The star-shaped disc is provided with a plastic-coated injection molding part; a motor; manufacturing process of star-shaped disc

Abstract

The invention relates to a star-shaped disc (1) for an electric machine rotor, having arms (2) provided for winding by winding conductors, having a switching ring (3) from which several contacts (4) project, the switching ring (3) being held in a recess (5) of the star-shaped disc (1) in a rotationally fixed manner, the star-shaped disc (1) having a plastic overmolded part (6) on the outside, the plastic-coated injection molded part (6) fixes the switch ring (3) on the star-shaped disc (1) in an axial direction (7) in a form-fitting manner. The invention also relates to an electric machine and to a method for producing a star-shaped disc (1).

Description

Technical Field

[0001] The invention relates to a star disk for a rotor of an electric machine, the star disk having (pole) arms which are provided for winding a winding conductor or for winding a conductor forming a winding, the star disk having a switching ring from which a number of contacts (i.e. contacts for contacting the winding conductors) project axially, the switching ring being held in a rotationally fixed manner (e.g. by positive engagement and / or material bonding) in a (centered) recess or recess or centering diameter of the star disk. Background Art

[0002] According to the prior art of the present applicant, namely DE 2022 110 466 A1, a star disk and a method for producing a star disk are known, wherein the star disk is produced by a forging process. This publication discloses a method for producing a disk-shaped solid injection-molded component, in particular for producing a star disk for an electric motor, wherein, in the finished state, the solid injection-molded component extends along a main extension plane and has at least one rib portion extending substantially radially relative to an axis extending perpendicularly to the main extension plane. The production method comprises forging a starting body, wherein the starting body has a main region and a secondary region, the main region comprising at least one radially extending rib portion of the finished solid injection-molded component, and removing the secondary region, for example by machining and, additionally or alternatively, by a stamping process, to at least partially expose the at least one rib portion, in particular a central region of the at least one rib portion.

[0003] DE 2021 122 066A1 discloses a star disk for the rotor of a separately excited synchronous motor, wherein at least the surface of the star disk is made of plastic, current rails for connecting the rotor winding are embedded in the star disk by injection molding, and contact elements for receiving winding wires are respectively provided at both ends of the star disk, said contact elements protruding from the surface of the star disk.

[0004] DE 2013 004 659 A1 discloses a switching ring for an electric motor and an electric motor having such a switching ring. The switching ring has at least one electrically conductive switching ring element with a plurality of contact points for electrical connection to subwindings of the stator or rotor of the electric motor and optionally at least one connection point for electrical connection to the outside. The switching ring has an insulating layer comprising a polymer and produced by an electrodeposition process. Summary of the Invention

[0005] The technical problem underlying the present invention is to provide a star disk which improves the positioning of the contacts, facilitates achieving a high insulation quality, is uncomplicated to manufacture, and offers a particularly high stability.

[0006] In the present spider, this problem is solved by having a (two-part) plastic overmold on the outside of the spider, which secures, holds, or fixes the switching ring in the axial direction to the spider in a form-fitting manner. This eliminates the need for a separate or additional fastening of the switching ring to the spider, as the switching ring is held by the plastic overmold (the plastic overmold itself, i.e., by the plastic overmold). This also offers numerous manufacturing advantages, as separate fastening devices and assembly processes can be dispensed with.

[0007] The switching ring can be manufactured by injection molding and have one or more bridges embedded in the plastic. The bridges can have one or more contacts. Preferably, the bridges are embedded in the plastic forming the switching ring. To this end, the bridges can be designed with (integral) contacts, with the bridges being largely or over a large area covered by the plastic, leaving only the contacts free of plastic. This allows the switching ring to be electrically insulated, with the exception of the contacts, so that the switching ring's functionality is not affected. Particularly preferably, the contacts are winding contacts or slip ring contacts. These contacts can be "crimp" or solder contacts.

[0008] A bridge is understood to be a component that serves as a current rail. This current rail is usually made of a material with good electrical conductivity, such as aluminum or copper.

