JP2006017242A - Sealing device for processing equipment - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a sealing device for processing equipment capable of successfully performing a process required for realizing a high degree of contaminantless. <P>SOLUTION: The sealing device 4 acts as a static pressure type noncontact gas sealing one schemed so as to seal both regions A, B while holding a noncontact state between sealing ends 5a, 7a by ejecting a sealing gas 10 from a sealing gas passage 9. The sealing gas passage 9 penetrates continuously a plastic cover 3, a sealing case 6 and a static sealing ring 7 and finally has an opening between sealing end faces 5a, 7a. A first sealing gas passage 91 formed in the plastic cover 3 and a second sealing gas passage 92 formed in a sealing case 6 communicate with each other to be connected in an abutting portion of a cover shoulder 3 and sealing case end 6a. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention is a processing apparatus for performing cleaning processing of a substrate (semiconductor wafer, electronic device substrate, liquid crystal substrate, photomask, glass substrate, etc.) using a rotary table, and a processing region in which the rotary table is disposed. The present invention relates to a sealing device installed in a processing apparatus that requires a high degree of contamination prevention measures. Specifically, in a processing apparatus in which the drive unit of the rotary table is covered with a cylindrical plastic cover, The present invention relates to a sealing device for a processing apparatus that is provided to shield between a processing region in which the is disposed and a region in a plastic cover.

For example, when a substrate such as a semiconductor wafer is cleaned using a rotary table, it is necessary to keep the processing area where the rotary table is placed clean, and particles enter the processing area from the drive side of the rotary table. It is necessary to prevent this. Therefore, in a processing apparatus that requires such a high level of anti-contamination measures, conventionally, a processing region in which a rotary table is disposed between a rotary table and a plastic cover that covers the drive unit and the plastic are used. It has been proposed to provide a seal device that shields an area in the cover (hereinafter referred to as “cover area”), and as such a seal apparatus, a labyrinth seal or a magnetic fluid seal is generally employed ( For example, see Patent Document 1). Thus, by providing such a sealing device, particles are prevented from entering from the cover inner region to the processing region and the substrate or the like is not contaminated, and the processing residue (cleaning liquid) generated in the processing region is prevented. Or harmful substances intrude into the cover area and cause troubles in the drive system of the rotating shaft.
JP-A-11-265868

  However, depending on the sealing device such as the labyrinth seal used in the conventional processing apparatus, the processing area and the cover inner area cannot be sufficiently shielded, and it is possible to prevent contamination in the processing apparatus such as the substrate cleaning apparatus. The fact is that we cannot expect. That is, in the labyrinth seal, the annular gap constituting the labyrinth is likely to be non-uniform depending on the rotation accuracy and the equipment accuracy, and the shielding function between the two regions is not sufficiently exhibited due to the breathing action resulting from the non-uniform labyrinth gap. In addition, since the quality of the magnetic fluid seal is unstable, it is difficult to exert a sufficient sealing function like the labyrinth seal.

  The present invention has been made in view of the above points, and can reliably shield a processing area in which a rotary table is arranged and an in-cover area in which a drive system including a rotating shaft is arranged, and is highly contamination-free. It is an object of the present invention to provide a sealing apparatus for a processing apparatus that can perform a process such as substrate cleaning required for the above-mentioned without causing a sealing problem.

  The present invention particularly relates to a sealing device provided to shield between a processing region where a rotary table is disposed and a region in the plastic cover in a processing device in which the drive unit of the rotary table is covered with a cylindrical plastic cover. In order to achieve the above object, it is proposed that the following non-contact mechanical seal be configured.

That is, the sealing device for a processing apparatus of the present invention is
A rotary seal ring fixed concentrically to the rotary table on its rotary axis;
A cylindrical seal case placed in a plastic cover and attached to the support machine frame of the drive unit;
A stationary seal ring that is concentrically formed with the rotary seal ring and that is directly opposed to the rotary seal ring, and is held axially movable on the inner periphery of the seal case;
A spring member interposed between the seal case and the stationary seal ring to press and bias the stationary seal ring to the rotary seal ring;
An annular cover step formed on the inner periphery of the plastic cover and abutting the end of the seal case;
A series of seal gas passages that pass through the plastic cover, the seal case, and the stationary seal ring and open between the seal end faces that are the opposite end faces of the two seal rings, the first seal gas passage portion and the seal formed in the plastic cover A second seal gas passage portion formed in the case, and a seal gas passage that is connected in communication at the abutting portion between the cover step and the end of the seal case,
A non-contact type mechanical seal that shields and seals between the two regions while maintaining a non-contact state by ejecting a seal gas from the seal gas passage through the seal end surface.

