JP7023091B2 - Bearing equipment and rotary machinery - Google Patents

Description

The present disclosure relates to a bearing device and a rotary machine including the bearing device.

In rotating machines such as compressors and steam turbines, stable support of the rotating shaft system is one of the issues. In order to solve this problem, it is effective to improve the support characteristics (damping, rigidity, etc.) of the bearing portion that supports the rotating shaft, and studies have been made from this viewpoint.
In Patent Document 1, oil is supplied to the gap formed between the inner ring and the outer ring, and when the axis of rotation vibrates and the gap is displaced, viscous incompressible oil fills the gap. A squeeze film damper that exerts the effect of dampening the vibration of the rotation axis by flowing is disclosed.

U.S. Pat. No. 5,421,655

In the squeeze film damper, as shown in Patent Document 1, the oil film forming gaps are generally arranged in an arc shape in the circumferential direction in the radial cross section, and the shape of the oil film forming gaps and the like are generally arranged. No studies have been made to improve the damping effect. Therefore, at present, the damping effect above a certain level has not been obtained.

One embodiment is intended to rotatably support a rotary shaft system and improve the damping effect of the squeeze film damper on the rotary shaft system in a bearing device provided with a squeeze film damper.

(1) The bearing device according to the embodiment is
Bearings for rotatably supporting the axis of rotation,
A squeeze film damper provided on the outer peripheral side of the bearing portion and including inner ring and outer ring facing each other with at least one oil film forming gap interposed therebetween.
Equipped with
The at least one oil film forming gap is from the central axis of the rotating shaft to the oil film forming gap in the axial cross section along the axial direction of the rotating shaft or the radial cross section along the radial direction of the rotating shaft. Including specially shaped gaps where the distance is not constant,
The axial length of the special shape gap in the axial cross section is defined as the first reference length Lst ₁ .
Using the minimum distance r _min and the maximum distance r _max of the special shape gap from the central axis in the radial cross section and the angle range Δθ occupied by the special shape gap, Δθ × ( _rmin + r _max ) / 2 When the second reference length represented by is Lst ₂ ,
The special shape gap has the first condition that the total length L ₁ of the special shape gap in the axial cross section is 1.1 × Lst ₁ or more, or the total length L ₂ of the special shape gap in the radial cross section is 1. . At least one of the second conditions of 1 × Lst ₂ or more is satisfied.

By supplying oil to the oil film forming gap and flowing viscous incompressible oil in the oil film forming gap, it is possible to obtain a damping effect of damping the load applied from the rotating shaft. This damping effect suppresses vibration of the rotating shaft system and enables stable support of the rotating shaft system. Further, by adjusting the flow amount of the oil, the oil film pressure in the oil film forming gap can be adjusted, whereby the damping performance can be adjusted.

According to the configuration of the above (1), the special shape gap is an axial cross section (hereinafter, also simply referred to as “axial cross section”) along the axial direction of the rotating shaft (hereinafter, also simply referred to as “axial direction”). The total length L1 in the above is 1.1 times or more the _first reference length Lst1 or a radial cross section along the radial direction of the rotation axis (hereinafter, also simply referred to as “diametrical direction”) (hereinafter, simply “diametrical cross section”). Since the total length L ₂ in) is 1.1 times or more the second reference length of Lst ₂ , the area of the oil film forming gap formed in the squeeze film damper can be expanded. As a result, the damping effect produced by the squeeze film damper can be increased, so that vibrations and the like generated in the rotation axis system can be effectively damped, and stable support of the rotation axis becomes possible.

(2) In one embodiment, in the configuration of (1) above,
It is provided with a plurality of elastic portions discretely provided in the circumferential direction between the inner ring and the outer ring.
According to the configuration of the above (2), the rigidity of the squeeze film damper can be determined by the rigidity of the elastic portion by providing the elastic portion. Therefore, since the rigidity and the damping performance of the squeeze film damper can be set independently, the optimum setting can be made for each to enhance the damping effect.

(3) In one embodiment, in the configuration of (2) above,
The elastic portion is arranged so as to extend in the axial direction of the rotation axis.
According to the configuration of (3) above, since each of the plurality of elastic portions is arranged so as to extend in the axial direction of the rotating shaft, the elastic portion causes the rotating shaft to have an even elastic force in the axial direction of the rotating shaft. Can be supported.

