JP5611700B2 - Non-metallic mechanical seal - Google Patents

Description

  The present invention relates to a vertical rotating machine (for example, a stirrer used in the fields of pharmaceuticals, medicines, foods, semiconductors, etc.) that is required to avoid the occurrence of contamination due to contact of a metal surface with a fluid to be sealed. ) Related to a non-metallic mechanical seal that is preferably used as a shaft sealing means.

  For vertical rotating machines that require advanced contamination prevention measures such as stirrers used in the fields of pharmaceuticals, foods, semiconductors, etc., the sealed fluid (in-machine) It is necessary to use a structure that can prevent metal corrosion caused by contact with the fluid in the region.

  Conventionally, as a shaft sealing means for such a vertical rotating device, a cylindrical seal case attached to the housing of the rotating device, a case-side sealing ring provided on the inner periphery thereof, and the seal case in the vertical direction A shaft-side sealing ring provided on the rotary shaft of the rotating device that penetrates the inner periphery of the relative rotational sliding contact portion by the relative rotational sliding contact action of the sealing end surfaces that are the upper and lower opposing end surfaces of both sealing rings. It is configured to seal the in-machine area that is the side area and the out-of-machine area that is the outer peripheral side area, and contains a metal component in the member, part, or surface thereof that contacts the sealed fluid that is the fluid in the in-machine area. Non-metallic mechanical seals composed of non-metallic materials that have not been proposed have been proposed. For example, in the mechanical seal disclosed in Patent Document 1, each seal ring that comes into contact with the sealed fluid is made of ceramics such as carbon or alumina, and the seal case is a portion that comes into contact with the sealed fluid. The former is made of ceramics which are non-metal materials.

JP 2005-133852 A

  However, in such a non-metallic mechanical seal, since the member, component or the surface thereof that contacts the sealed fluid is made of a non-metallic material, metal corrosion caused by contact with the sealed fluid is prevented. Although it can be prevented, drainage such as abrasion powder may be generated from the relative rotational sliding contact portion of the sealing ring. In such a case, the generated drain may fall into the in-machine region, and it is difficult to completely avoid contamination of the in-machine region.

  The present invention has been made in view of such circumstances, and reliably avoids contamination of the in-machine region even under conditions where drainage such as abrasion powder is generated from the relative rotational sliding contact portion of the sealing ring. It is an object of the present invention to provide a non-metallic mechanical seal that can be suitably used as a shaft sealing means for a vertical rotating machine that requires a high degree of contamination.

The present invention relates to a cylindrical seal case attached to a housing of a saddle type rotary device, a ceramic case-side sealing ring fixed to the inner periphery thereof, and the rotary device penetrating the seal case vertically. An axially expandable PTFE bellows whose upper end is fitted and fixed to the rotating shaft, a shaft-side sealing ring that is connected to the lower end of the bellows and faces the case-side sealing ring, a lower end of the bellows, and a shaft-side seal A spring retainer engaged with the ring so as not to rotate relative to the case and so as not to be displaced relative to the case side sealing ring, and an outer peripheral region of the bellows for pressing the spring retainer toward the case side sealing ring. comprises a spring member, the relative rotational sliding action of the sealing end face a top and bottom opposing end surfaces of the seal ring, the sealed fluid region and the outer peripheral side region of the inner peripheral side region of the relative rotational sliding contact area Together configured to seal a certain air space, the mechanical of Nonmetaru structure member in contact with the sealed fluid, a portion or their surface are constituted by Nonmetaru material containing no metal component is a gas having a corrosive In the seal, in order to achieve the above object, in particular, the seal case is made of a metal material, and an annular bottom wall projecting from the inner peripheral portion of the seal case in the direction of the rotation axis and a seal ring from the inner peripheral end portion thereof. A drain collecting rod is formed integrally with a cylindrical peripheral wall that extends upward between the opposing peripheral surfaces of the rotary shaft and extends upward from the relative rotational sliding contact portion, and contacts at least the fluid to be sealed in the seal case surfaces and form a series of coating layers by Nonmetaru material having corrosion resistance to the entire surface of the drain recovery trough, Yu the shaft side seal ring sliding property of the corrosion resistance and the case-side seal ring The hard resin material is composed of a composite resin material mainly composed of PTFE, and the bellows and the shaft-side seal ring are formed at the time of forming the bellows and / or the shaft-side seal ring or the bellows and the shaft-side seal ring. with boundaries of both are connected to be integrated in a state that does not appear clearly after the molding process, the spring retainer proposes a coefficient of thermal expansion is kept form configured by a resin material for the bellows equal or close is there.

