JP3072045B2 - Vertical power turbine and gas turbine equipped with the same - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vertical output turbine whose output shaft is supported almost vertically and a gas turbine provided with the same.

[0002]

2. Description of the Related Art For example, when there is a shortage of space in a horizontal direction at a place where a gas turbine is to be installed, a load device such as a generator to be driven by the gas turbine is mounted on a gas turbine installation reference plane. In addition to being installed below (underground), the output turbine may be a vertical type with an output shaft supported vertically so that it can be easily connected to a load device. In this case, since the output shaft of the gas turbine rotates at high speed, it is supported by journal bearings and thrust bearings, and it is necessary to forcibly supply a large amount of lubricating oil to these bearings for cooling. is there. The lubricating oil after lubricating this bearing is sufficient for a general horizontal output turbine if the falling lubricating oil is received in an oil receiving container. It flows down and leaks out through the gap between the output shaft and the casing.

[0003]

Therefore, it is conceivable to use an oil seal for preventing leakage of lubricating oil. As the oil seal, a surface-contact type in which a ring-shaped disk fixed to a bearing housing is pressed against a flange on a rotating shaft side by a spring, or a ring-type mechanical seal in which a seal ring is brought into contact with an outer peripheral surface of a rotating shaft (actually opened). 1987
When the output shaft rotates at a high speed as described above, the oil seal wears due to sliding with the rotating shaft, so that it is necessary to periodically perform inspection, maintenance, or replacement. Further, not only is the space for mounting the oil seal required, but also the output flange connected to the load device at the lower end of the output shaft complicates the structure of the mounting portion of the oil seal. Further, if the output shaft is lengthened in order to secure a space for the oil seal, there is a high possibility of causing a problem of shaft vibration.

Accordingly, the present invention provides a vertical power turbine capable of recovering lubricating oil after lubricating bearings without leaking, with a simple configuration that does not require a large installation space and that can be stably mounted. It is an object of the present invention to provide a gas turbine provided with such a gas turbine.

[0005]

In order to achieve the above-mentioned object, a vertical output turbine according to the present invention is an output turbine whose output shaft is set to be substantially vertical and takes out the energy of working gas as power. A plurality of bearings, which are spaced apart in the axial direction of the output shaft, rotatably support the output shaft, and house the bearings, and penetrate below the output shaft.
And the bearing box below the lowermost bearing
A shaft end oil reservoir which is located inside and receives the lubricating oil after bearing lubrication, and after lubricating other bearings located above the shaft end oil reservoir and above the lowermost bearing. One or more intermediate oil sumps for receiving lubricating oil, and an oil drainage passage for discharging lubricating oil from the oil sump to the outside of the bearing housing , further comprising a shaft end oil sump in the bearing housing .
The output shaft forms a penetrated bottom wall, and the shaft end oil
The inner peripheral standing wall of the reservoir and the output shaft or a part fixed thereto
A labyrinth seal portion is formed between the material and the material .

In the vertical output gas turbine, the lubricating oil after lubricating the bearing located above the lowermost bearing is:
Temporarily stored in one or more intermediate sumps. After lubricating the lowermost bearing, the lubricating oil is received in a shaft end oil reservoir located below this bearing. The lubricating oil accumulated in each of the oil reservoirs is discharged to the outside of the bearing housing through an oil drain passage. Therefore, leakage of the lubricating oil to the outside of the bearing housing is prevented. In addition, the bottom wall of the bearing box is formed by the oil sump at the shaft end
And the bottom wall of the bearing housing is also used for the shaft end oil reservoir
The structure is further simplified and separated into the bearing housing.
Lubricating oil from each of the bearings located between
The oil is securely received by the shaft end oil sump and leaks below it.
Never. Further, an inner peripheral standing wall of the shaft end oil reservoir,
A rabbit between the output shaft or a member fixed to the output shaft
A rinse seal is formed. This allows the lubricating oil and
This is the finely divided oil vapor that forms the oil sump at the shaft end and the output shaft.
Between the labyrinth seal part
Can be prevented.

