JPS5816020B2 - Water Cooled Rotary Electric Machine Coil - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to improvements in the coils of water-cooled rotating electric machines, and particularly to improvements in the suction and drainage parts of the stator coil end portions of turbine generators.

The capacity of rotating electric machines such as generators is increasing every year, and recently the rotor coil and stator coil are made hollow, that is, cylindrical, and cooled by flowing water through this hollow part. A direct water-cooled power type is adopted.

Therefore, the connection between the coils requires both electrical connection and cooling medium connection at the same time, and the connection body (suction and drainage adapter) provided at the connection part has a complicated shape, and its size has also increased as the capacity increases. It will become yours.

Generally speaking, brazing is often used to connect the connecting body and coil in terms of strength and reliability of the connection, and gas brazing, high-frequency brazing, etc. are used as heating methods. .

This connecting body, i.e., the suction/drainage adapter, is generally manufactured by casting because its structure is complex, i.e., it has a shape with a hollow part because of the connection with the coil and the flow of cooling water inside. is normal.

However, these castings tend to have defects such as bubbles and cracks inside them, are unreliable, and have the disadvantage of being expensive.

Therefore, recently, studies have been conducted on a more reliable and inexpensive forging-based intake/drainage adapter.

When manufacturing a suction/drainage adapter using the forging method, the first problem is how to forge it into a complex shape with a hollow part, and how to shape it, but this can be overcome with some effort. It is.

However, the biggest problem is that when the suction/drainage adapter and the hollow coil, i.e., the end of the hollow conductor, are brazed together, melted brazing material flows into the hollow part of the hollow conductor and causes clogging. Demeru.

To explain the reason for this clogging in a little more detail, in the case of a cast suction/drainage adapter, a hollow conductor is inserted, and the hollow part through which the cooling water flows is made deep (by using a somewhat long shell). can do.

Therefore, in the case of this casting-based suction/drainage adapter, no matter how much melted wax flows out, it will only accumulate to some extent at the bottom of this deep hollow, and the depth of the accumulated molten wax will be reduced. It does not reach the hollow part of the hollow conductor and does not clog, but when using the forging method,
It is difficult to process the deep part of the suction and drainage adapter, resulting in a hollow part with a shallow depth, and the melted wax metal will accumulate at a certain depth in the lower part of the hollow part. , it reaches the hollow part of the hollow conducting wire and causes clogging.

The present invention has been developed with this in mind, and its purpose is to sufficiently prevent clogging of hollow conductive wires due to molten solder during brazing, which is a problem in putting a highly reliable and inexpensive forging method into practical use. It is possible to provide this kind of coil.

That is, in the present invention, a conductive spacer is inserted between the contact surfaces of the lowermost layer of the end portion of the hollow conducting wire inserted into the suction/drainage adapter and the inner wall of the suction/drainage adapter, that is, between the opposing surfaces.

This is also done by recessing the end of the hollow conductive wire by the thickness of the conductive spacer, that is, inserting it with a step.

In this way, the wax melted during brazing will enter between the hollow conductors and between the hollow conductor and the adapter, but the excess wax will collect at the bottom layer of the hollow conductor due to gravity.

In this case, as mentioned above, since there is a step at the lower part of the hollow conductor, this wax accumulates in this step, and wax is prevented from entering the hollow from the end face of the hollow conductor and clogging. It is.

The present invention will be described in detail below based on the illustrated embodiments.

FIG. 1 is a schematic diagram of a stator of a water-cooled turbine generator.

A suction/drainage adapter 2 is used for electrical connection and cooling medium connection between the stake coils 4 and 5.

Electrical connections are made using the suction/drainage adapter and the connecting conductor 3, and cooling medium connections are made using the suction/drainage adapter and the water passage fitting 6.

The second tooth shows the details of this suction/drainage adapter 2.

The suction/drainage adapter 2 is formed by forging, and its interior (
A hollow portion is formed.

The connection between the suction and drainage adapter 2 and the hollow conductor 8 is made by inserting the end of the hollow conductor into the hollow part of the suction and drainage adapter and using brazing material. 3, and a conductive spacer 10 is inserted between the lowermost layer of the hollow conducting wire 8 and the inner wall of the suction/drainage adapter 2.

In this case, the conductive spacer 10 is placed recessed from the end surface of the hollow conducting wire 8 for reasons that will be described later.

Then, in a levered state, the whole is heated, for example, by high frequency to heat the hollow conductor, the suction/drainage adapter 2, and the conductive spacer 10.
It is fixed with solder.

With this configuration, the conductive spacer 10 is disposed between the lowest layer of the hollow conductor 8 and the suction/drainage adapter 2, and is also recessed from the end of the hollow conductor 8. A dam 11 (see Fig. 3) is formed at the bottom of the hollow part, so even if excess molten brazing material flows out during brazing, this brazing material will gather at the dam 11 under its own weight, filling this dam completely and leaving the hollow. It will no longer reach the hollow part of the conducting wire 8, and therefore, even if the suction/discharge adapter is made by forging and has a shallow hollow part, clogging of the hollow conducting wire 8 by molten wax can be sufficiently prevented.

The thickness of the conductive spacer 10 and the size of the recess from the end of the hollow conductor should be determined by predicting the remaining amount of bath-melted brazing material in advance. The diameter of the dent should be about 3 mm, and the size of the dent should be about 10 mm, depending on the soldering area.

Further, as a material for the conductive spacer 10, a copper plate, which has good conductivity, would be suitable.

What is provided as 9 in the drawings in the above implementation sequence is a cover that allows a layer to be formed on one side wall of the suction/drainage adapter 2 before brazing, and when formed in this way, the conductive spacer 10 and suction This is effective because voids are reduced in the brazing material between the drain adapter 2 and between the conductive spacer and the hollow conducting wire 8.

That is, the cover 9 is formed by the wall of the suction/drainage adapter on the opposite side where the conductive plate 10 is arranged, and when the solder material melts, the cover 9 is pressed onto the hollow conductor side.

Then, the wall of the suction/drainage adapter 2 and the conductive spacer 1
0 and the hollow conductive wire 8 is in close contact with it, and there are no voids in the brazing material between them.

In the present invention, as explained above, the conductive spacer is inserted between the hollow conductor and the suction/drainage adapter so as to be recessed from the end face of the hollow conductor, so that a relief part for the solder is formed in this part, and therefore, it is highly reliable and This kind of coil without clogging of the hollow conductor wire can be obtained by using the inexpensive method.

[Brief explanation of drawings]

Fig. 1 is a longitudinal side view showing the bottom of a water-cooled generator stator equipped with the coil of the present invention, Fig. 2 is an enlarged side view showing the inside of the Q frame in Fig. FIG. 4 is a sectional view taken along line AA in the figure, and FIG. 4 is a sectional view taken along line BB in FIG. 2... Suction/drainage adapter, 4, 5...
Coil, 8...Hollow conductor, 10...Suhechi.

Claims (1)

[Scope of Claims] 1. A hollow conductor, and a suction/drainage adapter which is electrically connected to the end of the hollow conductor and also connects a cooling medium, and which is formed by forging. Connection with the hollow conductor. The end of the hollow conductor is inserted into a hollow formed in the suction/drainage adapter, and in a water-cooled rotary electric machine coil formed by brazing material, the inner wall of the suction/drainage adapter and the bottom layer of the hollow conductor are connected to each other. A coil for a water-cooled rotating electric machine, characterized in that a conductive spacer is interposed between the conductors and the spacer is disposed recessed from the end face of the hollow conductor.