STATOR FOR AN ELECTRIC AXIAL FLOW MACHINE, METHOD FOR MANUFACTURING SUCH A STATOR AND ELECTRIC AXIAL FLOW MACHINE WITH SUCH A STATOR

Description

[0001] The present invention relates to a stator for an electric machine designed as an axial flux machine. The invention further relates to a method for manufacturing such a stator. It also relates to an electric axial flux machine comprising such a stator.

[0002] In the development of electrical machines, especially axial flux machines, there is a growing demand for ever-increasing specific power density. Stators of axial flux machines are now often constructed with toothed coils, where the iron core is represented by SMC (Soft Magnetic Composites). The toothed coils are typically anchored or mounted within the housing of the axial flux machine by means of a thin-walled plastic component. This plastic component is connected to a cover of the axial flux machine, so that the plastic component is located in the air gap between the rotor and the stator. The connection between the plastic component and the cover is often only glued. As a result, the transmissible torques are limited by the strength / stability or rigidity of the adhesive bond between the plastic component and the cover.Furthermore, the plastic component located in the air gap between the rotor and stator leads to a further reduction or limitation of the torque transmission. In addition, it is necessary to press the individual laminations together for a laminated tooth coil stack. A conventional stator for an electric axial flux machine, as well as a conventional electric axial flux machine itself, are known, for example, from DE 10 2021 124 998 A1. Furthermore, EP 2 962 383 B1 discloses an electric axial flux machine in which the stator teeth of these conventional axial flux machines are connected to each other and to a housing radially surrounding the stator by a ring structure.

[0003] CN 112 713 670 A discloses a disc rotor motor with a rotor assembly and a stator assembly. The stator assembly comprises a motor end cap, a fixed mandrel, several split flap cores, and a winding skeleton, wherein several of the split flap cores are provided in the winding skeleton and arranged between the motor end cap and the fixed mandrel.

[0004] From JP 2011 182576 A, an axial gap motor is known in which a rotor and a stator with a gap in the axial direction of the motor are arranged opposite each other. The stator comprises a guiding frame of a support frame structure with radial columns at predetermined intervals in the circumferential direction and a plurality of gap cores which are held in the frame at intervals of the columns and arranged in the circumferential direction.

[0005] Furthermore, CN 114 301 206 A discloses a disc drive motor with a disc stator assembly fixedly mounted on a main shaft. The disc stator assembly comprises upper and lower spoke-like stator supports, the upper and lower spoke-like stator supports being fixedly connected to the main shaft at axially spaced intervals. A plurality of upper and lower stator coil slots are formed at circumferential intervals in the upper and lower spoke-like stator supports. The disc stator assembly further comprises a plurality of stator coil modules, the plurality of stator coil modules being arranged at circumferential intervals on an outer circumferential side of the main shaft and positioned between the upper and lower spoke stator supports. The upper and lower ends of each of the stator coil modules are inserted into corresponding upper and lower stator coil slots.

[0006] The object of the invention is to increase the torque transmission capacity of an axial flux machine.

[0007] This problem is solved by the subject matter of the independent claims. Further possible embodiments of the invention are disclosed in the dependent claims, the description, and the figures. Features, advantages, and possible embodiments set forth in the description for one of the subject matter of the independent claims are to be regarded, at least analogously, as features, advantages, and possible embodiments of the respective subject matter of the other independent claims, as well as of any possible combination of the subject matter of the independent claims within the scope of the invention as defined by the claims, optionally in conjunction with one or more of the dependent claims.

[0008] According to the invention, a stator for an electric axial flux machine is proposed. The stator comprises a support structure, coil units, a clamping ring, and a stator outer shell.

[0009] The support structure comprises two coaxially arranged and axially spaced support disks and a rotor shaft bearing. Each support disk has discrete star-shaped extensions that radiate outwards from an annular portion of the disk. Therefore, the support disks can also be called star disks or star disks. The star-shaped extensions originate from the annular portion and lie in the same plane as the annular portion itself. The star-shaped extensions are identical in size and geometry and are equidistant from each other circumferentially. Radially outward ends of the star-shaped extensions lie on a common circumcircle, the center of which coincides with the center of one of the annular portions.The centers lie on a longitudinal center axis of the support structure, and the longitudinal center axis of the support structure coincides with a longitudinal center axis of the rotor shaft bearing.