[0009] For example, it is advantageous for the star disk to have a star disk base body that forms, has, or geometrically defines arms extending in a star shape. Preferably, the arms of the star disk base body may have head portions at their free ends that extend in a circumferential direction toward both sides. Preferably, the arms and head portions may have an anchor-shaped cross-section. Due to the high rotational speeds encountered during operation of the star disk, forces, particularly centrifugal forces, act on the star disk. Therefore, it is advantageous to use steel as the material or substance for the star disk, as a star disk base body made of steel, particularly a forged one, can effectively compensate for the forces occurring during operation.

[0010] The plastic overmolding preferably includes a portion that overlaps the star disk, such as a cover, ring, ring segment, or plate. Preferably, the switching ring overlaps radially outward (i.e., on the outside in the axial direction) and, in addition or as an alternative, in the radial direction. In the case of a cover, the plastic overmolding can rest in the form of a wall on the circumference of the switching ring in the axial direction and overlap the surface of the switching ring in the axial direction. This provides for the configuration of the switching ring within the plastic overmolding, as well as for a supplementary or alternative embedding thereof within the plastic overmolding, which covers the switching ring in the axial direction and in the circumferential direction at the end face of the star disk. In the case of a ring, the switching ring can rest in the form of a wall on the circumference of the switching ring in the axial direction. This allows for the configuration of the switching ring within the plastic overmolding, as well as for a supplementary or alternative embedding thereof within the plastic overmolding, which covers the switching ring on the outside in the circumferential direction.

[0011] Furthermore, the switching ring can have a geometry that includes depressions and ridges extending in the axial direction on one side and projections or projections and depressions or indentations extending in the radial direction on the other side, so that a predetermined portion of the switching ring is completely, predominantly, partially, or partially covered by a portion of the plastic overmold. In the case of the switching ring, the depressions and ridges have the advantage of eliminating substances or materials not required for the switching ring, thereby saving weight. The ridges facilitate the placement of the switching ring in the overmold mold. The ridges preferably form a centering geometry that facilitates relative placement. The ridges also have the advantage of simplifying the alignment of the switching ring on the star disk. Thus, the projections can be offset 180° in the circumferential direction. The depressions can be arcuate or semicircular, preferably extending from the radially outer side to the radially inner side. The projections can have an underside that rests axially on the surface of the star disk base. Preferably, a bulge is formed on at least a portion of the projection, which bulge is covered in the axial direction by the plastic overmolding. This makes the switching ring particularly stable and enables the switching ring to be held particularly stably.

[0012] Furthermore, a positive connection to the plastic overmolding and a supplementary or alternative material connection can be present on the outer side of the switching ring. The switching ring is held on the spider by the positive connection and the supplementary or alternative material connection. Different contours or shapes can be used for the positive connection, which can be achieved, for example, by the aforementioned recess and, supplementary or alternatively, by other shapes extending from the recess.

[0013] The switching ring is advantageously radially centered on the outside, preferably on the front outside or end side, within a receptacle of the spider base body. The receptacle is preferably formed in the form of a stepped shoulder or step in the axial direction or in the form of a groove. In addition to centering, this facilitates positioning the switching ring on the spider. The design of the receptacle also facilitates covering the switching ring with the plastic overmold, as the receptacle creates a space in which the plastic overmold can accumulate and thus adhere to the switching ring.

[0014] In addition, the switch ring can have one puncture channel or preferably three puncture channels distributed around the circumference. Preferably, the puncture channels are evenly spaced apart from each other in the circumferential direction. The puncture channels can be arranged at the position of the preferably arc-shaped recess in the circumferential direction. Each puncture channel can extend at least partially in the radial direction, preferably from the radially outer side to the radially inner side within the switch ring. A portion of the plastic overmolding can be arranged in the puncture channel to thereby hold the switch ring on the star disk. The puncture channel is configured to reliably position the bridge piece during the manufacture of the switch ring (by plastic overmolding). In addition, the puncture channel is preferably filled or completely filled or completely enclosed during the formation of the plastic overmolding so that the switch ring is held or fixed on the star disk by the plastic overmolding. In other words, in addition to being used to encapsulate or ensure the durability of the plastic overmolding, the puncture channel also serves to reliably position the bridge piece during the overmolding process of manufacturing the switch ring.

