JP2011057393A - Ball bearing and supporting unit - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a ball bearing which is free from lowering in the rotation easiness of the main ball even when used to support a vertically placed conveying object in a high temperature condition. <P>SOLUTION: The ball bearing 10 includes a body 3 rotatably supporting the main ball 2 and a lid 4 having an opening 7 for protruding out the main ball 5. The lid 4 includes an inward extending part 13 in which the inside of an extending end 13a works as the opening 7. The inward extending part 13 is formed to prevent outward movement as the main ball 2 abuts on an extending end 13a. An inclination angle in the diameter expansion direction of an inner surface 13b of the inward extending part 13 from the extending end 13a to a base end side is larger than that in the direction of a tangent L1 of the abutting position P1 of the main ball 2 abutting the extending end 13a. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a ball bearing and a support unit that support a transferred object such as a glass substrate for a liquid crystal display panel or a plasma display panel so as to be displaceable in an arbitrary direction along the transfer surface.

In manufacturing factories such as liquid crystal display panels and plasma display panels, processing such as film formation, resist coating, exposure, and etching is performed on a glass substrate in a processing chamber (chamber).
A support unit that supports the glass substrate is used for the processing operation, the transfer operation to the processing chamber, and the like.
In recent years, with the increase in size of glass substrates, support units capable of vertically placing glass substrates have been used.
FIG. 6 shows an example of a vertically installed type support unit. The support unit 23 is configured by providing a plurality of ball bearings 20 on a support body 22 erected on a base 21.

As shown in FIG. 7, the ball bearing 20 includes a main body 3 that supports the main sphere 2 that supports the glass substrate 1, a lid 24 having an opening 27, and a screw fixing portion 8 that extends from the main body 3. And.
The main sphere 2 is rotatably supported by the support recess 6 of the main body 3 via the sub sphere 5 (see Patent Documents 1 and 2).
The main sphere 2 protrudes outward (forward) through the opening 27. The inner surface of the peripheral edge of the opening 27 is formed in a direction substantially along the outer surface of the main sphere 2.
As shown in FIG. 6, the glass substrate 1 is supported by the ball bearing 20 in a vertically placed state. Since the main sphere 2 is rotatable, the glass substrate 1 can be displaced along the one surface 1a.

International Publication No. 2005/003001 Pamphlet JP 2005-119838 A

However, when the ball bearing 20 is used in the support unit 23 that supports the vertically placed glass substrate 1, the main sphere 2 becomes difficult to rotate when used under high temperature conditions, and this causes the glass substrate. In some cases, traces remained on 1 and wear of the main sphere 2 increased.
The present invention has been made in view of such a situation, and the ease of rotation of the main sphere is reduced even when it is used to support a vertically-conveyed object under high temperature conditions. An object of the present invention is to provide a ball bearing and a support unit that are free from damage.

The present invention is a ball bearing that supports a transported object so that it can be displaced in any direction along its transport surface, and rotates a resin main sphere that supports the transported object via a plurality of sub-spheres. A main body portion having a spherical support concave portion to be freely supported, and a lid portion having an opening for projecting the main sphere outward, wherein the lid portion is formed in an annular shape, and the main portion The inner end of the extension end is an inner extension portion that becomes the opening, and the inner extension portion is formed by the main sphere contacting the extension end. It is formed so that outward movement is prevented, and the inner surface of the inwardly extending portion from the extending end to the base end side is more than the tangential direction of the contact position of the main sphere that is in contact with the extending end. Provided is a ball bearing in which an inclination angle in a diameter expansion direction is increased.
The inner diameter of the opening is preferably 60 to 96% of the outer diameter of the main sphere.
It is preferable that a movement prevention wall for preventing the secondary sphere from moving outward is formed on the main portion.
The inner surface of the main part is preferably formed along the axial direction of the lid part.
It is preferable that the inner radius of the support recess is larger than the sum of the outer radius of the main sphere and the outer radius of the subsphere.

  The present invention provides a support unit in which the above-mentioned ball bearing is provided on a plate-like support body standing on a base, and the support body can support an object to be conveyed by the ball bearing.

According to the present invention, the inwardly extending portion is formed so that the inclination angle of the inner surface is larger than the inclination angle of the tangent line, so that it contacts the main sphere only at the extension end.
Since the contact area with the main sphere is small, even if the main sphere thermally expands under high temperature conditions, it is difficult to get stuck in the opening.
Accordingly, the ease of rotation of the main sphere does not decrease, and it is possible to prevent the trace of the main sphere from remaining on the object to be transported and the wear of the main sphere from increasing.
It is the first time by the present inventor that the problem that the main sphere is difficult to rotate when the object to be conveyed is placed in a vertical state under high temperature conditions is caused by the main sphere getting stuck in the opening due to thermal expansion. Because of the findings found, the technical significance of the present invention is great.

