JP6475585B2 - Rotor protecting resin composition and rotor - Google Patents

Description

  The present invention relates to a rotor-protecting resin composition and a rotor using the same.

  A rotor constituting an electric motor has a structure in which a winding is wound in a slot of a core fixed to a rotating shaft, and ends of the winding are protruded from the slot to both ends of the core. In such a rotor, foreign matter that has entered the electric motor may damage the winding in the slot or the winding end protruding from the slot, causing wear or disconnection. Further, when the rotor rotates at high speed, there is a possibility that wear or wire breakage may occur due to contact between the windings. Therefore, conventionally, the winding ends protruding at both ends of the winding in the slot and the core, particularly the winding ends protruding at both ends of the core, which are likely to be worn or disconnected, can be covered with a mold resin for protection. (For example, refer to Patent Documents 1 to 3).

  However, the technique of covering and protecting with this mold resin requires a mold to be prepared according to the product shape, resulting in low production efficiency and high manufacturing cost. Further, since it is difficult to sufficiently impregnate the winding end portion with the resin, there is a problem that voids and cracks are likely to occur.

  For this reason, a technique for applying the coating without using a mold using a liquid resin composition at room temperature has been studied. In this case, the liquid resin composition is required to have an impregnation property that sufficiently impregnates the inside of the winding end and a thick coating property that can form a coating having a sufficient thickness outside the winding. . Even if either the impregnation property or the thick coating property is insufficient, a sufficient protection effect for the winding cannot be obtained. However, in a liquid resin composition, it is very difficult to achieve both impregnation properties and thick coating properties. A liquid resin composition having both of these characteristics and useful for protecting the winding of the rotor has not yet been found.

Japanese Patent Laid-Open No. 07-123618 Japanese Patent Laid-Open No. 03-070441 JP 2007-166683 PR

  The present invention was made in order to solve the above-described problems of the prior art, has good impregnation and thick coatability, and the winding wound around the slot of the core and the winding protruding at both ends of the core, In the rotor protective resin composition capable of preventing abrasion or disconnection due to contact between the windings accompanying foreign matter or high speed rotation, etc., and durability using such a rotor protective resin composition The purpose is to provide an excellent rotor.

As a result of intensive studies to solve the above problems, the present inventors have found that a resin composition containing an organic bentonite known as an anti-settling agent can achieve the above object, and It came to be completed.
That is, this invention is the resin composition for rotor protection and rotor which have the structure of the following [1]-[6].
[1] A resin composition for protecting a rotor which is liquid at room temperature and contains (A) an epoxy resin, (B) dicyandiamide or a derivative thereof, (C) silica powder, and (D) an organic bentonite. A rotor-protecting resin composition containing 1-2 parts by mass of component (D) with respect to 100 parts by mass.
[2] The resin composition for protecting a rotor according to [1], wherein the component (A) contains a bisphenol type epoxy resin.
[3] The rotor protecting resin composition according to [1] or [2], wherein the component (C) includes pulverized crystalline silica powder having an average particle size of 0.1 to 12 μm.
[4] The rotor resin composition according to any one of [1] to [3], wherein the component (D) is an organic bentonite having an average particle size of 0.5 μm or less when dispersed.
[5] The rotor protective resin composition according to any one of [1] to [4], wherein the viscosity at 25 ° C. is 210 to 350 Pa · s and the viscosity at 150 ° C. is 10 to 50 Pa · s. object.
[6] A rotor characterized in that a winding end is covered with a cured product made of the rotor protecting resin composition according to any one of [1] to [5].

  According to the present invention, the impregnation property and the thick coating property are good, the winding wound around the core slot or the winding projecting at both ends of the core is a contact between foreign matter or windings accompanying high-speed rotation, etc. Thus, it is possible to provide a rotor-protecting resin composition that can be prevented from being worn out or broken, and a rotor that is excellent in durability using such a rotor-protecting resin composition.

It is a top view which shows the rotor of one Embodiment of this invention.

Hereinafter, the present invention will be described in detail.
The resin composition for protecting a rotor of the present invention is a liquid composition at room temperature containing (A) an epoxy resin, (B) dicyandiamide or a derivative thereof, (C) silica powder, and (D) an organic bentonite.

