Sliding bearing

Abstract

To provide a sliding bearing that can prevent foreign matter from entering the interior. [Solution] A sliding support 1 is disposed between an upper structure U and a lower structure L, comprising an upper shoe 12 fixed to the upper structure U, a lower shoe 11 fixed to the lower structure L, a support 13 disposed between the upper shoe 12 and the lower shoe 11 and movable relative to both the upper shoe 12 and the lower shoe 11 in a substantially horizontal direction, and a cover 14 surrounding the space A between the upper shoe 12 and the lower shoe 11, wherein the cover 14 comprises an upper cover 61 fixed to the upper shoe 12 and a lower cover 62 fixed to the lower shoe 11, and at least one of the upper cover 61 and the lower cover 62 is formed of an elastic material, and when the upper cover 61 and the lower cover 62 are in close contact, at least one of the upper cover 61 and the lower cover 62 that is formed of an elastic material undergoes elastic deformation.

Description

Technical Field

[0001] This disclosure relates to a sliding bearing.

Background Art

[0002] In Patent Document 1, in a sliding seismic isolation device including an upper plate, a lower plate, and a sliding body that slides between the upper plate and the lower plate, an upper dust cover is attached to the periphery of the lower surface of the upper plate, and a lower dust cover is attached to the periphery of the upper surface of the lower plate to prevent external dust, dirt, garbage, etc. from entering the internal space between the lower surface of the upper plate and the upper surface of the lower plate.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] There is room for improvement in the technology disclosed in Patent Document 1.

[0005] An object of this disclosure is to provide a sliding bearing capable of suppressing the entry of foreign matter into the interior.

Means for Solving the Problems

[0006] <1>The sliding bearing according to Aspect 1 of this disclosure is a sliding bearing disposed between an upper structure and a lower structure facing the upper structure, an upper plate fixed to the upper structure, a lower plate fixed to the lower structure, a support disposed between the upper plate and the lower plate and relatively movable in a substantially horizontal direction with respect to both the upper plate and the lower plate, a cover surrounding the space between the upper plate and the lower plate, and includes The aforementioned cover is An upper cover fixed to the upper shoe, A lower cover fixed to the lower shoe, Equipped with, At least one of the upper cover and the lower cover is formed of an elastic material. When the upper cover and the lower cover are in close contact, at least one of the upper cover and the lower cover, which is made of an elastic material, undergoes elastic deformation. [Effects of the Invention]

[0007] According to this disclosure, it is possible to provide a sliding bearing that can suppress the entry of foreign matter into the interior. [Brief explanation of the drawing]

[0008] [Figure 1] This is a cross-sectional view showing the overall configuration of a sliding bearing according to the first embodiment, where the sliding bearing is installed between the superstructure and the substructure, in a first state where no seismic load is applied, and in a neutral position where the horizontal relative positions of the lower shoe and the upper shoe are aligned. [Figure 2] This is a cross-sectional view showing the main part of a sliding bearing according to the first embodiment, showing the sliding bearing in a first state after it has been installed between the superstructure and the substructure, where no seismic load is applied, and in a neutral position where the horizontal relative positions of the lower shoe and the upper shoe are aligned. [Figure 3] This is a cross-sectional view showing the main part of a sliding bearing according to the first embodiment, in a second state where the sliding bearing is installed between the superstructure and the substructure and subjected to an earthquake load, and in a state where the horizontal relative positions of the lower shoe and the upper shoe are shifted. [Figure 4] This is a cross-sectional view showing the main part of a sliding bearing according to the first embodiment, in a second state where the sliding bearing is installed between the superstructure and the substructure, and is subjected to an earthquake load, and in a state where the horizontal relative positions of the lower shoe and the upper shoe are further shifted. [Figure 5]This is a cross-sectional view showing the overall configuration of a sliding bearing according to the second embodiment, showing the sliding bearing in a first state after it has been installed between the superstructure and the substructure, where no seismic load is applied, and in a neutral position where the horizontal relative positions of the spherical seat and the shoe are aligned. [Figure 6] This is a cross-sectional view showing the overall configuration of a sliding bearing according to the second embodiment, where the sliding bearing is installed between the superstructure and the substructure, is in a second state where an earthquake load is applied, and the relative horizontal position of the spherical seat and the shoe is shifted. [Modes for carrying out the invention]

[0009] [First Embodiment] The sliding support 1 according to the first embodiment of this disclosure will be described below with reference to Figures 1 to 4. Figure 1 is a cross-sectional view showing the overall configuration of the sliding bearing 1 according to the first embodiment, and shows the sliding bearing 1 after it has been installed between the superstructure U and the lower structure L, in a first state where no seismic load is applied, and the lower shoe 11 and the upper shoe 12 are in a neutral position with their horizontal positions aligned.

[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, and receives a vertical load F. The upper structure U and the lower structure L are positioned vertically opposite each other, with their horizontal positions overlapping. The sliding bearing 1 prevents the shaking from the lower structure L from being transmitted to the upper structure U when an earthquake occurs at the location where the upper structure U is installed.

[0011] The sliding bearing 1 shown in Figure 1 is a double pendulum type spherical sliding bearing and comprises a lower shoe 11, an upper shoe 12, a support 13, and a cover 14.

[0012] The lower shoe 11 is fixed to the lower structure L. The lower stack 11 has a lower base plate 21, a lower concave plate 22, a lower sliding plate 23, and a lower stopper ring 24. The lower base plate 21 is flat and is fixed to the upper surface of the lower structure L. The lower concave plate 22 is fixed to the upper surface of the lower base plate 21. Note that the lower concave plate 22 may be directly fixed to the upper surface of the lower structure L without providing the lower base plate 21. On the lower concave plate 22, a concave spherical surface portion 31 that is recessed downward is formed on the upper surface at approximately the horizontal center.

[0013] The lower sliding plate 23 is fixed to the upper surface of the lower concave plate 22. The lower sliding plate 23 has a concave spherical first sliding surface S1 that is recessed downward, similar to the concave spherical surface portion 31 of the lower concave plate 22. On the lower sliding plate 23, an annular protruding portion 35 that protrudes upward from the first sliding surface S1 is formed on the outside of the entire circumference in the horizontal direction of the first sliding surface S1. However, it is not limited to this, and the annular protruding portion 35 may not be provided. The lower stopper ring 24 is annular and is fixed to the upper surface of the annular protruding portion 35 of the lower sliding plate 23. The upper surface of the lower stopper ring 24 is planar and extends substantially horizontally. The outer peripheral surface on the horizontal outer side of the lower stopper ring 24 is substantially flush with the outer peripheral surface on the horizontal outer side of the lower sliding plate 23 over the entire circumference. However, it is not limited to this, and the lower stopper ring 24 may not be provided. Also, these outer peripheral surfaces do not have to be substantially flush. The entire lower stopper ring 24 is disposed on the horizontal outer side of the first sliding surface S1 of the lower sliding plate 23.

[0014] The support 13 is slidably installed on the first sliding surface S1 of the lower stack 11. The support 13 comprises a second sliding surface S2 and a third sliding surface S3. The second sliding surface S2 is the lower surface of the support 13 and is slidably mounted on the first sliding surface S1 of the lower shoe 11. The second sliding surface S2 is a convex spherical shape that is convex downwards. The radius of the spherical surface formed by the second sliding surface S2 is equal to the radius of the spherical surface formed by the first sliding surface S1. The third sliding surface S3 is the upper surface of the support 13. The third sliding surface S3 is a convex spherical shape that is convex upwards.

[0015] The upper shoe 12 is fixed to the superstructure U. The upper shoe 12 includes an upper base plate 41, an upper concave plate 42, an upper sliding plate 43, and an upper stopper ring 44. The upper base plate 41 is flat and is fixed to the lower surface of the superstructure U. The upper concave plate 42 is fixed to the lower surface of the upper base plate 41. Alternatively, the upper concave plate 42 may be directly fixed to the lower surface of the superstructure U without providing the upper base plate 41. The upper concave plate 42 has a concave spherical portion 51 formed on its lower surface that is recessed upwards towards the approximate center in the horizontal direction.

[0016] The upper sliding plate 43 is fixed to the lower surface of the upper concave plate 42. The upper sliding plate 43 has a concave spherical fourth sliding surface S4 that is concave upward, similar to the concave spherical portion 51 of the upper concave plate 42. The upper sliding plate 43 has an annular projection 55 formed on the outer side of the entire horizontal circumference of the fourth sliding surface S4, which protrudes downward from the fourth sliding surface S4. However, this is not limited to the annular projection 55, and it may be omitted. The upper stopper ring 44 is annular in shape and is fixed to the lower surface of the annular projection 55 of the upper sliding plate 43. The upper stopper ring 44 has a flat surface that extends approximately horizontally on its lower surface. The upper stopper ring 44 has an outer peripheral surface on its horizontally outer side that is substantially flush with the outer peripheral surface on its horizontally outer side over its entire circumference. However, this is not the only option, and the upper stopper ring 44 may be omitted. Furthermore, these outer surfaces do not necessarily have to be substantially flush. The upper stopper ring 44 is positioned horizontally outward from the fourth sliding surface S4 of the upper sliding plate 43. The upper shoe 12 is slidably mounted on the third sliding surface S3 of the support 13 at the fourth sliding surface S4. The radius of the spherical surface formed by the fourth sliding surface S4 is equal to the radius of the spherical surface formed by the third sliding surface S3. The support 13 is positioned between the upper shoe 12 and the lower shoe 11, and is movable relative to both the upper shoe 12 and the lower shoe 11 in a substantially horizontal direction. The upper shoe 12 and the lower shoe 11 move relative to each other laterally via the support 13, and in the process, they also move relative to each other vertically. The upper shoe 12 and the lower shoe 11 have a greater vertical gap as the lateral displacement increases.

