JP5501880B2 - Free ball bearings and bearing devices - Google Patents

Description

  The present invention relates to a free ball bearing and a bearing device suitable for application to a support table, a turntable, etc. used for conveying or positioning articles, for example, processing on semiconductor substrates and printed wiring boards, mounting of electronic components, flat panels. The present invention relates to a free ball bearing that can be used in the manufacture of electronic components such as semiconductor elements and semiconductor packages, food and pharmaceuticals, and a bearing device using the free ball bearing.

For example, in a transport facility for transporting an article, it is configured to support the article to be transported using a free ball bearing having a structure in which one ball (main ball) that is rotatable in all directions is projected. Is often adopted.
In such a transport facility, in order to stop or decelerate the movement of the article being conveyed, a configuration provided with a stopper that impacts the article, a cushion, a guide member that contacts the article, etc., apart from the free ball bearing In recent years, a structure has been proposed in which a free ball bearing itself can apply a braking force to an article being conveyed (for example, Patent Document 1). Such a transfer facility using a free ball bearing has an advantage that it is unnecessary to install a stopper, a cushion, a guide member and the like.

The free ball bearing (transfer sphere support device) described in FIGS. 1A and 1B of Patent Document 1 described above is a concave spherical member that rotatably supports a main sphere on a concave spherical surface via a plurality of subspheres. And a lid member having an inner hole from which the upper part of the main sphere protrudes, and a free rolling state of the main sphere in which an edge of the inner hole approaches with a small gap between the main sphere and the inner sphere The braking state of the main sphere in which the edge of the hole is in press contact with the main sphere can be switched.
2 (a) and 2 (b) of Patent Document 1, a pressurizing member having an annular subsphere contact portion is moved up and down by a driving means (specifically, an electromagnet 34 constituted by an electromagnetic wire ring), A free ball bearing (transfer) which restrains the rolling of the secondary sphere by bringing the secondary sphere contact portion into contact with the upper edge of the secondary sphere group when the pressure member is lowered, and gives a braking action to the rotation of the primary sphere. Sphere support device).

Japanese Patent Laid-Open No. 2004-1987

In the configuration in which the lid member is brought into contact with the main sphere and the main sphere is braked as in the free ball bearing (transfer sphere support device) described in FIGS. May cause damage to the main sphere, and a groove formed on the surface of the main sphere may cause a gap between the main sphere and make it difficult to give movement resistance to the moving article.
As shown in FIGS. 2A and 2B of Patent Document 1, the configuration in which the auxiliary sphere is pressed by the elevating pressure member can stably maintain the performance of giving desired movement resistance to the article over a long period of time. It is advantageous.

By the way, free ball bearings used for, for example, processing of semiconductor substrates and printed wiring boards, mounting of electronic components, manufacturing of flat panels, manufacturing of electronic components such as semiconductor elements and semiconductor packages, and manufacturing of food and pharmaceuticals are expensive. Dustproofness is required.
In the free ball bearing (transfer sphere support device) described in FIGS. 1A and 1B of Patent Document 1 described above, contact with the main sphere of the lid member occurs, and FIG. In the free ball bearing (transfer sphere support device) described in b), the pressing member that moves up and down on the lower side of the lid member (reference numeral 5a in Patent Document 1) and the secondary sphere contact. For this reason, there has been a demand for preventing scattering of particles.

  Further, the free ball bearing having the above structure has a complicated structure for braking the main sphere, and it has not been easy to reduce the size and cost.

  In view of the above-described problems, an object of the present invention is to provide a free ball bearing and a bearing device capable of simplifying the structure and preventing particle scattering.