[0010] The coil units are each arranged between two pairs of star-shaped extensions of the support disks, arranged consecutively in the circumferential direction. The coil units are directly adjacent to the pairs of star-shaped extensions, thus fixing them circumferentially to the support structure. Each pair of star-shaped extensions consists of a star-shaped extension from one of the support disks and a star-shaped extension from the other, arranged at the same angle. The support disks are arranged so that they are rotationally fixed relative to each other.

[0011] Each coil unit has a laminated core, which is formed in particular from a stack of laminations whose individual laminations are stacked or laminated in the radial direction. The respective end sections of the laminated core of the coil units project beyond the support structure in the axial direction. In other words, the laminated core of each coil unit projects beyond the support disks on both sides along the longitudinal center axis of the support structure. The star-shaped extensions of the support disks have radially outward-facing fixing ends that project radially outward beyond the coil units. In other words, a first radius (measured from the longitudinal center axis of the support structure to the fixing ends) is larger than a second radius (measured from the longitudinal center axis of the support structure to a radially outward-facing edge of the respective laminated core).

[0012] The coil units are radially clamped towards the rotor shaft bearing by means of the clamping ring, which is clamped circumferentially around the end sections of the coil units. The clamping ring is preferably formed in one piece. For example, it can be provided that the clamping ring is radially expanded by means of a clamping force and / or thermally and then placed around the end sections of the coil units. As soon as the clamping force and / or thermal influence is removed, the clamping ring narrows radially, thereby clamping the coil units towards the rotor shaft bearing or towards the longitudinal center axis of the support structure. For this purpose, an inner radius of the clamping ring may be smaller than the second radius. A force-fit exists between the clamping ring, i.e., its inner contact surface, and the end sections of the coil units, particularly by means of an interference fit.

[0013] The stator outer shell is arranged between the support disks and radially surrounds the coil units in the circumferential direction. Furthermore, the stator outer shell is rotationally fixed to the support structure at the fixing ends of the star extensions. In particular, the stator outer shell is designed to function as an external structure for torque support. For example, the stator outer shell can include a support block designed to align with a counter bearing of the axial flux machine housing to act as a torque support.

[0014] The carrier discs and / or the clamping ring and / or the stator outer shell can be made of a metallic material. A fiber-reinforced material is also conceivable.

[0015] By clamping the radially laminated stacks between the support structure and the clamping ring, the individual laminations of the coil units or stacks are not pulled out of the stator by the magnetic forces acting during operation of the axial flux machine. This eliminates the need for a positive-locking connection of the individual laminations, thus simplifying stator manufacturing. In general, the stator described herein is particularly easy to manufacture, especially automatically, since the individual elements of the axial flux machine are particularly well-suited for handling by a machine, especially a robot. Compared to conventional stators, significantly higher torques can be transmitted because, unlike the prior art, the individual laminations of the stacks are not supported by a plastic component.

[0016] Each coil unit has a rail support body made of an electrically insulating material. The rail support body has two support blocks at its ends, so that the contact carrier terminates at the support blocks on both sides along its axial length. In the stator, the rail support body is radially supported on the clamping ring by means of the support blocks. Specifically, the rail support body is attached directly or indirectly to the laminated core. By supporting the rail support body on the clamping ring via its support blocks, the respective coil unit is securely fixed between the star-shaped extensions of the carrier disks via the rail support body and the laminated core.

[0017] According to a possible further development of the stator, the support structure is provided with a rotor bearing cylinder. The respective support disk is connected to the rotor bearing cylinder at its respective end face by means of force-fit, form-fit, and / or material-fit connections, in particular by bolting. This results in the support disks being axially spaced from one another along the length of the rotor bearing cylinder. The rotor bearing cylinder is specifically designed as an annular cylinder, with an inner circumferential surface of the rotor bearing cylinder or annular cylinder configured to serve as a bearing point for a rotor shaft of the axial flux machine. This means that the rotor shaft bearing can be formed by the rotor bearing cylinder. This enables a particularly efficient bearing arrangement of the rotor shaft at the center of the axial flux machine or coaxially with the longitudinal center axis of the support structure.Generally, the support structure can be designed as a single piece, for example, by forming the support discs and the rotor bearing cylinder together as one unit. Alternatively, the support structure can be a multi-part construction, in which the support discs and the rotor shaft bearings, in particular the rotor bearing cylinder, are each provided separately and connected to the support structure by means of force-fit, form-fit, and / or material-fit connections. In any case, the rotor bearing cylinder has a dual function: firstly, it acts as the rotor shaft bearing, and secondly, it acts as a connecting element by means of which the two support discs are rotationally fixed to each other.

