JPS61142947A - Preparation of varnish for rotary electric machine - Google Patents

Abstract

PURPOSE:To promote the hardening of varnish, by making curing catalyst adhere previously to the tight binding members or insulating members of coils before the members are penetrated with varnish. CONSTITUTION:Binding yarns 3 before bound tight are dipped in curing catalytic solution. After that, the binding yarns 3 are dried and acetone is volatilized. Then, curing catalyst adheres to the binding yarns 3 and remains. And after the ends of coils 2 are tightly bound with the binding yarns 3, varnish is dropped at the coil ends and DC current is conducted through the coils 2. The coils 2 and the binding yarns 3 are penetrated with varnish by dropping varnish. Heat is generated on the coils 2 by electrical conduction to the coils 2, and varnish adhering to the coils 2 is heated at first and starts hardening reaction to complete the hardening within some minutes. In this manner, even if varnish adhering to the tight binding members or insulating members is not heated enough, the hardening of varnish can be promoted by the curing catalyst.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to a varnish treatment method for a rotating electric machine, in which varnish is cured using heat generated by a coil.

[Technical Background of the Invention] This type of varnish treatment method involves dropping thermosetting varnish onto the coil end of the stator coil to allow it to penetrate, and then hardening the varnish by passing direct current through the coil to generate heat. The drip method is known.

[Problems with the Background Art] However, in the above method, the heat source is the coil itself, so although the varnish attached to the coil is sufficiently heated,
For example, if the varnish adheres to the binding thread that binds the coil end, it will take time for the heat from the coil to be transmitted to the binding thread, so there is a tendency for the heating to be insufficient. For this reason, varnish that adheres to parts other than the coil, such as binding threads and insulating paper, cures more slowly than varnish that adheres to the coil, and there is a possibility that incomplete curing may occur. Therefore, in the past, in order to completely cure the varnish attached to the binding threads and insulating paper, a heating process was performed after the stator was placed in a heating furnace after being heated by energization, or the energization time was made sufficiently long with a margin. The reality is that they were forced to do so. For this reason, there are disadvantages in that the processing time becomes long, productivity deteriorates, and a large amount of electric power is required.

[Object of the Invention] An object of the present invention is to fully cure the varnish attached to the binding members and insulating members of the coil, thereby fully exhibiting the effects of varnish treatment, and to improve productivity by shortening the processing time. It is an object of the present invention to provide a varnish treatment method for a rotating electrical machine that can improve the performance of the rotating electric machine.

[Summary of the Invention] The present invention solves the tendency of the varnish attached to the binding member or the insulating member to be insufficiently heated by attaching a curing catalyst to the binding member or the insulating member of the coil before the varnish penetrates. However, it is unique in that it uses a curing catalyst to accelerate the curing of the varnish.

[Embodiment of the Invention] An embodiment in which the present invention is applied to varnish treatment of a stator will be described below with reference to the drawings. First, in Fig. 2 which shows the outline of the drip method, 1 is a stator core, 2 is a coil,
Reference numeral 3 designates a binding thread serving as a binding member for binding the coil end of the coil 2, and reference numeral 4 designates a dripping nozzle. Varnish is dripped onto the coil end of the coil 2 from the dripping nozzle 4, and permeates into the coil 2 and the binding thread 3. This varnish has a composition, for example, of 50 phr of epoxy resin, 5 ophr of acid anhydride, and 2 phr of curing catalyst (aluminum complex/active silanol).

