JP2004340014A - Turbine generator - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide the structure of a bearing suitable for the turbine generator by which low temperature waste heat energy can be effectively utilized, and a power generating system which materializes low pressurization of a pump employed for the lubricating system of the bearing, power cut and reduction of structural strength. <P>SOLUTION: In the turbine generator, a turbine 21 and a generator 22 are configured in a single axis 25. While providing a main bearing 35 between a turbine rotor 23 and a generator rotor 24, the main bearing 35 is arranged in the vicinity of the center of gravity of the whole rotating body. A turbine side auxiliary bearing 36 having a diameter smaller than the main bearing has is provided to a shaft end on the opposite side of the generator of the turbine. A generator side auxiliary bearing 37 having a diameter smaller than the main bearing has is provided to a shaft end on the opposite side of the turbine of the generator rotor. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a turbine generator that recovers relatively low-temperature waste heat and converts this heat energy into electric power, and more particularly to a bearing structure of a turbine generator in which a turbine and a generator are configured as a single shaft. is there.
[0002]
[Prior art]
2. Description of the Related Art In a power generation facility using high-temperature energy, such as a thermal power plant, generally, high-temperature steam is generated using water as a working medium, and power is generated by rotating a steam turbine generator. Further, in the gas turbine power generation equipment, high-temperature combustion gas is generated, and the gas turbine generator is rotated and driven by this to generate power. These all convert high-temperature thermal energy into electric energy. On the other hand, there is known a power generation device that effectively uses relatively low-temperature waste heat such as exhaust gas at about 200 to 400 ° C. or waste water at 100 to 150 ° C. This power generation device is a closed-system power generation device using a so-called Rankine cycle or the like, and uses a low-boiling-point working medium instead of water as a working medium to make the apparatus compact (for example, see Patent Document 1). 1).
[0003]
In such small-scale applications, that is, facilities having a power generation output of about 10 kW or less, a turbine generator with a higher speed and a smaller size is required from the viewpoint of reducing the installation space and shortening the collection period of the introduction cost. I have. Patent Document 2 discloses a steam turbine generator in which a generator is provided on the same shaft as an axial-flow multistage steam turbine.
[0004]
Further, in conventional turbine generators for recovering waste heat, lubricating oil is generally used for lubricating bearings. The bearings are located in both the high and low pressure areas.The lubricating oil supplied to each bearing is collected in an oil tank provided in the low pressure section, supplied to each bearing by an oil circulation pump, and lubricated in the oil circulation system. Oil is cooled to reduce the oil temperature that has risen in the bearings. In the oil circulation pump that circulates lubricating oil, it is necessary to increase the pressure from the low pressure part (condenser) to the pressure difference between the high pressure part (steam generator) and the pump structure that can withstand high pressure, and large power is required. There is a problem of needing.
[0005]
[Patent Document 1]
Japanese Patent Application Laid-Open No. 2000-110514 [Patent Document 2]
Japanese Unexamined Patent Publication No. 2001-525512
[Problems to be solved by the invention]
The present invention has been made in view of the above-described circumstances, and provides a bearing structure suitable for a turbine generator capable of effectively utilizing low-temperature waste heat energy, and a low-pressure pump used for a lubrication system of the bearing. It is an object of the present invention to provide a power generation system with reduced power and reduced structural strength of the pump.
[0007]
[Means for Solving the Problems]
In a turbine generator according to the present invention, in a turbine generator having a turbine and a generator configured as a single shaft, a main bearing is provided between the turbine rotor and the generator rotor, and the main bearing is disposed near a center of gravity of the entire rotating body. A turbine-side auxiliary bearing having a smaller diameter than the main bearing is provided at a shaft end of the turbine rotor opposite to the generator, and a generator-side auxiliary bearing having a smaller diameter than the main bearing is provided at a shaft end of the generator rotor opposite to the turbine. Is provided.
