Electromechanical device and manufacturing method for fiber-reinforced plastic component

Abstract

To provide an electromechanical device capable of reducing problems arising from the thermal characteristics of fiber-reinforced plastics.SOLUTION: An electromechanical device 1 includes a rotor 10 including a rod-shaped rotor shaft 12, a cylindrical magnet back yoke 14 arranged on the surface of the rotor shaft 12, and rotor magnets 16 cylindrically arranged along the outer circumference of the magnet back yoke 14, a stator 20 including an electromagnetic coil 22 arranged cylindrically along the outer circumference of the rotor 10 and a cylindrical coil back yoke 24 arranged around the outer circumference of the electromagnetic coil 22, and a case 30 covering the rotor 10 and the stator 20. At least one component of the electromechanical device 1, specifically at least one of the rotor 10, stator 20, and case 30, is formed at least in part from fiber-reinforced plastic using a natural-derived resin.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to an electromechanical device and a method for manufacturing a fiber-reinforced plastic member. [Background technology]

[0002] In recent years, in the technical field of electric motors, as coreless motors have become less iron-lossy, they have made technological advances and surpassed cored motors in torque characteristics, and research is underway to further reduce iron loss. Research into reducing iron loss is also being conducted in the technical field of generators, which have a similar configuration to electric motors. In this specification, devices that include permanent magnets and electromagnetic coils and convert kinetic energy into electrical energy through rotation, such as electric motors and generators, are referred to as "electromechanical devices."

[0003] In general electromechanical devices, components made of metal materials are widely used. For example, the case that covers the internal structure is generally made of metal. In this case, the magnetic field lines caused by the rotor magnet and winding current react magnetically with the case, generating eddy currents, which in turn generate eddy current loss, a type of iron loss.

[0004] In response to this, conventionally, there is known an electromechanical device that includes a component at least partially formed from fiber-reinforced plastic (see, for example, Patent Document 1). In conventional electromechanical devices, eddy currents are not generated in the fiber-reinforced plastic portion even when subjected to magnetic lines of force, making it possible to reduce eddy current loss.

[0005] In addition, since fiber-reinforced plastic is a lightweight and strong material (high specific strength), it is possible to reduce the weight and size of components by using fiber-reinforced plastic instead of components made of metal materials. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Japanese Patent Application Laid-Open No. 2013-27228 Summary of the Invention [Problem to be solved by the invention]

[0007] However, when replacing metal materials with fiber-reinforced plastics in electromechanical devices, thermal properties such as heat resistance and thermal conductivity become important in addition to electrical and magnetic properties. Because the thermal properties of fiber-reinforced plastics are inferior to those of metal materials such as aluminum-based materials, problems arise in conventional electromechanical devices due to the thermal properties of fiber-reinforced plastics (particularly problems related to heat resistance and heat dissipation).

[0008] Therefore, the present invention has been made in view of the above-mentioned problems, and aims to provide an electromechanical device that can reduce the problems caused by the thermal properties of fiber-reinforced plastics. It is also an object of the present invention to provide a method for manufacturing a fiber-reinforced plastic member that can be suitably used as a component of the above-mentioned electromechanical device. [Means for solving the problem]

[0009] Some fiber-reinforced plastics are said to have relatively good thermal properties, but this is because the base material (fiber) is made of a material with good thermal properties (e.g., carbon), and the contribution of the resin is small. In general, fiber-reinforced plastics use petroleum-based synthetic resins such as epoxy resins and polyester resins as the resin.

[0010] In addition to synthetic resins, naturally occurring resins such as cashew resins and lacquer resins are known. However, naturally occurring resins are primarily used in the field of crafts as paint components, and due to issues such as their properties (e.g., allergies and curing time) and availability, they have rarely been considered as materials for components in industrially mass-produced products such as fiber-reinforced plastics and electromechanical devices.

[0011] Here, we will explain natural resins in more detail. Lacquer-based resins, a well-known natural resin, are primarily used as a component of paint in lacquerware. Lacquerware is a culture that emphasizes the technical value of producing products by applying paint containing lacquer, a natural resin, to wood with a brush. From a practical standpoint, the purpose of applying lacquer-containing paint to wood is to provide water repellency and durability to compensate for the wood's shortcomings. In the field of industrial products, new materials that have become available due to technological advances, particularly petroleum-based synthetic resins that are cheaper and easier to process than wood, have become popular, and it can be said that products made from wood are in decline. As a result, the technical value of lacquerware is also declining.

