Pump with multipart electronics housing

Abstract

The invention relates to a pump, preferably a centrifugal pump, particularly preferably a heating circulation pump, with at least one electronics housing for the pump electronics, wherein the electronics housing is assembled from at least two housing parts and at least two printed circuit boards are arranged one above another in the axial direction within the electronics housing, characterized in that at least one mounting frame is introduced between the printed circuit boards, wherein the mounting frame is used for mounting and / or fixing at least one of the printed circuit boards and has at least one sealing element which is in sealing contact with at least one of the housing parts.

Description

[0001] Pump with multi-part electronics housing

[0002] The invention relates to a pump, preferably a centrifugal pump, particularly preferably a heating circulation pump, with at least one electronics housing for the pump electronics, wherein the electronics housing is composed of at least two housing parts and at least two circuit boards are arranged one above the other in the axial direction within the electronics housing.

[0003] Such a centrifugal pump can be designed as a heating circulation pump. Modern heating circulation pumps are equipped with control logic for energy-efficient pump operation. In addition to a control module and any operating and display elements, this also includes a frequency converter for controlling the speed of the pump drive. The necessary electronics are housed in an electronics housing that is attached to the circumference or front of the pump motor. The individual components are usually separated according to function or the waste heat they produce and housed on different circuit boards. For example, a power board with the frequency converter components and another board containing control modules and / or HMI interface components is conceivable.

[0004] During pump operation, the electronic components generate waste heat, which must be dissipated from the electronics housing to protect them. A separate heat sink in the electronics housing ensures sufficient heat dissipation. For this reason, the electronics housing can also be constructed in several parts, with one part being the metal heat sink, onto which a plastic housing cover is placed. In general, such an electronics housing can also be assembled from any desired housing components.

[0005] Since pumps, especially centrifugal pumps and heating circulation pumps, are used to pump fluids, the electronics must be sealed from the environment to prevent fluids from penetrating the interior of the housing. For this reason, heating circulation pumps require at least splash protection according to IP-44.

[0006] The interface between the housing parts and the resulting connection gap between the housing parts is problematic here. One option for sealing this gap is the use of a simple sealing cord, which is inserted into the gap between the housing parts. However, this requires a minimum available surface area in the contact area between the housing parts for the sealing cord to rest on, which implies a certain minimum thickness of the housing wall. Properly positioning the sealing element on the corresponding connecting edges for assembly is also somewhat tricky and complicates the entire installation process. To simplify the process, the seal was often glued on, which, however, requires an additional assembly step.

[0007] The object of the present application is to simplify the structure as well as the entire assembly process for the electronics housing of the pump.

[0008] This object is achieved by a pump according to the features of claim 1. Advantageous embodiments of the pump are the subject of the dependent claims. The object is also achieved by a method according to the features of claim 15.

[0009] According to the invention, at least one mounting frame, separate from the at least two housing parts, is inserted between the circuit boards. The mounting frame serves to accommodate and / or secure at least one of the circuit boards. Additionally, the mounting frame has at least one sealing element that is in sealing contact with at least one of the housing parts and thus serves to seal the housing against fluids entering from the outside.

[0010] The mounting frame also serves as an assembly aid during the assembly of the electronics housing, particularly during the axial stacking of the circuit boards and / or the joining of the housing parts. Because the mounting frame is inserted between the circuit boards, it serves as a centering aid for aligning the circuit boards. The mounting frame also ensures sufficient spacing between the circuit boards. In addition to this function as an assembly aid, the mounting frame also serves as a seal carrier for accommodating one or more sealing elements for sealing the housing.

[0011] The axial direction refers to the direction in which the circuit boards are stacked and the housing components are mounted on top of each other. The mounting frame has a frame surface that, viewed in the axial direction, has a top and bottom side.

