Lantern with heat dissipation elements

Abstract

The present invention relates to a pump assembly having a lantern (2) disposed between a pump housing (1) and a motor housing (4), in which a surface enlarging element (9) is disposed for heat dissipation.

Description

Technical Field

[0001] The present invention relates to a pump mechanism having a lantern disposed between a pump casing and a motor casing.

[0002] Such a pump mechanism can be, for example, a centrifugal pump mechanism. A centrifugal pump is based on the operating principle of transmitting energy to a fluid by changing a vortex as a result of the torque generated by a uniformly rotating impeller through which the fluid flows.

[0003] A centrifugal pump is usually driven by an electric motor. In centrifugal pump technology, a piston engine is also used as a driving means in the same way as such an electric drive unit. An electric motor generates a constant torque. An electric motor is an electromechanical energy converter that converts electrical energy into mechanical energy. Depending on the form of electrical energy available, a DC motor, an AC motor, or a three-phase motor is used. Electrical energy is generally converted into rotational motion in this specification.

[0004] An electric motor driving a centrifugal pump is usually connected to the pump via a lantern at specific intervals. The motor drive shaft, in this specification, passes through the center of the openings of two flanges or covers for fixing to the motor and the pump casing. A lantern is usually produced by casting.

[0005] Such a lantern and the corresponding production method are described, for example, in EP1038611A2. Depending on the type and number of connecting lugs described, a particularly stable design of the lantern is possible.

[0006] When a pump mechanism is used to pump fluid, heat can be released from the pump casing towards the electric motor at high temperatures. This can cause many problems for the electric motor. High temperatures reduce energy conversion efficiency. Motor components, specifically the stator and rotor windings, are subjected to thermal load, which can shorten their lifespan. Furthermore, the rotor magnets may be damaged. In the case of a pump mechanism with integrated power electronics circuits, heating of electronic components is particularly serious. For these reasons, the electric motor control system may have to reduce power consumption and speed to prevent overheating of at least one of the electric motor and power electronics circuits. If overheating occurs, the pump may not be able to operate within its desired operating range.

[0007] To avoid the problems described, attempts are typically made to implement a large gap between the high-temperature pump casing and the electric motor, especially by using long lanterns. A larger gap means a larger pump mechanism, which may prevent the pump mechanism from being installed in any location. A larger gap also requires a longer drive shaft, which in turn requires proper mounting to absorb the imbalances that occur during operation. As a result, the overall system vibration may increase. [Overview of the project]

[0008] The object of the present invention is to provide a lantern as a coupling element between a pump casing and a drive motor. The coupling element is intended to dissipate as effectively as possible the heat released by the pump casing when pumping a hot fluid, and to minimize heat transfer to the motor and power electronics circuit in at least one direction. The coupling element is further intended to be distinguished by its compact structure. The structure of the coupling element should be convenient for changing replacement parts. The coupling element should be able to be implemented simply and cost-effectively.

[0009] The objective is achieved according to the present invention by a pump mechanism having a lantern. Preferred modifications can be found in the dependent claims, specification, and drawings.

[0010] According to the present invention, a surface-enhancing element for heat dissipation is positioned in the lantern of the pump mechanism, which is located between the pump casing and the motor casing. The surface-enhancing element is ideally designed as a cooling rib to optimize the heat dissipation of the lantern. The cooling rib has a plate shape and / or trapezoidal and / or triangular and / or curved and / or annular design. Thanks to the optimized heat dissipation of the lantern, the pump casing, which can become hot due to the pumping of hot fluid, and the motor casing are effectively thermally separated.

[0011] The optimization of heat dissipation in the lantern is achieved through the advantageous structure of the lantern. The fan of the motor mechanism generates a cooling airflow, which cools the ribs of the motor casing and then flows over the lantern. The lantern is constructed such that, as specified herein, the inner diameter remains constant along the length of the lantern base body, while the outer diameter widens. In this particularly advantageous manner, the cooling airflow flows over the cooling ribs of the lantern, efficiently dissipating heat. At the same time, the structure of the lantern deflects the cooling airflow away from the pump casing, thereby reducing the flow resistance to the pump casing.

[0012] In a modified version of the present invention, the outer diameter of the lantern base widens on the pump side, resulting in an improved flow pattern of the cooling airflow generated by the motor fan. A decrease in flow resistance, i.e., a increase in flow velocity, is advantageous for improving heat dissipation of the motor casing and the lantern.

[0013] According to a modified version of the present invention, the lantern is designed to be rotationally symmetric. The symmetrical structure of the lantern is advantageous for guiding and optimizing the flow of cooling air, thereby enhancing the heat dissipation of the lantern. Thermally separating the pump casing from the motor casing is also advantageously aided by the symmetrical configuration of the lantern.

