JPS5840032B2 - Vertical water-lubricated bearing device for hydraulic machinery - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a vertical water-lubricated bearing device for hydraulic machines such as water turbines and pump water turbines.

A conventional vertical water-lubricated bearing device has the structure shown in Figs. 1 and 2. Fig. 1 shows the case where it is applied to a Kabran water turbine; Fig. 1 is a cross-sectional view of the structure of the water turbine; The figure is a detailed view of the bearing device.

In the conventional technology, one pad is attached to each of the plurality of bearing pads 5a mounted inside the bearing case 5 facing the main shaft 4.
Water supply pipes 10 were arranged one by one.

As a result, a large number of pipings are mixed inside the bearing outer peripheral chamber 11a, making piping work difficult in terms of space and increasing manufacturing costs.

In addition, since a large number of pipe joints are used, leakage due to loose joints, etc. Furthermore, it is difficult to make the pipe lengths the same, and uneven pressure inside the bearing due to differences in water head loss in the pipes can be avoided. This caused instability in terms of reliability and bearing performance.

Furthermore, since the bearing pads 5a are each connected by one pipe 10, if foreign matter, sand, scale, etc. flow into the pipes for some reason, they will directly enter the bearing surface and cause damage to the bearing and the mating shaft. It was easy to cause problems such as giving.

Further, in the conventional bearing, the bearing outer circumferential chamber 11a communicates with the bearing upper chamber 11 and the bearing lower housing 12 through communication holes 13a and 13b.

As shown in FIG. 1, this bearing lower chamber 12 communicates with pressure water 15 flowing through the guide vane 1 and into the runner 3 along the outer periphery of the upper cover 2 through the lower gap of the upper cover 2. , and the bearing lower chamber 12, the bearing outer peripheral chamber 11a, and the bearing upper chamber 11b depending on the operating state of the water turbine.

The pressure in 11c varies and may sometimes produce negative pressure.

Conventionally, this bearing has been placed in water in order to improve its cooling effect, and has been further supplied with water by the bearing outer circumferential cooling water supply chamber 9. Since the cooling water on the outer periphery is sucked out and replaced with air, the cooling effect is completely lost, causing temperature instability in the bearing.

In the figure, 6a and 6b are the lower part of the bearing, respectively.
Upper water sealing device, 7 bearing cover, 8 main shaft water sealing device, 1
Reference numeral 4 denotes a drain pipe for draining the water after lubrication at the bearing pad 53 to the outside of the bearing.

SUMMARY OF THE INVENTION An object of the present invention is to provide a vertical water lubrication device for hydraulic machinery that eliminates the drawbacks of the prior art described above and has improved reliability and economical efficiency.

The main point of this invention is to provide a fresh water chamber on the back surface of the bearing case that is sealed separately from the upper and lower chambers of the bearing, a water supply pipe is connected to this fresh water chamber, and the surface of the bearing case facing the main shaft is A bearing pad is provided, and the bearing case is provided with a water supply hole that communicates the bearing pad with a fresh water chamber, and a drain pipe that drains water that has finished lubricating the bearing pad to the outside of the bearing. The main feature is that a pipe that communicates with the lower chamber is provided through the fresh water chamber.

The present invention will be explained below with reference to an embodiment shown in the drawings.

FIG. 3 shows an embodiment of the present invention.

In this embodiment, water is supplied to the bearing pad 5a by a fresh water chamber 11d which is completely separated and independent from the lower bearing chamber 12 and the upper bearing chambers 11b and 11c around the outer periphery of the bearing, instead of using the conventional one pipe for each pipe. , bearing pad 5a, and bearing case 5.
Pressure water is supplied to the inner surface of the bearing through a water supply hole 16 extending radially through the bearing.

By doing so, the difference in water head loss due to the difference in the length of the piping in the conventional clean water chamber 11d is eliminated, and the internal pressure of each bearing pad 5a becomes uniform.

Furthermore, since the number of piping is small and the water head loss is reduced, the internal pressure of the bearing can be kept high and the load capacity of the bearing can be increased.

Therefore, economy and reliability are improved.

