JP2001304334A - Bearing - Google Patents

Abstract

PROBLEM TO BE SOLVED: To ideally support a vibrating body, to permit small displacement of high accuracy under the condition of extra-high load and extra-high speed. SOLUTION: A laminated structural body 1 is interposed between a lower rigid body 2' supported by a bucket swung up by the centrifugal force, and an upper rigid body 2 supporting a vibrator 7 in opposition to the lower rigid body 2' in the load direction. The laminated structural body 1 is formed by laminating first laminated plates 3 of high rigidity and second laminated plates 4 which are lower in rigidity than the first laminated plates 3, alternately in a plurality of layers. Through-holes are opened in the first laminated plates 3 and second laminated plates 4, and a space is formed by the inner side face of the upper rigid body 2, the inner side face of the lower rigid body 2' and the inner side face of the laminated structural body, and the space is occupied by a fluid 5. The fluid is displaceable but is low in rigidity and without hysteresis so as to be convenient, and the laminated structural body 1 is a hollow body unrigidly displaceable in all directions which are orthogonal to the centrifugal direction. The laminated structural body is preferably formed into annular or cylindrical shape and symmetrically displaced in an orthogonal direction to the axis to contribute to the improvement of experimental accuracy.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a bearing, and more particularly to a bearing which approaches ideal physical conditions of infinite longitudinal rigidity, no lateral rigidity, and no frictional force.

[0002]

2. Description of the Related Art An on-ground structure such as a high-rise building or an underground structure such as a tunnel receives a complex force from the ground during an earthquake. The behavior of such structures during an earthquake is
It needs to be simulated and examined in advance. In order to perform such a simulation, a full-scale model is generally used. As a shaking test technique using a reduced model that is cheaper than a full-scale model, a small shaking table on a centrifugal force test device,
A test method using a so-called centrifugal shaking table is known.
A centrifugal force experimental device that generates apparent gravity by generating centrifugal force can perform various experiments in a short time, at low cost, if it can satisfy the similarity rules of the related physical phenomena to a practically sufficient degree. This is expected to complement conventional high-precision full-scale tests using a large-scale shaking table (shake table).

[0003] The main objects of the experiments are very large and ultra-heavy objects such as tunnels formed in the submarine soft ground layer, dams in the mountains, and high-rise buildings standing on the landfill. In order to pursue, a model to be tested is required to be somewhat large. According to the similarity rule of the experiment, the centrifugal shaking table mounted on the experimental device of 100 G or less can be a reduced model of 1/100 in comparison with the full-scale shaking table of 1 G or less. ) Exciting force of the same magnitude, (2) Exciting displacement of 1/100 times, (3) 1
There is a need for a compact and lightweight structure that can be given a vibration frequency of 00 times and can be installed on a narrow bucket. The centrifugal shaking table that satisfies these conditions is used for bearings that support the vibration table.
To reduce friction, low friction bearings such as rolling bearings and oil film bearings are commonly used. The bearings of the centrifugal shaking table have (1) longitudinal rigidity of infinity in order not to excite vibrations in directions other than the excitation direction.
(2) There is no lateral stiffness in the sense of a high ratio of longitudinal to lateral stiffness to widen the excitation frequency range, (3) No frictional force to improve the reproduction waveform accuracy, and (4) Simple structure It is most desirable and ideal that damage is less likely to occur and that it can follow the deformation of the base and the vibrating body.

However, in practice, a frictional force acts on a bearing using rolling or sliding, and the frictional force has a bad influence as a nonlinear force that is inconvenient to the reproducibility of an earthquake waveform, which is an important performance as a shaking table. It is a factor that influences. When a rolling bearing is used, the moving direction changes too fast, as described above, for example, by vibrating at a vibration frequency 10 times that of an actual earthquake, so that the rolling element does not roll and the rolling surface When the vibration direction changes due to the occurrence of a slipping phenomenon, frictional force is generated and exerts an adverse effect that cannot be ignored on the experimental results. When oil film bearings are used, there should be essentially no frictional force, but in fact, pseudo-frictional force, which increases by orders of magnitude due to centrifugal force, acts on the load, so a high-pressure seal is required. Then, a frictional force is generated in the sealing portion. This is a nonlinear force and cannot be ignored in terms of shaking table control performance. Specifically, when a non-linear force such as a frictional force is generated, it becomes difficult for the shaking table control computer to calculate and provide an accurate excitation input signal to the shaking table, and a target actual waveform is generated. To reproduce the sound on the shaking table (waveform distortion)
Decrease.

FIGS. 19 and 20 show a centrifugal shaking table and the cause of its performance deterioration. FIG. 19 shows the centrifugal shaking table 100. A plurality of rolling bearings 102 are mounted on a shaking table base 101 to be fixed to a bucket.
The vibrating table 103 is supported and constrained so as to be able to roll and translate freely through the vibrating table 104.
The vibration table 103 is reciprocally driven by a vibrator 104 via a vibrating shaft 105 and vibrates in the direction of its axis. The reduced model 106 as a test sample is fixed to the vibration table 103. Rolling bearing 1
The rolling element 107 interposed between the vibration table 103 and the shaking table base 101
The frictional force between them has been reduced. Rolling element 107 during excitation
, The direction of movement and the direction of rotation change simultaneously and alternately, and the vibration speed when the direction is reversed becomes zero and stops instantaneously. The behavior at the time of the stop is affected by the frictional force. Furthermore, since the centrifugal vibration table 103 receives a high-frequency excitation force, the rolling element 107 cannot keep up with the frequent reverse rotation, and a phenomenon occurs that the rolling element 107 does not roll on the rolling surface but slips on the rolling surface. This phenomenon is accompanied by the occurrence of friction. The effect of the frictional force, which is a non-linear element, makes it difficult to perform calculations on the control of the shaker, thereby deteriorating the reproducibility of a vibration waveform such as an earthquake waveform. This deterioration has the problem of increasing the deviation between the target seismic wave and the controlled vibration waveform.

