JPS602045A - Stator for molded submerged motor - Google Patents

Abstract

PURPOSE:To protect an internal coil and core from water penetration securely by providing a low moisture permeability varnish film to the outside of a solidly molded layer. CONSTITUTION:A molded layer 3 is molded solidly with a thermosetting resin molding material such as a phenol resin, an epoxy resin and a non-saturated polyester resin. The surface of the molded layer 3 is coated with a low moisture permeability epoxy varnish film 4 and penetrating moisture from the outside is blocked and an internal coil 1 and core 2 are protected from moisture penetration. The low moisture permeability epoxy varnish film 4 is formed by spraying and ultraviolet rays curing. With this constitution, the internal coil 1 and core 2 can be securely protected from water penetration.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a submersible electric motor, and more particularly to a stator for a molded submersible electric motor that has been improved in order to improve corrosion resistance and productivity, and achieve smaller size, lighter weight, and lower cost.

In recent years, transformers, current transformers, switches, capacitors, transistors, small electric motors, etc. using thermosetting molding materials have been produced with the aim of improving productivity and improving the characteristics and functions of electrical equipment.

For example, in small electric motors of 100W class or less, part or all of the stator core and coils are made of unsaturated polyester BMO (Bulk Molding Com).
It is integrally molded by transfer molding or injection molding using a thermosetting molding material such as Pounds, phenol resin, or epoxy resin.

On the other hand, in submersible electric motors that are used underwater, there are problems with the moisture permeability of plastic, a reduction in insulation life, and a reduction in mechanical strength due to underwater use. Submersible electric motors have not been proposed.

Therefore, an object of the present invention is to provide a completely molded stator for a submersible motor, and the molded stator for a submersible motor according to the present invention will be described in detail below with reference to the drawings.

FIG. 1 is a cross-sectional view of essential parts showing one embodiment of a stator for a molded submersible electric motor according to the present invention, in which 1 is a coil wound around a core 2, 3 is a phenol resin, an epoxy resin, an unsaturated polyester resin, etc. A mold layer integrally molded using a thermosetting resin molding material, 4 is a film of low moisture permeability epoxy varnish applied to the surface of the mold layer 3,
It blocks water from entering from outside and protects the coil 1 and core 2 provided inside from water intrusion. The film 4 of this low moisture permeability epoxy varnish is made by applying it using a spray and then curing it with ultraviolet rays.

In the stator for a molded submersible electric motor constructed in this manner, the coil 11 core 2 and slot portion are molded using a thermosetting resin molding material such as phenol resin, epoxy resin, unsaturated polyester resin, etc. After the stator part is integrated, a phenol coating is formed as a waterproof coating around its outer periphery.

When the molded stator constructed in this way is used underwater, the life of the insulation of the internal coil 1 is seriously affected by water intrusion due to diffusion and water intrusion from crack points.

However, in the above configuration, since the pheno coating 4 as a waterproof coating is provided on the outer surface of the mold layer 4,
Water intrusion is prevented and the internal coil 1 and core 2 are reliably protected.

Next, an example of a method for manufacturing a stator for a molded submersible electric motor having the above configuration will be described. Regarding the case where an unsaturated polyester molding material is used, the molding material is 20 parts by weight of vinyl ester (epoxy acrylate) resin, 65 parts by weight of silica sand or calcium carbonate as a filler, and 1/2 part as a reinforcing agent. A mixture of 9 parts by weight of glass fiber of 8 to l/16 int., 05 parts by weight of benzoyl peroxide (BPO) as a hardening agent based on the resin, and other pigments, a low shrinkage agent, and an internal mold release agent was mixed in a kneader. The mixture is kneaded and supplied to transfer molding to produce a mold stator. In this case, to improve the adhesion between the resin and the filler and glass fiber, the cup)
Just add a non-stick agent.

Next, an ultraviolet curable low moisture permeability phenol is applied to the surface of the mold layer 4 by spray coating, and immediately cured by ultraviolet irradiation to form a waterproof film. As the ultraviolet curing phenol for waterproof coatings used here, the following are suitable.

