JPS61226570A - Disassembling method of rotary parts of hydraulic machine - Google Patents

Abstract

PURPOSE:To facilitate disassembly of a reversible pump-turbine by separating a turbine shaft from the lower shaft of a generator and lowering the turbine shaft as combined with runners along a guide metal. CONSTITUTION:To disassemble a reversible pump-turbine, first, a turbine shaft 7 is separated from the lower shaft 15 of a generator and the turbine shaft 7 is hung by a chain 23 suspended from a lower bracket 22. Then, the turbine shaft 7 is lowered as combined with runners 3 along a guide metal 21 onto a trolley. Removing the runners 3 from the turbine shaft 7 in this condition extremely facilitates disassembly work because of an ample working space thereabout. Further, since the turbine shaft 7 descends along the guide metal 21, it neither causes rocking motion nor damages a runner seal 14 and the like.

Description

[Detailed Description of the Invention] [Technical Field of the Invention] The present invention relates to a method for disassembling a hydraulic machine such as a water turbine or a pump-turbine, and more particularly to a method for disassembling the rotating part of a hydraulic machine in which the runner is disassembled from below the main engine. .

[Technical background of the invention and its problems] Water turbines or pump turbines used in hydroelectric power plants are
As shown in FIG. 4, a speed ring 2 is provided inside the spiral casing 1, and a runner 3 is located inside the speed ring 2. It is connected to the lower end of the water turbine main shaft 7 which is rotatably inserted into the sealing device ff1B. Further, a plurality of guide vanes 8 are arranged in a circular inner row on the outside of the runner 3, and the shafts of these guide vanes 8 are supported by the upper cover 4 and the lower cover 9, and are driven to open and close by the guide vane opening/closing mechanism 10. be done. Disassembly and assembly of the components of such hydraulic machines is generally performed from the top.

For example, to disassemble and inspect the runner 3, first disassemble the generator, the lower shaft, and the upper and lower brackets, and then remove the guide vane servo motor and guide vane opening 1WIIl.
The structure 10, bearing portion 5, seal device 6, water turbine main shaft 7, and upper cover 4 are disassembled and carried out, and then the runner 3 is disassembled and carried out. As described above, disassembly and inspection of Runner 3 cannot be carried out unless most of the parts of the generator and water turbine (or pump water turbine) are disassembled and taken out upwards, making it a task that requires many days. . During this period, the power plant will stop generating power, so disassembling and inspecting Runner 3 requires careful judgment based on the power supply schedule, and unless there are special circumstances, the entire machine will be overhauled once every few years. The reality is that it is only carried out occasionally. Therefore, repairs to the runner performed at times other than this overhaul period, such as cavitation inspections and repairs, will be carried out on the runner 3.
Normally, the installation is carried out without disassembling or transporting the equipment. For this reason, the runner 3 is not sufficiently inspected or repaired, and the upper cover 4 and lower cover 9 of the runner 3 cannot be inspected.

In order to eliminate such drawbacks, there are hydraulic machines that have a so-called runner handling structure in which the runner 3 is disassembled from the lower cover 9 side. FIG. 5 shows the structure of this type of water turbine and pump water turbine, and the lower cover 9 has a lower cover 98 that accommodates the shaft of the guide vane 8 on the outside of the maximum outer diameter of the runner 3.
and a discharge ring 9b that covers the bottom of the runner 3.

According to this type of hydraulic machine, the runner 3 can be disassembled and carried out by simply disassembling and carrying out the discharge ring 9b and the upper suction pipe 11, which is far more efficient than the hydraulic machine with the structure shown in Fig. 3. Disassembly of Runner 3 in a short number of days.
It has the advantage of being able to be carried out.

Figures 6 and 7 show a method of disassembling the runner 3 in a conventional runner undercutting structure, and Figure 116 shows a relatively large runner 3 and a bolt-tightening type runner 3. This is the decomposition method when . This disassembly method involves first disassembling and transporting the runner cone to secure sufficient space in the center of the runner 3, then connecting the hydraulic ratchet type up-down jack 12 to the water turbine main shaft 7 and lowering it downward. is possible relatively easily.