[0015] Furthermore, it is advantageous if the star disk base is configured with holes for receiving the anti-rotation projections on the switching ring. In other words, this provides a foolproof solution for securing the switching ring in position before overmolding and installation in the steel star disk. Preferably, the anti-rotation projections project axially in a direction different from that of the contacts. Thus, the switching ring can have contacts on the front side (i.e., the side facing away from the star disk base) and anti-rotation projections on the rear side (i.e., the side facing the star disk base). The anti-rotation projections can have a star-shaped contour or a circular, rectangular, or polygonal cross-section. Pin-like designs are also conceivable.

[0016] The switching ring can preferably have one or more anti-rotation projections. The or each anti-rotation projection enables the switching ring to be positioned on the spider base body without causing undesired movement of the switching ring in the circumferential direction. Thus, when the spider is manufactured using plastic overmolding, the switching ring can be held in the correct position for the manufacturing process.

[0017] It is expedient to position the laminations (preferably a lamination package formed from a plurality of individual laminations stacked in the longitudinal direction) in the axial direction between two spaced-apart star disks. Preferably, the two spaced-apart star disks are designed differently. Thus, according to the aforementioned embodiment, the first star disk is designed with a switching ring, while the second star disk is designed with a contactless plastic ring. Together with the lamination package arranged between the star disks, the two star disks can form a rotor. In this configuration, the winding wire is preferably wound around the two star disks, running in the longitudinal direction.

[0018] The present invention also relates to an electric machine having a rotor with a star disk as described above and a stator that interacts with the rotor during operation. This electric machine can be operated as a motor or a generator. In principle, the star disk design can also be transferred to the stator design.

[0019] The present invention also relates to a method for manufacturing a star disk, preferably a method for manufacturing a star disk as described above, wherein in a first step, a star disk base body is produced for the star disk. A switching ring with axially projecting contacts (but with its contact-free end face) is then placed onto the star disk base body (directly or indirectly, i.e., via one or more interposed components). To reduce or eliminate the risk of breakdown or short circuits, a distance and a minimum insulation thickness are maintained between the steel star disk and the conductive contacts. A plastic overmold is then applied to the surface of the star disk base body and at least a portion of the switching ring (directly or indirectly, i.e., via one or more interposed components), securing the switching ring axially to the star disk base body. This process simplifies the manufacture of the star disk, as a separate manufacturing step in which the switching ring is attached to the star disk can be omitted.

[0020] The switching ring can be produced in a previous step by injection molding using one or more bridges as inserts. Alternatively, one or more bridges can be overmolded with plastic, thus forming the switching ring. The contacts are preferably made of copper and provided with silver solder or embossed so that electrical contact with the connection components can be effectively established.

[0021] The position and / or orientation of the star disk base body and the switching ring are determined by the (overmolding) tool.

[0022] The spider base may be preheated.

[0023] It is expedient to firstly injection-mould the star disk base body and then (cut) machine the star disk base body, or to mill or turn the star disk base body from solid material.

[0024] Advantageously, the switching ring is filled in the subregion with the puncture channel. The puncture channel filling preferably takes place radially inward. The puncture channel filling allows the switching ring to be fixed to the star disk base body. This ensures rotation in the circumferential direction and axial retention.

[0025] In other words, the present invention relates to a star disk made of steel, which is machined from an injection molded part, machined from solid material, or cast. The star disk comprises a two-part plastic overmolded part with a switching ring or a switching ring with copper contacts or contacts, and a connected or separate overmolded part. The copper contacts can be formed with embossed silver solder, wherein these copper contacts are overmolded as separate components with plastic (preferably separately from the star disk) to form the switching ring. For production, the copper contacts are positioned in an overmolding tool. The finished overmolded switching ring has a flat support surface, an outer diameter, and pins or anti-rotation projections for aligning and securing the switching ring in the star disk (for the overmolding process). In the final overmolding process, the switching ring is positioned on the star disk and connected to the star disk in a form-fitting manner with plastic.

