EP3559472A1

EP3559472A1 - Water pump

Info

Publication number: EP3559472A1
Application number: EP17828693.6A
Authority: EP
Inventors: Franziska Agrawal
Original assignee: Einhell Germany AG
Current assignee: Einhell Germany AG
Priority date: 2016-12-20
Filing date: 2017-12-15
Publication date: 2019-10-30
Anticipated expiration: 2037-12-15
Also published as: ES2944335T3; EP3339649A1; AU2017381473B2; EP3559472B1; AU2017381473A1; CL2019001186A1; CN110226043B; FI3559472T3; WO2018114646A1; CN110226043A; PT3559472T; CA3042337A1; US20190257313A1; US11118589B2

Abstract

The invention relates to water pump, in particular a garden pump or a pump of a home water machine, which has a pump unit in a housing (GE), which pump unit can be driven by means of an electric motor and can pump water form a suction line (SL) to a pressure line (DL) as a conveyed liquid, wherein the housing comprises a pump housing (PG) connected to the suction line and a housing extension (GF) having the pressure line, which housing extension adjoins the pump housing, wherein the housing extension has a filter unit (FT) as a termination and an at least partially transparent window (FE) is arranged between the suction line and the pressure line such that a liquid level (FL) within the housing can be read on the pump housing from the outside before operation of the pump, and wherein the filter unit has a suction indicator (SA) such that the presence of suction pressure in the pump housing can be detected via the suction indicator or a leak at the suction line can be detected.

Description

water pump

The invention relates to a water pump, in particular a garden pump or a pump of a domestic water machine.

From the general state of the art, water pumps are known, which are designed to convey a liquid as centrifugal pumps or jet pumps. These are often equipped with a self-priming system, but with larger intake depths a relatively long intake time is achieved.

Such water pumps are provided as portable or permanently installed pumps with an electronic control unit, typically used as garden pumps or as part of a domestic water machine in domestic water works.

Pumps are often provided with an electronic control system, by means of which various additional functions or safety functions can be realized.

Thus, from DE 10 2013 106 970 A1 discloses a garden pump is known, which is equipped with a controller, so that when starting the pump in the intake phase after a period of 60 seconds, a short break of 4 seconds is programmed. This cycle can be repeated several times until the pump carries the water.

DE 10 2010 026 474 A1 discloses a garden pump arrangement with a pump driven by an electric drive motor and with a control device which contains a flow sensor and, in the case of - -

If a minimum flow rate through the pump output is exceeded, the drive motor switches off, wherein a delay time is specified between falling short of the minimum flow rate and the engine shutdown. Since the delay time is at least 1, 5 minutes and to turn on the drive motor after previous shutdown regardless of the output pressure of the pump, a user-operable control element is present, no pressure sensor is provided with a switch-on.

Known from the prior art garden pumps therefore provide opportunities to be able to provide appropriate remedy for any possibly for the pump or the user to faulty operations, such as dry running or scalding hazard by means of electronic control devices. However, for self-priming pumps, further steps must be taken by a user to ensure proper start-up, but usually only after thorough study of the operating instructions. However, since it can be observed that even with complex technical devices, the study of the operating instructions is often undertaken only when errors occur, but not during commissioning, in particular new users do not necessarily carry out installation steps or do so incorrectly ,

It is therefore an object of the invention to provide a water pump, which has an increased ease of use with respect to the initial installation and all other initial start-up.

This object is achieved by the independent claim 1. Further advantageous embodiments of the invention are each the subject of the dependent claims. These can be combined in a technologically meaningful way. - -

be combined. The description, in particular in conjunction with the drawings, additionally characterizes and specifies the invention.

