Ball seat and sliding bearing

Abstract

To provide a spherical seat and sliding bearing that allow for easy maintenance. [Solution] The spherical seat portion 10 is a sliding support 1 disposed between an upper structure U and a lower structure L facing the upper structure U, and comprises a spherical seat portion 10 fixed to the lower structure L when installed, and a slider 11 slidably provided on the sliding surface S1 of the spherical seat portion 10, and comprises a plurality of divisible dividing members 71, and when attached or detached, each of the separated dividing members 71 is movable in a substantially horizontal direction.

Description

Technical Field

[0001] The present disclosure relates to a spherical seat portion and a sliding bearing.

Background Art

[0002] In order to suppress the propagation of vibrations due to earthquakes to buildings, rubber bearings may be used (see, for example, Non-Patent Document 1).

Prior Art Documents

Patent Documents

[0003]

Non-Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] When using the above-mentioned rubber bearing, it is not easy to perform maintenance including its replacement. When using the rubber bearing as, for example, a bridge bearing, during maintenance, it is necessary to jack up the superstructure, which is the bridge girder, significantly with respect to the substructure, which is the pier, and it is difficult to perform the work without imposing traffic restrictions, etc. on the superstructure.

[0005] The present disclosure has been made in view of the above circumstances, and an object thereof is to provide a spherical seat portion and a sliding bearing that enable easy maintenance.

Means for Solving the Problems

[0006] <1> A spherical seat portion according to Embodiment 1 of the present disclosure is a sliding bearing disposed between an upper structure and a lower structure facing the upper structure, and comprises a spherical seat portion fixed to the lower structure when installed and a slider slidably provided on the sliding surface of the spherical seat portion, wherein the spherical seat portion comprises a plurality of divisible dividing members, and when attached or detached, each of the separated plurality of dividing members is movable in a substantially horizontal direction. [Effects of the Invention]

[0007] According to this disclosure, it is possible to provide a spherical seat and a sliding bearing that can be easily maintained. [Brief explanation of the drawing]

[0008] [Figure 1] This is a cross-sectional view showing a sliding bearing equipped with a spherical seat portion according to an embodiment, wherein the spherical seat portion is a cross-sectional view of section II as shown in Figure 2. [Figure 2] This is a plan view showing the spherical seat portion according to an embodiment, in which the first fixing device, the second fixing device, and the retaining member fixing device are omitted. [Figure 3] This is a plan view showing the main body of the spherical seat portion according to the embodiment. [Figure 4] This is a plan view showing the plate-shaped member of the spherical seat portion according to the embodiment. [Figure 5] This is a plan view showing the annular member of the spherical seat according to the embodiment. [Figure 6] This is a cross-sectional view taken from VI-VI in Figure 5, showing the annular member of the spherical seat portion according to the embodiment. [Modes for carrying out the invention]

[0009] The spherical seat and sliding bearing according to one embodiment of this disclosure will be described below with reference to the drawings. Figure 1 is a cross-sectional view showing the configuration of a sliding bearing 1 equipped with a spherical seat portion 10 according to this embodiment, and is a cross-sectional view of the spherical seat portion 10 as shown in section II of Figure 2. Figure 2 is a plan view showing the spherical seat portion 10 according to this embodiment, in which the first fixing device 31, the second fixing device 32, and the retaining member fixing device 33 are omitted. As shown in Figure 1, the sliding bearing 1 according to this embodiment includes a spherical seat portion 10.

[0010] The sliding bearing 1 is positioned between the superstructure U, which is a building structure such as a high-rise building or bridge girder, and the substructure L, which is a foundation structure installed in the ground. The superstructure U and the substructure L are positioned vertically opposite each other, with their horizontal positions overlapping. The sliding bearing 1 prevents the shaking of the lower structure L from being transmitted to the upper structure U when an earthquake occurs at the installation site. The sliding bearing 1 shown in Figure 1 is a spherical sliding bearing and comprises a spherical seat 10, a slider 11, and a shoe 12.

[0011] The spherical seat portion 10 is installed on the upper part of the lower structure L and fixed to the lower structure L. The ball seat portion 10 comprises a steel ball seat portion body 21, a steel plate-shaped member 22, a steel annular member 23, a first friction material 24, a steel friction material retaining member 25, a first fixing device 31 which is a steel bolt, a second fixing device 32 which is a steel bolt, and a retaining member fixing device 33 which is a steel bolt.

[0012] The spherical seat body 21 has a fixing portion 41 that extends horizontally from the lower part of the spherical seat body 21, and a convex portion 42 that is provided on the upper part of the spherical seat body 21 and protrudes upward from the radial center of the fixing portion 41. As shown in Figure 2, the fixing portion 41 is disc-shaped. However, it is not limited to this, and the fixing portion 41 may be other shapes such as rectangular, not disc-shaped.

[0013] Figure 3 is a plan view showing the main body 21 of the spherical seat portion 10 according to this embodiment. As shown in Figure 3, the convex portion 42 has a circular shape when viewed from above. The fixing portion 41 has a flange portion 51 that extends radially outward from the convex portion 42 from the entire circumference of the convex portion 42. As shown in FIG. 1, an outer through-hole 52 penetrating vertically is formed in the flange portion 51. A plurality of outer through-holes 52 are formed in the flange portion 51. A plurality of outer through-holes 52 are formed in the flange portion 51 at positions equidistant from the central axis of the fixing portion 41 and at equal intervals in the circumferential direction of the fixing portion 41. As shown in FIG. 3, specifically, eight outer through-holes 52 are formed in the flange portion 51. However, the number of formed outer through-holes 52 is not limited to eight.

[0014] As shown in FIG. 1, an inner threaded hole 53 penetrating vertically is formed in the flange portion 51. A plurality of inner threaded holes 53 are formed in the flange portion 51. A plurality of inner threaded holes 53 are formed in the flange portion 51 at positions equidistant from the central axis of the fixing portion 41 and at equal intervals in the circumferential direction of the fixing portion 41. As shown in FIG. 3, specifically, four inner threaded holes 53, which are half the number of the outer through-holes 52, are formed in the flange portion 51. However, the number of formed inner threaded holes 53 is not limited to four. The distance between the central axis of the fixing portion 41 and the central axis of the inner threaded hole 53 is shorter than the distance between the central axis of the fixing portion 41 and the central axis of the outer through-hole 52. Therefore, an outer through-hole 52 is formed outside the inner threaded hole 53 in the radial direction of the fixing portion 41 in the flange portion 51. Each of the inner threaded holes 53 is arranged at the central position between adjacent outer through-holes 52 in the circumferential direction of the flange portion 51. In the circumferential direction of the flange portion 51, one inner threaded hole 53 is arranged at every other outer through-hole 52. However, the arrangement of the inner threaded holes 53 is not limited to these.

