JP2003184871A - Ball transfer for clean room - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To obtain a ball transfer that can be used in a clean room by restraining the occurrence of dust, in a ball transfer that emission of the dust is inevitable because each sub sphere 20 being built-in for enabling free circulation contacts in friction respectively. <P>SOLUTION: In a ball transfer 10 consisting of main sphere 30 that directly supports a conveyance object, built-in sub spheres 20 to support its main sphere 30 and circulate freely and a case 11 including sphere receptacle section 11a of hemispherical recess shape so as to position always its sub spheres 20 in the place to support the main sphere 30, it makes many of non-circle holes 11b, 11c that sub spheres 20 are difficult to stick penetrate even to external of the case 11 in order to aspire the dust occurring inside of the case 11 and the dust, etc., being entered from outside. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a transfer device used when, for example, a heavy object is freely transferred in the horizontal direction by 360 °, and a positioning device that requires accurate positioning.

[0002]

2. Description of the Related Art FIG. 5 shows the structure of a conventional ball transfer 1. The conventional ball transfer 1 does not have a function of positively discharging the dust generated inside to the outside. Further, as shown in FIG. 6, there is also an example in which a hole 4b is formed in the case 4 ball receiving portion 4a so that dust that has entered from the outside is discharged.

Further, the one disclosed in Japanese Patent Application No. 11-319526 has a plurality of holes formed in the ball receiving portion 4a of the case 4 so that dust or the like that has entered from the outside naturally falls by gravity as described above. Ball receiving part 4 to guide dust to
A is provided with a guide groove.

[0004]

However, this type of product is a measure against dust entering the ball transfer from the outside in order to maintain the function of the ball transfer at the place where the dust is generated. Therefore, the dust is expected to be discharged naturally due to its own weight, and does not have a function of actively discharging the dust. Therefore, it is helpless for fine particles such as dust generated by friction between the sub-balls 20 to float, and particularly, the ball receiving portion 4a.
There was no effect of preventing the dust generated at the upper part from leaking out of the ball transfer 1.

Further, there is no effect of preventing the main ball 3 from rotating with the dust adhering thereto and adhering the dust to the conveyed object.

The present invention can be used in a clean room such as a semiconductor manufacturing plant where stringent cleanliness is required, a bio-related facility, a food-related facility, or the like, in an environment where the generation of dust is disliked or an environment in which foreign matter such as dust is disliked on a conveyed product. To provide a ball transfer that suppresses the amount of dust generation and that does not cause dust to adhere to conveyed objects.

[0007]

A ball transfer according to the present invention is a ball transfer in which a large number of sub balls are circulated in a case and the main balls are supported by the sub balls. In order to suck and discharge the dust, a dust suction hole penetrating the outside is opened in the hemispherical sphere receiving portion inside the case. It is desirable that this ball transfer has a non-circular shape so that the auxiliary ball does not suck the suction hole for sucking and discharging the dust. Further, in this ball transfer, a hole for sucking and discharging dust generated in the upper portion of the hemispherical sphere receiving portion may be provided in the upper portion of the hemispherical sphere receiving portion so that the dust can be effectively sucked and discharged.

In the ball transfer, when it is attempted to suck and discharge the dust inside by a negative pressure, a hole is provided in the central portion of the ball receiving portion, and when sucking from here, the auxiliary ball sticks to this hole, and as a ball transfer. Good rotation performance cannot be maintained. For this reason, the suction hole is made non-circular so that the spherical auxiliary ball does not stick to the suction hole even when suctioned under negative pressure, so that the auxiliary ball does not stick to the suction hole and dust is effectively discharged. Will be able to.

The main outlet through which the dust generated inside leaks to the outside is the gap between the main ball and the lid, that is, near the upper part of the ball receiving portion. By providing a dust suction hole in the upper part of the ball receiving portion, dust can be effectively sucked, and thus the amount of dust generated to the outside can be effectively suppressed.

Further, by sucking and discharging the dust generated inside, the main sphere is always kept in a clean state. As a result, it is possible to prevent the main sphere from rotating with the dust adhering thereto, transferring the dust to the conveyed object, and contaminating the conveyed object.

[0011]

FIG. 6 is an external perspective view of an example of the ball transfer 10 of the present invention. FIG. 1 is a sectional view thereof. The ball transfer 10 includes a case 11, and the case 11 has a ball receiving portion 11a that forms a hemispherical recess therein, and the ball receiving portion 11a has a suction hole 11b penetrating to the outside of the case at the center of the lower portion. .

Further, as shown in FIG. 2, above the ball receiving portion 11a, a suction hole 11c arranged in an arc shape so as to surround the suction hole 11b at the center of the ball receiving portion 11a is provided.
It is clear that a and the outside of the case 11 are penetrated.

[0013] In the ball transfer 10 consisting of a sub ball 20 uniformly laid in the ball receiving portion 11a of the case 11 so as to circulate freely and a main ball 30 supported by the sub ball 20, the dust Suction holes 11b, 1
The dust generated inside 1c or the dust mixed from the outside is sucked through the suction holes 11b and 11c, and the suction pipe 51a.
It is possible to suppress the generation of dust to the outside of the ball transfer 10 by discharging the dust to the outside of the clean room through.

The main sphere 30 that is in direct contact with the conveyed product rotates itself as the conveyed product moves, and this rotation causes the main sphere 30 to rotate.
And the ball receiving portion 11a inside the case 11 between the main ball 30
The auxiliary sphere 20 that supports the load of and is transmitted to the ball receiving portion 11a inside the case 11 rotates and moves on the ball receiving portion 11a inside the case 11 according to the rotation of the main ball 30.