  In such a sealing device, depending on the sealing conditions, a dynamic pressure generating groove is formed on the sealing end face of one sealing ring, and in addition to the static pressure by the sealing gas, the dynamic pressure by the dynamic pressure generating groove is applied between the sealing end faces. By making it act, it can comprise so that between sealing end surfaces may be hold | maintained in a non-contact state.

  The sealing device for a processing apparatus of the present invention is configured as a non-contact type mechanical seal that ejects a sealing gas from between a rotary sealing ring on the rotary table side and a stationary sealing ring on the plastic cover side to a processing region and a cover inner region. Therefore, as compared with the case where the labyrinth seal or the like described at the beginning is used, the space between the processing area where the rotary table is arranged and the area inside the cover where the driving means for the rotary shaft is arranged is surely shielded. It is something that can be done. Therefore, by using the sealing device for a processing apparatus according to the present invention, the processing in the processing area can be maintained in a clean atmosphere in which particle intrusion from the area in the cover is completely prevented, and processing such as substrate cleaning is good. It is possible to implement advanced anti-contamination measures. In addition, it is possible to eliminate problems such as cleaning liquid residues generated in the processing area and harmful substances used and generated in the processing area leaking into the cover area and adversely affecting the drive system of the rotating shaft.

  Further, when the downstream portion (first seal gas passage portion) of the seal gas passage is formed in the plastic cover, the gas flow from the first seal gas passage portion of the plastic cover to the second seal gas passage portion of the seal case is plastic. If it is configured so that it is performed in the radial direction of the cover, the plastic cover may be deformed by the gas pressure acting on the connection portion of both seal gas passage portions, and there is a risk of causing problems such as poor seal gas supply. However, in the processing apparatus sealing apparatus of the present invention, the gas flow from the first seal gas passage portion to the second seal gas passage portion is performed in the axial direction of the plastic cover. Regardless of the material and thickness of the plastic cover (thickness in the radial direction), the plastic cover will not be deformed. Problems noted was does not occur. Therefore, the material and shape (thickness) of the plastic cover can be freely set according to the use conditions of the processing apparatus without considering the strength against the gas pressure.

  Further, the sealing device for a processing apparatus of the present invention can be configured to hold the space between the sealing end surfaces in a non-contact state by the action of dynamic pressure by the dynamic pressure generating groove in addition to the static pressure by the seal gas, By configuring in this way, the sealing function and the contamination-free function can be satisfactorily exhibited even under conditions where the sealing function cannot be sufficiently exhibited with the static pressure type non-contact type mechanical seal. .

  FIG. 1 is a longitudinal front view showing an example of a processing apparatus equipped with a processing apparatus sealing apparatus 4 according to the present invention, and FIG. 2 is an enlarged view of a main part thereof. In this processing apparatus, the driving unit 2 of the turntable 1 is covered with a cylindrical plastic cover 3, and a substrate such as a semiconductor wafer, a substrate of an electronic device, a liquid crystal substrate, a photomask, or a glass substrate is used as the turntable 1. When performing an appropriate process (cleaning process, chemical process, etc.) using, the sealing device 4 shields the processing area A in which the rotary table 1 is arranged and the area (in-cover area) B in the plastic cover 3. It is devised to seal and keep the processing area A clean.

  The drive unit 2 is connected to the rotary table 2 and extends in the up-down direction, a bearing that rotatably supports the rotary shaft 2a, a drive unit for the rotary shaft 2a, and supports these in the cover inner region B. A support machine frame 2b is provided, and the rotary table 1 is driven to rotate. The turntable 1 is made of silicon carbide and has a rotating body shape such as a circular plate disposed horizontally in the processing region A. Further, as shown in FIG. 1, the plastic cover 3 has a cylindrical shape with an upper end opening formed integrally with a chemical-resistant plastic (in this example, PTFE is used), and is disposed on the lower surface side of the turntable 1. The drive unit 2 is covered. As shown in FIG. 1, an appropriate labyrinth seal 1a can be provided between the turntable 1 and the plastic cover 3 as required. By providing such a labyrinth seal 1a, a chemical solution or the like is supplied from the labyrinth seal 1a of the seal gas 10 to the processing region A, which will be described later, from the processing region A to the in-cover region B. Etc. can be effectively prevented.

