Clamping element, clamping ring, magnet element, each for a rotor of an electric axial flux machine, and such a rotor, axial flux machine and motor vehicle

Abstract

The invention relates to a clamping element (1), a clamping ring (2), a magnet element (3), a rotor (4), an electric axial flux machine and a motor vehicle. The clamping element (1) and the magnet element (3) are designed in such a way that, in the rotor (4), spring element tensioning surfaces (19, 20) of the clamping element (1) and magnet element clamping surface (28, 29) of the magnet element (1) bear directly against one another, wherein spring elements (9, 10) which support the spring element tensioning surfaces (19, 20) are elastically tensioned and, as a result, the magnet elements (3) are each clamped against a rotor axial surface (38) of the rotor (4) along the rotor longitudinal axis (x). When the rotor (4) is rotated, the magnet elements (3) are pushed radially outwards, as a result of which the spring elements (9, 10) relax, with the result that the spring element tensioning surface (19, 20) and the associated magnet element clamping surface (28, 29) continue to be in direct contact with one another, and as a result the magnet elements (3) continue to be clamped against the rotor axial surface (38).

Description

[0001] Clamping element, clamping ring, magnetic element, each for a rotor of an electric axial flux machine, as well as such a rotor, axial flux machine and motor vehicle

[0002] The present invention relates to a clamping element for a rotor of an electric axial flux machine, a clamping ring for a rotor of an electric axial flux machine, and a magnetic element for a rotor of an electric axial flux machine. The invention further relates to a rotor for an electric axial flux machine, an electric axial flux machine comprising such a rotor, and a motor vehicle comprising such an electric axial flux machine.

[0003] A conventional axial flux machine is described, for example, in DE 10 2020 101 639 A1 or in DE 102020 107 162 B3: A rotor of an axial flux machine has a disk with a circular contour. One of the circular or annular surfaces of the disk faces a stator of the axial flux machine. The stator and the rotor are arranged one behind the other along a main axis of the axial flux machine and spaced apart from each other by an air gap. Permanent magnets are attached along a circumferential direction of the rotor to the surface of the disk facing the rotor. During operation of an axial flux machine, a magnetic flux extends parallel to the rotor shaft.

[0004] There is a need to design an axial flux machine to be particularly stable in order to enable applications where the rotor is rotated at very high speeds. Therefore, measures must be taken to secure the permanent magnets radially, as they are accelerated radially outwards during operation of the axial flux machine due to centrifugal force. The maximum speed that can be achieved without problems in the axial flux machine is limited by the stability of the radial securing of the permanent magnets. Although DE 102020 100 528 A1 indicates that a metal cage can be used to secure the permanent magnets to the disk, such a metal cage undesirably increases the mass of the rotor. Furthermore, DE 10 2021 002 940 A1 proposes wrapping the permanent magnets with a bandage.However, such and similar measures lead to a particularly complicated rotor structure and a particularly complex manufacturing process.

[0005] Another conventional approach is to bond the magnets to the laminated core. Problems with this method include long manufacturing times for the rotor (due to the adhesive curing time) and the difficulty of consistently reproducing a high-quality adhesive bond in series production. Furthermore, adhesive bonds are susceptible to high operating temperatures, necessitating significant effort to ensure rotor cooling during operation. Additionally, the performance of an electric machine with such a rotor is limited by the mechanical properties of the adhesive and the bond itself.

[0006] The object of the present invention is to fix the position of magnets of an electric axial flux machine, by means of which particularly high torques can be provided at particularly high rotor shaft speeds, in a particularly efficient manner.

[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, across categories and embodiments 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, optionally in conjunction with one or more of the dependent claims.

[0008] According to the invention, a clamping element for the rotor of an electric axial flux machine is proposed. The clamping element comprises a mounting body by means of which the clamping element can be attached to an axial surface of the rotor. A clamping element underside surface is formed by a mounting body underside surface. Furthermore, the clamping element comprises a spring element that projects laterally from the mounting body and is thinner than the mounting body along a vertical axis of the clamping element. A distal end of the spring element has a spring element clamping surface which, when the spring element is relaxed, is spaced from the clamping element underside surface along the clamping element's vertical axis by a spring element normal distance. The spring element clamping surface is inclined relative to the clamping element underside surface by a clamping element-side centering angle.Preferably, the clamping element is made of a material that exhibits low magnetic permeability combined with high stiffness and strength. For example, the clamping element is made of stainless steel.

