CN108884713B - Pump assembly with axial flux electric drive - Google Patents

Abstract

The invention relates to a pump assembly (1) comprising at least a first housing (2) in which at least one first drive for conveying a fluid (4) is arranged rotatably supported means (3), wherein the first drive shaft (5) of the first drive means (3) extends along the axial direction (7) at least through the first side wall (6) of the first housing (2); wherein the at least one first rotor (8) of the first axial flux electric drive (9) outside the first housing (2) is arranged on the first drive shaft (5), wherein the first axial flux The electric drive (9) has only one stator (13).

Description

Pump assembly with axial flux electric drive

technical field

The invention relates to a pump assembly comprising at least a first housing in which at least one first drive means for conveying fluid is arranged rotatably supported, wherein a first drive shaft of the first drive means extends along the The axial direction extends at least through the first side wall of the first housing. The pump assembly is in particular a delivery device for a water-urea-solution (eg Adblue, diesel exhaust fluid or automotive urea), which is preferably installed in a motor vehicle for the treatment of exhaust gas from an internal combustion engine.

Background technique

Such pump assemblies for water-urea-solutions have been known for a long time. Here, the electrical drive unit is usually coupled to the drive shaft of the drive means. The drive means for delivering the fluid are driven via the drive shaft of such a rotary pump. For example, geared rotors (in the case of gear pumps) are known as drive means. Exactly for applications in motor vehicles, a pump assembly of as compact design as possible should be provided, wherein, in particular, the noise of the pump assembly should be avoided as much as possible. Furthermore, when transporting the water-urea-solution, care should be taken to avoid freezing of the solution in the lines as much as possible. Therefore, the water-urea-solution is usually transported from the pipeline back to the storage tank. For this purpose, however, the drive means should also be driven in the opposite rotational direction.

SUMMARY OF THE INVENTION

Proceeding from this, the task of the present invention is to at least alleviate or even solve the problems described with respect to the prior art. In particular, a compactly constructed pump assembly should be provided, which is distinguished by a low noise generation.

To solve this task, a pump assembly is proposed. Further implementation variants of the invention are pointed out.

The invention relates to a pump assembly comprising at least a first housing in which at least one first drive means for conveying fluid is arranged rotatably supported, wherein a first drive shaft of the first drive means is axially The direction extends at least through the first side wall of the first housing; wherein outside the first housing at least one first rotor of a first axial flux electric drive (Axialfluss-Elektroantrieb) is arranged on the first drive shaft , wherein the first axial flux electric drive has only one (associated with the first axial flux electric drive and the first) stator of the first rotor (ie in particular no further (second) stator).

In particular, the first housing encloses at least the first drive means in a fluid-tight manner, wherein a coupling for the introduction and removal of the fluid to be delivered is provided. The first drive shaft extends through the first side wall of the first housing, wherein a liquid-tight seal is also provided here between the first side wall and the first drive shaft. A first rotor of a first axial flux electric drive (AFM: Axial Flux Motor) is arranged outside the first housing, which is arranged on the first drive shaft for transmitting torque towards the first drive means. Damage to the electric drive due to the delivered fluid can be avoided due to the separate arrangement of the drive means and the electric drive.

In particular, the first housing encloses at least the first drive means, wherein a coupling for the introduction and removal of the fluid to be delivered is provided. The first drive shaft extends through the first side wall of the first housing. Outside the first housing, a first rotor of a first axial flux electric drive (AFM: Axial Flux Motor) is provided, which is arranged on a first drive shaft for transmitting torque towards the first drive means superior. Preferably, the first housing is not designed to be liquid-tight, so that the fluid to be conveyed can leave the first housing as a leakage flow, for example along the first drive shaft. However, the first housing is preferably embodied in such a way that due to this leakage flow from the first housing (ie not only the fluid outflow and/or the fluid inflow via the coupling for introducing and discharging the fluid) no pumping is performed. Significant impairment of the component's conveyor power. In particular, the leakage flow is up to 5% of the conveyor power (conveyor volume flow) of the pump assembly.

