JP5936725B1 - Journal bearing device and rotating machine - Google Patents

Abstract

A journal bearing device having a semi-annular bearing portion for preventing the rotor shaft from jumping up and sufficiently supplying lubricating oil to the bearing surface of the semi-annular bearing portion, and a rotation provided with the journal bearing device Provide machines. A journal bearing device includes a carrier ring, at least two bearing pads, a plurality of nozzle heads, and at least one semi-annular bearing portion. The plurality of nozzle heads includes a most downstream nozzle head that is located upstream of the semi-annular bearing portion in the rotation direction of the rotor shaft and that is located closest to the semi-annular bearing portion. At least one nozzle hole capable of discharging lubricating oil is provided in a range where the semi-annular bearing portion exists in the axial direction of the carrier ring. [Selection] Figure 6

Description

  The present disclosure relates to a journal bearing device and a rotating machine.

  For example, a rotary machine such as a steam turbine or a gas turbine has a journal bearing device that rotatably supports a rotor shaft. As this type of journal bearing device, there is known a journal bearing device having a plurality of tilting pads arranged around the rotor shaft.

  For example, a tilting pad type journal bearing device disclosed in Patent Document 1 has a carrier ring that surrounds a journal of a rotor shaft, and includes a lower half region of the outer peripheral surface of the journal and a lower half region of the inner peripheral surface of the carrier ring. Two tilting pads are disposed only between the two. The two tilting pads support the load of the rotor shaft directed downward. On the other hand, a guide metal is fixed to the upper half region of the inner peripheral surface of the carrier ring. The guide metal does not support the load of the rotor shaft, but is only for preventing the rotor shaft from jumping up.

International Publication No. 2010/097990

  In the journal bearing device disclosed in Patent Document 1, the guide metal does not support the load of the rotor shaft, but only for preventing the rotor shaft from jumping up. For this reason, when the rotor shaft jumps up and collides with the guide metal, there is a problem that it is difficult for the guide metal to smoothly support the load of the rotor shaft.

  In the journal bearing device disclosed in Patent Document 1, the width of the oil supply nozzle is narrower than the width of the guide metal. For this reason, a sufficient amount of lubricating oil is not supplied between the guide metal and the rotor shaft. Therefore, when the rotor shaft jumps up and collides with the guide metal, there is also a problem that it is difficult to suppress the rotor shaft jumping by utilizing the oil film pressure increase due to the wedge effect.

  In view of the circumstances described above, at least one embodiment of the present invention has a semi-annular bearing portion that prevents the rotor shaft from jumping up, and the lubricating oil is sufficiently supplied to the bearing surface of the semi-annular bearing portion. It is an object to provide a journal bearing device and a rotary machine including the journal bearing device.

(1) A journal bearing device according to at least one embodiment of the present invention includes:
A carrier ring that can surround the journal of the rotor shaft in a cylindrical space;
At least two bearing pads respectively arranged in a lower half region of the space so as to rotatably support the journal and arranged in a circumferential direction of the carrier ring;
A plurality of nozzle heads arranged in the space apart from each other in the circumferential direction of the carrier ring, each capable of supplying lubricating oil to the space;
At least one semi-annular bearing portion having a bearing surface disposed in the upper half area of the space in a state of being fixed to the carrier ring and capable of facing the upper half area of the outer peripheral surface of the journal with a bearing gap. When,
With
The plurality of nozzle heads includes a most downstream nozzle head that is located upstream of the semi-annular bearing portion in the rotational direction of the rotor shaft and located closest to the semi-annular bearing portion,
The most downstream nozzle head has at least one nozzle hole capable of discharging lubricating oil in a range where the semi-annular bearing portion exists in the axial direction of the carrier ring.

In the journal bearing device having the above configuration (1), the semi-annular bearing portion has a bearing surface, and when the rotor shaft jumps up and collides with the bearing surface, the bearing surface smoothly applies an upward load from the rotor shaft. Can be supported.
In addition, since the most downstream nozzle head has a nozzle hole in a range where the semi-annular bearing portion exists in the axial direction of the carrier ring, supply a sufficient amount of lubricating oil between the rotor shaft and the bearing surface. Can do. For this reason, when the rotor shaft jumps up and collides with the bearing surface, the pressure of the oil film increases due to the wedge effect, and the rotor shaft can be prevented from colliding with the bearing surface.

