EP3405650B1 - Pump assembly having an axial-flux electric drive - Google Patents

Description

The present invention relates to a pump assembly, at least comprising a first housing in which at least a first drive means for conveying a fluid is rotatably mounted, wherein a first drive shaft of the first drive means extends at least through a first side wall of the first housing along an axial direction , In particular, the pump arrangement is a delivery device for a water / urea solution (eg Adblue), which is preferably used in a motor vehicle for treating an exhaust gas of an internal combustion engine.

Such pumping arrangements for water-urea solutions have long been known. In this case, usually an electric drive unit is connected to the drive shaft of the drive means. About the drive shaft of such rotary pumps, the drive means is driven to convey a fluid. As drive means z. B. gear rotors (gear pumps) known. Especially for use in motor vehicles as compact as possible a pump assembly is to be provided, in particular, noises of the pump assembly are to be avoided as far as possible. Furthermore, it should be noted in the promotion of water-urea solutions that a freezing of the solution in the lines is avoided as possible. Usually, therefore, the water-urea solution is conveyed from the line back into a storage tank. However, the drive means is also to be driven in the opposite direction of rotation.

The JP 2007-166693 relates to an axial flow motor with a rotor and a stator. The motor is coaxial and arranged laterally adjacent to a pump with a pump housing. The pump is formed by an impeller. One first bearing is arranged in the pump housing. A second bearing is located outside the pump housing beyond the engine.

The US 2013/0071268 A1 discloses a urea gear pump disposed coaxially and laterally adjacent to an electric drive. The electric drive comprises a rotor and a stator arranged in the radial direction outside the rotor. The drive shaft of the pump is mounted on a bearing outside and another bearing within the pump housing.

The EP 2 273 121 A2 discloses a gear pump which is driven via a coaxial with the pump arranged magnetic drive with first magnet and second magnet.

The DE 102 58 364 A1 discloses an electric drive with rotor and stator for driving a pump. The drive is supported by two bearings. The pump is arranged laterally adjacent to the drive.

The US 2014/0265664 A1 discloses an axial flux motor with stator and rotor, via which a drive shaft for driving a pump (not shown and not specified) is driven. Next, a fan assembly for cooling the electric drive is provided. The drive shaft is mounted in the area of the engine via bearings.

On this basis, it is an object of the present invention, at least alleviate or even solve the problems described with reference to the prior art. In particular, a compact pump assembly to be proposed, which is characterized by a low noise.

To solve these problems, a pump assembly according to the features of claim 1 is proposed. Advantageous developments are the subject of the dependent claims. The features listed individually in the claims can be combined in a technologically meaningful manner and can be supplemented by explanatory facts from the description and details of the figures, with further embodiments of the invention are shown.

The invention relates to a pump assembly, at least comprising a first housing in which at least a first drive means for conveying a fluid is rotatably mounted, wherein a first drive shaft of the first drive means extends at least through a first side wall of the first housing along an axial direction; wherein at least one first rotor of a first axial flow electric drive is arranged outside the first housing on the first drive shaft, wherein the first axial flow electric drive has only one (first stator assigned to the first axial flux electric drive and first rotor) second) stator).

In particular, the first housing encloses at least the first drive means in a liquid-tight manner, wherein connections are provided for the supply and discharge of the fluid to be delivered. The first drive shaft extends through a first side wall of the first housing, wherein a fluid-tight seal between the first side wall and the first drive shaft is also provided here. Outside the first housing, a first rotor of a first axial flow electric drive (AFM: Axialflussmotor) is provided, which is arranged on the first drive shaft for transmitting a torque to the first drive means. Due to the separate arrangement of drive means and electric drive damage to the electric drive can be avoided by the pumped fluid.

In particular, the first housing encloses at least the first drive means, wherein connections are provided for supplying and discharging the fluid to be delivered. The first drive shaft extends through a first side wall of the first housing. Outside the first housing, a first rotor of a first axial flow electric drive (AFM: Axialflussmotor) is provided, which is arranged on the first drive shaft for transmitting a torque to the first drive means. Preferably, the first housing is not made liquid-tight, so that the fluid to be delivered as a leakage current, for. B. along the first drive shaft, can emerge from the first housing. However, the first housing is preferably designed so that as a result of this leakage flow from the first housing (ie, a fluid drain and / or fluid flow not exclusively via the connections for supply and discharge of the fluid) there is no significant impairment of the delivery rate of the pump assembly. In particular, the leakage current is at most 5% of the delivery rate (of the delivery volume flow) of the pump arrangement.

