PUMP WITH AN ELECTRONICS HOUSING AND AT LEAST A HEAT SINKER

Description

[0001] The invention relates to a pump, preferably a centrifugal pump, particularly preferably a heating circulation pump, with an electronics housing and at least one heat sink which is a component of the electronics housing, wherein the heat sink has a heat sink base plate forming a bottom of the electronics housing, on the outer surface of which heat sink base plate cooling fins extend.

[0002] Modern pumps such as heating circulation pumps are equipped with extensive electronics for controlling and regulating the pump, as disclosed, for example, in DE102015016260 A1. An important component can be a frequency converter for controlling the pump's speed. The frequency converter or the entire pump electronics consists of a wide variety of individual components, which include the input circuit for the voltage supply, an intermediate circuit, and power electronics for frequency modulating the operating voltage of the electric motor. These individual components differ in terms of their power loss and resulting heat loss, as well as their height and therefore the space required within the housing. Adequate cooling of the electronic components is achieved by means of a separate heat sink, which is an integral part of the electronics housing and guarantees sufficient heat dissipation from the housing.To increase the surface area, cooling fins extend from the outer surface of the heat sink.

[0003] Under certain operating conditions, undesirable natural vibrations of the fins can occur, triggered by vibrations of the pump during operation. To shift the natural frequencies, the fins are often stiffened to prevent resonant vibrations.

[0004] The object of the present invention is to show a simple way to avoid the above-mentioned problem.

[0005] This object is achieved by a pump, preferably a centrifugal pump, particularly preferably a heating circulation pump, according to the features of claim 1. Advantageous embodiments of the pump are the subject of the dependent claims.

[0006] According to the invention, at least some of the cooling fins are formed with a curved profile along the heat sink base plate. The curved profile follows a predefined radius of curvature. The curved profile stiffens the cooling fins, effectively preventing natural vibrations during pump operation. The measure according to the invention represents a particularly simple and cost-effective solution. A further advantage of this solution is the externally appealing appearance of the fins, since the curved profile enables a uniform appearance for all fins of the heat sink.

[0007] The pump can preferably be designed as a centrifugal pump, particularly preferably as a heating circulation pump.

[0008] Particularly advantageously, at least one cooling fin has a constant radius of curvature over its entire length, i.e., the cooling fin is curved over its entire axial length along the heat sink base plate and not just in individual sections. A particularly suitable radius of curvature for the cooling fins, especially for use in heating circulation pumps, is in the range between 10 cm and 15 cm, preferably between 11 cm and 14 cm, and particularly preferably between 12.5 cm and 13 cm.

[0009] According to one embodiment, all cooling fins can have the same radius of curvature, or at least a majority of the existing cooling fins. It is also conceivable for the radius of curvature of adjacent cooling fins to vary, e.g., for the cooling fins located closer to the pump's motor housing to be reduced. In particular, the radius of curvature can be reduced depending on the proximity to the motor housing. For example, it can be provided that the curvature of the fins is coaxial with the motor axis (axis of rotation). Furthermore, it can be provided that all or at least a majority of the cooling fins run parallel to one another.

[0010] According to an advantageous embodiment of the invention, the overhang length of the individual cooling fins of the heat sink can vary. The overhang length is measured from the outer surface of the heat sink base plate to the outer free end of the fin. As the overhang length increases, the cooling surface area increases, thus optimizing the achievable cooling performance.

[0011] Furthermore, the heat sink base plate can be provided with several steps. The inner bottom surface of the heat sink base plate is therefore not completely flat, but has several steps. Each resulting step defines a volume section within the electrical housing, whereby the volume sections defined by the steps differ in terms of their installation space height. The installation space height is limited by the distance between the heat sink base plate or the respective step and an opposite surface within the electronics housing. The opposite surface can, for example, be a circuit board mounted within the housing as a carrier for the electronic components of the pump electronics.