[0008]
According to the present invention described above, only one high-speed and large-load bearing can be provided, and a small anti-sway bearing can be employed. Therefore, the turbine generator can be manufactured more compactly and at lower cost while ensuring the reliability of the turbine generator.
[0009]
Here, it is preferable that the outer ring of the turbine-side auxiliary bearing and / or the generator-side auxiliary bearing is fixed to the main body of the turbine generator via an elastic body such as rubber. As a result, the turbine generator is operated at the maximum rotation speed of several tens of thousands to 100,000 rotations per minute, and even in a region exceeding the primary critical speed, the main bearing in the center is fixed to the turbine generator body with high rigidity. To support the axial thrust load. On the other hand, the bearings at the ends of both shafts mainly have a steady rest in the radial direction. An elastic body such as rubber, that is, an O-ring is interposed between the bearing support for accommodating the outer ring part of the auxiliary bearing and the bearing housing of the turbine generator main body, so that a damper effect is provided. Vibration in the region can be reduced.
[0010]
Further, it is preferable that the main bearing is disposed on a low pressure side of a turbine, and lubricating oil is supplied to the main bearing from a lubricating oil supply pump. Thus, by providing a main bearing that requires a larger amount of lubricating oil than the auxiliary bearing on the low pressure side of the turbine, the required pressure and power consumption of the lubricating oil supply pump can be reduced.
[0011]
Another embodiment of the turbine generator according to the present invention is a turbine generator that drives a turbine by expanding high-pressure steam of a working medium and generates power by a generator configured with the turbine and a single shaft. The lubrication of at least one of the bearings supporting the turbine is performed by a condensed liquid of a working medium for driving the turbine. Accordingly, when the load on the bearing is light, lubrication and cooling can be performed only with the working medium supplied from the working medium pump without performing oil lubrication, and the oil circulation pump can be eliminated. Therefore, the power can be reduced. In particular, by using the working medium for lubrication of the high-pressure side bearing, the lubricating oil is supplied only to the bearing in the low-pressure part, and the head of the lubricating oil circulation pump can be reduced, and power consumption can be reduced. It becomes possible. Also, the pressure resistance of the pump can be reduced.
[0012]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. In each of the drawings, members or elements having the same function are denoted by the same reference numerals, and redundant description will be omitted.
[0013]
FIG. 1 shows a configuration example of a gas turbine generator according to a first embodiment of the present invention, which is suitable for effectively recovering and utilizing low-temperature waste heat energy to generate power. The gas turbine generator generates power by rotating a turbine 21 by expanding high-pressure steam and by rotating a generator 22 directly connected to the turbine. That is, the turbine generator includes an axial flow type turbine 21 and a DC brushless generator 22, and the turbine rotor 23 and the generator rotor 24 are integrally fixed to a single main shaft 25. This turbine generator is vertically installed, and a turbine rotor 23 is fixed to an upper portion of a main shaft 25, and a generator rotor 24 is fixed to a lower portion of the main shaft 25. However, it goes without saying that this turbine generator may be used horizontally.
[0014]
A plurality of moving blades 27 are arranged and fixed in the axial direction on the turbine rotor 23, and a turbine casing 29 having a plurality of stationary blades 28 is arranged outside the moving blade 27. An outer shell 31 is provided outside the turbine casing 29, and forms a flow path between the turbine casing 29 and the outer shell 31 through which the low-pressure steam of the working medium flows after the turbine is rotationally driven. A suction pipe 32 is arranged on the suction side of the turbine, and a gas flow path 33a of a working medium made of high-pressure steam connected to the suction side of the turbine is formed. That is, the suction pipe 32 is housed inside the outer shell 31 of the turbine or a turbine discharge pipe 34 connected to the outer shell, and the turbine suction pipe 32 and the turbine discharge pipe 34 form a double pipe structure. . Accordingly, the high-pressure steam of the working medium flowing into the turbine 21 from the turbine suction pipe 32 inside the double pipe drives the turbine rotor 23 to rotate, and the steam of the low-pressure working medium flows into the turbine at the outer peripheral portion of the double pipe. It flows out through the flow path 33b inside the discharge pipe 34.