FIG. 20 shows the cause of the above-mentioned deterioration, and shows the above-mentioned centrifugal shaking table 100 mounted on a centrifugal bucket 108 which rises by receiving a centrifugal force. The centrifugal bucket 108 is supported by the bucket support 109 and swung to receive centrifugal acceleration. The centrifugal bucket 108 has a maximum deflection δ near its center. End points 110 and 111
In the centrifugal bucket 108, which can be regarded as a beam supported by the centrifugal force, a deflection δ corresponding to the magnitude of the centrifugal force is generated. Such a deflection also occurs in the entire centrifugal shaking table 100 fixed to the centrifugal bucket 108 which is bent in this manner, and the reduced model 106 in which each part receives a strong centrifugal force 111.
Undergoes deformation along the deformation of the centrifugal bucket 108.
Rolling element 107 supporting load by point contact or line contact
Since the local Hertz stress exceeds the limit value, it is susceptible to damages such as pitching and frenching.
If the centrifugal bucket 108 is designed to increase the centrifugal mass of the centrifugal bucket 108 to increase the rigidity of the centrifugal bucket 108 so as to be able to cope with such flexing, the dilemma of having to design to increase the capacity of the drive motor is plagued. It is.
Such bending changes depending on the magnitude of the centrifugal force, and disappears when the rotation of the centrifugal bucket 108 stops, and the centrifugal bucket 108 returns to its original shape.

FIG. 21 shows an oil film bearing 1 in which the rolling bearing 102 of the centrifugal shaking table 100 shown in FIG. 19 is substituted.
02 ′. In the oil film bearing 102 ′, a space 122 filled with lubricating oil is formed surrounded by the sealing member 121. As is well known, the oil film bearing 102 ′ includes a static oil film bearing in which the static pressure is supplied to the oil film bearing from the outside and a dynamic oil film bearing in which the static pressure is not supplied to the oil film bearing from the outside. is there. Each oil film bearing requires a sealing member 121 as shown. A high-pressure sealing member is often used as the sealing member 121 on which a large centrifugal force acts. When the internal oil pressure is low, the ability to load as a bearing decreases, and when the oil pressure increases, the frictional force generated on the seal sliding surface increases. Further, there is a problem that slight deformation or distortion of the oil film bearing surface causes oil leakage. Further, it becomes difficult to recover or stably supply the leaked oil, and the leak prevention structure for the countermeasure is complicated, resulting in a problem that the mounting mass increases.

As described above, there is a problem with the bearing structure in forming a compact, lightweight and compact centrifugal shaking table regardless of the type of the bearing, and this problem hinders the overall design. Has become.

The above-mentioned proposal in which such a frictional force is unlikely to be generated has been separately proposed. The proposed bearing is a method of supporting a centrifugal vibration table using laminated rubber. The above-described rolling bearing 102 of the centrifugal shaking table is replaced with a laminated structure 102 ″. FIG. 22 shows the laminated structure 102 ″. The laminated structure 102 ″ is shown in FIG.
As shown in FIG. 3, it is composed of an upper plate 131, a lower plate 132, and a laminated body 133 that is laminated between the plates in the centrifugal direction. The laminated body 133 has thin steel plates 134 and rubber sheets 135 alternately laminated. Such a laminated structure 102 ″ is sandwiched between the vibration table base 101 and the vibration table 103 as a bearing structure.

The vibration table 103 which receives a lateral force in the centrifugal force field is deformed into a parallelogram as shown in FIG. This deformation is expressed by a horizontal displacement amount β and a vertical displacement amount α. In addition to such a displacement, a tilt θ occurs due to the unbalanced load. Is defined in the vicinity of the center line L. Laminated rubber is generally resistant to compressive deformation, has a large lateral shift, deforms into a generally parallelogram, and has the property of returning to its original shape and returning to its initial position when external force disappears. Is high, there is a restoring force, there is little surface run-out, β> α, and θ is almost zero and can be ignored. The laminated structure having such advantages is employed in a vibration isolation structure of a building. When the vibration table is vibrated, if the longitudinal rigidity of the bearing is not sufficiently high, there is a problem that the vibration frequency is restricted because the longitudinal vibration components other than the vibration direction increase. If the lateral stiffness is not low, the vibrator requires a corresponding exciting force. Having resilience is not particularly advantageous in controlling vibration. In order to increase the ratio of the longitudinal rigidity to the lateral rigidity of the laminated rubber, the rubber film and the thin steel plate must be thinner and the number of laminated layers must be increased more, which makes the production more difficult, There is a problem that the cost is significantly increased. Actually, the number of laminations is limited, and even when this is used as a bearing, there is a problem that the usable range of the excitation frequency of the centrifugal vibration table cannot be increased.

