JP2017166517A - Split type mechanical seal - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an outside split type mechanical seal in which a disassembly and assembly including maintenance of the mechanical seal can be performed easily and safely.SOLUTION: A first seal ring 4 at a seal case 3 side and a second seal ring 7 at a rotating shaft 2 side that are relatively rotated and slid to be contacted to each other are constituted into a split type seal ring divided into two segments in a peripheral direction that are comprised of extremity end portions 42, 72 formed with seal end surfaces 4a, 7a, intermediate portions 43, 73 having a specified outer diameter related with the extremity ends and base end portions 44, 74 of specified outer diameter smaller than the former. Each of the split type seal rings 4, 7 are held and bound in a ring-like shape by outwardly fitting snap rings 41, 71 to the base end portions 44, 74 and at the same time the intermediate portions 43, 73 and the base end portions 44, 74 are bound and fixed in a ring form by binding rings 5, 8 while the seal members 6, 9 are being present.SELECTED DRAWING: Figure 2

Description

  The present invention is an outside-type mechanical seal equipped in pumps (seawater desalination pumps, irrigation pumps, various industrial pumps), rotating equipment such as blowers and compressors, and particularly in the circumferential direction of the sealing ring. The present invention relates to a split-type mechanical seal that forms a split-type seal ring divided into two.

  As this type of mechanical seal, the relative rotational sliding contact portion of the first sealing ring held in the seal case so as to be movable in the axial direction and the second sealing ring fixed to the rotating shaft is used. In an outside-type mechanical seal configured to shield and seal a sealed fluid region as an inner peripheral region and an unsealed fluid region as an outer peripheral region, for example, disclosed in FIG. 2 or FIG. 5 of Patent Document 1 As shown in FIG. 1 of Patent Document 2, both a split type mechanical seal (hereinafter referred to as “first conventional seal”) in which only the first seal ring is formed into a split seal ring divided into two in the circumferential direction. A split type mechanical seal (hereinafter referred to as “second conventional seal”) in which the seal ring is divided into two in the circumferential direction is well known.

  Thus, in the first conventional seal, the holding ring is held by the seal case through the O-ring so as to be movable in the axial direction, and the tightening ring is attached to the holding ring so as to be clamped in the axial direction. The circumferential surface facing the first sealing ring and the binding ring fitted on the first sealing ring is formed into a truncated conical tapered surface that gradually expands in the tightening direction to the holding ring of the binding ring, and the binding ring is held by the holding ring. The first sealing ring is bound and fixed in an annular shape by tightening to the right (moving the binding ring in the axial direction in the direction of expansion of the tapered surface).

  Further, in the second conventional seal, in addition to the above-described configuration, the holding ring is fixed to the rotating shaft, and the binding ring is attached to the holding ring so as to be freely tightened in the axial direction. By forming a frustoconical tapered surface that gradually expands in the tightening direction of the binding ring to the holding ring, and tightening the binding ring to the holding ring, The sealing ring is tightly fixed to the annular shape. Further, in the second conventional seal, an elastic member such as a rubber sheet is interposed between the opposed end surfaces in the axial direction of the divided seal ring and the holding ring and between the opposed peripheral surfaces of the divided seal ring and the binding ring. By tightening the binding ring to the holding ring, the split type sealing ring is pressed and held on the axial end surface of the holding ring via the elastic member, and fitted and held on the inner peripheral surface of the binding ring via the elastic member. Configure.

JP 2004-251376 A JP 2007-298123 A

  Such a split-type mechanical seal can be easily disassembled and assembled including maintenance work even when it is a large one, and is suitable as a shaft sealing means for large rotating equipment. The following problems have been pointed out.

  That is, in the first conventional seal, since the split seal ring (first seal ring) is directly bound by the metal binding ring, when the tightening of the binding ring to the holding ring is excessive, In other words, if the binding force of the split seal ring by the binding ring is excessive, the split part of the seal ring is distorted (in the extreme case, the split part is damaged), and the abutting surface of the split part There is a possibility that the sealed fluid may leak from between. Conversely, when the tightening of the binding ring to the holding ring is insufficient and the binding force of the split type sealing ring by the binding ring is insufficient, the internal pressure acting on the split type sealing ring (the inner peripheral surface of the first sealing ring) There is a risk that the sealed fluid may leak due to an opening between the abutting surfaces of the divided portions due to the pressure of the sealed fluid acting on the sealing member. Such a problem similarly occurs when the second seal ring is a split seal ring. In particular, when the split seal ring is made of ceramics such as silicon carbide that is weak against tensile load, soft carbon, or the like, This occurs remarkably when the pressure of the sealed fluid is high.

  On the other hand, the second conventional seal has an elastic member interposed between the split seal ring (first and second seal rings), the binding ring and the holding ring as described above. Even when the force is excessive or insufficient, or when the internal pressure acting on the split seal ring is high, the split face does not open or the end face of the seal does not distort, unlike the first conventional seal. The ring can be assembled into a proper annular shape without causing the split surfaces to be displaced in the radial direction and the axial direction, and the disadvantage of the first conventional seal is eliminated.