[0026] In other words, the present invention relates to a method in which the bridge can be pre-overmolded and / or pre-assembled together with the switch ring in a precisely positioned manner. The bridge and the switch ring can form a "switch ring" assembly. This assembly can have at least one defined centering geometry that is incorporated into the overmolding tool for the star disk to achieve reproducible positional accuracy. The star disk base body can be preheated and centered in the overmolding tool. By appropriately centering the star disk base body and the switch ring in the overmolding tool, the relative position of the star disk base body and the switch ring can also be precisely established.

[0027] The switching ring can also be called a contact switching ring. The bridge can also be called a contact bridge. The star disc base can also be called a steel insert or a star disc. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Different advantageous embodiments of the present invention are explained in more detail below with reference to the accompanying drawings. In the drawings:

[0029] Figure 1 is an exploded perspective view of a star disk according to the present invention,

[0030] Figure 2 is a longitudinal cross-sectional view of a star disk according to the present invention in a manufactured state,

[0031] Figure 3 is a front perspective view of the star disk with plastic overmolding.

[0032] Figure 4is a front perspective view of the star disc without the plastic overmolding,

[0033] Figure 5 is a rear perspective view of the star disc without the plastic overmolding,

[0034] Figure 6 is a front perspective view of the switch ring,

[0035] Figure 7 is a rear perspective view of the switch ring, and

[0036] FIG. 8 is a perspective view of various bridge members.

[0037] The accompanying drawings are merely schematic and serve only to facilitate understanding of the present invention. Identical elements bear identical reference numerals. Features of individual embodiments may be used interchangeably and alternatively or cumulatively. DETAILED DESCRIPTION

[0038] Figure 1 The star disk 1 according to the invention is shown for a rotor of an electric motor (not shown in detail), wherein the star disk 1 has several arms 2, which are provided for winding wires, and a switching ring 3, from which several contacts 4 (i.e., contacts for contacting the winding wires) project axially, wherein the switching ring 3 is held in a rotationally fixed manner in a recess or centering recess or centering diameter of the star disk 1. It should be emphasized that the star disk 1 has a plastic overmolding 6 on the outside, which secures, holds, or fixes the switching ring 3 in an axial direction 7 on the star disk 1 in a form-fitting manner.

[0039] Figure 1 The schematic diagram shows an exploded perspective view of a star disk according to the invention.

[0040] For greater clarity, radial directions 8 and circumferential directions 9 are defined in addition to the axial direction 7. The axial direction 7 extends in the direction of a center axis 10 of the star disk 1. The radial direction 8 is oriented perpendicular to the axial direction 7. The circumferential direction 9 describes the direction of rotation of the rotor in which the star disk 1 is arranged.

[0041] On one side, the star disk 1 has a star disk base body 11, which in turn has an annular body 12 with several pole arms 2 distributed in the circumferential direction 9 and arranged uniformly relative to one another and projecting outward in the radial direction 8. In the present figure, a total of six pole arms 2 are shown, one pole arm 2 every 60° in the circumferential direction 9.

[0042] Each pole arm 2 has a head portion 13 formed in a plate-like manner on the pole arm 2 so as to extend in the radial direction 8. The cross section of the head portion 13 and the pole arm 2 is designed to be anchor-shaped. The annular body 12 has a recess 5 on the axial front side, which is in the form of an annular step or notch extending in the axial direction 7. The switching ring 3 is positioned in this annular step or notch.

[0043] The switching ring 3 arranged on the front side of the star disk base 11 has a base body 15 made of plastic, which is provided by a plastic overmolding, and from which the contacts 4 protrude on the front side in the axial direction 7. The contacts 4 are formed on the bridge 47, wherein Figure 8a 、 Figure 8b and Figure 8c Three embodiments are shown in perspective views.

[0044] A total of six contacts 4 are arranged on the front side of the switching ring 3 along the circumferential direction 9 , spaced evenly apart from one another. The contacts 4 can be designed as blocks. The contacts 4 are shown schematically only, and other configurations are conceivable. The contacts 4 are made of a material other than plastic.