[0012] Furthermore, when using paints containing lacquer in the manufacture of industrial products, hand application is not a realistic choice from the perspective of production efficiency. Spray application using a spray gun is a common application method in the industrial product field, but spray application of lacquer-containing paints poses the problem of worker restrictions due to the allergenic nature of lacquer. Furthermore, paints containing lacquer pose problems, such as the need to adjust drying and curing conditions (temperature and temperature control are required for enzymatic oxidation curing) and the length of drying and curing time (basically natural drying). For this reason, lacquer-based resins have not been accepted in the industrial product field, where handling and cost of materials and manufacturing methods are important.

[0013] Cashew-based resins are also available as naturally derived resins, but they were originally developed to replace lacquer-based resins in light of issues related to their productivity (such as declining reforestation, labor shortages, and rising prices). For this reason, cashew-based resins have been used mainly in the field of crafts as a substitute for lacquer-based resins, and have not been accepted in the field of industrial products.

[0014] However, as a result of intensive research by the inventors of the present invention, it was discovered for the first time that naturally occurring resins such as cashew-based resin and lacquer-based resin have excellent thermal properties (particularly heat resistance and thermal conductivity). The present invention is based on this research and has the following features.

[0015] [1] The electromechanical device of the present invention is characterized in that at least some of its components are formed from fiber-reinforced plastic using a naturally occurring resin.

[0016] [2] One embodiment of the electromechanical device of the present invention is an electromechanical device comprising: a rotor having a rod-shaped rotor shaft, a cylindrical magnet back yoke arranged on the surface of the rotor shaft, and a rotor magnet arranged cylindrically along the outer periphery of the magnet back yoke; a stator having an electromagnetic coil arranged cylindrically along the outer periphery of the rotor and a cylindrical coil back yoke arranged on the outer periphery of the electromagnetic coil; and a case covering the rotor and the stator, wherein it is preferable that at least one of the rotor, the stator, and the case is at least partially formed from a fiber-reinforced plastic using the naturally occurring resin.

[0017] [3] In one embodiment of the electromechanical device of the present invention, the naturally occurring resin preferably contains a cashew-based resin as a main component.

[0018] [4] In one embodiment of the electromechanical device of the present invention, the naturally occurring resin preferably contains a lacquer resin as a main component.

[0019] [5] In one embodiment of the electromechanical device of the present invention, the stator preferably further includes an electromagnetic coil fixing member that fixes the electromagnetic coil from the inner circumferential side and is at least partially formed from fiber-reinforced plastic using the naturally occurring resin.

[0020] [6] In one aspect of the electromechanical device of the present invention, it is preferable that at least a portion of the rotor shaft is formed from fiber reinforced plastic using the naturally occurring resin.

[0021] [7] In one embodiment of the electromechanical device of the present invention, it is preferable that the rotor further includes a rotor magnet fixing member that fixes the rotor magnet from the outer periphery and is at least partially formed from fiber-reinforced plastic using the naturally occurring resin.

[0022] [8] The method for manufacturing a fiber-reinforced plastic member of the present invention is a method for manufacturing a fiber-reinforced plastic member at least a portion of which is formed from a fiber-reinforced plastic using a naturally-derived resin, and is characterized by including a substrate preparation step of preparing a substrate of the fiber-reinforced plastic, an impregnation step of impregnating the substrate with a resin containing the naturally-derived resin, and a curing step of curing the resin by baking.

[0023] [9] In one embodiment of the method for manufacturing a fiber-reinforced plastic member of the present invention, the fiber-reinforced plastic member manufactured by the method for manufacturing a fiber-reinforced plastic member is preferably a member that constitutes an electromechanical device. [Effects of the Invention]

[0024] The electromechanical device of the present invention has at least some of its components formed from fiber-reinforced plastic using naturally occurring resin. Therefore, by using a naturally occurring resin with good thermal properties, the electromechanical device can reduce issues caused by the thermal properties of fiber-reinforced plastic.

[0025] Conventionally, naturally occurring resins have generally been cured by natural drying, which has resulted in long processing times. On the other hand, the method for producing a fiber-reinforced plastic member of the present invention includes a curing step of curing the naturally occurring resin by baking. The method for producing a fiber-reinforced plastic member of the present invention cures the naturally occurring resin by baking, which involves applying heat from the outside, and therefore is a method for producing a fiber-reinforced plastic member that is suitable for the production of industrially mass-produced products and can shorten processing times compared to conventional methods. [Brief explanation of the drawings]

[0026] [Figure 1] 1A and 1B are diagrams shown for explaining an electromechanical device 1 according to an embodiment. [Figure 2] FIG. 1 is a diagram illustrating a thermal conductivity test piece 100 constructed for measuring the thermal conductivity of a naturally occurring resin (cashew-based resin) and an epoxy-based resin. [Figure 3] 1 is a bar graph showing the thermal conductivity of a naturally derived resin (cashew-based resin) and an epoxy-based resin. [Figure 4] 1 is a photograph showing test results regarding the heat resistance of a naturally derived resin (cashew-based resin) and an epoxy-based resin. [Figure 5] FIG. 10 is a cross-sectional view illustrating an electromechanical device 2 according to a modified example. DETAILED DESCRIPTION OF THE INVENTION

[0027] The electromechanical device and the method for manufacturing a fiber-reinforced plastic member of the present invention will be described below based on the embodiments shown in the drawings. The embodiments described below do not limit the invention according to the claims. Furthermore, not all of the elements and combinations thereof described in the embodiments are necessarily essential to the solution of the present invention.