[0015] As shown in FIG. 1, the convex portion 42 protrudes upward from the center in the radial direction of the fixing portion 41. In the center in the radial direction of the convex portion 42, a concave spherical surface portion 61 that is recessed downward in a hemispherical shape from the upper end surface of the convex portion 42 is formed.

[0016] In the convex portion 42, a mounting screw hole 62 that is recessed downward from the upper end surface of the convex portion 42 is formed outside the concave spherical surface portion 61 in the radial direction of the convex portion 42. In the convex portion 42, a plurality of mounting screw holes 62 are formed at equal intervals in the circumferential direction of the convex portion 42 at positions equidistant from the central axis of the convex portion 42. As shown in FIG. 3, specifically, eight mounting screw holes 62 are formed in the convex portion 42. The mounting screw holes 62 are in phase with the outer through holes 52 in the circumferential direction of the convex portion 42 and the fixing portion 41. However, it is not limited thereto, and the mounting screw holes 62 may not be in phase with the outer through holes 52.

[0017] As shown in FIG. 1, in the convex portion 42, the outer peripheral portion on the outer side in the radial direction is a tapered convex-side tapered surface portion 63 whose outer diameter becomes smaller as it moves away from the fixing portion 41 in the axial direction.

[0018] The ball seat portion main body 21 is divided into a plurality in the circumferential direction of the ball seat portion main body 21. In other words, the ball seat portion 10 includes a plurality of dividable divided members 71 in its ball seat portion main body 21. Specifically, as shown in FIG. 3, the ball seat portion main body 21 is composed of a pair, that is, two identical-shaped divided members 71 divided by a single plane including the central axis of the ball seat portion main body 21. This plane that divides the ball seat portion main body 21 passes through the central position between adjacent outer through holes 52 where no inner screw hole 53 is arranged in the circumferential direction of the flange portion 51. The divided member 71 has a semi-circular fan shape in a plan view seen from above and has a planar butting surface 72 that abuts against each other. The plurality of divided members 71 are made of steel. Note that it is not limited to the case where the ball seat portion main body 21 is divided into two, and it may be divided into three or more. Even when the ball seat portion main body 21 is divided into three or more, it is preferable to form the divided members into a fan shape in a plan view.

[0019] FIG. 4 is a plan view showing the plate-like member 22 of the ball seat portion 10 according to the present embodiment. As shown in Figure 4, the plate-shaped member 22 is a horizontally extending disc shape. However, it is not limited to this, and the plate-shaped member 22 may be other shapes such as a rectangle instead of a disc. As shown in Figure 1, the plate-shaped member 22 constitutes the lower part of the ball seat 10. When the ball seat 10 is installed on the lower structure L, the plate-shaped member 22 is positioned between the multiple divided members 71 that constitute the ball seat body 21 and the lower structure L. The outer diameter of the plate-shaped member 22 is the same as the outer diameter of the ball seat body 21, that is, the outer diameter of the fixing part 41 of the ball seat body 21. However, it is not limited to this, and the outer diameter of the plate-shaped member 22 does not have to be the same as the outer diameter of the fixing part 41. The plate-shaped member 22 has through-holes 81 that penetrate vertically. The plate-shaped member 22 has multiple through-holes 81. Multiple through-holes 81 are formed in the plate-shaped member 22 at equal intervals in the circumferential direction of the plate-shaped member 22, at positions equidistant from the central axis of the plate-shaped member 22. Specifically, eight through-holes 81 are formed in the plate-shaped member 22, the same number as the outer through-holes 52. However, the number of through-holes 81 is not limited to the same number as the outer through-holes 52, nor is it limited to eight. The distance between the central axis of the plate-shaped member 22 and the central axis of the through-holes 81 is equivalent to the distance between the central axis of the spherical seat body 21 and the central axis of the outer through-holes 52, as shown in Figure 3.

[0020] Figure 5 is a plan view showing the annular member 23 of the spherical seat portion 10 according to this embodiment. Figure 6 is a cross-sectional view taken along line VI-VI of Figure 5, showing the annular member 23 of the spherical seat portion 10 according to this embodiment. As shown in Figure 5, the annular member 23 is circular. However, the shape of the annular member 23 is not limited to this, and it is sufficient if it can integrate multiple divided members 71. As shown in Figure 1, the outer diameter of the annular member 23 is smaller than the outer diameter of the fixing portion 41 of the ball seat body 21 and the outer diameter of the plate-shaped member 22. The axial length of the annular member 23 is shorter than the axial length of the convex portion 42 of the ball seat body 21. As also shown in Figure 6, the radially inner circumference of the annular member 23 is a tapered concave tapered surface portion 91 in which the inner diameter decreases as it is located higher up. As shown in Figure 1, the taper of the concave tapered surface portion 91 is the same as the taper of the convex tapered surface portion 63 of the ball seat body 21. The maximum inner diameter of the concave tapered surface portion 91 is slightly smaller than the maximum outer diameter of the convex tapered surface portion 63.

[0021] The annular member 23 has a counterbore 92 that is recessed downward from the upper surface, and an annular member through-hole 93 that extends downward from approximately the center of the counterbore 92 and penetrates the annular member 23 vertically. Therefore, the upper end of the annular member through-hole 93 opens into the counterbore 92. The counterbore 92 exits through to the radially outer circumferential surface of the annular member 23. Multiple sets of annular member through holes 93 and counterbores 92 with openings at their tops are formed in the annular member 23. These sets of annular member through holes 93 and counterbores 92 with openings at their tops are formed in the annular member 23 at equal intervals in the circumferential direction of the annular member 23, at positions equidistant from the central axis of the annular member 23. Specifically, as shown in Figure 5, four sets of annular member through holes 93 and counterbores 92 with openings at their tops are formed in the annular member 23, the same number as the inner screw holes 53 of the ball seat body 21. The distance between the central axis of the annular member 23 and the central axis of the annular member through holes 93 is the same as the distance between the central axis of the ball seat body 21 and the central axis of the inner screw holes 53.

