Electric pump and associated production method

Abstract

The invention relates to a pump (1), comprising a pump device (2), an electric motor (3) for rotationally driving the pump device (2), and a pump housing (4), which has a motor housing part (5) for receiving the electric motor (3) and a pump housing part (6) for receiving the pump device (2), wherein a stator (7) of the electric motor (3) is inserted into a motor receiving chamber (9) of the motor housing part (5) and has a plurality of centring contours (10) which are distributed in the circumferential direction (U), wherein, for each centring contour (10), the motor housing part (5) has a mating contour (11), which mating contours, for centring the stator (7) in the motor housing part (5), interact with the centring contours (10), wherein the stator (7) has a plurality of flange sections (13) which are distributed in the circumferential direction (U) and each have a flange opening (14), wherein, for each flange section (13), the motor housing part (5) has a fastening region (16) in which the respective flange section (13) is fastened to the motor housing part (5) and which has an axially protruding flange pin (17) which passes through the flange opening (14) of the respective flange section (13) and has a pin head (18), which radially overlaps an opening edge surrounding the flange opening (14), so that the respective flange section (13) lies axially on the pin head (18) and is form-fittingly fastened to the motor housing part (5) by the pin head (18).

Description

[0001] Electric pump and related manufacturing process

[0002] The present invention relates to an electric pump for conveying a fluid, in particular a liquid. The present invention also relates to a method for manufacturing such an electric pump.

[0003] An electric pump can be equipped with a rotary pumping device, an electric motor for rotating the pumping device, and a pump housing in which the pumping device and the electric motor are located. Electric pumps are used in many different technical fields. Of particular interest in this paper are

[0004] In this context, electric pumps are used in motor vehicles to pump or drive fluids, preferably liquids. For example, each cooling circuit has a pump for driving a coolant. Lubrication circuits can be equipped with a pump for driving a lubricant.

[0005] Especially for series production of such electric pumps, it is necessary to achieve high manufacturing quality with simple measures that can be implemented inexpensively.

[0006] The present invention addresses the problem of providing an improved or at least a different embodiment for an electric pump of the type described above or for an associated manufacturing method, which is characterized by high manufacturing quality while at the same time low manufacturing costs can be realized.

[0007] The invention is based on the general idea of ​​centering the electric motor in the pump housing using centering contours formed on the stator and complementary mating contours formed on a motor housing part. For this purpose, the centering contours and the mating contours are configured to interact to center the stator relative to the motor housing part. This automatically centers the electric motor in the pump housing during assembly, thus automatically achieving high quality.Furthermore, the stator is fastened to the motor housing part by means of flange sections formed thereon, wherein the flange sections each have a flange opening, while fastening areas formed on the motor housing part each have a flange pin that extends axially through the respective flange opening and is positively fastened to the respective flange section by a pin head formed on the respective flange pin by thermal forming. Such a positive fastening, in which a head is formed on the respective pin by thermal forming, can be realized cost-effectively in series production. At the same time, all tolerances in the axial direction can be eliminated. At the same time, tolerances in the radial and circumferential directions can also be eliminated. These features therefore also support cost-effective production with high production quality.

[0008] In detail, the electric pump presented here for conveying a fluid comprises a rotationally drivable pump device, an electric motor for rotatingly driving the pump device, and a pump housing in which the pump device and the electric motor are arranged. It is further proposed that the pump housing have a motor housing part made of plastic for receiving the electric motor and a pump housing part for receiving the pump device, which are firmly connected to one another, directly or indirectly. The electric motor has a stator and a rotor that is rotatably mounted in the stator about a rotation axis that defines an axial direction, a radial direction, and a circumferential direction. The stator is inserted axially into a motor receiving space of the motor housing part. Furthermore, the stator has a plurality of centering contours radially outwardly, which are arranged distributed in the circumferential direction.The motor housing part has a plurality of counter-contours radially inward, which are designed to complement the centering contours and are arranged distributed in the circumferential direction. The centering contours and the counter-contours cooperate to center the stator in the motor housing part. Furthermore, the stator has a plurality of radially projecting flange sections at its inner longitudinal end facing the pumping device, which are arranged distributed in the circumferential direction and each have a flange opening. On an axial end face enclosing the motor receiving space, the motor housing part has a fastening area for each flange section, in which the respective flange section is fastened to the motor housing part.The respective fastening area has an axially projecting flange pin which passes through the flange opening of the respective flange section and has a pin head which radially overlaps an opening edge enclosing the flange opening, so that the respective flange section axially rests on the pin head on the one hand and axially on the end face on the other hand and is also positively fastened to the motor housing part by means of the pin head.

[0009] According to an advantageous embodiment, an axial gap can be formed axially between the end face of the motor housing part and the respective flange section, so that the respective flange section does not have direct contact with the end face of the motor housing part. This allows tolerance compensation. For example, the stator can rest axially against the motor housing part at its outer longitudinal end facing away from the pump device on an end face facing away from the flange sections in the motor receiving space. The axial gap allows tolerance-related axial dimensional deviations between the stator and the motor housing part to be compensated.

[0010] According to an advantageous embodiment, the respective flange section can have a chamfer at the flange opening, so that the opening edge is located at the chamfer and the pin head is supported in the chamfer on the opening edge. The chamfer forms a receiving space for the formation of the pin head during the thermal forming of the flange pin. The flange opening can expediently have an inner cross-section that is larger than an outer cross-section of the cylindrical flange pin, whereby tolerances in the radial direction and in the circumferential direction can be compensated when positioning the stator relative to the motor housing part. During the thermal forming of the flange pin to produce the pin head, the pin head can then fill the chamfer and fix the found relative position.

[0011] It can expediently be provided that at least two of the flange sections are designed geometrically differently and that the fastening sections are configured such that they only interact with the matching flange section for fastening the respective flange section to the motor housing part. As a result, the stator can only be fastened to the motor housing part with the flange sections in a single predetermined rotational position with respect to the motor housing part. This enables confusion-proof assembly of the stator on the motor housing part, even if the flange sections and the fastening sections are arranged evenly or symmetrically distributed in the circumferential direction. Alternatively, confusion-proof assembly can also be achieved if the flange sections and thus also the fastening sections are arranged asymmetrically orare arranged unevenly distributed such that there is only a single rotational position in which all flange sections fit one fastening section each.

[0012] According to an advantageous embodiment, the respective centering contour and the associated counter-contour can form a radially projecting centering element and a centering surface against which the centering element is radially supported. This allows for easy implementation of high-quality centering.

[0013] The centering surface can expediently be formed in a radial recess which is formed on the inside of the motor housing part or on the outside of the stator.

