Vibration isolator

Abstract

To provide a vibration resistant device capable of freely and relatively moving two boards arranged through a rolling element and realizing a low natural frequency.SOLUTION: In this vibration isolator 1, an upper surface opening part is sealed by a first diaphragm (4b), and in a first bearing mechanism 6 placed on it, a first shaft part 64 is loosely fitted to respective through-holes 161171 of a first plate 61 and a second plate 62 for arranging a rolling element 63 between them.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a vibration isolation device. [Background technology]

[0002] BACKGROUND ART A variety of vibration isolation devices are known for use in semiconductor manufacturing equipment, liquid crystal manufacturing equipment, high-magnification (electron) microscopes, and the like.

[0003] For example, Patent Document 1 discloses a vibration control unit having a rolling element between a first member and a second member. In this vibration control unit, the rolling element rolls on a first curved surface, which is a convex surface, relative to the first member, and also rolls on a second curved surface formed from a curved surface center different from that of the first curved surface relative to the second member.

[0004] Furthermore, for example, Patent Document 2 discloses a vibration isolation device in which a spherical member is provided between a load disk that supports a load and the load, and the load is supported by an air spring.

[0005] Furthermore, for example, Patent Document 3 discloses a vibration isolation mechanism equipped with a rolling device that is a horizontal movement permitting mechanism. In this rolling device, an upper and lower race are moved relative to each other in the horizontal direction via a plurality of steel balls. Permanent magnets are arranged in the center of the upper and lower races and the retainer that supports the steel balls, and separation is prevented by the mutual magnetic pole attractive force. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Japanese Patent Application Laid-Open No. 2003-120748 [Patent Document 2] Japanese Patent Application Laid-Open No. 2004-347125 [Patent Document 3] Japanese Patent Application Laid-Open No. 2010-31982 Summary of the Invention [Problem to be solved by the invention]

[0007] The configuration of Patent Document 1 requires the use of special rolling elements in which the first curved surface and the second curved surface have different shapes. Furthermore, the configuration of Patent Document 2 involves a complex air spring device configuration. On the other hand, the rolling device of Patent Document 3 involves a configuration in which the upper and lower races move relative to each other via steel balls, and therefore does not require special rolling elements or include an air spring with a complex device configuration.

[0008] However, in the configuration of Patent Document 3, the magnetic forces of the permanent magnets arranged in the upper and lower bearings and the retainer prevent the upper and lower bearings from moving horizontally. For this reason, it can be said that the configuration of Patent Document 3 has room for improvement in terms of realizing a lower natural frequency.

[0009] An object of one aspect of the present invention is to provide an anti-vibration device in which two plates arranged via rolling elements can move freely relative to each other, thereby realizing a low natural frequency. [Means for solving the problem]

[0010] In order to solve the above problems, a vibration isolation device according to one embodiment of the present invention comprises a fixed part whose upper opening is sealed by a first diaphragm, a first bearing mechanism placed on the first diaphragm, and a floating part placed on the first bearing mechanism, wherein the first bearing mechanism includes a first plate arranged on the first diaphragm side, a second plate arranged on the floating part side, a rolling element arranged between the first plate and the second plate, and a shaft part loosely fitted into a through hole provided in each of the first plate and the second plate, and which restricts the relative movement range of the first plate and the second plate in a direction along the plate surface. [Effects of the Invention]

[0011] According to one aspect of the present invention, it is possible to provide a vibration isolation device in which two plates arranged via rolling elements can move freely relative to each other, thereby realizing a low natural frequency. [Brief explanation of the drawings]

[0012] [Figure 1] 1 is a perspective view of the appearance of a vibration isolation device according to a first embodiment of the present invention. [Figure 2] 1 is a cross-sectional view of a vibration isolation device according to a first embodiment. [Figure 3] 3A and 3B are diagrams illustrating a first bearing mechanism provided in the vibration isolation device according to the first embodiment. [Figure 4] FIG. 4 is a perspective view of the first bearing mechanism shown in FIG. 3, with a portion thereof in cross section. [Figure 5] FIG. 3 is an exploded view of a second bearing mechanism provided in the vibration isolation device according to the first embodiment. [Figure 6] 6 is a cross-sectional view taken along the line BB' in FIG. 5. [Figure 7] 4A and 4B are diagrams illustrating a second bearing mechanism provided in the vibration isolation device according to the first embodiment. [Figure 8] 1 is a plan view of a vibration isolation table on which a vibration isolation device according to a first embodiment is disposed. [Figure 9] 5A and 5B are diagrams showing a modified example of the second bearing mechanism provided in the vibration isolation device according to the first embodiment. [Figure 10] FIG. 4 is a cross-sectional view of a vibration isolation device according to a second embodiment of the present invention. [Figure 11] FIG. 10 is a graph showing the measurement results of the horizontal vibration transmissibility of the anti-vibration device according to the embodiment of the present invention. [Figure 12] FIG. 10 is a graph showing the measurement results of the vibration transmissibility in the vertical direction of the anti-vibration device according to the embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0013] [Embodiment 1] <1> Vibration isolator An embodiment of the present invention will be described in detail below. Fig. 1 is an external perspective view of a vibration isolation device 1 according to embodiment 1 of the present invention. For the sake of convenience of explanation, Fig. 1 is a partially see-through view. Fig. 2 is a cross-sectional view taken along line AA' of the vibration isolation device 1 shown in Fig. 1.