The free ball bearing of the present invention includes a main body having a ball receiving portion in which a ball receiving recess having a hemispherical concave surface as an inner surface is formed, a plurality of receiving balls disposed on the hemispherical concave surface of the main body, A main sphere formed in a larger diameter than the receiving ball and rotatably supported by the hemispherical concave surface via the receiving ball; and a housing-like cover portion provided so as to surround the ball receiving portion of the main body The cover portion is formed with a main sphere protruding opening for protruding a part of the main sphere, and the cover portion is inserted between the hemispherical concave surface of the main body and the main sphere. A holding piece that increases the rotational resistance of the main sphere by restricting the movement of the receiving ball, and the main body is in a direction that matches the depth direction of the recess for receiving the ball with respect to the cover portion. It is possible to move in the height direction of the ball receiver. Te, a position for restricting movement of the pressing piece is subjected ball, the regulating spaced apart from the pressing pieces receiving ball is free ball bearing is capable of switching and is released positions.
In the free ball bearing of the present invention, the cover portion has a base end side portion surrounding the ball receiving portion of the main body, the main body has a shaft portion protruding from the ball receiving portion, and the shaft portion is The main body can be moved in the height direction of the ball receiving portion by protruding from the base end portion and moving the protruding portion in the direction of the ball receiving portion. .
In the free ball bearing of the present invention, the cover portion includes a cover portion main body and a receiving ball pressing ring provided in the cover portion main body, and the pressing piece is formed in the receiving ball pressing ring. Free ball bearing.
The free ball bearing of the present invention is a free ball bearing in which the pressing piece is formed integrally with the cover portion.
The free ball bearing of the present invention is a free ball bearing provided with a restriction releasing mechanism that urges the main body in a direction away from the pressing piece.
The bearing device of the present invention includes the free ball bearing, a support body that supports the free ball bearing, and a lifting mechanism that moves the main body of the free ball bearing in the height direction of the ball receiving portion. It is.

According to the free ball bearing of the present invention, the main body can be moved in the height direction of the ball receiving portion, and by the movement of the main body, the holding piece is inserted between the hemispherical concave surface and the main sphere to move the receiving ball. It is possible to switch between a position where the restriction is restricted and a position where the restriction is released.
At the movement restricting position, since the pressing piece is inserted between the hemispherical concave surface and the main sphere, the pressing piece functions to suppress scattering of particles from the ball receiving recess.
Therefore, contamination due to scattering of particles can be prevented.
Moreover, since the main body has a structure surrounded by the cover part, the movement in the height direction can be realized by a mechanism that moves the main body in the height direction at the center position.
Therefore, the structure can be simplified, and downsizing and cost reduction can be achieved.

In the free ball bearing of a 1st embodiment concerning the present invention, it is a figure showing the state where braking of a receiving ball by a receiving ball press ring is not performed, (a) is a fragmentary sectional view, and (b) is a bottom view. It is. It is a fragmentary sectional view which shows the braking state of the receiving ball of the free ball bearing of a front figure. In the free ball bearing of a 2nd embodiment concerning the present invention, it is a fragmentary sectional view showing the state where braking of a receiving ball by a receiving ball press ring is not performed. It is a fragmentary sectional view which shows the braking state of the receiving ball of the free ball bearing of a front figure. In the free ball bearing of a 3rd embodiment concerning the present invention, it is a fragmentary sectional view showing the state where the receiving ball is not braked by the receiving ball press ring. It is a fragmentary sectional view which shows the braking state of the receiving ball of the free ball bearing of a front figure. In the free ball bearing of a 4th embodiment concerning the present invention, it is a fragmentary sectional view showing the state where the receiving ball is not braked by the receiving ball press ring. It is a fragmentary sectional view which shows the braking state of the receiving ball of the free ball bearing of a front figure. It is a fragmentary sectional view showing one embodiment of a bearing device concerning the present invention. It is a fragmentary sectional view which shows the state which supported the to-be-supported object in the bearing apparatus of the front figure.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
(First embodiment)
A free ball bearing according to a first embodiment of the present invention will be described with reference to FIGS. In the following description, the upper side in FIG.
1A and 1B show a free ball bearing 10A according to a first embodiment, in which FIG. 1A is a partial cross-sectional view in a state where a receiving ball 41 is not braked, and FIG. 1B is a bottom view. FIG. 2 is a partial sectional view showing a braking state of the receiving ball 41 of the free ball bearing 10A.

The free ball bearing 10 </ b> A includes a main body 20, a housing-like cover portion 30 provided so as to surround the ball receiving portion 23 of the main body 20, and a plurality of receiving balls 41 arranged on the hemispherical concave surface 21 of the ball receiving portion 23. And a main sphere 42 rotatably supported on the hemispherical concave surface 21 via a receiving ball 41, and a spring 60 (regulation release mechanism) that elastically biases the main body 20 downward in the height direction of the ball receiving portion. ing.
Reference numeral 80 is a mounting table on which a supported object (not shown) is mounted, and reference numeral 80a is a passage through which the free ball bearing 10A can pass.

