Patent Publication Number: US-9845888-B2

Title: Mechanical seal

Description:
This application is the U.S. National Phase under 35 U.S.C. §371 of International Application PCT/JP2013/072654, filed Aug. 26, 2013, which claims priority to Japanese Patent Application No. 2012-189294, filed Aug. 29, 2012. The International Application was published under PCT Article 21(2) in a language other than English. 
     TECHNICAL FIELD 
     The present invention relates to a mechanical seal for sealing equipment used in oil refinery, petrochemical, steel-chemical and other applications, which handles high-temperature liquids of over 200° C., and specifically to a mechanical seal of high-temperature bellows seal type having a bellows and baffle sleeve. 
     BACKGROUND ART 
     One of the traditionally known mechanical seals used in applications where the temperature of sealed liquid exceeds 200° C. and flushing with coolant is not performed, is a mechanical seal of high-temperature bellows seal type like the one shown in  FIG. 10  (hereinafter referred to as “prior art; refer to Patent Literature 1, for example). 
     The mechanical seal of high-temperature bellows seal type according to the prior art as shown in  FIG. 10  is a mechanical seal installed on a shaft seal part  53  formed between a rotational shaft  50  and housing  51  to seal a space between the rotational shaft  50  and housing  51 ; wherein such mechanical seal has: a collar  54  installed on the housing  51  side; a bellows  55  connected to the collar  54 ; a retainer  56  connected to the bellows  55 ; a seal ring  57  engaged with the retainer  56 ; a mating ring  58  installed on the rotational shaft  50  side; and a cylindrical baffle sleeve  59  provided at a specific interval on the inner periphery side of the collar  54 . In addition, steam quench is supplied from a supply hole  64  provided in a seal cover  60 , which then flows through the space formed between the inner periphery of the stationary side of the mechanical seal and the outer periphery of the baffle sleeve  59  and reaches the end face of the seal to cool the mechanical seal part, and which also cleans and discharges the liquid seeping from the end face of the seal. 
     Then, the sliding torque on the end face of the seal ring  57  is transmitted to the retainer  56 , bellows  55 , and collar  54 , in this order, being received by the collar  54  fixed on the seal cover  60  with bolts  63 . Minute vibration (stick-slip) occurring in the circumferential direction as a result of change in the lubrication condition of the end face of the seal ring  57  propagates to the retainer  56  and to the bellows  55 . To suppress such minute vibration in the circumferential direction, the baffle sleeve  59  fixed on the seal cover  60  with bolts  63  extends to the inner periphery part of the retainer  56  to limit the outer diameter of the baffle sleeve  59  and innermost diameter of the retainer to a minimum gap at some parts (four equidistance points in many cases) along the circumference, while a damper  61  that contacts the inner periphery surface of the bellows  55  to exert vibration-damping effect is installed on the outer periphery surface of the baffle sleeve  59  so that when vibration occurs, the damping effect will prevent the amplitude of vibration from exceeding the minimum gap. 
     With this type of mechanical seal, normally the collar  54 , bellows  55 , and retainer  56  are joined by means of welding, for example, while the seal ring  57  made of carbon or other sliding material is hermetically shrink-fitted or press-fitted in the retainer  56 , and these members are preassembled as one piece at the factory, etc. 
     However, this mechanical seal according to the prior art has problems as described below. 
     When various members are installed on the seal cover  60 , the collar  54 , bellows  55 , retainer  56 , and seal ring  57  (hereinafter referred to as “seal members on the stationary side”) are installed on the equipment interior side (sealed liquid side) of the seal cover  60 , while the baffle sleeve  59  which is designed as one piece having an L-shaped cross-section can be installed only from the equipment exterior side (atmosphere side) of the seal cover  60 . As a result, the seal members on the stationary side, etc., cannot be preassembled with the baffle sleeve  59  and must therefore be assembled onsite. In addition, this onsite assembly requires a difficult process of wrapping around the baffle sleeve  59  the damper  61  installed between the inner periphery surface of the bellows  55  and outer periphery surface of the baffle sleeve  59 , and then inserting the bellows  55 . 
     PRIOR ART LITERATURES 
     Patent Literatures 
     Patent Literature 1: International Patent Laid-open No. 2010/113932 
     SUMMARY OF INVENTION 
     Problems to be Solved by Invention 
     The object of the present invention is to provide a mechanical seal that allows for preassembly of its seal members on the stationary side, baffle sleeve, damper, and other related parts at the factory, service center, etc., in a reliable and controlled manner, thereby requiring fewer assembly steps during onsite engineering works. 
     Means to Solve Problems 
     To achieve the aforementioned object, firstly the mechanical seal proposed by the present invention is a mechanical seal installed on a shaft seal part formed between a housing and rotational shaft to seal a space between the housing and rotational shaft, wherein such mechanical seal is characterized in that: the mechanical seal has a seal ring and a mating ring that faces and slides against the seal ring and either the seal ring or mating ring is supported via bellows on the equipment interior side of a seal cover installed on the housing, while the other rotates together with the rotational shaft; and a baffle sleeve with a roughly L-shaped cross-section is fixed on the equipment exterior side of the seal cover to guide quenching liquid to the sliding surfaces of the seal ring and mating ring, where the baffle sleeve is structurally split into a flange part and cylinder part. 