[0022] As shown in Figure 1, a pair of divided members 71 constituting the ball seat body 21 are joined together with their abutting surfaces 72 to form the ball seat body 21. Then, the annular member 23 is fitted onto the convex tapered surface 63 of the ball seat body 21 at its concave tapered surface 91. The annular member 23 is then rotated appropriately relative to the ball seat body 21 so that the phases of the multiple annular member through holes 93 align with the corresponding inner screw holes 53 of the ball seat body 21. The first fixing device 31, which is a bolt, is then inserted through the annular member through hole 93 of the annular member 23 and screwed into the inner screw hole 53 of the ball seat body 21 that is in phase with the annular member through hole 93 and tightened. This insertion and screwing of the first fixing device 31 is performed for all pairs of annular member through holes 93 and inner screw holes 53 that are in phase. Therefore, the ball seat portion 10 has four first fasteners 31, the same number as the annular member through holes 93 and the same number as the inner screw holes 53. The first fasteners 31 pass through the annular member through holes 93 of the annular member 23 and extend to an intermediate position of the inner screw holes 53 of the ball seat portion body 21, but do not reach the plate-shaped member 22 located below the ball seat portion body 21. Alternatively, the first fasteners 31 may be configured to pass through the annular member 23 and the ball seat portion body 21 and be screwed into the plate-shaped member 22.

[0023] When all the first fasteners 31 are tightened, the annular member 23 comes into contact with the fixing portion 41, aligning the axial heights of the multiple divided members 71. At the same time, the annular member 23 aligns the central axis of the convex tapered surface portion 63, which is divided into multiple divided members 71 of the spherical seat body 21, with its concave tapered surface portion 91, forming a single continuous convex tapered surface portion 63. In this way, the annular member 23 integrates the multiple divided members 71 into a single integrated spherical seat body 21. Once the multiple divided members 71 become a single integrated spherical seat body 21 by the annular member 23, this spherical seat body 21 has a single continuous concave spherical surface portion 61. Therefore, the spherical seat 10 includes an annular member 23 that surrounds and fixes the multiple divided members 71 when installed on the lower structure L. The spherical seat 10 also includes first fasteners 31 that fix the divided members 71 and the annular member 23 when installed. The first fastener 31 is a bolt that penetrates at least the annular member 23.

[0024] The first friction material 24 is in the form of a single sheet and, when laid on the concave spherical portion 61, forms a first sliding surface S1 that has a concave spherical shape, with its upper surface concave downwards in a hemispherical shape following the shape of the concave spherical portion 61. The portion of the first friction material 24 radially outward from the first sliding surface S1 is a laying portion 102 that is laid on the upper end surface of the convex portion 42 of the spherical seat body 21. The laying portion 102 covers the entire upper end surface of the convex portion 42 of the spherical seat body 21.

[0025] The ball seat portion 10 has friction material retaining members 25 that hold down the first friction material 24. The ball seat portion 10 has multiple friction material retaining members 25. The friction material retaining members 25 are plate-shaped and have an arc shape that divides a circle into approximately equal parts. Specifically, as shown in Figure 2, the ball seat portion 10 has four friction material retaining members 25 of the same shape. Therefore, the friction material retaining members 25 are specifically arc shapes that divide a circle into approximately four equal parts. Each friction material retaining member 25 has a retaining member through hole 111 that penetrates vertically. Each friction material retaining member 25 has multiple retaining member through holes 111. Specifically, each friction material retaining member 25 has two retaining member through holes 111. However, the shape and number of friction material retaining members 25 are not limited to these, as long as they can properly hold down the first friction material 24.

[0026] The friction material retaining members 25 are arranged so as to be positioned on a single circle, and each is placed on the laying portion 102 of the first friction material 24. Then, as shown in Figure 1, a retaining member fixing device 33, which is a bolt, is inserted through the retaining member through hole 111 of the friction material retaining member 25, passes through the laying portion 102, and is screwed into the mounting screw hole 62 of the spherical seat body 21 that is in phase with the retaining member through hole 111 and tightened. This insertion and screwing of the retaining member fixing device 33 is performed for all pairs of retaining member through holes 111 and mounting screw holes 62 that are in phase. Thus, the spherical seat 10 has eight retaining member fixing devices 33, the same number as the mounting screw holes 62. When all the retaining member fasteners 33 are tightened, all the friction material retaining members 25 clamp the laying portion 102 of the first friction material 24 between the upper end surface of the convex portion 42 of the ball seat body 21. At this time, as shown in Figure 2, all the friction material retaining members 25 are attached to the ball seat body 21 so as not to straddle any of the multiple divided members 71 that make up the ball seat body 21. Two friction material retaining members 25 are attached to each of the multiple divided members 71.

[0027] As shown in Figure 1, the lower structure L has a hole 121 that is recessed downward from the upper surface. Multiple holes 121 are formed in the lower structure L. Multiple holes 121 are formed in the lower structure L at positions equidistant from a single virtual axis that runs vertically, and at equal intervals in the circumferential direction of this virtual axis. Specifically, the lower structure L has eight holes 121, the same number as the outer through holes 52 and the same number as the plate-like member through holes 81. However, the number of holes 121 is not limited to the same number as the outer through holes 52, nor is it limited to eight. The distance between this virtual axis and the central axis of the hole 121 is the same as the distance between the central axis of the ball seat body 21 and the central axis of the outer through hole 52, and the same as the distance between the central axis of the plate-like member 22 and the central axis of the plate-like member through hole 81.