[0017] The lower stopper ring 24 and the upper stopper ring 44 should have the same shape at least on their outer circumferential surfaces in the horizontal direction. The lower stopper ring 24 and the upper stopper ring 44 do not necessarily have to have the same shape on their outer horizontal surfaces, but it is preferable that they have the same shape. The upper sliding plate 43 and the lower sliding plate 23 should preferably have the same shape for at least their outer peripheral surfaces in the horizontal direction. The upper sliding plate 43 and the lower sliding plate 23 do not necessarily have to have the same shape on their outer horizontal surfaces, but it is preferable that they have the same shape.

[0018] The cover 14 is provided to surround the space A between the upper shoe 12 and the lower shoe 11. Figure 2 is a cross-sectional view showing the main part of the sliding bearing 1 according to the first embodiment, and shows the sliding bearing 1 after it has been installed between the superstructure U and the lower structure L, in a first state where no load due to an earthquake is applied, and in a neutral position where the lower shoe 11 and the upper shoe 12 are aligned horizontally.

[0019] As shown in Figure 2, the cover 14 comprises an upper cover 61, a lower cover 62, an upper fastener 63, and a lower fastener 64.

[0020] The upper cover 61 is fixed to the upper shoe 12. In this configuration, the upper cover 61 is provided to cover both the horizontally outer peripheral surface of the upper sliding plate 43 of the upper shoe 12 and the horizontally outer peripheral surface of the upper stopper ring 44, and also to cover the lower surface of the upper stopper ring 44.

[0021] The upper cover 61 has an upper cylindrical portion 71, an upper locking portion 72, and a flat plate portion 73. The upper cylindrical portion 71 is cylindrical and is provided horizontally outward from the outer surface of at least the entire outer surface of the upper stopper ring 44 of the upper shoe 12. In other words, the upper cylindrical portion 71 only needs to be provided so as to cover the outer circumferential surface of the upper stopper ring 44, as long as it can secure enough clearance for the upper fixing device 63 to engage. However, if simply covering the outer circumferential surface of the upper stopper ring 44 is insufficient to secure enough clearance for the upper fixing device 63, it is preferable that the upper cylindrical portion 71 be provided so as to cover the outer circumferential surfaces of both the upper sliding plate 43 and the upper stopper ring 44. The upper locking portion 72 protrudes horizontally outward from the entire circumference of the upper end of the upper cylindrical portion 71. Therefore, the upper locking portion 72 is annular. However, it is not limited to this, and the upper cover 61 only needs to be provided so as to be fixed to the upper shoe 12.

[0022] The flat plate portion 73 is flat and extends horizontally inward from the entire circumference of the lower end of the upper cylindrical portion 71, as well as horizontally outward from the entire circumference of the lower end of the upper cylindrical portion 71. The flat plate portion 73 has an overall annular shape. The length of the flat plate portion 73 extending horizontally inward from the upper cylindrical portion 71 is longer than the length of the flat plate portion 73 extending horizontally outward from the upper cylindrical portion 71. The flat plate portion 73 faces the lower surface of the upper stopper ring 44. The flat plate portion 73 completely covers the lower surface of the upper stopper ring 44 and extends a predetermined length horizontally inward from the upper stopper ring 44. However, the horizontal extension of the flat plate portion 73 from the entire circumference of the lower end of the upper cylindrical portion 71 is not limited to this, as long as it completely covers the lower surface of the upper stopper ring 44.

[0023] The upper cover 61 is, for example, entirely made of an elastic material. The upper cover 61 may be made of a material other than an elastic material. When the upper cover 61 is formed from an elastic material, the elastic material is specifically rubber or resin. When the upper cover 61 is formed from an elastic material, that material may be something other than rubber or resin. When the elastic material forming the upper cover 61 is rubber, synthetic rubber is preferable, and ethylene propylene rubber is particularly desirable because it has excellent weather resistance (low temperature durability, UV resistance) and high flexibility. It can also be a synthetic rubber other than ethylene propylene rubber. In the sliding bearing 1 of the first embodiment, the upper cover 61 is formed of an elastic material.

[0024] The upper cover 61 is fixed to the upper shoe 12 by the upper fixing device 63, such that the upper cylindrical portion 71 covers at least substantially the entire outer surface of the upper stopper ring 44, and the flat plate portion 73 faces the lower surface of the upper stopper ring 44. The upper fixing device 63 is a band-shaped strip, and has clamping portions (not shown) that engage with each other at one end and the other end in the longitudinal direction. The upper fixing device 63 becomes annular by engaging the clamping parts (not shown) provided at one end in the longitudinal direction with the other end in the longitudinal direction. The fastening portion, not shown in the figure, for example, has a threaded portion, and by rotating this threaded portion with a tool, the length of the annular portion of the upper fixing device 63 can be adjusted. The upper fixing device 63 is formed of, for example, a metal material. The upper fixing device 63 may be made of a material other than metal. If the upper fixing device 63 is made of a metal material, it may be made of, for example, stainless steel. The upper fixing device 63 may be made of a metal material other than stainless steel.

[0025] When the upper cover 61 is fixed to the upper sliding plate 43 and the upper stopper ring 44 with the upper fixing device 63, first, the upper cylindrical portion 71 of the upper cover 61 is positioned so that it covers at least substantially the entire outer surface of the upper stopper ring 44, and the flat plate portion 73 faces the lower surface of the upper stopper ring 44. At that time, adhesive is applied between the inner circumferential surface of the upper cylindrical portion 71 and the outer circumferential surface of the upper sliding plate 43 and the outer circumferential surface of the upper stopper ring 44, and adhesive is applied between the upper surface of the flat plate portion 73 and the lower surface of the upper stopper ring 44.

[0026] Next, the upper fixing device 63, which is provided to cover the entire circumference of the portion between the upper locking portion 72 and the flat plate portion 73 on the horizontal outer side of the upper cylindrical portion 71 of the upper cover 61, is tightened with a tightening part (not shown). As a result, the upper fixing device 63 presses the upper cylindrical portion 71 of the upper cover 61 against the outer circumferential surface of the upper sliding plate 43 and the outer circumferential surface of the upper stopper ring 44 via adhesive, thereby fixing it to the outer circumferential surface of the upper sliding plate 43 and the outer circumferential surface of the upper stopper ring 44, and the adhesive fixes the flat portion 73 to the lower surface of the upper stopper ring 44. Therefore, the upper cover 61 is fixed to the upper shoe 12 with an upper fastener 63 which is a band, and adhesive is placed between the upper cover 61 and the upper shoe 12. However, this disclosure is not limited thereto, and the upper cover 61 may be fixed to the upper shoe 12 by means other than a band, and adhesive material does not need to be placed between the upper cover 61 and the upper shoe 12. Furthermore, while adhesive is provided between the upper cylindrical portion 71 and the upper sliding plate 43 and upper stopper ring 44, it does not need to be provided between the flat plate portion 73 and the upper stopper ring 44. Conversely, adhesive material may be placed between the flat plate portion 73 and the upper stopper ring 44, but not between the upper cylindrical portion 71 and the upper sliding plate 43 and the upper stopper ring 44. When the upper cover 61 is fixed to the upper shoe 12, the flat plate portion 73 is in a state where it is spread out approximately horizontally. Furthermore, the upper cover 61, when fixed to the upper shoe 12, does not necessarily need to have its flat plate portion 73 spread out in a nearly horizontal position.

[0027] The lower cover 62 is fixed to the lower shoe 11. In this configuration, the lower cover 62 is provided to cover both the horizontally outer peripheral surface of the lower sliding plate 23 of the lower shoe 11 and the horizontally outer peripheral surface of the lower stopper ring 24, and also to cover the upper surface of the lower stopper ring 24.

[0028] The lower cover 62 has a lower cylindrical portion 81, a lower locking portion 82, and a tubular portion 83. The lower cylindrical portion 81 is cylindrical and is provided horizontally outward from the outer surface of at least the entire outer surface of the lower stopper ring 24 of the lower shoe 11. In other words, the lower cylindrical portion 81 only needs to be provided so as to cover the outer circumferential surface of the lower stopper ring 24, as long as it can secure enough clearance for the lower fixing device 64 to engage. However, if simply covering the outer circumferential surface of the lower stopper ring 24 is insufficient to secure enough clearance for the lower fixing device 64, it is preferable that the lower cylindrical portion 81 be provided so as to cover the outer circumferential surfaces of both the lower sliding plate 23 and the lower stopper ring 24. The lower locking portion 82 protrudes horizontally outward from the entire circumference of the lower end of the lower cylindrical portion 81. Therefore, the lower locking portion 82 is annular. However, it is not limited to this, and the lower cover 62 only needs to be provided so as to be fixed to the lower shoe 11.

[0029] The tubular portion 83 extends horizontally inward from the entire circumference of the upper end of the lower cylindrical portion 81, and also protrudes horizontally outward from the entire circumference of the upper end of the lower cylindrical portion 81. The tubular portion 83 has an overall annular shape. The tubular portion 83 has a lower substrate portion 91 and an upper bulging portion 92. The substrate portion 91 is flat and extends horizontally inward from the entire circumference of the upper end of the lower cylindrical portion 81, and also protrudes horizontally outward from the entire circumference of the upper end of the lower cylindrical portion 81. The substrate portion 91 has a length extending horizontally inward from the lower cylindrical portion 81 that is longer than the length extending horizontally outward from the lower cylindrical portion 81. The substrate portion 91 faces the upper surface of the lower stopper ring 24. The substrate portion 91 completely covers the upper surface of the lower stopper ring 24 and extends a predetermined length horizontally inward from the lower stopper ring 24. Before being assembled as the sliding bearing 1, the bulge portion 92 connects the horizontal outer edge and the horizontal inner edge of the base portion 91, and bulges out above the base portion 91 in a mountain-like shape, with the horizontal width becoming narrower towards the top. After the sliding bearing 1 is installed between the upper structure U and the lower structure L, in a first state where no seismic load is applied, the bulge portion 92 undergoes slight elastic deformation to approach the base portion 91, as shown in Figure 2. The tubular portion 83 has an annular cross-section. However, this is not limited to this, and the cross-section of the tubular portion 83 does not have to be annular; a part of it may be missing, or it may be C-shaped, for example.

