JP2012016071A - Thrust axis bearing device for generator - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a thrust axis bearing device for a generator with reduced contact stress.SOLUTION: A thrust axis bearing device for a generator comprises: an axis bearing base 5 supported by a stationary part of a generator; a support bearing base 7 fixed on a slide side surface part of the axis bearing base 5; a pivot spring 1 provided on a slide side of the support bearing base 7; and an axis bearing pad 4 provided on a slide side of the pivot spring 1. The axis bearing pad 4 includes a base metal 4a with a concavity provided on a side of the stationary part and a reverse metal 4b which is provided on a slide side surface part of the base metal 4a and has a slide surface facing a rotor. The pivot spring 1 includes a pivot part 1b on the stationary part side contacting a concavity of the support bearing base 7, and a pivot part 1a on the slide side contacting the concavity of the base metal. A cross-sectional shape of the concavity of the support bearing base 7 in the radial direction of the axis bearing base 5 is a smooth curving shape of a convex towards the stationary part side, and the cross-sectional shape of the concavity of the support bearing base 7 in the circumferential direction of the axis bearing base 5 is linear. The cross-sectional shape of the tip of the pivot part 1b on the stationary part side in the radial direction of the axis bearing base 5 is a smooth curving shape of a convex towards the stationary part side.

Description

  The present invention relates to a thrust bearing device for a generator.

  A thrust bearing device for a vertical shaft type water turbine generator supports a water thrust load applied to the water turbine in addition to the dead weight of a rotating body such as a water turbine or a generator. In the case of a large-capacity generator, a load of 3000t to 4000t must be supported.

  As a structure of a bearing device for supporting the above-mentioned load, Patent Document 1 provides a recess on the back side of a bearing pad arranged radially around the rotation axis, and supports this portion with an elliptical spherical pivot, A device that can be tilted in a radial direction and a circumferential direction is disclosed. In Patent Document 1, in order to prevent the bearing pad from rotating in the circumferential direction, positioning is performed by making a hole in the outer peripheral portion of the pad and inserting a columnar member into the hole.

  As another structure of the bearing device, Non-Patent Document 1 discloses a bearing pad supported by a pivot spring at two points on the inner peripheral side and the outer peripheral side. Further, in Non-Patent Document 1, the height of the bearing pad is automatically adjusted by the arrangement of a cascade-type pivot that supports the inner periphery and the outer periphery of adjacent bearing pads. In this structure, the bearing pad and the pivot spring are positioned by a circular plate provided under the bearing pad.

JP 11-270550 A

Japanese Society of Tribology: “Slide Bearing Material Collection” Yokendo 2005 P78

  Conventional positioning of the bearing pad and the pivot spring is performed by contact between the bearing pad and the plate (flat plate) and contact between the pivot spring and the plate (flat plate). For this reason, when positioning, there is a concern that the contact stress between the bearing pad and the plate and the contact stress between the pivot spring and the plate may cause astringency.

  An object of the present invention is to reduce the contact stress between the bearing pad and the plate and the contact stress between the pivot spring and the plate at the time of positioning the bearing pad and the pivot spring, and prevent astringency.

  A thrust bearing device for a generator according to the present invention includes a bearing base supported by a fixed portion of a generator, a support base fixed to a sliding side surface portion of the bearing base, and a sliding side of the support base A thrust bearing device for a generator including a pivot spring installed on a sliding side of the pivot spring, the bearing pad comprising a base metal and a sliding side of the base metal And a back metal having a sliding surface facing the rotating body, a base metal concave part is provided on the base metal fixing part side, and the pivot spring is fixed in contact with the concave part of the support base And a sliding-side pivot portion in contact with the base metal concave portion, and the concave portion of the support pedestal has a smooth shape in which a shape of a radial cross section of the bearing base is convex toward the fixed portion side. The shape of the curved cross section in the circumferential direction of the bearing stand Is straight, the distal end portion of the fixed portion side pivot portion, characterized in that the shape of at least said pedestal radial cross-section is a smooth curved convex toward the fixed side.