[0015]
The generator rotor 24 is constituted by a permanent magnet type rotor in which permanent magnets are alternately arranged along the circumferential surface, and a generator stator 26 is arranged around the generator rotor 24 via a slight clearance. I have. Further, a cooling jacket 38 is provided on the outer peripheral portion of the generator stator 26, and a cooling liquid such as water or oil is supplied from the outside to efficiently cool the generator that generates heat, especially the generator stator 26. The generator 22 is a DC brushless type AC generator, and the output of the generator is taken out from a winding provided on the generator stator 26 via a power line 40 to the outside. The power line 40 is connected to a frequency converter (not shown) via a connector 43. The power output of the AC generator 22 is converted to a predetermined frequency / voltage (for example, 60 Hz / 200V) by the frequency converter, and power is supplied to the load device. Supplied.
[0016]
A sensor 41 for detecting a rotation speed is provided at an end of the main shaft of the generator rotor 24 on the side opposite to the turbine, and the rotation speed of the main shaft 25 is detected. The output of the sensor 41 is transmitted to the outside via a connector 43 via a signal line 42. The rotation speed of the turbine generator can be adjusted by adjusting the supply amount or supply pressure of the high-pressure steam of the working medium supplied to the turbine. That is, within the range of the allowable rotation speed at which the turbine generator can safely operate, the amount of high-pressure steam of the working medium to be supplied is increased when the amount of power generation is increased, and the amount of high-pressure steam of the working medium is reduced when the amount of power generation is reduced. By reducing the amount, the amount of power generation can be controlled. At this time, the above adjustment is possible by controlling the supply amount or supply pressure of the high-pressure steam to the turbine with the electric valve 16 (see FIG. 3) while detecting the rotation speed by the rotation speed sensor 41. Further, the supply amount of the working medium can also be controlled by controlling the speed of a working medium supply pump 15 (see FIG. 3) described later.
[0017]
The main shaft 25 is supported by a main bearing 35 at a substantially central portion between the turbine 21 and the generator 22. The main bearing 35 is configured by arranging angular contact ball bearings 35a and 35b in parallel, and is disposed substantially at the center of gravity of the entire rotating body including the turbine rotor 23 and the generator rotor 24. A turbine-side auxiliary bearing 36 composed of a single row of angular contact ball bearings is provided on the opposite side of the turbine rotor 23 from the generator side, that is, the end of the main shaft on the high pressure side of the turbine 21. A generator-side auxiliary bearing 37, which is also a single-row angular contact ball bearing, is arranged at the end of the main shaft of the generator rotor 24 on the side opposite to the turbine.
[0018]
Thus, in this turbine generator, the main shaft 25 is supported by the central main bearing 35 and the auxiliary bearings 36 and 37 provided at the turbine-side shaft end and the generator-side shaft end, respectively. That is, in this turbine generator, the main bearing 35 is disposed near the center of gravity of the entire rotating body, and a main load as a bearing is shared by the main bearing 35, and small-diameter auxiliary bearings 36 and 37 are provided at both ends of the main shaft in an auxiliary manner. It is arranged for anti-vibration. Therefore, only one high-speed, large-load main bearing can be provided, and a small anti-vibration bearing can be employed. Therefore, the turbine generator can be manufactured more compactly and at low cost while ensuring the reliability of the generator. Further, the auxiliary bearing 36 provided at the end of the turbine shaft needs to be disposed on the inner peripheral side of the high-pressure steam flow path of the working medium. It can be arranged inside the flow path 33a.