The first axial flow electric drive comprises a (single) stator and a first rotor, which are arranged coaxially with each other. The stator may comprise a soft magnetic material, for example a so-called "soft magnetic composite" (SMC), or a combination of electrical sheets and SMC. The coils of the stator comprise cores, which are preferably made of a soft magnetic material and produced obtuse. The SMC material is not sintered. Rather, a tempering takes place below a melting temperature, which is sufficient, however, that the cores retain their geometry permanently.

The rotor of the axial flow electric drive can have permanent magnets or even soft magnetic elements, for example in recesses. So can with permanent magnets as Axialfluss electric motor, a permanent-magnet synchronous or brushless DC motor, abbreviated BLDC, are formed, while, for example, with soft magnetic elements, a reluctance motor can be created as an electric motor in the axial design.

The structure of a stator, in particular using SMC and further details also relating to a rotor, for example, go from the post-published PCT / EP2015 / 075036 applicant, to which reference is made in the context of the disclosure of the present invention.

In particular, the first axial flow electric drive has an electrical power consumption of less than 100 watts, preferably less than 50 watts. In particular, the fluid is conveyed with a delivery pressure of at most 10 bar.

The first drive shaft is unsupported outside the first housing or supported by at least one bearing which receives only forces acting in the axial direction. In particular, therefore, there is no radial bearing, ie a bearing which serves to support forces acting in the radial direction, required outside the first housing. The first drive shaft is therefore mounted in particular exclusively in the first housing, so that the space for otherwise required bearings outside the first housing is not needed. For a particularly compact design of the pump assembly is possible.

It can be used as a bearing so-called friction or plain bearings. Preferably, at least the first drive shaft is supported exclusively via the first housing, for. B. on the first side wall and / or a second side wall, in particular, the material of the side walls forms the bearing surface.

In particular, a leakage flow of the fluid to be delivered along the first drive shaft can cause a lubrication of the bearings. Preferably, a pressure chamber of the pump assembly is fluidly connected via an opening at least in the first side wall with a region outside the first housing. In this way, a volume flow (controlled in terms of quantity) of the fluid to be delivered can emerge from the first housing and flow back into the first housing via the bearings.

According to a further advantageous embodiment, the first axial flow electric drive is arranged in a second housing that can be connected to the first housing in a repeatably detachable manner. Thus, the first Axialfluss electric drive is arranged protected from the fluid to be delivered, wherein the individual components of the pump assembly are independently interchangeable and / or to be maintained.

In particular, the first rotor is arranged immediately adjacent to the first side wall and between the first side wall and a stator of the first axial flow electric drive. In this arrangement, the first drive shaft can be made very short, since the first rotor connected to the first drive shaft is disposed immediately adjacent to the first end wall, through which the first drive shaft, starting from the first housing, extends into the second housing.

According to another embodiment, a stator of the first axial flow electric drive is arranged immediately adjacent to the first side wall and between the first side wall and the first rotor. Here, the first drive shaft is longer, since it also extends through the stator through to the first rotor.

The stator (ie its components, in particular coils, cores and return ring) is preferably arranged in a radial direction outside the at least one first drive means.

Preferably, the stator (ie at least one of the components of coil, core and return ring) along the axial direction overlapping with the first housing, preferably overlapping with at least one bearing of the first drive shaft, particularly preferably arranged overlapping with the at least one first drive means.

This preferred embodiment allows a particularly compact design of the pump assembly, wherein (at least) the at least one first drive means, the first side wall and the first rotor along the axial direction are arranged side by side and thus determine the size of the pump assembly along the axial direction.

In particular, the stator is inseparably connected to the first side wall. In particular, the stator forms at least a part of the first end wall.

Preferably, the first drive means is a first gear rotor. This can z. B. be designed as part of a gear pump, wherein the gear pump can be constructed as external gear pump with preferably involute, as internal gear pump or as a gerotor pump, for example as a gerotor pump or a sickle pump. Furthermore, the gear pump may be a screw pump.

In particular, at least the first gear rotor is made of a plastic.

