JPH10215534A - Manufacturing method of stator coil in rotating electric machine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent the mixture of solder into a refrigerant hole in the end of a hollow conductor of a stator coil, to control the corrosion of gaps and to promote the reliability of soldering between the stator coil in a rotating electric machine and a joint box as well as productivity. SOLUTION: In the soldering of the end of a stator coil, solders 4 and 5 having different melting points are arranged in the longitudinal direction of a conductor. The solder having high melting point is provided to the end side of the hollow conductor, and the solder having low melting point is provided to the next thereto (the opposite end side). After a melted solder adhesion prevention coating material 14 has been applied to the end of the hollow conductor 2, soldering is made by heat-fusion. The mixture of solder into a refrigerant hole of the hollow conductor 2 can be prevented, and problems such as later adjustment or remake after the soldering can be settled.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing a stator coil of a rotating electric machine having a large capacity.

[0002]

2. Description of the Related Art In general, a stator coil unit of a rotating electric machine of a generator or a motor needs to cool the inside of the armature in order to suppress heat generation. In particular, as one of the cooling methods of the stator coil unit of a large-capacity machine, a direct cooling system in which a refrigerant (insulating oil and pure water) is flowed inside a hollow conductor constituting a stator coil is adopted.

The stator coil unit uses at least one hollow conductor having a hole for refrigerant in the longitudinal direction, and comprises a stator coil, a connection box serving also as a refrigerant supply / drainage and electric connection terminal, and a connection hose 10. .

[0004] The stator coil is composed of a straight portion and an end portion, and the straight portion is accommodated in the core of the stator. Junction boxes are installed at both ends of the stator coil, and coolant is supplied and drained into the hollow conductors constituting the stator coils through bases provided in the connection boxes.
Thereby, it is configured to be cooled by the refrigerant from the inside of the stator coil.

On the other hand, connection terminals provided on the connection box are:
It is electrically connected to other stator coils. A connection hose is provided to connect the outside of the electric machine to the refrigerant supply / drainage of the stator coil. Refrigerant such as insulating oil and water is supplied to the connection hose from the outside of the rotating machine, flows in the order of the connection box, the stator coil, the connection box, and the connection hose, and is discharged outside the rotating machine.

[0006] The connection box has three parts, namely, a base for supplying and discharging the refrigerant to and from the inside and outside of the stator coil, a terminal for electrically connecting the outside of the stator coil, and a connection part for connecting the connection box and the stator coil. It is composed of This portion has two sides removed from the junction box to facilitate assembly of the junction box and stator coils. One surface is an outlet for the stator coil, and the other surface is provided for facilitating the assembly of the stator coil.

[0007] The junction box, the conductor bundle of the coil having the hollow conductor and the cover are heated and fused by brazing and joined to form a stator coil of the rotating machine. Prior to the brazing, the base for the supply and discharge of the refrigerant and the connection terminals are brazed to the connection box in advance.

The connection box and the stator coil are connected using a brazing method shown in FIG. First, a single brazing material 13 is placed in the longitudinal direction of the hollow conductor 2. Next, after assembling the stator coil 9 to the connection box 1, the cover 6 is attached.

Then, the stator coil 9 and the connection box 1 are integrated by brazing by heating and fusion. During the heating, pressure is applied to the cover 6. During the heating and fusion, the shortage on the surface of the connection box 1 is replenished by insertion.

[0010]

At the time of the above-mentioned conventional brazing, the brazing fillers arranged in advance in the longitudinal direction of the conductor of the hollow conductor 2 will penetrate the brazing between the conductors when they reach the solidus or higher. Is attached. On the other hand, if the amount of the brazing material that permeates between the conductors is excessively supplied, the wax flows to the end of the hollow conductor 2. In some cases, the brazing material may enter the refrigerant hole 3 at the end of the hollow conductor 2 and block the refrigerant hole 3.

When the stator coil 9 in which the hole 3 is closed in the coolant hole 3 of the hollow conductor 2 is used, the flow of the coolant inside the hollow conductor 2 is obstructed, and the cooling efficiency of the stator coil 9 is reduced. This triggers the stator coil 9 itself to overheat and burn, resulting in shutdown.

For these reasons, it is important to prevent the brazing material from entering the coolant hole 3 of the hollow wire 2. Therefore, after brazing the stator coil 9 and the connection box 1, it is necessary to check whether or not the hollow conductor 2 has penetrated into the coolant hole 3.
As a checking method, there is a visual inspection from a base of the connection box 1. As a result, when brazing has been found to enter the coolant hole 3 of the hollow conductor 2, the brazing portion between the connection box 1 and the stator coil 9 needs to be reworked or remanufactured.