The bearing having such a laminated structure has a laminated structure in which rubber is vertically stacked, and cannot sufficiently satisfy the condition (1) described above. This can be a problem during excitation. In order to avoid the problem, when the rigidity in the vertical direction is increased, the rigidity in the lateral direction is increased, so that the exciting force is further increased and a new problem is caused.

In a centrifugal shaker, it is desired to increase the limit of the vibration performance by providing a more ideal bearing capable of performing a small displacement under a condition of an extremely high load and a very high speed. Enlarging the limit of the vibration performance is not unique to the centrifugal vibrator described above, but is recently required by various vibrators.

[0013]

SUMMARY OF THE INVENTION An object of the present invention is to provide a bearing which can ideally support a vibrating body. Another object of the present invention is to provide a bearing capable of performing a small displacement under an ultra-high load and an ultra-high speed condition and ideally supporting a vibrating body. Still another object of the present invention is to provide a bearing capable of performing a small displacement under ultra-high load and ultra-high speed conditions, ideally supporting a vibrating body, and further increasing the loading capacity. Is to do.

[0014]

Means for solving the problem are described as follows. The technical items appearing in the expression are appended with numbers, symbols, and the like in parentheses (). The numbers, symbols, and the like are technical items that constitute at least one embodiment or a plurality of the embodiments of the present invention, in particular, the embodiments or the examples. Corresponds to the reference numerals, reference symbols, and the like assigned to the technical matters expressed in the drawings corresponding to the above. Such reference numbers and reference symbols clarify the correspondence and bridging between the technical matters described in the claims and the technical matters of the embodiments or examples. Such correspondence / bridge does not mean that the technical matters described in the claims are interpreted as being limited to the technical matters of the embodiments or the examples.

The bearing according to the present invention comprises a lower rigid body (2 ') supported by a base (not shown), and a vibrating body opposed to the lower rigid body (2') in a load direction such as a centrifugal direction. (7) an upper rigid body (2) supporting the laminated body (1) interposed between the upper rigid body (2) and the lower rigid body (2 '), (1) The first laminate (3) having a high rigidity and the second laminate (4) having a lower rigidity than the first laminate (3) are alternately laminated in a plurality of layers. The laminated plate (3) and the second laminated plate (4) are provided with holes penetrating therethrough, and have a laminated structure with the inner surface of the upper rigid body (2) and the inner surface of the lower rigid body (2 '). A space is formed by the inner surface of the body (1), and the space is occupied by the fluid (5). The fluid is freely displaceable but poor in rigidity, and it is convenient because hysteresis can be ignored.
The laminated structure (1) is a hollow body and is easily displaced rigidly in all directions perpendicular to the axial direction. The laminated structure is preferably formed in an annular or cylindrical shape, and is displaced in a direction perpendicular to the axis of the laminated structure, thereby contributing to an improvement in experimental accuracy.

A swelling portion (15) formed integrally with the upper rigid body (2) and directed toward the lower rigid body (2 ') is added. This bulge (15) can make the space narrower and reduce the amount of fluid entering it. A concave portion (22) which is opened on the upper side surface of the upper rigid body (2) and penetrates into the bulge portion (15) is provided on the upper rigid body (2) and the bulge portion (1).
5), and the piston (23) has a concave portion (2).
2), is guided by the inner peripheral surface of the concave portion (22) and is slidable in the axial direction, and the upper surface of the piston (23) is located above the upper surface of the upper rigid body (2). are doing. The vibrating body (7) is supported by the piston (23). The piston (23) follows the vertical displacement of the vibrator.

A bulge portion (15) formed integrally with the lower rigid body (2 ') toward the upper rigid body (2) is added. A concave portion (22 ') which is opened on the lower surface of the lower rigid body (2') and penetrates into the bulging portion (15) is formed continuously with the lower rigid body (2 ') and the bulging portion (15), and the piston is formed. (23 ') is fitted into the concave portion (22') and guided along the inner peripheral surface of the concave portion (22 ') so as to be slidable in the axial direction, and the lower surface of the piston (23') is a lower rigid body. (2 ′) It is located below the lower surface. The piston (23 ') will be supported by the base.

The bulging portion (15) and the piston (23, 2)
3 ′), a recessed space (25, 25 ′) is formed,
The recessed spaces (25, 25 ') are connected via holes (26, 26') formed in the bulging portion (15), and the recessed spaces (25, 25 ') are occupied by the fluid. . The outer peripheral surface of the bulging portion (15) is preferably formed in a conical surface. When the laminated structure (1) is displaced in a direction orthogonal to the axial direction, the conical surface comes into contact with the inner surface of the laminated structure (1).
5) effectively has the function of the stopper.

The bulging portion (15) is provided in the first divided body (3).
3) and a second divided body (34), and the first divided body (3
It is preferable that 3) and the second divided body (34) are rotatably connected via a spherical surface. This spherical bearing structure can absorb the rotational displacement of the first rigid body (2) and suppress the load on the laminated structure. The surface of the bulging portion (15) on the side facing the rigid body is formed in a groove surface, and the fluid can flow in the space along the groove surface.