  According to the present invention, it is possible to reduce the contact stress generated when positioning the bearing pad and the pivot spring, and to prevent the bearing pad from becoming astringent.

It is a fragmentary sectional view which shows positioning of the pivot spring by the plate in the conventional thrust bearing apparatus for generators. It is a fragmentary sectional view which shows positioning of the bearing pad in the conventional thrust bearing apparatus for generators. It is a fragmentary sectional view which shows the state which the bearing pad contacted the inner wall face of the plate in FIG. 2A. It is a schematic block diagram which shows the thrust bearing apparatus for generators which concerns on Example 1. FIG. FIG. 4 is a partial projection view of the generator thrust bearing device of FIG. 3 as viewed from above the bearing pads. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is an exploded perspective view showing a generator thrust bearing device according to a first embodiment. It is sectional drawing which shows the bearing pad of FIG. 5A. It is a fragmentary sectional view showing the state where the sliding side pivot part was installed in the hollow cylinder of the bearing pad of FIG. 5A. It is a fragmentary sectional view which shows the effect | action of the bearing pad of FIG. 5A, and a sliding side pivot part. It is a fragmentary sectional view which shows the relationship between the fixed part side pivot part provided in the pivot spring, and a support stand. It is a disassembled perspective view which shows the thrust bearing apparatus for generators which concerns on Example 2. FIG. It is the partial projection figure which looked at the thrust bearing device for generators of Drawing 8 from the upper part of a bearing pad. FIG. 6 is an exploded perspective view showing a generator thrust bearing device according to a third embodiment. It is a fragmentary sectional view which shows the state which installed the sliding side pivot part in the hollow cylinder of the bearing pad of FIG. It is a fragmentary sectional view which shows the state from which the contact point of the bearing pad of FIG. 10 and a sliding side pivot part changed.

  The present invention relates to a thrust bearing device including fan-shaped bearing pads arranged radially around a rotating shaft, such as a vertical shaft type water turbine generator.

  Hereinafter, the thrust bearing device for generators concerning one embodiment of the present invention is explained.

  The generator thrust bearing device includes a plurality of fan-shaped bearing pads that are radially arranged around a rotating shaft and support axial loads, a pivot that contacts two points on the inner and outer sides of the pad, A pivot spring with two pivots attached thereto, a support cradle for mounting the pivot spring, and a bearing cradle for mounting the support cradle. The bearing pad has a concave surface in contact with the pivot. It is attached to the support cradle so as to tilt only.

  The generator thrust bearing device is installed on a bearing base supported by a fixed portion of the generator, a support base fixed to a sliding side surface portion of the bearing base, and a sliding side of the support base A pivot spring and a bearing pad installed on the sliding side of the pivot spring are included. The bearing pad includes a base metal and a back metal provided on the sliding side surface portion of the base metal and having a sliding surface facing the rotating body, and a base metal concave portion is provided on the fixed portion side of the base metal. The pivot spring includes a fixed portion side pivot portion in contact with the concave portion of the support pedestal and a sliding side pivot portion in contact with the base metal concave portion, and the concave portion of the support pedestal has a radial cross-sectional shape of the bearing base. It is a smooth curve convex toward the fixed part side, and the shape of the cross section in the circumferential direction of the bearing base is linear, and the tip of the fixed part side pivot part is at least the shape of the radial cross section of the bearing base Is a smooth curved shape convex toward the fixed part side.

  In the thrust bearing device for a generator, the tip end portion of the sliding side pivot portion has a smooth curved surface convex toward the sliding side.

  In the thrust bearing device for a generator, the base metal concave portion is a curved surface in contact with the tip end portion of the sliding side pivot portion and has a smooth curved surface convex toward the sliding side.

  In the generator thrust bearing device, one pivot spring includes two sliding side pivot portions, and the base metal includes two base metal concave portions in contact with these sliding side pivot portions. The base metal recesses are arranged in the radial direction of the bearing base.

  In the thrust bearing device for a generator, one pivot spring includes two fixed portion side pivot portions, and these fixed portion side pivot portions are attached to two support bases installed in the circumferential direction of the bearing base. is set up.

