JP4227120B2 - Sealing device for processing equipment - Google Patents

Description

The present invention opens the end portion of the first gas passage formed in the plastic member and the end portion of the second gas passage formed in the metal member at the opposing surface portions of both members, and the opening end portions of both passages. and communicatively connected in a state of being sealed by O-ring made of incompressible elastic material loaded between the opposed surface portions, the high-pressure gas equipped with a high-pressure high-pressure fluid supply equipment which is configured to flow between the two gas passages The present invention relates to a sealing device for a processing apparatus.

  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 contamination prevention measures, as disclosed in Japanese Patent Application Laid-Open No. 11-265868, a labyrinth is provided between the rotary table and the cover body that covers the drive unit. By providing a seal, contamination of the substrate or the like due to particle intrusion from the area inside the cover (hereinafter referred to as “inside the cover area”) into the processing area where the rotary table is arranged, or processing residues (cleaning liquid, harmful substances, etc.) generated in the processing area ) In order to prevent troubles in the drive system of the rotary table due to entry into the cover inner area.

  However, with such a labyrinth seal, it is not possible to sufficiently shield the processing area and the in-cover area, and it is actually impossible to take all possible measures to prevent contamination in a processing apparatus such as a substrate cleaning apparatus. . 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 view of this, the present inventor firstly, in a processing apparatus in which the driving unit of such a rotary table is covered with a cylindrical cover body that is a plastic member, a sealing device between the processing area and the in-cover area ( It has been proposed to adopt a static pressure type non-contact gas seal (for example, refer to WO99 / 27281 (FIG. 8)) as a “processing device sealing device”. That is, as a sealing device for a processing device, between a sealing end surface which is an opposing end surface of a rotary sealing ring fixed to a rotary table and a stationary sealing ring held in a sealing case disposed in a cover body so as to be movable in the axial direction, A hydrostatic non-contact type mechanical seal configured to seal between both regions while maintaining a non-contact state by ejecting a seal gas such as nitrogen has been proposed. According to such a sealing apparatus for a processing apparatus, since the sealing gas is ejected to both areas from between the sealed end faces, the area between both the areas is completely shielded, and the processing area completely prevents particle intrusion from the area in the cover. In addition to being maintained in a clean atmosphere, cleaning liquid residues generated in the processing area and harmful substances used and generated in the processing area will not leak into the cover area, and there will be no generation of abrasion powder due to contact with the sealed end face. It is possible to realize advanced anti-contamination measures.

  By the way, in a static pressure type non-contact type mechanical seal, a series of sealing gas passages having a downstream end opened between the sealing end faces is formed in the sealing case and the stationary sealing ring, and the sealing gas passage is sealed. A sealing gas having a pressure higher than the fluid pressure in the fluid region (processing region) is ejected between the sealed end faces (see, for example, WO99 / 27281 (FIG. 8)). Therefore, it is necessary to form a seal gas supply line to the upstream end of the seal gas passage in the cover body because of the structure in which the stationary side members such as the seal case and the stationary seal ring are arranged in the cover inner region. That is, the upstream end of the seal gas passage, that is, the upstream end of the first fluid passage that is the seal gas passage portion formed in the seal case and the downstream end of the second fluid passage that is the seal gas passage portion formed in the cover body It is necessary to establish a communication connection at the surface facing the cover body.