  The epoxy resin of component (A) used in the present invention is not particularly limited as long as it has two or more glycidyl groups (epoxy groups) in one molecule, and a known epoxy resin is used. be able to.

  Examples of usable epoxy resins include, for example, bisphenol A type epoxy resins, bisphenol F type epoxy resins, bisphenol AD type epoxy resins, bisphenol S type epoxy resins, alkyl-substituted bisphenol type epoxy resins, hydrogenated bisphenol type epoxy resins, Biphenyl type epoxy resin, dicyclopentadiene type epoxy resin, cresol novolac type epoxy resin, ether or polyether type epoxy resin (1,4-cyclohexanedimethanol diglycidyl ether, 1,6-hexanediol diglycidyl ether, 4,4 '-Isopropylidene dicyclohexanol diglycidyl ether), ester or polyester type epoxy resin (hexahydrophthalic acid diglycidyl ester, 3,4-epoxy resin) Rohexylmethyl (3,4-epoxy) cyclohexanecarboxylate, triglycidyl isocyanurate, etc.), urethane type epoxy resin, polyfunctional epoxy resin, alicyclic epoxy resin, aliphatic epoxy resin, naphthalene type epoxy resin, fluorene type Epoxy resin, ethylene oxide modified bisphenol A type epoxy resin, propylene oxide modified bisphenol A type epoxy resin, glycidyl modified polybutadiene, glycidyl modified triazine resin, silicone modified epoxy resin, aminophenol type epoxy resin, flexible epoxy resin, methacrylic modified epoxy Resin, acrylic modified epoxy resin, special modified epoxy resin, side chain hydroxyl group alkyl modified epoxy resin, long chain alkyl modified epoxy resin, imide modified epoxy resin, CT N-modified epoxy resins. These can be used individually by 1 type or in mixture of 2 or more types.

  The epoxy resin is preferably liquid at normal temperature, but even if it is solid at normal temperature, it can be used in a liquid state by being diluted and dispersed in a liquid epoxy resin, a reactive diluent, a solvent or the like. Preferred liquid epoxy resins include bisphenol A type epoxy resins, bisphenol F type epoxy resins, bisphenol AD type epoxy resins, naphthalene type epoxy resins, biphenyl type epoxy resins, phenol novolac type epoxy resins, and the like.

  The dicyandiamide or its derivative (B) used in the present invention is a component that acts as a curing agent for the component (A). Because dicyandiamide and its derivatives have a high melting point (for example, dicyandiamide has a melting point of about 210 ° C.), the composition imparts good storage stability and shelf life. Moreover, the cured | curing material obtained expresses a favorable mechanical characteristic. Specific examples of dicyandiamide derivatives include various epoxy compounds such as glycidyl ethers such as phenyl glycidyl ether, butyl glycidyl ether, bisphenol A-diglycidyl ether, bisphenol F-diglycidyl ether, or glycidyl esters of carboxylic acid. And the like. Dicyandiamide or a derivative thereof can be used singly or in combination of two or more. For the purposes of the present invention, the use of dicyandiamide is preferred, and the use of dicyandiamide alone is more preferred.

  The blending amount of the dicyandiamide or its derivative as the component (B) is preferably 1 to 12 parts by mass, more preferably 4 to 10 parts by mass, and 7 to 9 parts by mass with respect to 100 parts by mass of the component (A). Even more preferred. If the amount is less than 1 part by mass, curing may be insufficient and the force for fixing the winding may be reduced. If the amount exceeds 12 parts by mass, the glass transition point of the composition may be lowered, and the force for fixing the winding may be increased at high temperatures. May decrease.

  In addition, if it is a range which does not inhibit the effect of this invention, you may use together what is conventionally known as a hardening | curing agent of an epoxy resin. Examples of curing agents that can be used in combination include phenolic resin curing agents such as novolak-type phenol resins, polyparavinylphenol resins, and phenol aralkyl resins; acid anhydrides such as maleic anhydride and phthalic anhydride; diethylenetriamine, triethylenetetramine, and the like. And amine curing agents.

  The silica powder of (C) component used for this invention is not specifically limited, Well-known silica powders, such as a crystalline silica and a fused silica, can be used. From the viewpoint of impregnation, crystalline silica is preferable, and pulverized crystalline silica is more preferable.