  In the mechanical seal of the present invention, the seal case has a first case portion that is a monolithic structure having a surface that contacts the fluid to be sealed, and other portions that do not have a surface that contacts the fluid to be sealed. A cylindrical structure that is divided into a second case portion, the drain recovery rod is integrally formed on the inner peripheral portion of the first case portion, and the surface of the first case portion that contacts the sealed fluid and the drain recovery A series of coating layers made of a synthetic resin material is preferably formed on the entire surface of the ridge. In this case, the seal case is divided into a first case part, which is an integral structure, and a second case part attached to the upper end part of the seal case. The sealing ring is fitted and fixed via the first and second O-rings, and an O-ring pressing portion that presses the second O-ring with the case-side sealing ring in the vertical direction is formed in the first case portion. It is preferable that a coating layer of the same material connected to the series of coating layers is formed on a contact surface of the O-ring pressing portion with the second O-ring.

  In the mechanical seal of the present invention, the drain case is formed in the seal case so as to open at a lower portion of the drain recovery space formed between the drain case and the drain recovery tank. It is preferable to form a coating layer of the same material connected to the series of coating layers on the peripheral surface. The seal case is attached to the housing in a state where an annular attachment portion formed at the lower end portion of the seal case is abutted with the upper end portion of the housing via a gasket, and the series of coating layers is formed on the surface of the attachment portion. It is preferable to form a coating layer of the same material that is connected to the same.

Furthermore, it mechanical seal near the Nonmetaru structure of the present invention, it is preferable to scan the pulling retainer is formed of a composite resin material mainly composed of PTFE.

  Since the mechanical seal of the non-metal structure of the present invention can collect drainage such as abrasion powder generated from the relative rotational sliding contact portion of the sealing ring with the drain collecting rod, the member, the portion that contacts the fluid to be sealed, or those parts Combined with the fact that the surface is made of a non-metal material, it is possible to reliably avoid contamination of the in-machine region and to prevent contamination. Therefore, according to the present invention, it is possible to provide a non-metallic mechanical seal having a very practical value that can be suitably used as a shaft sealing means for a vertical rotating machine that requires a high degree of contamination. it can.

FIG. 1 is a longitudinal front view showing an example of a non-metallic mechanical seal according to the present invention. FIG. 2 is an enlarged detailed view showing the main part of FIG. FIG. 3 is a longitudinal front view showing a modification of the mechanical seal. FIG. 4 is an enlarged detailed view showing the main part of FIG.

  Hereinafter, embodiments for carrying out the present invention will be specifically described with reference to the drawings.

  FIG. 1 is a longitudinal front view showing an example of a non-metallic mechanical seal according to the present invention, and FIG. 2 is an enlarged detailed view showing the main part of the mechanical seal shown in FIG. M1 ") is a corrosion-resistant bellows type mechanical seal that can be suitably used as a shaft sealing means for a vertical rotating device such as a stirrer handling a corrosive fluid, and a seal case 2 attached to the housing 1 of the rotating device; The case-side sealing ring 3 fixed to the seal case 2 and the rotational axis (vertical shaft) 4 of a rotating device that penetrates the seal case 2 concentrically in the vertical direction can be moved in the axial direction via a bellows 5 (vertical direction) A shaft-side sealing ring 6 held in a movable manner, and a spring member 8 that presses and contacts the shaft-side sealing ring 6 to the case-side sealing ring 3 via a spring retainer 7. By the relative rotational sliding contact action of the sealing end surfaces 3a and 6a, which are the opposite end surfaces of the machine, an in-machine region (sealed fluid region) A that is an inner peripheral side region of the relative rotational sliding contact part 3a and 6a and a peripheral outer region An end surface contact type mechanical seal configured to shield and seal an outer region (non-sealed fluid region) B, and a member that comes into contact with a sealed fluid that is a fluid (process fluid) in the in-machine region A; A portion or a surface thereof is made of a non-metal material that does not contain a metal component, and a drain rod 9 is formed integrally with the seal case 2. The sealed fluid is a corrosive gas or liquid, and the outside region B is an atmospheric region. In the rotating device, glass lining or fluororesin lining (generally, polytetrafluoroethylene resin lining) is applied to at least a portion of the surface of the housing 1 or the rotating shaft 2 that comes into contact with the fluid to be sealed. ing.