[0012] In brief, the electronics housing is divided into different installation space sections by the stepped geometric design of the base surface. Each step of the heat sink base plate can preferably create an installation space for a specific component group of electronic components of the pump electronics. The electronic components of the specific component groups sensibly differ in terms of their geometric dimensions, in particular their height when functionally assembled on a circuit board. Consequently, it is advantageous if the electronic components are grouped into specific component groups depending on their component size. Alternatively or additionally, it is also particularly advantageous if the grouping is based on the heat dissipation of the component, i.e. the required cooling performance.

[0013] Each or at least two, in particular three stages have said cooling fins on their outer surface of the heat sink base plate, in particular a specific number of cooling fins arranged adjacent to one another, which preferably extend parallel to one another on the surface of the heat sink base plate, ideally with an identical radius of curvature. The cooling fins of a stage are referred to as a cooling fin group. It can be provided that the cooling fins of a first stage differ from the cooling fins of a second stage, in particular with regard to the selected overhang length. Accordingly, the respective cooling fin groups can differ from one another with regard to the overhang lengths of their cooling fins.

[0014] The cooling fins of at least one cooling fin group can all, or at least the majority of the cooling fins, have the same overhang length. It is also conceivable for the cooling fins of at least one cooling fin group, or at least the majority of the cooling fins, to have varying overhang lengths. For example, it can be provided that the overhang lengths of adjacent cooling fins decrease continuously; for example, a first cooling fin has a first overhang length, an adjacent cooling fin has a reduced overhang length, and the cooling fin after it has a further reduced overhang length. For example, a decrease in the overhang length toward the pump's motor housing is conceivable.

[0015] As already explained above, the installation space within the electronics housing can be divided into different sections for different component groups. The grouping of component groups can depend not only on their installation height but also on the heat loss they produce. Against this background, it can be sensible for the component group with the greatest power loss or the highest cooling requirement to be arranged in the installation space of the electronics housing that is defined by the step of the heatsink base plate with the cooling fin group with the greatest overhang lengths. The high cooling performance required there can be achieved by enlarging the cooling fins there. It makes sense to arrange the components of the power electronics of a frequency converter and / or the power factor correction filter in this area, as these generate the greatest heat loss during operation.

[0016] Furthermore, it proves advantageous if the component group with the lowest power loss or the lowest cooling requirement and / or the greatest height is arranged in the installation space of the electronics housing formed by the step of the heat sink base plate with the cooling fin group with the shortest overhang lengths or without cooling fins. The component group with the lowest power loss includes, for example, the components of an EMC filter and / or the input or intermediate circuit of the frequency converter. Since these components require less cooling power, the installation space within the electronics housing can be increased at the expense of the overhang length of the cooling fins of the associated cooling fin group. This also enables the accommodation of comparatively large components with a greater installation height.

[0017] In short, this advantageous concept creates an increase in volume in the electronics housing area above by means of a group of cooling fins with a shorter overhang, so that tall pump electronics components can be placed in this area. However, since the reduced overhang of the associated cooling fins means that heat dissipation is reduced, these components must have comparatively low power dissipation. In contrast, a group of cooling fins with a comparatively long overhang only has a reduced volume available above in the electronics housing. This means that pump electronics components with a shorter overhang can be placed in this area, but due to the longer overhang of the associated cooling fins, these components may have higher power dissipation and thus greater heat dissipation.

[0018] According to a further embodiment of the invention, it can be provided that the cooling fins differ from one another not only in terms of their projection length, but also in terms of their axial spacing, i.e., the distance between two, in particular parallel, cooling fins. It can be provided that the axial spacing between the cooling fins of a cooling fin group is identical, and only different axial spacings are selected for the individual cooling fin groups. It is particularly preferred if the cooling fin group with the greatest projection length has the shortest axial spacing, while the cooling fin group with the shortest projection length has the largest axial spacing.

[0019] It makes sense to select the center distance based on the overhang of the cooling fins. The dimension of the center distance can be determined according to a predefined ratio between the center distance and the overhang. For example, the ratio between the center distance and the overhang of the cooling fins can be between 0.08 and 1. Preferably, the ratio between the center distance and the overhang for the cooling fin group with the largest overhang is in a range between 0.08 and 0.14, preferably between 0.095 and 0.125. The cooling fin group with the smaller or smallest overhang provides a ratio between 0.3 and 1, preferably between 0.4 and 0.89.

