JPH0446067B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of the Invention] The present invention relates to a method for insulating electrical equipment windings such as salient pole field windings for vehicular motors.

[Prior art and its problems]

The insulation layer of this type of electrical equipment winding is completely impregnated or filled with resin to eliminate voids (called poids) in the insulation layer, improving electrical insulation performance and heat transfer performance. There is a need to make devices smaller and lighter.

FIG. 2 is an explanatory diagram for explaining a conventional insulation treatment method, and shows a side sectional view of a salient pole type field winding as an example. In the figure, 2 is an iron core with a wide T-shape on the magnetic pole 2A side, and 5 is a field coil, which is formed into a racetrack shape by wrapping a strip-shaped insulated conductor multiple times in the vertical direction of the figure. The main insulating layer 4A is made of a heat-resistant material such as glass cloth, polyester film, polyimide film, etc. A tape composed of a base material such as a synthetic resin film, mica, and a glass non-woven fabric is used, and a thermosetting resin such as epoxy resin is applied to an unimpregnated coil wound with a glass cloth tape wound to a predetermined thickness for the outer insulating layer 4B. It is formed by impregnating an impregnating resin with vacuum pressure and then heating and curing it. Further, 6 is a filler layer filled between the iron core 2 and the field coil 5, which is made by heating and curing a thermosetting filler such as an epoxy resin composition containing an inorganic filler such as quartz powder. The field coil 5 is connected to the iron core 2.
By quickly and firmly fixing the coil, the field coil is mechanically strongly supported, and the heat generated in the coil conductor 3 is easily transmitted to the iron core 2 side.

By the way, in the insulation treatment process of a field coil obtained by impregnating an unimpregnated coil with an impregnated resin and then heating and curing it, the viscosity of the impregnated resin once decreases due to temperature rise and its fluidity increases. There is a problem in that the insulating layer 4 leaks out between the tape layers or through the tape weave, etc., resulting in voids in the insulating layer 4 that has been heat-cured. Special measures have been taken to prevent leakage. That is, a method in which a resin-impregnated coil is heated and cured while rotating, a method in which a seal varnish is applied to the outside of the insulating layer to form a resin leakage prevention layer, and then resin impregnation is performed.
A method is known in which a release and sealing film is wound around the outer peripheral surface of an unimpregnated coil. However, none of these methods can completely prevent the leakage of impregnated resin because the shape of the coil is complex and it is technically difficult to prevent resin leakage without interfering with resin impregnation. That is the reality. In addition, when heating and curing a resin-impregnated coil while rotating, a special rotary curing device is required, and a resin leakage prevention layer requires an additional work process such as adhesion or peeling of the prevention layer. Furthermore, the conventional insulation treatment method described above involves heating and curing of the impregnated resin impregnated into the unimpregnated coil to obtain the field coil, and the field coil is attached to the iron core and filled between the field coil and the iron core. There are various problems that lead to economic disadvantages, such as an increase in the number of insulation treatment steps and treatment time due to the need for a heat curing process for the filler layer and a heat curing process for the filler layer.

[Purpose of the invention]

The present invention was made in view of the above-mentioned situation, and
Insulation that can prevent resin leakage from the impregnated resin coil insulation layer through a simplified manufacturing process, and therefore economically provide electrical equipment windings such as high-performance salient pole field windings. The purpose is to provide a processing method.

[Key points of the invention]

The present invention provides an unimpregnated coil with a filler layer formed by applying a photocurable thermosetting resin composition containing an inorganic filler for suppressing fluidity to the magnetic pole surface of the iron core. The photocurable thermosetting resin composition has a reduced content of inorganic filler so that it can be installed in the iron core and then filled from the opening between the core leg of the iron core and the unimpregnated coil. An inorganic filler is filled between the coil and the unimpregnated coil to form a filler layer, and at the same time, the inorganic filler is fluidized so that it can be applied to the surface of the unimpregnated coil except for the part that should become the opening of the impregnated resin. After applying the photocurable thermosetting resin composition with a reduced content, the surface layer and coating film portion of the filler layer are cured by light irradiation treatment to prevent resin leakage from the filler layer and coating film portion. An insulation treatment method is provided that includes a step of forming a prevention means, and a step of storing the assembly in a vacuum pressurized impregnation tank, drying the unimpregnated coil, impregnating it with a thermosetting impregnated resin, and then heating and curing it. With this structure, a resin leak prevention means that partially utilizes the filler layer can be formed by short-time light irradiation, and the impregnated resin and the unirradiated portions of the filler layer can be heated and hardened in a single processing step. This allows them to be done at the same time.

[Embodiments of the invention]

The present invention will be explained below based on one embodiment.

