Manufacturing method for composite status leaves

Abstract

The method of manufacturing a status sleeve begins with using automated fiber placement to wrap a cylindrical mandrel with a heated prepreg tape. The prepreg tape has continuous fiber reinforcements within a polymer matrix. Next, the cylindrical mandrel is cooled and removed from the wrapped prepreg tape to obtain an unfinished cylindrical status sleeve. Each end of the unfinished status sleeve is trimmed. Next, a cylindrical fixture is used to abut first and second end rings to the first and second ends of the trimmed status sleeve, respectively. The first and second end rings are of the same material as the polymer matrix of the prepreg tape. Finally, the first and second rings are laser welded or fusion bonded to the first and second ends of the trimmed status sleeve.

Description

Technical Field

[0001] Cross - reference to Related Applications This non - provisional application claims priority based on Provisional Application No. 63 / 365,308, filed on May 25, 2022, the entire content of which is hereby incorporated by reference in its entirety into this specification.

[0002] The present invention generally relates to stator sleeves used in electric motors. More particularly, the present invention relates to a method for manufacturing a composite stator sleeve used in a high - performance electric motor having a liquid - cooled stator.

Background Art

[0003] Generally speaking, an electric motor has several important components that enable it to efficiently and effectively convert electrical energy into mechanical energy. Each component facilitates an important interaction between the magnetic field of the motor and the current flowing through its wire windings, helping to generate force in the form of rotation of the shaft. The mechanical energy generated by this rotation of the shaft helps to keep an electric vehicle running or to smoothly maintain the operation of a factory. These components can include a rotor, a stator, bearings, windings, and an air gap.

[0004] Rotor. The rotor is the moving part of an electric motor. It rotates the shaft that supplies the mechanical power described above. In a common configuration, the rotor has conductors embedded in it, and an electric current flows through these conductors, and this current interacts with the magnetic field of the stator to generate a force that rotates the shaft. However, some rotors have permanent magnets attached, and it is the stator that holds the conductors.

[0005] Stator and Stator Core. The stator is the fixed part of the electromagnetic circuit of the motor and usually consists of either windings or permanent magnets. The stator core is composed of a number of thin metal sheets called laminations. The laminations are used to reduce the energy losses that would occur if a solid core were used.

[0006] Bearings. The rotor of an electric motor is supported by bearings that allow it to rotate along its axis. These bearings are supported by the motor housing. The motor shaft extends outside the motor through the bearings, where the load is applied. The load is said to be "overhanging" because the force of the load extends beyond the outermost bearing.

[0007] Windings. Windings are wires wound in a coil shape, usually around a laminated soft iron core, and when excited with electric current, they form magnetic poles. Electric motors have two basic magnetic field pole configurations: salient poles and non-salient poles. In salient pole motors, the magnetic field of the poles is generated by windings wound around the poles below the magnetic pole surface. In non-salient pole motors, the windings are distributed in the slots of the magnetic pole surface.

[0008] Air gap. Although not a physical component, the air gap is the distance between the rotor and the stator. The air gap in a motor has a significant effect, and generally, a large gap has a strong negative impact on performance, so the air gap should be as small as possible. This is the main reason for the low power factor when the motor is operating. The magnetization current increases with the air gap, so the air gap needs to be minimized. However, a very small gap can cause mechanical interference problems.

[0009] High-performance electric motors can generate a significant amount of heat, particularly in the conductors. Therefore, many high-performance electric motors are configured with a rotor fitted with permanent magnets and a stator holding the conductors. The conductors can then be directly cooled using liquid cooling, resulting in a liquid-cooled stator. A stator leaf can be used to separate the stator from the rotor, enabling the use of a fluid coolant. Such liquid-cooled motors can be used in applications such as e-mobility where high efficiency and power-to-weight ratio are important. Applicable inner-rotor / outer-stator motors include, but are not limited to, induction motors (IM), internal permanent magnet motors (IPM), synchronous reluctance motors (SynRM), and IPM-SynRM motors. Furthermore, outer-rotor / inner-stator motors, such as in-wheel motors, can also benefit from this invention.

[0010] Status leaves are known in the latest technology. For example, U.S. Patent Application Publication No. 2003 / 0193260 teaches a powder metal status leaf. Metal status leaves are undesirable because their conductivity and the resulting eddy current losses reduce motor efficiency.

[0011] U.S. Patent No. 8,378,550 teaches a stator ree located outside the stator windings, rather than between the stator and rotor, as in the present invention. Such a coolant means is not as efficient as immersing the stator windings in the coolant, as in the present invention.

[0012] German Patent No. 102020119110 teaches StatusLeave an attempt to address the cooling of high-performance electric motors. However, this application improves upon that teaching in many ways, as will be further described below.

