JP2000120584A - Bearing device and vertical shaft drain pump using it - Google Patents

Abstract

PROBLEM TO BE SOLVED: To lubricate a thrust bearing sliding part with lubricating liquid even if water invades into an oil tank, and surely prevent a damage by arranging means for reserving lubricating liquid of the thrust bearing sliding part in the oil tank. SOLUTION: In this bearing device suitable to a vertical shaft drain pump, a thrust block 2 is fixed to a pump main shaft 1, a bearing case 4 is arranged on an outer peripheral position of the thrust block 2, and a plurality of segment guide bearings 3 are arranged along a circumferential direction between the thrust block 2 and the bearing case 4. A collar 9 is attached to a lower part of the thrust block 2, and a plurality of pad type thrust bearings 10 are arranged opposing to the collar 9. The whole is dipped in lubricating liquid 19 in an oil tank 6. In this case, an inner cylinder 8 and an external cylinder 8 as a lubricating liquid reserving part are arranged on the pad type thrust bearing part 10 so as to enclose the collar 9 and the thrust bearing 10 at prescribed clearances, and lubricating performance of the bearing part 10 is held in a high level.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a bearing device for supporting a main shaft of a large pump and a drainage pump using the same, and more particularly to a bearing device for a vertical shaft drainage pump.

[0002]

2. Description of the Related Art In the case of a large pump, bearing devices for supporting a main shaft are disposed at two positions, that is, an upper portion of a runner and a lower portion of a transmission. The bearing device disposed below the transmission is configured by combining a guide bearing portion and a thrust bearing portion. Further, the bearing device disposed above the runner is constituted only by the guide bearing portion. In these bearing devices, mineral oil-based turbine oil is used as a lubricating liquid. Turbine oil has a specific gravity of 0.87 and is smaller than pumped liquid (specific gravity 1.0). An example of a structure in which the bearing device includes only the guide bearing portion is disclosed in a collection of mechanical drawings (slide bearing, published by The Japan Society of Mechanical Engineers, first edition on November 20, 1969: pages 48 and 49).

[0003] Similarly, a configuration in which a guide bearing portion and a thrust bearing portion are combined in a bearing device is disclosed on pages 40 and 41 of the aforementioned mechanical drawings.

[0004] Usually, in this type of large pump, the bearing is lubricated with mineral oil-based turbine oil in the bearing device.
Stable long-term drainage operation.

However, on the other hand, due to rapid urbanization in recent years, when the amount of rainfall increases, the inflow of rainwater into the drainage station becomes large and rapid, and the drainage station may be flooded. By the way, even if the drainage plant is flooded, the mission of the plant is to be able to continuously perform drainage operation for a certain period.

[0006]

However, when the rainfall is large and the plant is flooded, mineral oil-based turbine oil (specific gravity 0.87) in the bearing device flows out, and turbine oil is required. The part is replaced by rainwater (pumping liquid). Calculating the lubricating film thickness formed on the sliding surface of the thrust bearing under the condition that the lubricating oil is replaced by rainwater, the surface pressure in the case of rainwater is 2.5 MPa, the film thickness is 10 μm or less, which is lower than the required film thickness. It was found that stable bearing performance could not be obtained.

On the other hand, since the guide bearing portion has a small bearing load, a ceramic bearing can be used even under the condition of replacing rainwater.

As described above, in the conventional bearing device, the drainage pump stops and the drainage operation becomes impossible due to damage caused by poor lubrication of the thrust bearing portion. That is, in the bearing device structure having the above-described thrust bearing portion, it is impossible to perform a long-time drainage operation due to the inflow of rainwater (pumped liquid) into the bearing portion.

An object of the present invention is to provide a bearing device capable of obtaining stable bearing performance for a long period of time in view of the problems of the prior art. An object of the present invention is to provide a vertical shaft drainage pump capable of obtaining reliability.

[0010]

In a bearing device according to the present invention, a thrust block is fixed to a pump main shaft, and a bearing case is arranged at an outer peripheral position of the thrust block.
A plurality of segment-shaped guide bearings arranged along the circumferential direction between the bearing case and the thrust block, a collar attached to the lower part of the thrust block, and a plurality of pad-type thrust bearings arranged facing the collar; An oil tank for storing the lubricating liquid for these bearings is provided, and a lubricating liquid storage section is provided only in the pad-type thrust bearing section in the oil tank.