     According to these characteristics, the collar, bellows, retainer, seal ring, baffle sleeve cylinder part, damper, and other related parts can be preassembled in a reliable and controlled manner at the factory or service center, thereby requiring fewer member assembly steps during onsite engineering works. This not only improves the ease of assembly, but also reduces human errors during onsite engineering works. In addition, while traditionally carving a one-piece baffle sleeve with roughly an L-shaped cross-section from a round bar requires a material of “outer diameter of the flange part×length of the cylinder part” in size, and machining the round bar to change its cross-section to roughly an L-shape is a very wasteful exercise because the majority of the round bar must be shaved off, the baffle sleeve under the present invention is formed of separate materials constituting its flange part and cylinder part, respectively, and therefore the waste associated with the prior art can be eliminated. Furthermore, the mechanical seal proposed by the present invention requires a significantly smaller installation space on the equipment exterior side of the seal cover compared to the prior art, thereby saving assembly space. 
     In addition, secondly, the mechanical seal proposed by the present invention is characterized, in addition to the first characteristics, in that: the flange part has a slit formed in one location in the circumferential direction and the inner periphery surface of the flange part is engaged with the outer periphery surface of the cylinder part, while the outer periphery surface of the flange part is engaged with a tapered surface for flange engagement provided on the equipment exterior side of the seal cover; and because the outer periphery surface of the flange part is fit along the tapered surface, the inner periphery surface of the flange part clamps the outer periphery surface of the cylinder part. 
     According to these characteristics, fitting the flange part at the specified position exerts clamping force in the diametral direction so as to keep the flange part and cylinder part connected just like a one-piece baffle sleeve. As a result, a baffle sleeve sufficiently capable of withstanding vibration and other external disturbances can be obtained. 
     In addition, thirdly, the mechanical seal proposed by the present invention is characterized, in addition to the first or second characteristics, in that: the flange part has multiple bolt holes in the circumferential direction and is fixed on the equipment exterior side of the seal cover via a bolt. 
     According to these characteristics, the flange part can be fitted at the specified position by means of the bolt, while clamping force is exerted in the diametral direction to keep the flange part and cylinder part connected just like a one-piece baffle sleeve. 
     In addition, fourthly, the mechanical seal proposed by the present invention is characterized, in addition to any of the first through third characteristics, in that: the flange part has a part having a small cross-section area formed at a position on the opposite side of the slit in the circumferential direction. 
     According to these characteristics, elastic deformation can be achieved easily as the flange part shrinks along its diameter. 
     In addition, fifthly, the mechanical seal proposed by the present invention is characterized, in addition to any of the first through fourth characteristics, in that: a ring-shaped convex part is provided on the outer periphery surface of the cylinder part of the baffle sleeve, in close proximity to the inner periphery surface of the cylindrical collar connected to one end of the bellows. 
     According to these characteristics, vibration of the baffle sleeve can be damped quite effectively when the baffle sleeve is fixed on the seal cover, because the inner periphery surface of the collar is in close proximity to the outer periphery surface of the ring-shaped convex part. 
     In addition, sixthly, the mechanical seal proposed by the present invention is characterized, in addition to any of the first through fifth characteristics, in that: a fixing means for fixing the baffle sleeve and collar is provided on the cylinder part of the baffle sleeve. 
     According to these characteristics, the baffle sleeve and collar can be fixed together by screwing in setscrews to prevent rattling of members during transport after preassembling the collar, baffle sleeve, etc., and during operation. 
     In addition, seventhly, the mechanical seal proposed by the present invention is characterized, in addition to any of the first through fifth characteristics, in that: a ring-shaped convex part with a tapered part on its outer periphery surface is provided on the outer periphery surface of the cylinder part of the baffle sleeve, in close proximity to the inner periphery surface of the cylindrical collar connected to one end of the bellows, while another tapered part is provided on the inner periphery surface of the collar in a manner facing the aforementioned tapered part; and these tapered parts are provided in such a way that they can contact each other by moving relative to each other in the axial direction, but do not interfere with each other during assembly. 
     According to these characteristics, the bolt for fixing the flange part on the equipment exterior side of the seal cover can be used to fix the tapered part of the ring-shaped convex part of the baffle sleeve with the tapered part of the collar in a manner contacting each other to prevent rattling of members without having to prepare any special fixing member during transport after preassembling the collar, baffle sleeve, etc. 
     Effects of Invention 
     The present invention provides excellent effects as described below: 
     (1) A baffle sleeve of roughly L-shaped cross-section is fixed on the equipment exterior side of the seal cover and extends on the inner periphery side of the seal ring, bellows, etc., where the baffle sleeve splits into a flange part and cylinder part, and accordingly the collar, bellows, retainer, seal ring, baffle sleeve cylinder part, damper, and other related parts can be preassembled in a reliable and controlled manner at the factory or service center, thereby requiring fewer member assembly steps during onsite engineering works. This not only improves the ease of assembly, but also reduces human errors during onsite engineering works. In addition, while traditionally carving a one-piece baffle sleeve with roughly an L-shaped cross-section from a round bar requires a material of “outer diameter of the flange part×length of the cylinder part” in size, and machining the round bar to change its cross-section to roughly an L-shape is a very wasteful exercise because the majority of the round bar must be shaved off, the baffle sleeve under the present invention is formed of separate materials constituting its flange part and cylinder part, respectively, and therefore the waste associated with the prior art can be eliminated. Furthermore, the mechanical seal proposed by the present invention requires a significantly smaller installation space on the equipment exterior side of the seal cover compared to the prior art, thereby saving assembly space. 