[0028] [Embodiment] 1. Electromechanical Devices 1 Fig. 1 is a diagram for explaining an electric machine device 1 according to an embodiment. Fig. 1(a) is a cross-sectional view of a section including a rotation axis A of a rotor 10 in the electric machine device 1, and Fig. 1(b) is a cross-sectional view taken along line BB in Fig. 1(a). Note that all of the drawings shown for explaining the electric machine device and its components, including Fig. 1, are schematic diagrams.

[0029] As shown in Fig. 1, the electric machine device 1 according to the embodiment includes a rotor 10, a stator 20, a case 30, and a bearing 40. At least some of the components of the electric machine device 1, more specifically at least some of at least one of the rotor 10, the stator 20, and the case 30 (all of these in the case of the electric machine device 1), are formed from fiber reinforced plastic using a naturally occurring resin. The electric machine device 1 according to the embodiment is a coreless motor. The electric machine device 1 may further include components other than those described above. Each component will be described below.

[0030] The rotor 10 includes a rotor shaft 12, a magnet back yoke 14, a magnet side yoke 15, a rotor magnet 16, and a rotor magnet fixing member 18.

[0031] The rotor shaft 12 is a rod-shaped member. The rotor shaft 12 in the electromechanical device 1 is hollow and has a substantially cylindrical shape. The rotor shaft 12 may be a member that is not completely hollow, or may be a solid member (with no internal space). At least a portion of the rotor shaft 12 is made of fiber-reinforced plastic using a naturally-derived resin, and in this embodiment, the entire rotor shaft 12 is made of this fiber-reinforced plastic. Details of the "naturally-derived resin" and the "fiber-reinforced plastic using a naturally-derived resin" will be described later.

[0032] The magnet back yoke 14 is a cylindrical member arranged on the surface of the rotor shaft 12. The magnet back yoke 14 is made of a soft magnetic material. By using a laminated steel plate material for the magnet back yoke 14, the thickness perpendicular to the direction of movement of the rotor magnet 16 (thickness along the vertical direction of the paper in FIG. 1(a)) can be made thinner (for example, about 100 μm) than the usual thickness (for example, about 350 μm). This makes it possible to reduce eddy current loss.

[0033] The magnet side yoke 15 is a disk-shaped member disposed at the end of the rotor magnet 16. The magnet side yoke 15 is made of a soft magnetic material.

[0034] The rotor magnet 16 is arranged cylindrically along the outer periphery of the magnet back yoke 14. In the electromechanical device 1, the rotor magnet 16 is composed of a total of eight permanent magnets, including four permanent magnets magnetized from the inner periphery to the outer periphery and four permanent magnets magnetized from the outer periphery to the inner periphery. The permanent magnets are arranged so that magnetization directions of different magnetization directions are adjacent to each other along the circumferential direction.

[0035] The rotor magnet fixing member 18 is a member that fixes the rotor magnet 16 from the outer periphery. The rotor magnet fixing member 18 is a cylindrical member. At least a portion of the rotor magnet fixing member 18 is made of fiber-reinforced plastic using a naturally-derived resin, and in this embodiment, the entire member is made of this fiber-reinforced plastic.

[0036] The stator 20 includes an electromagnetic coil 22, a coil back yoke 24, and an electromagnetic coil fixing member 26.

[0037] The electromagnetic coil 22 is arranged in a cylindrical shape along the outer periphery of the rotor 10. The electromagnetic coil 22 in the electromechanical device 1 is composed of two-phase electromagnetic coils, that is, an A-phase electromagnetic coil 22a and a B-phase electromagnetic coil 22b.

[0038] The coil back yoke 24 is a cylindrical member arranged on the outer periphery of the electromagnetic coil 22. The coil back yoke 24 is made of a soft magnetic material. The length of the coil back yoke 24 in the direction along the rotation axis A is approximately the same as the length of the rotor magnet 16 in the direction along the rotation axis A. The coil back yoke 24 is arranged so as to overlap with the rotor magnet 16 when viewed from a direction perpendicular to the rotation axis A.