  However, in both the first and second conventional seals, it is necessary to artificially hold the two divided portions in an annular shape when the divided seal ring is assembled, which includes maintenance work. It was difficult to assemble the mechanical seal easily and safely. For example, there is a risk that the sealing ring (divided part) may be damaged during work, or may cause personal injury.

  Further, in the second conventional seal, since the elastic member is interposed between the split seal ring and the binding ring as described above, the elasticity of the binding force due to the binding ring as in the first conventional seal is reduced. Although it can be covered with a member, the binding force of the split type sealing ring is obtained by tightening the binding ring to the holding ring (the fitting surface of the split type sealing ring and the binding ring is locked by the cam action of the tapered surface) Because the tightening force is obtained by the component of the axial force of the ring (tightening force to the retaining ring), as with the first conventional seal, the abutment surface of the split seal ring (both splits) when tightening the tightening ring There is a possibility that the abutting surface of the portion may be displaced in the axial direction, and it is difficult to assemble the sealing ring so that the sealing end surface is an appropriate annular plane. Such a problem naturally occurs also in the first conventional seal. However, when an elastic member is interposed between the split seal ring and the binding ring as in the second conventional seal, the binding ring to the holding ring is not provided. Since tightening (moving in the axial direction) is difficult to perform smoothly by interposing an elastic member, there is a higher possibility that the above problem will occur. Further, in the second conventional seal, the thickness of the elastic member interposed between the split type sealing ring and the binding ring cannot be increased beyond a certain level (if the thickness of the elastic member is increased more than necessary, the binding ring Smooth movement in the axial direction is further hindered), so the above-mentioned problems due to excessive or insufficient binding force cannot be completely eliminated by the elastic member, and distortion of the sealing end face due to excessive binding force or insufficient binding force There still remains a risk of leakage due to.

  If the sealed end face of the split seal ring does not have an appropriate annular plane due to distortion or the like, the sealed end face is generally corrected by a so-called sliding operation during mechanical seal assembly or maintenance. Alternatively, attempts have been made to perform so-called familiar operation prior to regular operation by setting the radial width of the sealed end surface to be extremely small. Since it requires skill, it is difficult to perform on the user side, and an excessive burden is imposed on the operator, resulting in an extremely large economic burden.

  In addition, in rotating equipment that handles corrosive fluids (for example, seawater desalination plant pumps and seawater transport pumps), mechanical seal components other than seal rings (for example, metal parts such as binding rings) can be replaced. Maintenance may be required, but when used in such applications, in the first and second conventional seals in which only the sealing ring is divided, the non-divided mechanical seal component is inserted and removed from the rotating shaft. Therefore, it is necessary to disassemble and reassemble a part of the rotating device (for example, the bearing portion of the rotating shaft and the connecting portion with the drive source), and the maintenance work of the mechanical seal is extremely troublesome.

  Further, in both of the first and second conventional seals, it is necessary to move the binding ring and the like largely in the axial direction when disassembling and assembling the split seal ring. It requires a certain amount of axial space (hereinafter referred to as “axial movement space such as a binding ring”). However, since various devices and parts such as the bearing portion exist in the peripheral region, there are many rotating devices that cannot sufficiently secure an axial movement space such as the binding ring. Therefore, when the first and second conventional seals are used as the shaft sealing means of such a rotary device, maintenance of mechanical seal components other than the seal ring as described above is performed even when maintenance of only the seal ring is performed. As in the case of performing the above, it is necessary to disassemble and reassemble the rotating equipment.

  An object of the present invention is to provide an outside-type split-type mechanical seal that solves all such problems and can be easily and safely disassembled and assembled including maintenance of the mechanical seal. is there.

In order to achieve the above-mentioned object, the present invention is divided into two in the circumferential direction, and a seal case attached to the housing of the rotating device in a state of being fastened in an annular shape,
A first binding ring that is divided into two in the circumferential direction and is held in a seal case so as to be movable in the axial direction while being fastened in an annular shape, and a state that is divided into two in the circumferential direction and fastened in an annular shape The second binding ring fixed to the rotating shaft of the rotating device and the separated portion that is separated in the circumferential direction and over the entire length with an adhesive are formed into a cylindrical body. First and second sealing members made of an elastic material, a split-type sealing ring that is divided into two in the circumferential direction, a tip portion that forms a sealing end surface, an intermediate portion having a constant outer diameter, and an outer diameter The first and second sealing rings, each of which has a small outer diameter and a base end portion having a constant outer diameter, are externally fitted to the base end portions of each of the split-type seal rings, and the split-type seal rings are tightly held in an annular shape. A snap ring, and a base end portion of the first seal member is sealed with the housing. The first tightening is performed with the intermediate portion of the first sealing ring and the base end portion on which the snap ring is externally fitted with the distal end portion of the first seal member interposed between the end surfaces facing the case in the axial direction. The ring is fastened and fixed in an annular shape by a ring, and the intermediate portion of the second sealing ring and the base end portion on which the snap ring is externally fitted are fastened and fixed in an annular shape by the second binding ring with the second seal member interposed therebetween, By the relative rotational sliding contact action of the sealing end faces of both sealing rings, the sealed fluid region that is the inner peripheral side region of the relative rotational sliding contact portion and the non-sealed fluid region that is the outer peripheral side region are shield-sealed. We propose a split-type mechanical seal characterized by this.

