JPH08205443A - Method for jointing liquid-cooled winding in electric rotating machine - Google Patents

Abstract

PURPOSE: To joint the liquid-cooled winding of an electric rotating machine while prolonging the lifetime by preventing leakage of the liquid. CONSTITUTION: A liquid-cooled winding is jointed by fitting the end parts 2B of a hollow strand in the openings 12C, 12D made at least in two side faces of a supply/discharge box, placing a brazing material between the end parts of respective hollow strands, and then pressing cover bodies 14A, 14B applied at least to two openings from two directions under the state where the brazing material is fused thermally, thereby purging the air in the brazing material into the space of a hollow conductor strand 2A in the longitudinal direction thereof. With such structure, void is minimized and short circuit of the hollow winding due to leakage in the vicinity of the supply/discharge box is prevented thus prolonging the lifetime of electric rotating machine significantly as compared with a conventional one.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an improvement in a method for manufacturing a liquid-cooled winding connecting portion used in, for example, a liquid-cooled rotary electric machine.

[0002]

2. Description of the Related Art In rotating electric machines, such as turbine generators and water turbine generators, indirect cooling by cooling from above the conductor insulation of windings has reached its limit with the increase in capacity, and recently conductors have become hollow. The conductor is directly cooled by circulating a cooling medium such as water or oil in the hollow portion.
An electrical connection and a supply / exhaust box for supplying or discharging a cooling medium are connected to the hollow conductor at the end of the hollow winding to branch the flow of electricity and current. Due to workability, this supply / discharge box is generally provided at the end of the hollow winding protruding from the stator core.

FIG. 4 is a sectional view showing a main part of a stator of a rotating electric machine having a stator frame 5 surrounding the stator core 1, the upper and lower hollow windings 2 and 3. Thin iron plates are stacked on the stator core 1, end plates 6 are applied to both ends thereof, the whole is integrated by bolts 7, and the stator core 5 is supported in the stator frame 5 via key means 17. A winding groove 8 extending in the axial direction is provided on the inner peripheral side of the stator core 1, and upper and lower hollow windings 2 and 3 are housed in the winding groove 8 with part of them protruding. . The upper and lower hollow windings 2 and 3 are composed of an upper hollow winding 2 and a lower hollow winding 3, which are formed by arranging a plurality of insulated hollow conductor wires 2A. 2 and the lower hollow winding 3 are stacked and housed in the winding groove 8, and the wedge 9
It is fixed to the stator core 1 by. The means for supporting the winding other than the winding groove 8 may be, for example, a through hole. A hollow winding end portion extending from the end of the stator core, for example, 2B, is fixed to a supply / discharge box 12 made of a conductive material by a brazing material 13.

The supply / discharge box 12 is electrically coupled by a connecting piece 10 connecting the upper and lower hollow windings 2 and 3 to form one turn, and is composed of a pump, a cooler and the like. A flow pipe 4 is provided which is connected to a device (not shown) for supplying and discharging the cooling medium. The circulation pipe 4 circulates the cooling medium in the direction of the arrow. It is needless to say that the joint between the supply / discharge box 12 and the end portion 2B of the hollow winding 2 is required to be solid so as not to leak electrically and fluidly. That is to prevent a slight leakage of the cooling medium.

As is well known, for example, once a turbine generator or the like is put into operation, the next periodic inspection will be several years later, and it will continue to be operated during that period. Therefore, if a slight leakage or bleeding of the cooling medium occurs, the electrical insulation is adversely affected, and eventually a major accident such as a short circuit occurs.

As described above, in forming the cooling passage in the machine, it is necessary to give careful consideration to leakage. At the same time, this kind of winding is required to have very high reliability so as not to cause a short circuit accident.

Therefore, the inventor of the present invention uses the feeding / discharging box 12 of FIG.
So I did the next experiment. That is, as shown in FIG. 5, the hollow winding end 2B and the feeding / discharging box 12 are joined by fitting the hollow winding end 2B into the feeding / discharging box 12 into the opening 15 of the feeding / discharging box 12, and then the lid 14 is inserted. Then, the whole is heated to melt and join the brazing filler metal 13 that has been previously sandwiched between the rows of the hollow conductor wires. At this time, brazing is provided from the outside between the feeding / discharging box 12, the lid 14, the hollow winding end portion 2B, the feeding / discharging box 12, and the hollow conductor wire. As a cooling winding for a rotating electric machine, there is JP-A-55-2322.