     (2) The flange part has a slit formed in one location in the circumferential direction and the inner periphery surface of the flange part is engaged with the outer periphery surface of the cylinder part, while the outer periphery surface of the flange part is engaged with the tapered surface for flange engagement provided on the equipment exterior side of the seal cover and, because the outer periphery surface of the flange part is fit along the tapered surface, the inner periphery surface of the flange part clamps the outer periphery surface of the cylinder part, and therefore fitting the flange part at the specified position exerts clamping force in the diametral direction so as to keep the flange part and cylinder part connected just like a one-piece baffle sleeve. As a result, a baffle sleeve sufficiently capable of withstanding vibration and other external disturbances can be obtained. 
     (3) The flange part has multiple bolt holes in the circumferential direction and is fixed on the equipment exterior side of the seal cover via a bolt, and accordingly the flange part can be fitted at the specified position by means of the bolt, while clamping force is exerted in the diametral direction to keep the flange part and cylinder part connected just like a one-piece baffle sleeve. 
     (4) The flange part has a part having a small cross-section area formed at a position on the opposite side of the slit in the circumferential direction, and accordingly elastic deformation can be achieved easily as the flange part shrinks along its diameter. 
     (5) A ring-shaped convex part is provided on the outer periphery surface of the cylinder part of the baffle sleeve, in close proximity to the inner periphery surface of the cylindrical collar connected to one end of the bellows, and accordingly vibration of the baffle sleeve can be damped quite effectively when the baffle sleeve is fixed on the seal cover, because the inner periphery surface of the collar is in close proximity to the outer periphery surface of the ring-shaped convex part. 
     (6) A fixing means for fixing the baffle sleeve and collar is provided on the cylinder part of the baffle sleeve, and accordingly the baffle sleeve and collar can be fixed together by screwing in setscrews to prevent rattling of members during transport after preassembling the collar, baffle sleeve, etc., and during operation. 
     (7) A ring-shaped convex part with a tapered part on its outer periphery surface is provided on the outer periphery surface of the cylinder part of the baffle sleeve, in close proximity to the inner periphery surface of the cylindrical collar connected to one end of the bellows, while another tapered part is provided on the inner periphery surface of the collar in a manner facing the aforementioned tapered part, and these tapered parts are provided in such a way that they can contact each other by moving relative to each other in the axial direction, but do not interfere with each other during assembly, and accordingly the bolt for fixing the flange part on the equipment exterior side of the seal cover can be used to fix the tapered part of the ring-shaped convex part of the baffle sleeve with the tapered part of the collar in a manner contacting each other to prevent rattling of members without having to prepare any special fixing member during transport after preassembling the collar, baffle sleeve, etc. 
    
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
         FIG. 1  Longitudinal section view showing an example of a mechanical seal conforming to Embodiment 1 of the present invention. 
         FIG. 2  Longitudinal section view showing another example of a mechanical seal conforming to Embodiment 1 of the present invention. 
         FIG. 3 ( a )  a longitudinal section view of the baffle sleeve in  FIGS. 1 and 2 , and (b) a front view of the flange part of the baffle sleeve in FIG. (a). 
         FIG. 4  Longitudinal section view showing an example of a mechanical seal conforming to Embodiment 2 of the present invention. 
         FIG. 5  Longitudinal section view showing an example of a mechanical seal conforming to Embodiment 3 of the present invention. 
         FIG. 6  Longitudinal section view showing the condition during transport of the collar, bellows, retainer, seal ring, and baffle sleeve of the mechanical seal conforming to Embodiment 3 of the present invention. 
         FIG. 7  Partial drawing explaining, by comparison, the assembly steps of a mechanical seal conforming to the present invention and that of a mechanical seal according to the prior art. 
         FIG. 8  Partial drawing explaining, by comparison, the assembly steps of a mechanical seal conforming to the present invention and that of a mechanical seal according to the prior art. 
         FIG. 9  Partial drawing explaining, by comparison, the assembly steps of a mechanical seal conforming to the present invention and that of a mechanical seal according to the prior art. 
         FIG. 10  Longitudinal section view showing a conventional mechanical seal of high-temperature bellows seal type. 
     
    
    
     MODES FOR CARRYING OUT THE INVENTION 
     Modes for carrying out a mechanical seal conforming to the present invention are explained in detail by referring to the drawings, but it should be noted that interpretations of the present invention are not limited to the following and various changes, modifications and improvements can be added according to the knowledge of those skilled in the art so long as they do not deviate from the scope of the present invention. 
     Embodiment 1 
     The mechanical seal conforming to Embodiment 1 of the present invention is explained by referring to  FIGS. 1 and 2 . 
       FIG. 1  is a longitudinal section view showing an example of a mechanical seal conforming to Embodiment 1 of the present invention, where, in  FIG. 1 , reference symbol  1  represents a housing of a shaft seal part in a pump or other equipment handling high-temperature liquid exceeding 200° C. in an oil refinery, petrochemical, steel, chemical, or other application, such as equipment handling hot oil in a vacuum distillation facility in an oil refinery plant, while reference symbol  2  represents a seal cover installed on the housing  1  by bolts or other fixing means (not illustrated). Note that the left side of the  FIG. 1  corresponds the equipment interior side, while the right side of the  FIG. 1  corresponds to the equipment exterior side (atmosphere side) 
     The mechanical seal shown in  FIG. 1  is a mechanical seal installed on a shaft seal part  4  formed between a rotational shaft  3  and housing  1  to seal a space between the rotational shaft  3  and housing  1 , wherein such mechanical seal has: a collar  6  installed on the equipment interior side of a seal cover  2 ; a bellows  7  connected to the collar  6 ; a retainer  8  connected to the bellows  7 ; a seal ring  9  shrink-fitted or press-fitted on the end face of the retainer  8 ; and a mating ring  10  installed on the rotational shaft  3  side. 
