JPS59180071A - Structure of water turbine or pump water wheel - Google Patents

Abstract

PURPOSE:To facilitate the maintenance of a shaft packing device by a method wherein an oil leakage preventing packing is provided at a sliding part of a bearing oil tank and a shaft and the oil tank as well as the bearing are permitted to move into the axial direction thereof in a pump or the pump water wheel. CONSTITUTION:The sliding part 11A of the oil tank 11 is provided with an elastic body packing 11D mounting a spring 11C so as to be opposed to the shaft 2, in order to provide a seal member 11B and the sliding part 2A with a surface pressure necessary for preventing the leakage of lubricating oil. The pacing 11D expands by introducing the pressure and may be deformed to the side of the shaft 2 so as to be contacted thereto closely. The packing is not contacted with the shaft 2 so as to preclude the supply of the pressure from a pressure supplying port 11E during normal operation. The packing 11D prevents the leakage of the lubricating oil upon inspection and maintenance of the shaft packing device 9 by adhering to the shaft 2 due to the pressure from the pressure supplying port 11E while the shaft 10 and the oil tank 11 may be moved into the axial upward direction thereof.

Description

[Detailed Description of the Invention] [Field of Application of the Invention] The present invention relates to a bearing structure for a water turbine or a pump-turbine, and in particular, to reduce shaft vibration of a high-head water wheel shunting pump-turbine, and to inspect and inspect a shaft sealing device. The present invention relates to a bearing structure suitable for easy maintenance.

[Prior art]

In Fig. 1, 1 is a runner fixed to the main shaft 2, n1 speed ring 3, and a guide vane 5 that flows from the casing 4.
It rotates and generates electricity using the pressure water that flows through it. On the other hand, in the case of a pump turbine, an electric motor installed on the upper part of the main shaft 2 causes the runner 1 to rotate in the opposite direction to power generation, thereby pumping water. Reference numeral 5 is a guide vane which performs all adjustment of the amount of water flowing into the runner 1, and the guide vane 5 is installed on the upper cover 6. A guide ring 8, which is also installed on the upper cover 6, is rotated by the operating force of a hydraulic servo motor (not shown). The upper cover 6VC further includes a shaft sealing device 9 and a bearing oil tank 1 for sealing pressure water flowing out from a gap existing between the main shaft 2 and the upper cover 6, which is a fixed part.
1 is added. Bearing oil tank 11
It is necessary to maintain the oil level 13 so that the performance of the bearing 10 can be fully exhibited. Insert as many parts as possible to maintain the entire oil level. In the structure of such a conventional water turbine, shunt or pump water turbine, the bearing 10 and the Oil tank]
It is usually designed to be located 400 to 500wn above. That is, L dimension i400~5 (10
The position of the bearing 10 + rt is determined so that wn. For this reason, the distance I from the bearing 10 to the center of the runner 1 is equal to this dimension 1. The decision will be made after considering all
Deflection occurs due to the radial fluid force acting on the runner 1 (generated while the pressure water passes through the runner 1), but since the fulcrum is the center of the bearing 10, the larger 11 is, the more The amount of deflection at the end becomes large.

In particular, when a water turbine or a pump turbine has a large capacity and a high head, the physical force of the radial surface 6 acting on the runner 1 becomes large, resulting in a large amount of deflection. Gap G between the opposing seals in G2] It is necessary to widen G2 to avoid contact between the two, and as the gap G2 increases, the amount of water leaking from G1 and G2 increases.
This will lead to a decrease in the efficiency of the water turbine or pump turbine.

On the other hand, for pump turbines, inspection and maintenance of the shaft sealing device 9 is generally performed by entering the inside of the upper cover 6 through a manhole provided in the upper plate 6A of the upper cover 6. It is. However, in cases where the head height is high, especially in pump turbines or water turbines exceeding 500 m, and in two-stage pump turbines as shown in Fig. 2, the guide vane 5 and guide cylinder 8'Jt are connected to form a link that transmits force. 15 etc., enter the upper cover 6 from the upper cover 6A and install the shaft sealing device 9.
Since it is impossible to inspect and maintain the concrete wall 16, a part of the concrete wall 16 is cut out and a manhole B' which is also provided in part A of the speed ring 3 and part of the upper cover 6 is passed from part 0. , all maintenance and inspections of the bearing equipment JT9 may be carried out. But even in this structure, the part of concrete protecting around casing 4? By removing part A of speed ring 3 and part yl of upper cover 6, will the strength of both parts be reduced? This is not a good idea.

