Rotary electric machine protection ring, method for manufacturing same, tape-like material laminate, and rotary electric machine

Abstract

In order to provide a rotary electric machine protection ring having improved fracture strength, capable of suppressing magnet levitation during high-speed rotation of a rotor, and capable of improving output density of a rotary electric machine, the rotary electric machine protection ring has a fiber weight content of 72 to 90% and an internal void ratio of 5.0% or less, and is formed by molding a laminate in which a material containing a matrix resin and reinforcing fibers is continuously or intermittently laminated in an annular shape.

Description

Rotating electrical machine protection ring, method for manufacturing the same, tape-shaped material laminate, and rotating electrical machine

[0001] The present invention relates to a rotating electrical machine protection ring that can be used for protecting the rotor of a rotating electrical machine such as a generator or a motor, and a rotating electrical machine using the same.

[0002] In recent years, in order to improve the performance of rotating electrical machines, it has been required to rotate the rotor of a rotating electrical machine at high speed about its axis. Examples of the structure of a rotating electrical machine include an SPM (Surface Permanent Magnet) type in which permanent magnets are arranged on the outer peripheral side of the rotor, and an IPM (Internal Permanent Magnet) type in which permanent magnets are embedded in the rotor. When such a rotating electrical machine is rotated at high speed, due to centrifugal force, the permanent magnets arranged on the outer periphery may fall off from the rotor, or the magnets may float and scatter together with the electromagnetic steel sheets outside them, that is, the rotor itself may be damaged.

[0003] Patent Document 1 describes a rotating electrical machine having a structure in which carbon fibers are wound around the outer periphery of the rotor of a rotating electrical machine with tension (tensile stress) applied thereto to form a reinforcing member, and capable of suppressing destruction and deformation of the rotating electrical machine accompanying rotation.

[0004] Patent Document 2 describes a rotor having a scattering prevention member produced by winding a ribbon-shaped material of a CFRP material around the outer surface of a permanent magnet in a rotor with high tension (for example, 250 to 500 N) and subjecting it to a heat curing treatment. It is described that by making the tightening force of the scattering prevention member exceed the centrifugal force generated in the permanent magnet during high-speed rotation of the rotor, deformation of the permanent magnet toward the outer diameter side can be suppressed.

[0005] Patent Document 3 describes a carbon fiber reinforced resin-made scattering prevention member formed by winding and laminating carbon fibers along the outer peripheral direction of a magnet, which prevents the magnet from floating or scattering when the rotor rotates at high speed (for example, 5000 rpm or more). It is described that the volume content ratio of the carbon fibers in this scattering prevention member is 75 vol% or more.

[0006] Japanese Patent Laid-Open No. 60-102850 Japanese Patent Laid-Open No. 2023-151124 Japanese Patent Laid-Open No. 2015-91202

[0007] Patent documents 1 and 2 describe a method for forming a reinforcing member or a scattering prevention member by winding and laminating a material consisting of a matrix material such as resin and carbon fibers, and then molding it by heat curing. However, they do not describe any preferred requirements for the molded member.

[0008] Although the invention described in Patent Document 3 states that the volume content of carbon fibers in the scattering prevention member is 75 vol% or more, this is insufficient as a preferred requirement for a scattering prevention member in order to realize a rotating electric machine that exhibits high fracture resistance at high power density.

[0009] Therefore, the present invention aims to provide a rotating electric machine protective ring that improves the fracture strength of a rotating electric machine protective ring manufactured by winding a material containing matrix resin and reinforcing fibers around the outside of the rotor of a rotating electric machine, can suppress magnet levitation during high-speed rotation of the rotor, and can improve the power density of the rotating electric machine, as well as a method for manufacturing the same. The present invention also aims to provide a rotating electric machine having such a rotating electric machine protective ring.

[0010] The present inventors, after diligent study to solve the above problems, have found a rotating electric machine protection ring having any of the following requirements, a method for manufacturing the same, and a rotating electric machine having such a rotating electric machine protection ring, and have completed the present invention. (1) A rotating electric machine protection ring formed by molding a laminate in which a material containing a matrix resin and reinforcing fibers is continuously or intermittently laminated in an annular shape, wherein the fiber weight content is 72 to 90% and the internal void ratio is 5.0% or less. (2) A rotating electric machine protection ring provided on the outside of a rotor, wherein when it is cut along the axial direction at two opposing locations in the circumferential direction and removed from the rotor in two parts, the shrinkage rate of the outer radius at the circumferential center position of the two divided rings compared to before cutting is 5% or more, as described in (1). (3) A rotating electric machine protection ring according to (1) or (2), wherein in the thickness direction, a resin-rich layer is continuously present in a region including the outer surface with a thickness ratio of 1 to 20%. (4) A rotating electric machine protective ring according to any one of (1) to (3), wherein the maximum height roughness Rz of the outer surface in the region excluding a range of 10 mm from both ends in the axial direction is 0.5 mm or less. (5) A rotating electric machine protective ring according to any one of (1) to (4), wherein the thickness is 3.5 mm or less. (6) A rotating electric machine protective ring according to any one of (1) to (5), wherein the matrix resin contains a reaction product of a thermosetting resin and an amine compound. (7) A rotating electric machine protective ring according to any one of (1) to (6), wherein the fiber weight content is 80 to 85%. (8) A rotating electric machine protective ring according to any one of (1) to (7), wherein the thickness ratio of the resin-rich layer is 3 to 11%. (9) A tape-shaped material laminate, wherein the internal void ratio is 5.0% or less when molded by heat curing at 150°C for 2 hours, and the material containing the matrix resin and reinforcing fibers is laminated in a ring shape, continuously or intermittently. (10) The tape-shaped material laminate according to (9), wherein the change in axial length before and after molding is 5.0 mm or less. (11) The tape-shaped material laminate according to (9) or (10), wherein the change in axial length before and after molding is 1.5 mm or less.(12) A tape-like material laminate according to any one of (9) to (10), wherein the ratio of the change in axial length before and after molding to the thickness of the tape-like material laminate (change in axial length / thickness of tape-like material laminate) is 1.5 or less. (13) A method for manufacturing a rotating electric machine protection ring, comprising a manufacturing step of winding a tape-like material containing a matrix resin and reinforcing fibers, with a fiber weight content of 72 to 90%, in a ring shape multiple times under a tensile stress of 300 to 4000 MPa. (14) A method for manufacturing a rotating electric machine protection ring according to (13), wherein the fiber weight content is 80 to 85% and the tensile stress is 900 to 4000 MPa. (15) A method for manufacturing a rotating electric machine protection ring according to (13) or (14), wherein the matrix resin contains an amine-based curing agent. (16) A rotating electric machine having a rotor, with a rotating electric machine protection ring as described in any of (1) to (8) above mounted on the outside of the rotor, wherein the rate of change of the outer diameter of the rotating electric machine protection ring is 0.1% or less when rotating at a peripheral speed of 280 m / s. (17) The rotating electric machine according to (16), further having a stator on the outside of the rotating electric machine protection ring as described in any of (1) to (8), wherein the air gap between the rotor and the stator is 10 mm or less. (18) The rotating electric machine according to (16) or (17), wherein the power density of a single unit is 15 kW / kg or more.

[0011] The rotating electric machine protection ring according to the present invention can keep the internal void ratio low by keeping the fiber weight content within a specific range, while preventing the formation of an excessively resin-rich layer on the outer surface. As a result, it becomes a rotating electric machine protection ring with high fracture strength, which can suppress magnet levitation during high-speed rotation of the rotor and improve the power density of the rotating electric machine. In addition, such a rotating electric machine protection ring can be manufactured by winding a tape-like material containing a matrix resin and reinforcing fibers while applying a tensile stress within a specific range. Such a rotating electric machine protection ring will have high fracture strength and a large inward clamping force. Therefore, it can better prevent magnet levitation and scattering during high-speed rotation, and the rotor can rotate at an even higher speed. Furthermore, because the ring has high dimensional stability and surface smoothness, the gap between the rotor and stator (hereinafter referred to as the air gap) can be reduced, further improving the power density of the rotating electric machine.

