JP6689661B2 - Fluid machinery using journal bearings - Google Patents

Description

  The present embodiment relates to a fluid machine using a journal bearing.

  In large fluid machines such as steam turbines, gas turbines, and compressors, journal bearings are used to support the load on the rotating shaft. There are two types of journal bearings, such as a two-arc type and a pad type, depending on the structure of the sliding surface. Hereinafter, the pad-type journal bearing will be described assuming that it is applied to a steam turbine.

  FIG. 14 shows a prior art pad journal bearing and steam turbine. The steam turbine has a rotary shaft 1 and a turbine casing 2 surrounding the rotary shaft 1, and the thermal energy of steam flowing inside the turbine casing 2 is used to rotate the rotary shaft 1 to obtain power. A bearing casing 3 is provided outside the turbine casing 2, and a pad-type journal bearing including a pad 4 and a bearing body 5 is provided inside the bearing casing 3. FIG. 15 is a sectional view taken along the line BB of FIG. 14, showing a conventional pad type journal bearing. A plurality of pads 4 are held on the inner peripheral surface of the bearing body 5. The radius of curvature of the outer peripheral surface of each pad 4 is smaller than the radius of curvature of the inner peripheral surface of the bearing body 5, and each pad 4 can freely tilt while contacting the bearing body 5.

  The bearing main body 5 and the bearing stand 6 on which the bearing main body 5 is mounted have an oil supply hole 7 formed therein. During operation of the steam turbine, a lubricating oil is supplied from an oil supply source (not shown) outside the bearing casing 3 with a pressure of several hundred kPa. Is supplied to the oil supply hole 7 and then flows into the bearing body 5. Further, the bearing body 5 is formed with an oil drain hole 8 having a diameter smaller than that of the oil supply hole 7, and a part of the lubricating oil flowing into the bearing body 5 passes through the oil drain hole 8 and the bearing casing. It is guided to an oil site (not shown) outside the unit 3 and used for confirmation of oil passage.

  When the rotating shaft 1 rotates, the lubricating oil inside the bearing body 5 is caught in the gap between the rotating shaft 1 and the pad 4, and an oil film pressure is generated to support the load of the rotating shaft 1. The lubricating oil is discharged to the outside of the bearing main body 5 from the axial end portion of the gap while passing through the gap. The discharged lubricating oil has a velocity component in the axial direction due to the oil film pressure in the gap and a velocity component in the outer peripheral direction due to the centrifugal force caused by the rotation of the shaft 1. As shown in FIG. It becomes like arrow 9. The lubricating oil discharged to the outside of the bearing body 5 falls freely inside the bearing casing 3 and is returned to the lubricating oil tank (not shown) through the return oil hole 10.

  Next, the seal mechanism of the steam turbine will be described with reference to FIG. In order to prevent high-temperature, high-pressure steam from flowing out of the interior of the casing 2 into the portion of the end of the turbine casing 2 through which the rotary shaft 1 penetrates, or to prevent atmospheric air from entering the interior of the casing 2. Therefore, a sealing mechanism called a gland portion 11 is provided. The gland portion 11 is provided with a labyrinth packing 12, and has a structure in which a gap between the rotary shaft 1 and the turbine casing 2 is shielded by multistage fins 13 to buffer the pressure difference in the axial direction (Patent Document 2). reference).

  When the pressure of the working steam pressure chamber 14 in the casing 2 is lower than the atmospheric pressure, steam is supplied from the steam supply line 17 to the gland section internal pressure chamber 15 via the gland steam header 18. Part of the supplied steam flows into the working steam pressure chamber 14, and the rest flows into the gland section machine outer pressure chamber 16 and is collected in the gland steam condenser 19. This can prevent the atmospheric air from flowing into the working steam pressure chamber 14.

  On the other hand, when the pressure of the working steam pressure chamber 14 in the casing 2 is higher than the atmospheric pressure, a part of the working steam that has flowed into the gland unit inside pressure chamber 15 passes through the gland steam header 18 to the surplus steam recovery line 20. Collected and the rest flows into the gland section outer pressure chamber 16 and is collected in the gland vapor condenser 19. This prevents high-temperature, high-pressure steam from flowing out of the working steam pressure chamber 14 to the outside of the casing 2.

  In any case, steam is used as the seal fluid in the gland portion 11, and the rotating shaft 1 may come into contact with the steam of several hundreds of degrees Celsius in the gland portion 11 depending on operating conditions.

JP2012-149694A JP, 2013-144967, A

  In recent years, in steam turbines, journal bearings are often provided in the immediate vicinity of the turbine casing for the purpose of cost reduction by shortening the shaft length of the rotating shaft and increasing rigidity of the rotating shaft by shortening the bearing span. On the other hand, as shown in the background art, a gland portion is provided at the end of the turbine casing, and the rotating shaft may come into contact with steam at several hundred degrees Celsius in the gland portion.