[0014] In a modified version of the present invention, the surface expansion element, designed as a cooling rib, is arranged on the hollow cylindrical base of the lantern.

[0015] The shell surface of the lantern preferably has an opening configured as a window. The opening can be used for mounting, accessing the shaft, allowing cooling air to enter, and for at least one of increasing the thermal resistance of the lantern.

[0016] The lantern design advantageously connects the pump casing and the motor casing directly. Essentially, no further components are needed to achieve this connection. Reducing the number of components is usually advantageous in lowering production costs.

[0017] In a modified version of the present invention, the lantern is composed of multiple parts. This can be done, for example, by using at least one of a detachable blade and cooling ribs, or by a divided configuration of the lantern, or by a combination thereof. Furthermore, a solution using different sleeves that can be pressed together is also conceivable, in which the cooling ribs are positioned on the outer surface of the sleeves.

[0018] According to the present invention, the thermal conductivity of the lantern material is less than 40 W / m·K, preferably less than 20 W / m·K, and particularly less than 10 W / m·K.

[0019] The lantern is preferably made of gray cast iron, aluminum, or stainless steel.

[0020] Lanterns can be produced by casting or 3D printing.

[0021] The thermal conductivity of the cooling ribs is, ideally speaking, greater than 150 W / m·K, particularly greater than 200 W / m·K, and preferably greater than 250 W / m·K.

[0022] The surface expansion elements are specifically designed as guide elements for guiding the cooling airflow. Optimized guidance of the cooling airflow increases heat dissipation from the lantern, and the heat is conducted from the pump casing to the lantern.

[0023] According to embodiments of the present invention, the surface expansion elements are oriented axially. The axial orientation of the cooling ribs is advantageous for the cooling airflow to overflow with low flow resistance, making the heat dissipation of the lantern particularly ideal.

[0024] In a modified version of the present invention, the surface expansion element is advantageously oriented radially. This orientation causes a deflection that optimizes the flow of cooling air away from the pump casing, while simultaneously allowing heat dissipation from the lantern. Preferably, thermal separation between the pump casing and the motor casing is obtained as a result.

[0025] The lantern, ideally, has elements for surface expansion. These elements can be configured in the form of cooling ribs. Surface expansion of the lantern is advantageous for thermally separating the pump casing from the motor casing. The surface expansion elements specified herein, in the form of cooling ribs, have plate shapes and / or trapezoidal and / or triangular and / or curved and / or annular designs.

[0026] The lantern preferably has a cylindrical design or a design in the shape of a trumpet bell. Such a spatial design is particularly advantageous for obtaining additional cooling of the lantern by the cooling air flow generated by the motor fan. In an alternative variant of the invention, the lantern can also have a design of at least one of a conical shape and a cuboid shape.

[0027] In a variant of the invention, the lantern is designed to be integrated with the motor-side pressure cover of the pump casing, with the pump-side motor cover, or with both. Thus, the lantern can advantageously be configured to be particularly compact and enables a pump mechanism having dimensions that allow it to be used even in a placement location with limited space conditions.

[0028] According to the invention, the lantern is designed as a bearing carrier on at least one of the pump side and the motor side. From this, the structure of the lantern becomes particularly compact, and at the same time, the cost increase is reduced by suppressing the number of parts.

[0029] A cutout in the form of a window for sucking a cooling air flow into the interior of the lantern to cool the shaft can advantageously be arranged in the lantern.

[0030] Further features and advantages of the invention can be found in the description of the exemplary embodiments using the drawings and in the drawings themselves.

Brief Description of the Drawings

[0031] [Figure 1] Shows a schematic view of a centrifugal pump unit according to the prior art. [Figure 2] Shows a schematic view of a centrifugal pump unit having a surface expansion element. [Figure 3] Shows a schematic view of a centrifugal pump unit having a surface expansion curved element. [Figure 4]A schematic diagram of a centrifugal pump unit having a trumpet bell-shaped lantern and surface expansion element is shown. [Figure 5] A schematic diagram of a centrifugal pump unit having a lantern shaped like a trumpet bell and a surface-expanding curved element is shown. [Figure 6] A schematic diagram of a centrifugal pump unit having a surface expansion element oriented radially is shown. [Figure 7] A schematic diagram of a centrifugal pump unit having a further configuration of surface expansion elements is shown. [Modes for carrying out the invention]

[0032] Figure 1 shows a schematic diagram of a prior art centrifugal pump unit. A lantern 2 is positioned between the pump casing 1 and the motor casing 4, interconnecting them. The centrifugal pump shown in the exemplary embodiment is used to pump fluid, which may be hot in some cases.