[0039] The electromagnetic coil fixing member 26 is a member that fixes the electromagnetic coil 22 from the inner circumferential side. The electromagnetic coil fixing member 26 is a cylindrical member. At least a portion of the electromagnetic coil fixing member 26 is made of fiber-reinforced plastic using a naturally-derived resin, and in this embodiment, the entire member is made of this fiber-reinforced plastic.

[0040] The case 30 is a member that covers the rotor 10 and the stator 20. The case 30 also has mounting holes 36 (bolt holes) that are used when attaching the electromechanical device 1 to other components. In this specification, the term "cover" includes both covering the entire object and covering part of the object. At least a portion of the case 30 is made of fiber-reinforced plastic using a naturally-derived resin, and in this embodiment, the entire case is made of this fiber-reinforced plastic.

[0041] The case 30 of the electromechanical device 1 is made up of a first case 32 and a second case 34. This is mainly for the purpose of assembling the electromechanical device 1, and the electromechanical device 1 can be assembled by arranging the necessary components inside the first case 32 and the second case 34, which are in a separated state, and then joining the first case 32 and the second case 34.

[0042] The bearing 40 is a member that supports the rotor shaft 12 of the rotor 10. As the bearing 40, for example, a ball bearing can be used.

[0043] 2. Naturally derived resins and fiber-reinforced plastics made from naturally derived resins 2A and 2B are diagrams illustrating a thermal conductivity test piece 100 constructed to measure the thermal conductivity of a naturally occurring resin (cashew-based resin) and an epoxy-based resin. Fig. 2A is a perspective view of the thermal conductivity test piece 100, and Fig. 2B is a side view of the thermal conductivity test piece 100. Figure 3 is a bar graph showing the thermal conductivity of a naturally derived resin (cashew-based resin) and an epoxy-based resin. The vertical axis of Figure 3 shows the temperature difference δ (equivalent to a thickness of 1 mm) (unit: K). Therefore, in Figure 3, the lower the bar, the better the thermal conductivity. Figure 4 shows photographs showing the test results for the heat resistance of a naturally derived resin (cashew-based resin) and an epoxy-based resin. Figure 4(a) is a photograph showing the test results for the epoxy-based resin (test results for CFRP-B, which will be described later), and Figure 4(b) is a photograph showing the test results for the cashew-based resin (test results for CFRP-A, which will be described later). In Figures 4(a) and 4(b), the samples on the left of the arrows are those that were not heated, and the samples on the right of the arrows are those that were heated.

[0044] As used herein, "naturally derived resin" refers to a resin containing naturally derived materials, such as plant sap and oils, and processed products thereof, or equivalents thereof, as its primary raw material. Note that, as used herein, "primary component" refers to the component that accounts for the largest proportion by weight of all components (excluding solvent components) that make up a given substance. Therefore, naturally derived resins may contain various additives. Additives commonly used in resins can be used. Furthermore, naturally derived resins may contain agar-agar, a component derived from the mucus of red algae such as Gelidium, which can provide viscosity adjustment and improved heat resistance. It has also been discovered that increased elasticity can be achieved by adding silicone-based materials (e.g., those used as sealants) to naturally derived resins.

[0045] Examples of plants from which naturally occurring materials can be extracted include cashew, lacquer, pistachio, macadamia, European hazel, almond, peach, apple, pear, cherry, strawberry, melon, watermelon, pecan, walnut, peanut, and ginkgo. Among the listed plants, lacquer sap can be used as a naturally occurring material or a raw material, while oils and fats extracted from seeds (including seed shells) or fruits of other plants can be used as naturally occurring materials or raw materials. When oils and fats extracted from the seeds or fruits of the above-listed plants are used as naturally occurring materials or raw materials, they can utilize waste products that are not generally used as foods, which is advantageous in terms of availability and cost. Examples of processing methods for converting sap and oils into processed products include heat treatment and chemical treatment to adjust the molecular structure of the compounds that make up the sap and oils.

[0046] In the present embodiment, it is preferable to use a naturally derived resin that has better thermal conductivity and heat resistance than general petroleum-based synthetic resins, is easy to adjust the viscosity of, is suitable for spray application, and can penetrate into the substrate of fiber-reinforced plastic. Furthermore, from the viewpoint of processability, it is preferable that the naturally derived resin in the present embodiment has excellent moldability by room temperature curing (primary curing) and can be cured by baking (secondary curing).