[0028] The spherical seat body 21, which is formed by integrating multiple divided members 71 by fixing the annular member 23 with the first fastener 31, and the plate-shaped member 22 are fixed to the lower structure L with the second fastener 32, which is a bolt. Specifically, the plate-shaped member 22, which is placed on the lower structure L such that the phases of the multiple plate-shaped member through holes 81 match the corresponding holes 121 of the lower structure L, and the spherical seat body 21, which is placed on the plate-shaped member 22 such that the phases of the multiple outer through holes 52 match the corresponding plate-shaped member through holes 81 of the plate-shaped member 22, are fixed to the lower structure L with the second fastener 32, which is a bolt. The second fastener 32 is inserted through one of the outer through holes 52 of the spherical seat body 21 and a plate-shaped member through hole 81 of the plate-shaped member 22 that is in phase with it, and reaches the hole 121 of the lower structure L that is in phase with them. If the lower structure L is made of reinforced concrete, mortar is filled into the hole 121 before the insertion of the second fastener 32. After the insertion of the second fastener 32, the mortar hardens, fixing the second fastener 32 to the lower structure L. This insertion and fixing of the second fastener 32 is performed for all pairs of outer through holes 52, plate member through holes 81, and hole 121 that are in phase with each other. Therefore, the spherical seat portion 10 has eight second fasteners 32, the same number as the outer through holes 52, the same number as the plate member through holes 81, and the same number as the hole 121. When all the second fasteners 32 are fixed to the lower structure L, the spherical seat portion 10 is fixed to the lower structure L. The outer diameter of the annular member 23 is such that it does not interfere with the second fasteners 32 that fix the spherical seat portion body 21 and the plate member 22 to the lower structure L. The spherical seat portion 10 is equipped with a second fastener 32 that secures the divided member 71 and the plate-shaped member 22 to the lower structure L when installed on the lower structure L. The second fastener 32 is a bolt that penetrates the divided member 71 and the plate-shaped member 22 and reaches a hole 121 provided in the lower structure L. In this way, the spherical seat portion 10 is fixed to the lower structure L when installed. If at least the upper surface of the lower structure L is made of steel, a screw hole may be formed in the upper surface of the lower structure L, and this screw hole may be used as the hole portion 121, into which the second fastener 32 may be screwed.

[0029] The spherical seat portion 10 is provided with a first sliding surface S1. The first sliding surface S1 is provided on the upper surface of the ball seat portion 10. The first sliding surface S1 is a concave spherical shape that is concave downwards. The slider 11 is slidably mounted on the first sliding surface S1 of the ball seat portion 10. The first sliding surface S1 is in sliding contact with the second sliding surface S2 of the slider 11. The first sliding surface S1 is the sliding surface on which the slider 11 slides.

[0030] In this case, it is preferable that the coefficient of friction of the first sliding surface S1 increases continuously towards the outer circumference. In this case, the coefficient of friction of the first sliding surface S1 increases smoothly without any steps from the center to the outer circumference.

[0031] Alternatively, the coefficient of friction of the first sliding surface S1 may increase gradually towards the outer circumference. In this case, for example, multiple annular portions of a predetermined width with a constant coefficient of friction are arranged concentrically and continuously on the first sliding surface S1, and the coefficient of friction of these multiple annular portions increases towards the outer circumference of the first sliding surface S1.

[0032] The slider 11 comprises a steel slider body 131 and a second friction material 132. The second friction material 132 is placed over the slider body 131 so as to cover the upper part of the slider body 131. The slider 11 is slidably installed on the first sliding surface S1 of the ball seat portion 10.

[0033] The slider 11 comprises a second sliding surface S2 and a third sliding surface S3. The second sliding surface S2 is provided at the lower part of the slider body 131. The second sliding surface S2 is a convex spherical surface that is convex downwards. The radius of the sphere formed by the second sliding surface S2 is the same as the radius of the sphere formed by the first sliding surface S1.

[0034] The second sliding surface S2 slides against the first sliding surface S1. The second sliding surface S2 is the sliding surface on which the ball seat portion 10 slides against the first sliding surface S1. The slider 11 is sized to be rotatable relative to the ball seat 10. The slider 11 slides relative to the ball seat portion 10 around the center of the first sliding surface S1 of the ball seat portion 10.

[0035] The third sliding surface S3 is the upper surface of the second friction material 132. The third sliding surface S3 is a convex spherical shape that is convex upwards. The third sliding surface S3 is in sliding contact with the fourth sliding surface S4 of the shoe 12. The third sliding surface S3 is the sliding surface on which the shoe 12 slides. The radius of the spherical surface formed by the third sliding surface S3 is greater than the radius of the spherical surface formed by the second sliding surface S2.

[0036] The shoe 12 is located above the slider 11 and below the superstructure U. The shoe 12 is equipped with a fourth sliding surface S4. The fourth sliding surface S4 is the lower surface of the shoe 12, facing downwards. The fourth sliding surface S4 is a concave spherical shape that is concave upwards. The fourth sliding surface S4 slides against the third sliding surface S3 of the slider 11. The fourth sliding surface S4 is the sliding surface on which the slider 11 slides against the third sliding surface S3. The radius of the sphere formed by the fourth sliding surface S4 is equal to the radius of the sphere formed by the third sliding surface S3. The slider 11 has a vertical length that is longer than the vertical length of the ball seat body 21, the vertical length of the plate-shaped member 22, and the vertical length of the annular member 23.

[0037] The shoe 12 slides relative to the slider 11 while maintaining a constant distance from the center of the third sliding surface S3 of the slider 11. The shoe 12 comprises a base member 141 and a sliding plate 142 fixed to the base member 141 and forming the fourth sliding surface S4 described above. The shoe 12 is fixed to the lower surface of the upper structure U on the base member 141.

[0038] In the sliding bearing 1 having the above-described configuration, for example, when an earthquake occurs at the installation site of the sliding bearing 1, the first sliding surface S1 and the second sliding surface S2 slide against each other, and the third sliding surface S3 and the fourth sliding surface S4 slide against each other.

[0039] (An example of the maintenance procedure for sliding bearing 1) This section describes an example of a maintenance procedure, such as replacing all or part of the sliding bearing 1. During maintenance, if necessary, the worker may install a jack (not shown) between the lower structure L and the upper structure U to jack up the upper structure U relative to the lower structure L. This jacking up causes the sliding bearing 1, specifically the shoe 12 fixed to the upper structure U, to rise relative to the ball seat 10 fixed to the lower structure L and the slider 11 mounted on the ball seat 10, and to move away from the slider 11.