[0008]

In the above joining method, when the hollow winding end portion 2B and the supply / discharge box 12 are brazed, the pressure is applied only from the row direction, and therefore the scissors are inserted between the rows of the hollow conductor wires. Since the brazing filler metal 13 that has penetrated penetrates only in the column direction and does not sufficiently penetrate into the step direction between the hollow conductor wires, the voids 16 shown in FIG. 6 easily occur between the hollow conductor wire steps. The void 16 may cause a leakage failure due to vibration and thermal expansion and contraction due to the operation of the device.

It is an object of the present invention to provide a method of manufacturing a liquid cooling winding connection part which prevents the occurrence of leakage failure and extends the life of the rotating electric machine.

[0010]

In order to solve the above-mentioned problems, a method of manufacturing a liquid cooling winding connecting portion of the present invention is such that a hollow winding is formed in an opening formed on at least two side surfaces of a supply / discharge box. While fitting the wire ends, a brazing material is interposed at each hollow winding winding end, and the brazing material is heated and melted to apply pressure to the lid body covering at least two openings from two directions. , To cover the opening with a lid.

[0011]

As a result, it is possible to pressurize the lid for closing the opening provided in the supply / discharge box from two directions by surrounding the hollow windings, for example, in two directions of rows and columns, for example, upper, lower and left, right directions. As a result, uniform pressure is applied, and the air in the brazing material is pushed out into the space in the longitudinal direction of the hollow conductor wire, so that the occurrence of voids is reduced and leakage near the supply / discharge box is reduced. It becomes possible to prevent a short circuit accident between the hollow windings, and the life of the rotary electric machine becomes longer than that of the conventional rotary electric machine.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below with reference to FIG.

In FIG. 1, the supply / discharge box 12 is provided at both ends of the upper and lower hollow windings 2 and 3, but the supply / discharge box 12 and the upper hollow winding 2 are provided at one end of the upper hollow winding 2. The case of brazing will be described with an exploded perspective view.

A plurality of connecting pieces 10 and a flow pipe 4 are attached to the back side of the supply / discharge box 12. Supply and discharge box 1 on the side opposite to the distribution pipe 4
The housing 2 is provided with a housing 12A for housing the upper hollow winding 2. A peripheral portion 12B formed around the accommodation portion 12A forms right cutout openings 12C and 12D which are cut out on the upper and right side surfaces.

The upper hollow winding 2 housed in the housing portion 12A is composed of a plurality of hollow conductor wires 2A. Housing 12
When the hollow winding ends 2B in which the brazing filler metal 13 is previously sandwiched between the hollow conductor strands are stored in A, the upper and right cutout openings 1 are formed.
2C and 12D are covered with lids 14A and 14B.

By heating the supply / discharge box 12 in this state, the hollow winding end portion 2B is pressed while pressing the two lids 14A and 14B electrically and without leakage, for example, by placing or inserting the solder. Supply / discharge box 12 and lids 14A, 14B
Are joined together.

During this operation, the lids 14A and 14B are pressed from the outside when the brazing material 13 is melted at a specified temperature.
The pressure applied by the lids 14A and 14B is applied between the hollow conductor wires or between the hollow conductor wires 2A and the supply / discharge box 12 or the lids 14A,
Since the brazing filler metal 13 is corrected to a size suitable for the flow in the gap between the portions 14B, it is possible to evenly secure the brazing flow between them.

That is, with the brazing material 13 melted, the lid 1
Pressurizing 4A and 14B from the two outer directions means, for example, uniform pressing in rows and steps between the periphery of the supply / discharge box 12 and each hollow conductor element wire 3A (pressurizing force in the direction of the arrow in FIG. 3). Since the air inside the brazing filler metal 13 is pushed out into the space in the longitudinal direction of the hollow conductor wire 2A, the occurrence of voids 16 is reduced, and the leakage in the vicinity of the supply / discharge box is reduced. The short circuit accident between the hollow windings due to is eliminated, and the life of the rotating electric machine is significantly extended as compared with that of the conventional rotating electric machine.

Further, the reduction of the generation of the voids 16 means that the mechanical strength can be improved because, for example, the periphery of the supply / discharge box 12 and each hollow conductor element wire 2A are connected by a uniform brazing material layer. 5, it is possible to prevent the supply / discharge box 12 and the hollow winding end 2B from coming off or being damaged.

On the other hand, it was confirmed by experiments that the brazing flow can be further controlled by providing a time difference between the timings of pressurizing the respective lids 14A and 14B.
That is, when the brazing filler metal 13 sandwiched between the hollow conductor wires is melted, first, the lid body 14A installed in the column direction of the hollow conductor wire 2A is pressurized, and after a little delay, the lid body 14B in the step direction is pressed. By pressurizing, the force that pushes out the air pools existing between the steps of the hollow conductor wire 2A in the longitudinal direction of the hollow conductor wire is generated, so that the generation of the void 16 can be reduced.