[0014] In the following explanation, the position of each component, the positional relationship between components, and the direction of movement will be explained using an XYZ three-dimensional coordinate system, in which the horizontal plane is defined as the XY plane and the vertical axis is defined as the Z axis. The vertical direction is defined as the Z axis direction. The XYZ three-dimensional coordinate system is also shown in each figure.

[0015] The vibration isolation apparatus 1 comprises a ceiling panel 2 that is in direct or indirect contact with an object to be isolated, a hanging panel 3 that hangs down from the periphery of the ceiling panel 2, and a base section 4 that covers the ceiling panel 2 and the hanging panel 3. The object to be isolated may be a stepper 80 (FIG. 8), which will be described later. The ceiling panel 2 and the hanging panel 3 are integrated and function as a so-called "floating section" that is used in a floating state in the vibration isolation apparatus 1 and serves to eliminate vibrations. On the other hand, the base section 4 functions as a so-called "fixed section" that is used in a fixed state in the vibration isolation apparatus 1.

[0016] The base 4 has an upper surface opening 4a that opens upward on its upper surface. As shown in FIG. 2, the upper surface opening 4a is sealed by a first diaphragm 4b. A first bearing mechanism 6 is placed on the first diaphragm 4b via a bearing retainer 4h. A ceiling plate 2 (floating portion) is placed on the first bearing mechanism 6. In other words, as shown in FIG. 2, in the vibration isolation device 1, the first bearing mechanism 6 is disposed between the inner surface of the ceiling plate 2 and the bearing retainer 4h placed on the first diaphragm 4b of the base 4.

[0017] The first diaphragm 4b has its periphery fixed to the periphery of the top opening 4a, and its central portion serves as a pressure-receiving surface. The first diaphragm 4b is configured to operate to support a load substantially in the vertical direction, and is capable of primarily providing a vibration-damping effect in the vertical direction. The first diaphragm 4b may be a so-called BF diaphragm that performs a rolling action, or a so-called general diaphragm that does not perform a rolling action. The first diaphragm 4b may be designed to be extremely thin (e.g., approximately 0.25 to 0.9 mm thick) and may be made of a strong polyester cloth or the like impregnated with rubber. The bearing retainer 4h is not fixed to the first diaphragm 4b, but rests on the first diaphragm 4b. The bearing retainer 4h and the base 4 are fitted together to such an extent that the first diaphragm 4b can operate.

[0018] (First bearing mechanism 6) The following describes the first bearing mechanism 6. The first bearing mechanism 6 includes a first plate 61 arranged on the first diaphragm 4b side (bearing retainer 4h side), a second plate 62 arranged on the ceiling plate 2 (floating portion) side, a rolling element 63 arranged between the first plate 61 and the second plate 62, and a first shaft portion 64.

[0019] The first platen 61 is placed on a bearing retainer 4h that is placed on the pressure-receiving surface located in the center of the first diaphragm 4b. Here, the bearing retainer 4h may be a component that belongs to the diaphragm side together with the first diaphragm 4b, or may be a component that belongs to the first bearing mechanism 6, or it may be a component that does not belong to either of these. The first platen 61 may be fixed to the bearing retainer 4h. The first platen 61 has a platen surface on the side closer to the pressure-receiving surface of the first diaphragm 4b and a platen surface on the side facing the second platen 62, which corresponds to the back surface of the first platen surface. These platen surfaces are substantially horizontal (parallel to the XY plane in FIG. 2) and are circular when viewed from above the vibration isolation device 1.

[0020] The upper surface of the second board 62 may be fixed to the inner surface of the ceiling board 2, or the ceiling board 2 may rest on the second board 62. In a mode in which the second board 62 is fixed to the inner surface of the ceiling board 2, the second board 62 may be fixed directly to the inner surface of the ceiling board 2, or may be fixed indirectly to the inner surface of the ceiling board 2 via another component. The second board 62 has an upper surface (board surface) and a board surface opposite the upper surface that faces the first board. These board surfaces are substantially horizontal (parallel to the XY plane in FIG. 2) and are circular when viewed from above the vibration isolation apparatus 1. The board surface of the second board 62 overlaps with the board surface of the first board 61 in a plan view (top view) (when the first bearing mechanism 6 is viewed from the positive side of the Z axis toward the negative side), and they are the same size.

[0021] The first board 61 and the second board 62 are each provided with through holes 161, 162 into which the first shaft portion 64 (shaft portion) can be loosely fitted. The through holes 161, 162 are located at the center of the surface of each of the first board 61 and the second board 62.

[0022] The first shaft portion 64 is loosely fitted into through holes 161, 162 provided in the first board 61 and the second board 62, respectively. A shaft stopper portion 65 is attached to each of both ends of the first shaft portion 64 to prevent the first shaft portion 64 from falling out of the through holes 161, 162. The shaft stopper portion 65 has an outer diameter larger than the diameter of the through holes 161, 162 through which the first shaft portion 64 is inserted.

