Lanterns with elements for heat discharge

Abstract

The invention relates to a pump assembly having a lantern (2). The lantern (2) is arranged between a pump housing (1) and a motor housing (4). Surface enlarging elements (9) are arranged at the lantern (2) for heat discharge.

Description

[0001] The invention relates to a pump arrangement with a lantern that is arranged between a pump housing and a motor housing.

[0002] One such pump arrangement could be, for example, a centrifugal pump arrangement. Centrifugal pumps are based on the operating principle of energy transfer to a fluid through a change in swirl caused by a torque exerted on the fluid flowing through it by a uniformly rotating impeller.

[0003] Centrifugal pumps are most often driven by electric motors. Besides electric drives, piston engines are also used in centrifugal pump technology. Electric motors generate a constant torque. An electric motor is an electromechanical energy converter that transforms electrical energy into mechanical energy. Depending on the form in which the electrical energy is available, DC, AC, or three-phase motors are used. Generally, the electrical energy is converted into rotational motion.

[0004] The electric motor driving a centrifugal pump is usually connected to the pump at a specific distance via a lantern. The motor drive shaft passes through openings in the center of the two flanges or covers for mounting to the motor and the pump housing. Lanterns are typically manufactured by casting.

[0005] Such a lantern and a corresponding manufacturing process are described, for example, in EP 1 038 611 A2. The type and number of connecting webs described enable a particularly stable lantern design.

[0006] DE 25 45 278 A1 discloses an air-cooled electric monoblock pump for hot liquids with a circular end body, metal arms and impeller blades.

[0007] DE 101 20 409 A1 shows a centrifugal pump designed as a side channel pump for conveying hot media with a distance section, wherein the distance section is designed as a two-part cooling section.

[0008] Document DE 30 16 681 A1 describes a pump arrangement according to the preamble of claim 1.

[0009] In pump systems used to transfer fluids at high temperatures, significant heat can be transferred from the pump housing to the electric motor. This can lead to several problems with the electric motor. High temperatures reduce the efficiency of energy conversion. The motor components, especially the stator and rotor windings, are subjected to thermal stress, which can shorten their service life. The rotor magnets can also be damaged. In pump systems with integrated power electronics, the heating of the electronic components is particularly critical. For these reasons, the electric motor control sometimes has to reduce the power consumption and speed to prevent overheating of the electric motor and / or the power electronics, which would prevent the pump from operating within its intended range.

[0010] Typically, extra-long lanterns are used to create a large distance between the hot pump housing and the electric motor in order to avoid the problems mentioned. However, a large distance also means a larger pump assembly, which then cannot be installed at every location. Furthermore, a large distance also results in a long drive shaft, which requires suitable bearings to withstand the imbalance that occurs during operation. Increased vibrations of the entire system can be the consequence.

[0011] The object of the invention is to provide a lantern as a connecting element between a pump housing and a drive motor. This connecting element should be able to dissipate the heat emitted from the pump housing during the pumping of hot fluids as efficiently as possible and conduct only a minimal amount of heat towards the motor and / or power electronics. Furthermore, the connecting element should be characterized by a compact design. The design of the connecting element should facilitate the replacement of spare parts. The connecting element should be simple and cost-effective to manufacture.

[0012] This problem is solved according to the invention by a pump arrangement with a lantern according to claim 1. Preferred embodiments can be found in the dependent claims, the description and the drawings.

[0013] According to the invention, surface-enhancing elements for heat dissipation are arranged on a lantern of a pump assembly located between a pump housing and a motor housing. Ideally, these surface-enhancing elements are designed as cooling fins to optimize the lantern's heat dissipation. The cooling fins are preferably plate-shaped, trapezoidal, triangular, arcuate, and / or annular. Due to the optimized heat dissipation of the lantern, the pump housing, which can reach high temperatures when pumping hot fluids, and the motor housing are almost thermally decoupled.

[0014] The optimized heat dissipation of the lantern is achieved through its advantageous design. The motor assembly's fan generates a cooling airflow that cools the motor housing fins and then flows over the lantern. According to the invention, the lantern is designed such that the inner diameter remains constant along the length of the lantern body, while the outer diameter widens. In this particularly advantageous manner, the cooling airflow passes over the lantern's cooling fins and efficiently dissipates the heat. Simultaneously, the lantern's design directs the cooling airflow over the pump housing, thus reducing flow resistance as the airflow approaches the pump housing.

[0015] According to the invention, the outer diameter of the lantern body widens towards the pump side, thereby improving the flow regime of the cooling airflow generated by the motor fan. Lower flow resistance means a higher flow velocity, which in turn promotes improved heat dissipation from the motor housing and the lantern.

