Rotary electrical machine and electric vehicle

Abstract

A rotary electrical machine (16) according to the present disclosure comprises a stator core (2), a frame (5) which accommodates the stator core (2), and a resin part (11, 15, 25) which is provided to a portion that is for fixing the stator core (2) and the frame (5) and which allows for measurement of insulation resistance.

Description

Rotating electric machines and electric vehicles

[0001] The present disclosure relates to a rotating electric machine and an electric vehicle.

[0002] Methods for fastening a stator of a rotating electric machine to a frame, such as a housing, case, or enclosure, to which the stator is attached, include shrink fitting, press fitting, and bolt fastening. Inventions have been published for preventing strength reduction due to residual stress in structural members, preventing rattle at fastening points, and suppressing motor vibration and noise. Patent Document 1 discloses a method for fastening an electric motor stator, characterized by filling a thermosetting resin adhesive layer at the joint between the rotating electric machine stator and the frame. Patent Document 2 also discloses a method for fastening the core and frame of a rotating electric machine with bolts, and fastening the bolt insertion points with a resin material.

[0003] A rotating electric machine is composed of various parts, such as a core made of laminated electromagnetic steel sheets, coils coated with an insulating coating, magnets, a shaft, bearings, and a frame. Over the long term, parts may need to be replaced for maintenance or other reasons. In such cases, if parts are replaced unintentionally by parties other than the manufacturer, there is a concern that the repaired product may easily break or that trouble may occur in the manufacturer's repair business. However, it is not easy to determine whether a part has been replaced unintentionally. Patent Document 3 discloses a method for determining whether printed circuit boards in a driving device of a rotating electric machine are disconnected by writing data to a memory.

[0004] JP 2009-201235 A JP 2019-186997 A JP 2021-170900 A

[0005] However, assembling an information recording device such as a memory into a rotating electrical machine is difficult, and a method for more easily determining whether or not a part has been replaced unintentionally is needed.

[0006] The present disclosure has been made to solve the above-mentioned problems, and aims to provide a rotating electric machine and an electric vehicle that can more easily determine whether or not a part has been replaced unintentionally.

[0007] The rotating electric machine according to the present disclosure is characterized by comprising a stator core, a frame for housing the stator core, and a resin part provided in a part for fixing the stator core and the frame, which allows insulation resistance to be measured.

[0008] The electric vehicle according to the present disclosure is characterized by comprising the above-described rotating electric machine mounted between an engine and a transmission via a drive shaft, and drive wheels to which the power of the engine and / or the rotating electric machine is transmitted from the drive shaft via a differential gear.

[0009] According to the present disclosure, the presence or absence of a disassembly history between the stator core and the frame can be easily determined by resistance measurement and visual inspection.

[0010] FIG. 1 is an axial cross-sectional view showing the configuration of a stator of a rotating electric machine according to embodiment 1. FIG. 2 is an enlarged cross-sectional view showing the configuration of a main part of the stator of the rotating electric machine according to embodiment 1. FIG. 3 is a perspective view showing the configuration of the stator of the rotating electric machine according to embodiment 1. FIGS. 4A and 4B are diagrams showing a method for measuring insulation resistance in the stator of the rotating electric machine according to embodiment 1. FIG. 5 is a diagram showing resistance characteristics of a resin part in the stator of the rotating electric machine according to the embodiment. FIG. 6 is a radial cross-sectional view showing the configuration of a stator of a rotating electric machine according to embodiment 2. FIG. 7 is an enlarged cross-sectional view showing the configuration of a main part of the stator of the rotating electric machine according to embodiment 2. FIG. 8 is a diagram showing a method for measuring insulation resistance in the stator of the rotating electric machine according to embodiment 2. FIG. 9 is an enlarged cross-sectional view showing the configuration of a main part of the stator of the rotating electric machine according to embodiment 3. FIG. 10 is a diagram showing a method for measuring insulation resistance in the stator of the rotating electric machine according to embodiment 3. FIG. 11 is a plan view showing the configuration of a main part of an electric motor according to embodiment 4.

