JP6386915B2 - mechanical seal - Google Patents

Description

  The present invention comprises a stationary sealing ring provided in a seal case, a sleeve that is detachably inserted and fixed to a rotary shaft that penetrates the seal case, and a rotary sealing ring provided in the sleeve, The present invention relates to a mechanical seal configured to shield and seal a sealed fluid region and an unsealed fluid region at a relative rotational sliding contact portion of a ring.

  As disclosed in Patent Documents 1 to 4, as a conventional mechanical seal, a seal case attached to a shaft seal portion casing of a rotating device, and a sleeve detachably inserted and fixed to a rotary shaft that penetrates the seal case A rotary seal ring fixed to the sleeve, a static seal ring held axially movable in the seal case, and a stationary seal ring interposed between the seal case and the static seal ring, into the rotary seal ring. A pressurizing spring member, and an in-machine region that is a sealed fluid region and an out-of-machine air region that is a non-sealed fluid region by a relative rotational sliding contact action of a sealed end surface that is an opposite end surface of both sealing rings. Those configured to shield are well known.

  Thus, in such a mechanical seal, the fixing ring is fitted to the base end portion of the sleeve that protrudes outside the sealing case, and the fixing ring is fixed to the rotating shaft and the sleeve with a screw or the like. Is fixed to the rotating shaft so as to be detachable.

  That is, in the mechanical seal disclosed in Patent Document 1 (hereinafter referred to as “first conventional mechanical seal”) and the mechanical seal disclosed in Patent Document 2 (hereinafter referred to as “second conventional mechanical seal”), a fixing ring The sleeve fixing portion that fits to the base end portion of the sleeve and the rotating shaft fixing portion that fits to the rotating shaft are integrally formed in a shape continuous in the axial direction, and screwed into the sleeve fixing portion. The fixing ring is fixed to the sleeve by tightening the plurality of sleeve fixing screws to the sleeve, and the fixing ring is fixed to the rotating shaft by tightening the rotating shaft fixing screws screwed into the rotating shaft fixing portion to the rotating shaft. It is configured to be fixed to.

  Further, in the mechanical seal disclosed in Patent Document 3 (hereinafter referred to as “third conventional mechanical seal”), a plurality of engagement holes arranged in parallel in the circumferential direction on the proximal end portion of the sleeve fitted with the fixing ring, and The screw insertion holes are formed in parallel in the circumferential direction, and the engagement pins inserted into the engagement holes are inserted into the insertion holes formed in the fixation ring, so that the fixing ring cannot be rotated relative to the proximal end of the sleeve. In addition, a plurality of rotating shaft fixing screws, which are inserted into the rotating shafts, are arranged at the same positions as the engaging pins and are screwed into the fixing rings, are inserted into the screw insertion holes. The sleeve is fixed to the rotating shaft via the fixing ring by being inserted into the rotating shaft and then tightened to the rotating shaft.

  Further, in the mechanical seal disclosed in Patent Document 4 (hereinafter referred to as “fourth conventional mechanical seal”), a plurality of screw insertion holes arranged in parallel in the circumferential direction at the proximal end portion of the sleeve fitted with the fixing ring. Then, the fixing ring is fixed to the sleeve by tightening the sleeve fixing screw screwed to the fixing ring to the sleeve, and the axial position is set to the same position as the sleeve fixing screw and screwed to the fixing ring. A plurality of combined rotating shaft fixing screws are inserted into the screw insertion holes and then tightened to the rotating shaft, whereby the sleeve is fixed to the rotating shaft via the fixing ring.

Japanese Patent Laid-Open No. 07-12238 JP 2010-209937 A JP 2010-216587 A JP 2005-048818 A

  However, in the first and second conventional mechanical seals, the fixing ring is configured to screw the rotating shaft fixing screw and the sleeve fixing screw at a predetermined interval in the axial direction, and the rotating shaft to which the rotating shaft fixing screw is screwed. Since it is long in the axial direction consisting of a fixing portion and a sleeve fixing portion to which a sleeve fixing screw is screwed, the sleeve portion (the base end portion of the sleeve and a fixing ring fixed thereto) is moved out of the seal case. The protruding amount of becomes extremely large. On the other hand, in many rotating devices, the installation space of the mechanical seal is limited, and generally the space outside the seal case when the mechanical seal is installed is small. Therefore, in the first and second conventional mechanical seals, as described above, since the sleeve portion protrudes greatly outside the seal, it is difficult to install the rotary seal device where the installation space of the mechanical seal is limited and can be applied. Rotating equipment is greatly limited.

  In contrast, in the third and fourth conventional mechanical seals, the axial position of the rotary shaft fixing screw and the engaging pin or sleeve fixing screw are the same, and the axial length of the fixing ring can be reduced. The sleeve portion projecting out of the seal case (the base end portion of the sleeve and the fixing ring fixed thereto) is small, and there is no problem as described above.