FIG. 1 is a fragmented cross-sectional view of a salient pole type field winding for explaining an embodiment of the insulation treatment method of the present invention.
This shows the state after the insulation process has been completed. In the figure, 2 is an iron core whose magnetic pole 2A side is expanded into a T-shape, 5 is a field coil, 3 is a coil conductor shaped into a race track of the field coil 5, and 4 is an outer peripheral surface of the coil conductor 5. In this embodiment, the main insulating layer 4A is made of a laminated mica tape with a polyimide film as a backing material, and the outer insulating layer is 4B is wrapped with glass cloth tape to a predetermined thickness, and an impregnated resin consisting of 30 parts by weight of bismaleimide triazine resin (BT2100, manufactured by Mitsubishi Gas Chemical) and 70 parts by weight of liquid bisphenol A type epoxy resin is vacuum impregnated and Hardened by heat. 1
0 is a resin leak prevention means for preventing resin leakage from the insulating layer of the field coil of the impregnated resin, and magnetic pole 2A
A filler layer 11A filled between the core leg portion 2B and the inner peripheral surface of the field coil 5, a filler layer 11B filled between the core leg portion 2B and the inner circumferential surface of the field coil, and an impregnated resin It consists of a photocured film 12 applied to the surface of the field coil except for the impregnation port 13, and is used as it is as an insulating layer and a fixed layer in the completed winding. In the case of this embodiment, the filler layer 11
A contains 30 parts by weight of bismaleimide triazine resin;
70 parts by weight of liquid bisphenol A type epoxy resin,
Photocuring consisting of 3 parts by weight of a heat curing catalyst containing equal amounts of benzyldimethylamine and zinc octylate, 3 parts by weight of the photosensitizer Darokyur (manufactured by Merck & Co., Ltd., trade name), and 300 parts by weight of quartz powder as an inorganic filler. Possible thermosetting resin composition A is added to filler layer 11B.
Resin composition B is obtained by reducing the curing catalyst in the above formulation A to 1 part by weight and reducing the quartz powder to 150 parts by weight.
For the photocured film, a photocurable resin composition C in which the curing catalyst in Formulation A was removed and the quartz powder was reduced to 2 parts by weight was used.

Next, the insulation treatment method of the present invention will be explained using FIG. First, the step of forming the resin leakage prevention means is to apply the resin composition A of the above composition to the coil side of the magnetic pole 2A to a thickness slightly thicker than a predetermined thickness, and then press the axial end surface of the unimpregnated coil to position it. At this time, the resin composition A contains a large amount of quartz powder and therefore has poor fluidity, so that the coil can be maintained at the same size for a predetermined period without shifting its position. Next, resin composition B is filled in the space between the unimpregnated coil and the core leg portion 2B, and further the impregnated resin injection port 13
A photocured film is formed by applying resin composition C to the surface of the glass tape layer of the non-impregnated coil using a brush or the like. The surface of the thus formed assembly of the iron core and unimpregnated coil is subjected to light irradiation treatment using an ultraviolet irradiation device for approximately 3 minutes at an irradiation amount of 80 W/cm and an irradiation distance of 10 cm, resulting in photocuring. membrane 12
By curing the exposed portions 14 of the filler layers 11A and 11B by photopolymerization, the resin leakage prevention means 10 using the filler layers can be formed.

In the step of forming the resin leakage prevention means 10 described above, the amount of curing catalyst and quartz powder in resin formulations A, B, and C is increased in formulation A to improve viscosity and shorten gelation time. Formulation B can facilitate positioning of unimpregnated coils.
In this case, the amount of the resin composition can be reduced to make it easier to fill the gap with the resin composition, and in Formulation C, which is used for a coating layer that is easy to photocure, the amount of quartz powder can be applied at the same time as the amount of the curing catalyst is reduced to zero. By reducing the amount to a small amount that facilitates light transmission through the film layer, application work with a brush is facilitated, and even thick coating films can be cured by light irradiation. Also, formulations A, B, C
By blending a photosensitizer into the resin to make it curable by light irradiation, the photocurable film 12 as well as the surface layer of the filler layer can be cured by light irradiation at room temperature for a short period of time without causing thermal softening and flow of the resin. Therefore, a mechanically strong and liquid-tight resin leak prevention means 10 that cannot be obtained by conventional methods can be formed by a short curing process.

The core and coil assembly that has gone through the above process is about 80
The insulating tape layer is stored in a vacuum pressurized impregnation tank heated to ℃ with the impregnation port 13 facing upward, and after the insulating tape layer is dried, the above-mentioned impregnating resin is impregnated with the vacuum pressure. Since gelation inside the filler layer progresses due to the curing catalyst, it is possible to prevent the impregnated resin and the filler layer from mixing at the boundary between the two and forming an uneven resin layer. The insulating tape layer can be completely impregnated with resin.

