Thrust bearing device

Abstract

To provide a thrust bearing device capable of effectively reducing the temperature of an oil film formed of lubricating oil and sufficiently improving the reliability.SOLUTION: The thrust bearing device in this embodiment includes a plurality of scrapers installed in an oil tank so as to laid in respective spaces between a plurality of thrust pads arranged side by side in the rotating direction. The upper face of the scraper is constructed to include a portion where the pressure of lubricating oil drops when a rotary shaft is rotated in the rotating direction and the lubricating oil flows from the rear side to the front side in the rotating direction between the lower face of a thrust collar and the upper face of the scraper. Besides, an oil path where the lubricating oil flows from an inlet located on the rear side in the rotating direction to an outlet located on the front side in the rotating direction is formed in the scraper. The outlet of the oil path is formed in the upper face of the scraper.SELECTED DRAWING: Figure 1D

Description

Technical Field

[0001] Embodiments of the present invention relate to a thrust bearing device.

Background Art

[0002] A thrust bearing device is configured to support a thrust load acting in the axial direction of a rotating shaft. The thrust bearing device is installed, for example, in a vertical rotating device such as a vertical water turbine in which the axial direction of the rotating shaft is along the vertical direction.

[0003] FIG. 7A is a diagram showing an example of a vertical water turbine 1 according to the related art.

[0004] In FIG. 7A, a part of a cross section along the vertical plane (xz plane) is shown. The vertical direction is the vertical direction z, the horizontal direction is the first horizontal direction x, and the direction orthogonal to the paper surface is the second horizontal direction y. In FIG. 7A, the part of the vertical water turbine 1 where the thrust bearing device 3 is installed is shown. In FIG. 7A, the rotation direction R of the rotating shaft 10 is indicated by a thick solid arrow.

[0005] [A] Vertical water turbine 1 As shown in FIG. 7A, the vertical water turbine 1 includes a rotating body including a rotating shaft 10 and a thrust collar 12.

[0006] [A-1] Rotating shaft 10 In the vertical water turbine 1, the rotating shaft 10 has a rotation center axis AX along the vertical direction z. The rotating shaft 10 is, for example, connected to a runner (not shown) on the lower end side, and a bearing bracket 2 is provided above the runner (not shown). Further, on the upper end side of the rotating shaft 10, for example, a drive shaft of a generator (not shown) is connected. The rotating shaft 10 rotates in the rotation direction R when water is supplied to the runner to perform a power generation operation, for example.

[0007] [A-2] Thrust collar 12 In the vertical shaft water turbine 1, the thrust collar 12 includes a cylindrical portion and is provided coaxially with respect to the rotating shaft 10 so as to surround the outer surface of the rotating shaft 10. Here, the portion of the thrust collar 12 located above the vertical z direction on its inner surface is fixed to the outer surface of the rotating shaft 10 using a ring key K10, and the thrust collar 12 rotates together with the rotating shaft 10. A gap exists between the portion of the thrust collar 12 located below the portion connected to the rotating shaft 10 and the outer surface of the rotating shaft 10.

[0008] [B] Thrust bearing device 3 The thrust bearing device 3 is positioned above the bearing bracket 2 to support the thrust load acting on the rotating shaft 10 in the axial direction (vertical direction z) via the thrust collar 12. Here, the thrust bearing device 3 is of the tilting stationary plate type and, as shown in Figure 7A, has an oil tank 30, a guide metal 31, a thrust bearing base 32, a coil spring 33, and a thrust pad 34, and rotatably supports the rotating shaft 10. Each part constituting the thrust bearing device 3 will be described in order.

[0009] [B-1] Oil tank 30 The oil tank 30 has an inner cylindrical portion 301 and an outer cylindrical portion 302, is installed to surround the rotating shaft 10, and contains lubricating oil L30 inside.

[0010] Of the oil tank 30, the inner cylinder portion 301 is cylindrical in shape, coaxially mounted with respect to the rotating shaft 10, and surrounds the rotating shaft 10. The inner cylinder portion 301 includes a portion sandwiched between the inner circumferential surface of the thrust collar 12 and the outer circumferential surface of the rotating shaft 10. Gaps are interposed between the inner circumferential surface of the inner cylinder portion 301 and the outer circumferential surface of the rotating shaft 10, and between the outer circumferential surface of the inner cylinder portion 301 and the inner circumferential surface of the thrust collar 12. The lower end of the inner cylinder portion 301 is fixed to the upper surface of the bearing bracket 2.

[0011] Of the oil tank 30, the outer cylinder portion 302, like the inner cylinder portion 301, is cylindrical in shape and is installed coaxially with respect to the rotating shaft 10, surrounding the rotating shaft 10 via the inner cylinder portion 301. The outer cylinder portion 302 is located outside the inner cylinder portion 301 and the thrust collar 12 in the radial direction of the rotating shaft 10. The lower end of the outer cylinder portion 302 is fixed to the upper surface of the bearing bracket 2.

[0012] As described above, the bearing bracket 2 is used as the bottom plate of the oil tank 30. In the oil tank 30, the inner cylinder portion 301 is installed as a side plate located on the inside in the radial direction of the rotating shaft 10, and the outer cylinder portion 302 is installed as a side plate located on the outside in the radial direction of the rotating shaft 10. In addition, the oil tank 30 has a lid portion 303 installed above the bearing bracket 2. Lubricating oil L30 is injected into the internal space of the oil tank 30, which is partitioned by the inner cylinder portion 301, the outer cylinder portion 302, and the lid portion 303 together with the bearing bracket 2.

[0013] In the internal space of the oil tank 30, a portion of the thrust collar 12 is immersed in the lubricating oil L30, while the guide metal 31, thrust bearing base 32, coil spring 33, and thrust pad 34 are also immersed in the lubricating oil L30.

[0014] [B-2] Guide Metal 31 The guide metal 31 is installed in the internal space of the oil tank 30. Here, the guide metal 31 is located radially outward of the inner cylinder portion 301 and the thrust collar 12, and inward of the outer cylinder portion 302 in the radial direction of the rotating shaft 10. The guide metal 31 is fixed to the inner circumferential surface of the outer cylinder portion 302 such that it protrudes radially inward from the inner circumferential surface of the outer cylinder portion 302. The inner circumferential surface of the guide metal 31 faces the outer circumferential surface of the thrust collar 12.

[0015] Although not shown in the diagram, multiple guide metals 31 are arranged inside the oil tank 30 containing the lubricating oil L30 in the rotational direction R of the rotating shaft 10. The multiple guide metals 31 are radial bearings and are configured to support the rotating shaft 10 so that it can rotate freely by receiving the radial load acting on the rotating shaft 10 in the radial direction via the outer circumferential surface of the thrust collar 12.

[0016] [B-3] Thrust bearing base 32 The thrust bearing base 32 is installed in the internal space of the oil tank 30. Here, the thrust bearing base 32 is installed on the upper surface of the bearing bracket 2 such that it is located below the lower surface S12 (sliding surface) of the thrust collar 12 in the axial direction of the rotating shaft 10.

[0017] [B-4] Coil spring 33 The coil springs 33 are installed on the upper surface S32 of the thrust bearing base 32 within the internal space of the oil tank 30. Multiple coil springs 33 are installed in this location.

[0018] [B-5] Thrust Pad 34 The thrust pad 34 is a stationary plate and is installed on the upper surface S32 of the thrust bearing base 32 via a coil spring 33 within the internal space of the oil tank 30. In other words, the thrust pad 34 is interposed between the lower surface S12 of the thrust collar 12 and the upper surface S32 of the thrust bearing base 32 in the axial direction of the rotating shaft 10. The thrust pad 34 is installed to receive the thrust load acting in the axial direction of the rotating shaft 10 via the lower surface S12 of the thrust collar 12.

[0019] [C] Details of Thrust Pad 34 Figure 7B shows a thrust pad 34 in a thrust bearing device relating to related technology.