[0014] Accordingly, the radially protruding centering element can then preferably be formed on the outside of the stator or alternatively on the inside of the motor housing part. The radially protruding centering element can, for example, be designed as a rib and preferably formed on the outside of the stator. In particular, it can be provided that the respective rib is configured such that it deforms plastically and / or elastically when the stator is inserted into the motor housing part in order to thereby bring about the desired centering. According to an advantageous embodiment, the stator can have a stator laminated core and a stator coil as well as a plastic jacket injection-molded onto the stator laminated core and the stator coil. A configuration in which the flange sections are integrally formed on the plastic jacket and are produced by injection-molding the plastic jacket onto the stator laminated core and the stator coil is particularly advantageous.This allows the flange sections to be produced with virtually no additional effort when molding the plastic jacket.

[0015] The motor housing part can also be injection-molded from plastic, with the mounting areas and flange pins being integrally formed on the motor housing part, so that they are produced by the injection molding of the motor housing part. This allows the mounting areas to be realized with virtually no additional cost.

[0016] According to an advantageous embodiment, the pump can have an annular circuit board that carries electronics. The electronics can be configured to control the electric motor and / or to supply electrical power to the electric motor. The circuit board can also have a circuit board opening in each of a plurality of circuit board sections that are arranged distributed in the circumferential direction, whereby the circuit board openings are also arranged distributed in the circumferential direction. The motor housing part or the stator can have a plurality of axially projecting circuit board pins, each of which penetrates one of the circuit board openings and has a step and a head. In the respective circuit board section, the circuit board rests axially on the one hand against the step and axially on the other hand against the head and is positively fastened to the motor housing part by the respective head.Thermal forming of the board pins for producing the heads and creating the positive fastening can also be achieved cost-effectively and reliably in the circuit board area. In particular, these board pins can also be formed integrally on the motor housing part.

[0017] The plate pins can be provided in addition to and separately from the flange pins, so that the plate pins are spaced from the flange pins in the circumferential direction. Alternatively, an embodiment is also feasible in which the plate pins are each formed by a longitudinal section of one of the flange pins. For example, a longitudinal section of the respective flange pin facing away from the end face of the motor housing part can serve as a plate pin. In principle, all flange pins can have such a longitudinal section, which forms such a plate pin. It is also conceivable for fewer plate pins to be provided than flange pins.

[0018] According to an advantageous embodiment, it can be provided that at least one electrical motor connection of the electric motor, which serves, for example, to supply power to the stator coil, and / or at least one electrical housing connection of the pump housing, which serves, for example, to supply power to the pump, is electrically connected to the electronics of the circuit board by means of plug connections. The plug connections can each have a first plug-in part and a complementary second plug-in part, which form a plug and a matching socket, which are plugged in in the axial direction to create the electrical connection. At least one of the first plug-in parts is arranged axially projecting at the inner longitudinal end of the stator and is electrically connected to the respective motor connection.Additionally or alternatively, at least one of the first plug-in parts can be arranged axially projecting on the front side of the motor housing part and electrically connected to the respective housing connection. The second plug-in parts are arranged axially aligned on the circuit board and electrically connected to the electronics. The first plug-in parts and the second plug-in parts can then be arranged and coordinated with one another such that, when the circuit board is axially attached to the stator and the motor housing part, all plug connections are axially inserted in a predetermined rotational position of the circuit board relative to the motor housing part. This results in particularly simple assembly for the pump.

[0019] In another embodiment, the pump housing can also be equipped with an intermediate part that is attached to the motor housing part and to which the pump housing part is attached. This intermediate part can be configured as a partition wall that separates the electric motor and the circuit board, and thus the electronics, from the pumping device. In particular, this intermediate part can separate a wet area formed in the pump housing part from a dry area formed in the motor housing part within the pump housing.

[0020] A particularly advantageous configuration is one in which the intermediate part axially rests on an upper side of the circuit board facing away from the stator, so that the intermediate part can be supported axially on the circuit board. Furthermore, the intermediate part can axially rest on the inner longitudinal end of the stator. For example, an annular step can be formed on the stator for this purpose, against which the intermediate part axially rests. An annular groove can be formed in this annular step, in which an annular seal is arranged, which axially rests on the intermediate part and seals the intermediate part against the stator. Furthermore, the intermediate part can have a circumferential, axially projecting collar that axially overlaps the end face of the motor housing part. In the area of ​​the axial overlaps, an annular seal can be formed radially between the motor housing part and the collar, which radially rests on the motor housing part and the collar and thus seals the intermediate part against the motor housing part.To axially limit this ring seal, the motor housing part can have a circumferential annular step radially on the outside. The collar can also have a circumferential annular step radially on the inside, axially opposite the annular step of the motor housing part. The ring seal is arranged axially between the two annular steps. The intermediate part can also have a plurality of connecting regions on its collar, each with an axially projecting housing pin, which are arranged distributed in the circumferential direction. The motor housing part can now have a support region for each connecting region, which support region has a pin opening through which the respective housing pin passes. The respective housing pin has a head which, on a side of the support region facing away from the intermediate part, is supported on an edge of the support region surrounding the pin opening, and thus fastens the intermediate part to the motor housing part in a form-fitting manner.Here, too, such a head can be manufactured by thermally forming the housing pin, which can be achieved inexpensively.

[0021] According to an advantageous embodiment, the respective head, the respective connecting region and the respective support region can be matched to one another in such a way that an axial gap is formed axially between the respective connecting region and the associated support region, which allows tolerance compensation.

[0022] The pump housing section can be welded to the intermediate section. Alternatively, the pump housing section can be detachably connected to the intermediate section using a bayonet lock.

[0023] A method according to the invention for producing an electric pump of the type described above comprises providing the stator with the centering contours and the flange sections, as well as providing the motor housing part with the mating contours and the flange pins. During the manufacturing process, the stator is inserted into the motor receiving space such that the flange pins axially penetrate the flange openings and the centering contours interact with the mating contours to center the stator in the motor housing part. After the stator has been inserted and centered in the motor housing part, the flange pins are thermally formed such that the pin heads are formed, which form-fit the respective flange section to the motor housing part. In other words, when the stator is inserted into the motor receiving space, the flange pins do not yet have pin heads and are essentially headless.

[0024] According to an advantageous embodiment, the motor housing part can be provided with the mating contours, the flange pins, and also with the circuit board pins. In this way, after the thermal forming of the flange pins, the circuit board can be arranged axially on the stator and the motor housing part such that the circuit board pins penetrate the circuit board openings. The circuit board pins are then thermally formed such that the heads are formed, which positively fasten the respective circuit board section to the motor housing part. In other words, when the circuit board is attached to the motor housing part, the circuit board pins do not yet have heads and are essentially headless. In an alternative embodiment, the circuit board pins can be designed as longitudinal sections on the flange pins. In this case, it can optionally be provided that the circuit board is slipped onto the circuit board pins before the flange pins are thermally formed.The flange pins and the circuit board pins can then be thermally formed simultaneously to fix the stator and the circuit board to the motor housing part at the same time.