[0009] Furthermore, the invention proposes a clamping ring for the rotor of the electric axial flux machine, wherein the clamping ring has a ring body to which two or more of the clamping elements are fixed. In particular, the clamping elements are equidistantly spaced from one another along a circumferential direction of the ring body.

[0010] Furthermore, according to the invention, a magnetic element for the rotor of the electric axial flux machine is proposed. The magnetic element has a bottom surface formed according to a sector of a ring. At its radially inner end, the magnetic element has a clamping surface on a radially inner edge region, which is inclined at a centering angle on the magnetic element side with respect to a top surface that is spaced a distance of one thickness of the magnetic element from its bottom surface.

[0011] Another aspect of the invention is formed by the rotor for the electric axial flux machine, which comprises the magnetic element or a plurality of such magnetic elements and the clamping element or a plurality of such clamping elements. In particular, the rotor can include the clamping ring. A contact point located in the magnetic element clamping surface, at which the spring element clamping surface and the magnetic element clamping surface directly and parallel to each other when the rotor is stationary, and the underside surface of the magnetic element are spaced apart from each other along a longitudinal axis of the rotor by a contact point normal distance. This contact point normal distance is greater than the spring element normal distance. Furthermore, the centering angles are equal – that is, the centering angle on the clamping element side and the centering angle on the magnetic element side are equal. Consequently, the magnetic element clamping surface and the spring element clamping surface are parallel to each other.Furthermore, the magnetic elements rest on the rotor axial surface via their underside surfaces. The clamping elements are tensioned against the rotor axial surface. Thus, the respective spring element clamping surface and the respective magnetic element clamping surface are in direct contact with each other, with the spring elements being elastically tensioned because the normal spacing between the spring elements is smaller than the normal spacing between the contact points. Consequently, the magnetic elements are tensioned or fixed to the rotor axial surface along the rotor's longitudinal axis by means of the spring elements. This means that, because the spring element clamping surfaces rest on the magnetic element clamping surfaces and are thereby tensioned against them, the magnetic elements are secured along the rotor's longitudinal axis between the rotor axial surface and the spring element clamping surfaces.When the rotor is rotated, for example by means of an electromagnetic rotating field provided by a stator of the axial flux machine, i.e. during operation of the axial flux machine, the magnetic elements are driven radially outwards, causing the spring elements to relax, so that the respective spring element clamping surface and the associated magnetic element clamping surface remain in direct contact with each other, and consequently the magnetic elements remain clamped to the rotor axial surface.

[0012] Furthermore, the invention proposes an electric axial flux machine comprising a rotor. The rotor and a rotor shaft of the axial flux machine are rotationally fixed to one another. The axial flux machine can also have two or more rotors. The electric axial flux machine is particularly well-suited as a traction machine for a motor vehicle and, in its intended installation position, forms a component of a motor vehicle, which constitutes a further aspect of the invention. The motor vehicle is therefore designed as a purely electric or hybrid-electric vehicle.

[0013] The design of the clamping element or clamping ring and the magnetic element(s) advantageously allows the magnetic elements to move radially to a certain extent, particularly at very high rotor speeds of the axial flux machine. Despite this radial movement, the magnetic elements remain securely fixed to the rotor's axial surface. Due to the geometries of the clamping elements and the magnetic elements, which correspond to each other and interact during operation to fix the magnetic elements to the rotor's axial surface, the magnetic elements move along a radial line due to centrifugal force, just as they would along a straight track. This enables the construction of high-performance axial flux machines that can be operated reliably at exceptionally high speeds.Furthermore, particular attention is paid to sustainability, as the adhesive between the magnetic elements and the rotor axial surface is not required. The elimination of this adhesive also simplifies the assembly and disassembly of the rotor.

[0014] According to another possible embodiment of the respective clamping element, it is designed as a mirror image with respect to a plane of symmetry in which the clamping element's vertical axis lies. This results in the clamping element having a second spring element that projects laterally from the mounting body. In this way, two magnetic elements directly adjacent to each other along the rotor's circumferential direction can be held or fixed by means of a common clamping element.