The main body 20 includes a block-shaped sphere receiving portion 23 in which a sphere receiving recess 22 having a hemispherical concave surface 21 as an inner surface is formed, and an opposite side of the opening of the sphere receiving recess 22 of the sphere receiving portion 23 ( The shaft portion 24 protrudes downward from the end portion on the base end side.
In FIG. 1A, an imaginary line indicated by reference numeral 20 a is the central axis of the shaft portion 24 of the main body 20. The center of the opening of the ball receiving recess 22 of the main body 20 and the deepest portion of the ball receiving recess 22 are located on the central axis 20a. Hereinafter, the central axis 20a is also referred to as a main body axis.
The main body 20 is configured to be movable in the height direction of the ball receiving portion (the vertical direction in FIGS. 1A and 2, the direction of the central axis 20 a), which is the direction coinciding with the depth direction of the ball receiving recess 22. ing.

The shaft portion 24 includes a shaft portion main body 26 that protrudes from an end surface (bottom surface 23 a) on the base end side of the ball receiving portion 23, and a receiving member 25 that is attached to the shaft portion main body 26.
The shaft body 26 is formed with an attachment hole 26b that opens to the tip 26a (lower end), and the receiving member 25 is attached to the attachment hole 26b.

The receiving member 25 serves as a receiving portion with which the lower end of the spring 60 comes into contact. The receiving member 25 has a head portion 25a and a screw shaft 25c extending from the upper surface 25b of the head portion 25a. The screw shaft 25c is a mounting hole portion 26b. And is screwed onto a threaded portion (not shown) on the inner surface of the mounting hole 26b.
The lower end portions of the shaft body 26 and the receiving member 25 protrude below the lower end portion 32i of a cylindrical shaft portion 32c (described later).
In the illustrated example, the shaft portion 24 is integrally formed with the ball receiving portion 23. However, the present invention is not limited to this, and the shaft portion may be configured separately from the ball receiving portion. In that case, the shaft portion can be made of metal.

The cover portion 30 includes a cover portion main body 30A, and a receiving ball pressing ring 50 provided in the inner space 11 secured between the ball receiving portion 23 and the cover portion main body 30A.
The cover portion main body 30A is configured by attaching a ring-shaped cap 33 to the outer peripheral portion of the base end side cover member 32 (base end side portion).
The base end side cover member 32 includes a ring-shaped bottom plate 32a, a peripheral wall portion 32b provided on the outer periphery of the bottom plate 32a and projecting to the upper surface side of the bottom plate 32a, and a cylindrical shaft portion 32c projecting to the lower surface side of the bottom plate 32a. And.
The peripheral wall portion 32 b is formed so as to surround the periphery of the ball receiving portion 23 of the main body 20.

A male screw 32f is formed on the outer surface of the cylindrical shaft portion 32c, and the cylindrical shaft portion 32c is inserted into the female screw hole 81a of the support 81 and screwed to the female screw 81b on the inner surface of the female screw hole 81a.
On the inner surface of the insertion hole 32g formed in the cylindrical shaft portion 32c, a thinned recess 32h is formed in a predetermined height range from the lower end portion 32i of the cylindrical shaft portion 32c. The step 32e at the upper end of the thinned recess 32h serves as a receiving portion with which the upper end of the spring 60 abuts.
In the state (standby state) shown in FIG. 1A, the bottom plate 32 a of the base end side cover member 32 is in contact with the bottom surface 23 a of the ball receiving portion 23.

The cap 33 includes a ring-shaped lid plate portion 33a in which a main sphere protruding opening 31 is formed, and a side wall portion 33b that hangs down from the outer peripheral edge thereof, and the ball receiving portion 23 is formed by the lid plate portion 33a. Is provided so as to cover an end surface (tip surface 23 b) around the opening of the ball receiving recess 22.
The cap 33 is formed by fitting a fitting convex portion 33c formed on the inner peripheral side of the side wall portion 33b into a fitting concave portion 32d formed on the outer peripheral side of the peripheral wall portion 32b of the base end side cover member 32. The end cover member 32 is attached.

The inner diameter of the main sphere protruding opening 31 is made smaller than the diameter of the main sphere 42 to prevent the main sphere 42 from falling off, and a part of the main sphere 42 protrudes outward (upward in FIG. 1A). It is set to let you.
The inner diameter of the main sphere protruding opening 31 is such that the main sphere 42 floats between the inner peripheral surface of the main sphere protruding opening 31 and the main sphere 42 in a state where the main sphere 42 is supported by the receiving sphere 41. The clearance C that enables this is secured.