[0025] According to another advantageous embodiment, the circuit board can be arranged on the stator and motor housing part in such a way that the circuit board is first aligned in a predetermined rotational position relative to the motor housing part and then axially attached to the stator and motor housing part in this rotational position. During axial attachment of the circuit board to the stator and motor housing part, the axial plug connections are inserted.

[0026] A particularly advantageous configuration is one in which, after thermally forming the board pins, the intermediate part is attached to the motor housing part in such a way that the housing pins axially penetrate the pin openings. The housing pins can then be thermally formed to form the heads that form-fit the respective connecting area to the respective or associated support area.

[0027] In another advantageous embodiment, it can be provided that after the intermediate part has been fastened to the motor housing part, the pump device is drivingly connected to the rotor. For example, the pump device can be configured as an impeller or vane wheel that pumps the respective fluid as it rotates. Other designs of the pump device are also conceivable, such as a gerotor or the like. After the rotor has been drivingly connected to the pump device, the pump housing part is fastened to the intermediate part. This can be done by a welded connection, for example by means of an ultrasonic welding process or by means of a friction welding process, or by means of a bayonet lock or by screw connections. The thermal forming of the respective pin to produce the head can also be referred to as hot forming, heat contact riveting or hot staking.

[0028] In the present context, a ‘configuration’ corresponds to a ‘design’ and / or a ‘facility’, so that the phrase ‘configured so that’ is synonymous with the phrase ‘designed so that’ and / or ‘arranged so that’.

[0029] Further important features and advantages of the invention emerge from the subclaims, from the drawings and from the associated description of the figures based on the drawings.

[0030] It is understood that the features mentioned above and those to be explained below can be used not only in the respective combinations specified, but also in other combinations or on their own, without departing from the scope of the invention. Components mentioned above and those to be mentioned below of a higher-level unit, such as a device, a device, or an arrangement, which are designated separately, may form separate parts or components of this unit or be integral areas or sections of this unit, even if this is shown differently in the drawings.

[0031] Preferred embodiments of the invention are illustrated in the drawings and are explained in more detail in the following description, wherein the same reference numerals refer to the same or similar or functionally identical components.

[0032] They show, schematically,

[0033] Figure 1 is a sectional view of part of a pump, Figure 2 is an isometric view of an electric motor and a motor housing part of the pump in an exploded view,

[0034] Figure 3 is an isometric view of the electric motor inserted into the motor housing part in another embodiment,

[0035] Figure 4 is a flow chart of a method for manufacturing such a pump,

[0036] Figure 5 is a cross-sectional view of a possible electronic water pump according to the state of the art,

[0037] Figure 6 is a cross-sectional view of an electronic water pump,

[0038] Figure 7 is a cross-sectional view of a stator assembly of an electronic water pump,

[0039] Figure 8 is a schematic diagram of a partial structure of an electronic water pump at a connection terminal,

[0040] Figure 9 is a cross-sectional view of a rotor assembly of an electronic water pump.

[0041] According to Figure 1, an electric pump 1, which is configured to convey a fluid, preferably a liquid, comprises a rotating drivable

[0042] Pump device 2, which is configured here as a vane or impeller. The pump 1 also has an electric motor 3, which is used to rotate the

[0043] Pump device 2. The pump 1 further comprises a pump housing 4 in which the pump device 2 and the electric motor 3 are arranged. For this purpose, the pump housing 4 comprises a motor housing part 5 made of plastic for accommodating the electric motor 3 and a pump housing part 6, in particular made of plastic, for accommodating the pump device 2. In the assembled state, the motor housing part 5 and the pump housing part 6 are firmly connected to one another. This connection can be direct or, as in the example shown, indirect, which will be explained in more detail below.

[0044] The electric motor 3 has a stator 7 and a rotor 8, wherein the rotor 8 is rotatably mounted in the stator 7 about a rotation axis R. The rotation axis R defines an axial direction, a radial direction and a circumferential direction U. The axial direction extends parallel to the rotation axis R. The radial direction is perpendicular to the axial direction and is in particular perpendicular to the rotation axis R. The circumferential direction U runs around the rotation axis R. The stator 7 is inserted into a motor receiving space 9 of the motor housing part 5.

[0045] According to Figure 2, the stator 7 has a plurality of centering contours 10 on the radial outside, which are distributed in the circumferential direction U. In the example in Figure 2, three such centering contours 10 are provided. However, in the view in Figure 2 only one of these centering contours 10 is visible. For each centering contour 10, the motor housing part 5 has a complementary counter-contour 11 on the radial inside, which is also distributed in the circumferential direction U. In the example in Figure 2, three such counter-contours 11 are therefore provided, although in the view in Figure 2 only two such counter-contours 11 can be seen. The counter-contours 11 are designed to be complementary to the centering contours 10 and are also distributed in the circumferential direction U in a manner complementary to the centering contours 10. The centering contours 10 interact with the counter contours 11 for radial centering of the stator 7 in the motor housing part 5.

[0046] According to Figures 1 to 3, the stator 7 has, at its inner longitudinal end 12 facing the pump device 2, a plurality of radially projecting flange sections 13 which are arranged distributed in the circumferential direction U and which each have a flange opening 14 which completely penetrates the respective flange section 13 axially. In the examples in Figures 2 and 3, three such flange sections 13 are provided in each case. The motor housing part 5 has, on an axial end face 15 enclosing the motor receiving space 9, a fastening area 16 for each flange section 13. In the respective fastening area 16, the associated flange section 13 rests axially on the end face 15 and is fastened to the motor housing part 5. The respective fastening area 16 has an axially projecting flange pin 17 which, according to Figure 3, axially penetrates the flange opening 14 of the respective flange section 13 and has a pin head 18 which can only be seen in Figure 1.The respective pin head 18 radially overlaps an opening edge surrounding the flange opening 14, so that the respective flange section 13 axially rests against the pin head 18 and the end face 15 and is positively secured to the motor housing part 5 by the pin head 18. In the state shown in Figures 2 and 3, the pin heads 18 at the free ends of the flange pins 17 have not yet been manufactured.

[0047] According to Figures 2 and 3, the respective flange section 13 can have a chamfer 19 at the associated flange opening 14. Consequently, the opening edge surrounding the respective flange opening 14 is located at this chamfer 19, and the pin head 18 is supported in this chamfer 19 on the opening edge or on the flange section 13. The respective chamfer 19 provides a volume into which the material of the flange pin 17 can expand during thermal forming to produce the pin head 18.