[0015] In another possible embodiment of the clamping element, it has a mounting opening that penetrates the mounting body and can be designed as a blind or through opening. The mounting opening can have an internal thread or be unthreaded. Alternatively or additionally, the clamping element has a mounting stud protruding from the mounting body, which can be an externally threaded stud or unthreaded. In this context, the rotor, in particular its rotor carrier disk and / or its rotor lamination stack, can have a bolt or an opening corresponding to the mounting opening, so that a positive-locking connection can be established between the rotor carrier disk and / or the rotor lamination stack and the clamping element, acting at least along the longitudinal axis of the rotor.This makes it particularly easy to clamp the clamping element to the rotor axial surface.

[0016] According to one possible further development of the clamping ring, its ring body and the clamping elements are formed integrally. Alternatively, the ring body and the clamping elements can first be manufactured separately and then joined together by force-fit, form-fit, and / or material-fit, for example by welding. This integral or at least material-fit structure of the clamping ring makes it particularly stable, which ensures that the magnetic elements are held very reliably on the rotor's axial surface.

[0017] To ensure particularly low-resistance spring action of the spring elements, another possible embodiment of the clamping ring provides that the clamping elements are connected to the ring body only via their mounting bodies, whereas the respective spring element and the ring body are not directly connected to each other. This prevents the spring elements from being obstructed either when the magnetic elements are tensioned or when they rebound as the magnetic elements are driven radially outwards due to rotor rotation. For example, the clamping ring has a gap between each spring element and an outer circumferential surface of the ring body.

[0018] According to another possible embodiment of the respective magnetic element, it is designed as a mirror image with respect to a radial plane of symmetry. This gives the respective magnetic element a second clamping surface, which is inclined relative to the upper surface of the magnetic element by the centering angle on the side of the magnetic element. This allows the respective magnetic element to be advantageously secured on both sides, i.e., on the right and left, by means of the clamping elements.

[0019] In a possible further development of the rotor, the magnetic elements and the clamping elements are each designed as mirror images, as explained above. Furthermore, between two magnetic elements that are directly adjacent to each other along one circumferential direction of the rotor, one of the clamping elements is clamped to the rotor axial surface along the rotor's longitudinal axis. This clamps the respective magnetic element to the rotor axial surface by means of two clamping elements arranged successively along the rotor's longitudinal axis and between the same clamping elements along the rotor's circumferential direction. This is because (see Fig. 6, Fig. 7, Fig. 8) a first, for example, left spring element clamping surface and a first, for example, right magnetic element clamping surface of one of the magnetic elements, between which the respective clamping element is arranged, are in contact with each other.In this process, a second, for example right spring element clamping surface of the same clamping element and a second, for example left magnetic element clamping surface of the second of the magnetic elements, between which the clamping element in question is arranged, are in contact with each other.

[0020] In particular, the rotor has a support collar ring on its outer circumference, by means of which the magnetic elements are radially secured. For this purpose, the support collar projects along the rotor's longitudinal axis towards the rotor's axial surface and extends axially beyond it. When the rotor rotates, the magnetic elements press radially outwards with their radially outer circumferential surface and consequently against the support collar ring, which is thereby elastically deformed – within the scope of the axial flux machine's intended operation. As a result, the magnetic elements have only one degree of freedom of movement with respect to the rotor's axial surface, namely radial outwards, deforming the support collar ring. All other degrees of freedom are restricted due to the clamping of the magnetic elements by the clamping elements.

[0021] The clamping elements are clamped to the rotor axial surface along the rotor's longitudinal axis, for example, by means of a clamping unit. The clamping unit includes, in particular, a screw element that corresponds to the mounting opening or the mounting stud of the respective clamping element to create a screw connection between the rotor disk and / or the rotor lamination stack. Specifically, the clamping elements are clamped axially towards the rotor disk, with the rotor lamination stack positioned between the rotor disk and the clamping elements. This secures the rotor lamination stack to the rotor disk by means of the clamping elements clamped to the rotor disk.

[0022] 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 themselves, can be used not only in the combinations specified, but also in other combinations or individually, without departing from the scope of the invention.

[0023] The drawing shows in

[0024] Fig. 1 shows a perspective view of a clamping ring with several clamping elements for a rotor of an electric axial flux machine,

[0025] Fig. 2 shows a perspective view of a magnetic element for the rotor,

[0026] Fig. 3 shows a perspective exploded view of the rotor,

[0027] Fig. 4 shows an axial view of the assembled rotor along its longitudinal axis, Fig. 5 shows a view of the assembled rotor cut along the section plane VV (see Fig. 4),

[0028] Fig. 6 shows a sectioned view of the rotor during assembly, taken along the section plane VI-VI (see Fig. 1 and Fig. 2).