In the bearing device of the present invention, as described above, the means for storing the lubricating liquid in the thrust bearing sliding portion in the oil tank is provided. Since it is lubricated with a lubricating liquid, damage is reliably prevented.
In addition, since the amount of the lubricating liquid flowing out of the oil tank can be reduced, it is effective in preventing contamination. Further, since the sliding portion of the thrust bearing can be prevented from being damaged by foreign matter, the reuse can be achieved by replacing only the lubricating liquid.

By using the bearing device having the above structure for a vertical shaft drain pump of a drainage station, a large amount of rainfall occurs, the drainage station is flooded, and thrust bearings are provided even if rainwater enters the oil tank in the bearing of the vertical shaft pump. Since the lubricating liquid in the sliding portion is not replaced by rainwater, a bearing device exhibiting stable bearing performance over a long period of time can be obtained. By applying this bearing device to a pump, high reliability as a pump can be obtained.

[0013]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to FIGS. FIG. 1 is a longitudinal sectional view showing a first embodiment of the bearing device according to the present invention. The bearing device 16 shown in FIG. 1 is mainly used for a vertical shaft drain pump described later, and is disposed below the transmission 18 to support the pump main shaft 1.

The bearing device 16 is configured as follows. A thrust block 2 is fixed to the pump main shaft 1. A bearing case 4 is arranged at an outer peripheral position of the thrust block 2. A plurality of segment-shaped guide bearings 3 are arranged between the bearing case 4 and the thrust block 2 along the circumferential direction. A collar 9 is attached to a lower portion of the thrust block 2. A plurality of pad-type thrust bearings 10 arranged opposite to the collar 9; an oil tank 6 for storing a lubricating fluid 19 for these bearings;
The inner cylinder 7 and the outer cylinder 8, which are the lubricating fluid storage sections only in the pad-type thrust bearing section in the oil tank, are provided with the collar 9 and the thrust bearing 1.
0 is provided so as to surround it at a predetermined interval.

Here, the oil tank 6 comprises an inner cylindrical member 6a and an outer cylindrical member 6b fixed to the bearing casing 11. Further, a cover 27 is fixed to an upper portion of the outer peripheral side cylindrical member 6b. The guide bearing 3 is a bearing case 4
After a predetermined bearing clearance is set by the bolts 5 mounted on the nuts, the nuts 21 are fixed at fixed positions by nuts 21.

The lubricating fluid reservoir is a pad-type thrust bearing 10
The inner cylinder 7 and the outer cylinder 8 are fixed to the lower portion of the thrust block 2 so as to surround the inner and outer circumferences of the inner cylinder.

The guide bearing 3 and the thrust bearing 10
At the time of assembling, a predetermined amount of mineral oil-based turbine oil is injected into the oil tank 6 as the lubricating liquid 19. A lateral hole 8a is provided in the outer cylinder 8 to reliably remove air remaining in a gap surrounded by the inner cylinder 7 and the outer cylinder 8 fixed to the lower part of the thrust block 2. The thrust portion stopper 12 is removed, and turbine oil is supplied. After confirming that the air in the gap surrounded by the inner cylinder 7 and the outer cylinder 8 fixed to the lower part of the thrust block 2 has escaped from the lateral hole 8a, the thrust portion stopper plug 12 is attached.

In the bearing device thus constructed, when the drainage pumping station is flooded, rainwater flows through the gap between the inner cylindrical member 6a constituting the oil tank 6 and the pump main shaft 1 as shown by the arrow in the figure. It flows in and enters the oil tank. Thereafter, while pushing out the lubricating liquid 19 from the oil tank 6, the clearance reaches the gap formed by the bearing casing 11 and the lower surface of the pad-type thrust bearing 10, passes through the outer peripheral portion of the outer cylinder 8, and passes through the cover 27 and the thrust block 2 From the bearing device to the outside of the bearing device. At this time, since the lubricating liquid 19 at the time of installation is smaller in specific gravity than river water, the lubricating liquid 19 remains in the gap surrounded by the inner cylinder 7 and the outer cylinder 8 fixed to the lower part of the thrust block 2.

On the other hand, during the rotation of the pump main shaft 1, the speed component in the circumferential direction is large, and almost no upward flow component is generated.
Therefore, rainwater does not flow into the gap surrounded by the inner cylinder 7 and the outer cylinder 8 fixed to the lower part of the thrust block 2.