     The collar  6  is formed of metal and has a cylinder shape, and is installed on the equipment interior side of the seal cover  2  via a ring-shaped gasket  15 . 
     The bellows  7  is constituted by multiple metal diaphragm sheets that have been formed as wavy rings via stamping, etc., which are then arranged in line and the outer diameters and inner diameters of adjacent diaphragm sheets are alternately connected by means of gas welding, etc., to form an accordion-like cylinder shape as a whole, one end of which is integrally connected to the collar  6  side by means of gas welding, etc. 
     The retainer  8  is formed of metal and has a cylinder shape, and is integrally connected to the other end of the bellows  7  by means of gas welding, etc. The retainer  8  is made of the same material used for the bellows  7  or other material having roughly the same coefficient of thermal expansion. 
     Normally the retainer  8 , bellows  7 , and collar  6  are welded into one piece and then its entire surface is ion-plated uniformly to a thickness of no more than 10 μm using special chromium nitride, titanium nitride, or other corrosion-resistant, wear-proof material. This uniform corrosion resistance over the entire surface of the retainer  8 , bellows  7 , and collar  8  means that the corrosion resistance of ion-plating becomes the corrosion resistance of the entire structure, even when the material of any constituent part has lower corrosion resistance, which significantly reduces the limitations on material selection. 
     The seal ring  9  is formed of silicon carbide, carbon, other ceramics, etc., and has a cylinder shape, forming a seal surface  16  vertical to the axial line of the rotational shaft  3  on the sliding surface with the mating ring  10 . 
     The seal ring  9  is shrink-fitted or press-fitted on the end face of the retainer  8 , and the width of the seal end face on the side of the seal ring  9  opposite the mating ring is roughly the same as or slightly smaller than the width of the seal end face that slides against the mating ring  10 . 
     A cylindrical baffle sleeve  17  is installed at a specific interval on the inner periphery side of the seal ring  9 , retainer  8 , bellows  7 , and collar  6 , and this baffle sleeve  17  ensures quenching liquid supplied from a quenching liquid supply hole  35  provided in the seal cover  2  is guided to the seal surface  16 . The baffle sleeve  17  is made of stainless steel or other hard material or ion-plated to a thickness of no more than 10 μm using hard chromium plating, special chromium nitride, titanium nitride, or other corrosion-resistant, wear-proof material. 
     One or more cutouts (not illustrated) are provided on the inner periphery side of the retainer  8 . 
     On the other hand, the tip of the baffle sleeve  17  fixed on the seal cover  2  extends to near the seal end face of the seal ring  9  to form male teeth (not illustrated) that engage with the cutout (s) in the retainer  8  with a very small gap left in between, so as to form a clutch structure  18  constituted by the cutout(s) in the retainer  8  meshing with the teeth of the baffle sleeve  17  in a manner movable in the axial direction. Because of this structure, the sliding torque on the seal end face of the seal ring  9  is received by the baffle sleeve  17  and not transmitted to the bellows  7 , and consequently the bellows  7  will not be affected by any stick-slip occurring on the seal end face of the seal ring  9  as a result of unstable lubrication of the seal surface. 
     A damper  19  is provided between the outer periphery surface of the baffle sleeve  17  and inner periphery surface of the bellows  7  to damp the vibration of the bellows  7  should the bellows  7  vibrate. The damper  19  has a band shape, for example, and is installed in a ring-shaped groove  20  formed on the outer periphery surface of the baffle sleeve  17 . This way, fatigue of the bellows can be postponed to ensure durability. Additionally, one or more cutouts are provided in the outer periphery part of the damper  19  and inner periphery part of the retainer  8  to guide the quenching liquid supplied from the quenching liquid supply hole  35  to the seal surface  16  by means of the baffle sleeve  17 , so that a very small amount of liquid leaking from the seal surface  16  can be cleaned and discharged. 
       FIG. 2  is a longitudinal section view showing another example of a mechanical seal conforming to Embodiment 1 of the present invention, which is different from the mechanical seal shown in  FIG. 1  in that the end face of the retainer  8  hermetically contacts the end face of the seal ring  9  via a lap joint in between, but since the rest of the constitution is the same as in  FIG. 1 , redundant explanations are omitted. 
     The mechanical seal shown in  FIG. 2  is a mechanical seal installed on the shaft seal part  4  formed between the rotational shaft  3  and housing  1  to seal a space between the rotational shaft  3  and housing  1 , wherein such mechanical seal has: the collar  6  installed on the equipment interior side of the seal cover  2 ; the bellows  7  connected to the collar  6 ; a retainer  11  connected to the bellows  7 ; a seal ring  12  hermetically contacting the end face of the retainer  11  with a lap joint in between; and the mating ring  10  installed on the rotational shaft  3  side. 