  In the thrust bearing device for a generator, the side surface portion of the sliding side pivot portion has a portion having a smooth curved cross-sectional shape by a plane perpendicular to the sliding side surface of the bearing base. The dimension of the cross section of the plane perpendicular to the sliding surface of the bearing base in the direction parallel to the sliding surface of the bearing base is on the fixed portion side of the part. Maximum on the sliding side from the end.

  This will be described in detail below with reference to the drawings.

  FIG. 1 is a partial sectional view showing positioning of a pivot spring by a plate in a conventional thrust bearing device for a generator.

  In this figure, the fixed portion side pivot portion 201 b of the pivot spring 201 is supported by a support receiving base 207 installed on the upper surface of the bearing base 205. The bearing pad 204 is supported by the sliding side pivot portion 201 a of the pivot spring 201. The bearing pad 204 and the fixed portion side pivot portion 201b are positioned in the horizontal direction by the plate 206.

  FIG. 2A is a partial cross-sectional view showing positioning of a bearing pad in a conventional thrust bearing device for a generator.

  This figure shows a state in which the bearing pad 204 is installed and positioned on the sliding side pivot portion 201a. A gap 101 is provided between the bearing pad 204 and the sliding side pivot portion 201 a and the inner wall surface of the plate 206.

  2B is a partial cross-sectional view showing a state in which the bearing pad 204 is in contact with the inner wall surface of the plate 206 in FIG. 2A.

  This figure shows a state in which the bearing pad 204 is inclined with respect to the sliding-side pivot portion 201 a or is displaced from a predetermined position so that the side surface of the bearing pad 204 is in contact with the inner wall surface of the plate 206.

  For this reason, there is a concern that the bearing pad 204 and the fixed portion side pivot portion 201b may come into contact with the inner wall surface of the plate 206 and cause astringency.

  Hereinafter, description will be made using examples.

  FIG. 3 is a schematic configuration diagram of the generator thrust bearing device according to the embodiment.

  In this figure, the generator thrust bearing device includes an annular bearing base 5 supported by a fixed portion of the generator, a support base 7 fixed to the upper surface of the bearing base 5, and an upper portion of the support base 7. And the bearing pad 4 installed on the upper part of the pivot spring 1.

  There are a plurality of bearing pads 4, which are arranged radially around the rotating shaft 2, and are applied to the weight of the rotating body composed of the rotating shaft 2, the thrust runner 3 fixed to the rotating shaft 2, and the water wheel. Supports the total load combined with the water thrust load. Here, “radially arranged around the rotating shaft 2” means a state in which they are arranged in the circumferential direction of the rotating shaft 2 at substantially the same distance from the center of the rotating shaft 2.

  The generator thrust bearing device is filled with oil, and when the rotating shaft 2 and the thrust runner 3 rotate, an oil film is formed between the thrust runner 3 and the bearing pad 4. The thrust bearing device for a generator has a structure that can be appropriately tilted in the radial direction and the circumferential direction depending on the situation so that the thrust load can be effectively supported by the oil film pressure.

  However, a force for rotating the bearing pad 4 in the circumferential direction is generated by the shear stress of the oil film accompanying the rotation of the thrust runner 3. In order to limit the movement of the bearing pad 4 by this force, it is necessary to position the bearing pad 4 and the pivot spring 1 that supports the bearing pad 4.

  In the present embodiment, the sliding-side pivot portion 1 a (convex portion) is provided on the upper surface portion of the pivot spring 1 and is inserted into the concave portion (base metal concave portion) of the hollow cylinder 4 c provided on the lower surface portion of the bearing pad 4. Positioning is done by doing.

  FIG. 4 is a partial projection view of the generator thrust bearing device of FIG. 3 as viewed from above the bearing pad 4.

  In this figure, the bearing pad 4 installed in the circumferential direction above the bearing base 5 has a substantially trapezoidal shape on the upper surface, and the outer portion in the radial direction of the bearing base 5 is wide. The bearing pads 4 each have two hollow cylinders 4c, and are positioned by inserting two sliding side pivot portions 1a provided on the pivot spring 1 into the recesses of the hollow cylinder 4c.

