STORAGE DEVICE AND LATHE

Abstract

A bearing device (100, 100') supporting a rotary shaft (1) rotatable about an axis extending in a horizontal direction, the bearing device (100, 100') comprising: a bearing body (2) which supports the rotating shaft (1); a support ring (3) comprising a support ring body (31) covering the bearing body (2) from an outer peripheral side, and a base portion (32) integrally provided with the support ring body (31) and having a bottom surface (32b) facing downward; and a bearing housing (4) which is provided separately from the support ring (3) and which contains a bearing surface (41s) which is to be in contact with the bottom surface (32b), wherein the bearing body (2) includes a ring part (21) covering the rotary shaft (1) from the outer peripheral side, and a lower cushion (24) supported directly or indirectly by an inner peripheral surface of the ring part (21) and in sliding contact with an outer peripheral surface of the rotary shaft (1), and the support surface (41s) extends along at least one extension line of a straight line connecting the axis to a center of the lower cushion (24) in a circumferential direction when viewed in a direction of the axis.

Description

Technical area

[0001] The present disclosure relates to a bearing device and a lathe.

[0002] Priority is claimed to Japanese Patent Application No. 2021-177357 filed on October 29, 2021, the contents of which are incorporated herein by reference. State of the art

[0003] For example, a rotating machine including a gas turbine or a steam turbine is provided with a bearing device that rotatably supports a rotating shaft. A journal bearing that supports a radial load of the rotating shaft and a thrust bearing that supports a load applied in a direction of an axis (center axis) of the rotating shaft are used as the bearing device.

[0004] Among these bearings, a sliding bearing disclosed in PTL 1 described below is known as an example of the sliding bearing. A device disclosed in PTL 1 to be described below includes a tubular backup ring (backup ring) covering a bearing body from an outer peripheral side, and a bearing housing (bearing housing) supporting the backup ring from below. The bearing housing contacts a pair of flange portions projecting from an outer peripheral surface of the backup ring on both sides in a horizontal direction with respect to an axis from below. Citation listPatent literature

[0005] [PTL 1] Japanese Unexamined Patent Application Publication No. H11-125246 Summary of the inventionTechnical problem

[0006] However, in the device disclosed in PTL 1, the flanges of the backup ring are supported by the bearing housing, but a load exerted on the backup ring from the rotating shaft acts strongly on an inner side of the flanges of the backup ring when viewed from an axial center. Therefore, since the bearing housing cannot securely support the backup ring, there are concerns that the backup ring may be deformed. As a result, it may be difficult to stably support the rotating shaft.

[0007] The present disclosure has been made to solve the above-mentioned problem, and an object of the present disclosure is to provide a bearing device and a lathe that can support the rotary shaft more stably. Solution to the problem

[0008] To solve the above-mentioned problem, a bearing device is provided that supports a rotary shaft rotatable about an axis extending in a horizontal direction. The bearing device includes a bearing body that supports the rotary shaft; a support ring including a support ring body covering the bearing body from an outer peripheral side, and a base portion integrally provided with the support ring body and including a bottom surface facing downward; and a bearing housing provided separately from the support ring and including a bearing surface to be in contact with the bottom surface. The bearing body includes a ring part covering the rotary shaft from the outer peripheral side, and a bottom pad that is directly or indirectly supported by an inner peripheral surface of the ring part and that is in sliding contact with an outer peripheral surface of the rotary shaft.The support surface extends along at least one extension line of a straight line connecting the axis to a center of the lower cushion in a circumferential direction when viewed in a direction of the axis. Advantageous effects of the invention

[0009] According to the present disclosure, it is possible to provide a bearing device and a rotary machine that can support a rotary shaft more stably. Brief description of the drawings Fig. 1 is a schematic diagram showing a configuration of a rotating machine (steam turbine) according to an embodiment of the present disclosure. Fig. 2 is a cross-sectional view showing a configuration of a bearing device according to an embodiment of the present disclosure. Fig. 3 is an enlarged cross-sectional view of main portions of the bearing device according to the embodiment of the present disclosure. Fig. 4 is an enlarged cross-sectional view of main portions showing a first modification example of the bearing device according to the embodiment of the present disclosure. Fig. 5 is an enlarged cross-sectional view of main portions showing a second modification example of the bearing device according to the embodiment of the present disclosure. Fig. 6 is an enlarged cross-sectional view of main portions showing a third modification example of the bearing device according to the embodiment of the present disclosure. Fig. 7 is a cross-sectional view showing a fourth modification example of the bearing device according to the embodiment of the present disclosure. Description of Embodiments