     The seal ring  12  has a lapped seal end face on both ends and the seal ring  12  is structurally separate from the retainer  11 , while the end face on the seal ring  12  side of the retainer  11  also has a lapped seal end face, and both are sealed using a lap joint structure where lapped surfaces are hermetically sealed together. Since the seal ring  12  is structurally separate from the retainer  11 , the flatness of the seal end face of the seal ring  12  that slides against the mating ring  10  is not affected by any difference in thermal expansion even in a high-temperature ambience, and hermetic property is retained as a result. Any pressure deformation or thermal deformation of the retainer  11  itself has no bearing, either. Furthermore, there is no need for shrink fitting or press fitting, subsequent heat treatment, or any other special step, which means jigs for these steps are not required, either, leading to cost reduction and fewer man-hours. Moreover, the seal ring  12  can be replaced with ease. 
     The seal-side end face of the retainer  11  is hermetically contacting the seal end face of the seal ring  12  by means of the spring load of the bellows  7  and push force of fluid pressure, but since the seal ring  12  does not rotate, the seal end face of the retainer  11  is a virtually stationary sealing surface that does not slide by rotation. 
     A cutout is provided on the inner periphery side of the seal ring  12  and the clutch structure  18  constituted by the cutout meshing with the teeth of the baffle sleeve  17  in a manner movable in the axial direction is formed. 
     In addition, a ring-shaped concave part  14  is formed to partially shrink the outer diameter on the outer periphery surface of the retainer  11  and seal ring  12 , and an alignment case  13  for aligning the retainer  11  and seal ring  12  is installed in this concave part  14 . 
     The mechanical seal shown in  FIG. 2  is structured in such a way that its seal ring  12  and retainer  11  are separate, where the seal ring  12  and retainer  11  are sealed together via a lap joint structure, while the seal ring  12  and baffle sleeve  17  adopt a clutch structure to mesh with each other in a manner movable in the axial direction, and accordingly the sliding torque on the seal end face of the seal ring  12  is received by the baffle sleeve  17  and not transmitted to the bellows  7 , and consequently the bellows  7  will not be affected by any stick-slip occurring on the seal end face of the seal ring  12  as a result of unstable lubrication of the seal surface, due to free sliding at the lap joint. 
     As shown in  FIG. 3 , the baffle sleeve  17  used by the mechanical seals in  FIGS. 1 and 2  comprises a flange part  21  and cylinder part  22 , has a roughly L-shaped cross-section, and the flange part  21  and cylinder part  22  are separate. To be specific, the flange part  21  and cylinder part  22  are made of different members, respectively, and formed in such a way that an inner periphery surface  23  of the flange part  21  engages with an outer periphery surface  24  of the base end of the cylinder part  22 . Also, as shown in  FIGS. 1 and 2 , an outer periphery surface  25  of the flange part  21  is constituted so that it engages with a tapered surface for flange engagement  26  provided on the equipment exterior side of the seal cover  2 . Formed at the tip of the cylinder part  22  is the clutch structure  18  that meshes with a cutout in the retainer  8  in a manner movable in the axial direction (or clutch structure  18  that meshes with a cutout in the seal ring  12  in a manner movable in the axial direction in the case of the mechanical seal in  FIG. 2 ), while the ring-shaped groove  20  is formed on the outer periphery surface of the cylinder part  22  for placing the damper  19  for damping the vibration of the bellows  7  along the inner periphery surface of the bellows  7 . 
     As shown in  FIG. 3 ( b ) , the flange part  21  has a slit  27  formed in one location in the circumferential direction so that, when the flange part  21  engages with the tapered surface for flange engagement  26 , it is pressed from the outer side toward the center and the diameter of the flange part  21  shrinks as a result. In addition, the flange part  21  has multiple bolt holes  28  drilled and arranged in the circumferential direction so that it can be fixed onto the equipment exterior side of the seal cover  2  via a bolt  29 . Furthermore, the flange part  21  has multiple separation tapped holes  30  drilled and arranged in the circumferential direction for easy separation of the flange part  21  from the seal cover  2 . 
     Moreover, the flange part  21  has a part having a small cross-section area, such as a cutout  31  or through hole  32 , formed at a position on the opposite side of the slit  27  in the circumferential direction, to facilitate elastic deformation when the flange part  21  shrinks along its diameter. 
     When the outer periphery surface  25  of the flange part  21  engages with the tapered surface for flange engagement  26  provided on the equipment exterior side of the seal cover  2  while the inner periphery surface  23  of the flange part  21  is engaged with the outer periphery surface  24  of the cylinder part  22 , and the bolt  29  is then tightened, the flange part  21  shrinks along its diameter to create a condition where its inner periphery surface  23  is clamping the outer periphery surface  24  of the cylinder part  22 , or a condition of interference fit. As a result, the flange part  21  and cylinder part  22  are integrally fixed on the seal cover  2 . 
     Embodiment 2 
     The mechanical seal conforming to Embodiment 2 of the present invention is explained by referring to  FIG. 4 . 
     The mechanical seal conforming to Embodiment 2 is different from Embodiment 1 in terms of baffle sleeve shape/structure, but the remainder is the same as in  FIG. 1 , and therefore in  FIG. 4 , the same symbols as those in  FIG. 1  represent the corresponding members. The following primarily explains the differences from Embodiment 1. 
