JPH09109084A - Vacuum feeder - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide oil-free, low dusting and low torque charactersticks of a vacuum feeder. SOLUTION: A vacuum feeder 1 for moving articles in a vacuum container A has a ball screw 2 composed of a screw shaft 21, a nut member 22 and a group of balls 23, a driving means 6 for rotatory-driving the screw shaft 21 of the ball screw 2, a linear moving body 3 connected to the nut member 22 of the ball screw 2 so as to be linearly moved along the screw shaft 21 in association with the rotation of the screw shaft 21, and linear bearing means 4, 5 for guiding the linear movement of the linear moving body 3. A fluorinated solid lubricating film is formed at rolling contact and sliding contact parts in constitutent elements 2, 3, 4, 5 exposed to the atmosphere in the vacuum container A.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to, for example, a plasma C
The present invention relates to a vacuum feeder suitable for moving an article such as a semiconductor substrate or a liquid crystal panel in a vacuum container such as a VD apparatus or a sputtering apparatus.

[0002]

2. Description of the Related Art Conventionally, as a feeder, one using a ball screw is known, but when such a feeder is used for moving an article in a vacuum container as described above, Oil or grease cannot be used as a lubricant. This is because a large amount of dust is generated, scattering in a vacuum, and early depletion in a high temperature atmosphere.

On the other hand, a solid lubricating film made of a soft metal such as Ag is formed by coating on the rolling and sliding parts of the feeder.

[0004]

A solid lubricating film made of a soft metal as described above is better than a fluid lubricant such as oil or grease, but is still soft and therefore has a poor rolling contact or sliding contact area. It is pointed out that it is difficult to reduce the torque due to high frictional resistance, and that the amount of dust generated is large and the vacuum environment is easily contaminated.

Therefore, an object of the present invention is to make it possible to exhibit oil-free, low dust-generating property and low torque characteristics in a vacuum feeder.

[0006]

SUMMARY OF THE INVENTION The present invention is a vacuum feeding device for moving an article in a vacuum container, wherein a ball screw consisting of a screw shaft, a nut member and a ball group and a screw shaft of the ball screw are rotated. Driving means for driving, a linear moving body connected to the nut member of the ball screw and linearly moving along the screw shaft as the screw shaft rotates, and linear bearing means for guiding the linear movement of the linear moving body. Having a rolling contact in the components exposed to the atmosphere in the vacuum vessel,
A fluorine-based solid lubricating film is formed on the sliding contact portion.

The present invention is a vacuum feeding device for moving an article in a vacuum container, comprising a ball screw consisting of a screw shaft, a nut member and a ball group, and a driving means for rotationally driving the screw shaft of the ball screw. A linear moving body connected to the nut member of the ball screw and linearly moving along the screw shaft as the screw shaft rotates, linear bearing means for guiding the linear movement of the linear moving body, and attached to a vacuum container. And a case where the linear moving body is housed through the linear bearing means, and a fluorine-based solid lubricating film is formed at the rolling contact and sliding contact parts of the components exposed to the atmosphere in the vacuum container. There is.

The above-mentioned driving means is provided between the rotary power source and the rotary power source and the screw shaft of the ball screw, and applies the rotary power from the rotary power source to the screw shaft of the ball screw. Power transmission means for transmitting the power and for partitioning the space for arrangement of the rotational power generation source and the space for arrangement of the ball screw to hermetically seal each other.

[0009]

DETAILED DESCRIPTION OF THE INVENTION The details of the present invention will be described below with reference to the embodiments shown in FIGS. 1 and 2
FIG. 1 is a vertical sectional view schematically showing a structure of a vacuum feeding device, and FIG. 2 is a vertical sectional view schematically showing a structure of a power transmission means of a driving means.

In the figure, A indicates a vacuum container, and 1 indicates the entire vacuum feeding device. The vacuum feeding device 1 includes a ball screw 2, a rod-shaped linear moving body 3, linear bearing means 4, 5, driving means 6, a cylindrical case 7, and a support bearing 8.

The ball screw 2 includes a screw shaft 21, a nut member 22, a group of balls 23 interposed between the screw grooves of the screw shaft 21 and the nut member 22, and a circulator tube (not shown) for circulating the group of balls 23. Have and. The ball screw 2 is arranged and housed inside the case 7.