[0012] Perspective view of a rotating electric machine protection ring according to an embodiment of the present invention Schematic diagram of a manufacturing apparatus for a rotating electric machine protection ring according to an embodiment of the present invention Schematic diagram of a manufacturing apparatus for a rotating electric machine protection ring according to an embodiment of the present invention (with a cooling mechanism) Schematic diagram of a manufacturing apparatus for a rotating electric machine protection ring according to an embodiment of the present invention (with a heating mechanism) Schematic diagram for illustrating the winding direction of a material including resin and reinforcing fibers on a core when forming a tape-shaped material laminate according to an embodiment of the present invention Schematic diagram of a cross section perpendicular to the fiber orientation direction when the fibers are oriented in one direction in a rotating electric machine protection ring Diagram illustrating the measurement of the outer radius of a rotating electric machine protection ring mounted on a rotor Schematic diagram of a cut and divided rotating electric machine protection ring

[0013] (Configuration of the Rotating Electric Machine Protection Ring) As shown in Figure 1, the rotating electric machine protection ring of the present invention is manufactured as a cylindrical laminate 1 by winding a material containing matrix resin and reinforcing fibers multiple times in a ring shape around a core 3, which is the component to be ultimately tightened, such as the rotor of a rotating electric machine. The reinforcing fibers are usually used in the form of bundles, but the material containing matrix resin and reinforcing fiber bundles may be a tape-like material in which the matrix resin has been impregnated into the reinforcing fiber bundles in advance, or it may be a material in which the matrix resin has been impregnated while the reinforcing fiber bundles are being driven to be wound in a ring shape.

[0014] The laminate constituting the rotating electric machine protection ring of the present invention is formed by laminating a material containing a matrix resin and reinforcing fibers in a ring shape, either continuously or intermittently. That is, the above material may be wound continuously from the beginning to the end of the winding, or it may be wound intermittently in multiple stages.

[0015] In this invention, the outer ring-shaped member used to protect the rotor of a rotating electric machine is referred to as a rotating electric machine protection ring or simply a ring. The laminate 1 may refer to the state after a material containing a matrix resin and reinforcing fibers has been wound and stacked and then molded, or it may refer to the state in which the material containing a matrix resin and reinforcing fibers has only been wound and stacked, i.e., the state in the manufacturing process before molding. Furthermore, a laminate 1 before molding, in which a tape-like material has been wound in a ring shape multiple times, may also be referred to as a tape-like laminate.

[0016] The type of fiber constituting the above-mentioned reinforcing fiber bundle is not particularly limited, and glass fiber, carbon fiber, aramid fiber, boron fiber, alumina fiber, and silicon carbide fiber can be used. Two or more of these fibers may be mixed and used. From the viewpoint of obtaining a lightweight and highly rigid rotating electric machine protection ring, it is preferable to use carbon fiber. The number of fibers constituting the fiber bundle can range from 1,000 to 50,000. The strand strength, which is the strength of the carbon fiber bundle, is preferably 4,000 MPa or higher. There is no upper limit, but those with a strength of 8,000 MPa or less may be used. The strand strength is determined in accordance with the resin-impregnated strand test method of JIS-R-7608 (2004) and follows the procedure below. Ten strands were impregnated with a resin composition containing 97% or more by mass of (3',4'-epoxycyclohexane)methyl-3,4-epoxycyclohexylcarboxylate, with an epoxy equivalent of 130 g / eq and a viscosity of 240 mPa·s at 25°C, and a composition of boron trifluoride monoethylamine and acetone = 100 / 3 / 4 (parts by mass). The strength of these strands was measured for 30 minutes in an oven set to atmospheric pressure and a temperature of 125°C, and the average value was defined as the strand strength. An example of the epoxy resin is "Celoxide (registered trademark)" 2021P (manufactured by Daicel Chemical Industries, Ltd.).

[0017] The resin used as the main component in the matrix resin described above is not particularly limited, but thermosetting resins such as epoxy resins, unsaturated polyester resins, phenolic resins, vinyl ester resins, and cyanate ester resins can be used in an uncured state. Two or more of these resins may be mixed and used. Furthermore, it is preferable to use these resins together with a curing agent that reacts with the thermosetting resin, as described later, as part of a resin composition.

[0018] When using an epoxy resin composition as the resin composition, it is preferable to include the following components [A] and [B]. Component [C] is preferable to include when adjusting the tackiness or complex viscosity of the resin composition. In this invention, "component" means a compound contained in the composition. Component [A]: Epoxy resin Component [B]: Curing agent that reacts with component [A] Component [C]: Thermoplastic resin.

[0019] Examples of component [A] include epoxy resins such as diaminodiphenylmethane type, diaminodiphenylsulfone type, aminophenol type, bisphenol type, metaxylenediamine type, 1,3-bisaminomethylcyclohexane type, isocyanurate type, hydantoin type, phenol novolac type, orthocresol novolac type, dicyclopentadiene type, trishydroxyphenylmethane type, and tetraphenyloleethane type.

[0020] Commercially available diaminodiphenylmethane-type epoxy resins include ELM434 (manufactured by Sumitomo Chemical Co., Ltd.), ELM434VL (manufactured by Sumitomo Chemical Co., Ltd.), "Araldite®" MY720 (manufactured by Huntsman Advanced Materials Co., Ltd.), "Araldite®" MY721 (manufactured by Huntsman Advanced Materials Co., Ltd.), "Araldite®" MY9512 (manufactured by Huntsman Advanced Materials Co., Ltd.), "Araldite®" MY9663 (manufactured by Huntsman Advanced Materials Co., Ltd.), and "Epotote®" YH-434 (manufactured by Nippon Steel Chemical & Material Co., Ltd.).

[0021] Examples of commercially available diaminodiphenylsulfone-type epoxy resins include TG3DAS (manufactured by Mitsui Chemicals Fine, Inc.).

[0022] Commercially available aminophenol-type epoxy resins include ELM120 (manufactured by Sumitomo Chemical Co., Ltd.), ELM100 (manufactured by Sumitomo Chemical Co., Ltd.), "jER®" 630 (manufactured by Mitsubishi Chemical Corporation), "Araldite®" MY0500 (manufactured by Huntsman Advanced Materials Co., Ltd.), "Araldite®" MY0510 (manufactured by Huntsman Advanced Materials Co., Ltd.), "Araldite®" MY0600 (manufactured by Huntsman Advanced Materials Co., Ltd.), and "Araldite®" MY0610 (manufactured by Huntsman Advanced Materials Co., Ltd.).

[0023] Bisphenol-type epoxy resins include bisphenol A type epoxy resin and bisphenol F type epoxy resin.

[0024] Commercially available bisphenol A type epoxy resins include "jER®" 825, 828, 1001, and 1007 (all manufactured by Mitsubishi Chemical Corporation), "Epiclon®" 850 (manufactured by DIC Corporation), "Epotote®" YD-128 (manufactured by Toto Chemical Co., Ltd.), DER-331 (manufactured by Dow Chemical Company), and DER-332 (manufactured by Dow Chemical Company).

[0025] Commercially available bisphenol F type epoxy resins include "Araldite®" GY282 (manufactured by Huntsman Advanced Materials), "jER®" 806, 807, and 1750 (all manufactured by Mitsubishi Chemical Corporation), "Epiclon®" 830 (manufactured by DIC Corporation), and "Epotote®" YD-170 (manufactured by Toto Chemical Co., Ltd.).