That is, the composition is low viscosity epoxy acrylate 4
0 to 60 parts by weight, hydroxyethyl acrylate 60
Good results were obtained when 1 part by weight of epoxy acrylate was added to 40 parts by weight of a mixture containing 1 part by weight of epoxy acrylate as a curing catalyst. Then, 20 parts by weight of a glass flake filler having an aspect ratio of 60 to 80 was added to 100 parts by weight of the resin mixture.
Add up to 40 parts by weight. By variously changing these formulations, 9.
．． It was possible to obtain 49 g/m'241t of pheno.

FIG. 2 is a sectional view of a main part showing an example of a life estimation test device for a stator for a molded submersible electric motor made by the method described above. In the figure, 10 is a molded stator shown in FIG. 1 having a structure according to the present invention, and 11 is a water tank that accommodates the molded stator 10, with both ends of the molded stator 10 protruding outside from the water tank 11. It is configured. Water 12 is supplied into the water tank 11 via the water pipe 13, and is discharged via the drain pipe 14 to drain the water inside the water tank 11.

In such a configuration, when the molded stator 10 is set in the water tank 11 and the water tank 11 is filled with water 12, the coil provided inside the molded stator 10 is energized. Heat to ~120°C. In this state, a life estimation test can be performed by measuring changes over time in insulation resistance between the core and the water 12 and between the main coil and the sub coil. The results measured in this way are as shown in Figure 3.
Even after 5,000 hours had elapsed, no decrease in insulation resistance was observed, and L2×10''MΩ was maintained, which was good.

As explained above, in the molded stator for a submersible electric motor according to the present invention, since a low moisture permeability phenol coating is provided on the outer surface of the mold layer that is integrally molded, the internal coils and core are protected against water intrusion. This has the excellent effect of easily obtaining a molded stator that is small, lightweight, and inexpensive, with high corrosion resistance and high productivity.

[Brief explanation of the drawing]

FIG. 1 is a sectional view of a main part showing an embodiment of a stator for a molded submersible electric motor according to the present invention, and FIG. 2 is a sectional view of a main part showing an example of a life test apparatus for a stator for a molded submersible motor shown in FIG. FIG. 3 is a diagram showing the results of a life test using the apparatus shown in FIG. 2. 1... Coil, 2... Core, 3... Mold layer,
4...Low moisture permeability varnish film, 5...Can, 6...
・Insert screw, 7...Airtight terminal. Agent Masuo Oiwa (2 others) Procedural amendment (voluntary) Commissioner of the Japan Patent Office 1. Indication of case Patent application No. 108625/1982 2. Title of invention Stator for molded submersible electric motor 3. Relationship with the case of the person making the amendment Patent applicant address: 2-2-3 Marunouchi, Chiyoda-ku, Tokyo Name:
(601) Mitsubishi Electric Co., Ltd. Representative Hitoshi Katayama, Department 4, Agent 5, Subject of amendment (1) Detailed explanation of the invention in the specification column 6, Contents of amendment (1) Specification W, page 4, line 16 It says "supply" to the eyes.
"Yori" is corrected. (2) On page 5, line 14, “To grin, JISZ-02
The phrase "according to the 08 method" is corrected to "The moisture permeability of the cured product is determined by the JIS-20208 method." (3) r 0Jt9 g /go20 on page 5, line 15
-7 t J and r 049 g / v? -21
Correct it to 1HJ. (4) On page 6, line 17, ``It's good.'' followed by ``In Figure 3, ○ indicates the core wide insulation resistance, and X indicates the main coil insulation resistance.
This shows the insulation resistance between sub-coils. ” to join.

Claims (1)

[Claims] The outer periphery of the coils, core, and slots that make up the stator part of the underwater motor are molded using thermosetting resin molding materials such as phenolic resin, epoxy resin, and unsaturated polyester resin, and this A stator for a molded submersible electric motor, characterized in that a low moisture permeability varnish film for water blocking is formed by applying and curing a low moisture permeability ultraviolet curing varnish on the surface of a mold layer.