[0030] The lower cover 62 is formed to be elastically deformable. The lower cover 62 has a tubular portion 83 formed of an elastic material. The lower cover 62 does not have to be made entirely of an elastic material; it is sufficient if at least a portion of the tubular portion 83 is made of an elastic material. Of the upper cover 61 and the lower cover 62, the lower cover 62, which is made of an elastic material, has a tubular portion 83, while the upper cover 61 has a flat plate portion 73. The lower cover 62 is, for example, entirely made of an elastic material. The elastic material forming the lower cover 62 is specifically rubber or resin. The elastic material forming the lower cover 62 may be something other than rubber or resin. When the elastic material forming the lower cover 62 is rubber, synthetic rubber is preferable, and ethylene propylene rubber is particularly desirable because it has excellent weather resistance (low temperature durability, UV resistance) and high flexibility. It can also be a synthetic rubber other than ethylene propylene rubber.

[0031] The lower cover 62 is fixed to the lower shoe 11 by the lower fixing device 64, such that the lower cylindrical portion 81 covers at least substantially the entire outer surface of the lower stopper ring 24, and the base portion 91 of the tubular portion 83 faces the upper surface of the lower stopper ring 24. The lower fixing device 64 is a band-shaped strip, and has clamping portions (not shown) that engage with each other at one end and the other end in the longitudinal direction. The lower fixing device 64 becomes annular by engaging the clamping portions (not shown) provided at one end in the longitudinal direction with the other end in the longitudinal direction. The clamping portion, not shown in the figure, for example has a screw portion, and by rotating this screw portion with a tool, the length of the annular portion of the lower fixing device 64 can be adjusted. The lower fixing device 64 is formed of, for example, a metal material. The lower fixing device 64 may be made of a material other than metal. If the lower fastener 64 is made of a metal material, it may be made of, for example, stainless steel. The lower fixing device 64 may be made of a metal material other than stainless steel.

[0032] When the lower cover 62 is fixed to the lower sliding plate 23 and the lower stopper ring 24 with the lower fixing device 64, first, the lower cylindrical portion 81 of the lower cover 62 is positioned so that it covers at least substantially the entire outer surface of the lower stopper ring 24, and the base portion 91 of the tubular portion 83 faces the upper surface of the lower stopper ring 24. At that time, adhesive is applied between the inner circumferential surface of the lower cylindrical portion 81 and the outer circumferential surface of the lower sliding plate 23 and the outer circumferential surface of the lower stopper ring 24, and adhesive is applied between the lower surface of the base plate portion 91 and the upper surface of the lower stopper ring 24.

[0033] Next, the lower fixing device 64, which is provided to cover the entire circumference of the portion between the lower locking portion 82 and the tubular portion 83 on the horizontal outer side of the lower cylindrical portion 81 of the lower cover 62, is tightened with a tightening part (not shown). As a result, the lower fixing device 64 presses the lower cylindrical portion 81 of the lower cover 62 against the outer surface of the lower sliding plate 23 and the outer surface of the lower stopper ring 24 via adhesive, thereby fixing it to the outer surface of the lower sliding plate 23 and the outer surface of the lower stopper ring 24, and the adhesive fixes the base portion 91 of the tubular portion 83 to the upper surface of the lower stopper ring 24. Therefore, the lower cover 62 is fixed to the lower shoe 11 with a lower fastener 64 which is a band, and adhesive is placed between the lower cover 62 and the lower shoe 11. However, this disclosure is not limited thereto, and the lower cover 62 may be fixed to the lower shoe 11 by means other than a band, and adhesive material does not need to be placed between the lower cover 62 and the lower shoe 11. Furthermore, while adhesive is provided between the lower cylindrical portion 81 and the lower sliding plate 23 and lower stopper ring 24, it does not need to be provided between the base portion 91 of the tubular portion 83 and the lower stopper ring 24. Conversely, adhesive material may be placed between the substrate portion 91 of the tubular portion 83 and the lower stopper ring 24, but not between the lower cylindrical portion 81 and the lower sliding plate 23 and the lower stopper ring 24. With the lower cover 62 fixed to the lower shoe 11, the base portion 91 of the tubular portion 83 is spread out approximately horizontally. Furthermore, when the lower cover 62 is fixed to the lower shoe 11, the base portion 91 of the tubular portion 83 does not necessarily have to be in a state where it is spread out approximately horizontally.

[0034] In the cover 14, the lower cover 62 is fixed to the lower shoe 11 with a lower fastener 64, and the upper cover 61 is fixed to the upper shoe 12 with an upper fastener 63. The lower surface, which is one of the main surfaces of the flat plate portion 73 of the upper cover 61, is positioned toward the tubular portion 83 of the lower cover 62. The lower surface, which is one of the main surfaces of the flat plate portion 73, is positioned approximately horizontally with respect to both the upper shoe 12 and the lower shoe 11. Furthermore, the lower surface of the flat plate portion 73, which is its primary surface, does not have to be positioned approximately horizontally with respect to both the upper shoe 12 and the lower shoe 11, but may be inclined. With the lower cover 62 fixed to the lower shoe 11 by a lower fastener 64 and the upper cover 61 fixed to the upper shoe 12 by an upper fastener 63, the lower surface, which is one of the main surfaces of the flat plate portion 73 of the upper cover 61, abuts against the tubular portion 83 of the lower cover 62 from above over its entire circumference. As a result, the flat plate portion 73 of the upper cover 61 elastically deforms the tubular portion 83 of the lower cover 62 all around, reducing the height of the bulging portion 92 from the base portion 91. As shown in Figure 2, even when the sliding bearing 1 is installed between the superstructure U and the lower structure L and no seismic load is applied, the flat plate portion 73 of the upper cover 61 elastically deforms the tubular portion 83 of the lower cover 62 over its entire circumference, reducing the height of the bulging portion 92 from the base portion 91. As a result, the flat portion 73 of the upper cover 61 and the tubular portion 83 of the lower cover 62 are in close contact around their entire circumference. In other words, the cover 14 is elastically deformed when the upper cover 61 and the lower cover 62 are in close contact, at least one of the upper cover 61 and the lower cover 62, which is made of an elastic material, is elastically deformed. In the sliding bearing 1 of the first embodiment, the upper cover 61 is also formed of an elastic material, so the upper cover 61 also undergoes some elastic deformation.

[0035] The flat plate portion 73 of the upper cover 61 elastically deforms the tubular portion 83 of the lower cover 62 so that the height of the bulging portion 92 from the base portion 91 is reduced. The flat plate portion 73 of the upper cover 61 elastically deforms the tubular portion 83 of the lower cover 62 around its entire circumference, thereby the cover 14 surrounds the space A between the upper shoe 12 and the lower shoe 11 around its entire circumference when the sliding bearing 1 is in a first state where no vertical load due to an earthquake is applied, both before and after it is installed between the upper structure U and the lower structure L, preventing foreign matter such as dust, dirt, debris, and rainwater from entering the space A between the upper shoe 12 and the lower shoe 11 from the outside.

[0036] Figure 3 is a cross-sectional view showing the main part of the sliding bearing 1 according to the first embodiment, showing the sliding bearing 1 in a second state after it has been installed between the superstructure U and the lower structure L and has been subjected to an earthquake load, and in a state in which the lower shoe 11 and the upper shoe 12 are shifted in horizontal position. In the sliding bearing 1, when the upper structure U and the lower structure L shown in Figure 1 move relative to each other, both the upper shoe 12, which is fixed to the upper structure U, and the lower shoe 11, which is fixed to the lower structure L, move horizontally relative to the support 13 provided between them. At that time, the first sliding surface S1 of the lower shoe 11 and the second sliding surface S2 of the support 13 slide against each other, and the third sliding surface S3 of the support 13 and the fourth sliding surface S4 of the upper shoe 12 slide against each other. When the upper shoe 12 moves horizontally relative to the lower shoe 11, the upper shoe 12 also moves vertically relative to the lower shoe 11. As shown in Figure 3, when the lower shoe 11 and the upper shoe 12 shift their relative positions in the horizontal direction, the upper shoe 12 moves upward relative to the lower shoe 11. In response to this, the tubular portion 83 of the lower cover 62 deforms upward, maintaining a state of close contact with the flat portion 73 of the upper cover 61 around its entire circumference. In other words, even when subjected to an earthquake load, the upper cover 61 and the lower cover 62 of the cover 14 remain in close contact, causing at least one of the upper cover 61 and the lower cover 62, which is made of an elastic material, to undergo elastic deformation. In the sliding bearing 1 of the first embodiment, the upper cover 61 is also formed of an elastic material, so the upper cover 61 also undergoes some elastic deformation. In this way, the flat plate portion 73 of the upper cover 61 elastically deforms the tubular portion 83 of the lower cover 62 around its entire circumference, so that even when the lower shoe 11 and the upper shoe 12 are misaligned in the horizontal direction, the cover 14 surrounds the space A between the upper shoe 12 and the lower shoe 11 around its entire circumference, preventing foreign matter such as dust, dirt, debris, and rainwater from entering the space A between the upper shoe 12 and the lower shoe 11 from the outside. If the relative movement between the lower shoe 11 and the upper shoe 12 is less than or equal to a predetermined distance, the cover 14 maintains a state in which the flat plate portion 73 of the upper cover 61 is in close contact with the tubular portion 83 of the lower cover 62 around its entire circumference, causing the tubular portion 83 to be elastically deformed, and moves relative to it in the horizontal direction. Here, when the upper shoe 12 and the lower shoe 11 move relative to each other in the horizontal direction, they also move relative to each other in the vertical direction, causing the gap between them to widen or narrow. The tubular portion 83 changes its amount of elastic deformation in response to this expansion and contraction of the gap, thereby maintaining a tight seal with the flat plate portion 73. Although the flat plate portion 73 is small, it maintains close contact with the tubular portion 83 by changing its own amount of elastic deformation in response to the expansion and contraction of this gap. As a result, even when the upper shoe 12 is in a state of relative horizontal movement with respect to the lower shoe 11, the cover 14 surrounds the space A between the upper shoe 12 and the lower shoe 11 all around, as long as the amount of relative horizontal movement is less than or equal to a predetermined distance, thereby preventing foreign matter such as dust, dirt, debris, and rainwater from entering the space A between the upper shoe 12 and the lower shoe 11 from the outside. In other words, as long as the relative horizontal movement between the upper shoe 12 and the lower shoe 11 is within a predetermined distance, at least one of the upper cover 61 and the lower cover 62 undergoes elastic deformation, maintaining a tight seal around the entire circumference of both the upper cover 61 and the lower cover 62.