[0011] This embodiment relates to a rotating electric machine that requires high-precision control in fields such as automobiles, railways, industry, and air conditioning. In the following description, directions in the rotating electric machine are defined as the circumferential direction in the circumferential direction of the rotating electric machine, the axial direction of the rotation axis of the rotor of the rotating electric machine, and the radial direction in the circumferential direction from the rotation axis of the rotating electric machine. Hereinafter, an embodiment of the rotating electric machine according to this embodiment will be described with reference to the drawings.

[0012] Embodiment 1. Fig. 1 is a plan cross-sectional view showing a part of a frame that houses a stator of a rotating electric machine according to embodiment 1. Fig. 2 is an enlarged cross-sectional view showing a fitting portion of the stator of the rotating electric machine and the frame that houses the stator, which is located in area A of Fig. 1. Fig. 3 is a schematic perspective view showing the stator and frame of the rotating electric machine.

[0013] 1, a stator 1 of a rotating electric machine has a stator core 2 formed by laminating a plurality of electromagnetic steel plates, and coils 4 provided on teeth 3 provided on the stator core 2. The teeth 3 penetrate the stator core 2 in the axial direction, and a plurality of teeth 3 are provided along the circumferential direction of the stator core 2. Note that the number of teeth 3 provided on the stator core 2 is not particularly limited.

[0014] The frame 5 has a frame protrusion 6 that fits into the stator core 2. The stator core 2 has a stator core recess 7 that fits into the frame 5. The frame protrusion 6 and the stator core recess 7 serve to position the stator core 2 and prevent rotation when fitting, and are provided at one or more locations on the outer periphery of the stator core 2 and the inner diameter of the frame 5.

[0015] As shown in Fig. 2, the frame protrusion 6 has a through hole 8 penetrating in the circumferential direction and a conductor 9 inserted into the through hole 8. The conductor 9 has an insulating coating 10 applied to the contact portion with the through hole 8. Although Fig. 3 shows one through hole 8 as an example, the number of through holes 8 is not particularly limited. There are no restrictions on the shapes of the through hole 8 and the conductor 9, but a cylindrical shape is preferable in order to provide the insulating coating 10 uniformly.

[0016] The insulating coating 10 has a volume resistivity of 1×10 14It is preferable that the resistivity is greater than Ω·m, and the thickness is 30 μm or more, preferably 100 μm or more, so that there is no dielectric breakdown even when a high voltage of 1000 V is applied.

[0017] An adhesive layer 11 is applied between the frame protrusion 6 and the stator core recess 7 as a resin portion for fixing the stator core 2 and the frame 5. The adhesive layer 11 has insulating properties to low resistance or nonlinear resistance. The volume resistivity of the adhesive layer 11 in this disclosure is 1×10 14 The volume resistivity is preferably 1×10 Ω·m or less. 14 By making the resistivity Ω·m or less, the difference in resistivity with the insulating coating 10 can be made clear.

[0018] The adhesive layer 11 can adjust its volume resistivity by blending a filler into the resin. In the case of a general insulating material, the volume resistivity is 1×10 14 It has an insulating property greater than Ω·m. The insulation resistance can be changed by adding metallic aluminum powder, iron powder, copper powder, silver powder, gold powder, nickel powder, palladium powder, or carbon black as a filler to the resin.

[0019] For example, in the case of silver powder, by blending up to 50% by weight into the resin of the adhesive layer 11, the volume resistivity can be increased to 1×10 14 Furthermore, by blending 50% by weight or more of silver powder into the resin, a conductive path is formed by the silver powder in the resin, and the resistance can be adjusted to 1×10 5 The resistivity can be adjusted to Ω·m or less. In addition, by blending a varistor such as zinc oxide, silicon carbide, triiron tetroxide, bismuth oxide, or antimony trioxide as a filler, the adhesive layer 11 can be adjusted to exhibit nonlinear resistance characteristics.

[0020] The thickness of the adhesive layer 11 is preferably such that it will not be mechanically damaged within the normal range of use of the rotating electric machine and will not undergo dielectric breakdown even when a high voltage of 1000 V is applied, and is preferably 30 μm or more and 200 μm or less, more preferably 50 μm or more and 100 μm or less.

