JPS5844867B2 - How to adjust the runner seal gap - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for adjusting a runner seal gap of a water turbine or a pump turbine in which a lower runner seal is formed between a launch and a lower cover, and in particular, the present invention relates to a method for adjusting a runner seal gap of a water turbine or a pump turbine in which a lower runner seal is formed between a launch and a lower cover. The present invention relates to a runner seal gap adjustment method suitable for adjusting the lower seal gap by easily processing the sealing surface of the lower seal when the lower seal gap occurs.

Generally, a water turbine or a pump water turbine is provided with a runner seal mechanism to prevent water leakage around the runner, and the runner seal mechanisms are provided at the upper and lower parts of the launch, respectively, and a small gap is formed in the seal portion.

FIG. 1 is an explanatory diagram showing -flJ of a sealing mechanism in such a water turbine or pump water turbine.

On the upper side of the runner 1, an inner upper seal gap 3A and an outer upper seal gap 3B are formed between one launch 10 runner crown and the upper cover 2, and the inner upper seal gap 3A is formed with the outer upper seal gap 3.
In many cases, it is set smaller than B.

Further, on the lower side of the runner 1, an inner lower seal gap 5A and an outer lower seal gap 5B are formed between the runner band 1B of the runner 1 and the lower cover 4,
In many cases, the inner lower seal gap 5A is set smaller than the outer lower seal gap 5B.

Here, the lower cover 4, which is one of the elements forming the runner seal mechanism, is generally buried in concrete 6 around the lower cover, and its installation is such that it cannot be disassembled later.

Although the concrete 6 around the lower cover is reinforced with reinforcing bars or the like, the lower cover 4 may be deformed due to movement during concrete placement or due to aging.

FIG. 2 is an explanatory diagram showing such a deformed state of the lower cover 4.

The inner lower seal gap 5A formed between the lower cover 4 and the launch band 1B is set to be a uniform gap during assembly and installation, but due to aging of the concrete 6 around the lower cover, etc. The lower cover displacement 4A may occur, and the inner lower seal gap 5A may become smaller than the predetermined gap amount.

If the inner lower seal gap 5A becomes smaller than a predetermined gap amount, there is a risk that when the runner 1 rotates, the runner band 1B and the lower cover 4 will come into contact and be damaged.

Therefore, the inner lower seal gap 5A is periodically inspected, and if it is smaller than a predetermined gap amount, it is necessary to enlarge the seal gap to a predetermined gap amount. Since it is buried in the surrounding concrete 6, it is necessary to disassemble the water turbine parts including the runner 1 and the upper cover 2 and adjust the sealing surface of the lower cover 4, which requires a large amount of work to disassemble and assemble the water turbine parts. There is a drawback that.

The present invention has been made in order to eliminate the above-mentioned conventional drawbacks, and is a runner seal gap adjustment method that allows the lower seal gap to be adjusted in a short period of time without disassembling water turbine parts such as the launch and upper cover. The purpose is to provide

According to the present invention, a machined hole is formed in the seal gap forming part of a runner band of a water turbine or a pump-turbine that faces a lower cover and forms a seal gap, and a cutting tool is attached to this machined hole to form a sealing surface of the lower cover. The runner is rotated while cutting, and after the cutting is completed, the cutting tool is removed to close the machined hole.

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 3 is an explanatory diagram showing an embodiment of the runner seal gap adjusting method according to the present invention.

The lower cover 4 shown in FIG. 3 causes a lower cover displacement 4A due to movement of the concrete 6 around the lower cover,
The inner lower seal gap 5A is made smaller than a predetermined gap amount.

Inner lower seal gap 5 at lower end of launch band 1B
In the seal gap forming part forming A, there is a processing hole 1.
1 is provided.

As shown in FIG. 4, the machining hole 11 is sequentially shifted in height in different steps in the circumferential direction of the runner band 1B, so that a cutting tool 12 (described later) can process the entire area of the sealing surface of the lower cover 4. There are multiple locations like this.

A cutting tool 12 for processing the sealing surface of the lower cover 4 can pass through the processing hole 11, and the size of the cutting tool 12 is determined based on the size of the cutting tool 12 and the adjustment range of the inner lower seal gap 5A. It is determined based on the machining range of the sealing surface, and is provided so that the cutting surface by the cutting tool 12 is continuous, but the size is set such that the strength of the runner band 1B is not extremely reduced.