  In FIG. 14, when the journal bearing is placed in the vicinity of the turbine casing 2, the rotary shaft journal portion (a portion corresponding to the journal bearing of the rotary shaft 1) is affected by the heat that the rotary shaft 1 receives from the steam in the gland portion 11. It is considered that 22 also thermally expands. The opposing pad 4 also thermally expands due to the shear friction of the lubricating oil on its inner peripheral surface, but the journal bearing including the pad 4 is in contact with the lubricating oil and the atmosphere at a temperature of several tens of degrees Celsius at most, and therefore the rotating shaft journal portion. The thermal expansion of 22 becomes larger, and the gap between the rotary shaft 1 and the pad 4 becomes narrower.

  When the gap between the rotary shaft 1 and the pad 4 becomes extremely narrow, the shear friction of the lubricating oil on the inner peripheral surface of the pad 4 increases, and the temperature of the sliding material used on the inner peripheral surface of the pad 4 increases. There is a risk of rising and decreasing strength. Further, there is a risk that the sliding material may be damaged by the contact between the rotary shaft 1 and the pad 4.

Furthermore, when the gap between the rotary shaft 1 and the pad 4 becomes extremely narrow, there is a risk that the dynamic characteristics of the bearing change and the vibration stability of the rotary shaft deteriorates. As shown in Patent Document 1, when the equivalent spring constant of the force that the rotary shaft receives from the working fluid is K, the vertical spring constant of the journal bearing is Kx, and the horizontal spring constant is Ky, the vibration stability condition of the rotary shaft is It can be written as
K ≦ | Kx−Ky | / 2 (1)
That is, it is known that the smaller the anisotropy | Kx-Ky | of the spring constant of the journal bearing, the worse the vibration stability.

  FIG. 16 is directed to a conventional pad-type journal bearing (see FIG. 15), in which the gap between the rotary shaft 1 and the pad 4 is changed, and the vertical spring constant Kx and the horizontal spring constant Ky of the bearing, And the anisotropy | Kx-Ky |. When the bearing gap becomes smaller, Kx becomes larger, but Ky becomes larger than that, so that the anisotropy | Kx-Ky | becomes small. That is, when the gap between the rotary shaft 1 and the pad 4 becomes extremely narrow, there is a risk that the vibration stability of the rotary shaft 1 deteriorates.

  The present embodiment has been made in consideration of such a point, and in a fluid machine such as a steam turbine, a gas turbine, and a compressor, a rotating shaft arranged in the main body casing of the fluid machine has a high temperature inside the casing. Even when receiving heat from fluid, a fluid machine that can maintain the strength of the bearing sliding material and the vibration stability of the rotating shaft by ensuring an appropriate gap between the rotating shaft and the bearing sliding surface. The purpose is to provide.

  In the present embodiment, a main body casing of a fluid machine, a rotary shaft rotatably arranged in the main body casing, and a journal bearing arranged outside the main body casing to rotatably support the rotary shaft. And a lubricating oil nozzle for injecting lubricating oil to the surface of the rotating shaft is provided between the main body casing and the journal bearing.

  In the present embodiment, a main body casing of a fluid machine, a rotary shaft rotatably arranged in the main body casing, and a journal bearing arranged outside the main body casing to rotatably support the rotary shaft. And a compressed air nozzle for injecting compressed air to the surface of the rotating shaft is provided between the main body casing and the journal bearing.

  In the present embodiment, a main body casing of a fluid machine, a rotary shaft rotatably arranged in the main body casing, and a journal bearing arranged outside the main body casing to rotatably support the rotary shaft. The journal bearing has an upper half part and a lower half part, and has an opening on the main body casing side of the upper half part of the journal bearing and has a sliding surface of the rotary shaft and the journal bearing. Is a fluid machine having an oil receiver for storing the lubricating oil discharged from the gap, and having a guide path for guiding the lubricating oil to the rotating shaft side.

  In the present embodiment, a main body casing of a fluid machine, a rotary shaft rotatably arranged in the main body casing, and a journal bearing arranged outside the main body casing to rotatably support the rotary shaft. The journal bearing has an upper half portion and a lower half portion, and in the main body casing side of the lower half portion of the journal bearing, from the gap between the rotary shaft and the sliding surface of the journal bearing. A fluid machine having an oil container for accumulating discharged lubricating oil, the oil container having an opening for overflowing the lubricating oil in the oil sump above the lowest point of the rotating shaft. .

  According to the present embodiment, an appropriate gap can be secured between the rotary shaft and the bearing sliding surface, and the strength of the bearing sliding material and the vibration stability of the rotary shaft can be maintained.