[0021] By configuring it in this manner, if the stator 1 of the rotating electric machine is disassembled and separated from the frame 5 by something unintentional other than the manufacturer, the adhesive layer 11 will be damaged, and by measuring the insulation resistance of the adhesive layer 11 between the stator core 2 and the outer periphery of the conductor 9 to which the insulating coating 10 is applied, it can be determined whether or not disassembly has occurred.

[0022] The materials used in the rotating electric machine according to the first embodiment will be described below. The stator core 2 is not particularly limited, and can be formed from a steel sheet laminate formed by stacking electromagnetic steel sheets, iron, or an iron-silicon alloy. Furthermore, the stator core can be obtained by molding a powder magnetic core formed from soft magnetic metal powder such as an iron-carbon alloy, or a magnetic powder in which soft magnetic metal oxide powder is coated with a resin binder such as a silicone resin. It can also be obtained by molding a high-density powder magnetic core.

[0023] The forming method is not particularly limited, and may be a method of cutting out material, a method of laminating electromagnetic steel sheets pressed into a desired shape, or the like. Among these, a stator core 2 obtained by forming a steel sheet laminate made by laminating silicon steel sheets is preferred, and in particular, from the viewpoint of preventing eddy current loss, a stator core 2 obtained by forming a steel sheet laminate made by laminating silicon steel sheets with insulating films formed on their surfaces is more preferred. The thickness of the silicon steel sheets is not particularly limited, but is generally 0.2 mm to 0.5 mm.

[0024] The coils 4 inserted into the teeth 3 have a conductor surface covered with an enamel coating. The conductor of the coil 4 is not particularly limited as long as it is conductive, and wires made of copper, aluminum, etc. can be used. Copper is preferably used because it has low resistance and generates little heat when current flows through it. The enamel coating can be made of polyester, polyurethane, nylon, polyesterimide, polyamideimide, polyimide, polyphenylene sulfide, polyether ether ketone, etc. A heat-resistant temperature of 155°C or higher is preferred, and polyester, polyesterimide, polyamideimide, polyimide, polyphenylene sulfide, polyether ether ketone, etc. can be used alone or in combination of two or more layers. The winding method may be either concentrated winding or distributed winding.

[0025] The frame 5 can be made of iron or aluminum so as to ensure sufficient strength for the frame protrusions 6. The conductor 9 can be made of the same conductive material as the frame 5, such as iron or aluminum. The insulating coating 10 is not particularly limited as long as it is an electrically insulating material that can be used as paint, and examples thereof include thermoplastic resin, thermosetting resin, and photosensitive resin.

[0026] Examples of thermoplastic resins include polyurethane, polyvinyl resin, cellulose resin, fluororesin, and acrylic resin. Examples of thermosetting resins include epoxy resin, phenolic resin, melamine resin, unsaturated polyester resin, and polyamide resin. Examples of photosensitive resins include urethane acrylate, acrylic resin acrylate, and epoxy acrylate. A mixture of two or more resins selected from these may also be used. A ceramic coating containing silicon or other components as a main component may also be used. The insulating coating 10 can be formed by coating the surface of the conductor 9 using various known methods. Specific examples include impregnation with a liquid resin, spray coating, and molding.

[0027] The resin component of the adhesive layer 11 is preferably a thermosetting resin, such as an epoxy resin, a phenolic resin, a melamine resin, an unsaturated polyester resin, or a polyamide resin. Epoxy resins are particularly preferred because of their excellent heat resistance and durability.

[0028] Specific examples of epoxy resins include bisphenol A epoxy resins, brominated bisphenol A epoxy resins, hydrogenated bisphenol A epoxy resins, bisphenol F epoxy resins, bisphenol S epoxy resins, bisphenol AF epoxy resins, biphenyl epoxy resins, naphthalene epoxy resins, fluorene epoxy resins, novolac epoxy resins, phenol-novolac epoxy resins, orthocresol-novolac epoxy resins, tris(hydroxyphenyl)methane epoxy resins, glycidyl ether epoxy resins such as tetraphenylolethane epoxy resins, glycidyl ester epoxy resins obtained by condensation of epichlorohydrin and carboxylic acid, triglycidyl isocyanate, and heterocyclic epoxy resins such as hydantoin epoxy resins obtained by reaction of epichlorohydrin and hydantoins. The adhesive layer 11 may be formed from any one of the above resins, or a mixture of two or more of the resins may be used. The adhesive layer 11 of this embodiment may contain a curing agent for curing the insulating resin (for example, a thermosetting resin such as an epoxy resin).