The tip of the cutting tool 12 is provided with a cutting blade that contacts the seat surface of the lower cover 4, and the base end thereof is provided with a processing machine device 13 and a drive device 14 using an electric motor or compressed air. There is.

These processing machinery device 13 and drive device 14 are fixed to the inner surface of the runner band IB by welding or fixing bolts, etc., and supply rotational force to the cutting tool 12, and the inner lower seal gap 5A is machined to a predetermined gap amount. Feed is applied to the cutting tool 12 so that the cutting tool 12 is rotated.

In addition, a winch 21 and a pulley 22 are supported on the lower cover 4, and a wire rope 2 that is wound around the winch 21 is supported on the lower cover 4.
3 is connected to the runner 1 at its tip via a pulley 22.

That is, by rotating the winch 210, the wire rope 2
3, the runner 1 and cutting tool 12 are rotated in the circumferential direction along the seat surface of the lower cover 4.

Next, the operation of the above embodiment will be explained.

First, the seal gap forming portion at the lower end of the runner band 1B,
That is, as shown in FIG. 4, a plurality of processing holes 11 are bored in a portion of the lower cover 4 that faces the sealing surface and forms the inner lower seal gap 5A.

Then, the cutting tool 12 is passed through the processing hole 11 provided in the launch band 1B, and the processing machine device 13 and drive device 14 that drive the cutting tool 12 are connected to the runner band 1B.
Fix it to the inner surface of B.

The cutting tool 12 is given an appropriate rotational speed by the drive device 14, and the feed amount is set by the processing machine 13 so as to obtain an appropriate inner lower seal gap 5A.

The runner 1 is rotated by winding the winch 210, and the cutting blade of the cutting tool 12 is moved for cutting along the seat surface of the lower cover 4.

Here, the cutting tool 12 may be provided in all of the plurality of processing holes 11 provided in the height direction of the launch band 1B, and the entire seat surface of the lower cover 4 may be processed simultaneously, or each processing hole may be The seat surface of the lower cover 4 may be sequentially machined in the height direction by sequentially attaching the cutting tools 12 to the holes 11.

After the proper gap amount is given to the inner lower sheet gap 5A in this way, the cutting tool 12, processing machine device 13, drive device 14, etc. are removed from the runner 1,
A blind plug 31 as shown in FIG. 6 is fitted into the processing hole 11 provided in the runner band 1B.

According to the above embodiment, the sealing surface of the lower cover 4 is adjusted while rotating the runner 1 with the cutting tool 12, the processing machine device 13, and the drive device 14 attached to the runner band 1B of the runner 1. Therefore, Runner 1
, it becomes possible to adjust the inner lower seal gap 5A to an appropriate gap amount without disassembling the water turbine parts such as the upper cover 2.

As described above, the present invention provides for drilling a machined hole in the seal gap forming part of the launch band of a water turbine or a pump turbine that faces the lower cover to form a seal gap, and attaching a cutting tool to the machined hole. The runner is rotated while cutting the seal surface of the lower cover, and after cutting is completed, the cutting tool is removed to close the machined hole, so the seal gap amount can be adjusted in a short period of time without disassembling the water turbine parts. It has the effect of being able to.

[Brief explanation of drawings]

Fig. 1 is a sectional view showing a runner seal mechanism in a general water turbine or pump water turbine, Fig. 2 is a sectional view of a main part showing a deformed state of the lower seal gap, and Fig. 3 is a sectional view of a runner seal gap adjustment method according to the present invention. FIG. 4 is a side view showing how the processing hole is arranged, FIG. 5 is a plan view showing how the winch is installed, and FIG. 6 shows how the blind plug is fitted. FIG. 1..."...Runner, 4...Lower cover, 5
A...Inner lower seal gap, 11...
...Machining hole, 12...Cutting tool, 13...
...Processing machine equipment, 14... Drive device.

Claims (1)

[Scope of Claims] 1. A machined hole is drilled in the seal gear forming portion of the runner band of a water turbine or pump-turbine that faces the lower cover to form a seal gap, and a cutting tool is attached to this machined hole to form a seal gap of the lower cover. A method for adjusting a runner seal gap, comprising rotating a runner while cutting a seal surface, and removing the cutting tool after cutting is completed to close the machined hole. 2. The runner seal gap adjustment method according to claim 1, wherein a plurality of the machined holes are formed in the height direction of the launch band so that a surface cut by the cutting tool is continuous.