  However, in the third and fourth conventional mechanical seals, a plurality of engagement holes and screw insertion holes are formed in parallel in the circumferential direction at the same axial position in the sleeve, so that the sleeve strength is reduced, The fixing strength of the sleeve to the rotating shaft is reduced. In particular, in the third conventional mechanical seal, the sleeve and the fixing ring are fixed by the engaging action of the engaging pin. Therefore, the connection between the sleeve and the fixing ring is unstable, and the reliability of fixing the sleeve is low. .

  In the first, second, and fourth conventional seals, the fixing ring is fixed to the sleeve by the tightening force of the sleeve fixing screw to the sleeve, so that the fixing ring is fixed to increase the fixing strength of the fixing ring to the sleeve. If the tightening force of the screw is increased, the sleeve may be distorted, and the thickness (diameter thickness) of the sleeve must be increased more than necessary.

  An object of the present invention is to solve the above-described problems in the first to fourth conventional mechanical seals and to provide a mechanical seal capable of easily and reliably fixing a sleeve to a rotating shaft. It is what.

  The present invention includes a stationary seal ring provided in a seal case, a sleeve detachably inserted and fixed to a rotary shaft that penetrates the seal case and the stationary seal ring, and a rotary seal ring provided in the sleeve. In the mechanical seal configured to shield and seal the in-machine region and the out-of-machine region at the relative rotational sliding contact portions of both seal rings, in order to achieve the above-described purpose, in particular, a sleeve inserted through the rotating shaft is provided. An engagement ring that is engaged and held at the base end of the sleeve so as not to be relatively movable in the axial direction, a fixing ring that is inserted through the rotation shaft so as to face the engagement ring, and screwed to fix the fixing ring to the rotation shaft The fixing screw and the connecting screw for connecting the two rings so as not to move relative to each other in the axial direction are fixed to the rotating shaft.

  In a preferred embodiment of such a mechanical seal, a plurality of recesses are formed on the outer peripheral surface of the sleeve at predetermined intervals in the circumferential direction, and the recesses are engaged with the inner peripheral surface of the engagement ring. A convex portion is formed, and the engagement ring is engaged and held by the sleeve so as not to be relatively movable in the axial direction and to be relatively non-rotatable by the engagement of the concave and convex portions. Further, the engagement ring is divided into two in the radial direction, and each of the divided portions is connected to the fixing ring by a connection screw. In addition, the seal is loaded at one end of the sleeve with a tapered portion having an opening larger than the outer diameter of the rotating shaft portion through which the sleeve is inserted and gradually reducing the diameter from the opening toward the other end of the sleeve. A concave portion is formed, and an annular seal member made of an elastic material loaded in the seal loading concave portion is loaded, and the annular seal member is pushed between the tapered portion and the rotating shaft by the connection of the connecting screws of the two rings. It is preferable that the gap between the sleeve and the rotating shaft be sealed.

  The mechanical seal of the present invention connects the engagement ring engaged with the base end portion of the sleeve so as not to be relatively movable in the axial direction and the fixing ring fixed to the rotating shaft with a fixing screw with a connecting screw. Since it is configured to be removably fixed to the rotating shaft, it is necessary to screw the rotating shaft fixing screw and the sleeve fixing screw into the fixing ring at two positions spaced apart in the axial direction. Compared with the first and second conventional mechanical seals, the length of the sleeve and the fixing ring in the axial direction can be reduced, so that the mechanical seal can be mounted well on a rotating device in which the space for installing the mechanical seal is limited. Further, in the mechanical seal of the present invention, since it is not necessary to provide a through hole for fixing the engagement ring or the fixing ring to the sleeve, a plurality of the seals are arranged in parallel in the circumferential direction at the same axial position. Unlike the third and fourth conventional mechanical seals that need to form through holes (engagement holes and screw insertion holes), the sleeve and the fixing ring The sleeve can be firmly fixed to the rotating shaft as compared with the third conventional mechanical seal that is fixed by the engaging action of the engaging pin. Further, in the mechanical seal of the present invention, as compared with the first, second and fourth conventional mechanical seals, the fixing ring is fixed to the sleeve by tightening the sleeve fixing screw to the sleeve. By tightening, the sleeve is not distorted and the thickness of the sleeve can be reduced.

  Therefore, according to the present invention, the problems in the first to fourth conventional mechanical seals as described at the beginning can be solved, and the fixing of the sleeve to the rotary shaft can be easily and reliably performed in a stable state. It is possible to provide a mechanical seal that can exhibit a mechanical seal function appropriately and satisfactorily.

FIG. 1 is a cross-sectional view showing an example of a mechanical seal according to the present invention (the cross section is taken along the line II in FIG. 3). FIG. 2 is an enlarged detailed view showing the main part of FIG. FIG. 3 is a sectional view taken along line III-III in FIG. 4 is a cross-sectional view taken along line IV-IV in FIG. FIG. 5 is a cross-sectional view corresponding to FIG. 2 showing a part of the assembly process of the mechanical seal according to the present invention. FIG. 6 is a cross-sectional view corresponding to FIG. 1 showing a modification of the mechanical seal according to the present invention. FIG. 7 is an enlarged detailed view showing the main part of FIG.

    Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

  FIG. 1 is a cross-sectional view showing an example of a mechanical seal according to the present invention (the cross section is taken along the line II in FIG. 3), and FIG. 2 is a detailed view showing an enlarged main part of FIG. 3 is a cross-sectional view taken along line III-III in FIG. 2, FIG. 4 is a cross-sectional view taken along line IV-IV in FIG. 2, and FIG. 5 corresponds to FIG. 2 showing a part of the assembly process of the mechanical seal. FIG.

  A mechanical seal M shown in FIG. 1 is installed in a rotary device such as a pump that handles a high-temperature fluid such as hot oil, and includes a seal case 2 attached to a shaft seal casing 1 of the rotary device, and a shaft seal casing. 1, a sleeve 4 that is detachably inserted into and fixed to a rotating shaft 3 that protrudes out of the rotating device through the seal case 2, a rotary seal ring 5 provided on the sleeve 4, and a seal case 1. A stationary sealing ring 6, and is an outer peripheral side region of the relative rotational sliding contact portions 5 a, 6 a due to the relative rotational sliding contact action of the sealing end surfaces 5 a, 6 a that are opposite end surfaces of both sealing rings 5, 6. The sealed fluid region A and the non-sealed fluid region B which is the inner peripheral side region thereof are shield-sealed, and a stationary side sealing element M1 configured by a sealing case 2 and a stationary sealing ring 6 provided on the sealing case 2 and the like. And sleeve 4 and this A rotary side sealing element M2 constituted by a rotary seal ring 5 or the like provided on the shaft is integrally connected by a set claw 7 when the mechanical seal M is attached to or detached from the shaft seal casing 1 and the rotary shaft 3. Cartridge type. In this example, the sealed fluid region A is an internal region (in-machine region) of the rotating device and a high-pressure high-temperature fluid region, and the non-sealed fluid region B is an external region (external region) of the rotating device. It is an atmospheric region. In the following description, front and rear mean the left and right in FIGS. Moreover, the side of both the sealing rings 5 and 6 is referred to as a distal end side, and the opposite side is referred to as a proximal end side.

  As shown in FIG. 1, the seal case 2 protrudes from the case main body 21 attached with the front end portion (rear end portion) 21a in contact with the shaft seal casing 1 and the axially intermediate portion of the inner peripheral surface thereof. The baffle 22 attached to the provided annular convex portion 21b, the flange 23 attached to the base end portion (front end portion) 21c of the case body 21, and the annular closing plate 24 attached to the base end portion (front end portion). It is a metal cylindrical structure consisting of The case main body 21 has a cylindrical shape in which the inner diameter of the distal end portion 21a is substantially matched with the inner diameter of the shaft seal casing 1 and the inner diameter of the annular convex portion 21b is smaller than the inner diameters of the distal end portion 21a and the base end portion 21c. The baffle 22 is attached to the base end portion (front end portion) of the annular convex portion 21b of the case body 21, and is sealed from the inner peripheral portion with a gap between the baffle 22 and the inner peripheral portion of the annular convex portion 21b. It is a thin cylindrical shape that extends in the axial direction to the vicinity of the inner periphery of the relative rotational sliding contact portions 5a, 6a of the rings 5, 6. The flange 23 is an annular body having an annular wall 23 a that protrudes inward from the inner peripheral portion of the distal end. Between the annular wall 23 a and an annular closing plate 24 attached to the proximal inner peripheral portion of the flange 23. An annular secondary seal space 25 is formed. The seal case 2 is moved in the axial direction by attaching and detaching nuts 1b that are screwed into a plurality of bolts 1a (only one is shown) protruding in the axial direction from the shaft seal casing 1 to be axially sealed. It can be attached to and removed from the casing 1.

  As shown in FIG. 1, the sleeve 4 is inserted and fixed to the rotary shaft 3 with a base end portion (front end portion) 41 protruding outside the seal case 2 and a tip end portion 42 protruding into the shaft seal casing 1. An annular flange 43 having an outer diameter slightly smaller than the inner diameter of the shaft seal casing 1 is integrally formed at the tip end portion 42. On the outer peripheral surface of the base end portion 41 of the sleeve 4, an annular recess 44 is formed which is located at a boundary portion (a portion corresponding to the closing plate 24) with the sleeve portion in the seal case 2. As described above, by engaging a plurality of (only one shown) set claws 7 attached to the base end surface of the seal case 2 (the base end surface of the flange 23) with the annular recess 44, the seal case 2 and the sleeve 4 That is, the stationary side sealing element M1 including the seal case 2 and the rotary side sealing element M2 including the sleeve 4 are integrally connected in the same form as the assembly form of the mechanical seal M.

  As shown in FIGS. 1 to 4, the sleeve 4 is inserted and fixed to the rotary shaft 3 by fixing means including an engaging ring 8, a fixing ring 9, a connecting screw 10, and a fixing screw 11.

