Bearing pad and bearing device

Abstract

This bearing pad comprises a bearing pad body having a pad surface. A first space to which cooling oil is supplied from the outside, a second space formed between the pad surface and the first space and opened to the outside of the bearing pad body, and a plurality of impingement holes communicating the first space and the second space in the thickness direction of the bearing pad body are formed inside the bearing pad body. This configuration makes it possible to provide a bearing pad and a bearing device that have further improved cooling capacity.

Description

Bearing Pad and Bearing Device ,

[0006]

[0001] The present disclosure relates to a bearing pad and a bearing device. This application claims priority to Japanese Patent Application No. 2024 - 173429 filed in Japan on October 2, 2024, the content of which is incorporated herein by reference.

[0002] Rotating machines such as gas turbines and steam turbines mainly include a rotating shaft which is a rotating body, and a bearing device that rotatably supports the rotating shaft. Examples of bearing devices include a journal bearing that supports a radial load and a thrust bearing that supports an axial load. Among these, for example, a journal bearing has a housing that surrounds the rotating shaft from the outer peripheral side, and a plurality of arcuate bearing pads supported on the inner surface of the housing and facing the outer peripheral surface of the rotating shaft.

[0003] Lubricating oil is interposed between the inner peripheral surface (pad surface) of the bearing pad and the outer peripheral surface of the rotating shaft. The smooth rotation of the rotating shaft is enabled by the oil film formed by this lubricating oil. Here, heat generation due to friction occurs between the rotating shaft rotating at high speed and the oil film. If the heat generation increases, the performance of the bearing device may deteriorate. Therefore, for example, as shown in Patent Document 1 below, a mechanism for supplying cooling oil to the inside of the bearing pad is known. In the configuration of this document, it is said that the bearing pad can be cooled by a part of the lubricating oil staying inside the pad during the supply of the lubricating oil to the pad surface.

[0004] Japanese Patent Application Laid - Open No. 2022 - 84138

[0005] However, recently, since the further high - speed rotation of rotating machines has been promoted, there are cases where the conventional configuration cannot sufficiently cool the bearing pad.

[0006] The present disclosure provides a bearing pad and a bearing device with further improved cooling capacity.

[0007] The bearing pad according to this disclosure comprises a bearing pad body having a pad surface, the bearing pad body having a first space into which cooling oil is supplied from the outside, a second space formed between the pad surface and the first space and opening to the outside of the bearing pad body, and a plurality of impingement holes that connect the first space and the second space in the thickness direction of the bearing pad body.

[0008] According to this disclosure, it is possible to provide bearing pads and bearing devices with further improved cooling capacity.

[0009] This is a cross-sectional view showing the configuration of a bearing device according to the first embodiment of this disclosure. This is a cross-sectional view taken from the axial direction showing the configuration of a bearing pad according to the first embodiment of this disclosure. This is a cross-sectional view taken from the circumferential direction showing the configuration of a bearing pad according to the first embodiment of this disclosure. This is a cross-sectional view taken from the axial direction showing the configuration of a bearing pad according to a modified example of the first embodiment of this disclosure. This is a cross-sectional view taken from the circumferential direction showing the configuration of a bearing pad according to a modified example common to each embodiment of this disclosure.

[0010] <First Embodiment> (Configuration of Bearing Device 1) Hereinafter, a bearing device 1 according to the first embodiment of this disclosure will be described with reference to Figures 1 to 3. This bearing device 1 is a member for supporting the rotating shaft 90 of a rotating machine such as a gas turbine or a steam turbine. As shown in Figure 1, the rotating shaft 90 is cylindrical in shape extending along the axis X and is rotatable about the axis X. Typically, one bearing device 1 is provided at each end of the rotating shaft 90. That is, this bearing device 1 is a journal bearing and supports the radial load of the rotating shaft 90.

[0011] The bearing device 1 comprises a housing 10, a pivot 20, and a bearing pad 30. The housing 10 is cylindrical in shape and covers the rotating shaft 90 from the outer circumference. The inner surface of the housing 10 is cylindrical in shape with the axis X as the center. Although not shown in detail, the housing 10 may be divided into an upper half and a lower half with respect to the position of the axis X.

