JPS62228671A - Bearing device for pelton turbine - Google Patents

Abstract

PURPOSE:To increase the load capacity of bearing metals by forming a gap between a bearing metal arranged at a position to be applied with an unbalanced load by a jet under the one-jet operation and a rotary main shaft larger than gaps between other bearing metals and the rotary main shaft. CONSTITUTION:A runner 2 is fitted to a main shaft 1, buckets 6 are fitted to the outer periphery of the runner 2, and nozzles 7 are arranged around the runner 2. Clearances between a main shaft 3 and individual bearing metals 11 are maintained at CNW except for a bearing metal 11a arranged at a position facing the spray direction A of the jet sprayed through a nozzle 7a under the one-jet operation. Only the clearance of the bearing metal 11a is formed larger than CNW. Accordingly, an unbalanced load having been concentratively applied to one bearing metal can be distributed to bearing metals on both sides.

Description

[Detailed Description of the Invention] [Objective of the Invention] (Industrial Field of Application) The present invention relates to a bearing device for a Pelton water turbine, and in particular, the present invention relates to a bearing device for a Pelton water turbine. The present invention relates to a bearing device for a Pelton water turbine in which the bearing metal is arranged so as to increase the load capacity of the bearing metal without increasing the size or complexity of the bearing device.

(Prior art) In bearing devices for machines such as Pelton water turbines where the peripheral speed of the rotating main shaft is high, a sliding bearing having a plurality of segment-shaped bearing metals is used to prevent damage to the rotating main shaft. .

Figures 5 and 6 show a vertical shaft Pelton water turbine with a rotating main shaft arranged in the vertical direction. It is formed by directly connecting the generator main shaft 5. A plurality of buckets 6 are attached to the outer circumference of the runner 2, and a plurality of nozzles 7 are arranged around the runner 2 to eject high-speed jets toward the buckets 6. The runner 2, which rotates by receiving the jet ejected from the nozzle with the bucket 6, absorbs the water power of the jet and transmits the water power to the rotating main shaft 1, causing the rotating main shaft 1 to rotate at high speed. Therefore, in order to support the rotating main shaft 1, a water turbine bearing 8 and a power generation 15N bearing 9 are provided on the water turbine top@3 and the generator main shaft 5, respectively, and a generator upper bearing 10 is further provided as necessary. .

Sliding bearings are adopted for the water turbine bearing 811'3 and the Jl bearing 9, and as shown in FIG. A plurality of segment-shaped bearing metals 11.13 of the same shape are connected to the main shaft 3 of the water turbine and the main shaft 5 of the generator with a constant clearance CNW, CI4°.
It is structured to surround.

In a Pelton water turbine equipped with such a bearing device, in order to improve efficiency or adjust output during partial load operation, operation is performed with only some of the plurality of nozzles 7 released. There is. In particular, during one-jet operation with only one nozzle open and all other nozzles closed, water power acts on one point of the runner 2 in the jet ejection direction A, so the rotating main shaft 1 experiences a bending moment due to the jet. acts, and the rotating main shaft 1 is largely deflected. For this reason,
At the water turbine bearing 8 position, the FD 13 on the water turbine is eccentric in the jet jetting direction, and at the power generation @bearing 9 position, the generator main shaft 5 is eccentric in the opposite direction to the jet jetting direction A. A large load acts in the eccentric direction of the main shafts 3 and 5, and a large eccentric load acts on each bearing metal 11a and 13a located in this eccentric direction. Since such a load causes premature wear of the bearing metal, it has conventionally been necessary to use a bearing metal with a large load capacity, which is placed at the location 1d where the uneven load is applied. If a part of the bearing metal is made larger due to the unbalanced load that occurs during one-jet operation, as in the case of There was a problem that the efficiency of the entire water turbine decreased as well as the cost increased due to the

Therefore, as shown in FIG. 7, without increasing the size of the bearing metal 21 at the position where the unbalanced load occurs, the pressure oil supply line is connected to the external pressure oil generator 22 and pressure oil control device 23. A technique has been proposed to increase the load capacity of the bearing metal 21 by supplying high-pressure lubricating oil to the bearing metal 21 through the bearing metal 24, but such a bearing device has a problem in that the structure is complicated and the cost is high. In addition, if the pressure oil supply system fails during operation, the bearings will immediately burn out, leading to a serious accident.

