JPH01114345A - Field coil of rotary electric machine - Google Patents

Abstract

PURPOSE:To prevent an outflow of insulation resin impregnated to the inside of an elementary coil by vacuum pressurization by adhering powder resin to the outer surface of the elementary coil and forming a sealing layer with high viscosity. CONSTITUTION:A field coil consists of elementary coils 1, and insulation resin 2 is impregnated between strands of the inside of the elementary coil 1 by vacuum pressurization. In addition, a specific amount of powdery resin is adhered to the outer surface of the elementary coil 1 such as the field coil to make it highly viscous, and a sealing layer 3 to prevent an outflow of insulation resin 2 from the inside of the elementary coil 1 to the outside is formed. According to the constitution, the characteristic of a heat machine is improved, and the field coil of a rotary electric machine with no coming off of the sealing layer or no generation of cracking can be obtained.

Description

[Detailed description of the invention] (Purpose of the invention) (Industrial application field) The present invention relates to a field line axis of a rotating electric machine.

(Prior Art) Conventionally, as a field wire axis of a rotating electrical machine such as a DC machine, for example, a field wire ring is formed by winding a plurality of wire conductors and has a gap between the conductors of a wire ring 1, as shown in the attached figure. A solvent-based resin or a solvent-free resin (simply shown as insulating resin 2 in the figure) is impregnated into the voids inside the seal layer 3 by vacuum pressure impregnation or immersion, and then heated and cured (hereinafter referred to as "insulation treatment"). The sealing layer 3 is formed by applying a sealing varnish.

(Problems to be Solved by the Invention) The field wire ring formed with this insulation treatment has the following problems: the insulating resin 2 temporarily decreases in viscosity during heat curing during the insulation treatment, dissolves the sealing layer 3, and flows out; Wire ring 1, insulation resin 2
Due to the difference in the coefficient of thermal expansion of the sealing layer 3, there are problems such as peeling between the strand ring 1 and the sealing layer 3 and cracking of the sealing layer 3 due to the temperature rise during operation. insulation and cooling properties are reduced. To prevent the insulating resin 2 from flowing out, there are two methods: immersing the insulating resin 2 in a field wire ring or impregnating it with vacuum pressure and then immediately curing it by heating while rotating the whole thing, or using an ultraviolet curing type before immersion or vacuum pressure impregnation. Varnish, photo-curing varnish, or thermosetting varnish is applied as the sealing layer 3 and then cured, but the former requires a rotating device in a heating furnace, and the latter requires a curing device and is hard to cure. There are drawbacks such as an additional processing step.

On the other hand, to prevent cracks in the sealing layer 3, the thermomechanical properties are improved by filling the applied sealing varnish with glass fibers, but in this case, if the glass fibers are not evenly distributed in the sealing layer 3, the varnish There will be areas with more varnish and areas with less varnish, and cracks may occur at the boundaries between them or in areas with more varnish. For example, even if the glass fibers can be distributed uniformly, the varnish may not be sufficiently impregnated between the glass fibers, and if sufficient impregnation is not performed, air bubbles are likely to remain.

There are problems such as deterioration of the insulation properties and cooling properties of the field wire ring.

The present invention was made in consideration of the above circumstances, and it prevents the insulating resin from flowing out with a sealing layer that does not dissolve in the insulating resin, and further improves the thermomechanical properties, so that the sealing layer can rotate without peeling or cracking. The purpose is to provide field wire rings for electric machines.

[Structure of the invention]

(Means for Solving the Problems) In order to solve the above problems, in the field wire ring of the present invention, powdered resin is attached to the outer surface of the wire ring to form a highly viscous sealing layer. do.

(Function) In this way, the sealing layer prevents the insulating resin that has been vacuum-pressurized and impregnated inside the strand ring from flowing out.

(Example) The figure is a schematic cross-sectional view of the field wire ring of the present invention.