[0019]
The outer ring of the auxiliary bearing 36 is fixed to the main body of the turbine generator via an elastic body 51 such as rubber, as shown in FIG. That is, two O-rings 51 are interposed between fitting portions of the bearing support 52 for accommodating the outer ring portion of the auxiliary bearing and the bearing housing 53 of the turbine generator main body. Therefore, the bearing support accommodating the outer ring portion is fixed by the retaining ring for the hole so as not to move in the axial direction with respect to the bearing housing, and a set screw for adjusting the play and hydraulic pressure of the auxiliary bearing is provided. . Here, the inner ring of the auxiliary bearing 36 is press-fitted and fixed to the main shaft, but a bearing nut or other means may be used to facilitate assembly.
[0020]
As shown in FIG. 2B, the auxiliary bearing 37 has an outer ring fixed to the main body of the turbine generator via an elastic body 54 such as rubber. That is, two O-rings 54 are interposed in the fitting portion between the bearing support 55 for accommodating the outer ring portion of the auxiliary bearing and the bearing housing 56 of the main body of the turbine generator. The bearing support 55 is sandwiched between the members so as not to move in the axial direction with respect to the bearing housing 56. Here, the inner ring of the auxiliary bearing 37 is press-fitted and fixed to the main shaft, but it may be fixed using a bearing nut or other means to facilitate assembly.
[0021]
This turbine generator is operated at a maximum rotation speed of several tens of thousands to 100,000 rotations per minute, and is used in a region exceeding a primary critical speed. In such a configuration, the central main bearing 35 is fixed to the turbine generator body with high rigidity to support the axial thrust load. On the other hand, the bearings 36 and 37 at the ends of both shafts have a main function of preventing steadying in the radial direction. As described above, an elastic body such as rubber, that is, O-rings 51, 54 is interposed between the bearing support for accommodating the outer ring portion of the auxiliary bearing and the bearing housing of the turbine generator main body, thereby reducing the damper effect. It reduces vibration when passing through critical speeds, such as when starting. In addition, by interposing the elastic bodies 51 and 54 in the auxiliary bearings 36 and 37, an excessive force is not applied to the auxiliary bearing even if there is a slight misalignment between the main bearing and the auxiliary bearing.
[0022]
The axial thrust load generated during the operation of the turbine is supported by a main bearing 35 configured by a parallel combination of angular contact ball bearings 35a and 35b. As described above, the auxiliary bearings 36 and 37 are used for steadying and basically do not receive a load. However, during operation, the temperature of each part, especially the temperature around the rotating body, becomes higher than that of the non-rotating part such as the turbine casing, so that a difference occurs between the thermal expansion of the main shaft and the thermal expansion of the non-rotating part such as the turbine casing. In the angular contact ball bearings used for the auxiliary bearings 36 and 37, the amount of play and pressurization in the axial direction is determined in consideration of the difference in the amount of thermal expansion, and an axial load is supported as occasion demands.
[0023]
In this embodiment, lubricating oil is supplied to the main bearing 35 and the auxiliary bearings 36 and 37 from a lubricating oil supply pump. The main bearing 35 is disposed on the low pressure side of the turbine 21, and the auxiliary bearing 36 is disposed on the high pressure side (in the gas flow path 33 a) of the turbine 21. By providing the main bearing 35 that requires a larger amount of lubricating oil than the auxiliary bearings 36 and 37 on the low pressure side of the turbine, the required pressure and power consumption of the lubricating oil supply pump can be reduced.
[0024]
Lubricating oil is supplied to the main bearing 35, the turbine-side auxiliary bearing 36, and the generator-side auxiliary bearing 37 for lubrication and cooling. The lubricating oil discharged from the lubricating oil supply pump 17 (see FIG. 3) flows through the lubricating oil supply pipes 46a and 47a to the main bearing 35 and the auxiliary bearing 36, and is supplied in parallel to collect the lubricating oil. The flow returns to the lubricating oil supply pump via the pipes 46b and 47b. The lubricating oil is also supplied to the auxiliary bearing 37 sequentially or in parallel. At this time, an oil cooler and a dust filter are provided in each part as needed. Also, a part of the lubricating oil supplied to each bearing is mixed into the working medium of the turbine, and a part of the lubricating oil also enters the inside of the generator. Is provided separately. The separated lubricating oil returns to the lubricating oil circulation pump, and the separated working medium is condensed and returns to the working medium supply pump. Since the turbine generator has a vertical axis configuration in which the turbine 21 is on the upper side and the generator 22 is on the lower side, a preferable mounting position of the oil separating device for separating oil collected by natural flow is power generation. The lower end of the machine 22.