The receiving ball holding ring 50 includes a ring-shaped top plate portion 51 disposed between the cover plate portion 33 a of the cap 33 and the tip end surface 23 b of the ball receiving portion 23, and the entire circumference of the inner peripheral end of the top plate portion 51. And a ring-shaped pressing piece 52 protruding downward in a rib shape.
The holding piece 52 is configured to be inserted between the hemispherical concave surface 21 of the main body 20 and the main sphere 42 so as to restrict the movement of the receiving ball 41.
The outer diameter of the pressing piece 52 is slightly smaller than the inner diameter of the opening of the ball receiving recess 22, and when the main body 20 is in the raised position (see FIG. 2), the pressing piece 52 is hemispherical of the ball receiving recess 22. It does not contact the concave surface 21. At this time, the holding piece 52 does not contact the main ball 42.

  The main sphere 42 has a larger diameter than the receiving sphere 41 and is rotatably supported by the hemispherical concave surface 21 via the receiving sphere 41.

  The free ball bearing 10A in the illustrated example has the main body axis 20a fixed in the vertical direction, but is not limited thereto, and can be used in a direction in which the main body axis 20a is inclined with respect to the vertical direction.

As the main body 20 of the free ball bearing 10 </ b> A, the cover body 30 </ b> A, the receiving ball 41 and the main ball 42, and the receiving ball holding ring 50, a metal, a plastic, or the like can be adopted.
As the main sphere 42, it is possible to adopt a conductive (surface resistivity is 10 ³ to 10 ¹⁰ Ω / □) or a semiconductive resin.

As the conductive resin material for forming the main sphere ball 42, a material obtained by dispersing and mixing a conductive metal filler in the base resin, a material obtained by adding an antistatic polymer to the base resin, or the like can be used.
Base resins include POM (polyacetal), PAI (polyamideimide), PBI (polybenzimidazole), PCTFE (polychlorotrifluoroethylene), PEEK (polyetheretherketone), PEI (polyetherimide), PI (polyimide) ), PPS (polyphenylene sulfide), melamine resin, aromatic polyamide resin (aramid resin), and the like. Further, LCP (liquid crystal polymer), PBT (polybutylene terephthalate), PES (polyether sulfone), and other resins can also be used. Vespel (registered trademark of DuPont, which is an aromatic polyamide resin) and PBI are preferable from the viewpoint of stability of characteristics with respect to the environment in the vacuum apparatus.
The receiving ball 41 and the main body 20 can also be made of a semiconductive resin.

As for the main body 20, the cover part main body 30A, and the receiving ball pressing ring 50, those formed of the conductive resin material can be adopted.
In addition, as the main body 20 of the free ball bearing, the cover body 30A, the receiving ball 41 and the main ball 42, and the receiving ball holding ring 50 according to the present invention, a material that is not conductive or semiconductive (for example, metal It is also possible to adopt a material formed of plastic, etc.

In the state shown in FIG. 1A, since the head portion 25a of the receiving member 25 is biased downward by the spring 60, the main body 20 has a lower standby position (the bottom surface 23a of the ball receiving portion 23 is the base end side cover member). 32 at a position in contact with the bottom plate 32a.
Since the main body 20 is in the standby position, the receiving ball pressing ring 50 is at a position spaced upward from the receiving ball 41 in the ball receiving portion 23. In this state, since the movement of the receiving ball 41 is not limited, the rotational resistance of the main ball 42 is relatively small.
When the main body 20 is in the standby position, the pressing piece 52 is disposed at a position where the receiving ball 41 can be prevented from jumping out from the ball receiving recess 22.
For this reason, even in this standby position, since the pressing piece 52 is almost closed between the inner surface near the opening of the ball receiving recess 22 and the main ball 42, the pressing piece 52 is used for ball receiving. It functions to suppress scattering of particles from the recess 22.

As shown in FIG. 2, the protruding portion of the shaft portion 24 (the portion where the shaft portion 24 protrudes from the cylindrical shaft portion 32c) is pressed upward (in the direction of the ball receiving portion 23) by the push-up shaft 82, and the main body 20 is pressed by the spring 60. When the pressure piece 52 is pushed up against the urging force, the holding piece 52 is inserted between the hemispherical concave surface 21 and the main ball 42 from the opening side of the ball receiving recess 22 of the ball receiving portion 23 to receive the receiving ball 41. Regulate the movement of
As a result, the rotation of the receiving ball 41 of the ball receiving portion 23 is suppressed, and the rotation resistance of the main ball 42 increases.
In the state shown in FIG. 2, the upper surface 25b of the head portion 25a of the receiving member 25 abuts on the lower end portion 32i of the cylindrical shaft portion 32c, and the upward movement of the main body 20 is restricted. For this reason, it can prevent that an excessive force is applied to the ball | bowl receiving part 23 and the receiving sphere 41, and a damage arises.
Further, a clearance C that allows the main sphere 42 to move between the inner peripheral surface of the main sphere protruding opening 31 and the main sphere 42 is secured.