In particular, it is proposed to produce at least the first gear rotor from a sintered material having a porosity, the gear rotor having, in addition to the porosity, a further noise reduction means. This is done in particular on the content of DE 10 2015 201 873 directed. It has been found that by a variation of the density in the wheel body of the gear rotor, the transmission path of the structure-borne sound waves from the generation of the ring gear to the hub interrupted or the sound waves can be broken or reflected so that the structure-borne sound signal at the output, namely the shaft / bore of the Gear rotor, significantly less fails. The variations in density can be rotationally symmetrical or local. Also possible is a gear rotor in disc arrangement with different densities executed. The angle of the plane of the individual layers may differ from the preferred plane, the horizontal plane of the component. Since the structure-borne noise spreads better in materials with higher density than in materials with lower density, it is also possible to introduce sound guide channels in the gear rotor or only in the teeth, which deflect or weaken the structure-borne sound waves targeted. The channels and / or local density variations can be filled both with pure material of different density and with combinations of different materials such as iron powder or oil.

These sound-reducing geometries can be realized with different manufacturing methods. These include, for example, an intelligent filling shoe, in particular a rotationally rotating filling shoe for filling with at least two different materials, as for example from US Pat DE 10 2014 006 374 evident. As a result, for example, density variations can already be produced during the pressing process. Furthermore, may also be referred to as a green-in-green manufacturing process, as it is known from the DE 10 2009 042 598 can be used, for example, to produce density variations. Manufacturing process as a conventional pressing of metallic Powder, as it also in modified form from the WO 2013/067995 A1 shows, and an additive manufacturing of metallic material and / or plastic, for example with a device, as known from DE 10 2013 103006 A1 by way of example, can also be used, in particular to produce low-noise gear rotors. But it can also be used manufacturing methods, as they are basically from the EP 2 221 131 A1 , of the EP 1 407 877 A1 , of the EP 1 34527 A2 or even the JP S60-162 702 A emerge.

A further development provides that the stator is formed by the first housing. For example, this can be embedded in the first housing, the stator. This is possible, for example, by means of a green-in-green process, which has already been described above and to which reference is made in this regard. Also, the stator can be inserted into the first housing. Thus, for example, an outer side of the first housing may have a cutout in which the stator can be pressed. For example, the first housing in this area may be made of plastic while the stator is made of metallic material. For example, a return ring can be pressed, on which the stator poles are arranged.

In particular, in this embodiment, it is advantageous if the stator (that is to say at least one of the components of coil, core and return ring) is arranged overlapping with at least one bearing of the first drive shaft, particularly preferably overlapping with the at least one first drive means.

It is preferred if the first housing has an amagnetic material at least in a region adjacent to the stator, preferably the electromagnetic return ring and in particular to the cores of the stator. As a result, the necessary training of the electromagnetic field for Generation of a torque on the rotor of the axial flow motor not or only slightly disturbed.

According to a further advantageous embodiment, a second Axialfluss electric drive outside of the first housing and on a, the first side wall opposite the second side wall of the first housing is arranged; wherein the second Axialfluss electric drive is connected either to the first drive shaft or to a second drive shaft of a arranged in the first housing second drive means for transmitting torque.

In particular, the second Axialfluss electric drive with the second drive shaft is connected to transmit torque, wherein the second drive means is a second gear rotor, which is arranged with the first gear rotor for conveying the fluid meshing, wherein the two gear rotors are braced against each other via the two Axialfluss electric drives ,

The tension of the two gear wheels causes a constantly backlash-free meshing of the gear wheels, so that noise can be minimized. In particular, this tension can also be set when the direction of rotation of the drive means is reversed (eg when a water-urea solution is returned to a tank to prevent ice formation in the lines).

According to a further embodiment, the two Axialfluss electric drives are indeed the same structure, but offset with respect to the arrangement of the stator poles arranged at opposite ends of the gear rotor. By offsetting it is possible, for example, to achieve a balance between generated electromagnetic waves of the axial flow electric drive. For example, depending on the structure of the axial flow electric drives, the offset may be designed so that trough caused by the first axial flow electric drive, and Wellenberg, caused by the second Axialfluss- electric drive, in their torque effect more or less superimposed. This achieves a balanced, especially more uniform drive of the gear rotor. This in turn leads to a reduction of noise emissions on the intermeshing gears. The equalization of the torque on the driven shaft leads in particular to a quieter contacting of the individual teeth of the meshing gears. An impact of the meshing teeth can be minimized at least.