Thus, from the first fluid passage formed in the first member such as the seal case in this way to the second fluid passage formed in the second member such as the cover body (or from the second fluid passage to the first fluid passage). In general, as a high-pressure fluid supply device for supplying a high-pressure fluid such as a seal gas, the first and second gas passages are opened at the opposing surface portions of both members, and the opening end portions of both passages are disposed between the opposing surface portions. It is well known that a high-pressure gas is made to flow between both gas passages in a state of being connected in a sealed state by an O-ring made of a loaded incompressible elastic material (rubber or the like) (for example, Patent Documents). 1). That is, as shown in FIG. 5A, when the opposing surface portions 201a and 202a of the first and second members 201 and 202 are flat, one O-ring 203 is loaded between the opposing surface portions 201a and 202a. Then, both the passages 206 and 207 are opened in the seal space (inner peripheral region of the O-ring 203) 205 formed by the O-ring 203 between the opposed surface portions 201a and 202a, so that both the passages 206 and 207 are connected to the O-ring 203. Connect with communication in a sealed state. As shown in FIG. 6A, when the opposing surface portions 201a and 202a of the first and second members 201 and 202 are concentric cylindrical surfaces, two O's are provided between the opposing surface portions 201a and 202a. The rings 203 and 204 are loaded, and both passages 206 and 207 are opened in an annular seal space (region between the O-rings 203 and 204) 205 formed by the O-rings 203 and 204 between the opposing surface portions 201a and 202a. Thus, the passages 206 and 207 are connected in communication with the O-rings 203 and 204 being sealed.
JP 2004-47652 A (FIG. 2)

  By the way, in the processing apparatus described above, the seal case that is the first member 201 is made of a metal material because of its high function and structure, so that the cover body is the second member 202. Since it faces the treatment area, in general, the strength of a seal case may not be required to prevent the generation of metal ions due to contact with fluids or corrosion due to contact with corrosive fluids. And made of a corrosion-resistant plastic material such as polytetrafluoroethylene (PTFE). The metal seal case is coated with a corrosion-resistant plastic material on the portion in contact with the fluid or seal gas in the processing area in consideration of prevention of generation of metal ions.

  Thus, when the first member 201 is made of a high strength metal material like a seal case, and the second member 202 is made of a low strength plastic material like a cover body. As shown in FIG. 5A, a high-pressure fluid supply device (hereinafter referred to as “first fluid supply device”) using one O-ring 203 and two O-rings 203 and 204 as shown in FIG. The following problems occur in any of the high-pressure fluid supply devices used (hereinafter referred to as “second fluid supply devices”).

  That is, in both the first and second fluid supply devices, when the high-pressure fluid 208 such as the seal gas is caused to flow between the passages 206 and 207, the opposing surface portions 201a and 201a are moved by the high-pressure fluid 208 introduced into the seal space 205. A pressing force in the direction of separating this acts on 202a, and the second member 202, which is inferior in strength to the first member 201, is deformed as shown in FIGS. 5 (B) and 6 (B). As a result, the space between the opposing surface portions 201a and 202a is opened.

  For this reason, in the conventional first and second fluid supply devices, the deformation of both the members 201 and 202 is not considered, and the O-rings 203 and 204 usually have a hardness of Hs70 or higher. Since it is used at a compression rate of 5 to 15%, when the second member 202 is deformed and the opposing surface portions 201a and 202a are opened as described above, as shown in FIGS. 5 (B) and 6 (B). The O-ring 203 (in the second fluid supply device, the O-ring (the O-ring 203 in the example shown in FIG. 6B)) loaded at a location where the deformation amount of the second member 202 becomes larger is the first. Corresponding to the deformation of the two members 202, the elastic deformation cannot be completed, the pressure contact force (seal force) to the opposing surface portions 201a, 202a of the O-ring 203 is reduced, and the sealing function by the O-ring 203 is reduced, Lost in extreme cases Put away.

  As a result, the fluid 208 leaks from the connecting portion between the two passages 206 and 207, and a good fluid supply cannot be performed. In particular, in the above-described sealing apparatus for a processing apparatus, when the sealing gas is not sufficiently supplied from the cover body to the sealing case, a sufficient gas pressure is supplied between the sealing end faces to keep the sealing gas non-contact. However, the sealing function is deteriorated or lost, and the significance of using a static pressure type non-contact type mechanical seal instead of the labyrinth seal as a sealing device is lost.

The present invention has been made in view of this point, and leaks even when the second member is deformed between the metal first member and the plastic second member, such as a high-pressure fluid such as a seal gas. Equipped with a high-pressure fluid supply device that can flow well without any problem, and by installing this high-pressure fluid supply device, a processing area in which a rotary table is arranged, and an in-cover area in which a drive system including a rotation shaft is arranged It is an object of the present invention to provide a sealing apparatus for a processing apparatus that can reliably shield a substrate and perform processing such as substrate cleaning that requires a high level of contamination without causing a sealing problem. Is.