[0033] The fluid enters the pump casing 1 of the centrifugal pump through the intake port 7. An impeller is located inside the pump casing 3. The impeller transfers kinetic energy to the fluid, which then exits the centrifugal pump through the exhaust port 8. The space filled with the fluid and impeller is defined by the pump casing 1 and the casing cover. The impeller is non-rotatably coupled to the shaft, which is driven by a motor mechanism. The motor mechanism comprises a motor electronic circuit 3, a rotor, a stator, a shaft, a pump-side motor cover, and a motor casing 4. The motor cover houses bearing carriers that support bearings.

[0034] The fan impeller 6, positioned on the shaft, draws cooling airflow axially through the fan casing 5, causing the cooling airflow to flow over the motor casing 4 and through the space between the motor casing 4 and the motor electronic circuit 3. The cooling airflow, indicated by the arrow in Figure 1, flows over the lantern 2 and hits the pump casing 1. As a result, the flow pattern of the cooling airflow is negatively affected, reducing heat dissipation.

[0035] Figure 2 shows a schematic diagram of a centrifugal pump unit having a surface expansion element 9. In this exemplary embodiment of the present invention, the surface expansion element 9 is designed as a cooling rib. The cooling rib extends axially along the length of the base body of the lantern 2 and is located on the outside of the hollow cylindrical lantern 2. According to the present invention, the width of the axial cooling rib is greater than 1 mm, preferably greater than 2 mm, particularly greater than 3 mm, and in addition or independently thereof, less than 14 mm, preferably less than 12 mm, particularly less than 10 mm. The height of the axial cooling rib is greater than 3 mm, preferably greater than 5 mm, particularly greater than 7 mm, and in addition or independently thereof, less than 50 mm, preferably less than 45 mm, particularly less than 40 mm.

[0036] In this exemplary embodiment, the thermal conductivity of the lantern material is less than 40 W / m·K, preferably less than 20 W / m·K, and particularly less than 10 W / m·K, and the thermal conductivity of the cooling ribs is greater than 150 W / m·K, particularly greater than 200 W / m·K, and preferably greater than 250 W / m·K. The base body of the lantern 2 is preferably made of gray cast iron or stainless steel.

[0037] According to the present invention, the surface expansion element 9 is oriented in the axial direction. Orienting the cooling ribs in the axial direction is advantageous in reducing the flow resistance of the cooling airflow over the cooling ribs, as indicated by the arrows in the figure, and makes the heat dissipation of the lantern 3 particularly ideal.

[0038] A cutout 10 in the form of a window is further positioned in the lantern 2 to draw in a cooling airflow into the interior of the lantern in order to cool the shaft.

[0039] Figure 3 shows a schematic diagram of a centrifugal pump unit having surface-expanding curved elements 9. In this exemplary embodiment, multiple surface-expanding elements 9, designed as curved or arched cooling ribs, are arranged on the base body of the lantern 2. The dimensions of the cooling ribs correspond to the dimensions in Figure 2. The cooling airflow generated by the fan impeller 6 flows over the cooling ribs of the motor casing 4 and then over the cooling ribs of the lantern 2. Thanks to the curved shape of the cooling ribs of the lantern 2, the cooling airflow is deflected as shown by the arrows in Figure 3 and does not strike the pump casing 1 perpendicularly. As a result, the flow mode of the cooling airflow is improved overall, increasing the heat dissipation capacity of the lantern 2 and the motor casing 4.

[0040] Figure 4 shows a schematic diagram of a centrifugal pump unit having a trumpet bell-shaped lantern 2 and a surface expansion element 9. The trumpet bell shape in the exemplary embodiment of the lantern 2 is particularly optimized in terms of the cooling airflow generated by the fan impeller 6. The cooling airflow shown in Figure 4 does not strike the pump casing 1 perpendicularly, but instead is guided over the pump casing 1 by the trumpet bell shape of the lantern 2. This optimization of the flow increases the velocity of the cooling airflow, and as a result, the heat dissipation of the axially positioned surface expansion element 9 in the lantern 2 is also improved. At the same time, the heat dissipation surface of the lantern 2 is enlarged, resulting in a further increase in heat dissipation capacity.

[0041] In a modified version of the present invention, the trumpet-bell-shaped lantern 2 may also have an asymmetrical design to ideally form a flow on the asymmetrically formed pump casing 1. Here, the shape of the lantern 2 is adapted to the shape of the pump casing 1.

[0042] Figure 5 shows a schematic diagram of a centrifugal pump unit having a trumpet bell-shaped lantern 2 and a surface-expanding curved element 9. The lantern 2 shown in this exemplary embodiment largely corresponds to the lantern 2 in Figure 4. Furthermore, the surface-expanding element 9 is designed in the form of a curved cooling rib. As a result, the cooling airflow indicated by the arrow is guided onto the pump casing 1, and at the same time generates a vortex flow that improves the heat dissipation capacity.