[0018] In another possible embodiment of the stator, it features one or more centering cylinders. Each centering cylinder is arranged coaxially on the annular portion of the carrier disk and extends axially away from the coil units. The coil units are supported at their end sections on an outer circumferential surface of the centering cylinder and clamped radially between the centering cylinder and the clamping ring. It is particularly recommended that the stator has one such centering cylinder per carrier disk, meaning that the stator may, for example, have two centering cylinders. This allows the coil units to be held in a particularly efficient and secure position between the star-shaped extensions of the carrier disks.The centering cylinder(s) allow the stator to be manufactured with advantageously tight tolerances, which are beneficial for the axial flux machine's particularly high torque transmission capacity. This is because the coil units are arranged in a highly precise circular configuration.

[0019] In another possible embodiment of the stator, in connection with the centering cylinder, two or more alignment pins are formed on the (respective) annular portion of the carrier disk, each extending axially outwards from the annular portion. These alignment pins are designed to assist in the coaxial alignment of the centering cylinder with respect to the carrier disk. This makes the coaxial alignment of the centering cylinder with respect to the carrier disk particularly simple and / or efficient during assembly of the axial flux machine components, especially its stator, while still ensuring that the centering cylinder and the carrier disk are aligned with exceptional coaxial precision. This is because the longitudinal center axis of the centering cylinder and the longitudinal center axis of the support structure coincide.

[0020] The need for particularly secure positioning of the respective coil unit between the star-shaped extension pairs of the carrier disks is given special consideration when – as provided in another possible embodiment of the stator – the rail support body is radially fixed between the clamping ring and the stator outer shell by means of which the support blocks are tensioned towards the clamping ring by the stator outer shell. This reliably prevents unintentional or undesired radial disengagement of the coil units, as this radial disengagement is blocked both by the clamping ring and by the stator outer shell in conjunction with the respective rail support body.

[0021] Another possible stator configuration involves each coil unit having an electrical coil, and the stator itself having a busbar arrangement. This busbar arrangement comprises several axially spaced busbars located on the outer circumference between the stator's outer shell and the coil units. Each busbar is electrically connected to two or more of the electrical coils. For example, if the axial flux machine is a three-phase electric machine, the busbar arrangement has four busbars: three representing the three phases and the fourth serving to implement a neutral connection. In any case, the busbar arrangement is configured to function as a stator connection.For this purpose, the busbar arrangement has in particular a phase interface which is designed to be electrically contacted with an electrical power supply, so that electrical drive energy can be supplied to the stator via the phase interface during operation of the axial flux machine, by means of which the rotor of the axial flux machine can be driven.

[0022] The rail support bodies primarily function as carriers or support elements for the conductor rails of the conductor rail assembly. For this purpose, the rail support bodies can be thinner between the support blocks, i.e., between the ends of the respective rail support body, so that a receiving space for the conductor rails is formed between the support blocks. Since the rail support body is made of an electrically insulating material, such as plastic, the conductor rails are electrically insulated from each other, even though two or more conductor rails may be arranged in the receiving space of the respective rail support body and directly contact it. Furthermore, the rail support body acts as an electrical insulating element between the conductor rails and the respective coil.