It is a partial sectional view showing a ball bearing which is one embodiment of the present invention. It is sectional drawing to which the principal part of the ball bearing was expanded. It is a figure which shows schematic structure of the support unit in which the ball bearing was used. It is sectional drawing to which the principal part of the ball bearing in the state which the main sphere contact | abutted to the extension end of the inward extension part was expanded. It is sectional drawing which expanded further the principal part of the ball bearing of the state which the main ball contact | abutted to the extension end. It is a figure which shows schematic structure of the support unit in which an example of the conventional ball bearing was used. It is a partial cross section figure which shows an example of the conventional ball bearing.

  FIG. 1 is a partial cross-sectional view showing a ball bearing 10 according to an embodiment of the present invention. FIG. 2 is an enlarged cross-sectional view of a main part of the ball bearing 10. FIG. 3 is a diagram showing a schematic configuration of the support unit 23 in which the ball bearing 10 is used. FIG. 4 is an enlarged cross-sectional view of a main part of the ball bearing 10 in a state where the main ball 2 is in contact with the extended end 13a. FIG. 5 is an enlarged cross-sectional view of the main part of the ball bearing 10 in a state where the main sphere 2 is in contact with the extended end 13a.

As shown in FIG. 3, the support unit 23 is configured by providing one or a plurality of ball bearings 10 on a plate-like support body 22 erected on a base 21.
The support 22 can support the glass substrate 1 with the ball bearing 10.
The angle of the support 22 is not particularly limited, and the angle α (the angle of the one surface 1a with respect to the horizontal plane) of the glass substrate 1 to be supported can be arbitrarily set in the range of 0 to 360 °.
In the illustrated example, the support 22 is formed to be slightly inclined with respect to the base 21 from the vertical, and the angle α with respect to the horizontal plane of the glass substrate 1 can be set to 70 to 90 °, for example.
The ball bearings 10 are provided on the one surface 22a of the support 22 at a predetermined interval.

As shown in FIGS. 1 and 2, the ball bearing 10 includes a main body 3 that supports a main sphere 2 that supports a glass substrate 1 (conveyed object), a lid 4 having an opening 7, and a main body 3. And a screw fixing portion 8 extending therefrom.
In the following description, the left side in FIG. 1 may be referred to as the front, and the right side may be referred to as the rear.

The main sphere 2 is rotatably supported by the support recess 6 of the main body 3 via a plurality of subspheres 5.
The main sphere 2 is made of resin. Damage to the glass substrate 1 can be prevented by using resin.
As the resin constituting the main sphere 2, 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 be used.
The sub sphere 5 is a sphere having a diameter smaller than that of the main sphere 2 and can be formed of a metal such as stainless steel, ceramic, resin, or the like. The sub sphere 5 is provided in the support recess 6 so as to be freely rollable.

The main body 3 is formed in a substantially cylindrical shape, and the support recess 6 is a spherical recess formed on the front side of the main body 3.
The inner radius of the support recess 6 is preferably larger than the sum of the outer radius of the main sphere 2 and the outer radius of the subsphere 5. Thereby, even when the outer diameter of the main sphere 2 becomes larger due to thermal expansion, the rotation of the main sphere 2 does not occur.

As shown in FIG. 2, the outer surface of the main body 3 is formed with an annular locking groove 3a along the circumferential direction and a pair of flat portions 3b that can accommodate a tool such as a spanner.
As shown in FIG. 1, the screw fixing portion 8 extends rearward from the rear surface side of the main body portion 3, the screw portion 8 a is formed on the outer peripheral surface thereof, and the fixing formed on the one surface 22 a of the support body 22. It is fixed by screwing into the hole 22b.

As shown in FIG. 2, the lid 4 includes an annular main part 11, a cylindrical fixing part 12 extending rearward from the main part 11, and an inward extension from the front end of the main part 11. An inward extending portion 13 is provided.
The lid 4 can be made of resin, metal, or the like. Examples of the resin constituting the lid 4 include PAI, PBI, PCTFE, PEEK, PEI, PI, PPS, melamine resin, aromatic polyamide resin (aramid resin), LCP, PBT, PES, and the like. The same material is preferred.
A locking portion 12a projecting inward is formed on the inner surface of the rear end portion of the fixing portion 12, and the locking portion 12a is fitted into the annular locking groove 3a of the main body portion 3, whereby the lid portion 4 is mounted on the main body. It is fixed to part 3.