(2) In some embodiments, in the configuration (1),
The bearing surface is made of a bearing alloy.
In the journal bearing device having the configuration (2), the bearing surface made of the bearing alloy can smoothly support the upward load from the rotor shaft.

(3) In some embodiments, in the configuration (1) or (2),
The at least one semi-annular bearing portion is
Two semi-annular bearing portions spaced apart from each other in the axial direction of the carrier ring;
Each of the plurality of nozzle heads is
A pillar projecting from the inner peripheral surface of the carrier ring along the radial direction of the carrier ring;
Two arm portions respectively extending along the axial direction of the carrier ring from both sides of the tip portion of the column portion,
In the axial direction of the carrier ring, the range in which the two arm portions of the most downstream nozzle head exist overlaps the range in which the two semi-annular bearing portions exist,
The at least one nozzle hole is formed in each of the two arm portions of the most downstream nozzle head.

  In the configuration (3), a sufficient amount of lubricating oil can be supplied between the rotor shaft and the bearing surface by at least one nozzle hole formed in each of the two arm portions of the nozzle head.

(4) In some embodiments, in the configuration (3),
The two arm portions of the most downstream nozzle head are longer than the two arm portions of at least one other nozzle head.

In the gap between the bearing pad and the outer peripheral surface of the journal, the oil film pressure increases, so that the lubricating oil leaks from the gap. For this reason, even if lubricating oil is supplied to both sides of the gap, the lubricating oil does not act effectively and leaks out.
In this respect, in the configuration (4), since the two arm portions of at least one other nozzle head are short, the supply amount of the lubricating oil to both sides of the gap between the bearing pad and the outer peripheral surface of the journal is suppressed. More lubricating oil can be supplied to the vicinity of the center of the gap, and the lubricating oil can be used effectively.

(5) In some embodiments, in the above configuration (1) or (2),
The at least one semi-annular bearing portion is
One semi-annular bearing portion located at the center of the bearing pad in the axial direction of the carrier ring.

  In the above configuration (5), the semi-annular bearing portion is located in the center of the bearing pad in the axial direction of the carrier ring, and the lubricating oil is provided in the gap between the outer peripheral surface of the journal and the bearing surface with a simple configuration. Can supply enough.

(6) In some embodiments, in the configuration (5),
A bearing housing that houses the carrier ring;
And at least two spherical keys provided between the bearing housing and the carrier ring and supporting the carrier ring in a swingable manner.
The range where the at least two spherical keys exist in the axial direction of the carrier ring overlaps the range where the at least one semi-annular bearing portion exists.

  In the configuration (6), since the position of the semi-annular bearing portion overlaps with the position of the at least two spherical keys in the axial direction of the carrier ring, the support rigidity for the semi-annular bearing portion is increased. Can be high. Thereby, when a rotor shaft jumps up, a semi-annular bearing part can support a rotor shaft much more smoothly.

(7) In some embodiments, in any one of the configurations (1) to (6),
The width of the at least one semi-annular bearing portion in the axial direction of the carrier ring increases from the inside toward the outside in the radial direction of the carrier ring.

  In the configuration (7), since the width of the semi-annular bearing portion increases from the inside to the outside in the radial direction of the carrier ring, the connection strength between the semi-annular bearing portion and the carrier ring is increased. Can be high. For this reason, when the rotor shaft jumps up, the semi-annular bearing portion can support the rotor shaft smoothly and stably.

(8) In some embodiments, in any one of the configurations (1) to (7),
The at least one semi-annular bearing portion has irregularities on the bearing surface.
In the configuration (8), the semi-annular bearing portion has irregularities on the bearing surface, and the irregularities function as an oil reservoir. For this reason, it is possible to prevent the oil film from being cut on the bearing surface, and when the rotor shaft jumps up, the semi-annular bearing portion can smoothly support the rotor shaft.

(9) In some embodiments, in the configuration (8),
The at least one semi-annular bearing portion has at least one oil groove on the bearing surface;
The at least one oil groove extends along the circumferential direction of the carrier ring from the upstream end of the semi-annular bearing portion in the rotational direction of the rotor shaft.