Further, the supply / discharge box 12 and the hollow winding end portion 2B
With the joining method of No. 1, the generation of voids 16 can be reduced,
When these are brazed, pressure is applied from two directions, row and step, so the brazing filler metal 13 sandwiched in the row direction between the strands flows in the longitudinal direction and flows out to the end face of the hollow winding end, There is a risk that the hole of the conductor wire 2A may be blocked. Moreover, since the hollow winding end 2B and the inside of the supply / discharge box 12 are opened, it is difficult to confirm the brazing of the hole of the hollow conductor wire 2A during the brazing operation.

As a method of preventing this, there is a method of chamfering the end face of the hollow conductor wire 2A as shown in FIG. That is, the hollow winding end portion 2C of the hollow conductor element wire 2A has a circumference diameter L of the end portion 2C that is larger than the circumference diameter L1 of the hollow conductor element wire 2A.
An inclined surface 2D in which 2 is successively reduced is formed.

Using this configuration, as shown in FIG.
Even if the brazing material flows out, the brazing material 13 accumulates in the hollow winding end portion 2C, so that the hollow conductor element wire 2A can be prevented from being clogged by the brazing material 13.

As described above, according to this embodiment, it is possible to reduce the occurrence of voids and prevent the hollow winding from being clogged with the brazing material, so that it is possible to prevent the heating of the hollow winding from occurring. It has become possible to obtain a liquid-cooled hollow winding with low reliability.

[0025]

As described above, according to the method of joining the feed / discharge box and the end of the hollow winding of the present invention, the occurrence of voids can be reduced, and the hollow windings are insulated from each other by insulation deterioration. Since the short circuit can be prevented, the life of the rotating electric machine can be significantly extended as compared with the conventional one.

[Brief description of drawings]

FIG. 1 is an exploded perspective view illustrating a case where a hollow winding end portion used in a stator core of a rotating electric machine according to the present invention is connected to a supply / discharge box.

FIG. 2 is a perspective view of a hollow winding end portion shown as another embodiment of the present invention.

3 is a vertical cross-sectional view of the end of the hollow winding of FIG.

FIG. 4 is a vertical cross-sectional view showing a connection of hollow winding end portions used in a stator core of a conventional rotating electric machine.

FIG. 5 is an exploded perspective view showing the connection relationship between the hollow winding end portion and the supply / discharge box used by the present inventor in the experiment.

FIG. 6 is a side cross-sectional view in which a part of the hollow conductor wire of FIG. 5 is enlarged and cross-sectioned.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Stator core, 2 ... Upper hollow winding, 2A ... Hollow conductor element wire, 2B ... Hollow winding end part, 3 ... Lower hollow winding, 4 ... Flow pipe, 5 ... Stator frame, 6 ... End Plate, 7 ... Bolt, 8 ... Winding groove, 9 ... Wedge, 10 ... Connection piece, 12 ... Supply / discharge box, 12A ... Housing section, 12C, 12D ... Opening section, 13 ... Brazing material, 14,
14A, 14B ... Lid, 15 ... Opening, 16 ... Void,
17 ... key.

Claims (3)

[Claims] 1. At least two supporting means for supporting a hollow winding provided on the inner diameter side of a stator core of a rotating electric machine, and a plurality of hollow conductor wires through which a cooling medium can flow, which are arranged on said supporting means. Between the hollow winding and the feeding / discharging box for supplying and discharging the cooling medium to / from the hollow winding in which the ends of the hollow winding are fitted and the ends of the hollow winding are fixed by brazing. And a connecting piece for flowing an electric current between the hollow windings, wherein a hollow winding end is provided in an opening formed on at least two side surfaces of the supply / discharge box. While fitting the parts, brazing filler metal is interposed between the hollow winding end portions, and they are heated to melt the brazing filler metal and press the lids that cover at least two openings from two directions. A method for manufacturing a liquid-cooled winding connecting portion of a rotating electric machine, characterized in that the opening is closed with a lid. 2. A plurality of hollow winding end portions are fitted into the opening of the supply / discharge box, and when the brazing material is melted, at least two lids are used to apply pressure while staggering each time,
The method for manufacturing a liquid-cooled winding connecting portion of a rotating electric machine according to claim 1, wherein the method is performed by brazing. 3. The liquid for a rotary electric machine according to claim 1, wherein an inclined surface having a peripheral diameter smaller than that of the end of the hollow winding is formed at the end of the hollow winding through which the cooling medium can flow. Manufacturing method of cold winding connection.