[0020] The wall thickness of the cooling fins can be selected to be identical for all cooling fins and is preferably in a value range between 2 mm and 7 mm, in particular around 5.7 mm.

[0021] Ideally, electrical components with comparatively high power dissipation should be in as direct contact as possible with the heat sink base plate to optimize heat dissipation via the heat sink. Depending on the design and installation space, this is not always easily possible. In this case, a thermal coupling element can be inserted between the component surface and the heat sink to optimize heat dissipation. Components with comparatively low power dissipation do not need to be in direct contact with the heat sink, as natural convection is sufficient for the necessary heat dissipation.

[0022] Further advantages and features of the invention will be explained in more detail below using an exemplary embodiment illustrated in the figures. They show: Figure 1a, 1b: perspective side views of the heating circulation pump according to the invention, Figure 2: a plan view of the underside of the heat sink of the heating circulation pump according to the invention, Figures 3a, 3b, 3c, 3d: sectional views along the section lines AA and BB and CC and DD of the Figure 2 and Figures 4a, 4b: two longitudinal sections through the heat sink to illustrate the cooling fin dimensions Figure 5: a sectional view along the section line CC according to a modified embodiment of the invention.

[0023] The Figure 1a, 1bshow perspective side views of the pump according to the invention, which can advantageously be designed as a centrifugal pump or heating circulation pump. This consists of a hydraulic part 1, whose impeller is connected to the rotor of the electric motor 2 via the pump shaft. The electronics housing 3, which is composed of a metallic heat sink 4 and a plastic part 5, is mounted on the axial end face of the electric motor housing.

[0024] How this Figures 1a and 1b as well as the top view of the underside of the heat sink 4 according to Figure 2As can be seen, the heat sink 4 consists of a heat sink base plate 6, which forms the housing base of the electronics housing 3, over which the housing 3 is mounted on the motor 2. The outer surface of the heat sink base plate 6 has a plurality of cooling fins 10. All cooling fins run parallel to one another. No fins are provided in the area of ​​the mounting surface of the heat sink 4 on the motor housing.

[0025] None of the fins 10 run in a straight line along the bottom surface; instead, they exhibit a curved shape with a defined radius of curvature. The radius of curvature is in the range between 12.5 and 13 cm, with the fins' shape being approximately coaxial with the motor axis. The radius of curvature can be reduced within the specified range, depending on the distance of the fin 10 from the motor axis. The curved shape of the fins 10 shifts the natural frequency of the fins 10, preventing unwanted resonant vibrations from occurring during normal pump operation.

[0026] In addition, according to the illustration Figure 2It can be seen that the axial distance, ie the distance between two adjacent ribs 10, varies. In particular, the ribs 10a to the right in the plane of the drawing, which are further away from the motor axis, show a smaller mutual axial distance, while the ribs 10b, 10c closer to the motor axis have a larger mutual axial distance. The technical reason will be explained below with reference to the Figure 3a , 3b be explained.

[0027] The Figure 3a , 3b , 3c show longitudinal sections through the electronics housing 3 of the pump, once along the section axis AA, once along the section axis BB and once along the section axis CC. Figure 3dshows a cross-section through the electronics housing 3 along the section axis DD. The heat sink base plate 6 is designed in steps, i.e. the inner bottom surface of the plate 6 has several steps 6a, 6b, 6c, 6d, the distance of which from the internal main board 20 of the electronics housing varies. This results in a different available installation space height between the heat sink base plate 6 and the board 20 for the individual steps 6a-6d, which can be utilized by the electronic components mounted on the board 20. The steps 6a-6c have the curved cooling fins 10 on their outer surface of the heat sink base plate 6. The cooling fins 10a of the first step 6a have the greatest overhang length, which, as in Figure 3a visible, decreases steadily from right to left in the direction of motor 2.

[0028] The cooling fins 10b of stage 6b have a reduced overhang length compared to the first stage 6a, although all fins 10b of stage 6b have the same overhang length. The cooling fins 10c of the third stage 6c have the shortest overhang length (see Figure 3b , 3c ), whereby here too, all ribs 10c of the third stage 6c have the same length. Furthermore, it can be seen that the ribs 10b, 10c are the same ribs, but their projection length changes due to the stages 6b, 6c (see Figure 3d ).

