JPS62264119A - Floating-supporting device - Google Patents

Abstract

PURPOSE:To floating-support a heavy article, with the simple constitution, by installing a magnet onto the front surface or back surface of a ceramic plate having a spiral groove which generates a dynamic pressure through revolution and arranging a ferromagnetic body onto the flat surface side of a receiving board. CONSTITUTION:As for a floating supporting device for floating a semiconductor part, etc., a dynamic pressure is generated from the spiral groove surface 30 by revolving a ceramic plate 26 by a motor 24, and a receiving board 26 is floating-supported. Since a permanent magnet 27 is fixedly installed onto the back surface of the ceramic plate 26, and since a ferromagnetic body is arranged onto the receiving surface 29 of a receiving board 28, the ceramic plate 16 held through a holding metal fitting 25 onto a spherical receiving part 50 always maintains the parallel position relation with the receiving surface 29, and the receiving board 28 is stably floating-supported, always holding a fluid lubrication film 40. Thus, a relatively large heavy article can be floating-supported with the simple constitution, and can be transported with high stability.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a floating support device for moving articles such as semiconductor components in a clean environment, and more specifically, a floating support device in which a spiral groove is formed on a rotating shaft of a motor or the like. The present invention relates to a floating support device using a support mechanism in which a ceramic plate is provided and rotated, and an object is supported by a fluid film generated by the rotation of a spiral groove.

[Conventional technology]

Conventionally, the third type of moving equipment used to move goods in clean environments such as semiconductor manufacturing and bioindustry
As shown in the figure, a large number of air nozzles 2 are formed on the floor 1 on which goods are transported, and high-pressure air is supplied from under the floor 3 as shown by arrow A to air the floating platform 4 placed on the floor 1. Articles are transferred by a carrier box 5 attached to a floating table 4 which is pushed up and transferred by force. Here, a beam near motor (secondary side) 6 is fixed to the floating table 4,
Since it is fixed to the floor or attracted (repulsed) by the near motor (primary side) 7, it can be moved to a predetermined position along the floor surface l. Therefore, the air nozzles 2 are arranged evenly over the entire length of the floor surface 1, and a valve seat 9 supported by a spring mechanism 8 is provided under the floor surface 3 so as to be able to move toward and away from the upper surface of the valve seat 9. A valve 10 is formed at a position facing the air nozzle 2, and an electromagnet 11 causes a permanent magnet 1 to
2 repulses, the valve seat 9 lifts up, and the valve lO becomes the air nozzle 2.
The levitation platform 4 can be sequentially opened and closed to reduce the amount of high-pressure air consumed.

4 and 5 show the rail 13 attached to the base 17.
2 is another conventional example in which a movable table 15 can run on the top.
Articles 16 can be transferred on a moving table 15 on which a total of four i14 are movably mounted on parallel rails 13 of books.

In this case, the rails 13 are fixed at a predetermined interval.
has a substantially trapezoidal cross-sectional shape, and both slopes 18
What about ball bearings? K19 is formed respectively, and the ball hair ring 21 fitted into this makes Il!
The movable table 15 is held via J14.

In particular, at the joint portion between this Ill 14 and the rail 13, an oil groove 20 is formed in the guide groove 19 of the rail 13, and a large number of ball bearings 21 are arranged along the guide groove 19 inside the JI 114. At the same time, grease can be supplied to the ball bearing 21 from a grease nipple 22, and this ball bearing 21 is connected to a piano l5I (not shown) stretched in the oil groove 20.
This prevents the legs 14 from falling off even if they come off the rails 13.

[Problem that the invention seeks to solve]

In the support device using the conventional air levitation method (example in Figure 3), the floating platform 4 and the floor l do not make solid contact, so no impact force is applied to the article, and no vibration is applied (transportation is possible). Although there are advantages, in order to levitate the floating platform 4, air must always be ejected from the air nozzle 2 on the floor 1 facing the lower part of the floating platform 4, and the downward flow or horizontal flow formed in the clean room This will obstruct airflow,
This poses the problem of contamination of goods.