(Problems to be Solved by the Invention) In this way, in conventional bearing devices, the bearing metal is increased in size by increasing the size of the bearing metal or by supplying pressure oil to the bearing metal to cope with the unbalanced load that occurs during one jet operation. We have been working to increase the load capacity of

However, the conventional technology has the problem that the bearing device becomes larger or more complex, and the cost of the entire bearing device increases.

SUMMARY OF THE INVENTION Therefore, it is an object of the present invention to provide a bearing device for a Pelton water turbine which is compact, has a simple structure, and has a large load capacity of the bearing metal, by solving the problems of the above-mentioned prior art.

(Structure of the Invention) (Means for Solving the Problems) In order to achieve the above object, the present invention provides an unbalanced load caused by the jet during one jet operation in which a jet is ejected from one nozzle toward a bucket of a runner. The gap between the bearing metal disposed at the receiving position and the rotating main shaft is made larger than the gap between the other bearing metals and the rotating main shaft/sleeve.

(Function) During 1-jet operation, the rotating main shaft is bent and eccentrically located inside the bearing due to the bending moment caused by diene 1~, and an eccentric load from the jet acts on the bearing metal located in the eccentric direction of the rotating main shaft. The large clearance between the bearing metal that receives the load and the rotating main shaft absorbs the amount of eccentricity of the rotating main shaft, and the eccentric load concentrated on one bearing metal can be dispersed to the bearing metals on both sides.

(Example) Hereinafter, an example of a bearing device for a Pelton water turbine according to the present invention will be described with reference to FIGS. 1 to 4.

Note that the same reference numerals are used for parts that are the same as in the prior art.

FIG. 1 shows a bearing device according to the present invention adopted as the rotating main shaft of a vertical shaft Pelton water turbine. are formed by being directly connected. A plurality of buckets 6 are attached to the outer circumference of the runner 2, and a plurality of nozzles 7 are arranged at predetermined intervals around the runner 2 so as to spray jets of pressurized water toward the buckets 6. has been done. In the case of this embodiment, as shown in FIG. 2, the number of nozzles 7 is four, and the jets ejected from each nozzle 7aPJ to 7d hit the bucket 6 at a position 90 degrees apart from each other. . In addition, during 1-jet operation in which only one nozzle is left open and the other nozzles are closed in order to improve efficiency or adjust output during partial load operation, nozzle 7a is used among the above-mentioned nozzles 7a to 7d. .

Also, the runner 2 rotates by receiving the jet in the bucket 6.
The main shaft of the water turbine 3 is provided with a water wheel bearing 8, and the main shaft of the generator 5 is provided with a generator bearing 9 to support the main shaft 1 rotated by water power transmitted through the main shaft. A generator upper bearing 10 is provided at the upper end of the generator 5 . The water turbine bearing 8 has six segment-shaped bearing metals 11 of the same shape arranged around a skirt-like support portion 3a integrally formed on the outer periphery of the water turbine main shaft 3, as shown in FIG. , the back of each bearing metal 11 is supported by a pivot 12 provided on a bearing stand (not shown).The clearance between the water turbine owner @3 and each bearing metal 11 is as follows: 1 jet for operation 1r, 1 for nozzle The bearing metal 11a is kept ON, 4, except for the bearing metal 11a disposed at a position opposite to the jetting direction A of the jet ejected from the bearing metal 11a.
Clearance of a only C,,=(1,25~2.5)C
N, which is larger than the other bearing metals 11.

Similarly, the power line bearing 9 is connected to the support part 5 on the generator @5.
A bearing metal 13 whose back side is supported by a pivot 12 is arranged around a, and the clearance between the generator main shaft 5 and each bearing metal 13 is in the opposite direction to the jet ejection direction A during one jet operation. The bearing metal 13a is maintained at CNG except for the bearing metal 13a disposed at the opposing position.
Clearance of a only C-(1,25~2.5)C14
o and other LG bearing metals 13.