The first axial flux electric drive comprises a (single) stator and a first rotor, which are arranged coaxially to each other. The stator can have a soft magnetic material, for example a so-called "soft magnetic composite (SMC)", or a combination of electroplates and SMC. The coils of the stator comprise a core, which is preferably pressed and baked from a soft magnetic material. The SMC material is not sintered here. Conversely, tempering is carried out below the melting temperature, however this is sufficient for the core to maintain its geometry continuously.

The rotor of an axial flux electric drive can have permanent magnets or also soft magnetic elements, for example in recesses. Permanently excited synchronous or brushless DC motors, abbreviated BLDC, can thus be formed together with permanent magnets as axial flux motors, while, for example, reluctance motors can be created in axial construction together with soft magnetic elements as electric motor.

The construction of the stator, in particular with the use of SMC and further details, also relates to a rotor, for example known from the applicant's post-published document PCT/EP2015/075036, to which reference is made within the scope of the present disclosure.

The first axial flux electric drive especially has an electrical power consumption of less than 100 watts, preferably less than 50 watts. The fluid is delivered in particular with delivery pressures of up to 10 bar.

According to a preferred configuration, the first drive shaft is not supported outside the first housing or is supported by at least one bearing, which only absorbs forces acting in the axial direction. A radial bearing is therefore not required here, in particular outside the first housing, ie a bearing for support with respect to forces acting in the radial direction. In particular, the first drive shaft is therefore only supported in the first housing, so that no installation space is required for bearings that are otherwise required outside the first housing. A particularly compact embodiment of the pump assembly is thereby achieved.

Here, so-called friction bearings or sliding bearings can be used as bearings. Preferably, at least the first drive shaft is supported only via the first housing, for example via the first side wall and/or the second side wall, wherein in particular the material of the side wall forms the bearing surface.

Here, especially the leakage flow of the fluid to be delivered along the first drive shaft causes lubrication of the bearing. Preferably, the pressure chamber of the pump assembly is fluidically connected to the region outside the first housing via the opening at least in the first side wall. As a result, a (quantitatively) controlled volume flow of the fluid to be delivered can leave the first housing and flow back into the first housing via the bearing.

According to a further advantageous configuration, the first axial flux electric drive is arranged in a second housing, which can be releasably connected to the first housing in a reproducible manner. Thereby, the first axial flux electric drive is arranged in a protected manner with respect to the fluid to be delivered, wherein the individual components of the pump assembly can be replaced and/or maintained independently of one another.

In particular, the first rotor is directly adjacent to the first side wall and is arranged between the first side wall and the stator of the first axial flux electric drive. In the case of this arrangement, the first drive shaft can be implemented very short, since the first rotor connected to the first drive shaft is arranged directly adjacent to the first end wall, the first drive shaft extending from the first housing The departure extends through the first end wall into the second housing.

According to another configuration, the stator of the first axial flux electric drive is directly adjacent to the first side wall and is arranged between the first side wall and the first rotor. Here the first drive shaft can be embodied longer, since it also extends through the stator towards the first rotor.

Preferably, the stator, ie its components, in particular the coils, cores and loops, is arranged in the radial direction outside the at least one first drive means.

Preferably, the stator (ie at least one of the components of the coil, the core and the loop) overlaps the first housing in the axial direction, preferably overlaps the at least one bearing of the first drive shaft, particularly preferably Arranged on top of the at least one first drive means.

This preferred configuration enables a particularly compact construction of the pump assembly, wherein (only) the at least one first drive means, the first side wall and the first rotor are arranged side by side in the axial direction and thus determine the direction of the pump assembly along the Structural dimensions in the axial direction.

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

Preferably, the first drive means is a first gear rotor. It can be embodied, for example, as a component of a gear pump, wherein the gear pump can be designed as an external gear pump with preferably involute teeth, as an internal gear pump or also as a ring gear pump. For example, it is constructed as an internal gear oil pump (Gerotorpumpe, sometimes also called a cycloid pump) or an internal gear pump (Sichhelpumpe, sometimes also called a crescent pump). Furthermore, the gear pump may be a screw pump (Schraubenspindelpumpe, also sometimes referred to as a screw pump).