[0029] The type of curing agent is not particularly limited as long as it cures the thermosetting resin. Specific examples of curing agents that can be used include amine-based curing agents and acid anhydride-based curing agents. Examples of amine-based curing agents include ethylenediamine and polyamidoamine. Examples of acid anhydride-based curing agents include phthalic anhydride, hexahydrophthalic anhydride, 4-methylhexahydrophthalic anhydride, tetrahydrophthalic anhydride, 4-methyltetrahydrophthalic anhydride, and tetrabromophthalic anhydride. Furthermore, epoxy resin curing accelerators increase the curing rate of epoxy resins. Such curing accelerators can be used as appropriate as long as they accelerate the curing of epoxy resins, and the type is not particularly limited.

[0030] The insulation resistance of the adhesive layer 11 can be changed by blending a filler. Specific fillers include varistors such as zinc oxide, silicon carbide, triiron tetroxide, bismuth oxide, and antimony trioxide, carbon black, and metals such as aluminum powder, iron powder, copper powder, silver powder, gold powder, nickel powder, and palladium powder. Blending these varistors, carbon black, or metal powders can increase the volume resistivity to 1×10 14 It can be adjusted to Ω·m or less.

[0031] The nonlinear resistance characteristics of the adhesive layer 11 are achieved by blending varistors such as zinc oxide, silicon carbide, triiron tetroxide, bismuth oxide, and antimony trioxide. In the case of nonlinear resistance characteristics, the number-average particle size of these fillers is preferably 10 to 130 μm to ensure good expression of nonlinear resistance characteristics. Outside this range, the nonlinear resistance characteristics deteriorate. If the particle size is less than 10 μm, the number of grain boundaries of the filler that develops nonlinear resistance characteristics is insufficient, and if it is greater than 130 μm, the viscosity of the adhesive layer 11 increases, resulting in poor application properties.

[0032] The filler content is preferably 20% by volume or more and 70% by volume or less with respect to the total amount of adhesive layer 11. In this case, it is possible to further increase the electric field strength at which the resistivity of adhesive layer 11 begins to decrease. If the filler content is less than 20% by volume, adhesive layer 11 becomes insulating, and if the filler content is more than 70% by volume, the viscosity increases, making it difficult to apply the adhesive layer.

[0033] Next, a method for determining whether or not the stator core 2 and the frame 5 have been disassembled in the rotating electric machine according to the first embodiment will be described. Figures 4A and 4B are diagrams for explaining a method for measuring the insulation resistance of the adhesive layer 11 in the rotating electric machine according to the first embodiment. Figure 4A is a cross-sectional view illustrating the measurement method, and Figure 4B is a perspective schematic view.

[0034] In the rotating electric machine according to the first embodiment, when the stator 1 and the frame 5 are disassembled and separated, the adhesive 11 is damaged. The adhesive 11 is used to determine whether the stator 1 and the frame 5 have been disassembled, and if damage to the adhesive 11 can be confirmed from the outside of the rotating electric machine, it can be easily determined whether or not the disassembly has occurred.

[0035] If damage to the adhesive 11 cannot be visually confirmed, connect an ammeter 30 to the stator core 2 and the conductor 9, and measure the insulation resistance of the adhesive 11 between the stator core 2 and the conductor 9, as shown in Figures 4A and 4B. Note that, in this measurement, the position of connection with the stator core 2 is not limited to the stator core 2 shown in Figure 4B. Because the stator core 2 and the frame 5 are in contact except for the area insulated by the adhesive 11 or the insulating coating 10, a similar determination can be made by measuring the insulation resistance between the frame 5 and the outer periphery of the conductor 9 to which the insulating coating 10 is applied.