The present invention is, to shield between the plastic processing area rotary table is disposed in the Aru processing apparatus covered with the cover body and the cover body region forming a top opening shaped cylindrical drive portion of the rotating table A hydrostatic non-contact type mechanical seal equipped with a high-pressure fluid supply device configured as described below is proposed.

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 metal seal case having a cylindrical shape attached to the support machine frame of the drive unit in a state of being placed in the cover body and in contact with the upper end portion thereof ;
A stationary seal ring that is concentric with the rotary seal ring and that is opposed to the rotary seal ring and is held axially movable in 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;
The upstream end portion of the first gas passage formed in the seal case and the downstream end portion of the second gas passage extending upward through the cover body are opened at the opposing surface portions of both members, and the opening end portions of both passages are formed. By connecting a pair of O-rings made of an incompressible elastic material having a hardness of Hs60 or less between the facing surface portions at a compression rate of 5 to 40%, the two gas passages are connected in communication in a sealed state. A high-pressure seal gas is supplied to the first gas passage from the processing region, and even when the cover body is deformed by the seal gas, the contact pressure to the facing surface portion is a predetermined sealing function due to the elastic deformation of the O-ring. A high-pressure fluid supply device configured to be maintained sufficient to ensure
A gas ejection path that passes through the stationary sealing ring and is connected to the downstream end of the first gas passage and opens between the sealing end faces that are opposite end faces of both sealing rings,
This is configured as a static pressure non-contact type mechanical seal that shields and seals between the two regions while maintaining a non-contact state between the sealed end faces by ejecting a seal gas from the gas jet passage. is there.
In addition, it is preferable to use the thing made from a fluororubber as an O-ring.

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 cover body 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 in which the rotary table is arranged and the area in the cover in which the driving means for the rotary shaft is arranged is surely shielded. It is something that can be done. Even when a part of the seal gas supply line (second gas passage) is formed in a cover body that is easily deformed, the seal gas of a predetermined pressure is passed between the sealed end faces even when the cover body is deformed. Can be supplied properly. Therefore, by using the sealing apparatus for a processing apparatus according to the present invention, the processing area can be maintained in a clean atmosphere in which particle intrusion from the in-cover area is completely prevented, and processing such as substrate cleaning is performed satisfactorily. And can 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.

  FIG. 1 is a longitudinal front view showing an example of a processing apparatus equipped with a sealing apparatus for a processing apparatus according to the present invention, FIGS. 2 and 3 are enlarged views of the main part, and FIG. 4 is a stationary sealing ring described later. FIG. In this processing apparatus, the drive unit 2 of the turntable 1 is covered with a plastic cylindrical cover body 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 provided. When an appropriate process (cleaning process, chemical process, etc.) is performed using the rotary table 1, the processing area H in which the rotary table 1 is arranged and the area (in-cover area) L in the cover body 3 are defined in the present invention. The processing device sealing device 4 is shielded and sealed to keep the processing region H clean.

  The drive unit 2 includes a bearing that rotatably supports a rotary shaft 2a that is connected to the rotary table 2 and extends in the vertical direction, a drive unit for the rotary shaft 2a, and a support machine frame 2b that supports these in the cover inner region L. The rotary table 1 is rotationally driven. The turntable 1 uses a plastic (PTFE or the like) rich in chemical resistance as its constituent material or coating material, and has a rotating body shape such as a circular plate disposed horizontally in the processing region H. is there.

  As shown in FIG. 1, the cover body 3 has a cylindrical shape with a top opening formed integrally with a chemical-resistant plastic (in this example, using PTFE), and is disposed on the lower surface side of the rotary table 1. Covers part 2. An appropriate labyrinth seal 1a can be provided between the rotary table 1 and the cover body 3 as required, as shown in FIG. By providing such a labyrinth seal 1a, intrusion of a chemical solution or the like from the processing region H into the in-cover region L in combination with a jetting action of the sealing gas 10 from the labyrinth seal 1a to the processing region H described later. Can be effectively prevented.