[0020] Figure 7B shows a cross-section along the horizontal plane (xy plane) (part BB in Figure 7A), where the vertical direction is the second horizontal direction y, the horizontal direction is the first horizontal direction x, and the direction perpendicular to the plane of the paper is the vertical direction z. Figure 7B shows the rotating shaft 10 and thrust pad 34 of the vertical shaft water turbine 1 (see Figure 7A).

[0021] As shown in Figure 7B, the thrust pad 34 has an arc-shaped (sector-shaped) cross-section along the horizontal plane (xy-plane). Multiple thrust pads 34 are installed so as to be spaced apart in the rotational direction R of the rotating shaft 10. In other words, multiple thrust pads 34 are arranged radially in the horizontal plane (xy-plane).

[0022] Figure 7C shows a portion of a plurality of thrust pads 34 arranged in the rotational direction R of a rotating shaft 10 in a thrust bearing device relating to related technology.

[0023] Figure 7C shows a cross-section along a vertical plane (part AA in Figure 7B), where the vertical direction is the vertical direction z, the horizontal direction is the rotational direction R of the rotating shaft 10, and the direction perpendicular to the plane of the paper is the radial direction of the rotating shaft 10. Figure 7C shows two thrust pads 34 (34a, 34b) arranged adjacent to each other in the rotational direction R between the lower surface S12 of the thrust collar 12 and the upper surface S32 of the thrust bearing base 32. Figure 7C also shows the flow F1, F1a, F2, F3 of the lubricating oil L30 when the thrust collar 12 rotates with the rotating shaft 10 in the rotational direction R.

[0024] When the thrust collar 12 rotates in the rotational direction R together with the rotating shaft 10, the lubricating oil L30 travels from the rear side Bk to the front side Fw in the rotational direction R. As a result, the lubricating oil L30 flows into the space between the lower surface S12 (sliding surface) of the thrust collar 12 and the upper surface S34 (sliding surface) of the thrust pad 34, and an oil film of the lubricating oil L30 is formed. The gap between the lower surface S12 of the thrust collar 12 and the upper surface S34 of the thrust pad 34 is on the order of several tens to several hundreds of μm. And as the lubricating oil L30 flows into the gap at a high speed (several tens of m / s), the temperature of the lubricating oil L30 rises and the pressure of the lubricating oil L30 increases. For this reason, the thrust load acting in the axial direction of the rotating shaft 10 via the lower surface S12 of the thrust collar 12 is supported by the pressure increase of the lubricating oil L30 by the thrust pad 34.

[0025] The upper surface S34 of the thrust pad 34 is chamfered at the rear side Bk (front edge portion) and the front side Fw (rear edge portion) in the rotational direction R so that the inflow and outflow of the lubricating oil L30 are performed smoothly.

[0026] Specifically, the upper surface S34 of the thrust pad 34 includes an upper surface front edge portion S341, an upper surface central portion S342, and an upper surface rear edge portion S343, and the upper surface front edge portion S341, the upper surface central portion S342, and the upper surface rear edge portion S343 are provided so as to be arranged in sequence along the rotational direction R. The upper surface S34 of the thrust pad 34 is configured such that when the thrust collar 12 rotates, the gaps between the upper surface front edge portion S341 and the lower surface S12 of the thrust collar 12 and between the upper surface central portion S342 and the lower surface S12 of the thrust collar 12 decrease along the rotational direction R. Here, the rate at which the gap between the upper surface front edge portion S341 and the lower surface S12 of the thrust collar 12 decreases along the rotational direction R is larger than the rate at which the gap between the upper surface central portion S342 and the lower surface S12 of the thrust collar 12 decreases along the rotational direction R. And the upper surface S34 of the thrust pad 34 is configured such that when the thrust collar 12 rotates, the gap between the upper surface rear edge portion S343 and the lower surface S12 of the thrust collar 12 increases along the rotational direction R.

[0027] [D] Flow of Lubricating Oil L30 In the thrust bearing device of the related art, regarding the flows F1, F1a, F2, and F3 in which the lubricating oil L30 flows when the thrust collar 12 rotates in the rotation direction R, it will be described with reference to FIG. 7C.

[0028] A part of the flow F1 of the high-temperature lubricating oil L30 flowing out from between the lower surface S12 of the thrust collar 12 and the upper surface of one thrust pad 34 (34a) collides with the side surface located on the rear side Bk in the rotation direction R of another thrust pad 34 (34b) located on the front side Fw in the rotation direction R with respect to the one thrust pad 34 (34a). Thereafter, the flow F1 of the high-temperature lubricating oil L30 becomes a flow F2 directed downward in the vertical direction z and mixes with the lubricating oil L30 having a low temperature. As a result, the lubricating oil L30 is cooled, and the flow F3 of the cooled lubricating oil L30 heads toward the upper surface side of another thrust pad 34 (34b).

[0029] On the other hand, among the high-temperature lubricating oil L30 flowing out from between the lower surface S12 of the thrust collar 12 and the upper surface S34 of one thrust pad 34 (34a), the flow F1a other than a part of the flow F1 proceeds while adhering to the lower surface S12 of the thrust collar 12. And the flow F1a flows into the space between the lower surface S12 of the thrust collar 12 and the upper surface of another thrust pad 34 (34b).

[0030] The temperature of the flow F1a of the lubricating oil L30 is higher than the temperature of the flow F3 of the lubricating oil L30 whose temperature has been lowered by cooling. For this reason, when a high proportion of the flow F1a of the high-temperature lubricating oil L30 enters between the lower surface S12 of the thrust collar 12 and the upper surface S34 of the thrust pad 34 (34b), the temperature of the oil film composed of the lubricating oil L30 intervening therebetween rises. As a result, as the temperature of the oil film rises, the lubricating oil L30 constituting the oil film deteriorates, and there is a possibility that the bearing performance deteriorates, so it may be difficult to continuously operate the vertical shaft water turbine 1.

[0031] Various techniques have been proposed to reduce the temperature of the oil film consisting of lubricating oil L30 interposed between the lower surface S12 of the thrust collar 12 and the upper surface S34 of the thrust pad 34. For example, a "direct lubrication method" has been proposed in which a low-temperature lubricating oil is sprayed onto the thrust collar using auxiliary equipment such as a pump. [Prior art documents] [Patent Documents]

[0032] [Patent Document 1] Japanese Patent Publication No. 2017-160967 [Patent Document 2] Japanese Patent Publication No. 2020-112214 [Patent Document 3] Japanese Patent Publication No. 2021-014855 [Patent Document 4] Japanese Patent Publication No. 2021-055677 [Patent Document 5] Japanese Patent Publication No. 2021-060066 [Patent Document 6] International Publication No. 2018 / 029834 [Patent Document 7] International Publication No. 2019 / 142383 [Overview of the project] [Problems that the invention aims to solve]

[0033] However, conventionally, it has not been easy to effectively reduce the temperature of the oil film made of lubricating oil, and it can be difficult to sufficiently suppress the deterioration of the lubricating oil. For example, in the "direct lubrication method" described above, auxiliary equipment such as pumps is used, which increases the cost of the equipment and may reduce operating efficiency due to the need for maintenance of the auxiliary equipment. As a result, it is not easy to effectively reduce the temperature of the oil film and sufficiently improve reliability.