[0048] In the embodiment shown here, an axial gap 20 is formed axially between the respective flange section 13 and the end face 15 of the motor housing part 5. This axial gap is clearly visible in Figure 1 and indicated in Figure 3. The axial gap 20 enables axial tolerance compensation between the stator 7 and the motor housing part 5.

[0049] In the embodiment shown in Figure 3, at least two of the three flange sections 13 are geometrically identical, while the third flange section 13 has a geometrically different design. In Figure 3, the two identical flange regions 13 each have a round outer contour transverse to the axial direction. The other, third flange region 13, in contrast, has an angular outer contour characterized by three sides running perpendicular to one another. The fastening sections 16 can now be configured such that they only interact with the matching flange section 13 to fasten the respective flange section 13 to the motor housing part 5. In the example in Figure 3, one of the fastening sections 16 has two rectilinear web elements 21 with which the flange section 13 with the angular outer contour can be contacted in the circumferential direction.In contrast, the two other flange sections 13 with the rounded outer contour do not have any such web elements with which the rounded flange section 13 could come into contact. The web sections 21 ensure that the stator 7 is secured in its rotational position in the motor housing part 5 by means of the flange pins 17 after the stator 7 has been inserted into the motor receiving space 9 and before the stator 7 is secured to the motor housing part 5.

[0050] According to Figure 2, the respective centering contour 10 and the associated counter-contour 11 can form a radially projecting centering element 22 and a centering surface 23, against which the centering element 22 is radially supported. The centering surface 23 can be formed in a radial recess, which in the example of Figure 2 is formed inside the motor housing part 5. In the example of Figure 2, the radially projecting centering element 22 is therefore formed on the stator 7 and can be implemented in particular in the form of an axially extending rib projecting radially from the stator 7.

[0051] The stator 7 can, in the usual way, have a stator laminated core 24 (shown in Figure 2) and a stator coil (not shown here), as well as a plastic jacket 25 that is injection-molded onto the stator laminated core 24 and the stator coil. The plastic jacket 25 is shown and designated analogously in Figures 6 to 8 as a stator injection-molded layer SO, while the stator 6, according to Figures 6 and 7, is designated in the broadest sense by the reference symbols S and S1, respectively. The flange sections 13 can now expediently be integrally formed on this plastic jacket 25. The flange sections 13 are thus produced by injection-molding the plastic jacket 25 onto the stator laminated core 24 and the stator coil. The motor housing part 5 can also be an injection-molded part, on which the flange pins 17 are integrally formed. The web elements 21 described above can also be expediently formed integrally on the motor housing part 5.

[0052] According to Figure 1, the pump 1 can also be equipped with an annular circuit board 26 which carries electronics 61, only partially shown here. According to Figure 1, the electronics 61 are located on an underside 62 of the circuit board 26 facing the stator 7 and protrudes axially into an annular recess 63 which is formed for this purpose on the inner longitudinal end 12 of the stator 7. The circuit board 26 has a plurality of circuit board sections 27. Each circuit board section 27 contains a circuit board opening 28. The circuit board sections 27 are arranged distributed in the circumferential direction U. For example, three such circuit board sections 27, each having a circuit board opening 28, can be arranged distributed in the circumferential direction U. The motor housing part 5 has on its front side 15 for each circuit board opening 28 a circuit board pin 29 which axially penetrates the respective circuit board opening 28 and has a step 30 and a head 31.The circuit board 26 is axially supported in the respective circuit board section 27 on the step 30 and on the head 31 and is positively fastened to the motor housing part 5 by the head 31. The circuit board pins 29 are also expediently formed integrally on the motor housing part 5. The circuit board pins 29 are formed here on the motor housing part 5. In another embodiment, not shown here, the circuit board pins 29 can also be formed on the stator 7. The circuit board pins 29 are implemented separately and spaced apart from the flange pins 17 in the circumferential direction U. In another embodiment, not shown here, the circuit board pins 29 can each be formed by a longitudinal section of one of the flange pins 17. The respective flange pin 17 then has a first longitudinal section adjoining the end face 15 of the motor housing part 5, which forms the flange pin 17, and a second longitudinal section adjoining it, for example via a step, which forms the plate pin 29.

[0053] The electric motor 3 can have at least one electrical motor connection (not visible here), which can be electrically connected, for example, to a winding of the stator coil. The pump housing 4 can also have at least one electrical housing connection, which can be arranged, for example, in a connection socket 32 ​​(shown in Figures 2 and 3). A power supply to the electric motor 3 can be realized, for example, via the connection socket 32. The respective motor connection and the respective housing connection can be electrically connected to the electronics of the circuit board 26 by means of plug connections. These plug connections each have a first plug-in part 33 and a complementary second plug-in part (not visible here). The first plug-in part 33 and the associated second plug-in part form a plug and a socket, which are plugged in in the axial direction to create the electrical connection.In the examples of Figures 2 and 3, several of the first plug-in parts 33 are arranged on the inner longitudinal end 12 of the stator 7 and electrically connected to the respective motor connection. Furthermore, several of the first plug-in parts 33 are also arranged on the end face 15 of the motor housing part 5 and electrically connected to the respective housing connection. The second plug-in parts, not shown here, are arranged on the circuit board 26 and electrically connected to the electronics. In the assembled state, the first plug-in parts 33 are each plugged into one of the second plug-in parts, so that the motor connections and the housing connections are electrically connected to the electronics. This makes it possible, in particular, to transmit externally provided electrical energy via the connection socket 32 ​​and the housing connections to the electronics and from there to the motor connections, for example in order to supply current to the stator coil.Particularly advantageous is the configuration presented here, in which the first plug-in parts 33 and the second plug-in parts are arranged and coordinated with one another such that, when the circuit board 26 is axially mounted in a predetermined rotational position of the circuit board 26 relative to the motor housing part 5, all plug-in connections are axially plugged in, in particular simultaneously. In other words, when the circuit board 26 is axially mounted, all plug-in connections are necessarily plugged in.

[0054] According to Figure 1, the pump housing 4 can also be equipped with an intermediate part 34, in particular made of plastic, which is fastened to the motor housing part 5 and to which the pump housing part 6 is fastened. The pump housing part 6 is thus indirectly fastened to the motor housing part 5 via the intermediate part 34. The intermediate part 34 lies axially on an upper side 35 of the circuit board 26 facing away from the stator 7. For example, the intermediate part 34 can be axially supported on the circuit board 26 via support elements 59. The intermediate part 34 also lies axially on the inner longitudinal end 12 of the stator 7. In the example in Figure 1, an annular web 36 projecting axially from the intermediate part 34 engages in an annular groove 37 formed on the inner longitudinal end 12 of the stator 7. In addition, an annular seal 60 is arranged in the region of this annular groove 37 in order to seal the stator 7 against the intermediate part 34.The intermediate part 34 also has an axially projecting collar 38 which runs around the circumference in the direction U and axially overlaps the end face 15 of the motor housing part 5. The intermediate part 34 has on this collar 38 a plurality of connecting regions 39 which are distributed in the circumference direction U and which each have an axially projecting housing pin 40. The motor housing part 5 has a support region 41 for each connecting region 39 which has a pin opening 42 through which the respective housing pin 40 axially passes. In the assembled state, the respective housing pin 40 has a head 43 which is located on a side of the support region 41 facing away from the intermediate part 34.