According to the invention, a water pump, in particular a garden pump or a pump of a domestic water machine, specified, which has a housing driven by an electric motor pump unit, which can pump water as a pumped liquid from a suction line to a pressure line, wherein the housing with a Suction line connected pump housing and an adjoining the pump housing housing extension with the pressure line, the housing extension as a conclusion has a filter unit and between the suction line and the pressure line an at least partially transparent window is arranged so that before operation of the pump Liquid level within the housing on the pump housing can be read from the outside, and wherein the filter unit has a suction, so that the presence of suction pressure in the pump housing via the suction or even a leak on the suction line can be seen.

Accordingly, a water pump is indicated, in which the filling of the suction line is displayed before startup by an at least partially transparent window is arranged on the housing. For a user, therefore, it can be seen that the suction line was filled to the prescribed liquid level with the pumped liquid. Since the pump housings are typically made of opaque materials in prior art pumps, the user does not receive any information as to whether water would be in the pump or not. Since pumps can be executed without return valve in some applications and beyond typically present in a first installation with completely empty suction, it is therefore for - -

the safe operation of the water pump is required to carry out the installation steps in accordance with the instructions in the operating instructions. If this does not happen, there is a risk that, for example, a seal of the pump could be damaged if the pump runs dry for a long time. The invention now remedy to the effect that on the partially transparent window, the liquid level within the housing is read from the outside, so that the user is signaled whether there may still be installation measures to be taken here. This procedure considerably reduces the risk of the pump operating contrary to the instructions in the operating instructions. This is particularly important when the water pump from a lower level, typically of two meters or more, must suck water because here the built-up by the water pump suction pressure is insufficient to fill the suction line. In addition to a filling of the suction line, however, the presence of suction pressure is important for a correct operation. For this purpose, the invention provides a suction display in the area of the filter unit. In particular, when drawing in water from a low level, for example up to 8 m, it may be necessary for the pump to run dry for a long time in order to suck water from this area. During this time, however, a user in prior art pumps does not receive any information as to whether the suction process is proceeding correctly. For example, should there be a leak on the suction side, the pump would run dry for a long time without aspiration of water, so that only over a time window off can be done switching off. However, since there is a corresponding suction pressure by the pump during successful suction during the time window, therefore, is reliably signaled from the outside by means of the suction that the suction process will be completed successfully, without having to wait expectantly the suction result. In this case - -

In any case, would be given on the part of the water reservoir a correct installation, otherwise no suction pressure could be displayed. If, however, no liquid is sucked in with correctly indicated suction behavior via the suction indicator, at most a not complete sealing at the connection to the suction line would be a possible source of error. By displaying suction pressure on the filter cover via the suction indicator, therefore, the reliability of the water pump is significantly improved. According to a further embodiment of the invention, the suction display during the suction of liquid exerts a pressure on a display element, so that suction pressure can be seen on a filter cover.

In this case, the pressure can be exerted on the suction display via a membrane, which is held by a receptacle arranged on the side facing away from the filter cover. The membrane can be acted upon with respect to the receptacle by means of a resilient element, in particular a spiral spring or an adjustable with respect to their bias coil spring with a force. It is also possible to provide a, preferably coaxially arranged for suction indication, further suction display.

Accordingly, both fixed and variable or even multiple ranges of suction pressure can be displayed. Depending on the application and the associated installation height of the water pump, therefore, a corresponding default setting can be made by selecting the appropriate suction indicator.

In order to read the liquid level in the interior of the water pump, it is provided according to an advantageous embodiment of the invention, the - -