(4) In one embodiment, in any of the configurations (1) to (3) above,
The special shape gap has a zigzag shape in the axial cross section or the radial cross section.
Here, the "zigzag shape" refers to a shape in which a plurality of linear line segments are continuously connected to each other at an angle other than 180 degrees at an end portion or a portion other than the end portion.
According to the configuration of (4) above, since the special shape gap has a zigzag shape in the axial cross section or the radial cross section, not only the area of the oil film forming gap formed in the squeeze film damper can be expanded, but also the zigzag shape can be expanded. Has a curved portion formed by connecting linear line segments, so that the flow path resistance increases at the curved portion and the oil film pressure in the oil film forming gap increases. The damping effect can be synergistically increased by these two factors. As a result, vibrations and the like generated on the rotating shaft can be effectively damped, and stable support of the rotating shaft becomes possible.

(5) In one embodiment, in any of the configurations (1) to (3) above,
The special shape gap has a corrugated shape in the axial cross section or the radial cross section.
According to the configuration of (5) above, since the special shape gap has a corrugated shape in the axial cross section or the radial cross section, the area of the oil film forming gap formed in the squeeze film damper can be expanded and the damping effect can be increased. .. In this embodiment, since the special shape gap has a curved surface as a whole, it is easy to expand the area of the oil film forming gap as compared with the case of the zigzag shape.

(6) In one embodiment, in any of the configurations (1) to (5) above,
The special shape gap has a curved surface shape that is convex outward or inward at the axial center portion of the squeeze film damper in the axial cross section.
According to the configuration of (6) above, since the special shape gap has a curved surface shape that is convex outward or inward at the axial center portion of the squeeze film damper in the axial cross section, the oil film forming gap formed in the squeeze film damper. The area of can be expanded. As a result, the damping effect can be increased, so that vibrations and the like generated in the rotating shaft system can be effectively damped, and stable support of the rotating shaft becomes possible.

(7) In one embodiment, in any of the configurations (1) to (6) above,
The bearing portion includes a tilting pad.
According to the configuration (7), the squeeze film damper having the above configuration is provided on the outer peripheral side of the bearing portion including the tilting pad, and the rotation shaft can be stably supported by these combinations. In addition, the rotation axis can be rotated stably due to the seizure prevention effect of the oil film formed around the tilting pad.

(8) In one embodiment, in any of the configurations (1) to (6) above,
The bearing portion includes a rolling bearing.
According to the configuration of (8) above, the squeeze film damper having the above configuration is provided on the outer peripheral side of the bearing portion including the rolling bearing, and the rotating shaft can be supported by the combination thereof. As a result, the synergistic effect of low friction support by the bearing part including the rolling bearing and the damping effect of the squeeze film damper ensures the rigidity of the support side even during high-speed rotation, and the damping effect of vibration generated in the rotating shaft system. Can be increased and the rotating shaft can be stably supported.

(9) The rotary machine according to the embodiment is
With the rotation axis
A bearing device having any of the configurations (1) to (8) and
To prepare for.
Since the rotating machine having the above configuration (9) can increase the damping effect produced by the squeeze film damper, the vibration generated in the rotating shaft system can be effectively damped, and the rotating shaft can be stably supported.

According to some embodiments, the damping effect of the squeeze film damper on the rotation axis system can be improved, so that vibration and the like generated in the rotation axis system can be suppressed, and the rotation axis can be stably supported.

It is a radial sectional view of the bearing apparatus which concerns on one Embodiment. It is a radial sectional view of the bearing apparatus which concerns on one Embodiment. (A) is a radial cross-sectional view of the bearing device according to one embodiment, and (B) is an axial cross-sectional view taken along the line AA in (A). (A) is a radial cross-sectional view of the bearing device according to one embodiment, and (B) is an axial cross-sectional view along the line BB in (A). It is sectional drawing which shows the squeeze film damper of the bearing apparatus which concerns on one Embodiment. It is a schematic diagram of the axial cross section which shows the special shape gap of the bearing apparatus which concerns on one Embodiment. It is a schematic diagram of the radial cross section which shows the special shape gap of the bearing apparatus which concerns on one Embodiment. (A) to (F) show elastic portions according to some embodiments, (A) and (B) are sectional views, and (C) to (F) are front views. It is sectional drawing which shows the squeeze film damper of the bearing apparatus which concerns on one 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 as embodiments or shown in the drawings are not intended to limit the scope of the present invention to this, but are merely explanatory examples. do not have.
For example, expressions that represent relative or absolute arrangements such as "in one direction", "along a certain direction", "parallel", "orthogonal", "center", "concentric" or "coaxial" are exact. Not only does it represent such an arrangement, but it also represents a tolerance or a state of relative displacement at an angle or distance to the extent that the same function can be obtained.
Further, for example, the expression representing a shape such as a quadrangular shape or a cylindrical shape not only represents a shape such as a quadrangular shape or a cylindrical shape in a geometrically strict sense, but also has a concavo-convex portion or a concavo-convex portion within a range where the same effect can be obtained. The shape including the chamfered portion and the like shall also be represented.
On the other hand, the expressions "equipped", "equipped", "equipped", "included", or "have" one component are not exclusive expressions excluding the existence of other components.

