Method for manufacturing a stator, tool arrangement for winding a stator of an electric machine with a wire mat, magazine sleeve for receiving stator teeth and stator of an electric machine
The method uses a cylindrical magazine sleeve with axially spaced receiving areas and locking sleeves to address precision and stability issues in stator tooth positioning, achieving compact and efficient stator manufacturing with reduced costs and improved flexibility.
Patent Information
- Application Number
- DE102024121128
- Authority / Receiving Office
- DE · DE
- Patent Type
- Applications
- Current Assignee / Owner
- Filing Date
- 2024-07-25
- Publication Date
- 2026-01-29
AI Technical Summary
Current methods for manufacturing stators in electric machines face challenges with precision and stability of stator teeth positioning during winding, leading to tolerance variations, higher reject rates, and limited flexibility in scaling and miniaturization due to large winding heads and complex, costly solutions.
A method involving a cylindrical magazine sleeve with axially spaced receiving areas and retaining sections, ring-shaped locking sleeves, and an ejection device for precise positioning and winding of stator teeth, allowing for compact designs and efficient assembly.
The method improves process stability, reduces scrap rates, and enables smaller stator designs with lower costs by ensuring precise stator tooth positioning and flexible adaptation to different sizes, enhancing production speed and efficiency.
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Abstract
Description
[0001] The present invention relates to a method for manufacturing a stator of an electric machine. The invention further relates to a tool arrangement for winding a stator of an electric machine with a wire mat, a magazine sleeve for receiving stator teeth, and a stator of an electric machine.
[0002] Various methods for manufacturing stators for electrical machines are known in current practice. These methods typically involve feeding stator teeth into a predetermined position and subsequently winding them with conductors. A common problem with these methods is the precision and stability of the stator teeth's positioning during the winding process. In particular, the lack of stable fixation of the stator teeth often leads to tolerance variations, which in turn result in a higher reject rate and reduced efficiency of the assembly processes.
[0003] Another disadvantage lies in the size of the winding head, which often requires more installation space, thus limiting the miniaturization of electrical machines. Current methods also offer only limited possibilities for scaling the components, reducing flexibility in manufacturing different stator sizes.
[0004] To improve process stability and reduce scrap rates, various concepts have been developed, but these often require complex and costly solutions. One example is the use of special holding and guiding elements designed to keep the stator teeth in position during the winding process. However, these solutions are often associated with high material and assembly costs and offer limited flexibility.
[0005] The object of the invention is to avoid or at least reduce the problems known from the prior art and to provide an improved method for manufacturing a stator of an electric machine. Furthermore, the object of the invention is to realize an optimized tool arrangement for winding a stator of an electric machine with a wire mat, an improved magazine sleeve for receiving stator teeth, and an optimized stator of an electric machine.
[0006] This problem is solved by a method for manufacturing a stator of an electrical machine comprising the following steps: • Provision of a wire mat; • Provision of a plurality of stator teeth; • Provision of a cylindrical magazine sleeve to hold the stator teeth; • wherein the magazine sleeve has a first receiving area for the stator teeth and at least one axially spaced second receiving area and • wherein the first receiving area has a first holding section and a second holding section axially spaced apart from it and • wherein the second receiving area has a third holding section and a fourth holding section axially spaced from it and • wherein the retaining sections have grooves distributed around their circumference and extending radially into the retaining sections, • wherein each stator tooth can be positioned in a groove of the first holding section and a groove of the second holding section; • wherein each stator tooth can be positioned in a groove of the third holding section and a groove of the fourth holding section; • Provision of a first cylindrical ring-shaped locking sleeve and a second cylindrical ring-shaped locking sleeve, which are configured to be placed on the magazine sleeve and which each have locking grooves distributed circumferentially on one end face and extending axially from this into the respective locking sleeve; • At least one ejection device by which the stator teeth, which can be positioned in the grooves, can be moved radially outwards; • Mounting the first receiving area of the magazine sleeve with stator teeth; • Mounting the second receiving area of the magazine sleeve with stator teeth; • Attaching the first locking sleeve to the first retaining section of the magazine sleeve and • Place the second locking sleeve onto the second retaining section of the magazine sleeve, so that the locking grooves are aligned with the grooves of the first retaining section and the second retaining section; • Actuation of the ejector from a home position, so that the stator teeth are displaced radially outwards from the slots of the first retaining section and the slots of the second retaining section; • Rotating the locking sleeves and winding the wire mat onto the stator teeth; • Actuation of the ejector into its home position • Axial displacement of the locking sleeves with the stator teeth positioned via the locking grooves in the locking sleeves relative to the magazine sleeve, so that the first locking sleeve is placed on the third holding section of the magazine sleeve and the second locking sleeve is placed on the fourth holding section of the magazine sleeve and the locking grooves are aligned with the grooves of the third holding section and the fourth holding section; • Actuation of the ejector from a home position, so that the stator teeth are moved radially outwards from the slots of the third retaining section and the slots of the fourth retaining section, respectively, between the stator teeth located in the locking sleeves.