  As shown in FIGS. 1 and 2, the processing device sealing device 4 includes a rotary sealing ring 5 fixed to the rotary table 1 concentrically with the rotation axis thereof, and a cover body 3 arranged to support the drive unit 2. A cylindrical seal case 6, which is a metal member attached to the machine frame 2 b, is concentric with the rotary seal ring 5 and directly faces the rotary seal ring 5. A stationary seal ring 7 held movably in a direction, and a spring member 8 interposed between the seal case 6 and the stationary seal ring 7 to press and urge the stationary seal ring 7 to the rotary seal ring 5; In the present invention, the seal gas ejection path 9 that passes through the stationary seal ring 7 and opens between the seal end faces 5a and 7a, which are opposite end faces of the seal rings 5 and 7, and the seal gas 10 is supplied to the seal gas ejection path 9. The high-pressure fluid supply device 11, and between the sealed end faces 5 a and 7 a The static gas type non-contact type mechanical system configured so as to shield and seal between the two regions H and L while maintaining the non-contact state by ejecting the seal gas 10 from the seal gas ejection path 9. It is a seal.

  As shown in FIGS. 1 and 2, the seal case 6 is made of metal (for example, SUS312 or the like) including a cylindrical sealing ring holding portion 61 and an annular spring holding portion 62 projecting inwardly from the lower end portion thereof. Stainless steel). The seal case 6 is attached to the support machine frame 2b in a state where the sealing ring holding portion 61 is fitted in the upper end portion 31 of the cover body 3 and the spring holding portion 62 is engaged with the annular step portion 32 of the cover body 3. It has been.

  The rotary seal ring 5 is an annular body formed of a material (silicon carbide in this example) that is harder than the constituent material of the stationary seal ring 7 (carbon in this example). As shown in FIG. It is fixed to the lower surface. The lower end surface of the rotary sealing ring 5 is a sealed end surface (hereinafter also referred to as “rotational side sealing end surface”) 5a which is a smooth annular surface.

  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 that is a smooth annular surface, and a pair of fluorines arranged in parallel in the vertical direction. It is fitted and held on the inner peripheral part of the seal case 6 (inner peripheral part of the sealing ring holding part 61) through the rubber O-rings 12 and 13 so as to be movable in the axial direction (movable in the vertical direction). The outer diameter of the stationary side sealing end surface 7a is set slightly smaller than the outer diameter of the rotation side sealing end surface 5a, and the inner diameter of the stationary side sealing end surface 7a is set slightly larger than the inner diameter of the rotation side sealing end surface 5a. The O-rings 12 and 13 are engaged and held in annular O-ring grooves 71 and 72 formed in the outer peripheral portion of the stationary seal ring 7, and the O-rings 12 and 13 and the seal case are allowed to move in the axial direction. Secondary seal between 6 and 6. Further, a circular hole 73 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 73 is formed. By engaging the drive pin 14 (made of steel), the stationary seal ring 7 is allowed to move relative to the seal case 6 while allowing its axial movement within a predetermined range. The number of the circular holes 73 and the drive pins 14 that engage with the circular holes 73 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 seal ring 7 and the lower spring holding portion 62, 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 FIG. 1, the seal gas ejection path 9 is an annular space formed between a static pressure generating groove 91 formed on the stationary-side sealing end surface 7 a and an opposing peripheral surface between the sealing case 6 and the stationary sealing ring 7. The communication space 92 sealed by the O-rings 12, 13, the ejection path 93 penetrating the stationary sealing ring 7 from the communication space 92 to the static pressure generating groove 91, and the ejection path 93. And a diaphragm 94.