[0029] Fig. 7 shows a view of the assembled rotor cut along the section plane VI-VI, with the magnetic elements clamped to a rotor lamination stack of the rotor by means of the clamping elements, and in

[0030] Fig. 8 shows a view of the assembled rotor, cut along the section plane VI-VI, as it is rotated.

[0031] The following section describes a clamping element 1, a clamping ring 2, and a magnetic element 3, each for a rotor 4 of an electric axial flux machine, as well as the rotor 4, an electric axial flux machine comprising the rotor 4, and a motor vehicle comprising the axial flux machine. The axial flux machine and the motor vehicle are not shown in the figures. In the figures, identical and functionally equivalent elements are designated with the same reference numeral.

[0032] The motor vehicle is designed as a purely electric or hybrid-electric vehicle, in particular as a passenger car. It features an axial flux machine as its traction machine. The motor vehicle can have two or more such axial flux machines or a combination of at least one axial flux machine and at least one radial flux machine as traction machines. The (respective) axial flux machine has a rotor 4 or two or more such rotors 4, wherein the rotor 4 or rotors 4 and a rotor shaft of the axial flux machine are rotationally fixed to one another.

[0033] Fig. 1 shows a perspective view of the clamping ring 2, which has several clamping elements 1. It can be seen that the clamping elements 1 are identical except for their positional orientation relative to a ring body 5 of the clamping ring 2. Therefore, one of the clamping elements 1 will be described, and these descriptions will apply equally to the other clamping elements 1. In the present example, the clamping elements 1 are each made of stainless steel. Each clamping element 1 is a mirror image of the other with respect to a plane of symmetry 6, in which a vertical axis 7 of the clamping element 1 lies. Furthermore, each clamping element 1 has a fastening body 8, a first spring element 9, and a second spring element 10. A clamping element underside surface 12 of the clamping element 1 is formed by a fastening body underside surface 11 of the fastening body 8.The spring elements 9, 10 each project laterally (i.e., along a rotor circumferential direction 13 of the rotor 4) from the mounting body 8 and are each thinner than the mounting body 8 along the clamping element vertical axis 7. As can be seen in Fig. 1, the spring elements 9, 10 are each arranged at an upper edge of the mounting body 8, such that a clamping element upper surface 14 of the respective clamping element 1 is formed by a mounting body upper surface 15 of the mounting body 8 and a respective spring element upper surface 16 of the spring elements 9, 10. Each lateral distal end 17, 18 of the respective spring element 9, 10 has a spring element clamping surface 19, 20 which - when the spring element 9, 10 is relaxed (see Fig. 1, Fig. 3, Fig. 6, Fig. 8) - is spaced from the clamping element underside surface 12 by a spring element normal distance 21 (see Fig. 6).Furthermore, the spring element clamping surfaces 19, 20 are inclined relative to the clamping element underside surface 12 by a clamping element-side centering angle α (see Fig. 6). It can also be seen in Fig. 1 that the respective clamping element 1 has a mounting opening 22 that penetrates the mounting body 8 along the clamping element vertical axis 7.

[0034] The clamping elements 1 of the clamping ring 2 are each fixed to the ring body 5. According to the present example, the clamping elements 1 and the ring body 5 are formed integrally, with the clamping elements 1 being equidistant from one another along a circumferential direction of the ring body 5 that coincides with the circumferential direction 13 of the rotor. The clamping elements 1 extend radially (i.e., along a radius r of the rotor 4) from an outer circumferential surface 23 of the ring body 5 to the radial outside. In this example, the clamping elements 1 are each connected to the ring body 5 only via their mounting bodies 8, whereas the respective spring elements 9, 10 and the ring body 5 are not directly connected to each other. Although the clamping ring 2 with twelve clamping elements 1 is shown here in the example, it should be understood that clamping rings 2 with any other suitable number of clamping elements can, of course, be readily implemented. Fig.Figure 2 shows a perspective view of the respective magnetic element 3, which has a magnetic element underside surface 24 that is formed at least substantially according to a sector of a circular ring. It can be seen in Figure 2 that the respective magnetic element 3 is formed as a mirror image with respect to a radial plane of symmetry 25. At its radially inner magnetic element end 26, the respective magnetic element 3 has two magnetic element clamping surfaces 28, 29 on a radially inner edge region 27, which are inclined by a magnetic element-side centering angle β with respect to a magnetic element upper surface 30, which is spaced apart from the magnetic element underside surface 24 by a thickness 31 of the magnetic element 3.