[0013] The purpose of a stator leaf is to form a barrier between the stator and rotor of an electric motor, allowing coolant to flow through the stator for cooling, thereby increasing motor efficiency. Therefore, an improved stator leaf is needed to enable a higher-performance electric motor. This invention meets these needs and provides other relevant advantages. [Prior art documents] [Patent Documents]

[0014] [Patent Document 1] U.S. Patent Application Publication No. 2003 / 0193260 Specification [Patent Document 2] U.S. Patent No. 8,378,550 [Patent Document 3] German Patent No. 102020119110

[0015] Summary of the Invention An exemplary embodiment of the present invention is a method for manufacturing a statutory reef, which is configured to be assembled as part of a cooled electric motor having a stator having a wound stationary conductor and a rotor having a rotating permanent magnet, wherein a coolant is configured to cool the wound stationary conductor. The method for manufacturing a statutory reef is a step of providing a cylindrical mandrel, a step of winding the cylindrical mandrel with a prepreg tape using an automatic fiber arrangement, the automatic fiber arrangement being in situ compaction, a step of heating the prepreg tape during the automatic fiber arrangement, a step of cooling the wound prepreg tape by waiting for an elapsed time, a step of removing the cylindrical mandrel from the wound prepreg tape to obtain an unfinished cylindrical statutory reef, and a step of trimming each end of the unfinished statutory reef to obtain a trimmed stator having the first end opposite a second end. The method includes the steps of obtaining a sleeve, providing a first end ring and a second end ring, wherein the first end ring and the second end ring comprise a polymer, wherein the polymer of the first and second end rings is the same material as the polymer matrix of a prepreg tape, and using cylindrical fasteners, bringing the first and second end rings into contact with the first and second ends of a trimmed status sleeve, respectively, and forming a completed status sleeve configured to be installed on a cooled electric motor by laser welding or melt-bonding the first and second rings to the first and second ends of the trimmed status sleeve.

[0016] Next, alternative embodiments will be described. The winding of the prepreg tape of the continuous fiber reinforcement may be in a hoop-wrap orientation. The continuous fiber reinforcement may contain S2 glass, IM7 carbon and / or boron. The polymer matrix may contain PA, PET, PBT, POM, PPS, PEEK, PAEK and / or PEKK.

[0017] Heating of the prepreg tape during automatic fiber placement may include hot gas torch convection heating, laser heating, flash lamp heating, or infrared heating.

[0018] The first and second end rings may contain a carbon black-filled polymer.

[0019] The status leaf may be impermeable to the coolant.

[0020] The prepreg tape may be unidirectional.

[0021] The step of removing the cylindrical mandrel from the wrapped prepreg tape may include cooling and shrinking the cylindrical mandrel to reduce its size. Cooling the cylindrical mandrel may include flowing a cooled liquid into the cylindrical mandrel.

[0022] The step of removing the cylindrical mandrel from the wrapped prepreg tape may include dissolving the cylindrical mandrel in a liquid configured to dissolve the material of the cylindrical mandrel.

[0023] The step of removing the cylindrical mandrel from the wrapped prepreg tape may include folding the cylindrical mandrel.

[0024] An exemplary embodiment of the present invention is a method for manufacturing a statutory reef, which is configured to be assembled as part of a cooled electric motor having a stator with a wound stationary conductor and a rotor with a rotating permanent magnet, wherein a coolant is configured to cool the wound stationary conductor.A method of manufacturing a stator sleeve includes providing a cylindrical mandrel, wrapping the cylindrical mandrel with a prepreg tape using automated fiber placement, heating the prepreg tape during automated fiber placement, cooling the wrapped prepreg tape by waiting an elapsed time, removing the cylindrical mandrel from the wrapped prepreg tape to obtain an unfinished cylindrical stator sleeve, providing an outer mold that forms the outer surface of the finished sleeve and the unfinished cylindrical stator sleeve is not fully consolidated, placing the unfinished cylindrical stator sleeve, inserting a conformable bladder into the composite sleeve, pressurizing the conformable bladder, heating an assembly comprising the outer mold, the unfinished cylindrical stator sleeve, and the conformable bladder, where the unfinished stator sleeve is fully consolidated to obtain an unfinished stator sleeve, cooling the assembly, removing the unfinished stator sleeve from the outer mold and removing the conformable bladder, trimming each end of the unfinished stator sleeve to obtain a trimmed stator sleeve having a first end opposite a second end, providing a first end ring and a second end ring, where the first and second end rings comprise a polymer, the polymer of the first and second end rings is the same material as the polymer matrix of the prepreg tape, abutting the first and second end rings against the first and second ends of the trimmed stator sleeve using a cylindrical fixture tool, and forming a finished stator sleeve configured to be installed in a cooled electric motor by laser welding or fusion bonding the first and second rings to the first and second ends of the trimmed stator sleeve, respectively.