  FIG. 5A is an exploded perspective view illustrating a thrust bearing device for a generator according to an embodiment.

  In this figure, the hollow cylinder 4c which has a concave spherical surface is provided in the inner peripheral side and outer peripheral side of the lower surface of the bearing pad 4, and the cylindrical hole (recessed part) is provided. By inserting a sliding side pivot portion 1a having a convex spherical surface provided in the pivot spring 1 into this hole, the bearing pad 4 is supported at two points. The tip of the sliding side pivot portion 1a is not limited to a convex spherical surface, but may be a smooth curved surface convex toward the sliding side.

  Further, a fixed portion side pivot portion 1 b which is a convex portion provided on the pivot spring 1 is installed on a support receiving base 7 having a semicylindrical concave portion provided on the bearing stand 5. The tip of the fixed part side pivot part 1b is preferably semi-cylindrical. Further, the distal end portion of the fixed portion side pivot portion 1b may have a hemispherical shape. That is, the distal end portion of the fixed portion side pivot portion 1b has a smooth curved shape in which the shape of the cross section in the radial direction of at least the bearing base 5 is convex toward the fixed portion side.

  The semi-cylindrical concave portion of the support pedestal 7 has a smoothly curved shape that protrudes downward (such as a convex shape toward the fixed portion). (Smooth curve shape). And as for the semicylindrical recessed part of the support stand 7, it is desirable for the shape of the cross section of the circumferential direction of the bearing stand 5 to be linear form.

  Thereby, the pivot spring 1 can be tilted only in the radial direction of the bearing stand 5.

  FIG. 5B is a cross-sectional view showing the bearing pad 4 of FIG. 5A.

  In this figure, the bearing pad 4 has a structure in which a back metal 4b is fixed to the upper surface of a base metal 4a, and a hollow cylinder 4c having a recess 4d (base metal concave part) is fixed to the lower surface of the base metal 4a. The upper surface of the back metal 4b is a sliding surface with the rotating body. The upper surface portion of the recess 4d is a concave spherical surface (the curvature does not necessarily have to be constant as long as the concave surface is a smooth curved surface).

  As shown by the arrangement of the hollow cylinders 4 c in FIG. 5A, the base metal recesses (recesses 4 d) are arranged in the radial direction of the bearing base 5.

  In the present embodiment, the shape of the concave and convex portions does not necessarily have a constant curvature.

  6A is a partial cross-sectional view showing a state in which the sliding side pivot portion 1a is installed in the hollow cylinder 4c of the bearing pad 4 of FIG. 5A.

  FIG. 6B is a partial cross-sectional view showing the operation of the hollow cylinder 4c and the sliding side pivot portion 1a of the bearing pad of FIG. 5A.

  In FIG. 6A, the uppermost part (vertex) of the sliding side pivot part 1a is supported in contact with the uppermost surface part of the hollow cylinder 4c.

  On the other hand, in FIG. 6B, the sliding-side pivot portion 1a and the hollow cylinder 4c are in the right side of the drawing, and the convex spherical surface of the sliding-side pivot portion 1a and the concave spherical surface of the hollow cylinder 4c are in contact. Here, the point where the convex spherical surface and the concave spherical surface are in contact with each other is called a contact point.

Thereby, in addition to the thrust direction load F ₁ , the reaction force F ₃ when the contact point of the bearing pad 4 with the sliding side pivot portion 1 a moves is applied even when the circumferential load F ₂ is applied. The bearing pad 4 is positioned. For this reason, the conventional plate 6 shown to FIG. 1, 2A and 2B becomes unnecessary. Further, since the contact point moves by the load F ₂ in the circumferential direction changes, it is possible to prevent the solid astringency of bearing pads 4.

  Next, positioning of the pivot spring 1 will be described.

  FIG. 7 is a partial cross-sectional view showing the relationship between the fixed portion side pivot portion provided on the pivot spring and the support cradle.