  In a preferred embodiment of such a split type mechanical seal, the seal case is attached to the mechanical seal attachment portion of the housing, and the mechanical seal attachment portion is constituted by a separate member from the main body portion of the housing and is attached to the main body portion. It is attached. In addition, the second binding ring is divided into a binding body and a fixed body that are divided into two in the circumferential direction and fastened in an annular shape, and the second sealing ring is connected to each other by connecting the two bodies together. It is comprised so that it may fix to a rotating shaft in the state which interposed 2 seal members. Moreover, it is preferable that an annular groove into which the inner peripheral portion of the snap ring is fitted is formed on the outer peripheral surface of the base end portion of each sealing ring. Moreover, it is preferable that a plurality of snap rings of the same shape and the same material, which are arranged in close contact with each other in the axial direction, are fitted to the base end portion of each seal ring. In addition, the distal end portion of each seal member has a cylindrical shape that presses against the outer peripheral surface of the intermediate portion of the split seal ring and the base end portion with which the snap ring is fitted, and the base end surface of the seal ring. preferable.

  In the split type mechanical seal of the present invention, all mechanical seal components can be disassembled and assembled in a direction perpendicular to the rotation axis. Easily disassemble and assemble mechanical seals including maintenance even when sufficient space cannot be secured, and even when mechanical seal components other than split seal rings need to be replaced and maintained. Can do. Furthermore, since the split seal ring can be held in an annular shape by a snap ring, it is possible to perform a tightening operation with a tightening ring. Therefore, the assembly work of the split seal ring can be easily performed. Therefore, according to the split type mechanical seal of the present invention, the mechanical seal can be easily disassembled and assembled including maintenance. Moreover, the split-type mechanical seal of the present invention is also suitable as a shaft sealing means for rotating equipment that cannot sufficiently secure a moving space in the axial direction, such as a binding ring, and that requires maintenance of mechanical seal components other than the sealing ring. It can be used for a wide range of applications.

  Further, in the split type mechanical seal of the present invention, each split type seal ring is made of an elastic material by fastening the split surfaces of each of the binding rings, that is, by fastening each of the binding rings perpendicularly to the split surface. Unlike the case where the split type sealing ring is bound by tightening the binding ring in the axial direction using the cam action as in the first and second conventional seals, since the binding is performed in a state where the seal member is interposed, When the split seal ring is assembled (at the time of binding), the split portion does not shift in the axial direction. Moreover, the thickness in the binding direction (diameter thickness) of the seal member (tip portion) interposed between the split-type sealing ring and the binding ring can be sufficiently increased (the compression allowance at the time of binding is increased). Therefore, even if the binding force by the binding ring is increased, the split seal ring is not distorted. Therefore, the split type sealing ring can be assembled in an appropriate form without causing distortion at the sealing end face, and it is not necessary to perform the sliding operation and the familiar operation as described above. Moreover, as described above, it is possible to increase the tightening force due to the tightening ring and increase the thickness in the tightening direction of the seal member, so that leakage may occur from the split surface of the split seal ring even when used under high pressure conditions. And can also be suitably used for high PV value rotating equipment.

  As described above, the split mechanical seal of the present invention is excellent in sealing function, disassembly and assembling workability and can greatly expand the application, and its practical value is extremely large.

FIG. 1 is a sectional view showing an example of a split mechanical seal according to the present invention. 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 taken along line VV in FIG. 6 is a cross-sectional view taken along line VI-VI in FIG. FIG. 7 is a cross-sectional view corresponding to FIG. 1 showing a modification of the split-type mechanical seal according to the present invention. FIG. 8 is a sectional view taken along line VIII-VIII in FIG.

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

  FIG. 1 is a cross-sectional view showing an example of a split-type mechanical seal according to the present invention, FIG. 2 is a detailed view showing an enlarged main part of FIG. 1, and FIG. 3 is taken along line III-III in FIG. 4 is a sectional view taken along line IV-IV in FIG. 1, FIG. 5 is a sectional view taken along line V-V in FIG. 1, and FIG. 6 is taken along line VI-VI in FIG. It is sectional drawing which follows. In the following description, front and rear mean the left and right in FIGS.

  The split mechanical seal shown in FIG. 1 is installed between a rotary device housing (pump housing or the like, hereinafter referred to as “device housing”) 1 and a rotary shaft (impeller shaft or the like) 2. A seal case 3 attached to the device housing 1, and a first seal ring 4 held by the seal case 3 so as to be movable in the axial direction (front-rear direction) via a first binding ring 5 and a first seal member 6. The second sealing ring 7 fixed to the rotary shaft 2 via the second binding ring 8 and the second seal member 9 is interposed between the seal case 3 and the first binding ring 5 so as to provide the first sealing. A spring member 10 that urges the ring 4 in the axial direction to press-contact the second seal ring 7 with the second seal ring 7, and the relative rotational sliding contact action of the sealed end faces 4 a and 7 a that are the opposite end faces of the seal rings 4 and 7. Due to the inner circumference of the relative rotational sliding contact portions 4a and 7a An outside type configured to shield and seal a sealed fluid region (in-machine region) H that is a region and a non-sealed fluid region (external region, which is an atmospheric region in this example) L that is an outer peripheral side region thereof This is an end face contact type mechanical seal.