[0040] For example, when replacing the entire slider 11 or the slider body 131 of the slider 11, or when replacing the entire ball seat 10, the ball seat body 21 of the ball seat 10, or the first friction material 24 of the ball seat 10, the worker first releases each of the second fasteners 32 from the hole 121 of the lower structure L and pulls them out from the plate member through hole 81 of the plate member 22 and the outer through hole 52 of the ball seat body 21. By removing all of the second fasteners 32 in this way, the fixing of the plate member 22 and the ball seat body 21 of the ball seat 10 to the lower structure L is released, and the connection between the plate member 22 and the ball seat body 21 is also released.

[0041] Next, the worker moves the plate-shaped member 22 almost horizontally to the side and pulls it out from between the ball seat body 21 and the lower structure L, and then pulls it out from between the shoe 12 and the lower structure L. As a result, the ball seat body 21 and the annular member 23, first friction material 24, friction material retaining member 25, first fixing device 31, and retaining member fixing device 33, all of which are fixed to the ball seat body 21, move downward by the thickness of the plate-shaped member 22, and the ball seat body 21 comes into contact with the lower structure L. At the same time, the slider 11 placed on the ball seat body 21 also moves downward by the thickness of the plate-shaped member 22.

[0042] Next, the worker unscrews each of the first fasteners 31 from the inner screw holes 53 of the ball seat body 21 and pulls them out through the annular member through-hole 93 of the annular member 23. By removing all of the first fasteners 31 in this way, the annular member 23 is released from its fixation to the ball seat body 21. Alternatively, after removing all of the second fasteners 32 and all of the first fasteners 31, the plate-shaped member 22 may be moved approximately horizontally to the side and pulled out from between the ball seat body 21 and the lower structure L.

[0043] Next, the worker unscrews each of the retaining member fasteners 33 attached to at least one of the pair of divided members 71 constituting the ball seat body 21 from the mounting screw holes 62 of the divided member 71 and pulls them out from the retaining member through holes 111 of the friction material retaining member 25. Once all the retaining member fasteners 33 attached to at least one of the pair of divided members 71 are removed in this way, each of the pair of divided members 71 constituting the ball seat body 21 becomes independently movable approximately horizontally to the side, becomes detachable, and can be pulled out from between the slider 11 and the shoe 12 and the lower structure L. In other words, when the ball seat 10 is attached to and detached from the lower structure L, each of the separated divided members 71 is movable approximately horizontally. The worker lifts the annular member 23 upward and separates it from the convex portion 42. The worker then moves each of the pair of divided members 71 approximately horizontally to the side, for example, in opposite directions, and pulls them out from between the slider 11 and the shoe 12 and the lower structure L. The retaining member fixing device 33 can be removed at any time before each of the multiple divided members 71 is moved approximately horizontally.

[0044] Subsequently, for example, when the lift of the annular member 23 is released, the annular member 23 moves downward and comes into contact with the lower structure L. In this state, the annular member 23 is pulled out from between the shoe 12 and the lower structure L by moving it approximately horizontally to the side. Next, when the lift of the slider 11 is released, the slider 11 moves downward and comes into contact with the lower structure L. In this state, the worker pulls out the slider 11 from between the shoe 12 and the lower structure L by moving it approximately horizontally to the side. Alternatively, the slider 11 may be pulled out from between the shoe 12 and the lower structure L first, and then the annular member 23 may be pulled out from between the shoe 12 and the lower structure L. Or, with the annular member 23 surrounding the slider 11, the annular member 23 and the slider 11 may be pulled out together from between the shoe 12 and the lower structure L.

[0045] Then, after appropriate maintenance is performed, the worker inserts the slider 11 between the shoe 12 and the lower structure L by moving it approximately horizontally to the side. Next, the worker lifts the slider 11 and inserts the annular member 23 between the shoe 12 and the lower structure L by moving it approximately horizontally to the side. At this time, the annular member 23 surrounds the slider 11. Alternatively, the worker inserts the annular member 23 between the shoe 12 and the lower structure L by moving it approximately horizontally to the side. Next, the worker lifts the annular member 23 and inserts the slider 11 between the shoe 12 and the lower structure L by moving it approximately horizontally to the side. At this time, the annular member 23 surrounds the slider 11. Alternatively, the annular member 23 surrounds the slider 11, and the annular member 23 and the slider 11 may be inserted together between the shoe 12 and the lower structure L.

[0046] Next, the worker lifts the slider 11 and the annular member 23, and moves the first friction material 24, the retaining member fixing device 33, and the pair of divided members 71 that make up the ball seat body 21, which is fixed to the convex portion 42 by the retaining member fixing device 33, to the side in a nearly horizontal manner, thereby inserting them between the shoe 12 and the lower structure L and bringing the abutting surfaces 72 into contact with each other. Next, the worker lowers the annular member 23 and fits it onto the convex portion 42 of the ball seat body 21. Next, the worker positions the annular member 23 so that the phases of the multiple annular member through holes 93 align with the corresponding inner screw holes 53 of the ball seat body 21. Then, the worker inserts the first fixing device 31, which is a bolt, through the annular member through hole 93 of the annular member 23 and screws it into the inner screw hole 53 of the ball seat body 21 that is in phase with the annular member through hole 93 and tightens it. The worker inserts and screws the first fastener 31 into all pairs of annular member through holes 93 and inner screw holes 53 that are in phase with each other.

[0047] Next, the worker lowers the slider 11 onto the convex portion 42 of the spherical seat body 21.

[0048] Next, the worker lifts the ball seat body 21, the annular member 23, the first friction material 24, the friction material retaining member 25, the first fixing device 31 and the retaining member fixing device 33, and the slider 11, and moves the plate-shaped member 22 approximately horizontally to the side, thereby inserting it between the ball seat body 21 and the lower structure L. Next, the worker positions the plate-shaped member 22 so that the phases of the multiple plate-shaped member through holes 81 align with the corresponding holes 121 in the lower structure L, and positions the ball seat body 21 so that the phases of the multiple outer through holes 52 align with the corresponding plate-shaped member through holes 81 in the plate-shaped member 22. Then, the worker inserts the second fixing device 32 through one of the outer through holes 52 of the ball seat body 21 and the plate-shaped member through hole 81 of the plate-shaped member 22 that is in phase with it, and brings it to the hole 121 in the lower structure L that has been pre-filled with mortar and is in phase with them. This insertion and reach of the second fixing device 32 is performed for all pairs of the outer through-hole 52, the plate-shaped member through-hole 81, and the hole portion 121, which are in phase with each other.