  The static pressure generating groove 91 is a shallow concave groove that is continuous or intermittently formed in a concentric ring shape with the stationary side sealing end surface 7a, and the latter is adopted in this example. That is, as shown in FIG. 4, the static pressure generating groove 91 is composed of a plurality of arc-shaped concave grooves 91 a that are concentrically arranged in parallel with the stationary-side sealed end surface 7 a. One end (upstream end) of the ejection path 93 is opened between the O-ring grooves 71 and 72 on the outer peripheral surface of the stationary seal ring 7 and communicates with the communication space 92. Further, the other end portion (downstream end) of the ejection passage 93 is branched, and each branch portion 93a is opened to each arc-shaped concave groove 91a constituting the static pressure generating groove 91 as shown in FIG. . The restrictor 94 is composed of an orifice, a porous member, and the like, and is disposed in an upstream portion of the branching portion 93 a in the ejection passage 93.

  As shown in FIG. 1, the high-pressure fluid supply device 11 includes a first gas passage 111 that is a first fluid passage formed in a seal case 6 that is a metal first member, and a cover body that is a second member made of plastic. 2, the second gas passage 112 formed as a second fluid passage, and the opposed surface portion of the cover body 3 and the seal case 6 (the opposed circumference of the upper end portion 31 of the cover body 3 and the sealing ring holding portion 61 of the seal case 6). A pair of O-rings 113 and 114 loaded in a compressed state between the surface portions 31a and 61a, and a supply gas control device (not shown) for supplying and stopping the seal gas 10 to the second gas passage 112. To do.

  As shown in FIGS. 1 and 2, the O-rings 113 and 114 are annularly formed on the outer peripheral portion (the outer peripheral portion of the sealing ring holding portion 61) 61 a of the seal case 6 in parallel with a predetermined interval in the axial direction. The O-ring grooves 63 and 64 are engaged and held. The O-rings 113 and 114 are made of an incompressible elastic material having a hardness of Hs60 (JIS spring type) or less, and between the facing surface portions 31a and 61a of the cover body 3 and the seal case 6 (more precisely, the cover body 3 Between the inner peripheral surface portion 31a of the upper end portion 31 and the bottom surface portions 63a and 64a of the O-ring grooves 63 and 64 formed in the seal case 6) in a compressed state with a compression ratio of 5 to 40%. The opposed surface portions 31a and 61a between the cover body 3 and the seal case 6 are sealed, and a sealed space 115 as an annular sealed space is formed between the opposed surface portions 31a and 61a. In this example, fluorine rubber having excellent chemical resistance and the like is used as a constituent material of the O-rings 113 and 114.

  As shown in FIGS. 1 and 2, the first gas passage 111 is a through hole that penetrates the seal ring holding portion 61 of the seal case 6 in the radial direction, and one end (upstream end) is opened to the seal space 115. At the same time, the other end (downstream end) is opened in the communication space 92 of the gas ejection path 9. As shown in FIGS. 1 and 2, the second gas passage 112 is a through hole that extends upward in the cover body 3 and opens in the inner peripheral surface portion 31a of the upper end portion 31, and has one end (upstream end). A gas supply source (not shown) of the supply gas control device is connected and the other end (downstream end) is opened in the seal space 115. That is, the first and second gas passages 111 and 112 constitute a series of passages connected in communication via a seal space 115 sealed by O-rings 113 and 114. The passages 111, 112, and 115 are The gas ejection path 9 is connected to and communicated via the communication space 92.

  It should be noted that the seal case portion that comes into contact with the fluid and the seal gas 10 in the processing region H, that is, the outer surface of the sealing ring holding portion 61 and the inner surface of the first gas passage 111 are coated with a chemical-resistant plastic such as PFA or PTFE. A layer 65 is formed.

  Thus, according to the high-pressure fluid supply device 11, the clean seal gas 10 having a higher pressure than both the regions H and L and containing no particles flows from the second gas passage 112 to the first gas passage 111 through the seal space 115. Then, the gas is further ejected from the gas ejection path 9 between the sealed end faces 5a and 7a. As the sealing gas 10, a gas that does not have any adverse effect even if it flows into the regions H and L 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 supply of the seal gas 10 by the high-pressure fluid supply device 11 is generally performed during the operation of the rotary table 1 (while the rotary shaft 2a is being driven), and 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. Depending on the sealing conditions and the like, the sealing gas 10 may be continuously supplied regardless of whether the turntable 1 is started or stopped.