Window to arrange directly on the pump housing, in which case, for example, a configuration in the form of a porthole or a small slot-like window opening would be possible. However, it is also provided in other embodiments to arrange the at least partially transparent window on the preferably cylindrical housing extension, this can be done both by the fact that the housing extension is provided with a slot-like configuration of the transparent window, so that the water level between the suction line and the pressure line can be read from the outside. In yet another embodiment, it is provided that the at least partially transparent window is part of the filter unit preferably acting as a filling opening. Since the filter unit can typically also be used as a filling opening and thus forms the conclusion of the housing extension, at this point due to the transparent design of the housing both the correct filling of the suction line as well as any additional accumulation of material in the filter from the outside can be read. For this purpose, the filter unit has side walls which can be produced at least in sections, preferably completely from an optically at least partially transparent material. The abovementioned measures, individually and in combination, permit a high level of user comfort, in particular during maintenance or commissioning of the water pump. In addition, it is also possible, both alternatively and additionally instead of the Abiesens on the transparent window by the user to provide a liquid sensor which detects the liquid level in the region of the pump housing and signals at the transparent window. Accordingly, the correct filling of the suction line is displayed automatically, the transparent window in this case would be the cover, for example, a light emitting diode. A coupling of the liquid sensor to a control unit, for example, a commissioning - -

would prevent if not filled, is also provided in the context of the invention.

According to a further embodiment of the invention, a pressure sensor is arranged on the pressure line, which is connected to a control unit.

The combination of pressure sensor and control unit makes it possible, in particular, to detect pressure loss on the consumer side, so that in combination with a pressure reservoir, for example a water tank or the like, a domestic water machine can be created which only reacts with delay to pressure loss on the consumer side. Furthermore, the pressure sensor can activate status displays via the control unit, which can display operating states of the water pump in the form of LEDs, for example.

According to a further embodiment of the invention, a return valve is provided, which is part of the filter unit serving as a filling opening.

In order to be able to fill the suction line at the start of commissioning, the pumped liquid is introduced via the filling opening on the side of the water pump. However, the return valve is intended to prevent this precisely, so that it must be put out of operation during commissioning, provided that the filling of the pumped liquid is to be made above the return valve. In that the return valve is part of the filling opening, the return valve is forcibly shut down by removing the filling opening.

In another embodiment, a return valve is provided which has an automatic vent. - -

If now the filling of the suction line to be made at initial startup below the return valve, yet a venting possibility is provided to be able to discharge the air present in the suction line accordingly. The invention provides an automatic venting here, which, for example, can divert the exiting air without the intervention of a user.

For automatic venting, the return valve can have at least one passage channel, which serves as a vent when the suction line is filled with conveying fluid when the return valve is closed, wherein the at least one passage channel can be closed by a sealing ring when the pump unit is activated. In this case, the passage channel can be arranged on a valve disk of the return valve. The sealing ring can be arranged with an overlying adjusting disc on the side of the pressure line along a valve stem of the return valve under spring bias.

In this embodiment, the check valve can be installed integrated into the water pump, wherein the ventilation of the water pump when filling with water on the side of the suction pipe requires no manual intervention by passageways are provided on the valve head, which are secured with a sealing washer and a support disk. When filling water into the suction line, the pump is depressurised, so that the sealing ring leaves the passage open, so that air can escape through the passage channels. The size of the passage channels is chosen so that the water can flow into the suction line, while at the same time can escape the air. During operation of the water pump creates pressure in the pressure chamber and the sealing disc closes. - -

In addition, it is provided that the return valve actuates a switch which emits a signal to a control device in the event of dry running.

Accordingly, the state of dry running is reliably detected, especially with a longer intake time due to water bubbles or increased water temperature, so that the control device can monitor a safe pumping operation with a corresponding time specification for the maximum dry running time. The switch is preferably magnetically activated so that, for example, a REED switch or a Hall sensor is used, which is actuated by means of a magnet arranged on the return valve. Alternatively or additionally, the switch can also trigger a scalding fuse, which is activated, for example, if the water pump is operated against a closed pressure line, in which case the water inside the water pump is heated by the pump unit.