1 to 4 show bearing devices 10 (10A, 10B, 10C, 10D) according to some embodiments. In FIGS. 3 and 4, (A) is a cross-sectional view seen from the radial direction, and (B) is a cross-sectional view taken from the axial direction along the AA line or the BB line in (A). ..
In FIGS. 1 to 4, the bearing devices 10 (10A to 10D) include a bearing portion 14 on the outer peripheral side of the rotating shaft 12, and a squeeze film damper 16 on the outer peripheral side of the bearing portion 14. The bearing portion 14 rotatably supports the rotating shaft 12. The squeeze film damper 16 has an inner ring 18 and an outer ring 20 facing each other with the oil film forming gap S interposed therebetween. One or more oil film forming gaps S are formed.

With the above configuration, oil is supplied to the oil film forming gap S from the oil supply unit (not shown), and the viscous incompressible oil is made to flow in the oil film forming gap S to attenuate the load applied from the rotating shaft 12. It is possible to obtain a damping effect. This damping effect suppresses vibration of the rotating shaft system and enables stable support of the rotating shaft system. Further, by adjusting the flow amount of the oil, the oil film pressure of the oil film forming gap S can be adjusted, whereby the damping performance can be adjusted.

The oil film forming gap S is the central axis O of the rotary shaft 12 in the axial cross section along the axial direction (arrow a direction) of the rotary shaft 12 or the radial cross section along the radial direction (arrow b direction) of the rotary shaft 12. Includes a specially shaped gap Sf (see FIGS. 6 and 7) in which the distance from the oil film forming gap S to the oil film forming gap S is not constant. The bearing devices 10 (10A to 10D) shown in FIGS. 1 to 4 have an embodiment in which the entire area of the oil film forming gap S has a special shape gap Sf. The special shape gap Sf may be formed in a part of the oil film forming gap S.

Here, as shown in the schematic diagram of FIG. 6, the axial length of the special shape gap Sf in the axial cross section is defined as the first reference length Lst ₁ . Further, as shown in the schematic diagram of FIG. 7, the minimum distance r _min and the maximum distance r _max of the special shape gap Sf in the radial cross section from the central axis O and the angle range Δθ occupied by the special shape gap Sf are used. , Δθ × (r _min + r _max ) / 2, let Lst ₂ be the second reference length. At this time, the special shape gap Sf is the first condition in which the total length L ₁ of the special shape gap Sf in the axial cross section is 1.1 × Lst ₁ or more, or the total length L ₂ of the special shape gap Sf in the radial cross section is 1. . At least one of the second conditions of 1 × Lst ₂ or more is satisfied.

According to the above configuration, in the special shape gap Sf, the total length L ₁ in the axial cross section is 1.1 times or more the first reference length Lst 1, or the total length L ₂ in the radial cross section has the second reference length. Since it is 1.1 times or more the Lst ₂ , the area of the oil film forming gap S formed in the squeeze film damper 16 can be expanded. As a result, the damping effect produced by the squeeze film damper 16 can be increased, so that vibrations and the like generated in the rotation axis system can be effectively damped, and stable support of the rotation axis 12 becomes possible.