  According to the sealing device 4 configured as described above, when the sealing gas 10 is supplied to the static pressure generating groove 91 by the high pressure fluid supply device 11, the sealing end face 5a is generated by the sealing gas 10 introduced into the static pressure generating groove 91. , 7a generates an opening force that acts in the direction of opening it. 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 91 forms a static pressure fluid film between the sealed end surfaces 5a and 7a, and the presence of this fluid film results in the outer peripheral region (processing region) of the sealed end surfaces 5a and 7a. A space between H and the inner peripheral side region (cover inner region) L is sealed. The pressure of the sealing gas 10 and the spring force (spring load) of the spring member 8 are appropriately determined according to the sealing conditions so that the gap between the sealed end faces 5a and 7a is appropriate (generally 5 to 15 μm). Set to

  Therefore, in the processing apparatus (substrate cleaning apparatus) using the static pressure type non-contact type mechanical seal 4 functioning as the sealing apparatus as described above, the rotary sealing ring 5 provided in the rotary table 1 and the cover body 3 Since the sealing gas 10 is jetted to both regions H and L from between the sealing end surfaces 5a and 7a, which are the end surfaces facing the stationary sealing ring 7 provided in the region, the processing region H and the cover inner region L 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 region L does not enter the processing region H, and the processing region H is kept clean. On the contrary, the processing residue generated in the processing area H enters the in-cover area L, and the drive system of the rotating shaft 2a does not cause trouble. In addition, all of the parts (rotary table 1, cover body 3, seal case 6, seal rings 5, 7 and O-rings 12, 13, 113, 114, etc.) in contact with the fluid in the processing region H and the seal gas 10 are PTFE. , Silicon carbide, carbon, fluorine rubber or the like, which is made of a material excellent in chemical resistance that does not generate metal ions, or is coated with a coating layer 65 of such a material, so that no metal ions are generated. Advanced contamination prevention measures can be implemented.

  By the way, since a fluid (nitrogen) having a higher pressure than the two regions H and L is used as the seal gas 10, the second gas passage 112 formed in the cover body 3 and the first gas passage 111 formed in the seal case 6 are used. The connection portion (seal space 115) is acted on by a pressure of the seal gas 10 to push and spread between the facing surface portions 31a and 61a of the cover body 3 and the seal case 6, and as a result, FIG. 3, the plastic cover body 3, which is inferior in strength to the metal seal case 6, is deformed, and the upper end portion 31 of the cover body 3 holding the O-rings 113 and 114 and the seal case 6 are deformed. The space between the facing surface portions 31a and 61a with the sealing ring holding portion 61 is opened.

  However, even when the cover body 3 is deformed by using the O-rings 113 and 114 having the hardness and compression rate set as described above, the opening amount due to the deformation of the cover body 3 as shown in FIG. According to δ, the O-rings 113 and 114 are elastically deformed so as to bulge in the deformation direction (the outer diameter direction of the cover body 3), and the contact pressure (exactly to the opposing surface portions 31a and 61a of the O-rings 113 and 114). Is the contact pressure to the opposing surface portions 31a and 63a for the O-ring 113, and the contact pressure to the opposing surface portions 31a and 64a for the O-ring 114), which is sufficient to ensure a predetermined sealing function. Is done.

  Therefore, even when the cover body 3 is deformed, the supply of the seal gas 10 from the second gas passage 112 to the first gas passage 111 is performed satisfactorily without causing leakage, and the seal gas 10 having an appropriate pressure is static pressure. It will be introduced into the generation groove 91. As a result, the sealed end surfaces 5a and 7a are held in an appropriate non-contact state, and the sealing function by the sealing device 4 is satisfactorily exhibited, and it is possible to take all possible measures for preventing contamination. .

