by layer.

[0060] The substrate and cooling ribs of the cooling assembly are constructed layer by layer by coating a thin layer of powder onto a construction platform. A laser beam is then directed onto a selected area, where it melts the metal powder and bonds it into a solid layer. A new layer is then coated, and the process is repeated until the cooling assembly is created.

[0061] Preferably, a high-power laser is used, typically a fiber laser or a CO2 laser. The laser beam is precisely controlled to melt and fused the metal powder. Laser parameters such as power, intensity, and velocity are set according to the process and the requirements of the selected material, especially metallic materials. For example, laser parameters can also be locally adapted to achieve a defined and desired microstructure.

[0062] After additive manufacturing, the cooling components may be post-processed to achieve, for example, a flat surface and / or a smooth shape with a high profile for the cooling ribs.

[0063] In an alternative variation of the invention, the cooling component may also be manufactured by casting.

[0064] For example, the cooling components are constructed from the same and consistent materials.

[0065] In an alternative variation of the invention, the cooling assembly includes a structure for noise reduction, wherein the structure has, for example, a tab-like connecting portion.

[0066] The structure includes at least one tab-like connector, which may be constructed from braided material at the interconnected tab-like connectors, positioning the free ends of the cooling ribs in their respective positions. Here, the structure can be inserted, for example. In a system already in operation, the structure can also be inserted retrofitted. Alternatively, the structure can be permanently and integrally connected to the cooling assembly. Furthermore, the structure itself can be constructed as a single, integral piece, or it can be composed of unconnected individual components.

[0067] In one variation of the invention, the structure is configured as a separate component that is inserted into the cooling ribs of the cooling assembly. This embodiment is well-suited for noise reduction of existing, in-use electric motors used to drive centrifugal pumps, wherein the structure can be easily inserted into the cooling assembly afterward.

[0068] In another variation of the invention, the structure is integrated into the cooling assembly. Here, it is not a loose, plug-in implementation variation, but a permanently integrated and non-removable structural variation.

[0069] In a particular variant of the invention, the structure is constructed from unconnected individual elements. These elements are distributed, for example, on the cooling assembly such that they prevent vibration of the cooling ribs at their free ends for passive noise reduction. Here, these elements may extend from one cooling rib to an adjacent cooling rib, or they may span multiple cooling ribs.

[0070] According to the present invention, a system for driving a centrifugal pump with a cooling component is used in highly noise-sensitive applications while reducing noise levels. Attached Figure Description

[0071] Other features and advantages of the invention are derived from the description of embodiments based on the accompanying drawings and from the drawings themselves.

[0072] Here, in which: Figure 1 An exemplary implementation of a system for driving a centrifugal pump is shown. Figure 2 An exemplary embodiment of a cooling assembly is shown, which is arranged between the power electronics housing and the electric motor. Figure 3 Another variation of the cooling assembly is shown. Figure 4 An embodiment with notched cooling ribs is shown. Figure 5 Another embodiment with notched cooling ribs is shown. Figure 6Another embodiment with notched cooling ribs is shown. Figure 7 Another embodiment with notched cooling ribs is shown. Figure 8 An alternative embodiment with notched cooling ribs is shown. Figure 9 An embodiment of a cooling rib with a sinusoidal height profile is shown. Figure 10 An embodiment of a cooling assembly with corrugated cooling fins is shown. Figure 11 Another variation of the system is shown. Figure 12 One embodiment of the cylindrical cooling assembly is shown. Detailed Implementation

[0073] Figure 1 An exemplary embodiment of a system 1 for driving a centrifugal pump 2 is shown, the system comprising an electric motor 25 and power electronics 24. Modern high-efficiency pumps have a suction port 3 and a pressure port 4, through which the centrifugal pump 2 is integrated into the piping system.