[0026] Examples of commercially available dicyclopentadiene-type epoxy resins include "Epiclon®" HP7200 (manufactured by DIC Corporation).

[0027] Furthermore, in the present invention, epoxy resin compositions may also contain epoxy compounds other than those mentioned above as appropriate.

[0028] Examples of component [B] are not particularly limited, but can be selected from amine-based curing agents, alcohol compounds, phenol compounds, cationic curing agents, anionic curing agents, radical curing agents, acid anhydride compounds, and imidazole compounds. Examples of amine-based curing agents include dicyandiamide or its derivatives, diaminodiphenylsulfone or its derivatives. Here, dicyandiamide can be used in combination with ureaamine-based curing agents or urea compounds to control the reactivity of the induced curing reaction. Since these curing accelerators containing urea compounds react with component [A], they are considered curing agents in this invention and are included in the examples of component [B]. Examples of urea compounds include 3-(3,4-dichlorophenyl)-1,1-dimethylurea (DCMU99), 3-(4-chlorophenyl)-1,1-dimethylurea, phenyldimethylurea, and toluenebisdimethylurea.

[0029] Commercially available dicyandiamides include DICY-7 and DICY-15 (both manufactured by Mitsubishi Chemical Corporation). Diaminodiphenylsulfone has structural isomers depending on the position of the amino group. Commercially available 4,4'-diaminodiphenylsulfones include "SeikaCure®"-S (manufactured by Seika Co., Ltd.) and "SumiCure®"-S (manufactured by Sumitomo Chemical Co., Ltd.). Commercially available 3,3'-diaminodiphenylsulfones include 3,3'-DAS (manufactured by Mitsui Chemicals Fine, Inc.).

[0030] Rotating electric machines are generally cooled during operation to suppress heat generation during rotation. Cooling methods include air cooling, water cooling, and oil cooling. In the case of water cooling and oil cooling, the rotating electric machine protection ring needs to maintain its desired performance even when exposed to water or cooling oil for extended periods. From this perspective, amine-based curing agents with a relatively stable chemical structure are suitably used for any of these cooling methods.

[0031] Examples of component [C] include polyamides, polycarbonates, polyacetals, polyphenylene oxides, polyphenylene sulfides, polyarylates, polyesters, polyamide-imides, polyimides, polyetherimides, polyimides having a phenyltrimethylindan structure, polysulfones, polyethersulfones, copolymer oligomers of polyethersulfones and polyetherethersulfones, polyether ketones, polyetherether ketones, polyaramids, polyethernitriles and polybenzimidazoles, polyvinyl alcohols, polyvinyl acetals, polyvinyl formals, polyvinyl acetal, polyvinyl butyrals, polyvinyl acetates, hydrogenated bisphenol A / pentaerythritol phosphite polymers, hydrogenated terpenes, and hydrogenated terpene phenols.

[0032] [C] Examples of commercially available components (thermoplastic resins) include the commercially available polyethersulfone products "Sumika Excel®" PES3600P, "Sumika Excel®" PES5003P, "Sumika Excel®" PES5200P, and "Sumika Excel®" PES7600P (all manufactured by Sumitomo Chemical Co., Ltd.), and "VIRANTAGE®" VW-10700RFP (manufactured by Solvay Advanced Polymers Co., Ltd.), as well as the commercially available polyetherimide product "Ultem®" 10 Examples include 00, "Ultem®" 1010, "Ultem®" 1040 (all manufactured by SHPP Japan LLC), and other commercially available thermoplastic resins such as "J-POVAL®" (manufactured by Nippon Vinegar Vinegar POVAL Co., Ltd.), "Vinylec®" (manufactured by JNC Corporation), "Eslec®" (manufactured by Sekisui Chemical Co., Ltd.), "Ultrasen®" (manufactured by Tosoh Corporation), JPH-3800 (manufactured by Johoku Chemical Industry Co., Ltd.), and YS Polystar UH130 (manufactured by Yasuhara Chemical Co., Ltd.).

[0033] As described above, the rotating electric machine protection ring in the present invention is preferably composed of a laminate 1 in which a tape-like material, in which a matrix resin is impregnated into a reinforcing fiber bundle, is wound multiple times in an annular shape.

[0034] For such tape-like materials, slit tapes or tow pregs made of prepregs in which the reinforcing fiber bundles are impregnated with matrix resin in advance may be used, or materials in which the reinforcing fiber bundles are impregnated with matrix resin during the manufacturing process of the laminate 1 by methods such as filament winding may be used. In the present invention, from the viewpoint of easily improving the dimensional accuracy of the tape-like material, it is preferable to use slit tapes or tow pregs made of prepregs in which the reinforcing fiber bundles are impregnated with matrix resin in advance.

[0035] In the present invention, the preferred fiber weight content of the material containing the matrix resin and reinforcing fibers is 72 to 90%, more preferably 74 to 88%, even more preferably 75 to 85%, and most preferably 80 to 85%. If the fiber weight content of the material is lower than this range, the dimensional change in the ring axial direction during the manufacturing process becomes large, an excessive resin-rich layer is formed on the outer surface, and the surface smoothness of the rotating electric machine protection ring decreases. In the present invention, the outer surface refers to the surface located on the outside when the rotating electric machine protection ring is mounted on the outer circumference of the rotor. On the other hand, with materials having a fiber weight content higher than this range, it becomes difficult to sufficiently impregnate the reinforcing fibers with resin, and the material becomes prone to breaking when wound in a tape-like form and subjected to tensile stress. In addition, when laminating the material, air trapped between layers becomes difficult to escape during molding, increasing the internal void ratio of the rotating electric machine protection ring and reducing its fracture strength.

[0036] When the material containing the matrix resin and reinforcing fiber bundles is in the form of a tape, the width of the material is not particularly limited, but it is preferable to use a material with a width of 1 mm to 20 mm because it makes it easy to wind it to form a laminate. The width of the material is determined by the method described later.

[0037] The rotating electric machine protection ring of the present invention preferably has an outer diameter (reference numeral 50 in Figure 1) of 1 to 25 cm, more preferably 6 to 23 cm, and even more preferably 8 to 20 cm. This outer diameter can be determined by measuring any one point on the ring.

[0038] (Method for manufacturing a rotating electric machine protective ring) In the present invention, the rotating electric machine protective ring is composed of a cylindrical laminate 1 made of a material including a matrix resin and reinforcing fibers. In the manufacturing apparatus, as illustrated in Figure 2, a predetermined path is formed from the bobbin 4 on which the material is wound to the starting point of winding in the core 3 by a path-forming device (path-forming device) mainly consisting of rolls and guides. In the present invention, such a predetermined path is not necessarily limited to a single path, but can be configured in various ways by combining path-forming devices according to the purpose.

[0039] In the manufacturing method of the laminate 1, the material is unwound from the bobbin 4, traveled along the path while in contact with rolls, guides, etc., and then wound around the core 3 multiple times in a ring shape to form the laminate 1. The travel speed of the material is preferably 1 to 50 m / min. In the present invention, a tensile stress within the range described later is applied to the material from a certain point in the path (including the point where travel begins) to the starting point of winding. Here, the application of tensile stress to the material can be performed using the stress application mechanism 7 shown in Figure 2, etc.

[0040] The configuration of the stress application mechanism 7 is not particularly limited, but examples include applying torque to the bobbin 4 by a brake, applying frictional resistance to the material by the multi-stage roll 5, and applying frictional resistance to the material by the nip roll 6. Figures 2, 3, and 4 show an example in which a stress application mechanism 7 using a multi-stage roll 5 is provided in the path from the bobbin 4 to the core 3, and the tension applied to the moving material increases each time it passes through each roll of the multi-stage roll.