  In this figure, a fixed portion side pivot portion 1b which is a semi-cylindrical convex portion is provided on the lower surface of the pivot spring 1. The fixed portion side pivot portion 1 b is installed in a semi-cylindrical recess of a support receiving base 7 attached to the bearing base 5. Movement and rotation of the pivot spring 1 in the circumferential direction are suppressed by the recess of the support cradle 7, and the pivot spring 1 is only on the support cradle 7 in the longitudinal direction of the pivot spring 1 (in the radial direction of the bearing base 5). It will be in the state where it was positioned so that it could tilt. As a result, the conventional plate 6 becomes unnecessary, and there is no contact between the plate 6 and the pivot spring 1, and it is possible to prevent astringency.

  In the present embodiment, the shape of the upper surface portion of the bearing pad 4 is a substantially trapezoidal shape, but is not limited thereto, and may be a substantially rectangular shape, a triangular shape, or the like.

  In this embodiment, the bearing pad 4 has a configuration in which a hollow cylinder 4c having a concave portion 4d (base metal concave portion) is fixed to the lower surface of the base metal 4a. However, in order to provide the base metal concave portion, a hollow cylinder is not necessarily provided. There is no need to provide 4c, and a configuration in which the concave portion 4d is provided directly on the lower surface of the base metal 4a and a configuration in which the hollow cylinder 4c is not provided may be employed.

  In the first embodiment, when a large circumferential force is suddenly applied to the bearing pad 4, a rotational force acts on the bearing pad 4, and accordingly, the pivot spring 1 also tries to rotate. In such a case, the side surface portion of the semicylindrical concave portion provided on the support pedestal 7 and the side surface portion of the fixed portion side pivot portion 1b which is a semicylindrical convex portion provided on the lower surface of the pivot spring 1 come into contact. A large contact stress may occur between them.

  FIG. 8 is an exploded perspective view of the generator thrust bearing device according to the second embodiment.

  FIG. 9 is a projection view of the generator thrust bearing device viewed from above the bearing pad 4 of the generator thrust bearing device according to the second embodiment.

  In these drawings, the fixed portion side pivot portion 1b, which is a semi-cylindrical convex portion, is provided at two locations in the direction perpendicular to the longitudinal direction of the pivot spring 1 (the circumferential direction of the bearing stand 5). The fixed portion side pivot portion 1 b is supported by two support receiving bases 7 attached to the bearing base 5. Thereby, since the pivot spring 1 is positioned, damage between the pivot spring 1 and the support cradle 7 can be suppressed.

  The semi-cylindrical concave portion of the support pedestal 7 has a smoothly curved shape that protrudes downward (such as a convex shape toward the fixed portion). (Smooth curve shape). And as for the semicylindrical recessed part of the support stand 7, it is desirable for the shape of the cross section of the circumferential direction of the bearing stand 5 to be linear form.

  Thereby, the pivot spring 1 can be tilted only in the radial direction of the bearing stand 5.

  In addition, the shape of the fixed portion side pivot portion 1b is not a semi-cylindrical convex shape, but a convex spherical shape, and the concave portion of the support receiving base is a concave spherical shape, thereby preventing astringency during positioning. Furthermore, it can be ensured.

  FIG. 10 is an exploded perspective view showing the generator thrust bearing device according to the third embodiment.

  In this figure, the sliding side pivot part 1a has a larger diameter than the support part 301a of the sliding side pivot part 1a, and the side part of the sliding side pivot part 1a has a curvature in the vertical direction. Yes.

  11A is a partial cross-sectional view showing a state in which a pivot is installed on the hollow cylinder of the bearing pad of FIG. FIG. 11B is a partial cross-sectional view showing a state where the contact point between the bearing pad and the pivot in FIG. 10 has changed.

  These drawings show a case where the side surface portion of the sliding side pivot portion 1a has a curvature in the vertical direction. That is, the sliding side pivot portion 1a has a portion having a maximum diameter (thickness) on the upper side (sliding side) from the lower end portion of the portion inserted into the base metal concave portion (the concave portion of the hollow cylinder 4c). ing.