Incidentally, the hardness and compression rate of the O-rings 113 and 114 are appropriately set in the above range according to the pressure of the seal gas 10, that is, the amount of deformation of the cover body 3. As shown in FIG. 3, the opening amount of the facing portion between the seal case 6 and the seal case 6 is small at the portion where the lower O-ring 114 is loaded, and large at the portion where the upper O-ring 113 is loaded. The hardness and compression rate of the O-ring are set based on the deformation amount (opening amount) δ at the place where the upper O-ring 113 is loaded. When the relationship between the deformation amount δ (mm) and the seal fluid pressure (pressure of the seal gas 10) supplied to the gas passages 111 and 112 was confirmed by experiment, it was as shown in FIG. Despite somewhat of deformation amount [delta], hardness described above, according to the O-ring 113, 114 of the compression ratio, gas leakage from between the two gas passages 111 and 112 did not occur at all. In this experiment, the O-rings 113 and 114 are made of fluoro rubber, and the cover body 3 is made of PTFE having a thickness M of the upper end portion 31 of 14 mm and a length N of 55 mm. The seal ring holding portion 61 of the seal case 6 is fitted to the upper end portion 31 of the cover body 3 with a 0.1 mm gap.

  The processing apparatus sealing apparatus 4 and the high-pressure fluid supply apparatus 11 according to the present invention are not limited to the above-described configuration, and can be appropriately improved and modified without departing from the basic principle of the present invention. is there.

  For example, in the above-described example, the sealing device is configured as the static pressure type non-contact type mechanical 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. FIG. As shown, the sealed end faces 5a and 7a may be configured as a composite non-contact type mechanical seal 104 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 type mechanical seal 104 as the processing apparatus sealing device shown in FIG. 6, dynamic pressure is generated on the sealing end face (rotary side sealing end face) 5a of the rotary sealing ring 5 which is one sealing end face. A groove 19 is formed, and the dynamic pressure is generated between the sealed end faces 5 a and 7 a by the dynamic pressure generating groove 19. 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 on the rotation-side sealing end face 5a as shown in FIGS. The first groove portion 20a extending from the portion facing the static pressure generating groove 91 in the outer diameter direction and in the direction opposite to the rotation direction (a direction) of the rotary seal ring 5 and the inner diameter direction and the rotary seal ring 5 A plurality of grooves 20 composed of second groove portions 20b extending in an inclined manner in the direction opposite to the rotation direction (a direction) 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 (of 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. 7, the inner and outer diameters E and F of the dynamic pressure generating groove 19 are the outer diameter of the sealing end surface (stationary sealing end surface) 7a of the stationary sealing ring 7 (≦ the outer diameter of the rotating sealing end surface 5a) A. And B <F <A, D <E <C with respect to the inner diameter (≧ the inner diameter of the rotation-side sealing end surface 5a) D and the outer diameter B and the inner diameter C of the static pressure generating groove 91 (arc-shaped concave groove 91a). It is set appropriately within the range having the relationship. In this example, the condition of 0.5 ≦ (F−B) / (A−B) ≦ 0.9 or 0.5 ≦ (C−E) / (C−D) ≦ 0.9 is satisfied. Is set. As shown in FIG. 8 (A), 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. As shown, the base end portions of the first groove portion 20a and the second groove portion 20b have a zigzag shape that is inclined in the circumferential direction.

  According to such a composite non-contact mechanical seal 104, 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) H side is suppressed, and the trapping characteristic of the sealing gas 10 by the dynamic pressure generating groove 19 is extremely good. It will be 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. 6 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 of the processing apparatus equipped with the sealing device 104 shown in FIG. 6, the use conditions, etc., the rotary table 1 or the rotary shaft 2a may be rotated in both directions instead of in one direction. 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 that are arranged in the radial direction and symmetrical with respect to the diameter line on the rotation-side sealing end surface 5a is predetermined in the circumferential direction. A plurality of sets are formed in parallel at intervals, and when the rotary seal ring 5 rotates in the forward direction, dynamic pressure is generated by the first dynamic pressure generating groove, and the rotary seal ring 5 rotates in the reverse direction. In some cases, the second dynamic pressure generating groove is configured to generate dynamic pressure. 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.

