JP2506627B2 - Ironless armature - Google Patents

Description

TECHNICAL FIELD The present invention relates to an armature of a coreless motor widely used in the field of OA, FA and electrical equipment such as copying machines, automatic welding machines, NC machine tools, car air conditioners, etc. Relates to an ironless armature having a structure in which an armature winding formed of an insulated wire or a self-bonding insulated wire is sealed with a thermosetting resin composition and used at a relatively high temperature.

Structure of the conventional example and its problems The characteristics and reliability of the iron-free core motor usually largely depend on the performance of the armature part. Particularly in an ironless core armature in which an armature winding is formed of an insulated wire or a self-bonding insulated wire and is sealed with a thermosetting resin composition, the performance of the thermosetting resin composition is important. It has an influence.

Ironless armatures are usually 150-180 mm when the start / stop frequency is high or the ambient temperature is high in a relatively large motor of several watts to several kilowatts.
It may be used under relatively high temperature of ℃. Therefore, for a coreless armature, dimensional stability during heat in such a relatively high temperature range, thermal rigidity, hot strength, and heat deterioration resistance are important for securing this type of motor characteristics and reliability. In order to satisfy these characteristics, for example, an armature winding sealed with an epoxy resin composition has been put into practical use. The epoxy resin composition is a composite of an epoxy resin and a filler, a release agent, and other additives added as necessary. The reason why epoxy resin is used is that it has excellent heat resistance, mechanical properties, electrical properties, and the like, and because the curing reaction proceeds relatively slowly, there is little curing strain and it is easy to ensure high dimensional stability. . Furthermore, since the melting viscosity at the time of sealing the armature winding is relatively low, it is easy to seal the fine armature winding, and this is advantageous in maintaining the motor characteristics with less deformation of the armature winding. is there. Furthermore, since a relatively large amount of filler such as alumina, aluminum hydroxide, silica, zirconium silicate, etc. can be mixed in the resin composition, the difference in thermal expansion between the conductor of the armature winding and the resin composition for sealing it. Shrinkage, or the thermal conductivity of the resin composition becomes relatively large, for example, dimensional stability during heating, thermal rigidity, hot strength, and heat resistance as an ironless core armature even at high temperatures of 150 to 180 ° C. This is because various characteristics such as the above can be practically secured.

As described above, the epoxy resin and the compound with a large amount of the filler are important ironless armature constituent members for securing high-level characteristics and reliability as a motor. On the other hand, the curing of the epoxy resin is relatively gentle. The advancing fact has been a serious drawback from a productivity point of view.

On the other hand, unsaturated polyester resins are extremely effective for polymerizing and curing very rapidly and improving productivity, but the practical heat resistance of these unsaturated polyester resins is, for example, 80 to 100 ° C in phthalic anhydride system. , Isophthalic acid or terephthalic acid type, the temperature is about 150 ℃, and if various thermoplastic resins are used together as a constant shrinkage agent to secure the dimensional accuracy of the iron-free core armature, the characteristics of the iron-free core armature at high temperature In addition, it becomes more difficult to maintain reliability. That is, the productivity of the ironless core armature and the characteristics and reliability of the motor are in conflict with each other.

OBJECT OF THE INVENTION The present invention is used at a relatively high temperature of 150 to 180 ° C. by encapsulating an armature winding with a thermosetting resin composition that is extremely fast in polymerization and curing and also has heat resistance. It aims to provide an iron core armature with extremely high productivity.

Structure of the Invention The structure of the ironless core armature of the present invention is an armature winding portion and a resin composition for sealing the armature winding portion.
It is a composite composed of an unsaturated polyester resin containing 40% by weight of a trifunctional triazine compound and at least 70% by weight of an inorganic filler.

 The structure of the present invention will be described in more detail below.

First, the armature winding referred to in the present invention is a wire wound with an insulated electric wire or a self-bonding insulated electric wire, and its winding terminal is usually in a state of being electrically connected to a commutator piece. The shape of such an armature winding can be selected from a flat shape to a cup shape based on the design concept of the ironless motor. Furthermore, the armature winding may include the commutator and the armature shaft that is an armature-constituting member.

The resin composition referred to in the present invention is a composite of an unsaturated polyester resin containing 5 to 40% by weight of a trifunctional triazine compound and 70% by weight or more of an inorganic filler.