[0041] Bobbin 4 is formed by winding the above material around an inner tube to create a bobbin shape. To separate the above material from the bobbin without resistance, a film may be attached to the inner circumference of the above material. Alternatively, metal may be used for the inner tube of the bobbin.

[0042] As described above, the path forming device mainly consists of rolls and guides, and includes those that come into contact with the material to define its running path. The rolls include both free rolls and driving rolls. However, the path forming device is not limited to only rolls and guides. The stress applying mechanism 7 described above can be a path forming device.

[0043] In the present invention, the tensile stress (MPa) can be calculated by dividing the tension applied to the material containing the matrix resin and the reinforcing fiber by the cross-sectional area of the material. For example, in the case of a tape-shaped material, the tension (N) applied to the tape-shaped material is obtained by dividing it by the product of the thickness A (mm) and the width B (mm) of the tape-shaped material. For the thickness A (mm) and B (mm) of the tape-shaped material, a 1 m length is sampled, and the thickness (mm) and width (mm) at 10 positions every 10 cm in the length direction are measured using a micrometer or a ruler, and the average value of each is obtained by rounding the third decimal place.

[0044] In the present invention, in order to prevent deformation of the core 3 during rotation, a tensile stress within a predetermined range is applied to the material in the predetermined path (the path from the bobbin to the starting point of winding the material on the core 3).

[0045] The tensile stress within the predetermined range is preferably 300 MPa or more, more preferably 700 MPa or more, still more preferably 900 MPa or more, and most preferably 1100 MPa or more in order to suppress magnet levitation during high-speed rotation of the rotor. Also, it is desirable to set the tensile stress range below the tensile strength of the reinforcing fiber. For example, 6000 MPa or less or 4000 MPa or less is preferable.

[0046] The core 3 is a member that is finally tightened by the material, such as the rotor of a rotating electrical machine.

[0047] As shown in Fig. 5, the laminate 1 is formed by winding a material containing a matrix resin and reinforcing fibers around the end face 13 of the core 3 at the same height position when the end face 13 of the core 3 is placed in the vertical direction. That is, when the circumferential direction 14 (angle 15 is 0°) of the core 3 is taken as the reference direction, it may be wound around in the reference direction, or it may be wound around in a helical shape by changing the angle 15 from the reference direction. At this time, the winding is performed by rotating the core 3 in the direction of the rotation direction 9 of the core shown in Fig. 2 and the like.

[0048] When an uncured thermosetting resin is used as the resin constituting the material, a rotating electric machine protection ring can be obtained by curing a laminate 1, which is obtained by winding the material in an annular shape, by applying heat or heat and pressure using methods such as autoclave molding or wrap tape molding. At this time, the tape-shaped material laminate 1, which is formed by winding and laminating tape-shaped material subjected to high tensile stress, may experience an increase in axial length (reference numeral 40 in Figure 1) during heat molding. This phenomenon occurs because the matrix resin present at the end of the laminate, which softens during heating, flows outward in the axial direction due to residual stress. In a rotating electric machine protection ring, the ring end where the axial length has increased due to the flow of the matrix resin becomes thinner, reducing the magnet levitation suppression effect. Furthermore, the dimensions may not be as designed, potentially causing malfunctions in the rotating electric machine. Therefore, it is necessary to reduce the change in axial length during heat molding as much as possible. A preferred change in axial length at this time is 5.0 mm or less, more preferably 4.0 mm or less, even more preferably 3.0 mm or less, and most preferably 1.5 mm or less. In this invention, by increasing the fiber content of the tape-like material used, the amount of flowing matrix resin can be reduced, thereby reducing the change in axial length. Furthermore, in this invention, the ratio of the change in axial length to the thickness of the tape-like material laminate (change in axial length / thickness of tape-like material laminate) is preferably 5.0 or less, more preferably 4.0 or less, even more preferably 3.0 or less, and most preferably 1.5 or less. The method for evaluating the change in axial length before and after heat molding will be described in detail in the section on calculating the change in axial length before and after heat molding of the laminate in the later examples. The thickness of the tape-like material laminate is evaluated in the same way as the thickness of the rotating electric machine protection ring described later.

[0049] Furthermore, as shown in Figure 3, the cooling mechanism 10 may cool at least a portion, preferably all, of the material from a higher temperature to 20°C or lower, preferably 15°C or lower, and even more preferably 5°C or lower, before or during the stress application process. In the case of materials using thermosetting resins, cooling is preferable because it can suppress molecular motion, improve viscosity, and prevent thread breakage. On the other hand, as shown in Figure 4, the heating mechanism 11 may heat at least a portion, preferably all, of the material before or during the stress application process. In the case of materials using thermosetting resins, heating is preferable because it can promote the curing reaction, improve viscosity, and prevent thread breakage. Here, "before or during the stress application process" refers to the stage before or during which a tensile stress of 300 MPa or more is applied to the material. For example, when the multi-stage roll 5 and nip roll 6 described above are used as components of the stress application mechanism 7, it refers to the stage before or during which a tensile stress of 300 MPa or more is applied to the material.

[0050] When using thermoplastic resin as the material, by applying heat with a laser or the like at the same time as winding the material during lamination, the structure of the laminate 1 and the rotating electric machine protection ring can be obtained simultaneously.

[0051] (Fiber weight content of the rotating electric machine protection ring) The fiber weight content of the rotating electric machine protection ring in the present invention is 72 to 90%, preferably 74 to 88%, more preferably 75 to 85%, and most preferably 80 to 85%. Unless there is a weight loss during the manufacturing process such as component volatilization, the fiber weight content of the rotating electric machine protection ring will be substantially equal to or nearly equal to the fiber weight content of the tape-like material. If the fiber weight content is lower than this range, the fracture strength and rigidity of the ring may decrease, which may reduce the effect of suppressing magnet levitation during high-speed rotation of the rotor. The method for evaluating the fiber weight content of the rotating electric machine protection ring will be described in detail in the section on measurement of the fiber weight content of the rotating electric machine protection ring in the later examples.

[0052] (Thickness of the Rotating Electric Machine Protection Ring) In the present invention, the thickness of the rotating electric machine protection ring can be made as thin as possible, within the range that can suppress magnet levitation during high-speed rotation of the rotor. The thinner the ring, the smaller the air gap can be, and the power density of the rotating electric machine can be improved. On the other hand, if the ring is too thin, the effect of suppressing magnet levitation during high-speed rotation of the rotor will be reduced, and the risk of magnet detachment or rotor damage may not be sufficiently reduced. The suppression of magnet levitation is affected by the tensile stress and fiber content applied to the tape-like material during the manufacturing of the ring, and the optimal ring thickness is selected by balancing these conditions. In the present invention, the thickness of the ring can be designed to be 3.5 mm or less. Furthermore, the ring thickness that exhibits a sufficient magnet levitation suppression effect during high-speed rotation of the rotor is preferably 0.5 mm or more, more preferably 0.7 mm or more, and even more preferably 0.9 mm or more. The method for evaluating the ring thickness will be described in detail in the section on calculating the thickness of the rotating electric machine protection ring in the later examples.

[0053] (Surface Smoothness of Rotating Electric Machine Protection Ring) As mentioned above, one of the challenges in improving the power density of a rotating electric machine is to reduce the thickness of the rotating electric machine protection ring and reduce the air gap. However, if localized protrusions exist on the outer surface of the ring when the air gap is reduced, the risk of damage due to contact with the stator increases. Furthermore, if the design philosophy prioritizes reducing this risk of damage and is based on safety, the air gap will be made larger than intended, leading to a decrease in power density. In addition, there is concern about eccentricity during high-speed rotation due to differences in thickness within the ring. Therefore, it is preferable for the outer surface of the ring to be smooth. However, when a material that has been wound and laminated under high tensile stress is heat-molded, irregularities tend to occur on the ring surface after molding due to the flow of the matrix resin. In contrast, in the present invention, the amount of flowing matrix resin is reduced, that is, the fiber content of the material used is increased to suppress the occurrence of irregularities. When the evaluation index is set to the maximum surface height roughness Rz as defined in JIS B0601-2013, and measured by the method detailed in the section on evaluation of the outer surface smoothness of the rotating electric machine protection ring in the later examples, the preferred Rz of the outer surface of the rotating electric machine protection ring in the present invention is 0.5 mm or less, more preferably 0.4 mm or less, and even more preferably 0.35 mm or less. By setting Rz within this range, rotor eccentricity during high-speed rotation can be suppressed, and damage due to contact between the ring and the stator can be easily suppressed.