Therefore, when the Pelton water turbine equipped with the bearing device according to the above embodiment is operated with one jet in order to improve efficiency and adjust the output during partial load operation, the water power generated by the jet is applied to one point of the runner 2. The rotating main shaft 1, which consists of the water turbine main shaft 3, the generator main shaft 5, etc., has a diagonal. As a result of the bending moment exerted by the rotating shaft 1, the rotating main shaft 1 is bent in an arched shape as shown by the broken line in FIG. Therefore, at the 8th position of the water turbine bearing, the main shaft 3 of the water turbine is eccentric in the direction of jet ejection, as shown by the broken line in Fig. 2, and at the 9th position of the power generation rock bearing, the power generation shaft 5 is in the opposite direction to the jet ejection direction A. Since the bearings 8.9 are eccentric in the direction, a large load acts on each bearing 8.9 in the eccentric direction of the bearings 3, 5, and each bearing metal 11a is located in the eccentric direction, that is, in the jet ejection direction.

A large unbalanced load will act on 13a. However, in the bearing device of this embodiment, as described above, each bearing meckle 11a is located in the eccentric direction of the water turbine main shaft 3 and the generator main shaft 5, and receives a large eccentric load.

13a's clearance C1, CLG is the other bearing metal 1
Since the clearances C and C of 1.13 are formed to be too large, the rotating main shaft 1 is
The main shafts 3 and 5 are eccentric and have a large rearance CC.
absorbs the amount of eccentricity of each main shaft 3.5, and the eccentric load that was conventionally supported by one bearing metal 11a, 13a is transferred to the bearing metal 11b on both sides.

13b, water wheel bearings 8 and '5
The load on the bearing metal of the 1 mA bearing 9 can be evenly distributed.

Incidentally, the large clearance values Cv and CLG of the water turbine bearing 8 and the generator bearing 9 are both determined by experiments. For example, in the case of the water turbine bearing 8, as shown in FIG. 3,
The load on the bearing metal 11a at a position opposite to the eccentric direction of the water turbine main shaft 3, that is, the ejection direction A of the jet, is represented by 8 curves, and the load on the bearing metal 11b located on both sides of this bearing metal 11a is represented by a C curve, and each bearing metal 11a is represented by a C curve. , 11b, we find that C
It has been found that when L/C, is less than 1.2, the load on the bearing metal 11a increases, and when O L,/CN exceeds 12.5, the load on the bearing metal 11b increases.

For this reason, if the clearance of the bearing metal 11a on which an unbalanced load acts is set to C, = (1, 2 to 2.5) CNW, the unbalanced load that was conventionally supported by the bearing metal 11a can be removed by the bearing metals 11a on both sides. The load on the bearing metal of the water turbine bearing 8 can be made even. Also, for the same reason, the clearance of the generator bearing 9 is set to C3゜=(1
, 25-2.5) Set to CIIG.

In addition, during steady operation when the same hanging jet is ejected from all nozzles 7, the water power of the jet moves equally to the runner 2, so the bending moment due to the jet does not act on the rotating main shaft @1. 1 rotates smoothly without eccentricity or shaft wobbling. For this reason, the water turbine bearing 8
Also, no unbalanced load occurs on the generator bearing 9, and the load acting on each bearing metal 11. No problem arises.

FIG. 4 shows another embodiment of the bearing device according to the present invention, in which the bearing metal 14 of the water turbine bearing 8 and the generator bearing 9 is shown.
．． The total number of 15 is an integral multiple of the total number of nozzles, and a bearing metal with a large clearance between the rotating main shaft 1 and the bearing metal is arranged at a position where it receives the unbalanced load from the jet. A rotating main shaft and a bearing metal having a small clearance are arranged between them, and bearing metals having a large clearance and bearing metals having a small clearance are arranged alternately. In the case of this embodiment, since the number of nozzles 7 is four, the number of bearing metals 14 in the water turbine bearing 8 is eight, and these bearing metals 14 are supported by the pivot 12 and arranged so as to surround 3 on the water turbine owner @. are doing. Among the bearing metals 14, four bearing metals 14 are arranged at positions facing the jet ejection direction of the nozzles 7a to 7d.
a indicates four bearing metals 14b between which the clearance between the bearing metals 14a and the water turbine bearing 3 is CMW.
The clearance C1- is made larger than that, and this clearance is set to C=(1,25 to 2.5)CI4.

Similarly, the power generation Ia+ll bearing 9 has a bearing metal 15 of 8.
The clearance CN6 of the four bearing metals 15a disposed at a position δ relative to the jet ejection direction of each nozzle 7a to ff17d is the same as that of the other bearing metal 15b.
The clearance is larger than the clearance CL6, and this clearance is set to C1o=(1,25 to 2°5)CNo.