The linear moving body 3 has a hole 31 formed at the center of the inner end portion on the side of the ball screw 2 and opening toward the inner end surface, and the outer peripheral surface of the outer end portion on the side of the vacuum container A. Has a spline groove 32 formed therein. This linear moving body 3
Is arranged and housed coaxially with the ball screw 2 inside the case 7, and the inner end portion of the nut member 2 of the ball screw 2 is
The outer end portion of the screw shaft 21 of the ball screw 2 is inserted into the hole 31 on the inner end side in a non-contact state. In addition, the ball screw 2 is inserted into the hole 31 of the linear moving body 3.
Even if the screw shaft 21 is inserted, an exhaust hole 33 is provided at an appropriate position of the linear moving body 3 in order to facilitate the exhaust from the hole 31 when the vacuum container A is evacuated.

The linear bearing means 4 and 5 are provided axially adjacent to each other between the inner periphery of the case 7 and the outer end of the linear moving body 3 to prevent the linear moving body 3 from rotating and to move in the axial direction. Show only slides. The linear bearing means 4 and 5 are
Spline nuts 41 and 5 fixed to the inner circumference of the case 7
A ball spline configured by 1 and the group of balls 42 and 52 and the spline groove 32 at the outer end portion of the linear moving body 3 is preferably used. The linear bearing means 4 and 5 are not limited to the above-mentioned ball splines, but may be a well-known linear motion type bearing or the like although not shown.

The driving means 6 is provided between the rotary power generating source 61 such as a servo motor and the rotary power generating source 61 and the screw shaft 21 of the ball screw 2 and the rotary power generating source 6 is provided.
1 transmits the rotary power to the screw shaft 21 of the ball screw 2 and the space for disposing the rotary power generation source 61 and the ball screw 2
Power transmission means 6 for partitioning the installation space of
2 is included. In the drive means 6, one shaft end of the shaft body 622 of the power transmission means 62 is connected to the inner end portion of the screw shaft 21 of the ball screw 2 via a flexible coupling 9. The power transmission means 62 is, as shown in FIG. 2, a case 621, a shaft body 622, a rolling bearing 623 composed of two angular ball bearings, a magnetic fluid seal 62.
4 and a bearing unit including the oil seal 625 and the like are preferably used. The magnetic fluid seal 624 includes an annular magnet 626 and an annular plate 62 made of a magnetic material on both sides in the axial direction.
7, 628 and magnetic fluid 629. in this case,
In order to prevent thermal deterioration of the magnetic fluid seal 624 and the rolling bearing 623 and stabilize the performance, the magnetic fluid seal 624 is used.
It is preferable to provide cooling means for cooling the rolling bearing 623. The power transmission means 62 is not limited to the bearing unit described above, and a well-known magnet coupling or the like (not shown) is preferably used.

The case 7 is attached to the outer wall of the vacuum container A in a horizontal posture, and its internal space communicates with the internal space of the vacuum container A. In addition, the linear moving body 3
In order to improve positioning accuracy and the like, two nut members 22 of the ball screw 2 may be arranged in parallel, and a preload may be applied between them by a spring or the like. Further, the support bearing 8 of the ball screw 2 may be omitted to save space.

Incidentally, although not shown, a fluorine-based solid lubricating film is formed on the rolling and sliding parts of the ball screw 2, the linear moving body 3 and the linear bearing means 4 and 5 described above. Specifically, the solid lubricating film is the ball screw 2
In the case of, the ball rolling groove of the screw shaft 21 and the nut member 22, on the surface of the ball and the inner surface of the circulator tube, and in the case of the linear bearing means 4 and 5, the ball rolling groove of the spline nut and It is preferable to form them on the surfaces of the ball group and the spline groove 32 of the linear moving body 3, respectively. And as a fluorine-based solid lubricating film,
An example is one in which polytetrafluoroethylene (PTFE) is dispersed and mixed in a binder made of a thermosetting synthetic resin.

When a corrosive gas may be supplied to the inside of the vacuum vessel A, the components of the ball screw 2, the linear moving body 3 and the linear bearing means 4, 5 are made of a corrosion resistant material (for example, JIS standard SUS304). , SUS440C, ceramics, or the like, or a metal material other than the corrosion-resistant material (for example, JIS standard SUJ-2 or the like), and a solid lubricating film can be formed on the entire surface thereof by coating.

Next, the operation of the above-mentioned vacuum feeding device 1 will be described. First, by operating the rotational power generation source 61 of the drive means 6, the screw shaft 21 of the ball screw 2 is rotationally driven in either forward or reverse direction through the power transmission means 62. With the rotation of the screw shaft 21, the rotation of the nut member 22 of the ball screw 2 that is screwed into the screw shaft 21 is prevented, so that the nut member 22 is slid in the axial direction with the linear moving body 3.