[0054] (Internal Void Ratio of Rotating Electric Machine Protection Rings) In rotating electric machine protection rings obtained by molding a material containing matrix resin and reinforcing fibers, it is necessary to reduce the proportion of internal voids, which are a factor in reducing strength. However, in rotating electric machine protection rings made by laminating materials with a high fiber content, it is difficult to remove the air trapped between the layers during lamination during molding. In addition, the impregnation of the matrix resin into the reinforcing fibers is poor, and voids tend to exist in the material used. Therefore, it is difficult to reduce the internal void ratio using materials with a high fiber content with conventional technology. However, in the present invention, even when using a tape-like material with a very high fiber content (for example, 75% by weight or more), the residual stress generated in the material allows air to escape during molding, making it possible to obtain a rotating electric machine protection ring with a low internal void ratio. The reason for this is thought to be that the tensile stress applied when winding and laminating the tape-like material is appropriate for the material used, allowing air to escape during winding and subsequent heat curing. The appropriate tensile stress for obtaining a sufficient void reduction effect is preferably 300 MPa or more, more preferably 700 MPa or more, even more preferably 900 MPa or more, and most preferably 1100 MPa or more. The preferred internal void ratio of the ring, which makes it less likely to break even when subjected to large loads generated by the high-speed rotation of the rotor, is 5.0% or less, more preferably 4.0% or less, and even more preferably 3.0% or less. Furthermore, the tape-shaped laminate according to the present invention has the above-mentioned internal void ratio for a ring obtained by heat curing at 150°C for 2 hours. The method for evaluating the internal void ratio of the rotating electric machine protection ring will be described in detail in the section on calculation of the internal void ratio of the rotating electric machine protection ring in the later examples.

[0055] (Cross-sectional view of the rotating electric machine protective ring) In the rotating electric machine protective ring of the present invention, as an example of a cross-section perpendicular to the circumferential direction, Figure 6 shows a schematic diagram of a cross-section perpendicular to the fiber orientation direction when the fibers are oriented in one direction. A resin-rich layer 20 is formed on the outer surface side and a fiber-rich layer 21 is formed on the core side.

[0056] Here, a resin-rich layer is defined as a layer in which matrix resin 19 accounts for 50% or more by volume at the same thickness location, and a fiber-rich layer is defined as a layer in which fibers 18 account for more than 50% by volume at the same thickness location. In other words, a region in the radial direction of the rotating electric machine protection ring that has a constant thickness and contains more matrix resin 19 than other areas, where the volume ratio of matrix resin 19 is 50% or more, is called a resin-rich layer, and a region in the radial direction of the rotating electric machine protection ring that has a constant thickness and contains more fibers 18 than other areas, where the volume ratio of fibers 18 exceeds 50% is called a fiber-rich layer.

[0057] In the present invention, when manufacturing the rotating electric machine protection ring, a material containing a matrix resin and a reinforcing fiber bundle is subjected to appropriate tensile stress and then wound and laminated. As a result, when heat molding is performed, the matrix resin seeps out from the inside to the surface, forming a resin-rich layer. In the resin-rich layer, it is preferable that a portion contains 70% or more of the matrix resin 19 by volume, more preferably 80% or more, and even more preferably 90% or more.

[0058] As described above, there is a need for a rotating electric machine protection ring that will not break even when subjected to large loads generated by the high-speed rotation of a rotor. One form of failure is delamination from the end of the winding when the material is wound and laminated. In this case, a resin-rich layer is present at the end of the winding of the rotating electric machine protection ring in the present invention. Even if a peeling force is generated at the end of the winding, the resin-rich layer present on and near the surface deforms and can resist delamination, thereby improving the peeling strength, i.e., the fracture strength of the ring. To form the resin-rich layer at the end of the winding, it is effective to form the resin-rich layer over the entire outer surface of the ring. On the other hand, since the resin-rich layer has a low content of reinforcing fibers, its contribution to the effect of suppressing magnet levitation during high-speed rotation is small. The preferred ratio of the thickness of the resin-rich layer 20 that is continuously present in the region including the surface to the thickness of the rotating electric machine protection ring is 1 to 20%, more preferably 2 to 18%, even more preferably 3 to 16%, and most preferably 3 to 11%. In this context, "continuous existence" means that the resin-rich layer is not divided into multiple intermittent layers, but extends continuously from the surface of the ring to a certain depth. If this ratio is lower than this range, a sufficient improvement in peel strength may not be achieved. If it is higher than this range, there will be excess resin-rich layer 20, leading to an increase in the thickness of the ring. The method for evaluating the ratio of the thickness of the resin-rich layer in the region including the surface to the thickness of the ring will be described in detail in the section on the ratio of the resin-rich layer of the rotating electric machine protection ring in the later examples.

[0059] (Shrinkage Rate of Rotating Electric Machine Protection Ring) A rotating electric machine protection ring, manufactured by winding a material under high tensile stress, generates a tightening force toward the center of the rotor located inside. This creates the effect of suppressing magnet levitation when the rotor rotates at high speed. When such a rotating electric machine protection ring is removed from the rotor, the ring shrinks radially in proportion to the magnitude of this inward tightening force. This phenomenon can be used to estimate the magnitude of the inward tightening force exerted by the rotating electric machine protection ring, i.e., the effect of suppressing magnet levitation. The greater the tightening force, the more effectively magnet levitation can be suppressed even in high-speed rotation regions. Since it is difficult to remove a ring with a large inward tightening force from the rotor, when evaluating the above tightening force, the ring is cut at a specific point to divide it into two parts before removal. The actual evaluation method will be described in detail in the section on calculating the ring shrinkage rate when cut in the later examples. The shrinkage rate of a ring that can suppress magnet levitation at high speed rotation is preferably 5% or more, more preferably 8% or more, and even more preferably 10% or more. Furthermore, a larger shrinkage rate is preferable because it exhibits a higher magnet levitation suppression effect, but the upper limit is, for example, 80% or less or 60% or less, due to the upper limit of tensile stress when the tape-shaped material is wound and laminated.

[0060] (Rotating Electric Machine) The rotating electric machine according to the present invention comprises a rotor and a rotating electric machine protective ring disposed on the outside of the rotor. As described above, the rotating electric machine protective ring is made by forming a laminate in which a material containing reinforcing fibers and matrix resin is wound multiple times in an annular manner around a core material such as a rotor. The molding is performed by heating, or by heating and pressurizing. As a result, a rotating electric machine is obtained in which the rotating electric machine protective ring is mounted around the rotor.

[0061] In such a rotating electric machine, the rotating electric machine protection ring mounted on the rotor can have an outer diameter change rate of 0.1% or less when the rotor is rotating at a peripheral speed of 280 m / s or less. This outer diameter change rate is preferably 0.09% or less, more preferably 0.08% or less, and particularly preferably 0.07% or less. The method for evaluating this outer diameter change rate will be described in detail in the section on measurement of the outer diameter change rate of the rotating electric machine protection ring during rotation in the later embodiments.