  From the viewpoint of impregnation, the silica powder of component (C) preferably has an average particle size of 0.1 to 12 μm, more preferably 5 to 9 μm. That is, if the average particle size of the silica powder used is in the range of 0.1 to 12 μm, the impregnation property of the composition can be improved. Here, the average particle diameter of the silica powder is a 50% particle diameter (D50 value) in the number cumulative distribution measured by a laser diffraction particle size distribution measuring apparatus.

  Examples of commercially available products of pulverized crystalline silica having an average particle size of 0.1 to 12 μm suitable as the component (C) include, for example, crystallite 5A having an average particle size of 8 μm, crystallite AA having an average particle size of 6 μm (above, All of them are trade names of Tatsumori Co., Ltd.). In addition, when using several types of silica powder from which a commercially available average particle diameter differs, the average particle diameter after mixing should just satisfy | fill the said conditions.

  (C) The compounding quantity of the silica powder of a component has the preferable range of 200-400 mass parts with respect to 100 mass parts of epoxy resin of (A) component, and the range of 250-350 mass parts is more preferable. If the amount is less than 200 parts by mass, the heat inside the rotor is not sufficiently dissipated, the temperature rises, and the life characteristics of the components constituting the rotor such as a commutator (commutator) may be deteriorated. On the other hand, when it exceeds 400 parts by mass, the viscosity increases, the impregnation property decreases, and voids are easily generated.

  In addition, as long as the effect of this invention is not impaired, you may mix | blend the various fillers conventionally mix | blended with the epoxy resin composition. The filler used in combination may be either inorganic or organic. Examples of the inorganic filler include silicon nitride, alumina, aluminum nitride, calcium carbonate, magnesia, boehmite, aluminum hydroxide, talc and the like. Silica other than spherical fused silica, such as crushed fused silica or crystalline silica, can also be used. Examples of the organic filler include a silicone resin, a fluorine resin such as polytetrafluoroethylene, an acrylic resin such as polymethyl methacrylate, a cross-linked product of benzoguanamine, melamine, and formaldehyde. Furthermore, a composite material of an organic compound and an inorganic compound, such as a composite material of silica and an acrylic resin, is also used. These fillers may be surface-treated with a silane coupling material such as alkoxysilane, acyloxysilane, silazane, organoaminosilane or the like in order to improve dispersibility and the like.

  The organic bentonite of component (D) used in the present invention is a complex obtained by modifying the crystal surface of montmorillonite, which is a clay mineral, with a quaternary ammonium salt such as trialkylbenzylammonium, dimethyldialkylammonium, or trimethylalkylammonium. It will be. This organic bentonite swells and thickens when suspended in an organic solvent, and when a shearing force is applied to the dispersion, the flaky crystals are arranged in parallel to the flow, so the viscosity decreases, and the dispersion is rested again. In this state, the flaky crystals are associated with each other by hydrogen bonding of the hydroxyl groups present on the end faces of the flaky crystals, and the flaky crystals form a network so that the viscosity increases. By blending such an organic bentonite, the composition of the present invention can be given good impregnation properties and good thick coatability.

  Examples of commercially available products of organic bentonite include, for example, S.B., S.B.C, S.B.E, S.B.W, S.B.P, S.B.WX, S.B.N-400, S.B. NX, S.B. , Esben NZ, Esben NZ70, Organite, Organite D, Organite T (above, product name manufactured by Hojun Co., Ltd.); Lucentite SAN, Lucentite STN, Lucentite SEN, Lucentite SPN, Somasif ME-100, Somasif MAE, Somasif MTE, Somasif MEE, Somasif MPE (above, product names manufactured by Corp Chemical Co.); T, Clayton 40 (or more, Rockwood Additives Co., Ltd. trade name), and the like. An organic bentonite can be used individually by 1 type or in mixture of 2 or more types.

  The organic bentonite as component (D) preferably has an average particle size of 0.5 μm or less when dispersed, and more preferably 0.3 μm or less. If the average particle size at the time of dispersion is 0.5 μm or less, good thick coatability can be obtained while maintaining good impregnation properties. Examples of commercially available organic bentonite having an average particle size of 0.5 μm or less at the time of dispersion include Esben, Esben C, Esben E, Esben W, Esben P, Esben WX, and the like. Here, the average particle size at the time of dispersion means an average particle size (median diameter (d50)) when dispersed in an organic solvent, and can be measured by, for example, a laser diffraction type particle size distribution measuring apparatus.