The figure which shows the fluid machine by 1st Embodiment. Sectional view on the AA line of FIG. The figure which shows the fluid machine by 2nd Embodiment. The figure which shows the fluid machine by 3rd Embodiment. The figure which shows the fluid machine by 4th Embodiment. The sectional view on the AA line of FIG. The figure which shows the fluid machine by 5th Embodiment. The figure which shows the fluid machine by 6th Embodiment. The figure which shows the fluid machine by 7th Embodiment. The sectional view on the AA line of FIG. The figure which shows the fluid machine by 8th Embodiment. The sectional view on the AA line of FIG. The figure which shows the fluid machine by 9th Embodiment. The figure which shows the fluid machine of a prior art. The BB sectional view taken on the line of FIG. The figure which shows the trial calculation result of the influence which a bearing clearance gives to a spring constant in a pad type journal bearing.

(First embodiment)
Hereinafter, embodiments of a journal bearing and a fluid machine using the journal bearing according to the present embodiment will be described with reference to the drawings. Although each drawing assumes the case where the pad type journal bearing is applied to the steam turbine, the present invention is similarly applicable to other types of journal bearings and fluid machinery.

  1 and 2 are views showing a fluid machine according to a first embodiment. Here, FIG. 1 is a view showing a fluid machine according to the first embodiment, and FIG. 2 is a sectional view taken along the line AA of FIG.

  As shown in FIGS. 1 and 2, a steam turbine serving as a fluid machine includes a turbine casing (main body casing of the fluid machine) 2 and a rotary shaft 1 rotatably arranged in the turbine casing 2.

  1 and 2, the steam turbine uses the thermal energy of steam flowing inside the turbine casing 2 to rotate the rotary shaft 1 to obtain power. A bearing casing 3 is provided outside the turbine casing 2, and a pad-type journal bearing 50 including a pad 4 and a bearing body 5 is provided inside the bearing casing 3. Further, the pad-type journal 50 includes an upper half portion 50A and a lower half portion 50B which are divided into two. Further, a plurality of pads (bearing sliding material) 4 are held on the inner peripheral surface of the bearing body 5. The radius of curvature of the outer peripheral surface of each pad 4 is smaller than the radius of curvature of the inner peripheral surface of the bearing body 5, and each pad 4 can freely tilt while contacting the bearing body 5.

  The bearing main body 5 and the bearing stand 6 on which the bearing main body 5 is mounted have an oil supply hole 7 formed therein. During operation of the steam turbine, a lubricating oil is supplied from an oil supply source (not shown) outside the bearing casing 3 with a pressure of several hundred kPa. Is supplied to the oil supply hole 7 and then flows into the bearing body 5. Further, the bearing main body 5 is formed with an oil discharge hole having a diameter smaller than that of the oil supply hole 7, so that a part of the lubricating oil flowing into the bearing main body 5 passes through the oil discharge hole and is discharged from the bearing casing 3. It is guided to an external oil site (not shown) and used to confirm oil passage.

  When the rotating shaft 1 rotates, the lubricating oil inside the bearing body 5 is caught in the gap between the rotating shaft 1 and the pad 4, and an oil film pressure is generated to support the load of the rotating shaft 1. The lubricating oil is discharged to the outside of the bearing main body 5 from the axial end portion of the gap while passing through the gap. The discharged lubricating oil has an axial velocity component due to the oil film pressure in the gap and an outer peripheral velocity component due to the centrifugal force caused by the rotation of the shaft 1. As shown in FIG. It becomes like arrow 9. The lubricating oil discharged to the outside of the bearing body 5 falls freely inside the bearing casing 3 and is returned to the lubricating oil tank (not shown) through the return oil hole 10.

  Next, the seal mechanism of the steam turbine will be described. In order to prevent high-temperature, high-pressure steam from flowing out of the interior of the casing 2 into the portion of the end of the turbine casing 2 through which the rotary shaft 1 penetrates, or to prevent atmospheric air from entering the interior of the casing 2. Therefore, a sealing mechanism called a gland portion 11 is provided. A labyrinth packing 12 is provided in the gland portion 11 and has a structure in which a gap between the rotary shaft 1 and the turbine casing 2 is shielded by a multi-stage fin 13 to buffer a pressure difference in the axial direction.

  When the pressure of the working steam pressure chamber 14 in the casing 2 is lower than the atmospheric pressure, steam is supplied from the steam supply line 17 to the gland section internal pressure chamber 15 via the gland steam header 18. Part of the supplied steam flows into the working steam pressure chamber 14, and the rest flows into the gland section machine outer pressure chamber 16 and is collected in the gland steam condenser 19. This can prevent the atmospheric air from flowing into the working steam pressure chamber 14.