[0012] Multiple pivots 20 (four as an example) are provided on the inner circumferential surface 10a of the housing 10. The pivots 20 are arranged at equal intervals in the circumferential direction with respect to the axis X. Each pivot 20 protrudes radially inward from the inner circumferential surface 10a. In a cross-sectional view perpendicular to the axis X, the pivots 20 have a pointed shape in which the circumferential dimension gradually decreases from the radially outer side to the radially inward side.

[0013] A bearing pad 30 is supported at the tip of the pivot 20. The bearing pad 30 is pivotably supported by the top of the pivot 20. This is to absorb any runout or vibration that may occur in the rotating shaft 90. When viewed from the direction of the axis X, the bearing pad 30 has an arc shape centered on the axis X.

[0014] The bearing pad 30 comprises a bearing pad body 31 and an inner member 35.

[0015] The surface of the bearing pad body 31 facing the outer circumference is called the "back surface 41". The back surface 41 is a curved surface that is convex in an arc shape toward the radially outward direction when viewed from the direction of the axis X. The center of this arc is at the position of the axis X. The back surface 41 is in contact with the pivot 20. The surface of the bearing pad body 31 facing the inner circumference is called the "pad surface 42". The pad surface 42 is a curved surface that is concave in an arc shape toward the radially outward direction when viewed from the direction of the axis X. The center of this arc is at the position of the axis X. Lubricating oil is supplied to the pad surface 42 from a lubrication device (not shown). The oil film of this lubricating oil is interposed between the pad surface 42 and the outer circumference 90a of the rotating shaft 90, thereby reducing the frictional resistance between the outer circumference 90a and the pad surface 42. Therefore, the bearing pad 30 can rotatably support the rotating shaft 90. Furthermore, the end faces (circumferential end faces 43) of the bearing pad body 31 that face both sides in the circumferential direction extend radially when viewed from the axis X direction.

[0016] (Detailed configuration of bearing pad 30) Next, the internal configuration of the bearing pad body 31 will be described in detail with reference to Figures 2 and 3. The bearing pad body 31 has a first space 32, a second space 33, and an impingement hole 34. That is, as shown in Figure 2, when viewed from the axis X direction, multiple spaces (first space 32 and second space 33) are formed on one side of the bearing pad 30 in the circumferential direction, i.e., at a position biased toward the front side in the rotational direction of the rotating shaft 90. These spaces form a passage for supplying cooling oil, which is supplied from a separate system from the lubricating oil mentioned above, into the interior of the bearing pad body 31. The cooling oil is a cooling medium for cooling the bearing pad 30. Note that the lubricating oil and cooling oil may be the same type of oil or different types of oil.

[0017] Specifically, the first space 32 is formed at a relatively outer peripheral position inside the bearing pad body 31. In a cross-sectional view from the axial X direction, the first space 32 has a rectangular or arc-shaped cross-section. A supply section 51 for guiding cooling oil supplied from the outside is connected to the first space 32. The supply section 51 is a hole connecting the back surface 41 and the first space 32.

[0018] A second space 33 is formed in the bearing pad body 31 in the portion on the inner circumference side of the first space 32. The second space 33 is formed at a position that is biased toward the pad surface 42 side than the first space 32. In a cross-sectional view taken from the direction of the axis X, the second space 33 is rectangular or arc-shaped. Of the surfaces forming the inner surface of the second space 33, the surface located on the back side of the pad surface 42 is called the "top surface 61". It is desirable that the distance between this top surface 61 and the pad surface 42 be set to be as small as possible, as far as the strength and rigidity of the bearing pad body 31 allow. This is to facilitate the exchange of heat between the cooling oil supplied in the second space 33 and the pad surface 42.

[0019] The first space 32 and the second space 33 are connected by a plurality of impingement holes 34. The impingement holes 34 are holes that connect the first space 32 to the second space 33 in the thickness direction of the bearing pad 30, that is, in the radial direction with respect to the axis X. Cooling oil supplied to the first space 32 is ejected into the second space 33 as a jet when it passes through these impingement holes 34. In other words, it is desirable that the diameter of the impingement holes 34 be small enough to create a jet. This diameter value is appropriately determined based on the pressure of the pumping device (not shown) that supplies the cooling oil. It is desirable that the impingement holes 34 are arranged in a grid pattern when viewed from the radial direction. The density of these impingement holes 34 may be set to increase as you move towards the front side in the rotational direction of the rotating shaft 90.