The position where the holding piece 52 restricts the movement of the receiving ball 41 (movement restricting position) is a position below the opening of the ball receiving recess 22 (on the bottom side of the ball receiving recess 22), and the ball Since the pressing piece 52 is almost closed between the inner surface near the opening of the receiving recess 22 and the main ball 42, the pressing piece 52 and the receiving ball 41 are brought into contact at this position. Scattering of particles from the ball receiving recess 22 hardly occurs.
When the push-up shaft 82 is lowered, the main body 20 is lowered by the urging force of the spring 60 to return to the standby position, the movement restriction of the receiving ball 41 is released, and the rotational resistance of the main ball 42 is reduced again.

The free ball bearing 10A can be used as follows, for example.
As shown in FIG. 1A, in the state where the main body 20 is in the standby position and the main sphere 42 is not restricted in rotation, an object to be supported (mother glass for display, silicon substrate (wafer)) is placed on the main sphere 42. Etc.).
In this state, a positioning operation (positioning of the surface of the supported object) is performed by a positioning device (not shown). For example, the position in the surface direction of the supported object is determined by a positioning member (not shown), and the movement of the supported object in the surface direction is regulated at that position. Since the rotation of the main sphere 42 is not suppressed, the positioning operation is easy.
After positioning by the positioning device, as shown in FIG. 2, the main body 20 of the free ball bearing 10A is pushed up, the receiving ball 41 is moved by the receiving ball holding ring 50, and the receiving ball 41 and the main ball 42 are rotated. By suppressing, it is possible to prevent the positional deviation of the surface of the supported object.

  The movement restriction of the supported object by the positioning member is preferably performed in a state where the rotation of the main sphere 42 is suppressed. Thereby, it is possible to prevent the positional deviation of the supported object after the movement restriction by the positioning device is released.

The movement restriction of the receiving ball 41 by the receiving ball holding ring 50 is not required to completely prevent the circulation and rotation of the receiving ball 41, and suppresses the circulation and rotation of the receiving ball 41. As a result, the rotation of the main ball 42 is prevented. It only has to be suppressed.
In addition, since the main sphere 42 can be slightly rotated following the fine movement of the supported object, the supported object is less likely to slide on the main sphere 42 than when the rotation of the main sphere 42 is completely stopped. The supported object can be reliably braked.

According to the free ball bearing 10 </ b> A, the main body 20 can be moved in the height direction of the ball receiving portion 23, and the holding piece 52 is inserted between the hemispherical concave surface 21 and the main ball 42 by the movement of the main body 20. Thus, the position where the movement of the receiving ball 41 is restricted and the position where the restriction is released can be switched.
At the movement restricting position, since the pressing piece 52 is inserted between the hemispherical concave surface 21 and the main sphere 42, the pressing piece 52 functions to suppress scattering of particles from the ball receiving recess 22.
Therefore, contamination due to scattering of particles can be prevented.

Further, in the free ball bearing 10A, since the main body 20 is surrounded by the cover portion 30, the height direction movement of the main body 20 is realized by a mechanism that moves only the shaft portion 24 at the center position in the height direction. it can.
Therefore, the structure for moving the main body 20 can be simplified, and the overall size and cost can be reduced.

In the free ball bearing 10 </ b> A, since the movement of the receiving ball 41 is restricted by the pressing piece 52 when the main body 20 is raised, the rotation of the main ball 42 is suppressed at the position where the main ball 42 is raised.
For this reason, when the movement restriction | limiting of a to-be-supported object is required, the main sphere 42 can be made to contact | abut to a to-be-supported object reliably. Therefore, it is possible to reliably prevent the position shift of the supported object.

(Second Embodiment)
With reference to FIG. 3 and FIG. 4, the free ball bearing of 2nd Embodiment which concerns on this invention is demonstrated. In the following description, the same components as those described above are denoted by the same reference numerals, and the description thereof is omitted or simplified.
The free ball bearing 10B is different from the free ball bearing 10A of the first embodiment in that the spring 60 is not provided.