[0043] Figure 6 shows a schematic diagram of a centrifugal pump unit having a lantern 2 with its surface expansion elements 9 oriented radially. The lantern 2 has a plurality of radially arranged surface expansion elements 9, which are designed as radial cooling rib rings in this exemplary embodiment. The base body of the lantern 2 in Figure 6 corresponds to the lantern 2 in Figure 2. Thus, in this exemplary embodiment, four cooling rib rings are additionally arranged on the hollow cylindrical base body. The cooling rib rings have different heights, increasing toward the pump casing 1, thereby giving the lantern 2 a frustoconical shape due to the cooling rib rings.

[0044] According to the present invention, the width of the cooling rib ring is greater than 1 mm, preferably greater than 2 mm, particularly greater than 3 mm, and in addition or independently thereof, less than 14 mm, preferably less than 12 mm, particularly less than 10 mm. The height of the smallest cooling rib ring is, as specified herein, greater than 3 mm, preferably greater than 5 mm, particularly greater than 7 mm, and in addition or independently thereof, less than 30 mm, preferably less than 25 mm, particularly less than 20 mm. At the same time, the height of the largest cooling rib ring is greater than 20 mm, preferably greater than 25 mm, particularly greater than 30 mm, and in addition or independently thereof, less than 100 mm, preferably less than 90 mm, particularly less than 80 mm.

[0045] According to the present invention, the cooling rib rings are arranged perpendicular to the lantern 2 at equal intervals, and the height of the cooling rib rings increases symmetrically in the direction of the pump casing 1. In alternative modifications of the present invention, the arrangement of the cooling rib rings is not equal to one another, and in addition, or independently thereof, their orientation is not perpendicular to the lantern 1. The orientation of the cooling rib rings can be assumed to be an angle at which the flow is optimized.

[0046] The thickness of the material for lantern 2 is greater than 1 mm, preferably greater than 2 mm, and particularly greater than 3 mm, and in addition to or independently of this, less than 14 mm, preferably less than 12 mm, and particularly less than 10 mm.

[0047] In an exemplary embodiment of the present invention, the cooling rib ring can be arranged in a sleeve mounted on the hollow cylindrical base of the lantern 2.

[0048] The surface enlargement elements 9 are advantageously oriented radially in the form of cooling rib rings. This orientation causes a deflection that optimizes the flow of cooling air away from the pump casing 1, while simultaneously enabling efficient heat dissipation of the lantern 2 by forming swirling flows in the individual cooling rings. As a result, thermal separation between the pump casing and the motor casing is preferably achieved.

[0049] Figure 7 shows a schematic diagram of a centrifugal pump unit having a further configuration of surface expansion element 9 designed in the form of a radially oriented cooling ring. In both cases, the inlet duct, which is offset by 90°, guides a cooling airflow into the interior of the lantern through the window 10 of the lantern 2 to cool the drive shaft. The cooling rib ring is designed to have a interrupted portion in the area of ​​the window 10 and is not perfectly rotationally symmetrical.

Claims

1. A pump mechanism having a lantern (2) positioned between a pump casing (1) and a motor casing (4), wherein a surface-expanding element (9) for heat dissipation is positioned on the lantern (2), the inner diameter of the base body remains constant over the length of the base body of the lantern (2), the outer diameter of the base body widens toward the pump casing side so that a cooling airflow flowing from the motor casing (4) toward the pump casing (1) along the axial outer surface of the base body is guided toward the axial outer surface of the pump casing (1), and the surface-expanding element (9) is positioned on the axial outer surface of the base body.

2. The pump mechanism according to claim 1, characterized in that the lantern (2) is designed to be rotationally symmetric.

3. The pump mechanism according to claim 1 or 2, characterized in that the lantern (2) is directly connected to the pump casing (1) and the motor casing (2).

4. The pump mechanism according to any one of claims 1 to 3, characterized in that the thermal conductivity of the surface expansion element (9) is greater than 150 W / m·K.

5. The pump mechanism according to any one of claims 1 to 4, characterized in that the thermal conductivity of the lantern (2) is less than 40 W / m·K.

6. The pump mechanism according to any one of claims 1 to 5, characterized in that the surface expanding element (9) is designed as a guide element for at least one of guiding a cooling airflow and reducing flow resistance.

7. The pump mechanism according to any one of claims 1 to 6, characterized in that the surface expansion element (9) is oriented in the axial direction.

8. The pump mechanism according to any one of claims 1 to 6, characterized in that the surface expansion element (9) is oriented radially.

9. The pump mechanism according to any one of claims 1 to 8, characterized in that the surface enlargement element (9) has a plate shape and / or trapezoidal and / or curved and / or triangular and / or annular design.

Images