In this method, after the fastening bolts between the runner 3 and the water turbine main shaft 7 are disassembled within the upper cover 4, the runner 3 can be suspended by the up-down jack 12. However, this method requires that the launch be relatively large, that the runner cone be of a bolted type, and that an expensive hydraulic ratchet type up-down jack is required.

On the other hand, the method shown in FIG. 7 uses a telescopic multi-stage hydraulic cylinder 1 instead of the hydraulic ratchet type up-down
3 was used. However, even with this method, the runner must be relatively large and the runner cone must be bolted together, and furthermore, sufficient work must be required to connect the multistage hydraulic cylinder 13 to the water turbine main shaft 7 at the center of the runner after the runner cone has been disassembled. Space is required.

Further, the fastening bolts between the runner 3 and the water turbine main shaft 7 must be disassembled within the narrow upper cover 4, and an expensive multi-stage hydraulic cylinder is also required. Roughly speaking, in any of the above methods, if a reamer bolt is used as the fastening bolt between the runner 3 and the water turbine main shaft 7, it is relatively easy to separate the runner 3 and the water turbine main shaft 7; In the case of a structure in which a square key is adopted between the runners 7 and 7, the square keys often become rusty over time, and the work of separating the runner 3 within the narrow upper cover 4 is not easy. In addition, the water turbine main shaft 7
There was a problem in that the runner came into contact with a minute gap in the runner seal 14 formed by the ζ runner 3 and the upper cover 4, which caused lateral vibration or inclination when the runner was lowered, and the runner seal 14 was damaged. Therefore, when lowering the water turbine main shaft 7, it is necessary to lower the water turbine main shaft 7 concentrically until the runner seal 14 is completely detached from the upper cover 4, which requires a considerable amount of work time.

[Object of the Invention] Therefore, the object of the present invention is to solve the problems of the above-mentioned prior art, and to solve the problems of the above-mentioned prior art, and to solve the problem of lowering the main shaft of the water turbine in a hydraulic machine with a runner undercut structure, regardless of the mounting method of the runner cone or the dimensions of the runner. Another object of the present invention is to provide a method for disassembling a hydraulic machine that facilitates the separation of runners.

[Summary of the Invention i2N] In order to achieve the above object, the present invention provides a mechanism for separating the runner from the main engine along a guide device while preventing lateral vibration while keeping the runner of a hydraulic machine with a runner undercut structure connected to the main shaft of the water turbine. The main feature of this system is that the runner is suspended downward, and the bolts connecting the runner and the main shaft of the water turbine are removed in the large working space to separate the runner and the main shaft of the water turbine.

[j'! Embodiment] FIGS. 1 and 2 show a method of disassembling a hydraulic machine according to an embodiment of the present invention, and the same parts as in the conventional example are designated by the same reference numerals. In these figures, the upper end of the water turbine main shaft 7 is connected to the lower end of the lower shaft 15 of the generator, and a hanging bracket 16 is attached to the flange 7a at the upper end of the water turbine main shaft 7. Above water wheel main shaft 7
is inserted into the bearing support stand 17 of the upper structure of the upper cover 4, and the runner 3 has a bolt '18 attached to the lower end of this main shaft 7.
It has been concluded. The water turbine main shaft 7 and the runner 3 are engaged with each other by a square key 19 to rotate integrally, and the upper surface of the port 18 is covered with a cover 20.

To disassemble this hydraulic machine, first, the bearing portion and sealing device (none of which are shown) disposed around the main shaft 7 of the water turbine are disassembled and transported outside. On the other hand, although the bearing portion is disassembled and removed, the bearing support stand 17 is fastened and fixed to the upper cover 4 because its inner diameter is made larger than the upper end flange 7a of the water turbine main shaft 7.

A guide metal 21 is concentrically attached to the bearing support 17 with a small gap smaller than the gap of the runner seal 14 with respect to the water turbine main shaft 7 in order to facilitate the lowering of the water turbine main shaft 7. In addition, the water turbine main shaft 7 and the lower shaft 15 can be attached by disassembling bolts (not shown) and separating them, and hanging the chain block 23 from the lower bracket 22 as shown in FIG. The main shaft 7 of the water turbine is hung by hanging on the suspension bracket 16 of the water turbine.