[0045] The plastic overmolded part 6 is arranged in the axial direction 7 on the front side of the switching ring 3. The plastic overmolded part 6 has a design similar to that of the star disk base 11. The plastic overmolded part 6 comprises an annular main body 17 with pole arms 18 distributed and arranged evenly relative to one another in the circumferential direction 9 and extending outward in the radial direction 8. In this illustration, a total of six pole arms 18 are shown, with one pole arm 18 arranged every 60° in the circumferential direction. Each pole arm 18 has a head portion 19, which is formed in a plate-like manner on the pole arm 18 in the radial direction 8. The head portion 19 and the pole arm 18 have an anchor-shaped cross-section. Of course, the number of pole arms 2 is the same as the number of pole arms 18.

[0046] The plastic overmolding 3 is prepared so that its rear side at least partially rests on the front surface 20 of the switching ring 3 (see Figure 4 ) and on the surface 21 of the front side of the star disk base 11.

[0047] exist Figure 2 The diagram shows the Figure 1 A cross-sectional view of the star disk 1 of the present invention in the assembled state. Here, the switching ring 3 is located within the recess 5. The switching ring 3 has an annular counter-step 22 on the axial rear side that matches the step forming the recess 5. This counter-step 22 is formed radially further outward on the switching ring 3 and extends through the circumferential outer side 23 of the switching ring 3. The counter-step 22 is designed in the form of an inclined surface or step. Consequently, the switching ring 3 has two flat surfaces 24 and 25.

[0048] The first plane 24 of the switching ring 3 is the part of the switching ring 3 located in the recess 5 . The second plane 25 of the switching ring 3 describes how the switching ring 3 rests on the front surface 21 of the star disk base 11 .

[0049] The plastic overmolding 6 rests on the switching ring 3 and the star disk base 11. The plastic overmolding 6 is designed to rest on the free outer side 23 of the switching ring 3, which is not covered by the inner side 26 of the recess 5 of the star disk base 11. The annular body 17 of the plastic overmolding 6 rests with its inner side, inner wall, or inner circumference 27 at least partially radially inwardly on the free outer wall, outer circumference, or outer side 23 of the switching ring 3 and holds the switching ring 3 on the star disk base 11 in a form-fitting manner. The plastic overmolding 6 protrudes beyond the switching ring 3 in the axial direction 7.

[0050] exist Figure 3 , the detailed construction of the star disk 1 with the arrangement of the switching ring 3 and the plastic overmolding 6 is illustrated.

[0051] On the front side, the switching ring 3 has depressions 28 and elevations 29, 30, 31, which extend partially in the circumferential direction 9 and are formed in the axial direction 7. These depressions 28 and elevations 29, 30, 31 are formed on the second plane 25 of the switching ring 3. The depressions 28 and elevations 29, 30, 31 are arranged alternately adjacent to one another in the circumferential direction 9.

[0052] In this configuration, a total of three depressions 28 and three elevations 29, 30, 31 are formed. The contacts 4 are arranged in portions of the elevations 29, 30, 31.

[0053] Steps 32 are formed in the circumferential direction 9 between the elevations 29, 30, 31 and the depression 28, which form the transition from the elevations 29, 30, 31 to the depression 28 or vice versa. Steps 32 that are directly adjacent to one another in the circumferential direction 9 each form a centering geometry for the switching ring 3 in the overmolding tool, which facilitates the production of the plastic overmolded part 6.

[0054] A piercing channel 33 is formed within the projections 29, 30, and 31, extending radially from the outside to the inside. The piercing channel 33 extends linearly in the radial direction 8 and has a rectangular cross-section. The piercing channel 33 penetrates only the outside 23 and does not penetrate the inside or inner wall 34 of the switch ring 3. In addition to enhancing the plastic overmolding and ensuring durability, the piercing channel also serves to securely position the bridge during the overmolding process of the switch ring. The inside 34 of the switch ring 3 has three to six recesses for reliable process control during the overmolding process of the switch ring 3.