In this embodiment, since the number of nozzles 7 is four, the unbalanced loads of the water turbine bearing 8 and the generator bearing 9 are received by the four bearing metal 1.
The arrangement positions of 4a and 15a are -.

Therefore, when one jet operation is performed using any one of the nozzles 7a to 7d in the Pelton water turbine equipped with the bearing device according to the above embodiment, a bending moment 1~ is applied to the rotating main shaft 1 by the jet, Unbalanced loads act on each of the supporting metals 14 and 15 of the water turbine bearing 8 and the generator bearing 9. However, the bearing metal 14a is located at a position where this unbalanced load acts.

Clearance C1C of 15a is large LW in advance
LG is formed so that even if the rotating main shaft 1 is eccentric due to the bending moment, this eccentricity can be maintained by the clearance C,
LW LG can be absorbed by LW LG, and the uneven load that was conventionally supported by one bearing metal can be distributed to the bearing metals on both sides. Therefore, according to this embodiment, one jet operation can be performed using any one of the plurality of nozzles, and since the clearance for half of the bearing metal is formed large, all the nozzles can be used. Bearing loss in the bearing metal during steady operation can be reduced.

〔Effect of the invention〕

As is clear from the explanation below, according to the present invention,
During one jet operation, the gap between the bearing metal placed at a position that receives the unbalanced load from the jet and the rotating main shaft is made larger than the gap between other bearing metals and the rotating main shaft.
The large gap between the bearing metal and the rotating main shaft absorbs the amount of eccentricity of the rotating main shaft caused by the jet, and the uneven load concentrated on one bearing metal can be dispersed to the bearing metals on both sides. Therefore, it is possible to equalize the load on all bearing metals of the bearing device, and to reduce the load capacity of the bearing metals, where uneven loads were concentrated in the past, without increasing the size of the bearing metals, and without increasing the size of the bearing metals. It is possible to obtain a bearing device that is small, has a simple structure, and is low in cost.

[Brief explanation of drawings]

Figure 1 is a schematic configuration diagram of a vertical shaft Pelton turbine equipped with a bearing device according to the present invention, and Figure 2 (Δ) (+3) (C) is a
A schematic layout diagram taken along lines A-A, B-B, and C-C in the figure. Figure 3 shows changes in the load of the bearing metal located in the eccentric direction of the co-rotating main shaft and the bearing metal on both sides. 4(A), 4(B), and 4(C) are schematic explanatory views showing other embodiments of the bearing device according to the present invention, and FIG. 5 is a diagram showing a vertical shaft Pelton water turbine equipped with a conventional bearing device. Schematic explanatory diagram, Figure 6 (A
)(B)(C) are lines A-A, line B-B, and C-C in Figure 5.
FIG. 7 is a schematic layout diagram as viewed along the line, and is a schematic configuration diagram showing a modification of the conventional bearing device. DESCRIPTION OF SYMBOLS 1... Rotating main shaft, 2... Runner, 3... Water turbine main shaft, 5... Generator main shaft, 6... Bucket, 7... Nozzle, 8... Water turbine bearing, 9...・″1den #f1@Uke,
11, 13.14. . 15...Bearing metal, 11a, 13a, 14a. 15a... Bearing metal that receives unbalanced load, 12... Pivot, CNW, CuI2... Bearing clearance of water turbine bearing, CN6, CLG... Bearing clearance of generator bearing, A... During 1 jet operation direction of the jet. Applicant's agent Sato - Yu $1 (C) Third category (C) $Ushizu

Claims (1)

[Claims] 1. In a bearing device for a Pelton water turbine in which a rotating main shaft with a runner attached to the end is supported by a segment-shaped bearing metal; a jet is ejected from one nozzle toward the bucket of the runner. 1. A bearing device for a Pelton water turbine, characterized in that the gap between a bearing metal disposed at a position receiving an unbalanced load from the jet and the rotating main shaft is larger than the gap between other bearing metals and the rotating main shaft during one jet operation. . 2. The gap between the rotating main shaft and the bearing metal at the position receiving the above unbalanced load is 1.2 of the gap between the other bearing metal and the rotating main shaft.
A bearing device for a Pelton water turbine according to claim 1, characterized in that the bearing device is formed to be 2.5 times larger.