Method for manufacturing a stator

Abstract

The present application provides a kind of manufacturing method of stator (4), in the inside space of the slot (8) between the tooth portion (7) extended from annular magnetic yoke portion (6), using the mold for forming resin layer (50) on the wall surface (tooth wall surface (72), magnetic yoke wall surface (62)) of above-mentioned slot (8) to form above-mentioned resin layer (50), above-mentioned mold has blade (80) received in the inside of above-mentioned slot (8), by filling resin material in the space formed between the wall surface of above-mentioned slot (8) and above-mentioned blade (80) when receiving above-mentioned blade (80), to form above-mentioned resin layer (50), in above-mentioned blade (80), draft angle is set on the side face opposite to the wall surface of above-mentioned slot (8), above-mentioned draft angle is 15 μm ~ 100 μm, the surface roughness Ra of the face of setting above-mentioned draft angle is 0.2 μm ~ 2 μm.

Description

Technical Field

[0001] This invention relates to a method for manufacturing a stator. Background Technology

[0002] There are known techniques in rotating electrical machines such as motors (engines) or generators, in which insulating paper or resin material is filled into the slots of the stator to ensure insulation between the slots and the coils when the coils are housed in the slots (see, for example, Patent Document 1).

[0003] Patent document 1 discloses a technique of injecting resin between the coil and the peripheral wall of the slot and curing it to form an insulating layer.

[0004] Existing technical documents Patent documents Patent Document 1: Japanese Patent No. 6814568 Summary of the Invention

[0005] The technical problem that the invention aims to solve When improving the performance of a motor, a thin insulation layer is preferred in order to properly maintain the insulation of the coil while accurately configuring the coil and improving the space utilization efficiency of the slot. However, when forming the insulation layer within the slot, if the pull-out force of the forming component of the mold (called the blade or core) is large, the insulation layer may be damaged; therefore, countermeasures are needed.

[0006] The present invention was made in view of this situation, and its object is to provide a technique in which the insulating layer is not damaged when the molding component of the mold is pulled out during the molding of the insulating layer in the molding groove.

[0007] Technical solutions for solving technical problems According to the present invention, the following technology is provided.

[0008] (1) A method for manufacturing a stator, wherein a resin layer is formed inside a groove, which is a space between teeth extending from an annular magnetic yoke, using a mold for forming a resin layer on the wall surface of the groove. The mold described above has blades housed inside the groove, and the resin layer is formed by filling the space between the wall of the groove and the blades when the blades are housed with resin material. In the aforementioned blade, a draft angle is provided on the side facing the wall of the aforementioned groove. The above draft angle is between 15μm and 100μm. The surface roughness Ra of the surface with the above draft angle is 0.2 μm or more and 2 μm or less.

[0009] (2) The stator manufacturing method as described in (1), wherein, The surface roughness RSm of the surface with the above draft angle is 200μm or more and 700μm or less.

[0010] (3) The method for manufacturing a stator as described in (1) or (2), wherein, In the aforementioned blade, the aforementioned draft angle is provided on the surface facing the wall of the aforementioned tooth portion in the aforementioned groove.

[0011] (4) The stator manufacturing method as described in (3), wherein, In the aforementioned blade, the aforementioned draft angle is provided on the surface facing the wall of the aforementioned magnetic yoke portion within the aforementioned groove.

[0012] (5) The stator manufacturing method as described in (4), wherein, When the aforementioned blades are housed, the space formed between the wall of the aforementioned groove and the aforementioned blades is formed by the adjacent front end of the aforementioned teeth being closed by a mold component different from the aforementioned blades. In the aforementioned blade, the aforementioned draft angle is provided on the surface opposite to the aforementioned mold component.

[0013] (6) A method for manufacturing a stator as described in any one of (1) to (5), wherein, The aforementioned resin layer is a cured product of the resin material. The above-mentioned resin material contains one or two thermosetting resins selected from epoxy resin and phenolic resin.

[0014] (7) A method for manufacturing a stator as described in any one of (1) to (6), wherein, The thickness of the aforementioned resin layer is between 100 μm and 400 μm.

[0015] (8) A method for manufacturing a stator as described in any one of (1) to (7), wherein, The axial length of the aforementioned groove is between 100mm and 300mm.

[0016] (9) A method for manufacturing a stator as described in any one of (1) to (8), wherein, The area in which the draft angle is set in the blade includes at least the area in the groove that the blade passes through when it is pulled out of the groove.

[0017] Invention Effects According to the present invention, a technique is provided in which the insulating layer is not damaged when the molding component of the mold is pulled out during the molding process of the molding groove. Attached Figure Description

[0018] Figure 1 This is a cross-sectional view of the motor according to the embodiment, in a direction perpendicular to the direction of rotation axis.

[0019] Figure 2 This is a longitudinal cross-sectional view of the motor in the direction of its rotation axis according to the embodiment.

[0020] Figure 3 This is an enlarged view showing the periphery of the groove involved in the implementation method.

[0021] Figure 4 This is an enlarged view showing the periphery of the groove involved in the implementation method, from... Figure 3 The diagram showing the coil and resin seal inside the groove is omitted.

[0022] Figure 5 This is a cross-sectional view of the periphery of the groove involved in the implementation method. Figure 3 AA section diagram.

[0023] Figure 6 This is a cross-sectional view of the periphery of the groove involved in the implementation method. Figure 4 BB cross-sectional view.

[0024] Figure 7 This is a flowchart illustrating the stator manufacturing method involved in the implementation method.