  As shown in FIG. 1, the seal case 2 is a cylindrical body made of metal (SUS304 or the like) having a circular cross section on the inner peripheral surface, and a first case portion 10 having a surface that comes into contact with a fluid to be sealed and the other case. It is divided into a second case portion 11 that is a portion and does not have a surface that contacts the sealed fluid. Each case part 10 and 11 is comprised by the cylindrical body which is a metal integral structure, respectively. The 1st case part 10 is attached to the upper end part of the housing 1, and the 2nd case part Reference numeral 11 denotes an upper end portion of the first case 9. The seal case 2 is attached to the housing 1 in a state where an annular attachment portion 10 a formed at the lower end portion of the first case portion 10 is abutted with the upper end portion of the housing 1 via a gasket 12. The gasket 12 is made of a non-metal material having corrosion resistance. For example, the core 12 is made of an elastic material such as rubber, and is made of a corrosion-resistant resin material (PTFE) that covers a portion excluding the outer peripheral portion of the core. Polytetrafluoroethylene) or the like) having a composite structure is used.

  As shown in FIGS. 1 and 2, the case-side sealing ring 3 is an annular body that is fitted and fixed to the inner peripheral portion of the second case portion 11 via a pair of upper and lower first and second O-rings 13 and 14. The upper end surface (tip surface) is configured as a sealed end surface 3a which is a smooth annular plane orthogonal to the axis. The case-side sealing ring 3 is made of a nonmetal material having excellent corrosion resistance, for example, ceramics such as silicon carbide, and the O-rings 13 and 14 are made of a corrosion-resistant elastic material such as perfluoro rubber.

  The upper first O-ring 13 is sandwiched between the case-side sealing ring 3 and the second case portion 11 in the axial direction (vertical direction) and the radial direction (horizontal direction), and the lower second O-ring 15 is The side seal ring 3 and the first and second case portions 10 and 11 are clamped in the axial direction (vertical direction) and the radial direction. A space between the case portions 10 and 11 is sealed (secondary seal). The inner periphery of the upper end of the first case portion 10 is configured as an annular O-ring pressing portion 10b that sandwiches the second O-ring 15 with the case-side sealing ring 3 in the vertical direction.

  The bellows 5 is a cylindrical integrated structure made of PTFE (polytetrafluoroethylene), which is a non-metallic material having excellent corrosion resistance. As shown in FIGS. It is comprised in the expansion-contraction part 5a of the meandering cross section made to be extendable. As shown in FIG. 1, the fixing portion 5 b that is the upper end portion (base end portion) of the bellows 5 is fitted and fixed to the rotary shaft 4 by being fastened by a tight ring 15 made of metal (SUS315 or the like). That is, the binding ring 15 is divided into two in the radial direction, and is connected in a ring shape by a pair of clamping bolts (only one is shown) 15a, and is fixed to the engaging groove 15b formed in the inner peripheral portion. By tightening the tightening bolt 15a in a state where the annular protrusion 5c formed on 5b is engaged, the fixing portion 5b is firmly fitted and fixed to the rotating shaft 4. A stopper ring 16 fixed to the rotary shaft 4 is abutted with the upper end surface of the binding ring 15 by an appropriate number of set screws (only one shown) 16a. A drive collar 19 is attached to the lower end surface of the binding ring 15.

  As shown in FIGS. 1 and 2, the shaft-side seal ring 6 is an annular body made of a hard resin material that is a non-metal material having excellent corrosion resistance and sliding characteristics with the case-side seal ring 3. The lower end surface (the front end surface) is configured as a sealed end surface 6a which is a smooth annular plane orthogonal to the axis. In this example, the shaft-side seal ring 6 is a composite resin material containing PTFE as a main component, and the PTFE is suitably used to improve sliding characteristics (low friction) and mechanical strength with the case-side seal ring 3. It is comprised with the PTFE composite resin material with which the filler of this was filled.

  As shown in FIGS. 1 and 2, the shaft-side sealing ring 6 is integrally connected to a connecting portion 5 d that is a lower end portion (tip portion) of the bellows 5. That is, the shaft-side sealing ring 6 and the connecting portion 5d of the bellows 5 are connected to each other 5d during the forming process of the bellows 5 and / or the shaft-side sealing ring 6 or after the forming process of the bellows 5 and the shaft-side sealing ring 6. , 6 are integrated so that the boundary 20 between the two 5d and 6 does not appear clearly in the integrated state. The outer diameter of the connecting portion 5d of the bellows 5 is slightly larger than the expansion / contraction portion 5a and the fixing portion 5b of the bellows 5 so as to have the same diameter as the upper end portion (base end portion) of the shaft-side sealing ring 6. ing.