ここで、Ｂ＝１２πμＬ（Ｒ／ｃ）^３、μ：油の粘性係数、Ｒ：ダンパ径、Ｌ：ダンパ幅、ｃ：径方向隙間の大きさ、ε：回転軸の偏心量である。
ε＝ｅ／ｃ＝１－δ_０／ｃ
ここで、ｅ：回転軸の偏心量、δ_０：回転軸の軸受からの浮上量である。
（１）式から、油膜形成隙間の面積が大きいほど油膜減衰常数Ｃψが大きくなり、かつ油膜減衰常数Ｃψは径方向隙間の大きさｃの３乗に比例することがわかる。従って、回転軸１２から軸受装置に付加される圧力が大きくなり、油膜形成隙間Ｓが狭くなると、油膜圧が増加し、油膜減衰常数Ｃψが増加して減衰効果が増す。 The oil film damping constant Cψ, which represents the damping effect exerted by the oil film formation, is obtained from the following equation (1).

Here, B = 12πμL (R / c) ³ , μ: oil viscosity coefficient, R: damper diameter, L: damper width, c: radial gap size, ε: eccentricity of the rotating shaft.
ε = e / c = 1-δ ₀ / c
Here, e: the amount of eccentricity of the rotating shaft, and δ ₀ : the amount of floating of the rotating shaft from the bearing.
From equation (1), it can be seen that the larger the area of the oil film forming gap, the larger the oil film damping constant Cψ, and the oil film damping constant Cψ is proportional to the cube of the radial gap size c. Therefore, when the pressure applied to the bearing device from the rotating shaft 12 becomes large and the oil film forming gap S becomes narrow, the oil film pressure increases, the oil film damping constant Cψ increases, and the damping effect increases.

In one embodiment, as shown in FIG. 5, in the bearing device 10 (10A to 10D), side plates 21 are provided on both end faces in the axial direction of the squeeze film damper 16. The side plate 21 forms an oil discharge path Pd communicating with the oil film forming gap S between the outer ring 20 and both ends in the axial direction. By discharging the oil from the oil discharge path Pd, the flowing state of the oil can be maintained in the oil film forming gap S, whereby the load applied from the rotating shaft 12 can be attenuated. This damping effect suppresses vibration of the rotating shaft system and enables stable support of the rotating shaft system. Further, by adjusting the amount of oil discharged from the oil discharge path Pd, the oil film pressure of the oil film forming gap S can be adjusted, whereby the damping performance can be adjusted.

In one embodiment, as shown in FIGS. 1 to 4, a plurality of elastic portions 22 are discretely provided in the circumferential direction between the inner ring 18 and the outer ring 20. By providing the elastic portion 22, the rigidity of the squeeze film damper 16 can be determined by the rigidity of the elastic portion 22. Therefore, since the rigidity of the squeeze film damper 16 and the damping performance due to the formation of the oil film can be set independently, the optimum setting can be made for each in order to enhance the damping effect of the squeeze film damper 16.

In one embodiment, the elastic portion 22 is arranged so as to extend in the axial direction of the rotating shaft 12. By arranging the elastic portions 22, uniform elastic force can be exerted in the axial direction of the rotary shaft 12, and the rotary shaft 12 can be supported by the uniform elastic force in the axial direction of the rotary shaft 12.

In one embodiment, in the bearing device 10 (10A) shown in FIG. 1, the special shape gap Sf has a zigzag shape in a radial cross section.
According to this embodiment, since the special shape gap Sf has a zigzag shape in the radial cross section, the area of the oil film forming gap S formed in the squeeze film damper 16 can be expanded. Therefore, since the damping effect produced by the squeeze film damper 16 can be increased, the vibration and the like generated in the rotation axis system can be effectively damped, and the rotation shaft 12 can be stably supported.
Further, since the zigzag shape has a curved portion Be formed by connecting linear line segments, the flow path resistance increases at the curved portion Be, and the oil film pressure in the oil film forming gap S increases. The damping effect can be synergistically increased by these two factors.

In one embodiment, in the bearing device 10 (10C) shown in FIG. 3, the special shape gap Sf has a zigzag shape in an axial cross section. Thereby, the same operation and effect as the bearing device 10 (10A) shown in FIG. 1 can be obtained.
In one embodiment, in the radial cross section of the bearing device 10 (10C), the oil film forming gap S has an arc shape centered on the central axis O of the rotating shaft 12.

In one embodiment, in the bearing device 10 (10B) shown in FIG. 2, the special shape gap Sf has a corrugated shape in a radial cross section.
According to this embodiment, since the special shape gap Sf has a corrugated shape in the axial cross section, the area of the oil film forming gap S formed in the squeeze film damper 16 can be expanded, and the damping effect can be increased. Further, since the special shape gap Sf has a curved surface as a whole, the area of the oil film forming gap S can be easily expanded as compared with the case of the zigzag shape.