[0023] 2, both ends of the first shaft portion 64 to which the shaft slip-out prevention portions 65 are attached are embedded in a recess 261 that opens to the negative side of the Z axis and is provided around the through hole 161 of the first board 61, and a recess 262 that opens to the positive side of the Z axis and is provided around the through hole 162 of the second board 62. As a result, both ends of the first shaft portion 64 do not come into contact with the surface of the bearing retainer 4h that faces the first board 61, or the inner surface of the ceiling board 2.

[0024] In other words, through holes 161, 162 have a region with a small hole diameter and a region with a large hole diameter along the extending direction of the hole. The portion of first shaft portion 64 to which shaft slip-out prevention portion 65 is attached is located in the region with a large hole diameter.

[0025] The first shaft portion 64 restricts the relative movement range of the first platen 61 and the second platen 62 in a direction along the plate surface. This allows the second platen 62 to move freely in the horizontal direction within a predetermined allowable range. Specifically, as shown in FIG. 3, the first platen 61 and the second platen 62 have the same thickness (length in the Z-axis direction), and when this thickness is t, the inclination angle of the first shaft portion 64 is θ, and the radius of the first shaft portion 64 is r, the radius R(i) of the through holes 161, 162 provided in the first platen 61 and the second platen 62, respectively, is expressed by the following formula (1):

number

[0026] The radius R(i) of the through holes 161, 162 referred to here refers to the radius of the portion of each of the through holes 161, 162 through which the shaft anti-slip portions 65 at both ends of the first shaft portion 64 are inserted (corresponding to the area with the small hole diameter mentioned above).

[0027] The tilt angle θ of the first shaft portion 64 is the angle formed between the central axis of each of the through holes 161, 162 and the central axis of the first shaft portion 64. As shown in FIG. 3, when the distance between the first platen 61 and the second platen 62 is D and the stroke length between the first platen 61 and the second platen 62 is s, the tilt angle θ of the first shaft portion 64 is expressed by the following formula (2):

number

[0028] The rolling elements 63 are arranged between the first plate 61 and the second plate 62, with multiple rolling elements lined up along the plate surfaces. In other words, the first bearing mechanism 6 includes multiple rolling elements 63. The diameter of each rolling element 63 is equal to the distance D between the first plate 61 and the second plate 62.

[0029] The rolling element 63 has a surface that contacts the first plate 61 and a surface that contacts the second plate 62 that have the same curvature. As an example, a spherical steel ball can be used for the rolling element 63. Having the same curvature allows for smooth rolling, which contributes to the second plate 62 being able to move freely in the horizontal direction within a predetermined allowable range. Furthermore, using a spherical steel ball may reduce costs compared to using special rolling elements. It is preferable to use a steel ball that is harder (has a higher hardness) than the first plate 61 and the second plate 62. This makes it possible to suppress deterioration of the rolling element 63 over time. Note that the rolling element 63 is not limited to a spherical steel ball.

[0030] The rolling element 63 is held by a retainer 67. Because the rolling element 63 is rotatably held by the retainer 67, the rolling element 63 will not fall out from between the first plate 61 and the second plate 62, and a highly reliable vibration isolation device 1 can be provided.

[0031] As shown in FIG. 2, the retainer 67 is a plate-shaped structure disposed between the first plate 61 and the second plate 62. Here, FIG. 4 is a perspective view of the first bearing mechanism 6, showing only the first bearing mechanism 6. Note that FIG. 4 is a partial cross-sectional view for ease of explanation. As shown in FIG. 4, the retainer 67, which is a plate-shaped structure, is provided with holding holes 67d that rotatably hold the rolling elements 63. A holding hole 67d is provided for each rolling element 63. However, two or more rolling elements 63 may be collectively held by one holding hole.

[0032] To further explain the retainer 67, the retainer 67 includes a main body 67a of a board-shaped structure having a board surface that is substantially horizontal, similar to the first board 61 and the second board 62. The retainer 67 also includes a side portion 67b hanging down from the periphery of the board of the main body 67a. As shown in FIG. 4, the lower end of the side portion 67b abuts against the periphery of the board surface of the first board 61. The main body 67a is provided with a shaft insertion portion 67c through which the first shaft portion 64 passes. The shaft insertion portion 67c has an inner diameter larger than the diameter of the first shaft portion 64.

[0033] The retainer 67 may be formed by integrally forming a main body portion 67a and a side portion 67b, and is made of resin, for example.

[0034] In the base portion 4, an air chamber (not shown) is connected to a first working space S1 of a first diaphragm 4b that supports a load in the vertical direction via a communication hole SS1 (FIG. 1).

[0035] The vibration isolation device 1 of this embodiment includes, in addition to the above-mentioned first bearing mechanism 6, a plurality of second bearing mechanisms 7 on the side surface of the base portion 4. The components related to the second bearing mechanisms 7 will be described below.