[0025] Figure 8 This is a diagram illustrating the changes in the state within the tank during the resin layer formation process according to the embodiment.

[0026] Figure 9 This is a diagram illustrating the changes in the state within the tank during the resin layer formation process according to the embodiment.

[0027] Figure 10 This is a diagram showing the blades involved in the implementation method.

[0028] Figure 11 This is a diagram illustrating the dimensions of the groove in an embodiment. Detailed Implementation

[0029] <Outline> In this embodiment, an example in which an electric motor is used as a rotating electrical machine (electric motor, generator, or a dual-purpose machine of electric motor and generator) will be described. Figure 1 The diagram schematically shows a cross-sectional view of the motor 100 in a direction perpendicular to the direction of rotation axis. Figure 2 The diagram schematically shows a cross-sectional view of the motor 100 in the direction of its rotation axis. Figure 3 It is an enlarged representation of the area around the slot ( Figure 1 The diagram of region X schematically shows a cross-sectional view of the portion of coil 9 protruding from the end of slot 8. Figure 4 From Figure 3 The coil 9 of the omitting groove 8 and the resin sealing part 65 are shown in the following figure. Figure 5 yes Figure 3 AA section diagram. Figure 6 yes Figure 4 The BB cross-section diagram. Additionally, in Figure 3 , Figure 4 For convenience, the resin layer 50 is shown by applying ink. Furthermore, in the motor 100, the side of the rotating shaft 3 will be described as the inner circumferential side (or the rotating shaft side), while the side of the housing 1 will be described as the outer circumferential side.

[0030] The summary of this embodiment is as follows. In the motor 100, the walls (tooth wall 72, yoke wall 62) of the slot 8 of the stator 4 are covered with a resin layer 50 composed of an insulating resin composition. At this time, by setting a draft angle in the mold core (hereinafter, blade 80) and setting the surface roughness of the blade surface, the pull-out force of the blade 80 is suppressed, thereby suppressing the damage of the insulation layer. In addition, in this embodiment, the draft angle refers to the angle of the cross section that is inclined for pulling out the blade 80, and is described as the length of the horizontal direction of the inclined surface when the pull-out direction is set to the vertical direction relative to this specified horizontal direction.

[0031] The following is a detailed explanation.

[0032] <Basic Structure of Motor 100> The motor 100 has a housing 1, and a rotor 2, a stator 4 and a coil 9 housed inside the housing 1.

[0033] <Shell 1> The housing 1 is configured to have a cylindrical portion 1a and side plate portions 1b and 1c that close the axial ends of the cylindrical portion 1a. As the material of the housing 1, for example, aluminum alloy (casting) or resin material, or a material composed of these materials, can be used.

[0034] <Rotor 2> The rotor 2 is housed inside the housing 1. A rotating shaft 3, serving as the output shaft, is mounted at the center of the rotor 2. The two ends of the rotating shaft 3 are supported by side plates 1b and 1c via bearings 3a, respectively. Thus, the rotor 2 can rotate freely around the rotating shaft 3.

[0035] A permanent magnet 5 is built into rotor 2. Specifically, as follows: Figure 1 As shown, multiple (eight in this case) permanent magnets 5 are arranged at equal intervals on the same circumference. In this case, the magnetic poles of adjacent permanent magnets 5 are different from each other.

[0036] A cylindrical stator 4 is fixed to the inner circumference of the cylindrical section 1a in a manner that surrounds the outer circumference of the rotor 2. A small gap (air gap) is provided between the inner circumferential surface of the stator 4 and the outer circumferential surface of the rotor 2.

[0037] <Stator 4> The stator 4 has a stator core 41 and a coil 9 sealed in a slot 8.

[0038] The stator core 41 is configured such that multiple electromagnetic steel plates are stacked axially and tightly fixed together, as shown below. Figure 1 As shown, when viewed from the axial end, a ring-shaped magnetic yoke 6 and a plurality of teeth 7 extending from the magnetic yoke 6 toward the rotor 2 (inner circumferential side) are provided. The plurality of teeth 7 are arranged at equal intervals in the circumferential direction. Here, as... Figure 1 As shown, 24 teeth 7 are provided. Grooves 8 are provided between each tooth 7. Furthermore, a resin layer 50, which is surrounded by a resin composition and covered to form a thin wall, is provided on the tooth 7.

[0039] Furthermore, the axial length of the stator 4 is, for example, between 100 mm and 300 mm. A motor 100 with a stator 4 of this size is suitable, for example, as a drive motor for an electric vehicle.

[0040] <Coil 9> The coil 9 is in the shape of a flat U-shaped wire and is wound in a manner that spans the toothed portion 7 and is housed in two spaced slots 8. Here, the coil 9 is housed in a distributed winding manner in the bushing member 20 disposed in the slots 8.

[0041] The coil 9 has a coil body with a rectangular cross-section, which is a good conductor such as copper, and a resin coating layer covering the surface. The resin coating layer can be made of the same material as the resin material described later as resin layer 50.

[0042] <Teeth 7> The toothed portion 7 is provided corresponding to the permanent magnet 5 of the rotor 2. By sequentially energizing each coil 9, the rotor 2 is rotated by the attraction and repulsion between the coil and the corresponding permanent magnet 5.

[0043] The tooth portion 7 has a large circumferential width on its outer periphery and a small width on its inner periphery, and the tooth portion 7 is formed to taper towards the inner periphery. At the end of the tooth portion 7 on its inner periphery, a tooth front end 71 is formed that is circumferentially opposite to the tooth portion 8 in a manner that reduces the width of the groove 8.