[0025] Other features and advantages of the present invention will become apparent from the following more detailed description when taken in conjunction with the accompanying drawings which illustrate, by way of example, the principles of the invention.

[0026] The accompanying drawings illustrate the present invention.

Brief Description of the Drawings

[0027] [Figure 1] It is a cross-sectional view of an electric motor. [Figure 2A] It is an illustration of the in-situ compaction (ISC) process. [Figure 2B] It is a simplified side view similar to the figure of FIG. 2A showing the in-situ compaction process. [Figure 3] It is a figure showing an embodiment of a cylindrical sleeve removed from a cylindrical mandrel. [Figure 4A] It shows a compaction roller with slots. [Figure 4B] It is a figure showing the axial features added to the status sleeve. [Figure 5A] It is a figure showing the first end ring of the status sleeve. [Figure 5B] It is a figure showing the second end ring of the status sleeve. [Figure 6A] It is an enlarged cross-sectional view showing the structure of FIG. 5A attached to one end of the status sleeve. [Figure 6B] It is an enlarged cross-sectional view showing the structure of FIG. 5B attached to one end of the status sleeve. [Figure 7] It is an isometric view showing an end ring positioned with respect to the status sleeve using a cylindrical fixture. [Figure 8] It is a front view of the structure of FIG. 7 in a state where a laser welding machine applies laser energy to an end fixture and a status sleeve. [Figure 9] It is a side view of FIG. 8. [Figure 10] It is an isometric view of the completed status sleeve of the present invention. [Figure 11] It is a schematic diagram of another novel method of the present invention utilizing bladder forming. [Figure 12]This is a perspective view of a simple bladder molding die according to the present invention. [Figure 13] This figure shows the mold in Figure 12 with the sleeve and bladder inserted. [Figure 14] This figure shows the structure of Figure 13 when pressure and heat are applied to the bladder molding die. [Figure 15] This figure shows the cooling and depressurization of the structure shown in Figure 14. [Figure 16] As already described herein, the resulting sleeve, which can be trimmed and attached to an end ring, is shown. [Modes for carrying out the invention]

[0028] Composite materials have, quite literally, paved the way for their adoption in civil aircraft, step by step. At each stage, composites have proven increasingly capable of forming flight-critical components that possess the necessary strength and rigidity, and are virtually free of defects (surface pores and invisible internal voids) that could cause damage in the future as aircraft age. Until relatively recently, this near-zero porosity standard (less than 1%) was maintained by a combination of vacuum bag compaction and exposure to high heat and pressure in an autoclave for several hours during the curing process. In recent years, the development of oven-curable resins (systems that can compact to an acceptable porosity without an autoclave) has helped shorten curing cycles and reduce both the time and cost required for component manufacturing, as ovens are less expensive to operate than autoclaves. In parallel, automated filament winding, automated tape laying (ATL), and automated fiber placement (AFP) equipment have replaced manual layup in many applications, significantly increasing the speed at which components are laminated. These systems are equipped with rollers that compress the material immediately after placement to ensure adhesion and avoid the formation of air pockets that would create voids, but the compaction of the laminate is still typically carried out in the second step of a two-step process, in an autoclave, oven, or other heating device such as a heated tool, under a vacuum bag. This modern technique persists, at least partially, because today's certified aerospace composites are predominantly thermosetting.

[0029] There is an alternative, known as in-situ densification, which means densification in a fixed location. The key is to use a thermoplastic matrix rather than a thermosetting matrix. Thermoplastic materials are liquid to their melting point when heated and solidify when cooled, but do not require crosslinking like thermosetting resins. Densification of thermoplastic composites (TPCs) can then be achieved by rapidly heating the impregnated reinforcing material to the melting point of the thermoplastic polymer matrix, and then applying pressure as the tape or tow is placed on the tool and / or pre-placed laminate. True in-situ densification (ISC) is a one-step process, requiring no further heating or pressurizing steps after fiber placement or tape laying is complete.

[0030] The impact of eliminating an entire expensive step in the manufacturing process is so significant and obvious that some might wonder why no one has done it yet. For one thing (and there are other reasons to discuss), the aerospace industry pays a very high price for change. Substituting materials inevitably requires extensive and costly testing and recertification.