[0007] This approach offers the advantage of a significant reduction in installation space thanks to the segmented structure of the magazine sleeve. In particular, the axial division of the receiving areas and retaining sections allows for adjustment of the stator length without increasing the diameter. This enables smaller inner diameters, resulting in more compact designs. Furthermore, the specified assembly concept improves process stability, as the locking sleeves securely fix the stator teeth and reduce tolerance variations. This contributes to lower scrap rates and increases overall cost efficiency. The ejector also ensures precise positioning of the stator teeth, which increases production speed and reduces cycle times.The flexibility of the adjustable locking sleeves also allows the system to be easily adapted to different stator lengths, enabling its use in modular systems.
[0008] A further advantage is that the axially offset receiving areas can be loaded simultaneously, which significantly increases the process speed. In the embodiment according to claim 2, the magazine sleeve with a receiving area must be loaded twice, which is possible, but takes longer.
[0009] The object of the invention can also be achieved by a method for manufacturing a stator of an electrical machine comprising the following steps: • Provision of a wire mat; • Provision of a plurality of stator teeth; • Provision of a cylindrical magazine sleeve to hold the stator teeth; • wherein the magazine sleeve has a first receiving area for the stator teeth and • wherein the first receiving area has a first holding section and a second holding section axially spaced apart from it and • The retaining sections have grooves distributed throughout and extending radially into the retaining sections, • wherein each stator tooth can be positioned in a groove of the first holding section and a groove of the second holding section; • Provision of a first cylindrical ring-shaped locking sleeve and a second cylindrical ring-shaped locking sleeve, which are configured to be placed on the magazine sleeve and which each have locking grooves distributed circumferentially on one end face and extending axially from this into the respective locking sleeve; • At least one ejection device by which the stator teeth, which can be positioned in the grooves, can be moved radially outwards; • Mounting the first receiving area of the magazine sleeve with stator teeth; • Attaching the first locking sleeve to the first retaining section of the magazine sleeve and • Place the second locking sleeve onto the second retaining section of the magazine sleeve, so that the locking grooves are aligned with the grooves of the first retaining section and the second retaining section; • Actuation of the ejector from a home position, so that the stator teeth are displaced radially outwards from the slots of the first retaining section and the slots of the second retaining section; • Rotating the locking sleeves and winding the wire mat onto the stator teeth; • Actuation of the ejector into its home position; • Mounting the first receiving area of the magazine sleeve with stator teeth; • Actuation of the ejector from a home position, so that the stator teeth are moved radially outwards from the slots of the first retaining section and the slots of the second retaining section, respectively, between the stator teeth located in the locking sleeves;
[0010] The main advantage of this design is that the magazine sleeve, with its simple construction and single mounting area, can be manufactured cost-effectively. This simplified design reduces manufacturing costs and leads to savings in material and production expenses. At the same time, the specified assembly concept enables efficient handling and precise positioning of the stator teeth. However, a disadvantage is that the magazine sleeve must be loaded twice in succession, which can slightly reduce the production speed compared to a magazine sleeve with multiple mounting areas. Nevertheless, the simple design offers a robust and reliable solution, particularly suitable for applications where cost optimization is paramount.
[0011] A key element of both process variants is the feeding concept for the stator teeth from radially inside to outside using a magazine sleeve. The magazine sleeve has axially spaced receiving areas and retaining sections, each containing circumferentially distributed grooves for the precise positioning of the stator teeth. Advantageously, the magazine sleeve can be formed in one piece, particularly monolithically, which increases structural integrity and simplifies manufacturing.
[0012] By dividing the winding of the stator teeth into a "2-step sequence" and offering the possibility of further subdivision into multi-stage sequences, smaller inner diameters of stators can be achieved, leading to a significant reduction in installation space.
[0013] The reduction in winding head size can be achieved by rolling the wire mat on the same pitch circle. Furthermore, the joining aid facilitates the embossing of smaller radii at the groove exit. Magazine case
[0014] For the purposes of this patent application, a magazine sleeve is to be understood as a cylindrical component that serves to receive and hold stator teeth during the assembly of a stator of an electric machine.
[0015] The magazine sleeve comprises one or more axially spaced receiving areas, each with specific retaining sections. Each retaining section contains circumferentially distributed grooves extending radially into the retaining sections. These grooves are configured to precisely position and radially guide the stator teeth. Preferably, the magazine sleeve has at least two receiving areas, each area consisting of two axially spaced retaining sections. The retaining sections of a receiving area are designed to securely and stably hold the stator teeth in the corresponding grooves and guide them radially.
[0016] The function of the magazine sleeve is, among other things, to hold the stator teeth in a defined position during the assembly process, enabling precise and efficient winding of the wire mat around the stator teeth. This is achieved through the structural design of the retaining sections and grooves, which ensure stable fixation and guidance of the teeth.
[0017] By using one or more ejectors, which can be integrated into the magazine sleeve, the stator teeth can be moved radially outwards to allow for precise placement in the coiling wire mat. This significantly contributes to process stability and reduces tolerance variations, thereby increasing the quality of the final product and lowering production costs.
[0018] The magazine tube can be manufactured as a single piece, particularly monolithically. This means the magazine tube is made from a single piece of material, without the need to assemble separate parts. A monolithic design increases the structural integrity and stability of the magazine tube because there are no joints that could represent potential weak points. This results in a longer lifespan and greater reliability of the magazine tube. Stop section
[0019] For the purposes of this patent application, a holding section is a specified area of the magazine sleeve that serves to receive and fix the stator teeth during the assembly process.