  As shown in FIGS. 1 and 2, the sealing device 4 includes a rotary seal ring 5 fixed to the rotary table 1 concentrically with the rotation axis thereof, and a support machine frame 2b of the drive unit 2 disposed in the plastic cover 3. A cylindrical seal case 6 attached to the stationary seal ring 6 is concentric with the rotary seal ring 5 and is held in a state of being directly opposed to the rotary seal ring 5 so as to be axially movable on the inner periphery of the seal case 6. A seal ring 7, a spring member 8 that is interposed between the seal case 6 and the stationary seal ring 7 and presses and urges the stationary seal ring 7 toward the rotary seal ring 5, and an inner peripheral portion of the plastic cover 3. An annular cover step 3a that is formed and abuts against the seal case end 6a, and a sealing end face 5a that penetrates the plastic cover 3, the seal case 6 and the stationary sealing ring 7 and is an opposite end face of both sealing rings 5 and 7. , 7a Open a series of seals A passage 9, and a seal gas 10 is ejected from the seal gas passage 9 between the sealed end faces 5 a and 7 a, thereby shielding between the regions A and B while maintaining a non-contact state. A non-contact mechanical seal or static pressure non-contact gas seal configured to seal.

  As shown in FIGS. 1 and 2, the seal case 6 is a metal comprising a cylindrical upper and lower sealing ring holding part 61 and an annular spring holding part 63 projecting inward from the lower end of the lower sealing ring holding part 62. Made of stainless steel such as SUS316. The lower sealing ring holding part 62 and the spring holding part 63 are an integral structure, and these and the upper sealing ring holding part 61 are separate structures and are connected by an appropriate connector. The seal case 6 has a lower end portion (lower end portion of the lower sealing ring holding portion 62) 6a abutted against the cover step portion 3a and an outer peripheral portion (outer peripheral portion of the upper and lower sealing ring holding portion 61) at the upper end of the plastic cover 3. Attached to the support machine frame 2b via a spring holding part 63 in a state of being in close contact with a side inner peripheral part (inner peripheral part above the cover step part 3a) via an O-ring 11 made of fluoro rubber. Yes.

  The rotary seal ring 5 is an annular body formed of a material (for example, silicon carbide) harder than the constituent material (for example, carbon) of the stationary seal ring 7, and as shown in FIG. It is fixed to. The lower end face of the rotary seal ring 5 is a sealed end face (hereinafter also referred to as “rotary seal end face”) 5a which is a smooth annular face.

  As shown in FIG. 1, the stationary sealing ring 7 is an annular body having a sealing end surface (hereinafter also referred to as “stationary sealing end surface”) 7a which is a smooth annular surface, and a pair of fluororubbers arranged in parallel in the vertical direction. It is fitted and held on the inner peripheral portions of the upper and lower sealing ring holding portions 61 and 62 of the seal case 6 through the O-rings 12 and 12 so as to be movable in the axial direction (movable in the vertical direction). The outer diameter of the stationary sealing end face 7a is set slightly smaller than the outer diameter of the rotary sealing end face 5a, and the inner diameter of the stationary sealing end face 7a is set slightly larger than the inner diameter of the rotary sealing end face 5a. The O-rings 12 and 12 include an annular protrusion 7b formed on the outer periphery of the stationary seal ring 7 and annular protrusions 61a and 62a formed on the inner periphery of the upper and lower seal ring holders 61 and 62 so as to face the upper and lower sides thereof. Are loaded into an annular space formed between the two. Further, a circular hole 7c extending in the axial direction is formed at the lower end of the stationary seal ring 7, and a metal (for example, stainless steel such as SUS316) implanted in the spring holding part 63 of the seal case 6 in the circular hole 7c. By engaging the drive pin 13 (made of steel), the stationary seal ring 7 is allowed to move relative to the seal case 6 while allowing its axial movement in a predetermined range. The number of the circular holes 7c and the drive pins 13 that engage with the circular holes 7c is arbitrary, and a plurality of them are provided as necessary.