A lower rigid body (2 ') and an upper rigid body (2)
And the laminated structure (1) form a set. A plurality of such sets are provided, and the respective spaces of the plurality of sets communicate with each other via the respective holes (13) formed in the respective lower rigid bodies (2 ') of the plurality of sets. Is preferred.

[0021]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view of a bearing according to an embodiment of the present invention. Fig. 1
As shown in FIG. The disc-shaped part comprises two disc-shaped plates,
It is formed of an upper plate 2 and a lower plate 2 '. The upper plate 2 and the lower plate 2 ′
It has high rigidity and forms a first rigid body and a second rigid body.

In the laminated structure 1, thin steel plates 3 and rubber sheets 4 are alternately laminated. The stacking direction coincides with the direction of centrifugal force during the experiment (hereinafter, generally referred to as the load direction). The width (hereinafter, referred to as an annular width) dR of the annular portion of the laminated structure 1 on the radial direction line is equal to the laminated structure 1
Is larger than the lateral displacement (maximum design displacement).

The upper surface of the laminated structure 1 is firmly joined to the lower surface of the upper plate 2, and the lower surface of the laminated structure 1 is firmly joined to the upper surface of the lower plate 2 '. Adjacent thin steel plate 3 and rubber sheet 4 are firmly joined to each other by an adhesive or a vulcanization treatment. A hollow 5 is formed in the bearing 10 by the laminated structure 1, the upper plate 2, and the lower plate 2 ′. The hollow 5 is filled with a fluid or semi-fluid (collectively referred to as fluid).

As the fluid, a substance having low resistance deformation characteristics such as liquid, sol, and gel is appropriate.
Examples include paraffin, silicon-based sol, silicon-based gel, micro steel balls, and combinations of these materials. Here, the low resistance deformation characteristics refer to physical properties that are so small that the deformation resistance can be ignored as compared with the magnitude of the external force that they receive.

FIG. 2 shows a centrifugal shaking table (hereinafter generally referred to as a shaking table) 2 in which the above-described bearing 10 is used.
0 is shown. The shaking table 20 is rotatably supported on a shaking table base 6 to be fixed to an object such as a bucket via a plurality of bearings 10 via a plurality of bearings 10. In the horizontal direction). The shaker 8 is fixed to the shaking table base 6. The vibration table 7 is reciprocally driven by a vibrator 8 via a vibrating shaft 9 and vibrates in the axial direction (X-axis direction). A double hydraulic cylinder device having two hydraulic chambers facing each other and alternately supplying hydraulic pressure may be used for the shaker. The reduced model 11 as a test sample is fixed to the vibration table 7.

As described above, the bearing 10 has high rigidity in the longitudinal direction (the direction of the axis of the ring of the laminated structure 1) and has a high rigidity in the lateral direction (the axis of the ring of the laminated structure 1 on the XY plane). 23 has physical properties similar to those of the laminated structure 102 ″ shown in FIG. 23, but is more remarkable in that the rigidity is low in the radial direction (direction perpendicular to the direction of the bearing 10). Since the body is on a ring and the fluid is filled in the hollow 5 of the entire structure, the solid laminated structure 1 shown in FIG.
The rigidity in the horizontal direction is lower, the deformation resistance is smaller, and the rigidity ratio in the vertical and horizontal directions (vertical rigidity / lateral rigidity) is higher than that in the case of 02 ".

A part of the centrifugal load applied to the upper plate 2 acts directly on the laminated structure 1 as a vertical external force, and the remainder of the load acts directly on the working fluid 5 as a vertical external force. . The static pressure generated in the fluid 5 acts on the inner cylindrical surface of the laminated structure 1 and the lower plate 2 '. The annular thin steel plate 3 of the laminated structure 1 has sufficiently high strength against internal pressure.

A rubber sheet 4 sandwiched between the upper and lower two thin steel plates 3 and joined to the thin steel plates 3 in a wide area.
Is sandwiched between the thin steel plates 3 with a strong load force and is pressed down, does not swell greatly toward the outside, and can sufficiently withstand its internal pressure. The deformation resistance of the internal fluid with respect to the lateral displacement force received from the vibrator 8 is so small that it can be ignored. Structure 2
It has a higher aspect ratio due to the smaller area of the layers.

FIG. 3 shows another embodiment according to the present invention. An elastic sealing film 51 made of rubber is adhered to the inner cylindrical surface of the laminated structure 1. When hydraulic fluid is used as the fluid 5, an oil-resistant nitrile rubber is used as a material of the elastic seal film 51. Natural rubber having excellent strength and elasticity is used for the rubber sheet. Natural rubber is suitable for high longitudinal stiffness and low lateral stiffness. The elastic sealing film 51 can prevent the hydraulic oil from entering between the thin steel plate 3 and the rubber sheet 4 and maintain the joining force therebetween. An injection hole 13 into which the hydraulic oil 5 can be injected is formed in the lower plate 2 ', and the injection hole 13 is closed with a screw plug.

As shown in FIG. 4, the respective injection holes 13 of the plurality of bearings 10 are communicated with each other by a pipe or an oil hole 14, so that the pressure of the fluid 5 inside each bearing 10 is equalized. The load applied to the vibration table 7 is evenly distributed to the plurality of bearings 10. Oil hole 14
It is formed inside the shaking table base 6.