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

In particular, it is proposed that at least the first gear rotor is produced from a sintered material with porosity, wherein the gear rotor has, in addition to the porosity, a further noise reduction device. Reference is made here in particular to the content of document DE 10 2015 201 873. It has been demonstrated that, by changing the density in the wheel body of the geared rotor, the transmission path of the sound-structured waves from the generation at the ring gear to the hub can be interrupted or the sound waves can be refracted or reflected in such a way that the sound-structured signal is at the output ie significantly less losses at the shaft/bore of the gear rotor. The change in density can be implemented here rotationally symmetrically or locally. It is also possible for the geared rotor to have a differently implemented density in the disk assembly. The angles of the planes of the individual layers can be different here from the preferred plane (Vorzugsebene, sometimes also called the reference plane), the horizontal plane of the component. Since structure-borne sound propagates better in materials with higher densities than in materials with lower densities, it is also possible to introduce sound-guiding channels into the gear rotor or only into the In the teeth, they deflect or attenuate the structure-borne sound waves in a targeted manner. Here, the passage and/or the local density change can be carried out not only with pure materials of different densities but also with combinations of different materials such as iron powder or also oil.

The sound-reducing geometry can be achieved using different fabrication methods. To this belong, for example, intelligent filling shoes, in particular rotationally rotating filling shoes for filling with at least two different materials, as is known, for example, from DE 10 2014 006 374. In this way, a density change can already be established, for example, during the pressing process. Furthermore, a production method known as "Grün-in-Grün" can also be used, as is known from the document DE 10 2009 042 598, in order to produce density variations, for example. Manufacturing methods such as conventional pressing of metal powders, as is also known in modified form from document WO 2013/067995 A1, and additive manufacturing of metal materials and/or plastics, for example as exemplified by document DE 10 2013 The device known from 103006 A1 can also be used, in particular to facilitate the manufacture of low-noise gear rotors. However, it is also possible to use the following production methods, which are basically known from document EP 2 221 131 A1, document EP 1 407 877 A1, document EP 1 34527 A2 or also document JP S60-162 702 A.

A development provides that the stator is formed by the first housing. For this purpose, for example, the stator can be inserted into the first housing. This can be achieved, for example, by means of the green-in-green method, which has already been described above and reference is made to this method in this context. The stator can also be inserted into the first housing. For example, the outer side of the first housing can have a cutout into which the stator can be pressed. For example, the first housing can be made of plastic in this region, while the stator can be made of metallic material. For example, a loop on which the stator poles are arranged can be pressed in.

In the case of this configuration, it is particularly advantageous if the stator (ie at least one of the components of the coil, core and return ring) overlaps the at least one bearing of the first drive shaft, particularly preferably the at least one first drive means Arranged on top of each other.

Preferably, the first housing has a diamagnetic material at least in the region adjacent to the stator, preferably the electromagnetic circuit (ring) and in particular adjacent to the core of the stator. As a result, the required construction of the electromagnetic field for generating torque at the rotor of the axial flux motor is not disturbed, or only slightly disturbed.

According to another advantageous design, the second axial flux electric drive is arranged outside the first housing and on a second side wall of the first housing which is located opposite the first side wall; wherein the second The axial flux electric drive is connected in a torque-transmitting manner either with the first drive shaft or with the second drive shaft of the second drive means arranged in the first housing.

In particular, the second axial flux electric drive is connected in a torque-transmitting manner to the second drive shaft, wherein the second drive means is a second gear rotor, which is arranged in meshing engagement with the first gear rotor for conveying fluid, In this case, the two geared rotors are arranged clamped to each other via two axial flux electric drives.

The clamping of the two gear rotors results in a constant backlash-free meshing of the gear rotors, which reduces noise. In particular, the clamping can also be set in the case of reversing the direction of rotation of the drive means (for example, in the case of feeding the water-urea-solution back into the tank in order to avoid freezing in the lines) .