[0044] <Slot 8> The groove 8 is the space between adjacent teeth 7, and the tooth wall surfaces 72 of the radially opposed teeth 7 are arranged to be parallel. The front ends 71 ​​of the teeth form the inner peripheral side opening of the groove 8. The groove 8 has: a plurality of coils 9 disposed on the outer peripheral side (the side of the yoke 6); and a resin sealing part 65 disposed on the inner peripheral side (the side of the front end 71 of the teeth).

[0045] <Resin layer 50> For example, such as Figures 3-5As shown, the resin layer 50 is integrally surrounded and covered by the resin composition around and covers the periphery of the tooth 7, and has: an inner surface resin layer 51 covering the inner wall surface (tooth wall surface 72) of the tooth 7; an outer surface resin layer 52 covering the upper surface 75a and the lower surface 75b of the tooth 7; and an inner surface resin layer 53 covering the inner wall surface (magnetic yoke wall surface 62) of the magnetic yoke 6.

[0046] The resin layer 50, formed by insert molding, surrounds and covers the teeth 7 in a thin-walled manner, thereby tightly fixing the stator 4, and more specifically, tightly fixing the multiple stacked electromagnet plates in the teeth 7. Alternatively, the resin layer 50 does not necessarily need to surround the teeth 7 in a thin-walled manner; the resin layer 52 on the outer surface of the teeth can be omitted. Insulation between the coil 9 and the inner wall surface of the slot 8 (the tooth wall surface 72 of the teeth 7 or the yoke wall surface 62 of the yoke 6) is ensured by the resin layer 51 on the inner surface of the teeth and the resin layer 53 on the inner surface of the yoke.

[0047] The thickness of the resin layer 51 on the inner surface of the tooth is 100 μm or more and 400 μm or less. The lower limit of the thickness is preferably 150 μm or more, more preferably 200 μm or more. The upper limit of the thickness is preferably 350 μm or less, more preferably 300 μm or less.

[0048] From the viewpoint of ensuring the flowability of the resin composition in the extremely narrow section between the mold (blade 80) and the tooth 7 (tooth wall 72) relative to the stator shaft length (i.e., the thickness of the stator 4) during insert molding, the lower limit of the thickness is preferably set within the above-mentioned range.

[0049] In a structure in which the coil 9 is mounted and wound on the toothed portion 7 and arranged in the slot 8, from the viewpoint of improving the space utilization efficiency within the slot 8 and ensuring the degree of freedom in the size of the usable coil 9, magnetic flux density, and other performance, the upper limit of the thickness is preferably set within the above-mentioned range.

[0050] The thickness of the resin layer 53 on the inner surface of the yoke can be the same as or different from the thickness of the resin layer 51 on the inner surface of the tooth. The thickness of the resin layer 52 on the outer surface of the tooth is not particularly limited and can be set to be the same as that of the resin layer 51 on the inner surface of the tooth.

[0051] Furthermore, as described later, the surface of the blade 80 used in forming the resin layer 50 has a surface with a draft angle. In the portion contacting the surface with the draft angle, the thickness of the resin layer 50 (the inner surface resin layer 51 of the tooth) becomes a thickness reflecting the draft angle. For example, as... Figure 6 As shown, the resin layer 51 on the inner surface of the tooth is thicker on the lower side (lower surface 75b side) and thinner on the upper side (upper surface 75a side).

[0052] <Physical properties of resin layer 50> The physical properties of the cured resin material constituting the resin layer 50 are as follows, for example.

[0053] The thermal conductivity of the cured resin material is 0.5 W / (m·K) or higher. The lower limit of the thermal conductivity is preferably 1.0 W / (m·K) or higher, more preferably 2 W / (m·K) or higher. The upper limit of the thermal conductivity is not particularly limited, and a practical value is, for example, 10 W / (m·K).

[0054] The glass transition temperature (Tg) of the resin composition in resin layer 50 is 120°C or higher, preferably 140°C or higher, and more preferably 160°C or higher. By setting the glass transition temperature (Tg) to the above range, the motor 100 can be used at high temperatures, and the resistance to heating of the coil 9 can be enhanced, enabling it to be used with high output.

[0055] The resin composition of resin layer 50 will be described in detail below.

[0056] <Materials of Resin Layer 50> The resin composition of the resin layer 50 preferably contains a thermosetting resin (A), a filler (B), and a curing agent (C).

[0057] [Thermosetting resin (A)] Examples of thermosetting resins (A) include epoxy resins, cyanate ester resins, polyimide resins, benzoxazine resins, unsaturated polyester resins, phenolic resins, melamine resins, silicone resins, bismaleimide resins, phenoxy resins, and acrylic resins. One of these thermosetting resins (A) may be used alone or in combination with two or more.

[0058] From the viewpoint of having high insulation properties, epoxy resin and phenolic resin are preferred as thermosetting resin (A). From the viewpoint of ensuring flow in extremely narrow sections during molding, epoxy resin is particularly preferred.