[0036] As shown in FIG. 2, the base unit 4 has side openings 4c that open laterally on its side surface. As shown in FIG. 2, the side openings 4c include one side opening 4c on the side surface of the base unit 4 facing the positive direction of the X axis and one side opening 4c on the side surface of the base unit 4 facing the negative direction of the X axis. Both side openings 4c are located at the same height (height along the Z axis) from the bottom end of the base unit 4 (the end furthest along the negative direction of the Z axis). As shown in FIG. 2, each side opening 4c is sealed by a second diaphragm 4d. Note that, while the configuration of one side opening 4c will be described below, the other side opening 4c has the same configuration.

[0037] The second diaphragm 4d has its periphery fixed to the periphery of the side opening 4c, and the center portion of the second diaphragm 4d serves as a pressure-receiving surface. The second diaphragm 4d is configured to operate to support a load substantially in the horizontal direction, and is capable of primarily achieving a vibration-isolating effect in the horizontal direction. Like the first diaphragm 4b, the second diaphragm 4d may be a so-called BF diaphragm that exhibits a rolling action in its operation, or a so-called general diaphragm that does not exhibit a rolling action. Like the first diaphragm 4b, the second diaphragm 4d may be designed to be extremely thin (e.g., approximately 0.25 to 0.9 mm thick) and may be constructed of a strong polyester cloth or the like coated with rubber.

[0038] A second bearing mechanism 7 is provided between the pressure-receiving surface of the second diaphragm 4d and the inner surface of the hanging plate 3 (floating portion). More specifically, a bearing retainer 4e is placed on the pressure-receiving surface of the second diaphragm 4d. The bearing retainer 4e is not fixed to the second diaphragm 4d, but is placed on the second diaphragm 4d. The bearing retainer 4e and the base portion 4 are fitted together to such an extent that the second diaphragm 4d is operable.

[0039] (Second bearing mechanism 7) The following describes the second bearing mechanism 7. The second bearing mechanism 7 includes a third plate 71 (first plate) arranged on the second diaphragm 4d side (bearing retainer 4e side), a fourth plate 72 (second plate) arranged on the hanging plate 3 side, a rolling element 73 arranged between the third plate 71 and the fourth plate 72, and a second shaft portion 74 (shaft portion).

[0040] The third plate 71 is placed on a bearing retainer 4e that is placed on the pressure-receiving surface of the second diaphragm 4d. Here, the third plate 71 is fixed to the bearing retainer 4e. The third plate 71 has a plate surface on the side closer to the pressure-receiving surface of the second diaphragm 4d and a plate surface on the side facing the fourth plate 72, which corresponds to the back surface of the third plate 71. These plate surfaces are substantially vertical surfaces (parallel to the YZ plane in FIG. 2) and are circular when viewed from the side of the vibration isolation device 1 (the positive or negative side of the X axis).

[0041] One side of the fourth plate 72 may be fixed to the inner surface of the hanging plate 3, or may be unfixed and pressed against the inner surface of the hanging plate 3 by the air pressure in the second working space S2. Even when one side of the fourth plate 72 is fixed to the inner surface of the hanging plate 3, the fourth plate 72 may be pressed against the inner surface of the hanging plate 3 by the air pressure in the second working space S2 while being fixed. The fourth plate 72 may be directly fixed to the inner surface of the hanging plate 3, or may be indirectly fixed to the inner surface of the hanging plate 3 via another component. The fourth plate 72 has one side (plate surface) and an opposite plate surface facing the third plate 71. These plate surfaces are substantially vertical (parallel to the YZ plane in FIG. 2 ) and are circular when viewed from the side of the vibration isolation apparatus 1 (the positive or negative side of the X axis).

[0042] Fig. 5 is an exploded view of the second bearing mechanism 7, and for ease of explanation, the second shaft portion 74 is not shown. Fig. 5 shows the surface of the fourth plate 72 facing the third plate 71 and the surface of the third plate 71 facing the fourth plate 72, and shows the state in which there are multiple rolling elements 73 held by a retainer 77 on the third plate 71 side.

[0043] The third and fourth disks 71 and 72 are each provided with through holes 171 and 172 into which the second shaft portion 74 can be loosely fitted. The through holes 171 and 172 are located at the center of the surface of each of the third and fourth disks 71 and 72.

[0044] The second shaft portion 74 is loosely fitted into through holes 171, 172 provided in the third plate 71 and the fourth plate 72, respectively. A shaft retaining portion 75 is attached to each of both ends of the second shaft portion 74 to prevent the second shaft portion 74 from falling out of the through holes 171, 172. The shaft retaining portion 75 has an outer diameter larger than the diameter of the through holes 171, 172.

[0045] Here, Fig. 6 is a cross-sectional view taken along line BB' in Fig. 5. As shown in Figs. 2 and 6, both ends of second shaft portion 74 to which shaft retaining portion 75 is attached may protrude from the surfaces of third plate 71 and fourth plate 72. The protruding portions are configured to be housed in hole 4f (Fig. 2) formed in bearing retainer 4e and hole 3f (Fig. 2) formed in the side surface of hanging plate 3.

