EP3530959B1 - Pump unit - Google Patents

Description

The invention relates to a pump unit, in particular a heating circulating pump unit, with a centrifugal pump, with an electric motor driving the centrifugal pump and with control electronics arranged in an electronics housing, which has at least one printed circuit board equipped with electronic components.

Such pump units are state-of-the-art in numerous design variants; in this context, reference is only made to the circulating pump marketed by the Grundfos Group under the type designation Alpha2 for heating, cooling and hot water applications. This pump unit has an electronics housing, which includes an electronic frequency converter, which forms part of the control electronics of the pump unit and has at least one printed circuit board equipped with electronic components, which is equipped with a microcontroller and other components. The electronics are made up of several printed circuit boards arranged on top of one another in a sandwich-like manner, with the electronic components arranged on them being arranged according to the spatial, structural and thermal requirements. The electronics installed in such pump units today is highly complex and has at least one microcontroller which, in addition to the actual control function, also performs other functions, e.g. B. to ensure the most automatic adjustment of the operating point of the pump to the hydraulic environment.

Even if the control electronics have non-volatile memory, the contents of which are retained when the power supply is switched off, there are components that must continue to be supplied with power in order to ensure their functionality, even if the power supply to the pump unit is interrupted for a long period of time, as is the case here For example, this is typically the case outside of the heating period in the case of heating circulating pump units. In this context, assemblies such as an electronic real-time clock or an assembly for temperature detection outside of the heating period are only mentioned as examples.

Out of WO 2010/068148 A1 a water tank arrangement for a dust-emitting construction machine is known, which includes an electric motor-driven submersible pump in the water tank, which is closed at the top by a hood, in which four separate compartments for a battery, a spare battery, a charger and an electronic circuit board for controlling the electric motor the pump are arranged. The battery is used to operate the pump, while the circuit board for the control electronics ensures a constant voltage supply.

Against this background, the invention is based on the object of designing a generic pump unit in such a way that at least partial functions of its control electronics are retained for as long as possible even when the supply voltage is switched off.

This object is achieved according to the invention by the features listed in claim 1. Advantageous configurations of the invention result from the dependent claims, the following description and the drawings.

The pump unit according to the invention, which is in particular a heating circulating pump unit, has a preferably wet-running centrifugal pump, an electric motor driving the centrifugal pump and control electronics which are arranged in an electronics housing and have at least one printed circuit board equipped with electronic components. According to the invention, a battery is arranged in the electronics housing, which is arranged in a battery holder arranged on the printed circuit board and open at least on one side, the battery in the installed position of the printed circuit board to the open side of the battery holder by a form-fitting element is secured positively or materially in the battery holder against falling out.

The basic idea of the invention is to provide a battery for buffering the power supply of parts of the control electronics, which is arranged on a printed circuit board, but which is not attached and electrically connected to the printed circuit board by means of soldering lugs, as in comparable applications in electronic controls, but in a specially battery holder provided for this purpose is arranged, which is open on at least one side in order to be able to insert the battery into it and which, in the installed position, is closed in a form-fitting manner on its open side by a form-fitting element, enclosing the battery, or in which the battery is firmly bonded in the battery holder to prevent it from falling out is secured. Even if an exchange of the battery from the battery holder is conceivable, at least in the case of positive locking, an exchange of the battery is not intended for the intended application. The battery holder is therefore primarily used to attach the battery, which is favorable in terms of production, in particular assembly technology, using the narrow spatial conditions Conditions of the electronics housing. Although the battery can be cohesively secured in the battery holder against falling out, z. B. by introducing a corresponding hot-melt adhesive or other adhesive, but the form-fitting securing by means of a form-fitting element is particularly advantageous since it does not require any additional steps in the assembly process.