[0062] Furthermore, the rotating electric machine according to the present invention may include a rotor, a rotating electric machine protective ring, and a stator outside the rotating electric machine protective ring. The smaller the air gap between the rotor and the stator, the higher the magnetic flux density can be, and consequently, the higher the power density of the rotating electric machine can be. A preferred air gap for realizing a high-power rotating electric machine is 10 mm or less, more preferably 7 mm or less, and even more preferably 5 mm or less. The rotating electric machine protective ring described in the present invention can suppress magnet levitation at high speed rotation even with a thin thickness, and its high surface smoothness contributes to reducing the air gap. There is no particular restriction on the lower limit of the air gap, but it is preferable to provide a small gap (for example, 0.3 mm or 0.5 mm) that is sufficient to avoid contact between the rotating electric machine protective ring and the stator.

[0063] According to this technology, deformation of the outer diameter of the permanent magnet is suppressed during high-speed rotation, enabling even higher rotation speeds, and thus improving the output or power density of such a rotating electric machine. The power density of a single rotating electric machine, which is the output density that can be generated by the machine alone, is preferably 15 kW / kg or more, more preferably 20 kW / kg or more, and particularly preferably 30 kW / kg or more. There is no particular upper limit to the power density of the single rotating electric machine, and a higher value is preferable as it results in a higher-performance rotating electric machine, but technically, those of 100 kW / kg or less are used. The power density of a rotating electric machine is calculated by dividing the output of the rotating electric machine by the weight of the rotating electric machine. The output of a rotating electric machine is expressed as the product of the rotational speed and torque. The rotational speed and torque are measured using general methods such as using a motor bench.

[0064] The upper and lower limits of the numerical ranges described above can be combined in any way. Furthermore, throughout this specification, weight, like mass, refers to the quantity of the object itself, excluding the effects of gravity.

[0065] The present invention will be described in detail below using examples, but the scope of the present invention is not limited to the following examples. The rotating electric machine protection rings and rotating electric machines obtained in each example and comparative example were evaluated based on the following method.

[0066] (Calculation of the thickness of the rotating electric machine protection ring) The thickness [mm] of the rotating electric machine protection ring was calculated using the rotor radius R1 [mm] and the outer radius R2 [mm] of the rotating electric machine protection ring, as shown in the following equation (1). Using a radius measuring instrument R caliper, an arbitrary point on the circumference was selected, and R1 and R2 were measured at that same position. Thickness of the rotating electric machine protection ring [mm] = R2 - R1 (1)

[0067] (Evaluation of the outer surface smoothness of the rotating electric machine protection ring) Using the "SURFTEST SJ-220 series" manufactured by Mitutoyo Corporation, the outer surface of the rotating electric machine protection ring mounted on the rotor was scanned along the axial direction using a probe, and the surface shape was measured. However, the area 10 mm from both ends in the axial direction of the ring, where the thickness may be reduced due to the flow of the matrix resin, was excluded from the scanning area. The maximum surface height roughness Rz (JIS B0601-2013) calculated from the obtained surface shape was used as an evaluation index for outer surface smoothness. The smaller Rz, the smoother the outer surface and the better the rotating electric machine protection ring is considered to be.

[0068] (Calculation of ring shrinkage rate upon cutting) When the outer radius of the rotating electric machine protection ring when mounted on the rotor is R3 [mm], and the outer radius of the ring removed from the rotor after cutting is R4 [mm], the ring shrinkage rate upon cutting was calculated using the following formula (2): Ring shrinkage rate upon cutting [%] = (R3 - R4) × 100 / R3 (2) The outer diameter was measured using a radius measuring instrument R caliper. After cutting, the ring is removed and shrinks significantly, so the radius may differ from place to place. Given the existence of such variability, a series of procedures to improve the reproducibility of the evaluation will be explained below with reference to Figures 7 and 8. First, for the rotating electric machine protection ring mounted on the rotor, the outer radius R3 is measured at the axial center position (22 in Figure 7, hereinafter referred to as the R3 measurement point) at an arbitrary position in the circumferential direction. Next, two opposing points on the circumferential direction of the rotating protection ring while it is mounted on the rotor are selected such that the center position of these two points on the circumferential direction becomes the R3 measurement point. At these two points (23 in Figure 7), the ring is cut along the axial direction using a grinder or the like, dividing it into two parts and removing it from the rotor in a semi-cylindrical state. That is, when 22 in Figure 7 is the R3 measurement point, the ring is cut along 23. The outer radius R4 of the ring is measured at the center position on the circumferential direction of the removed semi-cylindrical ring (24 in Figure 8) (i.e., the same position as the R3 measurement point (25 in Figure 8, R4 measurement point)). Since two semi-cylindrical rings are obtained from one rotating electric machine protection ring, the outer radii R3 and R4 are measured for each of these two semi-cylindrical rings as described above, and the ring shrinkage rate is calculated from equation (2) for each, and the average value is taken as the ring shrinkage rate at the time of cutting.

[0069] (Calculation of Internal Void Ratio of Rotating Electric Machine Protection Ring) The internal void ratio of the rotating electric machine protection ring was evaluated by cutting the ring along the axial direction at an arbitrary position in the circumferential direction, polishing the cross section perpendicular to the circumferential direction, and observing the cross section using an optical microscope. Using a KEYENCE VHX-6000 microscope, the internal void ratio was calculated by binarizing the cross section image observed at a magnification of 500x, separating the black dot areas (internal voids) from the rest of the image. The ratio of the area of ​​the black dot areas was used as the internal void ratio. Using the automatic area measurement tool built into the VHX-6000, the threshold was manually set while viewing the image so that only the black dot areas (internal voids) were extracted. This process was repeated 50 times, changing the observation location, and the average value was taken as the internal void ratio of the rotating electric machine protection ring. However, interlayer cracking during ring cutting may cause continuous defects inside the ring, which may be observed as black areas in the cross section observation. To exclude the influence of continuous defects that occurred during this cutting process, in this evaluation, observation areas containing continuous defects with a length of 1 mm or more were excluded from the evaluation area.

[0070] (Percentage of resin-rich layer in rotating electric machine protection rings) After polishing a cross-section perpendicular to the circumferential direction of a rotating electric machine protection ring cut along its axial direction, it was observed using an optical microscope. At this time, a preferred magnification was selected so that the entire thickness of the ring cross-section was captured. For example, a ring with a thickness of approximately 1.5 mm is preferably observed at a magnification of 100 to 150 times. From the above cross-sectional observation, the ratio of the thickness of the resin-rich layer present in the region including the surface to the thickness of the ring was calculated. This process was repeated 30 times, changing the observation location each time, and the average value was taken as the percentage of the surface resin-rich layer in the thickness direction of the rotating electric machine protection ring.

[0071] (Measurement of Fiber Weight Content of Rotating Electric Machinery Protection Ring) The fiber weight content of the rotating electric machinery protection ring was calculated using the following formula (3). The weight W1 [g] of a fragment of the rotating electric machinery protection ring, cut along the axial direction, having an arbitrary length in the circumferential direction and including the entire thickness in the radial direction of the ring, was measured. The ring fragment was heated at 500°C for 3 hours under a nitrogen atmosphere to burn off the resin components, and the weight W2 [g] of the remaining reinforcing fibers was measured. Fiber weight content [%] = W2 × 100 / W1 (3)

[0072] (Measurement of Fiber Weight Content of Tape-Shaped Material) The fiber weight content of the tape-shaped material used was calculated using the following formula (4). The weight W3 [g] of a piece of tape-shaped material of an arbitrary length (e.g., 500 mm) cut perpendicular to the longitudinal direction was measured. The piece of tape-shaped material was then heated at 500°C for 3 hours under a nitrogen atmosphere to burn off the resin components, and the weight W4 [g] of the remaining reinforcing fibers was measured. Fiber weight content [%] = W4 × 100 / W3 (4)

[0073] (Calculation of change in axial length before and after heat molding of the laminate) In the process of manufacturing a rotating electric machine protection ring by molding under the conditions described in Example 1 below, the axial length of the laminate before heat molding was measured at 16 points where the circumferential distance between adjacent points was equal (i.e., measured at each position that divides the circumference into 16 equal parts), and the average value was taken as L1. The axial length of the laminate after heat molding was measured at 16 points at the same positions as before heat molding, and the average value was taken as L2. The change in axial length before and after heat molding was calculated using the following formula (5). The axial length was measured using a digital caliper. Change in axial length before and after heat molding [mm] = L2 - L1 (5)

[0074] (Measurement of the fracture strength of the rotating electrical machine protection ring) The fracture strength of the rotating electrical machine protection ring was evaluated using the following method, referencing the method described in ASTM D2290. A two-part semi-cylindrical jig, with the rotating electrical machine protection ring attached to its side surface, was assembled to form a roughly cylindrical shape. This jig was then clamped and pulled outward using an Instron universal testing machine (manufactured by Instron) at a crosshead speed of 2.5 mm / min. The maximum load generated before the ring fractured was defined as the fracture strength.