[0059] Examples of epoxy resins include bisphenol A type epoxy resin, bisphenol F type epoxy resin, bisphenol E type epoxy resin, bisphenol S type epoxy resin, bisphenol M type epoxy resin (4,4'-(1,3-phenylene diisopropylidene) bisphenol type epoxy resin), bisphenol P type epoxy resin (4,4'-(1,4-phenylene diisopropylidene) bisphenol type epoxy resin), bisphenol Z type epoxy resin (4,4'-cyclohexylene bisphenol type epoxy resin), etc.; phenolic varnish type epoxy resin, cresol varnish type epoxy resin, triphenolic methane type phenolic varnish type epoxy resin, tetraphenolic varnish type epoxy resin, etc. Phenolic varnish-type epoxy resins include phenolic ethane type epoxy resins and phenolic varnish-type epoxy resins with polycyclic aromatic hydrocarbon structures; biphenyl type epoxy resins; xylene-type epoxy resins and biphenyl arylane type epoxy resins; naphthalene-type epoxy resins include naphthalene ether type epoxy resins, naphthol type epoxy resins, naphthiodiol type epoxy resins, difunctional to tetrafunctional naphthalene epoxy resins, binaphthalene type epoxy resins, and naphthalene arylane type epoxy resins; anthracene type epoxy resins; phenoxy type epoxy resins; dicyclopentadiene type epoxy resins; norbornene type epoxy resins; adamantane type epoxy resins; and fluorene type epoxy resins. One of these types can be used alone, or two or more can be used in combination.

[0060] From the viewpoint of further improving heat resistance and insulation reliability, the epoxy resin is preferably selected from one or more of the following: bisphenol type epoxy resin, phenolic varnish type epoxy resin, biphenyl type epoxy resin, arylalkylene type epoxy resin, naphthalene type epoxy resin, anthracene type epoxy resin, and dicyclopentadiene type epoxy resin.

[0061] Examples of phenolic resins include phenolic varnish resins such as phenol, cresol, and bisphenol A varnish resins, as well as methyl phenolic resins. One type can be used alone, or two or more can be used in combination.

[0062] Among phenolic resins, phenolic varnish resin is preferred.

[0063] The content of thermosetting resin (A) relative to the total amount of resin composition in resin layer 50 is preferably 1% by mass or more, more preferably 5% by mass or more. On the other hand, this content is preferably 30% by mass or less, more preferably 20% by mass or less, relative to the total amount of resin composition in resin layer 50.

[0064] If the content of thermosetting resin (A) is above the lower limit mentioned above, the operability of the total amount of resin composition of resin layer 50 is improved, the inner surface resin layer 51 of the tooth is easily formed, and the strength of the inner surface resin layer 51 of the tooth is improved.

[0065] If the content of thermosetting resin (A) is below the above-mentioned upper limit, the coefficient of linear expansion and elastic modulus of the resin layer 51 on the inner surface of the tooth will be further improved, and the thermal conductivity will be further improved.

[0066] [Filler (B)] From the viewpoint of improving the thermal conductivity of the resin layer 50 (more specifically, the resin layer 51 on the inner surface of the tooth) and obtaining strength, the filler (B) in this embodiment can be used.

[0067] As filler (B), inorganic fillers are preferred, and thermally conductive fillers are particularly preferred. More specifically, from the viewpoint of achieving a balance between thermal conductivity and electrical insulation, examples of fillers (B) include silicon dioxide, aluminum oxide, boron nitride, aluminum nitride, and silicon carbide. These can be used alone or in combination of two or more. Among them, aluminum oxide and boron nitride are preferred as fillers (B).

[0068] The content of filler (B), i.e. the content of the filler mentioned above, relative to the total amount of the resin composition, is preferably 60% by mass or more.

[0069] [Curing agent (C)] When epoxy resin or phenolic resin is used as the thermosetting resin (A), the resin composition preferably also contains a curing agent (C).

[0070] As the curing agent (C), one or more selected from the curing catalyst (C-1) and the phenolic curing agent (C-2) can be used.

[0071] Examples of solidification catalysts (C-1) include organometallic salts such as zinc naphthenate, cobalt naphthenate, tin octoate, cobalt octoate, cobalt diacetylacetonate (II), and cobalt triacetylacetonate (III); tertiary amines such as triethylamine, tributylamine, and 1,4-diazabicyclo[2.2.2]octane; imidazoles such as 2-phenyl-4-methylimidazolium, 2-ethyl-4-methylimidazolium, 2,4-diethylimidazolium, 2-phenyl-4-methyl-5-hydroxyimidazolium, and 2-phenyl-4,5-dihydroxymethylimidazolium; organophosphorus compounds such as triphenylphosphine, tri-p-tolylphosphine, tetraphenylphosphine tetraphenylborate, triphenylphosphine-triphenylborane, and 1,2-bis-(diphenylphosphino)ethane; phenolic compounds such as phenol, bisphenol A, and nonylphenol; organic acids such as acetic acid, benzoic acid, salicylic acid, and p-toluenesulfonic acid, or mixtures thereof. As a curing catalyst (C-1), one of these substances may be used alone, or two or more derivatives of these substances may be used together.

[0072] The content of the curing catalyst (C-1) is not particularly limited, but it is preferably 0.001% by mass or more and 1% by mass or less relative to the total amount of the resin composition.

[0073] Furthermore, examples of phenolic curing agents (C-2) include phenolic varnish resins such as phenolic resin, cresol varnish resin, triphenol methane varnish resin, naphthol varnish resin, and aminotriazine varnish resin; modified phenolic resins such as terpene-modified phenolic resin and dicyclopentadiene-modified phenolic resin; aralkyl resins such as phenolic aralkyl resins with a phenylene skeleton and / or a biphenylene skeleton, and naphthol aralkyl resins with a phenylene skeleton and / or a biphenylene skeleton; bisphenol compounds such as bisphenol A and bisphenol F; and methyl phenolic resins. These can be used alone or in combination with two or more.