According to a further configuration, the two axial flux electric drives, although constructed identically, are arranged at opposite ends of the gear rotor offset with respect to the arrangement of the stator poles. By means of this offset it is possible, for example, to obtain a balance between the generated electromagnetic waves of the axial flux electric drive. For example, depending on the design of the electric axial flux drive, the offset can be designed in such a way that the valleys (Wellental) caused by the first electric axial flux drive and the peaks (Wellenberg) caused by the second electric axial flux drive are Approximate overlap in torque action. As a result, a balanced, in particular uniform drive of the gear rotor is achieved. This in turn results in a reduction in noise emission at the intermeshing gears. The averaging of the torque at the driven shaft results in, inter alia, a smoother contact of the individual teeth of the intermeshing gears. At least the collision of the intermeshing teeth can be minimized.

In particular, the first axial flux electric drive forms at least one heating element, which is thermally connected to the first side wall via at least one thermally conductive structure. In particular, the stator with its coils can be used as the heating element of the first housing. The heat release occurring here can be carried into the first housing via the first side wall, for example in a conductive manner. For this purpose, for example, a corresponding current can be made available via the power electronics, 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 with its rear face to the first housing, ie for example itself forms the first side wall. Therefore, the stator as the first side wall is preferably placed directly on the first housing or, for example, inserted into the first side wall of the cover formed as the first housing.

For the production of the stator or the first side wall or the thermally conductive structure, it is possible, for example, to share a metallic, electrically conductive powder, for example in the case of a rotating filling shoe for filling with at least two different materials, as described for example by document DE 102014 006 374 was informed. This makes it possible, for example, during the pressing process (of the stator, the first side wall) not only to create a density change but also to create conductive heat paths (heat-conducting structures) and electrically heatable paths (heat-conducting structures).

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

For heat generation, temperature sensors can be used, for example. Such a temperature sensor may itself be installed at the pump assembly. Another configuration provides that a temperature sensor present on the power electronics of the pump assembly is used to determine whether and how strongly current is sent through the stator. Such can for example be stored in the controller associated with the urea injection. Thus, for example, in the event of detection of an excessively low temperature, heating is already achieved before the actual start of the internal combustion engine. If one thinks of today's keyless systems for opening and starting, the opening may therefore have triggered preventive heating. As a result, heating of the pump itself is possible, which is supplemented, for example, with heat generated, for example, by tank heating or as waste heat by a still hot internal combustion engine. As a result, the system can also be put into use or remain put into use even at low temperatures.

Furthermore, according to one configuration, compensation for different thermal expansions of different materials in the pump assembly is provided. The fluid or urea solution can be subjected to temperatures which can fluctuate strongly environmentally but also operationally, for example in the case of deep frosting eg at -35°C and due to the injection of urea solution of +100°C for at least a short time. The reason for the condition of the case. The same applies to the individual components, which have expanded or contracted differently due to the ambient temperature. Thus, the pump assembly can have, for example, a spring-tensioned return device (Nachführung, sometimes also called a tracking device) in its interior, which allows, for example, a reduction in the amount of play that would otherwise be generated.

The use of the pump assembly according to the invention for the transport of water-urea-solutions in motor vehicles is proposed.

In addition to the first gearwheel, the motor vehicle urea pump can have a second gearwheel on the second shaft, wherein the two gearwheels mesh with each other and build up pressure there. Both gears can be constructed from the same material. But the two gears can also be constructed of different materials from each other. For example, one of the gears may consist of plastic and the other of metal. Compound gears can also be used, that is to say the gears have different materials, for example the core consists of metal and the surface consists of plastic or vice versa. Preferably, helical gears are used in the case of intermeshing gears. However, it can also be advantageous for the pressure increase to use spur gears. Preferably, one or more gears are produced as end wheel gears with production quality, wherein the gears have, in accordance with DIN 3961 and DIN 3962, with respect to at least one parameter, preferably the total profile error F _α , the profile angle error f _Hα and profile shape error f _α , at least quality 6, preferably at least quality 5 or better, the quality quality of the designed gear with at least one of these values, especially at least these three values. For example, the first housing can also have an additional damping (Dämpfung, sometimes also called damping), by means of which the pump noise is reduced. Here, for example, density variations as described above can be used. The additional possibilities described here can also be used to reduce the structure-borne sound in or at the housing to obtain additional attenuation.