[0020] The magazine sleeve can preferably comprise several retaining sections spaced axially apart, forming different receiving areas. These axially spaced retaining sections allow multiple rows of stator teeth to be positioned and fixed within the magazine sleeve, thus increasing the efficiency and precision of the assembly process.
[0021] Advantageously, a retaining section can be cylindrical. This simplifies the manufacturing and handling of the magazine sleeve. The cylindrical design also allows for easy integration of the retaining sections and supports the coaxial and rotatable mounting of the magazine sleeve. Stator teeth
[0022] For the purposes of this patent application, a stator tooth is an elongated, tooth-like component in cross-section that, once completed, forms part of the stator of an electrical machine and serves to guide the magnetic flux within the stator and to accommodate the wire windings. The function of a stator tooth includes, among other things, serving as a support for the winding conductors and conducting the magnetic field generated by the winding. Locking sleeve
[0023] For the purposes of this patent application, a locking sleeve is a cylindrical ring-shaped device that is fitted onto the magazine sleeve to position and guide the stator teeth during the assembly process. A locking sleeve has locking grooves distributed around its end face and extending axially into the sleeve. These locking grooves are configured to align with the grooves of the magazine sleeve's retaining sections to ensure precise and stable positioning and guidance of the stator teeth when they are radially displaced outwards during the manufacturing process. The locking sleeve securely guides the stator teeth in the grooves and holds them in position during the winding process.
[0024] Since the wire mat is rolled over the locking sleeve during the stator manufacturing process, it also contributes to precise positioning of the wire mat relative to the stator teeth. This is crucial for the stability and accuracy of the assembly process, as the locking sleeves prevent or at least significantly reduce slippage or tilting of the stator teeth during the rolling and radial displacement of the stator teeth. Wire mesh
[0025] For the purposes of this patent application, a wire mat is an essentially flat, structured arrangement of winding conductors. During the stator manufacturing process, the wire mat is wound onto the magazine sleeve via locking sleeves. The stator teeth are thereby inserted into correspondingly provided spaces in the center of the wire mat's winding. Expulsive agent
[0026] For the purposes of this patent application, an ejector is a device used to move the stator teeth, which are positioned in the grooves of the magazine sleeve, radially outwards. The function of the ejector is, among other things, to precisely and controllably push the stator teeth out of the grooves of the magazine sleeve's retaining sections in order to position them correctly for further assembly and winding. The radial movement of the stator teeth ensures that they can be inserted into the designated spaces in the wire mat and securely fixed there.
[0027] Advantageously, the ejector comprises at least one first cam element pivotably mounted on the magazine sleeve. Preferably, the ejector may also comprise a second cam element, likewise pivotably mounted on the magazine sleeve. These cam elements are designed such that they can push the stator teeth out of the grooves of the magazine sleeve by means of a pivoting movement. The pivotable arrangement of the cam elements enables flexible and precise actuation of the stator teeth.
[0028] Besides its configuration as a cam element, an ejector can also be implemented in other embodiments. A preferred alternative is the use of a pneumatic or hydraulic system. In this case, the ejector consists of one or more cylinders driven by compressed air or hydraulic fluid. These cylinders are arranged to push the stator teeth radially outward via piston rods. The use of pneumatic or hydraulic systems allows for high force transmission and precise control of the movement, thus increasing the efficiency and accuracy of the assembly process.
[0029] Another advantageous embodiment involves the use of electric actuators. In this case, the ejector is equipped with one or more electric motors that, via threaded spindles or linear actuators, radially push the stator teeth out of the grooves of the magazine sleeve. These motorized systems enable precise and repeatable positioning of the stator teeth and can be easily integrated into automated manufacturing processes.
[0030] Furthermore, the ejection mechanism can also be implemented as a mechanical spring assembly. In this variant, springs are pre-tensioned and positioned in the magazine sleeve or the retaining sections. Releasing a locking mechanism releases the springs, forcing the stator teeth radially outward. This mechanical solution is simple and reliable and requires no external power source. joining aid
[0031] For the purposes of this patent application, an assembly aid is a device or design attached to the radially outer ends of the stator teeth to prevent the stator teeth from tilting in the corresponding grooves of the magazine sleeve's retaining sections and to ensure precise positioning during the assembly process. The function of the assembly aid is, among other things, to guide the stator teeth stably and to securely fix them in the grooves of the magazine sleeve to enable accurate and stable positioning. This significantly contributes to increased process reliability and assembly accuracy. The assembly aid facilitates the handling of the stator teeth and ensures that they do not slip or tilt during assembly.
[0032] Several embodiments of the joining aid are conceivable. One possible embodiment is a separate component that is attached to the radially outer ends of the stator teeth. This design allows for flexible adaptation and can be replaced or modified as needed. After the wire mat has been wound up, the joining aid can advantageously be removed, for example, for reuse.
[0033] Another embodiment involves forming the joining aid as a single piece with the stator tooth. This integral design increases mechanical stability and reduces the number of individual parts required, simplifying assembly and lowering production costs. This type of joining aid remains permanently attached to the stator tooth and provides stable guidance throughout the stator's entire life cycle.