[0046] The second shaft portion 74 restricts the relative movement range of the third platen 71 and the fourth platen 72 in a direction along the plate surface (YZ plane). This allows the fourth platen 72 to move freely in the vertical and horizontal directions within a predetermined allowable range. Specifically, as shown in FIG. 7, the third platen 71 and the fourth platen 72 have the same thickness (length in the X-axis direction). When the thickness is t, the inclination angle of the second shaft portion 74 is θ, and the radius of the second shaft portion 74 is r, the radius R(ii) of the through holes 171, 172 provided in the third platen 71 and the fourth platen 72, respectively, is expressed by the following formula (3):

number

[0047] Here, the tilt angle θ of the second shaft portion 74 is the angle formed between the central axis of each of the through holes 171, 172 and the central axis of the second shaft portion 74. As shown in FIG. 7, when the distance between the third plate 71 and the fourth plate 72 is D and the stroke length between the third plate 71 and the fourth plate 72 is s, the tilt angle θ of the second shaft portion 74 is expressed by the following formula (4):

number

[0048] The rolling elements 73 are arranged between the third plate 71 and the fourth plate 72, with multiple rolling elements 73 lined up along the plate surfaces. In other words, the second bearing mechanism 7 includes multiple rolling elements 73. The diameter of the rolling elements 73 is equal to the distance D between the third plate 71 and the fourth plate 72. The diameter of the rolling elements 73 may be the same as or different from that of the rolling elements 63 of the first bearing mechanism.

[0049] Furthermore, the surfaces of the rolling elements 73 that come into contact with the third plate 71 and the fourth plate 72 have the same curvature. Specifically, spherical steel balls can be used for the rolling elements 73, similar to the rolling elements 63 of the first bearing mechanism 6. It is preferable to use steel balls that are harder (have a higher hardness) than the third plate 71 and the fourth plate 72.

[0050] The number of rolling elements 63 and 73 to be arranged can be determined appropriately based on the required specifications, etc. Although one rolling element is sufficient from a structural standpoint, at least three rolling elements are arranged to allow the board to move smoothly along the board surface. In one example, five or more, preferably ten, rolling elements 63 are arranged in the first bearing mechanism 6. Furthermore, three or more rolling elements 73 are arranged in the second bearing mechanism 7.

[0051] The rolling elements 73 are held by a retainer 77. Because the rolling elements 73 are rotatably held by the retainer 77, they will not fall out from between the third plate 71 and the fourth plate 72, making it possible to provide a highly reliable vibration isolation device 1. As shown in FIG. 5 , the retainer 77 is a plate-shaped structure disposed between the third plate 71 and the fourth plate 72. The retainer 77 is provided with holding holes 77d that rotatably hold the rolling elements 73. One holding hole 77d is provided for each rolling element 73. However, two or more rolling elements 73 may be held together by one holding hole.

[0052] The retainer 77 is provided with a shaft insertion portion 77c through which the second shaft portion 74 is inserted. The shaft insertion portion 77c has an inner diameter larger than the diameter of the second shaft portion 74. The retainer 77 is held by the third plate 71 and the fourth plate 72 via the second shaft portion 74. The retainer 77 may have the same configuration as the retainer 67 of the first bearing mechanism 6. However, the retainer 77 may be composed of only the plate-shaped main body portion 67a without the side portion 67b included in the retainer 67.

[0053] The base portion 4 has a second working space S2 for each second diaphragm 4d that supports vertical and horizontal loads, and the second working space S2 is connected to an air chamber (not shown) via a communication hole SS2 (Figure 1).

[0054] In order to reduce the size of the vibration isolation device 1, the size of the floating portion formed by the ceiling panel 2 and the hanging panel 3 may be reduced, while a relief window 3c as shown in Fig. 1 may be provided in the hanging panel 3 so that the floating portion can move freely in the horizontal direction within a predetermined allowable range relative to the base panel 4. The relief window 3c may not be provided, or an opening area different from the relief window 3c in the embodiment shown in Fig. 1 may be provided.

[0055] As described above, in the first bearing mechanism 6, the first shaft portion 64 is loosely fitted into the through holes 161, 162 provided in the first platen 61 and the second platen 62, respectively. This allows the second platen 62 to move freely in the horizontal direction within a predetermined allowable range, thereby providing a vibration isolation device that achieves a low natural frequency. Furthermore, in the second bearing mechanism 7, the rolling element 73 is sandwiched between the third platen 71 and the fourth platen 72, which are relatively movable in the vertical direction within a predetermined allowable range, thereby effectively suppressing vibration transmissibility in the horizontal direction. In addition, because the rolling element 73 is a spherical steel ball, the first (second) bearing mechanism can slide smoothly in the horizontal direction (vertical direction), thereby reducing the natural frequency in the horizontal direction.

[0056] Specifically, with the vibration isolation device 1 of this embodiment, the natural frequency in the horizontal direction can be set to 1.00 or less, preferably 0.8 or less, and with the vibration isolation device 1 of this embodiment, the natural frequency in the vertical direction can be set to 2.55 or less, preferably 2.2 or less.

[0057] <2> Vibration isolation table An example of a vibration isolation table 100 equipped with the above-described vibration isolation apparatus 1 is shown in Fig. 8. Fig. 8 is a plan view showing a state in which the vibration isolation apparatus is installed directly or indirectly under a plate-shaped stepper support base 90 on which a stepper 80, which is an object to be isolated from vibration, is placed.

