JP2010121683A - Shaft seal device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a shaft seal device based on the new concept which exhibits effective sealing performance with respect to axial eccentricity and axial forward/backward movement, has an advantage of lip seal and labyrinth seal, simultaneously, is excellent in sealing performance from a low speed to a high speed of circumferential speed of the rotary shaft, and does not cause deadly sealing performance reduction at a stretch even when a frictional damage of contact seal member occurs. <P>SOLUTION: The shaft seal device is produced by synthetic resin with elastic storage profile, and consists of a seal body 3, in which a periphery of a flat disc seal plate 5 having a central hole 6 bigger than a diameter of a rotary shaft 1 is fixed to an annular securing section 7, and a sleeve 4, which has a sliding surface 9 inclined to the opposite side with respect to a sealed object as it approaches the radial outside in a part of a body section 8 outer fixed to the rotary shaft. The annular securing section of the seal body is attached to a casing 2, and the rotary shaft is fixed so that the sliding surface of the sleeve may contact an inner circumferential section of the seal plate from the opposite side of the sealed object. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a shaft seal device for rotating / oscillating shafts of general industrial machines, blowers, pumps, and the like, and more specifically, leakage of working fluid from the rotating / oscillating shaft or dust, mist, powder from the outside. The present invention relates to a shaft seal device that prevents intrusion and can be used from a low peripheral speed to a high peripheral speed.

  Conventionally, there are contact type seals and non-contact type seals as shaft seal devices that seal between the rotating shaft and the casing against the working fluid, and contact type seals include contact type mechanical seals and lip seals, which are non-contact types. The mold seal includes a non-contact mechanical seal and a labyrinth seal. Mechanical seals are capable of high-pressure shaft seals, but are very expensive and have a problem of large installation space. Depending on the usage environment, lip seals or labyrinth seals are used alone or in combination. Often done. In general, the lip seal is suitable for a relatively low peripheral speed and high sealing performance, and the labyrinth seal is suitable for a high peripheral speed and relatively low sealing performance.

  Here, when the working fluid is gas, it becomes a non-lubricated seal, and a non-contact type labyrinth seal is used.When the working fluid is liquid, it becomes a lubricated seal, and contacts such as lip seals, oil seals, packings, etc. A mold seal is used, but both seals have poor shaft runout.

  Labyrinth seals use the principle of reducing leakage by causing pressure loss by repeatedly passing the working fluid through narrow gaps and wide spaces. Used as a seal for rotating shafts or swinging shafts such as blowers and blowers. In order to reduce the amount of leakage, a device for minimizing the gap and a device for forming a complicated flow path have been devised, but the sealability, shaft shrinkage / expansion, and followability to shaft runout are poor. In order to prevent metal touch with the shaft, the metal labyrinth seal needs to provide a gap between the shafts, or provide a resin coat and a resin sleeve. In the labyrinth seal made of resin, the seal portion is initially worn to contact with the shaft so as to obtain an optimum clearance. In the contact-type seal, the load on the seal increases due to shaft center fluctuation or the like, and seal leakage or seal damage may occur.

  In Patent Document 1, the outer peripheral portion of a disc-shaped seal member made of ethylene tetrafluoride resin having a circular hole in the central portion is fixed to a retaining ring, and the inner peripheral portion of the disc-shaped seal member is axially fixed. A lip seal is described in which a lip portion is formed by brazing. Here, as the lip seal substrate, a tetrafluoroethylene resin filled with an appropriate amount of graphite powder or carbon fiber is used to improve wear resistance, pressure resistance, and heat resistance.

  In Patent Document 2, in a labyrinth seal in which the tip of a metal fin is opposed to the outer periphery of a rotor via a minute gap, the fin is formed so that the minute gap has a value that achieves basic sealing performance. In addition, a labyrinth seal for a fluid machine is described in which a thin coating film made of a fluororesin is formed on the surface including the tip of the fin. For example, the rotor has a diameter of 200 mm and rotates at a peripheral speed of 100 m / s, the fin member has five 5 mm height fins arranged at a pitch of 5 mm, and the tip of each fin has a minute opposing gap. It faces the outer peripheral surface of the rotor with 180 μm interposed.