[0034] Therefore, the problem that the present invention aims to solve is to provide a thrust bearing device that can effectively reduce the temperature of the oil film made of lubricating oil and can sufficiently improve reliability. [Means for solving the problem]

[0035] The thrust bearing device of this embodiment comprises an oil tank, thrust pads, and scrapers, and supports thrust loads acting vertically on a rotating shaft whose rotational axis is aligned vertically. The oil tank is installed to surround the rotating shaft and contains lubricating oil. Multiple thrust pads are installed inside the oil tank, spaced apart in the direction of rotation of the rotating shaft, and receive thrust loads via thrust collars fixed to the rotating shaft. Multiple scrapers are installed inside the oil tank, interposed between each of the multiple thrust pads aligned in the direction of rotation. The upper surface of the scraper is configured to include a portion where the oil pressure of the lubricating oil decreases as the lubricating oil flows from the rear to the front in the direction of rotation between the lower surface of the thrust collar and the upper surface of the scraper when the rotating shaft rotates in the direction of rotation. In addition, an oil passage is formed in the scraper through which lubricating oil flows from an inlet located on the rear side in the direction of rotation to an outlet located on the front side in the direction of rotation. The outlet of the oil passage is formed on the upper surface of the scraper. The oil passage inlet is formed on a surface aligned vertically in the scraper. The oil passage outlet is formed on the upper surface of the scraper at the point where the oil pressure of the lubricating oil between the lower surface of the thrust collar and the upper surface of the scraper is lowest when the rotating shaft rotates in the rotational direction. The upper surface of the scraper includes a rear upper surface portion located on the rear side in the rotational direction and a front upper surface portion located on the front side in the rotational direction. The gap between the rear upper surface portion and the lower surface of the thrust collar is a first width constant in the rotational direction, and the gap between the front upper surface portion and the lower surface of the thrust collar is a second width constant in the rotational direction, with the first width being narrower than the second width. [Brief explanation of the drawing]

[0036] [Figure 1A] Figure 1A shows the main parts of a thrust bearing device according to the first embodiment. [Figure 1B] Figure 1B shows a thrust pad 34 and a scraper 35 arranged in the rotational direction R in a thrust bearing device according to the first embodiment. [Figure 1C] Figure 1C shows a thrust pad 34 and a scraper 35 arranged in the rotational direction R in a thrust bearing device according to the first embodiment. [Figure 1D]Figure 1D is a diagram showing an enlarged view of a part of the scraper 35 in a thrust bearing device according to the first embodiment. [Figure 2A] Figure 2A shows a thrust pad 34 and a scraper 35 arranged in the rotational direction R in a thrust bearing device according to the second embodiment. [Figure 2B] Figure 2B is a diagram showing an enlarged view of a part of the scraper 35 in a thrust bearing device according to the second embodiment. [Figure 3A] Figure 3A shows a thrust pad 34 and a scraper 35 arranged in the rotational direction R in a thrust bearing device according to the third embodiment. [Figure 3B] Figure 3B is a magnified view of a portion of the scraper 35 in a thrust bearing device according to the third embodiment. [Figure 4A] Figure 4A shows a thrust pad 34 and a scraper 35 arranged in the rotational direction R in a thrust bearing device according to the fourth embodiment. [Figure 4B] Figure 4B is a diagram showing an enlarged view of a part of the scraper 35 in the thrust bearing device according to the fourth embodiment. [Figure 5A] Figure 5A shows a thrust pad 34 and a scraper 35 arranged in the rotational direction R in a thrust bearing device according to the fifth embodiment. [Figure 5B] Figure 5B is a diagram showing an enlarged view of a part of the scraper 35 in the thrust bearing device according to the fifth embodiment. [Figure 6A] Figure 6A shows a thrust pad 34 and a scraper 35 arranged in the rotational direction R in a thrust bearing device according to the sixth embodiment. [Figure 6B] Figure 6B is a diagram showing an enlarged view of a part of the scraper 35 in the thrust bearing device according to the sixth embodiment. [Figure 6C] Figure 6C is a diagram showing an enlarged view of a part of the scraper 35 in the thrust bearing device according to the sixth embodiment. [Figure 7A] Figure 7A shows an example of a vertical-axis water turbine 1 related to the relevant technology. [Figure 7B] Figure 7B shows a thrust pad 34 in a thrust bearing device relating to related technology. [Figure 7C] Figure 7C shows a portion of a plurality of thrust pads 34 arranged in the rotational direction R of a rotating shaft 10 in a thrust bearing device relating to related technology. [Modes for carrying out the invention]

[0037] <First Embodiment> [A] Configuration Figure 1A shows the main parts of a thrust bearing device according to the first embodiment.

[0038] Figure 1A, like Figure 7B, shows a cross-section along the horizontal plane (xy plane) (part BB in Figure 7A), where the vertical direction is the second horizontal direction y, the horizontal direction is the first horizontal direction x, and the direction perpendicular to the plane of the paper is the vertical direction z.

[0039] As shown in Figure 1A, the thrust bearing device of this embodiment, similar to the case of the related technology described above (see Figure 7B), has multiple thrust pads 34 arranged in the rotational direction R of the rotating shaft 10. In addition, unlike the case of the related technology described above, the thrust bearing device of this embodiment is equipped with multiple scrapers 35. Except for this point and related points, this embodiment is the same as the case of the related technology described above. For this reason, explanations of overlapping parts will be omitted as appropriate.

[0040] [A-1] Scraper 35 In the thrust bearing device of this embodiment, each of the multiple scrapers 35 is interposed between each of the multiple thrust pads 34 arranged in the rotational direction R, as shown in Figure 1A. The scrapers 35 are installed, for example, so as to be closer to the portion of the thrust pad 34 located on the rear side Bk in the rotational direction R than to the portion located on the front side Fw in the rotational direction R.

[0041] Figures 1B and 1C show the thrust pads 34 and scraper 35 arranged in the rotational direction R in the thrust bearing device according to the first embodiment. Figure 1D is an enlarged view of a part of the scraper 35 in the thrust bearing device according to the first embodiment.

[0042] Figure 1B, like Figure 7C, shows a cross-section along a vertical plane (part AA in Figure 1A), where the vertical direction is the vertical direction z, the horizontal direction is the rotational direction R of the rotating shaft 10, and the direction perpendicular to the plane of the paper is the radial direction of the rotating shaft 10. Figure 1B shows two thrust pads 34 (34a, 34b) arranged adjacent to each other in the rotational direction R between the lower surface S12 of the thrust collar 12 and the upper surface S32 of the thrust bearing base 32. Figure 1B also shows the flow of lubricating oil L30 F1a, F1b, F2, F21, F22 when the thrust collar 12 rotates with the rotating shaft 10 in the rotational direction R.

[0043] Figure 1C shows a surface aligned with the horizontal plane, where the vertical direction is the second horizontal direction y, the horizontal direction is the first horizontal direction x, and the direction perpendicular to the plane of the paper is the vertical direction z. Figure 1C shows magnified views of the top surfaces of the thrust pad 34 and the scraper 35.

[0044] Figure 1D, like Figure 1B, shows a cross-section along a vertical plane, and shows a magnified view of the upper end portion of the scraper 35. Figure 1D also shows the pressure distribution, which illustrates the relationship between the pressure P (vertical axis) of the lubricating oil L30 interposed between the lower surface S12 of the thrust collar 12 and the upper surface S35 of the scraper 35 and the position in the rotational direction R (horizontal axis) when the thrust collar 12 rotates with the rotating shaft 10 in the rotational direction R.

[0045] As shown in Figure 1B, the scraper 35, like the thrust pads 34 (34a, 34b), is installed in the internal space of the oil tank 30 (see Figure 7A) between the lower surface S12 of the thrust collar 12 and the upper surface S32 of the thrust bearing base 32. The scraper 35 is installed to obstruct the flow of lubricating oil L30. Although not shown, the scraper 35 is, for example, directly fixed to the upper surface S32 of the thrust bearing base 32. Alternatively, the scraper 35 may be fixed to the upper surface S32 of the thrust bearing base 32 via a coil spring 33, similar to the thrust pads 34.

[0046] As shown in Figure 1C, the scraper 35 has, for example, a rectangular top surface, and is installed so that the longitudinal direction of the top surface is aligned with the radial direction.