Since the inner diameter of the main portion 11 is smaller than the inner diameter of the support recess 6, the lower surface 11 a of the main portion 11 is formed facing the internal space of the support recess 6.
For this reason, the lower surface 11a is a movement prevention wall that prevents the subsphere 5 from falling off due to outward movement.
The lower surface 11a can be formed substantially perpendicular to the axial direction (front-rear direction in FIG. 2).
The lower surface 11a is preferably formed so that the center of the subsphere 5 is positioned within the rear sphere range 6a of the spherical support recess 6. That is, the center of the secondary sphere 5 is positioned in the latter half sphere range 6a that is a space formed by the flat surface 14 and the support recess 6 passing through the center 6b of the support recess 6 forming a hemispherical surface and perpendicular to the axial direction. In addition, the movement of the subsphere 5 can be limited. As a result, it is possible to prevent the subspheres 5 from being separated from each other and the operation of the main sphere 2 from becoming unstable.

  The inner surface 11b of the main portion 11 preferably has a substantially constant diameter and is formed along the axial direction. Since the inner diameter of the main part 11 is larger than the outer diameter of the main sphere 2, the main part 11 does not contact the main sphere 2 when the main sphere 2 is in contact with the extended end 13 a (see FIG. 4). .

The inward extending portion 13 extends inward at a constant length from the front end of the main portion 11 over the entire circumference, and the opening 7 inside the extending end 13a is circular.
As shown in FIG. 2, since the inner diameter R1 of the opening 7 is made smaller than the outer diameter R2 of the main sphere 2, the main sphere 2 protruding outward (forward) through the opening 7 is an inwardly extending portion. 13 restricts outward movement.
As shown in FIG. 4, the inward extending portion 13 is formed such that the main sphere 2 abuts on the extending end 13 a and is prevented from moving outward (forward). The extension end 13a is preferably formed at the forefront part of the inward extension part 13 or a position close thereto.
The inward extending portion 13 is formed so that the main sphere 2 can move in the front-rear direction from the rear position shown in FIG. 2 to the front position shown in FIG.
In the rear position shown in FIG. 2, the main sphere 2 is separated from the extending end 13a. However, in the front position shown in FIG. 4, the main sphere 2 is in contact with the extending end 13a over the entire circumference.

As shown in FIG. 2, when the inner diameter R1 of the opening 7 is 96% or less of the outer diameter R2 of the main sphere 2, the main sphere 2 is unlikely to be fixed to the opening 7 even under high temperature conditions. Become. This is considered to be because the difference between the inner diameter R1 of the opening 7 and the outer diameter R2 of the main sphere 2 is large, and even if the main sphere 2 is thermally expanded, it is difficult to get stuck in the opening 7.
It is preferable that the inner diameter R1 of the opening 7 is 60% or more of the outer diameter R2 of the main sphere 2 because the amount of protrusion of the main sphere 2 from the opening 7 is sufficiently secured.
Therefore, if the inner diameter R1 of the opening 7 is 60 to 96% with respect to the outer diameter R2 of the main sphere 2, the amount of protrusion of the main sphere 2 is sufficient, and the main sphere 2 is easy to rotate under high temperature conditions. Can be secured.

As shown in FIG. 5, the inner surface 13b of the inwardly extending portion 13 is a surface formed from the extending end 13b to the base end portion 13c, and the inclination angle β with respect to the axial direction corresponds to the extending end 13a. The inclination angle in the diameter expanding direction is made larger than the tangential line L1 direction of the contact position P1 of the main sphere 2 in contact.
That is, the inclination angle β of the inner surface 13b is larger than the inclination angle γ of the tangent L1.
For this reason, when the main sphere 2 is in contact with the extended end 13a, the inwardly extending portion 13 is in contact with the main sphere 2 only at the extended end 13a.

Hereinafter, an example of how to use the support unit 23 using the ball bearing 10 will be described.
The support unit 23 shown in FIG. 3 is a glass substrate processing and processing in a processing chamber (chamber) that performs processing such as film formation, resist coating, exposure, and etching in a manufacturing factory such as a liquid crystal display panel or a plasma display panel. It can be used for transporting (loading and unloading) glass substrates to and from the chamber.
For example, it can be installed in the interior of the processing chamber, the glass substrate carrying-in path to the processing chamber, or the carrying-out path.
The said process is performed on high temperature conditions (for example, 100 degreeC or more, especially 200 degreeC or more (for example, 200-300 degreeC)). The above treatment is usually performed in a vacuum environment.

In the support unit 23, the glass substrate 1 is supported by the ball bearing 10. The ball bearing 10 contacts the one surface 1a of the glass substrate 1.
Since the main sphere 2 is freely rotatable with a small frictional resistance in an arbitrary direction, the glass substrate 1 supported by the main sphere 2 by point contact has a small frictional resistance in an arbitrary direction along the one surface 1a (conveying surface). You can move with.