[0074] In the illustrated implementation variant, the electric motor 25 is implemented as a canned motor. A canned motor is a special type of wet rotor motor in which the stator windings are protected from the transported medium by cylindrical, as thin-walled as possible tubes in the machine's air gap.

[0075] The power electronics 24 of system 1 are arranged in the electronics housing 5. A cooling assembly 6 is located in the lower part of the electronics housing 5. The housing of the electric motor 25 also has a cooling assembly 23.

[0076] Figure 2 and Figure 3 A cooling assembly 6 is shown, which can be mounted on the underside of the electronics housing 5. The cooling assembly 6 has fourteen cooling ribs 7, which are spaced apart from each other at equal intervals. The cooling ribs 7 extend from the substrate 8 and gradually narrow from the substrate 8. Here, the thickness of the cooling ribs 7 decreases along their height.

[0077] The cooling assembly 6 has a circular region 9 with shortened cooling ribs 7, within which two drilled sleeves 10 are arranged for fastening to the electric motor 25.

[0078] The cooling rib 7 has a lower region 11 with height H and an upper region 12 with height h, the upper region forming a height profile 13 for noise reduction. The upper region 12 has a notch 14 for forming the height profile 13. Each notch 14 forms a geometry.

[0079] exist Figure 2 The height profile 13 is constructed periodically and rectangularly with notches 14.

[0080] exist Figure 3 The height profile 13 is constructed periodically and wavyly, wherein the notch 14 is implemented as a corresponding wavy segment.

[0081] Figures 4 to 8 Exemplary detailed sections of the different cooling components 6 are shown. Each cooling component 6 has a plurality of cooling ribs 7, which are spaced apart by a distance. The spacing between the cooling ribs 7 is four times the thickness of the cooling ribs 7.

[0082] The cooling ribs 7 are oriented and arranged parallel to each other. Here, the cooling ribs 7 are constructed as flat cuboids standing upright on the substrate 8.

[0083] The cooling rib 7 has a lower region 11 and an upper region 12, the upper region forming a height profile 13 for noise reduction. The height of the lower region 11 is 85% of the total height of the cooling rib 7, and the height of the upper region 12 is 15% of the total height of the cooling rib 7.

[0084] The upper region 12 has notches 14 for forming a height profile 13, and each notch 14 forms a geometry with a width B and a depth T.

[0085] exist Figure 4 A variant implementation is shown in which each notch 14 has a different depth T and width B. This results in a non-uniform height profile 13, wherein the relatively arranged height profiles 13 achieve a very low sound pressure level, thereby effectively reducing noise generation when the system 1 is in operation.

[0086] Figure 5 A variation of the implementation is disclosed, in which each notch 14 has exactly the same depth T and width B. The height profile 13 is thus rectangular and uniformly constructed. The notches 14 of the cooling ribs 7 are partially staggered from the notches 14 of the nearest cooling ribs 7. Thus, the height profiles 13 of directly adjacent cooling ribs 7 are constructed such that their phases are shifted by π / 2.

[0087] exist Figure 6 In the variant implementation, the height profiles 13 of directly adjacent cooling ribs 7 are constructed with their phase shifted by π. This phase shift advantageously achieves passive noise reduction of the cooling assembly 6.

[0088] exist Figure 7 A variant implementation is shown in which the height profile 13 has a trapezoidal notch 14, and in which the height profiles 13 of directly adjacent cooling ribs 7 are constructed such that they are phase-shifted by π relative to each other.

[0089] Figure 8 A variant of the cooling assembly 6 with a triangular height profile 13 featuring cooling ribs 7 is shown.

[0090] Figure 9 An embodiment of a cooling rib 7 with a sinusoidal height profile 13 is shown. The height profiles 13 of directly adjacent cooling ribs 7 are constructed such that their phases are shifted by π relative to each other.

[0091] Figure 10 A variation of the cooling assembly 6 is shown, in which cooling ribs 7 are arranged in a corrugated manner on the substrate 8.