  As shown in FIG. 1, the spring retainer 7 has a lower end portion (tip portion) 7 a fitted into the connecting portion 5 d of the bellows 5 and the shaft-side sealing ring 6, and an upper end portion (base end portion) 7 b that is an expandable portion of the bellows 5. 5 is made of a resin material having a thermal expansion coefficient equal to or close to that of PTFE which is a constituent material of the bellows 5. In this example, the composite resin material is composed of PTFE as a main component and is made of a PTFE composite resin material in which PTFE is filled with carbon. The inner diameter of the upper end portion 7a of the spring retainer 7 is set so that it can be tightly fitted to the connecting portion 5d of the bellows 5 and the shaft-side sealing ring 6, but the inner diameter of the lower end portion 7b is connected to the bellows 5. Although it is smaller than the outer diameter of the part 5d and the shaft side sealing ring 6, it is set slightly larger than the outer diameter of the expansion / contraction part 5a of the bellows 5, and the spring retainer 7 is devised so as not to interfere with the expansion / contraction part 5a.

  The lower end surface (tip surface) of the spring retainer 7 is formed with a recess 7c that engages with a plurality of annular protrusions 6c that are formed on the outer peripheral surface of the upper end side of the shaft-side sealing ring 6 at regular intervals in the circumferential direction. Thus, the engagement between the projection 6c and the recess 7c prevents the relative rotation of the both 6 and 7. An annular step 7d formed at the boundary between the upper and lower ends 7a and 7b in the inner peripheral portion of the spring retainer 7 is an annular step formed at the boundary between the expandable portion 5a and the connecting portion 5d at the outer peripheral portion of the bellows 5. It is abutted against the portion 5f, and is devised so that a pressing biasing force by a spring member 8 to be described later acts on the bellows 5 through the spring retainer 7 by the engagement of both step portions 5f and 7d.

  As shown in FIG. 1, the spring retainer 7 engages a recess 7 e formed on the upper end of the spring retainer 7 with an appropriate number (only one shown) of drive pins 18 planted on the binding ring 15 or the drive collar 17. By doing so, relative rotation of the spring retainer 7 with respect to the rotating shaft 2 is prevented while allowing its axial movement within a predetermined range.

  As shown in FIG. 1, the spring member 8 is composed of a plurality of coil springs (only one is shown) loaded at equal intervals in the circumferential direction between the spring retainer 7 and the drive ring 17. The spring retainer 7 (and the bellows 5) is urged downward to press-contact the side seal ring 6 to the case-side seal ring 3.

  As shown in FIGS. 1 and 2, the drain recovery rod 9 has a metal rotating body shape integrally formed with a portion (first case portion) 10 having a surface in contact with the sealed fluid in the seal case 2. The annular bottom wall 21 projecting in the direction of the rotation axis from the inner peripheral portion of the first case portion 10 and the space between the opposed peripheral surfaces of the sealing rings 3 and 6 and the rotation shaft 4 upward from the inner peripheral end portion thereof. It consists of a cylindrical peripheral wall 22 that extends and reaches a relative rotational sliding contact portion (sealing end face) 3a, 6a of the sealing rings 3, 6 in the upward direction. The upper end 22a of the peripheral wall 22 extends above the sealed end surfaces 3a and 6a so that drains such as abrasion powder discharged from between the sealed end surfaces 3a and 6a do not enter between the peripheral wall 22 and the rotary shaft 4. In addition, it is set appropriately within a range not interfering with the bellows 7. In general, the upper end 22a of the peripheral wall 22 is set so as to be positioned at a position substantially corresponding to the upper end portion (boundary portion 20 with the bellows 5) of the shaft-side sealing ring 6. Note that the lower surface of the peripheral wall 22 is continuous with the lower surface of the mounting portion 10 a of the first case portion 10.

  Thus, in the first mechanical seal M1, the members (the case side sealing ring 3, the bellows 5, the shaft side sealing ring 6, the gasket 12 and the second O ring 14) that come into contact with the fluid to be sealed are corrosion-resistant as described above. In addition to non-metal materials (PTFE, etc.), members (drain recovery rods) or parts (first case part 10) that cannot be made of non-metal materials from the viewpoint of strength, processing, etc. are in contact with the sealed fluid The entire mechanical seal has a nonmetal structure by forming a coating layer of a nonmetal material on the surface to be processed.