[0055] The pin opening 42 is supported by the edge of the support area 41, so that the head 43 positively fastens the intermediate part 34 to the motor housing part 5. The head 43 can be produced by thermally forming the free end of the housing pin 40. In the example in Figure 1, the connecting area 39 and support area 41 are supported against one another in such a way that the connecting area 39 is supported directly axially on the support area 41. The pump housing part 6 can now be welded to the intermediate part 34. A bayonet lock or a screw connection for detachably connecting the pump housing part 6 to the intermediate part 34 is also conceivable.

[0056] Figure 1 also shows a sealing ring 44, which is arranged radially between the collar 38 and the motor housing part 5. For axial positioning of the sealing ring 44, the motor housing part 5 has an annular step 45, and the intermediate part 34 has a further annular step 46, which is axially opposite the annular step 45 of the motor housing part 5.

[0057] According to Figure 4, in a method 47, in a step 48, the stator 7 is provided with the centering contours 10 and the flange sections 13. In a step 49, which can be carried out simultaneously before or after step 48, the motor housing part 5 is provided with the mating contours 11 and the flange pins 17. In a step 50, the stator 7 is inserted into the motor receiving space 9 such that the flange pins 17 axially penetrate the flange openings 14 and the centering contours 10 interact with the mating contours 11 to center the stator 7 in the motor housing part 5. In a step 51, the flange pins 17 are thermally formed such that the pin heads 18 are formed, which secure the respective flange section 13 to the motor housing part 5 in a form-fitting manner.

[0058] The provision of the motor housing part 5 carried out in step 49 can be carried out such that the motor housing part 5 is provided with the mating contours 11, the flange pins 17, and also with the circuit board pins 29. In a step 52, which is carried out after the thermal forming of the flange pins 17 carried out in step 51, the circuit board 26 is arranged axially on the stator 7 and on the motor housing part 5 such that the circuit board pins 29 axially penetrate the circuit board openings 28. In a step 53, the circuit board pins 29 are thermally formed such that the heads 31 are formed, which fasten the respective circuit board section 27 to the motor housing part 5 in a form-fitting manner.Step 52, in which the circuit board 26 is arranged on the stator 7 and the motor housing part 5, can optionally be carried out such that the circuit board 26 is first aligned in a predetermined rotational position relative to the motor housing part 5 and then axially attached to the stator 7 and the motor housing part 5 in this rotational position. In this case, the axial attachment of the circuit board 26 to the stator 7 and the motor housing part 5 can also inevitably lead to automatic plugging of the plug connections.

[0059] Alternatively, it is fundamentally possible to combine steps 50 and 52, so that the stator 7 is inserted into the motor housing 9 according to step 50, and the printed circuit board 26 is attached to the stator 7 and the motor housing part 5 according to step 52, without the flange pins 17 being thermally formed beforehand. Likewise, steps 51 and 53 can be combined, so that the flange pins 17 and the printed circuit board pins 29 are thermally formed sequentially or simultaneously. This applies in particular if the printed circuit board pins 29 are formed by longitudinal sections of the flange pins 17.

[0060] After the thermal forming of the plate pins 29 carried out in step 53, the intermediate part 34 can be attached to the motor housing part 5 in a step 54 such that the housing pins 40 axially penetrate the pin openings 42. In a step 55, the housing pins 40 can be thermally formed such that the heads 43 are formed, which form-fit the respective connecting region 39 to the respective support region 41. After the thermal forming of the housing pins 40 carried out in step 55 for fastening the intermediate part 34 to the motor housing part 5, the pump device 2 can be drivingly connected to the rotor 8 in a step 56. For example, the rotor 8 has a rotor shaft 58, which can be connected to the pump device 2 in a rotationally fixed manner, in particular via an axial gearing.After the driving connection of the rotor 8 to the pump device 2 carried out in step 56, the pump housing part 6 can be fastened to the intermediate part 34 in a step 57.

[0061] Figure 5 shows a conventional electric or electronic water pump, which has a cover plate 1a, a control 2a, a housing 3a, an insulating sleeve 4a, a stator 5a, two sealing rings 6a, a bearing seat 7a, a spiral housing 8a, an impeller 9a, a rotatable shaft 10a, an axial bearing 11a, a rotor 12a, two graphite bearings 13a, a heat-conducting layer 14a and several screws 15a.

[0062] This conventional electronic water pump has the following disadvantages:

[0063] (1) The cooling of the controller 2a depends on separate flow channels for heat transfer, resulting in a large hydraulic efficiency loss and low heat dissipation efficiency, leading to low motor power density and large size.

[0064] (2) The structure is complex, the axial space utilization is low and the bearing size is large.

[0065] (3) Both the stator 5a and the rotor 12a must be installed with an insulating sleeve for waterproof sealing, and there are also many other parts, such as sealing rings. The assembly process is complex, the cost is high, and the probability of sealing failure is high.

[0066] (4) Conventional assembly by screwing is more expensive.

[0067] Furthermore, there are prior art solutions in which the stator 5a or rotor 12a is formed as an injection-molded part, but the degree of integration of the injection-molded parts is low and one or more of the problems mentioned above remain.

[0068] The purpose of the electronic water pump shown in Figures 6 to 9 is to overcome or at least improve the disadvantages of the previously described electronic water pump.

[0069] Figures 6 to 9 show an electronic water pump.

[0070] The electronic water pump shown in Figure 6 comprises a stator assembly S, a rotor assembly R, an impeller assembly T, a controller C, a heat sink P, a cover plate H and a connector N.

[0071] In the axial direction of the stator assembly S, the impeller assembly T is arranged at the first end of the stator assembly S (hereinafter, the end of the stator assembly S from the impeller assembly T is referred to as the second end), and the controller C is arranged between the impeller assembly T and the stator assembly S. For the convenience of description, the following refers to the definitions of the first end and the second end of the stator assembly S; and the end facing in a same direction as the first end of the stator assembly S of each other component is referred to as the first end, and the end facing the second end of the stator assembly S is referred to as the second end.