  In the first and second embodiments, the bearing pad 4 is positioned, but when a sudden circumferential force is generated, the side surface portion of the concave portion of the hollow cylinder 4c provided on the lower surface of the bearing pad 4 There is a possibility that the side surface portion of the sliding side pivot portion 1a comes into contact.

  Therefore, in this embodiment, even if a sudden circumferential force is generated by providing a curvature on the side surface portion of the sliding side pivot portion 1a, only the side surface portion provided with the curvature makes contact. . In this case, the contact point between the side surface portion of the concave portion of the hollow cylinder 4c and the sliding side pivot portion 1a varies depending on the circumferential force, the speed of change of the contact point, and the like. For this reason, a contact point is not decided and damage to the sliding side pivot part 1a whole can be suppressed.

  Note that the terms “upper surface”, “lower surface”, “upper surface portion”, “lower surface portion”, “upper portion”, “lower portion” and the like described in this specification represent the direction in which gravity acts as the lower side. . The upper surface portion of the bearing pad of the thrust bearing device for the generator is a surface that slides facing the rotating body, and the bearing stand located at the lower portion of the thrust bearing device for the generator is supported by the fixed portion of the generator Therefore, “upper surface” is “sliding side surface”, “lower surface” is “fixed part side surface”, “upper surface part” is “sliding side surface part”, and “lower surface part” is “fixed part side”. The “surface part” and “upper part” may be called “sliding side”, and the “lower part” may be called “fixed part side”.

  1: pivot spring, 1a: sliding side pivot part, 1b: fixed part side pivot part, 2: rotating shaft, 3: thrust thruster, 4: bearing pad, 4a: base metal, 4b: back metal, 4c: hollow cylinder, 4d: recessed part, 5: bearing stand, 6: plate, 7: support cradle.

Claims (6)

  A bearing base supported by a fixed portion of the generator, a support base fixed to the sliding side surface portion of the bearing base, a pivot spring installed on the sliding side of the support base, and the pivot spring A thrust bearing device for a generator including a bearing pad installed on the sliding side of the base metal, wherein the bearing pad is provided on the sliding side surface portion of the base metal and the base metal and faces the rotating body. A base metal recess is provided on the fixed part side of the base metal, and the pivot spring is provided on the fixed part side pivot part in contact with the concave part of the support receiving base and the base metal concave part. The concave portion of the support pedestal is a smooth curved shape in which the shape of the cross section in the radial direction of the bearing base is convex toward the fixed portion side, and the circumference of the bearing base is The shape of the cross section in the direction is linear, and the fixed part side pivot The tip, the thrust bearing device for an electrical machine, wherein at least the shape of the radial section of the bearing pedestal is a smooth curved convex toward the fixed side.   The thrust bearing device for a generator according to claim 1, wherein a tip end portion of the sliding side pivot portion has a smooth curved surface convex toward the sliding side.   The thrust bearing for a generator according to claim 2, wherein the base metal concave portion has a curved surface that is in contact with the tip end portion of the sliding side pivot portion and is convex toward the sliding side. apparatus.   One pivot spring includes two sliding side pivot portions, and the base includes two base metal concave portions in contact with the sliding side pivot portions, and the base concave portions are The thrust bearing device for a generator according to any one of claims 1 to 3, wherein the thrust bearing device is arranged in a radial direction of the bearing base.   Each of the pivot springs includes two fixed portion side pivot portions, and the fixed portion side pivot portions are installed on the two support bases installed in the circumferential direction of the bearing base. The thrust bearing device for a generator according to any one of claims 1 to 4.   The side surface portion of the sliding side pivot portion has a portion having a smooth curved cross section by a plane perpendicular to the sliding side surface of the bearing base, and this portion is inserted into the base metal recess. And the dimension of the cross section by a plane perpendicular to the sliding side surface of the bearing base in the direction parallel to the sliding side surface of the bearing base is larger than the end of the part on the fixed part side. The thrust bearing device for a generator according to any one of claims 1 to 5, wherein the thrust bearing device is maximum on a sliding side.

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