[0034] Preferably, the joining aid is made of plastic, which is suitable due to its good mechanical properties and ease of processing. Plastic offers sufficient strength and flexibility to securely guide and fix the stator teeth, while at the same time being light enough not to significantly increase the overall mass of the stator. Advantageous embodiments
[0035] Preferably, the magazine sleeve has specific retaining sections, each complemented by cylindrical ring-shaped locking sleeves. These locking sleeves are designed to fit onto the retaining sections of the magazine sleeve and have locking grooves on their end faces. These locking grooves are designed to align with the grooves of the magazine sleeve's retaining sections, thus ensuring secure fixation and precise positioning of the stator teeth.
[0036] According to a further preferred embodiment of the invention, the winding and unwinding can also be carried out synchronously and section by section for each layer of wire mat, thus enabling precise and controlled stator production. This increases process reliability and minimizes the risk of errors during production. The section by section approach also allows for flexible adaptation of the process to different wire mat layers, which expands the versatility and applicability of the method.
[0037] It is particularly advantageous if the ejection stroke corresponds to the thickness of the wire mat layer, so that when the next layer is wound up there is no collision with the stator tooth, but rather it is inserted radially.
[0038] Furthermore, according to another advantageous embodiment of the invention, the stator teeth positioned in the retaining sections may have an assembly aid at their radially outer ends, which prevents a stator tooth from tilting in the corresponding grooves of the retaining sections. This contributes significantly to stability and accuracy during assembly. The assembly aids ensure that the stator teeth remain precisely positioned in the grooves, which improves the quality of the final product and reduces the reject rate. The increased process stability leads to more robust and efficient manufacturing.
[0039] According to a further particularly preferred embodiment of the invention, the joining aid may have a cam-like contour with a first guide surface and a second guide surface which come into contact with the wire mat during radial offset of the stator tooth, so that the cam-like contour of the joining aid with its guide surfaces ensures precise guidance of the stator teeth in contact with the wire mat during the offset. This improves the precision of the assembly and prevents unintentional displacement or tilting of the stator teeth. The increased accuracy contributes to a better quality of the stator winding and simultaneously reduces the effort required for rework.
[0040] Furthermore, the invention can also be further developed such that the first guide surface differs geometrically from the second guide surface, resulting in an asymmetrical design of the joining aid. The asymmetrical design of the guide surfaces of the joining aid enables differentiated guidance and stabilization of the stator teeth. This can be specifically tailored to the different requirements and loads of the assembly processes, thus increasing the flexibility and adaptability of the method. The improved guidance contributes to process stability and reduces the probability of assembly errors.
[0041] In a further preferred embodiment of the invention, it can also be provided that a majority of the stator teeth, preferably all stator teeth, are at least partially enclosed by insulating paper before being inserted into the magazine sleeve. Partially encasing the stator teeth with insulating paper results in improved electrical insulation and mechanical stability. Furthermore, it facilitates the handling of the stator teeth during assembly, which increases process speed and efficiency.
[0042] It can also be advantageous to further develop the invention such that the insulating paper is fixed in the joining aid of a stator tooth. This prevents the insulating paper from slipping or detaching during the assembly process, which increases the quality and reliability of the insulation.
[0043] According to a further preferred embodiment of the invention, a majority of the slots, preferably all slots, may have parallel flanks. The parallel flanks of the slots enable uniform and stable positioning and guidance of the stator teeth. This increases precision during assembly and contributes to the reduction of manufacturing defects.
[0044] Finally, the invention can also be advantageously implemented such that the ejector comprises at least one first cam element which is pivotably arranged on the magazine sleeve. The pivotable cam element provides flexible and precise actuation of the stator teeth. This facilitates the accurate positioning and offset of the teeth during assembly, which improves the quality and accuracy of the final product.
[0045] In a further preferred embodiment of the invention, the ejector can be provided to include at least a second cam element that is pivotably arranged on the magazine sleeve. The integration of a second pivotable cam element allows for further precision in the actuation of the stator teeth. This enables an even more accurate and uniform distribution of forces during offsetting, which improves assembly quality and reduces the risk of damage to the teeth or the wire mat.
[0046] Furthermore, it may also be preferable for the first cam element and the second cam element to be essentially geometrically identical. The geometric identity of the cam elements ensures uniform and consistent actuation of the stator teeth. This results in high repeatability and consistency of the assembly process and also simplifies maintenance and component replacement.
[0047] It may also be preferable for the first cam element and / or the second cam element to be pivotably mounted on an end face of the magazine sleeve. The pivotable mounting of the cam elements on the end face of the magazine sleeve enables stable and precise actuation. Furthermore, this configuration allows for a compact tool assembly.
[0048] Furthermore, in a further preferred embodiment of the invention, it is advantageous that the magazine sleeve is mounted coaxially and rotatably relative to the locking sleeves, which allows for flexible and precise adjustment of the position of the stator teeth. This, in turn, simplifies assembly and increases the process speed.
[0049] According to a preferred further development of the invention, the wire mat can be provided with winding conductors having a trapezoidal cross-section, which allows for better space utilization and higher packing density. This leads to improved efficiency and performance of the stator. The trapezoidal winding conductors also contribute to the mechanical stability of the windings.