[0047] As shown in Figure 1D, a gap exists between the upper surface S35 of the scraper 35 and the lower surface S12 of the thrust collar 12. For example, the width of the gap between the upper surface S35 of the scraper 35 and the lower surface S12 of the thrust collar 12 is approximately the same as the width of the gap between the upper surface S34 of the thrust pad 34 and the lower surface S12 of the thrust collar 12.

[0048] As shown in Figure 1D, the upper surface S35 of the scraper 35 is configured to include a portion where the oil pressure of the lubricating oil L30 increases and a portion where the oil pressure of the lubricating oil L30 decreases when the rotating shaft 10 rotates in the rotational direction R and the lubricating oil L30 flows between the lower surface S12 of the thrust collar 12 and the upper surface S35 of the scraper 35 from the rear side Bk to the front side Fw in the rotational direction R.

[0049] Specifically, as shown in Figure 1D, the upper surface S35 of the scraper 35 includes a rear upper surface portion S351 and a front upper surface portion S352, and the rear upper surface portion S351 and the front upper surface portion S352 are arranged sequentially along the rotational direction R.

[0050] Of the upper surface S35 of the scraper 35, the rear upper surface portion S351 is an inclined surface that is tilted with respect to the lower surface S12 of the thrust collar 12 such that when the thrust collar 12 rotates, the gap between it and the lower surface S12 of the thrust collar 12 narrows as it moves from the rear side Bk (downstream side) to the front side Fw (upstream side) in the rotation direction R. Here, the upper surface S35 of the scraper 35 is configured such that the gap between the rear upper surface portion S351 and the lower surface S12 of the thrust collar 12 decreases from a first width W1 to a second width W2 along the rotation direction R.

[0051] In contrast, the front upper surface portion S352 of the upper surface S35 of the scraper 35 is an inclined surface that is tilted with respect to the lower surface S12 of the thrust collar 12 such that when the thrust collar 12 rotates, the gap between the front upper surface portion S352 and the lower surface S12 of the thrust collar 12 widens as the rotation direction R moves from the rear side Bk to the front side Fw. Here, the upper surface S35 of the scraper 35 is configured such that when the thrust collar 12 rotates, the gap between the front upper surface portion S352 and the lower surface S12 of the thrust collar 12 increases from a second width W2 to a third width W3 along the rotation direction R.

[0052] As a result, in this embodiment, as shown in Figure 1D, the pressure of the lubricating oil L30 interposed between the lower surface S12 of the thrust collar 12 and the upper surface S35 of the scraper 35 increases at the rear upper surface portion S351, becoming positive pressure. At the same time, the pressure of the lubricating oil L30 interposed between the lower surface S12 of the thrust collar 12 and the upper surface S35 of the scraper 35 decreases at the front upper surface portion S352, becoming negative pressure. The pressure of the lubricating oil L30 interposed between the lower surface S12 of the thrust collar 12 and the upper surface S35 of the scraper 35 changes from positive pressure to negative pressure at the boundary portion (apex portion) between the rear upper surface portion S351 and the front upper surface portion S352.

[0053] [A-2] Oilway H35 In addition, as shown in Figure 1D, an oil passage H35 is formed in the scraper 35. Here, the oil passage H35 is formed at the rear side Bk of the scraper 35 in the direction of rotation R, with an inlet H351 and an outlet H352 of the scraper 35 in the front side Fw of the scraper 35 in the direction of rotation R. The oil passage H35 is L-shaped, and lubricating oil L30 flows from the inlet H351 to the outlet H352.

[0054] As shown in Figure 1D, in this embodiment, the inlet H351 of the oil passage H35 is formed on the surface of the scraper 35 along the vertical direction z. The outlet H352 of the oil passage H35 is formed on the front upper surface S352 of the upper surface S35 of the scraper 35. Here, the outlet H352 of the oil passage H35 is formed at the point where the oil pressure of the lubricating oil L30 interposed between the lower surface S12 of the thrust collar 12 and the upper surface S35 of the scraper 35 is lowest when the rotating shaft 10 rotates in the rotational direction R.

[0055] As shown in Figure 1C, in this embodiment, multiple oil passages H35 are arranged in a row with spaces between them in the radial direction of the rotating shaft 10. Here, each of the outlets H352 of the multiple radially arranged oil passages H35 is configured to have the same flow path cross-sectional area.

[0056] [B] Effect In the thrust bearing device of this embodiment, the flows F1a, F1b, F2, F21, and F22 of the lubricating oil L30 when the thrust collar 12 rotates with the rotating shaft 10 in the rotational direction R will be explained with reference to Figures 1B and 1D.

[0057] As shown in Figure 1B, in this embodiment, as in the case of related technology (see Figure 7C), the flow F1a of high-temperature lubricating oil L30 that flows out from between the lower surface S12 of the thrust collar 12 and the upper surface of one thrust pad 34 (34a) proceeds while adhering to the lower surface S12 of the thrust collar 12. Then, a portion of the flow F1b of the lubricating oil L30 flow F1a flows into the space between the lower surface S12 of the thrust collar 12 and the rear upper surface portion S351 of the scraper 35.

[0058] However, in this embodiment, as shown in Figure 1D, the flow path for the lubricating oil L30 between the lower surface S12 of the thrust collar 12 and the rear upper surface S351 of the scraper 35 narrows along the rotational direction R. As a result, the lubricating oil L30 interposed between the lower surface S12 of the thrust collar 12 and the rear upper surface S351 of the scraper 35 becomes positively pressurized. Consequently, the flow F1b of the lubricating oil L30 is obstructed by the positively pressurized lubricating oil L30 interposed between the lower surface S12 of the thrust collar 12 and the rear upper surface S351 of the scraper 35.

[0059] Furthermore, although not shown in Figure 1B, a portion of the flow F1 (see Figure 7C) of the high-temperature lubricating oil L30 that flows out from between the lower surface S12 of the thrust collar 12 and the upper surface of one thrust pad 34 (34a) collides with the side surface Bk located on the rear side of the rotational direction R of the other thrust pad 34 (34b), which is located Fw on the forward side of the rotational direction R compared to the first thrust pad 34 (34a). Subsequently, this flow F1 of high-temperature lubricating oil L30 becomes a flow F2 directed downward Lo in the vertical direction z, and mixes with the lower-temperature lubricating oil L30 (see Figure 1B).

[0060] As described above, of the flow F2 of the cooled lubricating oil L30, a portion of the flow F21 flows into the oil passage H35 in this embodiment, as shown in Figure 1B. The lubricating oil L30 that flows into the oil passage H35 then flows out of the oil passage H35 as flow F22. The flow F22 of the lubricating oil L30 that flows out of the oil passage H35 is directed towards the upper surface of the other thrust pads 34 (34b).

[0061] As shown in Figure 1D, the outlet H352 of the oil passage H35 is formed on the front upper surface S352 of the scraper 35. The outlet H352 of the oil passage H35 is located in the negative pressure area where the oil pressure of the lubricating oil L30 interposed between the lower surface S12 of the thrust collar 12 and the front upper surface S352 of the scraper 35 is lowest when the rotating shaft 10 rotates in the rotational direction R. Therefore, in the oil passage H35 of this embodiment, the differential pressure between the inlet H351 and the outlet H352 becomes large, so the lubricating oil L30 is automatically injected from the outlet H352 of the oil passage H35, as shown in Figure 1B. As a result, in this embodiment, the flow of lubricating oil L30 progressing from the rear upper surface S351 to the front upper surface S352 on the upper surface S35 of the scraper 35 is obstructed by the lubricating oil L30 injected from the outlet H352 of the oil passage H35.