In the state shown in FIG. 3, the main body 20 is in the standby position due to its own weight, and the rotation resistance of the main ball 42 is relatively small because the rotation of the receiving ball 41 is not limited.
As shown in FIG. 4, when the main body 20 is moved upward, the holding piece 52 is inserted between the hemispherical concave surface 21 and the main sphere 42 to restrict the movement of the receiving ball 41. As a result, the rotation of the receiving ball 41 is suppressed, and the rotation resistance of the main ball 42 increases.
When the push-up shaft 82 is lowered, the main body 20 is lowered by its own weight and returned to the standby position, the rotation suppression of the receiving ball 41 is released, and the rotation resistance of the main ball 42 is reduced again.

  Also in the free ball bearing 10 </ b> B, the holding pieces 52 suppress particle scattering from the ball receiving recess 22.

(Third embodiment)
With reference to FIG. 5 and FIG. 6, the free ball bearing of 3rd Embodiment which concerns on this invention is demonstrated.
The free ball bearing 10C is different from the free ball bearing 10A of the first embodiment in that the receiving ball pressing ring 50 is not provided.
The main body 120 includes a ball receiving portion 123 in which a ball receiving recess 22 is formed, and a shaft portion 124 protruding downward from the ball receiving portion 123.
The lower end portion 124a of the shaft portion 124 protrudes downward from the lower end portion 32i of the cylindrical shaft portion 32c.
The cap 133 of the cover part 130 includes a cover plate part 133a, a side wall part 133b depending from the outer peripheral edge thereof, and a pressing piece 152 protruding downward from the inner peripheral edge of the cover plate part 133a.

The holding piece 152 performs the same function as the holding piece 52 of the receiving ball holding ring 50 in the free ball bearing 10 </ b> A of the first embodiment (rotation restriction of the main ball 42 due to movement restriction of the receiving ball 41). It is formed integrally with the portion 133a.
In the state shown in FIG. 5, the main body 120 is in the standby position, and the rotation of the receiving ball 41 is not restricted. Therefore, the rotation resistance of the main ball 42 is relatively small.
As shown in FIG. 6, when the shaft portion 124 is pressed upward by the push-up shaft 82 and the main body 120 is moved upward, the pressing piece 152 of the cap 133 is inserted between the hemispherical concave surface 21 and the main sphere 42. Thus, the movement of the receiving ball 41 is restricted. As a result, the rotation of the receiving ball 41 is suppressed, and the rotation resistance of the main ball 42 increases.
In the state shown in FIG. 6, the push-up shaft 82 is larger in diameter than the insertion hole 32g formed in the cylindrical shaft portion 32c, and is in contact with the lower end portion 32i of the cylindrical shaft portion 32c. The upward movement is restricted. For this reason, it can prevent that an excessive force is applied to the ball receiving portion 123 and the receiving ball 41 to cause damage.
When the push-up shaft 82 is lowered, the main body 120 is lowered by its own weight and returned to the standby position, the rotation suppression of the receiving ball 41 is released, and the rotation resistance of the main ball 42 is reduced again.

(Fourth embodiment)
With reference to FIG. 7 and FIG. 8, the free ball bearing of 4th Embodiment which concerns on this invention is demonstrated.
The free ball bearing 10D includes a main body 220 having a ball receiving portion 223 in which a ball receiving recess 22 is formed, a cover portion 230, a receiving ball 41 disposed on the hemispherical concave surface 21 of the ball receiving portion 23, and a hemisphere. A main sphere 42 rotatably supported on the concave surface 21 and a spring 260 (regulation release mechanism).
The cap 233 of the cover portion 230 includes a lid plate portion 233a, a side wall portion 233b depending from the outer peripheral edge thereof, and a pressing piece 252 protruding downward from the inner peripheral edge of the lid plate portion 233a.
The main body 220 includes a ball receiving portion 223 in which a ball receiving recess 22 is formed, and a shaft portion 224 that protrudes downward from the ball receiving portion 223.

The shaft portion 224 is fixed to the central shaft portion 225 and extends downward by being screwed to the central shaft portion 225 extending downward from the ball receiving portion 223 and the screw portion 225a on the outer surface of the central shaft portion 225. It has an extension shaft portion 226 and a restriction tube portion 227 having a screw portion 227a screwed to a screw portion 232g on the inner surface of the cylindrical shaft portion 232c on the outer surface.
An annular convex portion 226a is formed at an intermediate position in the longitudinal direction of the outer surface of the extending shaft portion 226, and the upper surface 226b of the annular convex portion 226a serves as a receiving portion with which the lower end of the spring 260 (regulation release mechanism) abuts.
A portion below the annular convex portion 226a of the extending shaft portion 226 is inserted into the insertion hole 227b of the restriction cylinder portion 227 so as to be movable up and down. The annular convex portion 226 a is formed so as to be in contact with the upper end of the restricting cylinder portion 227 so as to restrict the downward movement of the extending shaft portion 226.
The lower end portion 226 c of the extending shaft portion 226 protrudes downward from the lower end portion 227 c of the restriction cylinder portion 227.