Some embodiments will be explained in more detail with reference to the drawing. Show it:

1 is a perspective side view of a part of a water pump according to the invention according to a first embodiment of the invention,

2 is a perspective side view of a part of a water pump according to the invention according to a second embodiment of the invention,

3 shows a perspective side view of a part of a water pump according to the invention according to a third embodiment of the invention, - -

4 shows a cross section through a filter cover for a water pump according to the invention according to a perspective side view,

Fig. 5 is a cross-sectional view through another filter cover

for a water pump according to the invention,

Fig. 6 is a cross-sectional view through another filter cover

for a water pump according to the invention,

Fig. 7 is a cross-sectional view through another filter cover

for a water pump according to the invention,

Fig. 8 is a cross-sectional view through another filter cover

for a water pump according to the invention, and

Fig. 9 is a return valve with an automatic vent for a water pump according to the invention. In the figures, identical or functionally identical components are provided with the same reference numerals.

In Fig. 1, a water pump according to the invention with those components is shown in a perspective side view obliquely from above, which are essential for the explanation of the invention. The other components necessary for carrying out the invention are, however, known to a person skilled in the art. - -

The water pump WP comprises in the illustration according to FIG. 1 a housing GE, which is formed from a pump housing PG and an adjoining cylindrically formed housing extension GF. On the bottom of the pump housing PG is a drain AB. At the upper end of the cylindrically shaped housing extension GF, a connection for a suction line SL is attached. A flange FN on the pump housing PG typically houses the pump unit driven by an electric motor (not shown in FIG. 1). The housing extension GF is completed by a filter unit FT, which has a filter cover FD on its upper side. Furthermore, the housing extension GF is connected to a connection for a pressure line DL, which can pass on the suctioned via the suction line SL water according to the application of the water pump. In order to control the possible accumulation of foreign bodies within the filter unit FT, optionally a transparent window (not shown in FIG. 1) can be provided which is particularly advantageous when the filter housing is made of non-transparent material. The housing extension GF or the pump housing PG will typically also be made of opaque plastic material or metallic materials.

During initial commissioning, it is necessary to fill the pump housing PG with water as the pumped liquid. In order to be able to recognize during start-up that the pump housing PG has been filled with delivery fluid, according to the invention a transparent window FE is provided which, when correctly filled, makes the fluid level FL readable from the outside. In the example shown in FIG. 1, the liquid level FL is signaled via a transparent window FE attached to the pump housing PG. The correct filling with pumped liquid can not only be achieved via an - -

NEN liquid level FL are displayed within the transparent window FE but also generally by a complete covering of the transparent window FE with conveyed liquid, so that only the presence but not the exact level of the pumped liquid is displayed. Both are understood according to the invention by the term liquid level FL. Alternatively or additionally, a screw cap SD made of transparent material or with a transparent insert may be provided.

Further embodiments of the transparent window FE will be described in more detail below with reference to FIGS. 2 and 3.

After the correct filling, the water pump WP sucks on the suction line SL conveying liquid. This is indicated by a suction indicator SA disposed in the filter cover FD, which is in the form of a pen, the suction indicator SA protruding from the filter cover FD prior to operation and pushed into the filter cover FD during operation of the water pump WP. Detailed embodiments will be described in more detail below with reference to FIGS. 4 to 8. Between pressure line DL and suction line SL, as will be described below with reference to FIG. 9, a return valve may be mounted. In order to be able to empty the delivery fluid located downstream of the return valve in the pressure line DL, for example when the water pump WP is shut down, the outlet AB is provided, so that the delivery fluid located in the pressure line DL can run off by producing an opening.

Another embodiment of the water pump WP is shown with reference to FIG. Here, the water pump WP is in a perspective - -

Side view shown towards a front. It can be seen that the housing extension GF is provided with a transparent window FE made in an elongated form, via which the correct filling of the suction line SL on the water pump WP can be read on the basis of the liquid level FL.