When the shaft eccentricity is large, a metal touch is generated in the conventional labyrinth seal. To avoid this, it is necessary to increase the clearance with the shaft, and as a result, leakage must be greatly allowed. In addition, there is no followability to the longitudinal movement of the shaft due to thermal expansion or the like. Furthermore, in recent years, the speed of machines has been increased, and conventional contact seals cannot cope with speed and shaft runout.
Japanese Patent Publication No. 2-38832 Japanese Patent Application No. 2001-129038

  Therefore, in view of the above-described situation, the present invention intends to solve a novel concept that has an effective sealing property against shaft eccentricity and shaft back-and-forth motion, and has the advantages of a lip seal and a labyrinth seal. This is a shaft seal device that offers excellent sealing performance from low to high peripheral speed of the rotating shaft, and shafts that do not lead to a fatal deterioration in sealing performance even if wear damage occurs on the contact seal member. The sealing device is provided.

  In order to solve the above-mentioned problems, the present invention is a shaft seal device that seals between a rotating shaft and a casing, and is made of a synthetic resin having elastic memory characteristics, and has a central hole larger than the diameter of the rotating shaft. A seal body in which an outer peripheral portion of a flat disc-shaped seal plate having an annular shape is fixed to an annular holding portion, and a part of a main body portion that is extrapolated and fixed to the rotating shaft, is opposite to an object to be sealed as it becomes radially outward. A sleeve having a sliding surface inclined to the side, and the annular holding portion of the seal body is attached to the casing, and the sliding surface of the sleeve is located on the inner peripheral portion of the seal plate from the opposite side to the object to be sealed. The shaft seal device is configured to be fixed to the rotating shaft so as to be in contact with each other (Claim 1).

  Here, a seal body in which a plurality of seal plates are fixed to the annular holding portion at intervals in the axial direction, and a sleeve in which inclined sliding surfaces corresponding to the seal plates are provided at intervals in the axial direction. It is also preferable (Claim 2).

  Preferably, the contact surface pressure of the seal plate against the sliding surface is adjusted at an axial position where the sleeve is fixed to the rotating shaft.

  Specifically, the thickness of the seal plate is 0.3 to 1.5 mm, and the thickness of the seal plate is 0.5 after the sliding surface of the sleeve comes into contact with the inner peripheral portion of the seal plate. The sleeve is displaced and fixed to the object to be sealed side by 10 times (claim 4).

  The contact width between the inner peripheral portion of the seal plate and the sliding surface of the sleeve is 0.5 to 5.0 mm.

  Furthermore, the inclination angle of the sliding surface of the sleeve with respect to the radial direction is 0 to 45 °, preferably 10 to 30 ° (Claim 6).

  It is more preferable that a cylindrical surface is continuously formed on the side of the sliding surface of the sleeve opposite to the object to be sealed (Claim 7).

  In addition, a labyrinth seal function is provided by setting the gap between a part of the annular holding portion of the seal body or the ring plate fixed to the annular holding portion and the outer peripheral surface of the sleeve or the outer peripheral surface of the rotating shaft to a minimum. It is also preferable that it be formed (claim 8).

  According to the shaft seal device of the first aspect as described above, the sleeve fixed to the rotary shaft from the side opposite to the object to be sealed, on the inner peripheral portion of the seal plate of the seal body in which the annular holding portion is attached to the casing. Since the slanted sliding surface is in contact, the inner peripheral portion of the seal plate having elastic memory characteristics acts as if it is a lip portion of a contact-type lip seal, so that the working fluid is more than the conventional labyrinth seal. Despite the fact that high sealing performance can be secured, the contact pressure between the inclined sliding surface and the inner periphery of the seal plate is low, so the generation of frictional heat is suppressed even when the rotating shaft has a high peripheral speed. In addition, since the amount of wear can be suppressed, the sealing performance higher than that of the labyrinth seal such as a lip seal can be maintained. In addition, since the inner periphery of the seal plate is always in contact with the inclined sliding surface of the sleeve, it can also be used as a seal for solids such as dust and lubricating oil, and it is excellent even when the peripheral speed of the rotating shaft is slow. In addition, the sealing performance can be maintained even if some negative pressure is generated when the operation is stopped. And the sliding form between the inner peripheral part of the seal plate and the sliding surface of the sleeve is thrust sliding, which can flexibly cope with shaft runout and shaft eccentricity. The allowable value is large, and it is possible to follow axial displacement and thermal expansion. In addition, since the sleeve is extrapolated to the rotating shaft, there is no need to rework the existing rotating shaft, and the sealing material and sleeve material are combined with the rotating shaft according to the operating conditions, heat resistance, chemical resistance and durability. Can be selected regardless of

  According to claim 2, a seal body in which a plurality of seal plates are fixed to the annular holding portion at intervals in the axial direction, and inclined sliding surfaces corresponding to the seal plates are provided at intervals in the axial direction. In the case of the sleeve, the sealing performance is further enhanced because multiple sealing is performed with a plurality of pairs of the sealing plate and the sliding surface.