  That is, the engagement ring 8 is a metal annular body engaged with the base end portion 41 of the sleeve 4 so as not to be relatively movable in the axial direction and to be relatively non-rotatable, and in the axial direction at equal intervals in the circumferential direction. A plurality of screw holes 8a penetrating therethrough are formed. Further, as shown in FIGS. 1 to 3, the outer peripheral surface of the base end portion 41 of the sleeve 4 is located on the sleeve base end side with respect to the annular recess 44, and a plurality of engagements are provided at predetermined intervals in the circumferential direction. A concavity 45 is formed. Further, a plurality of engaging convex portions 8 b that engage with the respective engaging concave portions 45 are formed on the inner peripheral surface of the engaging ring 8. As shown in FIGS. 2 and 3, each engagement recess 45 has a semicircular shape (cross section) perpendicular to the axis of the sleeve 4 and a cross section (longitudinal section) passing through the axis. A rectangular shape having a width that substantially matches the thickness (length in the axial direction) of the coupling ring 8, and each engaging convex portion 8 b has a sectional shape that substantially matches the sectional shape of each engaging concave portion 45. It is. Therefore, by engaging each engagement convex portion 8 b with each engagement concave portion 45, the engagement ring 8 is fitted and held on the base end portion 41 of the sleeve 4 so as not to be relatively movable in the axial direction and not relatively rotatable.

  Incidentally, as shown in FIG. 3, the engagement ring 8 is divided into two (two equal parts) in the radial direction, and at least one screw hole 8a and an engagement convex portion 8b are formed in each divided portion 8A. Yes. In this example, as shown in FIG. 3, four engagement recesses 45 are formed in the proximal end portion 41 of the sleeve 4 at equal intervals in the circumferential direction. Three screw holes 8a and two engaging projections 8b are formed.

  As shown in FIGS. 1 and 2, the fixing ring 9 includes a main body portion 91 inserted through the rotary shaft 3, a fitting portion 92 that protrudes from the outer peripheral portion thereof and engages with the proximal end portion 41 of the sleeve 4, and the outer periphery thereof. It is a metal ring-shaped body comprising a flange portion 93 protruding from the portion and fitted to the outer peripheral portion of the engagement ring 8.

  As shown in FIGS. 2 and 4, a plurality of screw holes 91 a penetrating in the radial direction at equal intervals in the circumferential direction are formed in the main body portion 91 of the fixing ring 9. As shown in FIG. 2 and FIG. 4, the base end surface and the inner and outer circumferences of the main body portion 91 are provided between the portion of the main body portion 91 where the screw holes 91 a are formed and the portion where the adjacent screw holes 91 a are formed. A recess 91b is formed in the surface.

  As shown in FIGS. 2 and 4, the main body portion 91 and the fitting portion 92 of the fixing ring 9 have a plurality of screw insertion holes 94 that coincide with the screw holes 8 a of the engagement ring 8 and penetrate in the axial direction. Is formed. As shown in FIGS. 2 and 4, each screw insertion hole 94 is opened to each recess 91 b formed in the main body 91 of the fixing ring 9.

  Thus, the sleeve 4 is fixed to the rotating shaft 3 by the fixing means 8 to 11 as follows.

  That is, the sleeve 4 is inserted through the rotary shaft 3 to be positioned at a predetermined position (a position where the sleeve 4 is connected to the seal case 2 by the set claw 7), and the fixing ring 9 is inserted through the rotary shaft 3. Next, the two split portions 8A of the engagement ring 8 are moved in the axial direction relative to the proximal end portion 41 of the sleeve 4 in an annular shape by engaging the respective engagement projections 8b with the engagement recesses 45 of the sleeve 4. In addition, the connection screws 10 inserted into the screw insertion holes 94 of the fixing ring 9 are screwed into the screw holes 8a of the engagement ring 8 as shown in FIG. By engaging, the engagement ring 8 and the fixing ring 9 are connected. In this example, hexagon bolts are used as the connecting screws 10, and the heads 10 a are housed in the recesses 91 b of the fixing ring 9.

  Then, as shown in FIG. 5B, each connecting screw 10 is tightened so that the fitting portion 92 of the fixing ring 9 abuts with the base end surface of the engaging ring 8 and the flange portion 93 of the fixing ring 9 is engaged. The ring 8 is fitted to the outer peripheral portion to complete the connection of the rings 8 and 9.

  After the two rings 8 and 9 are connected in this way, as shown in FIGS. 2 and 4, the fixing screw 11 screwed into each screw hole 91 a of the fixing ring 9 is fastened to the rotating shaft 3 to fix the fixing ring 9. Is fixed to the rotating shaft 3, thereby fixing the sleeve 4 to the rotating shaft 3. In this example, a hole set screw having no head is used as the fixing screw 11.

  The sleeve 4 and the rotary shaft 2 to which the sleeve 4 is inserted and fixed are sealed (secondary seal) by an annular seal member 12.

  That is, as shown in FIG. 2, the proximal end portion 41 of the sleeve 4 has an opening 46 a having a diameter larger than the outer diameter of the rotating shaft 3 portion through which the sleeve 4 is inserted, and the opening 46 a extends toward the distal end portion of the sleeve 4. A seal loading recess 46 having a tapered portion 46b that gradually decreases in diameter (rearward) is formed, and the annular seal member 12 made of an elastic material loaded in the seal loading recess 46 is loaded. Is pressed between the tapered portion 46b and the rotary shaft 3 by connecting the both rings 8 and 9 with the connecting screw 10, thereby sealing between the sleeve 4 and the rotary shaft 3.