[0072] The stator assembly S in Figure ? comprises a stator core S1, a stator injection-molded layer SO, a first bearing B1 and the terminal N. The stator injection-molded layer SO of the embodiment shown in Figures 6 to 8 corresponds to the plastic shell 25 of the embodiment shown in Figures 1 to 3. The terminal N comprises, as shown in Figure 7, a first connection terminal L1 for connecting the controller C to the external connection and a second connection terminal L2 for connecting the controller C to the stator winding. The stator injection-molded layer SO covers the inner circumference, the outer circumference and two axial ends of the stator core S1 to form a sealing structure on the surface of the stator core S1. The thinnest part of the stator injection-molded layer SO is located on the inner circumference of the stator core S1, and the thickness of the stator injection-molded layer SO at this part is, for example, 0.4 to 0.8 mm.

[0073] In the first end portion of the stator assembly S, the stator injection-molded layer SO extends to the inner circumference of the stator core S1 to form a cover-shaped separating structure S01. The middle portion of the separating structure S01 penetrates in the axial direction to form a center tube S011. The first bearing B1 is arranged in the center tube S011. The first bearing B1 is, for example, a sliding bearing, in particular a graphite bearing. The first bearing B1 can be integrally injection-molded with the center tube S011 using a mold during the formation of the stator injection-molded layer SO. The first bearing B1 is used for encasing the outer circumference of a shaft R2, which will be described below.

[0074] The stator injection-molded layer SO forms two spaced-apart concentric retaining rings on the outer circumference of the center tube S011, namely an inner retaining ring S012 and an outer retaining ring S013. An annular groove formed between the inner retaining ring S012 and the outer retaining ring S013 may correspond to the annular groove 37 of the embodiment shown in Figures 1 to 3 and is used for interaction with the heat sink P described below.

[0075] The first end of the stator assembly S is also provided with a connector, namely a first connection terminal L1 and a second connection terminal L2. The first connection terminal L1 and the second connection terminal L2 are metal parts. To facilitate the installation of the first connection terminal L1 and the second connection terminal L2, as shown in Figure 8, the stator injection-molded layer SO is formed with a bayonet-shaped clamping opening SO2 at the first end. A guide post SO3 projecting toward the first end is formed in the center of the bottom of the clamping opening SO2.

[0076] It should be understood that in Figure 8, the second connection terminal L2 is intended as an example for description, and that the connection structure between the first connection terminal L1 and the stator injection-molded layer SO is designed similarly.

[0077] In the example of the second connection terminal L2, the second connection terminal L2 comprises a first connection end L21 and a second connection end L22. The first connection end L21 is designed as a press-fit structure and is used for plugging into the electrical connection socket of the controller. The second connection end L22 contains two spaced-apart plug-in legs. The distance between the two plug-in legs is larger than the diameter of a lead wire W at the end and gradually decreases towards the first connection end L21 until it is smaller than the diameter of the lead wire W.

[0078] This structural design ensures that when the lead wire W is inserted into the two plug-in legs, the outer insulation layer (also called varnish) of the lead wire W can be destroyed by the plug-in legs, the lead wire W is electrically connected to the plug-in legs, and the lead wire W can be clamped by the two plug-in legs, thus eliminating the need for welding between the lead wire W and the second terminal end L22.

[0079] The second terminal end L22 can be inserted into the clamping opening S02, and the two form a press fit. The lead wire W, clamped between the two plug-in legs, rests against the guide column S03.

[0080] At the second end of the stator assembly S, the stator injection-molded layer SO is formed with an annular groove S04, and the annular groove S04 is used to cooperate with the cover plate H to be described below.

[0081] The terminal N is provided on the outer peripheral side of the stator core S1. The housing of the terminal N is also integrally formed with the stator assembly S during the injection molding process of the stator injection layer SO, or in other words, a partial structure of the stator injection layer SO also forms the housing of the terminal N.

[0082] The stator assembly S is attached at a first end to the impeller assembly T. The impeller assembly T comprises an impeller T1 and a spiral casing TO. The impeller T1 is enclosed at the first end section of the shaft R2. The impeller T1 of Figure 6 can correspond to the impeller or pump device 2 of the electric machine 1 of Figure 1.

[0083] The volute TO is an injection-molded part. Optionally, the material of the volute TO is the same as the material of the stator injection-molded layer SO. The volute TO covers the first end of the stator assembly S, and the volute TO and the stator injection-molded layer SO can be joined by fusion welding. In this embodiment, when the volute TO and the stator injection-molded layer SO are joined, an edge of the volute TO surrounds the stator injection-molded layer SO.

[0084] In addition to the impeller T1, the scroll casing TO also accommodates the controller C and the heat sink P. In the axial direction, the heat sink P is arranged closer to the impeller T1 than the controller C. The heat sink P is annular and includes a main body ring P1, an outer peripheral wall P2, and an inner peripheral wall P3. The outer peripheral wall P2 and the inner peripheral wall P3 both form flange-like structures extending in the axial direction, so that the cross section of the heat sink P on one axial side is substantially C-shaped. The end of the inner peripheral wall P3 extends into the annular groove between the inner retaining ring S012 and the outer retaining ring S013, as described above. The outer peripheral wall P2 abuts the end surface of the stator injection-molded layer SO located at the first end.A first seal E1 is provided between the outer peripheral side of the outer peripheral wall P2 and the spiral casing TO, and a second sealing ring E2 is provided between the inner side of the inner peripheral wall P3 and the center tube S011 of the stator injection-molded layer SO.

[0085] The above structure allows the separation structure S01 to perform the functions of a conventional insulating sleeve, ensuring that coolant on the impeller-T1 side is isolated from the motor side.

[0086] Optionally, the heat sink P is made of a metal material, such as aluminum or an aluminum alloy.

[0087] The control C is arranged in a semi-enclosed annular space defined by the plate-shaped heat sink P. A heat-conducting layer G is provided between the control C and the heat sink P. To reinforce the fixation of the control C, the control C is also fusion-welded to the stator injection-molded layer SO of the stator assembly S.

[0088] The stator injection-molded layer SO forms a short, column-fixed terminal L3 at the first end of the stator assembly S, and the end face of the control C facing the stator assembly S is formed with a corresponding recess (not shown in the figure). The fixed terminal L3 can be inserted into the recess of the control C and firmly connected to the control C, for example, by hot riveting.

[0089] Next, the rotor assembly R will be described with reference to Figure 9.