  According to the third aspect, since the contact surface pressure of the seal plate with respect to the sliding surface is adjusted at the axial position where the sleeve is fixed to the rotating shaft, the contact surface pressure is easily adjusted according to the use environment. be able to.

  According to claim 4, the thickness of the seal plate is 0.3 to 1.5 mm, and the thickness of the seal plate is 0 after the sliding surface of the sleeve comes into contact with the inner peripheral portion of the seal plate. Since the sleeve is displaced and fixed to the object to be sealed side by 5 to 10 times, the sealing plate is secured by increasing the thickness of the seal plate as the diameter of the rotating shaft increases. The contact surface pressure between the inner periphery of the seal plate and the sliding surface of the sleeve can be set on the basis of the thickness of the seal plate, and the adjustment is made by sliding the sleeve on the inner periphery of the seal plate. This can be confirmed by the amount of axial displacement of the sleeve after the surfaces contact.

  According to the fifth aspect, since the contact width between the inner peripheral portion of the seal plate and the sliding surface of the sleeve is 0.5 to 5.0 mm, the contact width is increased as the diameter of the rotating shaft increases. The sealing property can be secured by increasing the size.

  According to claim 6, since the angle of inclination of the sliding surface of the sleeve with respect to the radial direction is 0 to 45 °, preferably 10 to 30 °, the lip that directly presses the outer peripheral surface of the rotary shaft with the lip portion. The contact surface pressure can be made much lower than that of the seal, the generation of frictional heat can be suppressed even at a high peripheral speed, and the amount of wear can also be suppressed, so that it has sufficient durability.

  According to the seventh aspect of the present invention, the cylindrical surface is continuously formed on the opposite side of the sliding surface of the sleeve to the object to be sealed. Even if the sliding surface does not come into contact, the cylindrical surface continuous with the sliding surface and the inner peripheral portion of the seal plate come into contact with each other or approach each other with a minute gap. Constructed, a minimum sealing performance can be secured, an unexpected sudden leakage of working fluid can be prevented, and there is no fatal deterioration in sealing performance.

  According to claim 8, the interval between a part of the annular holding portion of the seal body or the ring plate fixed to the annular holding portion and the outer peripheral surface of the sleeve or the outer peripheral surface of the rotary shaft is set to a minimum, Since the labyrinth seal function is added, even when the sealing performance between the inner periphery of the seal plate and the sliding surface of the sleeve is impaired, the leakage of the working fluid can be suppressed to a minimum. It is possible to prevent the malfunction of the equipment due to the leakage of water.

  Next, details of the present invention will be described based on embodiments. FIG. 1 is a conceptual diagram of a shaft seal device according to the present invention, FIG. 2 is an explanatory diagram for explaining the followability when shaft runout or shaft movement occurs, in which 1 is a rotating shaft, 2 is a casing, Reference numeral 3 denotes a seal body, and 4 denotes a sleeve.

  The shaft seal device of the present invention is a shaft seal device that seals between the rotary shaft 1 and the casing 2, is made of a synthetic resin having elastic memory characteristics, and has a center hole 6 larger than the diameter of the rotary shaft 1. A flat disc-shaped sealing plate 5 having an outer peripheral portion fixed to the annular holding portion 7 and a part of the main body portion 8 that is externally fixed to the rotating shaft 1 are covered with the outer side in the radial direction. It comprises a sleeve 4 having a sliding surface 9 inclined to the opposite side to the sealed object, and an annular holding portion 7 of the seal body 3 is attached to the casing 2 so that the sleeve 4 slides from the opposite side to the sealed object. In this structure, the moving surface 9 is fixed to the rotary shaft 1 so as to contact the inner peripheral portion of the seal plate 5.