[0047] When manufacturing a fiber-reinforced plastic member, as described below, a naturally-derived resin may be applied to a substrate. When applying a naturally-derived resin to a thin film substrate or to the edge of a substrate, spray application using a spray gun, for example, can be used. Spray application is suitable for treating the edge of annular components related to magnets or coils, such as the rotor magnet fixing member 18 and the electromagnetic coil fixing member 26. When applying a naturally-derived resin to a thick substrate or when strongly imprinting the resin into the substrate, application using a brush or spatula, for example, can be used. To adjust the viscosity of the naturally-derived resin before curing in these work processes, for example, various thinners can be used.

[0048] In an embodiment, in order to satisfy the above conditions, it is preferable that the naturally derived resin contains a cashew-based resin as a main component. In this specification, "cashew-based resin" refers to a resin containing, as a main raw material, cashew nut shell oil obtained from the seed shells of the cashew, an evergreen tree of the Anacardiaceae family.

[0049] Cashew nut shell oil obtained from cashews is an oil whose main components are phenolic compounds such as anacardic acid, cardanol, and cardol. For industrial use, cashew nut shell oil is obtained by decarboxylating anacardic acid to cardanol, with cardanol being the main component. Cashew-based resins can be obtained by adding necessary minor components and polymerization initiators to such cashew nut shell oil and polymerizing it.

[0050] In addition, resins made from modified molecular structures of components contained in cashew nut shell oil are also included in the cashew-based resins of this specification. For example, a resin (cashew-derived benzoxazine resin) made from cardanol, which is a benzoxazine-like molecule obtained by forming a six-membered ring containing nitrogen (amine moiety) so as to include a hydroxyl group and a part of an aromatic ring, can also be used as a cashew-based resin.

[0051] Although cashew resin itself is a known material, it has mainly been used as a component of paint, and research into its structural and thermal properties has not progressed. Research by the inventors of the present invention has revealed that cashew resin has heat resistance capable of withstanding temperatures exceeding 300°C, and is superior in thermal conductivity, rigidity, and lightness to general epoxy resins, as well as excellent adhesiveness and shock absorption properties.

[0052] Here, we will explain the test on the thermal conductivity of cashew-based resin. In this test, a thermal conductivity test piece 100 was constructed, which included a heat source 110 capable of maintaining a constant temperature, a first thermally conductive material 120 made of a copper plate, a test material 130 made of resin, and a second thermally conductive material 140 also made of a copper plate (see FIG. 2). It can be said that the first thermally conductive material 120 and the second thermally conductive material 140 are bonded together by the test material 130. Two thermal conductivity test pieces 100 were prepared: one in which the test material 130 was made of cashew-based resin, and one (for comparison) in which the test material 130 was made of epoxy-based resin.

[0053] In the above test, "No. 53 Tou" manufactured by Cashew Corporation was used as the cashew resin. Also, "Cashew Dryer" manufactured by Cashew Corporation was used as the curing agent for the cashew resin.

[0054] In the above test, the epoxy resin used was "Bond Quick 5 (#16131)" manufactured by Konishi Co., Ltd. This epoxy resin is a two-component adhesive and is considered to have typical properties for epoxy resins.

[0055] The heat source 110 converts electrical power into heat and emits a constant amount of heat when supplied with a predetermined amount of electrical power. The heat emitted from the heat source 110 is transferred to the first thermally conductive material 120, the test material 130, and the second thermally conductive material 140. After a sufficient amount of time has passed since the start of the test, the temperatures at each location reach their saturation temperatures. Here, the saturation temperature of the portion of the first thermally conductive material 120 in contact with the test material 130 (the front portion of the test material) is defined as the high-side temperature, and the saturation temperature of the portion of the second thermally conductive material 140 in contact with the test material 130 (the rear portion of the test material) is defined as the low-side temperature. The temperature difference between the high-side and low-side temperatures obtained in the test can be divided by the thickness (in mm) of the test material 130 to calculate the temperature difference δ (equivalent to a 1 mm thickness), which is the temperature difference per mm of the test material 130. Temperature measurements were performed using a thermocouple from a Hioki E.E. Corporation Memory HiLogger LR8431.

[0056] As a result, the temperature difference δ (calculated at 1 mm thickness) in the cashew-based resin was approximately 30% of the temperature difference δ (calculated at 1 mm thickness) in the epoxy-based resin (see Figure 3). This confirmed that the cashew-based resin has significantly better thermal conductivity than the epoxy-based resin.

[0057] We also describe a test for the heat resistance of cashew-based resin. In this test, the test specimen was placed on the top cover of a convection kerosene heater (KSH-8BS-K5, manufactured by Sunpot Corporation) for 5 minutes (approximately 300°C, as confirmed by a non-contact radiation thermometer), and the condition during and after heating was observed. The test specimens used were CFRP-A, a carbon fiber reinforced plastic using cashew-based resin as the resin (matrix material), and CFRP-B, a carbon fiber reinforced plastic using epoxy-based resin as the resin. CFRP-A and CFRP-B were manufactured by impregnating a carbon fiber substrate with cashew-based resin or epoxy-based resin. The cashew-based resin and epoxy-based resin used in the above test were the same as those used in the thermal conductivity test.