[0075] (Measurement of the rate of change of the outer diameter of the rotating electric machine protection ring during rotation) The rate of change of the outer diameter of the rotating electric machine protection ring can be determined by a rotation test of the rotating electric machine. In the rotation test of the rotating electric machine, the rotating electric machine is rotated from a stationary state, and the rotation speed is gradually increased until the peripheral speed reaches 280 m / s, and then held for 20 seconds or more. Here, the peripheral speed can be calculated from the outer diameter and rotation speed of the rotating electric machine. For example, when a rotating electric machine with an outer diameter of 140 mm is rotated at 37,500 rpm, the peripheral speed will be approximately 275 m / s. The rate of change of the outer diameter of the rotating electric machine protection ring is defined as the value obtained by multiplying the displacement of the outer diameter (displacement of the outer diameter during the rotation test) when the peripheral speed of the rotating electric machine reaches 280 m / s and is held for 20 seconds, relative to the outer diameter R5 of the rotating electric machine protection ring before the rotation test (outer diameter of the ring before rotation), by 100.

[0076] The outer diameter R5 can be measured using a radius measuring instrument such as an R caliper. The displacement of the outer diameter during the rotation test is measured using a laser displacement meter while the rotating electric machine is rotating, 20 seconds after the peripheral speed reaches 280 m / s. The sensitivity of the laser displacement meter can be increased by applying paint to the surface of the rotating electric machine protective ring. The measurement points for both the outer diameter R5 and the displacement during the rotation test are the center points in the rotation axis direction of each equally divided line segment when the width direction of the ring (i.e., the rotation axis direction) from one end to the other is divided into six equal parts along the rotation axis direction, at any position in the circumferential direction of the rotating electric machine protective ring. The average value of the outer diameters measured at these six center points before the rotation test is taken as the outer diameter of the ring before rotation, and the average value of the displacements measured at these six center points during the rotation test is taken as the displacement during the rotation test. As for the means of rotation, there are no particular limitations, but it is sufficient if the rotating electric machine can be rotated stably to a predetermined rotation speed, and a spin tester can be used.

[0077] (Example of manufacturing tape-like material (1)) An epoxy resin composition consisting of the following components was used as the resin composition. Component [A]: 10 parts by mass of “jER®” 825 (bisphenol A type epoxy resin, manufactured by Mitsubishi Chemical Corporation) and 90 parts by mass of ELM434 (tetraglycidyldiaminodiphenylmethane (TGDDM), manufactured by Sumitomo Chemical Co., Ltd.) were used as the epoxy resin. Component [B]: 3.5 parts by mass of DICY7 (dicyandiamide, manufactured by Mitsubishi Chemical Corporation) and 10.0 parts by mass of “Seika Cure®”-S (4,4'-diaminodiphenyl sulfone, manufactured by Seika Co., Ltd.) were used as curing agents that react with component [A], and 4.0 parts by mass of DCMU99 (3-(3,4-dichlorophenyl)-1,1-dimethylurea, manufactured by Hodogaya Chemical Co., Ltd.) were used as curing accelerators. [C] Component: 12.0 parts by mass of "Sumika Excel®" PES5003P (manufactured by Sumitomo Chemical Co., Ltd.) was used as the thermoplastic resin.

[0078] This epoxy resin composition is impregnated into a sheet-like material obtained by opening up multiple carbon fiber bundles ("Torayca®" T1100S-12K, manufactured by Toray Industries, Inc.), resulting in a fiber basis weight of 100 g / m². ２ First, a prepreg with a resin content (resin composition content) of 24% by weight, i.e., a fiber weight content of 76% by weight, was prepared, and then slit to obtain a 7.0 mm wide slit tape (tape-like material (1)).

[0079] (Example of manufacturing tape-like material (2)) A 7.0 mm wide slit tape (tape-like material (2)) was obtained in the same manner as in Example of manufacturing tape-like material (1), except that the resin content was 18% by weight (i.e., the fiber weight content was 82% by weight).

[0080] (Example of manufacturing tape-like material (3)) An epoxy resin composition consisting of the following components was used as the resin composition. [A] Component: 10 parts by mass of “jER (registered trademark)” 828, 10 parts by mass of “jER (registered trademark)” 1001, 25 parts by mass of “jER (registered trademark)” 1007 (all bisphenol A type epoxy resins, manufactured by Mitsubishi Chemical Corporation), 40 parts by mass of “Epiclon (registered trademark)” 830 (bisphenol F type epoxy resin, manufactured by DIC Corporation), and 15 parts by mass of “Epiclon (registered trademark)” HP7200 (dicyclopentadiene type epoxy resin, manufactured by DIC Corporation). [B] component: 4.5 parts by mass of DICY7 (dicyandiamide, manufactured by Mitsubishi Chemical Corporation) was used as a curing agent that reacts with component [A], and 3 parts by mass of DCMU99 (3-(3,4-dichlorophenyl)-1,1-dimethylurea, manufactured by Hodogaya Chemical Co., Ltd.) was used as a curing accelerator. [C] component: 2 parts by mass of "Vinirec®" K (manufactured by JNC Corporation) was used as a thermoplastic resin.

[0081] This epoxy resin composition is impregnated into a sheet-like material obtained by opening up multiple carbon fiber bundles ("Torayca®" T800S-12K, manufactured by Toray Industries, Inc.), resulting in a fiber basis weight of 125 g / m². ２ After preparing a prepreg with a resin content of 24% by weight (i.e., a fiber weight content of 76% by weight), it was slit to obtain a 7.0 m wide slit tape (tape-like material (3)).

[0082] (Comparative manufacturing example of tape-like material (1)) A 7.0 mm wide slit tape (tape-like material (4)) was obtained in the same manner as in manufacturing example of tape-like material (1), except that the resin content was 30% by weight (i.e., the fiber weight content was 70% by weight).

[0083] (Comparative manufacturing example of tape-like material (2)) A 7.0 mm wide slit tape (tape-like material (5)) was obtained in the same manner as in manufacturing example of tape-like material (3), except that the resin content was 30% by weight (i.e., the fiber weight content was 70% by weight).

[0084] (Example 1) Using the rotating electric machine protection ring manufacturing apparatus shown in Figure 2, a laminate was fabricated by winding a tape-like material (1). In Figure 2, a cylindrical rotor with an outer diameter of 130 mm was placed as the core, and the tape-like material was unwound from a bobbin, passed through a path configuration device, and wound around the outer circumference of the rotor. The path configuration device included a multi-stage roll 5 and a nip roll 6. The unwinding speed of the tape-like material was set to 10 m / min, and the tape-like material was unwound from the bobbin 4 and run, passing through the multi-stage roll 5 and the nip roll 6 to increase the tensile stress, and the laminate (1) was obtained by winding it around the core 3 while applying a tensile stress of 2000 MPa.