Another embodiment of the water pump WP is shown in FIG. 3 shows the pump in a perspective side view, wherein here, in contrast to the previous embodiment, the housing of the filter unit FT consists of a transparent plastic material, so that the liquid level FL can be read within the side walls of the filter unit FT. For this purpose, the filter unit FT has side walls which are at least partially but preferably completely made of an optically transparent material. As an alternative or in addition to the embodiments according to FIGS. 1 to 3, it would also be possible to attach a liquid sensor which can electronically provide evidence of the presence of delivery liquid within the housing GE. As shown in Fig. 1, the filter unit FT has a filter cover FD, which according to further embodiments of the invention may be equipped with a suction indicator SA. The suction indicator SA will be described in more detail below with reference to FIGS. 4 to 8 in several embodiments.

In Fig. 4, the filter cover FD is shown schematically in a perspective cross-sectional view. It can be seen that a membrane MB, which can exert a certain axial spring force, opens outwards into a seal DI, so that a water-resistant seal between a receptacle AU and the filter cover FD opens. - -

completion is possible. In a central part of the membrane MB is provided with the suction indicator SA, which may be guided through an opening in the filter cover FD to the outside, wherein the membrane MB via a channel KA in the presence of a pressure inside the filter unit FT corresponding to the suction indicator SA pulls inward or pushes out without pressure. As a result, it is possible to detect the presence of a suction pressure in the interior of the water pump via the suction display SA designed as a pin-shaped display element and to display it to a user.

Another embodiment is shown in Fig. 5 in a cross-sectional view. Here, the seal DI is located within the channel KA on a cylindrical rod of the suction indicator SA. The membrane MB is arranged together with the suction indicator SA between the receptacle AU and filter cover FD. Again, the membrane MB is provided with a corresponding axial spring force, wherein the presence of suction pressure can also provide as described above for an axial displacement of the suction indicator SA through the filter cover FD therethrough. Another embodiment of a suction indicator SA is in Fig. 6 in a

Cross-sectional view shown. The suction indicator SA is in turn connected to a receptacle AU arranged on a membrane MB, which is arranged below the filter cover FD, so that the suction indicator SA can penetrate the filter cover FD by axial displacement. However, in contrast to the previously described embodiment according to FIG. 5, the suction indicator SA has larger external dimensions transversely to the axial displacement direction, so that the suction indicator SA is present not only in the form of a pin-shaped display element but in the form of an enlarged contact surface on the filter cover FD. On the opposite side of the membrane MB is at the - -

would AU AU provided a coil spring SF, which is connected via a spring plate FE with the suction indicator SA and the membrane MB in combination. The spring plate FE prevents the coil spring SF is in contact with the diaphragm MB, which could possibly lead to damage or at least impede the assembly. Inside the spiral spring SF, in turn, the channel KA is arranged, so that with a corresponding suction pressure, an axial displacement of the suction indicator SA is possible. The membrane MB is biased in the embodiment of FIG. 6 now with the coil spring SF, so that also correspondingly higher suction pressure values can be displayed. Furthermore, the suction indicator SA can also be used to build a pumping action by rhythmic actuation and thereby manually generate suction pressure. This could be advantageous, for example, when commissioning the water pump WP. The prerequisite for this is to install a check valve at the end of the suction line.

FIG. 7 again shows a variation of the embodiment just described. The spiral spring SF has on the side opposite the diaphragm MB a locking means FM, so that via a spring plate FE ', the bias of the coil spring SF can be adjusted by adjusting the adjustment by means of FM. In order not to impair the function, the locking means FM must also be in the axial direction with the channel KA in communication. Thus, it is possible to perform at different installation heights of the water pump WP with respect to the water level of the water to be pumped an adjustment of the suction indicator SA by adjusting the adjusting FM. The spring plate FE and the spring plate FE 'serve as mentioned above, only the mechanical protection of adjacent components, in particular the membrane MB, in other embodiments, the suction SA could be provided without spring plate FE. - -

The detection medium FM could also have corresponding area markings together with the recording AU or else be adjustable in discrete steps marked accordingly in the recording AU, so that a user can set the functional area of the suction display SA to the appropriate installation height of the water pump WP.