The battery is advantageously designed as a button cell and is arranged with its flat sides parallel to the circuit board in the battery holder. This results in a particularly compact, in particular flat structure. The battery is therefore not to be arranged in the areas in which tall electronic components such as capacitors, coils or the like are arranged, but in the areas in which the microelectronics, in particular the microcontrollers and the typically flat electronic components such as resistors and the like are provided. This area is preferred for arranging the battery, since it is subject to less thermal and voltage stress than the remaining part of the control electronics where the power electronics are arranged. This also determines the arrangement of the battery holder, which is also parallel to the printed circuit board and can be surface-soldered with its contacts, which also form the mechanical anchoring, i.e. in one operation with other electronic components to be arranged on the printed circuit board.

Advantageously, the battery holder is designed to be open on a narrow side perpendicular to the printed circuit board, so that the battery can be pushed into it parallel to the printed circuit board. This arrangement has great advantages, particularly when handling the printed circuit board further, since it is only necessary to ensure that the open side of the battery holder does not point downwards but to the side or upwards in order to ensure that the battery slides out.

According to a development of the invention, it is provided that the form-fitting element is not arranged on the circuit board on which the battery holder with the battery is located, but rather an opening in the circuit board, specifically in front of the opening of the battery holder, is penetrated by a form-fitting element in order to so to block the open narrow side of the battery holder at least partially so far that the battery is positively secured in the battery holder.

The arrangement of this form-fitting element separately from the circuit board has the great advantage that the opening of the battery holder with suitable attachment of the form-fitting element in the normal Assembly process of the pump unit can be incorporated without having to provide a separate handling process here.

For this purpose, the form-fitting element can advantageously be formed in the shape of a peg and attached to another component, e.g. B. advantageously be arranged a cover which closes the electronics housing. Alternatively, such a pin can also be provided on the component adjoining it on the other side, that is to say a further printed circuit board or the like. Thus, during assembly of the electronics housing, the form-fitting closure of the battery holder is automatically obtained, namely when the components are placed on top of each other, d. H. of the component that carries the pin and the printed circuit board on which the battery holder is arranged, the pin reaches the area in front of the opening of the battery holder and thus blocks it in a form-fitting manner. It goes without saying that this pin only has to pass through an opening in the printed circuit board if it protrudes from a component on the side which is arranged on the back of the printed circuit board which carries the battery holder.

The form-fitting element, which closes the opening of the battery holder, is advantageously part of a clip connection, the other part of which is formed by the opening in the printed circuit board. The pin, which passes through the opening, thus has a dual function, it passes through the printed circuit board and closes the opening of the battery holder in a form-fitting manner and at the same time serves to hold and fasten the printed circuit board itself to the cover or the cover to the printed circuit board. The clip fastening of the components thus enables them to be firmly and positively connected to one another simply by assembling them.

The positive-locking element, ie preferably a pin penetrating the opening in the printed circuit board, is designed in one piece with the cover as a plastic injection molded part, as is the rest of the housing of the electronics housing, which can also form part of the motor housing.

If, which is advantageous, the cover is cup-shaped, it can expediently receive the printed circuit board in a form-fitting manner and carry display and control elements in the area of its base and close off a tubular part of the electronics housing.

The cover is preferably welded to the electronics housing so that it is hermetically sealed, even if the electronics housing forms part of the motor housing or is formed in one piece with the motor housing and is separated from it by a transverse wall, as is also the case in the prior art mentioned in the introduction is realized. Such a construction is particularly favorable since the motor and electronics housing can then be formed from a common plastic injection molded part, the electronics housing is completely separated from the motor housing by the transverse wall and can be hermetically sealed by the closing cover. This welded connection for sealing the electronics housing ensures a hermetic seal of the electronics housing with the printed circuit boards and components arranged therein, operating elements and displays are provided on the cover side and are typically hermetically sealed and protected from the outside by a foil.

It should be emphasized at this point that although the battery holder is basically provided for replacing the battery, such a replacement is not provided for in the design of the pump unit described above, the arrangement of the battery in a battery holder essentially serves production and assembly purposes as well as reliable contacting.