[0031] Nevertheless, two-step compacted TPC is already being used in some aircraft applications. Although its processing temperature is much higher than that of thermosetting resins—close to 400°C compared to 180°C / 350°F for basic structures—its cycle time is much shorter because TPC requires only cooling and not crosslinking. Thermoplastics are also inherently tough and do not require special formulations to give the fatigue resistance required for aircraft applications. Furthermore, because thermoplastics can be reheated and modified, they can be welded (a cost-saving fastener-free assembly option). As the aircraft industry seeks materials and processing methods that will enable production speeds of at least 60 aircraft per month and support the envisioned digital manufacturing, multifunctional structures, and sustainability considered necessary for next-generation aircraft, TPC has emerged as a leading candidate. A significant percentage of recently completed large-scale aircraft demonstration projects have chosen TPC as the material.

[0032] The inventors of this invention have extensive experience in the aerospace industry and understand that automating the manufacturing process of thermoplastic resins using automated tape placement (ATP) can achieve improved productivity, reduced labor costs, and improved geometric repeatability compared to conventional hand lay-up. The inventors focused on improving electric motors used in a wide range of high-performance applications.

[0033] The present invention improves upon the prior art by incorporating end features to facilitate connection to the stator, fluid sealing, and assembly; optionally incorporating axial features on the outer diameter for ease of assembly, coolant flow paths, stator winding spacers, and reinforcing members; employing thermoplastic polymer composite materials to enable cobonding of the entire structure, provide excellent coolant / solvent resistance, enable high-speed manufacturing, and enable recycling after life; providing an innovative manufacturing method to facilitate the production of optimized stator leaves; and efficiently and rapidly manufacturing complex stator leaf assemblies.

[0034] As mentioned above, the purpose of the stator leaf is to create a barrier between the stator and rotor of an electric motor, allowing coolant to flow through the stator for cooling. A typical configuration is shown in Figure 1, which is an enlarged cross-sectional view of an internal permanent magnet motor (IPM) motor. Figure 1 shows a cross-sectional view of an electric motor 10 having an outer housing 11, a stator 12, windings 13, a rotor 14, a rotor sleeve 15, a stator leaf 16, and permanent magnets 17. It is understood that some electric motors may include a stator leaf but not have a rotor sleeve.

[0035] The stator sleeve 16 of the present invention is ideally formed as a thin-walled structure. This reduces the gap between the stator and rotor, improving efficiency. The stator sleeve has high strength and rigidity. This allows for a thinner wall thickness, minimizing sleeve deformation during use. Since the stator sleeve is impermeable to the coolant, fluid leakage through the material of the stator sleeve is not a problem. The stator sleeve has low magnetic permeability and therefore does not disturb the magnetic field between the rotor and stator. The stator sleeve also has low conductivity, resulting in less electrical loss due to eddy currents. The stator sleeve incorporates features such as end fittings for connection to and sealing with the stator, coolant flow paths, reinforcement, structures for integration with stator windings, and mounting structures to facilitate assembly and alignment.

[0036] Since any leakage of the coolant would lead to motor failure, it will be understood by those skilled in the art to read this disclosure that the liquid permeability of the stator of the present invention is zero.

[0037] Furthermore, the carbon fiber, glass fiber, and / or polymer composite materials of the present invention do not contribute to magnetic losses in electric motors. More specifically, glass fibers such as S2 glass are excellent electrical insulators, similar to polymers, and do not contribute to electrical losses in electric motors. Carbon fibers are conductive along the length of the fiber (approximately 2 to 20 microohms-m). However, the continuous carbon fiber composite materials used in the present invention are insulated from each other by the polymer matrix, so there are no conductive paths for eddy current losses.

[0038] This invention includes innovative materials and manufacturing methods for improving the latest technologies in stator structures. The basic approach is to use advanced thermoplastic composite materials with innovative manufacturing methods to produce improved stator structures.

[0039] A general method of the present invention involves first manufacturing a tube body using a process such as automated fiber placement (AFP), which can be in situ compaction (ISC), to produce a cylindrical sleeve structure. Any additional features, such as end fittings and / or axial structures, can then be incorporated.

[0040] The present invention begins with the manufacture of a composite sleeve. Continuous fiber reinforcements such as S2 glass, IM7 carbon, boron, or any other suitable fiber may be used. Continuous fibers with higher strength and stiffness are preferred. A polymer matrix is ​​used to hold the fibers in place within the sleeve, protect the fibers, transfer structural loads between fibers, and prevent refrigerant permeation. Thermoplastic polymers are preferred due to their ability to thermally cobond with other features, refrigerant resistance, and recyclability. Suitable polymers include, but are not limited to, PA, PET, PBT, POM, PPS, PEEK, PAEK, and PEKK, depending on the operating temperature and other factors.