  As shown in FIG. 3, the seal case 3 is a metal annular body that is divided into two on the diameter line in the circumferential direction, and by fastening both ends of the divided portions 3 </ b> A and 3 </ b> B with a pair of fastening bolts 31. , Is configured in an annular shape where the split surfaces meet. As shown in FIGS. 1 and 3, the seal case 3 has a rotating shaft attached to a mechanical seal mounting portion 1 a formed at the end of the device housing 1 by a plurality of mounting bolts 32 arranged at equal intervals in the circumferential direction. 2 is concentrically attached. The radial positioning of the seal case 3 with respect to the mechanical seal mounting portion 1a is performed by the outer periphery of the annular convex portion 1b in which the inner peripheral portion of the seal case 3 projects from the atmospheric region side end (front end surface) of the mechanical seal mounting portion 1a. This is done by fitting the part. Further, an annular flange portion 3a projecting inward from the front end thereof is formed on the inner peripheral portion of the seal case 3, and both the portions 1b and 3a are in a state where the seal case 3 is attached to the mechanical seal attachment portion 1a. Are directly opposed to each other at a predetermined interval in the axial direction. That is, the inner and outer diameters of the opposed end surfaces of the annular convex portion 1b and the flange portion 3a are the same. In this example, as shown in FIG. 1, the mechanical seal mounting portion 1a is made of a metal annular body made of a member different from the main body portion 1A of the device housing 1, and the main body portion 1A. Is fixed to the atmospheric region side end portion (front end portion) by a plurality of mounting bolts (not shown). Each mounting bolt 32 passes through a bolt insertion hole formed in the seal case 3 and the mechanical seal mounting portion 1 a and is screwed to the main body portion 1 </ b> A of the device housing 1.

  As shown in FIG. 2, the first sealing ring 4 includes a distal end portion 42 formed on a tapered surface (a truncated conical surface) whose outer peripheral surface gradually increases in the proximal direction (rearward direction) and an intermediate portion 43 connected thereto. And a base end portion 44 connected thereto, and as shown in FIG. 4, it is constituted by a split type sealing ring that is divided into two on the diameter line in the circumferential direction, and the split portions 4A and 4B are By being bound by the first snap ring 41, the end surfaces of the divided portions 4A and 4B are held (temporarily fixed) in an annular shape where the end surfaces abut each other. As a material of the first sealing ring 4, for example, SiC (silicon carbide) or carbon is used.

  The distal end surface (front end surface) of the distal end portion 42 of the first sealing ring 4 is configured as a sealed end surface 4a that is a smooth annular plane orthogonal to the axis. The outer diameter of the intermediate portion 43 of the first sealing ring 4 is constant and is set to be the same as the proximal outer diameter (the maximum diameter of the tapered surface) of the distal end portion 42. That is, the outer peripheral surface of the intermediate portion 43 forms a cylindrical surface that is flush with the outer peripheral surface of the tip portion 42. The outer diameter of the base end portion 44 is constant and is set smaller than the outer diameter of the intermediate portion 43. That is, the outer peripheral surface of the base end portion 44 has a smaller diameter than the outer peripheral surface of the intermediate portion 43, and is a cylindrical surface having the same diameter as or smaller than the outer diameter of the sealed end surface 4a.

  As shown in FIG. 2, the outer peripheral surface of the base end portion 44 of the first sealing ring 4 is located at the tip end position (boundary position with the intermediate portion 43), and the inner peripheral portion of the first snap ring 41 is engaged. An annular groove 44a that can be joined is formed.

  As shown in FIG. 4, the first snap ring 41 is made of a metal (SUS304 or the like) having a C shape obtained by cutting off one circumferential direction of the annular plate. The first snap ring 41 is the same as a general shaft snap ring defined in JIS G3311, by using an appropriate tool (snap ring pliers or the like) having both ends engaged with operation holes 41a formed in the first snap ring 41. The seal ring 4 is expanded (elastically deformed) more than the diameter of the base end portion 44 of the seal ring 4 so that the inner peripheral portion of the snap ring 41 engages with the annular groove 44a. Thus, the first sealing ring 4 is tightly held in an annular shape where both end surfaces of the divided portions 4A and 4B abut each other. The radial width and thickness (plate thickness) of the first snap ring 41 are constant. As shown in FIG. 2, the snap ring inner diameter in the form fitted in the annular groove 44a is the diameter of the annular groove 44a (the groove bottom). The outer diameter of the snap ring in this embodiment is set to be the same as or slightly smaller than the outer diameter of the intermediate portion 43 of the first sealing ring 4.