[0010] A steam turbine 200, which is an example of a rotating machine according to an embodiment of the present disclosure, and a bearing device 100 are described below with reference to Fig. 1 to 3. (Configuration of steam turbine)

[0011] As in Fig. 1, the steam turbine 200 includes a rotating shaft 1, a casing 10, bearing devices 100 (sliding bearings), and a thrust bearing device 101. The rotating shaft 1 extends along an axis O. Shaft ends of the rotating shaft 1 are supported by a pair of bearing devices 100 and only one thrust bearing device 101 to be rotatable about the axis O. The bearing devices 100 bear a load applied to the rotating shaft 1 in a radial direction. The thrust bearing device 101 bears a load applied in a direction of the axis O.

[0012] A plurality of rotor blade stages 11, arranged at intervals in the direction of the axis O, are provided on an outer peripheral surface of the rotating shaft 1. Each of the rotor blade stages 11 includes a plurality of rotor blades 12 that extend outward from the outer peripheral surface of the rotating shaft 1 in the radial direction and that are arranged at intervals in a circumferential direction.

[0013] A portion of the rotating shaft 1, where the rotor blade stages 11 are provided, is covered from an outer peripheral side with the casing 10. The casing 10 has a tubular shape centered on the axis O. A plurality of stator blade stages 13, arranged at intervals in the direction of the axis O, are provided on an inner peripheral surface of the casing 10. Each of the stator blade stages 13 includes a plurality of stator blades 14 that extend inward from the inner peripheral surface of the casing 10 in the radial direction and that are arranged at intervals in the circumferential direction. The rotor blade stages 11 and the stator blade stages 13 described above are alternately arranged in the direction of the axis O. That is, a stator blade stage 13 is adjacent to a rotor blade stage 11 in the direction of the axis O.

[0014] A steam supply pipe 15 is provided on one side of the casing 10 in the direction of the axis O. A steam discharge pipe 16 is provided on the other side of the casing 10 in the direction of the axis O. Steam supplied from the outside through the steam supply pipe 15 into the casing 10 alternately collides with the stator blade stages 13 and the rotor blade stages 11, exerting a rotational force on the rotating shaft 1. Accordingly, the rotating shaft 1 is rotated about the axis O.

[0015] The rotary shaft 1 has the shape of a column extending along the axis O, which extends in a horizontal direction. The "horizontal direction" mentioned here refers to a substantially horizontal direction, and minor manufacturing errors or design tolerances are permissible. (Configuration of storage device)

[0016] As in Fig. 2, the bearing device 100 includes a bearing body 2, a support ring 3, and a bearing housing 4. The bearing body 2 includes a ring part 21, lower cushions 24, upper cushions 25, lower springs 26, and upper springs 27. (Configuration of bearing body)

[0017] The ring part 21 covers the rotating shaft 1 from the outer peripheral side. The ring part 21 has a cylindrical shape centered on the axis O.

[0018] Each of the lower cushions 24 and the upper cushions 25 has an arcuate cross-sectional shape centered on the axis O and extends in the circumferential direction. The inner peripheral surfaces of the lower cushions 24 and the upper cushions 25 are in sliding contact with the outer peripheral surface of the rotating shaft 1 via a lubricant. The bearing body 2 forms a cushion bearing that includes four cushions as described above. (Configuration of support ring)

[0019] The support ring 3 includes a support ring body 31 and a base portion 32. The support ring body 31 covers the bearing body 2 from the outer peripheral side. The support ring body 31 has a cylindrical shape centered on the axis O. The pair of lower springs 26 and the pair of upper springs 27 are provided on an inner peripheral surface of the support ring body 31. The lower springs 26 are arranged in a region below the axis O. The upper springs 27 are arranged in a region above the axis O. The lower springs 26 and the upper springs 27 are provided to determine the position of the bearing body 2 with respect to the support ring body 31 in the circumferential direction. The pair of lower springs 26 and the pair of upper springs are arranged, for example, at intervals of 90° in the circumferential direction.

[0020] The positions of the lower springs 26 in the circumferential direction correspond to the positions of the above-mentioned lower cushions 24 in the circumferential direction. The positions of the upper springs 27 in the circumferential direction correspond to the positions of the above-mentioned upper cushions 25 in the circumferential direction. Furthermore, the dimensions of the lower spring 26 and the upper spring 27 in the circumferential direction are set to be equal to or slightly larger than the dimensions of the lower cushion 24 and the upper cushion 25 in the circumferential direction. Here, a radial load of the rotary shaft 1 carried by each lower cushion 24 is supported by each lower spring 26 via a lower pivot link 22 and the ring part 21.