  As shown in FIG. 1, the spring member 8 is composed of a plurality of coil springs (only one is shown) interposed between the stationary sealing ring 7 and the lower spring holding portion 63, and is stationary sealed. The ring 7 is pressed and urged to the rotary sealing ring 5 to generate a closing force that acts in the direction of closing the sealing end faces 5a and 7a.

  As shown in FIGS. 1 and 2, the seal gas passage 9 includes a first seal gas passage portion 91 formed in the plastic cover 3, a second seal gas passage portion 92 formed in the seal case 6, and a stationary sealing end face. 7a, a static pressure generating groove 93, an annular communication space 94 formed between the stationary seal ring 7 and the seal case 6 and sealed by the O-rings 12 and 12, and passing through the stationary seal ring 7. And a third seal gas passage portion 95 extending from the communication space 94 to the static pressure generating groove 93.

  As shown in FIG. 1, the first seal gas passage portion 91 penetrates the plastic cover 3 in the vertical direction (the axial direction of the plastic cover 3), and its upper end (downstream end) is opened to the cover step 3a. The lower end (upstream end) is connected to an appropriate seal gas supply path (not shown).

  As shown in FIG. 1, the second seal gas passage portion 92 includes a first gas passage 92a penetrating the lower sealing ring holding portion 62 in the axial direction and an upper sealing ring holding portion 61 from the lower end portion to the inner peripheral portion. It consists of a second gas passage 92b that penetrates. The upper end portion of the first gas passage 92a and the lower end portion of the second gas passage 92b are connected in a state of being sealed by a fluororubber O-ring 15 interposed between the upper and lower sealing ring holding portions 61 and 62. ing. The upper end portion (downstream end) of the second gas path 92 b is in communication with the communication space 94. A coating layer made of a chemical resistant plastic such as PFA or PTFE is formed on the surface of the seal case 6 and the inner surface of the second seal gas passage portion 92.

  The lower end portion (upstream end) of the first gas passage 92a of the second seal gas passage portion 92 is directly opposed to the upper end opening portion (downstream end opening portion) of the first seal gas passage portion 91 and is connected to the seal case end portion 6a. It is open. The opposing end portions of the both 91a and 92 are connected in a state of being sealed by a fluororubber O-ring 16 interposed between the cover step portion 3a and the seal case end portion 6a.

  The static pressure generating groove 93 is a shallow concave groove that is continuous or intermittent in a concentric ring shape with the stationary sealing end face 7a, and the latter is adopted in this example. That is, as shown in FIG. 3, the static pressure generating groove 93 is composed of a plurality of arc-shaped concave grooves 93 a that are concentrically arranged in parallel with the stationary sealing end surface 7 a. The communication space 94 is an annular space formed between the opposed peripheral surfaces of the sealing ring holding portion 7 a and the stationary sealing ring 7, and is sealed by O-rings 12 and 12. The vertical width (interval between the O-rings 12, 12) of the communication space 94 is set according to the amount of vertical movement required for the stationary seal ring 7.

  One end (upstream end) of the third seal gas passage portion 95 is opened on the outer peripheral surface of the annular protrusion 7b (opened in the communication space 94), and the other end (downstream end) is branched. As shown in FIG. 3, each branch portion 95 a is opened in each arc-shaped concave groove 93 a constituting the static pressure generating groove 93. It should be noted that a restrictor 96 such as an orifice is disposed at an appropriate position of the seal gas passage 9 (for example, an upstream portion of the third seal gas passage portion 95) as necessary.

  Thus, in the static pressure generating groove 93, the clean seal gas 10 having a pressure higher than both the regions A and B and containing no particles is contained in the seal gas passage 9 (the first seal gas passage portion 91 and the second seal gas passage portion). 92, the communication space 94 and the third seal gas passage portion 95). As the sealing gas 10, a gas that does not have any adverse effect even if it flows into the regions A and B is appropriately selected according to the sealing conditions. In this example, clean nitrogen gas that is inert to various substances and harmless to the human body is used. The seal gas 10 is generally supplied only during operation of the rotary table 1 (during driving of the rotary shaft 2a), and the supply is stopped after the operation is stopped. The operation of the rotary table 1 is started after the supply of the seal gas 10 is started and after the sealed end surfaces 5a and 7a are maintained in a proper non-contact state, and the supply of the seal gas 10 is stopped. This is performed after the operation of the rotary table is stopped and after the rotary shaft 2a is completely stopped. If necessary, the supply of the seal gas 10 can be continued regardless of whether the turntable 1 is started or stopped.