[0020] An inner member 35 is provided between the top surface 61 of the second space 33 and the bottom surface 62 facing the top surface 61. The inner member 35 is a rod-shaped pin fin connecting the top surface 61 and the bottom surface 62. The pin fin as the inner member 35 is provided so as to extend radially from the top surface 61 toward the bottom surface 62 facing the top surface 61. Multiple inner members 35 are provided at intervals in a region that does not overlap with the impingement holes 34 when viewed from the radial direction. Although not shown in detail, the arrangement density of these inner members 35 may be set to increase towards the front side in the rotational direction of the rotation axis 90. In addition, the cross-sectional shape of the inner member 35 when viewed from the radial direction may be a polygon or ellipse, in addition to a circle or rectangle. Furthermore, it is desirable that the pin fin and impingement holes 34 be arranged in a staggered pattern when viewed from the radial direction.

[0021] Furthermore, a discharge section 52 is formed on the side surface 64 of the second space 33, which faces the axial direction X, and communicates with the outside of the bearing pad body 31 (i.e., the outside of the pad side surface 44 facing the axial direction X). The discharge section 52 is a hole for discharging the cooling oil that remains in the second space 33 to the outside.

[0022] (Effects) When operating the bearing device 1, first, lubricating oil is supplied to the pad surface 42 through a lubrication device (not shown). Furthermore, cooling oil is supplied into the first space 32 using a pressure feeding device (also not shown). Next, the rotating shaft 90 is rotated. At this time, if the rotational speed is high, heat is generated due to friction between the lubricating oil film and the rotating shaft 90. This heat is transmitted to the bearing pad body 31 through the pad surface 42. If the heat generation increases, it can cause seizure, so it is necessary to cool the bearing pad body 31. Therefore, the above configurations are adopted in this embodiment.

[0023] Cooling oil supplied to the first space 32 is ejected into the second space 33 through a plurality of impingement holes 34. This jet strikes the top surface 61 of the second space 33, first removing heat from the pad surface 42 on the underside of the top surface 61 (cooling it). In other words, by using cooling oil for impingement cooling, the heat transfer rate is increased compared to simply circulating or stagnating the cooling oil in the internal space, thereby improving the cooling effect. Furthermore, the jet bounced off the top surface 61 scatters radially and strikes the inner member 35. At this time, heat is also released from the inner member 35 towards the cooling oil. As a result, the entire bearing pad body 31 is further cooled. The high-temperature cooling oil, having finished cooling, is discharged to the outside through the discharge section 52.

[0024] As described above, with this configuration, a first space 32 and a second space 33 are formed inside the bearing pad body 31, and a plurality of impingement holes 34 are formed between these spaces. As a result, the cooling oil supplied into the first space 32 becomes a jet as it passes through the impingement holes 34 toward the second space 33. That is, the flow velocity of the cooling oil increases. This jet of cooling oil collides with the top surface 61 of the second space 33, that is, the back side of the pad surface 42, thereby cooling the pad surface 42. Therefore, the possibility of sticking between the pad surface 42 and the outer circumferential surface of the rotating shaft 90 is minimized, making it possible to operate the rotating machine more stably.

[0025] According to the above configuration, multiple inner members 35 protrude from the top surface 61 within the second space 33. The jet of cooling oil ejected from the impingement hole 34 collides with the top surface 61, then dissipates into the surroundings and is blown onto these inner members 35. As a result, the inner members 35 are cooled by the cooling oil. In other words, compared to a case where the inner members 35 are not provided, the heat path leading to the pad surface 42, or the apparent surface area (contact area with the cooling oil), can be increased. Therefore, the pad surface 42 can be cooled more efficiently. As a result, the rotating machine can be operated more stably.