In one embodiment, the special shape gap Sf has a corrugated shape in an axial cross section. Thereby, the same action and effect as those of the embodiment shown in FIG. 2 can be obtained.

In one embodiment, in the bearing device 10 (10D) shown in FIG. 4, the special shape gap Sf has a curved surface shape that is convex outward or inward at the axial center portion of the squeeze film damper 16 in the axial cross section.
According to this embodiment, the area of the oil film forming gap S formed in the squeeze film damper 16 can be expanded. As a result, the damping effect can be increased, so that vibrations and the like generated in the rotation shaft system can be effectively damped, and stable support of the rotation shaft 12 becomes possible.
The embodiment shown in FIG. 4 is an embodiment in which the special shape gap Sf has a curved surface shape that is convex outward at the central portion in the axial direction of the squeeze film damper 16 in the axial cross section.

In one embodiment, in the radial cross section of the bearing device 10 (10D), the oil film forming gap S has an arc shape centered on the central axis O of the rotating shaft 12.

In one embodiment, as shown in FIGS. 1 to 4, the bearing portion 14 includes a tilting pad 24. The tilting pad 24 is connected to the inner surface of the inner ring 18 via a pivot 25. The tilting pad 24 can be tilted in any direction with the pivot 25 as a base point. A lubricating oil flow path (not shown) that opens on the inner side surface is formed in the tilting pad 24, and lubricating oil is supplied between the rotating shaft 12 and the tilting pad 24.
According to this embodiment, the rotating shaft 12 can be stably rotated by the seizure prevention effect of the oil film formed around the tilting pad 24.

In one embodiment, the bearing portion 14 includes a rolling bearing. According to this embodiment, the squeeze film damper 16 having the above configuration is provided on the outer peripheral side of the bearing portion including the rolling bearing, and the rotating shaft can be supported by a combination thereof. As a result, the synergistic effect of the low friction support by the bearing portion including the rolling bearing and the damping effect of the squeeze film damper 16 ensures the rigidity of the support side even at high speed rotation and the damping of vibrations generated in the rotating shaft system. The effect can be enhanced and the rotating shaft 12 can be stably supported.

In one embodiment, as shown in FIGS. 1 to 4, the elastic portion 22 is arranged in the gap between the inner ring 18 and the outer ring 20. In one embodiment, the elastic portion 22 is configured such that the elastic member is housed in the space _S0 which is discretely formed in the circumferential direction so as to communicate with the oil film forming gap S. The space S ₀ extends along the axial direction, and the radial dimension of the space S ₀ is larger than the radial dimension of the oil film forming gap S or the special shape gap Sf. In one embodiment, space S ₀ has a quadrilateral cross section.
FIG. 8 shows some embodiments of the elastic portion 22.

In the elastic portion 22 (22a) shown in FIG. 8A, one elastic rod-shaped member 26a having a rectangular cross section is accommodated in the space _S0 and extends in the axial direction.
In the elastic portion 22 (22b) shown in FIG. 8B, one elastic rod-shaped member 26b having a rectangular cross section is housed in the space _S0 and extends in the axial direction.
In the elastic portion 22 (22c) shown in FIG. 8C, an elastic body 26c in which two elastic bodies having a disc spring shape (conical cone shape) in cross section are stacked so as to have a small diameter in the center is housed in the space _S0 . Will be done. In one embodiment, one rod-shaped elastic body 26c extends in the axial direction of the rotating shaft 12. In another embodiment, the plurality of elastic bodies 26c are arranged discretely in the axial direction. The elastic body may be hollow or solid.

In one embodiment, the elastic rod-shaped members 26a, 26b and the elastic body 26c formed by one member are arranged in almost the entire axial region of the squeeze film damper 16.
In one embodiment, the elastic rods 26a, 26b and the elastic body 26c are made of, for example, elastic rubber.
The elastic rod-shaped members 26a and 26b and the elastic body 26c formed by one member can be easily accommodated in the space _S0 .