[0012] According to a preferred embodiment, the multi-part structure of the electronics housing comprises a heat sink and a second housing part made of a different material, e.g., plastic, which completes the electronics housing. The heat sink is typically made of metal, particularly aluminum. The heat sink preferably serves to accommodate the circuit board that carries the components with higher heat generation, in particular a power board for the components of a frequency converter. However, it is not excluded that the power board also contains additional control components or other components characterized by lower heat generation. The second circuit board is preferably a circuit board on which the remaining components are housed, e.g., any control modules or components for implementing a human-machine interface (HMI).Preferably, at least one housing part has a peripheral edge on the end face, which at least partially forms the interface with the mounting frame and, if applicable, the second housing part. This edge is at least partially in contact with the at least one sealing element arranged on the mounting frame. Preferably, the housing part or the edge is pressed onto the sealing element in the axial direction and compresses it in the axial direction, thus ensuring a sufficient sealing effect.

[0013] It is particularly preferred if a sealing element is arranged on the top and bottom sides of the frame surface of the mounting frame, with each sealing element being in contact with the front edge of one of the housing parts. The mounting frame thus comprises separate sealing elements for sealing the contact surface with both housing parts.

[0014] At least one, but particularly both, sealing elements can be incorporated into a groove running around the frame surface. It is conceivable to insert a precisely fitting sealing element, particularly a sealing lip, into the existing groove. However, it is preferred for the sealing elements to be injection-molded into the corresponding groove. A thermoplastic and injection-moldable elastomer (TPE), particularly a TPE-U or TPU (urethane-based thermoplastic elastomer, thermoplastic polyurethane), is then used as the sealing element.

[0015] In a preferred embodiment, the mounting frame has an axially extending, preferably circumferential, wall on its outer frame edge. The wall thus extends parallel to the outer wall of the first and / or second housing part, in particular the wall covers a partial area of ​​the outer wall of the first and / or second housing part in the form of an apron. Particularly preferably, the formed apron covers at least one of the interfaces between the housing part and the mounting frame, ideally the area around the intermediate sealing element. In its covering function, the apron provides additional splash protection. Such an apron also offers aesthetic advantages. Ideally, the apron extends both over the interface between the first housing part and the mounting frame and over the interface between the second housing part and the mounting frame.

[0016] It is advantageous if the mounting frame has an axially extending first stop surface running around the frame surface, which comes into contact with the inner wall of a housing part and serves to align the mounting frame relative to the housing part, in particular to align the mounting frame relative to the heat sink. It is possible for the first stop surface to be formed by a wall of the groove for receiving the sealing element, in particular by the inner groove wall.

[0017] According to an advantageous embodiment, the frame surface, in particular the top and / or bottom of the frame surface, can be profiled. It is preferred if the frame surface has a stepped profile on its top and / or bottom, in particular a continuous stepped profile. A stepped surface extending in the axial direction can serve as a stop surface for a wall surface of one of the housing parts and / or a circuit board to be accommodated by the mounting frame.

[0018] The mounting frame preferably comprises a second stop surface extending axially and circumferentially on the frame surface, which comes into contact with an outer wall of a housing part and serves to align the housing part relative to the mounting frame, in particular to align the plastic housing relative to the mounting frame. The second stop surface can be formed by the aforementioned stepped profile and / or by the wall extending along the outer frame edge, i.e., the skirt.

[0019] The first and second stop surfaces are formed on different sides of the mounting frame, for example, the first stop surface is on the underside, while the second stop surface is formed on the top. The mounting frame, in particular the frame surface, can be formed with one or more projections projecting vertically from the frame surface, which serve as bearing points for receiving at least one circuit board. The projections can also serve as spacers, ensuring sufficient axial spacing between the two circuit boards.

[0020] The design of the pump according to the invention, in particular of the electronics housing, can preferably be such that a first circuit board, in particular the power circuit board, is accommodated within the heat sink. The power circuit board is supported by corresponding wall projections of the heat sink. The novel mounting frame is placed on the end-face edge of the heat sink and simultaneously rests on the attached power circuit board. A second circuit board, in particular an HMI circuit board, is mounted directly on the mounting frame and fixed there to the mounting frame by any connecting means, preferably screwed to the mounting frame. The use of self-tapping screws, preferably made of plastic, is conceivable. Electrical contact between the two circuit boards is usually created by one or more contact means, in particular connecting pins, between the circuit boards.