The base end side cover member 232 includes a ring-shaped bottom plate 232a and a cylindrical shaft portion 232c that projects to the lower surface side of the bottom plate 232a.
A male screw 232f is formed on the outer surface of the cylindrical shaft portion 232c, and the cylindrical shaft portion 232c is inserted into the female screw hole 81a of the support 81 and screwed to the female screw 81b on the inner surface of the female screw hole 81a.
A thinned recess 232d is formed on the inner surface 232d of the cylindrical shaft portion 232c. The step 232e at the upper end of the thinned recess 232d serves as a receiving portion with which the upper end of the spring 260 abuts.

In the state shown in FIG. 7, the annular convex portion 226 a of the extension shaft portion 226 is biased downward by the spring 260, so that the main body 220 is in the standby position.
As shown in FIG. 8, when the shaft portion 224 (the lower end portion 226c of the extending shaft portion 226) is pressed upward by the push-up shaft 82 and the main body 220 is moved upward, the pressing piece 252 of the cap 233 becomes a hemispherical concave surface. 21 is inserted between the main ball 42 and the main ball 42 to restrict the movement of the receiving ball 41. As a result, the rotation of the receiving ball 41 is suppressed, and the rotation resistance of the main ball 42 increases.
In the state shown in FIG. 8, the push-up shaft 82 is in contact with the lower end portion 227 c of the restricting cylinder portion 227, and thus the upward movement of the main body 220 is restricted, so that the ball receiving portion 223 and the receiving ball 41 are excessive. It is possible to prevent breakage due to force applied.
When the push-up shaft 82 is lowered, the main body 220 is lowered and returned to the standby position by the urging force of the spring 260, and the rotational resistance of the main sphere 42 becomes smaller again.

FIG. 9 shows an embodiment of a bearing device according to the present invention.
This bearing device moves up and down a plurality of free ball bearings 10C, a support 81 that supports the free ball bearing 10C, a support table 83 to which the support 81 is fixed, and a push-up shaft 82 that is inserted into the support 81. Elevating mechanism 90 is provided.
The elevating mechanism 90 includes a drive unit 91 such as an air cylinder, an elevating shaft 92 that is moved up and down by the drive unit 91, and a first base 93 provided at the upper end of the elevating shaft 92. The base end portion of the push-up shaft 82 is fixed to the first base portion 93. Reference numeral 94 denotes a bellows for accommodating the upper part of the lifting shaft 92, and the lower end of the bellows 94 is attached to a second base part 95 provided on the support plate 110.
The elevating mechanism 90 can elevate the elevating shaft 92 to elevate the push-up shaft 82 and move the main body 120 of the free ball bearing 10C in the height direction.
The support table 83 can be moved up and down by a lifting mechanism (not shown).

This bearing device can be used as follows.
As shown in FIG. 9, when the support table 83 is raised, the free ball bearing 10 </ b> C protrudes on the mounting table 80 through the passage port 80 a.
The supported object 1 is carried in by the robot arm 100 and placed on the main ball 42 of the free ball bearing 10C.
At this time, the elevating mechanism 90 adjusts the height positions of the elevating shaft 92 and the push-up shaft 82 to place the main body 120 of the free ball bearing 10C at the standby position, and the rotation resistance of the main ball 42 is small (see FIG. 5). ), The supported object 1 can be easily moved on the main sphere 42.
In this state, a positioning operation (positioning in the surface direction of the supported object 1) of the supported object 1 is performed by a positioning device (not shown). Since the rotation resistance of the main sphere 42 is small, the positioning operation of the supported object 1 is easy.
Next, the main body 120 of the free ball bearing 10C is lifted by the lifting mechanism 90, and the rotational resistance of the main sphere 42 is increased by the pressing piece 152 (see FIG. 6), so that the supported object 1 is moved from a predetermined position by moving in the surface direction. It can be prevented from shifting.