[0041] Figure 2A is a photograph of the in-situ consolidation (ISC) process. Figure 2B is a simplified side view similar to the diagram in Figure 2A showing the in-situ consolidation process. The incoming tape 20 is first guided between one or more tape feed rollers 21. The tape is eventually placed on a tool 22 with a number of plies 23 arranged on it. As the tape passes the feed rollers, it is eventually fed onto the tool or onto the previous plies by a roller 24, which applies a force 25 that presses the tape onto the tool or onto the previous plies. The direction of travel is indicated by an arrow 26, which means that the tool is moving in one direction, the roller is moving in the other direction, or a combination of both. A high-temperature gas torch convection heater 27 is used to heat the prepreg tape 20. Once a sufficient number of ply layers have been placed, the tape is cut by a tape cutter 28.

[0042] Reinforced thermoplastic composites such as S2 / PEEK are used, but are not limited to, existing state-of-the-art AFP and ISC technologies to manufacture composite cylinders. For high compressive strength, unidirectional composite prepreg tapes, primarily aligned with the hoop wrap direction, are recommended. This means that the continuous length of the fibers is aligned with the circumference of the cylinder. The ISC process is shown in Figure 2A, along with an illustration of the process in Figure 2B, illustrating the formation of the cylinder. This figure shows high-temperature gas torch (HGT) heating technology, but lasers, flash lamps, IR heaters, or other suitable heating methods can also be used.

[0043] After the composite cylinder is compacted, it is removed from the mandrel and trimmed to the desired length. Removal of the composite sleeve from the mandrel is facilitated by cooling the mandrel, which can be incorporated into the mandrel using, for example, a refrigerant. It should be noted that in ISC processing, unlike autoclave compaction where the mandrel is heated together with the parts, a release agent is usually not required. The mandrel never reaches the polymer melting temperature that would hinder bonding. In the inventors' experience, inexpensive aluminum mandrels are preferred for removing parts after cooling due to their high CTE.

[0044] Figure 3 shows one embodiment of a cylindrical sleeve 18 being removed from a cylindrical mandrel 22.

[0045] Similarly, foldable or soluble mandrels may be used. While soluble or foldable mandrels may be used, they are generally not required in the ISC process. PLA (polylactic acid), eutectic salts, or any other suitable soluble mandrels may be used when removal is not possible by other means.

[0046] Alternatively, unconsolidated sleeve preforms may be produced using braiding, 3D braiding, knitting, or other weaving processes. For sleeve preforms, consolidation may be performed using vacuum bags, shrink wrap tape, or other suitable means instead of the ISC process. However, braiding or other weaving processes require thicker laminates because the unevenness of the fibers reduces the compressive strength of the composite cylinder.

[0047] Figure 4A shows a slotted consolidation roller 30. The slotted roller is used to form axial ribs 40. The slotted roller rolls along the longitudinal direction of the sleeve 18, where the curvature 31 matches the outer diameter of the sleeve. There is an annular gap 32 that forms the axial ribs 40. In other words, the axial ribs 40 on the outer diameter of the status sleeve 18 are formed using an in situ process, where pure polymer is melted onto the outer diameter of the sleeve, and the roller utilizes the annular gap 32 to form a square cross-sectional shape. Heat is applied to the neat material and the outer diameter of the status sleeve to melt and bond them together. The roller also applies the necessary compressive force to press the neat material against the sleeve to allow for close contact for molecular chain entanglement.

[0048] Figure 4B shows that in the ISC process, axial features 40 (such as status lofts) can be added using slots or other groove shapes in the compaction roller along with additional composite materials or polymer filaments.

[0049] Alternatively, features can be added using additive manufacturing processes such as fused filament manufacturing (FFF). These features can be added using continuous fiber composites, shredded fiber-filled materials, or neat polymer filaments.

[0050] Furthermore, the status slots may be filled with an insulator, such as a PEEK polymer insert, for electrical insulation. Such slot fillers are effective when incorporated into the status sleeve due to the additional benefit of increased bending stiffness.

[0051] A trimmer operation may be required to trim each end of the incomplete status leaf 18 to obtain a trimmed status leaf having a first end 18a facing a second end 18b.

[0052] To complete a production-ready stator reef, the end of the stator needs to be configured to operate within a specific motor. This means that various features and structures are required along the end of the stator reef. In this invention, end rings or other features may be added by melt bonding or other means. Figures 5A and 5B show two representative end rings 51 and 52 that can be attached to a stator reef.

[0053] Figure 6A is an enlarged cross-sectional view showing the structure (end ring 51) of Figure 5A attached to one end 18a of the status leaf 18. Similarly, Figure 6B is an enlarged cross-sectional view showing the structure (end ring 52) of Figure 5B attached to the other end 18b of the status leaf 18. The overlap between the status leaf and the end fitting can be seen.