Further, when attention is paid to the same connection box 1, there is a possibility that overheating at the time of brazing in a subsequent process may melt the already brazed portion and cause defects. After the stator coil 9 is housed in the rotating machine core 8, the electrical connection with the other stator coil 9 (connection with the connection terminal 11) and the brazing connection with the connection hose are joined by heat fusion. The brazing portion between the stator coil 9 and the hollow conductor 2 which is the brazing portion that has already been completed includes (1) brazing of a base and a connecting hose, (2) connecting terminal 11 and a connecting terminal 11 of another stator coil 9. Are affected by overheating due to these brazings. When this is overheated, there is a possibility that a defect may be caused by melting of the brazed portion. In order to prevent water leakage from occurring due to this defect, it is necessary to prevent brazing defects at the time of heating in a later step.

[0014]

SUMMARY OF THE INVENTION To achieve the above object, the present invention provides an electric rotating machine stator coil using a hollow conductor having a longitudinal refrigerant hole, which is connected to an external electrical connection and the hollow. In the method of manufacturing a stator coil of a rotating electric machine that connects a connection box for supplying and discharging a refrigerant to the inside of a conductor, brazing materials having different melting points are arranged in the longitudinal direction of the hollow conductor,
Further, a brazing material having a high melting point is arranged on the end side of the hollow conductor, and the hollow conductor and the connection box are brazed.

That is, brazing materials having different melting points are arranged in the longitudinal direction of the conductor at the end of the stator coil. Specifically, a brazing filler metal having a high melting point is used near the end of the stator coil, and a brazing filler metal having a low melting point is used next to the end (the opposite end side). Suitably, the temperature difference between the brazing materials having different melting points is about 30 ° C. or more.

Further, it is desirable to apply a coating material for preventing the adhesion of the molten solder to the end face of the hollow conductor before the heat fusion.

The melting point includes a solid point at which the solid becomes a liquid and a liquid point at which the liquid completely becomes a liquid. In the present invention, any of them may be used.

At the time of brazing, the brazing solder placed in the longitudinal direction of the hollow conductor beforehand reaches the melting point or higher, and the brazing penetrates between the conductors and is brazed. On the other hand, if the amount of the brazing material that permeates between the conductors is excessively supplied, the wax flows to the end of the hollow conductor 2.

In some cases, the brazing material may enter the coolant hole 3 at the end of the hollow conductor 2 and block the coolant hole 3. The brazing material arranged in the longitudinal direction of the conductor at the end of the stator coil 9 prevents the flow of the brazing material to the end of the hollow conductor 2 by arranging a brazing material having a high melting point at the end of the hollow conductor.

Even if the excess brazing material flows out to the end face of the hollow conductor 2, the coating material 14 on the end face of the hollow conductor 2 prevents the brazing from entering the coolant hole 3. Eventually, the wax that has been prevented from infiltrating accumulates in a groove 7 provided on the lower side near the end face of the hollow conductor 2. This contributes to preventing the brazing material from entering the coolant hole 3 of the hollow conductor 2.

The brazing by the brazing material arrangement as described above not only prevents the cooling hole 3 of the hollow conductor 2 from being closed, but also makes it difficult for the brazing at the end of the hollow conductor 2 to flow. The occurrence of defects is reduced, and it is also effective in suppressing crevice corrosion.

[0022]

FIG. 1, FIG. 2, FIG. 3, and FIG. 4 are views for explaining an embodiment of the present invention. An armature stator coil unit of a generator or a motor suppresses heat generation accompanying power generation. Therefore, it is necessary to cool the inside of the armature. In particular, as one of the cooling methods of the stator coil unit of the large-capacity machine, a direct cooling method in which a refrigerant (insulating oil and pure water) is flowed inside the hollow conductor 2 constituting the stator coil is adopted.

The stator coil unit comprises a stator coil 9 using at least one hollow conductor 2 having a coolant hole 3 in a longitudinal direction, a refrigerant supply / drainage connection hose 10, and a connection terminal 11 for electrical connection. It consists of a connection box 1 for connecting to a coil 9.

