JPS626499Y2 - - Google Patents

Description

[Detailed description of the invention] This invention is used between a vibration table on which a specimen is placed in a vibration testing machine and a vibrator that rocks the vibration table. This invention relates to a hydrostatic bearing coupling joint device for a vibration testing machine that allows movement in two directions to escape when the vibration is applied.

The shaking table on which the specimen is placed and the exciter are connected via a joint, but since the purpose of the shaking table is to investigate the behavior of structures during earthquakes, the above-mentioned joint is The following functions are required and must be satisfied.

It is necessary to reliably transmit the force and displacement from the vibrator without time delay, and it is necessary to minimize structural play and deflection when force is applied.

Generally, the vibrator is fixed to the basic body, but the vibrating table can perform two-dimensional or three-dimensional movements depending on its function. For this reason, it is necessary to transmit the axial force of the vibrator to the vibration table and to slide in a bearing for movement in a direction perpendicular to this. Further, at this time, it is necessary to make the sliding friction resistance extremely small, and a hydrostatic bearing is generally used.

In addition to the above, it is necessary to have a structure that does not put strain on the bearing even if the table is distorted during vibration and the mounting surface is tilted.

Conventionally, various types of joints have been considered for connecting the vibrator and the vibration table.
For example, as shown in Fig. 1, a spherical body d is provided between a vibration table a and a vibrator b, and a support e from the vibration table a, which is inserted into the spherical body d, is rotated. There is a joint c which is configured to be supported in a freely slidable manner and to connect this bearing surface to a hydraulic pressure source f, thereby serving as a hydrostatic bearing.

This joint is connected to the support e of the vibration table a by cantilever support, and there is no problem in transmitting the axial force of the vibrator and escaping displacement in the direction orthogonal to this, but the table a may become distorted. If "kinks" occur due to such reasons, the spherical surface side of the spherical body d is not a hydrostatic bearing, so there is a problem that it cannot slide due to small frictional resistance.

Furthermore, in order to release the displacement in the direction perpendicular to the displacement, the static pressure bearing in the direction perpendicular to the displacement becomes large, and a three-dimensional bearing becomes even larger. Since the weight of the bearing joint is added to the weight of the movable parts, a vibration exciter with a larger capacity than necessary is required, and the energy required for vibration at the required acceleration is also large.

Furthermore, as a conventional joint, a joint that transmits force through a connecting rod g having spherical surfaces at both ends, as shown in FIG. 2, has been put into practical use.

However, in this system, when the vibrating table a is moved in one direction by the vibrator b, the connecting rod g supported by the other part undergoes a rocking motion as shown in the figure. Therefore, control is required to eliminate the displacement caused by this rocking motion by the movement of each vibrator, which causes control difficulties.

The present invention aims to provide a hydrostatic bearing coupling joint device for a vibration testing machine that does not have the above-mentioned problems. A static pressure bearing is provided so as to be movable and rotatable, and a pair of coaxial static pressure bearings are connected to the vibration exciter side, and another pair of static pressure bearings are connected to the vibration table table side. Due to the relative movement in the axial direction between the four shafts of the cross shaft and the static pressure bearings installed on the shafts, the horizontal and vertical displacements of the vibrator and the vibration table are controlled. The relative rotation between the shaft portion and the static pressure bearing absorbs the horizontal and vertical inclinations between the vibrator and the vibration table.

Embodiments of the present invention will be described below based on the drawings.

As shown in FIGS. 3 to 5, each of the four shaft portions 1a of the cross shaft 1, which is orthogonal to each other at an angle of 90 degrees, is provided with a static pressure bearing 2 so as to be slidable and rotatable. One pair of pressure bearings is connected to the rod of the vibrator 4 via a connecting member 3, and the other pair of static pressure bearings is connected to the vibration table 5 side via a bracket 6, and connected to the shaft of the vibrator 4. All movements in two directions other than force transmission should be absorbed. Further, each hydrostatic bearing 2 of the cross shaft 1 is configured such that pressure oil is supplied to the bearing portion from a hydraulic pressure source 7, as shown in FIGS. 6 and 7.

With the above configuration, when an axial force from one vibrating machine 4 is applied, this force is transmitted to the vibrating table 5 through the cross shaft 1 by the joint device of the present invention. At this time, movement and tilting in the other two three-dimensional directions are also applied to the joint device that transmits the axial force to the vibration table, but in the orthogonal axial direction of the cross shaft 1. Cross shaft 1 and hydrostatic bearing 2 due to sliding or rotation of
These movements can be absorbed in between, and there is no possibility that these movements will be transmitted to the vibrator 4.

Therefore, the vibration exciter 4 is installed on the vibration table 5 so as to vibrate in the X, Y, and Z directions.
By using these vibration exciters 4 as connection joints between the vibration table table 5, the vibration waves of the vibration exciters can be accurately transmitted to the vibration table without being affected by vibration waves in other directions.

As described above, according to the device of the present invention, (i) there is no spherical surface machining, so machining accuracy can be easily increased and manufacturing costs can be reduced.

(ii) Since the cylindrical bearing part can be easily divided into two parts due to its structure, it is easy to assemble and disassemble.

(iii) Hydrostatic bearings allow pressurized oil to flow into the gap, but in flat bearings oil flows out around all four circumferences, but in cylindrical hydrostatic bearings oil flows out only to both end faces. This can be easily sealed with prior art shaft seals and oil recovery can occur within the bearing.

(iv) When the joint of the present invention is used, it is not affected by other vibration exciters, so accurate waveforms can be obtained with simple control.

(v) Since everything is composed of hydrostatic bearings, frictional resistance is small for all movements, and backlash can be minimized.

It has excellent effects such as

[Brief explanation of the drawing]

Figures 1 and 2 are both explanatory diagrams of a conventional joint, Figure 3 is a side view of the joint device of the present invention, Figure 4 is a sectional view taken along the line A-A in Figure 3, and Figure 5 is a joint. FIG. 6 is an explanatory diagram of a hydrostatic bearing, and FIG. 7 is a cutaway plan view of FIG. 6. 1... Cross axis, 2... Static pressure bearing, 4... Vibration machine, 5... Vibration table.

Claims (1)

[Scope of utility model registration request] A static pressure bearing is provided on each of the four circular cross-sectional shafts of the cross shafts, which are crossed at right angles, so as to be able to slide and rotate, and a pair of coaxial static pressure bearings are provided on the exciter side and on the other hand. A static pressure bearing connection joint device for a vibration testing machine, characterized in that the other pair of static pressure bearings are respectively connected to the vibration table table side.