[0062] [C] Summary As described above, in this embodiment, the flow F1b of high-temperature lubricating oil L30 that flows out from between the lower surface S12 of the thrust collar 12 and the upper surface of one thrust pad 34 (34a) is obstructed by the action of the rear upper surface portion S351. At the same time, in this embodiment, low-temperature lubricating oil L30 is automatically injected from the outlet H352 of the oil passage H35, so the flow of lubricating oil L30 progressing from the rear upper surface portion S351 to the front upper surface portion S352 is obstructed on the upper surface S35 of the scraper 35. In addition, in this embodiment, the flow F22 of low-temperature lubricating oil L30 flows through the oil passage H35 of the scraper 35 between the lower surface S12 of the thrust collar 12 and the upper surface of the other thrust pad 34 (34b). As a result, in this embodiment, the flow F1b of the high-temperature lubricating oil L30 is less likely to flow between the lower surface S12 of the thrust collar 12 and the upper surface of the other thrust pads 34 (34b), and is more likely to mix with the lower-temperature lubricating oil L30 (see Figure 1B).

[0063] Therefore, in this embodiment, it is possible to suppress the deterioration of the lubricating oil L30 due to the rise in temperature and effectively suppress the decrease in bearing performance.

[0064] <Second Embodiment> [A] Configuration Figure 2A shows the thrust pads 34 and scraper 35 arranged in the rotational direction R in a thrust bearing device according to the second embodiment. Figure 2B is an enlarged view of a part of the scraper 35 in the thrust bearing device according to the second embodiment.

[0065] Figure 2A, like Figure 1B, shows a cross-section along a vertical plane (part AA in Figure 1A), where the vertical direction is the vertical direction z, the horizontal direction is the rotational direction R of the rotating shaft 10, and the direction perpendicular to the plane of the paper is the radial direction of the rotating shaft 10. Figure 2B, like Figure 1D, shows a cross-section along a vertical plane, and shows a magnified view of the upper end portion of the scraper 35.

[0066] As shown in Figures 2A and 2B, the thrust bearing device of this embodiment includes a plurality of scrapers 35, similar to the first embodiment described above (see Figures 1B to 1D). However, the configuration of the scrapers 35 in the thrust bearing device of this embodiment differs from that of the first embodiment. Except for this point and related points, this embodiment is the same as the first embodiment. Therefore, explanations of overlapping parts will be omitted as appropriate.

[0067] [A-1] Scraper 35 In this embodiment, the scraper 35 is installed between the lower surface S12 of the thrust collar 12 and the upper surface S32 of the thrust bearing base 32, as shown in Figure 2A, similar to the case of the first embodiment (see Figure 1B).

[0068] As shown in Figure 2B, the upper surface S35 of the scraper 35 is configured to include a portion where the oil pressure of the lubricating oil L30 decreases when the rotating shaft 10 rotates in the rotational direction R and the lubricating oil L30 flows from the rear side Bk to the front side Fw between the lower surface S12 of the thrust collar 12 and the upper surface S35 of the scraper 35 in the rotational direction R. The upper surface S35 of the scraper 35 includes a rear upper surface portion S351 and a front upper surface portion S352, and the rear upper surface portion S351 and the front upper surface portion S352 are arranged sequentially along the rotational direction R.

[0069] In this embodiment, as shown in Figure 2B, the upper surface S35 of the scraper 35 is configured such that, unlike in the first embodiment (see Figure 1B), the gap between the rear upper surface portion S351 and the lower surface S12 of the thrust collar 12 is constant in the rotational direction R, resulting in a first width W1. Furthermore, the upper surface S35 of the scraper 35 is configured such that the gap between the front upper surface portion S352 and the lower surface S12 of the thrust collar 12 is constant in the rotational direction R, resulting in a second width W2. Here, the first width W1 is narrower than the second width W2.

[0070] As a result, in this embodiment, as shown in Figure 2B, the pressure of the lubricating oil L30 interposed between the lower surface S12 of the thrust collar 12 and the upper surface S35 of the scraper 35 is constant at the rear upper surface portion S351. In contrast, the pressure of the lubricating oil L30 interposed between the lower surface S12 of the thrust collar 12 and the upper surface S35 of the scraper 35 decreases at the front upper surface portion S352, generating negative pressure. The pressure of the lubricating oil L30 interposed between the lower surface S12 of the thrust collar 12 and the upper surface S35 of the scraper 35 begins to decrease at the boundary portion (step portion) between the rear upper surface portion S351 and the front upper surface portion S352, and changes to negative pressure. The flow path between the lower surface S12 of the thrust collar 12 and the upper surface S35 of the scraper 35 is wider at the front upper surface portion S352 than at the rear upper surface portion S351, so a decrease in the pressure of the lubricating oil L30 occurs.

[0071] [A-2] Oilway H35 In addition, as shown in Figure 2B, an oil passage H35 is formed in the scraper 35. Similar to the first embodiment (see Figure 1B), the oil passage H35 has an inlet H351 formed in the scraper 35 at the rear side Bk in the rotation direction R, and an outlet H352 formed in the scraper 35 at the front side Fw in the rotation direction R.

[0072] In other words, the inlet H351 of the oil passage H35 is formed on the surface of the scraper 35 along the vertical direction z. The outlet H352 of the oil passage H35 is formed on the upper surface S35 of the scraper 35. Here, the outlet H352 of the oil passage H35 is formed at the point where the oil pressure of the lubricating oil L30 interposed between the lower surface S12 of the thrust collar 12 and the upper surface S35 of the scraper 35 is lowest when the rotating shaft 10 rotates in the rotational direction R.

[0073] [B] Effect In the thrust bearing device of this embodiment, the flows F1a, F1b, F2, F21, and F22 of the lubricating oil L30 when the thrust collar 12 rotates with the rotating shaft 10 in the rotational direction R will be explained with reference to Figures 2A and 2B.

[0074] As shown in Figure 2A, the flow F1a of high-temperature lubricating oil L30 that flows out from between the lower surface S12 of the thrust collar 12 and the upper surface of one thrust pad 34 (34a) proceeds while adhering to the lower surface S12 of the thrust collar 12. Then, a portion of the flow F1b of the lubricating oil L30 flow F1a flows into the space between the lower surface S12 of the thrust collar 12 and the rear upper surface S351 of the scraper 35.

[0075] However, as shown in Figure 2A, in this embodiment as well, some of the flow F21 of the lubricating oil L30 flow F2, whose temperature has decreased, flows into the oil passage H35. The lubricating oil L30 that flows into the oil passage H35 then flows out of the oil passage H35 as flow F21. The flow F22 of the lubricating oil L30 that flows out of the oil passage H35 is directed towards the upper surface of the other thrust pads 34 (34b).

[0076] As shown in Figure 2B, the outlet H352 of the oil passage H35 is formed on the front upper surface S352 of the scraper 35. The outlet H352 of the oil passage H35 is located in the negative pressure area where the oil pressure of the lubricating oil L30 interposed between the lower surface S12 of the thrust collar 12 and the front upper surface S352 of the scraper 35 is lowest when the rotating shaft 10 rotates in the rotational direction R. For this reason, in the oil passage H35 of this embodiment as well, the differential pressure between the inlet H351 and the outlet H352 is large, so the lubricating oil L30 is automatically injected from the outlet H352 of the oil passage H35. As a result, the flow of lubricating oil L30 progressing from the rear upper surface S351 to the front upper surface S352 on the upper surface S35 of the scraper 35 is obstructed by the lubricating oil L30 injected from the outlet H352 of the oil passage H35.

[0077] [C] Summary As described above, in this embodiment, as in the first embodiment, low-temperature lubricating oil L30 is automatically injected from the outlet H352 of the oil passage H35 formed in the scraper 35, thereby obstructing the flow of lubricating oil L30 from the rear upper surface portion S351 to the front upper surface portion S352 on the upper surface S35 of the scraper 35. In this embodiment, the flow F22 of low-temperature lubricating oil L30 flows through the oil passage H35 of the scraper 35 between the lower surface S12 of the thrust collar 12 and the upper surface of the other thrust pads 34 (34b). As a result, the flow F1b of high-temperature lubricating oil L30 is less likely to flow between the lower surface S12 of the thrust collar 12 and the upper surface of the other thrust pads 34 (34b), and is more likely to mix with the low-temperature lubricating oil L30 (see Figure 2A).