  The seal loading recess 46 is formed in the inner peripheral portion of the proximal end of the sleeve 4, and as shown in FIG. 2, the diameter gradually decreases from the cylindrical opening 46 a and the distal end to the outer peripheral surface of the rotary shaft 3. It consists of a conical taper part 46b.

  The annular seal member 12 is an annular body having a trapezoidal cross section in which a part of the outer peripheral surface is formed on the tapered surface 12 c corresponding to the tapered portion 46 b of the seal loading recess 46. That is, in this example, as shown in FIG. 5, the annular seal member 12 has a base end portion (front end portion) 12a whose outer peripheral surface is slightly smaller in diameter than the inner peripheral surface of the opening 46a of the seal loading recess 46, or substantially the same. It is formed in a cylindrical shape having the same diameter and whose inner peripheral surface is slightly larger than the outer peripheral surface of the rotary shaft 3 or substantially the same diameter as this, and the front end portion (rear end portion) 12b is a seal loading recess. 46 is an annular body formed in a truncated cone shape having a tapered surface 12c substantially coinciding with the inner peripheral surface of the tapered portion 46b, and the inner peripheral surface having the same diameter as the inner peripheral surface of the base end portion 12a. As shown in FIG. 5 (A), the size is such that it can be stored in the seal loading recess 46 in an uncompressed state. As the constituent material of the annular seal member 12, an elastic material having heat resistance (for example, expanded graphite or an expanded graphite composite material containing this as a main component) is used. In this example, expanded graphite manufactured by Nippon Pillar Industries Co., Ltd. The composite material "Pillar foil" is used.

  Thus, before the connection between the engagement ring 8 and the fixing ring 9 is started, the annular seal member 12 is inserted into the seal loading recess 46 of the sleeve 4 inserted through the rotary shaft 3 as shown in FIG. And the pressing ring 13 is inserted into the opening 46 a of the seal loading recess 46. The pressing ring 13 is made of a material harder than the annular seal member 12, and is made of a metal material such as stainless steel.

  Thereafter, the connection of the engagement ring 8 and the fixing ring 9 with the connection screw 10 is started, and the connection screw 10 is tightened. At this time, as the connecting screw 10 is tightened, the fixing ring 9 relatively moves toward the engaging ring 8 engaged and held by the sleeve 4, and the body portion 91 of the fixing ring 9 causes the ring to pass through the pressing ring 13. The seal member 12 is pushed in the direction of the taper portion 46 b (rearward direction) of the seal loading recess 46. After the tapered surface 12c of the annular seal member 12 abuts against the tapered portion 46b of the seal loading recess 46, the annular seal member 12 moves in the axial direction along with the movement of the fixing ring 9 (and the pressing ring 13). When the coupling between the engagement ring 8 and the fixing ring 9 is completed in the radial direction, as shown in FIG. 5B, the annular seal member 12 has the tapered portion 46b of the seal loading recess 46 and the rotary shaft 3 as shown in FIG. Between the sleeve 4 and the rotary shaft 3 is strongly sealed. The shape of the tapered portion 46b of the annular seal member 12 and the seal loading recess 46 is such that the connection between the engagement ring 8 and the fixing ring 9 is completed (the fitting portion 92 of the fixing ring 9 is the base of the engagement ring 8). The annular seal member 12 is set so as to be in a compressed form that exhibits an appropriate sealing function in a state where it abuts the end face.

  As shown in FIG. 1, the rotary sealing ring 5 is an annular body having a front end surface (front end surface) formed on a sealing end surface 5 a that is a smooth plane perpendicular to the axis, and the sealing end surface 5 a is a base end portion 41 of the sleeve 4. In the state toward the front, the driving ring 53 and the drive pin 53 are fitted and fixed to the driving ring 51 fixed to the distal end portion 42 and the annular flange portion 43 of the sleeve 4. The rotary seal ring 5 is made of a hard material such as cemented carbide, and the drive ring 51 is made of a metal material such as stainless steel.

  As shown in FIG. 1, the stationary sealing ring 6 is an annular body having a front end surface (rear end surface) formed on a sealing end surface 6 a that is a smooth plane orthogonal to the axis, and an annular convex portion of the main body portion 21 of the seal case 2. Adapter ring 61 fitted and fixed to the main body 21 in a state of being brought into contact with 21 b, a cylindrical bellows 62 whose base end portion is fixed to the adapter ring 61 and can be expanded and contracted in the axial direction, and a distal end portion of the bellows 62 The retainer ring 63 is fixed to the seal case 2 so as to be movable in the axial direction. That is, the stationary seal ring 6 is fitted and fixed to the retainer ring 63 with the sealed end face 6 a facing the sealed end face 5 a of the rotary seal ring 5 on the outer peripheral side of the baffle 22 of the seal case 2. It is pressed and urged in the axial direction to come into contact with the rotary seal ring 5. The stationary seal ring 6 is made of a softer material than the rotary seal ring 5 such as carbon, the adapter ring 61 is made of a metal material such as stainless steel, and the bellows 62 is made of a metal material such as nickel alloy (Inconel). The retainer ring 63 is made of a metal material such as nickel steel.