[0058] 8, the vibration isolation table 100 has a configuration in which the vibration isolation device 1 is placed directly or indirectly under a plate-shaped stepper support table 90 that supports a stepper 80, which is an object to be isolated from vibrations. This arrangement is designed to remove vibrations generated by the stepper 80 (object to be isolated from vibrations) and to prevent vibrations from the floor from being transmitted to the stepper 80.

[0059] Depending on the number of vibration isolation devices 1 to be installed and how they are arranged (see FIG. 8), it is not necessary to provide the second diaphragms 4d and the second bearing mechanisms 7 on all four side surfaces of the base unit 4 of all vibration isolation devices 1. That is, as shown in FIG. 1, the second diaphragms 4d and the second bearing mechanisms 7 may be arranged on only two opposing surfaces of the four side surfaces of the base unit 4 of each vibration isolation device 1 (a pair arranged in a mirror image relationship).

[0060] 8, the stepper support table 90 has a rectangular shape when viewed from above, and has an anti-vibration device 1CH1 located at the center of one of its long edges, and anti-vibration devices 1CH2 and 1CH3 located at both ends of the other long edge. In this example of arrangement, the first bearing mechanism 6 of the anti-vibration device 1CH1 has ten rolling elements, while the first bearing mechanism 6 of each of the anti-vibration devices 1CH2 and 1CH3 may have five rolling elements.

[0061] [Modification] In the above-described embodiment, the second shaft portion 74 provided in the second bearing mechanism 7 is located at the center of the surfaces of the third and fourth boards 71 ​​and 72. However, this is not limited to this. For example, as shown in FIG. 9, the second shaft portion 74' may be installed at two locations on the positive side of the Z axis from the center of the surfaces of the third and fourth boards 71 ​​and 72. These two locations are located a predetermined distance apart in the Y axis direction.

[0062] Even in this modified example, the second shaft portion 74' is loosely fitted into the through holes 171, 172 of the third plate 71 and the fourth plate 72, and in the second bearing mechanism 7' of this modified example, as with the second bearing mechanism 7 of the above-mentioned embodiment, the rolling element 73 is sandwiched between the third plate 71 and the fourth plate 72, which can move relative to each other in the vertical direction within a predetermined allowable range, thereby effectively suppressing the vibration transmission rate in the vertical direction.

[0063] [Embodiment 2] Other embodiments of the present invention will be described below. For ease of explanation, the same reference numerals will be used to designate components having the same functions as those described in the above embodiment, and the description thereof will not be repeated.

[0064] Fig. 10 is a cross-sectional view of the vibration isolation device of this embodiment, and corresponds to Fig. 2 in the first embodiment. In the first embodiment described above, the retainer 67 provided in the first bearing mechanism 6 is a disk-shaped structure made of resin. In contrast, the vibration isolation device 1' of this embodiment differs from the first embodiment in that the retainer 67' provided in the first bearing mechanism 6 includes a biasing member.

[0065] Specifically, the retainer 67' provided in the first bearing mechanism 6 of this embodiment is a coil spring that is a biasing member.

[0066] The retainer 67', which is a coil spring, has one end abutting against the first plate 61 and the other end abutting against the second plate 62. A rolling element 63 is arranged in the hollow portion of the core of the coil spring. The rolling element 63, arranged in the hollow portion of the core of the coil spring, is held rotatably between the first plate 61 and the second plate 62 by the coil spring. The diameter of the hollow portion of the core of the coil spring is slightly larger than the diameter of the rolling element 63.

[0067] The retainer 67', which is a coil spring, is made of a metal wire (e.g., stainless steel wire, hard steel wire, or piano wire) having a wire diameter of 0.3 mm to 1.0 mm, preferably 0.5 mm to 0.8 mm, wound in a coil shape. If the wire diameter of the coil exceeds 1.0 mm, friction will create resistance when the rolling element 63 rolls. Furthermore, if the wire diameter of the coil is less than 0.3 mm, the rolling element 63 will not be held securely. Therefore, a coil spring having a wire diameter between the above-mentioned wire diameter ranges is configured to not impede the rolling element 63, but to prevent the rolling element 63 from rolling beyond a predetermined allowable range and falling, and to bias the curved surface of the rolling element 63 to keep the rolling element 63 within the allowable range.

[0068] 10, one coil spring is provided for each rolling element 63. However, this is not limiting, and one coil spring may be provided for two or more rolling elements 63.

[0069] 10, in the first bearing mechanism 6' of this embodiment, the first shaft portion 64 (see FIG. 2, etc.) described in the first embodiment is inserted into the through holes of the first board 61 and the second board 62. The relationship between the through holes of the first board 61 and the second board 62 and the first shaft portion 64 is the same as that described in the first embodiment.

[0070] According to the configurations of the above-described embodiments, it is possible to provide a vibration isolation device that realizes a low natural frequency. Such an effect will also contribute to the achievement of, for example, Goal 9 of the Sustainable Development Goals (SDGs) advocated by the United Nations, "Build resilient infrastructure, promote inclusive and sustainable industrialization, and promote innovation and resilience."