[0021] The base portion 32 is formed integrally with a lower half portion of the support ring body 31. The base portion 32 has a substantially rectangular cross-sectional shape when viewed in the direction of the axis O. A lower surface of the base portion 32 is a bottom surface 32b. The bottom surface 32b extends in a horizontal plane. Surfaces of the base portion 32 facing the horizontal direction are side surfaces 32s. The bottom surface 32b and the side surface 32s are perpendicular to each other when viewed in the direction of the axis O. (Configuration of bearing housing)

[0022] The bearing housing 4 is provided as a separate body to support the support ring 3 from below. The bearing housing 4 includes a bearing housing body 41, a pair of side wall portions 42, and a bottom portion 43. The bearing housing body 41 has a rectangular cross-sectional shape when viewed in the direction of the axis O. An upper surface of the bearing housing body 41 is a seating surface 41s. The seating surface 41s contacts the bottom surface 32b of the aforementioned base portion 32. Further, a recessed portion as a receiving space V for receiving a device such as a lifter 6 is formed at a central portion of the bearing housing body 41 (i.e., a region located directly below the axis O and in which the seating surface 41s does not extend). The lifter 6 is used to adjust the position of the support ring 3 in a vertical direction.That is, the support surface 41s of the bearing housing body 41 is divided into two in the horizontal direction by the receiving space V.

[0023] Inner end edges 41t of the support surface 41s, which are closer to the inside (the axis O), are provided at positions that satisfy the following conditions. Here, an extension line of a straight line connecting the axis O to a center of the lower cushion 24 in the circumferential direction when viewed in the direction of the axis O is denoted by s1. Further, an extension line of a straight line connecting the axis O to an inner end portion of the lower cushion 24 in the circumferential direction is denoted by s2. Further, an extension line of a straight line connecting the axis O to an outer end portion of the lower cushion 24 in the circumferential direction is denoted by s3. Each of the inner end edges 41t of the support surface 41s is positioned more on an inside side (i.e., a side closer to the axis O) than these extension lines s1 and s2.In other words, the support surface 41s extends at a portion where at least these extension lines s1 and s2 are positioned. Furthermore, outer end edges 41u of the support surface 41s are positioned further on an outer side (i.e., a side farther from the axis O) than these extension lines s1 and s3. In other words, the support surface 41s extends at a portion where at least these extension lines s1 and s3 are positioned.

[0024] In particular, as in Fig. 3, a portion surrounded by the extension lines s1 and s2 of a virtual plane parallel to the support surface 41s is a load acting surface 41a. Further, a portion surrounded by the extension lines s1 and s3 of the virtual plane parallel to the support surface 41s is a load acting surface 41b. In the present embodiment, each inner end edge 41t of the support surface 41s is positioned further on an inner side (a side closer to the axis O) than the load acting surface 41a. In other words, the entire load acting surface 41a is supported by the bearing housing body 41. Further, each outer end edge 41u of the support surface 41s is positioned further on an outer side (a side farther from the axis O) than the load acting surface 41b. In other words, the entire load acting surface 41b is supported by the bearing housing body 41.

[0025] The side wall portions 42 extend upward from the outer end edges 41u of the support surface 41s. Inner surfaces 42s, which are inward-facing surfaces of the side wall portions 42, contact the side surfaces 32s of the base portion 32. The bottom portion 43 is in the form of a plate that supports the bearing housing body 41 from below. (Effects)

[0026] Conventionally, it has been customary to individually design a bearing device 100 each time depending on a gas turbine or a steam turbine, which is an object to which the bearing device is to be applied, when manufacturing the bearing device 100. For this reason, there has been a problem that manufacturing costs and a manufacturing period for the bearing device 100 are increased. Accordingly, in the bearing device 100 according to the present embodiment, the support ring 3 supporting the bearing body 2 and the bearing housing 4 are formed of separate bodies. Therefore, it is possible to individually produce only the support ring 3 depending on the dimensions of the bearing body 2 and standardize the bearing housing 4. As a result, manufacturing costs and a manufacturing period can be reduced.