  As shown in FIG. 2, the second sealing ring 7 includes a distal end portion 72 formed on a tapered surface (a truncated conical surface) whose outer peripheral surface gradually increases in the proximal direction (rearward direction) and an intermediate portion 73 connected thereto. And a base end portion 74 connected thereto, and as shown in FIG. 5, it is formed into a split seal ring that is divided into two on the diameter line in the circumferential direction. By being bound by the two snap rings 71, the end surfaces of the divided portions 7A and 7B are held (temporarily fixed) in an annular shape where the end surfaces abut each other. As a material of the second sealing ring 7, for example, SiC (silicon carbide) or carbon is used.

  As shown in FIG. 2, the second sealing ring 7 is configured as a split type sealing ring having the same shape as the first sealing ring 4, and the front end surface (rear end surface) of the front end portion 72 is smooth and perpendicular to the axis. The outer end of the intermediate portion 73 is constant and is set to be the same as the base end outer diameter (the maximum diameter of the tapered surface) of the distal end portion 72. The surface forms a cylindrical surface that is flush with the outer peripheral surface of the tip end portion 72. Further, the outer diameter of the base end portion 74 is constant and is set smaller than the outer diameter of the intermediate portion 73, and the outer peripheral surface thereof is smaller than the outer peripheral surface of the intermediate portion 73, and the outer diameter of the sealed end surface 4a is The cylindrical surface has the same diameter or a smaller diameter. Further, as shown in FIG. 2, the outer peripheral surface of the base end portion 74 of the second seal ring 7 is located at the tip position (boundary position with the intermediate portion 73), and the inner peripheral portion of the second snap ring 71. An annular groove 74a that can be engaged with each other is formed.

  As shown in FIG. 5, the second snap ring 71 is made of the same material and the same shape as the first snap ring 41, and has a C shape in which one circumferential direction of the annular plate is cut out. The second snap ring 71 is similar to the first snap ring 41 or the general shaft snap ring defined in JIS G3311, with an appropriate tool (snap) having both ends engaged with the operation holes 71a formed therein. The base end in a state where the inner peripheral portion of the snap ring 71 is engaged with the annular groove 74a by being expanded (elastically deformed) beyond the diameter of the base end portion 74 of the second sealing ring 7 by a ring pliers or the like. The second sealing ring 7 is tightly held in an annular shape where both end surfaces of the divided portions 7A and 7B abut each other by being fitted on the portion 74.

  By the way, the elastic force of the snap rings 41 and 71 is determined by the shape of the material, the plate thickness and the like. However, if the elastic force is high, it is difficult to attach the snap rings 41 and 71 to the seal rings 4 and 7 ( If the elastic force is low, it is not sufficient to hold the split seal rings 4 and 7 tightly in an annular shape. There is not enough (the binding force for holding the split seal rings 4 and 7 by the snap rings 41 and 71 is insufficient). Therefore, when the split-type seal rings 4 and 7 are held tightly by the single snap rings 41 and 71, the snap rings 4 and 7 (especially the base end portions 44 and 74) depend on the outer diameter of the seal rings 4 and 7 but depend on the snap diameter. In some cases, the elastic force of the rings 41 and 71 cannot be determined so as to satisfy both the mounting workability and the binding holding force. In such a case, the split seal rings 4 and 7 are held tightly by the plurality of snap rings 41 and 71, and the elastic force of each snap ring 41 and 72 is low enough to facilitate the mounting operation. In this case, it is only necessary to supplement the binding holding force that is insufficient with one snap ring 41, 72 with a plurality of snap rings 41, 71. When a plurality of snap rings 41 and 71 are used in this way, the groove widths of the annular grooves 44a and 74a are set so that the inner peripheral portions of the plurality of snap rings 41 and 71 are in close contact with each other. It is desirable to set so as to be able to engage with the annular grooves 44a and 74a without causing backlash in the axial direction.

  In this example, each of the split seal rings 4 and 7 is held tightly by two snap rings 41 and 71 as shown in FIG. The groove widths of the annular grooves 44a and 74a are such that the inner peripheral portions of the annular grooves 44a and 74a can be engaged with the annular grooves 44a and 74a without causing any backlash in the axial direction when the two snap rings 41 and 71 are in close contact with each other. Is set to Both the sealing rings 4 and 7 are both made of a hard material such as a ceramic such as silicon carbide or a superalloy, or one of them is made of a ceramic such as silicon carbide or a cemented carbide. It is composed of a hard material and the other is composed of softer carbon or the like. In this example, both seal rings 4 and 7 are made of silicon carbide.

  As shown in FIG. 4, the first binding ring 5 is a metal annular body that is divided into two on the diameter line in the circumferential direction, and both ends of the divided portions 5 </ b> A and 5 </ b> B are orthogonal to the axis by a pair of fastening bolts 51. By being fastened in the direction to be engaged, it is configured in an annular shape in which the end faces of the divided portions 5A and 5B abut each other.