As a result, the lubricating liquid 19 remaining in these gaps is not washed by rainwater.

For this reason, since the thrust bearing sliding portion 20 is immersed in the lubricating liquid 19, continuous operation can be performed for a long time.

The lubricating fluid 19 remaining in the gap surrounded by the inner cylinder 7 and the outer cylinder 8 fixed to the lower part of the thrust block 2
Is large, the amount of the lubricating liquid 19 flowing out of the bearing device can be reduced, and the contamination due to flooding can be reduced.
Also, an inner cylinder 7 and an outer cylinder 8 fixed to the lower part of the thrust block.
There is no inflow of rainwater into the gap surrounded by, so that there is no damage to the bearing portion due to foreign substances and the like contained in the rainwater. Therefore, when re-installing after flooding, the pad-type thrust bearing 1
Since the 0 and the collar 9 can be diverted and only the lubricating liquid 19 needs to be replaced, the replacement cost can be greatly reduced.

Further, even during flooding, the lubricating fluid 19 is held in the thrust bearing sliding portion 20, so that the pump can be started and stopped. Therefore, even if the pump of the main engine stops due to a trouble of equipment other than the pump, the restart can be easily performed and high reliability can be achieved.

FIG. 2 is a longitudinal sectional view showing a second embodiment of the bearing device according to the present invention.

1 differs from FIG. 1 in that a guide bearing is not provided on the outer peripheral side of the thrust block 2 and a pad-type thrust bearing 10 in the oil tank 6 is provided with a lubricant storage. .

According to this embodiment, basically the same operation and effect as those of the first embodiment can be obtained.

Table 1 shows the results obtained by analyzing the static pressure of the thrust bearing portion surrounded by the inner cylinder 7 and the outer cylinder 8 fixed to the lower part of the thrust block 2 of the present invention.

[0028]

[Table 1]

The calculation positions of the static pressure are P1, P shown in FIG.
2, P3 and P4. P1 is inside the outer cylinder 8 near the lower surface of the thrust block 2 and on the outer peripheral side of the thrust bearing 10. In P2, the radius and the circumferential position are the same as P1, and only the height direction is changed to be near the lower end of the outer cylinder 8. P3 is outside the inner cylinder 8 near the lower surface of the thrust block 2 and on the inner peripheral side of the thrust bearing 10. In P4, the radius and the circumferential direction position were the same as P2, and only the height direction was changed to be near the lower end of the inner cylinder 7. The rotation speed is 274 rpm of the rated operation of the actual machine, and the lubricating fluid is turbine oil VG68.

As shown in Table 1, comparing the pressures of P1 and P2, P2 is higher by 0.0033 MPa. Also,
Comparing the pressures of P3 and P4, P4 is 0.001.
5MPa higher.

From these analysis results, the thrust block 2
Since the static pressure near the lower surface of the thrust block 2 surrounded by the inner cylinder 7 and the outer cylinder 8 fixed to the lower part is lower than the vicinity of the lower ends of the inner cylinder 7 and the outer cylinder 8, the static pressure is surrounded by the inner cylinder 7 and the outer cylinder 8. It has been found that the lubricating liquid 19 in the formed gap is not pushed out from the gap and is retained.

FIG. 3 is a longitudinal sectional view showing a third embodiment of the bearing device according to the present invention.

1 is different from FIG. 1 in that the lubricating fluid storage portion is fixed to the lower portion of the thrust block 2 in the inner cylinder 7.
And the outer cylinder 8 and the rectifying plate 13 provided on the lower surface of the thrust bearing 10.

According to the present embodiment, basically, the same functions and effects as those of the first and second embodiments can be obtained. Further, the gap formed between the straightening plate 13 provided on the lower surface of the thrust bearing and the inner cylinder 7 and the outer cylinder 8 can be narrowed, so that rainwater hardly enters. In addition, since the flow is rectified in the inflow direction (radial direction) of the rainwater, the lubricating liquid and the rainwater are rectified by the rectification plate 13.
Can be reliably separated into boundaries, thereby improving reliability.

FIG. 4 is a longitudinal sectional view showing a fourth embodiment of the bearing device according to the present invention.

This embodiment is different from the first embodiment in that the lubricating fluid reservoir is fixed to the lower part of the thrust block 2 and the inner cylinder 7 is coated with a fluororesin 7a on the outer periphery and the inner cylinder 7 is And the outer cylinder 8 coated with the fluororesin 7a.

