JP3270575B2 - Guide vane sealing device - Google Patents

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 guide vane sealing device used in a hydraulic machine such as a water turbine or a pump turbine.

[0002]

2. Description of the Related Art A hydraulic machine such as a water wheel or a pump wheel is provided with a guide vane for adjusting a water amount. As shown in FIG. 2, the guide vane is disposed at the end of the water channel 4 on the side of the water turbine runner 3, and is formed so that both upper and lower sides thereof are pivotally supported and can rotate.

That is, at the upper and lower ends of the guide vane 1,
The upper and lower shafts 1a and 1b are provided, and these shafts are formed so as to rotate while being supported by bushes 5a and 6a. The bushes 5a, 6a are supported by upper and lower covers 5, 6 which are water channel walls.

At the bottom of the guide vane 1, that is, at the base of the guide vane 1 and the shaft 1b, as shown in an enlarged manner in FIG. A stepped shaft portion 1c is provided for avoidance and for receiving the thrust of the guide vane.

The upper shaft 1a penetrates through the upper cover 5 and is connected to an external guide vane operating device (not shown), and the lower shaft 1b may be included inside the lower cover. However, it is generally open to the outside in many cases.

When the lower shaft 1b is open to the outside, the pressure difference between the inside of the pump turbine (the water passage 4) and the outside causes
Guide vane end face, ie, stepped shaft portion 1c and bush 6a
Leaks 7a or 7b from the gap δ.

In order to prevent such water leakage, generally,
A packing called a lip packing or a squeeze packing is provided in the gap δ. That is, FIG.
As shown in the figure, the packing 8 is mounted in the groove 6c provided in the bush 6a, so that the gap δ between them is eliminated to prevent water leakage.

In this case, rubber, cloth-containing rubber, leather, and various other synthetic resins are used as the material of the packing 8. However, in the pump turbine, foreign matters such as soil and sand are mixed in the leaking water. Therefore, a rubber that is durable against the foreign matter is generally used.

The sealing effect when the packing 8 is used will be briefly described with reference to FIG.
When (P1 = high pressure side, P2 = low pressure side) acts on the packing 8, the packing 8 is deformed and adheres to the gap wall (seal surface). Due to this close contact, a pressure higher than the fluid pressure is generated on the sealing surface, and sealing is achieved. For a detailed explanation of this relationship, see "Seal Technology; Modern Editor; Showa 47
December, page 85 ".

In the case of the sealing device formed as described above, in order to obtain a proper sealing effect, it is necessary to specify the relationship between the packing 8 and the size of the gap δ. And the magnitude of the pressure differs. For example, taking an O-ring widely used in squeeze packing as an example, when a material having a hardness of 80 A and a cross-sectional diameter of 8 mm is used under a pressure of 100 kg / cm ² , the gap δ is the cross-section of the O-ring. It is less than 2% of the diameter.

In order to obtain a sufficient sealing effect as described above, the dimension of the gap δ needs to be accurate. However, in the case of this type of guide vane, the end face of the guide vane 1, that is, the step shaft portion 1c and Due to the structure of the pump-turbine, the clearance between the bush 6a and the assembly tolerance is increased due to the processing tolerance of several types of components after the assembly is completed, and becomes several times to more than ten times the appropriate clearance required for the packing 8. In some cases, it was difficult to obtain a sufficient sealing effect.

Under such circumstances, a sealing device has recently been proposed in which the gap size is not affected by the processing tolerance of parts.

That is, as shown in FIG. 6, a seal ring 13 having a packing 8 applied to a portion to be sealed.
The seal ring 13 is pressed against the seal wall surface by a pressing means, that is, a plurality of coil springs 10a arranged at predetermined intervals in the circumferential direction of the seal ring.
Press against the gap wall surface to be sealed with
Is maintained at a predetermined value.

In this case, since the seal ring is formed by the plurality of springs 10a and is pressed against the seal surface by the pressing means, the processing tolerances of several types of parts are added, and the size of the gap δ is increased. Even if the gap δ changes due to the vibration of the guide vane 1 due to the fluid force, the seal ring follows this change and acts in a direction to always keep the gap small, and the sealing effect can be maintained. .

Incidentally, as a related one, for example, JP-A-61-82074 can be mentioned.

[0016]

However, even if the sealing device thus formed is used for the guide vane portion of a high head pump turbine, the water leaking from the pump turbine will cause dirt, sand, etc. When soil and sand enter the springs scattered in the circumferential direction of the seal ring because it is mixed with foreign matter, it becomes difficult to come out just like soil and sand enter the inside of the basket-like thing, The expansion and contraction of the spring becomes dull.