Then, the upper suction pipe and discharge ring (both not shown) disposed below the runner 3 are disassembled and carried outside.

In this state, the bolt 18 is not removed, and the water turbine main shaft 7 and runner 3 remain assembled.

Next, the chain block 23 is operated to rotate the water turbine main shaft 7.
The runner 3 is lowered in the assembled state and placed on the carry-in/out trolley 24 as shown in FIG.

Therefore, according to this *embodiment, since the main shaft 7 of the water turbine is lowered along the guide metal 21, the small seal gap of the runner seal 14 formed between the runner 3 and the upper cover 4 is not damaged. It is possible to perform descending work. A wide working space is created around the lowered water turbine main shaft 7 and runner 3, and the coupling cover 2
0 and the bolt 18 using an L-shaped hydraulic wrench (not shown) can be easily carried out in this large work space. Even if the square key 19 that engages the runner 3 and the water turbine main shaft 7 becomes rusty, the separation work can be carried out using a hydraulic jack or the like in a large working space with no space constraints. Cutting becomes easier. Furthermore, after the water turbine main shaft 7 and runner 3 have been separated, the water turbine main wheel 7 can be hoisted up by the chain block 23 and the runner 3 can be carried outside using the carry-in/out trolley 24 for predetermined inspections and repairs. can.

Another embodiment of the present invention shown in FIG.
A plurality of guide bolts 26 are arranged radially on this support plate 25, and the other configurations are the same as those in the *embodiment. In this way, the same effect as the guide metal 21 of the embodiment described above can be obtained.

[Effects of the Invention] As is clear from the above description, according to the present invention, the runner and the main shaft of the water turbine are suspended downward from the main engine along the guide device attached to the bearing support stand, and then the runner is Since the main shaft of the water turbine is separated from the main shaft of the water turbine, damage to the runner seal due to lateral vibration of the main shaft of the water turbine can be prevented, and the work of separating the runner can be easily performed in a wide space. Furthermore, the water turbine main shaft and runner can be separated from each other regardless of the dimensions of the runner, the method of connecting the runner cone to the runner, or whether the torque transmission method is a bolt type or a square key. Furthermore, an inexpensive chain block can be used to lower the runner and the main shaft of the water turbine, and there is no need to use an expensive hydraulic ratchet type up-down jack or multi-stage hydraulic cylinder.

[Brief explanation of the drawing]

FIGS. 1 and 2 are longitudinal 11-plane views showing the disassembly process of a hydraulic machine according to an embodiment of the present invention, FIG. 3 is a sectional view of a guide device according to another embodiment of the present invention, and FIG. 4 5 is a half-sectional view showing an example of a conventional hydraulic machine, FIG. 5 is a half-sectional view of another example of the conventional hydraulic machine, and FIGS. 6 and 7 are cross-sectional views showing the disassembled state. 3... Runner, 5... Bearing part, 7-... Water turbine main shaft, 8... Guide vane, 9.9a... Lower cover, 9
b...Discharge ring, 11...Upper suction pipe, 16...Hanging bracket, 17...Bearing support base,
21... Guide metal, 23... Chain block, 25... Support plate, 26... Guide bolt. Agent Ben, Kensuke Norichika and 1 other person) Figure 1 Figure 2 Figure 3 Figure 4 Figure 5 Figure 6

Claims (1)

[Claims] The lower cover is divided into a discharge ring that covers the lower part of the runner and a lower cover that accommodates the lower shaft of the guide vane.In water turbines or pump water turbines in which the runner is disassembled and transported from below, the bearing part except the bearing support is formed separately. After disassembling and transporting, a guide device was attached to this bearing support stand to prevent the lateral vibration of the water turbine main shaft. The upper suction pipe and discharge ring are disassembled and carried outside, and the turbine main shaft and runner, which are connected to each other along the guide device, are suspended downward using a chain block in their assembled state, and then the water turbine main shaft and runner are separated. A method for disassembling a rotating part of a hydraulic machine, characterized in that the runner is carried outside.