     In  FIG. 4 , a baffle sleeve  37  comprises a flange part  38  and cylinder part  39 , has a roughly L-shaped cross-section, and the flange part  38  and cylinder part  39  are separate, where the basic structure is the same as that of the baffle sleeve  17  in Embodiment 1. 
     The baffle sleeve  37  has a ring-shaped convex part  40  in close proximity to the inner periphery surface of the collar  6 . This ring-shaped convex part  40  projects in the diametral direction from the outer periphery surface of the baffle sleeve  37 , and in the axial direction, it is provided at a position facing the inner periphery surface on the seal cover  2  side of the collar  6 . 
     Due to the ring-shaped convex part  40  provided on the baffle sleeve  37 , the inner periphery surface of the collar  6  comes in close proximity to the outer periphery surface of the ring-shaped convex part  40  when the baffle sleeve  37  is fixed on the seal cover  2 , which is very effective in damping the vibration of the baffle sleeve  37 . 
     Axial through-cutouts are provided at multiple positions on the ring-shaped convex part  40  in the circumferential direction so that quenching liquid supplied from the quenching liquid supply hole  35  can be guided toward the seal surface  16  side along the baffle sleeve  37 . 
     Furthermore, tapped holes  41  are provided in the cylinder part  39  of the baffle sleeve  37  at positions facing the inner periphery surface of the collar  6 . In  FIG. 4 , two tapped holes  41  are provided in the baffle sleeve  37  in the axial direction, but it is sufficient that at least one hole is provided in the axial direction, but preferably multiple holes are provided at an equal pitch in the circumferential direction. Setscrews  42  are screwed into these tapped holes  41  from the inner side of the baffle sleeve  37  in the diametral direction to contact with the inner periphery surface of the collar  6 . By screwing in the setscrews  42 , the baffle sleeve  37  is fixed with the collar  6  to prevent rattling of members during transport after preassembling the collar  6 , baffle sleeve  37 , etc., and also during operation. 
     Embodiment 3 
     The mechanical seal conforming to Embodiment 3 of the present invention is explained by referring to  FIGS. 5 and 6 . 
     The mechanical seal conforming to Embodiment 3 is different from Embodiment 1 in terms of baffle sleeve and collar shapes, but the remainder is the same as in  FIG. 1 , and therefore in  FIGS. 5 and 6 , the same symbols as those in  FIG. 1  represent the corresponding members. The following primarily explains the differences from Embodiment 1. 
     In  FIG. 5 , the baffle sleeve  37  comprises the flange part  38  and cylinder part  39 , has a roughly L-shaped cross-section, and the flange part  38  and cylinder part  39  are separate, where the basic structure is the same as that of the baffle sleeve  17  in Embodiment 1. 
     The baffle sleeve  37  has a ring-shaped convex part  45  in close proximity to the inner periphery surface of the collar  6 . This ring-shaped convex part  45  projects in the diametral direction from the outer periphery surface of the baffle sleeve  37 , and in the axial direction, it is provided at a position facing the inner periphery surface on the seal cover  2  side of the collar  6 . 
     Also, the outer periphery surface of the ring-shaped convex part  45  is formed in a tapered shape to provide a tapered part  46 , and another tapered part  47  is provided on the inner periphery surface of the collar  6  in a manner facing the aforementioned tapered part  46 . These tapered parts  46 ,  47  are provided in such a way that they can contact each other by moving relative to each other in the axial direction, but do not interfere with each other during assembly. In  FIG. 5 , the tapered parts  46 ,  47  form tapered shapes that decrease in diameter toward the equipment interior side of the seal cover  2 , and when the bolt  29  is tightened, the collar  6  moves right while the baffle sleeve  37  moves left and because of this relative movement, the tapered parts  46 ,  47  contact each other and the collar  6  and baffle sleeve  37  are fixed together as a result. 
     In addition, axial through-cutouts are provided at multiple positions on the ring-shaped convex part  45  in the circumferential direction so that quenching liquid supplied from the quenching liquid supply hole  35  can be guided toward the seal surface  16  side along the baffle sleeve  37 . 
     Although  FIG. 5  shows only the ring-shaped convex part  45 , the present invention is not limited to the foregoing and the ring-shaped convex part  40  in Embodiment 2 can be used together. 
       FIG. 6  is a longitudinal section view showing the condition during transport of the collar  6 , bellows  7 , retainer  8 , seal ring  9 , and baffle sleeve  37 , where the bolt  29  is tightened to cause the tapered parts  46 ,  47  to contact each other and fix the collar  6  and baffle sleeve  37  together. Because the tapered part  46  is provided on the outer periphery surface of the ring-shaped convex part  45  on the baffle sleeve  37  and the tapered part  47  is provided on the inner periphery surface of the collar  6  in a manner facing the tapered part  46 , and because these tapered parts  46 ,  47  are provided in such a way that they can contact each other by moving relative to each other in the axial direction, but do not interfere with each other during assembly, the bolt  29  for fixing the flange part  38  on the equipment exterior side of the seal cover  2  can be used to fix the tapered part  46  of the ring-shaped convex part  45  of the baffle sleeve  37  with the tapered part  47  of the collar  6  in a manner contacting each other to prevent rattling of members without having to prepare any special fixing member during transport after preassembling the collar  6 , baffle sleeve  37 , etc. 
     Next, the assembly steps of the mechanical seal conforming to Embodiment 1 of the present invention, such as the mechanical seal shown in  FIG. 1 , are explained by comparing them against those of the mechanical seal according to the prior art by referring to  FIGS. 7 to 9 . 