[0037] Here, as shown in Figure 3, even when the upper shoe 12 moves horizontally relative to the lower shoe 11 and the amount of relative movement reaches a predetermined distance, the cover 14 is set so that, up to this predetermined distance, the flat plate portion 73 of the upper cover 61 is in close contact with the tubular portion 83 of the lower cover 62 around its entire circumference, maintaining a state in which the tubular portion 83 is elastically deformed. Here, this predetermined distance is set to the maximum value of the relative horizontal movement of the lower shoe 11 and upper shoe 12, which is expected due to thermal and drying shrinkage of the building, including the superstructure U and the substructure L. Specifically, this predetermined distance is set to, for example, ±25 mm based on the neutral position where the lower shoe 11 and the upper shoe 12 are aligned horizontally. In this case, even if the lower shoe 11 and the upper shoe 12 are misaligned by ±25 mm relative to the neutral position where their horizontal positions are aligned, the cover 14 maintains a state in which the flat plate portion 73 of the upper cover 61 is in close contact with the tubular portion 83 of the lower cover 62 around its entire circumference, causing the tubular portion 83 to be elastically deformed.

[0038] Figure 4 is a cross-sectional view showing the main part of the sliding bearing 1 according to the first embodiment, showing the sliding bearing 1 in a second state after it has been installed between the superstructure U and the lower structure L and has been subjected to an earthquake load, and further showing the state in which the horizontal relative positions of the lower shoe 11 and the upper shoe 12 have been shifted.

[0039] In the sliding bearing 1, for example, when an earthquake occurs at the installation site of the sliding bearing 1, the upper shoe 12 fixed to the superstructure U and the lower shoe 11 fixed to the lower structure L move relative to each other in the horizontal direction via the support 13 provided between them. Depending on the magnitude of the earthquake, as shown in Figure 4, the flat plate portion 73 of the upper cover 61 of the cover 14 shifts horizontally and laterally from the tubular portion 83 of the lower cover 62, except for a small portion, reducing the amount of contact and making it impossible to maintain a tight seal, thus releasing the seal on space A. However, it then returns and rides up onto the tubular portion 83 of the lower cover 62, increasing the amount of contact. Due to the relative back-and-forth movement caused by the earthquake, the flat plate portion 73 of the upper cover 61 repeatedly increases and decreases the amount of contact with the tubular portion 83 of the lower cover 62. In other words, when the relative horizontal movement between the upper shoe 12 and the lower shoe 11 exceeds a predetermined distance, the tight seal between the upper cover 61 and the lower cover 62 over its entire circumference is released. However, when the relative horizontal movement between the upper shoe 12 and the lower shoe 11 returns to this predetermined distance, the upper cover 61 and the lower cover 62 return to a tight seal over their entire circumference.

[0040] Even when the relative horizontal movement of the upper shoe 12 and the lower shoe 11 causes the flat plate portion 73 of the upper cover 61 to ride onto the tubular portion 83 of the lower cover 62, increasing the amount of contact, the tubular portion 83 is formed to be elastically deformable, so it can easily deform and allow the flat plate portion 73 to ride onto the tubular portion 83 smoothly. Furthermore, if the bulging portion 92 of the tubular portion 83 has a mountain-shaped cross-section, the flat plate portion 73 can be made to ride up even more smoothly.

[0041] When the sliding bearing 1 is shipped from the factory, the upper shoe 12, lower shoe 11, and support 13 are placed in the neutral position, the upper cover 61 is attached to the upper shoe 12 with adhesive and upper fastener 63, and the lower cover 62 is attached to the lower shoe 11 with adhesive and lower fastener 64. Then, for example, a wide band made of rubber or the like is wrapped around the entire horizontal outer surface of the cover 14, which is composed of an upper cover 61, a lower cover 62, an upper fastener 63, and a lower fastener 64, and a protective sheet made of, for example, highly foamed polyethylene is wrapped around the entire horizontal outer surface of this wide band. Then, masking tape is applied to the horizontal outer side of this protective sheet, so as to span across the protective sheet and the outer surface of the upper concave plate 42, thereby securing the protective sheet to the outer surface of the upper concave plate 42. With the horizontal outer surface of the cover 14 covered and protected in this manner with a wide band, protective sheet, and masking tape, the sliding bearing 1 is transported to the construction site and installed. The sliding bearing 1 is in the first state during transport. Wide bands, protective sheets, and masking tape will be removed and discarded before completion of construction.

[0042] The sliding bearing 1 according to the first embodiment described above comprises an upper shoe 12 fixed to the upper structure U, a lower shoe 11 fixed to the lower structure L, a support 13 positioned between the upper shoe 12 and the lower shoe 11 and movable relative to both the upper shoe 12 and the lower shoe 11 in a substantially horizontal direction, and a cover 14 surrounding the space A between the upper shoe 12 and the lower shoe 11. The sliding bearing 1 comprises a cover 14 which includes an upper cover 61 fixed to the upper shoe 12 and a lower cover 62 fixed to the lower shoe 11. Furthermore, both the upper cover 61 and the lower cover 62 are made of an elastic material, and when the upper cover 61 and the lower cover 62 are in close contact, the upper cover 61 and the lower cover 62, both made of an elastic material, undergo elastic deformation. Therefore, even if the upper shoe 12 and the lower shoe 11 move relative to each other in the vertical direction due to their relative horizontal movement, the upper cover 61 and the lower cover 62 will elastically deform, maintaining a tight seal between the upper cover 61 and the lower cover 62, thereby preventing foreign matter such as dust, dirt, debris, and rainwater from entering the inside of the sliding bearing 1.

[0043] Here, of the upper cover 61 and the lower cover 62, only the lower cover 62 may be made of an elastic material. In this case, the lower cover 62, which is made of an elastic material, undergoes elastic deformation when the upper cover 61 and the lower cover 62 are in close contact. Therefore, even in this case, if the upper shoe 12 and the lower shoe 11 move relative to each other in the horizontal direction, causing them to move relative to each other in the vertical direction, the lower cover 62 will elastically deform, maintaining the tight seal between the upper cover 61 and the lower cover 62, thereby preventing foreign matter such as dust, dirt, debris, and rainwater from entering the inside of the sliding bearing 1.

[0044] Furthermore, of the upper and lower covers, only the upper cover may be made of an elastic material. In this case, the upper cover, made of an elastic material, undergoes elastic deformation when the upper and lower covers are in close contact. Therefore, in this case as well, even if the upper shoe 12 and the lower shoe 11 move relative to each other in the vertical direction due to their relative horizontal movement, the upper cover will elastically deform, maintaining the tight seal between the upper cover and the lower cover, thereby preventing foreign matter such as dust, dirt, debris, and rainwater from entering the inside of the sliding bearing 1.

[0045] In other words, at least one of the upper cover and the lower cover is made of an elastic material, and when the upper cover and the lower cover are in close contact, at least one of the upper cover and the lower cover made of an elastic material undergoes elastic deformation.

[0046] In the sliding support 1 according to the first embodiment, the lower cover 62, which is made of an elastic material, has a tubular portion 83, and the other upper cover 61 has a flat plate portion 73, with the lower surface, which is one of the main surfaces of the flat plate portion 73, being positioned toward the tubular portion 83. As a result, the flat plate portion 73 of the upper cover 61 and the tubular portion 83 of the lower cover 62 come into close contact, and the tubular portion 83, which is made of an elastic material, undergoes mainly elastic deformation. Therefore, even if the upper shoe 12 and the lower shoe 11 move relative to each other in the vertical direction due to their relative horizontal movement, the tubular portion 83 of the lower cover 62 mainly undergoes elastic deformation, maintaining the tight seal between the upper cover 61 and the lower cover 62, thereby effectively suppressing the entry of foreign matter such as dust, dirt, debris, and rainwater into the interior of the sliding bearing 1.

[0047] Furthermore, the lower cover 62 has a tubular portion 83, and the tubular portion 83 has an annular cross-section. Therefore, the tubular portion 83 has, in the horizontal direction, an outer partition portion facing the outside air opposite to the space A between the lower shoe 11 and the upper shoe 12, and an inner partition portion facing space A. Therefore, even if the horizontally outer partition wall portion of the tubular portion 83 is damaged by ultraviolet rays, wind and rain, the horizontally inner partition wall portion, which is less affected by ultraviolet rays, wind and rain, can suppress the entry of foreign matter into space A.

[0048] In addition, because the upper cover 61 has a flat plate-shaped portion 73, it can adhere closely to the tubular portion 83 of the lower cover 62 over a wider area than the horizontal area of ​​the lower surface of the upper stopper ring 44 of the upper shoe 12 when the upper cover 61 is not provided. Therefore, even if the upper shoe 12 and the lower shoe 11 move relative to each other in the horizontal direction, the flat plate portion 73 elastically deforms the tubular portion 83 of the lower cover 62 over a wide area, maintaining the tight seal between the upper cover 61 and the lower cover 62, and effectively suppressing the entry of foreign matter such as dust, dirt, debris, and rainwater into the inside of the sliding bearing 1.