[0023] As proposed in another possible embodiment, the stator's rail support structure can have two electrically insulated coil contact elements, each electrically connected to a corresponding busbar contact element of the rail support structure. The coil ends of the corresponding coil unit are each electrically contacted with one of the coil contact elements. Furthermore, one busbar is electrically connected to one busbar contact element, and another busbar is electrically connected to a different busbar contact element. Specifically, conductor tracks that electrically connect each coil contact element and its corresponding busbar contact element are embedded in the electrically insulating material of the rail support structure.In other words, the conductive traces by which the respective coil contact element and the corresponding busbar contact element are electrically connected can be encased in the electrically insulating material of the busbar support. The coil contact element is, in particular, designed as a socket, with the corresponding coil end being designed as a plug-in element corresponding to the socket. The busbar contact element is, for example, designed as a contact pin that extends from the corresponding conductive trace out of the busbar support or its electrically insulating material. This contact pin extends, in particular, into the receiving space for the busbars.The coil contact element, into which the corresponding coil end can be inserted, thereby electrically contacting the coil contact element and the corresponding coil end, can be formed, in particular, on the respective support block of the rail support body. To ensure a particularly reliable electrical connection between the busbars and the busbar contact elements, it is specifically provided that the busbars and the busbar contact elements, especially the contact pins, are fastened to one another by means of a thermal joining process, for example, welding.

[0024] The rail support structure thus functions not only as an additional connecting and stabilizing element for the respective coil unit, but also as an electrical connecting element between the busbars and the coils of the coil units. This allows the stator of the axial flux machine to be manufactured particularly easily and / or with minimal effort, as it comprises a very small number of individual components.

[0025] According to another possible embodiment of the stator, the stator outer shell has two half-shells that abut each other circumferentially by means of two connecting blocks. It is specifically provided that the two half-shells of the stator outer shell are identical. Each connecting block has one of the connecting elements from the first half-shell and one of the connecting elements from the second half-shell. The connecting elements extend radially outwards from an outer circumferential surface of the respective half-shell, meaning that each connecting element projects radially from the outer circumferential surface of the respective half-shell. This allows each connecting block to be used for torque support. For example, each connecting block acts as a support block for the stator.

[0026] Because the stator outer shell has two half-shells connected by the connecting blocks, manufacturing the stator is particularly simple and / or cost-effective, as the circumferential arrangement of the stator outer shell around the coil units, especially around the rail support bodies, can be carried out very easily. Furthermore, the stator outer shell can be clamped radially against the coil units, especially the rail support bodies, with particular efficiency, so that the rail support bodies and consequently the coil units are securely locked against radial disengagement.

[0027] The invention further relates to an electrical machine, in particular an axial flux or diagonal flux machine, which has as its stator the stator described herein.

[0028] Furthermore, the invention relates to a method for manufacturing the stator for the axial flux machine. In this method, the support structure with the two support disks is provided. The coil units are arranged between two circumferentially successive pairs of star extensions of the support disks, thereby fixing the coil units circumferentially with respect to the support structure. In addition, the coil units are clamped radially towards the rotor shaft bearing by clamping the clamping ring circumferentially around the end sections of the coil units. Furthermore, the stator outer shell is rotationally fixed to the fixing ends of the star extensions with respect to the support disks, thereby positioning it between the support disks. By fixing the stator outer shell to the support disks, the coil units are radially enclosed circumferentially by the stator outer shell.Accordingly, the stator elements are assembled from the inside out.

[0029] Further features of the invention may become apparent from the claims, the figures, and the description of the figures. The features and combinations of features mentioned above in the description, as well as the features and combinations of features shown below in the description of the figures and / or in the figures alone, are not only usable in the combinations specified, but also in other combinations or individually, without departing from the scope of the invention as defined in the claims.

[0030] The drawing shows in: Fig. 1 a perspective view of a rotor bearing cylinder for a stator of an axial flux machine, Fig. 2 a perspective view of a support structure for the stator, comprising the rotor bearing cylinder and two support disks, Fig. 3 a perspective and partially schematic view of a coil unit for the stator, Fig. 4 a perspective view of the support structure in which a coil unit is radially inserted between two pairs of star extensions of the support disks, Fig. 5 a perspective view of the support structure in which the coil units are clamped radially towards a rotor shaft bearing by means of a clamping ring, Fig. 6 a perspective view of the support structure in which several busbars are mounted circumferentially on busbar support bodies of the coil units, and Fig. 7 a perspective view of the stator.

[0031] In the figures, identical and functionally equivalent elements are provided with the same reference symbols.