[0085] Subsequently, a ring (1-1) was fabricated by wrapping the outer circumference of this laminate (1) with wrap tape and heat-curing it at 150°C for 2 hours. The fiber weight content and thickness of ring (1-1) are shown in Table 1.

[0086] Furthermore, instead of the rotor described above, a roughly cylindrical jig with an outer diameter of 130 mm was used as the core when winding the tape-like material. The number of winding layers was adjusted so that the thickness was approximately 1 mm and the width was approximately 10 mm. The ring (1-2) for fracture strength evaluation was then manufactured under the same conditions as the production of the ring (1-1) described above.

[0087] Rings (1-1) and (1-2) were evaluated using the method described above, and the results are shown in Table 1.

[0088] (Example 2) A laminate (2), a ring (2-1), and a fracture strength evaluation ring (2-2) having the physical properties shown in Table 1 were prepared in the same manner as in Example 1, except that a tape-like material (2) was used. The obtained laminate (2), rings (2-1) and (2-2) were evaluated using the method described above, and the results are shown in Table 1.

[0089] (Example 3) A laminate (3), a ring (3-1), and a ring (3-2) for fracture strength evaluation were prepared in the same manner as in Example 1, except that a tape-like material (3) was used, and having the physical properties shown in Table 1. The obtained laminate (3), rings (3-1) and (3-2) were evaluated using the method described above, and the results are shown in Table 1.

[0090] (Example 4) A laminate (4), a ring (4-1), and a ring (4-2) for fracture strength evaluation were fabricated in the same manner as in Example 2, except that the tensile stress during winding was set to 3000 MPa, and having the physical properties shown in Table 1. The obtained laminate (4), rings (4-1) and (4-2) were evaluated using the method described above, and the results are shown in Table 1.

[0091] (Example 5) A laminate (8), a ring (8-1), and a ring (8-2) for fracture strength evaluation were fabricated in the same manner as in Example 2, except that the tensile stress during winding was set to 500 MPa, and having the physical properties shown in Table 1. The obtained laminate (8), rings (8-1) and (8-2) were evaluated using the method described above, and the results are shown in Table 1.

[0092] (Example 6) A laminate (9), a ring (9-1), and a ring (9-2) for fracture strength evaluation were fabricated in the same manner as in Example 2, except that the tensile stress during winding was set to 1000 MPa, and having the physical properties shown in Table 1. The obtained laminate (9), ring (9-1), and (9-2) were evaluated using the method described above, and the results are shown in Table 1.

[0093] (Comparative Example 1) A laminate (5), a ring (5-1), and a ring (5-2) for fracture strength evaluation were prepared in the same manner as in Example 1, except that a tape-like material (4) was used, and having the physical properties shown in Table 2. The obtained laminate (5), rings (5-1) and (5-2) were evaluated using the method described above, and the results are shown in Table 2.

[0094] (Comparative Example 2) A laminate (6), a ring (6-1), and a ring (6-2) for fracture strength evaluation were prepared in the same manner as in Example 1, except that a tape-like material (5) was used, and having the physical properties shown in Table 2. The obtained laminate (6), rings (6-1) and (6-2) were evaluated using the method described above, and the results are shown in Table 2.

[0095] (Comparative Example 3) A laminate (7), a ring (7-1), and a ring (7-2) for fracture strength evaluation were prepared in the same manner as in Example 1, except that the tensile stress during winding of the tape-like material was set to 200 MPa. The obtained laminate (7), rings (7-1) and (7-2) were evaluated using the method described above, and the results are shown in Table 2.

[0096]

[0097]

[0098] 1. Laminate 101. Rotating electric machine protection ring 102. Tape-like material containing matrix resin and reinforcing fibers 2. Winding direction of the tape-like material 3. Core 4. Bobbin 5. Multi-stage roll 6. Nip roll 7. Stress application mechanism 9. Rotation direction of the core 10. Cooling mechanism 11. Heating mechanism 12. Contact roll 13. End face of core 3 14. Circumferential direction of the ring 15. Winding angle from the reference direction 16. Outer surface side in the ring cross-section 17. Inner (core) side in the ring cross-section 18. Reinforcing fibers 19. Matrix resin 20. Resin-rich layer 21. Fiber-rich layer 22. R3 measurement point 23. Ring cutting line 24. Semi-cylindrical ring 25. R4 measurement point 30. End of winding 40. Axial length of the rotating electric machine protection ring 50. Outer diameter of the rotating electric machine protection ring

Claims

1. A rotating electric machine protective ring, formed by molding a laminate in which a material containing a matrix resin and reinforcing fibers is continuously or intermittently laminated in a ring shape, wherein the fiber weight content is 72-90% and the internal void ratio is 5.0% or less.

2. A rotating electric machine protective ring provided on the outside of a rotor, wherein when the ring is cut along the axial direction at two opposing locations in the circumferential direction and removed from the rotor in two parts, the shrinkage rate of the outer radius at the circumferential center position of the two divided rings compared to before cutting is 5% or more, as described in claim 1.

3. The rotating electric machine protective ring according to claim 1, having a resin-rich layer that is continuously present in the region including the outer surface in the thickness direction with a thickness ratio of 1 to 20%.

4. The rotating electric machine protection ring according to claim 1, wherein the maximum height roughness Rz of the outer surface in the region excluding a range of 10 mm from both ends in the axial direction is 0.5 mm or less.

5. The rotating electric machine protection ring according to claim 1, wherein the thickness is 3.5 mm or less.

6. The rotating electric machine protection ring according to claim 1, wherein the matrix resin comprises a reaction product of a thermosetting resin and an amine-based compound.

7. The rotating electric machine protective ring according to any one of claims 1 to 6, wherein the fiber weight content is 80 to 85%.

8. The rotating electric machine protection ring according to claim 7, wherein the thickness ratio of the resin-rich layer is 3 to 11%.

9. A tape-shaped laminate of materials comprising a matrix resin and reinforcing fibers, laminated continuously or intermittently in a ring shape, wherein the internal void ratio is 5.0% or less when molded by heat curing at 150°C for 2 hours.

10. The tape-shaped material laminate according to claim 9, wherein the change in axial length before and after molding is 5.0 mm or less.

11. The tape-shaped material laminate according to claim 9, wherein the change in axial length before and after molding is 1.5 mm or less.

12. The tape-like material laminate according to claim 9, wherein the ratio of the change in axial length before and after molding to the thickness of the tape-like material laminate (change in axial length / thickness of the tape-like material laminate) is 1.5 or less.

13. A method for manufacturing a rotating electric machine protective ring, comprising a manufacturing process of winding a tape-like material containing a matrix resin and reinforcing fibers, with a fiber weight content of 72 to 90%, multiple times in a ring shape under a tensile stress of 300 to 4000 MPa.

14. The method for manufacturing a rotating electric machine protective ring according to claim 13, wherein the fiber weight content is 80 to 85% and the tensile stress is 900 to 4000 MPa.

15. A method for manufacturing a rotating electric machine protection ring according to claim 13 or 14, wherein the matrix resin contains an amine-based curing agent.

16. A rotating electric machine having a rotor, with a rotating electric machine protection ring according to any one of claims 1 to 6 mounted on the outside of the rotor, wherein the rate of change of the outer diameter of the rotating electric machine protection ring is 0.1% or less when rotating at a peripheral speed of 280 m / s.

17. The rotating electric machine according to claim 16, further comprising a stator outside the rotating electric machine protective ring according to any one of claims 1 to 6, wherein the air gap between the rotor and the stator is 10 mm or less.

18. The rotating electric machine according to claim 16, wherein the power density of a single unit is 15 kW / kg or more.

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