Furthermore, since the air itself for flotation must be highly purified, operating costs are high.

In addition, the conventional linear guide system (examples in Figures 4 and 5) can be used even for extremely large loads.
In addition, since accurate positioning is possible, NC lathes,
×-Y tables, optical mechanical measuring stands, etc. are widely used, but if the length of the rail exceeds 3 m, it becomes difficult to manufacture, so it is not suitable for transporting long distances with large equipment. .

In addition, if the ball hair ring 21 is stationary or moving at low speed and receives an excessive load or impact load, local permanent deformation will occur in the 7th ring 21 and the guide 1A19 to the ball, and then There were still problems, such as causing a major hindrance to the smooth movement of the motors.

Therefore, the present invention aims to eliminate these conventional drawbacks and provides a means for transporting articles without using a large amount of air as in the aforementioned air slider.
Another object of the present invention is to provide an inexpensive floating support device that can support a relatively large heavy object with a simple structure, improve its stability, and transport it.

[Means for solving problems]

In the present invention, a ceramic plate having a spiral groove is rotatably provided on a rotating shaft, and a pedestal having a flat surface with a smooth finish facing the ceramic plate is provided with a slight gap between the ceramic plate and the ceramic plate. a floating support 'jt' which supports the pedestal in a floating manner by rotating the rotating shaft to generate fluid dynamic pressure between the rotating ceramic plate and the pedestal; The floating support device is characterized in that a magnet is provided on the surface or back surface of the ceramic plate, and a ferromagnetic material is provided on the flat side of the pedestal. In this case, the magnet may be a permanent magnet, an electromagnet, or both, and a wide range of ferromagnetic materials can be used as long as the fi'L- magnetic pole is located on the flat side of the pedestal. Can be done. Therefore, in this floating support device, the ceramic plate is attracted to the flat surface of the pedestal by the magnetic force of the magnet, the parallelism between the plane and the ceramic plate surface is easily maintained, and a single magnetic pole is located on the side of the flat surface of the pedestal. By arranging the magnets in this way, there is little change in the magnetic field for the ferromagnetic material, and stable support is possible.

〔Example〕

Embodiments of the present invention will be described with reference to FIGS. 1 and 2. A support part 23 fixes a disk-shaped ceramic plate 26 and a permanent magnet 27 to the tip of a drive shaft 31 of a motor 24 with a holding fitting 25. The motor 24 is connected to the floor 1 with legs 24+.
Fixed.

The surface 30 of the ceramic plate 26 is a spiral surface as shown in FIG. 2, and spiral grooves with a uniform depth of 3 to 50 um are formed on the flat surface, which is finished as a smooth surface with undulations of 1 μm or less. It is formed. That is, in this spiral surface 30, the white portion shown in the figure is a land 42, and the surface of the land 42 is finished to be a smooth plane, and the waviness of the land 42 on the entire surface of the spiral surface 30 is 1 μm or less. ing. In addition, unexpected portions 43 and 44 are pressure equalizing grooves 44 that connect the inner circumferential ends of each spiral /I 43 and all the spiral grooves 43, and in this embodiment, the spiral grooves 43 and the pressure equalizing grooves 44 are connected to each other. have the same groove depth. Note that the ceramic plate 26 on which the spiral surface 30 is formed is S.
iC+ 5IJa+^1203 or the like can be used, but any ceramic with high strength and good thermal conductivity can be used.

The method for processing the spiral surface 30 is as follows: First, the surface of the disk-shaped ceramic plate 26 is finished by lapping to have a flatness such that the waviness of the entire surface is 1 μm or less and to a mirror finish, and then the spiral groove 43 is finished. And pressure equalization? ! 44
It is preferable to expose only the area where grooves 4 are to be processed, mask the other lands 42 with plastic or resin, and then perform soft blasting with alumina particles. The depth of the groove can be changed by changing various factors such as the air pressure of the Sijift blast and the particle size of the alumina, but in order to increase the dynamic pressure generated by the rotation of the spiral groove 43, the depth of the groove should be 3 to 50 μm. Preferably within the range.

