JPH07177695A - Structure of stator wedge for high speed electric rotating machine - Google Patents

Abstract

PURPOSE:To reduce siren sound by employing a stator wedge having curves face or flat face exhibiting low resistance in the direction of wind produced through rotation of a rotor. CONSTITUTION:A high speed rotor equipped with a rotor coil, a rotor duct piece, a rotor wedge, etc., is disposed on the inner diametral side. Similarly, a stator coil, a stator duct piece, a stator wedge 1A, etc., are disposed on the outer diametral side of the rotor. The stator wedge 1A is formed of a curved face or a flat face exhibiting low resistance in the direction of the wind produced through high speed rotation of the rotor. The stator wedge 1A has substantially trapezoidal shape at the section being set in a slot of stator core and only the part thereof being set in a stator duct preferably has a curved face or a flat face exhibiting low resistance in the direction of wind. This structure reduces siren sound.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a structure of a stator wedge of a high-speed rotating electric machine such as a 4-pole turbine generator, and particularly reduces the amount of noise such as siren noise generated in a duct. To improve the structure of the stator wedge.

[0002]

2. Description of the Related Art A main structure of a rotating portion of a conventional high speed rotating electric machine is cut in a radial direction and shown in FIG. A rotor 9 is arranged on the inner side in the radial direction, and a stator 5 is arranged on the outer side thereof with a constant air gap 11 therebetween. In the slot of the stator 5, a plurality of stator coils 2 are arranged at regular intervals in the circumferential direction. Reference numeral 1 is a stator wedge. The rotor coil 7 is housed in the slot of the rotor 9 and
The rotor coils 7 are fixed in the slots of the rotor 9 by rotor wedges 6 which are bonded to each other in the radial direction by a varnish or the like. Reference numeral 8 is a rotor duct piece which is provided at a predetermined interval in the axial direction of the iron core of the rotor 9 and is adjacent to each other.
The rotor coils 7 are arranged in the respective intermediate portions with their longitudinal directions oriented in the radial direction, and when the rotor 9 rotates, air is guided to the duct portion for cooling. In the stator 5, the stator coil 2, the stator wedge 1 and the stator duct piece 3 are separated by the air gap 11, and the rotor coil 7, the rotor duct piece 8 and the rotor coil 9 in the rotor 9 are arranged. Arranged substantially symmetrically opposite to the tow wedge 6.

By the way, the cross sectional shapes of the rotor wedge 6 and the stator wedge 1 cut in the radial direction have conventionally been generally trapezoidal or rectangular (not shown) shown in FIG. 6, respectively. FIG. 7 shows a BB 'cross section of FIG. There are two layers of the stator coil 2 on the side of the stator 5, and the stator coil 1 is fixed to the stator 5 by the stator wedge 1 adhered to the radially inner end surface thereof. The core 10 mainly made of soft magnetic iron is arranged further to the center side than the stator wedge 1 except for the duct portion 4. The rotating part of the conventional high-speed rotating electric machine is configured as described above. By the way, recently, from the viewpoint of noise pollution, noise reduction is required for the operation of the high-speed rotating electric machine. According to the noise analysis result of the generator, the main noises generated are the magnetic noise and the duct noise, which are about the same in magnitude. Therefore, in the conventional one, as a measure for reducing noise, these noises generated in the above configuration are separately installed with soundproofing means such as sound insulation, sound absorption, or vibration damping structure of outer panel of generator. The amount of noise generated is reduced, that is, the sound generated once is secondarily reduced to prevent the noise.

[0004]

However, in any case, the conventional soundproofing means described above have a problem that they require a great amount of money including material costs and construction costs, but are still insufficient. . It is an object of the present invention to provide a structure of a stator wedge of a high speed rotating electric machine which solves the above problems (problems) of the conventional one.

[0005]

In order to solve the above-mentioned problems, the structure of the stator wedge of the high-speed rotating electric machine of the present invention comprises a rotor coil, a rotor duct piece, a rotor wedge, etc. on the inner diameter side. In a high-speed rotating electric machine comprising a rotor and a stator having a stator coil, a stator duct piece and a stator wedge on the outer diameter side, the shape of the stator wedge is a semi-elliptical shape or the like. It is configured to have a curved surface portion or a flat surface portion having a low resistance against the direction of the wind generated by the rotation of the rotor. In this case, the stator wedge has a substantially trapezoidal shape in a section of the stator core which is mounted in the slot, and only the portion arranged in the stator duct is rotated by the rotation of the semi-elliptical rotor. It is desirable to form a shape having a curved surface portion or a flat surface portion having a low resistance against the direction of the generated wind. Further, instead of this, the stator wedge is formed to have a cross-sectional shape over the entire length in the axial direction, such as a semi-elliptical shape, which has a curved surface portion or a flat surface portion having a small resistance to the wind direction. It may be done.