According to the present embodiment, basically the same operation and effect as those of the first embodiment can be obtained. Further, since the stored lubricating liquid 19 slides on the contact surface of the inner cylinder 7 and the outer cylinder 8 fixed to the lower part of the thrust block 2 and coated with the fluororesin 7a, the rotational speed of the lubricating liquid 19 is reduced. In addition, power can be saved by reducing stirring loss.

FIG. 5 is a longitudinal sectional view showing a fifth embodiment of the bearing device according to the present invention.

This embodiment differs from the first embodiment in that, in a plurality of pad-type thrust bearing structures arranged opposite to the lower surface of the thrust block 2, the thrust bearing 10 is directly mounted on the lower surface of the thrust block 2. It is in the point provided. The point that the lubricating liquid storage section is provided only in the thrust bearing 10 is the same as FIG. The lubricating liquid storing section has the same structure as that of FIG.

According to this embodiment, basically the same operation and effect as those of the first embodiment can be obtained. Further, since no collar is attached between the thrust bearing 10 and the thrust block 2, the structure is simple and the cost can be reduced.

Next, a case where the bearing device of the present invention is applied to a vertical shaft drain pump will be described.

That is, as shown in FIG. 6, the vertical shaft drain pump has a pump main shaft 1, a runner 17 fixed to a lower portion of the pump main shaft 1, the pump main shaft 1, and a water flow passage formed therein. It has a pump casing 14 and a bearing device 16 of the present invention which is mounted above the pump casing 14 and rotatably supports the pump main shaft 1.

The bearing device 16 includes a thrust block 2 fixed to the pump main shaft 1, a bearing case 4 arranged at an outer peripheral position of the thrust block 2,
And a plurality of segment-shaped guide bearings 3 arranged along the circumferential direction between the thrust block 2 and the thrust block 2.
Only the collar 9 attached to the lower part, the plurality of pad-type thrust bearings 10 arranged opposite to the collar 9, the oil tank 6 for storing a lubricating liquid for these bearings, and the pad-type thrust bearing portion in the oil tank. And a lubricating fluid storage unit provided.

According to the embodiment, even if rainwater flows into the bearing device 16 of the present invention from the upper surface 14a of the pump casing 14, the lubricating liquid 19 is stored in the thrust bearing portion, so that the thrust bearing sliding portion 20 It is in a state of being immersed in the lubricating liquid 19, and stable bearing performance can be obtained.

Therefore, the vertical shaft drain pump having the bearing device of the present invention can obtain high reliability as a pump.

[0046]

As described above, in the bearing device of the present invention, as described above, only the thrust bearing portion is provided in the oil tank so that the lubricating fluid storage portion is provided. Since the bearing sliding portion is lubricated with the lubricating liquid, damage is reliably prevented. In addition, since the amount of the lubricating liquid flowing out of the oil tank can be reduced, it is effective in preventing contamination. Furthermore, since the sliding portion of the thrust bearing can be prevented from being damaged due to foreign matter or the like, it is sufficient to replace only the lubricating liquid at the time of replacement after flooding, thereby saving replacement costs.

As a result, stable bearing performance can be maintained for a long period of time even if rainwater enters the oil tank due to flooding.

Also, by applying a bearing device capable of maintaining stable bearing performance to a vertical shaft drainage pump, high reliability as a pump can be obtained.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view showing a first embodiment of a bearing device according to the present invention.

FIG. 2 is a longitudinal sectional view showing a second embodiment of the bearing device according to the present invention.

FIG. 3 is a longitudinal sectional view showing a third embodiment of the bearing device according to the present invention.

FIG. 4 is a longitudinal sectional view showing a fourth embodiment of the bearing device according to the present invention.

FIG. 5 is a longitudinal sectional view showing a fifth embodiment of the bearing device according to the present invention.