[0021] The second housing part, in particular the plastic cover, is preferably placed on the mounting frame and directly connected to the heat sink via one or more connecting elements. The connection between the heat sink and the plastic cover is preferably secured by one or more screws. The connecting elements, in particular screws, simultaneously ensure that the components are pressed against each other in the axial direction, thus achieving better axial compression of the sealing elements of the mounting frame.

[0022] As already explained above, electrical contact is established between the at least two circuit boards by means of one or more contact means. In an advantageous embodiment of the invention, such contact means can also extend through the frame surface of the mounting frame in the axial direction or, ideally, can be integrated into the structure of the mounting frame, for example, cast in. This supports precise contact between the circuit boards during the assembly process. The contact means can comprise one or more connecting pins that extend in the axial direction and can be inserted into corresponding plug contacts on the circuit boards. A grounding screw that runs through the frame surface or is integrated there can also be provided as the contact means.

[0023] In addition to the pump according to the invention, the invention also includes an assembly method for a pump according to the invention. The assembly method consists of the following process steps:

[0024] - Inserting a power board into the pump housing designed as a heat sink,

[0025] - Position the mounting frame, preferably by placing it on the surrounding edge of the heat sink and resting it on the power board mounted in the heat sink. The stop surfaces of the mounting frame are ideal for precisely aligning the mounting frame with the power board and, in particular, with the heat sink.

[0026] - Mounting the second board, especially an HMI board, on the mounting frame. Contours on the frame surface are also preferred for precisely centering the board on the mounting frame. Fixing the board to the mounting frame.

[0027] - Placing the second housing part on the heat sink, wherein preferably a stop surface formed on the frame serves to align the second housing part to the mounting frame and consequently to the heat sink.

[0028] - Fixing both housing parts to each other by means of one or more connecting elements, in particular screws.

[0029] Further advantages and features of the invention will be explained in more detail below with reference to an exemplary embodiment illustrated in the figures. Figure 1 shows a side view of the electronics housing according to the invention for the pump according to the invention.

[0030] Figure 2: a top view of the electronics housing of Figure 1 ,

[0031] Figure 3: two detailed views of the mounting frame according to the invention from different perspectives,

[0032] Figure 4: a top view of the heat sink with the power board inserted,

[0033] Figure 5: the representation of Figure 4 with the mounting frame inserted,

[0034] Figure 6: the representation according to Figure 5 with the second board mounted,

[0035] Figure 7: a sectional view of the assembled electronics housing and

[0036] Figure 8: a representation of the heat sink with inserted power board and arranged mounting frame according to an advantageous modification.

[0037] Figure 1 shows a side view, and Figure 2 a top view of the assembled electronics housing of a pump according to the invention, which may, for example, be a heating circulation pump. The illustrated electronics housing can be mounted on the front axial end of the pump unit.

[0038] The electronics housing shown is constructed in several parts and comprises a metallic heat sink 10, which forms the housing base and has a plurality of cooling fins 11 on the outside of the base. The base section without cooling fins serves as the mounting surface on the pump unit. The heat sink 10 is open at the top and has a peripheral edge 13 on the front side (see Figure 4). The electronics housing is closed by a plastic cover 20, which is placed in the axial direction A on the top side or edge 13 of the heat sink 10. On the top side of the housing cover 20, which is accessible from the outside, there is an operating element 21, a display element 25 and a recess 22 with electrical contact points 23 for receiving and contacting additional signal lines, for example those provided by the customer.

[0039] Between the heat sink 10 and the plastic cover 20 is a mounting frame 30, whose skirt 31 can be seen running parallel to the outer wall of the heat sink 10 and the plastic cover 20. The skirt 31 extends around the entire circumference of the electronics housing, with the axial width varying noticeably in the circumferential direction.