  Thus, in the mechanical seal M, a sealed fluid region which is an outer peripheral side region of the relative rotating portions 5a and 6a due to the relative rotational sliding contact action of the sealed end faces 5a and 6a of the both sealing rings 5 and 6. A and the non-sealed fluid region B which is the inner peripheral side region thereof are shield-sealed. In this example, the shaft peripheral seal 14 is disposed in the secondary seal space 25 formed in the seal case 2, A portion in the sealing case 2 in the sealed fluid region B is formed in a quenching chamber B1 closed by a shaft peripheral seal 14. As shown in FIG. 1, the quenching fluid B <b> 1 (for example, steam or the like) is supplied to the quenching chamber B <b> 1 from a quenching fluid supply passage 26 formed in the main body 21 of the seal case 2.

  That is, as shown in FIG. 1, the shaft circumferential seal 14 comprises a pair of segment seals 14a, 14a formed by binding a plurality of arc-shaped segments to the rotary shaft 3 with garter springs, and seals the quenching chamber B1. Sealing (secondary sealing) is performed from the non-sealed fluid region B portion (atmospheric region) outside the case 2. As shown in FIG. 1, the quenching fluid supply passage 26 opens to the inner peripheral surface of the annular convex portion 21 b of the seal case 2, and the quenching fluid is provided between the opposing peripheral surfaces of the annular convex portion 21 b and the buffer 22. F1 is supplied. The quenching fluid F1 supplied between the opposed peripheral surfaces passes through the bellows 62 along the outer peripheral surface of the buffer 22 and flows to the sealed end surfaces 5a and 6a. Between the opposing peripheral surfaces in the direction of the axial seal 14 and discharged from the drain passage 27 formed in the main body portion 21 of the seal case 2 to the outside of the seal case 2, during which the cooling of the sealed end surfaces 5a and 6a, In addition to cleaning, the contaminated portion due to the sealed fluid residue leaking from the sealed end faces 5a and 6a is cleaned.

  Further, a flushing fluid supply passage 28 that opens to the sealed fluid region A is formed in the main body portion 21 of the seal case 2 on the outer peripheral side of the adapter ring 61. From the flushing fluid passage 28, a flushing fluid F2 (for example, The sealed end surfaces 5a and 6a are flushed by supplying a liquid which does not interfere with the sealed fluid or the non-sealed fluid.

  In addition, the abutting portion between the distal end portion 21a of the case main body 21 and the shaft seal casing 1, the abutting portion between the base end portion 21c of the case main body 21 and the flange 23, and the annular convex portion 21b of the seal case 2 and the adapter ring 61 are provided. The annular gaskets 2a, 2b, 64 are interposed in the abutting portions. In this example, the annular gaskets 2 a, 2 b, 64 and the O-ring 52 interposed between the rotary seal ring 5 and the driving ring 51 are made of the same material as the annular seal member 12.

  The mechanical seal M configured as described above is such that the set claw 7 is engaged with the annular recess 44 of the sleeve 4 and the stationary side sealing element M1 and the rotary side sealing element M2 are integrally connected to the mechanical seal assembly form. The seal case 2 is attached to and detached from the shaft seal casing 1 with the bolts and nuts 1a and 1b, and the sleeve 4 is attached to and detached from the rotary shaft 3 with the engagement ring 8 and the fixing ring 9 to be attached to and detached from the rotary device. it can.

  At this time, the sleeve 4 is fixed to the rotating shaft 3 by connecting the engaging ring 8 engaged with the sleeve 4 and the fixing ring 9 with the connecting screw 10 and fixing the fixing ring 9 to the fixing screw 11 as described above. Therefore, the fixing ring 9 for screwing the fixing screw 11 at one position in the axial direction has a rotating shaft fixing screw and a sleeve fixing screw at two positions spaced apart in the axial direction. As compared with the fixing rings of the first and second conventional mechanical seals that need to be screwed together, the axial length can be shortened. Accordingly, the base end portion 41 of the sleeve 4 protruding out of the seal case 2 needs to have a sufficient axial length necessary for engaging the engagement ring 8, so that the base end portion 41 of the sleeve 4 is out of the seal case 2. The axial length of the protruding sleeve portion (the base end portion 41 of the sleeve 4 and the fixing ring 9 connected to the base end portion 41 via the engagement ring 8) is shorter than that of the first and second conventional mechanical seals. Even in a rotating device that cannot secure a large axial space outside the seal case because the mechanical seal installation space is small, the mechanical seal M can be mounted satisfactorily, and the applicable rotating device is rarely restricted.