  That is, the surface of the first case portion 10 that is in contact with the sealed fluid and the surface of the drain recovery rod 9 that is in contact with the sealed fluid, that is, the entire surface of the recovery rod 9 are shown in FIGS. As shown in FIG. 2, a series of first to fifth coating layers 23a to 23e are formed of a non-metal material having corrosion resistance. The first coating layer 23a is formed on the inner peripheral surface which is a surface portion in contact with the fluid to be sealed in the first case portion 10, and the second coating layer 23b is connected to the first coating layer 23a to collect the drain. The third coating layer 23c is formed on the outer peripheral surface of the peripheral wall 22 of the drain recovery rod 9 and is continuous with the second coating layer 23b. The fourth covering layer 23d is formed on the inner peripheral surface of the peripheral wall 22 and is continuous with the third covering layer 23c. The fifth covering layer 23e is continuous with the fourth covering layer 23d and is the lower surface of the bottom wall 21. It is formed.

  By the way, the mounting portion 10a and the O-ring pressing portion 10b of the first case portion 10 are in contact with the gasket 12 and the second O-ring 14, respectively. By forming the coating layers 23f and 24g connected to the coating layers 23a to 23e, the non-metal structure is further perfected. That is, as shown in FIGS. 1 and 2, a portion of the surface of the mounting portion 10a that is in contact with the gasket 12 is formed with the sixth coating layer 23f of the same material continuous with the fifth coating layer 23e. A seventh covering layer 23g of the same material that is continuous with the first covering layer 23a is formed on the surface of the ring pressing portion 10b and in contact with the second O-ring 14.

  These series of coating layers 23a, 23b, 23c, 23d, 23e, 23f, and 23g are formed by lining and coating a non-metal material such as a synthetic resin having corrosion resistance. In this example, PFA ( A tetrafluoroethylene perfluoroalkoxyethylene copolymer).

  Further, the seal case 2 is formed with a drain collection path 25 that opens to a drain collection space 24 that is an annular space formed between the drain collection basket 9 and the seal case 2. That is, as shown in FIGS. 1 and 2, the drain collection path 25 is a circular hole that crosses the first case portion 10 in the radial direction and extends horizontally, and faces the upper surface of the bottom wall 21 of the drain collection basket 9. It opens to the lower part of the drain recovery space 23 in a state of being connected in a single shape.

  As shown in FIGS. 1 and 2, the drain recovery passage 25 has an inner peripheral surface on which the covering layers 23 a, 23 b, 23 c, 23 d, 23 e, 23 f, 23 g formed on the drain recovery basket 9 and the first case portion 10 are formed. A covering layer 23h made of the same material is formed. That is, an eighth covering layer 23h, which is a PFA lining layer continuous with the first and fifth covering layers 23a and 23e, is formed on the inner peripheral surface of the drain recovery path 25.

  A drain recovery line 28 is connected to the drain recovery path 25 through a connection adapter 26 and an on-off valve 27 as shown in FIGS. As shown in FIGS. 1 and 2, the connection adapter 26 is connected to the drain recovery passage 25 through an O-ring 29 made of a corrosion-resistant elastic material (perfluoro rubber, etc.) that contacts the end of the eighth covering layer 23h. Made of a synthetic resin (PEEK (polyetheretherketone) or the like), and a communication hole 26a is formed through which the drain recovery path 25 and the drain recovery line 28 communicate. The on-off valve 27 is opened when the drain is collected, and is closed during operation of the mechanical seal M1. Although not shown, the drain recovery line 28 is provided with a recovery means (such as a vacuum pump) for recovering drain such as wear powder from the drain recovery space 24.

  In the first mechanical seal M1 configured as described above, even when drainage such as abrasion powder is generated due to contact of the sealing end surfaces 3a and 6a, it can be recovered by the drain recovery rod 9. The sealed fluid region A is not contaminated by such drain.

  That is, when drainage such as abrasion powder is generated between the sealed end faces 3a and 6a, the drain is prevented from entering the sealed fluid A by the peripheral wall 6 of the drain recovery rod 9, and the peripheral wall 6 and the sealing rings 3 and 6 are prevented. It is dropped and collected into the drain collecting space 24 from between the two. Therefore, drains such as abrasion powder do not fall into the housing 1 from the sealed end surfaces 3a and 6a, and contamination of the in-machine region A by the drains is reliably prevented. The drain that has been dropped and collected in the drain collection space 24 is discharged from the drain collection path 26 to the drain collection line as necessary.