[0074] From the perspective of increasing the glass transition temperature and reducing the coefficient of linear expansion, the preferred phenolic curing agent (C-2) is phenolic varnish-type phenolic resin or methyl phenolic resin.

[0075] The content of the phenolic curing agent (C-2) is not particularly limited, but it is preferably 1% by mass or more, more preferably 5% by mass or more, relative to the total amount of the resin composition. On the other hand, this content is preferably 30% by mass or less, more preferably 15% by mass or less, relative to the total amount of the resin composition.

[0076] [Coupled Agent (D)] The resin composition may contain a coupling agent (D). The coupling agent (D) can improve the wettability of the interface between the thermosetting resin (A) and the filler (B).

[0077] There are no particular limitations on the coupling agent (D), but it is preferred to use one or more coupling agents selected from epoxy silane coupling agents, cationic silane coupling agents, amino silane coupling agents, titanate coupling agents and silicone oil coupling agents.

[0078] The content of coupling agent (D) is not particularly limited, but is preferably 0.05% by mass or more, more preferably 0.1% by mass or more, relative to 100% by mass of filler (B). On the other hand, this content is preferably 3% by mass or less, more preferably 2% by mass or less, relative to 100% by mass of filler (B).

[0079] [Phenoxy resin (E)] Furthermore, the resin composition may contain phenoxy resin (E). By containing phenoxy resin (E), the flexural strength of the resin layer 50 can be improved, and the elastic modulus can be reduced, thereby improving the stress relaxation force of the resin layer 50.

[0080] Furthermore, when phenoxy resin (E) is present, the viscosity increases and the fluidity decreases, which can suppress the formation of voids. Moreover, when the resin layer 50 is bonded to the metal part (i.e., the tooth 7) and used, the adhesion between the cured metal and the resin composition can be improved.

[0081] Examples of phenoxy resins (E) include phenoxy resins having a bisphenol backbone, phenoxy resins having a naphthalene backbone, phenoxy resins having an anthracene backbone, and phenoxy resins having a biphenyl backbone. Furthermore, phenoxy resins having structures with various of these backbones can also be used.

[0082] The content of phenoxy resin (E) relative to the total amount of the resin composition is preferably, for example, 3% by mass or more and 10% by mass or less.

[0083] [Mold Release Agent] The resin composition preferably contains a release agent. This improves the release properties after molding. Examples of release agents include natural waxes such as carnauba wax, synthetic waxes such as lignite ester wax or oxidized polyethylene wax, higher fatty acids such as zinc stearate and their metal salts, and paraffin wax. These can be used alone or in combination of two or more.

[0084] When using a release agent, its content in the total amount of resin molding material is preferably 0.01 to 3% by mass, more preferably 0.05 to 2% by mass. This reliably improves the release properties. As a result, the molding accuracy of the resin layer 51 on the inner surface of the tooth of the resin layer 50 can be improved.

[0085] [Other ingredients] Without impairing the effects of the present invention, the resin composition may also contain antioxidants, leveling agents, etc.

[0086] <Resin sealing part 65> A resin sealing portion 65 is provided on the inner circumferential side of the groove 8 (towards the front end 71 of the tooth). The resin sealing portion 65 can be provided by insert molding or as a separate part. The resin material used in the resin sealing portion 65 can be the same material described as the resin material used for the resin layer 50.

[0087] <Manufacturing Method of Stator 4> The manufacturing method of the stator 4 in this embodiment will be described. Figure 7 This is a flowchart illustrating the manufacturing method of stator 4.

[0088] First, prepare the stator 4 by stacking and fixing multiple electromagnetic steel plates axially (stator preparation step S10).

[0089] Next, blades 80 are arranged in groove 8, and by insert molding, an insulating resin composition is integrally wrapped around and covered the periphery of tooth 7 (tooth wall surface 72, upper surface 75a, and lower surface 75b) and the inner wall surface of yoke 6 (yoke wall surface 62) to form resin layer 50 (resin layer forming step S20). Details of resin layer forming step S20 will be described later.

[0090] Next, coils 9 are arranged in the groove 8 where the resin layer 50 is provided (coil arrangement process S30). After all the coils 9 are housed, resin material is filled into the area on the inner periphery of the groove 8 to obtain a resin sealing part 65 (coil sealing process S40).

[0091] Next, referring to the flowchart above, Figure 8 and Figure 9 The resin layer formation process S20 will be described in more detail. Figure 8 and Figure 9 This is a diagram showing the state transition within tank 8 in the resin layer formation process S20. Figure 8 It is a cross-sectional view obtained by cutting along a plane perpendicular to the axis. Figure 9 Is with Figure 3 A cross-sectional view of the portion corresponding to section AA.

[0092] The resin layer forming process S20 includes a core configuration process S21, a resin filling process S22, and a mold core removal process S23.

[0093] Figure 8 (a) and Figure 9 (a) indicates the state before the blade is inserted at 80°. And, as... Figure 8 (b) and Figure 9 As shown in (b), the core configuration step S21 is the step of inserting a blade-shaped blade 80 inside the groove 8. In this embodiment, the blade 80 is inserted into the groove 8 from the upper side shown in the figure. At this time, the upper and lower ends of the blade 80 protrude from the upper and lower ends of the groove 8.