As described above, without using an oil seal mechanism such as a mechanical seal having various problems,
An oil reservoir is provided below each of a plurality of bearings in a bearing housing, and a simple mechanism for collecting lubricating oil flowing down the output shaft into an oil reservoir and then discharging the oil reservoir, wherein a plurality of oil reservoirs are provided. Therefore, the individual components do not have a large shape and can be attached without requiring a large installation space.
Moreover, since there is no sliding portion, almost no inspection or maintenance is required. Also, if the lubricating oil overflows from the shaft end oil reservoir, it may leak out of the bearing housing immediately. Even if a large-capacity oil tank cannot be installed, the lubricating oil does not overflow from the shaft end oil reservoir and leak from the shaft end to below the bearing housing.

[0008]

It is preferable that an oil drain is provided on the output shaft or a member fixed to the output shaft so as to project lubricating oil radially outward by centrifugal force and drop into the oil reservoir. As a result, the lubricating oil that has dropped to the oil drain while traveling along the output shaft is blown off by centrifugal force due to the rotation of the oil drain that rotates integrally with the output shaft, and is forcibly dropped into the oil sump. Does not leak to the outside through the gap with the bearing box while traveling down the output shaft.

[0010]

Further, it is preferable that the inside of the bearing housing is maintained at a negative pressure by exhaust means. Thereby, the oil vapor in the bearing housing can be prevented from leaking out of the bearing housing, so that the oil sealing effect is further improved.

A gas turbine according to the present invention is a compressor for compressing air, a combustor for mixing and burning fuel in compressed air, and is driven by combustion gas from the combustor to drive the compressor. A gas generator having a compressor driving turbine, and the above-described vertical output gas turbine of the present invention using the combustion gas as a working gas are provided. Thereby, a gas turbine having all the above-mentioned effects of the vertical output gas turbine according to the present invention can be obtained.

[0013]

Preferred embodiments of the present invention will be described below in detail with reference to the drawings. FIG. 1 shows a gas turbine according to an embodiment of the present invention to which a vertical power turbine according to an embodiment of the present invention is applied.

A load device (not shown) such as a generator serving as a drive load of the gas turbine 1 has a drive shaft set substantially perpendicular to a horizontal reference plane L of a base K, and serves as a prime mover. Is supported on a reference plane L. The gas turbine 1 is of a two-shaft type, and has a gas generator 2 for generating high-temperature and high-pressure combustion gas G, a vertical output turbine 6 using the combustion gas G as a working gas, and a gas generator 2 for generating gas. And an intermediate duct 4 for introducing the combustion gas G into the output turbine 6. The gas generator 2 compresses the air flowing from the intake port 7 with a compressor (not shown), guides the compressed air to a combustor, mixes the fuel with the compressed air in the combustor, and burns the fuel. The compressor driving turbine is rotationally driven by using the generated high temperature and high pressure combustion gas G as power. The rotation axis of the gas generator 2 is the reference plane L of the base K.
, That is, horizontal in this example.

The vertical output turbine 6 has an output shaft 8 set substantially vertically, and an output flange 13 at the lower end of the output shaft 8 is connected to a load device (not shown). A gas introduction passage 18 communicating between the exhaust port 15 of the gas generator 2 and the cascade of the output turbine 6 is formed by the intermediate duct 4. The latter half of the gas introduction passage 18 is a scroll passage S that spirally surrounds the output shaft 8. A bearing box 10 for the output shaft 8 is provided inside the intermediate duct 4. The bearing box 10 is fixed to a base K, in which the output shaft 8 is rotatably supported by an upper journal bearing 22, an intermediate thrust bearing 23, and a lower journal bearing 24.