[0027] Here, the area of ​​the above-mentioned bearing surface 41s is important for stably supporting the backup ring 3 with the bearing housing 4. In particular, a radial load exerted by the rotating shaft 1 acts on the bearing housing 4 in areas surrounded by the extension lines s2 and s3 of the straight lines connecting the axis O with both end portions of the lower springs 26 in the circumferential direction. As a result, it is difficult to stably support the rotating shaft 1.

[0028] Therefore, the above-mentioned configuration is adopted in the present embodiment. According to this configuration, the support surface 41s of the bearing housing 4 extends along the extension line s1 of the straight line connecting the axis O to the center of the lower cushion 24 in the circumferential direction. Specifically, the entire load acting surface 41a is supported by the bearing housing body 41. A radial load applied by the rotating shaft 1 can be directly and stably supported by the support surface 41s. As a result, since deformation of the support ring 3 is suppressed, smooth rotation of the rotating shaft 1 can be maintained.

[0029] Furthermore, a radial load applied by the rotating shaft 1 is transmitted to the bearing housing 4 via the lower springs 26. Accordingly, it is necessary to support the radial load in areas where the lower springs 26 extend in the circumferential direction. According to the above-mentioned configuration, since the support surface 41s extends along the extension line s2 of the straight line connecting the axis O to the inner end portion of each lower spring 26 in the circumferential direction, the radial load can be supported more stably.

[0030] Furthermore, the radial load exerted by the rotating shaft 1 includes a component facing the horizontal direction in addition to a vertically downward component. According to the above-mentioned configuration, the component facing the horizontal direction can be stably supported by the side wall portions 42 of the bearing housing 4.

[0031] Furthermore, according to the above-mentioned configuration, the position of the support ring 3 in the vertical direction can be accurately adjusted by the lifter 6 accommodated in the accommodation space V. In other words, according to the above-mentioned configuration, even in a case where the accommodation space V is inevitably formed, the radial load exerted by the rotary shaft 1 can be stably supported by the bearing housing.

[0032] Furthermore, according to the above-mentioned configuration, the center of the upper cushion 25 in the circumferential direction is positioned on the extension line s1 of the straight line connecting the center of the lower cushion 24 in the circumferential direction to the axis O. That is, the upper cushion 25 is arranged to be point-symmetrical to the lower cushion 24 with respect to the axis O. Accordingly, a reaction force to a force applied from the rotary shaft 1 to the lower cushion 24 can be stably supported by the upper cushion 25.

[0033] Furthermore, according to the above-mentioned configuration, the center of the upper spring 27 is positioned on the extension line s1 of the straight line connecting the center of the lower spring 26 to the axis O. That is, the upper spring 27 is arranged to be point-symmetrical to the lower spring 26 with respect to the axis O. Accordingly, a reaction force to a force applied from the rotary shaft 1 to the lower spring 26 can be stably supported by the upper spring 27. (Other embodiments)

[0034] The embodiment of the present disclosure has been described in detail above with reference to the drawings. However, the specific configuration of the present disclosure is not limited to the embodiment, and the present disclosure includes design changes or the like without departing from the scope of the present disclosure.

[0035] In the embodiment, an example was described in which the inner end edge 41t of the support surface 41s is positioned further on an inner side (a side closer to the axis O) than the load acting surface 41a. Fig. However, the configuration shown in Figure 4 can also be used as a first modification example. In this example, the inner end edge 41t is provided at a position overlapping with the above-mentioned extension line s2. In this case, it is possible to increase the volume of the accommodation space V while supporting the entire load acting area 41a with the bearing housing body 41.

[0036] In addition, a Fig. 5 can also be used as a second modification example. In this example, the inner end edge 41t is provided between the extension lines s1 and s2 (i.e., an intermediate position on the load acting surface 41a). In this case, it is possible to further increase the volume of the receiving space V while receiving a minimum load acting on the extension lines s1 to s3. In order to maximize the volume of the receiving space V while receiving a load, it is desirable to have a Fig. 6 as a third modification example. In this example, the inner end edge 41t is positioned on the extension line s1.

[0037] Furthermore, in the embodiment, the lower cushions 24 and the upper cushions 25 are provided in contact with the ring part 21 and adapted to be directly supported by the ring part 21. However, a configuration in which a lower pivot connection 22 is provided between each lower cushion 24 and the ring part 21 and an upper pivot connection 23 is provided between each upper cushion 25 and the ring part 21, as in a Fig.7 can be used as a fourth modification example. The lower pivot links 22 and the upper pivot links 23 are arranged at center positions of the lower cushions 24 and the upper cushions 25 when viewed in the direction of the axis O, and support the lower cushions 24 and the upper cushions 25 so that the lower cushions 24 and the upper cushions 25 can oscillate. The lower pivot links 22 and the upper pivot links 23 are formed such that the dimensions of the lower pivot links 22 and the upper pivot links 23 are gradually reduced in the circumferential direction from the outside to the inside in the radial direction when viewed in the direction of the axis O, and can support the lower cushions 24 and the upper cushions 25 at tip portions thereof so that the lower cushions 24 and the upper cushions 25 can oscillate.In this case, the lower cushions 24 and the upper cushions 25 are adapted to be supported indirectly by the ring part 21.