[0025]
Here, it is clear that the lubricating oil cannot be supplied from the outside unless the pressure is larger than the pressure around the bearing. The main bearing 35 is arranged on the low pressure side of the turbine 21, and the peripheral pressure of the main bearing becomes a considerably small value with respect to the lubricating oil supply pressure. Therefore, more lubricating oil is supplied to the main bearing 35 having a large diameter and a large load capacity than the auxiliary bearings 36 and 37. On the other hand, since the auxiliary bearing 36 on the turbine side is arranged on the high pressure side of the turbine, the pressure around the bearing is high, and the supply amount of the lubricating oil is smaller than that of the main bearing. Supply is secured. Thus, by optimizing the arrangement of the bearings, the required pressure and power consumption of the lubricating oil supply pump are minimized.
[0026]
FIG. 3 shows an outline of a power generation device of a closed system using the above-described turbine generator. A steam generator 11 that collects waste heat and generates high-pressure steam as a working medium, an expander 13 that drives a turbine 21 connected to a generator 22 by expanding the high-pressure steam, and drives the turbine 21 A condenser 14 for cooling the low-pressure steam afterwards with a cooling medium to form a condensate, and a liquid feed pump 15 for feeding the condensate of the working medium condensed by the condenser to the steam generator 11 are provided. I have.
[0027]
Here, it is preferable to use HFC123 or trifluoroethanol (CF ₃ CH ₂ OH) having a boiling point of about 40 ° C. as the working medium. Thereby, these heat energies are converted into high-pressure steam of the working medium by using a relatively low-temperature heat source such as a relatively low-temperature exhaust gas of about 200 to 400 ° C. or a waste water of 100 to 150 ° C. The expander 13 rotates the turbine 21 directly connected to the generator 22 to generate power. The condenser 14 is provided with a cooling medium cooling pipe, and generates condensate by cooling steam after driving the turbine.
[0028]
Next, an outline of a basic operation procedure of the turbine generator will be described. First, the oil circulation pump 17 supplies lubricating oil to the bearings 35, 36, and 37 of each part of the turbine generator. Next, the working medium supply pump 15 supplies the condensed liquid of the working medium to the steam generator 11. The heat generating fins provided on the outer surface of the steam generator 11 take in waste heat from hot air of, for example, about 200 to 300 ° C. to vaporize the working medium and create a high-pressure high-temperature gas. The high-pressure high-temperature gas is supplied into the turbine (expander 13) from the turbine suction pipe 32, drives the turbine, rotates the generator 22, and starts power generation. The low-temperature and low-pressure working medium gas discharged from the turbine passes between the turbine casing and the outer shell, and is guided from the turbine discharge pipe 34 to the condenser 14. Then, the cooling medium provided in the condenser emits heat to condense and liquefy the working medium. The liquefied working medium returns to the working medium supply pump 15 under natural flow. By continuously repeating the above closed loop, the turbine generator operates effectively.
[0029]
Here, the oil circulation pump 17 pumps up the lubricating oil in the oil tank 18 and sends it to the bearings 35, 36, 37. The lubricating oil that has lubricated and cooled the bearings 35, 36 and 37 is returned to the oil tank 18, and is cooled by the cooler 18a using a part of the working medium.