[0035] Fig. 3 shows an exploded view of the rotor 4, which comprises a rotor disk 32, a rotor lamination stack 33, the clamping elements 1 (here in the form of the clamping ring 2), and the magnetic elements 3. The rotor lamination stack 33 and the rotor disk 32 are in direct contact with each other. Furthermore, the rotor 4 has a screw element 34 for each clamping element 1, the respective external thread 35 of which corresponds to an internal thread 36 (see Fig. 6) of the respective mounting opening 22 to create a threaded connection. The rotor 4, here its rotor disk 32, has a support collar ring 37 on its outer circumference, which projects axially from the rotor disk 32 along a longitudinal axis x of the rotor 4 and thus axially extends beyond the rotor lamination stack 33. For the sake of clarity, not all clamping elements 1, magnetic elements 3, and screw elements 34 shown in Fig. 3 are labeled with the corresponding reference numeral.

[0036] Fig. 4 shows an axial view of the assembled rotor 4 along its longitudinal axis x, showing that one of the clamping elements 1 is arranged between each pair of magnet elements 3, which are directly adjacent to each other along the rotor circumferential direction 13. The spring elements 9, 10 each cover one of the magnet element clamping surfaces 28, 29 along the longitudinal axis x, so that the magnet elements 3 are arranged along the longitudinal axis x between the rotor lamination stack 33 and the clamping elements 1.

[0037] Fig. 5 shows a sectioned view of the rotor 4 in its assembled state, taken along the section plane VV shown in Fig. 4. It can be seen that an axial surface of the rotor lamination stack 33 forms a rotor axial surface 38, on which the magnet elements 3 each rest via their underside surface 24, and that the magnet elements 3 bear radially outwards against the support collar ring 37, which encloses the magnet elements 3 circumferentially. Furthermore, the clamping elements 1 rest on the same rotor axial surface 38, so that the rotor lamination stack 33 is arranged between the clamping elements 1 or magnet elements 3 and the rotor disk 32. The clamping elements 1 are axially clamped to the rotor disk 32 by means of the screw elements 34.

[0038] For this purpose, the screw elements 34 each engage through a corresponding screw element opening 39 in the rotor disk 32 and through a corresponding screw element opening 40 in the rotor lamination stack 33, and further into the mounting opening 22 of the respective clamping element 1. The external thread 35 of the respective screw element 34 and the internal thread 36 of the respective mounting opening 22 provide a threaded connection, so that the rotor lamination stack 33 is clamped between the clamping elements 1, in particular their respective underside surface 12, and the rotor disk 32. Furthermore, the magnetic elements 3 are clamped between the rotor lamination stack 33 or the rotor axial surface 38 and the spring elements 9, 10 by means of the clamping elements 1, as will be explained in more detail below with reference to Figs. 6, 7 and 8.

[0039] Fig. 6 shows a sectioned view of the rotor 4 during assembly, taken along the section plane VI-VI shown in Figs. 1 and 2. It can be seen how the magnetic elements 3 rest on the rotor axial surface 38 via their respective underside surfaces 24. Fig. 6 shows a first, right-hand magnetic element clamping surface 28 of the magnetic element 3 shown on the left in Fig. 6, and a second, left-hand magnetic element clamping surface 29 of the magnetic element 3 shown on the right in Fig. 6. A clamping element 1 is placed between these two magnetic elements 3. Fig. 6 also shows the spring element normal spacing 21 and a contact point normal spacing 41, whereby a contact point 42 of the respective magnetic element 3, located in the respective magnetic element clamping surface 28, 29, is spaced from its underside surface 24 along the rotor longitudinal axis x by the contact point normal spacing 41.The contact point normal distance 41 is greater than the spring element normal distance 21. Since the centering angles a, β are equal, the respective spring element clamping surfaces 19, 20 and the corresponding magnetic element clamping surfaces 28, 29 touch each other directly and parallel to each other at the respective contact point 42, as shown in Fig. 7. Fig. 7 shows a sectioned view of the assembled rotor 4 along section plane VI-VI, with the magnetic elements 3 clamped to the rotor lamination stack 33 by means of the screw elements 34. Since the spring element normal distance 21 is smaller than the contact point normal distance 41, the spring elements 9, 10 are clamped to the magnetic element clamping surfaces 28, 29 during assembly of the rotor 4 by screwing the screw elements 34 through the rotor disk 32 and through the rotor lamination stack 33 to the clamping elements 1 as intended.This causes the spring elements 9, 10 to be bent about a radius parallel to the radius (shown by arrows 43), so that in this state, as shown in Fig. 7, a clamping force is exerted on the magnetic element clamping surfaces 28, 29 by means of the tensioned spring elements 9, 10. By means of this clamping force, the magnetic elements 3 are axially clamped – that is, along the rotor longitudinal axis x – between the clamping elements 1 and the rotor axial surface 38. In addition, the magnetic elements 3 are clamped by means of this clamping force along the rotor circumferential direction 13 between two clamping elements 1 that are adjacent to each other along the rotor circumferential direction 13.