The stator coil 9 includes a straight portion 91 and an end portion 92. The straight portion 91 is housed in the core 8 of the armature stator. The connection box 1 is provided at end portions 92 at both ends of the stator coil 9. Connection box 1
The coolant is supplied and drained into the hollow conductor 2 constituting the stator coil 9 through the base 12 provided in the stator coil 9.

Thus, the inside of the stator coil 9 is cooled by the refrigerant. On the other hand, the connection terminal 11 provided on the connection box 1 is electrically connected to another stator coil 9. A connection hose 10 is provided for connecting the outside of the electric machine to the refrigerant supply / drainage of the stator coil 9. Refrigerant such as insulating oil or water is supplied to the connection hose 10 from the outside of the rotating machine, flows in the order of the connection box 1, the stator coil 9, the connection box 1, and the connection hose 10, and is discharged outside the rotating machine. Has become.

The connection box 1 has three parts, namely, a base 12 for supplying and discharging the refrigerant to and from the inside and outside of the stator coil 9,
Connection terminal 11 for making an electrical connection with the outside of stator coil 9
And a connection portion between the connection box 1 and the stator coil 9. In this part, two surfaces of the connection box 1 are deleted to facilitate the assembly of the connection box 1 and the stator coil 9. One surface is an outlet for the stator coil 9 and the other surface is provided for facilitating the assembly of the stator coil 9.

The junction box 1 and the conductor bundle of the stator coil 9 having the hollow conductor 2 and the cover 6 are heated and fused by brazing and joined to form the stator coil 9 of the rotating machine. Prior to the brazing, the coolant supply / drain base 12 must be set in advance.
And the connection terminal 11 are connected to the connection box 1 by brazing.

In the present invention, the brazing method is performed in the following order. First, a brazing material having a different melting point is applied to each of the vertical layers at the end of the stator having at least one or more hollow conductors 2 in the longitudinal direction of the hollow conductor 2.
Place more than one. Specifically, the brazing material 4 and the brazing material 5 are used from a portion near the end face of the hollow conductor 2.

The brazing material 4 is JIS standard BCuP-1 or a brazing material corresponding thereto. This brazing material 4 contains 4.8 to 5.3% by weight of phosphorus and the balance of copper, and has a melting point (solidus point) of about 705 ° C and a melting point (liquidus point) of about 900 ° C.

The brazing material 5 is JIS standard BCuP-5 or a brazing material corresponding thereto. This brazing material 5 contains 4.8 to 5.3% by weight of phosphorus and 14.5 to 15% by weight of silver.
5% by weight, balance being copper, melting point (solid point) about 643
℃, melting point (liquidus point) is about 815 ℃. However, the brazing material 4 is suitably a brazing material whose melting point is higher than that of the brazing material 5 by about 30 ° C. or more.

After the brazing material is arranged, it is fused by heating and brazing. The combination of the brazing materials having different melting points as described above makes it possible to prevent the brazing material from penetrating into the coolant holes 3 at the end surfaces of the hollow conductor 2. Even if excess wax flows into the coolant hole 3 of the hollow conductor 2, the excess wax accumulates in the groove 7 near the end face of the hollow conductor 2.

After the above-mentioned brazing is completed,
It is further brazed. After the stator coil 9 is housed in the generator core 8, the electrical connection with the other stator coil 9 (connection with the connection terminal 11) and the brazing connection with the connection hose 10 are joined by brazing. . By this heat fusion brazing, the stator coils 9 and 1 which have been already brazed are
The brazing portion of the hollow wire 2 composed of at least
(2) Overheating due to the heat fusion brazing of the connection terminal 11 and the connection terminal 11 of the other stator coil 9 with the heat fusion brazing of the connection hose 10. The brazing material used for brazing the base 12, the connection hose 10, and the electrical connection terminal 11 is the brazing material 4 used for the hollow conductor 2 and the connection box 1.
(BCuP-1 according to JIS standard or a brazing material equivalent thereto) is used. As a result, brazing defects are less likely to occur in the brazed portion. This is a method for preventing a brazing defect due to overheating of the stator coil 9 and the connection box 1.

A coating material 14 is applied to the end of the hollow conductor 2 to prevent the brazing material from entering the coolant hole 3. Before brazing, a coating material 14, for example, magnesium hydroxide, is applied to each conductor end. At the time of heat fusion, the brazing filler metal having a high liquidus point and the brazing filler metal having a low liquidus point penetrate between the conductors, and these excess brazes flow into the coolant holes 3 of the hollow conductor 2. However, the coating material 14 applied to the end of the hollow conductor 2 in advance makes it possible to prevent the brazing material from entering the coolant hole 3 on the end surface of the hollow conductor 2.