In the elastic portion 22 (22d) shown in FIG. 8D, a plurality of coil springs 26d are arranged discretely in the space _S0 in the axial direction of the rotation shaft 12.
The elastic portion 22 (22e) shown in FIG. 8 (E) accommodates an elastic body _26e having an S-shaped cross section in the space S0. In one embodiment, one elastic body _26e extends axially in space S0. In another embodiment, a plurality of elastic bodies 26e are arranged discretely in the axial direction in the space _S0 .
The elastic portion 22 (22f) shown in FIG. 8F accommodates an elastic body _26f having a Z-shaped cross section in the space S0. In one embodiment, one elastic body _26f is axially extended in space S0. In another embodiment, a plurality of elastic bodies 26f are arranged discretely in the axial direction in the space _S0 .

In one embodiment, the inner ring 18 and the outer ring 20 are integrally formed via the elastic portion 22. At this time, in one embodiment, the elastic portion 22 constitutes a spring member.

FIG. 9 shows a squeeze film damper 16 of the bearing device 10 (10E) according to the embodiment. In this squeeze film damper 16, an O-ring 28 is interposed between the inner ring 18 and the outer ring 20, and an oil film forming gap S is formed. Two O-rings 28 are provided at both ends of the oil film forming gap S in the axial direction, and an oil film forming gap S is formed between these O-rings 28. Oil is supplied to the oil film forming gap S from the oil supply unit (not shown), and the oil supplied to the oil film forming gap S is the O-ring 28 and the inner when the oil film forming gap S becomes smaller due to the load applied from the rotary shaft system. It is discharged from between the ring 18 and the outer ring 20. The flow of this oil can exert a damping effect.

By forming at least a part of the oil film forming gap S formed between the inner ring 18 and the outer ring 20 of the bearing device 10 (10E) as the special shape gap Sf, the damping effect of the squeeze film damper 16 can be improved. Therefore, the vibration and the like generated in the rotation shaft system can be effectively damped, and the rotation shaft 12 can be stably supported.
The sizes of the oil film forming gap S and the oil discharge passage Pd shown in FIGS. 5 and 9 are exaggerated and shown, and actually form a minute gap.

The rotary machine according to the embodiment includes a rotary shaft 12 and a bearing device 10 having the above configuration.
According to this rotating machine, the damping effect generated by the squeeze film damper 16 can be increased, so that the vibration and the like generated in the rotating shaft system can be effectively damped, and the rotating shaft 12 can be stably supported. Therefore, it can be applied to rotating machines such as compressors and steam turbines.

According to some embodiments, the damping effect of the squeeze film damper in a bearing device provided with a squeeze film damper to rotatably support the rotary shaft system and in a rotating machine including the bearing device, for example, a compressor or a steam turbine. By improving the above, vibration and the like generated in the rotating shaft system can be suppressed, and the rotating shaft can be stably supported.

10 (10A, 10B, 10C, 10D, 10E) Bearing device 12 Rotating shaft 14 Bearing part 16 Squeeze film damper 18 Inner ring 20 O-ring 21 Side plate 22 (22a, 22b, 22c, 22d, 22e, 22f) Elastic part 24 Tilting pad 25 Pivot 26a, 26b Elastic rod-shaped material 26c, 26e, 24f Elastic body 26d Coil spring 28 O-ring O Central axis S Oil film formation gap Sf Special shape gap S ₀ Space

Claims (9)