[0032] The following describes an electrical machine designed as an axial flux machine (not shown), whose stator 1 (see Fig. 7 ) and a method for manufacturing stator 1 is described jointly. This includes showing Fig. 1 A perspective view of a rotor bearing cylinder 2, whose inner circumferential surface 3 is configured to function as a bearing for a rotor (not shown) of the axial flux machine. Over a length 4 of the rotor bearing cylinder 2, two end faces 5 of the rotor bearing cylinder 2 are spaced exactly apart from each other.

[0033] Fig. 2 Figure 1 shows a perspective view of a support structure 6 of the stator 1, wherein the support structure 6 comprises the rotor bearing cylinder 2 and two support disks 7. The support disks 7 are arranged coaxially to each other, that is, they share a common longitudinal center axis 8. Along the longitudinal center axis 8, the support disks 7 are axially spaced apart from each other, in this case over the length 4 of the rotor bearing cylinder 2. The rotor bearing cylinder 2 is arranged coaxially to the two support disks 7, so that the support disks 7 and the rotor bearing cylinder 2 share the longitudinal center axis 8. The longitudinal center axis 8 is, in particular, a longitudinal center axis or rotor axis (not shown) of the axial flux machine. Accordingly, the longitudinal center axis 8 and the longitudinal center axis of the rotor coincide. The support structure 6 also has a rotor shaft bearing 9, which in this example is formed by the rotor bearing cylinder 2.

[0034] The respective carrier disk 7 has a circular ring portion 10, from which a plurality - in this case fifteen by way of example - star extensions 11 extend radially outwards, of which only a few are provided with the corresponding reference numeral in the Fig. for the sake of clarity.

[0035] The support structure 6 is formed here by connecting the support disks 7 and the rotor bearing cylinder 2 to each other. It is provided here that the respective support disk 7 and the rotor bearing cylinder 2 are connected to each other by connecting the support disks 7 and the rotor bearing cylinder 2 as shown in Fig. 2 They are shown being screwed together. Fig. 2 For the sake of clarity, not all of the screw elements 12 required for bolting the respective carrier disc 7 to the rotor bearing cylinder 2 are marked with the corresponding reference symbol. It is due to Fig. 2 It can also be seen that the respective carrier disk 7 is connected to the rotor bearing cylinder 2 at one of its respective end faces 5.

[0036] Fig. 3 Figure 1 shows a perspective and partially schematic view of a coil unit 13 for the stator 1. The respective coil unit 13 has a radially laminated laminated core 14, which is formed from a plurality of individual laminations (not shown) arranged in the radial direction (see arrow 15 in Figure 1). Fig. 3 The stator core 13 is stacked. A coil insulation sheath 17 is arranged between an electrical coil 16 of the coil unit 13 and the stator core 14, by means of which the electrical coil 16 and the stator core 14 of the coil unit 13 are electrically insulated from each other. The electrical coil 16 of the coil unit 13 has a plurality of turns (not shown), with the coil 16 and the turns terminating at two coil ends 18. The stator core 14 has two end sections 19 that project laterally out of the coil 16 along a coil axis (not shown) of the electrical coil 16. Furthermore, each end section 19 of the stator core 14 projects laterally beyond the coil insulation sheath 17, i.e., along the circumferential direction of the stator 1. This creates a gap 20 between each end section 19 and the electrical coil 16. The coil 16 is therefore spaced apart from the respective end section 19 by the respective gap 20.

[0037] In the present example, each coil unit 13 also has a rail support body 21. The rail support body 21, which is made of an electrically insulating material, in particular plastic, has two support blocks 22, via which the rail support body 21 terminates along its axial longitudinal extent. In other words, each support block 22 forms a longitudinal end of the rail support body 21.

[0038] In the present example, it is further provided that the respective rail support body 21 has two electrically isolated coil contact elements 23 and two electrically isolated busbar contact elements 24. The coil contact elements 23 are each electrically connected to one of the busbar contact elements 24, for which purpose the rail support body 21 has conductor tracks (not shown). The conductor tracks are embedded in the electrically insulating material of the rail support body 21 and connect the respective coil contact element 23 and the corresponding busbar contact element 24. Fig. 3 It is evident that the respective coil end 18 and each of the coil contact elements 23 are electrically connected to each other, in this case by the fact that the corresponding coil end 18 is inserted into the coil contact element 23, which is designed as a coil end receptacle or socket. The busbar contact elements 24, which are electrically connected to the coil contact elements 23, are designed in this case as a respective contact pin.