  Further, since the first mechanical seal M1 has a non-metal structure in which the member, part or surface that contacts the sealed fluid is made of a non-metallic material as described above, the metal ions generated by the contact between the sealed fluid and the metal Contamination due to the occurrence of such as does not occur.

  By the way, when the metal member which should form a series of coating layers is divided | segmented into the several part connected with a volt | bolt etc., a coating layer is not formed in series in these connection places, but a coating effect is impaired (for example, There is a risk that the coating layer may be torn or damaged at the connection location to expose the metal surface). However, in the first mechanical seal M1, the seal case 2 is divided into a first case portion 10 having a surface in contact with the fluid to be sealed and a second case portion 11 having no surface, and the first case portion 10 and Since the drain recovery rod 9 is an integral structure, that is, a series of coating layers 23a, 23b, 23c, 23d, and 23e can be formed on the surfaces of the members or portions 9 and 10 where the coating layer of the nonmetal material is to be formed. There is no fear that the metal surface is locally exposed. Further, both ends (first and fifth coating layers 23a, 23e) of the series of coating layers 23a, 23b, 23c, 23d, 23e are extended, and the extended portions (sixth and seventh coating layers 23f, 23g) are extended. ) Is brought into contact with the gasket 12 and the second O-ring 14, so that the contact between the first case portion 10 and the drain recovery rod 9 which are metal members or portions and the fluid to be sealed is a series of coating layers 23a and 23b. , 23c, 23d, 23e, 23f, and 23g.

  As understood from these points, the first mechanical seal M1 can reliably solve the contamination problem caused by contact between the sealed fluid and the metal surface, contact between the sealing rings, or the like. Therefore, it can be suitably used as a shaft sealing means for a vertical rotating machine requiring a countermeasure against contamination.

  Further, in the first mechanical seal M1, the spring retainer 7 fitted to the bellows 5 is made of a resin material having a thermal expansion coefficient equivalent to or close to that of PTFE that is a constituent material of the bellows 5. In the case where the thermal expansion of the bellows 5 does not occur or hardly occurs in the fitting portions of the both 5 and 7, no excessive load (stress) acts on the bellows 5.

  Further, since the bellows 5 and the shaft-side seal ring 6 which is a different material from the bellows 5 are integrally connected so that the boundary 20 between the two 5 and 6 does not clearly appear, Of course, when the sealing fluid is a liquid, even when it is a gas, the sealed fluid does not leak at all from the connecting portion 20 of both 5 and 6, and the sealed fluid can be satisfactorily sealed. it can. Even when the fluid to be sealed is a gas (dry operation), the shaft-side seal ring 6 is made of a PTFE composite resin material that is excellent in sliding characteristics with the ceramic case-side seal ring 3. The end faces 3a and 6a are not abnormally worn or heated, and can be in relative sliding contact with each other.

  Therefore, unlike the known bellows type mechanical seal (for example, refer to Japanese Patent Laid-Open No. 8-261333) in which the bellows and the shaft-side seal ring are made of a single piece of the same material, the shaft-side seal ring 6 is connected to the bellows 5. Combined with the fact that it is made of a resin material that is superior in sliding characteristics with the other seal ring (case side seal ring 3) compared to the component material (PTFE), A good mechanical seal function can be exhibited regardless of the properties.

  The mechanical seal of the non-metal structure of the present invention is not limited to the above-described embodiment, and can be improved and changed as appropriate without departing from the basic principle of the present invention.