In the support unit 23 shown in FIG. 3, since the ball bearing 10 faces substantially sideward, the main sphere 2 is easy to move forward as compared with the case where it is upward (see FIG. 4).
For example, when the ball bearing 20 shown in FIG. 7 is used in such a form of use, the main sphere 2 may move forward and get stuck in the opening 27. However, as described below, Such a situation does not occur with such a ball bearing 10.

In the ball bearing 10, the inward extending portion 13 is formed so that the inclination angle β of the inner surface 13 b is larger than the inclination angle γ of the tangent L 1, so that it contacts the main sphere 2 only at the extension end 13 a.
Unlike the ball bearing 20 (see FIG. 7) in which the inner surface of the peripheral portion of the opening 27 can be in contact with the main sphere 2 with a large area because the contact area with the main sphere 2 is small, the main sphere 2 is heated under high temperature conditions. Even if it expand | swells, it will be hard to be in the state stuck in the opening part 7. FIG.
Therefore, the ease of rotation of the main sphere 2 is not reduced, and it is possible to prevent the trace of the main sphere 2 from remaining on the glass substrate 1 and the wear of the main sphere 2 from increasing.

The inventor of the present application finds that when the glass substrate is placed vertically under high temperature conditions, the main sphere becomes difficult to rotate due to the main sphere being stuck in the opening, and the present invention is completed based on this knowledge. I let you.
The inventor of the present application has first seen that the problem that the main sphere is difficult to rotate when the glass substrate is placed in a vertical state under high temperature conditions is caused by the main sphere getting stuck in the opening due to thermal expansion. This is a finding that has been made and the technical significance of the present invention is great.

In order to confirm the effect of the present invention, the ball bearing 10 shown in FIG. 1 is faced downward (the front side shown in FIG. 1 is directed downward), and the temperature of the ball bearing 10 is gradually increased from 100 ° C. to 300 ° C. Tests were placed under the conditions to be reached.
The outer diameter of the main sphere 2 was 9.52 mm (normal temperature), and the inner diameter of the opening 7 of the lid 4 was 7.6 mm (normal temperature). Both the main sphere 2 and the lid 4 were made of PI.
The inclination angle β of the inner surface 13b of the inward extending portion 13 is 50.2 °, which is confirmed to be larger than the inclination angle of the tangent line L1 at the contact position P1.
As a result of this test, it was confirmed that the main sphere 2 was not in a state of being fitted into the opening 7, and the main sphere 2 was maintained in a good rotational state.

  The application object of the ball bearing of the present invention is not limited to a glass substrate for a liquid crystal display panel or a plasma display panel, but may be a silicon substrate, a ceramic substrate, a metal substrate, or the like.

DESCRIPTION OF SYMBOLS 1 ... Glass substrate (conveyed object), 1a ... One side (conveyance surface), 2 ... Main ball, 3 ... Main-body part, 4 ... Cover part, 5 ... Subsphere , 6 ... Support recess, 7 ... Opening part, 10 ... Ball bearing, 11 ... Main part, 11a ... Lower surface of main part (movement blocking wall), 11b ... Main part Inner surface, 13 ... inward extending portion, 13a ... extension end, 13b ... inner surface of inner extending portion, 21 ... base, 22 ... support, 23 ... Support unit, L1 ... tangent at contact position, P1 ... contact position, R1 ... inner diameter of opening, R2 ... outer diameter of main sphere, .beta. Inclination angle of the inner surface, γ ... the inclination angle of the tangent at the contact position.

Claims (6)

A ball bearing that supports the object to be conveyed so as to be displaceable in any direction along its conveying surface,
A main body having a spherical support recess for rotatably supporting a resin main sphere supporting the object to be conveyed via a plurality of subspheres, and a lid having an opening for projecting the main sphere outward. With
The lid portion has a main portion formed in an annular shape, and an inward extending portion that extends inward from the main portion and the inside of the extending end becomes the opening.
The inward extending portion is formed such that outward movement is prevented by the main sphere abutting on the extending end,
The inner surface of the inwardly extending portion from the extended end to the base end side has a larger inclination angle in the diameter-expanding direction than the tangential direction of the contact position of the main sphere in contact with the extended end. Ball bearing characterized by.   The ball bearing according to claim 1, wherein an inner diameter of the opening is 60 to 96% of an outer diameter of the main sphere.   The ball bearing according to claim 1, wherein the main portion is formed with a movement blocking wall that blocks outward movement of the subsphere.   The ball bearing according to claim 1, wherein an inner surface of the main portion is formed along an axial direction of the lid portion.   5. The ball bearing according to claim 1, wherein an inner radius of the support recess is larger than a sum of an outer radius of the main sphere and an outer radius of the sub sphere. A ball bearing according to any one of claims 1 to 5 is provided on a plate-like support that is erected on a base,
The support unit is capable of supporting an object to be conveyed by a ball bearing.

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