In particular, at least the first axial flow electric drive forms at least one heating element, which is connected in a heat-conducting manner to the first side wall via at least one heat-conducting structure. In particular, the one stator can be used with its coils as a heating element of the first housing. The heat development occurring there can, for. B. are introduced conductively via the first side wall in the first housing. By the power electronics for this purpose, for example, a corresponding current can be made available, which flows through the coils of the stator poles. In order to create a good heat transfer, it is particularly advantageous if the stator is completely connected to the rear surface with the first housing, ie z. B. forms the first side wall itself. The stator is therefore preferably mounted as a first side wall directly on the first housing or z. B. used in a designed as a cover of the first housing first side wall.

For producing the stator or the first side wall or of heat conducting structures, it is possible, for example, to use a metallic, electrically conductive powder, for example in a rotatory filling shoe for filling with at least two different materials, such as, for example, US Pat DE 10 2014 006 374 evident. Thus, for example, not only density variations but also conductive heat paths (heat conduction structure) and electrically heatable paths (heat conduction structure) already during the pressing process (the stator, the first side wall) are produced.

In particular, the first side wall forms at least part of a fluid-carrying channel. Preferably, at least a part of the side wall contacts the conveyed fluid in the region of the channel (eg in the region of the drive means). In particular, only this portion is formed with a heat-conducting structure, so that the heat generated in the region of the stator can be delivered via the heat-conducting structure targeted to the fluid.

For example, a temperature sensor can be used for the heat generation. Such a temperature sensor may be attached to the pump assembly itself. Another embodiment provides that an existing temperature sensor is used on a power electronics of the pump assembly to decide whether and how much a current is sent through the stator. Such can be stored for example in a control unit, which is assigned to the urea injection. For example, in the event of detection at low temperatures, the heating can take place even before the actual start of the internal combustion engine. If one thinks of today's keyless systems for opening and starting, therefore, the opening could already trigger the precautionary heating. This would allow the pump itself to be heated, which would be supplemented, for example, with heat, e.g. from a tank heating or as waste heat from a still warm combustion engine. Thus, the system could be immediately operational or remain operational even at low temperatures.

Furthermore, it is provided according to an embodiment that a compensation of a different thermal expansion of the different materials is provided in the pump assembly. The fluid or the urea solution can Temperatures are exposed, which may fluctuate due to environmental conditions, but also for operational reasons, for example, in deep frost of, for example - 35 ° C and due to the conditions when injecting the urea solution of at least short-term + 100 ° C. This also has an effect on the individual components, which already stretch or contract differently due to the ambient temperature. Therefore, the pump assembly may, for example, have in its interior a spring-loaded tracking, which allows a minimization of, for example, otherwise resulting gap dimensions.

It is proposed the use of the pump assembly according to the invention for promoting a water-urea solution in a motor vehicle.

In addition to a first gear, the motor vehicle urea pump may also have a second gear on a second shaft, wherein the two gears mesh with each other and thereby build up a pressure. Both gears can be made of the same material. But it can also be constructed of two different materials, both gears, for example, one gear may consist of a plastic, the other gear of a metal. Also, compound gears may be used, that is, the gear has different materials, such as a core of metal and a surface of plastic or vice versa. Helical gears are preferably used in intermeshing gears. However, it can also be advantageous for the pressure increase to use straight-toothed gears. Preferably, the gear or wheels are produced as spur gear wheels with a manufacturing quality in which the gear quality of the gear designed according to DIN 3961 and DIN 3962 with respect to at least one parameter, preferably a total profile error F _α , a profile angle error f _Hα and a profile shape error f _α of at least the quality 6, preferably of at least the quality 5 or better at at least one of these values, especially at least these three values. For example, the first housing may also have an additional damping, by means of which a pumping noise is reduced. Such density variations as described above can be used here, for example. Other ways described herein to minimize structure-borne noise in or on the housing can be used to achieve the additional damping.

Further, attenuation of a noise or a noise spectrum can not be achieved only by different sintering materials and / or densities of sintered materials. Also by targeted porosity of the sintered material or closing of pores, for example by adding copper, for example in conjunction with different densities, possibly by using green-in-green production process with inner and outer material as well as by one or more coatings on components, for example, with a plastic, damping can be adjusted specifically.