This can prevent the hole from being blocked by the infiltration of the brazing material into the coolant hole 3 of the hollow conductor 2 not only when the solder is placed but also when the excessive solder flows out due to the insertion. The excess braze has a structure that accumulates in a groove 7 at a lower portion near the end surface of the hollow conductor 2.

After the brazing is completed, the coating material 14 is removed from the viewpoint of preventing corrosion progress at the brazing portion between the generator stator coil 9 and the connection box 1. This is performed after the brazing of the connection boxes 1 at both ends of the stator coil 9 is completed. Using the bases 12 of the connection boxes 1 on both sides, washing water is sufficiently injected from the base 12 of one connection box 1 and drained from the base 12 of the other connection box 1. After the completion, to confirm that the coating material 14 has been removed, a visual check is performed from the base 12 of the connection box 1.

This makes it possible to manufacture the rotating electric machine stator coil 9 for preventing the hole 3 for the refrigerant from being blocked in the hollow conductor 2.

[0037]

According to the present invention, during the brazing of the hollow conductor 2 of the stator coil 9 and the junction box 1, the hollow conductor 2
It is possible to effectively prevent the infiltration of the solder into the coolant holes 3. The problem of reworking or remanufacturing after brazing is solved. In addition, even when brazing the junction box 1 by heating and fusion after this brazing, it is effective to prevent the occurrence of defects in the already brazed portion due to overheating.

Thus, the stator coil 9 and the connection box 1
Thus, it is possible to prevent corrosion from progressing by preventing the occurrence of defects in the brazed portion, to improve brazing reliability, and to improve productivity.

[Brief description of the drawings]

FIG. 1 is a work state diagram when brazing a stator coil and a connection box shown for explaining the method of the present invention.

FIG. 2 is a schematic view showing a structure of a stator coil of a large-capacity generator.

FIG. 3 is a perspective view showing a state after brazing of a stator coil and a connection box;

FIG. 4 is a work state diagram for explaining a conventional stator coil manufacturing method when brazing a stator coil and a connection box;

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Connection box, 2 ... Hollow conductor, 3 ... Refrigerant hole, 4 ... Brazing material, 5 ... Brazing material, 6 ... Cover, 7 ... Groove, 8 ... Core, 9 ...
Stator coil, 10 connection hose, 11 connection terminal, 1
2 ... base, 13 ... brazing material, 14 ... coating material.

 ────────────────────────────────────────────────── ─── Continuing on the front page (72) Inventor, Masahiko Sakamoto 7-1-1, Omika-cho, Hitachi City, Ibaraki Prefecture Within Hitachi Research Laboratory, Hitachi, Ltd.

Claims (6)

[Claims] 1. A connection box for electrical connection to the outside and for supplying / discharging a coolant to / from the inside of the hollow conductor is connected to an end of a stator coil of a rotary electric machine using a hollow conductor having a longitudinal coolant hole. In a method for manufacturing a stator coil of a rotating electric machine,
A brazing material having a different melting point is arranged in the longitudinal direction of the hollow conductor, and a brazing material having a higher melting point is arranged on an end side of the hollow conductor to braze the hollow conductor and the connection box. A method for manufacturing a stator coil of a rotating electric machine. 2. The temperature difference between the high melting point brazing material and the low melting point brazing material according to claim 1,
A method for manufacturing a stator coil of a rotating electric machine at 0 ° C. or higher. 3. The stator coil according to claim 1, wherein the high melting point brazing material has a melting point of 850 ° C. to 1000 ° C., and the low melting point brazing material has a melting point of 640 ° C. to 900 ° C. Production method. 4. The method according to claim 1, wherein the brazing material comprises phosphorus (P) and copper (Cu) as main components, and other elements are added as necessary. Method. 5. The brazing filler metal having a high melting point according to claim 1, wherein phosphorus (P) is 0.5 to 5% by weight, and the balance is copper (Cu).
Silver (Ag) is added if necessary, and the composition of the lower brazing material is 4.5-6% by weight of phosphorus and the balance of copper, and silver (Ag) Of manufacturing a stator coil of a rotating electric machine to which is added. 6. The method for manufacturing a stator coil of a rotating electric machine according to claim 1, wherein a coating material for preventing adhesion of a molten solder is applied to an end of the hollow conductor.