[0092] Figure 11 Another exemplary embodiment of a system 1 for driving a centrifugal pump 2 is shown, the system comprising an electric motor 25 and power electronics 24. The centrifugal pump 2 has a suction port 3 and a pressure port 4, through which the centrifugal pump is integrated into the piping system.

[0093] In the illustrated variant, the electric motor 25 is implemented as a motor connected via a flange. The power electronics 24 of the electric motor 25 are arranged in a housing 5, which is spaced apart from the electric motor 25 by a cooling assembly 6. The housing of the electric motor 25 also has a cooling assembly 23.

[0094] exist Figure 12 A variant of the cylindrical cooling assembly 23 is shown. The cooling assembly 23 has twelve cooling ribs 7, which are spaced at the same interval.

[0095] The upper region 12 of the cooling rib 7 has a notch 14 for forming a height profile 13, and each notch 14 forms a geometry with a width B and a depth T.

[0096] In the illustrated cylindrical variant, each notch 14 has an identical depth T and width B. The height profile 13 is thus rectangular and uniform in itself. The height profiles 13 of directly adjacent cooling ribs 7 are constructed with a phase shift of π relative to each other. This phase shift advantageously achieves passive noise reduction of the cooling assembly 23.

Claims

1. A system (1) for driving a centrifugal pump (2), wherein, The system (1) has at least one cooling assembly (6, 23), the cooling assembly including cooling ribs (7), wherein the cooling ribs (7) are arranged in rows at intervals from each other. Its features are, At least a portion of the cooling ribs (7) has a lower region (11) and an upper region (12) with height (H), the upper region forming a height profile (13) for noise reduction, wherein the upper region (12) has a notch (14) for forming the height profile (13), and each notch (14) forms a geometry having a width (B) and a depth (T).

2. The system of claim 1, wherein, The height profile (13) is constructed periodically.

3. The system of claim 1 or 2, wherein, The height profile (13) has the same geometry in all cooling ribs (7) of the cooling assembly (6,23).

4. The system of any one of claims 1 to 3, wherein, At least one height profile (13) is constructed in a wavy and / or rectangular and / or triangular and / or trapezoidal and / or serrated shape.

5. The system of any one of claims 1 to 4, wherein, The height profiles (13) of adjacent cooling ribs (7) are constructed in a phase-shifting manner, wherein, preferably, the height profiles (13) of directly adjacent cooling ribs (7) are constructed in a phase-shifting manner.

6. The system according to claim 5, characterized in that, The phase of the height profile (13) of the adjacent cooling ribs (7) is shifted by more than π / 8, preferably more than π / 6, especially more than π / 4, and / or less than 13π / 8, preferably less than 11π / 8, especially less than 9π / 8.

7. The system according to any one of claims 1 to 6, characterized in that, The depth (T) and width (B) of the geometry are constructed identically in all the notches (14).

8. The system according to any one of claims 1 to 7, characterized in that, The upper region (12) is more than 10%, preferably more than 15%, especially more than 20%, and / or less than 50%, preferably less than 40%, especially less than 30%, of the height (H) of the lower region (11).

9. The system according to any one of claims 1 to 8, characterized in that, The cooling rib (7) is constructed as a flat cuboid erected on the substrate (8).

10. The system according to any one of claims 1 to 9, characterized in that, The cooling rib (7) is at least partially constructed as a corrugated plate erected on the substrate (8).

11. The system according to any one of claims 1 to 10, characterized in that, The cooling assembly (23) is constructed in a manner that integrates it into the housing of the electric motor 25.

12. The system according to any one of claims 1 to 11, characterized in that, The cooling components (6, 23) are connected to the power electronics.

13. The system according to any one of claims 1 to 12, characterized in that, The cooling components (6,23) are constructed as a single piece.

14. The use of a system (1) for driving a centrifugal pump (2) in a highly noise-sensitive application with reduced noise generation.

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