[0094] In the core configuration process S21, a space 88 for filling the thermosetting resin composition is formed between the wall surface of the groove 8 (tooth wall surface 72 of the tooth 7 and magnetic yoke wall surface 62 of the magnetic yoke 6) and the blade 80. Since a draft angle is provided in the blade 80, the distance between the inner wall surface of the groove 8 and the blade 80 widens as it approaches the lower surface 75b side.

[0095] Next, as Figure 8 (c) and Figure 9 As shown in (c), the resin filling step S22 is a step of filling the space 88 formed by the core configuration step S21 with the above-mentioned thermosetting resin composition.

[0096] Next, as Figure 8 (d) and Figure 9 As shown in (d), the mold core removal process S23 is the process of pulling out and removing the blade 80 in the process following the resin filling process S22. This process is performed in the so-called molded state before post-curing. At this time, the temperature of the resin layer 50 is, for example, 100°C. An operating through-hole 85 is provided near the upper end 80a of the blade 80. A prescribed clamp is installed in the through-hole 85, and the blade 80 is pulled out upward in the figure. The resin layer 50 is formed on the wall surface of the groove 8 (tooth wall surface 72 of the toothed part 7, magnetic yoke wall surface 62 of the magnetic yoke part 6).

[0097] Because a draft angle is provided in the blade 80, the blade 80 is easy to pull out. That is, compared with the case without a draft angle, the pull-out force can be reduced and damage to the resin layer 50 can be suppressed.

[0098] <Leaf 80> The blade 80 used in the resin layer formation process S20 will be described.

[0099] The blade 80 is configured in an appropriate shape according to the shape of the groove 8 and the resin layer 50, but in this embodiment, it is a long, thin-walled blade shape. Figure 10 (a) is a top view of blade 80. Figure 10 (b) is a side view. Figure 10 (c) is the main view.

[0100] Specifically, the blade 80 has first to fourth blade surfaces 81 to 84 that are housed in the groove 8. The first blade surface 81 and the second blade surface 82 are surfaces opposite to the tooth wall surface 72 of the tooth portion 7. The third blade surface 83 is a surface opposite to the magnetic yoke wall surface 62. The fourth blade surface 84 is a surface facing the front ends 71 ​​of the tooth portion, and when the front ends 71 ​​of the tooth portion are closed by the mold component, it is a surface facing the mold component.

[0101] When the first to fourth blade surfaces 81 to 84 are housed in the slot 8, the ends in the insertion direction and the proximal ends in the insertion direction protrude from the slot 8. A through-hole 85 is provided at the proximal end for mounting a prescribed clamp to operate the blade 80.

[0102] When the blade 80 is housed in the groove 8, the distance between the blade 80 and the groove 8 (including the mold component 95) is a distance corresponding to the thickness of the resin layer 50. In this embodiment, a draft angle is provided on the blade 80, so the above-mentioned distance also changes according to the draft angle.

[0103] In the blade 80, draft angles d1 and d2 are provided on the surfaces (first blade surface 81, second blade surface 82, and third blade surface 83) opposite to the wall surface (tooth wall surface 72, yoke wall surface 62) of the groove 8. In particular, draft angle d1 is provided on the first blade surface 81 and the second blade surface 82 opposite to the tooth wall surface 72 with a larger area. Alternatively, the draft angle may be provided on only one of the first blade surface 81 or the second blade surface 82.

[0104] The draft angle d1 can be set to, for example, 15 μm or more and 100 μm or less. The lower limit of the draft angle is preferably 17 μm or more, more preferably 20 μm or more. The upper limit of the draft angle is preferably 50 μm or less, more preferably 40 μm or less.

[0105] When the blade 80 is housed in the slot 8, sometimes the front end 71 of the adjacent tooth 7 is closed by a mold component different from the blade 80. In this case, a draft angle can also be set on the surface (fourth blade surface) opposite to the mold component in the blade 80.

[0106] The area in the blade 80 where a draft angle is provided is at least the area that passes through the groove 8 when the blade is pulled out of the groove 8. More specifically, the portion facing the resin layer 50 when the resin layer 50 is formed has a draft angle. That is, when molding the resin layer 50, the portion protruding outward from the groove 8 may not have a draft angle.

[0107] The blade 80 can use common mold steel, such as SKD-11 (JIS standard).

[0108] The surfaces of blade 80 (the surfaces in contact with resin layer 50), specifically the first to fourth blade surfaces 81 to 84, are smoothed to ensure that their surface roughness Ra and RSm are within the specified ranges. This prevents strain or other effects on resin layer 50 when blade 80 is removed.

[0109] The surface roughness Ra of the blade 80 is 0.2 μm to 2 μm. Since smoother surfaces are preferred, there is no particular limitation on the lower limit; any value above the aforementioned range is acceptable. The upper limit is preferably 2.0 μm or less, more preferably 1.5 μm or less. The surface roughness Ra is measured in accordance with JIS B 0601-2001. By making the surface roughness Ra of the blade 80 within the aforementioned range, the surface of the blade 80 is made smooth, ensuring good pull-out properties and good adhesion between the resin layer 50 and the stator core 41.

[0110] The surface roughness RSm of blade 80 is 200 μm or more and 700 μm or less. Since smoother surfaces are preferred, there is no particular limitation on the lower limit; any value above the aforementioned range is acceptable. The upper limit is preferably 600 μm or less, and more preferably 500 μm or less. The surface roughness RSm is measured in accordance with JIS B 0601-2001. By making the surface roughness RSm of blade 80 within the aforementioned range, the surface of blade 80 is made smooth, ensuring good pull-out properties and good adhesion between resin layer 50 and stator core 41.