The battery holder is typically provided with at least one, preferably two, spring contacts which hold the battery in a non-positive manner within the holder and press it in the direction of the printed circuit board. These springs are used both for contacting and for applying force. If the battery holder is made of conductive sheet metal, which is advantageous, then the button cell is contacted on one side by the battery holder itself, which is surface-soldered on the printed circuit board, both for attachment and for contacting, whereas the contacting on the other side of the Flat battery done via the circuit board itself. For this purpose, a fleece made of carbon is advantageously arranged between a flat contact on the printed circuit board and the battery, which fleece ensures long-term stable contact between the components and has a low contact resistance.

Advantageously, the tubular part of the electronics housing has another printed circuit board fitted with electronic components, which is electrically conductively connected via contacts to mating contacts on the first printed circuit board, which carries the battery holder with the battery, and is otherwise separated by an insulating film arranged in between. This additional printed circuit board carries the large electronic components and power components of the frequency converter of the control electronics.

This ensures good electrical and thermal separation of the components in the electronics housing, so that it is ensured that the battery and the microelectronics arranged next to it are protected from high voltages and impermissibly high heat influences.

The electronics housing, in particular the printed circuit board carrying the battery holder with the battery, advantageously has an electronic real-time clock which is buffered by the battery, so that it is ensured that the real-time clock continues to run even when the power supply to the pump unit is switched off. In this way, even time intervals can be detected by the control electronics, which are outside the operating times of the pump unit.

It is particularly advantageous if, according to a further development of the invention, the opening in the printed circuit board is arranged approximately in the middle of the printed circuit board. As a result, a bending moment on the printed circuit board, which can be caused by pressing a membrane button formed in the cover, can be kept small. With this arrangement, the force arm, which is essential for the moment load, can be kept small.

Fig. 1

ein erfindungsgemäßes Pumpenaggregat in Explosionsdarstellung,

Fig. 2

das Elektronikgehäuse des Pumpenaggregats gemäß Fig. 1 in Explosionsdarstellung aus gegenüber Fig. 1 entgegengesetzter Richtung,

Fig. 3

in vergrößerter Darstellung den Deckel und die darin eingegliederte Leiterplatte in vergrößerter Darstellung entsprechend Fig. 2,

Fig. 4

in vergrößerter perspektivischer Darstellung die in den Deckel eingegliederte Leiterplatte und

Fig. 5

den Deckel mit eingegliederter Leiterplatte in Darstellung gemäß Fig. 4 mit in den Batteriehalter eingesetzter Batterie.

The invention is explained in more detail below with reference to an embodiment shown in the drawing. Show it:

1

a pump unit according to the invention in an exploded view,

2

the electronics housing of the pump set according to 1 in exploded view from opposite 1 opposite direction

3

in an enlarged view the cover and the printed circuit board incorporated therein in an enlarged view accordingly 2 ,

4

in an enlarged perspective view of the circuit board integrated into the cover and

figure 5

the cover with integrated printed circuit board in accordance with the illustration 4 with the battery inserted in the battery holder.

That based on 1 Pump assembly shown has a pump with a pump housing 1, which has a suction port 2 and a pressure port 3 in the usual way and a pump chamber for receiving a in the 1 not visible impeller, which is arranged at the end of a rotor 4, which is rotatably mounted in a bearing plate 5, which closes off the pump chamber of the pump housing 1 and rests via a sealing ring 6 on the flange 7 of a can 8, which the pump chamber with the in operation fluid located there is separated from the surrounding motor compartment, which has a stator 9 surrounding the can 8, which is arranged in a motor housing 10, which, including the bearing plate 5, the seal 6 and the flange 7, is firmly and tightly connected to the pump housing 1.

On the side facing away from the pump, the motor housing 10 is adjoined by an electronics housing 11, which is designed as a plastic injection molded part and is hermetically sealed by a cover 12, also made of plastic, which is tightly and firmly connected to the tubular part of the electronics housing by welding.