  Further, the base end portion 41 of the sleeve 4 is only formed with an engagement recess 45 for engaging the engagement ring 8, and a through-hole (engagement hole) like the third or fourth conventional mechanical seal is formed. In addition, since the screw insertion hole is not formed at all, the strength of the sleeve 4 does not decrease. Moreover, the engagement ring 8 is merely engaged with the sleeve 1 so as not to be relatively movable in the axial direction (and cannot be relatively rotated), but is firmly connected to the fixing ring 9 by the connection screw 10 in the axial direction. The fixing ring 9 can be firmly fixed to the sleeve 4 as compared with the case where the fixing ring is fixed to the sleeve by the engagement pin as in the third conventional mechanical seal. Therefore, as compared with the third and fourth conventional mechanical seals, the sleeve 4 can be securely and firmly fixed to the rotating shaft 3, and the reliability of the sleeve fixing is high.

  In the first, second, and fourth conventional mechanical seals, if the tightening force of the sleeve fixing screw is increased in order to firmly fix the fixing ring to the sleeve, the tightening force may cause distortion of the sleeve. Therefore, it is necessary to make the thickness of the sleeve thicker than necessary. However, in the above-described mechanical seal M, the fixing ring 9 is fixed to the sleeve 4 by connecting with the engaging ring 8 engaged with the sleeve 4 by a connecting screw, so that the sleeve 4 is distorted. The fixing ring 9 can be firmly fixed to the sleeve 4 without causing the thickness of the sleeve 4 to be as thin as possible.

  By the way, in the first to fourth conventional mechanical seals, a seal (secondary seal) between the sleeve and the rotating shaft is performed by an O-ring engaged and held in an O-ring groove formed on the inner peripheral surface of the sleeve. However, the degree of compression of the O-ring in the radial direction (the sealing force on the circumferential surface facing the sleeve and the rotating shaft) cannot be increased beyond a certain level in order to facilitate insertion of the sleeve into the rotating shaft. Therefore, under the condition that the fluid to be sealed is at a high pressure, the sealing force between the sleeve and the rotating shaft may be insufficient, and there is a possibility that a stable mechanical seal function cannot be exhibited.

  However, in the above-described mechanical seal M, the annular seal member 12 loaded in the seal loading recess 46 formed on the sleeve 4 is compressed in the radial direction by the taper portion 46b of the recess 46 by being pressed and compressed in the axial direction. Since the opposed peripheral surfaces of the shaft 3 and the sleeve 4 are strongly pressed against each other, the sealing force between the rotating shaft 3 and the sleeve 4 is greatly increased as compared with the first to fourth conventional mechanical seals. Therefore, even under the condition that the fluid to be sealed is at a high pressure, the space between the rotating shaft 3 and the sleeve 4 can be well sealed, and a stable mechanical seal function can be exhibited. Moreover, since the compression of the annular seal member 12 is automatically performed as the engagement ring 8 and the fixed ring 9 are connected, the assembly work of the mechanical seal M can be performed very efficiently and easily.

  The configuration of the present invention is not limited to the above-described embodiment, and can be appropriately improved and changed without departing from the basic principle of the present invention.

  For example, as described above, the annular seal member 12 is preferably trapezoidal in cross section with a part of the outer peripheral surface being a tapered surface 12c. However, when the annular seal member 12 is pressed and compressed in the axial direction, The shape is arbitrary as long as it is compressed and deformed in the radial direction by the tapered portion 46b. For example, an O-ring having a circular cross section may be used as the annular seal member 12. Further, the pressing ring 13 for directly pressing the annular seal member 12 in connection with the engagement ring 8 and the fixing ring 9 may be formed integrally with the main body 91 of the fixing ring 91.

  Further, the engagement ring 8 may be engaged with the sleeve 4 so as not to be relatively movable in the axial direction, and does not necessarily have to be engaged with the sleeve 4 so as not to be relatively rotatable. However, the engagement ring 8 is engaged with the sleeve 4 so as not to be relatively movable in the axial direction and is engaged so as not to be relatively rotatable. 8 and the fixing ring 9 can be connected more efficiently and easily.

  Further, in the mechanical seal M used under a condition that the fluid to be sealed is not so high in pressure, as shown in FIG. 6, an O-ring formed on the inner peripheral surface of the sleeve 4 as in the first to fourth conventional mechanical seals. You may make it seal between the rotating shaft 3 and the sleeve 4 with the O-ring 65 engaged with the groove | channel. In this case, as shown in FIG. 7, when the engagement ring 8 and the fixing ring 9 are connected, the base end surface of the sleeve 4 can be abutted against the main body 91 of the fixing ring 9, and the sealing ring The protruding amount of the sleeve 4 in the axial direction to the outside of the case 2 (and the length in the axial direction of the fixing ring 9) can be further reduced. The configuration of the mechanical seal M shown in FIGS. 6 and 7 is the same as that of the mechanical seal M shown in FIGS. 1 to 5 except for the points described above. 7, detailed description is omitted by using the same reference numerals as those shown in FIGS.

  Further, the present invention is not limited to the above-described mechanical seal M of the cartridge structure, and any mechanical seal (for example, each component member) that needs to be detachably fixed to the rotary shaft 3 for maintenance or the like. It can be applied to a mechanical seal that is incorporated into a rotating device by a specific procedure.