FIG. 5 shows still another embodiment according to the present invention. Further, a stopper 15 is added.
The stopper 15 is formed integrally with the lower surface of the upper plate 2 and is formed as a part of the stopper 15. The bulging portion bulges toward the lower plate 2 '. The stopper 15 is fitted into the laminated structure 1 symmetrically with respect to the center line L. An annular space having a gap width β ′ is formed between the inner cylindrical surface of the laminated structure 1 and the outer peripheral surface of the stopper 15, and the gap width is formed between the upper surface of the lower plate 2 ′ and the lower surface of the stopper 15. A disk-shaped space that is α 'is formed,
The fluid 5 is filled in a continuous space formed by the annular space and the disk-shaped space. α ′ and β ′ are shown in an exaggerated manner.

[0032] Hydraulic oils generally have a bulk modulus of similar order to rubber. The stopper 15 has three functions. Its first function is to reduce the volume of the fluid 5. The gap width α 'and the gap width β'
The allowable vertical and horizontal displacements are set to expected values,
The space filled with the fluid 5 is designed to be as narrow as possible. Since the stopper 15 is made of steel and has a much higher longitudinal elastic modulus than rubber or hydraulic oil, the volume of the fluid is minimized, and since most of the internal volume is filled with high-rigidity steel, the stopper 15 is used as a bearing. High rigidity is given in the vertical direction. α ', β'
Is shown exaggerated.

The second function of the stopper 15 is a stopper function. When an excessive vertical compressive force acts on the upper plate 2, the stopper 15 which moves in the vertical direction is forcibly stopped on the upper surface of the lower plate 2 '. 15 is forcibly stopped on the inner cylindrical surface of the laminated structure 1. By such a restraint, an excessive external force can be suppressed from acting on the rubber sheet 4, and further, the parts of the centrifugal vibration table 20 supported by the bearing 10, the vibration table 7, and the vibrator 8 Damage can be prevented from occurring. Stopper 1
The third function of No. 5 is a sliding bearing function. The sliding surface between the stopper 15 and the displaced laminated structure 1 and the sliding surface between the displaced stopper 15 and the upper plate 2 are:
It is formed as a sliding surface of a sliding bearing (oil film bearing), and the oil film bearing thus formed is formed as a bearing having essentially no oil leakage to the outside.

FIG. 6 shows still another embodiment of the present invention. The stopper 15 has an upper protrusion 16 and a lower protrusion 17. The upper plate 2 is formed with an upper concave portion 18 into which the upper protrusion 16 enters, and a lower concave portion 19 into which the lower protrusion 17 enters. Lower protrusion 1
7 is just fitted into the lower recess 19 with a spigot.

The outer peripheral surface of the upper projection 16 and the upper plate 2
An annular space having a gap width of β ″ is formed between the inner peripheral surface and the disc-shaped space having a gap width of α ″ between the upper surface of the upper protrusion 16 and the lower surface of the upper plate 2. Have been. The fluid 5 is filled in a continuous space formed from these spaces. The stopper 15 of the present embodiment is
As a separate body independent of the steel plate and the steel bar. The function of the stopper 15 has the above-mentioned three functions as in the previous embodiment.

FIG. 7 shows still another embodiment of the present invention. A large recess 22 is formed in the upper plate 2, and the piston 2 is vertically movable in the recess 22.
3 is inserted. The recess 22 reduces the volume of the space formed by the upper plate 2, the lower plate 2 ′, and the laminated structure 1. A seal 24 is provided between the recess 22 and the piston 23. An injection hole (or supply hole) 13 shown in FIG. 3 is formed in the lower plate 2 ', into which a plug is screwed.

The piston 23 and the recess 2 of the upper plate 2
2 is connected to the injection hole 13 through the communication hole 26. As in the embodiment shown in FIG. 4, the injection holes 13 of the plurality of bearings 10 communicate with each other by the oil holes 14, and the respective buffer spaces 25 are made hydraulically or pneumatically uniform. The space formed between the outer cylindrical surface of the upper plate 2 and the inner cylindrical surface of the laminated structure 1 is filled with the fluid 5, and the fluid 5 is shielded from the buffer space 25 by the seal ring 27. .

When the bucket is greatly displaced as shown in FIG. 21, the buffer spaces 25 communicate with each other between all the bearings 10 as in the embodiment shown in FIG. The longitudinal compressive force acting on the surface is uniformized. The buffer space 25 can allow vertical deformation of the piston 23 corresponding to the total amount of compression deformation α ′ of the multi-stage rubber sheet 4. The vibration table 7 is supported by the piston 23 while the piston 23 is displaced from 1 G to the target G in this manner. α '
Is shown exaggerated.

FIG. 8 shows still another embodiment according to the present invention. The piston 23 'is supported by the lower plate 2', unlike the piston 23 shown in FIG. The large recess (or protrusion) 22 'into which the piston 23' fits is formed as a part of the lower plate 2 'unlike the recess 22 shown in FIG. The injection hole 13 'and the plug are formed below the piston 23'. A buffer space 25 'formed between the upper surface of the piston 23' and the lower surface of the upper plate 2 is connected to the injection hole 13 through a communication hole 26 '.