Furthermore, 500m'! -Single stage pump and head over 6
In a two-stage pump turbine that exceeds 1,000 m'r, the pressure of the pressure water to be sealed by the shaft sealing device 9 is high (in a shaft'M device that fully utilizes carbon banking, for example, in a two-stage pump turbine that is used at a head of 1,000 m, Sealing pressure is 50kg/rrn
2), so by increasing the number of stages of carbon backing in one axial direction, the design is such that the amount of water leakage is reduced to a predetermined amount.

That is, a 500 m class single stage pump turbine uses a three stage packing, but a 1009 m class two stage Ponobu water turbine requires all four to five stage packings to be installed.

In this way, as the number of packing stages increases, the size of I above the shaft sealing device area should be 400 to 500.
We will have to install all bearings and bearing oil tanks, so we apologize for the inconvenience.
This results in a shaft system design that is unfavorable for shaft vibration.

In short, bearings for conventional water wheel shunting or pump water turbines have drawbacks in terms of performance, strength, inspection, and maintenance, and are not reliable in terms of reliability due to the large amount of vibration in the runner.

[Purpose of the invention]

An object of the present invention is to provide a pump or pump water wheel that completely prevents leakage of lubricating oil from the sliding parts of the shaft and bearing oil tank, and that facilitates inspection and maintenance of the shaft sealing device.

[Overview of the invention]

The key point of the present invention is to provide a packing for preventing oil leakage n'2 on the sliding part between the bearing oil tank and the shaft to prevent oil leakage, and to provide a packing for maintenance. Oil leakage? The purpose is to make the oil tank and bearing fully movable in the axial direction while preventing this.

[Embodiments of the invention]

The present invention will be explained in detail with reference to FIGS. 2 to 5.

The structure of the bearing 10 is as shown in FIG.
[Packing part attached to the inner periphery of the shaft 2 of 1] IA is fully installed, and at the same time, there is a rotating part 2h x 8 that slides with this packing and prevents the lubricating oil in the oil tank 11 from leaking, and the entire bottom surface of the oil tank 11 is sealed. As close as possible to the top surface of the device 9, and extend it to the entire dimension S#
The mounting position # of the bearing 10 can be significantly shortened compared to the L dimension in FIG. As a result, it is possible to shorten ttl + the dimension Ml between the center of the bridge 10 and the center of the runner 1 - H dimension of the conventional structure, and furthermore, with respect to the radial fluid force of the runner, H >> M Therefore, the slit Gl in the seal portion between the runner 1 and the lower cover 7, - the upper cover 6,
The amount of deflection of the 02 section is reduced, it can be narrowed to G1.02, the amount of water leaking from the 02 section can be reduced, and the efficiency of the water wheel shunting pump water turbine can be completely improved.

Details of the sliding parts 11A and 2 of the shaft 2 of the bearing oil tank 11 will be explained with reference to FIG. The sliding part 11A of the oil tank 11 is made of a highly wear-resistant material such as carbon.
B and the sliding part 2A are equipped with a spring 110'ft to provide the necessary surface pressure to completely prevent leakage of lubricating oil to the outside, and a gasket 1 made of an elastic material such as rubber.
It is provided facing the 1Dt axis 2. This packing], ID is a ring-shaped 'tL, and by introducing the full pressure of fluid or gas from 11E into the center and expanding, the shaft 2
It has a structure that allows it to deform to the side and fit tightly,
During constant operation, no pressure is supplied from the IIE, so the shaft 2 is kept out of contact. During inspection and maintenance of the shaft sealing device 9, the packing 11]) prevents lubricating oil from leaking by applying the pressure supplied from 11E to the edge shaft, and in this state, it moves upward in the axial direction while completely preventing oil leakage. The bearing 10 and oil tank 11 are moved to appropriate positions.