[0026] According to the above configuration, the inner member 35 connects the top surface 61 and the bottom surface 62. This maximizes the surface area of ​​the inner member 35 itself. In addition, the cooling oil that has dispersed from the top surface 61 can be made to collide with the inner member 35 again. Therefore, it becomes possible to cool the pad surface even more efficiently. Furthermore, the inner member 35 can bear a portion of the radial load generated from the top surface 61 toward the bottom surface 62. Therefore, it becomes possible to further improve the cooling effect on the bearing pad 30 while increasing the rigidity of the bearing pad 30.

[0027] According to the above configuration, the inner member 35 is a pin fin. This allows for a large contact area with the cooling oil while maximizing the flow path of the cooling oil within the second space 33. Therefore, the cooling effect on the bearing pad 30 can be further improved.

[0028] The first embodiment of this disclosure has been described above. Various changes and modifications can be made to each of the above configurations without departing from the gist of this disclosure.

[0029] For example, as a modified configuration, the configuration shown in Figure 4 can be adopted. In the example shown in the figure, the position of the discharge section 52 of the second space 33 is different from that of the first embodiment. Specifically, this discharge section 52 is provided not on the side of the second space 33, but on the surface facing forward in the rotational direction (front surface 63). With this configuration, the flow of coolant discharged from the second space 33 and the flow of coolant ejected from the impingement hole 34 are less likely to interfere with each other. As a result, flow loss is reduced, and the cooling effect can be further improved. It is also possible to adopt a configuration in which the discharge section 52 is provided on both the side and the front surface 63.

[0030] <Second Embodiment> Next, a second embodiment of the present disclosure will be described with reference to Figure 5. Components similar to those in the first embodiment are denoted by the same reference numerals, and detailed descriptions are omitted.

[0031] As shown in Figure 5, the configuration of the inner member B 135 in this embodiment differs from that of the first embodiment. The inner member B 135 is a lattice structure including a plurality of beams 71 extending in the thickness direction of the bearing pad 30. More specifically, the inner member B 135 has a three-dimensional shape formed by combining a plurality of triangular pyramidal beams 71. Such a structure can be easily obtained by three-dimensional additive manufacturing. In this embodiment, the inner member B 135 fills the second space 33 from the top surface 61 to the bottom surface 62. Although not shown in detail, it is desirable that the beams 71 of the inner member B 135 be arranged in a region that does not overlap with the impingement hole 34 when viewed from the radial direction.

[0032] (Effects) According to the above configuration, the inner member 35 is a lattice structure. This allows for a large contact area with the cooling oil while maximizing the flow path of the cooling oil within the second space 33. Therefore, it is possible to further improve the cooling effect on the bearing pad 30. Furthermore, according to the above configuration, the inner member 35 is a lattice structure. This allows the lattice structure to bear a portion of the radial load generated from the top surface 61 to the bottom surface 62, for example. Therefore, it is possible to further increase the rigidity and strength of the bearing pad 30.

[0033] <Other Embodiments> Although each embodiment of this disclosure has been described in detail above with reference to the drawings, the specific configuration is not limited to these embodiments and may include design changes and the like that do not depart from the gist of this disclosure.

[0034] For example, as a modification common to each embodiment, the configuration shown in Figure 6 can be adopted. In the example shown in the figure, the pin fins as the inner member 35 protrude from the top surface 61 of the second space 33, and their tips face the bottom surface 62 with a gap between them. This configuration also allows for the cooling effect due to the splashing of the cooling oil as described above. On the other hand, the configuration of the first embodiment described above is advantageous from the viewpoint of ensuring the rigidity of the bearing pad body 31.

[0035] Furthermore, in each of the embodiments described above, the bearing device 1 as a journal bearing was used as an example to explain each configuration. However, the bearing pad 30 can be suitably applied not only to journal bearings but also to thrust bearings. Specifically, the structure using impingement cooling described above can be applied to the thrust pad of a thrust bearing. Even in this case, the same effects and advantages as described above can be obtained.

[0036] Furthermore, the number and arrangement of the bearing pads 30 described in Figure 1 are merely examples and can be modified as appropriate according to the design and specifications.