Fig. 1:

eine Explosionsdarstellung einer ersten Pumpenanordnung in perspektivischer Ansicht;

Fig. 2:

die Explosionsdarstellung der ersten Pumpenanordnung gemäß Fig. 1 in einer Seitenansicht im Schnitt;

Fig. 3:

die erste Pumpenanordnung gemäß Fig. 1 und 2 in einer Seitenansicht im Schnitt;

Fig. 4:

die erste Pumpenanordnung gemäß Fig. 3 in einer Draufsicht;

Fig. 5:

eine Explosionsdarstellung einer zweiten Pumpenanordnung in perspektivischer Ansicht;

Fig. 6:

die Explosionsdarstellung der zweiten Pumpenanordnung gemäß Fig. 5 in einer Seitenansicht im Schnitt;

Fig. 7:

die zweite Pumpenanordnung gemäß Fig. 5 und 6 in einer Seitenansicht im Schnitt;

Fig. 8:

eine dritte Pumpenanordnung in einer Seitenansicht;

Fig. 9:

eine vierte Pumpenanordnung in einer Seitenansicht;

Fig. 10:

eine fünfte Pumpenanordnung in einer Seitenansicht; und

Fig. 11:

eine sechste Pumpenanordnung in einer Seitenansicht.

The invention and the technical environment will be explained in more detail with reference to the figures. It should be noted that the invention should not be limited by the embodiments shown. In particular, unless explicitly stated otherwise, it is also possible to extract partial aspects of the facts explained in the figures and to combine them with other components and findings from the present description including figures. The same reference numerals designate the same objects, so that explanations of other figures can be used if necessary. They show schematically:

Fig. 1:

an exploded view of a first pump assembly in a perspective view;

Fig. 2:

the exploded view of the first pump assembly according to Fig. 1 in a side view in section;

3:

the first pump assembly according to Fig. 1 and 2 in a side view in section;

4:

the first pump assembly according to Fig. 3 in a plan view;

Fig. 5:

an exploded view of a second pump assembly in a perspective view;

Fig. 6:

the exploded view of the second pump assembly according to Fig. 5 in a side view in section;

Fig. 7:

the second pump assembly according to FIGS. 5 and 6 in a side view in section;

Fig. 8:

a third pump assembly in a side view;

Fig. 9:

a fourth pump assembly in a side view;

Fig. 10:

a fifth pump assembly in a side view; and

Fig. 11:

a sixth pump assembly in a side view.

Fig. 1 shows an exploded view of a first pump assembly 1 in a perspective view. Fig. 2 shows the exploded view of the first pump assembly 1 according to Fig. 1 in a side view in section. Fig. 3 shows the first pump assembly 1 according to Fig. 1 and 2 in a side view in section and Fig. 4 the first pump assembly 1 according to Fig. 3 in a top view. The Fig. 1 to 4 will be described together below. Inlet and outlet lines for the fluid 4 and electrical components (control unit, electrical connections, etc.) are not shown here, since their arrangement is usually known to those skilled in the art.

The pump arrangement 1 comprises a first housing 2 with a first side wall 6 and a receptacle 10 for the drive means 3, 21; here two meshing gear rotors. The drive means 3, 21 are rotatably mounted in the first housing 2 for conveying a fluid 4, wherein a first drive shaft 5 of the first drive means 3 extends through the first side wall 6 of the first housing 2 along an axial direction 7 therethrough. Outside the first housing 2, a first rotor 8 of a first axial flow electric drive 9 is arranged on the first drive shaft 5.

The first housing 2 surrounds the drive means 3, 21 in particular vapor-tight and liquid-tight, wherein connections for the supply and discharge of the fluid 4 to be delivered are provided. The first drive shaft 5 extends through a first side wall 6 of the first housing 2, wherein a liquid-tight seal between the first side wall 6 and the first drive shaft 5 is also provided here. The first axial flow electric drive 9 comprises a (first) stator 13 and a first rotor 8, which are arranged coaxially with one another. The coils 15 of the stator 13 cooperate with magnets 22 of the first rotor 8 for generating a torque for driving the first rotor 8 and thus the first drive shaft 5 in the circumferential direction 16. The stator 13 has a plurality of coils 15, which are arranged in a circumferential direction 16 evenly spaced on a return plate of the stator 13.