[0006]

In the present invention, the shape of the stator wedge is formed so as to have a curved surface portion or a flat surface portion having a small resistance to the direction of the wind generated by the rotation of the rotor, such as a semi-elliptical shape. The amount of noise generated was reduced. In this case, only the part of the stator duct piece of the stator wedge is
With the above-mentioned shape, the air gap size of the duct part is slightly increased, but the other air gap sizes are not changed, so that the noise generation amount can be reduced without lowering the power generation efficiency. Also, if the above shape is used over the entire axial length of the stator wedge, the amount of noise generated is reduced, and
The man-hours for processing the stator wedge are greatly reduced.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS First, the principle of the present invention will be described before explaining the specific means for reducing noise of the present invention. In the present invention, the following consideration was made on the point of reducing the noise itself generated in order to reduce noise. That is, the conventional knowledge about the duct sound is as follows. Low
When the rotor 9 rotates inside the stator 5 in the radial direction at high speed, the rotor duct piece 8 passes inside the stator wedge 1 in the radial direction at high speed. The duct sound refers to a siren sound generated at this time by cutting the wind at the portions of the stator wedge 1 and the rotor duct piece 8.

The following two factors are generally considered as factors that generate or change the loudness of this duct sound (siren sound). The first factor is the peripheral velocity of the outer diameter portion of the rotating rotor 9, and the smaller the peripheral velocity, the smaller the loudness of the duct sound. However, reducing the peripheral speed of the rotor to reduce the duct noise reduces the amount of power generation, so this means cannot be said to be effective for a practical generator. The second factor is the distance between the rotor 9 and the stator 5, that is, the width of the air gap 11, and the duct noise can be reduced by increasing the width of the air gap 11. However, increasing the width of the air gap 11 reduces the magnetic gap (reduces the magnetic flux density in the magnetic field portion), and it is clear that this means also lowers the power generation efficiency and is not practical. The frequency of the duct sound generated in such a rotating machine is derived by the following equation (1). f = (N × Z) / 60 (1) However, N: Rotational speed (rpm) of the rotor Z: Number of rotor ducts In the present invention, in order to provide a basic noise countermeasure,
As a result of various analyzes focusing on the duct sound,
By improving the shape of the tawedge 1, at the same time, the air gap size of the duct part is substantially increased to reduce the amount of noise generated without lowering the power generation efficiency. Will be described. Regarding the same configuration as the conventional one, the reference numerals in FIGS. 6 and 7 are used as they are in the description of each embodiment of the present invention.

Embodiment 1: A station which is Embodiment 1 of the present invention
Figure 1 (A), (B) and (C) shows the shape of the tow wedge 1A.
Shown in. FIG. 1 (A) shows an example in which the shape of only the portion arranged in the stator duct portion 4 is improved so that its radial cross section is semi-elliptical. It has a substantially trapezoidal shape. FIG. 2B shows this cross-sectional relationship so that it can be compared. The broken line shows a semi-elliptical cross section of the stator wedge 1A arranged in the stator duct section 4. Further, the solid line shows the cross section of the stator wedge 1A in the other portions, which is substantially trapezoidal. It should be noted that FIG. 7C is a modification showing that such an outer shape is included in the substantially trapezoidal shape. In order to increase the magnetic gap, the stator wedge 1A is made of (normal or strong) magnetic material or magnet material, and the portion arranged in the stator duct portion 4 has a smaller cross-sectional shape to make the surface smoother. Therefore, the radial cross section is semi-elliptical as described above, but the other parts do not impair the power generation or rotation efficiency, that is, the magnetic flux generated in the air gap 11. In order not to disturb the, it has a generally trapezoidal shape as in the past. FIG. 2A shows the first embodiment.
In this case, as the shape of the stator wedge 1B, the cross-sectional shape of the stator duct portion is
Similar to the conventional one, the external shape is slightly modified while maintaining a substantially trapezoidal shape. Specifically, the width of the upper bottom is
It is formed in a modified trapezoid having a flat portion that becomes smaller than the conventional one. In the case of this embodiment,
Only the portion of the tawedge stator duct piece is responsive to the direction of the wind generated by the rotation of the rotor, such as a semi-elliptical shape.
Since it is formed so as to have a flat portion with low resistance, the amount of noise generated can be reduced. 1 and 2
In the first embodiment shown in FIG. 3, the radial cross-sections of the stator wedges 1A and 1B arranged in the stator duct section are semi-ellipse and modified trapezoid, respectively, but the invention is not limited to this shape. For example, a trapezoidal shape may be provided with an arm on each ridge, in short, a shape having a curved surface portion or a flat surface portion having a small resistance to the direction of the wind generated by the rotation of the rotor. Good.