[0055] On the outer side 23 , at the locations of the ridges 29 , 30 , 31 , a first arcuate or semicircular recess or depression 35 extending radially inwards is formed with a radius and oriented symmetrically to the puncture channel 33 in the circumferential direction 9 . The depression 35 penetrates the outer side 23 of the switching ring 3 .

[0056] A second arc-shaped or semicircular recess or depression 36 extending radially inwards is also formed with a radius in the recess 28. The second recess 36 penetrates the outer side 23 of the switching ring 3.

[0057] The switching ring 3 has two first projections 38 extending in the radial direction 8. The first projections 38 are oriented 180° apart from one another in the circumferential direction 9. The first projections 38 are formed partially on the elevations 29 and 30 in the radial direction 8 and partially on the depression 28. The contacts 4 are positioned on the portions of the projections 38 on the elevations 29 and 30, respectively.

[0058] The plastic overmold 6 is designed to coincide with the cover 39 in the axial direction 7 . The second flat surface 25 of the switch ring 3 is embedded circumferentially by the plastic overmold 6 . The aforementioned piercing channel 33 is filled with the plastic overmold 6 . The recesses 35 , 36 are contoured, meaning they are not completely filled in the radial direction 8 . A circular hole or free space 40 is formed within the plastic overmold 6 . This means there is an area without the plastic overmold 6 . Due to the circular shape and arrangement of the free space 40 , the contour of the recesses 35 , 36 is formed by the contour of the free space 40 in the plastic overmold 6 . The plastic overmold 6 is designed so that its front side faces the depression 28 and the elevations 29 , 30 , 31 , respectively, with a flat surface.

[0059] The pole arms 2 and the head part 13 of the star disk base body 11 are covered on the surface side by the plastic overmolding 6 .

[0060] exist Figure 4 shows a star disk 1 according to the present invention with a switch ring 3 without the plastic overmold 6. This illustration shows the additional recesses 41 and 42 previously covered by the plastic overmold 6. In addition to the previously described first protrusion 38 and the first and second recesses 35 and 36, the switch ring 3 also has further recesses 41 and 42 and a protrusion 43. On the radially outer side of the switch ring 3, within the areas of the ridges 29 and 31, a subsection with a third recess 41 is formed. This third recess 41 extends partially in the circumferential direction 9. Simultaneously, within these subsections, a second protrusion 43 is formed, which extends partially in the circumferential direction 9. A fourth recess 42 is formed on the first protrusion 38 in the circumferential direction 9, adjacent to the puncture channel 33.

[0061] For a detailed view of the switching ring 3 according to the same viewing angle, see Figure 6 .

[0062] exist Figure 5 The diagram shows the star disk base 11 according to Figure 4 Rear view of the star disk 1. The star disk base 11 has a flat rear side. The star disk base 11 has a single axial through-hole 44 in the annular body 12, into which an anti-rotation projection 45 is partially recessed in the axial direction 7. The anti-rotation projection 45 is formed on the back side of the switching ring 3. The profile of the anti-rotation projection 45 is star-shaped.

[0063] exist Figure 7 The rear view of the switch ring 3 is shown in FIG. Figure 7 The switching ring 3 is shown in a rear perspective view. The complete structure of the two planes 24, 25 of the switching ring 3 can be seen here. The aforementioned projections 38, 43 are formed on the second plane 25 and extend partially in the radial direction 8 along the circumferential direction 9. Figure 7 As can be seen in FIG, the extension of the first projection 38 in the radial direction 8 is greater than the extension of the second projection 43. The first projection 38 and the second projection 43 have a bottom side 46 which is arranged to rest on the surface 21 of the star disk base 11, that is, on the surface of the annular body 12. Figure 7 The anti-rotation protrusion 45 described above is also shown in FIG. The first flat surface 24 of the switch ring 3 is annular and is designed to be constant in the circumferential direction 9 .