[0090] The rotor assembly R comprises a rotor core R1, the shaft R2, a thrust bearing R3 and a rotor injection molding layer RO. The shaft R2 is fixed to the inner circumference of the rotor core R1 so as to be non-rotatable relative to the rotor core R1. The thrust bearing R3 is provided on the shaft R2. The thrust bearing R3 is arranged at one end of the rotor core R1 near the first end in the axial direction of the rotor assembly R. The rotor injection molding layer RO covers the outer circumference and two axial ends of the rotor core R1. Furthermore, at the first end, the rotor injection molding layer RO surrounds the axial gap between the thrust bearing R3 and the shaft R2. At the second end, the rotor injection molding layer RO surrounds the axial gap between the rotor core R1 and the shaft R2. In the present embodiment, both axial ends of the rotor core R1 are partially countersunk in the inner circumferential region to form a first recess R1a and a second recess R1b, respectively.At the first end (top in Figure 9), the first recess R1a allows the thrust bearing R3 to partially extend within it. At the second end portion (bottom in Figure 9), the second recess R1b allows a second bearing B2, shown below it in Figure 6, to partially extend within it. This solution reduces the overall axial size of the motor.

[0091] Referring back to Figure 6, when the rotor assembly R is embedded in the stator assembly S and the two are assembled, the cover plate H is arranged at the second end of the stator assembly S to close that end. The base body of the cover plate H is made of plastic. Optionally, the cover plate H is made of the same material as the stator injection-molded layer SO.

[0092] The outer periphery of the cover plate H forms an axially extending annular flange H1. The outer diameter of the annular flange H1 is substantially equal to the outer diameter of the annular groove S04 of the stator injection-molded layer SO, and the inner diameter of the annular flange H1 is substantially equal to the inner diameter of the annular groove S04. When the cover plate H is matched to the stator assembly S, the annular flange H1 extends into the annular groove S04. When the cover plate H is arranged at the second end of the stator assembly S, the annular flange H1 and the stator injection-molded layer SO can be joined together by fusion welding. The central part of the cover plate H on the side facing the stator assembly S is partially raised to form a projection H2, wherein the above-mentioned second bearing B2 is fixed in the projection H2. The second bearing B2 is, for example, a plain bearing, in particular a graphite bearing.The second bearing B2 can be formed integrally with the projection H2 by means of a mold during the injection molding process of the cover plate H.

[0093] The present application has at least one of the following advantages:

[0094] (i) Both the rotor assembly and the stator assembly are one-piece injection-molded structures with simple assembly process and good sealing effect.

[0095] (ii) For the rotor injection molding, the rotor core and thrust bearing are injection-molded and sealed as one piece, reducing the axial length, reducing the number of parts, and saving additional sealing costs. For the stator injection molding, the stator, the original housing, the connector, the original insulating sleeve, and the graphite bearing are injection-molded as one piece, eliminating the original insulating sleeve and making the overall spatial structure more compact and significantly reducing the volume.

[0096] (iii) Placing the controller between the motor and the flow channel, with a heat sink and thermal interface layer in the center, eliminates the need for additional heat dissipation channels, reduces fluid efficiency loss, and enables better cooling of the controller. This increases the motor power density and reduces the size of the entire water pump. (iv) The volute casing and stator injection layer, the stator injection layer and cover plate, and the controller and stator assembly are all joined by plastic welding. No bolts are required throughout the pump, reducing costs.

[0097] (v) The stator enameled copper wire is inserted into the injection-molded stator using terminals with mechanically broken enamel, eliminating the need for welding or soldering. The terminals and control system are connected using press-fits, eliminating the need for welding or soldering, reducing process costs.

[0098] (vi) The overall structure is simple and reliable, and the number of sealing rings is reduced from four to two, which greatly reduces the probability of sealing failure.

[0099] List of reference symbols

[0100] pump

[0101] Pumping device

[0102] electric motor

[0103] Pump housing

[0104] Engine housing part

[0105] Pump housing part stator

[0106] rotor

[0107] Engine compartment

[0108] Centering contour

[0109] Counter contour

[0110] Longitudinal end

[0111] Flange section

[0112] Flange opening

[0113] front side

[0114] Mounting area

[0115] flange pin

[0116] tenon head

[0117] chamfer

[0118] web element

[0119] web element

[0120] Centering element

[0121] Centering surface

[0122] Stator laminated core

[0123] plastic sheath

[0124] circuit board

[0125] Board section

[0126] Board opening

[0127] Board pin stage 1 Head 2 Connection socket 3 Plug-in element 4 Intermediate part 5 Top side 6 Ring web 7 Ring groove 8 Collar 9 Connection area 0 Housing pin 1 Support area 2 Pin opening 3 Axial gap 4 Ring seal 5 Ring step 6 Ring step 7 Process 8 to 57 Process steps

[0128] 58 Rotor shaft

[0129] 59 Support element 0 Ring seal

[0130] 61 Electronics

[0131] 62 bottom

[0132] 63 recess

[0133] B1 first camp

[0134] B2 second camp

[0135] C Control

[0136] E1 first sealing ring

[0137] E2 second sealing ring

[0138] G Thermally conductive layer

[0139] H cover plate

[0140] H1 Ring flange H2 Projection

[0141] L21 first connection end

[0142] L22 second connection end

[0143] L3 connection

[0144] N connection

[0145] P Heatsink

[0146] P1 main body ring

[0147] P2 outer peripheral wall

[0148] P3 inner peripheral wall

[0149] R Rotor assembly

[0150] RO rotor injection molding layer

[0151] R1 rotor core

[0152] R1a first recess

[0153] R1b second recess

[0154] R2 wave

[0155] R3 thrust bearing

[0156] S Stator assembly

[0157] 50 stator injection molding layer

[0158] 51 Stator core

[0159] 501 Separation structure S01

[0160] 5011 Middle pipe

[0161] 5012 inner retaining ring

[0162] 5013 outer retaining ring

[0163] 502 clamp opening

[0164] 503 Guide column

[0165] 504 ring groove

[0166] T Impeller arrangement

[0167] TO spiral casing

[0168] T1 impeller

[0169] W Conductor wire

Claims

Patent claims 1 . An electric pump (1) for conveying a fluid, comprising a rotationally drivable pumping device (2), an electric motor (3) for rotationally driving the pumping device (2), and a pump housing (4) in which the pumping device (2) and the electric motor (3) are arranged. The pump housing (4) has a plastic motor housing part (5) for accommodating the electric motor (3) and a pump housing part (6) for accommodating the pumping device (2), which are firmly connected to one another. The electric motor (3) has a stator (7) and a rotor (8) that is rotatably mounted in the stator (7) about a rotational axis (R) that defines an axial direction, a radial direction, and a circumferential direction (U). The stator (7) is inserted axially into a motor receiving space (9) of the motor housing part (5). The stator (7) has a plurality of centering contours (10) radially on the outside, which are distributed in the circumferential direction (U).wherein the motor housing part (5) has a counter-contour (11) radially inward for each centering contour (10), which counter-contours are arranged distributed in the circumferential direction (U), wherein the centering contours (10) and the counter-contours (11) cooperate to center the stator (7) in the motor housing part (5), wherein the stator (7) has, at its inner longitudinal end (12) facing the pump device (2), a plurality of radially projecting flange sections (13), which are arranged distributed in the circumferential direction and each have a flange opening (14), wherein the motor housing part (5) has, on an axial end face (15) enclosing the motor receiving space (9), a fastening region (16) for each flange section (13), in which the respective flange section (13) is fastened to the motor housing part (5), wherein the respective fastening region (16) has an axially projecting flange pin (17) which passes through the flange opening (14) of the respective flange section (13) and has a pin head (18) which radially overlaps an opening edge enclosing the flange opening (14), so that the respective flange section (13) bears axially against the pin head (18) and is positively fastened to the motor housing part (5) by the pin head (18).