  On the other hand, when the pressure of the working steam pressure chamber 14 in the casing 2 is higher than the atmospheric pressure, a part of the working steam that has flowed into the gland unit inside pressure chamber 15 passes through the gland steam header 18 to the surplus steam recovery line 20. Collected and the rest flows into the gland section outer pressure chamber 16 and is collected in the gland vapor condenser 19. This prevents high-temperature, high-pressure steam from flowing out of the working steam pressure chamber 14 to the outside of the casing 2.

  In any case, steam is used as the seal fluid in the gland portion 11, and the rotating shaft 1 may come into contact with the steam of several hundreds of degrees Celsius in the gland portion 11 depending on operating conditions.

  Further, between the turbine casing 2 and the journal bearing 50, specifically, within a range from a position where the rotary shaft 1 exits the turbine casing 2 to a position where the rotary shaft 1 faces the pad 4 of the journal bearing, A nozzle (lubricating oil nozzle) 23 for injecting lubricating oil to the surface of the is provided. Further, the bearing body 5 is provided with an injection oil extraction hole 24 communicating with the oil supply hole 7, and the injection oil extraction hole 24 and each nozzle 23 are connected by an injection oil pipe 25.

  Next, the operation of the present embodiment having such a configuration will be described.

  1 and 2, when the lubricating oil is supplied to the oil supply hole 7 at a pressure of several hundred kPa during the operation of the steam turbine, part of the lubricating oil passes through the injection oil extraction hole 24 and the injection oil pipe 25, It is ejected from the nozzle 23 over the surface of the rotary shaft 1 over the range L ′ in the axial direction and over the range α ′ in the circumferential direction. The lubricating oil that has collided with the surface of the rotating shaft 1 freely falls inside the bearing casing 3 and is returned to the lubricating oil tank (not shown) through the return oil hole 10.

  On the other hand, as shown in FIGS. 1 and 2, a gland portion 11 is provided at the end of the turbine casing 2. Steam is used as the seal fluid in the gland portion 11, and the rotating shaft 1 may come into contact with the steam of several hundreds of degrees Celsius in the gland portion 11 depending on operating conditions. In such a case, heat may flow from the steam to the rotary shaft 1. In particular, when the axial distance between the gland portion 11 and the journal bearing 50 is set to be short, the heat inflow becomes remarkable.

  In the present embodiment, as described above, the lubricating oil of several tens of degrees Celsius is injected within the range from the position where the rotary shaft 1 comes out of the turbine casing 2 to the position where the rotary shaft 1 faces the pad 4 of the journal bearing. Therefore, the heat that has flowed into the rotary shaft 1 side from the gland portion 11 is carried away by the lubricating oil, and the thermal expansion of the rotary shaft journal portion (the portion corresponding to the journal bearing 50 of the rotary shaft 1) 22 is suppressed.

  As described above, according to the present embodiment, thermal expansion of the rotary shaft journal portion 20 is suppressed, and thus a sufficient gap is secured between the rotary shaft 1 and the sliding surface of the pad 4. As a result, the temperature of the pad (bearing) is kept low, and the strength of the material of the pad 4 can be maintained. Further, the anisotropy of the spring constant of the journal bearing 50 is secured, and the vibration stability can be maintained. Furthermore, since a part of the lubricating oil of the journal bearing 50 is used as the cooling medium of the rotating shaft 1, it is not necessary to additionally install a system for circulating the cooling medium.

(Second embodiment)
Next, a fluid machine according to the second embodiment will be described with reference to FIG.

  FIG. 3 is a diagram showing a steam turbine (fluid machine) according to the second embodiment. As shown in FIG. 3, the mounting angle of the nozzle 23 is set so that the lubricating oil 26 injected from the nozzle 23 has a velocity component in the axial direction of the rotary shaft 1. The other configurations of the second embodiment shown in FIG. 3 are substantially the same as those of the first embodiment shown in FIGS. 1 and 2. In the second embodiment shown in FIG. 3, the same parts as those in the first embodiment shown in FIGS. 1 and 2 are designated by the same reference numerals, and detailed description thereof will be omitted.

  In FIG. 3, an axial range L in which the lubricating oil 26 injected from the nozzle 23 collides with the rotating shaft 1 in this embodiment is shown. The range L in which the lubricating oil 26 collides with the rotating shaft 1 is larger than the axial range L ′ in which the lubricating oil 26 collides with the rotating shaft 1 shown in FIG.

  As described above, in the present embodiment, since the lubricating oil 26 is sprayed while being inclined so as to have a velocity component in the axial direction of the rotating shaft 1, the area in which the lubricating oil 26 contacts the rotating shaft 1 becomes large. As a result, the amount of heat carried by the lubricating oil 26, which is the cooling medium, from the rotary shaft 1 increases, and the thermal expansion of the rotary shaft journal portion 22 is more reliably suppressed.

  Therefore, the clearance between the rotating shaft 1 and the sliding surface of the pad 4 can be secured more reliably. As a result, the temperature of the pad 4 is suppressed low, and it becomes more reliable to maintain the strength of the material of the pad 4. Further, the anisotropy of the spring constant of the journal bearing 50 is ensured, and the vibration stability is more reliably maintained.