[0050] In a further preferred embodiment of the invention, a winding conductor of the wire mat may have a different trapezoidal shape depending on its radial position. Winding conductors whose trapezoidal shape varies depending on their radial position can enable optimized space utilization and a uniform distribution of electrical and mechanical loads.
[0051] Advantageously, the invention can also be further developed such that a winding conductor of the wire mat has a substantially constant cross-sectional area, regardless of its radial position. The constant cross-sectional area increases the reliability and consistency of the stator's electrical properties.
[0052] The object of the invention can also be achieved by a tool arrangement for winding a stator of an electric machine with a wire mat comprising: • a cylindrical magazine sleeve for holding stator teeth; • wherein the magazine sleeve has a first receiving area for the stator teeth and at least one axially spaced second receiving area and • wherein the first receiving area has a first holding section and a second holding section axially spaced apart from it and • wherein the second receiving area has a third holding section and a fourth holding section axially spaced from it and • wherein the retaining sections have grooves distributed around their circumference and extending radially into the retaining sections, • wherein each stator tooth can be positioned in a groove of the first holding section and a groove of the second holding section; • wherein each stator tooth can be positioned in a groove of the third retaining section and a groove of the fourth retaining section; and • a first cylindrical ring-shaped locking sleeve and a second cylindrical ring-shaped locking sleeve, which are configured to be fitted onto the magazine sleeve and which each have locking grooves distributed circumferentially on one end face and extending axially from this face into the respective locking sleeve; and • an ejection device by which the stator teeth, which can be positioned in the grooves, can be moved radially outwards;
[0053] The specified tool arrangement enables precise and efficient winding of the stator. Furthermore, the cylindrical magazine sleeve with axially spaced receiving areas and holding sections allows for flexible adjustment of the stator length without increasing the diameter, resulting in an overall reduction in installation space.
[0054] The object of the invention can also be solved by a tool arrangement for winding a stator of an electric machine with a wire mat comprising: • a cylindrical magazine sleeve for holding stator teeth; • wherein the magazine sleeve has a first receiving area for the stator teeth and • wherein the first receiving area has a first holding section and a second holding section axially spaced apart from it and • wherein the retaining sections have grooves distributed around their circumference and extending radially into the retaining sections, • wherein each stator tooth can be positioned in a groove of the first holding section and a groove of the second holding section and • a first cylindrical ring-shaped locking sleeve and a second cylindrical ring-shaped locking sleeve, which are configured to be fitted onto the magazine sleeve and which each have locking grooves distributed circumferentially on one end face and extending axially from this face into the respective locking sleeve; and • an ejection device by which the stator teeth, which can be positioned in the grooves, can be moved radially outwards;
[0055] This tool arrangement with a uniform receiving area and axially spaced holding sections also enables efficient assembly of the stator teeth.
[0056] The object of the invention can also be achieved by a cylindrical magazine sleeve for receiving stator teeth and for use in a tool arrangement according to claim 18 or 19 and / or a method according to claim 1; • wherein the magazine sleeve has a first receiving area for the stator teeth and at least one axially spaced second receiving area and • wherein the first receiving area has a first holding section and a second holding section axially spaced apart from it and • wherein the second receiving area has a third holding section and a fourth holding section axially spaced from it and • Whereas the retaining sections have grooves distributed throughout and extending radially into the retaining sections, • wherein each stator tooth can be positioned in a groove of the first holding section and a groove of the second holding section; • wherein one stator tooth can be positioned in a groove of the third holding section and a groove of the fourth holding section.
[0057] The cylindrical magazine sleeve with axially spaced receiving areas and retaining sections enables flexible and precise positioning of the stator teeth. This results in improved process reliability and higher production speeds. The magazine sleeve also facilitates a reduction in the winding head size, which decreases the required installation space and increases assembly efficiency.
[0058] Finally, the object of the invention can also be achieved by a stator of an electric machine with circumferentially distributed stator teeth and stator slots extending axially through the stator, in which winding conductors of a wire mat are inserted, wherein the axial mounting tolerance of the wire mat in the stator slots is between 0 and 1 mm. The tight tolerances result in a precise fit of the winding conductors, thus optimizing the use of the available space. This contributes to a reduction in the overall stator volume and enables smaller and more efficient electric machines.
[0059] For the purposes of this patent application, the axial assembly tolerance of the wire mat in the stator slots refers to the permissible range of deviation in the axial direction (along the longitudinal axis of the stator) within which the wire mat is inserted into the stator slots and fixed there.
[0060] This axial mounting tolerance defines how precisely the wire mat must be positioned in the stator slots to ensure optimal stator function and performance. A tight axial mounting tolerance means that the wire mat may only deviate slightly from its ideal position.
[0061] Each winding conductor has an active length. This is defined as the section of a winding conductor that runs within a stator slot of the stator. The winding conductors typically protrude slightly axially from the end faces of the stator before transitioning into a contour that deviates from the linear axial extent to form the winding heads. This section between the active length of the winding conductor and the winding heads essentially defines the axial assembly tolerance of the wire mat. In other words, the wire mat can still be axially offset within the stator between the two winding heads, or exhibit a corresponding assembly tolerance, since the winding heads mechanically limit the axial offset relative to the end faces of the stator. The section between the active length of the winding conductor and the winding heads can therefore preferably be 0-1 mm.