Referring now to Figure 8, there is shown a third embodiment of a spring loaded suction indicator SA. In this embodiment, the suction indicator SA described in connection with FIG. 6 is modified so that it is hollow-cylindrical in the axial direction, so that a further suction indicator SA 'can be inserted coaxially into the interior of the suction indicator SA. The further suction indicator SA 'is in turn connected to a further membrane MB', which comes to lie below the recording AU in a further recording AU '. The further membrane MB 'is likewise prestressed via a spiral spring SF', which is connected to the further membrane MB 'via a spring plate FE'. Consequently, there is a double suction SA or SA ', wherein depending on the suction pressure only one or both displays emerge from the filter cover FD. Such an embodiment can be used, for example, to represent two different pressure ranges by means of the suction indicators SA or SA 'depending on the desired installation height of the water pump WP. Thus, when installing the water pump WP at a first lower level only the suction indicator SA would be pulled into the filter cover FD, since at this level the pressure in the suction line would not be high enough to against the coil spring SF 'lowering the suction indicator SA to effect. At a second larger height of the water pump WP with respect to the water to be pumped, the pressure is then high enough, so that in addition the further suction indicator SA 'is pulled into the filter cover FD. About the - -

Spring constants of the coil springs SF and SF 'can hereby be made a factory area differentiation. A locking medium FM, as shown in Fig. 7, is not required here, but could for example be provided for the further suction SA ', as this would be accessible from below by a user or a user.

The suction indicator SA and the further suction indicator SA ', if present, according to the embodiments of Figures 4 to 8 allow the presence of a suction-side leakage indicate, since then the pin-shaped displays can not be pulled into the filter cover FD. As already mentioned in the introduction, this is advantageous during commissioning, especially at high installation heights. Typically, the installation height can be up to 8 m, wherein in the two-part suction of FIG. 7, a division of up to 4 m for the first suction SA and from 4 m for the second suction SA 'could be selected.

To prevent backflow of water into the suction line SL, water pumps are often equipped with return valves. However, since at the beginning of the pumping operation when the water pump WP is started up, the suction line SL must be filled with water, such return valves are mechanically blocked, so that they are deactivated. According to the invention, it is provided to install a return valve within the filter unit FT, which simultaneously acts via the filter cover FD as a filling opening for the introduction of pumped liquid during startup. Therefore, the filter unit FT is removed together with the return valve, so that no such mechanical actuation by a user or a user is necessary. - -

A further embodiment uses for this purpose an automatic venting, wherein essential elements of such a return valve RV in the cross-sectional view of FIG. 9 are outlined. The return valve RV comprises a valve plate VT, which opens via a valve stem VS in a housing plate GP. The housing plate GP is arranged on the housing GE. The valve plate VT and the valve stem VS are arranged on the pressure side of the pressure line DL side and can be sealed by a sealing ring DR against the suction side of the suction line SL. The valve shaft VS is biased by a corresponding spiral spring SP, which is supported against the housing plate GP. Accordingly, due to the return valve RV no water from the pressure line DL back into the suction line SL. During filling, however, the pump is depressurized, so that via a corresponding sealing washer DS sealed passageways DK in the valve plate VT, which are additionally held by a lock washer SS, are open, so that both water can be brought through the passageways DK in the suction line SL , as well as air from the suction line SL can escape via the passage channels DK. The sealing disc DS is arranged directly above the passage channels DK on the side of the pressure line DL and is covered by the locking washer SS.

Accordingly, a return valve RV is created, which prevents both running back in normal operation and allows automatic venting during startup. Since the displacement of the valve plate VT is related to the presence of suction pressure, the return valve RV can also be supplemented by a switch ST, which can be used to detect dry running or overheating. For this purpose, the valve plate VT is with - -

a magnet holder MH provided which can receive a magnet MT. Outside the line area there is the switch ST, which as a REED switch or Hall sensor can detect the displacement of the magnet MT and thus transmits a signal to a control device.