The blending amount of the organic bentonite as the component (D) is in the range of 1 to 2 parts by mass, preferably in the range of 1.2 to 1.8 parts by mass with respect to 100 parts by mass of the epoxy resin as the component (A). It is.
If it is less than 1 part by mass, good coatability cannot be obtained. On the other hand, when it exceeds 2 parts by mass, the impregnation property is lowered and voids are easily generated.

  In the rotor protecting resin composition of the present invention, a curing accelerator can be blended for the purpose of promoting the curing of the component (A) and the component (B). If a hardening accelerator can accelerate | stimulate hardening with the said (A) component and (B) component, it can be used without being restrict | limited especially.

  Examples of usable curing accelerators include urea-based curing accelerators, imidazole-based curing accelerators, amine-based curing accelerators, organic phosphine-based curing accelerators, diazabicyclo-based curing accelerators, organic boron salt-based curing accelerators, Examples thereof include polyamide-based curing accelerators. From the viewpoint of storage stability and the like, among these, a urea curing accelerator and an imidazole curing accelerator are preferable, and a urea curing accelerator is more preferable.

Specific examples of the urea curing accelerator include, for example, aromatic dimethylurea, aliphatic dimethylurea, 3- (3,4-dichlorophenyl) -1,1-dimethylurea (DCMU), 3- (3-chloro- 4-methylphenyl) -1,1-dimethylurea, 2,4-bis (3,3-dimethylureido) toluene, 1,1′-4 (methyl-m-phenylene) bis (3,3′-dimethylurea) ), 4,4′methylenebis (phenyldimethylurea) and the like.
Specific examples of the imidazole curing accelerator include 2-methylimidazole, 2-undecylimidazole, 2-heptadecylimidazole, 1,2-dimethylimidazole, 2-ethyl-4-methylimidazole, and 2-phenylimidazole. Etc.

  A hardening accelerator may be used individually by 1 type, and 2 or more types may be mixed and used for it. The blending amount is preferably in the range of 0.5 to 3.0 parts by mass and more preferably in the range of 0.5 to 1.5 parts by mass with respect to 100 parts by mass of the epoxy resin as the component (A). If the amount is less than 0.5 parts by mass, a sufficient effect for promoting the curing cannot be obtained. If the amount exceeds 3.0 parts by mass, the effect for promoting the curing does not change so much and the heat resistance may decrease.

  In addition to the above-mentioned components, the resin composition for protecting a rotor of the present invention generally contains a viscosity modifier, a diluent, and a coupling agent, which are generally blended in this type of composition as long as the effects of the present invention are not impaired. Adhesion aids such as curing aids, antifoaming agents, colorants (pigments, dyes), surfactants, flame retardants, thixotropic agents, and other various additives can be blended as necessary. . Each of these additives may be used alone or in combination of two or more.

  Examples of the viscosity modifier include cellosolve acetate, ethyl cellosolve, butyl cellosolve, butyl cellosolve acetate, butyl carbitol acetate, propylene glycol phenyl ether, diethylene glycol dimethyl ether, diethylene glycol diethyl ether, diacetone alcohol, N-methylpyrrolidone, dimethylformamide, γ- Examples include butyl lactone and 1,3-dimethyl-2-imidazolidone.

  Examples of the diluent include n-butyl glycidyl ether, t-butylphenyl glycidyl ether, allyl glycidyl ether, 2-ethylhexyl glycidyl ether, styrene oxide, phenyl glycidyl ether, cresyl glycidyl ether and the like.

  As the coupling agent, γ-glycidoxypropyltrimethoxysilane, γ-aminopropylmethyldimethoxysilane, γ-mercaptopropyltrimethoxysilane and other silane coupling agents, titanate coupling agents, aluminum coupling agents, Examples include a zircoat coupling agent and a zircoaluminate coupling agent.

  The rotor protecting resin composition of the present invention is prepared by thoroughly mixing the components (A) to (D) described above and additives such as curing accelerators and diluents blended as necessary. It can be prepared by performing a kneading process using a Perth, a kneader, a three-roll mill, a planetary stirrer or the like and then degassing under reduced pressure.