[0062] In this context, it is further preferred that the stator be segmented. It may also be preferred that a majority of the stator slots, preferably all stator slots, have parallel flanks.
[0063] Using the manufacturing process described above, it is now possible to achieve correspondingly tight assembly tolerances, which promotes a particularly compact design of the electric machine.
[0064] The invention will now be explained in more detail with reference to figures, without limiting the general concept of the invention.
[0065] It shows: Fig. 1 an empty magazine tube with two receiving areas in a perspective view, Fig. 2 a loaded magazine tube with two receiving areas in a perspective view, Fig. 3 a detailed cross-sectional view of a stator tooth mounted in the magazine sleeve, Fig. 4 a two-part locking sleeve in a perspective view, Fig. 5 a loaded magazine sleeve with the attached two-part locking sleeve, Fig. 6 a cross-sectional view of the loaded magazine sleeve during radial displacement of the stator teeth from the first receiving section by means of the ejector, Fig. 7 A cross-sectional view of the loaded magazine sleeve during radial displacement of the stator teeth from the first receiving section with an inserted ejector, Fig. 8 the magazine sleeve with the locking sleeve shifted to the second receiving area with extruded stator teeth held in it in a perspective view, Fig. 9 a cross-sectional view of the loaded magazine sleeve during radial displacement of the stator teeth from the second receiving section using the ejector, Fig. 10 a perspective view of the magazine sleeve with all stator teeth driven out of it and held in the locking sleeve, Fig. 11 a perspective view of the magazine sleeve with the wound stator teeth in a perspective view, Fig. 12 an electrical machine in a schematic axial section view, Fig. 13 a winding conductor in a stator slot in a schematic representation.
[0066] Based on the Fig. Section 1-13 now describes in more detail a method for manufacturing a stator 50 of an electric machine 51. Such an electric machine 51 is also shown as an example in the Fig. 12 outlined.
[0067] First, a wire mat 5, a plurality of stator teeth 2, and a cylindrical magazine sleeve 1 for receiving the stator teeth 2 are provided. The wire mat 5 is designed as a wave winding with winding conductors having a trapezoidal or rectangular cross-section.
[0068] How to use the Fig. As can be clearly seen, the magazine sleeve 1 has a first receiving area 11 for the stator teeth 2 and at least one axially spaced second receiving area 12.
[0069] The first receiving area 11 has a first holding section 21 and a second holding section 22 axially spaced from it. Similarly, the second receiving area 12 has a third holding section 23 and a fourth holding section axially spaced from it. The holding sections 21, 22, 23, and 24 are cylindrical ring-shaped and are each arranged at the axial ends of the receiving areas 11 and 12, resulting in a spatial shape reminiscent of a "double dumbbell". The holding sections 21, 22, 23, and 24 are connected to each other by the shaft 41 and are arranged coaxially with the shaft 41.
[0070] The retaining sections 21, 22, 23, 24 further have extensively distributed grooves 31, 32, 33, 34 extending radially into the retaining sections 21, 22, 23, 24, wherein a stator tooth 2 can be positioned in a groove 31 of the first retaining section 21 and a groove 32 of the second retaining section 22. A stator tooth 2 can also be positioned in a groove 33 of the third retaining section 23 and a groove 34 of the fourth retaining section 24. It can be seen from the Fig. 1. It can be seen that the grooves 31, 32 of the first and second holding sections 21, 22 are offset by approximately one groove width relative to the grooves 33, 34 of the third and fourth holding sections 23, 24, which allows for sequential winding of the wire mat 5, as will be explained in more detail later.
[0071] In a first manufacturing step, the first receiving area 11 and the second receiving area 12 of the magazine sleeve 1 are fitted with the stator teeth 2. Fig. Figure 2 shows the state of the magazine sleeve 1 fitted with the stator teeth 2 accordingly.
[0072] The stator teeth 2, positioned in the retaining sections 21, 22, 23, 24, have an engagement aid 10 at their radially outer ends 9, which prevents a stator tooth 2 from tilting in the corresponding grooves 31, 32, 33, 34 of the retaining sections 21, 22, 23, 24. The engagement aid 10 has a cam-like contour with a first guide surface 13 and a second guide surface 14, which come into contact with the wire mat 5 when the stator tooth 2 is radially displaced. In the embodiment shown, the first guide surface 13 differs geometrically from the second guide surface 14, so that the engagement aid 10 is asymmetrically designed. The engagement aid 10 is arranged on the arrow-shaped tooth head 43 of a stator tooth 2. To ensure radial guidance of the stator teeth 2, the tooth base 42 is dovetail-shaped and is in clearance contact with the flanks 35 of the corresponding groove 31,32,33,34.
[0073] The stator teeth 5 are at least partially enclosed by insulating paper 8 before being inserted into the magazine sleeve 1. Even if it is in the Fig. Unless shown in Figure 3, the insulating paper 8 can be fixed in the joining aid of a stator tooth 5. In the illustrated embodiment of the magazine sleeve 1, the grooves 31, 32, 33, 34 have parallel flanks 35.