  Normally, there is a working fluid made of gas or liquid inside the casing 2, and the shaft sealing device prevents the working fluid from leaking to the outside (in the axial direction). In this case, the working fluid becomes an object to be sealed, and the side opposite to the object to be sealed means the outside in the axial direction. Here, the to-be-sealed object side is the object side to be sealed by the shaft seal device. In addition, when a shaft seal device is provided between the bearing and the inside of the casing 2 in order to prevent the lubricating oil used for the bearing from entering the inside of the casing 2, the lubricating oil becomes an object to be sealed. The side opposite to the sealing material means the inside in the axial direction. Further, in order to prevent dust in the atmosphere from entering the inside of the casing 2 or the bearing, when a shaft sealing device is provided on the outer side in the axial direction, the dust becomes an object to be sealed, and the opposite side to the object to be sealed is It means the inside in the axial direction. In the present embodiment, a shaft seal device is used to prevent the working fluid inside the casing 2 from leaking to the outside. Therefore, in FIG. 1, the left side is the inside of the casing 2, and the right side is the outside.

  Specifically, the material of the seal plate 5 is a resin having elastic memory characteristics, a base material such as PTFE or ultrahigh molecular weight PE, a solid lubricant such as carbon, graphite, molybdenum disulfide, glass fiber, carbon, etc. A material filled with a reinforcing material such as fiber is used. The sleeve 4 is made of carbon steel, stainless steel, Cu-based metal or fiber reinforced resin. If it is the said material, regardless of a combination, it selects according to use environments, such as humidity and corrosion resistance.

  In the present embodiment, PTFE filled with carbon and carbon fibers is used as the seal plate 5, and S45C is used as the sleeve 4. The seal plate 5 is produced by forming the above-described seal material into a cylindrical shape and slicing it with a predetermined width. Up to this point, the manufacturing method is the same as the manufacturing method of the seal member of the lip seal. That is, unlike the lip seal, the lip portion is not brazed in the axial direction. Further, in the relationship between the seal plate 5 and the annular holding portion 7, both are separate members and the outer peripheral portion of the seal plate 5 is fixed to the annular holding portion 7 in an airtight state, or the seal plate 5 and the annular holding portion 7 are There is a structure that is a single piece, made by integral molding made of synthetic resin, or by grinding from a block.

  And the thickness of the said sealing plate 5 is 0.3-1.5 mm, The inclination | tilt angle (theta) with respect to the radial direction of the sliding surface 9 of the said sleeve 4 is 0-45 degrees, Preferably it is 10-30 degrees. is there. The contact width W between the inner peripheral portion of the seal plate 5 and the sliding surface 9 of the sleeve 4 was set to 0.5 to 5.0 mm.

  If the thickness of the seal plate 5 is smaller than 0.3 mm, the mechanical strength is weak, sufficient elastic restoring property cannot be obtained, and it is difficult to secure a desired sealing property. If the thickness of the seal plate 5 is larger than 1.5 mm, the rigidity becomes strong, and the amount of frictional heat generated and the amount of wear increase due to strong rubbing against the seal plate 5, and the followability to shaft runout and shaft movement is reduced. This is not preferable. Further, the inclination angle θ of the sliding surface 9 may be in the range of 0 to 45 ° in principle, but is practically set in the range of 10 to 30 °. If the inclination angle θ of the sliding surface 9 is smaller than 10 °, it is difficult to obtain a sufficient contact surface pressure, and the allowable range for the axial movement becomes narrow. If the inclination angle θ is larger than 30 °, it is sufficient. Although a sufficient contact surface pressure can be ensured, it is not preferable because the amount of wear increases because it rubs strongly against the shaft runout against the inner peripheral portion of the seal plate 5. Further, the contact width W between the inner peripheral portion of the seal plate 5 and the sliding surface 9 is increased in proportion to the increase in the diameter of the rotary shaft 1, but the contact width W is normally set to 0.5 to 5.0 mm. To do. If the contact width W is less than 0.5 mm, sufficient sealing performance cannot be obtained. If the contact width W is greater than 5.0 mm, the amount of frictional heat generated increases, or the contact state is biased during shaft runout or shaft movement. It is not desirable to occur.

  For example, when the diameter of the rotating shaft 1 is 65 mmφ, the thickness of the seal plate 5 is 1.2 mm, and the inclination angle θ of the sliding surface 9 of the sleeve 4 is 30 °. When the diameter of the rotary shaft 1 is 30 mmφ, the thickness of the seal plate 5 is 0.8 mm, and the inclination angle θ of the sliding surface 9 of the sleeve 4 is 20 °.