Furthermore, it is not only possible to obtain attenuation of the noise or the noise spectrum by means of different sintered materials and/or densities in the case of sintered materials. It is also possible by a targeted opening of the sintered material or by closing the pores, for example by adding copper, for example joining different densities, possibly by using the green-in-green manufacturing method with inner and outer materials, and also by means of a The attenuation is set in a targeted manner, for example, by means of a coating of plastic on the component.

Description of drawings

The invention and the technical field are subsequently explained in more detail on the basis of the accompanying drawings. It should be pointed out that the invention should not be limited by the embodiments shown. In particular, unless explicitly shown otherwise, it is also possible to extract some aspects of the factual situations illustrated in the figures and combine them with other components and knowledge from the present description in conjunction with the figures. The same reference numerals denote the same objects, so that explanations from other figures can be supplemented if necessary. in,

Figure 1 schematically shows an exploded view of the first pump assembly in a perspective view;

Fig. 2 schematically shows an exploded view of the first pump assembly according to Fig. 1 in a side view in section;

FIG. 3 schematically shows the first pump assembly according to FIGS. 1 and 2 in cross section in side view;

Fig. 4 schematically shows the first pump assembly according to Fig. 3 in a top view;

Figure 5 schematically shows an exploded view of the second pump assembly in a perspective view;

Fig. 6 schematically shows an exploded view of the second pump assembly according to Fig. 5 in a side view in section;

Figure 7 schematically shows the second pump assembly according to Figures 5 and 6 in cross section in side view;

Figure 8 schematically shows the third pump assembly in side view;

Figure 9 schematically shows a fourth pump assembly in side view;

Figure 10 schematically shows a fifth pump assembly in side view; and

Figure 11 schematically shows the sixth pump assembly in side view.

Detailed ways

Figure 1 shows an exploded view of the first pump assembly 1 in a perspective view. FIG. 2 shows an exploded view of the first pump assembly 1 according to FIG. 1 in cross section in a side view. FIG. 3 shows the first pump assembly 1 according to FIGS. 1 and 2 in a side view in section, and FIG. 4 shows the first pump assembly 1 according to FIG. 3 in a top view. 1 to 4 are collectively described below. The inlet and outlet lines for the fluid 4 and the electrical components (control unit, electrical connections, etc.) are not shown here, since their arrangements are generally known to those skilled in the art.

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

In particular, the first housing 2 encloses the drive means 3 , 21 in a gas-tight and liquid-tight manner, wherein couplings for the introduction and removal of the fluid 4 to be delivered are provided. The first drive shaft 5 extends through the first side wall 6 of the first housing 2 , wherein a liquid-tight seal is also provided here between the first side wall 6 and the first drive shaft 5 . The first axial flux electric drive 9 comprises a (first) stator 13 and a first rotor 8, which are arranged coaxially to each other. The coils 15 of the stator 13 cooperate with the magnets 22 of the first rotor 8 to generate 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 on the return plate of the stator 13 at a uniform distance from one another in the circumferential direction 16 .

The first drive shaft 5 is supported within the first housing 2 only via radial bearings (loaded in radial direction 24 ) and possibly axial bearings (loaded with forces in axial direction 7 ). The first drive shaft 5 is arranged unsupported outside the first housing 2 .

The first axial flux electric drive 9 is arranged in a second housing 12 which can be releasably connected to the first housing 2 in a repeatable manner. The first axial flux electric drive 9 is thus arranged in a protected manner with respect to the fluid 4 to be delivered, wherein the individual components of the pump assembly 1 can be replaced and/or maintained independently of one another.

The first rotor 8 is here arranged directly adjacent to the first side wall 6 and between the first side wall 6 and the stator 13 of the first axial flux electric drive 9 . In the case of this arrangement, the first drive shaft 5 can be implemented very short, since the first rotor 8 connected to the first drive shaft 5 is arranged directly adjacent to the first end wall 6 , the first drive shaft 5 . Proceeding from the first housing 2 through this end wall into the second housing 12 .