(Third Embodiment)
Next, a fluid machine according to the third embodiment will be described with reference to FIG.

  FIG. 4 is a diagram showing a steam turbine (fluid machine) according to the third embodiment. As shown in FIG. 4, the mounting angle of the nozzle 23 is set so that the lubricating oil 26 injected from the nozzle 23 has a velocity component in the tangential direction of the rotating shaft 1. The other configuration of the third embodiment shown in FIG. 4 is substantially the same as that of the first embodiment shown in FIGS. 1 and 2. In the second embodiment shown in FIG. 4, the same parts as those of the first embodiment shown in FIGS. 1 and 2 are designated by the same reference numerals, and detailed description thereof will be omitted.

  As shown in FIG. 4, the range in the circumferential direction in which the lubricating oil 26 injected from the nozzle 23 collides with the rotating shaft 1 in this embodiment is indicated by α. In FIG. 4, the circumferential range α in which the lubricating oil 26 collides with the rotating shaft 1 is larger than the circumferential range α ′ in which the lubricating oil 26 collides with the rotating shaft 1 shown in FIG.

  As described above, in the present embodiment, since the lubricating oil 26 is jetted while being inclined so as to have a velocity component in the tangential direction of the rotating shaft 1, the area in which the lubricating oil 26 contacts the rotating shaft 1 becomes large. As a result, the amount of heat carried by the lubricating oil 26, which is the cooling medium, from the rotary shaft 1 increases, and the thermal expansion of the rotary shaft journal portion 22 is more reliably suppressed.

(Fourth Embodiment)
Next, a fluid machine according to a fourth embodiment will be described with reference to FIGS. 5 and 6. Here, FIG. 5 is a diagram showing a fluid machine according to a fourth embodiment, and FIG. 6 is a sectional view taken along the line AA of FIG.

  As shown in FIG. 5 and FIG. 6, within the range from the position where the rotary shaft 1 emerges from the turbine casing 2 to the position where the rotary shaft 1 faces the pad 4 of the journal bearing, the shaft is attached to the surface of the rotary shaft 1. A nozzle (compressed air nozzle) 23A for injecting compressed air over the range of L'in the direction and over the range of α'in the circumferential direction is provided. Further, each nozzle 23 and a compressed air supply source (not shown) are connected by a compressed air pipe 27.

  Other configurations of the fourth embodiment shown in FIGS. 5 and 6 are substantially the same as those of the first embodiment shown in FIGS. 1 and 2. In the fourth embodiment shown in FIGS. 5 and 6, the same parts as those in the first embodiment shown in FIGS. 1 and 2 are designated by the same reference numerals, and detailed description thereof will be omitted.

  In a plant in which a fluid machine such as a steam turbine shown in FIGS. 5 and 6 is installed, a system for supplying compressed air of several hundred kPa is permanently installed for the purpose of controlling peripheral devices. In the present embodiment, the permanent compressed air system as shown on the left is used as the supply source of the air injected from the nozzle 23A.

  During the operation of the steam turbine, the compressed air supplied to the compressed air pipe 27 is jetted from the nozzle 23A onto the surface of the rotary shaft 1, collides with the rotary shaft 1, and then is discharged into the bearing casing 3. In the steam turbine, the return oil system that reaches the lubricating oil tank (not shown) from the inside of the bearing casing 3 through the return oil hole 10 is controlled to a pressure close to atmospheric pressure. The air released inside the bearing casing 3 in this embodiment is also collected through the return oil system shown on the left.

  In FIGS. 5 and 6, a gland portion 11 is provided at the end of the turbine casing 2. Steam is used as the seal fluid in the gland portion 11, and the rotating shaft 1 may come into contact with the steam of several hundreds of degrees Celsius in the gland portion 11 depending on operating conditions. In such a case, heat flows from the steam into the rotating shaft 1.

  In the present embodiment, compressed air of several tens of degrees Celsius at most is injected into the range from the position where the rotary shaft 1 comes out of the turbine casing 2 to the position where the rotary shaft 1 faces the pad 4 of the journal bearing, so that the ground is abundant. The heat flowing from the portion 11 is carried away by the compressed air, and the thermal expansion of the rotary shaft journal portion 22 is suppressed.

  Since the thermal expansion of the rotary shaft journal portion 22 is suppressed in this way, a sufficient gap is secured between the rotary shaft 1 and the sliding surface of the pad 4. As a result, the temperature of the pad material is kept low, and the strength of the material of the pad 4 can be maintained. Further, the anisotropy of the spring constant of the journal bearing 50 is ensured, and the vibration stability can be maintained more reliably.