[0071] [Appendix 1] The present invention is not limited to the above-described embodiments, and various modifications are possible within the scope of the claims. Embodiments obtained by appropriately combining the technical means disclosed in different embodiments are also included in the technical scope of the present invention.

[0072] [Appendix 2] The vibration isolation device according to aspect 1 of the present invention comprises a fixed part whose upper opening is sealed by a first diaphragm, a first bearing mechanism placed on the first diaphragm, and a floating part placed on the first bearing mechanism, wherein the first bearing mechanism includes a first plate arranged on the first diaphragm side, a second plate arranged on the floating part side, a rolling element arranged between the first plate and the second plate, and a shaft part loosely fitted into a through hole provided in each of the first plate and the second plate, and which restricts the relative movement range of the first plate and the second plate in a direction along the plate surface.

[0073] According to the first aspect, the two plates arranged via the rolling elements can move freely relative to each other, and it is possible to provide a vibration isolation device that achieves a low natural frequency.

[0074] Specifically, while in Patent Document 3 the horizontal movement of the board is hindered by magnetic force, in the configuration of Aspect 1, the shaft portion of the first bearing mechanism is loosely fitted into through holes provided in the first board and the second board, allowing the second board to move freely in the horizontal direction within a predetermined allowable range. As a result, it is possible to provide a vibration isolation device that achieves a lower natural frequency than before.

[0075] A vibration isolation device according to a second aspect of the present invention may be configured as follows: in the first aspect, the fixed portion has a side opening sealed by a second diaphragm, and further includes a second bearing mechanism between the second diaphragm and the floating portion; the second bearing mechanism includes a first plate arranged on the second diaphragm side, a second plate arranged on the floating portion side, a rolling element arranged between the first plate and the second plate, and a shaft portion loosely fitted into a through hole provided in each of the first plate and the second plate, and which restricts the relative range of movement of the first plate and the second plate in a direction along the plate surface.

[0076] According to the configuration of the second aspect, the second bearing mechanism is provided in addition to the first bearing mechanism. The second bearing mechanism sandwiches the rolling elements between the first and second plates, which are relatively movable in the vertical direction within a predetermined allowable range, and therefore can effectively suppress vibration transmissibility in the vertical direction.

[0077] A vibration isolation device according to aspect 3 of the present invention may be configured in the manner of aspect 1 or 2, wherein the rolling elements are held by a retainer, the retainer being a plate-like structure arranged between the first plate and the second plate, and the plate-like structure being provided with a retaining hole that holds the rolling elements in a rotatable manner.

[0078] According to the configuration of the third aspect, the rolling element is rotatably held by the retainer, which is the plate-shaped structure, so that the rolling element does not fall out from between the first plate and the second plate, and a highly reliable vibration isolation device can be provided.

[0079] The vibration isolation device according to aspect 4 of the present invention may be configured as in aspect 1 or 2, wherein the rolling element is rotatably held by a retainer including a biasing member disposed between the first plate and the second plate.

[0080] According to the configuration of the fourth aspect, the rolling element is rotatably held by a retainer including the biasing member, so that the rolling element does not fall out from between the first plate and the second plate, and a highly reliable vibration isolation device can be provided.

[0081] A vibration isolation device according to a fifth aspect of the present invention may be configured in the fourth aspect, such that the retainer includes a coil spring as the biasing member, one end of the coil spring abutting against the first plate and the other end abutting against the second plate, and the rolling element is arranged in a hollow portion of the core of the coil spring.

[0082] According to the configuration of the fifth aspect, the rolling element is rotatably held by a retainer including the coil spring, so that the rolling element does not fall from between the first plate and the second plate, and a highly reliable vibration isolation device can be provided.

[0083] The vibration isolation device according to aspect 6 of the present invention is any one of aspects 1 to 5, and may be configured such that the surface of the rolling element that abuts against the first plate and the surface that abuts against the second plate have equal curvatures.

[0084] According to the configuration of the sixth aspect, the first (second) bearing mechanism can slide smoothly in the horizontal direction (vertical direction), and the natural frequency in the horizontal direction can be reduced.

[0085] A seventh aspect of the present invention relates to the vibration isolation device of any one of the first to sixth aspects, and may be configured such that the first bearing mechanism includes a plurality of the rolling elements.

[0086] According to the configuration of the seventh aspect, the first bearing mechanism can slide smoothly in the horizontal direction, and the natural frequency in the horizontal direction can be reduced.

[0087] An anti-vibration device according to an eighth aspect of the present invention may be configured in accordance with the second aspect, wherein the second bearing mechanism includes a plurality of the rolling elements.

[0088] According to the configuration of the eighth aspect, the second bearing mechanism can slide smoothly in the horizontal and vertical directions, and the natural frequency in the horizontal direction can be reduced.

[0089] A ninth aspect of the present invention relates to the vibration isolation device of any one of the first to eighth aspects, wherein the rolling elements are spherical steel balls.

[0090] According to the configuration of the ninth aspect, by providing rolling elements made of spherical steel balls, the first (second) bearing mechanism can slide smoothly in the horizontal direction (vertical direction), thereby reducing the natural frequency in the horizontal direction.