  In the configuration (9), the oil groove extending along the circumferential direction from the upstream end is formed on the bearing surface of the semi-annular bearing portion, and the oil groove functions as an oil reservoir. Here, since the oil groove extends from the upstream end, the lubricating oil easily flows into the oil groove, and the oil film breakage on the bearing surface can be more reliably prevented.

(10) A rotating machine according to at least one embodiment of the present invention includes:
The journal bearing device according to any one of the above configurations (1) to (9) is provided.

In the rotating machine having the above configuration (10), the semi-annular bearing portion has a bearing surface, and when the rotor shaft jumps up and collides with the bearing surface, the bearing surface smoothly applies an upward load from the rotor shaft. Can be supported.
In addition, since the most downstream nozzle head has a nozzle hole in a range where the semi-annular bearing portion exists in the axial direction of the carrier ring, supply a sufficient amount of lubricating oil between the rotor shaft and the bearing surface. Can do. For this reason, when the rotor shaft jumps up and collides with the bearing surface, the pressure of the oil film increases due to the wedge effect, and the rotor shaft can be prevented from colliding with the bearing surface.

  According to at least one embodiment of the present invention, there is provided a journal bearing device having a semi-annular bearing portion for preventing the rotor shaft from jumping up and sufficiently supplying lubricating oil to the bearing surface of the semi-annular bearing portion, and A rotary machine including the journal bearing device is provided.

It is sectional drawing which shows the schematic structure of the turbine which concerns on one Embodiment of this invention. It is a figure showing roughly a longitudinal section of a journal bearing device concerning one embodiment. FIG. 3 is an enlarged view of a region III in FIG. 2. FIG. 4 is a schematic sectional view taken along line IV-IV in FIG. 2. FIG. 5 is a schematic cross-sectional view taken along line VV in FIG. 2. It is an expanded view which shows a carrier ring, a side plate, a bearing pad, a semi-annular bearing part, and a nozzle head schematically. It is a figure which respectively shows the schematic longitudinal cross-section of the upper half part of the journal bearing apparatus which concerns on other embodiment. It is a figure which respectively shows the schematic longitudinal cross-section of the upper half part of the journal bearing apparatus which concerns on other embodiment. It is a figure which respectively shows the schematic longitudinal cross-section of the upper half part of the journal bearing apparatus which concerns on other embodiment. It is a figure which shows roughly the circumferential direction orthogonal cross section of a semi-annular bearing part. FIG. 11 is a schematic cross-sectional view taken along line XI-XI in FIG. 10. It is a figure equivalent to FIG. 11 of the semi-annular bearing part which concerns on other embodiment.

Hereinafter, some embodiments of the present invention will be described with reference to the accompanying drawings. However, the dimensions, materials, shapes, relative arrangements, etc. of the components described in the embodiments or shown in the drawings are not intended to limit the scope of the present invention, but are merely illustrative examples. Absent.
For example, expressions expressing relative or absolute arrangements such as “in a certain direction”, “along a certain direction”, “parallel”, “orthogonal”, “center”, “concentric” or “coaxial” are strictly In addition to such an arrangement, it is also possible to represent a state of relative displacement with an angle or a distance such that tolerance or the same function can be obtained.
For example, an expression indicating that things such as “identical”, “equal”, and “homogeneous” are in an equal state not only represents an exactly equal state, but also has a tolerance or a difference that can provide the same function. It also represents the existing state.
For example, expressions representing shapes such as quadrangular shapes and cylindrical shapes represent not only geometrically strict shapes such as quadrangular shapes and cylindrical shapes, but also irregularities and chamfers as long as the same effects can be obtained. A shape including a part or the like is also expressed.
On the other hand, the expressions “comprising”, “comprising”, “comprising”, “including”, or “having” one constituent element are not exclusive expressions for excluding the existence of the other constituent elements.

FIG. 1 is a cross-sectional view showing a schematic configuration of a turbine 1 according to an embodiment of the present invention.
The turbine 1 is a steam turbine applicable to, for example, combined cycle power generation, and is connected to the generator 3. The turbine 1 generates torque using steam, and the generator 3 generates power using the torque output from the turbine 1.