[0058] As a result of the test, it was observed that CFRP-B emitted a thin layer of smoke during heating, and that some parts were carbonized and turned black after heating (see Figure 4(a). The area indicated by the dashed line is the carbonized part). On the other hand, for CFRP-A, no smoke was observed during heating, and although some parts turned dark brown after heating, no significant deterioration was observed (see Figure 4(b)). This confirmed that cashew-based resins have superior heat resistance compared to epoxy-based resins.

[0059] In an embodiment, the naturally derived resin preferably contains a lacquer resin as a main component. In this specification, "lacquer resin" refers to a resin containing, as a main component, the sap (lacquer) of a plant of the genus Urushi (particularly Urushi) of the family Anacardiaceae.

[0060] The components of lacquer vary depending on the place of origin, but one of the most notable is urushiol. Urushiol is a phenolic compound with a structure similar to cardanol and cardol, which are found in cashew nut shell oil. Lacquer resin can be obtained by polymerizing lacquer components such as urushiol.

[0061] Furthermore, resins made from modified molecular structures of components contained in lacquer are also included in the lacquer-based resins of this specification.

[0062] Lacquer resin is also a well-known material, but because it has mainly been used as a component of paint, little research has been done into its structural and thermal properties. Research by the inventors of the present invention has revealed that lacquer resin, like cashew resin, has heat resistance that can withstand temperatures exceeding 300°C, and is superior to general epoxy resins in thermal conductivity, rigidity, and lightness, as well as in adhesiveness and shock absorption.

[0063] In this specification, "fiber reinforced plastic using a naturally derived resin" refers to a fiber reinforced plastic that uses the above-mentioned naturally derived resin as the resin (matrix material). The fiber reinforced plastic using a naturally derived resin may also use a synthetic resin in addition to the naturally derived resin (for example, a resin that uses a mixture of a naturally derived resin and a synthetic resin). In this case, it is preferable that the naturally derived resin is the main component of the resin.

[0064] The fibers used as the substrate of the fiber-reinforced plastic are not particularly limited, and examples thereof include carbon fibers, glass fibers, natural fibers (hemp, cotton, etc.), and chemical fibers (nylon, Tetoron (registered trademark), Zylon (registered trademark), etc.) From the viewpoints of strength and thermal properties, it is preferable to use carbon fibers as the substrate.

[0065] 3. Manufacturing method of fiber-reinforced plastic components The method for manufacturing a fiber-reinforced plastic member according to the embodiment is a method for manufacturing a fiber-reinforced plastic member at least a portion of which is formed from fiber-reinforced plastic using a naturally occurring resin, and includes a substrate preparation step, an impregnation step, and a curing step. The fiber-reinforced plastic member manufactured by the method for manufacturing a fiber-reinforced plastic member according to the embodiment is a member that constitutes the electromechanical device 1, specifically, the rotor shaft 12, rotor magnet fixing member 18, electromagnetic coil fixing member 26, and case 30. Each step will be described below.

[0066] The substrate preparation process is a process of preparing a fiber-reinforced plastic substrate. The impregnation process is a process of impregnating the substrate with a resin containing a naturally-derived resin. The substrate preparation process and the impregnation process are essentially the same as known fiber-reinforced plastic manufacturing methods, and therefore detailed descriptions are omitted. Known fiber-reinforced plastic manufacturing methods include autoclave molding, resin transfer molding (RTM), vacuum-assisted resin transfer molding (VaRTM), sheet molding compound (SMC), sheet winding, filament winding, and continuous pultrusion molding. Any method can be selected depending on the shape of the component to be manufactured. Alternatively, the viscosity of the resin containing a naturally-derived resin may be adjusted by adding a solvent or the like, and then spray-applied to the substrate. The above manufacturing methods may also be combined as appropriate. Depending on the selected method, the substrate is molded into a shape corresponding to the fiber-reinforced plastic component to be manufactured at some point before the curing process.

[0067] The curing process is a process of curing the resin by baking. In this specification, "baking" refers to a heat treatment performed in the final stage of molding. A specific baking method can be selected according to the substrate preparation process, the impregnation process, the substrate molding method, etc., and examples of the baking method include heating the mold used in molding and direct heating using an oven or heater.

[0068] The heating temperature for baking can be, for example, 80°C to 160°C in the case of cashew resin, and is preferably 200°C or higher in the case of lacquer.