  In order to assemble the shaft seal device of the present invention at a predetermined position, as shown in FIG. 1, the annular holding portion 7 of the seal body 3 is closely fitted to the annular step portion 10 of the casing 2 and is screwed to the casing 2. The annular holding portion 7 is pressed and held by the fixed fixture 11. Then, the sleeve 4 is slid from the side opposite to the object to be sealed of the rotary shaft 1, and the sliding surface 9 of the sleeve 4 is brought into contact with the inner peripheral portion of the seal plate 5. From this position, the sleeve 4 is further displaced to the sealed object side by 0.5 to 10 times the thickness of the seal plate 5 and fixed. The contact surface pressure between the inner peripheral portion of the seal plate 5 and the sliding surface 9 of the sleeve 4 is adjusted by the amount of movement of the sleeve 4. Actually, it is preferable to use a dedicated gauge so that the relative position of the annular holding portion 7 of the seal body 3 and the sleeve 4 can be accurately set. In order to fix the sleeve 4 to the rotary shaft 1, a screw threaded through the sleeve 4 from the radial direction and penetrated is pressed against the outer peripheral surface of the rotary shaft 1.

  In applications where sealing performance is important, an O-ring is attached to the inner peripheral surface of the sleeve 4 and pressed against the outer peripheral surface of the rotary shaft 1 to prevent the sleeve 4 from leaking between the rotary shafts 1. To do. When the sleeve 4 is made of synthetic resin, a lip portion is integrally formed on the inner peripheral portion of the sleeve 4 opposite to the sliding surface 9 to form a dust seal, and the lip portion is formed on the outer periphery of the rotary shaft 1. It is possible to prevent dust from entering by pressing against the surface.

  Furthermore, in the present invention, the cylindrical surface 12 is continuously formed on the side of the sliding surface 9 of the sleeve 4 opposite to the object to be sealed. Even when the inner peripheral portion of the seal plate 5 is inevitably worn out due to long-time operation and is no longer in contact with the sliding surface 9, the worn seal plate 5 is worn by the elastic restoring property of the seal plate 5. The inner peripheral portion of the cylindrical surface 12 is positioned on the outer periphery of the cylindrical surface 12 and is slightly in contact with the cylindrical surface 12 or is not in contact with a small gap, thereby forming a labyrinth seal similar to the conventional one. Thereby, even if the seal plate 5 is worn out, it is possible to prevent a fatal leakage of the working fluid.

  The followability of the shaft seal device of the present invention with respect to shaft runout and shaft movement will be described with reference to FIG. FIGS. 2 (a) and 2 (b) show a case where shaft runout occurs, (a) shows a case where the rotating shaft is displaced downward, and (b) shows a case where the rotating shaft is displaced upward. However, the inner peripheral portion of the seal plate 5 and the sliding surface 9 of the sleeve 4 are always kept in contact with each other, and the sealing performance is ensured. 2 (c) and 2 (d) show a case where axial movement occurs, (c) shows the case where the rotating shaft is displaced to the opposite side to the object to be sealed, and (d) shows the case where the rotating shaft is sealed. In this case, the inner peripheral portion of the seal plate 5 and the sliding surface 9 of the sleeve 4 are always in contact with each other, and the sealing performance is ensured. 2 exaggerates the displacement of the rotating shaft, the actual displacement is about 1 mm or less, but there may be a displacement of 2 mm or more due to the influence of eccentricity or shaft runout. Even in this case, the present invention can ensure good sealing performance.

  A more specific embodiment of the shaft seal device will be described with reference to FIG. The seal body 3 integrates the outer peripheral portion of the seal plate 5 by insert molding at the time of molding the annular holding portion 7 made of synthetic resin. At that time, the annular first ring plate 13 is formed before and after the seal plate 5. And the second ring plate 14 and simultaneously held by the annular holding portion 7. The first ring plate 13 is a plate-like member having substantially the same shape as the seal plate 5, and the diameter of the center hole 15 is set larger than that of the center hole 6 of the seal plate 5. The diameter of the center hole 16 of the second ring plate 14 is set to a size that can ensure a certain clearance from the outer peripheral surface of the rotary shaft 1, the base portion has a thickness in the axial direction, and the seal plate 5 A space portion 17 is formed between the inner portion in the radial direction. Further, the annular holding portion 7 is formed with a plurality of attachment holes 18 for screwing directly to the casing 2. On the other hand, the sleeve 4 is formed with the sliding surface 9 at the end of the body portion 8 on the side of the object to be sealed, and continuously with the cylindrical surface 12. The cylindrical surface 12 is provided with a stepped portion to form an enlarged diameter portion 19, a screw hole 20 penetrating in the radial direction is formed in the enlarged diameter portion 19, and a screw 21 screwed into the screw hole 20. Can be fixed in pressure contact with the outer peripheral surface of the rotary shaft 1.