[0111] Furthermore, the surface roughness Ra and RSm of the blade 80, as set as described above, can be set on either the first blade surface 81 or the second blade surface 82, which is opposite to the large tooth wall surface 72, or only on either of these surfaces. Regarding the relatively small third blade surface 83 or the fourth blade surface, its surface roughness Ra and RSm can be large values ​​that deviate to a certain extent from the above range.

[0112] <Summary of Implementation Methods> The features of this embodiment are summarized below.

[0113] (1) A method for manufacturing a stator 4, wherein the resin layer is formed inside a groove 8, which is a space between teeth 7 extending from an annular magnetic yoke 6, using a mold for forming a resin layer on the wall surface (tooth wall surface 72, magnetic yoke wall surface 62) of the groove 8. The mold described above has blades 80 housed inside the groove 8. The resin layer 50 is formed by filling the space between the wall surface (tooth wall surface 72, magnetic yoke wall surface 62) of the groove 8 and the blades 80 with resin material when the blades 80 are housed. In the aforementioned blade 80, a draft angle is provided on the side opposite to the wall surface (tooth wall surface 72, magnetic yoke wall surface 62) of the aforementioned groove 8. The above draft angles are 15μm to 100μm. The surface roughness Ra of the surface with the above draft angle is set to 0.2μm~2μm.

[0114] (2) The method for manufacturing the stator 4 as described in (1), wherein, The surface roughness RSm of the surface with the above draft angle is 200μm or more and 700μm or less.

[0115] (3) The method for manufacturing the stator 4 as described in (1) or (2), wherein, In the blade 80, the draft angle is provided on the surface opposite to the wall surface (tooth wall surface 72) of the tooth 7 in the groove 8.

[0116] (4) The method for manufacturing the stator 4 as described in (3), wherein, In the blade 80, the draft angle is provided on the surface opposite to the wall surface (magnetic yoke wall surface 62) of the magnetic yoke portion 6 in the groove 8.

[0117] (5) The method for manufacturing the stator 4 as described in (4), wherein, When the blade 80 is housed, the space formed between the wall surface (tooth wall surface 72, magnetic yoke wall surface 62) of the groove 8 and the blade 80 is formed by the front end (71) of the adjacent tooth 7 being closed by a mold component different from the blade 80. In the blade 80, the draft angle is provided on the surface opposite to the mold component.

[0118] (6) The method of manufacturing the stator 4 as described in any one of (1) to (5), wherein, The aforementioned resin layer 50 is a cured resin material. The above-mentioned resin material contains one or two thermosetting resins selected from epoxy resin and phenolic resin.

[0119] (7) A method for manufacturing the stator 4 as described in any one of (1) to (6), wherein, The thickness of the resin layer 50 is more than 100 μm and less than 400 μm.

[0120] (8) A method for manufacturing the stator 4 as described in any one of (1) to (7), wherein, The axial length of the groove 8 is more than 100mm and less than 300mm.

[0121] (9) The method of manufacturing the stator 4 as described in any one of (1) to (8), wherein, The area in the blade 80 where the draft angle is provided includes at least the area that the blade 80 passes through in the groove 8 when it is pulled out of the groove 8.

[0122] The embodiments of the present invention have been described above, but these are merely examples of the present invention, and various structures other than those described above may also be employed.

[0123] Example The present invention will now be described in detail using examples, but the present invention is not limited to any of the examples described herein. In the following examples, when preparing simulation molds of stators and blades, and forming a resin layer (corresponding to the structure of resin layer 50 in the embodiments) on the inner wall surface of the slot, the relationship between the draft angle, surface roughness Ra, RSm and pull-out properties of the blades was evaluated.

[0124] <Composition of the thermosetting resin composition> The thermosetting resin composition (material of resin layer 50) used in the evaluation is as follows.

[0125] (Inorganic filler) • Inorganic filler 1: Molten spherical alumina (manufactured by Micron, Inc., average particle size 20 μm) • Inorganic filler 2: Molten spherical silica (manufactured by Tokuyama Corporation, average particle size 0.2μm) • Inorganic filler 3: Molten spherical alumina (manufactured by ADMATECHS Company Limited, average particle size 0.6 μm) (Coloring agent) • Colorant 1: Carbon black (Coupled agent) Coupling agent 1: N-phenyl-3-aminopropyltrimethoxysilane Coupling agent 2: 3-Mercaptopropyltrimethoxysilane (Epoxy resin) • Epoxy Resin 1: Biphenyl type epoxy resin (manufactured by Mitsubishi Chemical Corporation, YX4000HK) • Epoxy Resin 2: Triphenolmethane type epoxy resin (manufactured by Mitsubishi Chemical Corporation, YL6677) (Curing agent) • Hardener 1: Phenolic varnish-type phenolic compound (manufactured by Sumitomo Bakelite Co., Ltd.) (Curing accelerator) • Curing accelerator 1: Tetraphenylphosphonium 4,4'-sulfonyl diphenol salt • Curing Accelerator 2: Tetraphenylphosphonium bis(naphthalene-2,3-dioxy)phenylsilicate (Wax (mold release agent)) • Wax 1: Carnauba wax (manufactured by AIR WATER INC.) Wax 3: Diethanolamine / Diphosphite (Ion scavenger) • Ion scavenger 1: Hydrotalcite (manufactured by Kyowa Chemical Industry Co., Ltd.) (Other additives) • Triazole compound 1: Triazole compound (manufactured by Shikoku Chemical Corporation) (Low-stress materials) • Low-stress material 1: Silicone oil (manufactured by Shin-Etsu Chemical Co., Ltd., KR-480) • Low-stress material 2: Epoxy / polyether modified silicone oil (manufactured by Dow Corning Co., Ltd., FZ-3730) (Preparation of resin composition) First, the raw materials prepared according to Table 1 were mixed in a mixer at room temperature, and then rolled at a temperature between 70°C and 110°C. Next, the resulting mixture was cooled and pulverized to obtain the resin composition.