The unsaturated polyester resin referred to in the present invention is a solution of a copolymerizable monomer of unsaturated polyester alkyd, to which various additives such as a polymerization inhibitor are optionally added, and at least a trifunctional triazine compound is added. 5-40% by weight
It is contained.

The unsaturated polyester alkyd is composed of an unsaturated dicarboxylic acid as a carboxylic acid component and optionally a saturated dicarboxylic acid, and a glycol component as an alcohol component. Examples of unsaturated dicarboxylic acids include fumaric acid, maleic acid, itaconic acid and citraconic acid. As the saturated dicarboxylic acid, orthophthalic acid, phthalic anhydride and the like can be used, but isophthalic acid, terephthalic acid, tetra- and hexahydrophthalic acid and the like are preferable. As glycol components, ethylene glycol, 1.2- and 1.3-propanediol, 1.3- and 1.4-butanediol, diethylene glycol, dipropylene glycol, neopentyl glycol, alkylene oxide adducts of bisphenols, Examples include hydrogenated bisphenols and their alkylene oxide adducts, halogenated bisphenol alkylene oxide adducts, and 1,4-cyclohexanedimethanol.

The unsaturated polyester alkyd may be appropriately used with a vinyl-based or allyl-based copolymerizable monomer, but in the present invention, 5 to 40% by weight of the unsaturated polyester resin is a trifunctional triazine compound. is there.

The trifunctional triazine compound is a compound having three allyl groups by adding allyl alcohol to the triazine ring,
Examples include triallyl isocyanurate and triallyl cyanurate. When the content of such a triazine compound having three allyl groups in the unsaturated polyester resin is 5% by weight or less, the desired characteristics as an ironless core armature cannot be maintained, and when it is 40% by weight or more, the curing strain becomes large, and the desired dimensional accuracy is obtained. Is not obtained, causing serious defects such as cracking.

At least 70% by weight of an inorganic filler is added to an unsaturated polyester resin containing 5 to 40% by weight of the above trifunctional triazine compound. As the inorganic filler, calcium carbonate,
It is preferable to use glass fibers in combination with a granular filler such as clay or hydrated alumina. The amount of this inorganic filler added is
As proposed by the present inventor in Japanese Patent Application No. 59-23114, more than 70% by weight and less than 85% by weight is desirable in order to obtain desired dimensional accuracy. If it is less than 70% by weight, the curing strain is large,
The desired dimensional accuracy cannot be obtained. On the other hand, when it is 85% by weight or more, the thermosetting resin composition becomes too small, and the cured product after polymerization becomes brittle.

A composite of the above unsaturated polyester resin having 5 to 40% by weight of a trifunctional triazine compound and at least 70% by weight or more of an inorganic filler further comprises dicumyl peroxide, t-butyl perbenzoate, 2 as a polymerization initiator. -Using 5-dimethyl-2,5-di-t- (butylperoxy) hexane, etc., and if necessary, higher fatty acid, higher alcohol or higher fatty acid ester and metal soaps, carbon black, antimony trioxide, etc. The additives generally used as various composites can be appropriately used. The mixing ratio and mixing method of such additives are determined within a range that satisfies the characteristics and reliability of the iron-free core armature.

Description of Examples Next, the present invention will be specifically described by way of examples, but the present invention is not limited to these examples.

The unsaturated polyester alkyd of the unsaturated polyester resin used terephthalic acid as the saturated dicarboxylic acid component and fumaric acid as the unsaturated dicarboxylic acid component. Triallyl isocyanurate was used as the trifunctional triazine compound, and styrene, α-methylstyrene, divinylbenzene, diallyl ossophthalate, diallyl isophthalate, and other vinyl esters were used as the copolymerizable monomer.

Dicumyl peroxide was used as a polymerization initiator for the above unsaturated polyester resins, calcium carbonate / glass fiber (polymerization ratio 90/10) as an inorganic filler, and a certain amount of fatty acid ester and carbon black were used as other additives.

Of the above components, the proportion (% by weight) of the inorganic filler in the resin composition, the proportion (% by weight) of the trifunctional triazine compound in the unsaturated polyester resin, and the copolymerizability other than the trifunctional triazine compound The proportions (% by weight) of the monomers were distributed as shown in Table 1, and kneaded together in a kneader. In Table 1, the example according to the example of the present invention is 1
-8, Comparative Examples are 1-9. As a conventional example, an epoxy resin composition used for this type of ironless core armature was used.