The first drive shaft 5 is supported only within the first housing 2 via radial bearings (which receive forces in the radial direction 24) and possibly thrust bearings (which receive forces in the axial direction 7). Outside the first housing 2, the first drive shaft 5 is arranged unsupported.

The first Axialfluss electric drive 9 is arranged in a second housing 12 that is repeatably connected to the first housing 2 releasably connected. Thus, the first Axialfluss electric drive 9 is arranged protected from the fluid to be delivered 4, wherein the individual components of the pump assembly 1 are mutually independently interchangeable and / or to be maintained.

Here, the first rotor 8 is arranged immediately adjacent to the first side wall 6 and between the first side wall 6 and the stator 13 of the first axial flow electric drive 9. In this arrangement, the first drive shaft 5 can be made very short, since the first rotor 8 connected to the first drive shaft 8 is disposed immediately adjacent to the first end wall 6, through which the first drive shaft 5, starting from the first housing 2, in the second housing 12 extends into it.

The stator 13 comprises a soft magnetic material 17, for example a so-called "soft magnetic composite" (SMC), or a combination of electrical sheets and SMC.

Fig. 5 to 7 show a second pump assembly. 1 Fig. 5 shows an exploded view of a second pump assembly 1 in a perspective view. Fig. 6 shows the exploded view of the second pump assembly 1 according to Fig. 5 in a side view in section. Fig. 7 shows the second pump assembly 1 according to FIGS. 5 and 6 in a side view in section.

On the comments too Fig. 1 to 4 is referred to. In contrast to the first pump arrangement 1, here the first rotor 8 and the stator 13 are arranged reversed. Here, the stator 13 of the first axial flow electric drive 9 is arranged directly adjacent to the first side wall 6 and between the first side wall 6 and the first rotor 8. Here, the first drive shaft 5 is longer to carry out, since it also extends through the stator 13 through to the first rotor 8.

Here, the stator 13 can be used with its coils 15 as a heating element 25 of the first housing 2. The heat development occurring there can, for. B. are conductively introduced via the first side wall 6 in the first housing 2. By the power electronics, for example, a corresponding current can be made available for this, which flows through the coils 15 of the stator poles of the stator 13. In order to provide a good heat transfer, the stator 13 is completely connected with its rear surface with the first housing 2, in this case with the first side wall 6.

The first side wall 6 forms at least part of a fluid channel 4 (in the region of the first drive means 3 and the second drive means 21). In this case, at least a part of the first side wall 6 contacts the conveyed fluid 4 in the region of the channel (eg in the region of the drive means 3, 21). Here, a heat conduction structure 26 is formed only in this subarea, so that the heat generated in the region of the stator 15 can be specifically delivered to the fluid 4 via the heat conduction structure 26.

Fig. 8 shows a third pump assembly 1 in a side view. On the comments too Fig. 1 to 7 is referred to. In contrast to the first and second pump arrangement 1 here is a second axial flow electric drive 18 outside of the first housing 2 in a third housing 23 and at one, the first side wall 6 opposite second side wall 19 of the first housing 2 arranged. The second axial-flow electric drive 18 is connected in a torque-transmitting manner to a second drive shaft 20 of the second drive means 21 arranged in the first housing 2, wherein the second drive means 21 is a second gear wheel which is arranged in mesh with the first gear wheel for conveying the fluid 4.

Fig. 9 shows a fourth pump assembly 1 in a side view. On the comments too Fig. 8 will be referred. In contrast to the third pump arrangement 1, the second axial flow electric drive 18 is connected to transmit torque to the first drive shaft 5.

Fig. 10 shows a fifth pump assembly 1 in a side view. On the remarks to the Fig. 5 to 7 is referred to. Unlike the Fig. 5 to 7 the stator 13 (ie its components, coils 15, cores and return ring 14) is arranged in a radial direction 24 outside the at least one first drive means 3. In this case, the stator 13 (ie at least one of the components of coils 15, cores and return ring 14) along the axial direction 7 overlapping with the first housing 2, here overlapping with at least one bearing 11 (radial bearings, thrust bearings, plain bearings, friction bearings) of the first Drive shaft 5 and arranged overlapping with the at least one first drive means 3. This preferred embodiment allows a particularly compact construction of the pump arrangement 1, wherein (exclusively) the at least one first drive means 3, the first side wall 6 (with the bearing 11 eg as part of the first side wall 6) and the first rotor 8 along the axial direction 7 are arranged side by side and thus determine the size of the pump assembly 1 along the axial direction 7.