Of course, the oil in the oil tank 11 may be drained and lifted. The method of movement and the method of holding after movement will be explained with reference to FIG.

The bearing 102- and the oil tank 11'It are lifted up by the hanging hook 18 and held at a height N that allows a person to pass through the entire inner circumference of the upper plate 6A of the upper cover 6 and enter the shaft sealing device section. Or, for lifting, there are 17 bolts and 1 oil tank.
It is also possible to set up an appropriate number around the entire circumference of one piece and hang it up.

What is the case in Figure 5 when the lubricating oil in the oil tank 11 is not drained? Pressure 1 is applied to the inside of the packing 11D via 11E to deform the packing III, and the cylindrical surface is brought into close contact with the entire main shaft 2 to completely prevent oil leakage. As mentioned above, it is also possible to drain all the oil before lifting.

Furthermore, in the bearing part of the conventional structure, as shown in Fig. 1,
It is necessary to provide a skirt 12 on the shaft 2, but the skirt 1
2 is considered as a spring system together with the bearing 10 and the bearing oil tank 11 located on the outer circumferential side thereof when installing the shaft system #F.

In other words, the support rigidity (spring constant) of the bearing support portion of the shaft 2 is considered as a spring system in which the springs of the skirt 12, the bearing 10, and the shaft oil tank 11 are arranged in series, so each spring constant 1 is determined by n. Skirt part, K, 2. to the bearing. ,
If the spring constant of the bearing oil tank is 'k K + I, then the overall spring constant KT is +o Kll K+2. f K+ 1+ + t )+ + , + t
becomes. If the skirt 12 is unnecessary as in the present invention, KT' becomes -. Here, if KT' KT > 0, the shaft support structure of the present invention has a greater rigidity of the shaft support portion, and is therefore more effective against vibrations of the shaft system.

That is, f K+o+ + 1) (K+o K+ + +KI
ll K+2 +KI lK12), but Klo
, if ++ and KI2 > 0, then (10).

That is, in contrast to the conventional shaft support structure of a water turbine or pump water turbine that has the entire skirt 12 on the shaft 2, in the present invention where the skirt 12 is omitted, the shaft support rigidity of the submersible or pump water turbine is increased. Therefore, it is possible to completely reduce shaft vibration.

As mentioned above, by increasing the rigidity of the shaft support,
In addition to the effects of a) and bl above, the effect of reducing shaft vibration can be obtained. [Effects of the Invention] According to the present invention, the dimension from the center of the bearing to the center of the runner is shortened, and the total amount of n-axis runout can be reduced. Is it possible to seal the gear between the runner seal part and fixed part? Is it possible to shrink the seal cap part? The amount of pressure water lost through the process can be completely reduced.

In addition, since the height direction is almost free, workability is improved, and there is no need to use the entire passage for workers, so there is no reduction in strength.

[Brief explanation of the drawing]

Figure 1 is a cross-sectional view of a conventional water wheel shunt or pump turbine, (11
) Figure 2 is a cross-sectional view of the water turbine or pump-turbine of the present invention;
The figure is a sectional view of the oil leakage prevention structure of the bearing oil tank of the present invention.
The figure is a sectional view showing a method of moving the bearing and the oil tank, and FIG. 5 is a diagram of the structure for preventing oil leakage during movement. 2...Main shaft, 11A...Bearing oil tank oil leak prevention part, 1
1B...Sliding member with two people,] IC...Spring, 11
D...(12) House/Zuhaku ω diagram

Claims (1)

[Claims] 1. Full installation of the lunch at the lower end, complete installation of the generator or generator motor at the upper end lI''jfc main shaft of the water turbine or pump water wheel, radial load, unbalanced load on the rotating part, rotating part type i? A water wheel or pump, characterized in that an oil leak prevention device is provided between the oil tank and the main shaft, in a bearing and an oil tank that are provided to support and completely reduce vibrations of the rotating part. Structure of a water turbine. 2. The structure of a water turbine or pump water turbine as set forth in claim 1, characterized in that it is fully equipped with inspection and maintenance seals that are used only during inspection and maintenance.