[0030]
Next, a second embodiment of the present invention will be described with reference to FIGS. Generally, bearings of conventional turbine generators use lubricating oil for lubrication and cooling. Bearings are provided in both the high-pressure section and the low-pressure section of the turbine generator. Lubricating oil supplied to each bearing is collected in an oil tank provided in the low-pressure section, and supplied to each bearing by an oil circulation pump. Then, the lubricating oil is cooled in the oil circulation system, and the oil temperature raised in the bearing portion is reduced. In the oil circulation pump, it is necessary to increase the pressure from the condenser pressure in the low-pressure section to the pressure difference between the steam generator pressure in the high-pressure section and the pump structure to withstand high pressure, and also requires large power.
[0031]
In the turbine generator shown in FIG. 4, at least the high pressure side bearing of the turbine is lubricated not with the lubricating oil but with the condensate of the working medium. That is, the pressurized condensate of the working medium from the working medium feed pump 15 is supplied to the bearing 36. The lubrication of the bearings 35 and 37 on the low pressure side of the turbine generator is performed by using lubricating oil as in the first embodiment, and the lubricating oil is circulated by using a low-head oil circulation pump 17.
[0032]
Since the load on the high-pressure bearing 36 is light, it is possible to sufficiently lubricate and cool only the condensate of the working medium supplied from the working medium feed pump 15 without supplying any lubricating oil. If only lubricating oil is supplied to the bearings in the low pressure section, the head of the oil circulation pump can be made smaller, and power can be reduced. Also, the pressure resistance of the pump can be reduced.
[0033]
For this reason, the turbine generator shown in FIG. 4 includes a pipe 48 for supplying the condensed liquid of the working medium to the high-pressure side bearing. The working medium used for lubrication and cooling of the bearing 36 flows out into the high-pressure gas flow path and becomes high-pressure gas, which contributes to driving of the turbine. Other configurations of the turbine generator are the same as those shown in FIG.
[0034]
FIG. 5 shows a configuration example of a power generation system when the turbine generator shown in FIG. 4 is used. The basic configuration including the steam generator 11, the expander 13, the condenser 14, the liquid feed pump 15, and the like is the same as in the above-described embodiment. In this embodiment, as described above, the low-pressure bearings 35 and 37 are oil-lubricated, and the high-pressure bearing 36 is lubricated by the working medium. The condensed liquid of the working medium is guided to the high-pressure bearing 36 from the discharge side of the working medium feed pump 15, and is released into the high-pressure gas after the lubrication and cooling of the bearing 36. The oil circulation pump 17 is returned to the oil tank 18 after lubricating and cooling the bearings 35 and 37. In the oil tank 18, a part of the working medium is used to cool the lubricating oil whose temperature has been increased by the cooler 18a.
[0035]
In this embodiment, the pump is driven by a liquid turbine 17a that is rotated by the condensed liquid pressurized by the working medium supply pump 15. Thereby, the system can be simplified. However, the oil circulation pump 17 may be an electric pump. Although oil cooling (18a) is performed with the liquid after driving the liquid turbine in FIG. 5, the liquid may be directly supplied from the pump 15, or the bearing 36 may be lubricated with a working medium, and thereafter, lubricated. Oil cooling with liquid may be used.
[0036]
Since the generator-side auxiliary bearing 37 has a light load, it can be lubricated by a working medium. The working medium supply pump 15 is for feeding the condensate of the working medium to the steam generator 11 and has a higher pressure than the high-pressure steam, so that it is supplied to the turbine-side auxiliary bearing 36 in the high-pressure steam. It is possible to liquid. The main bearing 35 and the generator-side auxiliary bearing 37 are in a low-pressure atmosphere and can be circulated by a low-head oil circulation pump. The oil tank 18 has almost the same pressure as the low-pressure steam. Although not shown, equalizing pipes may be provided in the upper part of the oil tank 18 and the low-pressure steam system.
[0037]
It should be noted that the above-described embodiment describes one mode of the embodiment of the present invention, and it is needless to say that various modifications can be made without departing from the spirit of the present invention.