As shown in FIG. 10, when the free ball bearing 10 </ b> C is lowered together with the support table 83, the supported object 1 is placed on the placement table 80.
The supported object 1 can be subjected to processing such as film formation as necessary.

As shown in FIG. 9, the support table 83 is raised and the supported object 1 is lifted again by the free ball bearing 10C.
When lifting the supported object 1, the rotational resistance of the main sphere 42 is increased by the pressing piece 152 (see FIG. 6), thereby preventing displacement due to movement of the supported object 1 in the surface direction. .
Next, the supported object 1 can be carried out by the robot arm 100.
In addition, at the time of carrying out, positioning operation (positioning of the surface direction of a to-be-supported object) can also be performed by the positioning device (not shown). That is, the positioning operation is performed with the main body 120 placed at the standby position and the rotation resistance of the main sphere 42 is small (see FIG. 5), and then the rotation resistance of the main sphere 42 is increased again (see FIG. 6). The supported object 1 can be carried out.

  As described above, in this bearing device, the rotational resistance of the main sphere 42 can be adjusted according to a required operation by adjusting the height position of the push-up shaft 82 by the lifting mechanism 90. 1 can be carried out smoothly and accurately.

Since the free ball bearing according to the present invention has a much higher coefficient of friction than that when released when restrained, a method of using the main ball so as not to rotate when restrained is also possible.
The free ball bearing according to the present invention can be suitably used for a substrate positioning table (support table) for accurately positioning a substrate such as a display mother glass or a silicon substrate (wafer).
The present invention includes, for example, articles in clean rooms such as processing of semiconductor substrates and printed wiring boards, mounting of electronic components, manufacturing of flat panels, manufacturing of electronic components such as semiconductor elements and semiconductor packages, and manufacturing of food and pharmaceuticals. Can be widely used for transport (for example, use as a part of a transport device), positioning, and the like.

10A, 10B, 10C, 10D ... free ball bearing, 20, 120, 220 ... main body, 21 ... hemispherical concave surface, 23 ... ball receiving part, 30, 130, 230 ... cover part , 30A ... cover body, 31 ... opening for protruding main sphere, 41 ... receiving ball, 42 ... main ball, 50 ... receiving ball holding ring, 52 ... holding piece, 32, 132, 232 ... Base end side cover member (base end side portion), 24, 124, 224 ... Shaft, 60, 260 ... Spring (regulation release mechanism), 81 ... Support , 90... Elevating mechanism.

Claims (6)

A main body (20) having a ball receiving portion (23) in which a ball receiving recess (22) having a hemispherical concave surface (21) as an inner surface is formed;
A plurality of receiving balls (41) disposed on the hemispherical concave surface of the main body;
A main sphere (42) formed larger in diameter than the receiving ball and rotatably supported by the hemispherical concave surface via the receiving ball;
A housing-like cover portion (30) provided so as to surround the ball receiving portion of the main body,
The cover part is formed with a main sphere protruding opening (31) for protruding a part of the main sphere,
The cover portion has a pressing piece (52) that is inserted between the hemispherical concave surface of the main body and the main sphere to increase the rotational resistance of the main sphere by restricting the movement of the receiving sphere. ,
The main body is movable with respect to the cover portion in a height direction of the ball receiving portion which is a direction coinciding with a depth direction of the recess for receiving the ball, and by this movement, the pressing piece moves the receiving ball. A free ball bearing (10A) characterized in that it can be switched between a position where the restriction is released and a position where the holding piece is separated from the receiving ball and the restriction is released. The cover portion has a proximal end portion (32) surrounding the ball receiving portion of the main body,
The main body has a shaft portion (24) protruding from the ball receiving portion,
The shaft portion protrudes from the base end side portion, and the main body can be moved in the height direction of the ball receiving portion by moving the protruding portion in the direction of the ball receiving portion. The free ball bearing according to 1. The cover portion includes a cover portion main body (30A) and a receiving ball pressing ring (50) provided in the cover portion main body.
The free ball bearing according to claim 1, wherein the pressing piece is formed on the receiving ball pressing ring.   The free ball bearing according to claim 1, wherein the pressing piece is formed integrally with the cover portion.   The free ball bearing according to any one of claims 1 to 4, further comprising a restriction release mechanism (60) for urging the main body in a direction away from the pressing piece.   A free ball bearing according to any one of claims 1 to 5, a support body (81) for supporting the free ball bearing, and a lifting mechanism for moving a main body of the free ball bearing in the height direction of the ball receiving portion ( 90).

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