[0078] Therefore, in this embodiment as well, it is possible to suppress the deterioration of the lubricating oil L30 due to the rise in temperature and effectively suppress the decrease in bearing performance.

[0079] Furthermore, since the scraper 35 of this embodiment can be manufactured by simple processing, processing costs can be reduced.

[0080] <Third Embodiment> [A] Configuration Figure 3A shows the thrust pads 34 and scraper 35 arranged in the rotational direction R in the thrust bearing device according to the third embodiment. Figure 3B is an enlarged view of a part of the scraper 35 in the thrust bearing device according to the third embodiment.

[0081] Figure 3A, like Figure 1B, shows a cross-section along a vertical plane (part AA in Figure 1A), where the vertical direction is the vertical direction z, the horizontal direction is the rotational direction R of the rotating shaft 10, and the direction perpendicular to the plane of the paper is the radial direction of the rotating shaft 10. Figure 3B, like Figure 1D, shows a cross-section along a vertical plane, and shows a magnified view of the upper end portion of the scraper 35.

[0082] As shown in Figures 3A and 3B, the thrust bearing device of this embodiment includes a plurality of scrapers 35, similar to the first embodiment described above (see Figures 1B to 1D). However, unlike the first embodiment, the thrust bearing device of this embodiment is provided with protrusions 351 on the scrapers 35. Except for this point and related points, this embodiment is the same as the first embodiment. Therefore, explanations of overlapping parts will be omitted as appropriate.

[0083] In this embodiment, as shown in Figures 3A and 3B, the protrusion 351 is provided on the side surface of the scraper 35 that is aligned with the vertical direction z and located on the rear side Bk in the rotational direction R, and is located below the inlet H351 of the oil passage H35.

[0084] [B] Effect In the thrust bearing device of this embodiment, the flows F1a, F1b, F2, F21, and F22 of the lubricating oil L30 when the thrust collar 12 rotates with the rotating shaft 10 in the rotational direction R will be explained with reference to Figures 3A and 3B.

[0085] As shown in Figure 3A, in this embodiment as well, a portion of the flow F21 of the lubricating oil L30 flow F2, whose temperature has decreased, flows into the oil passage H35. The lubricating oil L30 that flows into the oil passage H35 then flows out of the oil passage H35 as flow F21. The flow F22 of the lubricating oil L30 that flows out of the oil passage H35 is directed towards the upper surface of the other thrust pads 34 (34b).

[0086] In this embodiment, as shown in Figures 3A and 3B, a protrusion 351 is provided in the portion of the oil passage H35 located below the inlet H351. As a result, the flow F2 of the lubricating oil L30, whose temperature has decreased, is obstructed and blocked by the protrusion 351. This reduces the pressure of the flow F2 of the lubricating oil L30 flowing into the inlet H351 of the oil passage H35, and the differential pressure between the inlet H351 and the outlet H352 in the oil passage H35 becomes even larger. Consequently, in this embodiment, the flow velocity of the lubricating oil L30 injected from the outlet H352 of the oil passage H35 is higher than in the first embodiment.

[0087] [C] Summary As described above, in this embodiment, the flow velocity of the lubricating oil L30 injected from the outlet H352 of the oil passage H35 is higher than in the first embodiment, so the flow of lubricating oil L30 progressing from the rear upper surface portion S351 to the front upper surface portion S352 on the upper surface S35 of the scraper 35 can be more effectively inhibited. As a result, the flow F1b of high-temperature lubricating oil L30 is less likely to flow between the lower surface S12 of the thrust collar 12 and the upper surface of the other thrust pads 34 (34b), and is more likely to mix with the lower-temperature lubricating oil L30 (see Figure 3A).

[0088] Therefore, in this embodiment, it is possible to effectively suppress the deterioration of the lubricating oil L30 due to the rise in temperature.

[0089] <Fourth Embodiment> [A] Configuration Figure 4A shows the thrust pads 34 and scraper 35 arranged in the rotational direction R in the thrust bearing device according to the fourth embodiment. Figure 4B is an enlarged view of a part of the scraper 35 in the thrust bearing device according to the fourth embodiment.

[0090] Figure 4A, like Figure 1B, shows a cross-section along a vertical plane (part AA in Figure 1A), where the vertical direction is the vertical direction z, the horizontal direction is the rotational direction R of the rotating shaft 10, and the direction perpendicular to the plane of the paper is the radial direction of the rotating shaft 10. Figure 4B, like Figure 1D, shows a cross-section along a vertical plane, and shows a magnified view of the upper end portion of the scraper 35.

[0091] As shown in Figures 4A and 4B, the thrust bearing device of this embodiment includes a plurality of scrapers 35, similar to the first embodiment described above (see Figures 1B to 1D). However, the configuration of the scrapers 35 in the thrust bearing device of this embodiment differs from that of the first embodiment. Except for this point and related points, this embodiment is the same as the first embodiment. Therefore, explanations of overlapping parts will be omitted as appropriate.

[0092] [A-1] Scraper 35 In this embodiment, the scraper 35 is installed between the lower surface S12 of the thrust collar 12 and the upper surface S32 of the thrust bearing base 32, as shown in Figure 4A, similar to the case of the first embodiment (see Figure 1B).

[0093] As shown in Figure 4B, the upper surface S35 of the scraper 35 is configured to include a portion where the oil pressure of the lubricating oil L30 increases and a portion where the oil pressure of the lubricating oil L30 decreases when the rotating shaft 10 rotates in the rotational direction R and the lubricating oil L30 flows from the rear side Bk to the front side Fw in the rotational direction R between the lower surface S12 of the thrust collar 12 and the upper surface S35 of the scraper 35. The upper surface S35 of the scraper 35 includes a rear upper surface portion S351 and a front upper surface portion S352, and the rear upper surface portion S351 and the front upper surface portion S352 are arranged sequentially along the rotational direction R.

[0094] However, in this embodiment, as shown in Figure 4B, the upper surface S35 of the scraper 35 is configured such that the gap between the rear upper surface portion S351 and the lower surface S12 of the thrust collar 12 is constant in the rotational direction R, unlike in the first embodiment (see Figure 1B). Furthermore, the upper surface S35 of the scraper 35 is configured such that the gap between the front upper surface portion S352 and the lower surface S12 of the thrust collar 12 is constant in the rotational direction R, resulting in a second width W2. Here, the first width W1 is wider than the second width W2.

[0095] As a result, in this embodiment, as shown in Figure 4B, the pressure of the lubricating oil L30 interposed between the lower surface S12 of the thrust collar 12 and the upper surface S35 of the scraper 35 increases at the rear upper surface portion S351. Then, the pressure of the lubricating oil L30 interposed between the lower surface S12 of the thrust collar 12 and the upper surface S35 of the scraper 35 decreases at the front upper surface portion S352.

[0096] [A-2] Oilway H35 In addition, as shown in Figure 4B, an oil passage H35 is formed in the scraper 35. The oil passage H35 has an inlet H351 located at the rear side Bk in the rotation direction R of the scraper 35, and an outlet H352 located at the front side Fw in the rotation direction R of the scraper 35.

[0097] In this embodiment, unlike in the first embodiment (see Figure 1B), the oil passage H35 is U-shaped, and lubricating oil L30 flows from the inlet H351 to the outlet H352. Here, the inlet H351 of the oil passage H35 is formed on the rear upper surface portion S351. The outlet H352 of the oil passage H35 is formed on the front upper surface portion S352.

[0098] [B] Effect In the thrust bearing device of this embodiment, the flows F1a, F1b, F2, F21, and F22 of the lubricating oil L30 when the thrust collar 12 rotates with the rotating shaft 10 in the rotational direction R will be explained with reference to Figures 4A and 4B.