[0039] Fig. 4 shows a perspective view of the support structure 6, in which there is a space between two pairs of star extensions 25 (also in Fig. 2 (as shown) a coil unit 13 is radially inserted into each of the carrier disks 7. By radially inserting the coil units 13 into the carrier structure 6, the coil units 13 are fixed circumferentially with respect to the carrier structure 6 by arranging the respective coil unit 13 between the circumferentially successive pairs of star extensions 25 of the carrier disks. The respective star extensions 11 engage in corresponding gaps 20 of the coil units 13, so that the end sections 19 of the respective lamination stack 14 project beyond the carrier structure 6 on both sides along the longitudinal center axis 8. Fig. 4 Furthermore, it can be seen that the star extensions 11 are so long in the radial direction that radially outer fixing ends 26 of the star extensions 11 project radially outwards beyond the coil units 13.

[0040] In Fig. 4 It is further shown that in the present example, the stator 1 has a centering cylinder 27 which is arranged coaxially on the annular portion 10 of the carrier disk 7. It can be provided that the stator 1 has two centering cylinders 27, namely one centering cylinder 27 for each carrier disk 7. In order to align the support structure 6, in particular the carrier disks 7 and the centering cylinder 27, particularly easily and / or with minimal effort and with particular precision, two or more, in this case three, alignment pins 28 are formed on the annular portion 10 of the respective carrier disk 7, each extending axially, i.e., along the longitudinal center axis 8, outwards from the annular portion 10.The centering cylinder 27, which is designed as a hollow cylinder, also extends axially, i.e. parallel to the longitudinal center axis 8, away from the coil units 13, and the coil units 13 are supported via their end sections 19 on an outer circumferential surface 29 of the centering cylinder 27.

[0041] Fig. 5 shows a perspective view of the support structure 6, as it appears in Fig. 4 is shown, with the difference that in the Fig. 5 In the illustrated support structure 6, the coil units 13 are clamped radially towards the rotor shaft bearing 9, i.e., towards the rotor bearing cylinder 2, in this case towards the centering cylinder 27, by means of a clamping ring 30. In this example, the stator 1 or the support structure 6 is provided with two clamping rings 30, namely one clamping ring 30 on each side of the stator 1 or on each side of the support structure 6. The clamping ring is clamped circumferentially around the end sections 19 of the coil units 13, thereby clamping the coil units 13 radially towards the centering cylinder 27 or radially towards the rotor shaft bearing 9. A force-fit, in particular an interference fit, is realized between the end sections 19 of the coil units 13 and an inner circumferential surface (not shown) of the respective clamping ring 30.This clamps the end sections 19 and consequently the coil units 13 radially between the centering cylinder 27 and the clamping ring 30. Furthermore, it is made of... Fig. 5 It can be seen that the respective rail support body 21 is supported radially on the clamping ring 30 via its support blocks 22. This means that the clamping ring 30 has been inserted, for example, between the respective support block 22 and a radially outer edge of the respective end section 19. Alternatively, it is conceivable that the respective coil unit 13 was first inserted radially into the support structure 6 without the rail support body 21, then the clamping ring 30 was attached, and subsequently the rail support body 21 was coupled to the coil 16.

[0042] Fig. 6 Figure 1 shows a perspective view of the support structure 6, in which several busbars 31 of a busbar arrangement 32 are mounted circumferentially on the busbar support bodies 21 of the coil units 13. This means that the stator 1 has the busbar arrangement 32, i.e., the busbar 31, the busbars 31 being axially spaced apart from one another. The respective busbar 31, which can be composed of several busbar segments 33 along the circumferential direction of the stator 1 or the support structure 6, runs around the outer circumference of the coil units 13. The respective busbar 31 is electrically contacted with two or more of the electrical coils 16, for example, by electrically connecting the corresponding busbar 31 to one or more of the busbar contacting elements 24, in particular by welding.To avoid a short circuit between the busbars 31, it is of course provided that for each coil unit 13 a first of the busbars 31 is electrically connected to a first of the busbar contacting elements 24 and another or second of the busbars 31 is electrically connected to the corresponding other of the busbar contacting elements 24 of the same coil unit 13.