On the other hand, about 10μ for 1st class ester imide wire with conductor diameter
An electric machine in which the self-fusing insulated electric wire provided with the phenoxy resin-based fusion layer of m has 30 turns / coil, and the armature winding terminals arranged in a 13-coil flat shape are electrically connected to each commutator piece. The child winding was prepared.

The armature winding and the armature shaft were loaded in a mold preheated to 170 ° C. ± 3 deg, and the resin composition shown in Table 1 was obtained by transfer molding under the conditions of a plunger pressure of 80 Kgf / cm ² and a curing time of 80 sec. By enclosing the product, a flat ironless armature with a thickness of 3 mm was obtained. However, in the case of the epoxy resin composition used as the conventional example, the curing time was set to 300 seconds, and further post-curing was performed at 150 ° C. for 6 hours.

Table 2 shows the results of measurement of the surface runout of the above ironless core armature with reference to the armature axis.

As shown in Table 2, when the iron-free core armature is prepared by using various resin compositions and armature windings, when the trifunctional triazine compound in the unsaturated polyester resin exceeds 40% by weight (Comparative Example 1), curing strain is large. The ironless armature is cracked. In this case, even if the curing was controlled by changing the gate cross-sectional area, the gate shape, or each molding condition, cracking could not be prevented. This phenomenon occurs when the amount of filler in the resin composition is 65% by weight, 60% by weight
The same applies to (Comparative Examples 7 and 8). In the case of the embodiment, the curing time is shortened from 300 seconds to 60 seconds as compared with the conventional example, and the ironless core armature has the same dimensional accuracy without further curing.

Next, leave the ironless armature in the sealed container at 180 ° C.
Table 3 shows the amount of surface runout change when heated at ± 5deg and 500H.

As shown in Table 3, both the one using divinylbenzene as the copolymerizable monomer of the unsaturated polyester resin (Comparative Example 4) and the one using vinyl ester (Comparative Example 9) were heated at 180 ° C. Cracks have occurred in the ironless core armature, and other than that, each Comparative Example 2, 3, 5, 6) has more than twice the dimensional change during heating as an ironless core armature as compared with the Examples and the conventional examples. It has become. However, the example has the same dimensional stability under heat as the conventional example.

Next, a molded product with the same thickness as the ironless armature (3 mm ^t × 10 mmW
Table 4 shows the heating loss after heating at 180 ° C for 1800H for 100 x 100 mml).

When divinylbenzene is used as the copolymerizable monomer of the unsaturated polyester resin as shown in Table 4 (Comparative Example 4).
Has excellent heat deterioration resistance, but as shown in Table 2, it has a serious defect that cracks occur when it is heated as an ironless core armature. As compared with the other comparative examples, it is apparent that the examples all have good heat deterioration resistance as in the conventional example.

As described above, the examples according to the present invention have markedly superior dimensional stability and heat resistance during heating of the ironless core armature as compared with the comparative examples using the unsaturated polyester resin, and the epoxy shown as the conventional example is shown. It is possible to secure the reliability under high temperature similar to that using the resin composition. In particular, in the case of the example according to the present invention, the curing of the resin composition as the ironless core armature is shortened from 300 seconds to 60 seconds compared with the conventional example, and further, the step of 150 ° C. and 6H can be abolished as post-curing. The productivity has improved remarkably.

EFFECTS OF THE INVENTION As described above, according to the present invention, the resin composition for sealing the armature winding contains 5 to 40% by weight of an unsaturated polyester resin having a trifunctional triazine compound, and 70 to 85% by weight of an inorganic filler. It is composed of a composite of. Such an ironless core armature according to the present invention has markedly superior dimensional stability during heat and heat resistance as compared with those using a general unsaturated polyester resin as a resin composition, and is conventionally under relatively high temperature. The epoxy resin composition used can seal the armature winding and ensure the same level of reliability as a coreless armature. Moreover, when the armature winding is sealed with the epoxy resin composition, curing 30
Compared with the process of 0 sec and post-curing 6H, according to the present invention example, 60
Since the ironless armature can be obtained in sec, the productivity can be remarkably increased.

Claims (1)

(57) [Claims] 1. A non-iron core armature for encapsulating an armature winding portion with a resin composition of at least 70% by weight of an inorganic filler and an unsaturated polyester resin. A non-ferrous core armature, characterized in that the weight% is a trifunctional triazine compound.