[0099] As shown in Figure 4A, the flow F1a of high-temperature lubricating oil L30 that flows out from between the lower surface S12 of the thrust collar 12 and the upper surface of one thrust pad 34 (34a) proceeds while adhering to the lower surface S12 of the thrust collar 12. Then, a portion of the flow F1b of the lubricating oil L30 flow F1a flows into the space between the lower surface S12 of the thrust collar 12 and the rear upper surface portion S351 of the scraper 35.

[0100] As shown in Figure 4A, in this embodiment as well, a portion of the flow F21 of the lubricating oil L30 flow F2, whose temperature has decreased, flows into the oil passage H35. The lubricating oil L30 that flows into the oil passage H35 then flows out of the oil passage H35 as flow F21. The flow F22 of the lubricating oil L30 that flows out of the oil passage H35 is directed towards the upper surface of the other thrust pads 34 (34b).

[0101] However, as shown in Figure 4B, the lubricating oil L30 interposed between the lower surface S12 of the thrust collar 12 and the rear upper surface S351 of the scraper 35 becomes positively pressurized. Therefore, in this embodiment as well, the flow F1b of the lubricating oil L30 is obstructed by the positively pressurized lubricating oil L30 interposed between the lower surface S12 of the thrust collar 12 and the rear upper surface S351 of the scraper 35.

[0102] In this embodiment as well, as shown in Figure 4A, a portion of the cooled lubricating oil L30 flow F21 flows into the oil passage H35. The lubricating oil L30 that flows into the oil passage H35 then flows out of the oil passage H35 as flow F22. The flow F22 of lubricating oil L30 that flows out of the oil passage H35 is directed towards the upper surface of the other thrust pads 34 (34b).

[0103] As shown in Figure 4B, the pressure of the lubricating oil L30 interposed between the lower surface S12 of the thrust collar 12 and the upper surface S35 of the scraper 35 increases at the rear upper surface S351, becoming positive pressure. Then, the pressure of the lubricating oil L30 interposed between the lower surface S12 of the thrust collar 12 and the upper surface S35 of the scraper 35 decreases at the front upper surface S352. Therefore, in the oil passage H35 of this embodiment, the differential pressure between the inlet H351 and the outlet H352 is large, so the lubricating oil L30 is automatically injected from the outlet H352 of the oil passage H35, as shown in Figure 4A. As a result, in this embodiment, the flow of lubricating oil L30 progressing from the rear upper surface S351 to the front upper surface S352 on the upper surface S35 of the scraper 35 is obstructed by the lubricating oil L30 injected from the outlet H352 of the oil passage H35.

[0104] [C] Summary As described above, in this embodiment, the flow F1b of high-temperature lubricating oil L30 that flows out from between the lower surface S12 of the thrust collar 12 and the upper surface of one thrust pad 34 (34a) is obstructed by the action of the scraper 35. At the same time, in this embodiment, low-temperature lubricating oil L30 is automatically injected from the outlet H352 of the oil passage H35 formed in the scraper 35, so the flow of lubricating oil L30 progressing from the rear upper surface portion S351 to the front upper surface portion S352 on the upper surface S35 of the scraper 35 is obstructed. Then, in this embodiment, the flow F22 of low-temperature lubricating oil L30 flows through the oil passage H35 of the scraper 35 between the lower surface S12 of the thrust collar 12 and the upper surface of the other thrust pad 34 (34b). As a result, in this embodiment, the flow F1b of the high-temperature lubricating oil L30 is less likely to flow between the lower surface S12 of the thrust collar 12 and the upper surface of the other thrust pads 34 (34b), and is more likely to mix with the lower-temperature lubricating oil L30 (see Figure 4A).

[0105] Therefore, in this embodiment, it is possible to suppress the deterioration of the lubricating oil L30 due to the rise in temperature and effectively suppress the decrease in bearing performance.

[0106] Furthermore, since the scraper 35 of this embodiment can be manufactured by simple processing, processing costs can be reduced.

[0107] <Fifth Embodiment> [A] Configuration Figure 5A shows the thrust pads 34 and scraper 35 arranged in the rotational direction R in the thrust bearing device according to the fifth embodiment. Figure 5B is an enlarged view of a part of the scraper 35 in the thrust bearing device according to the fifth embodiment.

[0108] Figure 5A, like Figure 1B, shows a cross-section along a vertical plane (part AA in Figure 1A), where the vertical direction is the vertical direction z, the horizontal direction is the rotational direction R of the rotating shaft 10, and the direction perpendicular to the plane of the paper is the radial direction of the rotating shaft 10. Figure 5B, like Figure 1D, shows a cross-section along a vertical plane, and shows a magnified view of the upper end portion of the scraper 35.

[0109] As shown in Figures 5A and 5B, the thrust bearing device of this embodiment includes a plurality of scrapers 35, similar to the first embodiment described above (see Figures 1B to 1D). However, the configuration of the oil passages H35 formed in the scrapers 35 differs from that of the first embodiment. Except for this point and related points, this embodiment is the same as the first embodiment. Therefore, explanations of overlapping parts will be omitted as appropriate.

[0110] In this embodiment, as shown in Figures 5A and 5B, the oil passage H35 is configured such that the cross-sectional area of ​​the flow path narrows as it moves from the inlet H351 to the outlet H352.

[0111] [B] Effect In the thrust bearing device of this embodiment, the flows F1a, F1b, F2, F21, and F22 of the lubricating oil L30 when the thrust collar 12 rotates with the rotating shaft 10 in the rotational direction R will be explained with reference to Figures 5A and 5B.

[0112] As shown in Figure 5A, in this embodiment as well, a portion of the flow F21 of the lubricating oil L30 flow F2, whose temperature has decreased, flows into the oil passage H35. The lubricating oil L30 that flows into the oil passage H35 then flows out of the oil passage H35 as flow F21. The flow F22 of the lubricating oil L30 that flows out of the oil passage H35 is directed towards the upper surface of the other thrust pads 34 (34b).

[0113] In this embodiment, as shown in Figures 5A and 5B, the flow path cross-sectional area of ​​the oil passage H35 narrows from the inlet H351 to the outlet H352. Therefore, in this embodiment, the flow velocity F2 of the lubricating oil L30 at a lower temperature is higher than in the first embodiment.

[0114] [C] Summary As described above, in this embodiment, the flow velocity of the lubricating oil L30 injected from the outlet H352 of the oil passage H35 is higher than in the first embodiment, so the flow of lubricating oil L30 progressing from the rear upper surface portion S351 to the front upper surface portion S352 on the upper surface S35 of the scraper 35 can be more effectively inhibited. As a result, the flow F1b of high-temperature lubricating oil L30 is less likely to flow between the lower surface S12 of the thrust collar 12 and the upper surface of the other thrust pads 34 (34b), and is more likely to mix with the lower-temperature lubricating oil L30 (see Figure 3A).

[0115] Therefore, in this embodiment, it is possible to effectively suppress the deterioration of the lubricating oil L30 due to the rise in temperature.

[0116] <Sixth Embodiment> [A] Configuration Figure 6A shows the thrust pads 34 and scraper 35 arranged in the rotational direction R in the thrust bearing device according to the sixth embodiment. Figures 6B and 6C are enlarged views of a portion of the scraper 35 in the thrust bearing device according to the sixth embodiment.

[0117] Figure 6A, like Figure 1C, shows a surface aligned with the horizontal plane, where the vertical direction is the second horizontal direction y, the horizontal direction is the first horizontal direction x, and the direction perpendicular to the plane of the paper is the vertical direction z. Figure 6A shows magnified views of the top surfaces of the thrust pad 34 and the scraper 35.