  The turbine 1 has a housing (cabinet) 5, a rotor shaft 7, a stationary blade row fixed to the housing 5, and a plurality of blade rows fixed to the rotor shaft 7. The rotor shaft 7 is supported by the journal bearing devices 9 and 10 and the thrust bearing device 11 so as to be rotatable around a horizontal axis, and at least a part of the rotor shaft 7 extends in the housing 5. The generator 3 is connected to one end side of the rotor shaft 7.

  A cylindrical internal flow path 12 is formed between the housing 5 and the rotor shaft 7, and a stationary blade row and a moving blade row are disposed in the internal flow channel 12. Each stationary blade row includes a plurality of stationary blades 14 arranged in the circumferential direction of the rotor shaft 7, and each stationary blade 14 is fixed to the housing 5. Each moving blade row includes a plurality of moving blades 15 arranged in the circumferential direction of the rotor shaft 7, and each moving blade 15 is fixed to the rotor shaft 7. In each stationary blade row, the flow of steam is accelerated, and in each blade row, steam energy is converted into rotational energy of the rotor shaft 7.

That is, the turbine 1 roughly includes a stationary assembly 17 and a rotating assembly 19 that can rotate relative to the stationary assembly 17, and the housing 5 and the stationary blade 14 constitute a part of the stationary assembly 17. The rotor shaft 7 and the rotor blade 15 constitute a part of the rotating assembly 19.
Further, the turbine 1 has at least one sealing device 20. The sealing device 20 is disposed between the stationary assembly 17 and the rotating assembly 19, and defines a sealing gap between the stationary assembly 17 and the rotating assembly 19 for restricting fluid flow.

Hereinafter, the journal bearing device 10 according to some embodiments of the present invention will be described with reference to FIGS.
FIG. 2 is a diagram schematically illustrating a longitudinal section of the journal bearing device 10 according to an embodiment, and is a schematic sectional view taken along line II-II in FIG. 4. FIG. 3 is an enlarged view of region III in FIG. 4 is a schematic cross-sectional view taken along line IV-IV in FIG. FIG. 5 is a schematic cross-sectional view taken along line VV in FIG. FIG. 6 is a developed view schematically showing the carrier ring, the side plate, the bearing pad, the semi-annular bearing portion, and the nozzle head. 7, 8, and 9 are schematic vertical cross-sectional views of the upper half of the journal bearing device 10 according to another embodiment. FIG. 10 is a diagram schematically showing a circumferentially orthogonal cross section of the semi-annular bearing portion, and is a schematic cross sectional view taken along line XX in FIG. 11. FIG. 11 is a schematic cross-sectional view along the line XI-XI in FIG. FIG. 12 is a view corresponding to FIG. 11 of a semi-annular bearing portion according to another embodiment.

As shown in FIGS. 2 and 4, the journal bearing device 10 includes a bearing housing 30, a carrier ring 32, at least two bearing pads 34, a plurality of nozzle heads 38, a pair of partition walls 40, and at least And one semi-annular bearing portion 42.
The bearing housing 30 includes, for example, a pedestal 30a and a cover 30b fixed to the pedestal 30a.

  The carrier ring 32 is disposed inside the bearing housing 30. The carrier ring 32 has a cylindrical inner peripheral surface, and the inner peripheral surface of the carrier ring 32 can surround a part of the rotor shaft 7, that is, the journal 7 a with a cylindrical space 44. The space 44 is defined between the outer peripheral surface of the journal 7 a and the inner peripheral surface of the carrier ring 32. The carrier ring 32 has a cylindrical shape, for example.

  The at least two bearing pads 34 are respectively arranged in the lower half region of the space 44 and are arranged in the circumferential direction of the carrier ring 32. The bearing pad 34 has a fan shape when viewed along the axial direction of the carrier ring 32, and has a curved inner surface 34a and outer surface 34b each having a divided cylindrical shape. The inner surface 34a of the bearing pad 34 is formed of a bearing alloy, for example, white metal, and is disposed to face the outer peripheral surface of the journal 7a.

  The at least two bearing pads 34 are provided so as to be tiltable or swingable, and the gap between the journal 7a and the bearing pad 34 can be gradually changed in the circumferential direction or the axial direction of the journal 7a. For this purpose, for example, a tilting unit (not shown) is provided between each of the at least two bearing pads 34 and the carrier ring 32. The tilting unit is constituted by a pivot, for example. Alternatively, the outer surface 34b of the bearing pad 34 and the inner peripheral surface of the carrier ring 32 are configured to have different curvatures.