[0040] Fig. 8 shows a sectioned view of the assembled rotor 4 along the section plane VI-VI, with the rotor rotating in operation of the axial flux machine, i.e., driven, for example, by an electromagnetic rotating field generated by a stator (not shown) of the axial flux machine. Due to the rotation of the rotor 4 about its longitudinal axis x, the magnetic elements 3 are accelerated radially outwards, causing them to move radially outwards and thereby elastically deform the support collar ring 37. The magnetic element clamping surfaces 28, 29 are moved radially outwards accordingly, causing the elastically tensioned spring elements 9, 10 to yield or relax (see arrows 44), with the spring element clamping surfaces 19, 20 always remaining in contact with the magnetic element clamping surfaces 28, 29 and sliding on the magnetic element clamping surfaces 28, 29.This ensures that the magnetic elements 3 are securely held against the rotor axial surface 38 during their radial outward movement and are also guided radially between the clamping elements 1. The magnetic elements 3 are specifically granted a single degree of freedom for movement, namely translationally in a radial outward direction, while the other degrees of freedom are restricted by clamping the magnetic elements 3 between the clamping elements 1 or between the clamping elements 1 and the rotor axial surface 38. The clamping element 1, the clamping ring 2, the magnetic element 3, the rotor 4, the electric axial flux machine, and the motor vehicle each provide various means of efficiently fixing the position of the magnets of an electric axial flux machine, which can generate particularly high torques at especially high rotor shaft speeds.

[0041] Reference symbol list

[0042] 1 clamping element

[0043] 2 clamping rings

[0044] 3 magnetic element

[0045] 4 Rotor

[0046] 5 ring bodies

[0047] 6. Plane of symmetry

[0048] 7 Clamping element vertical axis

[0049] 8 Fasteners

[0050] 9 spring element

[0051] 10 spring element

[0052] 11 Mounting body underside surface

[0053] 12 Clamping element underside surface

[0054] 13 Rotor circumferential direction

[0055] 14 Clamping element top surface

[0056] 15 Mounting body top surface

[0057] 16 Spring element upper surface

[0058] 17 spring element ends

[0059] 18 spring element ends

[0060] 19 spring element clamping surface

[0061] 20 spring element clamping surface

[0062] 21 Spring element normal distance

[0063] 22 Mounting opening

[0064] 23 External perimeter area

[0065] 24 Magnetic element underside surface

[0066] 25 Plane of symmetry

[0067] 26 magnetic element ends

[0068] 27 edge area

[0069] 28 Magnetic element clamping surface

[0070] 29 Magnetic element clamping surface

[0071] 30 Magnetic element top surface

[0072] 31 Thickness 32 Rotor disc

[0073] 33 Rotor lamination package

[0074] 34 screw element

[0075] 35 external threads

[0076] 36 internal threads

[0077] 37 Support collar ring

[0078] 38 Rotor axial area

[0079] 39 Screw element opening

[0080] 40 screw element opening

[0081] 41 Contact point normal distance

[0082] 42 Contact point

[0083] 43 Arrow

[0084] 44 Arrow a Centering angle ß Centering angle x Rotor longitudinal axis r Radius

Claims

Patent claims 1. Clamping element (1) for a rotor (4) of an electric axial flux machine, comprising: - a fastening body (8) by means of which the clamping element (1) can be fastened to a rotor axial surface (38) of the rotor (4), wherein a clamping element underside surface (12) of the clamping element (1) is formed by a fastening body underside surface (15) of the fastening body (8), - a spring element (9) which projects laterally from the fastening body (8) and is thinner than the fastening body (8) along a clamping element vertical axis (7), wherein a distal spring element end (17) of the spring element (9) has a spring element clamping surface (19) which, when the spring element (9) is relaxed, is spaced apart along the clamping element vertical axis (7) by a spring element normal distance (21) from the clamping element underside surface (12), wherein the spring element clamping surface (19) is inclined relative to the clamping element underside surface (12) by a clamping element-side centering angle (a).