[0049] Here, the upper cover 61 has a flat plate-shaped portion 73 and the lower cover 62 has a tubular portion 83, which helps to prevent rainwater and other liquids from accumulating on the horizontally outer side of the lower cover 62. Therefore, even if the upper cover 61 and the lower cover 62 move relative to each other horizontally and a gap is created, it is possible to prevent rainwater and the like that accumulated on the horizontally outer side of the lower cover 62 from entering the lower shoe 11. Here, if rainwater or the like that accumulated on the horizontally outer side of the lower cover 62 enters the lower shoe 11, the rainwater or the like may flow into the first sliding surface S1 of the lower shoe 11, which is located below the lower cover 62, potentially degrading the quality of the first sliding surface S1. However, because the lower cover 62 has a tubular portion 83, this degradation of the quality of the first sliding surface S1 can be suppressed.

[0050] Furthermore, of the upper cover 61 and the lower cover 62, one of which is formed of an elastic material does not necessarily have to have a tubular portion 83, and the other does not necessarily have to have a flat plate portion 73. Furthermore, one main surface of the flat plate portion 73 does not necessarily have to be positioned toward the tubular portion 83. Specifically, the lower cover 62 does not necessarily have to have a tubular portion 83 formed of an elastic material. Furthermore, the upper cover 61 does not necessarily have to have a flat plate-shaped portion 73. Furthermore, one main surface of the flat plate portion 73 does not necessarily have to be positioned toward the tubular portion 83.

[0051] For example, the upper cover fixed to the upper shoe 12 may be made of an elastic material and have a tubular portion, and the lower cover fixed to the lower shoe 11 may have a flat plate portion, with the lower surface, which is one of the main surfaces of the flat plate portion, being positioned toward the tubular portion. In this case, the flat portion of the lower cover and the tubular portion of the upper cover come into close contact, causing the tubular portion, which is mainly made of an elastic material, to undergo elastic deformation. Therefore, even if the upper shoe 12 and the lower shoe 11 move relative to each other in the vertical direction due to their relative horizontal movement, the tubular portion of the upper cover mainly undergoes elastic deformation, maintaining the tight seal between the upper and lower covers, and effectively suppressing the entry of foreign matter such as dust, dirt, debris, and rainwater into the interior of the sliding bearing. In this case as well, since the lower cover has a flat plate-like portion, it can adhere closely to the tubular portion of the upper cover over a wider area than the horizontal area of ​​the upper surface of the lower stopper ring 24 of the lower shoe 11 when the lower cover is not provided. Therefore, even if the upper shoe 12 and the lower shoe 11 move relative to each other in the horizontal direction, the flat plate portion elastically deforms the tubular portion of the upper cover over a wide area, maintaining the tight seal between the upper and lower covers, and effectively suppressing the entry of foreign matter such as dust, dirt, debris, and rainwater into the interior of the sliding bearing. However, in this case, rainwater may accumulate on the flat surface on the horizontal outer side of the lower cover, and therefore, if the upper and lower covers move relative to each other horizontally and a gap is created, rainwater accumulated on the horizontal outer side of the lower cover may enter the lower shoe 11. Therefore, it is preferable that the upper cover 61 has a flat plate-shaped portion 73 and the lower cover 62 has a tubular portion 83.

[0052] Furthermore, in the sliding bearing 1 according to the first embodiment, at least one of the upper cover 61 and the lower cover 62 elastically deforms until the relative horizontal movement between the upper shoe 12 and the lower shoe 11 reaches a predetermined distance, maintaining a tight seal around the entire circumference of the upper cover 61 and the lower cover 62. Therefore, until the relative horizontal movement between the upper shoe 12 and the lower shoe 11 reaches a predetermined distance, the entry of foreign matter such as dust, dirt, debris, and rainwater into the interior of the sliding bearing 1 can be effectively suppressed.

[0053] Furthermore, in the sliding bearing 1 according to the first embodiment, when the relative horizontal movement between the upper shoe 12 and the lower shoe 11 exceeds a predetermined distance, the tight seal between the upper cover 61 and the lower cover 62 is released. However, when the relative horizontal movement between the upper shoe 12 and the lower shoe 11 returns to this predetermined distance, the upper cover 61 and the lower cover 62 return to a tight seal around the entire circumference. Therefore, even if the relative horizontal movement between the upper shoe 12 and the lower shoe 11 exceeds a predetermined distance, it returns to the predetermined distance, effectively suppressing the entry of foreign matter such as dust, dirt, debris, and rainwater into the interior of the sliding bearing 1.

[0054] Furthermore, in the sliding bearing 1 according to the first embodiment, at least one of the upper cover 61 and the lower cover 62 is formed of an elastic material such as rubber. Therefore, even if the upper shoe 12 and the lower shoe 11 move relative to each other in the vertical direction due to their relative horizontal movement, at least one of the upper cover 61 and the lower cover 62, which are made of rubber or the like, will elastically deform, maintaining the tight seal between the upper cover 61 and the lower cover 62, and effectively suppressing the entry of foreign matter such as dust, dirt, debris, and rainwater into the interior of the sliding bearing 1.

[0055] Furthermore, the elastic material may be something other than rubber. In other words, as described above, when the upper shoe 12 and the lower shoe 11 move relative to each other in the horizontal direction, they also move relative to each other in the vertical direction, causing the gap between them to widen or narrow. Therefore, the lower cover 62 has a tubular portion 83 that can change the amount of elastic deformation in response to the expansion and contraction of this gap. However, the lower cover only needs to maintain a tight seal with the upper cover by elastically deforming in accordance with the relative vertical movement of the upper shoe 12 and the lower shoe 11. Therefore, for example, by forming the lower cover from a sponge-like material that can conform to deformation, and allowing the lower cover to be elastically deformed by the flat plate portion 73 of the upper cover 61, it is possible to create a shape other than a tube. Alternatively, this configuration may be inverted so that the upper cover is made of a deformation-following sponge-like material, and the lower cover has a flat plate-like portion that elastically deforms the upper cover. Alternatively, the upper and lower covers can be made to have the same shape and be formed from similar sponge-like materials.

[0056] Furthermore, in the sliding bearing 1 according to the first embodiment, the upper cover 61 is fixed to the upper shoe 12 with an upper fixing device 63 which is a band, and the lower cover 62 is fixed to the lower shoe 11 with a lower fixing device 64 which is a band, and adhesive material is placed between the upper cover 61 and the upper shoe 12, and between the lower cover 62 and the lower shoe 11. As a result, the upper cover 61 is fixed to the upper shoe 12 by an upper fastener 63 which is a band, and the lower cover 62 is fixed to the lower shoe 11 by a lower fastener 64 which is a band. Furthermore, the upper cover 61 and the upper shoe 12 are also fixed together by adhesive between them, and the lower cover 62 and the lower shoe 11 are also fixed together by adhesive between them. Therefore, the upper cover 61 can be easily and securely fixed to the upper shoe 12, and the lower cover 62 can be easily and securely fixed to the lower shoe 11.

[0057] Furthermore, the upper cover 61 does not necessarily have to be secured to the upper shoe 12 by the upper fastener 63, which is a band. Furthermore, the lower cover 62 does not necessarily have to be fixed to the lower shoe 11 with the lower fastener 64, which is a band. Furthermore, adhesive material does not need to be placed between the upper cover 61 and the upper shoe 12. Furthermore, adhesive does not need to be placed between the lower cover 62 and the lower shoe 11.

[0058] Furthermore, in the sliding bearing 1 according to the first embodiment, one main surface of the flat plate portion 73 that is positioned toward the tubular portion 83 is positioned substantially horizontally with respect to both the upper shoe 12 and the lower shoe 11. Therefore, even if the upper shoe 12 and the lower shoe 11 move relative to each other in the vertical direction due to their relative horizontal movement, the main surface of the flat plate portion 73 can be reliably brought into close contact with the tubular portion 83. Furthermore, the main surface of the flat plate portion 73 that is positioned toward the tubular portion 83 does not necessarily have to be positioned substantially horizontally with respect to both the upper shoe 12 and the lower shoe 11. For example, one main surface of the flat plate portion 73 that is positioned toward the tubular portion 83 may be positioned at an angle to both the upper shoe 12 and the lower shoe 11.

[0059] In the first embodiment described above, a spherical sliding bearing 1 was described as an example, in which the first sliding surface S1 of the lower shoe 11 is a concave spherical surface and the fourth sliding surface S4 of the upper shoe 12 is a concave spherical surface; however, the present disclosure is not limited thereto. For example, this can also be applied to a planar sliding bearing in which the first sliding surface S1 of the lower shoe 11 is planar and the fourth sliding surface S4 of the upper shoe 12 is planar.

[0060] [Second Embodiment] Next, with reference to Figures 5 and 6, the sliding bearing 1a according to the second embodiment of this disclosure will be described. Figure 5 is a cross-sectional view showing the overall configuration of the sliding bearing 1a according to the second embodiment, and shows the state in which the sliding bearing 1a is installed between the superstructure Ua and the lower structure La, and is in a first state in which no seismic load is applied, and the spherical seat portion 11a and the shoe 12a are in a neutral position with their horizontal positions aligned.

[0061] The sliding bearing 1a is also positioned between the superstructure Ua, which is a building structure such as a high-rise building or bridge girder, and the substructure La, which is a foundation structure installed in the ground. The superstructure Ua and the substructure La are positioned horizontally and opposite each other vertically. The sliding bearing 1a prevents the shaking from the lower structure La from being transmitted to the upper structure Ua when an earthquake occurs at the location where the upper structure Ua is installed. The lower structure La is a flat plate with an upper surface that extends approximately horizontally.

[0062] The sliding bearing 1a shown in Figure 5 is a single-pendulum type spherical sliding bearing and comprises a spherical seat 11a, a shoe 12a, a support 13a, a cover 14a, and a fixing device 122.