[0016] According to one embodiment of the invention, the lantern is rotationally symmetrical. The symmetrical design of the lantern promotes optimized airflow and intensifies heat dissipation. Advantageously, the symmetrical design of the lantern also supports thermal decoupling of the pump housing from the motor housing.

[0017] In one variant of the invention, the surface-enlarging elements, which are designed as cooling fins, are arranged on a hollow cylindrical base body of the lantern.

[0018] Preferably, the outer surface of the lantern has openings, which are preferably designed as windows. This can serve for mounting purposes, for access to the shaft and / or for the inflow of cooling air and / or for increasing the thermal resistance of the lantern.

[0019] Advantageously, the lantern directly connects the pump housing and the motor housing. In principle, no additional component is needed to create this connection. Reducing the number of components is usually beneficial for reducing manufacturing costs.

[0020] In one embodiment of the invention, the lantern is designed in multiple parts. This can be achieved, for example, with removable blades and / or cooling fins, and / or by a split lantern design. Furthermore, a solution with different sleeves that can be slid over one another is also conceivable, with cooling fins arranged on one outer side of each sleeve.

[0021] Preferably, the thermal conductivity of the lantern material is less than 40 W / m·K, preferably less than 20 W / m·K, and in particular less than 10 W / m·K.

[0022] Preferably, the lantern is made of cast iron, aluminum, or stainless steel.

[0023] The lantern can be manufactured using a casting process or 3D printing.

[0024] Ideally, the thermal conductivity of the cooling fins is more than 150 W / m·K, in particular more than 200 W / m·K, preferably more than 250 W / m·K.

[0025] According to the invention, the surface-enlarging elements are designed as guide elements for directing a cooling airflow over the pump housing and for reducing flow resistance. The flow-optimized guidance of the cooling airflow increases the heat dissipation of the lantern, which is directed from the pump housing into the lantern.

[0026] According to one embodiment of the invention, the surface-enlarging elements are axially aligned. The axial alignment of the cooling fins promotes the flow of cooling air with reduced flow resistance and results in particularly efficient heat dissipation from the lantern.

[0027] In one embodiment of the invention, the surface-enlarging elements are advantageously radially oriented. This orientation achieves a flow-optimized discharge of the cooling airflow over the pump housing and simultaneously enables efficient heat dissipation from the lantern. This preferably results in thermal decoupling of the pump housing and the motor housing.

[0028] According to the invention, the lantern has elements for increasing its surface area. These elements can be designed in the form of cooling fins. The thermal decoupling of the pump housing from the motor housing is facilitated by the increased surface area of ​​the lantern. The surface-enlarging elements are designed in the form of plates, trapezoids, triangles, arcs, or rings, similar to cooling fins.

[0029] According to the invention, the lantern is shaped like a trumpet. This spatial design is particularly advantageous for achieving additional cooling of the lantern by the cooling airflow generated by the motor fan. In an alternative embodiment of the invention, the lantern can also be conical and / or cuboid in shape.

[0030] In one embodiment of the invention, the lantern is formed integrally with the motor-side pressure cover of the pump housing and / or integrally with the pump-side motor cover. Advantageously, this allows the lantern to be designed to be particularly compact and enables a pump arrangement with dimensions that can also be used in installation locations with limited space.

[0031] Preferably, the lantern is designed as a bearing support on the pump side and / or motor side. This results in a particularly compact lantern design and simultaneously reduces assembly effort by decreasing the number of parts. Advantageously, cutouts in the form of windows can be arranged in the lantern to allow cooling air to enter the lantern interior for cooling the shaft.

[0032] 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.

[0033] This shows: Fig. 1 a schematic representation of a centrifugal pump unit according to the prior art, Fig. 2 a schematic representation of a centrifugal pump unit with surface-enlarging elements, Fig. 3 a schematic representation of a centrifugal pump unit with surface-enlarging, arc-shaped elements, Fig. 4 a schematic representation of a centrifugal pump unit according to the invention with a trumpet-shaped lantern and surface-enlarging elements, Fig. 5 a schematic representation of another centrifugal pump unit according to the invention with a trumpet-shaped lantern and surface-enlarging, arc-shaped elements, Fig. 6 a schematic representation of a centrifugal pump unit with radially oriented, surface-enlarging elements, Fig. 7 a schematic representation of a centrifugal pump unit with a further embodiment of the surface-enlarging elements.

[0034] Fig. 1 Figure 1 shows a schematic representation of a centrifugal pump unit according to the prior art. A lantern 2 is arranged between a pump housing 1 and a motor housing 4, connecting them. The centrifugal pump shown in the exemplary embodiment is used for pumping fluids that may have high temperatures.

