JPS6251070B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a coreless armature in which the armature winding portion is integrally made rigid by resin. Generally, the armature winding is made into a rigid body by wrapping a predetermined number of electric wires around it and fixing it together with the supporting iron core using a binder such as varnish. However, in the case of an armature winding without a supporting core, such as a coreless armature, it is necessary to make the armature winding itself an integral rigid body by some method. In particular, in the case of armature windings used as relatively large coreless armatures ranging from a few watts to several hundred watts, the properties required for making an integral rigid body are sophisticated, such as strength at high temperatures, dimensional stability, and heat resistance. An integral rigid body that can meet impact resistance, electrical insulation, etc. is required. Therefore, at least the armature winding portion of the above-mentioned coreless armature is generally made into an integrally rigid body with a thermosetting resin molding material having a density of 1.8 to 2.0 g/cc and usually containing 50% or more of an inorganic filler. It was spot on. The above-mentioned relatively large coreless armatures, ranging from a few watts to several hundred watts, are often used as motors to perform incremental motion by taking advantage of their extremely fast control response, and are used in fields that cannot be followed by pulse motors. There are many examples. That is, the fields include magnetic disks, facsimile machines, serial printers, line printers, card readers, card punches, data recorders, copying machines, automatic welding machines, machine tools, etc. However, due to the increasing performance and precision of these devices, motors that minimize the weight imbalance of the coreless armature, suppress vibrations during motor operation, and further improve control response. That is, there has been a desire for a highly accurate, high quality, low inertia ironless armature with a highly balanced weight balance as a rotating body. The present invention has been made in view of the above-mentioned requirements, and in a non-iron core armature in which the armature winding portion is integrally made rigid by resin, anti-commutation is applied from the commutator side winding end of the armature winding. The thermosetting resin has a structure in which the density of the thermosetting resin decreases toward the end of the winding on the child side, and has a high-density portion extending to the end of the winding on the anti-commutator side. It is. The present invention will be explained in more detail below. The iron-core armature that is the object of the present invention is used as a motor with power ranging from several watts to several hundred watts, and if it is a wire-wound type iron-core armature, it may be flat or flat. There is no problem even if it is cup-shaped. Further, as the resin for making at least the armature winding portion integrally rigid, thermoplastic resins and thermosetting resins are applicable, and thermosetting resins are particularly suitable.
The base of this thermosetting resin is epoxy resin, unsaturated polyester resin, diallyl phthalate resin, polyurethane resin, silicone resin, etc., and is used as a compound system with the most suitable polymerization initiator or curing agent for each system. . Furthermore, a blowing agent or a substance that forms pores, such as glass microballoons or synthetic resin microballoons, is usually used. Alternatively, inorganic fillers, internal mold release agents, pigments, etc. are used as appropriate to adjust linear expansion, thermal conductivity, etc. The present invention will be explained in detail below with reference to Examples. Example: An insulated wire with a self-bonding layer with a wire diameter of 0.25 mm was
An armature winding consisting of a commutator and an armature winding group consisting of 23 windings each wound 50 times in a flat stacked arrangement was prepared. On the other hand, as a thermosetting resin, 70 parts by weight of unsaturated polyester resin (trade name #7596, manufactured by U-Pica Japan),
30 parts by weight of a low shrinkage agent (trade name #A-80, manufactured by Nippon U-Pica), 1 part by weight of a polymerization initiator (trade name: Perbutyl Z, manufactured by NOF Corporation), and a blowing agent (trade name: F-30, manufactured by Matsumoto Yushi Corporation). A product was prepared by mixing and kneading 200 parts by weight of calcium carbonate, 30 parts by weight of zinc stearate, and 10 parts by weight of fine polyethylene powder. The putty-like thermosetting resin thus obtained was prepared in advance into a predetermined donut shape. Next, the thermosetting resin preformed into the donut shape is placed on the commutator side winding end and the anti-commutator side winding end of the armature winding.
The thermosetting resin was placed in a heated mold, and the thermosetting resin was cured by heating. In this way, the particular coreless armature has the cross-sectional configuration shown in FIG. In the figure, 1 is an armature winding, 2 is a thermosetting resin, 3 is a commutator, 4 is an armature shaft press-fitted into the commutator 3, and 5
6 is the end of the winding on the commutator side, and 6 is the end of the winding on the opposite commutator side. The minimum thickness of the armature winding portion of this coreless armature is 2 mm, and the outer diameter of the armature is 94 mm.
Furthermore, a rib for weight balance correction is provided on the outer periphery of the armature corresponding to the winding end 6 on the side opposite to the commutator of the armature winding. Comparative Example The armature winding used in the example was heated to 150℃±
It was placed in a transfer mold heated to 3 degrees, and an epoxy resin molding material was used to obtain a coreless armature having the same dimensions as the example and the configuration shown in FIG. 1. FIG. 2 is a characteristic diagram showing the density distribution of the thermosetting resin in the iron core armatures of the above examples and comparative examples. As shown in the figure, the density distribution of the conventional coreless armature used as a comparative example has an even density distribution in the direction from the commutator side winding part 5 to the anti-commutator side winding end 6 of the armature winding. However, as shown in the embodiment of the present invention, the density of the thermosetting resin decreases in the direction from the commutator side winding end 5 of the armature winding 1 to the opposite commutator side winding end 6. It is a configuration that has
The winding end portion 6 on the opposite commutator side, that is, the armature outer peripheral portion is again configured to have a high density. Even if an armature integrated with a thermosetting resin having the above density distribution undergoes rotational breakdown at high temperatures, the thermosetting resin on the rotational breakdown surface has a high density, that is, it has a high density and is further on the side opposite to the commutator of the armature winding. The ends of the windings also have a high-density structure, and the armature of the example is no different from the conventional iron-core armature in terms of centrifugal force resistance, such as withstanding 120° C. and 12,000 rpm. FIG. 3 is a characteristic diagram showing the thermal expansion of the highest density part and the lowest density part of the thermosetting resin used in the examples. As is clear from the figure, in this example, the expansion coefficients are the same up to a high temperature of 180°C. In other words, there is no difference in dimensional stability under high temperatures from conventional iron core armatures. Although the embodiments have been described using a thermosetting foamed resin, partial foaming of a general thermoplastic resin can also be used, and the present invention is not particularly limited to a thermosetting foamed resin. Furthermore, it is naturally applicable to a cup-shaped coreless armature. Next, the effect will be explained. Table 1 shows the moments of inertia of the coreless armatures of the example and comparative example shown in FIG.