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

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

Reference is made to the embodiments of FIGS. 1 to 4 . In contrast to the first pump assembly 1 , here the first rotor 8 and the stator 13 are arranged interchangeably. The stator 13 of the first axial flux electric drive 9 is here arranged directly adjacent to the first side wall 6 and between the first side wall 6 and the first rotor 8 . The first drive shaft 5 can be constructed longer here, since it also extends through the stator 13 as far as the first rotor 8 .

Here, the stator 13 with its coils 15 can be used as the heating element 25 of the first housing 2 . The heat released there can be carried into the first housing 2 via the first side wall 6 , for example, in a conductive manner. For this purpose, for example, a corresponding current can be made available via the power electronics, which current flows through the coils 15 of the stator poles of the stator 13 . In order to create a good heat transfer, the stator 13 is completely connected with its rear face to the first housing 2 , in this case to the first side wall 6 .

The first side wall 6 forms at least part of the channel through which the fluid 4 is guided (in the region of the first drive means 3 and the second drive means 21 ). Here, at least a part of the first side wall 6 is in contact with the fluid 4 conveyed in the region of the channel, for example in the region of the drive means 3 , 21 . In this case, the heat-conducting structure 26 is formed only in this partial region, so that the heat generated in the region of the stator 15 can be supplied to the fluid 4 in a targeted manner via the heat-conducting structure 26 .

Figure 8 shows the third pump assembly 1 in side view. Reference is made to the embodiments of FIGS. 1 to 7 . In contrast to the first and second pump assemblies 1 , here the second axial flux electric drive 18 is arranged outside the first housing 2 in the third housing 23 and the first side wall of the first housing 2 6 at the opposite second side wall 19 . The second axial flux electric drive 18 is connected in a torque-transmitting manner to a second drive shaft 20 of a second drive means 21 arranged in the first housing 2 , wherein the second drive means 21 is a second gear rotor, It is arranged in meshing engagement with a first gear rotor for conveying fluid 4 .

Figure 9 shows the fourth pump assembly 1 in side view. Reference is made to the embodiment of FIG. 8 . In contrast to the third pump assembly 1 , the second axial flux electric drive 18 is connected to the first drive shaft 5 in a torque-transmitting manner.

Figure 10 shows the fifth pump assembly 1 in side view. Reference is made to the embodiments of FIGS. 5 to 7 . 5 to 7 , the stator 13 (ie its components, the coils 15 , the core and the loop 14 ) is arranged in the radial direction 24 outside the at least one first drive means 3 . Here, the stator 13 (ie at least one of the components of the coil 15 , the core and the return ring 14 ) overlaps the first housing 2 in the axial direction 7 , here with at least one bearing 11 of the first drive shaft 5 . (radial bearing, axial bearing, plain bearing, friction bearing) are arranged one on top of the other and on top of the at least one first drive means 3 . This preferred configuration enables a particularly compact construction of the pump assembly 1, in which (only) the at least one first drive means 3, the first side wall 6 (together, for example, the bearing 11 as a component of the first side wall 6) and the first rotor 8 are arranged side by side in the axial direction 7 and thus determine the structural dimensions of the pump assembly 1 in the axial direction 7 .

Figure 11 shows the sixth pump assembly 1 in side view. Reference is made to the embodiments of FIGS. 1 to 4 . In contrast to the first pump assembly 1 , here the first drive shaft 5 is arranged outside the first housing 2 in a supported manner by means of a bearing 11 , wherein the bearing 11 only absorbs the forces acting in the axial direction 7 . The radial bearing, ie the bearing 11 for support with respect to the forces acting in the radial direction 24 , is therefore not arranged outside the first housing 2 here. Here too, the first drive shaft 5 is only supported in the first housing 2 , so that no installation space is required outside the first housing 2 for the bearing 11 which is otherwise required. A particularly compact embodiment of the pump assembly 1 is thereby achieved.