Further, the fluid 40 interposed between the receiving surface 29 and the spiral surface 30 may be air, a compressible fluid such as carbon dioxide gas, or an incompressible fluid such as water, oil, grease, or liquid metal. Moreover, even a lithium-ion fluid in which ultrafine particles are dispersed in a high boiling point liquid can be used.

In this case, if the fluid is other than gas, consideration may be given to using a support mechanism with a fluid sealing structure or a fluid circulation structure.

Furthermore, it is desirable that the receiving surface 29 be a smooth flat surface, but if the fluid 40 has a high viscosity, a fluid film will be formed even if it is not smooth. rotation speed and size,
The type of fluid 40 to be interposed on both surfaces, the smoothness of the receiving surface 29, the material of the member constituting the receiving surface 29, etc. are selected as appropriate. However, if the receiving surface 29 deviates from the ideal plane, large dynamic pressure cannot be obtained, so SiC+S
A hard ceramic with a small coefficient of thermal expansion, such as +J4, is desirable.

A plate-shaped permanent magnet 27 is provided on the back surface of the ceramic plate 26, and the side facing the ceramic plate 26 is all magnetized to the same magnetic pole.
is fixed to the holding fitting 25. The rotation of the motor 24 is controlled by an arm 35 attached to the tip of the drive shaft 31.
The information is transmitted to the ceramic plate 26 by rotating the bottle 36 fixed to the 11th surface of the holding fitting 25. Furthermore, since the pedestal 28 to which the receiving surface 29 is fixed is made of steel, the surface 30 of the ceramic plate 26 is kept parallel to the receiving surface 29 with a slight gap between them due to the magnetic force of the permanent magnet 27. There is. Furthermore, the holding fitting 25 and the drive shaft 31
is a spherical bearing 50, so the bearing surface 29 and the motor 2
Even if the axis 31' of the drive shaft 31 of No. 4 deviates from the perpendicular positional relationship, the surface 30 of the ceramic plate 26 and the pedestal 2
The parallelism with the receiving surface 29 on the 8 side is maintained by the permanent IF stone 27, and the rotation of the motor 24 is controlled by the ceramic plate 2.
Furthermore, the thrust load from the pedestal 28 side is supported by the dynamic pressure of the fluid 40 formed between the receiving surface 29 and the surface 30 of the ceramic plate 26 .

Therefore, the pedestal 28 (including the receiving surface 29) is supported without substantially contacting the rotating ceramic plate 26.

In FIG. 1, the pedestal 2B is a schematic representation of a moving platform on which items are placed on the top (not shown) and transported.
4 may be of any known type.

Furthermore, although the permanent magnet 27 is used as the magnet, any electromagnet can be used, and the permanent magnet 27 not only has a simple structure but also requires no maintenance. Moreover, if it is an electromagnet, power will be supplied by a slip ring or a brush, which has the advantage of providing strong magnetic force.

In this embodiment, the ceramic Fi 26 formed with a spiral groove rotated by a motor is placed facing a smooth receiving surface, so that as the motor 24 rotates, the spiral groove 43 draws surrounding fluid into the center of rotation. A fluid film is formed between the receiving surface 29 and the spiral surface 30 of the ceramic plate 26 on which the spiral groove 43 is formed, and it sufficiently resists the force that tries to bring these two planes closer together. The two planes can move relative to each other in a direction parallel to the receiving surface without contacting each other. That is, if the pedestal 28 is formed on the bottom of a heavy object, the ceramic plate 26 with the spiral groove 43 provided below it is connected to the motor 2.
If the receiving surface 29, which is the lower surface of the pedestal 28, is supported by the supporting mechanism configured to rotate at step 4, dynamic pressure of the fluid interposed between the two planes will be generated by the rotation of the ceramic plate 26. Therefore, the pedestal 28 is made of ceramic plate 26.
Supported without contacting the top. The pedestal 28 can also move in parallel on the ceramic plate 26 in a floating state.