[0126] (Stator simulation mode) exist Figure 11 The shape of the slot in the stator simulation mold is shown. Here, one slot is shown.

[0127] The dimensions of the groove are as follows.

[0128] Slot width (L1): 4.5mm Groove length (L2): 24.3mm Slot height: 150mm (Blade (mold core)) Used with Figure 10 The blades shown are of the same shape. As mentioned above, Figure 10 (a) is a top view. Figure 10 (b) is a side view. Figure 10 (c) is the main view.

[0129] On the inked portions shown in the figure (the surfaces corresponding to the first blade surface 81 and the second blade surface 82 of the embodiment), draft angles were set according to Examples 1-4 and Comparative Examples 1-4. Furthermore, according to Examples 1-4 and Comparative Examples 1-4, the surface roughness of the areas where draft angles were set was set was also set. The set draft angles and surface roughness Ra and RSm are shown in Table 2.

[0130] <Surface roughness Ra, RSm> The surface roughness Ra and RSm of the blade were measured using a measuring device (KEYENCE CORPORATION, model VR-5000) in accordance with JIS B 0601-2001.

[0131] <Forming of Resin Layer> The blade is placed in the groove, and the space between the groove and the blade is filled with the resin composition obtained in the above adjustment. The blade is then pulled out in its original molding state (temperature 100°C). Regarding the thickness of the resin layer, the maximum thickness is 300 μm, and the minimum thickness is set to the thickness minus the set draft angle.

[0132] <Resin strain during blade removal> After the blades were removed from the groove, the condition of the resin layer was visually inspected, and an evaluation was conducted based on whether strain had occurred. The evaluation is shown in Table 2.

[0133] The evaluation shall be conducted in accordance with the following evaluation criteria A to C.

[0134] A: Strain cannot be confirmed visually. B: A small amount of strain can be visually confirmed. C: Visually confirm strain <Coil Filling Properties> When blades were placed in the tank and resin was filled to form a resin layer, the presence of short-shot (the state where the resin was not filled and cooled) was visually confirmed. The evaluation is shown in Table 2.

[0135] The evaluation will be conducted according to the following two-stage evaluation criteria.

[0136] OK: No short shot occurred; NG: A short shot occurred.

[0137] [Table 1] [Table 2] This application claims priority based on Japanese Patent Application No. 2024-042078, filed on March 18, 2024, the entire contents of which are incorporated herein by reference.

[0138] Symbol Explanation 1: Housing, 2: Rotor, 4: Stator, 6: yoke, 7: Tooth, 8: Slot, 9: Coil, 50: Resin layer, 51: Inner surface resin layer of tooth, 52: Outer surface resin layer of tooth, 55: Surface of resin layer, 55a, 55b: End, 62: yoke wall, 65: Resin seal, 71: Tooth front end, 72: Tooth wall, 80: Blade, 81: First blade surface, 82: Second blade surface, 83: Third blade surface, 84: Fourth blade surface, 100: Motor.

Claims

1. A method for manufacturing a stator, characterized in that: Inside a groove that serves as a space between teeth extending from a ring-shaped magnetic yoke, a resin layer is formed using a mold for molding a resin layer on the wall surface of the groove. The mold has blades housed inside the groove, and the resin layer is formed by filling the space between the groove wall and the blades when the blades are housed with resin material. In the blade, a draft angle is provided on the surface opposite to the wall of the groove. The draft angle is between 15 μm and 100 μm. The surface roughness Ra of the surface with the draft angle is 0.2 μm or more and 2 μm or less.

2. The method for manufacturing a stator as described in claim 1, characterized in that: The surface roughness RSm of the surface with the draft angle is set to be above 200 μm and below 700 μm.

3. The method for manufacturing a stator as described in claim 1 or 2, characterized in that: In the blade, the draft angle is provided on the surface facing the wall of the tooth in the groove.

4. The method for manufacturing a stator as described in claim 3, characterized in that: In the blade, a draft angle is provided on the surface facing the wall of the magnetic yoke in the groove.

5. The method for manufacturing a stator as described in claim 4, characterized in that: When the blade is housed, the space formed between the wall of the groove and the blade is formed by the front end of the adjacent tooth being closed by a mold component different from the blade. In the blade, the draft angle is provided on the surface opposite to the mold component.

6. The method for manufacturing a stator according to any one of claims 1 to 5, characterized in that: The resin layer is a cured resin material. The resin material contains one or two thermosetting resins selected from epoxy resin and phenolic resin.

7. The method for manufacturing a stator according to any one of claims 1 to 6, characterized in that: The thickness of the resin layer is between 100 μm and 400 μm.

8. The method for manufacturing a stator according to any one of claims 1 to 7, characterized in that: The axial length of the groove is more than 100mm and less than 300mm.

9. The method for manufacturing a stator according to any one of claims 1 to 8, characterized in that: The region in the blade for which the draft angle is set includes at least the region through which the blade passes when it is pulled out of the groove.

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