The intermediate duct 4 is connected to the casing 21 (or the bearing housing 1) of the output turbine 6 via expansion joints 51 and 52.
0), and a rear portion of the intermediate duct 4 is supported by a base K by a support frame (not shown).
The output turbine 6 is supported on a base K via support legs 19, and an upper part thereof is connected to an exhaust duct (not shown).

The combustion gas G generated in the gas generator 2 of the gas turbine 1 is ejected in a horizontal direction from the exhaust port 15 and flows into the scroll passage S through the gas introduction passage 18 of the intermediate duct 4. The combustion gas G that has flowed into the scroll flow path S spreads annularly around the output shaft 8 of the output turbine 6 along the scroll flow path S, and flows along the inner peripheral surface shape of the scroll flow path S while the output turbine Turn the flow direction toward the axial direction of 6, and as the working gas,
It is jetted from the outlet 27 toward a cascade of rotor blades 20 of the turbine rotor 17 of the output turbine 6 and stationary blades (nozzles) 22 fixedly supported on the casing 21, and an output shaft on which the turbine rotor 17 is fixed. 8 is driven to rotate. The output shaft 8 drives a load device.

FIG. 2 is a longitudinal sectional view of the bearing housing 10.
In the figure, the lubricating oil supplied to the lower oil distribution box 30 through the oil supply pipe 29 is supplied to the lower journal bearing 24 via the oil supply pipe 31, and the upper oil component is supplied via the oil supply pipe 32. Sent to the distributor 33,
Oil supply piping 3 from the upper oil distribution box 33
4 and 35 to the upper journal bearing 22 and the thrust bearing 23.

A portion of the output shaft 8 below the thrust bearing 23 is provided with an oil guide portion 3 bulging outward in a ring shape.
4 is formed, and an oil drain 37 is formed at the lower end of the oil guide portion 34. An intermediate oil reservoir 38 is provided below the oil guide portion 34 so as to surround the output shaft 8, and is fixed to the bearing housing 10. The intermediate oil reservoir 38 receives the lubricating oil after being lubricated by the upper journal bearing 22 and the thrust bearing 23,
It has a container shape that opens upward. Intermediate oil sump 38
The inner peripheral standing wall 38a is located closer to the output shaft 8 and closer to the axis than the outer peripheral end surface of the oil guide portion 34, so that the lubricating oil falling from the oil guiding portion 34 is It does not flow downward from the gap between the output shaft 8 and the output shaft 38a.

Further, a shaft end oil reservoir 39 is disposed below the lowermost journal bearing 24 so as to surround the output shaft 8. The shaft end oil reservoir 39 receives the lubricating oil lubricated by the lowermost journal bearing 24 and the lubricating oil dropped from above the bearing 24. The shaft end oil reservoir 39 forms the bottom wall of the bearing housing 10, and its inner peripheral standing wall 39 a is close to the output shaft 8.

An output flange 13 that rotates integrally with the output shaft 8 is spline-fitted to the lower end of the output shaft 8 and is fixed with a nut 14. At the upper end of the output flange 13, a cylindrical cover 41 provided with an oil drain 40 similar to that described above on the outer peripheral surface is fixed, and this cover 41 covers the upper and outer peripheries of the inner peripheral standing wall 39a of the shaft end oil reservoir 39. ing. The inner wall 39a of the cover 41 and the shaft end oil reservoir 39
As shown in FIG. 3, the labyrinth seal portion 42
Are formed. The labyrinth seal portion 42 includes
The compressed air extracted from the compressor of the gas generator 2 may be supplied to enhance the sealing property. A labyrinth seal portion 43 is also provided between the outer peripheral surface of the output flange 13 and the inner peripheral standing wall 39a.