[0069] In the method for manufacturing a fiber-reinforced plastic member according to the embodiment, a curing agent may be added to the resin in order to shorten the curing time and increase the strength.

[0070] 4. Effects of the manufacturing method of the electromechanical device 1 and the fiber-reinforced plastic member In the electromechanical device 1 according to the embodiment, at least some of the components are formed from fiber-reinforced plastic using naturally occurring resin. Therefore, by using naturally occurring resin with good thermal properties, the electromechanical device can reduce issues caused by the thermal properties of fiber-reinforced plastic.

[0071] Furthermore, in the electric machine device 1 according to the embodiment, at least one of the rotor 10, the stator 20, and the case 30 (all of these in the electric machine device 1) is at least partially formed from fiber-reinforced plastic using a naturally-derived resin. Therefore, by using a naturally-derived resin with good thermal properties, the electric machine device 1 according to the embodiment is an electric machine device that can reduce issues caused by the thermal properties of fiber-reinforced plastic. Furthermore, according to the electric machine device 1, at least some of the main components of the electric machine device 1 are formed from fiber-reinforced plastic using a naturally-derived resin, so it is possible to reduce eddy current loss and make the electric machine device 1 lighter and more compact.

[0072] Furthermore, the electromechanical device 1 according to the embodiment can achieve the same effects as conventional electromechanical devices that have components at least partly made of fiber-reinforced plastic, such as reducing eddy current loss and making it possible to reduce weight and size.

[0073] Furthermore, the electromechanical device 1 according to the embodiment is an electromechanical device made of naturally derived resin, which is excellent as a recyclable resource because it is obtained from resources that can grow in the natural environment, has excellent global circulation cycle properties through afforestation, etc., and is suitable for industrial product applications.

[0074] Furthermore, according to the electromechanical device 1 of the embodiment, when the naturally derived resin contains cashew-based resin as its main component, the cashew-based resin has excellent heat resistance, thermal conductivity, rigidity, light weight, adhesiveness, and shock absorption properties, making it possible to improve thermal properties and strength.

[0075] Furthermore, according to the electromechanical device 1 of the embodiment, when the naturally derived resin contains lacquer-based resin as its main component, the lacquer-based resin is used, which has excellent heat resistance, thermal conductivity, rigidity, light weight, adhesiveness and shock absorption properties, making it possible to improve thermal properties and strength.

[0076] Furthermore, according to the electromechanical device 1 according to the embodiment, the stator 20 has the electromagnetic coil fixing member 26, so that the electromagnetic coil 22 can be fixed by a member that has good thermal properties and does not interfere with magnetism.

[0077] Furthermore, according to the electric machine device 1 of the embodiment, at least a portion (all of the electric machine device 1) of the rotor shaft 12 is made of fiber reinforced plastic using naturally occurring resin, which makes it possible to achieve even greater weight reduction.

[0078] Furthermore, according to the electromechanical device 1 of the embodiment, the rotor 10 has the rotor magnet fixing member 18, so that the rotor magnet 16 can be fixed with a member that has good thermal properties and does not interfere with magnetism.

[0079] The method for manufacturing a fiber-reinforced plastic member according to the embodiment hardens a naturally derived resin by baking it with external heat, making it suitable for manufacturing industrially mass-produced products and capable of shortening processing time compared to conventional methods.

[0080] Furthermore, according to the manufacturing method of the fiber-reinforced plastic member of the embodiment, since the fiber-reinforced plastic member manufactured by the manufacturing method of the fiber-reinforced plastic member is a member that constitutes the electromechanical device 1, it is possible to manufacture a fiber-reinforced plastic member that is suitable for the electromechanical device 1.

[0081] Although the present invention has been described based on the above embodiment, the present invention is not limited to the above embodiment and can be embodied in various forms without departing from the spirit of the present invention, and for example, the following modifications are also possible.

[0082] (1) The position, size, shape, etc. of each component described in the above embodiment are merely examples and may be changed within the scope of the present invention without impairing the effects of the present invention. Furthermore, the drawings showing the structure of objects used to explain the above embodiment are schematic diagrams and may not accurately depict the position, size, etc. of each component.

[0083] (2) Although the electric machine device 1 according to the above embodiment is a coreless motor, the present invention is not limited to this. The electric machine device according to the present invention may be an electric motor or a generator other than a coreless motor.

[0084] (3) In the above embodiment, the rotor 10, the stator 20, and the case 30 are all at least partially made of fiber-reinforced plastic using a naturally derived resin, but the present invention is not limited to this. Only one or two of the rotor, the stator, and the case may be at least partially made of fiber-reinforced plastic using a naturally derived resin.