If this phenomenon occurs in the spring at a certain position in the circumferential direction, the inclination of the seal ring prevents smooth rotation of the guide vanes, damages the packing, and furthermore, insufficient prevention of water leakage. I hate it.

The present invention has been made in view of the above, and it is an object of the present invention to keep the pressing force acting on the seal ring at a predetermined value even when soil and sand are mixed in water, and to keep the seal ring constantly. An object of the present invention is to provide a guide vane sealing device that can move smoothly, smoothly rotate a guide vane, and maintain a sufficient sealing effect without breaking a packing.

[0019]

That is, according to the present invention, the pressing means for pressing the seal ring in the gap direction is formed by a coil spring of one ring having substantially the same diameter as the seal ring. It is arranged concentrically with the guide vane shaft to achieve the intended purpose.

[0020]

In other words, in the sealing device thus formed, the spring as the pressing means is a single-ring coil spring arranged concentrically with the lower shaft of the guide vane.
Even if earth and sand enter this part, there is no danger that the spring in the specific part in the circumferential direction will not operate as in the past,
Therefore, the pressing force acting on the seal ring is substantially equal in the circumferential direction, the seal ring always moves smoothly, and the guide vane can rotate smoothly.

Further, since the deviation of the seal ring is reduced, the deviation of the packing is eliminated and the packing is not damaged.

[0022]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described in detail with reference to the illustrated embodiments.

FIG. 1 is a sectional view showing a lower portion of the guide vane 1, that is, a periphery of the lower shaft 1b. A seal ring 13 is disposed between the end surface of the bush 6a supporting the lower shaft and the end surface of the step shaft portion 1c.

The seal ring 13 is formed of a hard material, has a concave groove 13a on the surface on the side of the stepped shaft, and has a flange portion for locking the spring on the upper side of the outer peripheral side wall. 13b.

A packing 8 made of a rubber material is fitted into the groove 13a of the seal ring. Needless to say, in this case, a part of the packing is formed so as to protrude from the surface of the seal ring 13.
Further, of the joining surfaces of the packing 8 and the wall surface of the concave groove 13a, the joining surface on the high pressure side, that is, the joining surface on the water channel side (left side in the figure) is hermetically joined to the seal ring 13, and The joint surface of the concave groove 13a is formed so that the pressure of the fluid does not act.

A groove 6c is also formed on the surface of the bush 6a facing the inner wall of the seal ring.
Is inserted to prevent leakage from below the seal ring 13.

[0027] Seal ring flange 13b and bush 6a
A spring 10, which is a pressing means of the seal ring, is interposed between them in a compressed manner. As is apparent from the figure, in particular, this spring is a one-ring coil spring arranged concentrically with the lower shaft 1a.

The reference numeral 12 in the drawing denotes a stopper for stopping the rotation of the seal ring 13, which stops the movement of the seal ring 13 in a direction other than the gap direction.

Further, a skirt-like projection 11 for regulating the shape of the gap on the high pressure side is provided on the step shaft portion 1c of the guide vane. The presence of the protrusion allows the fluid to flow around the protrusion 11 and flow around the seal ring 13, so that the fluid force acts on the surface of the seal ring 13 on the side opposite to the sealing surface first.

In the sealing device thus formed, the spring 10 as the pressing means is a single-ring coil spring arranged concentrically with the lower shaft 1a. Even if it invades, the coil spring is one ring, and there is no danger that the spring action of a specific portion in the circumferential direction will not operate as in the conventional case.
Is substantially equal in the circumferential direction, the seal ring 13 always moves smoothly, and the guide vane 1 can rotate smoothly.

Further, since the deviation of the seal ring 13 is reduced, the packing 8 is not slid and the packing is not damaged, so that a sufficient sealing effect can be maintained.

In the above description, one embodiment has been described for forming and arranging the spring of the seal ring. However, the structure of the spring of the seal ring has various other considerations. Will be.

FIG. 6 shows another embodiment. In this figure, the spring 10 is formed concentrically with the lower shaft 1b as in the previous embodiment, but is not disposed on the outer peripheral side of the seal ring 13 but at the radial center of the seal ring 13 and A groove 15 is formed in the lower part, and a ring of spring 10 is arranged in the groove.

With such a configuration, since the lower shaft is a concentric one-ring spring, the same effect as that of the above-described embodiment can be achieved. Since the spring 10 is disposed between the two walls of the groove 15, the earth and sand hardly enter between the spring lines of the spring 10, which will be more effective.

FIG. 8 shows another embodiment. In the case of this embodiment, the spring line interval h of the coil spring 10 is changed. That is, the interval between the spring lines located at the lower part is made larger than that at the upper part.