Next, the field winding that has undergone the resin impregnation process is transferred to a heat curing furnace, where it is heat hardened at 150°C for 6 hours and then at 200°C for 6 hours, thereby heat curing the impregnated resin and filler layer. The first
A field winding as shown in the figure is formed. Although the fluidity of the impregnated resin temporarily increases in the initial stage of the heat curing process, no resin leakage was observed, and no abnormalities in appearance such as blistering were observed in the insulating layer 4 of the field coil 5 after the curing process. No abnormal sound was detected in the insulating layer, indicating defects such as peeling between tape layers or voids, even in the hammering sound inspection.

It should be noted that the formulation of the resin composition in the present invention is not necessarily limited to the explanation of the above-mentioned examples, and a suitable composition is selected in consideration of the maximum allowable temperature and insulation structure of the electrical equipment insulation to be applied. It goes without saying that the type of electrical equipment to which the invention can be applied is not limited to the salient pole type field winding.

〔Effect of the invention〕

As described above, the present invention involves filling the space between an unimpregnated coil and an iron core with a photocurable thermosetting resin composition containing an inorganic filler, positioning the coil, and then leaving an impregnation opening for the impregnated resin. A photocurable resin composition is applied to the outer surface of the unimpregnated coil, and the exposed portions of the filler and the coating film are cured by ultraviolet irradiation treatment, thereby forming a resin leakage prevention means consisting of a filler layer and a photocured film. and a step of impregnating an unimpregnated coil with an impregnated resin under vacuum pressure and then heating and curing the unirradiated portions of the impregnated resin and filler layer. As a result, the fluidity of the filler is controlled by the inorganic filler, making it easier to position the unimpregnated coil, and a relatively thick photocured film and the surface of the filler layer can be coated with short-term ultraviolet irradiation without increasing fluidity. The inside of the filler layer can be gelled using a curing catalyst prior to resin impregnation treatment, so by using a filler layer tightly supported on the iron core, it can be made mechanically strong and liquid-tight. The resin leakage prevention means can be formed in a short time. Therefore, it is possible to prevent resin leakage, which was a conventional problem during the subsequent resin impregnation and heat curing process of the unimpregnated coil, and the insulating layer has no voids and has excellent electrical insulation and thermal conductivity. It is possible to provide an insulation treatment method suitable for providing electrical equipment windings. In addition, by forming the resin leakage prevention means using a photocurable resin composition, it is possible to form a prevention means with excellent resin leakage prevention performance in a short time, and it is also possible to form the prevention means with excellent resin leakage prevention performance in a short time. Since the curing process can be performed simultaneously in one heat curing process, the processing time can be significantly shortened compared to the conventional method in which the curing process of the coil insulation layer and the curing process of the filler layer were performed separately. The present invention provides an economically advantageous method for insulating electrical equipment windings, since it does not require extra steps such as removal of resin leakage prevention means or special manufacturing equipment such as a rotary impregnation device in conventional methods. can do.

[Brief explanation of the drawing]

FIG. 1 is a fragmented sectional view of a salient pole field winding for explaining an embodiment of the insulation treatment method of the present invention, and FIG. 2 is a fragmented sectional view of a salient pole field winding for explaining a conventional insulation treatment method. It is a sectional view of a line. 2...Iron core, 2A...Magnetic pole, 2B...Iron core leg, 3...
Coil conductor, 4... Insulating layer, 5... Field coil, 10
... Resin leakage prevention means, 11A, 11B... Filler layer, 12... Photocured film, 13... Impregnation port for impregnated resin.

Claims (1)

[Claims] 1. A method for insulating windings of electrical equipment in which a resin-impregnated coil is fixed to a salient pole-shaped iron core via a filler layer, in which an unimpregnated coil is coated with an insulating tape layer of a wound coil conductor. A photocurable thermosetting resin composition containing an inorganic filler for suppressing fluidity is attached to the surface of the filler layer formed by adhering it to the magnetic pole surface of the iron core, and then the iron core is The photocurable thermosetting resin composition with a reduced content of inorganic filler is applied between the core leg and the unimpregnated coil so that it can be filled from the opening between the core leg and the unimpregnated coil. The photo-curing method has a reduced content of inorganic filler so as to have fluidity that allows it to be applied to the surface of the unimpregnated coil except for the portion that should become the opening of the impregnated resin. After applying a thermosetting resin composition, a light irradiation treatment is performed to form a photocured film on the surface layer of the unimpregnated coil and a filling adhered to the surface of the magnetic pole of the iron core whose surface layer portion has been hardened. forming a resin leakage prevention layer consisting of a filler layer and a filler layer filled in the opening between the core leg and the unimpregnated coil;
and a method for insulating an electrical equipment winding, comprising the steps of vacuum impregnating the unimpregnated coil with a thermosetting impregnated resin and simultaneously heating and curing the impregnated resin and the resin leakage prevention layer.