[0085] (4) In the electromechanical device of the present invention, at least some of the components other than the rotor, stator, and case may be made of fiber-reinforced plastic using a naturally occurring resin.

[0086] 5 is a cross-sectional view illustrating an electric machine device 2 according to a modified example. The electric machine device 2 according to the modified example includes a reduction gear mechanism 50 in addition to a rotor 10, a stator 20, a case 30, and a bearing 40. The reduction gear mechanism 50 has a gear 52, a gear shaft 54, a gear shaft bearing 56, and a reduction gear mechanism case 58. A pinion 19 corresponding to the gear 52 is attached to the rotor shaft 12. The gear shaft bearing 56 and the reduction gear mechanism case 58 are at least partially formed from fiber-reinforced plastic using a naturally derived resin. The electric machine device of the present invention may also be configured as described above.

[0087] The above-described reduction mechanism 50 is an example of "components other than a rotor, a stator, and a case." The electromechanical device of the present invention may include a reduction mechanism different from the above-described reduction mechanism 50. Furthermore, the electromechanical device of the present invention may include other components instead of or in addition to the reduction mechanism.

[0088] (5) In the above embodiment, the rotor shaft 12, rotor magnet fixing member 18, electromagnetic coil fixing member 26, and case 30 are all formed from the fiber-reinforced plastic, but the present invention is not limited to this. The rotor shaft, rotor magnet fixing member, electromagnetic coil fixing member, and case may each be partially formed from the fiber-reinforced plastic.

[0089] (6) In the above embodiment, the electric machine device 1 has the rotor magnet fixing member 18 and the electromagnetic coil fixing member 26 made of fiber-reinforced plastic, but the present invention is not limited to this. One or both of the rotor magnet fixing member and the electromagnetic coil fixing member may be made of a material other than fiber-reinforced plastic. Also, one or both of the rotor magnet fixing member and the electromagnetic coil fixing member may not be provided. [Explanation of symbols]

[0090] 1, 2...electrical machine device, 10...rotor, 12...rotor shaft, 14...magnet back yoke, 15...magnet side yoke, 16...rotor magnet, 18...rotor magnet fixing member, 19...pinion, 20...stator, 22...electromagnetic coil, 22a...A-phase electromagnetic coil, 22b...B-phase electromagnetic coil, 24...coil back yoke, 26...electromagnetic coil fixing member, 30...case, 32...first case, 34...second case, 36...mounting hole, 40...bearing, 50...reduction mechanism, 52...gear, 54...gear shaft, 56...gear shaft bearing, 58...reduction mechanism case, A...rotating shaft

Claims

1. An electromechanical device, at least some of whose components are formed from fiber-reinforced plastic using a naturally occurring resin.

2. a rotor having a rod-shaped rotor shaft, a cylindrical magnet back yoke arranged on the surface of the rotor shaft, and a rotor magnet arranged cylindrically along the outer periphery of the magnet back yoke; a stator having an electromagnetic coil arranged cylindrically along an outer periphery of the rotor and a cylindrical coil back yoke arranged on the outer periphery of the electromagnetic coil; An electromechanical device comprising a case that covers the rotor and the stator, 2. The electromechanical device according to claim 1, wherein at least one of the rotor, the stator, and the case is at least partially formed from fiber-reinforced plastic using the naturally occurring resin.

3. 2. The electromechanical device according to claim 1, wherein the naturally derived resin contains cashew-based resin as a main component.

4. 2. The electromechanical device according to claim 1, wherein the naturally derived resin contains a lacquer-based resin as a main component.

5. 3. The electromechanical device according to claim 2, wherein the stator further includes an electromagnetic coil fixing member that fixes the electromagnetic coil from the inner circumferential side and at least a portion of which is formed from fiber-reinforced plastic using the naturally occurring resin.

6. 3. The electromechanical device according to claim 2, wherein at least a portion of the rotor shaft is formed from fiber reinforced plastic using the naturally occurring resin.

7. 3. The electromechanical device according to claim 2, wherein the rotor further comprises a rotor magnet fixing member that fixes the rotor magnet from the outer periphery and is at least partially formed from fiber-reinforced plastic using the naturally occurring resin.

8. A method for producing a fiber-reinforced plastic member at least a portion of which is formed from a fiber-reinforced plastic using a naturally-derived resin, comprising: a substrate preparation step of preparing a substrate of the fiber reinforced plastic; an impregnation step of impregnating the base material with a resin containing the naturally occurring resin; and a curing step of curing the resin by baking.

9. 9. The method for producing a fiber-reinforced plastic member according to claim 8, wherein the fiber-reinforced plastic member produced by the method for producing a fiber-reinforced plastic member is a member that constitutes an electromechanical device.

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