  As shown in FIG. 1, the first binding ring 5 is an annular first body projecting inwardly perpendicular to the axis from both ends (front and rear ends) in the axial direction of the annular main body 52 and the inner periphery thereof. A circular holding portion 55 extending rearward from the inner peripheral portion of the second wall portions 53 and 54 and the rear second wall portion 54 and a circle projecting outward from the outer peripheral portion of the main body portion 52 perpendicular to the axis. It consists of an annular annular flange 56. The inner peripheral surface of the main body portion 52 of the first binding ring 5 forms a cylindrical surface parallel to the axis, and the inner peripheral surface of the first wall portion 53 is the outer peripheral surface (tapered surface) of the tip portion 42 of the first sealing ring 4. ) Is formed on a tapered surface (a truncated conical surface that gradually increases in diameter rearward). As shown in FIG. 2, the first binding ring 5 is held by the seal case 3 so as to be movable in the axial direction by fitting the holding portion 55 to the inner peripheral portion of the flange portion 3 a of the seal case 3. As shown in FIG. 1, a metal annular drive collar 57 is attached to the annular collar portion 56 of the first binding ring 5, and the inner peripheral portion of the drive collar 57 is attached to the outer peripheral surface of the main body portion 52. A metallic cylindrical diffusion prevention cover 58 extending forward along the side is fixed. The drive collar 57 and the diffusion prevention cover 58 fixed to the drive collar 57 are divided into two in the circumferential direction at the same position as the first binding ring 5. The drive collar 57 is divided into a first binding ring 59 by a plurality of mounting bolts 59. It is assembled in an annular shape by being attached to the five annular flanges 56. As shown in FIG. 4, engagement concave portions 57a are formed in the outer circumferential portion of the drive collar 57 at two locations in the circumferential direction, and the drive pins 33 screwed to the seal case 3 in the respective engagement concave portions 57a. By engaging, relative rotation of the first binding ring 5 with respect to the seal case 3 is prevented. Further, the diffusion of leakage vapor from the sealed end faces 4a and 7a is prevented by the diffusion preventing cover 58. As shown in FIG. 1, a cutout portion 56a through which the drive pin 33 passes is formed at the outer peripheral portion of the annular flange portion 56 of the first binding ring 5 at a position corresponding to each engagement recess 57a.

  As shown in FIG. 2, the first seal member 6 has a cylindrical tip portion 61, a cylindrical first intermediate portion 62 that extends rearward from the inner peripheral portion of the rear end thereof, and a diameter that gradually increases from the rear end portion and extends rearward. A cylindrical body made of an elastic material having a relatively high hardness, comprising a second intermediate portion 63 in the shape of a truncated cone and an annular base end portion 64 connected to the rear end thereof, as shown in FIGS. One place in the circumferential direction is separated over the entire length, and the separated portion 6a is bonded to the cylindrical body by an adhesive. In this example, the first seal member 6 is made of nitrile rubber (NBR).

  As shown in FIG. 2, the distal end portion 61 of the first seal member 6 is fitted into the main body portion 52 of the binding ring 5 while being engaged with both wall portions 53 and 54 of the first binding ring 5. 1 snap ring 41 is fitted into the intermediate portion 43 and the base end portion 44 of the seal ring 4 in a state of abutting with the base end surface (the rear end surface of the base end portion 44) of the first seal ring 4 that is tightly bound in an annular shape. The thickness (the thickness in the radial direction) is the distance between the opposed peripheral surfaces (the radial distance) between the main body portion 52 of the first binding ring 5 and the intermediate portion 43 and the base end portion 44 of the first sealing ring 4. ) Is set larger by a predetermined amount (diameter interference). Thus, by fastening the first binding ring 5, as shown in FIG. 4, the first sealing ring 4 has an annular shape with the distal end portion 61 of the first seal member 6 compressed in the radial direction interposed therebetween. It is supposed to be fixed to BDSM. As shown in FIG. 2, the outer diameter of the distal end portion 61 of the first seal member 6 is constant, and the portion that fits into the intermediate portion 43 and the snap ring 41 of the first sealing ring 4 (hereinafter referred to as “first distal end portion”). The thickness of 61a in the radial direction is a portion (hereinafter referred to as a “second tip portion”) that fits into the base end portion 44 of the sealing ring 4 (excluding the portion with which the snap ring 41 is engaged). The portion 61c is naturally thinner than the radial thickness of 61b, but is sandwiched between the base end portion 44 and the second wall portion 54 of the first binding ring 5 (hereinafter referred to as “third tip portion”) 61c. And the thickness in the radial direction of first and second intermediate portions 62 and 63 of the first seal member 6 to be described later.

  As shown in FIG. 2, the first intermediate portion 62 of the first seal member 6 has its outer peripheral surface in contact with the inner peripheral surface of the holding portion 55 of the first binding ring 5 over the entire surface. 55 is fitted inside. Therefore, the first sealing ring 4, the first binding ring 5, and the distal end portion 61 and the first intermediate portion 62 of the first seal member 6 are not integrally formed with each other (hereinafter referred to as “stationary sealing ring element”). "). Further, the base end portion 64 of the first seal member 6 is clamped and fixed between the axially opposed end surfaces of the device housing 1 and the seal case 3. In this example, as shown in FIG. 2, the base end portion 64 is held between the opposed end surfaces of the annular convex portion 1b formed on the mechanical seal mounting portion 1a and the flange portion 3a formed on the seal 3. The space between the device housing 1 (mechanical seal mounting portion 1a) and the seal case 3 is sealed (secondary seal). Therefore, since the space between the first seal ring 4 or the first binding ring 5 and the seal case 3 is sealed (secondary seal) by the first seal member 6, a special secondary seal such as an O-ring is provided. There is no need to provide means. On the other hand, the second intermediate portion 63 of the first seal member 6 is different from the other first seal member portions (the tip portion 61, the first intermediate portion 62, and the base end portion 64) as shown in FIG. The housing 1 (mechanical seal mounting portion 1a), the seal case 3, the first sealing ring 4 and the first binding ring 5 are in a non-contact state capable of relative displacement. Therefore, the stationary sealing ring elements 4, 5, 61, 62 are allowed to move in the axial direction with respect to the seal case 3 that fixes the proximal end portion 64 of the first seal member 6 due to the elastic deformation of the second intermediate portion 63. The That is, the followability of the first seal ring 4 is ensured by the second intermediate portion 63 of the first seal member 6.