[0040] Detailed representations of the mounting frame 30 according to the invention are shown in Figures 3a and 3b, wherein Figure 3a shows the top side, i.e. the side facing the plastic cover 20, and Figure 3b shows the underside facing the heat sink 10. The mounting frame is made of plastic, for example. Visible here is the outer wall 31, which is perpendicular to the frame surface and forms the apron lying on the outside of the housing. The underside (Figure 3b) comprises a circumferential groove 32 immediately adjacent to the apron 31, into which a seal 33 made of TPE, in particular TPE-U or TPU, is injected. The top side of the mounting frame (Figure 3a) is profiled and forms a double step with a first step 34 and a subsequent second step 35. The steps 34, 35 running around the entire frame surface are formed in particular close to the outer edge region of the mounting frame 30.The second step 35, in particular its step surface perpendicular to the frame surface, can serve as a stop surface for the circuit board 40, in particular an HMI board (see Figure 6), and ensures a rough alignment and positioning of the circuit board 40 on the mounting frame 30. The apron 31 running along the outer edge of the mounting frame 30 serves as a stop surface for the plastic housing 20, the outer wall of which abuts the inside of the apron 31.

[0041] Between the second step 35 and the skirt 31, a groove 36 is also formed on the upper side, into which another circumferential seal 37 made of TPE, e.g., TPU, is injected. A plurality of holes 38 serve to pass through screws to screw the plastic cover 20 directly to the heat sink 10. Projections 39, which are higher than the first step 34 but lower than the second step 35, serve as support points for the circuit board 40 and ensure a defined distance between the power board 50 mounted in the heat sink 10 and the circuit board 40.

[0042] Figures 4 to 7 will explain the individual assembly steps for the electronics housing. Figure 4 shows the heat sink 10 with the power board 50 inserted therein. Individual bearing points formed on the inner wall of the heat sink 10 serve to hold the power board 50. Holes 14 are used to screw the heat sink 10 to the plastic cover 20. In the next step (Figure 5), the underside of the mounting frame 30 is placed onto the front edge 13 of the heat sink 10. The front edge of the edge 13 penetrates the groove 32 of the mounting frame 30 and contacts the seal 33 inserted there (Figure 7). The inner wall of the groove 32 also serves as a stop surface against which the inner side of the edge 13 of the heat sink 10 rests. This allows the mounting frame 30 to be mounted precisely on the heat sink 10.The sectional view in Figure 7 shows the stop of the heat sink 10 against the inner wall of the groove. As described, the end face of the edge 13 contacts the seal 33, compressing it in the axial direction.

[0043] Before attaching the second circuit board 40, the electrical contact means are first attached to the power board 50. One or more connectors are used here. The pin-like connectors 60 are inserted through holes 51 in the power board 50. A grounding screw 61 is inserted into a matching hole 52 in the circuit board 50.

[0044] The next step involves mounting the HMI board 40 on the mounting frame 30, as shown in Figure 6. The step 35 is used to roughly align the board position. Finally, the plastic cover 20 is placed on the mounting frame 30, with the apron 31 of the mounting frame 30 serving as a positioning aid by the outer side of the plastic cover 20 abutting the inner wall of the apron 31. The front, circumferential edge of the plastic cover 20 extends into the groove 36 and contacts the sealing element 37 located there (see Figure 7). Finally, the plastic cover 20 is screwed to the heat sink 10, with the screws being inserted from the top of the plastic cover 20 into the drill holes 24 provided there.Tightening the screws exerts an axial force on the housing parts 10, 20, increasing the compression of the seals 33, 37 by the respective edges of the housing parts 10, 20 and achieving an overall sufficient seal for the electronics housing. The outer skirt 31 of the mounting frame 30 covers both the interface of the heat sink 10 with the mounting frame 30 and the interface of the plastic cover 20 with the mounting frame 30.

[0045] As an alternative to the embodiment according to Figures 1 to 7, the mounting frame 30' could also be modified such that the electrical connectors 60' and the grounding screw 61' are integrated into the mounting frame 30', in particular cast in, as shown in Figure 8.