  Furthermore, since compressed air is used as the cooling medium for the rotating shaft 1 and the used air is recovered through the existing return oil system, it is not necessary to add a system for recovering the cooling medium.

(Fifth Embodiment)
Next, a fluid machine according to the fifth embodiment will be described with reference to FIG. FIG. 7 is a diagram showing a fluid machine according to the fifth embodiment.

  As shown in FIG. 7, the mounting angle of the nozzle 23A is set so that the compressed air 28 injected from the nozzle 23A has a velocity component in the axial direction of the rotary shaft 1.

  Other configurations of the fifth embodiment shown in FIG. 7 are substantially the same as those of the first embodiment shown in FIGS. 1 and 2. In the fifth embodiment shown in FIG. 7, the same parts as those in the first embodiment shown in FIGS. 1 and 2 are designated by the same reference numerals, and detailed description thereof will be omitted.

  FIG. 7 shows an axial range L in which the compressed air 28 injected from the nozzle 23A collides with the rotary shaft 1 in this embodiment. The range L in which the compressed air 28 collides with the rotary shaft 1 is larger than the axial range L ′ in which the compressed air 27 collides with the rotary shaft 1 shown in FIG.

  As described above, in the present embodiment, the compressed air 28 is jetted while being inclined so as to have a velocity component in the axial direction of the rotary shaft 1, so that the area in which the compressed air 28 contacts the rotary shaft 1 becomes large. As a result, the amount of heat that the compressed air 28, which is the cooling medium, carries away from the rotary shaft 1 increases, and the thermal expansion of the rotary shaft journal portion 22 is more reliably suppressed.

(Sixth Embodiment)
Next, a fluid machine according to the sixth embodiment will be described with reference to FIG. Here, FIG. 8 is a view showing a fluid machine according to the sixth embodiment.

  As shown in FIG. 8, the mounting angle of the nozzle 23A is set so that the compressed air 28 injected from the nozzle 23A has a velocity component in the tangential direction of the rotary shaft 1.

  The other structure of the sixth embodiment shown in FIG. 8 is substantially the same as that of the first embodiment shown in FIGS. 1 and 2. In the sixth embodiment shown in FIG. 8, the same parts as those in the first embodiment shown in FIGS. 1 and 2 are designated by the same reference numerals, and detailed description thereof will be omitted.

  In FIG. 8, the range in the circumferential direction in which the compressed air 28 injected from the nozzle 23A collides with the rotating shaft 1 in this embodiment is indicated by α. The range L in which the compressed air 28 collides with the rotary shaft 1 is larger than the circumferential range α ′ in which the compressed air 28 collides with the rotary shaft 1 shown in FIG.

  As described above, in the present embodiment, the compressed air 28 is jetted while being inclined so as to have a velocity component in the tangential direction of the rotary shaft 1, so that the area in which the compressed air 28 contacts the rotary shaft 1 becomes large. As a result, the amount of heat that the compressed air 28, which is the cooling medium, carries away from the rotary shaft 1 increases, and the thermal expansion of the rotary shaft journal portion 22 is more reliably suppressed.

(Seventh embodiment)
Next, a fluid machine according to the seventh embodiment will be described with reference to FIGS. 9 and 10. 9 is a diagram showing a fluid machine according to the seventh embodiment, and FIG. 10 is a sectional view taken along the line AA of FIG.

  As shown in FIG. 9, the pad-type journal bearing 50 has an upper half portion 50A and a lower half portion 50B that are divided into two parts, of which the oil is formed on the side end surface 50a of the upper half portion 50A on the turbine casing 2 side. A receiver 29 is provided.

  As shown in FIGS. 9 and 10, in the process of passing through the gap between the rotary shaft 1 and the pad 4, the lubricating oil is discharged from the axial end of the gap toward the outside of the bearing body 5 in the direction of arrow 9. . The discharged lubricating oil has an axial velocity component due to the oil film pressure in the gap and an outer peripheral velocity component due to the centrifugal force due to the rotation of the shaft. The oil receiver 29 of the present embodiment receives the lubricating oil discharged in the direction of arrow 9. Further, the oil receiver 29 has a guide passage 30 that guides the lubricating oil in the oil receiver 29 to the rotary shaft 1 side and includes a barrier 30a. That is, as shown in FIGS. 9 and 10, the guide passage 30 of the oil receiver 29 includes an opening 31 that opens above the rotary shaft 1 so that the lubricating oil that has collided with the barrier 30 a of the guide passage 30 of the rotary shaft 1 can be prevented. Free fall on the surface. Lubricating oil that has fallen freely on the surface of the rotary shaft 1 further falls inside the bearing casing 3 and is returned to a lubricating oil tank (not shown) through the return oil hole 10.