[0054] Figure 7 shows end rings 51, 52 positioned relative to the status sleeve 18 using a cylindrical fixture 60. The fixture helps to align and hold the end rings in place relative to the status sleeve. For example, the tool 60 has a large diameter portion 61 that contacts the end ring 51 when the end ring 51 is first slid. Next, the status sleeve can be slid. Finally, the end ring 51 can be slid on the tool 60. In this way, all three parts are held together in contact. The end rings can then be joined to the sleeve using a laser welding machine 70 or the like, as shown in the figure.

[0055] Figure 8 is a front view of the structure shown in Figure 7, in which a laser welding machine 70 is applying laser energy 71 to the end fittings and status leaves. The laser energy 71 is applied to the status leaves 18 and end rings 52, which are permanently connected to each other.

[0056] Figure 9 is a side view of the laser welding of the end fitting shown in Figure 8. The laser beam 71 is directed towards the end fitting and the roller. The roller 72 helps to facilitate the connection between the end ring and the status sleeve. The roller applies consolidation pressure to the sleeve and ring. Both heat and pressure are required to melt and bond the plastics together. The laser energy melts the surface, and the roller applies the pressure necessary to bond the two parts together. Those skilled in the art will understand that the end ring can be permanently connected to the status sleeve by other techniques such as fusion welding or friction welding.

[0057] In Figures 8 and 9, the status sleeve typically has a yellowish-brown color, indicating the natural color of the S2 / PEEK composite, while the end fittings are darker (such as black), indicating that they are PEEK filled with an IR-absorbing material such as carbon black. S2 / PEEK is transparent to IR lasers, but carbon black-filled PEEK absorbs IR laser energy, causing the surface of the carbon black-filled PEEK to heat up, enabling fusion bonding to the S2 / PEEK sleeve.

[0058] Figure 10 shows the completed status leaf assembly 16. One advantage of the present invention is that the polymer used to manufacture the end ring and the polymer used in the polymer matrix of the prepreg can be the same material. This allows for a good connection between the status leaf and the end ring, whether laser welded or fused.

[0059] Figure 11 shows an alternative configuration for manufacturing the status leaf of the present invention using bladder forming.

[0060] Bladder forming is an alternative consolidation technique. The idea is to start with a composite sleeve 80 that does not need to be completely consolidated. Such a sleeve could be, for example, partially ISC (in situ consolidation) or a braided sleeve.

[0061] The manufacturing process may include the following steps: First, a composite sleeve preform 80 is manufactured. Step A shows inserting a suitable bladder 81 into the composite sleeve 80. Next, the sleeve and bladder are inserted into molds 82 and 83. Step B shows pressurizing the bladder 84 to shape the sleeve into the molds 82 and 83. Step C shows heating the assembly above the polymer melting temperature 85. This heat is applied under pressurization. Next, the assembly is cooled 86 as shown in step D, and the compacted parts and bladder are removed from the molds. Figure 11 is for illustrative purposes only because the shape is a simple cavity, but those skilled in the art will understand that the shape may be cylindrical or any other shape.

[0062] Figures 12-16 are perspective views that better depict the process described in Figure 11. Figure 12 is a perspective view of a very simple mold 82 and 83. This is a two-part mold, but it may contain any number of parts and sections. Once pressurization and heating are complete, the inside of the mold forms a surface 87 which will eventually form the outer surface of the sleeve 80. Figure 13 shows adding the sleeve 80 and inserting the fitable bladder 81 into the inside of the sleeve. Figure 14 shows adding the upper mold 83, then pressurizing 84 and heating 85 onto the fitable bladder 81. After sufficient time to complete the formation of the sleeve, Figure 15 shows that the assembly may be cooled 86 and the bladder 81 may be depressurized. Figure 16 shows that the upper mold 83 can be removed, and then the bladder can be removed. The sleeve 80 can then be removed. It should then be understood that the sleeve 80 can be trimmed as previously described, and the end ring can be added as previously described.

[0063] This method has advantages, which will be explained below. The internal pressure and the resulting expansion tend to remove wrinkles in the fibers, thereby improving the compressive and tensile strengths. This process completely densifies the laminate, reducing porosity and eliminating penetration. If excess polymer or filler polymer is available, external features such as ribs, end rings, or other features can be formed.

[0064] Bladders may be made of different materials depending on temperature, expansion, and other factors. Bladders can be made as elastomers such as silicone, metals such as aluminum, or polymers with higher melting points such as polyimide.

[0065] Bladders can be biased in various ways. Firstly, bladders can be biased by internal pressure, such as pneumatic pressure. Secondly, bladders can be biased by applied forces using various structures, clamps, and / or weights. Thirdly, structures can be biased by utilizing materials with a higher coefficient of thermal expansion (CTE) compared to the surrounding structures.

