JPH0467030B2 - - Google Patents

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] As shown in Fig. 4, a water turbine or a pump turbine used in a hydroelectric power plant is equipped with a speed ring 2 inside a spiral casing 1, and a speed ring 2 inside the spiral casing 1. is where runner 3 is located, and this runner 3 is
It is connected to the lower end of a water turbine main shaft 7 rotatably inserted into a bearing portion 5 attached to the upper cover 4 and a sealing device 6 . Further, a plurality of guide vanes 8 are arranged in a circular 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 controlled by the guide vane opening/closing mechanism 10. Driven to open and close. Disassembly and assembly of the components of such hydraulic machines is generally performed from the top.

For example, to disassemble and inspect runner 3, first,
The rotor, lower shaft, and upper and lower brackets of the generator are disassembled, and then the guide vane servo motor, guide vane opening/closing mechanism 10, bearing section 5, sealing device 6, water turbine main shaft 7, and upper cover 4 are disassembled and transported. 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 takes many days. . During this period, the power plant will stop generating electricity, so disassembling and inspecting runner 3 requires careful judgment in accordance with 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 that are 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 was not sufficiently inspected and repaired, and the upper cover 4 and lower cover 9 sides of the runner 3 could not be inspected.

In order to eliminate such drawbacks, there are also hydraulic machines with a so-called runner under-cut structure in which the runner 3 is disassembled from the lower cover 9 side. Figure 5 shows the structure of this type of water turbine and pump water turbine.
The runner 3 is divided into a lower cover 9a that accommodates the shaft of the guide vane 8 outside the maximum outer diameter of the runner 3, and a discharge ring 9b that covers the lower part 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 first, and compared to the hydraulic machine of the apparatus shown in FIG. This has the advantage of being able to disassemble and transport Runner 3 in a much shorter period of time.

Figures 6 and 7 show a method of disassembling the runner 3 in a conventional runner undercutting structure. This is the decomposition method when it is an expression. 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 runner be relatively large, that the runner cone be of the bolted type, and that it requires an expensive hydraulic ratchet type up-down jack.

On the other hand, the method shown in FIG. 7 uses a telescopic multi-stage hydraulic cylinder 13 instead of the hydraulic ratchet type up-down jack. 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. Furthermore, 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, but if the structure uses a square key between the runner 3 and the water turbine main shaft 7, the square key may rust over time. Therefore, it is not easy to separate the runner 3 within the narrow upper cover 4. Further, when the main shaft 7 of the water turbine laterally oscillates or tilts when it is lowered, it comes into contact with a small gap in the runner seal 14 formed by the runner 3 and the upper cover 4, causing damage to the runner seal 14. 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 problem of the above-mentioned conventional technology, and to solve the problem of lowering the main shaft of the water turbine and moving the runner, regardless of the method of attaching the runner cone or the dimensions of the runner, in a hydraulic machine with a runner-free structure. An object of the present invention is to provide a method for disassembling a hydraulic machine that facilitates separation.

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

[Embodiment of the Invention] 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 1 is attached to the flange 7a at the upper end of the water turbine main shaft 7.
6 is installed. The water turbine main shaft 7 is inserted into a bearing support 17 of the upper structure of the upper cover 4, and is fastened to the lower end of the main shaft 7 to the runner 3 with a bolt 18. Note that 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 bolt 18
The upper surface is covered with a coupling 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 through a minute 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. Further, the water turbine main shaft 7 and the lower shaft 15 are separated by disassembling the mounting bolts (not shown), and the chain block 23 is suspended 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 lower the water turbine main shaft 7 and runner 3 in the assembled state.
It is placed on the loading/unloading trolley 24 as shown in FIG.

Therefore, according to this embodiment, the guide metal 21
Since the water turbine main shaft 7 is lowered along the runner 3 and the upper cover 4, the lowering work can be easily carried out without damaging the minute seal gap of the runner seal 14 formed by the runner 3 and the upper cover 4. Furthermore, a wide work space is created around the lowered water turbine main shaft 7 and runner 3, and it is easy to disassemble the coupling cover 20 and the bolts 18 using an L-shaped hydraulic wrench (not shown) in this wide work space. It can be implemented. 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 without space constraints. After separation from the runner 3, the main shaft 7 of the water turbine is lifted up by the chain block 23, and the runner 3 is carried out by the carry-in/out trolley 24 for predetermined inspection and repair.

Another embodiment of the present invention shown in FIG.
5 is attached, and a plurality of guide bolts 26 are arranged radially on this support base 25, and the other configurations are the same as those of the previous 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 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 reamer bolt method 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]

1 and 2 are longitudinal sectional views showing a disassembly process of a hydraulic machine according to one embodiment of the present invention, and FIG. 3 is a sectional view of a guide device showing another embodiment of the present invention.
Figure 4 is a half-sectional view showing an example of a conventional hydraulic machine, Figure 5 is a half-sectional view of another example of a conventional hydraulic machine, and Figures 6 and 7 are cross-sectional views showing its disassembled state. It is. 3... Runner, 5... Bearing part, 7... Water turbine main shaft, 8... Guide vane, 9, 9a... Lower cover, 9b... 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.

Claims (1)

[Claims] 1. Water turbines or pump turbines in which 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, and the runner is disassembled and transported from below, excluding the bearing support stand. The bearing part is disassembled and carried out, a guide device is attached to this bearing support stand to prevent the lateral vibration of the water turbine main shaft, and the lower end of the chain of the chain block is hooked to the upper end of the water turbine main shaft to hold the water turbine main shaft in a suspended state.
The upper suction pipe and the discharge ring below the runner are disassembled and carried outside, and the water turbine main shaft and runner, which are connected to each other along the guide device, are suspended downward by a chain block in their assembled state.
A method for disassembling a rotating part of a hydraulic machine, characterized in that the main shaft of the water turbine and the runner are then separated and the runner is carried outside.