[0064] Reference Signs List

[0065] 1 star-shaped disk

[0066] 2 pole arms

[0067] 3 Switching ring

[0068] 4 contacts

[0069] 5 recess

[0070] 6 Plastic overmolded parts

[0071] 7 Axial direction

[0072] 8 Radial direction

[0073] 9 Circumferential direction

[0074] 10 Central axis

[0075] 11 Star disk base

[0076] 12 Annular body of the star disk base

[0077] 13 Head

[0078] 15 Switch ring base

[0079] 17 Base of plastic overmolded parts

[0080] 18 Pole arm of plastic overmolded part

[0081] 19Head part of plastic overmolded part

[0082] 20 Surface of the switch ring

[0083] 21 Surface of the star disk substrate

[0084] 22 relative steps

[0085] 23 Outside of the switch ring

[0086] 24 First plane of the switch ring

[0087] 25 Second plane of the switch ring

[0088] 26. The inner side of the concave portion of the star-shaped disk base

[0089] 27 Inside of plastic overmolded parts

[0090] 28 First Depression

[0091] 29 First Bump

[0092] 30 Second Bump

[0093] 31 Third Bulge

[0094] 32 steps

[0095] 33 puncture channel

[0096] 34 inside

[0097] 35 First recess

[0098] 36 Second recessed portion

[0099] 38 first protrusion

[0100] 39 Cover

[0101] 40 Free Space

[0102] 41 Third recessed portion

[0103] 42 Fourth recessed part

[0104] 43 Second protrusion

[0105] 44 through holes

[0106] 45 Anti-rotation protrusion

[0107] 46 lower side

[0108] 47 bridge piece

Claims

1. A star disk (1) for a motor rotor, wherein: The star disk (1) has a plurality of arms (2) which are provided for winding a winding wire, the star disk having a switching ring (3) from which a plurality of contacts (4) project, wherein the switching ring (3) is held in a rotationally fixed manner in a recess (5) of the star disk (1), wherein the star disk (1) has a plastic overmolding (6) on the outside, which fixes the switching ring (3) on the star disk (1) in an axial direction (7) in a form-fitting manner.

2. The star disk (1) according to claim 1, characterized in that The switching ring (3) is produced by injection molding and has one or more bridges (47) embedded in the plastic.

3. The star disk (1) according to claim 1, characterized in that The star disk (1) has a star disk base (11) which forms a number of arms (2) extending in a star shape.

4. A star disk (1) according to any one of claims 1 to 3, characterized in that The plastic overmolding (6) has a portion that overlaps the switching ring (3) as a cover (39), a ring or a tab.

5. The star disk (1) according to any one of claims 1 to 3, characterized in that The switching ring (3) has a geometry which, on one side, comprises depressions (28) and elevations (29, 30, 31) extending in the axial direction (7) and, on the other side, comprises projections (38, 43) and depressions (35, 36, 41, 42) extending in the radial direction (8), so that a predetermined portion of the switching ring (3) is completely or partially covered by a portion of the plastic overmolding (6).

6. A star disk (1) according to any one of claims 1 to 3, characterized in that On the outer side (23) of the switching ring (3) there is a positive connection and a supplementary or alternative material connection to the plastic overmolding (6).

7. A star disk (1) according to any one of claims 1 to 3, characterized in that The switching ring (3) is centered on the outside (23) in a receptacle of the star disk base (11).

8. An electric machine comprising a rotor having a star disk (1) according to any one of claims 1 to 7 and a stator which interacts with the rotor during operation.

9. A method for producing a star disk (1) according to any one of claims 1 to 7, wherein: In a first step, a star disk base (11) is produced for the star disk (1), a switching ring (3) with axially projecting contacts (4, 16) is placed against the star disk base (11), and a plastic overmolding (6) is applied to a surface (21) of the star disk base (11) and to at least a part of the switching ring (3), so that the switching ring (3) is fixed to the star disk base (11) in the axial direction (7).

10. The method according to claim 9, characterized in that The switching ring ( 3 ) is produced by injection molding in a previous step.

11. The method according to claim 9, characterized in that The position and / or orientation of the star disk base (11) and the switching ring (3) are determined by a tool.

12. The method according to claim 9, characterized in that The star-shaped disk base (11) is preheated.

13. The method according to claim 9, characterized in that The switching ring (3) is filled with a puncture channel filler.

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