[0035] The fluid enters the pump housing 1 of the centrifugal pump through a suction port 7. The impeller is located inside the pump housing 3. The impeller transfers kinetic energy to the fluid, which exits the centrifugal pump through the discharge port 8. The space filled with fluid and impeller is bounded by the pump housing 1 and a housing cover. The impeller is non-rotatably connected to a shaft, which drives the impeller via a motor assembly. The motor assembly comprises the motor electronics 3, a rotor, a stator, the shaft, a pump-side motor cover, and a motor housing 4. A bearing support, which carries a bearing, is located in the motor cover.

[0036] A fan impeller 6, mounted on the shaft, draws in a cooling airflow axially through the fan housing 5 to flow over the motor housing 4 and through the space between the motor housing 4 and the motor electronics 3. The arrows in the Fig. 1 dargestellte Kühlluftstrom überströmt die Laterne 2 und prallt gegen das Pumpengehäuse 1. Dadurch wird das Strömungsregime des Kühlluftstroms negativ beeinflusst und die Wärmeabfuhr reduziert.

[0037] Fig. 2 Figure 1 shows a schematic representation of a centrifugal pump unit with surface-enlarging elements 9. In this embodiment, the surface-enlarging elements 9 are designed as cooling fins. The cooling fins extend axially along the length of the base body of the lantern 2 and are arranged on the outside of the hollow cylindrical lantern 2. Preferably, the width of the axial cooling fins is more than 1 mm, preferably more than 2 mm, particularly more than 3 mm, and / or less than 14 mm, preferably less than 12 mm, particularly less than 10 mm. The height of the axial cooling fins is more than 3 mm, preferably more than 5 mm, particularly more than 7 mm, and / or less than 50 mm, preferably less than 45 mm, particularly less than 40 mm.

[0038] In this embodiment, the thermal conductivity of the lantern material is less than 40 W / m·K, preferably less than 20 W / m·K, particularly less than 10 W / m·K, and the thermal conductivity of the cooling fins is more than 150 W / m·K, particularly more than 200 W / m·K, preferably more than 250 W / m·K. Preferably, the base body of the lantern 2 is made of gray cast iron, aluminum, or stainless steel.

[0039] In this example, the surface-enlarging elements 9 are axially aligned. The axial alignment of the cooling fins promotes the flow of cooling air, indicated by arrows in the figure, with reduced flow resistance and leads to particularly efficient heat dissipation from the lantern 2.

[0040] Furthermore, the lantern has two cutouts 10 in the form of windows to allow the cooling airflow to enter the lantern interior for cooling the shaft.

[0041] Fig. 3 Figure 1 shows a schematic representation of a centrifugal pump unit with surface-enlarging, arc-shaped elements 9. Several surface-enlarging elements 9 are arranged on the base body of the lantern 2; in this embodiment, these elements are designed as arc-shaped or curved cooling fins. The dimensions of the cooling fins correspond to those shown in Figure 2. Fig. 2 The cooling airflow generated by the fan impeller 6 flows over the cooling fins of the motor housing 4 and subsequently over the cooling fins of the lantern 2. Due to the curved shape of the cooling fins of the lantern 2, the cooling airflow is directed as shown by the arrows in the Fig. 3 The deflection shown does not impact the pump housing 1 perpendicularly. This improves the overall flow regime of the cooling airflow and increases the heat dissipation performance of the lantern 2 and the motor housing 4.

[0042] Fig. 4 Figure 1 shows a schematic representation of a centrifugal pump unit according to the invention with a trumpet-shaped lantern 2 and surface-enlarging elements 9. The trumpet shape of the exemplary embodiment of the lantern 2 is particularly optimized for the flow of the cooling airflow generated by the fan impeller 6. The arrows in Fig. 4 The depicted cooling airflow does not strike the pump housing 1 perpendicularly, but is guided over the pump housing 1 by the trumpet-shaped design of the lantern 2. This flow optimization results in a higher flow velocity of the cooling airflow, which also improves the heat dissipation of the surface-enlarging elements 9 arranged axially on the lantern 2. Simultaneously, the heat-dissipating surface area of ​​the lantern 2 is increased, further enhancing the heat dissipation capacity.

[0043] In one embodiment of the invention, the trumpet-shaped lantern 2 can also be asymmetrically designed to optimally shape the flow over an asymmetrically designed pump housing 1. In this case, the shape of the lantern 2 is adapted to the shape of the pump housing 1.

[0044] Fig. 5 Figure 1 shows a schematic representation of another centrifugal pump unit according to the invention, with a trumpet-shaped lantern 2 and surface-enlarging, arc-shaped elements 9. The lantern 2 shown in this embodiment largely corresponds to the lantern 2 from [reference missing]. Fig. 4 Additionally, the surface-enlarging elements 9 are designed in the form of curved cooling fins. This directs the cooling airflow, indicated by arrows, over the pump housing 1 and simultaneously creates a swirl that improves heat dissipation performance.