The auxiliary sphere 20 moved in accordance with the rotation of the main sphere 30.
Is an end space 11 of the ball receiving portion 11a inside the case 11.
When it reaches d, the load of the main ball 30 and the ball receiving portion 11a is released and the ball moves freely, but the lid 12 moves to the opposite end space 11d in search of a gap without moving ahead.

The sub-ball 20 moved to the space 11d on the opposite side is moved by its own weight to the main ball 30 and the case 11 and the ball receiving portion 11
It falls between a and a, and again supports the load of the main ball 30 and transmits the load to the case 11 ball receiving portion 11a.

At this time, as shown in FIG. 3, since the sub spheres 20 are rotating in the same direction, the sub spheres adjacent to each other are in contact with each other at the contact portion 20a, and are rubbed with each other. This friction produces dust.

A pressure difference that makes the inside of the case 11 a negative pressure is provided with respect to the outside of the case 11, and dust generated by friction between the auxiliary balls 20 is generated from the suction holes 11b and 11c formed in the ball receiving portion 11a of the case 11. Aspirate and discharge. Suction piping 5 so that the dust discharged at this time can be collectively discharged to the outside of the clean room
It is desirable to apply 1a.

When dust is sucked and discharged from the suction hole 11b provided in the ball receiving portion 11a inside the case 11 by a negative pressure, the sub ball 20 is sucked into the suction hole 11b provided in the ball receiving portion 11a. The secondary ball 2 that should have been moved
In order to prevent the movement of 0, it is desirable that the suction hole 11b has a non-circular shape such as a square or an irregular shape such as a circular arc so that the sub-sphere 20 is not easily sucked as shown in FIG.

The dust suction hole is arranged not only in the center of the lower part of the ball receiving portion 11a but also above the ball receiving portion 11a, so that the dust generated above the ball receiving portion 11a and the main ball 30 and the lid 1 are provided.
It is possible to positively suck and discharge dust that has entered from the outside through the gap 12a formed between the two. Further, compressed air is injected into the suction hole 11b at the center of the ball receiving portion 11a, and at the same time, dust is sucked together with the compressed air from the suction hole 11c above the ball receiving portion 11a, so that unnecessary dust is more effectively sucked. Can be discharged. At this time, a cleaning liquid or the like may be used instead of the compressed air.

By positively sucking and discharging dust,
The main ball 30 is always kept clean. As a result, it is possible to reduce dust and the like generated by the friction between the auxiliary balls 20 and the like, which adheres to the main ball 30 and adheres to the conveyed product as the main ball 30 rotates.

Normally, the ball transfer 10 is attached to the apparatus so as to support a plurality of objects to be conveyed when it is used. At that time, FIG. 7 shows an example of an attachment state in which the ball transfer 10 of the present invention is attached to a transfer device.
In this case, the upper portion 41 of the mounting member 40 is lower than the lower portion 42.
By applying a negative pressure, the dust inside the ball transfer 10 can be sucked and discharged through the through holes 11b and 11c in the lower portion of the case 11. Further, by providing a mounting part such as a screw on the lower part of the case 11, for example, the intake block 50 can be easily mounted. Further, by providing the pipe 51a to the intake port 51 of the intake block 50, it becomes possible to surely suck and discharge dust.

Further, if a product 60 obtained by unitizing a plurality of the ball transfers 10 of the present invention is used, the suction pipe 5 is provided for the plurality of ball transfers 10 of the present invention.
Only one 1a is required for one ball transfer unit 60, so that the effect can be easily and reliably exhibited. An example thereof is shown in FIG.

[0024]

According to the present invention, the dust generated inside is sucked and discharged from the suction hole at a negative pressure, so that dust generation as a ball transfer is suppressed and the dust is not attached to the conveyed object. Therefore, in a clean environment such as a clean room, which cannot be used conventionally, it is possible to carry out a carrying operation and a positioning operation while maintaining a clean environment with respect to a carried object which does not like the adhesion of dust.

[Brief description of drawings]

FIG. 1 is a sectional view of a ball transfer of the present invention.

FIG. 2 is a bottom view of the ball transfer of the present invention.

FIG. 3 is an enlarged view of a friction portion of a secondary ball of a ball transfer.

FIG. 4 is a sectional view of an example of a conventional ball transfer.

FIG. 5 is a cross-sectional view of another example of the conventional ball transfer.

FIG. 6 is a schematic perspective view of an example of the ball transfer of the present invention.

FIG. 7 is a sectional view of an embodiment of the ball transfer of the present invention.

FIG. 8 is a sectional view of an embodiment of a ball transfer unit using the ball transfer of the present invention.

[Explanation of symbols]

10 ... Ball transfer 11 ... Case 11a ... Ball receiving part 11b ... Suction hole 11c ... Suction hole 11d ... Space 12 ... Lid 12a ... gap 20 ... Vice sphere 20a ... Contact part 30 ... Main sphere 40 ... Ball transfer mounting member 41 ... Above the mounting member 42 ... Below the mounting member 50 ... Intake block 60 ... Ball transfer unit

Claims (3)

[Claims] 1. A ball transfer in which a large number of sub-balls are circulated in a case and which is composed of a main ball supported by the sub-balls, and a hemisphere inside the case for sucking and discharging dust generated inside. A ball transfer characterized by having a hole for dust suction penetrating to the outside in the ball receiving portion. 2. The ball transfer according to claim 1, wherein a suction hole for sucking and discharging dust has a non-circular shape so that the auxiliary ball does not stick to the suction hole. 3. The ball transfer according to claim 1, wherein the hemispherical ball receiving portion has a hole for sucking and discharging the dust so that the dust generated at the upper portion of the hemispherical ball receiving portion can be effectively sucked and discharged. Ball transfer characterized by being installed on top of the.