[0066] For example, a glass fiber / PA composite cylinder could potentially be bladder-molded using an air-pressurized silicone bladder. Alternatively, a solid silicone cylinder could be used instead of a bladder, but in this case, the high CTE of silicone (assuming a mold made of lower-CTE steel, etc.) would result in pressurization at the melting temperature of PA. In the case of a glass fiber / PEEK cylinder, a silicone bladder would decompose at a higher temperature (>343C) than required to melt PEEK, so a higher-temperature bladder such as PI or aluminum would be needed. Alternatively, a solid aluminum cylinder could be used instead of a bladder, but in this case, the high CTE of aluminum (assuming a mold made of lower-CTE steel, etc.) would result in pressurization at the melting temperature of PEEK.

[0067] Although several embodiments have been described in detail for illustrative purposes, various modifications can be made to each without departing from the scope and spirit of the invention. Therefore, the invention is not limited except as provided for in the appended claims. [Explanation of symbols]

[0068] 10 Electric motor 11. Outer housing 12 staters 13 windings 14 rotors 15 Rotor Sleeves 16 Status Leaves 17 Permanent Magnets 18. Sleeves and staters before completion. 20 tapes, prepregs 21 Tape feed roller 22 Tools, Mandrels 23. Pry, Pry (plural) 24 Laura 25 power 26 Direction of travel 27 Heaters, high-temperature gas torch convection heaters 28 Tape cutter 30-slot compaction roller 31 Curvature 32 Annular gap 40 Axial Features / Ribs, Status Ribs 51 Endring, Status Leaves 52 Endring, Status Leaves 60 Cylindrical fasteners 70 Laser Welding Machines 71 Laser energy 72 Laura 80 Composite material sleeve preform 81 Compatible Bladder 82 Mold, bottom 83 Mold, top 84 Pressure 85 fever 86 Cooling 87 Surface, inside of the mold, outside of the sleeve

Claims

1. A method for manufacturing a stator leaf configured to be assembled as part of a cooled electric motor having a stator with a winding stationary conductor and a rotor having a rotating permanent magnet, wherein the coolant is configured to cool the winding stationary conductor, The steps include providing a cylindrical mandrel, A step of wrapping the cylindrical mandrel with prepreg tape using an automated fiber arrangement, wherein the automated fiber arrangement is in situ compaction, and The aforementioned prepreg tape contains a continuous fiber reinforcing material within the polymer matrix. The steps include heating the prepreg tape during the automatic fiber arrangement process, The steps include: cooling the wrapped prepreg tape by waiting for a certain amount of time to elapse; The steps include removing the cylindrical mandrel from the wrapped prepreg tape to obtain an incomplete cylindrical status leaf, The steps include trimming each end of the incomplete status leaf to obtain a trimmed status leaf having a first end opposite to a second end, A step of providing a first end ring and a second end ring, wherein the first end ring and the second end ring include a polymer, The polymer of the first and second end rings is the same material as the polymer matrix of the prepreg tape. The steps include using a cylindrical fastener to bring the first and second end rings into contact with the first and second ends of the trimmed status leaf, respectively, The steps include forming a completed status leaf configured to be installed on the cooled electric motor by laser welding or fusion joining the first and second end rings to the first and second ends of the trimmed status leaf, respectively; Methods that include...

2. The method according to claim 1, wherein the winding of the prepreg tape around the continuous fiber reinforcement material is in a hoop-wrap orientation.

3. The method according to claim 1 or 2, wherein the continuous fiber reinforcement comprises S2 glass, IM7 carbon, and / or boron.

4. The method according to claim 1 or 2, wherein the polymer matrix comprises PA, PET, PBT, POM, PPS, PEEK, PAEK, and / or PEKK.

5. The method according to claim 1 or 2, wherein heating of the prepreg tape during automatic fiber placement includes hot gas torch convection heating, laser heating, flash lamp heating, or infrared heating.

6. The method according to claim 1 or 2, wherein the first and second end rings comprise a carbon black-filled polymer.

7. The method according to claim 1 or 2, wherein the status leaf is impermeable to the coolant.

8. The method according to claim 1 or 2, wherein the prepreg tape is unidirectional.

9. The method according to claim 1 or 2, wherein the step of removing the cylindrical mandrel from the wrapped prepreg tape includes cooling the cylindrical mandrel to shrink it and reduce its size.

10. The method according to claim 9, wherein cooling of the cylindrical mandrel includes flowing a cooled liquid into the cylindrical mandrel.

11. The method according to claim 1 or 2, wherein the step of removing the cylindrical mandrel from the wrapped prepreg tape comprises dissolving the cylindrical mandrel in a liquid configured to dissolve the material of the cylindrical mandrel.