[0049] Subsequently, the superstructure U is jacked down, lowering the superstructure U and the shoe 12 fixed to the superstructure U. As a result, the shoe 12 comes into contact with the third sliding surface S3 of the slider 11 at the fourth sliding surface S4, and the superstructure U is supported by the lower structure L via the sliding support 1.

[0050] In this embodiment, the spherical seat portion 10 and sliding support 1 require the upper structure U to be jacked up to a height that allows the slider 11, which has the longest vertical length among the spherical seat portion body 21, plate-shaped member 22, annular member 23, and slider 11, to be pulled out from between the shoe 12 and the lower structure L.

[0051] In contrast, if the entire spherical seat body 21 and plate-shaped member 22 were made of a single piece, then, for example, the height to which the spherical seat 10 and the slider 11 could be moved together approximately laterally while the slider 11 was mounted, and pulled out from between the shoe 12 and the lower structure L, would be the required jack-up amount of the upper structure U. Therefore, the required jack-up amount of the upper structure U would be clearly higher than that of the spherical seat 10 and sliding support 1 according to this embodiment.

[0052] Therefore, the sliding bearing 1 can keep the amount of jacking up the superstructure U required during maintenance low. For this reason, it is preferable to use the sliding bearing 1 for bridges where the substructure L is a bridge pier (substructure) and the superstructure U is a bridge girder (superstructure). In other words, by using the sliding bearing 1 for bridges, the amount of height increase of the superstructure U required during maintenance can be reduced, thereby suppressing the step difference that occurs in the superstructure U, and making it possible to complete maintenance without traffic restrictions on the superstructure U.

[0053] The spherical seat portion 10 according to the embodiment described above includes a plurality of divisible dividing members 71, and each of the separated dividing members 71 is movable in a substantially horizontal direction when attached or detached. Therefore, even if the amount of jacking up the upper structure U is kept low during maintenance, the spherical seat portion 10 can be pulled out from between the upper structure U and the lower structure L by moving each of the separated dividing members 71 in a substantially horizontal direction. Furthermore, by pulling out the dividing members 71 from between the upper structure U and the lower structure L, the slider can be removed from between the upper structure U and the lower structure L. Thus, the spherical seat portion 10 makes it possible to keep the amount of jacking up the upper structure U required during maintenance low. In addition, because the spherical seat portion 10 makes it possible to reduce the amount of jacking up the upper structure U during maintenance, the sliding bearing 1 on which the spherical seat portion 10 is provided can be made larger. Because the spherical seat portion 10 makes it possible to make a sliding bearing 1 with a sliding amount and damping amount that can withstand large earthquakes.

[0054] Furthermore, the spherical seat portion 10 according to this embodiment includes a plate-shaped member 22 that is positioned between the multiple divided members 71 and the lower structure L during installation. Therefore, the spherical seat portion 10 can be pulled out from between the upper structure U and the lower structure L by moving the plate-shaped member 22 substantially horizontally before the multiple divided members 71, and then each of the separated multiple divided members 71 can be moved substantially horizontally and pulled out from between the upper structure U and the lower structure L. Thus, the spherical seat portion 10 can keep the height of the multiple divided members 71 lower by the height of the plate-shaped member 22, thereby further reducing the amount of jacking up the upper structure U required during maintenance. In addition, the height to which the multiple divided members 71 are lowered can be adjusted by adjusting the thickness of the plate-shaped member 22. Note that the spherical seat portion 10 does not necessarily have to include a plate-shaped member 22 that is positioned between the multiple divided members 71 and the lower structure L during installation.

[0055] Furthermore, the spherical seat portion 10 according to this embodiment includes an annular member 23 that surrounds and fixes the multiple divided members 71 during installation. Therefore, the spherical seat portion 10 can hold the multiple divisible divided members 71 together by the annular member 23 so that they do not separate during installation, thereby suppressing rattling in the installed state. In addition, since the annular member 23 surrounds and fixes the multiple divided members 71, the positioning of the multiple divided members 71 can be easily performed. Note that the spherical seat portion 10 does not necessarily have to include an annular member 23 that surrounds and fixes the multiple divided members 71 during installation.

[0056] Furthermore, the spherical seat portion 10 according to this embodiment is equipped with a first fixing device 31 that secures the divided member 71 and the annular member 23 when installed. Therefore, when the spherical seat portion 10 is installed, the multiple divisible divided members 71 can be securely held together by the annular member 23 and the first fixing device 31, and rattling in the installed state can be reliably suppressed. Note that the spherical seat portion 10 does not necessarily have to be equipped with a first fixing device 31 that secures the divided member 71 and the annular member 23 when installed.

[0057] Furthermore, in the spherical seat portion 10 according to this embodiment, since the first fastener 31 is a bolt that penetrates at least the annular member 23, the divided member 71 and the annular member 23 can be easily fixed by the first fastener 31 during installation. Note that the first fastener 31 does not necessarily have to be a bolt that penetrates at least the annular member 23.

[0058] Furthermore, the spherical seat portion 10 according to this embodiment is equipped with a second fixing device 32 for fixing the divided member 71 and the plate-shaped member 22 to the lower structure L during installation. Therefore, during installation, the spherical seat portion 10 can be integrated with the lower structure L by the second fixing device 32 so that the divided member 71 and the plate-shaped member 22 do not move. However, it is not necessary to provide the second fixing device 32 for fixing the divided member 71 and the plate-shaped member 22 to the lower structure L during installation.

[0059] Furthermore, in the embodiment of the spherical seat portion 10, since the second fixing device 32 is a bolt that penetrates the divided member 71 and the plate-shaped member 22 and reaches the hole 121 provided in the lower structure L, it is easy to integrate the divided member 71 and the plate-shaped member 22 with the lower structure L using the second fixing device 32 to prevent movement during installation. Note that the second fixing device 32 does not necessarily have to be a bolt that penetrates the divided member 71 and the plate-shaped member 22 and reaches the hole 121 provided in the lower structure L.