The inner peripheral surface of the lower plate 2 'and the piston 2
The sliding surface forming gap formed with the outer peripheral surface of 3 ′ can communicate with the injection hole 13 through another lateral communication hole 29 ′. The buffer space 2 of each of the plurality of bearings 10
5 'can communicate with each other and be uniform, as in the previously described embodiment. In the present embodiment, the bearing 10 is supported by the shaking table base 6 via the piston 23 '. The operation effect of the piston 23 'is the same as the operation effect of the piston 23 in the embodiment of FIG. In the present embodiment, a seal ring corresponding to the seal ring 27 shown in FIG. 7 is unnecessary.

FIG. 9 shows still another embodiment of the present invention. This embodiment is different from the embodiment shown in FIG. 5 in the shape of the annular space filled with the fluid 5. The outer peripheral surface of the stopper 15 is formed as a conical surface 31. Inner cylindrical surface of laminated structure 1 and stopper 1
An annular space having a maximum gap width of β ′ is formed between the outer peripheral surface of the lower plate 5 and the circumferential surface, and the gap width is α ′ between the upper surface of the lower plate 2 ′ and the lower surface of the stopper 15. A disk-shaped space is formed, and a fluid 5 is filled in a continuous space formed by the annular space and the disk-shaped space.

An oil groove 32 is formed on the lower surface of the stopper 15 in opposition to the upper surface of the lower plate 2 '.
As shown in FIG. 10, the oil groove 32 is a circular groove and a two-dimensional lateral groove (a groove in a direction perpendicular to the center line L) connected in series. The oil groove 32 is open so as to be connected to the disk-shaped space and the annular space described above. α ′ and β ′ are shown in an exaggerated manner.

In the present embodiment, when the laminated structure 1 is deformed into a parallelogram on the center cross section by the lateral width β ′,
When the conical surface slides on the inner peripheral surface of the laminated structure 1 as shown in FIG. 11, seizure of the sliding surface can be effectively prevented. When the lower surface of the stopper 15 slides on the upper surface of the lower plate 2 ', seizure of the sliding surface can be effectively prevented.

FIG. 12 shows still another embodiment according to the present invention. The stopper 15 of the present embodiment is divided into two parts. The stopper 15 is divided into an upper part 33 and a lower part 34. Upper part 33 and lower part 3
4 has partial spherical surfaces opposed to each other. When the laminated structure 1 is deformed into a parallelogram, when the inclination θ between the upper plate 2 and the lower plate 2 ′ is not zero and the inclination is large enough to be ignored, the upper part 33 and the lower part The parts 34 slide relative to each other about the center point of the partial spherical surface, and the rotational sliding is based on the inclination θ (sliding between the laminated structure 1 and the stopper 15, and between the stopper 15 and the stopper 15). The above-mentioned burn-in of the lower plate 2 'can be effectively prevented.
The gap ε1 between the lower part 34 and the lower plate 2 ′
And the gap ε2 between the upper part 33 and the lower part 34 are shown in an exaggerated manner.

FIG. 13 shows still another embodiment according to the present invention. In addition to the injection hole 13 which is the same as the injection hole 13 shown in FIG. 5, a discharge hole 35 is formed in the outer peripheral region of the sliding surface between the laminated structure 1 and the lower plate 2 '. Stopper 15 and laminated structure 1, lower plate 2 '
The fluid 5 'filled in the space formed by the
The fluid 5 ′ is supplied from the discharge port 3 and discharged from the discharge hole 35, and operates as a hydrostatic bearing. When the stopper 15 is displaced and the pressure of the fluid 5 ′ increases and the gap ε1 between the stopper 15 and the lower plate 2 ′ increases, the flow rate of the fluid 5 ′ flowing from the injection hole 13 to the discharge hole 35 increases. However, if the supply source of the fluid 5 'has a constant flow rate characteristic, the increase in the flow rate causes a decrease in the pressure, so that the gap ε1 decreases, and as a result, the gap ε1 is maintained constant. The fluid 5 'operates as a hydrostatic bearing.

FIG. 14 shows still another embodiment of the present invention. The stopper 15 is provided on the lower plate 2 '.
Side. The injection hole 13 and the discharge hole 35 are provided in the stopper 15. The stopper 15 communicates with a disk-shaped space (gap) between the lower surface of the upper plate 2 and the upper surface of the stopper 15 via a first communication hole 36 formed in the stopper 15.

The discharge hole 35 is formed between the inner peripheral surface of the laminated structure 1 and the conical surface which is the outer peripheral surface of the stopper 15 via a second communication hole 37 formed in the stopper 15. Communicating with the annular space. In this embodiment, FIG.
As in the embodiment of FIG.
The cooling of the lubricating part is effective by the flow of the fluid. Further, FIG.
Unlike the arrangement of the discharge holes 35 of FIG.
The arrangement of No. 5 is less restrictive.