[Table] As is clear from Table 1, the moment of inertia of the example according to the present invention is 0.75 kg-cm ² , which is 15% lower than the comparative example of 0.885 kg-cm ² . There is. Furthermore, the weight imbalance of the ironless armatures of the examples and comparative examples is as shown in Table 2.

[Table] There are few examples. If the weight imbalance of the coreless armature is to be corrected to, for example, 0.1g or less, in this example, the high-density thermosetting resin at the end of the winding on the side opposite to the commutator of the armature winding will be reduced by approximately 0.2g. In the comparative example, approximately 0.45g of the same portion had to be removed. That is, in the example, the total weight of the ironless armature has less variation than in the comparative example, so as a result, the moment of inertia has less variation, and a high degree of reliability can be obtained in the controllability of the motor. In addition, as in the example, the high-density part of the thermosetting resin provided at the end of the winding opposite to the commutator of the armature winding has high strength, so it can be used in the removal work when correcting the weight imbalance of the iron-core armature is no different from the case of the conventional coreless armature shown in the comparative example. As described above, according to the present invention, various characteristics such as high strength and dimensional stability required for relatively large iron-core armatures ranging from several watts to several hundred watts can be achieved at the same level as those of conventional iron-core armatures. It is possible to lower the inertia and suppress its fluctuations while maintaining a certain level of inertia.
In other words, this iron coreless motor achieves both high performance and high precision at the same time.

[Brief explanation of the drawing]

FIG. 1 is a sectional view of a coreless armature, FIG. 2 is a characteristic diagram showing the density distribution of a thermosetting resin, and FIG. 3 is a characteristic diagram showing the thermal expansion of thermosetting resins having different densities. 1... Armature winding, 2... Resin, 3... Commutator, 4... Armature shaft, 5... Commutator side winding end,
6... Winding end on the anti-commutator side.

Claims (1)

[Claims] 1. In a wound type coreless armature in which single coils are aligned and shaped into a predetermined shape and made into a rigid body together with a commutator and shaft using resin, the ends of the windings on the commutator side and the ends of the windings on the opposite commutator side The ironless core armature is characterized in that the resin density is greater than the resin density at an intermediate portion between the commutator side winding end and the anti-commutator side winding end.