Further, a breather 44 for maintaining the inside thereof at a negative pressure is connected to the bearing housing 10 of FIG. 2, and the breather 44 is provided in the exhaust gas passage of the output turbine 6 of FIG. Connected to the ejector 45, the inside of the bearing box 10 is exhausted by the ejector effect. The breather 44 and the exhaust gas ejector 45 constitute an exhaust unit. A power type exhaust pump may be used instead of the exhaust gas ejector 45. Oil drain pipes (oil drains) 47 and 48 are connected to the intermediate oil reservoir 38 and the shaft end oil reservoir 39, respectively, for discharging the lubricating oil accumulated therein to the outside of the bearing housing 10 by natural fall. ing.

Next, the operation of the vertical output gas turbine 6 will be described. The lubricating oil after lubricating the upper journal bearing 22 and the thrust bearing 23 travels down the output shaft 8 and is guided radially outward of the output shaft 8 by the oil guide portion 34, and then the oil drain 37. As a result, the oil is blown radially outward of the output shaft 8 by centrifugal force, falls into the intermediate oil reservoir 38, is temporarily stored in the intermediate oil reservoir 38, and is then discharged to the outside by the oil drain pipe 47. You. On the other hand, the lubricating oil after lubricating the lowermost journal bearing 24 is blown radially outward of the output shaft 8 by the centrifugal force of the oil drain 40, and falls into the shaft end oil reservoir 39, and this shaft end Sump 39
After being temporarily stored inside, the oil is discharged to the outside by an oil drain pipe 48. The discharged lubricating oil is supplied again from the oil supply pipe 29 into the bearing housing 10 by a pump (not shown).

As described above, the lubricating oil collecting mechanism in the bearing housing 10 is provided with the oil reservoirs 38, 39 at positions below the lower two bearings 23, 24 of the three bearings 22 to 24 in the bearing housing 10, respectively. This is a simple mechanism for collecting lubricating oil flowing down the output shaft 8 into the oil reservoirs 38 and 39 and then discharging the lubricating oil.

After the lubricating oil falling along the output shaft 8 is guided radially outward of the output shaft 8 by the oil guide portion 34, the lubricating oil is forcibly forced into the intermediate oil reservoir 38 while further flying outward by the oil drain 37. The lubricating oil hardly leaks downward from the gap between the output shaft 8 and the inner peripheral wall 38a of the intermediate oil reservoir 38. Since there is a larger space near the lower end of the output shaft 8 near the position where the intermediate oil reservoir 38 is located in the inner space of the bearing housing 10, the intermediate oil reservoir 38 is set to have a larger volume than the shaft end oil reservoir 39. Thus, most of the lubricating oil falling from above the intermediate oil reservoir 38 can be recovered. Therefore, even if the shaft end oil reservoir 39, which is the final stage means for receiving the lubricating oil, cannot have a large volume, the lubricating oil does not overflow and leak from the lower end of the output shaft 8 to below the bearing box 10. .

Therefore, the lubricating oil recovery mechanism in the output turbine 6 described above has a simple structure without using an oil seal mechanism such as a mechanical seal having various problems, and directly contacts the output shaft 8. Since there are no sliding parts, there is no need for regular inspection and maintenance, and there are few parts to replace. Further, since the two oil sumps 38 and 39 are arranged vertically separated from each other, their respective shapes do not become large, and can be attached without requiring a large installation space.
Furthermore, an oil drainer 3 that blows lubricating oil radially outward by centrifugal force
Since the lubricating oils 7 and 40 are provided, it is possible to reliably prevent the lubricating oil from leaking below the oil reservoirs 38 and 39 while traveling down the output shaft 8.

Further, since a labyrinth seal portion 42 is formed between the shaft end oil reservoir 39 and the output flange portion 13 fixed to the output shaft 8 and integrally rotating, the lubricating oil and the oil vapor in which the The labyrinth seal portion 42 can prevent the oil from leaking from between the shaft end oil reservoir 39 and the output shaft 8. Further, since the inside of the bearing housing 10 is evacuated and maintained at a negative pressure by exhaust means including a breather 44 and an exhaust gas ejector 45, the bearing housing 10
The oil vapor in the bearing housing 10 can be prevented from leaking to the outside of the bearing housing 10 due to the negative pressure in the inside, so that the oil leakage prevention effect is further improved.