[0043] Fig. 7 Figure 1 shows a perspective view of the stator 1, which has an outer shell 34 formed from two half-shells 35. The two half-shells 35 abut each other circumferentially by means of two connecting blocks 36 and are connected to each other by these connecting blocks 36. The connecting blocks 36 project radially from an outer circumferential surface of the outer shell 34. In this example, the two half-shells 35 are bolted together at the connecting blocks 36. The bolted elements involved in the bolted connection of the half-shells 35 are shown in Fig. 7 marked with reference number 37.

[0044] The stator outer shell 34 is arranged between the support disks 7 and radially surrounds the coil units 13 in the circumferential direction. Furthermore, the stator outer shell 34, or rather the half-shells 35, are connected at the fixing ends 26 to the star extensions 11, so that the stator outer shell 34 and the support structure 6 are rotationally fixed relative to each other. For this purpose, the stator outer shell 34 in this example has screw element receptacles 38, which are connected to screw element receptacles 39 (see Figure 1). Fig. 2 , 5 and 6The fixing ends 26 are arranged correspondingly. Each pair of star extensions 25 of the stator outer shell 34 has a screw element receptacle 38 on its inner circumferential surface, wherein a corresponding screw element 40 extends axially along the longitudinal center axis 8, i.e., axially, simultaneously through two screw element receptacles 39 and the corresponding screw element receptacle 38. In this way, the stator outer shell 34 is particularly securely and rotationally fixed to the support structure 6.

[0045] In this case, the respective rail support body 21 is radially fixed between the clamping rings 30 and the stator outer shell 34 by means of the stator outer shell 34 clamping the support blocks 22 towards the clamping rings 30. In other words, the rail support body 21 is held between the clamping rings 30 and the stator outer shell 34 as soon as the stator outer shell 34 circumferentially encloses the coil units 13 as intended.

[0046] In the process for manufacturing the stator 1, the support structure 6 with the two support disks 7 is provided. The coil units 13 are then arranged between two pairs of star extensions 25 of the support disks 7 or the support structure 6 that are directly adjacent to each other in the circumferential direction, thereby fixing the coil units circumferentially with respect to the support structure 6. By clamping the respective clamping ring 30 circumferentially around the end sections 19 of the coil units 13, the coil units 13 are clamped radially towards the rotor shaft bearing 9. In addition, the stator outer shell 34 is fixed to the fixing ends 26 of the star extensions 11 with respect to the support disks 7 in a rotationally fixed manner, thereby arranging it between the support disks 7 and radially enclosing the coil units 13 circumferentially with respect to the stator outer shell 34. Reference symbol list

[0047] 1 Stator 2 Rotor bearing cylinder 3 Inner circumferential surface 4 Length 5 End face 6 Support structure 7 Support disc 8 Longitudinal center axis 9 Rotor shaft bearing 10 Circular ring portion 11 Star extension 12 Screw element 13 Coil unit 14 Sheet metal package 15 Arrow 16 Electrical coil 17 Coil insulation jacket 18 Coil end 19 End section 20 Gap 21 Rail support body 22 Support block 23 Coil contacting element 24 Busbar contacting element 25 Star extension pair 26 Fixing end 27 Centering cylinder 28 Alignment pin 29 Outer circumferential surface of the centering cylinder 30 Tension ring 31 Busbar 32 Busbar assembly 33 Busbar segment 34 Stator outer shell 35 Half shell 36 Connecting block 37 Screw element 38 Screw element receptacle 39 Screw element receptacle 40 Screw element