  Other configurations of the seventh embodiment shown in FIGS. 9 and 10 are substantially the same as those of the first embodiment shown in FIGS. 1 and 2. In the seventh embodiment shown in FIGS. 9 and 10, the same parts as those of the first embodiment shown in FIGS. 1 and 2 are designated by the same reference numerals, and detailed description thereof will be omitted.

  As shown in FIGS. 9 and 10, a gland portion 11 is provided at the end of the turbine casing 2. Steam is used as the seal fluid in the gland portion 11, and the rotating shaft 1 may come into contact with the steam of several hundreds of degrees Celsius in the gland portion 11 depending on operating conditions. In such a case, heat flows from the steam into the rotating shaft 1.

  In the present embodiment, the lubricating oil of at most several tens of degrees Celsius is applied by free fall within the range from the position where the rotary shaft 1 comes out of the turbine casing 2 to the position where the rotary shaft 1 faces the pad 4 of the journal bearing. As a result, the heat flowing from the gland portion 11 is carried away by the lubricating oil, and the thermal expansion of the rotary shaft journal portion 22 is suppressed.

(Eighth Embodiment)
Next, a fluid machine according to the eighth embodiment will be described with reference to FIGS. 11 and 12. 11 is a diagram showing a fluid machine according to the eighth embodiment, and FIG. 12 is a sectional view taken along the line AA of FIG.

  As shown in FIG. 11, the pad-type journal bearing 50 has an upper half 50A and a lower half 50B, of which the oil container 32 is provided on the side end surface 50b of the lower half 50B on the turbine casing 2 side. There is.

  As shown in FIGS. 11 and 12, in the process of passing through the gap between the rotary shaft 1 and the pad 4, the lubricating oil is discharged from the axial end of the gap toward the outside of the bearing body 5 in the direction of arrow 9. . The discharged lubricating oil has an axial velocity component due to the oil film pressure in the gap and an outer peripheral velocity component due to the centrifugal force due to the rotation of the shaft. The oil container 32 of the present embodiment has a space called an oil sump 33, and lubricating oil is accumulated in this oil sump 33. Further, the oil container 32 has an opening 34 above the lowest point of the rotating shaft for overflowing the lubricating oil that has flowed into the oil sump 33.

  Other configurations of the eighth embodiment shown in FIGS. 11 and 12 are substantially the same as those of the first embodiment shown in FIGS. 1 and 2. In the eighth embodiment shown in FIGS. 11 and 12, the same parts as those of the first embodiment shown in FIGS. 1 and 2 are designated by the same reference numerals, and detailed description thereof will be omitted.

  11 and 12, the liquid level of the lubricating oil accumulated in the oil sump 33 is above the lowest point of the rotating shaft 1, and a part of the surface of the rotating shaft 1 is immersed in the lubricating oil inside the oil sump 33. Will be done. Further, the lubricating oil attached to the surface of the rotary shaft 1 in the oil sump 33 is discharged from the opening 34 as shown by the arrow 36 as the shaft rotates, so that the lubricating oil inside the oil sump 33 is constantly replaced. As shown in FIG. 11, fins 35 are provided in the gap between the rotary shaft 1 and the oil container 32 to minimize the gap, so that the accumulation of the lubricating oil in the oil sump 33 can be promoted. is there.

  As shown in FIGS. 11 and 12, a gland portion 11 is provided at the end of the turbine casing 2. Steam is used as the seal fluid in the gland portion 11, and the rotating shaft 1 may come into contact with the steam of several hundreds of degrees Celsius in the gland portion 11 depending on operating conditions. In such a case, heat flows from the steam into the rotating shaft 1.

  In the present embodiment, the rotating shaft 1 is immersed in lubricating oil of at most several tens of degrees Celsius within the range from the position where the rotating shaft 1 comes out of the turbine casing 2 to the position where the rotating shaft 1 faces the pad 4 of the journal bearing. As a result, the heat flowing from the gland portion 11 is carried away by the lubricating oil, and the thermal expansion of the rotary shaft journal portion 22 is suppressed.

(Ninth Embodiment)
Next, a fluid machine according to the ninth embodiment will be described with reference to FIG. FIG. 13 is a diagram showing a fluid machine according to the ninth embodiment.

  As shown in FIG. 13, the pad-type journal bearing 50 has an upper half portion 50A and a lower half portion 50B which are divided into two parts, of which an oil receiving portion is provided on a side end surface 50a of the upper half portion 50A on the turbine casing 2 side. 29 are provided.

  As shown in FIG. 13, in the process of passing through the gap between the rotary shaft 1 and the pad 4, the lubricating oil is discharged from the axial end of the gap toward the outside of the bearing body 5 in the direction of arrow 9. The discharged lubricating oil has an axial velocity component due to the oil film pressure in the gap and an outer peripheral velocity component due to the centrifugal force due to the rotation of the shaft. The oil receiver 29 of the present embodiment receives the lubricating oil discharged in the direction of arrow 9. Further, the oil receiver 29 has a guide passage 30 that guides the lubricating oil in the oil receiver 29 to the rotary shaft 1 side and includes a barrier 30a.