List of reference signs

1 Pump assembly

2 first shell

3 The first driving device

4 fluid

5 The first drive shaft

6 First side wall

7 Axial direction

8 first rotor

9 First Axial Flux Electric Drive

10 Housing

11 Bearings

12 Second housing

13 Stator

14 Loopback

15 coils

16 Circumferential direction

17 Materials

18 Second axial flux electric drive

19 Second side wall

20 Second drive shaft

21 Second drive device

22 Magnets

23 Third shell

24 Radial direction

25 Heating elements

26 Thermally conductive structure.

Claims (15)

1. A pump assembly (1) comprising at least a first housing (2) in which at least one first drive means for conveying a fluid (4) is rotatably supported (3), wherein the first drive shaft (5) of the first drive means (3) extends along the axial direction (7) at least through the first side wall ( 6); wherein at least one first rotor (8) of a first axial flux electric drive (9) outside said first housing (2) is arranged on said first drive shaft (5), Therein, the first axial flux electric drive (9) has only one stator (13), wherein the first drive shaft (5) is not supported outside the first housing (2) or through It is supported by at least one bearing (11) which only absorbs the forces acting in the axial direction (7). 2. A pump assembly (1) according to the preceding claim 1, wherein the first axial flux electric drive (9) is arranged in a second housing (12), the second housing (12) It is releasably connected to the first housing (2). 3. The pump assembly (1) according to claim 1 or 2, wherein the first rotor (8) is directly adjacent to and at the first side wall (6) ) and the stator (13) of the first axial flux electric drive (9). 4. The pump assembly (1) according to claim 1 or 2, wherein the stator (13) is directly adjacent to the first side wall (6) and between the first side wall (6) and the The first rotors (8) are arranged between them. 5. Pump assembly (1) according to claim 1 or 2, wherein the stator (13) is arranged outside the at least one first drive means (3) in a radial direction (24). 6. The pump assembly (1) according to claim 5, wherein the stator (13) is arranged overlapping the first housing (2) along the axial direction (7). 7. The pump assembly (1) according to claim 6, wherein the stator (13) is arranged in the axial direction (7) overlapping the at least one first drive means (3). 8. Pump assembly (1) according to claim 4, wherein the stator (13) is inseparably connected to the first side wall (6). 9. Pump assembly (1) according to claim 1 or 2, wherein the first drive means (3) is a first gear rotor. 10. Pump assembly (1) according to claim 1 or 2, wherein the stator (13) of the first axial flux electric drive (9) has a material (17) comprising a soft magnetic composite (SMC) ). 11. Pump assembly (1) according to claim 1 or 2, wherein at least the first axial flux electric drive (9) comprises at least one heating element (25) via at least one heating element (25) A thermally conductive structure (26) is thermally connected to the first side wall (6). 12. Pump assembly (1) according to claim 1 or 2, wherein a second axial flux electric drive (18) is external to and within the first housing (2) (2) is arranged at the second side wall (19) opposite to the first side wall (6); wherein the second axial flux electric driver (18) is either connected to the first driver The shaft ( 5 ) is connected in a torque-transmitting manner or is connected in a torque-transmitting manner with a second drive shaft ( 20 ) of a second drive means ( 21 ) arranged in the first housing ( 2 ). 13. The pump assembly (1) of claim 12, wherein the second axial flux electric drive (18) is torque-transmittingly connected to the second drive shaft (20), and wherein, The second drive means (21) is a second gear rotor (22), which is arranged in mesh with the first gear rotor for conveying the fluid (4), wherein the first gear rotor (22) is A geared rotor and the second geared rotor are arranged clamped to each other via the first axial flux electric drive (9) and the second axial flux electric drive (18). 14. Use of the pump assembly (1) according to any one of the preceding claims for transporting a water-urea-solution in a motor vehicle. 15. A pump assembly (1) comprising at least a first housing (2) in which at least one first drive means for conveying a fluid (4) is rotatably supported (3), wherein the first drive shaft (5) of the first drive means (3) extends along the axial direction (7) at least through the first side wall ( 6); wherein at least one first rotor (8) of a first axial flux electric drive (9) outside said first housing (2) is arranged on said first drive shaft (5), Therein, the first axial flux electric drive (9) has only one stator (13), wherein the stator (13) is arranged in the radial direction (24) on the at least one first drive means ( 3) outside.

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