[0045] Fig. 6 Figure 1 shows a schematic representation of a centrifugal pump unit with a lantern 2, whose surface-enlarging elements 9 are radially oriented. The lantern 2 has several radially arranged surface-enlarging elements 9, which in this embodiment are designed as radial cooling fin rings. The base body of the lantern 2 of the Fig. 6 corresponds to lantern 2 from Fig. 2 In this embodiment, four cooling fin rings are additionally arranged on the hollow cylindrical base body. The cooling fin rings have different heights, which increase towards the pump housing 1 in such a way that the lantern 2 takes on a frustoconical shape due to the cooling fin rings.

[0046] Preferably, the width of the cooling fin rings is more than 1 mm, preferably more than 2 mm, particularly more than 3 mm, and / or less than 14 mm, preferably less than 12 mm, particularly less than 10 mm. The height of the smallest cooling fin ring is more than 3 mm, preferably more than 5 mm, particularly more than 7 mm, and / or less than 30 mm, preferably less than 25 mm, particularly less than 20 mm. Simultaneously, the height of the largest cooling fin ring is more than 20 mm, preferably more than 25 mm, particularly more than 30 mm, and / or less than 100 mm, preferably less than 90 mm, particularly less than 80 mm.

[0047] In this example, the cooling fin rings are arranged vertically at equal intervals on the lantern 2, with the height of the cooling fin rings increasing symmetrically towards the pump housing 1. In an alternative variant, the arrangement of the cooling fin rings is not at equal intervals and / or the orientation is not perpendicular to the lantern 1. In this case, the orientation of the cooling fin rings can assume a flow-optimized angle.

[0048] The material thickness of the lantern 2 is more than 1 mm, preferably more than 2 mm, in particular more than 3 mm, and / or less than 14 mm, preferably less than 12 mm, in particular less than 10 mm.

[0049] In one embodiment of the invention, the cooling fin rings can be arranged on a sleeve that is mounted over the hollow cylindrical base body of the lantern 2.

[0050] Advantageously, the surface-enlarging elements 9, in the form of cooling fin rings, are radially oriented. This orientation ensures a flow-optimized discharge of the cooling airflow over the pump housing 1 and simultaneously enables efficient heat dissipation from the lantern 2 through vortex formation at the individual cooling rings. This preferably achieves thermal decoupling of the pump housing and motor housing.

[0051] Fig. 7 Figure 1 shows a schematic representation of a centrifugal pump unit with a further embodiment of the surface-enlarging elements 9, which are designed in the form of radially oriented cooling rings. Inlet channels, always offset by 90°, direct the cooling airflow through the windows 10 of the lantern 2 into the lantern interior to cool the drive shaft. The cooling fin rings have interruptions in the area of ​​the windows 10 and are not rotationally symmetrical.

Claims

1. Pump arrangement, in particular centrifugal pump arrangement, with a lantern (2) which is arranged between a pump casing (1) and a motor casing (4), wherein surface-enlarging elements (9) for dissipating heat are arranged on the lantern (2), wherein the surface-enlarging elements (9) are arranged on a base body of the lantern (2), wherein the internal diameter remains constant over the length of the base body of the lantern (2), characterized in that the surface-enlarging elements (9) are designed as guide elements for guiding a stream of cooling air over the pump casing (1) and for reducing the flow resistance, wherein the external diameter of the base body of the lantern (2) is widened towards the pump side.

2. Pump arrangement according to Claim 1, characterized in that the lantern (2) has a rotationally symmetrical design.

3. Pump arrangement according to either of Claims 1 and 2, characterized in that the lantern (2) directly connects the pump casing (1) and the motor casing (4).

4. Pump arrangement according to one of Claims 1 to 3, characterized in that the thermal conductivity of the surface-enlarging elements (9) is more than 150 W / m·K, preferably more than 200 W / m-K, in particular more than 250 W / m-K.

5. Pump arrangement according to one of Claims 1 to 4, characterized in that the thermal conductivity of the lantern (2) is less than 40 W / m-K, preferably less than 20 W / m-K, in particular less than 10 W / m·K.

6. Pump arrangement according to one of Claims 1 to 5, characterized in that the surface-enlarging elements (9) are oriented axially.

7. Pump arrangement according to one of Claims 1 to 5, characterized in that the surface-enlarging elements (9) are oriented radially.

8. Pump arrangement according to one of Claims 1 to 7, characterized in that the surface-enlarging elements (9) have a plate-shaped and / or trapeziform and / or curved and / or triangular and / or annular design.

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