  An oil container 32 is provided on the side end surface 50b of the lower half portion 50B on the turbine casing 2 side.

  As shown in FIG. 13, in the process of passing through the gap between the rotary shaft 1 and the pad 4, the lubricating oil is discharged from the axial end of the gap toward the outside of the bearing body 5 in the direction of arrow 9. The discharged lubricating oil has an axial velocity component due to the oil film pressure in the gap and an outer peripheral velocity component due to the centrifugal force due to the rotation of the shaft. The oil container 32 of the present embodiment has a space called an oil sump 33, and lubricating oil is accumulated in this oil sump 33. Further, the oil container 32 has an opening 34 above the lowest point of the rotating shaft for overflowing the lubricating oil that has flowed into the oil sump 33.

  As shown in FIG. 13, among the side end surfaces of the upper half portion 50A and the lower half portion 50B of the pad type journal bearing 50, the side end surfaces 50c and 50d on the side opposite to the turbine casing 2 side are respectively connected to the rotary shaft 1 and The oil drain shielding plates 37a and 37b are provided so as to face each other with a constant gap. The gap between the rotary shaft 1 and the oil drain shielding plates 37a and 37b is equal to the gap between the rotary shaft 1 and the pad 4.

  In FIG. 13, the lubricating oil is discharged to the outside of the bearing body 5 from the axial end of the gap while passing through the gap between the rotary shaft 1 and the pad 4. According to the present embodiment, it becomes difficult for the lubricating oil discharged from the end surface on the side opposite to the turbine casing 2 to pass through the narrow gap between the oil discharge shield plate 37 and the rotary shaft 1, and the discharge amount is reduced. It will be scarce. Accordingly, the amount of lubricating oil discharged from the side end surface on the turbine casing 2 side increases, and the amount of lubricating oil flowing into the oil receiver 29 and the oil container 32 also increases.

  As described above, according to the present embodiment, the lubricating oil discharged from the side end surface of the journal bearing 50 on the turbine casing 2 side can be used as the cooling medium of the rotating shaft 1. In this case, the flow rate of the lubricating oil that serves as the cooling medium can be increased, the amount of heat that the lubricating oil carries away from the rotating shaft 1 increases, and thermal expansion of the rotating shaft journal portion 22 can be suppressed more reliably.

1 rotating shaft, 2 turbine casing, 3 bearing casing, 4 pad, 5 bearing body, 6 bearing stand, 7 oil supply hole, 9 speed of lubricating oil discharged from the gap between the rotating shaft and pad, 10 return oil hole, 11 Gland part, 12 labyrinth packing, 13 fins, 14 working steam pressure chamber, 15 gland part inside pressure chamber, 16 gland part outside pressure chamber, 17 steam supply line, 18 gland steam header, 19 gland condenser, 20 surplus steam recovery Line, 21 ground vapor recovery line, 22 rotary shaft journal part, 23 nozzle, 23A nozzle, 24 jet oil extraction hole, 25 jet oil pipe, 26 lubricating oil jetted from nozzle, 27 compressed air pipe, 28 jetted from nozzle Compressed air, 29 oil pan, 30 oil pan barrier, 31 oil pan opening, 2 oil container, 33 oil container oil sump, 34 oil container opening, 35 oil container fin, 36 speed of lubricating oil discharged from oil sump, 37 oil drain shield, 50 journal bearing, 50A upper half , 50B lower half

Claims (3)

A main body casing of the fluid machine,
A rotating shaft rotatably arranged in the main body casing,
A journal bearing that is disposed outside the main body casing and that rotatably supports the rotating shaft,
The journal bearing has an upper half and a lower half,
On the main body casing side of the upper half of the journal bearing, an oil receiver is provided for receiving lubricating oil discharged from between the rotary shaft and the sliding surface of the journal bearing, and the oil receiver receives the lubricating oil through an opening. A fluid machine that has a guide path that leads to the rotating shaft side. A main body casing of the fluid machine,
A rotating shaft rotatably arranged in the main body casing,
A journal bearing that is disposed outside the main body casing and that rotatably supports the rotating shaft,
The journal bearing has an upper half and a lower half,
The main casing side of the lower half of the journal bearing, the oil container for accumulating the lubricating oil discharged from the gap between the sliding surface of the journal bearing and the rotary shaft is provided, the oil container wherein rotation A fluid machine having an opening above the lowest point of the shaft for allowing lubricating oil in the oil container to overflow. The out side end surfaces of the journal bearing, the side end face opposite to the main body casing, the rotating shaft and with a certain gap provided oil discharge shielding plate so as to face, the fluid machine according to claim 1 or 2, wherein .

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