[0074] Now, a first cylindrical ring-shaped locking sleeve 3a and a second cylindrical ring-shaped locking sleeve 3b are provided, which are configured to be attached to the magazine sleeve 1 and which each have locking grooves 13a, 13b distributed around one end face 18 and extending axially from this end face into the respective locking sleeve 3a, 3b. The locking sleeves 3a, 3b are in the Fig. Figure 4 shows the following. Here, the number of locking slots 13a, 13b corresponds to half the number of slots 31, 32 of the first and second holding sections 21, 22 and of slots 33, 34 of the third and fourth holding sections 23, 24. The locking slots 13a, 13b are designed such that they can be radially engaged by the stator teeth 2.
[0075] In the next process step, the first locking sleeve 3a is placed onto the first retaining section 21 of the magazine sleeve 1 and the second locking sleeve 3b is placed onto the second retaining section 22 of the magazine sleeve 1, so that the locking grooves 13a, 13b are aligned with the grooves 31, 32 of the first retaining section 21 and the second retaining section 22, which can be clearly seen from the Fig. This can be understood as shown in Figure 5. The magazine sleeve 1 is arranged coaxially with respect to the locking sleeves 3a and 3b and is rotatably mounted as a whole. When the magazine sleeve 1 is rotated, the locking sleeves 3a and 3b are also rotated.
[0076] The magazine sleeve 1 is provided with two ejection means 6 in the form of cam elements 15, 16 pivotable in the cam receptacles 40a, 40b, by which the stator teeth 5 positioned in the grooves 31, 32, 33, 34 can be moved radially outwards. These cam elements 15, 16 are pivotably arranged on the magazine sleeve 1 and are pivoted radially outwards from a home position, so that the stator teeth 2 are displaced radially outwards from the grooves 31, 32 of the first retaining section 21 and the grooves 32 of the second retaining section 22, as shown in the Fig. 6 can be seen. The cam elements 15,16 are in their basic position in the Fig. 7 and in their pivoted position in the Fig. 6 shown. One can see from the Fig. 6-7 also good that the first cam element 15 and the second cam element 16 are essentially geometric and are arranged on an end face of the magazine sleeve 1.
[0077] The locking sleeves 3a, 3b are then rotated, and the wire mesh 5 is wound onto the stator teeth 2. This process is not shown in the figures to avoid obstructing the view of the stator teeth and the magazine sleeve 1. The winding and ejection occur synchronously and in sections for each layer of the wire mesh 5. The ejection stroke always corresponds to the thickness of the wire mesh layer 5, ensuring that the next layer does not collide with the stator tooth 2 but is instead inserted radially.
[0078] After being rolled up, the ejector 6 is returned to its initial position, as described in the Fig. 7 can be seen.
[0079] Next, the locking sleeves 3a,3b with the stator teeth 2 positioned in the locking sleeves 3a,3b via the locking grooves 13a, 13b are axially displaced relative to the magazine sleeve 1, so that the first locking sleeve 3a is placed on the third retaining section 23 of the magazine sleeve 1 and the second locking sleeve 3b is placed on the fourth retaining section 24 of the magazine sleeve 1 and the locking grooves 13a, 13b are aligned with the grooves 33,34 of the third retaining section 23 and the fourth retaining section 24. A rotation of the locking sleeves 3a, 3b is not required in this process, since the grooves 31, 32 of the first and second retaining sections 21, 22 are offset circumferentially by approximately one groove width relative to the grooves 33, 34 of the third and fourth retaining sections 23, 24, so that in the Fig. In the month shown in Figure 8, the grooves 33,34 of the retaining sections 23,24 are located directly below the still free locking grooves 13a, 13b.
[0080] By reactivating the ejector 6 from its initial position, the stator teeth 2 are displaced radially outwards from the grooves 33 of the third retaining section 23 and the grooves 34 of the fourth retaining section 24, respectively, between the stator teeth 2 located in the locking sleeves 3a, 3b, which in the Fig. 9 can be seen. Fig. Figure 10 then shows the assembled state with all stator teeth 2 driven out of the magazine sleeve 1. The manufacturing process is thus based on a sequential displacement of the stator teeth 2 from the magazine sleeve 1 from radially inside to outside. This enables radially correct positioning of the stator teeth 2 depending on the number of already wound layers of the wire mat 5. With layer-by-layer positioning, the joining aid 10 can be used to ensure that the wire mat 5 is wound with a uniform pitch per layer, which prevents subsequent deformation during assembly of the stator teeth 2. This allows both process and assembly tolerances to be reduced and the shaping to be carried out with greater process reliability.
[0081] The figures show the manufacturing process with two axially adjacent receiving areas 11, 12 on the magazine sleeve 1. It is also possible to use a magazine sleeve 1 with only one first receiving area 11 for the stator teeth 2. In this case, the first receiving area 11 of the corresponding magazine sleeve 1 is also fitted with stator teeth 2, followed by the placement of the first locking sleeve 3a onto the first retaining section 21 of the magazine sleeve 1 and the placement of the second locking sleeve 3b onto the second retaining section 22 of the magazine sleeve 1, so that the locking grooves 13a, 13b are aligned with the grooves 31, 32 of the first retaining section 21 and the second retaining section 22.By actuating the ejector 6 from a home position, the stator teeth 2 are also displaced radially outwards from the slots 31 and 32 of the first retaining section 21 and the slots 32 of the second retaining section 22, and the locking sleeves 3a and 3b rotate, while the wire mat 5 is wound onto the stator teeth 2. Next, the first receiving area 11 of the magazine sleeve 1 is again fitted with stator teeth 2, and these are again displaced radially outwards from the slots 31 and 32 of the first retaining section 21 and the slots 32 of the second retaining section 22, between the stator teeth 2 located in the locking sleeves 3a and 3b, by actuating the ejector 6 from a home position.