[0029] The fourth stage 6d, however, has no ribs 10. Furthermore, the Figures 4a, 4bIt can be seen that the axial spacing between the respective ribs 10 varies. The ribs 10a of the first stage 6a all have the same axial spacing, but this is the smallest compared to all ribs 10b, 10c. The axial spacing between the ribs 10b, 10c of the second and third stages 6b, 6c is also identical, but larger than the axial spacing between the ribs 10a of the first stage 6a.

[0030] The components located in the individual stages 6a-6d are classified into different component groups AD. Component group B, which is installed in the stage 6c area, and component group C, which is located in the stage 6b area, contain the necessary components of the input and intermediate circuit of the pump electronics. It is evident that certain components 21 of the input or intermediate circuit, such as capacitors, have a comparatively large height (see Figure 3c , 3d). These are therefore arranged in the area of ​​stage 6c, as this provides sufficient height. It can be seen that the installation space of stage 6c is larger than that of stage 6b, at the expense of the overhang of the associated fins 10c. This is possible because the capacitor 21 has a relatively low power loss but requires more installation space.

[0031] Component group A contains semiconductor elements and other components of the power electronics of the frequency converter, as well as any power factor correction filter. These components require a comparatively low installation height, so they are arranged in the area of ​​stage 6a. However, the components located there are characterized by the greatest power loss and thus heat dissipation. The relatively small installation space of stage 6a allows for a significantly larger dimensioning of the overhang length of the fins 10a there, so that the achievable heat dissipation and cooling of component group A can be significantly improved. This is further promoted by the reduced center distance between the cooling fins 10a there.

[0032] Component group D includes the components of an EMC filter. These components are neither very high in height nor characterized by relatively high heat dissipation, so they are located in the area of ​​step 6d. Fins 10 cannot be provided in this area due to the interface with the motor housing.

[0033] As already mentioned above, the cooling fins are designed with different projection lengths and center distances. The ratio between center distance and projection length is dimensioned differently for the individual stages 6a, 6b, and 6c and is specified in the Figures 4a, 4bThe cooling fins 10a of the first stage 6a have a constant mutual center distance of 4 mm, while the overhang of the outermost fin 10a' in this area is 42 mm. The overhang of the subsequent fins 10a decreases continuously; the smallest fin 10a" in this area has a overhang of 32 mm. This results in a variable ratio between center distance and overhang of 0.095 to 0.125. The ratio of the cooling fins 10b of the second stage 6b is 0.4, while the ratio of the cooling fins 10c in the area of ​​stage 6c is 0.89. The wall thickness for all cooling fins 10a-10c is 5.7 mm.

[0034] Figure 5 shows a longitudinal section through the electronics housing according to a modified version. The only difference compared to the version of the Figures 1 to 4a , 4bThis is achieved by indirectly connecting individual components 21 to the heat sink base plate 6 by means of thermal coupling elements 22, thereby further optimizing heat dissipation from the components 21 in the heat sinks 6. This may be necessary, in particular, if a direct connection between the components 21 and the heat sink 6 is not possible due to the design.

Claims

1. Pump, preferably centrifugal pump, particularly preferably heating circulation pump, having an electronics housing (3) and at least one cooling body (4), which is a constituent part of the electronics housing (3), wherein the cooling body (4) has a cooling-body base plate (6) which forms a bottom of the electronics housing (3) and on whose outer surface cooling ribs (10) extend, characterized in that at least some of the cooling ribs (10) have a curved profile with a defined radius of curvature along the cooling-body base plate (6).

2. Pump according to Claim 1, characterized in that the radius of curvature is constant over the entire profile of a cooling rib (10) along the cooling-body base plate (6) and lies in particular in the range between 10 cm and 15 cm, preferably between 11 cm and 14 cm, particularly preferably between 12.5 cm and 13 cm.

3. Pump according to either of the preceding claims, characterized in that most of the cooling ribs (10), ideally all the cooling ribs (10), have a constant radius of curvature, wherein preferably the radius of curvature is identical for all the curved cooling ribs (10) or the radius of curvature is reduced for cooling ribs (10b, 10c) situated relatively close to the motor housing of the pump.