  For example, the bellows 5 and the shaft-side seal ring 6 can be molded separately and then adhesively connected by an adhesive, or, as shown in FIG. 3 and FIG. It is also possible to connect them together. That is, the non-metallic mechanical seal of the present invention shown in FIGS. 3 and 4 (hereinafter referred to as “second mechanical seal M2”) is formed with an annular tongue 5g at the tip 5d of the bellows 5, and this tongue 5g. Is a bellows-type mechanical seal in which the bellows 5 and the shaft-side sealing ring 6 are connected to each other by pinching in a radial direction between the annular protrusion 5d projecting from the base end surface of the shaft-side sealing ring 6 and the pinching ring 30; The pinching ring 30 is a composite resin material containing PTFE as a main component and is made of PTFE filled with carbon fibers. By the way, in the second mechanical seal M2, when the sealed fluid is a gas, no matter how firmly the bellows 5 and the shaft-side sealing ring 6 are connected, the leakage of the sealed fluid from the connecting portion is prevented. This is not preferable as a gas seal. In this respect, in the first mechanical seal M1, the bellows 5 and the shaft-side sealing ring 6 are integrally connected. Therefore, even when the fluid to be sealed is liquid or gas, such a problem is caused. It does not occur and can exhibit a good sealing function. The second mechanical seal M2 is shown in FIGS. 1 and 2 except for the connecting structure between the bellows 5 and the shaft-side seal ring and the fixing means for fixing the fixing portion 5b of the bellows 5 to the rotating shaft 4 described below. Since it has the same configuration as the first mechanical seal M1, the same components as those of the first mechanical seal M1 are denoted by the same reference numerals as those in FIGS. 1 and 2 in FIG. 3 and FIG. Description is omitted.

  Moreover, the fixing means to the rotating shaft 4 of the fixing | fixed part 5b of the bellows 5 is not limited to the structure which uses the binding ring 15 which is a split ring as shown in FIG. For example, as shown in FIG. 3, the fixing portion 5b of the bellows 5 may be fitted and fixed to the rotary shaft 4 via a stopper ring 31, a fastening ring 32, and a fixing ring 33 made of metal (SUS316 or the like). Good. That is, the stopper ring 31 is fixed to the rotating shaft 4 by tightening an appropriate number of set screws (only one is shown) 31 a screwed to the stopper ring 31 to the rotating shaft 4. The tightening ring 32 is configured by a truncated conical cam surface 32a whose inner peripheral surface expands toward the stopper ring 31, and an appropriate number (only one is shown) of tightening bolts 34 is provided on the stopper ring 31. It is attached by. The fixing ring 33 is externally fitted to the fixing portion 5b while being engaged with the annular protrusion 5c formed on the fixing portion 5b of the bellows 5, and the outer peripheral surface thereof is fitted to the cam surface 32a of the fastening ring 32. The cam surface 33a has a truncated conical shape. Therefore, by tightening the tightening bolt 34 and moving the tightening ring 32 in a direction (upward) close to the stopper ring 31, the fixing portion 5 b of the bellows 5 is moved by the cam surfaces 32 a and 33 a via the fixing ring 33. The rotating shaft 4 is firmly fixed. In the second mechanical seal M2 shown in FIG. 3, an appropriate number of drive pins 35 (only one is shown) project from the fixing ring 32 and engage with the recess 7e of the spring retainer 7. By doing so, relative rotation of the spring retainer 7 with respect to the rotating shaft 2 is prevented while allowing its axial movement within a predetermined range. Each coil spring constituting the spring member 8 is loaded between the spring retainer 7 and the stopper ring 31 in a state of being inserted through a through hole 32 b formed in the tightening ring 32.

  Further, in the non-metal mechanical seal of the present invention, the seal case 2 may be divided into a plurality of parts or may be configured as an integrated structure, but may be divided into a plurality of parts. In order to secure the series of the coating layer, the portion (first case portion 10) having a surface that comes into contact with the fluid to be sealed should be formed as an integral structure, and the drain collecting rod 9 should be formed integrally therewith. Is preferred. On the other hand, the portion (second case portion 11) that does not have a surface in contact with the fluid to be sealed may be an integral structure or may be divided into a plurality of portions.

  In addition, the non-metal material used in the mechanical seal of the non-metal structure of the present invention takes into account the member constituted by this, the member forming the covering layer, the function of the portion, and the sealing conditions (properties of the fluid to be sealed, etc.). Can be selected as appropriate.

  Further, the present invention can be suitably applied to a mechanical seal having no bellows in addition to the bellows type mechanical seal such as the first or second mechanical seal M1, M2.