[0063] The spherical seat portion 11a is fixed to the lower structure La. The spherical seat portion 11a is fixed to the flat upper surface of the lower structure La. The spherical seat portion 11a has a fixing portion 101 provided at the lower part of the spherical seat portion 11a that extends substantially horizontally, and a convex portion 102 provided at the upper part of the spherical seat portion 11a that protrudes upward in a mountain shape from the horizontal center of the fixing portion 101. The spherical seat portion 11a is fixed to the upper surface of the lower structure La by the fixing portion 101. The convex portion 102 has a concave spherical first sliding surface S1a formed on its upper surface, which is recessed downwards approximately in the center in the horizontal direction.

[0064] The support 13a is slidably mounted on the first sliding surface S1a of the spherical seat portion 11a. The support 13a includes a second sliding surface S2a and a third sliding surface S3a. The second sliding surface S2a is the lower surface of the support 13a and is slidably mounted on the first sliding surface S1a of the spherical seat portion 11a. The second sliding surface S2a is a convex spherical shape that is convex downwards. The radius of the sphere formed by the second sliding surface S2a is equal to the radius of the sphere formed by the first sliding surface S1a. The third sliding surface S3a is the upper surface of the support 13a. The third sliding surface S3a is a convex spherical shape that is convex upwards.

[0065] The shoe 12a is fixed to the superstructure Ua. The shoe 12a has a concave plate 42a and a sliding plate 43a. The concave plate 42a is fixed to the lower surface of the superstructure Ua. The concave plate 42a has a concave portion 111 formed at its lower end that is recessed upwards, approximately in the center of the horizontal direction. On the inner side of the concave portion 111 in the direction of the concaveness, a concave spherical portion 51a that is concave upward is formed.

[0066] The sliding plate 43a is positioned within the concave portion 111 of the concave plate 42a and fixed to the concave spherical portion 51a. The sliding plate 43a has a fourth sliding surface S4a on its lower surface that is concave and spherical, similar to the concave spherical portion 51a of the concave plate 42a, and is concave upward. The concave plate 42a has an annular projection 112 that protrudes downward from the fourth sliding surface S4 of the sliding plate 43a on the outer side of the entire horizontal circumference of the fourth sliding surface S4. The shoe 12a is slidably mounted on the third sliding surface S3a of the support 13a at the fourth sliding surface S4a. The radius of the sphere formed by the fourth sliding surface S4a is equal to the radius of the sphere formed by the third sliding surface S3a. The support 13a is positioned between the shoe 12a and the ball seat portion 11a. The shoe 12a is movable relative to the spherical seat 11a and the support 13a in a substantially horizontal direction. The shoe 12a and the ball seat 11a move relative to each other laterally via the support 13a, and in the process, they also move relative to each other vertically. The vertical distance between the shoe 12a and the ball seat 11a increases as the lateral displacement increases.

[0067] The cover 14a is provided to surround the space Aa between the shoe 12a and the lower structure La. The cover 14a is fixed to the shoe 12a. In this configuration, the cover 14a is provided so as to cover the horizontally outer peripheral surface of the annular projection 112 of the shoe 12a, and also cover the lower surface of the annular projection 112.

[0068] The cover 14a has a cylindrical portion 131, a locking portion 132, and a tubular portion 133. The cylindrical portion 131 is cylindrical and is provided horizontally outward from the outer surface of the annular projection 112 of the shoe 12a so as to cover the outer surface of the annular projection 112. The locking portion 132 protrudes horizontally outward from the entire circumference of the upper end of the cylindrical portion 131. Therefore, the locking portion 132 is annular. However, it is not limited to this, and the cover 14a only needs to be provided so as to be fixed to the shoe 12a.

[0069] The tubular portion 133 protrudes horizontally inward from the entire circumference of the lower end of the cylindrical portion 131, and also protrudes horizontally outward from the entire circumference of the lower end of the cylindrical portion 131. The tubular portion 133 has an overall annular shape. The tubular portion 133 has a substrate portion 141 and a bulging portion 142. The substrate portion 141 is flat and extends horizontally inward from the entire circumference of the lower end of the cylindrical portion 131, and also protrudes horizontally outward from the entire circumference of the lower end of the cylindrical portion 131. The substrate portion 141 has a length extending horizontally inward from the cylindrical portion 131 that is longer than the length protruding horizontally outward from the cylindrical portion 131. The substrate portion 141 faces the lower surface of the annular projection 112 of the shoe 12a. The substrate portion 141 completely covers the lower surface of the annular projection 112 of the shoe 12a. The bulging portion 142 connects the horizontal outer edge and the horizontal inner edge of the substrate portion 141 and bulges downward from the substrate portion 141, with its horizontal width becoming wider towards the bottom and then narrowing towards the bottom. The tubular portion 133 has an annular cross-section. However, this is not limited to the above, and the cross-section of the tubular portion 133 does not have to be annular; a part of it may be missing, or it may be C-shaped, for example.

[0070] The cover 14a is formed to be elastically deformable. The cover 14a has a tubular portion 133 formed of an elastic material. The cover 14a does not have to be made entirely of an elastic material; it is sufficient if at least a portion of the tubular portion 133 is made of an elastic material. The elastic material forming the cover 14a is specifically rubber or resin. The elastic material forming the cover 14a may be something other than rubber or resin. When the elastic material forming the cover 14a is rubber, synthetic rubber is preferable, and ethylene propylene rubber is particularly desirable because it has excellent weather resistance (low temperature durability, UV resistance) and high flexibility. It can also be a synthetic rubber other than ethylene propylene rubber.

[0071] The cover 14a is fixed to the shoe 12a by the fastener 122 such that the cylindrical portion 131 covers substantially the entire outer surface of the annular projection 112 of the shoe 12a, and the base portion 141 of the tubular portion 133 faces the lower surface of the annular projection 112. The fastener 122 is a band-shaped strip, and has clamping portions (not shown) that engage with each other at one end and the other end in the longitudinal direction. The fastener 122 becomes annular by engaging the clamping portions (not shown) provided at one end in the longitudinal direction with the other end in the longitudinal direction. The fastening portion, not shown in the figure, for example has a screw portion, and by rotating this screw portion with a tool, the length of the annular portion of the fastener 122 can be adjusted. The fastener 122 is formed from, for example, a metal material. The fastener 122 may be made of a material other than metal. If the fastener 122 is made of a metal material, for example, it may be made of stainless steel. The fastener 122 may be made of a metal material other than stainless steel.

[0072] When fixing the cover 14a to the annular projection 112 of the shoe 12a with the fastener 122, first, the cylindrical portion 131 of the cover 14a covers the outer circumferential surface of the annular projection 112 of the shoe 12a, and the base portion 141 of the tubular portion 133 faces the lower surface of the annular projection 112. At that time, adhesive is applied between the inner circumferential surface of the cylindrical portion 131 and the outer circumferential surface of the annular projection 112, and adhesive is applied between the upper surface of the substrate portion 141 of the tubular portion 133 and the lower surface of the annular projection 112.

[0073] Next, the fastener 122, which is provided to cover the entire circumference of the area between the locking portion 132 on the horizontal outer side of the cylindrical portion 131 of the cover 14a and the base portion 141 of the tubular portion 133, is tightened with a fastening portion (not shown). As a result, the fastener 122 presses the cylindrical portion 131 of the cover 14a against the outer surface of the annular projection 112 via adhesive, thereby fixing it to the outer surface of the annular projection 112, and the adhesive fixes the base portion 141 of the tubular portion 133 to the lower surface of the annular projection 112. Therefore, the cover 14a is fixed to the shoe 12a with a fastener 122 which is a band, and adhesive is placed between the cover 14a and the shoe 12a.

[0074] However, this disclosure is not limited thereto, and the cover 14a may be fixed to the shoe 12a by means other than a band, and there does not need to be any adhesive between the cover 14a and the shoe 12a. Furthermore, while adhesive is placed between the cylindrical portion 131 and the annular projection 112 of the shoe 12a, it does not need to be placed between the base portion 141 of the tubular portion 133 and the annular projection 112. Conversely, the adhesive may be placed between the substrate portion 141 of the tubular portion 133 and the annular projection 112, but not between the cylindrical portion 131 and the annular projection 112. With the cover 14a fixed to the shoe 12a, the base portion 141 of the tubular portion 133 is in a state where it is spread out approximately horizontally. Furthermore, when fixed to the shoe 12a, the cover 14a does not need to be in a state where the base portion 141 of the tubular portion 133 is spread out approximately horizontally.

[0075] With the cover 14a fixed to the shoe 12a by the fastener 122, when the sliding bearing 1a is installed between the upper structure Ua and the lower structure La, the flat upper surface, which is one of the main surfaces of the lower structure La, is positioned toward the tubular portion 133 of the cover 14a. The upper surface of the lower structure La is positioned approximately horizontally with respect to the shoe 12a. Furthermore, the upper surface of the lower structure La does not have to be positioned approximately horizontally with respect to the shoe 12a, but may be inclined. With the cover 14a fixed to the shoe 12a by the fastener 122, when the sliding bearing 1a is installed between the upper structure Ua and the lower structure La, the tubular portion 133 abuts from above over its entire circumference against the upper surface of the lower structure La that is horizontally outside the spherical seat portion 11a. As a result, the upper surface of the lower structure La elastically deforms the tubular portion 133 of the cover 14a so that the height of the bulging portion 142 from the substrate portion 141 is reduced around its entire circumference. As a result, the upper surface of the lower structure La and the tubular portion 133 of the cover 14a are in close contact around the entire circumference. In other words, the cover 14a undergoes elastic deformation by being in close contact with the upper surface of the lower structure L.