[0060] Furthermore, in the embodiment, the friction coefficient of the first sliding surface S1 of the spherical seat portion 10 increases continuously toward the outer circumference, thus enabling the construction of a sliding bearing with a sliding amount and damping amount that can withstand large-scale earthquakes. In addition, the slider 11 can be smoothly decelerated such that the deceleration gradually increases toward the outer circumference of the first sliding surface S1. Note that the friction coefficient of the first sliding surface S1 of the spherical seat portion 10 does not necessarily have to increase continuously toward the outer circumference.

[0061] Furthermore, in the embodiment, the friction coefficient of the first sliding surface S1 of the spherical seat portion 10 increases gradually towards the outer circumference, thus enabling the construction of a sliding bearing with a sliding amount and damping amount that can withstand large-scale earthquakes. In addition, the slider 11 can be decelerated relatively smoothly so that the deceleration gradually increases towards the outer circumference of the first sliding surface S1. Note that the friction coefficient of the first sliding surface S1 of the spherical seat portion 10 does not necessarily have to increase gradually towards the outer circumference.

[0062] Since the sliding bearing 1 according to this embodiment includes the spherical seat portion 10 described above, the amount of jacking up the superstructure U required during maintenance can be kept low. Furthermore, since the sliding bearing 1 is a bridge sliding bearing 1 positioned between the substructure L, which is the substructure, and the superstructure U, which is the superstructure, by providing the spherical seat portion 10 described above, it is possible to suppress the step difference that occurs in the superstructure U when the superstructure U is jacked up, and maintenance can be completed without traffic restrictions on the superstructure U. Specifically, the amount of jacking up the superstructure U that can be done without traffic restrictions when replacing bridge bearings is 3 mm to 4 mm, but with conventional bridge bearings, the amount of jacking up the superstructure U required when replacing them was greater than this. Therefore, conventional bridge bearing replacement required traffic restrictions in order to secure the amount of jacking up the superstructure U. In contrast, the spherical seat portion 10 according to this embodiment can reduce the amount of jacking up the superstructure U required when replacing the sliding bearing 1 equipped with it, as described above. Because the amount of jacking up the superstructure U can be reduced in this way, the sliding bearing 1 can be replaced without traffic restrictions. Furthermore, since the amount of jacking up of the superstructure U can be reduced, it is possible to enlarge the sliding bearing 1. Because it is possible to enlarge the sliding bearing 1, it is possible to create a sliding bearing 1 with a sliding amount and damping amount that can withstand large earthquakes.

[0063] In addition, the following modifications are possible in the spherical seat portion 10 according to this embodiment. The outer diameter of the plate-shaped member 22 may be made larger than the outer diameter of the ball seat body 21, and an outer through-hole for the plate-shaped member may be provided in the portion of the plate-shaped member 22 that extends radially outward from the ball seat body 21, passing through the plate-shaped member 22 axially. In this case, a hole is formed in the lower structure L to match the position of this outer through-hole for the plate-shaped member, and the plate-shaped member 22 is fixed to the lower structure L with a fastener consisting of a bolt that is inserted through this outer through-hole for the plate-shaped member and fixed to this hole. In this case, a screw hole is formed instead of the plate-shaped member through-hole 81 described above, and the ball seat body 21 is fixed to the plate-shaped member 22 with a fastener consisting of a bolt that is inserted through the outer through-hole 52 of the ball seat body 21 and screwed into this screw hole. That is, as in the ball seat 10 according to the embodiment, the ball seat body 21 may not be directly fixed to the lower structure L, but only to the plate-shaped member 22, or only the plate-shaped member 22 may be directly fixed to the lower structure L.

[0064] In this case, if a through-hole is provided in the portion of the plate-shaped member 22 that extends radially outward from the spherical seat body 21, and only the plate-shaped member 22 is directly fixed to the lower structure L, the first fixing device 31 may be configured to pass through the annular member 23 and the spherical seat body 21 and be screwed into the plate-shaped member 22, thereby eliminating the configuration for directly fixing the spherical seat body 21 only to the plate-shaped member 22.

[0065] Alternatively, a plate-shaped rubber cover may be provided around the entire perimeter of the shoe 12, fixed to the side of the shoe 12 and extending down to the lower structure L. This allows the entire sliding bearing 1 to be covered by the cover, thereby suppressing the ingress of foreign matter and rainwater into the sliding bearing 1.

[0066] (Note) In the above embodiment, the spherical seat and the sliding bearing are grasped, for example, as follows.

[0067] (1) A spherical seat according to one aspect of this disclosure is: A sliding bearing disposed between an upper structure and a lower structure facing the upper structure, comprising a spherical seat portion fixed to the lower structure during installation, and a slider slidably provided on the sliding surface of the spherical seat portion, It has multiple divisible dividing members, During attachment and detachment, each of the separated divided members is movable in a substantially horizontal direction.

[0068] Thus, the spherical seat section is equipped with multiple divisible segmented members, and each of the separated segmented members can move substantially horizontally during attachment and detachment. Therefore, even if the amount of jacking up the superstructure is kept low during maintenance, the spherical seat section can be pulled out from between the superstructure and the lower structure by moving each of the separated segmented members substantially horizontally. Furthermore, by pulling out the segmented members from between the superstructure and the lower structure, the slider can be removed individually from between the superstructure and the lower structure. Thus, the spherical seat section allows for a low amount of jacking up the superstructure required during maintenance. In addition, because the amount of jacking up the superstructure during maintenance can be reduced, the sliding bearing on which the spherical seat section is provided can be made larger. Because the sliding bearing can be made larger, it is possible to construct a sliding bearing with a sliding amount and damping amount that can withstand large earthquakes.

[0069] (2) In the spherical seat part relating to (1) above, The configuration may also include a plate-like member that is positioned between a plurality of the divided members and the lower structure during installation.

[0070] With this configuration, the spherical seat can be moved approximately horizontally before the multiple segmented members and pulled out from between the upper and lower structures. Subsequently, each of the separated segmented members can be moved approximately horizontally and pulled out from between the upper and lower structures. Therefore, the spherical seat can keep the height of the multiple segmented members lower by the height of the plate-like member, thus further reducing the amount of jacking up the upper structure required during maintenance. In addition, the height to which the multiple segmented members are lowered can be adjusted by adjusting the thickness of the plate-like member.