DESCRIPTION OF SYMBOLS 1 Shaft seal part casing 2 Seal case 2a Annular gasket 2b Annular gasket 3 Rotating shaft 4 Sleeve 5 Rotating sealing ring 5a Sealing end surface of rotating sealing ring 6 Stationary sealing ring 6a Sealing end surface of stationary sealing ring 7 Set claw 8 Engagement ring 8a Engagement Joint ring screw hole 8b Engagement ring engagement projection 9 Fixing ring 10 Connecting screw 11 Fixing screw 12 Annular seal member 12a Annular seal member proximal end 12b Annular seal member tip 12c Annular seal member taper surface 13 Press ring 14 Axis seal 14a Segment seal 21 Case body 21a Case body tip 21b Case body annular projection 21c Case body base end 22 Baffle 23 Flange 23a Flange annular wall 24 Closure plate 25 Secondary seal space 26 Quenching fluid supply passage 27 Drain passage 28 Flushing fluid supply passage 41 Base end portion of sleeve 42 Tip portion of sleeve 43 Annular flange portion of sleeve 44 Annular recess portion of sleeve 45 Engaging recess portion of sleeve 46 Seal loading recess portion 46a Opening portion of seal loading recess portion 46b Seal loading recess portion 46b Tapered part 51 Driving ring 52 O-ring 53 Drive pin 61 Adapter ring 62 Bellows 63 Retainer ring 64 Annular gasket 91 Fixing ring body 91a Fixing ring screw hole 91b Fixing ring recess 92 Fixing ring fitting part 93 Fixing ring fitting Threaded part 94 Screw insertion hole of fixing ring A Sealed fluid region B Unsealed fluid region B1 Quenching chamber F1 Quenching fluid F2 Flushing fluid M Mechanical seal M1 Stationary side sealing element M2 Rotation side sealing element

Claims (3)

The seal case includes a stationary seal ring, a sleeve that is detachably inserted and fixed to a rotary shaft that passes through the seal case and the stationary seal ring, and a rotary seal ring that is provided on the sleeve. In the mechanical seal configured to shield and seal the in-machine area and the out-of-machine area at the relative rotational sliding contact portion of the ring,
The sleeve inserted through the rotation shaft is screwed into the engagement ring that is engaged and held at the base end portion of the sleeve so as not to be relatively movable in the axial direction, and the fixed ring that is inserted through the rotation shaft so as to face the engagement ring. The fixing ring is fixed to the rotating shaft by a fixing screw that fixes the fixing ring to the rotating shaft and a connecting screw that connects the both rings so as not to move relative to each other in the axial direction .
A plurality of concave portions are formed on the outer peripheral surface of the sleeve at predetermined intervals in the circumferential direction, and convex portions that engage with the respective concave portions are formed on the inner peripheral surface of the engagement ring. The mechanical seal is characterized in that the engagement ring is engaged and held by the sleeve so as not to be relatively movable in the axial direction and not to be relatively rotatable . The seal case includes a stationary seal ring, a sleeve that is detachably inserted and fixed to a rotary shaft that passes through the seal case and the stationary seal ring, and a rotary seal ring that is provided on the sleeve. In the mechanical seal configured to shield and seal the in-machine area and the out-of-machine area at the relative rotational sliding contact portion of the ring,
The sleeve inserted through the rotation shaft is screwed into the engagement ring that is engaged and held at the base end portion of the sleeve so as not to be relatively movable in the axial direction, and the fixed ring that is inserted through the rotation shaft so as to face the engagement ring. The fixing ring is fixed to the rotating shaft by a fixing screw that fixes the fixing ring to the rotating shaft and a connecting screw that connects the both rings so as not to move relative to each other in the axial direction.
The mechanical seal is characterized in that the engagement ring is divided into two in the radial direction, and each of the divided portions is connected to the fixing ring by a connection screw . The seal case includes a stationary seal ring, a sleeve that is detachably inserted and fixed to a rotary shaft that passes through the seal case and the stationary seal ring, and a rotary seal ring that is provided on the sleeve. In the mechanical seal configured to shield and seal the in-machine area and the out-of-machine area at the relative rotational sliding contact portion of the ring,
The sleeve inserted through the rotation shaft is screwed into the engagement ring that is engaged and held at the base end portion of the sleeve so as not to be relatively movable in the axial direction, and the fixed ring that is inserted through the rotation shaft so as to face the engagement ring. The fixing ring is fixed to the rotating shaft by a fixing screw that fixes the fixing ring to the rotating shaft and a connecting screw that connects the both rings so as not to move relative to each other in the axial direction.
Seal loading having an opening having a diameter larger than the outer diameter of the rotating shaft portion through which the sleeve is inserted at one end of the sleeve and gradually reducing the diameter from the opening toward the other end of the sleeve. A concave portion is formed, and an annular seal member made of an elastic material loaded in the seal loading concave portion is loaded, and the annular seal member is pushed between the tapered portion and the rotating shaft by the connection of the connecting screws of the two rings. A mechanical seal configured to seal between the sleeve and the rotary shaft .

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