[0036] The adhesive 11 can change its insulation resistance characteristics by changing the type and amount of filler contained therein. 14 When an adhesive 11 of Ω·m or less is used and the stator core 2 and the conductor 9 are not disassembled, the volume resistivity between the stator core 2 and the conductor 9 is 1×10 14 Indicates a value of Ω·m or less. 1×10 14 If a resistance of Ω·m or more or continuity is measured, it can be determined that decomposition has occurred.

[0037] When an adhesive 11 with nonlinear insulation resistance is used, the resistance characteristics are as shown in FIG. 5. The low voltage band refers to up to 500 V, and the high voltage band refers to 500 V to 1000 V. When a voltage in the low voltage band is applied, the insulation resistance between the stator core 2 and the conductor 9 is 10 12 Ω or more, but when a high voltage is applied, the insulation resistance is two orders of magnitude lower, 10 10 It shows an insulation resistance of Ω or less. If two voltages, low voltage and high voltage, are applied and no difference in insulation resistance is observed, it can be determined that a different adhesive than that used at the time of manufacture has been applied, and that decomposition has occurred.

[0038] As described above, the rotating electric machine in this embodiment 1 is provided with a stator core 2 having a stator core recess 7 formed in the axial direction on its outer periphery, a frame 5 that houses the stator core 2 and has a frame protrusion 6 that fits into the stator core recess 7, and an adhesive layer 11 that bonds the stator core recess 7 to the frame protrusion 6 and whose insulation resistance can be measured. Therefore, when the stator is removed from the frame, the adhesive layer is destroyed, and it is possible to easily determine whether or not disassembly has occurred by measuring the resistance of the adhesive layer and visually inspecting it.

[0039] Embodiment 2. In the first embodiment, the stator core 2 and the frame 5 are described as being connected by fitting the stator core recess 7 and the frame protrusion 6 together. In the second embodiment, however, a description is given of a case where the stator core 2 and the frame 5 are connected by using bolts and nuts.

[0040] Fig. 6 is a plan cross-sectional view showing a part of the stator of the rotary electric machine in embodiment 2. Fig. 7 is an enlarged cross-sectional view showing a bolt fastening portion between the stator and the frame of the rotary electric machine.

[0041] 6, the stator 1 of the rotary electric machine is provided with bolt fastening through holes 12 on the outer periphery of the stator core 2. The number of bolt fastening through holes 12 is not particularly limited.

[0042] 7, the stator core 2 is housed inside the frame 5, and the stator core 2 and the frame 5 are fixed together with conductive bolts 13 and nuts 14. The bolts 13 are inserted through the bolt fastening through holes 12 in the stator core 2 and the bolt fastening through holes 52 in the frame 5.

[0043] A resin molded part 15 is attached to the periphery of the tip of the bolt 13 on the side fastened by the nut 14, as a resin part of the bolt 13 for fixing the stator core 2 to the frame 5, so that the thickness is approximately uniform.

[0044] The resin molding 15 has insulating properties, low resistance, or nonlinear resistance. The resin molding 15 has insulating properties to low resistance, or nonlinear resistance. In the case of a general insulating material, the volume resistivity is 1×10 14 The volume resistivity of the resin molded product 15 in the present disclosure is 1×10 14 It is preferably Ω·m or less.

[0045] The resin molding 15 can change its insulation resistance by blending metallic aluminum powder, iron powder, copper powder, silver powder, gold powder, nickel powder, palladium powder, or carbon black as a filler. For example, when blending silver powder, blending up to 50% by weight of silver powder into the resin can increase the volume resistivity to 1×10 14 Furthermore, by blending 50% by weight or more of silver powder into the resin, a conductive path is formed by the silver powder in the resin, and the resistance can be adjusted to 1×10 5 The resistivity can be adjusted to Ω·m or less. Furthermore, by blending a varistor such as zinc oxide, silicon carbide, triiron tetroxide, bismuth oxide, or antimony trioxide as a filler, the resin molded product 15 can be adjusted to exhibit nonlinear resistance characteristics. The thickness of the resin molded product 15 is preferably 100 μm or more and 1000 μm or less so that it will not be damaged and will not undergo dielectric breakdown even when a high voltage of 1000 V is applied.