The intermediate oil sump 38 may be provided in plural numbers, for example, one below the upper bearing 22 and one below the intermediate bearing 23.

[0029]

As described above, according to the vertical output turbine of the present invention or the gas turbine provided with the same, the lubricating oil
It is received in the intermediate oil sump and the shaft end oil sump and does not leak out of the bearing housing. This seal structure has a simple structure that does not use a member that directly contacts the output shaft, and requires little inspection and maintenance, and has no member that needs to be replaced periodically. In addition, since a plurality of oil reservoirs are provided, individual oil reservoirs do not have a large shape and can be attached without requiring a large installation space. Moreover, since a part of the lubricating oil is received in the intermediate oil sump, the shaft end oil sump, which is the last stage means for receiving the lubricating oil, can be used even if a large-capacity oil tank cannot be installed. And does not leak downward from the bearing housing. Sa
In addition, lubricating oil and oil vapor
Prevents leakage of the bearing housing to outside due to virulence seal
Is done.

[Brief description of the drawings]

FIG. 1 is a side view in which main parts of a gas turbine according to an embodiment of the present invention are cut.

FIG. 2 is a longitudinal sectional view showing a bearing box in the gas turbine.

FIG. 3 is a longitudinal sectional view showing a lower portion of the bearing housing of FIG. 2;

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Gas turbine, 2 ... Gas generator, 6 ... Vertical output turbine, 8 ... Output shaft, 10 ... Bearing box, 22-24 ... Bearing, 37, 40 ... Oil drain, 38 ... Intermediate oil sump, 39 ... Shaft end oil reservoir, 42: labyrinth seal part, 44: breather (part of exhaust means), 45: exhaust gas ejector (part of exhaust means), 47, 48 ... oil drain pipe

Continuation of the front page (56) References JP-A-3-164534 (JP, A) JP-A-57-91327 (JP, A) JP-A-8-296457 (JP, A) JP-A-8-296456 (JP) , A) Japanese Utility Model 60-10838 (JP, U) Japanese Utility Model 63-57896 (JP, U) Japanese Utility Model 59-22396 (JP, Y2) (58) Fields surveyed (Int. Cl. ⁷ , DB Name) F02C 7/06 F01D 25/16 F16N 31/00

Claims (4)

(57) [Claims] An output turbine in which an output shaft is set to be substantially vertical to extract energy of a working gas as power, the output turbine being spaced apart in the axial direction of the output shaft, and rotatably supporting the output shaft. A plurality of bearings, and a bearing that houses the bearing and penetrates below the output shaft
Box , located inside the bearing box below the lowermost bearing ,
A shaft end oil reservoir for receiving lubricating oil after bearing lubrication, and a lubricating oil for lubricating other bearings located above the shaft end oil reservoir and above the lowermost bearing 1 One or more and reservoir intermediate oil, and an oil discharge passage for discharging the lubricating oil to the outside of the bearing housing from the sump these oils, furthermore, the shaft end sump is the output of the bearing housing
The shaft forms a bottom wall that penetrates, and the inner peripheral standing wall of the shaft end oil reservoir and the output shaft or the output shaft or
A labyrinth seal is formed between
A vertical power turbine. 2. The oil drain according to claim 1, wherein the output shaft or a member fixed thereto is provided with an oil drain that causes lubricating oil to fly radially outward by centrifugal force and drop into the oil reservoir. Vertical power turbine. 3. The vertical power turbine according to claim 1, further comprising exhaust means for maintaining a negative pressure in the bearing housing. 4. A compressor for compressing air, a combustor for mixing and burning fuel in the compressed air, and a compressor driving turbine driven by combustion gas from the combustor to drive the compressor. A gas turbine comprising: a gas generator having the following features; and the vertical output turbine according to any one of claims 1 to 3 , wherein the combustion gas is a working gas.