  As shown in FIG. 1, the second binding ring 8 is a metal annular complex separated into an annular binding body 81 and an annular fixed body 82, and is shown in FIGS. 5 and 6. Thus, the circumferential direction is divided into two on the diameter line, and both ends of the divided portions 81A and 81B of the binding body 81 and both ends of the divided portions 82A and 82B of the fixed body 82 are axially connected by a pair of fastening bolts 83 and 84, respectively. Are fastened in a direction orthogonal to each other, whereby the binding body 81 and the fixed body 82 are fastened in an annular shape where the divided surfaces of the divided portions 81A, 81B and 82A, 82b abut, and a plurality of both bodies 81, 82 are provided. The connecting bolt 85 is integrally connected.

  As shown in FIGS. 1 and 5, the binding body 81 forms a cylindrical wall surface whose inner peripheral surface is parallel to the axis, and has an annular wall portion 81 a that protrudes inwardly at the front end portion (rear end portion). The inner peripheral surface of the wall portion 81a is a tapered surface that can abut the outer peripheral surface (tapered surface) of the tip portion 72 of the second sealing ring 7 (a truncated conical surface that gradually expands forward). ). As shown in FIGS. 1 and 6, the fixed body 82 includes a distal end portion 82 a fitted to the inner peripheral portion of the binding body 81 and a proximal end portion 82 b fitted and fixed to the rotary shaft 2 by a plurality of set screws 86. This is an annular body composed of an annular flange portion 82c projecting from the boundary portion between both portions 82a and 82b on the outer peripheral surface. An annular recess 82 d that forms an annular space having an L-shaped cross section with the outer peripheral surface of the rotating shaft 2 is formed on the inner peripheral portion of the distal end portion 82 a of the fixed body 82. As shown in FIG. 1, both bodies 81, 82 fit the distal end portion 82 a of the fixed body 82 to the inner peripheral portion of the binding body 81, and connect the flange portion 82 c of the fixed body 82 to the proximal end surface (front end surface) of the binding body 81. In this state, the flange portion 82c is attached to the binding body 81 by the connecting bolt 85, so that the second binding ring 8 is configured (integrated). Note that the inside diameter of the binding body 81 is equal to the inside diameter of the main body portion 52 of the first binding ring 5, and the wall portion 81 a of the binding body 81 is symmetrical with the first wall portion 53 of the first binding ring 5 in the axial direction. The axially facing distance between the wall 81a of the binding body 81 and the distal end portion 82a of the fixed body 82 in a state where both bodies 81 and 82 are connected is the wall 53 of the first binding ring 5. , 54 coincide with the axially opposed distance.

  As shown in FIG. 2, the second seal member 9 is an elastic material having a relatively high hardness comprising a cylindrical distal end portion 91 and a cylindrical proximal end portion 92 having an L-shaped cross section extending forward from the inner peripheral portion of the front end thereof. As shown in FIG. 5, a cylindrical body is formed by separating one portion in the circumferential direction over the entire length and bonding the separated portion 9 a with an adhesive. is there. In this example, the second seal member 9 is made of nitrile rubber (NBR) that is the same quality as the first seal member 6.

  As shown in FIG. 2, the distal end portion 91 of the second seal member 9 is opposed to the wall portion 81 a of the binding body 81 and the distal end portion 82 a of the fixed body 82 in the axial direction, like the distal end portion 61 of the first seal member 6. A state in which it is fitted in the binding body 81 in a state of abutting on the end surface and abuts on the base end surface (the front end surface of the base end portion 74) of the second sealing ring 7 that is bound in an annular shape by the second snap ring 71 The outer ring 73 is fitted on the intermediate portion 73 and the base end portion 74 of the seal ring 7, and the thickness (the thickness in the radial direction) thereof is the intermediate portion 73 and the base end portion of the binding body 81 and the second seal ring 7. It is set larger by a predetermined amount (radial tightening allowance) than the dimension of the distance between the opposed peripheral surfaces 74 (radial distance). Thus, by fastening the binding body 81, as shown in FIG. 5, the second sealing ring 7 is bound in an annular shape with the distal end portion 91 of the second seal member 9 compressed in the radial direction interposed. It is supposed to be fixed. Even in the second seal member 9, as shown in FIG. 2, the outer diameter of the tip portion 91 is constant, as in the first seal member 6, and the intermediate portion 73 and the snap ring of the second seal ring 7 are fixed. The thickness of the portion 91a fitted in 71 (hereinafter referred to as “first tip portion”) 91a in the radial direction is fitted in the proximal end portion 74 of the sealing ring 7 (excluding the portion engaged with the snap ring 71). The portion (hereinafter referred to as “second distal end portion”) 91b is naturally thinner than the radial thickness of the portion 91b (hereinafter referred to as “second distal end portion”). It is set to be thicker than the axial thickness of 91c (referred to as “third tip portion”).