     In the case of Embodiment 3, supplemental explanation is provided regarding the differences from Embodiment 1. 
     (1) Preassembly 
     With the mechanical seal proposed by the present invention, the collar  6 , bellows  7 , retainer  8 , seal ring  9 , cylinder part  22  of the baffle sleeve  17 , and damper  19  are preassembled in a reliable and controlled manner at a factory or service center (hereinafter referred to as “factory, etc.”) (the preassembled members are hereinafter referred to as “preassembled members”), thereby requiring fewer member assembly steps during onsite engineering works. 
     With the mechanical seal according to the prior art, on the other hand, the collar  54 , bellows  55 , retainer  56 , seal ring  57 , and other seal members on the stationary side can be installed with the one-piece baffle sleeve  59  with roughly an L-shaped cross-section only from the opposite side of the seal cover  60 , and therefore the seal members on the stationary side cannot be preassembled with the baffle sleeve  59 . 
     With the mechanical seal conforming to Embodiment 3 of the present invention, the collar  6 , bellows  7 , retainer  8 , seal ring  9 , and baffle sleeve  37  are preassembled in a fixed state via the tapered parts  46 ,  47 , when the bolt  29  is tightened, as shown in  FIG. 6 . 
     (2) Initial State Onsite, Etc. 
     With the mechanical seal proposed by the present invention, the preassembled members and gasket  15  are placed on the equipment interior side of the seal cover  2 , while the flange part  21  of the baffle sleeve  17  and bolt  29  are placed on the equipment exterior side. 
     With the mechanical seal according to the prior art, on the other hand, the seal members on the stationary side, damper  61 , and gasket  62  are placed on the equipment interior side of the seal cover  60 , while the one-piece baffle sleeve  59  and bolt  63  are placed on the equipment exterior side. 
     As shown in the explanation drawing, the installation space L′ for the mechanical seal conforming to the present invention is significantly smaller than the installation space L for the mechanical seal according to the prior art. This is to say that the mechanical seal conforming to the present invention can be assembled in a smaller space. 
     With the mechanical seal conforming to Embodiment 3 of the present invention, the bolt  29  shown in  FIG. 6  is loosened to separate the cylinder part  39  and flange part  38  of the baffle sleeve  37 , with the preassembled members and gasket  15  placed on the equipment interior side of the seal cover  2 , and flange part  38  of the baffle sleeve  37  and bolt  29  placed on the equipment exterior side. 
     (3) Installation of Secondary Seal 
     With both the mechanical seal conforming to the present invention and mechanical seal according to the prior art, a secondary seal member, or specifically the gasket  15  or gasket  62 , is installed on the seal cover side. 
     (4) Insertion of Sleeve 
     With the mechanical seal according to the prior art, the one-piece baffle sleeve  59  placed on the equipment exterior side of the seal cover  60  is inserted into the seal cover  60 . With the mechanical seal conforming to the present invention, on the other hand, the cylinder part  22  of the baffle sleeve  17  is preassembled and therefore insertion of the baffle sleeve  17  into the seal cover  2  is no longer required. 
     (5) Installation of Related Parts 
     With the mechanical seal according to the prior art, the damper  61 , which is a related part, is wrapped around the baffle sleeve  59  from the equipment interior side of the seal cover  60 , and then the seal members on the stationary side are inserted into the outer diameter side of the baffle sleeve  59 , but this process is a little difficult. With the mechanical seal conforming to the present invention, on the other hand, the corresponding damper  19  as an associated part is preassembled and therefore installation of the damper  19  into the cylinder part  22  of the baffle sleeve  17  is no longer required, which eliminates installation errors, non-installation, etc., and the designed performance can be ensured. 
     (6) Installation of Seal 
     With the mechanical seal conforming to the present invention, the preassembled members including the cylinder part  22  of the baffle sleeve  17  and damper  19  are directly installed on the seal cover  2  from the equipment interior side. 
     With the mechanical seal according to the prior art, on the other hand, the seal members on the stationary side are inserted into the outer diameter side of the baffle sleeve  59  while the damper  61  remains wrapped around the baffle sleeve  59 , which makes it difficult to ensure accurate installation. 
     (7) Fastening of Bolt 
     With the mechanical seal conforming to the present invention, the flange part  21  of the baffle sleeve  17  is positioned with the tapered surface  26  of the seal cover  2  to fasten the bolt  29 . As the bolt  29  is tightened, the flange part  21  shrinks along its diameter and its inner periphery surface clamps the outer periphery surface of the cylinder part of the baffle sleeve  17 , effectively creating a condition of interference fit. As a result, the flange part  21  and cylinder part are integrally fixed on the seal cover  2 . 
     With the mechanical seal according to the prior art, on the other hand, the bolt  63  is fastened to the seal cover  60  via the flange part of the baffle sleeve  59 . 