FIGS. 15 to 18 show still another embodiment of the present invention. These four embodiments are different in that the stopper 15 is divided into an upper portion 33 and a lower portion 34, and a sliding surface (lubrication surface) is formed between the upper portion 33 and the lower portion 34. This is the same as the twelfth embodiment. In the four embodiments shown in FIGS. 15 to 18, sliding surfaces (lubricating surfaces) opposed to each other between the upper portion 33 and the lower portion 34 are formed through communication holes 38 formed inside the lower portion 34. To the injection hole 13, the partial spherical gap 39 between the lower part 34 and the upper part 33 is closed by a ring-shaped seal 41, and the partial spherical gap 39 closed by the ring-shaped seal 41 is The annular space formed by the plate 2, the lower plate 2 ′, and the lower portion 34 is isolated from the disk-shaped space 42.

In these four embodiments, the gap width ε2 of the partial spherical gap 39 and the disc-shaped gap between the stopper 15 and the lower plate 2 ′ or between the stopper 15 and the upper plate 2 Since each of ε1 is actually a very small width, the stopper 15 has a sufficient stopper function also in the lateral direction. The lubricating oil supplied to the partial spherical gap 39 forms an oil film which, in relation to the upper part 33 and the lower part 34, forms a good lateral and longitudinal bearing. The lubricating oil in the partial spherical gap 39 leaking from the ring-shaped seal 41 does not leak to the outside by joining the fluid 5 in the annular space and the disk-shaped space described above.

As shown in FIGS. 15 to 18, the upper portion 33 and the lower portion 34 of the stopper 15 can be provided on either the upper plate 2 side or the lower plate 2 'side. The injection hole 13 and the discharge hole 35 are provided in the lower plate 2 ′ in common in the embodiments of FIGS. 15 to 18, and the communication hole 38 communicating with the partial spherical gap 39 is provided in FIG.
In the embodiment of the present invention, it is provided on the upper portion 33, and in the embodiment of FIGS. 15, 17 and 18, it is provided on the lower portion.

In the embodiment shown in FIGS. 15 and 17, the disc-shaped space 42 formed by the lubrication surface in the case of the lateral displacement is formed on the lower plate 2 'side, and is formed as shown in FIGS. In the embodiment, it is formed on the upper plate 2 side.
In the embodiment shown in FIGS. 16 and 18, a communication hole 43 is formed in the upper portion 33 in addition to the communication hole 38 as a communication hole for connecting the injection hole 13 to the disc-shaped space 42.
Is connected to the injection hole 13 via a partially spherical gap 39.

In the embodiment of FIG. 17, the upper plate 2 has a hemispherically projecting spherical seat 44 which is convex downward, and the stopper 15 is provided with the lower portion 34 and the upper plate 2.
And an upper portion 33 separated from the upper portion.
In this case, the ring-shaped outer peripheral end portion 45 of the upper portion 33 is
It is mounted on the ring-shaped upper end surface of the laminated structure 1. When the upper plate 2 is tilted with respect to the lower plate 2 ′, the upper plate 2
4 and relatively rotated through the ring-shaped outer peripheral end portion 45.
Can absorb the inclination of the upper plate 2 that cannot be absorbed only by the compression of the plurality of rubber sheets 4 of the laminated structure 1 that allows the minute rotation of the upper portion 33 with respect to the lower portion 34.

The rotation of the upper plate 2 with respect to the upper portion 33 via the spherical seat 44 can also absorb the initial inclination of the upper plate 2 when the bearing 10 is installed.
Lubricant such as lubricating oil and grease sealed in the clearance between the spherical seat 44 and the upper surface 33 may leak under centrifugal force because the spherical seat 44 is convex downward (centrifugally). Hateful.

As described above, the four embodiments shown in FIGS. 15 to 18 can solve the problem related to the inclination of the upper plate 2 with respect to the lower plate 2 '.

Although the above-mentioned technical disclosure has exemplified the centrifugal shaking table, the technical disclosure can be applied to other various shaking tables and shaking tables as they are. Any of the above-described bearings 10 can be used upside down. The center hole of the bearing 10, especially the center hole of the laminated structure 1, is not limited to a cylindrical hole, and may be formed as an elliptical cylindrical hole, a square, a rhombic polygonal cylindrical hole, or a conical hole. The elongated hole shape is preferable in that the internal pressure resistance is increased. The shape of the outer peripheral surface of the laminated structure 1 can be rectangular or another shape as long as the pressure resistance does not decrease. In all embodiments, the working fluid 5 in the bearing 10
Alternatively, a plug 14 shown in FIG. 4 for equalizing the pressure of the working fluid 5 'can be provided. Technical matters specific to each embodiment can be applied to all the other embodiments. For example, the shape of the stopper 15, cooling by the lubricating oil circulation system, each division of the stopper 15, each arrangement of the stopper 15, the working fluid 5 or the working fluid 5 ′
The form of each annular space filled with the gas, the form of the communication passage leading to the lubricating surface, the form of the groove formed in the lubricating surface, and the form of existence of the piston can be applied to all the embodiments.

[0056]

The bearing according to the present invention improves the load capacity of the shaking table or the shaking table and makes the bearing structure compact. For shaking table bearings, the control frequency is improved by reducing the frictional force compared to plain bearings and rolling bearings by expanding the vibration frequency range in which vibrations other than the vibration direction can be suppressed and testing. The reproducibility is greatly improved, and furthermore, the effects of increasing the reliability of the actual earthquake excitation test of various structures using the reduced model that is difficult to obtain the experimental accuracy are obtained.

[Brief description of the drawings]

FIG. 1 is a sectional view showing an embodiment of a bearing according to the present invention.