  The pair of partition walls 40 have shaft holes through which the rotor shaft 7 can be inserted, and define both ends of the space 44 in the axial direction of the carrier ring 32. The partition wall 40 is constituted by, for example, an annular side plate 46, and the side plate 46 is fixed to the carrier ring 32 by bolts.

  At least one semi-annular bearing portion 42 (42a, 42b, 42c, 42d) is disposed in the upper half area of the space 44 and is fixed to the carrier ring 32 by, for example, a bolt (not shown). In the present specification, the reference numeral 42 before the parentheses is used to indicate one or more of the reference numerals in the parentheses for convenience of explanation, and is not attached to the drawings.

  The semi-annular bearing portion 42 has a sector shape when viewed along the axial direction of the carrier ring 32. The semi-annular bearing portion 42 has a bearing surface 50 on the inner side in the radial direction of the carrier ring 32. The bearing surface 50 has a semi-cylindrical shape shorter than the bearing pad 34 and curved along the upper half region of the outer peripheral surface of the journal 7a. The bearing surface 50 and the upper half region of the outer peripheral surface of the journal 7a have a bearing gap Gb. Exist and face each other.

  The plurality of nozzle heads 38 are arranged in the space 44 so as to be separated from each other in the circumferential direction of the carrier ring 32, and can supply lubricating oil to the space 44. For example, a lubricating oil supply path (not shown) is formed in the carrier ring 32, and the lubricating oil is supplied to the nozzle head 38 through the supply path.

  The plurality of nozzle heads 38 includes one most downstream nozzle head 54. The most downstream nozzle head 54 is located upstream of the semi-annular bearing portion 42 in the rotational direction of the rotor shaft 7 and is located closest to the semi-annular bearing portion 42. The most downstream nozzle head 54 has at least one nozzle hole 56 a capable of discharging lubricating oil in a range where the semi-annular bearing portion 42 exists in the axial direction of the carrier ring 32.

  In the journal bearing device 10 described above, lubricating oil is supplied from the nozzle head 38 to the space 44 during operation of the turbine 1, that is, during rotation of the rotor shaft 7. The lubricating oil ejected from the nozzle head 38 flows between the inner surface 34a of the bearing pad 34 and the outer peripheral surface of the journal 7a, and forms an oil film therebetween. The bearing pad 34 rotatably supports the rotor shaft 7 while supporting a downward load based on the weight of the rotor shaft 7 through the oil film.

In addition, in the journal bearing device 10 described above, when the semi-annular bearing portion 42 has the bearing surface 50 and the rotor shaft 7 jumps up and collides with the bearing surface 50 for some reason, the bearing surface 50 is the rotor surface. The upward load from the shaft 7 can be smoothly supported.
Further, since the most downstream nozzle head 54 has the nozzle hole 56 a in the range where the semi-annular bearing portion 42 exists in the axial direction of the carrier ring 32, a sufficient amount is provided between the rotor shaft 7 and the bearing surface 50. Lubricating oil can be supplied. For this reason, when the rotor shaft 7 jumps and collides with the bearing surface 50, the pressure of the oil film increases due to the wedge effect, and the rotor shaft 7 can be prevented from colliding with the bearing surface 50.

In some embodiments, the bearing surface 50 is comprised of a bearing alloy. That is, the semi-annular bearing portion 42 has a main body 57 and a bearing film 58 made of a bearing alloy laminated on the main body 57, and the bearing film 58 constitutes the bearing surface 50. The bearing alloy is, for example, white metal.
According to the above configuration, the bearing surface 50 made of a bearing alloy can smoothly support the upward load from the rotor shaft 7.
In some embodiments, the semi-annular bearing portion 42 has a sector shape with a tension angle, that is, a central angle of 180 ° when viewed in the axial direction of the carrier ring 32.

  In some embodiments, as shown in FIGS. 2, 6 and 8, the at least one semi-annular bearing portion 42 includes two semi-annular bearing portions spaced apart from each other in the axial direction of the carrier ring 32. 42. Each of the plurality of nozzle heads 38 includes a column portion 38a protruding from the inner peripheral surface of the carrier ring 32 along the radial direction of the carrier ring 32, and an axial direction of the carrier ring 32 from both sides of the tip portion of the column portion. And two arm portions 38b extending along each of them.