[0091] A tenth aspect of the present invention relates to the vibration isolation device of any one of the first to ninth aspects, wherein the first and second plates have the same thickness, and when the thickness is t, the inclination angle of the shaft portion is θ, and the radius of the shaft portion is r, the radius R of the through holes provided in each of the first and second plates is expressed by the following formula (1):

number

number

[0092] An example of the present invention will be described below. In this example, the vibration isolation apparatus 1 of embodiment 1 was mounted at three locations on the vibration isolation table 100 shown in FIG. 8. The natural frequency in the horizontal direction of this vibration isolation table 100 was measured. In measuring the natural frequency in the horizontal direction, the horizontal vibration transmissibility was measured using FFT analysis (Fast Fourier Transform analysis). The natural frequency in the horizontal direction was calculated based on the measurement results of the horizontal vibration transmissibility.

[0093] The measurement results of the horizontal vibration transmissibility are shown in Fig. 11. The natural frequency in the horizontal direction based on the measurement results shown in Fig. 11 was 1.00 Hz. This result shows that a vibration isolation system with high vibration isolation performance has been achieved.

[0094] Furthermore, the measurement results of the vibration transmissibility in the vertical direction (perpendicular direction) of this vibration isolation table are shown in Figure 12. The natural frequency in the vertical direction based on the measurement results shown in Figure 12 was 2.53 Hz. This result also shows that a vibration isolation system with high vibration isolation performance has been achieved. [Explanation of symbols]

[0095] 1 Vibration isolator 2 Ceiling panels 3 hanging plate 4 Base 4a Top opening 4b First diaphragm 4c Side opening 4d Second diaphragm 4e Bearing retainer 6 First bearing mechanism 7 Second bearing mechanism 61 Volume 1 62 Volume 2 63, 73 Roller 64 First shaft (shaft) 67, 67´, 77 retainer 67a Main body 67b Side 67c, 77c shaft insertion part 67d, 77d holding hole 71 Volume 3 (Volume 1) 72. Set 4 (Set 2) 74. Second Shaft Section (Shaft Section) 100 Vibration Isolation Table Through holes 161, 162, 171, 172

Claims

1. a fixed portion having an upper surface opening sealed by a first diaphragm; a first bearing mechanism mounted on the first diaphragm; a floating portion mounted on the first bearing mechanism, The first bearing mechanism comprises: a first plate disposed on the first diaphragm side; A second board disposed on the floating portion side; A rolling element disposed between the first plate and the second plate; a shaft portion loosely fitted into a through hole provided in each of the first board and the second board, the shaft portion restricting the relative movement range of the first board and the second board in a direction along the board surface; A vibration isolation device characterized by:

2. the fixing portion has a side opening sealed by a second diaphragm; a second bearing mechanism is further provided between the second diaphragm and the floating portion; The second bearing mechanism is a first plate disposed on the second diaphragm side; A second board disposed on the floating portion side; A rolling element disposed between the first plate and the second plate; a shaft portion loosely fitted into a through hole provided in each of the first board and the second board, the shaft portion restricting the relative movement range of the first board and the second board in a direction along the board surface; 2. The vibration isolation device according to claim 1.

3. The rolling elements are held by a retainer, the retainer is a plate-shaped structure disposed between the first plate and the second plate, The plate-like structure is provided with a holding hole that holds the rolling element so that it can roll.

3. The vibration isolation device according to claim 1, wherein the vibration isolation device is a vibration isolation device.

4. The rolling elements are rotatably held by a retainer including a biasing member disposed between the first plate and the second plate.

3. The vibration isolation device according to claim 1, wherein the vibration isolation device is a vibration isolation device.

5. the retainer includes a coil spring as the biasing member, One end of the coil spring abuts against the first plate and the other end abuts against the second plate, The rolling element is disposed in a hollow portion of a core portion of the coil spring.

5. The vibration isolation device according to claim 4.

6. The rolling element has a surface that contacts the first plate and a surface that contacts the second plate that have equal curvatures.

3. The vibration isolation device according to claim 1, wherein the vibration isolation device is a vibration isolation device.

7. the first bearing mechanism includes a plurality of the rolling elements; 3. The vibration isolation device according to claim 1, wherein the vibration isolation device is a vibration isolation device.

8. the second bearing mechanism includes a plurality of the rolling elements; 3. The vibration isolation device according to claim 2.

9. The rolling elements are spherical steel balls.

3. The vibration isolation device according to claim 1, wherein the vibration isolation device is a vibration isolation device.

10. The first plate and the second plate have the same thickness, and when the thickness is t, the inclination angle of the shaft portion is θ, and the radius of the shaft portion is r, The radius R of the through holes provided in each of the first plate and the second plate is expressed by the following formula (1): [Equation 1] Here, the inclination angle θ of the shaft portion is the angle formed between the central axis of the through hole and the central axis of the shaft portion, When the distance between the first plate and the second plate is D and the stroke length between the first plate and the second plate is s, The inclination angle θ of the shaft portion is expressed by the following formula (2): [Equation 2] 3. The vibration isolation device according to claim 1, wherein the vibration isolation device is a vibration isolation device.

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