The electronics housing 11 is tubular and has a part that encompasses the motor housing 10 circumferentially, which has ventilation slots 13 arranged transversely and is separated from the actual electronics housing 11 by a transverse wall 14 .

This electronics housing 11 also forms the terminal box of the pump unit and has a coupling connection 15 which is provided for receiving a corresponding connector plug with which the pump unit is connected to the power supply.

Inside the electronics housing is a first printed circuit board 16, which is integrated within the cup-shaped cover 12 and is electrically isolated from a second printed circuit board 18 by an insulating film 17, to which it is electrically conductively connected via corresponding pin contacts. The second printed circuit board 18 carries the input, intermediate and power circuits of a frequency converter, correspondingly large components such as capacitors, coils and power semiconductors are arranged on this printed circuit board 18, namely on the motor housing 10, d. H. to the transverse wall 14 pointing side of the circuit board.

The first printed circuit board 16 carries the actual control electronics of the pump and is equipped with microcontrollers, flash memory, radio modules, antennas and the like in a manner known per se. The first printed circuit board 16 also carries all the display and control elements that can be seen or reached through the cover 12, which is closed off from the outside by a protective film 19.

The first circuit board 16 carries the display and control elements on the side facing the bottom of the cover 12 . On the other side, ie towards the insulating film 17 or the second printed circuit board 18, this printed circuit board 16 carries this side as in FIG figure 3 shown next to a microcontroller 20 and other miniaturized electronic components centrally a battery holder 21 for a battery 22 in the form of a button cell. The battery holder 21 is formed from conductive sheet metal and has a circuit board-parallel flat side 23, in which two spring contacts 24 are arranged, which hold the battery 22 frictionally between the battery holder 21 and the top of the circuit board 16 and at the same time make contact on one side. The battery holder 21 has a contact foot 25 on each of its two flat longitudinal sides, with which it is surface-soldered on the printed circuit board 16, on the one hand to mechanically fasten the battery holder 21 to the printed circuit board 16 and on the other hand to fix the positive side of the battery 22, which is is contacted by the spring contacts 24 to be electrically connected to a conductor of the printed circuit board 16 accordingly. The other contact of the battery 22, which is in accordance with the installation position 4 on the underside, ie facing the printed circuit board 16, is electrically conductively connected directly to a contact on the printed circuit board by means of a carbon fleece.

The battery holder 21 is open on its narrow transverse sides, being partially closed on one side by sloping sheet metal sections 26, these sheet metal sections 26 being formed by bending from the base body and being arranged in such a way that the battery 22 inserted in the battery holder 21 keep largely free of play. In the 4 The downward side of the battery holder 21 is open so that the battery 22 can be pushed into the battery holder 21 as long as the printed circuit board 16 is not yet mounted in the cover 12 . The battery 22 is thus parallel to the printed circuit board by the in 4 lower opening is inserted into the battery holder 21, the spring contacts 24 being tensioned and holding and contacting the battery positively within the holder. The button cell 22 bears against the sheet metal sections 26 on the peripheral side and is guided laterally through the long sides, which are also formed by sheet metal sections. In this position, the first printed circuit board 6 can be moved and manipulated in all directions without the risk of the battery 22 being pushed out through the opening at the in 4 lower narrow side falls out. This circuit board 16 is then in the pot-shaped Lid 12 is inserted by being aligned as intended by guide pins 27 and arranged inside the lid 12 .

A slot-shaped recess 28 is provided within the first printed circuit board 16, directly next to the battery holder 21, in front of the opening of its narrow side. An inwardly projecting pin 29 with a rectangular cross section is formed in the base of the cover 12, which penetrates the recess 28 when the first printed circuit board 16 is inserted into the cover 12 and then closes the opening of the battery holder 21 in a form-fitting manner, and is therefore independent of the force of the spring contacts 24 ensures that the battery 22 is held positively on all sides within the battery holder 21 in the intended position on the printed circuit board 16. At its end, the pin 29 has a wedge surface 30 which, in connection with the edge of the recess 28, forms a clip connection and ensures that this pin 29 is deflected into the cover 12 when the printed circuit board 16 is placed, and then at the end of this inclined surface 30 to spring back and thus to keep the printed circuit board 16 firmly within the cover 12 in a form-fitting manner.