  In the axial direction of the carrier ring 32, the range where the two arm portions 38 b of the most downstream nozzle head 54 exist overlaps the range where the two semi-annular bearing portions 42 exist. A plurality of nozzle holes 56 are formed in each of the two arm portions 38 b and the column portion 38 a of the most downstream nozzle head 54. At least one nozzle hole 56 a among the plurality of nozzle holes 56 is located in a range where the semi-annular bearing portion 42 or the bearing surface 50 exists in the axial direction of the carrier ring 32.

  According to the above configuration, a sufficient amount of lubricating oil is supplied between the rotor shaft 7 and the bearing surface 50 by the at least one nozzle hole 56a formed in each of the two arm portions 38b of the most downstream nozzle head 54. can do.

  In some embodiments, as shown in FIG. 6, the two arm portions 38 b of the most downstream nozzle head 54 are longer than the two arm portions 38 b of at least one other nozzle head 38.

In the gap between the bearing pad 34 and the outer peripheral surface of the journal 7a, the oil film pressure increases, so that the lubricating oil leaks from the gap. For this reason, even if lubricating oil is supplied to both sides of the gap, the lubricating oil does not act effectively and leaks out.
In this regard, according to the above configuration, since the two arm portions 38b of at least one other nozzle head 38 are short, the amount of lubricant supplied to both sides of the gap between the bearing pad 34 and the outer peripheral surface of the journal 7a is reduced. While suppressing, more lubricating oil can be supplied to the vicinity of the center of the gap, and the lubricating oil can be effectively utilized.

In some embodiments, a pair of nozzle heads 38 are disposed on each side of each bearing pad 34 in the circumferential direction of the carrier ring 32.
In some embodiments, two bearing pads 34 are arranged with a gap in the circumferential direction of the carrier ring 32, and a total of five nozzle heads 38 are arranged in the space 44.

In some embodiments, as shown in FIGS. 7 and 9, the at least one semi-annular bearing portion 42 is a semi-annular ring located in the center of the bearing pad 34 in the axial direction of the carrier ring 32. A bearing 42 is included.
According to the above configuration, the semi-annular bearing portion 42 is located in the center of the bearing pad 34 in the axial direction of the carrier ring 32, and the journal 7a has a simple configuration with the outer peripheral surface of the journal 7a and the bearing surface 50. A sufficient amount of lubricating oil can be supplied to the gap.

  In some embodiments, as shown in FIGS. 7 and 9, the at least one semi-annular bearing portion 42 is located in the center of the bearing pad 34 in the axial direction of the carrier ring 32. Only one 42 is included.

In some embodiments, the journal bearing device 10 further comprises at least two spherical keys 60. The at least two spherical keys 60 are respectively provided between the bearing housing 30 and the carrier ring 32 and are separated from each other in the circumferential direction of the carrier ring 32. At least two spherical keys 60 support the carrier ring 32 in a swingable manner.
In the axial direction of the carrier ring 32, the range in which at least two spherical keys 60 exist overlaps with the range in which at least one semi-annular bearing portion 42 exists.

  According to the above configuration, in the axial direction of the carrier ring 32, the position where the semi-annular bearing portion 42 exists overlaps with the position where at least two spherical keys 60 exist. Support rigidity can be increased. Thereby, when the rotor shaft 7 jumps up, the semi-annular bearing portion 42 can support the rotor shaft 7 more smoothly.

In some embodiments, a detent pin (not shown) is provided between the bearing housing 30 and the carrier ring 32 to prevent circumferential rotation of the carrier ring 32 with respect to the bearing housing 30.
In some embodiments, the journal bearing device 10 has at least one flat key (not shown) disposed between the bearing housing 30 and the carrier ring 32.
In some embodiments, the journal bearing device 10 has at least one half-pipe key (not shown) disposed between the bearing housing 30 and the carrier ring 32.

  In some embodiments, as shown in FIGS. 2, 7, and 11, the width of the at least one semi-annular bearing portion 42 a, 42 c in the axial direction of the carrier ring 32 may be the radial direction of the carrier ring 32. It is constant from the inside to the outside. That is, the semi-annular bearing portions 42 a and 42 c have a rectangular shape in a cross section orthogonal to the circumferential direction of the carrier ring 32.