2. Pump (1) according to claim 1, characterized in that - that an axial gap (20) is formed between the respective flange section (13) and the end face (15) of the motor housing part (5).

3. Pump (1) according to one of the preceding claims, characterized in that - that at least two of the flange sections (13) are geometrically different, - that the fastening sections (16) are configured such that they only interact with the matching flange section (13) for fastening the respective flange section (13) to the motor housing part (5), so that the stator (7) can only be fastened to the motor housing part (5) with the flange sections (13) in a single predetermined rotational position with respect to the motor housing part (5).

4. Pump (1) according to one of the preceding claims, characterized in that - that the respective centring contour (10) and the associated counter-contour (11) form a radially projecting centring element (22) and a centring surface (23) on which the centring element (22) is radially supported.

5. Pump (1) according to claim 4, characterized in that - that the centering surface (23) is formed in a radial recess which is formed on the inside of the motor housing part (5) or on the outside of the stator (7).

6. Pump (1) according to one of the preceding claims, characterized in that - that the stator (7) has a stator laminated core (24), a stator coil and a plastic sheath (25) injection-molded onto the stator laminated core (24) and the stator coil, - that the flange sections (13) are formed integrally on the plastic casing (25) and are produced by injection-molding the plastic casing (25).

7. Pump (1) according to one of the preceding claims, characterized in that - that the pump (1) has an annular circuit board (26) carrying an electronics, - that the plate (26) has a plurality of plate sections (27), each with a plate opening (28), which are arranged distributed in the circumferential direction (U), - that the motor housing part (5) or the stator (7) has a plurality of axially projecting plate pins (29), each of which passes through one of the plate openings (28) and has a step (30) and a head (31), - that the plate (26) in the respective plate section (27) lies axially against the step (30) and the head (31) and is positively fastened to the motor housing part (5) by the head (31).

8. Pump (1) according to claim 7, characterized in that - that at least one electrical motor connection of the electric motor (3) and / or at least one electrical housing connection of the pump housing (4) is electrically connected to the electronics of the circuit board (26) by means of plug connections, - that the plug connections each have a first plug-in part (33) and a complementary second plug-in part, which have a plug and a socket which are inserted in the axial direction to create the electrical connection, - that at least one of the first plug-in parts (33) is arranged on the inner longitudinal end (12) of the stator (7) and is electrically connected to the respective motor connection and / or at least one of the first plug-in parts (33) is arranged on the end face (15) of the motor housing part (5) and is electrically connected to the respective housing connection, - that the second plug-in parts are arranged on the circuit board (26) and are electrically connected to the electronics, - that the first plug-in parts (33) and the second plug-in parts are arranged and matched to one another in such a way that when the circuit board (26) is mounted axially in a predetermined rotational position of the circuit board (26) relative to the motor housing part (5), all plug-in connections are plugged axially.

9. Pump (1) according to one of the preceding claims, characterized in that - that the pump housing (4) also has an intermediate part (34) which is fastened to the motor housing part (5) and to which the pump housing part (6) is fastened.

10. Pump (1) according to claims 7 and 9, characterized in that - that the intermediate part (34) rests axially on an upper side (35) of the circuit board (26) facing away from the stator (7), - that the intermediate part (34) has a circumferential, axially projecting collar (38) which axially overlaps the end face (15) of the motor housing part (5), - that the intermediate part (34) has on its collar (38) a plurality of connecting areas (39) each with an axially projecting housing pin (40) which are arranged distributed in the circumferential direction (U), - that the motor housing part (5) has a support area (41) for each connecting area (39) which has a pin opening (42) through which the respective housing pin (40) passes, - that the respective housing pin (40) has a head (43) which is supported on a side of the support region (41) facing away from the intermediate part (34) on an edge of the support region (41) enclosing the pin opening (42) and thus fastens the intermediate part (34) to the motor housing part (5) in a form-fitting manner.

11. Method (47) for producing an electric pump (1) according to one of the preceding claims, - in which the stator (7) is provided with the centering contours (10) and the flange sections (13), - in which the motor housing part (5) is provided with the counter contours (11) and the flange pins (17), - in which the stator (7) is inserted into the motor receiving space (9) in such a way that the flange pins (17) axially penetrate the flange openings (14) and the centering contours (10) interact with the counter-contours (11) for centering the stator (7) in the motor housing part (5), - in which the flange pins (17) are thermally formed in such a way that the pin heads (18) are formed which fasten the respective flange section (13) to the motor housing part (15) in a form-fitting manner. 12 Method (47) according to claim 11, characterized in that - that the motor housing part (5) or the stator (7) is provided with the board pins (29), - that after the thermal forming of the flange pins (17), the plate (26) is arranged axially on the stator (7) and on the motor housing part (5) in such a way that the plate pins (29) penetrate the plate openings (28), - that the board pins (29) are thermally formed in such a way that the heads (31) are formed which fasten the respective board section (27) in a form-fitting manner to the motor housing part (5).

13. Method (47) according to claim 12, characterized by - that the circuit board (26) is arranged on the stator (7) and on the motor housing part (5) in such a way that the circuit board (26) is first aligned in a predetermined rotational position with respect to the motor housing part (5) and is then attached axially to the stator (7) and the motor housing part (5) in this rotational position, - that the axial plug connections are plugged in when the circuit board (26) is attached axially to the stator (7) and the motor housing part (5).

14. Method (47) according to claim 12 or 13, characterized in that - that after the thermal forming of the plate pins (29), the intermediate part (34) is attached to the motor housing part (5) in such a way that the housing pins (40) axially penetrate the pin openings (42), - that the housing pins (40) are thermally deformed in such a way that the heads (43) are formed which positively fasten the respective connecting region (39) to the respective support region (41).

15. Method (47) according to claim 14, characterized in that - that after fastening the intermediate part (34) to the motor housing part (5), the pump device (2) is drivingly connected to the rotor (8), - that after the driving connection of the rotor (8) to the pump device (2), the pump housing part (6) is fastened to the intermediate part (34).

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