  As shown in FIG. 3, in the state where the seal body 3 is attached to the casing 2 and the sleeve 4 is fixed to the rotary shaft 1, the inner peripheral portion of the first ring plate 13 is the diameter-expanded portion 19 of the sleeve 4. In the vicinity of the step portion, it is positioned with a small clearance between the cylindrical surface 12 and the inner peripheral portion of the second ring plate 14 has a small clearance with the outer peripheral surface of the rotary shaft 1. The inner peripheral portion of the seal plate 5 is in slight contact with the sliding surface 9. In this case, the seal plate 5 and the sliding surface 9 have a good sealing property due to the contact, but in this embodiment, the first ring plate 13, the second ring plate 14 and the space portion 17 constitute a labyrinth seal. In addition, the load on the seal plate 5 is reduced, and the reliability of the sealing performance is further increased.

  Also in this embodiment, as shown in FIG. 4, when the inner peripheral portion of the seal plate 5 is worn, the seal plate 5 is separated from the sliding surface 9 and becomes substantially parallel to the first ring plate 13. A labyrinth seal is formed with the cylindrical surface 12. Here, the contact surface pressure between the inner peripheral portion of the seal plate 5 and the sliding surface 9 can be set based on the position where the stepped portion of the enlarged diameter portion 19 of the sleeve 4 contacts the first ring plate 13.

  FIG. 5 shows a usage example in which two shaft sealing devices having the structure of FIG. 3 are arranged in tandem in the axial direction. Further, a large number of shaft sealing devices can be arranged in tandem, and the number of the shaft sealing devices can be appropriately selected according to the required sealing performance and reliability. In FIG. 5, reference numeral 22 denotes a bolt that is attached to the casing 2 through the attachment holes 18 of the annular holding portions 7.

  FIG. 6 shows a second embodiment of the shaft seal device according to the present invention, in which two seal plates 5 and 5 are incorporated in the seal body 3, and accordingly, a sliding surface 9 and a cylindrical surface 12 are formed on the sleeve 4. Two pairs are formed. The annular holding portion 7 of the seal body 3 has a structure in which a first seal plate 5A, a second seal plate 5B, and a ring plate 24 are fixed in a metal housing 23 with a packing 25 interposed therebetween. Yes. The sleeve 4 includes a first sliding surface 9A, a first cylindrical surface 12A, and a second sealing plate 5B, which are in contact with the inner peripheral portion of the first sealing plate 5A in order from the object to be sealed side of the body portion 8. In this structure, the second sliding surface 9B and the second cylindrical surface 12B that are in contact with the inner peripheral portion are formed, and the enlarged diameter portion 19 is further formed on the side opposite to the object to be sealed. The first cylindrical surface 12A and the second sliding surface 9B are continuous. The inner peripheral portion of the ring plate 24 is close to the outer peripheral surface of the enlarged diameter portion 19, and this portion constitutes a labyrinth seal. Since other configurations are the same as those described above, the same reference numerals are given to the same configurations, and descriptions thereof are omitted.

  FIG. 7 is an explanatory view of configuring the labyrinth seal in the same manner as described above even when the shaft seal device of FIG. 6 is operated for a long time and the inner peripheral portions of the first seal plate 5A and the second seal plate 5B are worn. is there. FIG. 7A shows a state immediately after use of the shaft seal device, and FIG. 7B shows a case where the inner peripheral portions of the first seal plate 5A and the second seal plate 5B are worn away. The inner peripheral portion of the plate 5A and the first cylindrical surface 12A and the inner peripheral portion of the second seal plate 5B and the second cylindrical surface 12B constitute a labyrinth seal. In this case, the first seal plate 5A is formed by forming a third sliding surface (not shown) at the same pitch as the other sliding surfaces on the opposite side of the second cylindrical surface 12B to the object to be sealed. When the inner peripheral portion of the second seal plate 5B is worn out, the sleeve 4 is moved to the object to be sealed by a distance equal to the above-mentioned pitch to replace the inner portion of the worn first seal plate 5A. The peripheral portion contacts the second sliding surface 9B with a predetermined contact surface pressure, and the worn inner peripheral portion of the second seal plate 5B contacts the third sliding surface with a predetermined contact surface pressure. A seal property close to that appears.