  In some embodiments, as shown in FIGS. 8 and 9, the width of the at least one semi-annular bearing portion 42 in the axial direction of the carrier ring 32 is from the inside to the outside in the radial direction of the carrier ring 32. It is getting bigger towards.

  According to the above configuration, the width of the semi-annular bearing portion 42 increases from the inner side toward the outer side in the radial direction of the carrier ring 32, so that the space between the semi-annular bearing portion 42 and the carrier ring 32 is increased. Connection strength can be increased. For this reason, when the rotor shaft 7 jumps up, the semi-annular bearing portion 42 can support the rotor shaft 7 smoothly and stably.

In some embodiments, as shown in FIGS. 8 and 9, the semi-annular bearing portion 42 b has a trapezoidal shape in a cross section orthogonal to the circumferential direction of the carrier ring 32.
According to the above configuration, the circumferentially orthogonal cross section of the semi-annular bearing portion 42 has a trapezoidal shape, so that the connection strength between the semi-annular bearing portion 42 and the carrier ring 32 can be increased.

In some embodiments, as shown in FIGS. 10 to 12, at least one semi-annular bearing portion 42 has irregularities on the bearing surface 50.
In the above configuration, the semi-annular bearing portion 42 has irregularities on the bearing surface 50, and the irregularities function as an oil reservoir. For this reason, it is possible to prevent the oil film from being cut off on the bearing surface 50, and the semi-annular bearing portion 42 can smoothly support the load from the rotor shaft 7 when the rotor shaft 7 jumps up.

  In some embodiments, as shown in FIGS. 10-12, the at least one semi-annular bearing portion 42 has at least one oil groove 62 in the bearing surface 50. At least one oil groove 62 extends along the circumferential direction of the carrier ring 32 from the upstream end of the semi-annular bearing portion 42 in the rotational direction of the rotor shaft 7. The oil groove 62 opens on the upstream end surface of the semi-annular bearing portion 42 and opens on the bearing surface 50.

  In the above configuration, the oil groove 62 extending in the circumferential direction from the upstream end is formed on the bearing surface 50 of the semi-annular bearing portion 42, and the oil groove 62 functions as an oil reservoir. Here, since the oil groove 62 extends from the upstream end, the lubricating oil easily flows into the oil groove 62, and the oil film breakage on the bearing surface 50 can be more reliably prevented.

In some embodiments, as shown in FIG. 11, the oil groove 62 extends over the entire inner surface of the semi-annular bearing portion 42 c in the circumferential direction of the carrier ring 32.
In some embodiments, as shown in FIG. 12, the oil groove 62 extends across the entire inner surface of the semi-annular bearing portion 42 d in the circumferential direction of the carrier ring 32.

In some embodiments, only one oil groove 62 is formed at the center of the semi-annular bearing portion 42 in the axial direction of the carrier ring 32.
In some embodiments, a plurality of oil grooves 62 are formed in the semi-annular bearing portion 42 so as to be separated from each other in the axial direction of the carrier ring 32.

In some embodiments, the semi-annular bearing portion 42 is formed integrally with the carrier ring 32 by casting.
In some embodiments, the main body 57 of the semi-annular bearing portion 42 is integrally formed with the carrier ring 32 by casting, and the bearing film 58 is formed on the inner surface of the main body 57 of the semi-annular bearing portion 42.
In some embodiments, the journal bearing device 10 may not have the partition 40.
In some embodiments, the bearing diameter D of the journal 7a is not less than 200 mm and not more than 1000 mm.

  In some embodiments, the plurality of nozzle heads 38 have a function as a pad stop that restricts the circumferential movement of the bearing pad 34.

The present invention is not limited to the above-described embodiments, and includes forms obtained by changing the above-described embodiments and forms obtained by combining these forms.
For example, the turbine 1 is not limited to a steam turbine, and may be a gas turbine. The journal bearing device 10 can also be applied to rotating machines other than the turbine 1, such as a blower, a compressor, a turbocharger, and a generator.