[0038] Furthermore, in the embodiment, for example, a four-cushion bearing provided with the upper cushions 25 was described. However, the upper cushions 25 need not necessarily be provided, and the above-mentioned configuration can also be applied to a bearing including only the lower cushions 24. Furthermore, an auxiliary device accommodated in the accommodation space V is not limited to the lifter, and a device for treating a lubricant or the like may be accommodated in the accommodation space V. <Ergänzende Anmerkungen>

[0039] The bearing device and the lathe according to the embodiments are understood, for example, as follows. (1) A bearing device 100 according to a first aspect is a bearing device 100 that supports a rotary shaft 1 rotatable about an axis O extending in a horizontal direction. The bearing device 100 includes: a bearing body 2 that supports the rotary shaft 1; a support ring 3 that includes a support ring body 31 covering the bearing body 2 from an outer peripheral side, and a base portion 32 that is integrally provided with the support ring body 31 and includes a bottom surface 32b facing downward; and a bearing housing 4 that is provided separately from the support ring 3 and includes a seating surface 41s to be in contact with the bottom surface 32b. The bearing body 2 includes a ring part 21 covering the rotary shaft 1 from the outer peripheral side, and a lower cushion 24 supported directly or indirectly by an inner peripheral surface of the ring part 21 and in sliding contact with an outer peripheral surface of the rotary shaft 1.The support surface 41s extends on at least one extension line s1 of a straight line connecting the axis O to a center of the lower cushion 24 in a circumferential direction, when viewed in a direction of the axis O.

[0040] According to the above-mentioned configuration, since the support surface 41s extends on the extension line s1 of the straight line connecting the axis O to the center of the lower cushion 24 in the circumferential direction, a radial load exerted by the rotary shaft 1 can be directly and stably supported by the support surface 41s.

[0041] (2) According to a second aspect, the bearing device 100 of (1) may further include a lower spring 26 provided between the support ring body 31 and the ring member 21, arranged at a position corresponding to the lower cushion 24 in the circumferential direction, and extending in the circumferential direction. The support surface 41s may extend along at least one extension line s2 of a straight line connecting the axis O to an inner end portion in the circumferential direction of end portions of the lower spring 26 in the circumferential direction, as viewed in the direction of the axis O.

[0042] Here, a radial load applied by the rotating shaft 1 is transmitted to the bearing housing 4 via the lower spring 26. Accordingly, it is necessary to bear the radial load in a region where the lower spring 26 extends in the circumferential direction. Since the bearing surface 41s extends along the extension line s2 of the straight line connecting the axis O to the inner end portion of the lower spring 26 in the circumferential direction, according to the above-mentioned configuration, the radial load can be supported more stably.

[0043] (3) According to a third aspect, in the bearing device 100 of (1) or (2), the bearing housing 4 may include a bearing housing body 41 on which the bearing surface 41s is formed at an upper portion, and side wall portions 42 which are provided integrally with the bearing housing body 41 and which clamp the support ring 3 from both sides in the horizontal direction.

[0044] The radial load exerted by the rotary shaft 1 includes a component facing the horizontal direction in addition to a vertically downward component. According to the above-mentioned configuration, the component facing the horizontal direction can be stably supported by the side wall portions 42.

[0045] (4) According to a fourth aspect, in the bearing device 100 of any one of (1) to (3), a recessed portion as a receiving space V may be formed at a central portion of the bearing housing 4 where the bearing surface 41s does not extend.

[0046] According to the above-mentioned configuration, since the lifter 6 or the like is arranged in the receiving space V, for example, the position of the support ring 3 in the vertical direction can be accurately adjusted. In other words, according to the above-mentioned configuration, even in a case where the receiving space V is inevitably formed, the radial load exerted by the rotary shaft 1 can be stably supported by the bearing housing 4.