Claims

1. Stator (1) for an electric axial flux machine, wherein the stator (1) comprises: - a support structure (6) which has two support disks (7) arranged coaxially with respect to one another and axially spaced apart from one another and a rotor shaft bearing (2, 9), wherein the support disks (7) each have discrete star extensions (11) which extend radially outwardly from an annular portion (10) of the support disks (7), - coil units (13) which are each arranged between two star extension pairs (25) of the support disks (7) following one another in the circumferential direction and directly adjoin the star extension pairs (25), whereby the coil units (13) are fixed in the circumferential direction in relation to the support structure (6), wherein - respective end sections (19) of a respective laminated core (14) of the coil units (13) project beyond the support structure (6) in the axial direction, - radially outer fixing ends (26) of the star extensions (11) project beyond the coil units (3) radially outwardly, - the respective coil unit (13) has a rail support body (21) which is formed from an electrically insulating material and has two support blocks (22) at which the rail support body (21) ends along its axial longitudinal extent, wherein the rail support body (21) is supported radially on a clamping ring (30) via the support blocks (22), - the clamping ring (30) which is clamped in the circumferential direction around the end sections (19) of the coil units (13), whereby the coil units (13) are clamped radially in the direction towards the rotor shaft bearing (2, 9), - a stator outer shell (34) which - is arranged between the support disks (7) and encloses the coil units (13) in a radially covering manner in the circumferential direction, - is fastened in a rotationally fixed manner to the support structure (6) at the fixing ends (26) of the star extensions (11).

2. Stator (1) according to claim 1, characterized in that the support structure (6) has a rotor bearing cylinder (2), and the respective support disk (7) is connected thereto at a respective end face (5) of the rotor bearing cylinder (2), so that the support disks (7) are axially spaced apart from one another over a length (4) of the rotor bearing cylinder (2).

3. Stator (1) according to claim 1 or 2, characterized by a centering cylinder (27) which is arranged coaxially on the annular portion (10) of the support disk (7) and extends axially away from the coil units (13), wherein the coil units (13) are supported via their end sections (19) on an outer peripheral surface (29) of the centering cylinder (27) and are clamped in the radial direction between the centering cylinder (27) and the clamping ring (30).

4. Stator (1) according to claim 3, characterized in that two or more alignment pins (28) are formed on the annular portion (10) of the support disk (7), which each extend axially outwardly from the annular portion (10) and are configured to support the coaxial alignment of the centering cylinder (27) in relation to the support disk (7).

5. Stator (1) according to one of the preceding claims, characterized in that the rail support body (21) is radially fixed between the clamping ring (30) and the stator outer shell (34) in that the support blocks (22) are clamped by means of the stator outer shell (34) in the direction towards the clamping ring (30).

6. Stator (1) according to one of the preceding claims, characterized in that the respective coil unit (13) has an electric coil (16) and the stator (1) has a busbar arrangement (32) which has, on the outer peripheral side between the stator outer shell (34) and the coil units (13), a plurality of busbars (31) axially spaced apart from one another, wherein the respective busbar (31) is in electrical contact with two or more of the electric coils (16).

7. Stator (1) according to claim 6, characterized in that the rail support body (21) has two coil contacting elements (23) electrically insulated from one another, which are each connected in an electrically conductive manner to a respective busbar contacting element (24) of the rail support body (21), wherein coil ends (18) of the coil (16) are each contacted in an electrically conductive manner with one of the coil contacting elements (23) and wherein one of the busbars (31) is connected in an electrically conductive manner to one of the busbar contacting elements (24) and another of the busbars (31) is connected in an electrically conductive manner to another of the busbar contacting elements (24).

8. Stator (1) according to claim 7, characterized in that respective conductor tracks which electrically conductively connect the respective coil contacting element (23) and the associated busbar contacting element (24) are embedded in the electrically insulating material of the rail support body (21).

9. Stator (1) according to one of the preceding claims, characterized in that the stator outer shell (34) has two half shells (35) which abut one another in the circumferential direction by means of two connecting blocks (36) and are connected to one another.

10. Method for producing a stator (1) for an axial flux machine configured according to one or more of the preceding claims, wherein - the support structure (6) is provided with the two support disks (7), - the coil units (13) are arranged between two star extension pairs (25) of the support disks (7) following one another in the circumferential direction, whereby the coil units (13) are fixed in the circumferential direction in relation to the support structure (6), - the coil units (13) are clamped radially in the direction towards the rotor shaft bearing (2, 9) by the clamping ring (30) being clamped in the circumferential direction around the end sections (19) of the coil units (13), - the stator outer shell (34) is fastened in a rotationally fixed manner to the support disks (7) at the fixing ends (26) of the star extensions (11), whereby it is arranged between the support disks (7) and the coil units (13) are enclosed in a radially covering manner by the stator outer shell (34) in the circumferential direction.

11. Axial flux machine with a stator (1) configured according to one or more of claims 1 to 9.