FIG. 2 is a partial sectional front sectional view showing an embodiment of the bearing according to the present invention.

FIG. 3 is a sectional view showing another embodiment of the bearing according to the present invention.

FIG. 4 is a partial sectional front sectional view showing another embodiment of the bearing according to the present invention.

FIG. 5 is a sectional view showing another embodiment of the bearing.

FIG. 6 is a sectional view showing still another embodiment of the bearing.

FIG. 7 is a sectional view showing still another embodiment of the bearing.

FIG. 8 is a sectional view showing still another embodiment of the bearing.

FIG. 9 is a sectional view showing still another embodiment of the bearing.

FIG. 10 is a bottom view showing improvement of a bulging portion.

FIG. 11 is a sectional view showing an operation mode of the embodiment of the bearing.

FIG. 12 is a sectional view showing another operation mode of the embodiment of the bearing.

FIG. 13 is a sectional view showing still another embodiment of the bearing.

FIG. 14 is a sectional view showing still another embodiment of the bearing.

FIG. 15 is a sectional view showing still another embodiment of the bearing.

FIG. 16 is a sectional view showing still another embodiment of the bearing.

FIG. 17 is a sectional view showing still another embodiment of the bearing.

FIG. 18 is a sectional view showing still another embodiment of the bearing.

FIG. 19 is a front view showing a known bearing.

FIG. 20 is a front view showing an operation mode of the bearing.

FIG. 21 is a front view showing another known bearing.

FIG. 22 is a front view showing still another known bearing.

FIG. 23 is a front view showing another known bearing.

FIG. 24 is a front view showing an operation mode of the bearing.

[Explanation of symbols]

 2 ... Upper rigid body 2 '... Lower rigid body 3 ... First laminated plate 4 ... Second laminated plate 5 ... Fluid 7 ... Vibration body 13 ... Hole 15 ... Bulging part 22, 22' ... Depression 23, 23 '... Piston 25, 25 '... space in recess 26, 26' ... hole 33 ... first divided body 34 ... second divided body

Claims (12)

[Claims] 1. A lower rigid body supported by a base, an upper rigid body facing the lower rigid body and supporting a vibrating body, and interposed between the upper rigid body and the lower rigid body. The laminated structure is formed by alternately stacking a plurality of layers of a first laminated plate having high rigidity and a second laminated plate having lower rigidity than the first laminated body, A hole is formed in the first laminated plate and the second laminated plate, and a space is formed by an inner surface of the upper rigid body, an inner surface of the lower rigid body, and an inner surface of the laminated structure, The space is occupied by a fluid bearing. 2. The bearing according to claim 1, further comprising a bulging portion formed integrally with said upper rigid body and directed toward said lower rigid body. 3. A concave portion which is opened on an upper side surface of the upper rigid body and penetrates into the bulging portion is formed continuously with the upper rigid body and the bulging portion, further comprising a piston, wherein the piston is fitted into the concave portion. 3. The bearing according to claim 2, wherein the upper side surface of the piston is located above the upper side surface of the upper rigid body so as to be slidable in the central axis direction while being guided by the inner peripheral surface of the concave portion. 4. The bearing according to claim 1, further comprising a bulging portion formed integrally with said lower rigid body and directed toward said upper rigid body. 5. A concave portion which is opened on a lower surface of the lower rigid body and penetrates into the bulging portion is formed continuously with the lower rigid body and the bulging portion, further comprising a piston, wherein the piston has the concave portion. The lower surface of the piston is positioned lower than the lower surface of the lower rigid body so that the lower surface of the piston is slidable in the central axis direction while being guided by the inner peripheral surface of the concave portion. bearing. 6. A recessed space is formed between the bulging portion and the piston, the recessed space is connected through a hole formed in the bulging portion, and the recessed space is formed by the fluid. A bearing according to claim 3 or 5 occupied. 7. An outer peripheral surface of the bulging portion is formed as a conical surface, and when the laminated structure is displaced in a direction orthogonal to the central axis direction, the conical surface contacts an inner surface of the laminated structure. The bearing according to claim 2 or 4, which is in contact with the bearing. 8. The bulging portion includes a first divided body and a second divided body, and the first divided body and the second divided body are rotatably connected via a spherical surface. The bearing according to claim 1, wherein the bearing is selected from the group consisting of: 9. The method according to claim 9, further comprising a bulging portion formed integrally with the upper rigid body toward the lower rigid body, wherein a lower surface of the bulging portion is formed in a groove surface, and the fluid is formed along the groove surface. 2. The bearing of claim 1, wherein said bearing flows within said space. 10. The lower rigid body further includes a bulge portion formed integrally with the lower rigid body toward the upper rigid body, and an upper surface of the bulge portion is formed in a groove surface, and the fluid is formed along the groove surface. 2. The bearing of claim 1, wherein said bearing flows within said space. 11. The lower rigid body, the upper rigid body,
The laminated structure forms a set, and the set is provided in a plurality, and the spaces in each of the plurality of sets are mutually connected through respective holes opened in the lower rigid body of each of the plurality of sets. 11. The bearing of claim 1, wherein the bearing is in communication. 12. The bearing according to claim 1, wherein said laminated structure is formed in an annular shape.