[0046] The resin component of the resin molded product 15 is not particularly limited as long as it is electrically insulating, and examples thereof include thermoplastic resins, thermosetting resins, photosensitive resins, etc. Among these, thermosetting resins are preferred, such as epoxy resins, phenolic resins, melamine resins, unsaturated polyester resins, and polyamide resins. Epoxy resins, which have excellent heat resistance and durability, are particularly preferred.

[0047] Specific examples of epoxy resins include bisphenol A epoxy resins, brominated bisphenol A epoxy resins, hydrogenated bisphenol A epoxy resins, bisphenol F epoxy resins, bisphenol S epoxy resins, bisphenol AF epoxy resins, biphenyl epoxy resins, naphthalene epoxy resins, fluorene epoxy resins, novolac epoxy resins, phenol-novolac epoxy resins, orthocresol-novolac epoxy resins, tris(hydroxyphenyl)methane epoxy resins, glycidyl ether epoxy resins such as tetraphenylolethane epoxy resins, glycidyl ester epoxy resins obtained by condensation of epichlorohydrin and carboxylic acid, triglycidyl isocyanate, and heterocyclic epoxy resins such as hydantoin epoxy resins obtained by reaction of epichlorohydrin and hydantoins. The resin molded product 15 may be made of any one of the above resins, or a mixture of two or more of the above resins. The resin molded article 15 of this embodiment may contain a curing agent for curing the insulating resin (for example, a thermosetting resin such as an epoxy resin).

[0048] The type of curing agent is not particularly limited as long as it cures the insulating resin. Specific examples of curing agents that can be used include amine-based curing agents and acid anhydride-based curing agents. Examples of amine-based curing agents include ethylenediamine and polyamidoamine. Examples of acid anhydride-based curing agents include phthalic anhydride, hexahydrophthalic anhydride, 4-methylhexahydrophthalic anhydride, tetrahydrophthalic anhydride, 4-methyltetrahydrophthalic anhydride, and tetrabromophthalic anhydride. Furthermore, the epoxy resin curing accelerator increases the curing rate of the epoxy resin. Such curing accelerators can be used as appropriate as long as they accelerate the curing of the epoxy resin, and the type is not particularly limited.

[0049] The insulation resistance of the resin molded article 15 can be changed by blending a filler. Specific fillers include zinc oxide, silicon carbide, triiron tetroxide, bismuth oxide, and antimony trioxide. By blending metallic aluminum powder, iron powder, copper powder, silver powder, gold powder, nickel powder, palladium powder, or carbon black, the volume resistivity can be increased to 1×10 14 It can be adjusted to Ω·m or less.

[0050] The nonlinear resistance characteristics of the resin molding 15 are exhibited by blending varistors such as zinc oxide, silicon carbide, triiron tetroxide, bismuth oxide, and antimony trioxide. In the case of nonlinear resistance characteristics, the number-average particle diameter of these fillers is preferably 10 to 130 μm to ensure good expression of nonlinear resistance characteristics. If the diameter is outside this range, the nonlinear resistance characteristics will deteriorate. If the diameter is less than 10 μm, the number of grain boundaries of the filler that exhibits nonlinear resistance characteristics will be insufficient, and if the diameter is greater than 130 μm, the viscosity of the resin molding 15 will increase, resulting in poor moldability.

[0051] The content of the filler is preferably 20% by volume or more and 70% by volume or less with respect to the total amount of the resin molded product 15. In this case, it is possible to further increase the electric field strength at which the resistivity of the resin molded product 15 begins to decrease. If the content is less than 20% by volume, the resin molded product 15 becomes insulating, and if it is more than 70% by volume, the viscosity increases, making it difficult to apply an adhesive.

[0052] Other configurations of the rotating electric machine in the second embodiment are the same as those of the rotating electric machine in the first embodiment, and corresponding parts are given the same reference numerals and description thereof will be omitted.