  Further, for example, when the main purpose is to increase the support rigidity for the semi-annular bearing portions 42a and 42b, as shown in FIGS. 7 and 9, the semi-annular bearing portions 42a and 42b are It only needs to be located in the center of the bearing pad 34 in the axial direction of the carrier ring 32, and the nozzle hole 56a of the most downstream nozzle head 54 is not necessarily formed at the position where the semi-annular bearing portions 42a and 42b exist. It does not have to be.

1 Turbine 3 Generator 5 Housing (cabinet)
7 Rotor shaft 7a Journal 9 Journal bearing device 10 Journal bearing device 11 Thrust bearing device 12 Internal flow path 14 Stator blade 15 Moving blade 17 Stationary assembly 19 Rotating assembly 20 Sealing device 30 Bearing housing 30a Pedestal 30b Cover 32 Carrier ring 34 Bearing pad 34a Inner surface 34b Outer surface 38 Nozzle head 40 Bulkhead portion 42 (42a, 42b, 42c, 42d) Semi-annular bearing portion 44 Space 46 Side plate 50 Bearing surface 54 Most downstream nozzle head 56, 56a Nozzle hole 57 Main body 58 Bearing film 60 Spherical key 62 Oil groove Gb Bearing gap

Claims (10)

A carrier ring that can surround the journal of the rotor shaft in a cylindrical space;
At least two bearing pads respectively arranged in a lower half region of the space so as to rotatably support the journal and arranged in a circumferential direction of the carrier ring;
A plurality of nozzle heads arranged in the space apart from each other in the circumferential direction of the carrier ring, each capable of supplying lubricating oil to the space;
At least one semi-annular bearing portion having a bearing surface disposed in the upper half area of the space in a state of being fixed to the carrier ring and capable of facing the upper half area of the outer peripheral surface of the journal with a bearing gap. When,
With
The plurality of nozzle heads includes a most downstream nozzle head that is located upstream of the semi-annular bearing portion in the rotational direction of the rotor shaft and located closest to the semi-annular bearing portion,
The most downstream nozzle head, in the range where the semi-annular bearing part is present in the axial direction of the carrier ring, have at least one nozzle hole capable of discharging the lubricating oil,
Journal bearing device wherein the bearing surface, characterized in that have a semi-cylindrical shape of the short axis than the bearing pads. The journal bearing device according to claim 1, wherein the bearing surface is made of a bearing alloy. The at least one semi-annular bearing portion is
Two semi-annular bearing portions spaced apart from each other in the axial direction of the carrier ring;
Each of the plurality of nozzle heads is
A pillar projecting from the inner peripheral surface of the carrier ring along the radial direction of the carrier ring;
Two arm portions respectively extending along the axial direction of the carrier ring from both sides of the tip portion of the column portion,
In the axial direction of the carrier ring, the range in which the two arm portions of the most downstream nozzle head exist overlaps the range in which the two semi-annular bearing portions exist,
The journal bearing device according to claim 1, wherein the at least one nozzle hole is formed in each of the two arm portions of the most downstream nozzle head. The journal bearing device according to claim 3, wherein the two arm portions of the most downstream nozzle head are longer than the two arm portions of at least one other nozzle head. The at least one semi-annular bearing portion is
The journal bearing device according to claim 1, wherein the journal bearing device has one semi-annular bearing portion positioned in the center of the bearing pad in the axial direction of the carrier ring. A bearing housing that houses the carrier ring;
And at least two spherical keys provided between the bearing housing and the carrier ring and supporting the carrier ring in a swingable manner.
6. The journal according to claim 5, wherein a range in which the at least two spherical keys exist in an axial direction of the carrier ring overlaps a range in which the at least one semi-annular bearing portion exists. Bearing device. The width of the at least one semi-annular bearing portion in the axial direction of the carrier ring increases from the inside toward the outside in the radial direction of the carrier ring. The journal bearing device according to any one of claims. The journal bearing device according to claim 1, wherein the at least one semi-annular bearing portion has irregularities on the bearing surface. The at least one semi-annular bearing portion has at least one oil groove on the bearing surface;
The said at least 1 oil groove is extended along the circumferential direction of the said carrier ring from the upstream end of the said semi-annular bearing part in the rotation direction of the said rotor shaft. Journal bearing device.   A rotary machine comprising the journal bearing device according to any one of claims 1 to 9.

Images