Now, the drip method of the present invention is executed as shown in the flowchart of FIG. That is, after manufacturing the stator core 1, the coil 2 is housed in the stator core 1. On the other hand, a curing catalyst such as an aluminum complex/activated silanol is dissolved in acetone, and the tying thread 3 before being tied is immersed in the curing catalyst solution. Thereafter, the binding thread 3 is dried to volatilize the acetone. As a result, the curing catalyst remains attached to the binding thread 3. Next, after the coil end of the coil 2 is tied up with the tying thread 3, it is set in a drip device (not shown), and varnish is dripped onto the coil end as shown in FIG. 2, and at the same time, a direct current is passed through the coil 2. By dropping the varnish, the varnish is applied to the coil 2 and the binding thread 3.
to penetrate. When the coil 2 is energized, the coil 2 generates heat, and the varnish attached to the coil 2 is first heated to start a curing reaction, and the curing is completed within a few minutes. Further, the binding thread 3 is also gradually heated by the heat generated by the coil 2, but since it is located on the outer periphery of the coil 2, the temperature rise is slower than that of the coil 2, and it is heated to a lower temperature. However, since the curing catalyst has been attached to the binding thread j in advance and the concentration of the curing catalyst IjX in the varnish that has adhered and penetrated into the binding thread 3 is significantly high, the curing reaction proceeds quickly even at low temperatures. ,
The curing is completed almost simultaneously with the varnish adhering to the coil 2.

In this way, according to this embodiment, not only the varnish attached to the coil 2 but also the varnish attached to the binding thread 3 can be completely and quickly cured by applying current to the coil 2, so that the rigidity of the coil 2 can be cured completely and quickly. And insulation can be sufficiently improved. Furthermore, by adding an extremely simple process of pre-adhering a curing catalyst to the binding thread 3, the large-scale post-heating process that was conventionally required can be eliminated, and the time for energizing the coil 2 can also be shortened. can. This results in
Processing time can be shortened, productivity can be improved, and power costs can also be reduced. It may be possible to add a large amount of curing catalyst to the varnish that is dripped onto the coil 2 in advance so that the varnish attached to the tying thread 3 will harden quickly even at low temperatures. This causes problems such as the so-called pot life of the resin is shortened, making it difficult to work with, and the permeability to the coil 2 and the binding thread 3 is reduced. In contrast, in the present invention, the curing catalyst concentration of the varnish adhering to the tying thread 3, which tends to be insufficiently heated, is selectively increased, so the pot life of the dripping varnish is shortened and the permeability is reduced. Not bad, very reasonable.

In the above embodiment, the curing catalyst is attached to the binding thread 3, but the present invention is not limited to this. For example, when a tape is used as the binding member, the curing catalyst is attached to the tape in advance. You can. Furthermore, the curing catalyst may be applied in advance not only to the binding member but also to insulating members such as interphase insulating paper and insulation tubes of crossover wires. Despite the fact that the rise is slow, it is possible to remove the varnish adhered to these without performing the eroding heat process or to remove the varnish from the coil 2.
Of course, complete curing can be achieved even if the energization time is short. In addition, when attaching a curing catalyst to the tape, interphase insulating paper, or insulating tube in advance,
It will be more effective if these are made of nonwoven fabric.

[Effects of the Invention] As described above, the present invention solves the problem of the tendency of the varnish adhering to the binding member or the insulating member to be insufficiently heated in a device that uses the heat generated by the coil to harden the varnish. However, the curing catalyst attached to these in advance can accelerate the curing of the varnish and allow it to be completely cured in a short time, so the insulation and rigidity of the coil can be sufficiently increased by completely curing the entire varnish. This has the excellent effect of shortening processing time and improving productivity.

[Brief explanation of the drawing]

The drawings show one embodiment of the present invention, with FIG. 1 being a flowchart of the process, and FIG. 2 being a side view showing the drip method. In the drawings, 2 is a coil, 3 is a binding string (binding member), and 4 is a dripping nozzle.

Claims (1)

[Claims] 1. In a device in which the varnish is infiltrated into a coil of a rotating electrical machine and the varnish is cured by applying electricity to the coil to generate heat, a curing catalyst is applied in advance to the binding member or insulating member of the coil before the varnish infiltrates. A varnish treatment method for a rotating electric machine, characterized in that the varnish is applied to a rotating electric machine.