  Further, the high-pressure fluid supply device 11 according to the present invention is applied as a means for supplying the seal gas 10 in the above-described processing device sealing devices 4 and 104, and also includes a metal member (first member) and a plastic member (first member). When a high-pressure fluid such as gas flows between two members), the plastic member may be deformed and the sealing function due to the O-ring may be reduced or lost. it can. Further, the high-pressure fluid device 11 uses two O-rings 113 and 114 like the second fluid supply device shown in FIG. 10, but depending on the shapes of the first and second members, FIG. As in the first fluid supply apparatus shown in FIG. 1, the apparatus can be configured to use one O-ring.

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 vertical front view equivalent to FIG. 2 which shows the state which the cover body deform | transformed. It is a top view which shows the principal part (stationary sealing ring) in the said sealing apparatus. It is a graph which shows the relationship between the sealing gas pressure in the said sealing apparatus, and the deformation amount (opening amount) of a cover body. It is a vertical side 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. It is a semi-cylindrical top view which shows the principal part (rotary sealing ring) in the said seal | sticker. It is a vertical front view of the principal part which shows a 1st fluid supply apparatus. It is a vertical front view of the principal part which shows a 2nd fluid supply apparatus.

Explanation of symbols

3 Cover body (second member)
4. Seal device for processing equipment (static pressure type non-contact type mechanical seal)
5 Rotating seal ring 5a Rotating side sealing end face 6 Seal case (first member)
7 Static seal ring 7a Static side seal end face 8 Spring member 9 Seal gas ejection path 10 Seal gas (high pressure fluid)
31a facing surface portion 61a facing surface portion 63a facing surface portion 64a facing surface portion 104 processing device sealing device (composite non-contact mechanical seal)
111 First gas passage (first fluid passage)
112 Second gas passage (second fluid passage)
113 O-ring 114 O-ring L Cover area H Processing area

Claims (2)

A processing region (H) in which the rotary table (1) is disposed in a processing apparatus in which the drive unit (2) of the rotary table (1) is covered with a plastic cover body (3) having a cylindrical shape with an upper end opening; A sealing device provided to shield a region (L) in the cover body (3),
A rotary seal ring (5) fixed to the rotary table (1) concentrically with the axis of rotation;
A metal seal case (6) having a cylindrical shape that is attached to the support machine frame (2b) of the drive unit (2) in a state of being arranged in the cover body (3) and in contact with the upper end portion (31) thereof. When,
A stationary seal ring (7) held concentrically with the rotary seal ring (5) and opposed to the rotary seal ring (5) and held axially movable in the seal case (6);
A spring member (8) interposed between the seal case (6) and the stationary seal ring (7) to press and urge the stationary seal ring (7) to the rotary seal ring (5);
The upstream end of the first gas passage (111) formed in the seal case (6) and the downstream end of the second gas passage (112) extending upward through the cover body (3) are connected to both members (3, 3). 6) a pair of O-rings (113, 114) made of an incompressible elastic material having an opening at the opposing surface portions (31a, 61a) and the opening ends of both passages (111, 112) having a hardness of H60 or less. Is loaded between the opposing surface portions (31a, 61a) at a compression rate of 5 to 40%, thereby communicating in a sealed state and processing from the second gas passage (112) to the first gas passage (111). Even when the high-pressure seal gas (10) is supplied from the region (H) and the cover body (3) is deformed by the seal gas (10), the opposing surface portion is caused by elastic deformation of the O-rings (113, 114). (31a, 61 A high pressure fluid supply device configured to) the contact pressure to be maintained in sufficient to secure a predetermined sealing function,
It passes through the stationary sealing ring (7), is connected to the downstream end of the first gas passage (111), and opens between the sealing end faces (5a, 7a) that are the opposite end faces of both sealing rings (5, 7). And a gas ejection passage (9) to perform,
By sealing gas between the sealed end faces (5a, 7a) from the gas jetting passage (9), the sealing gas is sealed between the two regions (H, L) while maintaining a non-contact state. A non-contact type mechanical seal is provided . The sealing device for a processing apparatus according to claim 1, wherein the O-ring (113, 114) is made of fluororubber .