[0053] Next, a method for determining whether the stator core 2 and the frame 5 have been disassembled in the rotating electric machine according to the second embodiment will be described. Fig. 8 shows a cross-sectional view for explaining a method for measuring the insulation resistance of the resin molding 15 in the rotating electric machine according to the second embodiment.

[0054] In the rotating electric machine according to the second embodiment, when the stator 1 and the frame 5 are disassembled and separated, the resin molding 15 is damaged. The resin molding 15 determines whether or not the stator 1 and the frame 5 have been disassembled, and if damage to the resin molding 15 can be confirmed from the outside of the rotating electric machine, it can be easily determined whether or not the disassembly has occurred.

[0055] 8, an ammeter 30 is connected to the stator core 2 and the surface of the resin molding 15, and the insulation resistance of the resin molding 15 is measured. Since the stator core 2, frame 5, bolt 13, and nut 14 are in contact during this measurement, a similar determination can be made by connecting the ammeter 30 to the frame 5, bolt 13, or nut 14 as a measuring unit and the resin molding 15 to measure the insulation resistance.

[0056] The insulation resistance characteristics of the resin molding 15 can be changed by changing the type and amount of filler contained therein. The stator 1 and the frame 5 are fixed by the bolt 13 and nut 14. The area around the tip of the bolt 13 is filled with a material having a volume resistivity of 1×10 14 When the resin molded product 15 is covered with a resin molded product 15 having a volume resistivity of 1×10 14Indicates a value of Ω·m or less. 1×10 14 If a resistance of Ω·m or more or continuity is measured, it can be determined that decomposition has occurred.

[0057] When a resin molding 15 having a nonlinear insulation resistance is used, the resistance characteristics are as shown in FIG. 10. The low voltage band is up to 500 V, and the high voltage band is 500 V to 1000 V. When a voltage in the low voltage band is applied, the insulation resistance of the resin molding 15 is 10 12 Ω or more, but when a high voltage is applied, the insulation resistance is two orders of magnitude lower, 10 10 It shows an insulation resistance of Ω or less. If two voltages, low voltage and high voltage, are applied and no difference in insulation resistance is observed, it can be determined that decomposition has occurred because a resin molding different from that used at the time of manufacture has been applied.

[0058] As described above, the rotating electric machine in this embodiment 2 is provided with a stator core 2, a frame 5 that houses the stator core 2, conductive bolts 13 and nuts 14 that secure the stator core 2 to the frame 5, and a resin molding 15 that covers the periphery of the tip of the bolt 13 and allows insulation resistance measurement. Therefore, when the bolts and nuts are removed from the stator core and the frame, the resin molding is destroyed, and it is therefore possible to easily determine whether or not disassembly has occurred by measuring the resistance of the resin molding and visually inspecting it.

[0059] Embodiment 3. In the second embodiment, the case where the periphery of the tip of the bolt 13 used to fix the stator core 2 and the frame 5 is covered with the resin molding 15 is described, but in the third embodiment, the case where the head of the bolt is covered will be described.

[0060] 9j is an enlarged cross-sectional view showing a bolt fastening portion between the stator and the frame of the rotating electric machine according to embodiment 3. As shown in Fig. 9, in the rotating electric machine according to embodiment 3, instead of the resin molding 15 of embodiment 2, a resin molding 25 as a resin portion of the bolt 13 for fastening the stator core 2 and the frame 5 is attached to the head of the bolt 13 so as to have a substantially uniform thickness.

[0061] 10 is a cross-sectional view showing a method for measuring the insulation resistance of the resin molding 25 in the rotating electric machine according to embodiment 3. Other configurations and measurement methods of the rotating electric machine according to embodiment 3 are the same as those of the rotating electric machine according to embodiment 2, and corresponding parts are designated by the same reference numerals and description thereof will be omitted.

[0062] As described above, the rotating electric machine of this embodiment 3 is provided with a stator core 2, a frame 5 that houses the stator core 2, conductive bolts 13 and nuts 14 that secure the stator core 2 to the frame 5, and a resin molding 25 that covers the head of the bolt 13 and whose insulation resistance can be measured. Therefore, when the bolts and nuts are removed from the stator core and the frame, the resin molding is destroyed, and it is possible to easily determine whether or not the resin molding has disassembled by measuring its resistance and visually inspecting it.