[0038]
【The invention's effect】
As described above, according to the present invention, in a turbine generator that extracts generated power from relatively low temperature waste heat, a main bearing is provided at the center and auxiliary bearings are provided at both shaft ends, so that the reliability of the turbine generator is improved. It is possible to manufacture more compactly and at low cost while ensuring the performance. Also, by lubricating and cooling the high-pressure side auxiliary bearing using the condensate of the working medium, the head of the oil circulation pump can be reduced, and energy saving and efficiency improvement of the entire power generation system can be achieved. .
[Brief description of the drawings]
FIG. 1 is a cross-sectional view illustrating a configuration example of a turbine power generator according to a first embodiment of the present invention.
FIG. 2 is an enlarged sectional view showing a structural example of an auxiliary bearing.
FIG. 3 is a diagram showing an outline of a power generation system using the turbine power generator of FIG.
FIG. 4 is a cross-sectional view illustrating a configuration example of a turbine power generator according to a second embodiment of the present invention.
5 is a diagram showing an outline of a power generation system using the turbine power generator of FIG.
[Explanation of symbols]
11 Steam generator 13 Expander (turbine)
14 Condenser 15 Pump 17 Oil circulation pump 17a Liquid turbine 18 Oil tank 18a Cooler 21 Turbine 22 DC brushless generator 23 Turbine rotor 24 Generator rotor 25 Main shaft 26 Generator stator 27 Moving blade 28 Stator blade 29 Turbine casing 31 Outer body 32 Turbine suction pipe 33a, 33b Gas flow path 34 Turbine discharge pipe 35 Main bearing 36 Turbine side auxiliary bearing 37 Generator side auxiliary bearing 38 Cooling jacket 40 Power line 41 Rotation sensor 42 Signal line 43 Connectors 46a, 46b, 47a, 47b Lubrication Oil piping 48 Piping 51, 54 for condensed liquid of working medium Elastic body (O-ring)
52,55 Bearing support 53,56 Bearing housing

Claims (10)

In a turbine generator in which a turbine and a generator are configured as a single shaft, a main bearing is provided between the turbine rotor and the generator rotor, and the main bearing is disposed near the center of gravity of the entire rotating body, so that the turbine rotor is located on the side opposite to the generator. A turbine-side auxiliary bearing having a smaller diameter than the main bearing is provided at a shaft end, and a generator-side auxiliary bearing having a smaller diameter than the main bearing is provided at a shaft end of the generator rotor opposite to the turbine. Turbine generator. The turbine generator according to claim 1, wherein an outer ring of the turbine-side auxiliary bearing and / or the generator-side auxiliary bearing is fixed to a main body of the turbine generator via an elastic body such as rubber. 3. The turbine generator according to claim 1, wherein the main bearing is configured by a parallel combination of angular ball bearings, and the turbine-side auxiliary bearing and the generator-side auxiliary bearing are configured by a single-row angular ball bearing. 4. . 2. The turbine generator according to claim 1, wherein the main bearing is arranged on a low pressure side of a turbine, and lubricating oil is supplied to the main bearing from a lubricating oil supply pump. 3. The turbine generator according to claim 1, wherein lubricating oil is supplied from a lubricating oil supply pump to auxiliary bearings disposed at the ends of the shafts. In a turbine generator, which drives a turbine by expanding high-pressure steam of a working medium and generates electric power by a generator constituted by the turbine and a single shaft, lubrication of at least one of the bearings supporting the single shaft is performed. Using a condensate of a working medium that drives the turbine. A main bearing is provided between the turbine and the generator, auxiliary bearings are provided at both shaft ends of the single shaft, and lubricating oil is supplied to the main bearing from a lubricating oil supply pump. The turbine generator according to claim 6. The turbine generator according to claim 7, wherein lubrication of an auxiliary bearing disposed at a shaft end on a high pressure side of the turbine is performed by a condensed liquid of a working medium pressurized by a working medium pump. The turbine generator according to claim 7, wherein a low-head oil circulation pump is used for circulation of the lubricating oil. The turbine generator according to claim 9, wherein the oil circulation pump is driven by a liquid turbine powered by a working medium from a working medium pump.

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