DESCRIPTION OF SYMBOLS 1 Housing of vertical rotary device 2 Seal case 3 Case side sealing ring 3a Sealing end surface of case side sealing ring 4 Rotary shaft of vertical rotary device 5 Bellows 5a Bellows fixing part (upper end)
5b Bellows expansion / contraction (intermediate)
5d Bellows connection (lower end)
6 Shaft side sealing ring 6a Sealing end face of shaft side sealing ring 7 Spring retainer 8 Spring member 9 Drain recovery rod 10 First case portion 10a Mounting portion 10b O-ring pressing portion 11 Second case portion 12 Gasket 13 First O-ring 14 Second O Ring 21 Bottom wall of drain recovery bowl 22 Perimeter wall of drain recovery bowl 23a First coating layer 23b Second coating layer 23c Third coating layer 23d Fourth coating layer 23e Fifth coating layer 23f Sixth coating layer 23g Seventh coating layer 23h Eighth coating layer 24 Drain collection space 25 Drain collection path A Sealed fluid area (in-machine area)
B Unsealed fluid area (outside machine area)

Claims (6)

A cylindrical seal case attached to the housing of the vertical rotary device, a ceramic case-side sealing ring fixed to the inner periphery of the cylindrical seal case, and an upper end of the rotary shaft of the rotary device penetrating the seal case vertically A PTFE bellows that can be expanded and contracted in the axial direction with fitting and fixed parts, a shaft-side sealing ring that is connected to the lower end of the bellows and faces the case-side sealing ring, and a relative rotation to the lower end of the bellows and the shaft-side sealing ring A spring retainer that is incapable of being relatively displaced in the case-side sealing ring direction, and a spring member that is disposed in an outer peripheral region of the bellows so as to press and bias the spring retainer in the case-side sealing ring direction. and comprising, by relative rotational sliding action of the sealing end face a top and bottom opposing end surfaces of the seal ring, the outer circumferential region with the sealed fluid region of the inner peripheral side region of the relative rotational sliding contact section air Together constitute the band to seal, member in contact with the sealed fluid is a gas having a corrosive, the parts or their surfaces in mechanical seal Nonmetaru structure that is constituted by Nonmetaru material containing no metal component ,
The seal case is made of a metal material, and the seal case has an annular bottom wall projecting in the direction of the rotation axis from the inner periphery thereof, and an upper portion between the opposing peripheral surfaces of the seal ring and the rotation shaft from the inner periphery end portion thereof. A drain recovery rod comprising a cylindrical peripheral wall extending and extending upward from the relative rotational sliding contact portion is integrally formed, and at least the surface in contact with the fluid to be sealed in the seal case and the entire surface of the drain recovery rod have corrosion resistance. a series of coating layers by Nonmetaru material having formed,
The shaft-side seal ring is made of a hard resin material that is excellent in corrosion resistance and sliding characteristics with the case-side seal ring and is composed of a composite resin material mainly composed of PTFE. The bellows and the shaft-side seal ring are And / or so as to be integrated so that the boundary between the two does not appear clearly during the molding process of the shaft-side seal ring or after the molding process of the bellows and the shaft-side seal ring,
A non-metallic mechanical seal characterized in that the spring retainer is made of a resin material whose thermal expansion coefficient is equal to or close to that of a bellows .   The seal case is divided into a first case part that is a monolithic structure having a surface that contacts the sealed fluid and a second case part that does not have a surface that is in contact with the sealed fluid and other parts. It is a cylindrical structure, and the drain collecting rod is integrally formed on the inner peripheral portion of the first case portion. The surface of the first case portion that contacts the sealed fluid and the entire surface of the drain collecting rod are made of a synthetic resin material. The non-metallic mechanical seal according to claim 1, wherein a series of coating layers is formed.   The seal case is divided into a first case part, which is an integral structure, and a second case part attached to the upper end of the seal case, and a case-side sealing ring is provided on the inner periphery of the second case part. The first case part is fitted and fixed via the first and second O-rings, and an O-ring pressing part that presses the second O-ring with the case-side sealing ring in the vertical direction is formed on the first case part, 3. The non-metallic mechanical seal according to claim 2, wherein a coating layer of the same material connected to the series of coating layers is formed on a contact surface of the O-ring pressing portion with the second O-ring.   The seal case is formed with a drain recovery path that opens at a lower portion of a drain recovery space formed between the drain recovery trough and the drain recovery trough, and is connected to the series of coating layers on the inner peripheral surface of the drain recovery path. The non-metallic mechanical seal according to any one of claims 1 to 3, wherein a coating layer of the same material is formed.   The seal case is attached to the housing in a state where an annular attachment portion formed at the lower end thereof is abutted with the upper end portion of the housing via a gasket, and the series of coating layers is formed on the surface of the attachment portion. The mechanical seal of the non-metal structure according to any one of claims 1 to 4, wherein a coating layer made of the same material is connected to the non-metallic structure. Spring retainer is characterized that you have been a composite resin material mainly composed of PTFE, mechanical seal Nonmetaru structure according to any one of claims 1 to 5.