[0076] Figure 6 is a cross-sectional view showing the overall configuration of the sliding bearing 1a according to the second embodiment, in a second state where the sliding bearing 1a is installed between the superstructure Ua and the lower structure La, and is subjected to an earthquake load, and in a state where the horizontal relative positions of the spherical seat portion 11a and the shoe 12a are shifted. When the shoe 12a is positioned horizontally relative to the spherical seat 11a, the shoe 12a also moves upward from the lower structure La. In this way, even when the shoe 12a moves upward from the lower structure La, the cover 14a maintains a state in which the tubular portion 133 of the cover 14a abuts from above on the upper surface of the lower structure La that is horizontally outside the spherical seat portion 11a of the lower structure La, and the upper surface of the lower structure La maintains the tubular portion 133 of the cover 14a in a state in which it is elastically deformed so that the height of the bulging portion 142 from the base portion 141 is reduced over its entire circumference. As a result, even if the shoe 12a moves upward from the lower structure La, the upper surface of the lower structure La that is horizontally outside the spherical seat portion 11a and the tubular portion 133 of the cover 14a remain in close contact around the entire circumference.

[0077] The upper surface of the lower structure La elastically deforms the tubular portion 133 around its entire circumference so that the height of the bulging portion 142 from the base portion 141, thereby the cover 14a surrounds the space Aa between the shoe 12a of the sliding support 1a and the lower structure La around its entire circumference, preventing foreign matter such as dust, dirt, debris, and rainwater from entering the space Aa between the shoe 12a and the lower structure La.

[0078] In the sliding bearing 1a, for example, when an earthquake occurs at the installation site of the sliding bearing 1a, the shoe 12a fixed to the upper structure Ua and the spherical seat 11a fixed to the lower structure La move relative to each other in the horizontal direction via the support 13a provided between them. During this time, the cover 14a remains in close contact with the lower structure La, maintaining its elastically deformed state.

[0079] The sliding bearing 1a according to the second embodiment described above comprises a shoe 12a fixed to the upper structure Ua, a spherical seat portion 11a fixed to the lower structure La, a support 13a disposed between the shoe 12a and the spherical seat portion 11a, and a cover 14a surrounding the space Aa between the shoe 12a and the lower structure La. In the sliding bearing 1a, the cover 14a is formed of an elastic material, and when the cover 14a and the lower structure La are in close contact, the cover 14a, which is made of an elastic material, undergoes elastic deformation. Therefore, even if the shoe 12a and the lower structure La move relative to each other in the vertical direction due to their relative horizontal movement, the cover 14a will elastically deform, maintaining a tight seal between the cover 14a and the lower structure La, thereby preventing foreign matter such as dust, dirt, debris, and rainwater from entering the inside of the sliding bearing 1a.

[0080] In the sliding bearing 1a according to the second embodiment, the cover 14a has a tubular portion 133, and the portion of the lower structure La that is in close contact with the cover 14a is flat. Therefore, when the tubular portion 133 of the cover 14a and the lower structure La are in close contact, the tubular portion 133, which is formed of an elastic material, mainly undergoes elastic deformation. Therefore, even if the shoe 12a and the lower structure La move relative to each other in the vertical direction due to their relative horizontal movement, the tubular portion 133 of the cover 14a mainly undergoes elastic deformation, maintaining the tight seal between the cover 14a and the lower structure La, thereby effectively suppressing the entry of foreign matter such as dust, dirt, debris, and rainwater into the interior of the sliding bearing 1a. Furthermore, the cover 14a does not necessarily have to have a tubular portion 133, and the upper surface of the lower structure La does not necessarily have to be flat.

[0081] Furthermore, in the sliding bearing 1a according to the second embodiment, the cover 14a is formed of an elastic material such as rubber. Therefore, even if the shoe 12a and the lower structure La move relative to each other in the vertical direction due to their relative horizontal movement, the cover 14a, which is made of rubber or the like, will elastically deform, maintaining the tight seal between the cover 14a and the lower structure La, and effectively suppressing the entry of foreign matter such as dust, dirt, debris, and rainwater into the inside of the sliding bearing 1a. Furthermore, the elastic material may be something other than rubber. In other words, as described above, when the shoe 12a and the lower structure La move relative to each other in the horizontal direction, they also move relative to each other in the vertical direction, causing the gap between them to widen or narrow. Therefore, the cover 14a has an elastically deformable tubular portion 133 that can change the amount of elastic deformation in accordance with the expansion and contraction of this gap. However, the cover only needs to maintain close contact with the lower structure La by elastically deforming in accordance with the relative vertical movement of the shoe 12a and the lower structure La. Therefore, for example, if the cover is formed from a sponge-like material that can conform to deformation, it is possible to create shapes other than a tube.

[0082] Furthermore, in the sliding bearing 1a according to the second embodiment, the cover 14a is fixed to the shoe 12a with a fastener 122 which is a band, and adhesive is placed between the cover 14a and the shoe 12a. As a result, the cover 14a is secured to the shoe 12a by the fastener 122, which is a band, and furthermore, the cover 14a and the shoe 12a are also secured to each other by the adhesive between them. Therefore, the cover 14a can be easily and securely fixed to the shoe 12a. Furthermore, the cover 14a does not necessarily need to be secured to the shoe 12a with the fastener 122, which is a band. Furthermore, it is not necessary to place adhesive between the cover 14a and the shoe 12a.

[0083] Furthermore, in the sliding bearing 1a according to the second embodiment, one main surface that is positioned toward the tubular portion 133 of the lower structure La is positioned substantially horizontally with respect to the shoe 12a. Therefore, even if the shoe 12a and the lower structure La move relative to each other in the vertical direction due to relative horizontal movement, one main surface of the lower structure La can be reliably brought into close contact with the tubular portion 133. Furthermore, the main surface of the lower structure La that is positioned toward the tubular portion 133 does not necessarily have to be positioned substantially horizontally with respect to the shoe 12a. For example, one main surface of the lower structure La that is positioned toward the tubular portion 133 may be positioned at an angle with respect to the shoe 12a.

[0084] In the second embodiment described above, a sliding bearing 1a is described as a spherical sliding bearing in which the fourth sliding surface S4a of the shoe 12a is a concave spherical surface, but the present disclosure is not limited thereto. For example, it can also be applied to a planar sliding bearing in which the fourth sliding surface S4a of the shoe 12a is planar.

[0085] (Note) The sliding bearing according to the above embodiment is grasped, for example, as follows.

[0086] (1) A sliding bearing relating to one aspect of this disclosure is: A sliding support positioned between a superstructure and a lower structure facing the superstructure, An upper shoe fixed to the aforementioned superstructure, A lower shoe fixed to the aforementioned lower structure, A support is positioned between the upper shoe and the lower shoe, and is movable relative to both the upper shoe and the lower shoe in a substantially horizontal direction. A cover that surrounds the space between the upper shoe and the lower shoe, Equipped with, The aforementioned cover is An upper cover fixed to the upper shoe, A lower cover fixed to the lower shoe, Equipped with, At least one of the upper cover and the lower cover is formed of an elastic material. When the upper cover and the lower cover are in close contact, at least one of the upper cover and the lower cover, which is made of an elastic material, undergoes elastic deformation. It is characterized by the following:

[0087] In this way, the cover surrounding the space between the upper and lower shoes is formed of an elastic material, with at least one of the upper cover fixed to the upper shoe and the lower cover fixed to the lower shoe being made of an elastic material. As the upper and lower covers are in close contact, at least one of the upper and lower covers made of the elastic material undergoes elastic deformation. Therefore, even if the upper and lower shoes move relative to each other in the vertical direction due to their relative horizontal movement, at least one of the upper and lower covers made of the elastic material undergoes elastic deformation, maintaining the close contact between the upper and lower covers and suppressing the entry of foreign matter into the interior of the sliding bearing.

[0088] (2) In the sliding bearing relating to (1) above, Of the upper cover and the lower cover, One of the parts formed from an elastic material has a tubular portion, The other has a flat plate-like portion, One main surface of the flat plate portion is positioned toward the tubular portion. The structure is also good.

[0089] With this configuration, the tubular portion and the flat plate portion, both made of elastic material, of the upper and lower covers come into close contact, and the tubular portion made of elastic material primarily undergoes elastic deformation. Therefore, even if the upper and lower shoes move relative to each other in the vertical direction due to their relative horizontal movement, the tubular portion will elastically deform, maintaining the close contact between the upper and lower covers, and effectively suppressing the entry of foreign matter into the interior of the sliding bearing.

[0090] (3) In the sliding bearing relating to (1) or (2) above, The lower cover has a tubular portion formed of an elastic material, The upper cover has a flat plate-like portion, One main surface of the flat plate portion is positioned toward the tubular portion. The structure is also good.

[0091] With this configuration, the tubular portion formed by the elastic material of the lower cover and the flat portion of the upper cover are in close contact, and the tubular portion formed by the elastic material mainly undergoes elastic deformation. Therefore, even if the upper and lower shoes move relative to each other in the vertical direction due to their relative horizontal movement, the tubular portion will elastically deform, maintaining the close contact between the upper and lower covers, and effectively suppressing the entry of foreign matter into the interior of the sliding bearing. Furthermore, since the lower cover has a tubular section formed from an elastic material, it is possible to prevent rainwater and other liquids from accumulating on the horizontally outer side of the lower cover. Therefore, even if the upper and lower covers move relative to each other horizontally and a gap is created, it is possible to prevent rainwater and other liquids accumulated on the horizontally outer side of the lower cover from entering the lower shoe.

[0092] (4) In the sliding bearing relating to any one of (1) to (3) above, Up to a predetermined distance, the relative horizontal movement between the upper shoe and the lower shoe is maintained by elastic deformation of at least one of the upper cover and the lower cover, thereby maintaining a tight seal between the upper cover and the lower cover. The structure is also good.

[0093] With this configuration, the entry of foreign matter such as dust, dirt, debris, and rainwater into the sliding bearing can be effectively suppressed up to a predetermined distance of relative horizontal movement between the upper and lower shoes.

[0094] (5) In the sliding bearing relating to (4) above, When the relative horizontal movement between the upper shoe and the lower shoe exceeds a predetermined distance, the tight seal between the upper cover and the lower cover is released. However, when the relative horizontal movement between the upper shoe and the lower shoe returns to the predetermined distance, the tight seal between the upper cover and the lower cover is restored. The structure is also good.