The resin composition for protecting a rotor of the present invention preferably has a viscosity of 210 to 350 Pa · s measured by an EHD type rotational viscometer at a temperature of 25 ° C. and a rotational speed of 0.5 rpm. If it is this range, favorable thick-coating property can be ensured.
In addition, the rotor protecting resin composition of the present invention preferably has a melt viscosity of 10 to 50 Pa · s at 150 ° C. measured by a rheometer at a rotation speed of 0.5 rpm. If it is this range, favorable impregnation property is securable. The melt viscosity at 150 ° C. is more preferably 15 to 45 Pa · s.

  Since the resin composition for protecting a rotor of the present invention has both good impregnation properties and good thick coating properties, the windings attached to the rotor can be used without using a conventional mold. A protective coating can be formed, and a rotor having excellent durability in which the windings are not worn or broken even by high-speed rotation can be obtained.

Next, the rotor of the present invention using the rotor protecting resin composition of the present invention will be described.
The rotor of the present invention, for example, is obtained by dripping and impregnating the winding wound around the rotor core and projecting from the end thereof with the liquid resin for rotor protection at room temperature of the present invention, and then the resin composition for rotor protection Can be produced by heat curing. The temperature at which the resin composition for protecting a rotor is cured is usually 150 to 170 ° C., and it is preferably heated for about 0.5 to 1.0 hour. Moreover, when dripping the rotor protective resin composition onto the winding, it is preferable to horizontally support and rotate the shaft (rotating shaft) inserted through the center of the rotor core. By performing the rotation while rotating the rotor core, the coating can be performed quickly and the uniformity of the coating thickness can be improved.

FIG. 1 shows an example of the rotor 10 of the present invention obtained as described above, and the end 2a of the winding 2 protruding from the end of the core 1 is the resin composition for protecting a rotor of the present invention. It is protected and fixed with a coating 3 made of As described above, since the rotor protective resin composition of the present invention is excellent in impregnation and thick coatability, the composition is sufficiently impregnated to the inside of the winding end 2a, and the outer side has a sufficient thickness. Covered. Therefore, the winding 2 is not worn or disconnected due to foreign matter or contact between the windings accompanying high-speed rotation, and the rotor 10 has excellent durability.
In FIG. 1, 4 is a shaft (rotating shaft), 5 is provided on the outer peripheral surface of the core 1, a slot around which the winding 2 is wound, and 6 is mounted on one end side of the core 1. The commutator connected commutatively (commutator) is shown.

  EXAMPLES Next, although an Example demonstrates this invention further in detail, this invention is not limited to these Examples at all. The materials used in the following examples and comparative examples are as shown in Table 1. Further, “part” means “part by mass” unless otherwise specified.

Example 1
An epoxy resin composition was prepared by uniformly mixing 100 parts of an epoxy resin, 8.0 parts of a curing agent I, 1.0 part of a curing accelerator, 300 parts of crystallized silica, and 1.5 parts of organic bentonite using a planetary mixer. .

(Examples 2-4, Comparative Examples 1-6)
An epoxy resin composition was prepared in the same manner as in Example 1 except that the composition was changed as shown in Table 2.

  About the epoxy resin composition obtained by each said Example and each comparative example, various characteristics were evaluated by the method shown below, and the result was combined with Table 2, and was shown.

<Epoxy resin composition>
(1) Initial viscosity (25 ° C)
Using an EHD viscometer manufactured by Toki Sangyo Co., Ltd., the measurement was performed at 25 ° C. and 0.5 rpm.
(2) Melt Viscosity Using a rheometer manufactured by TA Instruments, melt viscosity at a temperature of 150 ° C. was measured under the conditions of a measurement gap of 2 mm and a rotation speed of 0.5 rpm.
(3) Glass transition point (Tg)
A sample prepared by curing the epoxy resin composition at 150 ° C. for 1 hour was heated from room temperature to 250 ° C. (temperature increase rate) with a thermal analyzer TMA / SS150 (model name, manufactured by Seiko Instruments Inc.). 20 ° C./min) The thermal expansion curve was measured and determined from the midpoint of the displacement point.
(4) Coil impregnation A model coil in which a winding (AIW wire) with a diameter of 1.2 mm is wound 10 times around a slot portion of a core with a diameter of 40 mm and a length of 200 mm is prepared. And then cured by heating at 170 ° C. for 30 minutes, the cured product is cut in an arbitrary cross section, and the resin filling area (S _R ) and the resin unfilling area (S _V ) on the cut surface The filling rate (%) of the resin on the cut surface was calculated from the following formula. The closer the filling rate is to 100%, the better the impregnation property.
Filling rate (%) = {S _R / (S _R + S _V )} × 100
(5) Shelf life Using an EHD viscometer manufactured by Toki Sangyo Co., Ltd., the number of days until the viscosity at 25 ° C. measured under the condition of 0.5 rpm reached twice the initial viscosity was measured.