[0071] (3) In the spherical seat portion relating to (1) or (2) above, The configuration may also include an annular member that surrounds and secures multiple of the aforementioned segmented members during installation.

[0072] With this configuration, the spherical base can hold multiple divisible members together with the annular member, preventing them from separating during installation and thus suppressing rattling in the installed state. Furthermore, since the annular member surrounds and fixes the multiple divisible members, the positioning of the multiple divisible members can be easily performed.

[0073] (4) In the spherical seat section relating to (3) above, The configuration may also include a first fastener for fixing the divided member and the annular member during installation.

[0074] With this configuration, the spherical base can securely hold together multiple divisible members by the annular member and the first fixing device during installation, thereby reliably suppressing rattling in the installed state.

[0075] (5) In the spherical seat section relating to (4) above, The first fixing device is, The configuration may also include a bolt that penetrates at least the annular member.

[0076] With this configuration, the spherical base can be easily secured to the divided member and the annular member by the first fixing device during installation.

[0077] (6) In the spherical seat section relating to (2) above, The configuration may also include a second fastener for fixing the divided member and the plate-shaped member to the lower structure during installation.

[0078] With this configuration, the spherical base can be integrated with the lower structure by the second fixing device during installation, preventing the divided member and the plate-like member from moving.

[0079] (7) In the spherical seat section relating to (6) above, The second fixing device is, The bolt may be configured to penetrate the divided member and the plate-like member and reach a hole provided in the lower structure.

[0080] With this configuration, the spherical base can be easily integrated with the lower structure using the second fixing device to prevent movement of the divided member and the plate-like member during installation.

[0081] (8) In the spherical seat portion relating to any one of (1) to (7) above, The friction coefficient of the sliding surface may be configured to increase continuously towards the outer circumference.

[0082] With this configuration, the spherical bearing section can be made into a sliding bearing with a sliding amount and damping amount that can withstand large-scale earthquakes. In addition, the slider can be smoothly decelerated so that the deceleration gradually increases as it approaches the outer circumference of the sliding surface.

[0083] (9) In the spherical seat portion relating to any one of (1) to (7) above, The friction coefficient of the sliding surface may be configured to increase gradually towards the outer circumference.

[0084] With this configuration, the spherical bearing section can be made into a sliding bearing with a sliding amount and damping amount that can withstand large-scale earthquakes. In addition, the slider can be decelerated relatively smoothly so that the deceleration gradually increases as it approaches the outer circumference of the sliding surface.

[0085] (10) A sliding bearing relating to one aspect of this disclosure is A sliding support for a bridge, which is positioned between the superstructure and the substructure facing the superstructure, A spherical seat portion according to any one of (1) to (9), wherein the spherical seat portion is fixed to the substructure as the substructure, The system comprises a slider slidably mounted on the sliding surface of the spherical seat portion.

[0086] Since this sliding bearing is equipped with a ball seat as described in any one of (1) to (9), the amount of jacking up of the superstructure required during maintenance can be kept low. Furthermore, since this sliding bearing is a bridge sliding bearing positioned between the substructure (the substructure) and the superstructure (the superstructure), by incorporating the aforementioned spherical seat portion, it is possible to suppress the step difference that occurs in the superstructure when the superstructure is jacked up, making it possible to complete maintenance without traffic restrictions or other measures on the superstructure. Furthermore, because this sliding bearing reduces the amount of jacking required for the superstructure, it is possible to increase the size of the sliding bearing. Since it is possible to increase the size of the sliding bearing, it is possible to create a sliding bearing with sufficient sliding and damping capacity to withstand large-scale earthquakes. [Explanation of symbols]

[0087] 1. Sliding bearing 10 Ball seat part 11 Slider 12 Shoes 21. Sphere seat main body 22 Plate-shaped member 23 Annular member 24 1st friction material 25 Friction material retaining member 31 First fixture 32 Second fixture 33. Fixing device for retaining member 41 Fixed part 42 Convex part 51 Flange section 52 Outer through hole 53 Internal screw holes 61 Concave spherical part 62 mounting screw holes 63 Convex tapered surface 71 Divided members 72 Butt joint 81 Through hole in plate-shaped member 91 Concave tapered surface 92 Seat Gri 93 Through hole in annular member 102 Laying section 111 Through hole of retaining member 121 Hole 131 Slider body 132 2nd friction material 141 Base member 142 Sliding plate L Substructure S1 1st sliding surface (sliding surface) S2 2nd sliding surface S3 3rd sliding surface S4 4th sliding surface U superstructure

Claims

1. A sliding bearing disposed between an upper structure and a lower structure facing the upper structure, comprising a spherical seat portion fixed to the lower structure during installation, and a slider slidably provided on the sliding surface of the spherical seat portion, It has multiple divisible dividing members, A spherical seat in which each of the multiple separated divided members is movable in a substantially horizontal direction when attached or detached.

2. The spherical seat portion according to claim 1, further comprising a plate-shaped member positioned between a plurality of the divided members and the lower structure during installation.

3. The spherical seat portion according to claim 1, further comprising an annular member for surrounding and fixing a plurality of the aforementioned divided members during installation.

4. The spherical seat portion according to claim 3, further comprising a first fixing device for fixing the divided member and the annular member when installed.

5. The first fixing device is, The ball seat portion according to claim 4, wherein at least one bolt penetrates the annular member.

6. The spherical seat portion according to claim 2, further comprising a second fastener for fixing the divided member and the plate-shaped member to the lower structure during installation.

7. The second fixing device is, The ball seat portion according to claim 6, wherein the bolt penetrates the divided member and the plate-shaped member and reaches the hole provided in the lower structure.

8. The spherical seat portion according to claim 1, wherein the coefficient of friction of the sliding surface increases continuously towards the outer circumference.

9. The spherical seat portion according to claim 1, wherein the coefficient of friction of the sliding surface increases in stages towards the outer circumference.

10. A sliding support for a bridge, which is positioned between the superstructure and the substructure facing the superstructure, A spherical seat according to any one of claims 1 to 9, wherein the spherical seat is fixed to the substructure as the substructure, A sliding bearing comprising a slider slidably provided on the sliding surface of the spherical seat portion.

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