Embodiment 2: A station which is Embodiment 2 of the present invention.
The shapes of the tow wedges 1C and 1D are shown in FIGS. 3 (A) and 3 (B). Since the material used for the stator wedge is magnetic or magnet material, the machining of the stator wedges 1A and 1B having the shape shown in the first embodiment is partially lacking in machining efficiency because the sectional shape is partially changed. In this embodiment,
It is intended to improve this processing problem. That is, in the present embodiment, the shape of the portion arranged in the stator duct portion 4 in Embodiment 1 is continuous over the entire length of the stator wedge, and the one shown in FIG. The case of forming a semi-elliptical shape, and the case of FIG. 6B shows the case of forming a modified trapezoidal sectional shape as shown in the drawing. Also in this case, as described in the first embodiment, the radial cross-sections of the stator wedges 1C and 1D may be other cross-sections, in short, with respect to the direction of the wind generated by the rotation of the rotor. It may be formed in a cross section having a curved surface portion or a flat surface portion having a low resistance. In the case of the present embodiment, the power generation efficiency is slightly lowered, but it is excellent in that the amount of noise generated can be reduced and the man-hours for processing the stator wedge can be greatly reduced.

FIG. 4 is a partial axial sectional view of a stator portion of a high speed rotating electric machine to which the present invention is applied. As the stator wedge of the present invention, the stator wedge 1A of the first embodiment is used. Indicate the case. The portion of the stator wedge 1A located in the stator duct portion 4 has a small cross-sectional shape, and is therefore shown as being cut outward in the radial direction. FIG. 5 is a sectional view taken along the line AA 'of FIG.
The state where the stator wedge 1A according to the present invention is incorporated inside the stator coil 2 in the radial direction is shown.

[0012]

Since the stator wedge according to the present invention is constructed as described above, it has the following excellent effects. The smooth radial cross-section reduces siren noise (duct noise) and substantially increases the air gap in the stator duct without sacrificing power generation efficiency. be able to. According to the experiment, it is confirmed that the maximum siren sound (duct sound) of about 5 dB is reduced at the generation source as compared with the conventional high-speed rotating electric machine using the stator wedge. In the case of the configuration of the second embodiment, the power generation efficiency is slightly reduced, but the processing man-hours can be greatly reduced, and the noise generation amount can be reduced.

[Brief description of drawings]

1A and 1B show a configuration of a stator wedge according to a first embodiment of the present invention, in which FIG. 1A is a partial perspective view, FIG. FIG. 6C is an explanatory diagram showing a modified example.

2A and 2B show a structure of a stator wedge which is a modified example of the first embodiment of the present invention. FIG. 2A is a partial perspective view, and FIG. It is a figure.

3A and 3B show a structure of a stator wedge according to a second embodiment of the present invention. FIG. 3A is a partial perspective view of the example, and FIG. 3B is a partial perspective view of another example. is there.

FIG. 4 is a partial cross-sectional view of a stator portion of a high-speed rotating electric machine using the stator wedge according to the first embodiment of the present invention.

5 is a cross-sectional view taken along the line AA ′ of FIG.

FIG. 6 is a partial cross-sectional view of a high-speed rotating electric machine using a conventional type stator wedge.

7 is a sectional view taken along the line BB ′ of FIG.

[Explanation of symbols]

 1A-1D: Starter wedge

Claims (3)

[Claims] 1. A rotor equipped with a rotor coil, a rotor duct piece, a rotor wedge, etc. on the inner diameter side, and a stator coil, a stator duct piece, a stator wedge, etc., on the outer diameter side. In a high-speed rotating electric machine including a stator, the shape of the stator wedge is a semi-elliptical shape or the like.
A structure of a stator wedge of a high-speed rotating electric machine, characterized in that it is formed into a shape having a curved surface portion or a flat surface portion having a low resistance against the direction of the wind generated by the rotation of the rotor. 2. A wind generated by rotation of a rotor having a semi-elliptical shape only in a portion arranged in a stator duct, wherein the stator wedge has a substantially trapezoidal shape in a section attached to a slot of the stator core. The structure of the stator wedge of the high-speed rotating electric machine is formed in a shape having a curved surface portion or a flat surface portion having a low resistance with respect to the direction of. 3. The stator wedge has a cross-sectional shape over the entire length in the axial direction, such as a semi-elliptical shape, which has a curved surface portion or a flat surface having a small resistance to the wind direction generated by the rotation of the rotor. A structure of a stator wedge of a high-speed rotating electric machine formed to have a shape having a portion.