The features indicated above and in the claims, as well as the features which can be seen in the figures, can be implemented advantageously both individually and in various combinations. The invention is not limited to the exemplary embodiments described, but can be modified in many ways within the scope of expert knowledge.

Claims

Claims:

1 . Water pump, in particular a garden pump or a pump of a domestic water machine, which has a pump unit driven by an electric motor in a housing (GE) which can pump water from a suction line (SL) to a pressure line (DL) as a pumped liquid, the housing (GE) a pump housing (PG) and a housing extension (GF) adjoining the pump housing (PG) with the pressure line (DL) and the suction line (SL), the housing extension (GF) terminating as a filter unit (FT) and between the suction line (SL) and the pressure line (DL) an at least partially transparent window (FE) is arranged, so that before operation of the pump (WP) a liquid level (FL) within the housing (GE) is read from the outside, and wherein the filter unit (FT) has a suction indicator (SA), so that the presence of suction pressure in the pump housing (PG) or leakage in front of the suction line (SL) via the suction indicator (SA) can be seen ,

2. Water pump according to claim 1, wherein the suction indicator (SA) exerts a pressure on a filter cover (FD) arranged on a display element during the suction of liquid.

3. Water pump according to claim 2, wherein the pressure via a membrane (MB) on the suction indicator (SA) is exerted, which is held by a on the side facing away from the filter cover (FD) side receptacle (AU).

4. Water pump according to claim 3, wherein the membrane (MB) relative to the receptacle (AU) by means of a resilient element, in particular of a coil spring (SF) or with respect to their bias by means of a locking means (FM) adjustable coil spring (SF) is acted upon by a force.

Water pump according to one of claims 1 to 4, wherein a, preferably for suction indication (SA) coaxially arranged, further suction indicator (SA ') is provided which indicates a greater suction pressure.

Water pump according to one of claims 1 to 5, wherein the at least partially transparent window (FE) on the pump housing (PG) or on the preferably cylindrical housing extension (GF) is arranged.

Water pump according to Claim 6, in which the at least partially transparent window (FE) is part of the filter unit (FT) which preferably acts as a filling opening.

Water pump according to claim 7, wherein the filter unit (FT) has side walls which are at least partially, preferably made entirely of an optically at least partially transparent material.

Water pump according to one of claims 1 to 8, in which, alternatively or additionally, a liquid sensor is provided which detects the liquid level in the region of the pumping unit and signals at the transparent window (FE). O.Wasserpunnpe according to one of claims 1 to 9, wherein on the pressure line (DL), a pressure sensor is arranged, which is connected to a control unit. 1 1 .Water pump according to one of claims 1 to 10, wherein a return valve (RV) is provided, which is part of the filter unit serving as a filling opening.

12. Water pump according to one of claims 1 to 1 1, wherein a return valve (RV) is provided which has an automatic vent.

13. Water pump according to claim 12, in which the return valve (RV) has at least one passage channel (DK) which, when the return valve (RV) is closed, serves as ventilation during filling of the suction line (SL) with delivery fluid, wherein the at least one passage channel (DK) upon activation of the pump unit via a sealing ring (DR) is closed. 14. Water pump according to claim 13, wherein the passage channel (DK) on a valve disc (VT) of the return valve (RV) is arranged and the sealing ring (DR) with an overlying adjusting disc (SS) on the side of the pressure line (DL) along a valve stem (VS) of the return valve (RV) is arranged displaceably under spring bias.

15. Water pump according to one of claims 12 to 14, wherein the return valve (RV) a switch (ST) is actuated, which emits a signal to a control device in the event of dry running.

16.Wasserpumpe according to claim 15, wherein the switch (ST) is a magnetic switch, in particular a REED switch or a Hall sensor, which is actuated by means of a magnet arranged on the return valve. 17. Water pump according to one of claims 15 or 16, wherein the switch (ST) additionally or alternatively triggers a scalding fuse.