  When the sealing gas 10 is supplied to the static pressure generating groove 93, the sealing gas 10 introduced into the static pressure generating groove 93 generates an opening force that acts in the direction of opening the sealing end surfaces 5a and 7a. This opening force is due to the static pressure generated by the seal gas 10 introduced between the sealed end faces 5a and 7a. Therefore, the sealing end surfaces 5a and 7a are held in a non-contact state in which the opening force and the closing force (spring load) by the spring member 8 acting in the direction of closing the sealing end surfaces 5a and 7a are balanced. That is, the seal gas 10 introduced into the static pressure generating groove 93 forms a static pressure fluid film between the sealed end surfaces 5a and 7a. Due to the presence of this fluid film, the outer peripheral side region (processing region) of the sealed end surfaces 5a and 7a is formed. ) Between A and the inner peripheral side region (cover inner region) B is shield-sealed. The pressure of the sealing gas 10 and the spring force (spring load) of the spring member 8 are appropriately set according to the sealing conditions so that the gap between the sealed end faces 5a and 7a is appropriate (generally 5 to 15 μm). Is done.

  In the processing apparatus (substrate cleaning apparatus) using the sealing apparatus (static pressure type non-contact gas seal) 4 configured as described above, the rotary sealing ring 5 provided on the rotary table 1 and the plastic cover 3 are provided. Since the sealing gas 10 is jetted to both areas A and B from between the sealing end faces 5a and 7a, which are opposed to the stationary sealing ring 7 provided, the processing area A and the in-cover area B are completely blocked. Will be. Moreover, since both the sealing end surfaces 5a and 7a are held in a non-contact state by the sealing gas 10, particles such as wear powder due to the contact between the sealing end surfaces 5a and 7a are not generated. Therefore, dust generated in the in-cover area B does not enter the processing area A, and the processing area A is kept clean. On the contrary, the processing residue generated in the processing area A does not enter the in-cover area B, and the drive system of the rotating shaft 2a does not cause trouble.

  By the way, the seal gas passage 9 opens the downstream end 91d of the first seal gas passage portion 91 in the inner peripheral surface of the plastic cover 3 and the upstream side of the second seal gas passage portion 92, for example, as indicated by a chain line in FIG. The end 92d may be opened on the outer peripheral surface of the upper sealing ring holding portion 61 so that the two open ends 91d and 92d communicate with each other. However, in this case, both the open ends 91d and 92d are formed. Since the pressure by the high-pressure seal gas 10 acts on the communicating portion, the plastic cover 3 is deformed in the radial direction. As a result, there is a possibility that the sealing function at the communicating portion of both the open ends 91d and 92d is deteriorated or lost, and problems such as poor supply of the sealing gas may occur.

  However, in the sealing device 4, the first and second seal gas passage portions 91 and 92 are formed as described above, and the gas flow from the first seal gas passage portion 91 to the second seal gas passage portion 92 is performed. Since it is devised to be performed in the axial direction of the plastic cover 3, the plastic cover 3 is not deformed regardless of the material and thickness (diameter thickness) of the plastic cover 3, and the above-described problems occur. Absent. Therefore, the material and shape (wall thickness) of the plastic cover 3 can be freely set according to the use conditions of the processing apparatus without considering the strength against the gas pressure. Even when the labyrinth seal 1a as described above is provided between the cover 3 and the turntable 1, the plastic cover 3 is not deformed, so that the function of the labyrinth seal 1a is not impaired.

  The sealing device for a processing apparatus according to the present invention is not limited to the above-described configuration, and can be appropriately improved and modified without departing from the basic principle of the present invention.

  For example, in the above-described example, the sealing device is configured as the static pressure type non-contact gas seal 4 that holds the sealed end faces 5a and 7a in a non-contact state only by the static pressure by the seal gas 10, but as shown in FIG. Further, the sealed end faces 5a and 7a may be configured as a composite non-contact gas seal 104 which is a non-contact mechanical seal which is maintained in a non-contact state by generating a dynamic pressure in addition to a static pressure therebetween.