Fig. 11 shows a sixth pump assembly 1 in a side view. On the remarks to the Fig. 1 to 4 is referred to. In contrast to the first pump arrangement 1, here the first drive shaft 5 is arranged outside of the first housing 2 supported by a bearing 11, the bearing 11 receiving forces acting exclusively in the axial direction 7. So here it is not a radial bearing, so a bearing 11 which serves the support against forces acting in the radial direction 24, arranged outside of the first housing 2. Again, the first drive shaft 5 is mounted exclusively in the first housing 2, so that the space for otherwise required bearings 11 outside the first housing 2 is not needed. For a particularly compact design of the pump assembly 1 is possible.

Claims (14)

1. Pump arrangement (1) at least comprising a first housing (2) in which there is arranged in a rotatably mounted manner at least one first drive means (3) for delivering a fluid (4), wherein a first drive shaft (5) of the first drive means (3) extends at least through a first side wall (6) of the first housing (2) along an axial direction (7), wherein, outside the first housing (2), at least one first rotor (8) of a first axial flux electric drive (9) is arranged on the first drive shaft (5), wherein the first axial flux electric drive (9) has only one stator (13); wherein, outside the first housing (2), the first drive shaft (5) is not mounted or is mounted by way of at least one bearing (11), which exclusively accommodates forces acting in the axial direction (7).
2. Pump arrangement (1) as claimed in claim 1, wherein the first axial flux electric drive (9) is arranged in a second housing (12) which is able to be connected in a repeatably detachable manner to the first housing (2).
3. Pump arrangement (1) as claimed in one of the preceding claims, wherein the first rotor (8) is arranged directly adjacent to the first side wall (6) and between the first side wall (6) and a stator (13) of the first axial flux electric drive (9).
4. Pump arrangement (1) as claimed in one of the preceding claims 1 to 2, wherein the stator (13) is arranged directly adjacent to the first side wall (6) and between the first side wall (6) and the first rotor (8).
5. Pump arrangement (1) as claimed in claim 4, wherein the stator (13) is arranged outside the at least one first drive means (3) in a radial direction (24).
6. Pump arrangement (1) as claimed in claim 5, wherein the stator (13) is arranged so as to overlap the first housing (2) along the axial direction (7).
7. Pump arrangement (1) as claimed in claim 6, wherein the stator (13) is arranged so as to overlap the at least one first drive means (3) along the axial direction (7).
8. Pump arrangement (1) as claimed in one of the preceding claims 4 to 7, wherein the stator (13) is inseparably connected to the first side wall (6).
9. Pump arrangement (1) as claimed in one of the preceding claims, wherein the first drive means (3) is a first gearwheel rotor.
10. Pump arrangement (1) as claimed in one of the preceding claims, wherein the stator (13) of the axial flux electric drive (9) comprises materials (17) which comprise SMC (soft magnetic composite).
11. Pump arrangement (1) as claimed in one of the preceding claims, wherein at least the first axial flux electric drive (9) forms at least one heating element (25) which is connected in a heat-conducting manner to the first side wall (6) via at least one heat-conducting structure (26).
12. Pump arrangement (1) as claimed in one of the preceding claims, wherein a second axial flux electric drive (18) is arranged outside the first housing (2) and on a second side wall (19), opposite the first side wall (6), of the first housing (2), wherein the second axial flux electric drive (18) is connected in a torque-transmitting manner either to the first drive shaft (5) or to a second drive shaft (20) of a second drive means (21) which is arranged in the first housing (2).
13. Pump arrangement (1) as claimed in claim 12, wherein the second axial flux electric drive (18) is connected in a torque-transmitting manner to the second drive shaft (20), and wherein the second drive means (21) is a second gearwheel rotor (22) which is arranged so as to mesh with the first gearwheel rotor for delivering the fluid (4), wherein the two gearwheel rotors are arranged so as to be braced with respect to one another via the two axial flux electric drives (9, 18).
14. Use of the pump arrangement (1) as claimed in one of the preceding claims for delivering a water-urea solution in a motor vehicle.

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