Therefore, when a plurality of these support mechanisms are disposed on either the pedestal or the floor, it becomes a floating support device that transfers objects without contact.

Furthermore, in the present invention, a dynamic pressure group bearing using a ceramic member having spiral grooves formed thereon is also used on the sliding portion on the other side of the motor, that is, on the side not facing the pedestal 28. It is also possible to support a load, and in this case, there is no need to consider parallel movement, so either a spherical group bearing or a planar spiral group bearing can be applied, and in the case of the latter, the same reason as above applies. The stability can be improved by providing a magnet on the rotating side and fixing a ferromagnetic member on the other side.

〔Effect of the invention〕

The present invention rotates a ceramic plate with spiral grooves formed thereon, and rotates a ceramic plate with a smooth 2. ,: In a floating support device in which dynamic pressure is generated between ■ and a surface, a magnet is fixed on the surface or back of the ceramic plate so as to rotate together with the ceramic plate, and the other side is placed on the flat side of the pedestal. By disposing a ferromagnetic material, the ceramic surface on which the spiral group is formed is always maintained parallel to the plane of the opposing pedestal side by magnetic force, making it easy to form a fluid lubricant film. Furthermore, even if the ceramic plate and the pedestal move in parallel, they remain parallel, so a fluid lubricant film is maintained as well, and the ceramic disc maintains the pedestal in a stable state without substantially direct contact. In addition, even if the thrust load caused by the magnet increases, the increase in resistance of the fluid film is small and does not pose a practical problem, and the floating support applies the operating principle of a dynamic pressure group bearing. This is a device that can be provided with a function of stably forming a fluid film by simply adding a simple configuration to the device, which is useful in practice.

[Brief explanation of drawings]

FIG. 1 is a longitudinal cross-sectional view of an embodiment of the present invention, FIG. 2 is a front view of the ceramic seen from 1-1 in FIG. 1, and FIGS.
Each figure is an explanatory diagram showing a conventional example. I: Floor surface, 2: Air nozzle, 3: Under floor, 4: Levitation platform, 5
;Carrier box, 6: Linear motor (secondary side), 7
Nilinear motor (primary side), 8: Spring mechanism, 9: Valve seat,
lO: Valve, 11: Electromagnet, 12: Permanent magnet, 13: Rail, 14: j! jS 15: Moving table, 16-article, 17
; Base, 18; Slope, 19: Guide groove, 20: Oil groove, 21
: Pole bearing, 22 Nigelly nipple, 23:
Support part, 24: Motor, 24. ... Leg, 25: Holding metal fitting, 26: Ceramic plate, 27: Permanent magnet, 28: Pedestal, 29: Receiving surface, 30: Spiral surface, 31: Drive shaft,
40: Fluid, 50: Spherical receiver.

Claims (3)

[Claims] (1) A ceramic plate having a spiral groove is rotatably mounted on a rotating shaft, and a pedestal having a flat surface facing the ceramic plate with a smooth finish is attached to the ceramic plate with a slight gap therebetween. In a floating support device, the floating support device is configured to floatingly support a pedestal by generating a fluid dynamic pressure between the rotating ceramic plate and the pedestal by rotating the rotating shaft. A floating support device, characterized in that a magnet is provided on the surface or back surface of the ceramic plate, and a ferromagnetic material is provided on the flat side of the pedestal. (2) Claim 1, wherein the magnet is a permanent magnet.
Floating support device as described in section. (3) The floating support device according to claim 1, wherein the magnet is an electromagnet.