[0082] Fig. Figure 11 shows the guidance of the wire mat 5 during winding onto the locking sleeve 3a, 3b. Due to the increasing layer build-up during winding, flexible tool elements are provided which, in the appropriate radial position, ensure force- or friction-based fixation of the wire mat 5. The pressure rollers 44 must be tangentially stationary to allow sufficient space for feeding the wire mat 5 from the outside for winding. The circumferential speed of the pressure rollers 44 corresponds to the winding speed of the wire mat 5 during winding. They also enable a final process step in which the wire mat 5, wound onto the stator teeth 2, is radially compacted again in the area of the winding heads 54a, 54b by means of the pressure rollers 44.This may be necessary if local wire deformation occurs in the winding head 54a, 54b due to radial tooth mounting. This deviation can be corrected or brought into the desired installation space by a final rolling process. For this purpose, an additional radially internal force is applied to the pressure rollers 44, which reshapes any possible position or torsional inclination of the wires in the winding head 54a, 54b.
[0083] The Fig. Figure 12 shows a stator 50 of an electric machine 51 with circumferentially distributed stator teeth 2 and stator slots 52 extending axially through the stator 50, in which winding conductors of a wire mat 5 are inserted, wherein the axial mounting tolerance of the wire mat 5 in the stator slots 52 is between 0-1 mm.
[0084] Based on the Fig.It can be seen that the winding conductors 55 have an active length, which is defined as the section of a winding conductor 55 that runs in a stator slot 52 of the stator 50. The winding conductors 55 typically protrude slightly axially at the end faces of the stator 50 before transitioning into a contour 56 that deviates from the linear axial extent to form the winding heads 54a, 54b. This section 57 between the active length of the winding conductor 55 and the winding heads 54a, 54b essentially defines the axial assembly tolerance of the wire mat 5. The stator 50 thus has winding heads 54a, 54b that are minimally pronounced in the axial direction.
[0085] Prior art methods are based on a combination of axial and radial shaping of the wire mat 5 around existing stator teeth 2. Due to assembly tolerances, minimum distances must be maintained in the shaping process, as the mat is typically expanded from a smaller pitch circle to a larger one, e.g., for non-segmented internally slotted stators, or rolled from a larger pitch circle to a smaller one in the case of segmented internally slotted stators. In the method described here, the wire mat 5 is wound appropriately using the stator teeth 2 and the joining aid 10. Because the pitch circle diameter of the wire mat 5 remains constant, the wires in the winding head 54a, 54b do not change shape axially, but only radially (angle adjustment through the transition from a linear arrangement to the pitch circle). These reduced shaping requirements enable a reduction in assembly tolerances.Based on the joining aids 10, the straight section of the mat is moved into the appropriate position relative to the stator tooth without causing any change in shape at the exit radii in the tangential direction.
[0086] The stator 50 of the electric machine 51 has parallel tooth flanks 35 in its stator slots 52. The stator winding consists of winding conductors 55 of a wire mat 5, which have trapezoidal wire cross-sections. The trapezoidal shape varies depending on the radial position of the respective winding conductor 55 within the wire mat 5. Despite this variable shape, the wire cross-section remains constant, which ensures uniform electrical conductivity.
[0087] The cross-sectional shape of the winding conductor 55 is trapezoidal only in the slot area of the stator slots 52. In the area of one of the winding heads 54a, 54b, the winding conductor 55 has a rectangular cross-section. The transition from the trapezoidal to the rectangular shape is defined by a special transition shape, which enables a seamless and efficient connection of the different cross-sections.
[0088] The stator 50 is segmented and consists of two basic segment forms: the tooth segment and the yoke. The tooth segment comprises a single tooth 2 with a tooth head 43, which serves to receive the winding conductors 55. The yoke serves to connect the tooth segments and to stabilize the entire stator 50.
[0089] The invention is not limited to the embodiments illustrated in the figures. The foregoing description is therefore not to be considered limiting, but rather explanatory. The following claims are to be understood as meaning that a named feature is present in at least one embodiment of the invention. This does not preclude the presence of further features. Insofar as the claims and the foregoing description define 'first' and 'second' features, this designation serves to distinguish between two similar features without establishing any hierarchy. Reference symbol list 1 magazine sleeve 2 stator teeth 3 Locking sleeve 5 wire mat 6 Expulsive agents 8 insulating paper 9 ends 10 Joining aid 11 Recording area 12 Recording area 13 locking slots 14 Guide surface 15 cam element 16 cam element 18 Front 21 Stop section 22 Stop section 23 Stop section 24 Stop section 31 Nut 32 Nut 33 Nut 34 Nut 35 flanks 40 cam mount 41 wave 42 Tooth base 43 Tooth head 44 pressure rollers 50 Stator 51 electric machine 52 stator slots 53 Rotor 54 winding head 55 winding conductors 56 contour