[0047] (5) According to a fifth aspect, in the bearing device 100 of any one of (1) to (4), the bearing body 2 may further include an upper cushion 25 that is directly or indirectly supported by the inner peripheral surface of the ring member 21 and that is in sliding contact with the outer peripheral surface of the rotary shaft 1, and the upper cushion 25 may be positioned on the extension line s1 of the straight line connecting the lower cushion 24 to the axis O when viewed in the direction of the axis O.

[0048] According to the above-mentioned configuration, the upper cushion 25 is positioned on the extension line s1 of the straight line connecting the lower cushion 24 to the axis O. That is, the upper cushion 25 is arranged to be point-symmetrical to the lower cushion 24 with respect to the axis O. Accordingly, a reaction force to a force applied from the rotary shaft 1 to the lower cushion 24 can be stably supported by the upper cushion 25.

[0049] (6) A rotating machine (steam turbine 200) according to a sixth aspect includes the bearing device 100 of any one of (1) to (5), a rotating shaft 1 rotatably supported by the bearing device 100, and a casing 10 covering the rotating shaft 1 from the outside.

[0050] According to the above-mentioned configuration, it is possible to provide the rotating machine (steam turbine 200) which can work more stably. Industrial applicability

[0051] According to the present disclosure, it is possible to provide a bearing device and a rotary machine that can support a rotary shaft more stably. List of reference symbols 100, 100' storage device 200 steam turbines 1 rotating shaft 2 bearing bodies 3 support ring 4 bearing housings 6 lifters 10 housings 11 Rotor blade stage 12 rotor blades 13 Stator blade stage 14 Stator blade 15 Steam supply pipe 16 Steam discharge pipe 21 ring part 22 lower swivel connection 23 upper swivel connection 24 lower pillow 25 upper cushion 26 lower spring 27 upper spring 31 support ring body 32 Base section 32b floor area 32s side surface 41 Bearing housing body 41s contact surface 41t inner end edge 41u outer end edge 42 side wall section 42s inner surface 43 floor section 101 Thrust bearing device O axis V Recording room

Claims

[1] A bearing device (100, 100') supporting a rotary shaft (1) rotatable about an axis extending in a horizontal direction, the bearing device (100, 100') comprising: a bearing body (2) which supports the rotating shaft (1); a support ring (3) comprising a support ring body (31) covering the bearing body (2) from an outer peripheral side, and a base portion (32) integrally provided with the support ring body (31) and having a bottom surface (32b) facing downward; and a bearing housing (4) which is provided separately from the support ring (3) and which contains a bearing surface (41s) which is to be in contact with the bottom surface (32b), wherein the bearing body (2) includes a ring part (21) covering the rotary shaft (1) from the outer peripheral side, and a lower cushion (24) supported directly or indirectly by an inner peripheral surface of the ring part (21) and in sliding contact with an outer peripheral surface of the rotary shaft (1), and the support surface (41s) extends along at least one extension line of a straight line connecting the axis to a center of the lower cushion (24) in a circumferential direction when viewed in a direction of the axis. [2] Storage device (100, 100') according to claim 1, further comprising: a lower spring (26) provided between the support ring body (31) and the ring part (21), arranged at a position corresponding to the lower cushion (24) in the circumferential direction and extending in the circumferential direction, wherein the support surface (41s) extends on at least one extension line of a straight line connecting the axis to an inner end portion in the circumferential direction of end portions of the lower spring (26) in the circumferential direction when viewed in the direction of the axis. [3] A bearing device (100, 100') according to claim 1 or 2, wherein the bearing housing (4) includes a bearing housing body (41) on which the bearing surface (41s) is formed at an upper portion, and side wall portions which are integrally provided with the bearing housing body (41) and which clamp the support ring (3) from both sides in the horizontal direction. [4] The bearing device (100, 100') according to claim 1 or 2, wherein a recessed portion as a receiving space is formed at a central portion of the bearing housing (4) where the support surface (41s) does not extend when viewed in the direction of the axis. [5] Bearing device (100, 100') according to claim 1 or 2, wherein the bearing body (2) further includes an upper cushion (25) which is directly or indirectly supported by the inner peripheral surface of the ring member (21) and which is in sliding contact with the outer peripheral surface of the rotary shaft (1), and the upper cushion (25) is positioned on the extension line of the straight line connecting the lower cushion (24) to the axis when viewed in the direction of the axis. [6] Lathe, comprising: the bearing device (100, 100') according to claim 1 or 2; a rotary shaft (1) rotatably supported by the bearing device (100, 100'); and a housing (10) that covers the rotating shaft (1) from the outside.

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