In this configuration, the earth and sand flows down,
Also, since it accumulates in the lower part, if the spring line interval in this lower part is large, earth and sand easily pass through this part, and even if it stays, there is little clogging between the spring lines, affecting the expansion and contraction of the spring That is, the pressing force of the seal ring can be maintained at a predetermined value for a long time.

In this case, the same effect will be obtained even if the spring line interval is gradually increased from the upper side to the lower side, and it will be easier to manufacture the spring.

FIG. 9 shows still another embodiment. In this embodiment, the spring 10 is formed so that its diameter (D1, D2) increases as it goes downward.

Even with such a structure, an effect similar to that of the above-described spring is achieved, and the spring action is flexible and effective.

[0040]

As described above, the present invention provides:
Since the shape of the spring that presses the seal ring is a single ring that is concentric with the guide vane axis, even if earth and sand circulate, it will not leave the spring much between springs, and therefore, even if soil Even when sand is mixed, the pressure acting on the seal ring is kept at a predetermined value, the seal ring always moves smoothly, the guide vane can rotate smoothly, and the packing is not damaged enough. This kind of guide vane sealing device capable of maintaining a good sealing effect can be obtained.

[Brief description of the drawings]

FIG. 1 is a vertical sectional side view showing one embodiment of a sealing device of the present invention.

FIG. 2 is a longitudinal sectional side view showing the periphery of a guide vane of a pump turbine.

FIG. 3 is a longitudinal sectional side view showing an enlarged view of a lower portion of a guide vane shown in FIG. 2;

FIG. 4 is a vertical sectional side view showing a conventional sealing device.

FIG. 5 is a longitudinal sectional side view showing a sealing operation state of a conventional sealing device.

FIG. 6 is a vertical sectional side view showing a conventional sealing device.

FIG. 7 is a longitudinal sectional side view showing another embodiment of the sealing device of the present invention.

FIG. 8 is a longitudinal sectional side view showing still another embodiment of the sealing device of the present invention.

FIG. 9 is a longitudinal sectional side view showing still another embodiment of the sealing device of the present invention.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Guide vane, 1b ... Guide vane lower shaft, 1c ... Step shaft part, 3 ... Turbine runner, 6a ... Bush, 8 ... Packing, 9 ... Packing, 10 ... Coil spring (pressing means), 1
3. Seal ring.

──────────────────────────────────────────────────続 き Continuing from the front page (72) Inventor Fuminori Iwaki 3-1-1, Sachimachi, Hitachi-shi, Ibaraki Pref. Hitachi, Ltd. Hitachi Plant (56) References 58) Field surveyed (Int.Cl. ⁷ , DB name) F03B 3/16 F03B 11/00 F04D 29/12

Claims (6)

(57) [Claims] 1. A seal ring having a packing is provided between a shaft of a guide vane and a bush supporting the shaft. Wherein the pressing means for the seal ring is formed by a single ring-shaped coil spring concentric with the axis of the guide vane. Guide vane sealing device. 2. A seal ring having a packing is provided between a shaft of a guide vane and a bush supporting the shaft. In a guide vane sealing device adapted to prevent water leakage, the pressing means of the seal ring is formed by a coil spring, and the shape of the coil spring is formed in a ring shape concentric with the guide vane shaft. A sealing device for a guide vane. 3. A seal ring having a packing is provided between a shaft of a guide vane and a bush supporting the shaft. In the guide vane sealing device adapted to prevent water leakage, the pressing means of the seal ring is formed by a coil spring, and the shape of the coil spring is formed into a ring concentric with the guide vane shaft. A sealing device for a guide vane, wherein the distance between the coil spring wires is increased toward the lower side. 4. An outer peripheral side wall surface of the seal ring is provided with a flange protruding outward, and one end of the coil spring is locked to the flange.
The described guide vane sealing device. 5. The coil spring according to claim 1, wherein the lower the lower side, the larger the ring diameter.
Or the guide vane sealing device according to 4. 6. A seal ring disposed between a shaft of a guide vane and a bush supporting the shaft, and formed to be movable in a gap direction between the shaft and the bush. On the sealing surface side, a packing buried and fixed so as to partially protrude, and made of a flexible material, and pressing means for pressing the seal ring in the axial wall direction,
In the guide vane sealing device, the pressing means is formed of a coil spring concentric with the guide vane shaft and formed with a coil spring having a larger line spacing toward the lower side, and an outer peripheral side of the seal ring. A sealing device for a guide vane, wherein a flange protruding outward is provided in an upper portion of a wall surface, and one end of the coil spring is fixedly locked to the flange.