With the incorporation of the insulating film 17, the first printed circuit board 16 is connected to the second printed circuit board 18 by corresponding plug-in contacts, after which the cover 12 is inserted into the electronics housing 11 with its tabs 31 also projecting towards the electronics housing 11 and then welded to it around the circumference. The tabs 31 are used to guide the cover when it is integrated into the electronics housing 11.

Reference List

1 -

pump housing

2 -

suction port

3 -

pressure connection

4 -

rotor

5 -

bearing plate

6 -

sealing ring

7 -

flange

8th -

cracking tube

9 -

stator

10 -

motor housing

11 -

electronics housing

12 -

cover of 11

13 -

Air vents from 11

14 -

transverse wall in 11

15 -

coupling connection

16 -

first circuit board

17 -

insulating film

18 -

second circuit board

19 -

foil

20 -

microcontroller

21 -

battery holder

22 -

battery, button cell

23 -

Flat side of 21

24 -

spring contacts

25 -

contact feet

26 -

sheet metal section

27 -

pilot

28 -

recess in 16

29 -

cones

30 -

inclined surface on the pin

31 -

tabs on the lid

Claims (11)

1. A pump assembly, in particular a heating circulation pump assembly, with a centrifugal pump, with an electric motor which drives the centrifugal pump and with control electronics which are arranged in electronics housing (11) and comprise at least one circuit board (16) which is equipped with electronic components (20), characterised in that a battery (22) is arranged in the electronics housing (11), said battery being arranged in a battery holder (21) which is arranged on the circuit board (16) and is open at least at one side, wherein in the installed position of the circuit board (16), the battery (22) is secured in the battery holder (21), positively by way of a positive-fit element or materially, against falling out to the open side of the battery holder (21).
2. A pump assembly according to claim 1, characterised in that the battery (22) is a button cell (22) which with its flat sides is arranged in the battery holder (21) in a manner parallel to the circuit board.
3. A pump assembly according to claim 1 or 2, characterised in that battery holder (21) is designed open to a narrow side perpendicularly to the circuit board (16).
4. A pump assembly according to one of the preceding claims, characterised in that the positive-fit element (29) passes through a through-hole (28) in the circuit board (16) and at least partly blocks the open narrow side of the battery holder (21).
5. A pump assembly according to one of the preceding claims, characterised in that the positive-fit element (29) is designed in a stub-like manner and is arranged on a cover (12) which closes the electronics housing (11).
6. A pump assembly according to claim 4 or 5, characterised in that the positive-fit element (29) is part of a clip connection, whose other part is formed by the through-hole (28) in the circuit board (16) and with which the circuit board (16) can be clipfastened on the cover (12).
7. A pump assembly according to one of the preceding claims, characterised in that the positive-fit element (29) is designed as one piece with the cover (12) as a plastic injection moulded part.
8. A pump assembly according to one of the preceding claims, characterised in that the cover (12) is designed in a pot-like manner, positively receives the circuit board (16), in the region of its base comprises display and operating elements and is connected, preferably welded, to a tubular part of the electrics housing (11) which also forms a part of the motor housing or engages over this and is separated from this by a transverse wall (14).
9. A pump assembly according to claim 8, characterised in that a further circuit board (18) which is equipped with electronic components and which via contacts is electrically conductively connected to counter-contacts of the first circuit board (16) and is otherwise separated by an insulator (17) which is arranged therebetween, is arranged in the tubular part of the electronics housing (11).
10. A pump assembly according to one of the preceding claims, characterised in that the electronics housing (12) comprises frequency converter electronics as well as an electronic real-time clock which is buffered by the battery (22).
11. A pump assembly according to one of the claims 4 to 10, characterised in that the through-hole (28) is provided roughly in the middle of the circuit board (16).

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