4. Pump according to one of the preceding claims, characterized in that most of the cooling ribs (10), preferably all the cooling ribs (10), extend parallel to one another along the cooling-body base plate (6).

5. Pump according to one of the preceding claims, characterized in that the projecting length of the individual cooling ribs (10) of the cooling body (6) varies.

6. Pump according to one of the preceding claims, characterized in that the cooling-body base plate (6) comprises multiple shoulders (6a, 6b, 6c, 6d) or steps for subdividing the electronics housing (3) into different volume portions that differ from one another in terms of the available structural-space height, wherein the structural-space height is preferably determined by the distance between the cooling-body main plate (6), or the respective step (6a, 6b, 6c, 6d) thereof, and a circuit board (20) which is inserted into the electronics housing (3).

7. Pump according to Claim 6, characterized in that each step (6a, 6b, 6c, 6d) of the cooling-body base plate (6), within the electronics housing (3), defines a structural space for a specific component group (A-D) of electronic components of the pump electronics, wherein the electronic components are grouped into the specific component groups (A-D) preferably according to the component size and / or heat dissipation thereof.

8. Pump according to Claim 6 or 7, characterized in that at least two steps (6a, 6b, 6c) of the cooling-body base plate (6), preferably three steps, are provided with a respective cooling-rib group (10a, 10b, 10c), wherein the respective cooling-rib groups (10a, 10b, 10c) differ from one another in terms of the projecting lengths of their cooling ribs (10a, 10b, 10c).

9. Pump according to Claim 8, characterized in that the cooling ribs (10b, 10c) of at least one cooling-rib group all or mostly have the same projecting length, and / or the cooling ribs (10a) of at least one cooling-rib group all or mostly have varying projecting lengths, in particular projecting lengths which decrease continuously in the direction of an adjacent cooling-rib group (10b, 10c).

10. Pump according to one of Claims 7 to 9, characterized in that the component group (A) with the greatest power loss or the highest cooling requirement, in particular the components of the power electronics and / or of the power-factor-correction filter, is / are arranged in that structural space of the electronics housing (3) which is formed by that step (6a) of the cooling-body base plate (6) which has the cooling-rib group (10a) with the greatest projecting lengths.

11. Pump according to one of Claims 7 to 10, characterized in that the component group (C, B, D) with the smallest power loss or the lowest cooling requirement and / or the greatest structural height, in particular the components of an EMC filter and / or of an input circuit or intermediate circuit of the frequency converter, is / are arranged in that structural space of the electronics housing (3) which is formed by that step (6c, 6d) of the cooling-body base plate (6) which has the cooling-rib group (10c) with the smallest projecting lengths or which has no cooling ribs.

12. Pump according to one of the preceding claims, characterized in that the mutual centre distance of the cooling ribs (10) of the cooling-body base plate (6) from one another varies, wherein the centre distance between cooling ribs (10) of a cooling-rib group is preferably identical.

13. Pump according to Claim 12, characterized in that the cooling-rib group (10a) with the greatest projecting length has the smallest mutual centre distance.

14. Pump according to one of the preceding claims, characterized in that the ratio between centre distance and projecting length of the cooling ribs (10) lies between 0.08 and 1, preferably the ratio between centre distance and projecting length of the cooling-rib group (10a) with the greatest projecting length lies between 0.08 and 0.14, particularly preferably between 0.095 and 0.125, and / or the ratio for the cooling-rib group (10b, 10c) with the smallest projecting length lies between 0.3 and 1, particularly preferably between 0.4 and 0.89.

15. Pump according to one of the preceding claims, characterized in that the wall thickness of the cooling ribs (10), in particular all the cooling ribs, lies between 2 mm and 7 mm, in particular is 5.7 mm.

16. Pump according to one of the preceding claims, characterized in that the electronic components, in particular the components with the greatest power loss, are in direct contact with the cooling-body base plate (6) or are connected indirectly to the cooling-body base plate (6) by a thermally conductive coupling element (22).