[0063] 11 is a schematic diagram showing a main part of an electric vehicle according to embodiment 4. In embodiment 4, a case will be described below in which the rotating electric machine shown in embodiments 1 to 3 is applied to the drive system of an electric vehicle.

[0064] As shown in FIG. 11 , the rotating electric machine 16 is mounted between the engine 17 and the transmission 18 via a drive shaft 19. Clutches may be provided before and after the rotating electric machine 16. Furthermore, the power of the drive shaft 19 is transmitted to drive wheels 21 via a differential gear 20. The electric vehicle is equipped with two power sources, the rotating electric machine 16 and the engine 17, and the engine can be used continuously in an efficient state. During maintenance, the condition of the drive system including the rotating electric machine 16 is checked. By using parts from the manufacturer, rather than using parts from other manufacturers, the quality of the rotating electric machine can be guaranteed.

[0065] As described above, the electric vehicle in this fourth embodiment is equipped with a rotating electric machine described in any one of the first to third embodiments, which is assembled between the engine 17 and the transmission 18 via the drive shaft 19, and drive wheels 21 to which the power of the engine 17 and / or the rotating electric machine is transmitted from the drive shaft 19 via the differential gear 20. Therefore, it is possible to easily determine whether or not disassembly has occurred by measuring the resistance of the adhesive layer or the resin molding and by visual inspection, and therefore the quality of the rotating electric machine can be guaranteed by using parts from the manufacturer without using parts other than those of the manufacturer.

[0066] Although various exemplary embodiments and examples are described in this application, the various features, aspects, and functions described in one or more embodiments are not limited to the application of a particular embodiment, but may be applied to the embodiments alone or in various combinations. Therefore, countless variations not illustrated are contemplated within the scope of the technology disclosed in this specification. For example, this includes cases where at least one component is modified, added, or omitted, or where at least one component is extracted and combined with components of another embodiment.

[0067] REFERENCE SIGNS LIST 1 stator, 2 stator core, 5 frame, 6 frame protrusion, 7 stator core recess, 11 adhesive layer (resin part), 13 bolt, 14 nut, 15, 25 resin molded article (resin part), 16 rotating electric machine

Claims

1. A rotating electric machine comprising: a stator core; a frame that houses the stator core; and a resin part that is provided in a part for fixing the stator core and the frame and that allows insulation resistance to be measured.

2. A rotating electric machine according to claim 1, characterized in that it comprises: a stator core having a recess formed in the axial direction on its outer periphery; a frame that houses the stator core and has a protrusion that fits into the recess of the stator core; and a resin part that bonds the recess and the protrusion and allows insulation resistance to be measured.

3. A rotating electric machine as described in claim 2, characterized in that the convex portion has a through hole that penetrates to the outside, an insulating coating is applied to the contact portion with the through hole, and a conductor is provided that connects from the resin portion to the outside.

4. A rotating electric machine according to claim 1, characterized in that it comprises: a stator core; a frame that houses the stator core; conductive bolts and nuts that secure the stator core to the frame; and a resin part that covers the head or tip of the bolt and allows insulation resistance to be measured.

5. A rotating electric machine according to any one of claims 1 to 4, characterized in that the resin portion is made of a thermosetting resin and contains a filler.

6. A rotating electric machine according to claim 5, wherein the thermosetting resin is an epoxy resin.

7. A rotating electric machine according to claim 5 or 6, characterized in that the resin portion has non-linear resistance characteristics.

8. A rotating electric machine according to claim 7, wherein the filler is at least one selected from the group consisting of zinc oxide, silicon carbide, triiron tetroxide, bismuth oxide, and antimony trioxide.

9. An electric vehicle comprising: a rotating electric machine according to any one of claims 1 to 8, which is mounted between an engine and a transmission via a drive shaft; and drive wheels to which the power of the engine and / or the rotating electric machine is transmitted from the drive shaft via a differential gear.

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