[0095] With this configuration, even if the relative horizontal movement between the upper and lower shoes exceeds a predetermined distance, they will return to that predetermined distance, effectively preventing foreign matter such as dust, dirt, debris, and rainwater from entering the inside of the sliding bearing.

[0096] (6) In the sliding bearing relating to any one of the above (1) to (5), The elastic material is rubber. The structure is also good.

[0097] With this configuration, even if the upper and lower shoes move relative to each other in the vertical direction due to their relative horizontal movement, at least one of the upper and lower covers, which are made of rubber, will elastically deform, maintaining the tight seal between the upper and lower covers, and effectively suppressing the entry of foreign matter into the interior of the sliding bearing.

[0098] (7) In the sliding bearing relating to any one of the above (1) to (5), The upper cover is secured to the upper shoe with a band. The lower cover is secured to the lower shoe with a band. Adhesive is placed between the upper cover and the upper shoe, or between the lower cover and the lower shoe. The structure is also good.

[0099] With this configuration, the upper cover is secured to the upper shoe with a band, and the lower cover is secured to the lower shoe with a band. Furthermore, the space between the upper cover and the upper shoe, or between the lower cover and the lower shoe, is also secured with adhesive. This allows the upper cover to be easily and securely fixed to the upper shoe, and the lower cover to the lower shoe.

[0100] (8) In the sliding bearing relating to (2) or (3) above, One main surface of the flat plate portion is positioned substantially horizontally with respect to both the upper shoe and the lower shoe. The structure is also good.

[0101] With this configuration, even if the upper and lower shoes move relative to each other in the vertical direction due to their relative horizontal movement, one main surface of the flat plate portion can be reliably brought into close contact with the tubular portion.

[0102] (9) A sliding bearing relating to another aspect of this disclosure is: A sliding support positioned between a superstructure and a lower structure facing the superstructure, A shoe fixed to the aforementioned superstructure, A spherical seat portion fixed to the aforementioned lower structure, A support being positioned between the shoe and the ball seat, A cover enclosing the space between the shoe and the lower structure, Equipped with, The cover is formed of an elastic material, When the cover and the lower structure are in close contact, the cover undergoes elastic deformation. It is characterized by the following:

[0103] In this way, the cover surrounding the space between the shoe and the substructure is formed of an elastic material, and the cover elastically deforms as it adheres tightly to the substructure. Therefore, even if the shoe and the substructure move relative to each other in the vertical direction due to their relative horizontal movement, the cover elastically deforms, maintaining the tight adhesion between the cover and the substructure, thereby suppressing the entry of foreign matter into the interior of the sliding bearing.

[0104] (10) In the sliding bearing relating to (9) above, The cover has a tubular portion, The portion of the lower structure that is in close contact with the cover is flat. The structure is also good.

[0105] With this configuration, the tubular portion of the cover, formed from an elastic material, and the flat portion of the lower structure are in close contact, causing the tubular portion to primarily undergo elastic deformation. Therefore, even if the shoe and the lower structure move relative to each other in the vertical direction due to their relative horizontal movement, the tubular portion will elastically deform, maintaining the close contact between the cover and the lower structure, and effectively suppressing the entry of foreign matter into the interior of the sliding bearing.

[0106] (11) In the sliding bearing relating to (9) or (10) above, The elastic material is rubber. The structure is also good.

[0107] With this configuration, even if the shoe and the lower structure move relative to each other in the vertical direction due to their relative horizontal movement, the rubber cover will elastically deform, maintaining a tight seal between the cover and the lower structure, and effectively suppressing the entry of foreign matter into the interior of the sliding bearing.

[0108] (12) In the sliding bearing relating to any one of the above (9) to (11), The cover is secured to the shoe with a band. An adhesive is placed between the cover and the shoe. The structure is also good.

[0109] With this configuration, the cover is secured to the shoe with a band, and furthermore, the cover and shoe are secured together with adhesive. This allows the cover to be easily and securely attached to the shoe.

[0110] (13) In the sliding bearing relating to any one of (9) to (12) above, one main surface of the lower structure that is in close contact with the cover is arranged substantially horizontally with respect to the shoe. The structure is also good.

[0111] With this configuration, even if the shoe and the lower structure move relative to each other in the vertical direction due to their relative horizontal movement, one main surface of the lower structure can be reliably brought into close contact with the cover. [Explanation of Symbols]

[0112] 1,1a Sliding bearing 11 Lower shoe 11a Ball seat part 12 Kamikutsu 12a Shoes 13,13a Support 14,14a Cover 21 Lower base plate 22 Lower concave plate 23 Lower sliding plate 24 Lower stopper ring 31,51,51a Concave spherical part 35,55,112 Annular projection 41 Upper base plate 42 Upper concave plate 42a Concave Plate 43 Upper sliding plate 43a Sliding plate 44 Upper stopper ring 61 Upper cover 62 Lower cover 63 Upper fixture 64 Lower fixture 71 Upper cylindrical part 72 Upper locking part 73 Flat plate part 81 Lower cylindrical part 82 Lower locking part 83,133 Tubular section 91,141 Circuit board section 92,142 bulge 101 Fixed part 102 Convex part 111 Concave part 122 Fixtures 131 Cylindrical part 132 Locking part A,Aa Space L,La lower structure S1,S1a First folding surface S2,S2a Second folding surface S3,S3a Third fold moving surface S4,S4a Fourth Folding Surface U,Ua Upper Structure

Claims

1. A sliding support positioned between a superstructure and a lower structure facing the superstructure, An upper shoe fixed to the aforementioned superstructure, A lower shoe fixed to the aforementioned lower structure, A support is positioned between the upper shoe and the lower shoe, and is movable relative to both the upper shoe and the lower shoe in a substantially horizontal direction. A cover that surrounds the space between the upper shoe and the lower shoe, Equipped with, The aforementioned cover is An upper cover fixed to the upper shoe, A lower cover fixed to the lower shoe, Equipped with, The aforementioned upper shoe is, The upper sliding plate has an upper sliding surface which is concave spherical in shape and recesses upward and slides against the support, and an upper annular projection which is formed on the outer side of the entire horizontal circumference of the upper sliding surface and protrudes downward from the upper sliding surface. The aforementioned lower shoe is, The lower sliding plate has a concave spherical shape that is recessed downwards and slides against the support, and a lower annular projection formed on the outer side of the entire horizontal circumference of the lower sliding surface and projecting upward from the lower sliding surface. The upper cover is fixed to cover the outer circumferential surface of the upper sliding plate of the upper shoe. The lower cover is fixed to cover the outer circumferential surface of the lower sliding plate of the lower shoe. At least one of the upper cover and the lower cover is formed of an elastic material. When the upper cover and the lower cover are in close contact, at least one of the upper cover and the lower cover, which is made of an elastic material, undergoes elastic deformation. A sliding bearing characterized by the following features.

2. Of the upper cover and the lower cover, One of the parts formed from an elastic material has a tubular portion, The other has a flat plate-like portion, One main surface of the flat plate portion is positioned toward the tubular portion. The sliding bearing according to claim 1.

3. The lower cover has a tubular portion formed of an elastic material, The upper cover has a flat plate-like portion, One main surface of the flat plate portion is positioned toward the tubular portion. The sliding bearing according to claim 1.

4. Up to a predetermined distance, the relative horizontal movement between the upper shoe and the lower shoe is maintained by elastic deformation of at least one of the upper cover and the lower cover, thereby maintaining a tight seal between the upper cover and the lower cover. The sliding bearing according to claim 1.

5. When the relative horizontal movement between the upper shoe and the lower shoe exceeds a predetermined distance, the tight seal between the upper cover and the lower cover is released. However, when the relative horizontal movement between the upper shoe and the lower shoe returns to the predetermined distance, the tight seal between the upper cover and the lower cover is restored. The sliding bearing according to claim 4.

6. The elastic material is rubber. A sliding bearing according to any one of claims 1 to 5.

7. The upper cover is secured to the upper shoe with a band. The lower cover is secured to the lower shoe with a band. Adhesive is placed between the upper cover and the upper shoe, or between the lower cover and the lower shoe. A sliding bearing according to any one of claims 1 to 5.

8. One main surface of the flat plate portion is positioned substantially horizontally with respect to both the upper shoe and the lower shoe. The sliding bearing according to claim 2 or claim 3.

9. The aforementioned upper shoe is, The upper sliding plate further comprises an annular upper stopper ring fixed to the lower surface of the upper annular projection, The aforementioned lower shoe is, The lower sliding plate further comprises an annular lower stopper ring fixed to the upper surface of the lower annular projection, The upper cover is fixed to cover both the upper sliding plate and the upper stopper ring of the upper shoe, The sliding bearing according to claim 1, wherein the lower cover is fixed to cover both the outer circumferential surfaces of the lower sliding plate and the lower stopper ring of the lower shoe.

10. A sliding support positioned between a superstructure and a lower structure facing the superstructure, A shoe fixed to the aforementioned superstructure, A spherical seat portion fixed to the aforementioned lower structure, A support being positioned between the shoe and the ball seat, A cover enclosing the space between the shoe and the lower structure, Equipped with, The cover is formed of an elastic material, When the cover and the lower structure are in close contact, the cover undergoes elastic deformation. A sliding bearing characterized by the following features.

11. The cover has a tubular portion, The portion of the lower structure that is in close contact with the cover is flat. The sliding bearing according to claim 10.

12. The elastic material is rubber. The sliding bearing according to claim 10 or claim 11.

13. The cover is secured to the shoe with a band. An adhesive is placed between the cover and the shoe. The sliding bearing according to claim 10 or claim 11.

14. One main surface of the lower structure that is in close contact with the cover is positioned substantially horizontally with respect to the shoe. The sliding bearing according to claim 10 or claim 11.

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