(6) Formability The presence or absence of voids on the surface of the cured product of the epoxy resin composition obtained by heating and curing at 150 ° C. for 0.5 hour was visually confirmed and evaluated according to the following criteria.
○: No void ×: With void (7) Thick coatability Prepare a model coil in which a winding (AIW wire) with a diameter of 1.2 mm is wound 10 times around a core slot with a diameter of 40 mm and a length of 200 mm. After dripping and impregnating 4 ml of the epoxy resin composition at 25 ° C. and heating and curing at 170 ° C. for 30 minutes, the surface was visually observed and evaluated according to the following criteria depending on whether the internal enamel wire was visible. This thick coatability is an index indicating the effect of protecting the coil by the cured film. If the enameled wire is not visible, the thickness of the cured film is sufficient and a good protective effect is obtained for the coil. . Conversely, when the enameled wire is visible, it indicates that the thickness of the cured film is insufficient and a good protective effect cannot be obtained for the coil.
○: The enameled wire cannot be visually recognized. ×: The enameled wire can be visually recognized.

<Product (rotor)>
(1) Overload test After winding a winding (AIW wire) with a diameter of 1.2 mm around a core of a core having a diameter of 40 mm and a length of 200 mm, 4 ml of an epoxy resin composition was dropped and impregnated at 25 ° C. A coil was prepared by heating and curing for 30 minutes. After repeating 20 times of no load (15 seconds) and load (0.7 A, 30 seconds) on this coil, the load current was increased by 10% per second for 1 minute, and the presence or absence of wire breakage was examined. The case where disconnection did not occur in 1 minute was defined as “pass”, and the case where disconnection occurred was defined as “fail”. In addition, about the thing which a disconnection generate | occur | produced within 1 minute, the time until the disconnection was shown collectively.

  As is apparent from Table 2, the epoxy resin compositions of the examples all have good characteristics with respect to impregnation properties, moldability, and thick coatability, and the coil apparatus using the compositions has an overload test. Good results were obtained. On the other hand, in Comparative Examples 1 and 3 in which organic bentonite was not blended or under blended, the thick coatability was poor, and in Comparative Example 2 in which organic bentonite was excessively blended, the impregnation property and moldability were poor. Further, in Comparative Example 4 using dry silica instead of organic bentonite, the impregnation property is poor as well as thick coatability. The overload test of the coil device was also poor.

  DESCRIPTION OF SYMBOLS 1 ... Core, 2 ... Winding, 2a ... Winding end part, 3 ... Coating which consists of resin composition for rotor protection, 4 ... Shaft (rotary shaft), 5 ... Slot, 6 ... Commutator (commutator), 10 ... Rotor.

Claims (6)

(A) epoxy resin, (B) dicyandiamide or a derivative thereof, (C) silica powder, and (D) a resin composition for protecting a rotor which is liquid at room temperature,
(A) The rotor-protecting resin composition containing 1-2 parts by mass of the component (D) with respect to 100 parts by mass of the component.   The rotor protective resin composition according to claim 1, wherein the component (A) contains a bisphenol type epoxy resin.   The component (C) contains pulverized crystalline silica powder having an average particle size of 0.1 to 12 μm, and the rotor protecting resin composition according to claim 1 or 2.   The rotor protecting resin composition according to any one of claims 1 to 3, wherein the component (D) is an organic bentonite having an average particle size at the time of dispersion of 0.5 µm or less.   5. The rotor-protecting resin composition according to claim 1, wherein the viscosity at 25 ° C. is 210 to 350 Pa · s, and the viscosity at 150 ° C. is 10 to 50 Pa · s.   A rotor, characterized in that the outer periphery of the winding end is covered with a cured product made of the resin composition for protecting a rotor according to any one of claims 1 to 5.

Images