  The shaft seal device shown in FIG. 6 has different diameters of the center holes of the first seal plate 5A and the second seal plate 5B, but FIGS. 8 and 9 show two seal plates 5 and 5 having the same shape. It is an embodiment in the case of using. The annular holding portion 7 of the seal body 3 in FIG. 8 fixes the sealing plates 5 and 5 in a metal housing 23 with a packing 25 interposed therebetween, and the radial direction of the housing 23 opposite to the object to be sealed The wall portion 26 has a structure extending inward. The sleeve 4 shown in FIG. 8 has a structure in which a sliding surface 9 and a cylindrical surface 12 are repeatedly formed in the axial direction. Since other configurations are the same as those described above, the same reference numerals are given to the same configurations, and descriptions thereof are omitted. Here, the radial wall portion 26 of the housing 23 of the annular holding portion 7 and the outer peripheral surface of the enlarged diameter portion 19 of the sleeve 4 constitute a labyrinth seal.

  The annular holding portion 7 of the seal body 3 in FIG. 9 is made of synthetic resin, and the outer peripheral portions of the two seal plates 5 and 5 are integrally fixed by insert molding. An annular groove 27 is formed. Then, an O-ring 28 is fitted into the annular groove 27, fitted into the annular step portion 10 of the casing 2 in an airtight state, and attached by being pressed by the fixing bracket 11. Further, the sleeve 4 of FIG. 9 is the same as that shown in FIG. Since other configurations are the same as those described above, the same reference numerals are given to the same configurations, and descriptions thereof are omitted. Here, a labyrinth seal is configured by reducing the distance between the inner peripheral surface of the annular holding portion 7 and the outer peripheral surface of the enlarged diameter portion 19 of the sleeve 4.

  FIG. 10 shows an example of use in which the bearing 29 and the fan 30 have a long distance such as a blower or a pressure fan, and the shaft runout is large. When the casing 2 has no space for installing the shaft seal device Is shown. In such a case, it is possible to attach the sealing body 3 having the structure shown in FIG. 3 to the outside of the casing 2, but in the illustrated case, the outer peripheral portions of the plurality of sealing plates 5, 5 are provided on the outer surface of the casing 2. The packing 31 is interposed to maintain a predetermined interval, the pressing plate 32 is applied from the outside, and the bolt 33 is directly passed through the pressing plate 32, the seal plates 5A and 5B, and the packing 31 and tightened. In this case, the packing 31 and the pressing plate 32 serve as the above-described annular holding portion 7. And the sleeve 4 of this embodiment is the same as FIG. 6, the 1st sliding surface 9A, the 1st cylindrical surface 12A, the 2nd sliding surface 9B, and 1st from the to-be-sealed object side of the main-body part 8 in order. Two cylindrical surfaces 12B are formed. It can be used when rust corrosion of metal parts such as the bearing 29 is disliked.

  In the example shown in FIG. 11, the seal body 3 is similar to that of FIG. 11, but without using the sleeve 4, the chamfer is directly chamfered on the end of the rotating shaft 1 supported by the bearing 34 and protruding from the casing 2. Thus, the inclined sliding surface 35 is formed, and the inner peripheral portion of the seal plate 5 of the seal body 3 attached to the outer surface of the casing 2 is brought into contact. Of course, it is also possible to attach the same sleeve 4 to the end portion of the rotating shaft 1 and bring the inner peripheral portion of the seal plate 5 into contact with the sliding surface 9 thereof. Thus, the shaft seal device of the present invention can also be used as a dust seal, and when used as a shaft end cover such as a rolling roll, it is possible to prevent the cooling water from entering the bearing 34 of the roll.