2. Clamping element (1) according to claim 1, characterized in that it is designed as a mirror image with respect to a plane of symmetry (6) in which the vertical axis (7) of the clamping element lies, and therefore has a second spring element (10) that projects laterally from the fastening body (8).

3. Clamping element (1) according to claim 1 or 2, characterized by a fastening opening (22) penetrating into the fastening body (8) which is unthreaded or has an internal thread (36), and / or a fastening stud which is unthreaded or has an external thread and projects along the vertical axis (7) of the clamping element from the fastening body (8).

4. Clamping ring (2) for a rotor (4) of an electric axial flux machine, wherein the clamping ring (2) has a ring body (5) on which two or more clamping elements (1) designed according to one of the preceding claims are fixed.

5. Clamping ring (2) according to claim 4, characterized in that the ring body (5) and the clamping elements (1) are formed integrally together.

6. Clamping ring (2) according to claim 4 or 5, characterized in that the clamping elements (1) are each connected to the ring body (5) only via their fastening bodies (8), whereas the spring element (9) and the ring body (5) are not directly connected to each other.

7. Magnetic element (3) for a rotor (4) of an electric axial flux machine, wherein the magnetic element (3) has a magnetic element underside surface (24) formed according to a circular ring sector and has a magnetic element clamping surface (28) at its radially inner magnetic element end (26) in a radially inner edge region (27) which is inclined by a magnetic element-side centering angle (β) with respect to a magnetic element upper surface (30) which is spaced apart by a thickness (31) of the magnetic element (3) from its magnetic element underside surface (24).

8. Magnetic element (3) according to claim 7, characterized in that it is designed as a mirror image with respect to a radial plane of symmetry (25) and therefore has a second magnetic element clamping surface (29) which is inclined with respect to the upper surface of the magnetic element (30) by the centering angle (β) on the side of the magnetic element.

9. Rotor (4) for an electric axial flux machine, comprising magnetic elements (3) designed according to claim 7 or 8 and clamping elements (1) designed according to one of claims 1 to 3 and / or the clamping ring (2) designed according to one of claims 4 to 6, wherein - a contact point (42) located in the magnetic element clamping surface (28), at which the spring element clamping surface (19) and the magnetic element clamping surface (28) directly touch each other when the rotor (4) is stationary, and the underside surface (24) of the magnetic element are spaced apart along a longitudinal axis (x) of the rotor (4) by a contact point normal distance (41) which is greater than the spring element normal distance (21), - the centering angles (a, ß) are equal, - the magnetic elements (3) each rest on the rotor axial surface (38) via their magnetic element underside surface (24), - the respective spring element clamping surface (19, 20) and the respective magnet element clamping surface (28, 29) are in direct contact with each other, the spring elements (9, 10) being elastically tensioned and consequently the magnet elements (3) being tensioned along the rotor longitudinal axis (x) to the rotor axial surface (38) and so that when the rotor (4) is rotated, the magnet elements (3) are driven radially outwards, causing the spring elements (9, 10) to relax, so that the respective spring element clamping surface (19, 20) and the associated magnet element clamping surface (28, 29) remain in direct contact with each other, and consequently the magnet elements (3) remain tensioned to the rotor axial surface (38).

10. Rotor (4) according to claim 9, characterized in that - the magnetic elements (3) having the features specified in claim 8, and the clamping elements (1) having the features specified in claim 2, - between two magnetic elements (3) that are directly adjacent to each other along a rotor circumferential direction (13) of the rotor (4), one of the clamping elements (1) is clamped along the rotor longitudinal axis (x) to the rotor axial surface (38), so that the respective magnetic element (3) is clamped to the rotor axial surface (38) by means of two clamping elements (1) arranged successively in the rotor circumferential direction (13) along the rotor longitudinal axis (x) and is clamped along the rotor circumferential direction (13) between the same clamping elements (1).

11. Axial flux machine with a rotor (4) designed according to one of claims 9 or 10.

12. Motor vehicle with the axial flux machine designed according to claim 11.

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