[0118] Figures 6B and 6C, like Figure 1D, show cross-sections along a vertical plane, and provide a magnified view of the upper end portion of the scraper 35. Figure 6B shows the portion of the scraper 35 located radially inward (IN) (the X1-X1 portion in Figure 6A). In contrast, Figure 6C shows the portion of the scraper 35 located radially outward (OUT) (the X2-X2 portion in Figure 6A).

[0119] As shown in Figures 6A, 6B, and 6C, the thrust bearing device of this embodiment, like the first embodiment described above (see Figure 1C), has multiple oil passages H35 arranged radially in the scraper 35 with spaces between them. However, the thrust bearing device of this embodiment differs from the first embodiment in some aspects of the configuration of the oil passages H35. Except for this point and related points, this embodiment is the same as the first embodiment. Therefore, explanations of overlapping parts will be omitted as appropriate.

[0120] As shown in Figures 6A, 6B, and 6C, in this embodiment, unlike in the first embodiment (see Figure 1C), each of the multiple oil passages H35 arranged radially is configured such that the flow path cross-sectional area of ​​the outlet H352 gradually widens as you move radially from the inside IN to the outside OUT.

[0121] Specifically, as shown in Figure 6B, the outlet H352 of the innermost oil passage H35 located at IN among the multiple oil passages H35 arranged radially has a diameter of r1. In contrast, as shown in Figure 6C, the outlet H352 of the outermost oil passage H35 located at OUT among the multiple oil passages H35 arranged radially has a diameter of r2, which is larger than r1.

[0122] [B] Effect The operation of the thrust bearing device of this embodiment will now be explained.

[0123] When the thrust collar 12 rotates in the rotational direction R, the flow of lubricating oil L30 is faster radially outward (OUT) than radially inward (IN). In other words, in the multiple oil passages H35 arranged radially, the velocity of lubricating oil L30 flowing into the inlet H351 is higher radially outward (OUT) than radially inward (IN). Therefore, the temperature of the oil film made up of lubricating oil L30 also differs radially.

[0124] As described above, in this embodiment, the flow path cross-sectional area of ​​the outlet H352 of each of the multiple oil passages H35 arranged radially increases sequentially as you move radially from the inside IN to the outside OUT. Therefore, in this embodiment, the flow velocity of the lubricating oil L30 injected from the outlet H352 of the multiple oil passages H35 arranged radially can be made more uniform in the radial direction than in the case of the first embodiment (see Figure 1C). In other words, in this embodiment, the amount of lubricating oil L30 necessary for temperature reduction can be injected from each of the multiple oil passages H35 arranged radially, according to the oil film temperature distribution generated radially by the operation of the vertical shaft water turbine 1 (see Figure 7A).

[0125] [C] Summary Therefore, in this embodiment, it is possible to suppress the deterioration of the lubricating oil L30 due to the rise in temperature and effectively suppress the decrease in bearing performance.

[0126] <Other> While several embodiments of the present invention have been described, these embodiments are presented as examples only and are not intended to limit the scope of the invention. These embodiments can be carried out in a variety of other forms, and various omissions, substitutions, and modifications can be made without departing from the spirit of the invention. These embodiments and their variations are included in the scope and spirit of the invention, as well as in the claims and their equivalents. [Explanation of Symbols]

[0127] 1: Vertical shaft water turbine, 2: Bearing bracket, 3: Thrust bearing device, 10: Rotating shaft, 12: Thrust collar, 30: Oil tank, 31: Guide metal, 32: Thrust bearing base, 33: Coil spring, 34: Thrust pad, 34a: Thrust pad, 34b: Thrust pad, 35: Scraper, 301: Inner cylinder, 302: Outer cylinder, 303: Cover, 351: Protrusion, AX: Rotational axis, Bk: Rear side, Fw: Front side, H35: Oil passage, H351: Inlet, H352: Outlet, K10: Ring key, L30: Lubricating oil, Lo: Downward side, OUT: Outside, R: Direction of rotation, S12: Bottom surface, S32: Top surface, S34: Top surface, S341: Front edge of top surface, S342: Center of top surface, S343: Rear edge of top surface, S35: Top surface, S351: Rear side top surface, S352: Front side top surface

Claims

1. A thrust bearing device for supporting a thrust load acting in the vertical direction in a rotating shaft whose rotational axis is aligned vertically, An oil tank is installed to surround the aforementioned rotating shaft and contains lubricating oil inside, Multiple thrust pads are installed inside the oil tank so as to be spaced apart in the direction of rotation of the rotating shaft, and the thrust pads receive the thrust load via a thrust collar fixed to the rotating shaft, A plurality of scrapers are installed inside the oil tank, interposed between each of the plurality of thrust pads arranged in the rotational direction. It has, The upper surface of the scraper is configured such that, when the rotating shaft rotates in the rotational direction, the lubricating oil flows between the lower surface of the thrust collar and the upper surface of the scraper from the rear to the front in the rotational direction, and includes a portion where the oil pressure of the lubricating oil decreases. An oil passage is formed in the scraper through which the lubricating oil flows from an inlet located on the rear side in the direction of rotation to an outlet located on the front side in the direction of rotation. The inlet of the oil passage is formed on the surface of the scraper that is aligned with the vertical direction. The outlet of the oil passage is formed on the upper surface of the scraper at the point where the oil pressure of the lubricating oil interposed between the lower surface of the thrust collar and the upper surface of the scraper is lowest when the rotating shaft rotates in the rotational direction. The upper surface of the aforementioned scraper is The rear upper surface portion located on the rear side in the aforementioned rotational direction, The front upper surface portion located on the front side in the aforementioned rotational direction and Includes, The gap between the rear upper surface and the lower surface of the thrust collar is a first width that is constant in the rotational direction. The gap between the front upper surface and the lower surface of the thrust collar has a second width that is constant in the rotational direction. The first width is narrower than the second width, Thrust bearing device.

2. In the scraper, a protrusion is provided on the portion of the surface along the vertical direction that is located below the inlet of the oil passage. The thrust bearing device according to claim 1.

3. A thrust bearing device for supporting a thrust load acting in the vertical direction in a rotating shaft whose rotational center axis is aligned in the vertical direction, An oil tank is installed to surround the aforementioned rotating shaft and contains lubricating oil inside, Multiple thrust pads are installed inside the oil tank so as to be spaced apart in the direction of rotation of the rotating shaft, and the thrust pads receive the thrust load via a thrust collar fixed to the rotating shaft, A plurality of scrapers are installed inside the oil tank, interposed between each of the plurality of thrust pads arranged in the rotational direction. It has, The upper surface of the scraper is configured such that, when the rotating shaft rotates in the rotational direction, the lubricating oil flows between the lower surface of the thrust collar and the upper surface of the scraper from the rear to the front in the rotational direction, and includes a portion where the oil pressure of the lubricating oil decreases. An oil passage is formed in the scraper through which the lubricating oil flows from an inlet located on the rear side in the direction of rotation to an outlet located on the front side in the direction of rotation. The upper surface of the aforementioned scraper is The rear upper surface portion located on the rear side in the aforementioned rotational direction, The front upper surface portion located on the front side in the aforementioned rotational direction and Includes, The gap between the rear upper surface and the lower surface of the thrust collar is a first width that is constant in the rotational direction. The gap between the front upper surface and the lower surface of the thrust collar has a second width that is constant in the rotational direction. The first width is wider than the second width, The inlet of the oil passage is formed on the rear upper surface portion. The outlet of the oil passage is formed on the front upper surface portion. Thrust bearing device.

4. The oil passage is configured such that the cross-sectional area of ​​the flow path narrows as it moves from the inlet to the outlet. The thrust bearing device according to claim 1.

5. Multiple oil passages are arranged in the radial direction of the rotating shaft, spaced apart from each other. The outlets of the plurality of oil passages arranged in the radial direction are configured such that the cross-sectional area of ​​the flow path increases as you move from the inside to the outside in the radial direction. The thrust bearing device according to claim 1.

Images