The field wire shaft is constituted by a wire ring 1, and insulating resin 2 is impregnated between the wires in the wire ring 1 under vacuum pressure. Since the insulating resin 2 has a low viscosity and may leak out from the wire ring 1, a predetermined amount of powdered resin is adhered to the outer surface of the wire ring 1, that is, the field wire ring to create a high viscosity. A sealing layer 3 is formed to prevent the insulating resin 2 from flowing out from the inside of the strand ring 1.

The sealing layer 3 is formed after impregnating the insulating resin 2 with vacuum pressure inside the strand ring 1 of the field wire shaft. The powdered resin is a bisphenol type, epoxy novolac type, or alicyclic type epoxy resin containing a hardening agent, and is compatible with the liquid resin impregnated with vacuum pressure inside the wire ring 1. An epoxy resin (for example, PACKEM manufactured by Origin Electric Co., Ltd. (powder particle size 45 μm to 250 μm)) is used. This is applied at a rate of about 100 ml per sie using, for example, a fluidized dipping method, an electrostatic dynamic dipping method, a cascade method, or an electrostatic spray method.
By attaching it to the outer surface of the field wire ring at the density of the pupil,
A high viscosity sealing layer 3 approximately one film thick is placed on the outer surface of the field line shaft.
to form. Afterwards, the field wire ring was heat treated.

The insulating resin 2 has a low viscosity to improve impregnability, and has a long curing time to increase pot life. For this reason, the insulating resin 2 impregnated into the wire ring 1 under vacuum pressure tends to flow out easily, but immediately after the vacuum pressure impregnation, the insulating resin 2 is sufficiently attached to the outer surface of the wire ring 1. Powdered epoxy resin easily adheres to it. Powdered epoxy resin contains a hardening agent inside, so it hardens much faster than insulating resin 2, and immediately forms sealing layer 3 on the outer surface of strand ring 1. The insulating resin 2 formed and impregnated inside the strand ring 1 under vacuum pressure has an excellent effect of preventing the amount of rays from flowing out to the outside of the strand ring 1, and there are no voids inside the strand ring 1. become.

Table 1 shows the properties of the sealing layer 3 of the field wire ring obtained in the above example.

Table 1 As described above, according to this embodiment, the insulating resin 2 impregnated into the wire ring 1 under vacuum pressure is quickly formed by adhering powdered epoxy resin to the outer surface of the field wire ring. Seal layer 3
Since the wire ring 1 is sealed and insulated without leaking to the outside, there are no voids or peeling inside the strand ring 1, so it is electrically superior and has excellent mechanical and thermal properties. It is possible to obtain a field wire ring with excellent properties.

〔Effect of the invention〕

As described above, according to the present invention, after impregnating the wire ring of the field wire ring with an insulating resin under vacuum pressure, a powdered epoxy resin is attached to the outer surface of the field wire ring to form a high-viscosity sealing layer. As a result, a strong sealing layer can be easily formed, preventing the insulating resin inside the wire ring from leaking to the outside, and improving the heat transfer coefficient because there are no defects such as peeling, voids, or cracks inside the field wire ring. do.

It is possible to obtain an excellent field wire ring for a rotating electric machine that has excellent cooling properties, improved mechanical strength, and further improved moisture resistance.

[Brief explanation of the drawing]

The figure is a schematic cross-sectional view of a field wire ring according to the present invention. 1... Strand ring 2... Insulating resin 3... Seal layer agent Patent attorney Noriyuki Chika Yudo Ken Daishimaru

Claims (2)

[Claims] (1) A wire conductor is wound several times to form a wire ring, and a heat-curable liquid resin is impregnated with vacuum pressure between the wire conductors and on the outer peripheral surface of the wire ring. A field wire ring for a rotating electrical machine, characterized in that a powdered resin is attached to the outer surface to form a sealing layer that prevents leakage of liquid resin impregnated with vacuum pressure, and then heated and hardened. (2) Particle size of powdered resin is 45μm to 150μm
A field wire ring for a rotating electrical machine according to claim 1, characterized in that: