JP4555728B2 - Fixing structure of housing side seal ring in contamination-free rotating equipment - Google Patents

Description

  The present invention is a contamination-free rotating device (for example, a stirrer used in a manufacturing process of semiconductors, semiconductor manufacturing materials (electronic materials) or pharmaceuticals, etc.) that needs to strictly avoid contamination due to metal ions, etc. The present invention relates to a housing-side sealing ring fixing structure for fixing a housing-side sealing ring of a mechanical seal provided as a shaft sealing means to a shaft through wall portion of the housing.

  In this type of contamination-free rotating device, a housing-side sealing ring fixed to the shaft through-wall portion between the shaft-through wall portion of the housing and a rotating shaft that passes through the housing and protrudes out of the housing, and this A mechanical seal that seals the fluid in the housing is provided at the rotation portion relative to the shaft-side seal ring provided on the rotation shaft portion outside the housing, and each seal is used to prevent contamination by metal ions and the like. The ring is made of ceramics, carbon, or the like that does not generate metal ions and the like, and a portion that comes into contact with the fluid in the housing including the inner surface of the housing is coated with a fluororesin.

  Thus, in the mechanical seal disposed between the shaft through wall portion of the housing and the rotary shaft in this way, generally, the housing side sealing ring is connected to the shaft through wall via the annular metal seal flange. It is fixed to the part. That is, the seal flange is attached to the shaft through wall portion, and the back surface of the housing-side sealing ring is abutted and locked to the inner peripheral portion of the seal flange with the annular protrusion protruding therefrom. Thus, the housing side sealing ring is fitted and held (see, for example, FIG. 1 of Patent Document 1).

Japanese Patent Laid-Open No. 10-053480 (FIG. 1)

  However, in such a fixing structure of the housing-side sealing ring, since the metal seal flange is exposed in the housing and comes into contact with the fluid in the housing, contamination by metal ions cannot be prevented, Further, when the fluid in the housing is a corrosive fluid, the seal flange may be corroded, and strict contamination measures cannot be taken.

  In view of these points, the present invention is capable of fixing the housing-side sealing ring to the shaft through wall portion by the seal flange without the metal seal flange being in contact with the fluid in the housing. An object of the present invention is to provide a fixing structure for a housing-side sealing ring in a contamination-free rotating device that can take measures against nations.

  The present invention provides a housing-side sealing ring fixed to the shaft through-wall portion between the shaft-through wall portion of the housing and a rotating shaft that passes through the housing and protrudes out of the housing, and rotates outside the housing so as to face this. Contamination-free in which a mechanical seal that seals the fluid in the housing is disposed at a portion that rotates relative to the shaft-side sealing ring provided in the shaft portion, and the portion that comes into contact with the fluid in the housing including the inner surface of the housing is coated with fluororesin In a rotating device, a housing-side sealing ring fixing structure for fixing the housing-side sealing ring to the shaft-through wall portion of the housing, and in order to achieve the above object, in particular, the shaft-through wall portion, An annular flat surface coated with a fluororesin coating layer connected to the fluororesin coating layer on the inner surface of the housing and provided with a fixed surface orthogonal to the rotation axis An annular metal seal flange with a contact surface that can abut against the outer diameter side of the fixed surface is attached so that it can be tightened in the axial direction with the housing-side seal ring held inside. The O-ring interposed between the back surface of the housing-side sealing ring and the inner diameter side portion of the fixing surface is fixed between the both surfaces by tightening the shaft through the wall so that the surface abuts the outer diameter side portion of the fixing surface. It is proposed that the housing-side sealing ring be fixed to the shaft through wall portion in a state where the pressure is pressed for secondary sealing.

  In such a housing-side sealing ring fixing structure, the back surface of the housing-side sealing ring and the inner diameter side portion of the fixing surface may be in contact with each other only via an O-ring, and not in direct contact. Preferably, the O-ring is pressed against the inner peripheral surface of the seal flange by the pressure of the fluid in the housing acting on the gap formed between the back surface of the housing-side sealing ring and the inner diameter side portion of the fixed surface. It is preferable. Further, it is preferable that the perpendicularity of the fixed surface to the rotation axis is within (50/100) mm. In particular, when both seal rings are non-contact type mechanical seals that rotate relative to each other in a non-contact state, it is preferably within (10/100) mm, and more preferably within (5/100) mm. . Further, the inner diameter side portion of the shaft through wall portion is formed in an annular portion that bulges in the sealing ring direction from the outer diameter side portion, and the surface of the annular portion is covered with a fluororesin coating layer. Preferably, an annular engagement portion that engages with the annular portion is formed in the seal flange, and the radial action of the seal flange with respect to the shaft through wall portion is performed by the engagement action. It is preferable to configure. Further, in order to more strictly prevent the generation of particles due to contact with the fluid in the housing, it is preferable that a fluororesin coating is applied to at least a portion of the surfaces of both sealing rings that contacts the fluid in the housing.

  According to the fixing structure of the housing side seal ring of the present invention, the metal seal flange can be fixed to the shaft through wall portion by the seal flange without contacting the fluid in the housing. It is possible to take advanced contamination countermeasures without causing ion contamination. In addition, the housing-side sealing ring can be fixed with high accuracy, and the sealing function in the portion that rotates relative to the shaft-side sealing ring can be exhibited well.

  The configuration of the present invention will be specifically described below with reference to FIGS.

  1 and 2 show an example of a mechanical seal 1 that employs a housing-side sealing ring fixing structure according to the present invention. This mechanical seal 1 is made of a semiconductor manufacturing material (electronic material) as shown in FIG. ) Is installed in the contamination-free rotating device 2 used in the manufacturing process. That is, the contamination-free rotating device 2 is a reaction vessel such as a photoresistor as shown in FIG. 6, and penetrates the housing 21, which is a container body in which the shaft through wall portion 20 is formed at the top, and the shaft through wall portion 20. A rotating shaft 22 as a stirring shaft extending in the vertical direction, a stirring blade 23 provided at the lower end of the rotating shaft 22, and a prime mover (motor or the like) 24 that rotates the rotating shaft 22. 1 is interposed between the shaft penetrating wall portion 20 and the rotary shaft 22 and seals between an in-machine region (region in the housing 20) H and an out-of-machine region (atmosphere region) L. The portion of the reaction vessel 2 that comes into contact with the fluid in the housing (including the fluid to be reacted such as a photoresist and its vaporized components, including all the fluid present in the housing 21) is coated with a fluororesin coating. ing. That is, the inner surface of the housing 21, the outer peripheral surface of the rotating shaft 22, the surface of the stirring blade 23, and a part 20 a of the shaft penetrating wall portion 20 described later are coated with a fluororesin coating layer 2 a such as PFA (perfluoroalkoxyalkane) resin. 2b, 2c and 2d are coated.

  As shown in FIGS. 1 and 2, the mechanical seal 1 includes a seal flange 3 attached to the shaft through wall portion 20 of the housing 21 and a housing side sealing ring fixed to the shaft through wall portion 20 via the seal flange 3. 4, a spring retainer 5 disposed on the outer side (upper side) of the housing-side seal ring 4 and fixed to the rotation shaft 22, and a rotation shaft disposed between the housing-side seal ring 4 and the spring retainer 5. The shaft-side sealing ring 6 fitted and held in 22, the spring member 7 interposed between the shaft-side sealing ring 6 and the spring retainer 5, the seal flange 3 and the housing-side sealing ring 4 are passed through both A series of gas passages 8 opened between the sealing end faces 40 and 60 as opposed end faces of the sealing rings 4 and 6, and a sealing gas 90 having a pressure higher than the pressure in the in-machine region H (pressure in the housing 21) from the gas passage 8. A gas ejection mechanism 9 to be ejected between 40 and 60, a non-contact type mechanical seal of the static pressure type comprising a vibration isolating mechanism 10 for preventing vibration of the shaft side seal ring 6.

  Thus, in this mechanical seal 1, the structure for fixing the housing side sealing ring 4 to the shaft through wall portion 20 is configured as follows according to the present invention.

  The shaft penetrating wall portion 20 has an annular flange shape, and its inner diameter side portion 20a is an annular portion that bulges in the sealing ring direction (upward) from the outer diameter side portion 20b as shown in FIGS. Is formed. The surface (upper surface) of the annular portion 20a is a fixed surface 25 that is an annular flat surface coated with a fluororesin coating layer 2d continuous with the fluororesin coating layer 2a on the inner surface of the housing and is orthogonal to the rotation shaft 22. The perpendicularity of the fixed surface 25 with respect to the rotation axis 22 is preferably within (10/100) mm, and more preferably within (5/100) mm.

  As shown in FIGS. 1 to 3, the seal flange 3 has an annular locking portion 3b protruding from the upper end edge of the inner peripheral surface 3a, and the outer diameter side portion 3c is thicker in the axial direction than the inner diameter side portion 3d. It is comprised in the metal annular body which was made. The lower end surface of the inner diameter side portion 3d is an abutting surface 3e that is an annular plane orthogonal to the rotation shaft 22 and can abut against the outer diameter side portion 25a of the fixed surface 25. The lower end portion of the outer diameter side portion 3c is an annular engagement portion 3f that engages with the annular portion 20a of the shaft through wall portion 20 in an outer fitting manner, and the seal flange 3 is engaged by the engagement action of both portions 3f and 20a. It is devised so that the radial positioning with respect to the shaft penetration wall portion 20 is performed. As shown in FIGS. 1 to 3, the seal flange 3 is screwed into the outer diameter side portion 20b of the shaft through wall portion 20 by screwing an appropriate number of bolts 30 inserted through the seal flange 3 into the annular portion 20a. Are attached to the shaft through wall portion 20 so as to be freely tightenable in the axial direction. The tightening in the axial direction is completed when the contact surface 3e of the seal flange 3 abuts against the outer diameter side portion 25a of the fixed surface, and in this tightening completed state, the engaging portion 3f has the shaft through wall portion 20. It does not collide with the outer diameter side portion 20b.

  The housing-side sealing ring 4 is an annular body made of carbon. As shown in FIG. 1, the first and second O-rings 31, 32 are fitted to the seal flange 3 while being loosely fitted concentrically to the rotary shaft 22. The inner fitting is held through. The front end surface (upper end surface) of the housing side sealing ring 4 is configured as a smooth sealed end surface 40. The first O-ring 31 is loaded between the outer periphery of the upper end of the housing-side seal ring 4 and the engaging portion 3b of the seal flange 3, and a secondary seal is provided between the seal flange 3 and the housing-side seal ring 4. is doing. The second O-ring 32 is loaded between the back surface 4 a of the housing side sealing ring 4 and the inner diameter side portion 25 b of the fixed surface 25. As shown in FIGS. 1 to 3, the second O-ring 32 is engaged and held in a recess 4 b formed on the outer peripheral edge portion of the back surface 4 a of the housing-side sealing ring 4, and the contact surface 3 e comes into contact with the seal flange 3. By tightening the shaft through wall portion 20 so as to abut against the outer diameter side portion 25a of the fixed surface 25, the secondary side is properly provided between the back surface 4a of the housing side sealing ring 4 and the inner diameter side portion 25b of the fixed surface 25. It is clamped in a state to seal. In this state, the back surface 4a of the housing-side sealing ring 4 and the inner diameter side portion 25b of the fixed surface 25 are directly contacted via the second O-ring 32 as shown in FIGS. Is not in contact. The pressure of the fluid in the housing acts on the gap formed between the back surface 4a of the housing side sealing ring 4 and the inner diameter side portion 25b of the fixed surface 25, and the second O-ring 32 expands by the action of the fluid pressure. The contact pressure to the inner peripheral surface 3a of the seal flange 3 is increased due to the radial deformation. The O-rings 31 and 32 are made of fluorine rubber (for example, perfluoro rubber) having excellent corrosion resistance and heat resistance. The rear side portion of the inner peripheral surface of the housing-side sealing ring 4 is formed as a conical tapered surface 4c that expands downward.

  As shown in FIG. 1, the spring retainer 5 includes an annular wall portion 50, a cylindrical O-ring locking portion 51 that protrudes downward from the inner peripheral portion thereof, and a cylindrical shape that protrudes downward from the outer peripheral portion of the annular wall portion 50. It is made of metal (for example, SUS304) having the holding portion 52. The spring retainer 5 is configured such that the annular wall portion 50 and the O-ring locking portion 51 are fitted to the rotation shaft 22 and the set screw 53 screwed to the annular wall portion 50 is tightened to the rotation shaft 22 to thereby rotate the rotation shaft 22. It is fixed to. The outer peripheral surface of the rotary shaft 22 is coated with fluororesin as described above, but the upper end of the coating layer 2b is located slightly below the location where the set screw 53 contacts as shown in FIG. Has been.

  As shown in FIG. 1, the shaft-side sealing ring 6 is a ceramic annular body having a tip end surface (lower end surface) formed as a smooth sealing end surface 60 that directly faces the sealing end surface 40 of the housing-side sealing ring 4. The first O-ring 61 is arranged between the housing-side sealing ring 4 and the spring retainer 5 and between the inner peripheral surface of the shaft-side sealing ring 6 and the outer peripheral surface (the fluororesin coating layer 2b) of the rotary shaft 22. Is inserted and held on the rotary shaft 22 so as to be movable in the axial direction. The first O-ring 61 is made of a fluorine-based rubber (for example, perfluoro rubber) having excellent corrosion resistance and heat resistance. The downward movement of the first O-ring 61 is blocked by an annular O-ring locking surface 62 formed on the inner periphery of the lower end of the shaft-side sealing ring 6, and the upward movement is prevented by the O-ring of the spring retainer 5. It is blocked by the end face of the locking part 51. The end surface of the O-ring locking portion 51 is orthogonal to the axis, but the O-ring locking surface 62 is a tapered surface that is inclined in the inner circumferential direction and downward as shown in FIG. As will be described later, the outer peripheral portion of the shaft-side seal ring 6 is allowed to move in the axial direction of the shaft-side seal ring 6 via the pair of second O-rings 68 and 68 to the holding portion 52 of the spring retainer 5. Mated and held. A drive collar 63 made of metal (for example, SUS304) is abutted with the base end (upper end) of the shaft-side seal ring 6. The drive collar 63 is prevented from rotating relative to the shaft-side seal ring 6 by engaging a pin 64 projecting therefrom with a recess 65 formed in the shaft-side seal ring 6.

  As shown in FIG. 1, the spring member 7 is composed of a plurality of coil springs (only one is shown) interposed between the spring retainer 5 and the shaft side seal ring 6, and the shaft side seal ring 6 is housed in the housing. It presses and urges the side sealing ring 4 and generates a closing force that acts in a direction to close the space between the sealing end faces 40 and 60. The spring member 7 holds the base end portion in a recess formed in the annular wall portion 50 of the spring retainer 5 and presses and urges the shaft-side sealing ring 6 by bringing the tip end portion into contact with the drive collar 63. It is. Further, as shown in FIG. 2, a through hole 50a is formed in the annular wall portion 50 of the spring retainer 5, and a drive pin 66 inserted from above into the through hole 50a is screwed to the drive collar 63, thereby The side seal ring 6 is held by the spring retainer 5 so as not to be relatively rotatable while allowing axial movement.

  As shown in FIGS. 1 and 3, the gas passage 8 is a space formed in a fitting portion between the seal flange 3 and the housing-side sealing ring 4, and is an annular communication space sealed by O-rings 31 and 32. 81, a flange-side passage 82 that passes through the seal flange 3 in the radial direction and reaches the communication space 81, a plurality of static pressure generating grooves 83 formed in the sealing end face 40, and the housing-side sealing ring 4 It comprises a sealed ring side passage 84 extending from the communication space 81 to the static pressure generating grooves 83. As shown in FIG. 4, the static pressure generating grooves 83 are arcuate concave grooves that are arranged in parallel with the sealing end surface 40 in parallel, and the downstream end portion of the sealing ring side passage 84 is branched. The branch portion 84 a is opened in each static pressure generating groove 83.

  As shown in FIG. 1, the gas ejection mechanism 9 ejects a seal gas 90 having a pressure higher than the pressure in the in-machine region H from the gas passage 8 between the sealed end faces 40 and 60. The seal gas 90 having a pressure higher than the pressure in the in-machine region H is supplied to the static pressure generating grooves 83 through the flange side passage 82, the communication space 81, and the seal ring side passage 84, so that A static pressure is generated to keep the non-contact state. As the seal gas 90, a gas inert to the fluid in the housing (fluid excluding the seal gas) is used, and in this example, nitrogen gas is used. In addition, if necessary, a restrictor such as an orifice, a capillary tube, or a porous member is provided at an appropriate position of the gas passage 8 (sealed ring side passage 84, etc.), and the clearance between the sealed end faces 40, 60 is automatically adjusted. Configured to be That is, when the clearance between the sealing end surfaces 40, 60 becomes large due to vibrations of the rotating device 2, etc., the amount of seal gas flowing out between the sealing end surfaces 40, 60 from the static pressure generating grooves 83 ... Since the amount of seal gas supplied to the pressure generating grooves 83 becomes imbalanced, the pressure in the static pressure generating grooves 83 decreases, and the opening force becomes smaller than the closing force. And the gap is adjusted to an appropriate value. On the contrary, when the gap between the sealing end faces 40 and 60 becomes small, the pressure in the static pressure generating grooves 83 increases due to the same action as described above, and the opening force becomes larger than the closing force, and the sealing end face It changes so that the clearance gap between 40 and 60 may become large, and the clearance gap is adjusted to an appropriate thing.

  As shown in FIG. 3, the vibration isolation mechanism 10 includes a holding portion 52 of the spring retainer 5 that surrounds the outer periphery of the shaft-side seal ring 6 and a pair of annular O-ring grooves formed on the outer periphery of the shaft-side seal ring 6. 67, 67, a pair of second O-rings 68, 68 engaged and held in the respective O-ring grooves 67 and arranged in parallel in the axial direction, and the opposed peripheral surfaces of the shaft-side sealing ring 6 and the holding portion 52 of the spring retainer 5 An annular space 11 formed between them and sealed by second O-rings 68, 68 and a plurality of seal gas introduction passages 12 formed in the shaft-side seal ring 6.

  Each second O-ring 68 is made of an incompressible elastic material (fluorine rubber or the like) excellent in corrosion resistance and heat resistance, and is between the bottom surface of the O-ring groove 67 and the inner peripheral surface of the holding portion 52. Are filled in a moderately compressed state (a state in which the axial movement of the shaft-side sealing ring 6 is not hindered), and both axial ends of the annular space 11 are sealed. As shown in FIG. 3, each sealing gas introduction path 12 passes through the shaft-side sealing ring 6, and one end portion opens to the sealing end surface 60 and the other end portion opens to the annular space 11. As shown in FIG. 5, one end opening of each seal gas introduction passage 12 is directly opposed to the static pressure generating groove 83, and the opening diameter is set to be the same as or smaller than the groove width of the static pressure generating groove 83. .

  According to the mechanical seal 1 configured as described above, the in-machine region H can be satisfactorily sealed without causing contamination such as generation of metal ions.

  That is, when the sealing gas 90 is supplied from the gas passage 8 between the sealed end surfaces 40 and 60, an opening force is generated between the sealed end surfaces 40 and 60 so as to open the sealing gas. This opening force is due to the static pressure generated by the seal gas 90 supplied to the static pressure generating grooves 83. Therefore, the sealing end faces 40 and 60 are formed by the opening force and the closing force acting in the direction of closing the sealing end faces 40 and 60 (by the spring member 7 pressing and urging the housing side sealing ring 4 to the shaft side sealing ring 6. ) Is balanced and kept in a non-contact state. Then, since the seal gas 90 is higher than the pressure in the in-machine region H, the in-machine fluid does not enter between the sealed end faces 40, 60, and the in-machine region H is completely sealed, which deteriorates the surrounding environment. There is no fear.

  At this time, since the in-machine region H is sealed while the sealing end surfaces 40 and 60 are kept in a non-contact state, the abrasion powder due to the contact of the sealing end surfaces 40 and 60 does not enter the in-machine region H, and contamination. Contamination-free sealing function that does not cause any problems is demonstrated. Further, the seal gas 90 leaks from between the sealed end faces 40 and 60 to the in-machine region H. However, since the seal gas 90 is a nitrogen gas or the like that does not interfere with the in-machine region H, the seal gas 90 There is no problem caused by allowing leakage into the in-flight region H.

  Further, the housing-side seal ring 4 is fixed to the shaft through wall portion 20 via the metal seal flange 3, but the seal flange 3 is not exposed to the in-machine region H and does not come into contact with the fluid in the housing. Therefore, as described at the beginning, the metal ion contamination does not occur when the fluid in the housing contacts the seal flange 3.

  Further, since the seal flange 3 is attached to the shaft through wall portion 20 with the contact surface 3e abutting against the outer diameter side portion 25a of the fixed surface 25 of the shaft through wall portion 20, the seal flange 3 The fixing accuracy of the housing sealing ring 4, that is, the perpendicularity of the sealing end surface 40 with respect to the rotating shaft 22 and the parallelism with the mating sealing end surface 60 can be ensured appropriately, and the sealing function by both the sealing rings 4 and 6 is exhibited well. Can be made. In particular, by setting the perpendicularity of the fixing surface 25 to the rotating shaft 22 within (10/100) mm (more preferably within (5/100) mm) as described above, the fixing accuracy can be further improved. Can do.

  Further, the O-ring 32 loaded between the back surface 4a of the housing-side seal ring 4 and the fixed surface 25 that is a fluororesin coating surface enters the gap between the back surface 4a of the housing-side seal ring 4 and the fixed surface 25. The pressure of the fluid in the housing (usually seal gas 90 as will be described later) also makes pressure contact with the inner peripheral surface of the seal flange 3. Since this pressing contact force increases and decreases in proportion to the pressure of the fluid in the housing, the secondary sealing function by the O-ring 32 is always properly exhibited even under conditions where the pressure in the housing fluctuates. As a result, the possibility that the fluid in the housing contacts the seal flange 3 to cause metal ion contamination is reliably avoided.

  Further, a seal gas 90 having a pressure higher than that pressure leaks into the in-machine region H. This seal gas 90 enters the gap between the back surface 4a of the housing-side sealing ring 4 and the fixed surface 25, and seals into this gap. Intrusion of fluid in the housing other than gas is prevented. Therefore, the fluid in the housing other than the seal gas stays in this gap, and problems such as propagation of germs do not occur, and contamination can be more effectively prevented.

  By the way, in the mechanical seal 1 configured as a static pressure type non-contact type mechanical seal, the seal gas 90 supplied from the gas supply path 8 to the sealed end faces 40 and 60 is compressible. A self-excited vibration called a so-called pneumatic hammer is inevitably generated in the seal gas flow path between the sealed end faces 40 and 60. As a result, there is no problem with the housing-side seal ring 4 fixed to the seal flange 3, but the shaft-side seal ring 6 that is merely fitted and held on the rotary shaft 22 via the O-ring 61. The self-excited vibration vibrates with a minute amplitude equal to or less than the gap between the sealed end faces 40 and 60, and generates a vibration sound.

  However, such vibration noise is reliably prevented by the vibration isolation mechanism 10. That is, the seal gas 90 supplied to the static pressure generating groove 83 is held in an appropriate non-contact state between the sealed end faces 40 and 60, and the seal gas 90 supplied between the sealed end faces 40 and 60 is introduced into the seal gas. It introduce | transduces into the annular space 11 from the path | route 12 ..., and the inside of the annular space 11 is hold | maintained with the same pressure as the sealing end surfaces 40 and 60. FIG. Therefore, each O-ring 68 is pressed against the outer wall surface of the O-ring groove 67 by the seal gas 90 in the annular space 11, and is compressed in the axial direction of the shaft-side sealing ring 6. As a result, since each O-ring 68 is made of an incompressible elastic material, the outer peripheral surface of the shaft-side sealing ring 6 (the bottom surface of the O-ring groove 67) and the holding of the spring retainer 5 facing this are retained. The pressure-contact force of each O-ring 68 to the inner peripheral surface of the portion 52 increases, and the shaft-side sealing ring 6 is strongly fixed to the inner peripheral surface of the holding portion 52 of the spring retainer 5 via the O-rings 68 and 68. It will be. Therefore, a pneumatic hammer (self-excited vibration) does not occur in the seal gas flow path between the sealing end faces 40 and 60, and the shaft-side seal ring 6 does not vibrate. This is generally called “squeal”. The vibration sound that is generated is not generated.

  The housing-side sealing ring fixing structure according to the present invention is not limited to the case where the static pressure non-contact type mechanical seal 1 is used as the shaft sealing means of the contamination-free rotating device 2, and the relative structure of the both sealing rings 4 and 6. The present invention can also be suitably applied to the case of using a dry contact type mechanical seal that performs sealing by a rotating sliding contact action. In the case of a contact type mechanical seal, the squareness of the fixed surface 25 with respect to the rotating shaft 22 is within (10/100) mm (more preferably within (5/100) mm, as in the case of a non-contact type mechanical seal. However, it is preferable to set the squareness within (50/100) mm in order for both seal rings 4 and 6 to properly abut and make relative rotational sliding contact.

  Further, as shown in FIG. 7, a fluororesin coating layer (PFA (perfluoroalkoxyalkane)) is formed on the surface of both seal rings 4 and 6 and the portion in contact with the fluid in the housing (the portion facing the in-machine region H). Resin etc.) 2e and 2f may be formed. In this way, the generation of particles in the in-machine region H due to contact with the fluid in the housing can be more reliably prevented. In particular, the housing-side sealing ring 4 is also coated with a fluororesin coating on the portion in contact with the seal gas 90 to generate particles due to the contact with the seal gas 90 and the seal gas 90 from between the sealed end faces 40 and 60. It is possible to reliably avoid the possibility of entering the in-flight region H accompanying the aircraft. That is, as shown in FIG. 8, the fluororesin coating layer (PFA (perfluorocarbon) is formed on the outer peripheral surface of the housing-side sealing ring 4 facing the communication space 81, the static pressure generating grooves 83, and the inner peripheral surface of the sealing ring-side passage 84. Alkoxyalkane) resin, etc.) 2g, 2h, 2i are formed. Of course, if necessary, the sealing flange 3 may also be coated with a fluororesin on the inner peripheral surface of the communication space 81 and the flange side passage 82 in contact with the seal gas 90. In addition, about the sealing end surfaces 40 and 60, a fluororesin coating is not given.

It is a vertical front view of the principal part which shows an example of the contamination-less rotating apparatus which employ | adopted the fixing structure of the housing side sealing ring which concerns on this invention. It is a vertical side view of the principal part. FIG. 2 is an enlarged detailed view showing a main part of FIG. 1. It is a cross-sectional plan view of the principal part in alignment with the IV-IV line of FIG. It is a cross-sectional bottom view of the principal part in alignment with the VV line | wire of FIG. It is a rough vertical front view which shows the whole contamination-free rotating apparatus. It is a vertical side view equivalent to FIG. 3 which shows the modification of the said contaminationless rotation apparatus. It is a vertical side view equivalent to FIG. 3 which shows the other modification of the said contaminationless rotation apparatus.

Explanation of symbols

1 Mechanical seal (non-contact type mechanical seal)
2 Contaminless rotating equipment (reaction vessel)
2a Fluorine resin coating layer 2b Fluorine resin coating layer 2c Fluorine resin coating layer 2d Fluorine resin coating layer 2e Fluorine resin coating layer 2f Fluorine resin coating layer 2g Fluorine resin coating layer 2h Fluorine resin coating layer 2i Fluorine resin coating layer 3 Seal flange 3a Seal Flange inner peripheral surface 3b Annular locking portion 3c Seal flange outer diameter side portion 3d Seal flange inner diameter side portion 3e Seal flange contact surface 3f Annular engagement portion 4 Housing side sealing ring 4a Housing side sealing ring back surface 4b Housing Recess 4c tapered surface formed on the outer peripheral edge of the back surface of the side seal ring (the back side portion of the inner peripheral surface of the housing side seal ring)
DESCRIPTION OF SYMBOLS 5 Spring retainer 6 Shaft side sealing ring 7 Spring member 8 Gas passage 9 Gas ejection mechanism 10 Anti-vibration mechanism 11 Annular space 12 Seal gas introduction path 20a Inner diameter side part (annular part) of shaft penetration wall part
20b Outer diameter side portion 21 of shaft penetrating wall portion Housing 22 Rotating shaft
23 Stirring blade 24 Motor 25 Fixed surface 25a Outer diameter side portion 25b of fixed surface Inner diameter side portion 30 of fixed surface 30 Bolt 31 First O-ring 32 Second O-ring (rear surface of housing side sealing ring and inner diameter side portion of fixed surface O-ring interposed between
40 Sealing end face 50 of the housing-side sealing ring 50 Annular wall 50a of the spring retainer Through hole 51 O-ring locking part 52 of the spring retainer 52 Holding part 53 of the spring retainer Set screw 60 Sealing end face 61 of the shaft-side sealing ring First O-ring 62 O-ring locking surface 63 Drive collar 64 Pin 65 Recess 66 Drive pin 67 O-ring groove 68 Second O-ring 81 Communication space 82 Flange side passage 83 Static pressure generation groove 84 Sealing ring side passage 90 Seal gas H In-machine area (inside housing Area)
L Outboard area (atmosphere area)

Claims (7)

A housing-side sealing ring fixed to the shaft through wall and between the shaft through wall of the housing and the rotating shaft that passes through the housing and protrudes out of the housing are provided on the rotating shaft portion outside the housing. In a contamination-free rotating device in which a mechanical seal that seals the fluid in the housing is disposed at a relative rotation portion with the shaft-side seal ring, and a portion that contacts the fluid in the housing including the inner surface of the housing is coated with a fluororesin coating, A housing-side sealing ring fixing structure for fixing the housing-side sealing ring to the shaft through wall portion of the housing,
The shaft through wall is provided with a fixed surface that is an annular flat surface coated with a fluororesin coating layer connected to the fluororesin coating layer on the inner surface of the housing and orthogonal to the rotation axis, and abuts on the outer diameter side portion of the fixed surface. A ring-shaped metal seal flange with a possible contact surface is attached so that it can be clamped in the axial direction with the housing-side seal ring fitted inside, and the seal flange is attached to the outer diameter side of the fixed surface. By tightening the shaft through wall portion so as to abut each other, the O-ring interposed between the back surface of the housing-side sealing ring and the inner diameter side portion of the fixed surface is clamped to provide a secondary seal between both surfaces. A structure for fixing a housing-side sealing ring in a contamination-free rotating device, wherein the housing-side sealing ring is fixed to the shaft through wall portion in a state. The contamination-free according to claim 1, wherein the back surface of the housing-side sealing ring and the inner diameter side portion of the fixed surface are in contact with each other only through an O-ring, and are not in direct contact with each other. Fixing structure of housing side sealing ring in rotating equipment. The O-ring is configured to be pressed against the inner peripheral surface of the seal flange by the pressure of the fluid in the housing acting on the gap formed between the back surface of the housing-side sealing ring and the inner diameter side portion of the fixed surface. The structure for fixing a housing-side sealing ring in a contamination-free rotating device according to claim 2, wherein: The perpendicularity of the fixed surface with respect to the rotation axis is within (50/100) mm, wherein the housing-side sealing ring in the contamination-free rotating device according to claim 1, 2, or 3 is provided. Fixed structure. The inner diameter side portion of the shaft through wall portion is formed in an annular portion that bulges in the sealing ring direction from the outer diameter side portion, and the surface of the annular portion is configured as a fixed surface covered with a fluororesin coating layer. The fixing structure of the housing-side sealing ring in the contamination-less rotating device according to claim 1, 2, 3, or 4, wherein the housing-side sealing ring is fixed. An annular engagement portion that engages with the annular portion is formed on a seal flange, and the radial positioning of the seal flange with respect to the shaft through wall portion is performed by the engagement action. 5. A fixing structure of a housing-side sealing ring in the contamination-free rotating device described in 5. 6. A fluororesin coating is applied to at least a part of the surface of both sealing rings that contacts the fluid in the housing, or claim 1, 2, 3, 4, 5 or The fixing structure of the housing side sealing ring in the contamination-free rotating device according to claim 6.