FIG. 6 is a longitudinal sectional view showing a vertical shaft drainage pump to which the bearing device according to the present invention is applied.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Pump main shaft, 2 ... Thrust block, 3 ... Guide bearing, 4 ... Bearing case, 5 ... Adjustment bolt, 6 ... Oil tank, 7 ...
Inner cylinder, 7a: Fluororesin coated surface, 8: Outer cylinder, 8
a ... side hole, bearing casing, 9 ... collar, 10 ... thrust bearing, 11 ... bearing casing, 12 ... closure plug, 13 ...
Rectifying plate, 14: pump casing, 14a: upper surface of pump casing, 15: bearing device constituted only by guide bearing portion, 16: bearing device, 17: runner, 18: transmission, 19: lubricating liquid, 20: thrust Bearing sliding part, 21 ...
Nut, 27 ... cover.

 ────────────────────────────────────────────────── ─── Continuing on the front page (72) Inventor Shigenobu Nagasawa 603, Kandamachi, Tsuchiura-shi, Ibaraki F-term in Tsuchiura Works, Hitachi Ltd. (Reference) 3H022 AA01 BA06 CA15 CA18 CA43 DA13 3H071 AA01 BB03 CC26 CC27 DD46

Claims (6)

[Claims] 1. A thrust block is fixed to a pump main shaft, and a bearing case is arranged at an outer peripheral position of the thrust block, and a plurality of segment-shaped guides are arranged between the bearing case and the thrust block along a circumferential direction. In a bearing device provided with a bearing, a collar attached to a lower part of the thrust block, a plurality of pad-type thrust bearings arranged opposite to the collar, and an oil tank storing lubricating fluid for the bearing, A bearing device comprising a pad-type thrust bearing portion provided with a lubricating liquid storage portion. 2. A thrust block is fixed to a pump main shaft, a collar attached to a lower portion of the thrust block, a plurality of pad-type thrust bearings disposed opposite to the collar, and an oil tank storing lubricating fluid for the bearings. In the provided bearing device, a lubricating liquid storage part is provided in a pad type thrust bearing part in the oil tank. 3. A thrust block is fixed to a pump main shaft, and a bearing case disposed at an outer peripheral position of the thrust block, and a plurality of segment-shaped guides disposed along the circumferential direction between the bearing case and the thrust block. In a bearing device provided with a bearing, a plurality of pad-type thrust bearings disposed opposite to a lower surface of a thrust block, and an oil tank for storing lubricating liquid for the bearing, a lubricating liquid is stored in a pad-type thrust bearing portion in the oil tank. A bearing device comprising a part. 4. A pump main shaft, a blade fixed to a lower portion of the pump main shaft, a pump casing through which the pump main shaft is inserted, and a water flow passage formed therein, and mounted above the pump casing. A vertical shaft drainage pump having a bearing device rotatably supporting the pump main shaft, wherein the bearing device has a thrust block fixed to a pump main shaft, and a bearing case disposed at an outer peripheral position of the thrust block; A plurality of segment-shaped guide bearings arranged along the circumferential direction between the bearing case and the thrust block, a collar attached to the lower part of the thrust block, and a plurality of pad-type thrust bearings arranged facing the collar; And an oil tank for storing the lubricating liquid for the bearing, and a lubricating liquid storage section is provided in a pad-type thrust bearing section in the oil tank. A vertical shaft drainage pump characterized by the following. 5. A pump main shaft, a blade fixed to a lower portion of the pump main shaft, a pump casing through which the pump main shaft is inserted, and a water flow passage formed therein, and mounted above the pump casing. And a bearing device that rotatably supports the pump main shaft, wherein the bearing device has a thrust block fixed to the pump main shaft,
A collar attached to the lower part of the thrust block, a plurality of pad-type thrust bearings disposed opposite to the collar, and an oil tank for storing a lubricating liquid for these bearings, wherein a lubricating liquid is stored in a pad-type thrust bearing in the oil tank. A vertical shaft drain pump characterized by comprising means. 6. A pump main shaft, a blade fixed to a lower portion of the pump main shaft, a pump casing through which the pump main shaft is inserted to form a water flow passage therein, and a pump casing mounted above the pump casing. A vertical shaft drain pump having a bearing device rotatably supporting the pump main shaft, wherein the bearing device has a thrust block fixed to the pump main shaft, and a bearing case disposed at an outer peripheral position of the thrust block; A plurality of segment-shaped guide bearings disposed in the circumferential direction between the bearing case and the thrust block, a plurality of pad-type thrust bearings disposed opposite to the lower surface of the thrust block, and a lubricating fluid for the bearing. A vertical shaft drainage pump comprising an oil tank for storing, and a lubricating liquid storage section provided in a pad-type thrust bearing section in the oil tank. H.