At the outer end of the linear moving body 3, although not shown, a moving mechanism for moving an object, for example, a semiconductor substrate or a liquid crystal panel arranged in a vacuum container A such as a plasma CVD apparatus or a sputtering apparatus. Are connected,
Power is transmitted to the above-described moving mechanism as the linear moving body 3 moves back and forth in the axial direction.

The vacuum feeding device 1 of the present invention as described above is
Since the fluorine-based solid lubricating film is formed on the rolling and sliding parts of the internal components of the case 7 communicating with the vacuum container A, the frictional resistance at the rolling contact and sliding contact parts is lower than that of the conventional example. It can be remarkably reduced in size, the linear moving body 3 can be smoothly operated with a low torque, and the amount of dust generated can be remarkably reduced as compared with the conventional example. The inside of the vacuum container A can be kept clean, for example, by preventing unnecessary foreign matter from flowing in. Further, even when a corrosive gas is supplied into the vacuum container A, the corrosive gas does not corrode the constituent elements of the vacuum feeder 1, so that the life of the vacuum feeder 1 is extended. Will be achieved.

By the way, as described above, the linear moving body 3
Is supported by two linear bearing means 4 and 5 that are axially adjacent to each other, even if a moment load is applied to the linear moving body 3, the bending of the linear moving body 3 is suppressed and the posture is stabilized. Can be planned. When the support bearing 8 is not used, the ball screw 2 coupled to the linear moving body 3 is supported by the drive means 6 via the flexible coupling 8 and is not rigidly supported by the case 7. Therefore, when a moment load is applied to the linear moving body 3,
Safety can be ensured, for example, by preventing unreasonable stress from being applied to the connecting portion between the ball screw 2 and the linear moving body 3.

[0022]

According to the present invention, the fluorine-based solid lubricating film is formed at the rolling contact and sliding contact portions of the constituent elements exposed to the atmosphere in the vacuum container, so that the friction resistance there is reduced without oil. At the same time, since dust generation is suppressed, the linear moving body can be smoothly operated with low torque, and the atmosphere in the vacuum container can be kept clean. It is possible to provide an excellent feeder.

[Brief description of the drawings]

FIG. 1 is a vertical cross-sectional view schematically showing the configuration of a vacuum feeder according to an embodiment of the present invention.

FIG. 2 is a vertical cross-sectional view schematically showing the configuration of the power transmission means of FIG.

[Explanation of symbols]

 A vacuum container 1 vacuum feeding device 2 ball screw 3 linear moving body 4,5 linear bearing means 6 driving means 7 case

 ─────────────────────────────────────────────────── --- Continuation of the front page (72) Hiroaki Takebayashi, 3-5-8 Minamisenba, Chuo-ku, Osaka City Koyo Seiko Co., Ltd. (72) Koya Doi, 2-34 Minamiuematsucho, Yao City, Osaka Prefecture Machine Industry Co., Ltd.

Claims (3)

[Claims] 1. A vacuum feeding device for moving an article in a vacuum container, comprising: a ball screw including a screw shaft, a nut member, and a ball group, a driving unit that rotationally drives the screw shaft of the ball screw, and the ball. A linear moving member that is connected to a nut member of a screw and linearly moves along the screw shaft as the screw shaft rotates; and a linear bearing unit that guides the linear movement of the linear moving member. A vacuum feeding device, characterized in that a fluorine-based solid lubricating film is formed on the rolling contact and sliding contact parts of the components exposed to the atmosphere. 2. A vacuum feeding device for moving an article in a vacuum container, comprising a ball screw consisting of a screw shaft, a nut member and a ball group, a drive means for rotationally driving the screw shaft of the ball screw, and the ball. A linear moving body which is connected to a nut member of a screw and is linearly moved along the screw shaft according to the rotation of the screw shaft, a linear bearing unit which guides the linear movement of the linear moving body, and a linear bearing which is attached to the vacuum container. A moving body is housed via a linear bearing means, and a fluorine-based solid lubricating film is formed on the rolling contact and sliding contact parts of the components exposed to the atmosphere in the vacuum container. A vacuum feeding device characterized in that 3. The driving means is provided between the rotary power generation source and the rotary power generation source and the screw shaft of the ball screw, and transmits the rotary power from the rotary power generation source to the screw shaft of the ball screw. The vacuum feeding device according to claim 1 or 2, further comprising: a power transmission means for partitioning a space for arranging the rotational power generation source and a space for disposing the ball screw to hermetically seal each other.