  That is, in the composite non-contact gas seal 104 as the processing apparatus sealing device shown in FIG. 4, the dynamic pressure generating groove 19 is formed on the sealing end surface (rotating sealing end surface) 5a of the rotating sealing ring 5 which is one sealing end surface. The dynamic pressure generating groove 19 is formed to generate a dynamic pressure between the sealed end surfaces 5a and 7a. The shape of the dynamic pressure generating groove 19 can be appropriately set according to the sealing conditions and the like, but in this example, the dynamic pressure generating groove 19 is formed in the static seal end surface 5a as shown in FIG. 6 or FIG. The first groove portion 20a extending from the portion facing the pressure generating groove 93 in the outer diameter direction and in the direction opposite to the rotation direction (a direction) of the rotary seal ring 5 and the rotation of the rotary seal ring 5 in the inner diameter direction. A plurality of grooves 20 composed of second groove portions 20b extending in a slanting direction in the direction opposite to the direction (b) are configured in parallel with the circumferential direction of the sealed end surface 5a. Each groove 20 is a groove having a shallow depth of 1 to 10 μm, and has an outermost diameter side end portion (an outer diameter side end portion of the first groove portion 20a) and an innermost diameter side end portion (the second groove portion 20b). The inner diameter side end portion) is located in the overlapping region of both sealed end faces 5a and 7a. That is, as shown in FIG. 5, the inner and outer diameters E and F of the dynamic pressure generating groove 19 are the outer diameter of the sealing end surface (static sealing end surface) 7a of the stationary sealing ring 7 (≦ the outer diameter of the rotary sealing end surface 5a) A B <F <A, D <E <C with respect to the inner diameter (≧ the inner diameter of the rotary sealing end face 5a) D and the outer diameter B and the inner diameter C of the static pressure generating groove 93 (arc-shaped concave groove 93a). It is set appropriately within the range it has. In this example, the condition of 0.5 ≦ (F−B) / (A−B) ≦ 0.9 or 0.5 ≦ (C−E) / (C−BD) ≦ 0.9 is satisfied. Is set. As shown in FIG. 6, each groove 20 has a substantially square shape in which the first groove portion 20a and the second groove portion 20b coincide with each other at the base end portion, or as shown in FIG. The base end portions of the portion 20a and the second groove portion 20b have a zigzag shape that folds in the circumferential direction.

  According to such composite non-contact gas seals 104 and 141, dynamic pressure is generated by the dynamic pressure generating groove 19 in addition to the static pressure by the seal gas 10 between the sealed end faces 5a and 7a. The sealed end faces 5a and 7a are held in a non-contact state by pressure. Therefore, even when a situation occurs in which the sealed end faces 5a and 7a cannot be held in an appropriate non-contact state depending on the static pressure generated by the seal gas 10, the proper non-contact state can be maintained by the dynamic pressure. Further, the required supply amount of the seal gas 10 can be reduced by the static pressure by the seal gas 10 as compared with the static pressure type non-contact gas seal that is maintained in a non-contact state only by the static pressure. Further, since the dynamic pressure generating groove 19 is not opened outside the overlapping region of the sealed end surfaces 5a and 7a, the innermost diameter side end and the outermost diameter side end of each groove 20 are introduced between the sealed end surfaces 5a and 7a. In addition to functioning as a weir for the sealed gas 10, the leakage gap formed between the sealed end faces 5 a and 7 a is reduced. As a result, the amount of leakage of the sealing gas 10 introduced between the sealing end faces 5a and 7a to the processing region (sealed gas region) A side is suppressed, and the trapping characteristic of the sealing gas 10 by the dynamic pressure generating groove 19 is extremely good. It becomes something. Therefore, the consumption of the sealing gas 10 can be reduced, and even if there are particles accompanying the sealing gas 10, the intrusion can be suppressed as much as possible.

  The configuration of the sealing device 104 shown in FIG. 4 is the same as that of the sealing device 4 shown in FIG. 1 except for the configuration described above (the point where the dynamic pressure generating groove 19 is provided).