Claims

A pump, preferably a centrifugal pump, particularly preferably a heating circulation pump, with at least one electronics housing for the pump electronics (40, 50), wherein the electronics housing is composed of at least two housing parts (10, 20) and at least two circuit boards (40, 50) are arranged one above the other in the axial direction within the electronics housing, characterized in that at least one mounting frame (30) is introduced between the circuit boards (40, 50), wherein the mounting frame (30) serves to support and / or fix at least one of the circuit boards (40) and has at least one sealing element (33, 37) which is in sealing contact with at least one of the housing parts (10, 20). Pump according to claim 1, characterized in that one housing part is a heat sink (10) and the other housing part is a housing cover (20) which can be placed on the heat sink, in particular a plastic housing cover.Pump according to one of the preceding claims, characterized in that an end edge (13) of at least one of the housing parts (10, 20) is in contact with the mounting frame (30), in particular with the at least one sealing element (33, 37) arranged on the mounting frame (30), whereby the sealing element (33, 37) is preferably compressed in the axial direction. Pump according to claim 3, characterized in that a sealing element (33, 37) is arranged on each of the top and bottom sides of the frame surface of the mounting frame (30), wherein each sealing element (33, 37) is in contact with the end edge of one of the housing parts (10, 20). Pump according to one of claims 3 or 4, characterized in that the at least one sealing element (33, 37) is inserted into a circumferential groove (32, 36) in the frame surface and forms a sealing lip, wherein the sealing element (33, 37) preferably consists of an elastic and moldable material and is injected into the groove (32, 36), for example, consists of or comprises a thermoplastic elastomer.Pump according to one of the preceding claims, characterized in that the mounting frame (30) has a first stop surface which extends axially and runs around the frame surface, which comes into contact with the inner wall of a housing part (10) and serves to align the mounting frame (30) relative to the housing part (10), in particular to align the mounting frame (30) with respect to the heat sink (10), wherein the first stop surface is preferably formed by the wall of the groove (32) for receiving the sealing element (33). Pump according to one of the preceding claims, characterized in that the mounting frame (30) has a wall (31) which extends in the axial direction on the outer frame edge and which, in the form of an apron, conceals outer surface regions of at least one housing part (10, 20), in particular the contact point between at least one housing part (10, 20), preferably both housing parts (10, 20), and the mounting frame (30).Pump according to one of the preceding claims, characterized in that the mounting frame (30) has a second stop surface which extends axially and runs around the frame surface and which comes into contact with an outer wall of a housing part (20) and serves to align the housing part (10, 20). relative to the mounting frame (30), in particular for aligning the plastic housing (20) relative to the mounting frame (30), wherein preferably the second stop surface is formed by the wall (31) extending on the outer frame edge.

9. Pump according to one of the preceding claims, characterized in that the mounting frame (30) has one or more spacers (39) for mounting the mounting frame (30) on at least one circuit board (50) and / or for mounting a circuit board (40) on the mounting frame (30) at a defined distance.

10. Pump according to one of the preceding claims, characterized in that a first circuit board (50), in particular a power board, is inserted into the heat sink (10) and is mounted by the heat sink (10) and the mounting frame (30) is placed on the circumferential front edge of the heat sink (10) and is simultaneously supported on the first circuit board (50).

11. Pump according to claim 10, characterized in that a second circuit board (40), in particular a control and / or HMI circuit board, is mounted on the mounting frame (30) and fixed thereto, preferably screwed to the mounting frame (30).

12. Pump according to one of the preceding claims, characterized in that one or more electrical contact means (60, 61) for electrically contacting the circuit boards (40, 50) are introduced, in particular cast, into the mounting frame (30).

13. Pump according to one of the preceding claims, characterized in that the mounting frame (30) is made of plastic.

14. Pump according to one of the preceding claims, characterized in that the housing parts (10, 20) are screwed together, wherein the one or more screws extend through provided bores (38) in the mounting frame (30) extend, wherein a compression of the sealing elements (33, 37) in the axial direction is preferably brought about by the screw connection. Method for assembling a pump according to one of the preceding claims, with the following steps: a. introducing a power board (50) into a housing part of the pump designed as a heat sink (10), b. placing the mounting frame (30) on the power board (50) and / or the heat sink (10), in particular the circumferential, front edge (13) of the heat sink (10), c. placing a second board (40), in particular an HMI board, on the assembled mounting frame (30) and fixing the second board (40) on the mounting frame (30), preferably by means of one or more screw connections, d. placing the second housing part (20) on the mounting frame (30) and fixing it on the heat sink (10), preferably by means of axial screw connections.

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