     The effects of the mechanical seal conforming to each embodiment of the present invention are as follows: 
     (1) The baffle sleeve  17  or  37  conforming to the present invention splits into the flange part  21  or  38  and cylinder part  22  or  39 , and accordingly the collar  6 , bellows  7 , retainer  8 , seal ring  9 , baffle sleeve  17  or  37  cylinder part  22  or  39 , and damper  19  can be preassembled in a reliable and controlled manner at a factory, etc., thereby requiring fewer member assembly steps during onsite engineering works. This not only improves the ease of assembly, but also reduces human errors during onsite engineering works. In addition, while traditionally carving a one-piece baffle sleeve with roughly an L-shaped cross-section from a round bar requires a material of “outer diameter of the flange part×length of the cylinder part” in size, and machining the round bar to change its cross-section to roughly an L-shape is a very wasteful exercise because the majority of the round bar must be shaved off, the baffle sleeve  17  or  37  under the present invention is formed of separate materials constituting its flange part  21  or  38  and cylinder part  22  or  39 , respectively, and therefore the waste associated with the prior art can be eliminated. 
     (2) With the mechanical seal conforming to the present invention, the installation space on the equipment exterior side of the seal cover  2  can be made significantly smaller than under the prior art, which allows for assembly in a smaller space. 
     (3) With the baffle sleeve  17  or  37  conforming to the present invention, the slit  27  is formed in one location of the flange part  21  or  38  in the circumferential direction, where the inner periphery surface of the flange part  21  or  38  engages with the outer periphery surface of the cylinder part  22  or  39 , while the outer periphery surface of the flange part  21  or  38  engages with the tapered surface for flange engagement  26  provided on the equipment exterior side of the seal cover  2 , so when the outer periphery surface of the flange part  21  or  38  is fit along the tapered surface  26 , the inner periphery surface of the flange part  21  or  38  clamps the outer periphery surface of the cylinder part  22  or  39  and, accordingly, fitting the flange part  21  or  38  into the specified position of the seal cover  2  exerts clamping force in the diametral direction to keep the flange part  21  or  38  and cylinder part  22  or  39  connected just like a one-piece baffle sleeve. As a result, a baffle sleeve sufficiently capable of withstanding vibration and other external disturbances can be obtained. 
     (4) The flange part  21  or  38  of the baffle sleeve  17  or  37  conforming to the present invention has multiple bolt holes  28  in the circumferential direction and is fixed on the equipment exterior side of the seal cover  2  via the bolt  29 , which means that the flange part  21  or  38  can be fit in the specified position by means of the bolt  29 , while clamping force is exerted in the diametral direction to keep the flange part  21  or  38  and cylinder part  22  or  39  connected just like a one-piece baffle sleeve. 
     (5) The flange part  21  or  38  of the baffle sleeve  17  or  37  conforming to the present invention has a part having a small cross-section area formed at a position on the opposite side of the slit  27  in the circumferential direction, which facilitates elastic deformation as the flange part  21  or  38  shrinks along its diameter. 
     (6) With the baffle sleeve  37  conforming to Embodiment 2, the ring-shaped convex part  40  is provided and accordingly vibration of the baffle sleeve  37  can be damped quite effectively when the baffle sleeve  37  is fixed on the seal cover  2 , because the inner periphery surface of the collar  6  is in close proximity to the outer periphery surface of the ring-shaped convex part  40 . 
     (7) With the baffle sleeve  37  conforming to Embodiment 2, the tapped holes  41  and setscrews  42  are provided at positions facing the inner periphery surface of the collar  6 , and accordingly by screwing in the setscrews  42 , the baffle sleeve  37  is fixed with the collar  6  to prevent rattling of members during transport after preassembling the collar  6 , baffle sleeve  37 , etc., and also during operation. 
     (8) With Embodiment 3, the ring-shaped convex part with a tapered part on its outer periphery surface is provided on the outer periphery surface of the cylinder part of the baffle sleeve, in close proximity to the inner periphery surface of the cylindrical collar connected to one end of the bellows, while another tapered part is provided on the inner periphery surface of the collar in a manner facing the aforementioned tapered part, and these tapered parts are provided in such a way that they can contact each other by moving relative to each other in the axial direction, but do not interfere with each other during assembly, and accordingly the bolt  29  for fixing the flange part  38  on the equipment exterior side of the seal cover  2  can be used to fix the tapered part  46  of the ring-shaped convex part  45  of the baffle sleeve  37  with the tapered part  47  of the collar  6  in a manner contacting each other to prevent rattling of members without having to prepare any special fixing member during transport after preassembling the collar  6 , baffle sleeve  37 , etc. 
     REFERENCE SIGNS 
     
         
         
           
               1  Housing 
               2  Seal cover 
               3  Rotational shaft 
               4  Shaft seal part 
               6  Collar 
               7  Bellows 
               8  Retainer 
               9  Seal ring 
               10  Mating ring 
               11  Retainer 
               12  Seal ring 
               13  Alignment case 
               14  Concave part 
               15  Gasket 
               16  Seal surface 
               17  Baffle sleeve 
               18  Clutch structure 
               19  Damper 
               20  Ring-shaped groove 
               21  Flange part 
               22  Cylinder part 
               23  Inner periphery surface 
               24  Outer periphery surface at base end of cylinder part 
               25  Outer periphery surface of flange part 
               26  Tapered surface for flange engagement 
               27  Slit 
               28  Bolt hole 
               29  Bolt 
               30  Tapped hole 
               31  Slit 
               32  Through hole 
               35  Quenching liquid supply hole 
               37  Baffle sleeve 
               38  Flange part 
               39  Cylinder part 
               40  Ring-shaped convex part 
               41  Tapped hole 
               42  Setscrew 
               45  Ring-shaped convex part 
               46  Tapered part on outer periphery surface of ring-shaped convex part 
               47  Tapered part on inner periphery surface of collar