12. The method according to claim 1 or 2, wherein the step of removing the cylindrical mandrel from the wrapped prepreg tape includes the step of folding the cylindrical mandrel.

13. A method for manufacturing a stator leaf configured to be assembled as part of a cooled electric motor having a stator with a winding stationary conductor and a rotor having a rotating permanent magnet, wherein the coolant is configured to cool the winding stationary conductor, The steps include providing a cylindrical mandrel, A step of wrapping the cylindrical mandrel with prepreg tape using an automated fiber arrangement, wherein the automated fiber arrangement is in situ compaction, and The aforementioned prepreg tape contains a continuous fiber reinforcing material within the polymer matrix. The winding of the prepreg tape of the continuous fiber reinforcement material is in a hoop-wrap orientation. The continuous fiber reinforced material comprises S2 glass, IM7 carbon and / or boron. The polymer matrix comprises PA, PET, PBT, POM, PPS, PEEK, PAEK and / or PEKK. A step of heating the prepreg tape during the automatic fiber arrangement, wherein the heating includes high-temperature gas torch convection heating, laser heating, flash lamp heating, or infrared heating. The steps include: cooling the wrapped prepreg tape by waiting for a certain amount of time to elapse; The steps include removing the cylindrical mandrel from the wrapped prepreg tape to obtain an incomplete cylindrical status leaf, The steps include trimming each end of the incomplete status leaf to obtain a trimmed status leaf having a first end opposite to a second end, A step of providing a first end ring and a second end ring, wherein the first and second end rings include a polymer, The first and second end rings described above contain a carbon black-filled polymer. The polymer of the first and second end rings is the same material as the polymer matrix of the prepreg tape. The steps include using a cylindrical fastener to bring the first and second end rings into contact with the first and second ends of the trimmed status leaf, respectively, The steps include forming a completed status leaf configured for installation on a cooled electric motor by laser welding or fusion joining the first and second end rings to the first and second ends of the trimmed status leaf, respectively, and Methods that include...

14. A method for manufacturing a stator leaf configured to be assembled as part of a cooled electric motor having a stator with a winding stationary conductor and a rotor having a rotating permanent magnet, wherein the coolant is configured to cool the winding stationary conductor, The steps include providing a cylindrical mandrel, A step of wrapping a cylindrical mandrel with prepreg tape using an automated fiber placement system, The aforementioned prepreg tape contains a continuous fiber reinforcing material within the polymer matrix. The steps include heating the prepreg tape during the automatic fiber arrangement, The steps include: cooling the wrapped prepreg tape by waiting for an elapsed time; The steps include removing the cylindrical mandrel from the wrapped prepreg tape to obtain an incomplete cylindrical status leaf, The aforementioned unfinished cylindrical status leaf was not completely compacted. A step of providing an outer mold that forms the outer surface of the finished sleeve, The steps include: placing the aforementioned unfinished cylindrical status leaf, The steps include inserting a suitable bladder into a composite material sleeve, The steps include pressurizing the aforementioned compatible bladder, A step of heating an assembly comprising the outer mold, the unfinished cylindrical status leaf, and the adaptable bladder, wherein the unfinished status leaf is completely compacted, The steps include cooling the assembly, The steps include removing the unfinished status leaf from the outer mold and removing the compatible bladder, The steps include trimming each end of the incomplete status leaf to obtain a trimmed status leaf having a first end opposite to a second end, A step of providing a first end ring and a second end ring, wherein the first and second end rings include a polymer, The polymer of the first and second end rings is the same material as the polymer matrix of the prepreg tape. The steps include using a cylindrical fastener to bring the first and second end rings into contact with the first and second ends of the trimmed status leaf, respectively, The steps include forming a completed status leaf configured to be installed on the cooled electric motor by laser welding or fusion joining the first and second end rings to the first and second ends of the trimmed status leaf, respectively; Methods that include...

15. The method according to claim 14, wherein the winding of the prepreg tape around the continuous fiber reinforcement material is in a hoop-wrap orientation.

16. The method according to claim 14 or 15, wherein the continuous fiber reinforcement comprises S2 glass, IM7 carbon and / or boron.

17. The method according to claim 14 or 15, wherein the polymer matrix comprises PA, PET, PBT, POM, PPS, PEEK, PAEK and / or PEKK.

18. The method according to claim 14 or 15, wherein the heating of the prepreg tape during the automatic fiber arrangement includes high-temperature gas torch convection heating, laser heating, flash lamp heating, or infrared heating.

19. The method according to claim 14 or 15, wherein the first and second end rings include a carbon black-filled polymer.

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