[0037] Furthermore, in each of the above embodiments, examples were described in which the first space 32 and the second space 33 are positioned biased toward the front side in the rotational direction of the bearing pad body 31. However, it is also possible to form the above-mentioned spaces over the entire circumferential area of ​​the bearing pad body 31.

[0038] <Note> The bearing pad 30 and bearing device 1 described in each embodiment can be understood, for example, as follows.

[0039] (1) The bearing pad 30 according to the first aspect includes a bearing pad body 31 having a pad surface 42. Inside the bearing pad body 31, there are formed a first space 32 to which cooling oil is supplied from the outside, a second space 33 formed between the pad surface 42 and the first space 32 and opening to the outside of the bearing pad body 31, and a plurality of impingement holes 34 that communicate the first space 32 and the second space 33 in the thickness direction of the bearing pad body 31.

[0040] According to the above configuration, the jet flow of the cooling oil collides with the top surface 61 of the second space 33, that is, the back side of the pad surface 42, so that the pad surface 42 can be cooled.

[0041] (2) The bearing pad 30 according to the second aspect is the bearing pad 30 of (1), and further includes a plurality of inner members 35 that project in the thickness direction from the top surface 61 located on the pad surface 42 side in the second space 33.

[0042] According to the above configuration, the heat path connected to the pad surface 42 or the apparent surface area (contact area with the cooling oil) can be increased.

[0043] (3) The bearing pad 30 according to the third aspect is the bearing pad 30 of (2), and the inner member 35 connects the top surface 61 and a bottom surface 62 that faces the top surface 61 in the thickness direction.

[0044] According to the above configuration, while further improving the cooling effect on the bearing pad 30, the rigidity of the bearing pad 30 can be increased.

[0045] (4) The bearing pad 30 according to the fourth aspect is the bearing pad 30 of (2) or (3), and the inner member 35 is a pin fin that projects from the top surface 61.

[0046] According to the above configuration, while ensuring the maximum flow path of the cooling oil in the second space 33, a large contact area with the cooling oil can be ensured by the pin fins.

[0047] (5) The bearing pad 30 according to the fifth aspect is the bearing pad 30 of (2) or (3), and the inner member 35 is a lattice structure having a plurality of beams 71 extending in the thickness direction from the top surface 61.

[0048] According to the above configuration, while maximizing the flow path of the cooling oil in the second space 33, the contact area with the cooling oil can be greatly secured by the lattice structure. In addition, the rigidity and elasticity can be improved.

[0049] (6) The bearing device 1 according to the sixth aspect includes the bearing pad 30 according to any one of (1) to (5) and a housing 10 that supports the bearing pad 30.

[0050] According to the above configuration, a bearing device 1 with further improved cooling performance can be provided.

[0051] According to the present disclosure, a bearing pad and a bearing device with further improved cooling capacity can be provided.

[0052] 1... Bearing device 10... Housing 20... Pivot 30... Bearing pad 31... Bearing pad body 32... First space 33... Second space 34... Impingement hole 35... Inner member 41... Rear surface 42... Pad surface 43... Circumferential end face 51... Supply part 52... Discharge part 61... Top surface 62... Bottom surface 63... Front face 71... Beam 90... Rotating shaft 135... B inner member X... Axis

Claims

1. A bearing pad comprising a bearing pad body having a pad surface, wherein the bearing pad body has a first space into which cooling oil is supplied from the outside, a second space formed between the pad surface and the first space and opening to the outside of the bearing pad body, and a plurality of impingement holes that connect the first space and the second space in the thickness direction of the bearing pad body.

2. The bearing pad according to claim 1, further comprising a plurality of inner members that protrude in the thickness direction from the top surface located on the pad surface side within the second space.

3. The bearing pad according to claim 2, wherein the inner member connects the top surface and the bottom surface that is opposite to the top surface in the thickness direction.

4. The bearing pad according to claim 2 or 3, wherein the inner member is a pin fin protruding from the top surface.

5. The bearing pad according to claim 2 or 3, wherein the inner member is a lattice structure having a plurality of beams extending from the top surface in the thickness direction.

6. A bearing device comprising a bearing pad according to any one of claims 1 to 3, and a housing that supports the bearing pad.

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