It is a simplified sectional view showing the concept of the shaft seal device of the present invention. It is a principle figure which similarly shows sealing performance, (a) is a sectional view in a state where the rotating shaft is displaced downward due to axial runout, (b) is a sectional view in a state where the rotating shaft is displaced upward due to axial runout, (c) ) Is a cross-sectional view of the state where the rotary shaft is displaced to the opposite side of the object to be sealed by axial movement, and (d) is a cross-sectional view of the state where the rotary shaft is displaced to the side of the object to be sealed by axial movement. It is a fragmentary sectional view showing a 1st embodiment of a shaft seal device of the present invention. It is a fragmentary sectional view which shows the state where the inner peripheral part of the sealing board was worn out similarly. It is a fragmentary sectional view showing the state where the shaft seal device was similarly arranged in tandem. It is a fragmentary sectional view showing a 2nd embodiment of a shaft seal device of the present invention. Similarly, it shows the usage state of the shaft seal device of the second embodiment, (a) is a partial cross-sectional view showing a state immediately after use, (b) is a partial cross-sectional view showing a state in which the inner peripheral portion of the seal plate is worn out. . It is a fragmentary sectional view showing a 3rd embodiment of the present invention. It is a fragmentary sectional view showing a 4th embodiment of the present invention. It is a fragmentary sectional view which shows the usage example of this invention. It is a fragmentary sectional view which shows another example of use of this invention.

Explanation of symbols

1 rotating shaft, 2 casing,
3 Seal body, 4 Sleeve,
5 seal plate, 5A first seal plate,
5B 2nd seal plate, 6 center hole,
7 annular holding part, 8 body part,
9 sliding surface, 9A first sliding surface,
9B 2nd sliding surface, 10 annular step part,
11 fixing bracket, 12 cylindrical surface,
12A 1st cylindrical surface, 12B 2nd cylindrical surface,
13 first ring plate, 14 second ring plate,
15 center hole, 16 center hole,
17 space part, 18 mounting hole,
19 expanded diameter part, 20 screw hole,
21 screws, 22 bolts,
23 housing, 24 ring plate,
25 packing, 26 radial wall part,
27 annular groove, 28 O-ring,
29 bearings, 30 fans,
31 packing, 32 holding plate,
33 bolts, 34 bearings,
35 Sliding surface.

Claims (8)

  A shaft seal device for sealing between a rotating shaft and a casing, which is made of a synthetic resin having elastic memory characteristics, and has an outer peripheral portion of a flat disk-shaped sealing plate having a center hole larger than the diameter of the rotating shaft A seal body fixed to the annular holding portion, and a sleeve having a sliding surface inclined to the opposite side to the object to be sealed toward the outer side in the radial direction on a part of the main body portion to be extrapolated to the rotating shaft. The annular holding portion of the seal body is attached to the casing, and is fixed to the rotating shaft so that the sliding surface of the sleeve comes into contact with the inner peripheral portion of the seal plate from the side opposite to the object to be sealed. A shaft seal device.   2. A seal body in which a plurality of seal plates are fixed to the annular holding portion at intervals in the axial direction, and a sleeve in which inclined sliding surfaces corresponding to the seal plates are provided at intervals in the axial direction. The shaft seal device described.   The shaft seal device according to claim 1 or 2, wherein a contact surface pressure of the seal plate with respect to the sliding surface is adjusted at an axial position where the sleeve is fixed to the rotating shaft.   The thickness of the seal plate is 0.3 to 1.5 mm, and the thickness of the seal plate is 0.5 to 10 times after the sliding surface of the sleeve comes into contact with the inner periphery of the seal plate. The shaft seal device according to any one of claims 1 to 3, wherein the sleeve is displaced and fixed toward the object to be sealed.   The shaft seal device according to any one of claims 1 to 4, wherein a contact width between an inner peripheral portion of the seal plate and a sliding surface of the sleeve is 0.5 to 5.0 mm.   The shaft seal device according to any one of claims 1 to 5, wherein an inclination angle of the sliding surface of the sleeve with respect to a radial direction is 0 to 45 °, preferably 10 to 30 °.   The shaft seal device according to any one of claims 1 to 6, wherein a cylindrical surface is continuously formed on a side opposite to the object to be sealed of the sliding surface of the sleeve. A labyrinth seal function is provided by setting a distance between a part of the annular holding portion of the seal body or a ring plate fixed to the annular holding portion and the outer peripheral surface of the sleeve or the outer peripheral surface of the rotating shaft to a minimum. The shaft seal device according to any one of claims 1 to 7.

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