Furthermore, the fresh water chamber 11d includes a bearing lower chamber 12 and a bearing upper chamber 1.
Since it is an independent ice chamber that is completely isolated from 1b, it is not affected by any operating condition of the water turbine and is always kept at a constant pressure and filled with water, so the cooling effect is better and more stable. Therefore, the conventional bearing outer circumferential cooling pipe 9 can be omitted.

Moreover, since the fresh water chamber 11d is a common ice chamber for supplying water to each bearing pad 5a, even if foreign matter flows into the water supply pipe 10, it will not flow to the inner surface of the bearing and will settle on the bottom surface of the fresh water chamber 11d. Since the foreign matter 18 is left behind, accidents caused by foreign matter flowing in can be prevented.

That is, a first foreign object prevention plate is provided in the fresh water chamber 11d so as to be inclined in a direction (inner circumferential side of the upper cover 2) to direct the water supply from the water supply pipe 10 away from the bearing case 5 in the fresh water chamber 11d. 17a, and a second foreign matter prevention plate 17b that blocks the water supply directed away from the bearing case 5.
By providing this, there is almost no fear that foreign matter will flow into the bearing pad 5a.

The role of the bearing upper and lower chamber communication pipe 13 in this embodiment will be explained next.

This is because the bearing upper chambers 11b, 11c and the bearing lower chamber 12 have a completely independent clean water chamber 11d located between them, thereby forming an ice chamber each having an independent and separate pressure.

Generally, the pressure in the lower bearing chamber 12 is higher than that in the upper chambers 11b and 11c, and therefore a force tends to displace the entire bearing case 5 upward, which may cause uneven bearing in some cases.

In addition, if the bearing water supply pressure, that is, the pressure in the fresh water chamber 11d, decreases or disappears for some reason, the water flows from the bearing lower chamber 12 through the bearing inner surface to the bearing upper chambers 11b, 11.
Dirty water, muddy water, etc. under pressure will flow into C, and there is a risk of damage to the bearing and the mating shaft, seizure, etc.

Therefore, the communication pipe 13 balances the pressures in the upper and lower chambers of the bearing.

As is clear from the above description, this invention has the great effect of being able to improve reliability and performance as well as providing an economical water-lubricated bearing device of this type.

[Brief explanation of drawings]

FIG. 1 is an overall view of a conventional water turbine bearing section, FIG. 2 is a detailed sectional view of the bearing device portion in FIG. 1, and FIG. 3 is a detailed sectional view showing an embodiment of the present invention. Explanation of symbols, 5...Bearing case, 5a...
... Bearing pad, 10... Water supply pipe, 11a...
...Bearing outer pressure chamber (fresh water chamber), 11b...
・Bearing upper chamber, 12...Bearing lower chamber, 13...
... Bearing upper and lower chamber communication pipe, 16 ... Water supply hole, 17
...Foreign matter inflow prevention plate.

Claims (1)

[Scope of Claims] 1. A fresh water chamber is provided on the back surface of the bearing case and is sealed separately from the bearing upper and lower chambers, a water supply pipe is connected to this fresh water chamber, and a water supply pipe is connected to the fresh water chamber on the surface facing the main shaft of the bearing case. is provided with a bearing pad, and the bearing case is provided with a water supply hole that communicates the bearing pad with a clean water chamber, and a drain pipe that drains water that has finished lubricating the bearing pad to the outside of the bearing. - A vertical water-lubricated bearing device for a hydraulic machine, characterized in that a pipe communicating the lower chamber is provided through the fresh water chamber. 2. A sealed fresh water chamber is provided on the back side of the bearing case, separate and independent from the bearing upper and lower chambers, a water supply pipe is connected to this fresh water chamber, and a bearing pad is provided on the surface of the bearing case facing the main shaft, In addition, the bearing case is provided with a water supply hole that communicates the bearing pad with the clean water chamber, and a drain pipe that drains water after lubrication in the bearing pad to the outside of the bearing, and also communicates the upper and lower chambers of the bearing. a first foreign object prevention plate provided with a pipe passing through the fresh water chamber, and further provided at an angle in the fresh water chamber to direct the water supply from the water supply pipe in a direction away from a bearing case in the fresh water chamber; and the bearing. A vertical water-lubricated bearing device for a hydraulic machine, characterized in that a second foreign object prevention plate is provided to block the water supply directed away from the case.