  By the way, depending on the configuration and use conditions of the processing apparatus equipped with the composite non-contact gas seal 104 as the sealing apparatus shown in FIG. 4, the rotary table 1 or the rotating shaft 2a may be rotated in both directions instead of one direction. However, in such a case, the dynamic pressure generating groove 19 may be shaped so that dynamic pressure can be generated even when the rotary seal ring 5 rotates in either the forward direction or the reverse direction. The shape of the dynamic pressure generating groove 19 can be arbitrarily set according to the sealing conditions and the like, and various shapes have been proposed conventionally. For example, a dynamic pressure generating groove unit composed of a first dynamic pressure generating groove and a second dynamic pressure generating groove, which are arranged in the radial direction and symmetrical with respect to the diameter line, is arranged at a predetermined interval in the circumferential direction on the rotary sealing end surface 5a. When the rotary seal ring 5 rotates in the forward direction, dynamic pressure is generated by the first dynamic pressure generating groove, and when the rotary seal ring 5 rotates in the reverse direction. The configuration is such that the dynamic pressure is generated by the second dynamic pressure generating groove. As each of the first and second dynamic pressure generating grooves, for example, an L-shaped groove having a constant groove depth and groove width can be employed.

  Further, the rotary seal ring 5 may be fixed to the rotary shaft 2a or its sleeve, in addition to being provided on a rotary side member (for example, the rotary table 1) other than the rotary shaft 2a. Further, depending on the sealing conditions, the stationary seal ring 7 may be fixed to the seal case 6, and the rotary seal ring 5 may be held on the rotation side member so as to be movable in the axial direction and not to be relatively rotatable.

It is a vertical front view which shows an example of the processing apparatus equipped with the sealing device for processing apparatuses which concerns on this invention. It is an enlarged view of the principal part of FIG. It is a top view of the stationary sealing ring in the said sealing apparatus. It is a vertical front view equivalent to FIG. 2 which shows the modification of the sealing device for processing apparatuses which concerns on this invention. It is an enlarged view of the principal part of FIG. FIG. 5 is a half-top view of a rotary seal ring showing an example of a dynamic pressure generating groove. FIG. 6 is a half-top view of a rotary seal ring showing a modification of the dynamic pressure generating groove.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Rotary table 2 Drive part 2a Rotating shaft 2b Support machine frame 3 Plastic cover 4 Sealing device (static pressure type non-contact gas seal)
5 Rotating Seal Ring 5a Sealing End Face of Rotating Seal Ring 6 Seal Case 7 Stationary Seal Ring 7a Sealing End Face of Stationary Seal Ring 8 Spring Member 9 Seal Gas Passage 10 Seal Gas 19 Dynamic Pressure Generating Groove 91 First Seal Gas Passage Portion 92 2nd Seal gas passage 104 Seal device (Composite non-contact gas seal)
A Processing area B Plastic cover area (cover area)

Claims (2)

A sealing device provided to shield between a processing region where the rotary table is disposed and a region in the plastic cover in a processing device in which the driving unit of the rotary table is covered with a cylindrical plastic cover,
A rotary seal ring fixed concentrically to the rotary table on its rotary axis;
A cylindrical seal case placed in a plastic cover and attached to the support machine frame of the drive unit;
A stationary seal ring that is concentrically formed with the rotary seal ring and that is directly opposed to the rotary seal ring, and is held axially movable on the inner periphery of the seal case;
A spring member interposed between the seal case and the stationary seal ring to press and bias the stationary seal ring to the rotary seal ring;
An annular cover step formed on the inner periphery of the plastic cover and abutting the end of the seal case;
A series of seal gas passages that pass through the plastic cover, the seal case, and the stationary seal ring and open between the seal end faces that are the opposite end faces of the two seal rings, the first seal gas passage portion and the seal formed in the plastic cover A second seal gas passage portion formed in the case, and a seal gas passage that is connected in communication at the abutting portion between the cover step and the end of the seal case,
The sealing end surface is configured to be a non-contact type mechanical seal that shields and seals between the two regions while maintaining a non-contact state by ejecting a sealing gas from the sealing gas passage. Sealing device for processing equipment. A dynamic pressure generating groove is formed on the sealing end surface of one sealing ring, and in addition to the static pressure generated by the sealing gas between the sealing end surfaces, the dynamic pressure generated by the dynamic pressure generating groove is applied so that the sealing end surfaces are not in contact with each other. It is comprised so that it may hold | maintain, The sealing device for processing apparatuses of Claim 1 characterized by the above-mentioned.