Bearings for rotatably supporting the axis of rotation,
A squeeze film damper provided on the outer peripheral side of the bearing portion and including inner ring and outer ring facing each other with at least one oil film forming gap interposed therebetween.
Equipped with
The at least one oil film forming gap is from the central axis of the rotating shaft to the oil film forming gap in the axial cross section along the axial direction of the rotating shaft or the radial cross section along the radial direction of the rotating shaft. Including specially shaped gaps where the distance is not constant,
The axial length of the special shape gap in the axial cross section is defined as the first reference length Lst ₁ .
Using the minimum distance r _min and the maximum distance r _max of the special shape gap from the central axis in the radial cross section and the angle range Δθ occupied by the special shape gap, Δθ × ( _rmin + r _max ) / 2 When the second reference length represented by is Lst ₂ ,
The special shape gap has the first condition that the total length L ₁ of the special shape gap in the axial cross section is 1.1 × Lst ₁ or more, or the total length L ₂ of the special shape gap in the radial cross section is 1. .Satisfy at least one of the second conditions of 1 × Lst ₂ or more,
The bearing portion includes a tilting pad.
The special shape gap has a curved surface shape that is convex outward or inward at the axial center portion of the squeeze film damper in the axial cross section.
A bearing device characterized by that. Bearings for rotatably supporting the axis of rotation,
A squeeze film damper provided on the outer peripheral side of the bearing portion and including inner ring and outer ring facing each other with at least one oil film forming gap interposed therebetween.
Equipped with
The at least one oil film forming gap is from the central axis of the rotating shaft to the oil film forming gap in the axial cross section along the axial direction of the rotating shaft or the radial cross section along the radial direction of the rotating shaft. Including specially shaped gaps where the distance is not constant,
The axial length of the special shape gap in the axial cross section is defined as the first reference length Lst ₁ .
Using the minimum distance r _min and the maximum distance r _max of the special shape gap from the central axis in the radial cross section and the angle range Δθ occupied by the special shape gap, Δθ × ( _rmin + r _max ) / 2 When the second reference length represented by is Lst ₂ ,
The special shape gap has the first condition that the total length L ₁ of the special shape gap in the axial cross section is 1.1 × Lst ₁ or more, or the total length L ₂ of the special shape gap in the radial cross section is 1 . .Satisfy at least one of the second conditions of 1 × Lst ₂ or more,
The bearing portion includes a tilting pad.
A bearing device comprising a plurality of elastic portions discretely provided in the circumferential direction between the inner ring and the outer ring. The bearing device according to claim 2, wherein the elastic portion is arranged so as to extend in the axial direction of the rotating shaft. Bearings for rotatably supporting the axis of rotation,
A squeeze film damper provided on the outer peripheral side of the bearing portion and including inner ring and outer ring facing each other with at least one oil film forming gap interposed therebetween.
Equipped with
The at least one oil film forming gap is from the central axis of the rotating shaft to the oil film forming gap in the axial cross section along the axial direction of the rotating shaft or the radial cross section along the radial direction of the rotating shaft. Including specially shaped gaps where the distance is not constant,
The axial length of the special shape gap in the axial cross section is defined as the first reference length Lst ₁ .
Using the minimum distance r _min and the maximum distance r _max of the special shape gap from the central axis in the radial cross section and the angle range Δθ occupied by the special shape gap, Δθ × ( _rmin + r _max ) / 2 When the second reference length represented by is Lst ₂ ,
The special shape gap has the first condition that the total length L ₁ of the special shape gap in the axial cross section is 1.1 × Lst ₁ or more, or the total length L ₂ of the special shape gap in the radial cross section is 1 . .Satisfy at least one of the second conditions of 1 × Lst ₂ or more,
The bearing portion includes a tilting pad.
The bearing device characterized in that the special shape gap has a zigzag shape in the axial cross section or the radial cross section. Bearings for rotatably supporting the axis of rotation,
A squeeze film damper provided on the outer peripheral side of the bearing portion and including inner ring and outer ring facing each other with at least one oil film forming gap interposed therebetween.
Equipped with
The at least one oil film forming gap is from the central axis of the rotating shaft to the oil film forming gap in the axial cross section along the axial direction of the rotating shaft or the radial cross section along the radial direction of the rotating shaft. Including specially shaped gaps where the distance is not constant,
The axial length of the special shape gap in the axial cross section is defined as the first reference length Lst ₁ .
Using the minimum distance r _min and the maximum distance r _max of the special shape gap from the central axis in the radial cross section and the angle range Δθ occupied by the special shape gap, Δθ × ( _rmin + r _max ) / 2 When the second reference length represented by is Lst ₂ ,
The special shape gap has the first condition that the total length L ₁ of the special shape gap in the axial cross section is 1.1 × Lst ₁ or more, or the total length L ₂ of the special shape gap in the radial cross section is 1. .Satisfy at least one of the second conditions of 1 × Lst ₂ or more,
A bearing device characterized in that the specially shaped gap has a corrugated shape in the axial cross section or the radial cross section. The bearing according to any one of claims 2 to 5, wherein the special shape gap has a curved surface shape that is convex outward or inward at the axial central portion of the squeeze film damper in the axial cross section. Device. The bearing device according to claim 5, wherein the bearing portion includes a tilting pad. The bearing device according to claim 5, wherein the bearing portion includes a rolling bearing. With the rotation axis
The bearing device according to any one of claims 1 to 8.
A rotating machine characterized by being equipped with.

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