  The proximal end portion 92 of the second seal member 9 is clamped and fixed between the opposed peripheral surfaces of the rotating shaft 2 and the fixed body 82. That is, the base end portion 92 of the second seal member 9 is clamped and fixed between the fixed body 82 and the rotary shaft 2 while being fitted in the annular recess 82d of the fixed body 82 as shown in FIG. The space between the second binding ring 8 and the rotary shaft 2 is sealed (secondary seal).

  As shown in FIG. 1, the spring member 10 is loaded between the seal case 3 and the first binding ring 5 to urge the first binding ring 5 forward, that is, the first binding ring 5 has a first The first sealing ring 4 fitted and fixed via the seal member 6 is urged in the axial direction so as to press-contact the second sealing ring 5 and, as shown in FIG. The ring 5 includes a plurality of coil springs 10a arranged at equal intervals in the circumferential direction. In this example, each coil spring 10a has a recess 3b formed in the front end portion of the seal case 3 and a recess formed in the annular collar portion 56 of the first binding ring 5 (the through hole closed by the drive collar 57) as shown in FIG. Hole) 56b is held in a state where both ends are engaged. As shown in FIG. 1, the urging force (spring force) by the spring member 10 is the contact surface pressure between the seal rings 4 and 7 when the axial facing distance between the seal case 3 and the first binding ring 5 is set to a predetermined dimension. Is set to be appropriate. That is, the mechanical seal is assembled so that the axially facing distance between the seal case 3 and the first binding ring 5 is the predetermined dimension. Specifically, as shown in FIG. 1 and FIG. 6, a pair of adjustment plates (thickness discs matching the predetermined dimensions) 10b bolted to the outer periphery of the seal case 3 are connected to the seal case 3 and the second case. The second binding ring 8 (fixed body 82) is inserted between the first binding ring 5 and positioned so that the seal case 3 and the first binding ring 5 (annular flange 56) abut against the adjusting plate 10b. ) Is fixed to the rotary shaft 2 by the set screw 86. When the axial facing distance between the seal case 3 and the first binding ring 5 is set to the predetermined dimension, the first seal member 6 (mainly the second intermediate portion 63) is compressed in the axial direction. It has become.

  As shown in FIG. 1, a flushing passage 1c that opens to the inner peripheral portion is formed in the mechanical seal mounting portion 1a that constitutes the front end portion of the equipment housing 1, and the rotating shaft 2 extends from the opening portion of the passage 1c. And a thin cylindrical metal baffle 1d extending to the vicinity of the inner peripheral side of the relative rotational sliding contact portions 4a and 7a of the seal rings 4 and 7 is attached and supplied from the flushing passage 1c. The flushing fluid F is guided from the annular seal 1e formed between the mechanical seal mounting portion 1a, the first sealing ring 4 and the first peripheral surface of the first seal member 6 and the baffle 1d to the sealed end faces 4a and 7a. It is configured. As shown in FIG. 2, an annular protrusion 1f for reliably directing the flushing liquid F from the annular passage 1e to the sealed end faces 4a and 7a is formed on the outer peripheral portion of the baffle 1d. As the flushing fluid F, water that does not interfere with the fluid in the sealed fluid region H (sealed fluid) is used.

  In the divided mechanical seal configured as described above, the mechanical seal components such as the seal rings 4 and 7 can be disassembled and assembled in a direction (radial direction) perpendicular to the rotation axis. It has become. That is, when disassembling and assembling the mechanical seal, the sealing rings 4 and 7 and the binding rings 5 and 8 can collide and separate the divided portions from both sides in the radial direction of the rotating shaft. The snap rings 41 and 71 can be fitted to the seal rings 4 and 7 from one side in the radial direction of the rotary shaft 2 by opening the separated portions, and all mechanical seal components including the coil spring 10a can rotate. It is not necessary to move through the shaft 2. Therefore, even when the axial movement space such as the binding ring described at the beginning cannot be secured sufficiently, and when mechanical seal components other than the split seal rings 4 and 7 need to be maintained such as replacement. The mechanical seal can be easily disassembled and assembled, including maintenance.

  Furthermore, since the split-type sealing rings 4 and 7 are held in an annular shape by the snap rings 41 and 71, the fitting with the seal members 6 and 9 and the tightening work by the binding rings 5 and 8 can be performed. Maintenance including assembly work of the split seal rings 4 and 7 without the damage of the split parts 4A, 4B or 7A, 7B being dropped or causing personal injury when the mold seal rings 4 and 7 are assembled. Work and mechanical seal disassembly and assembly can be performed easily and safely.

  Further, by fastening the divided surfaces of the binding rings 5 and 8, that is, by tightening the binding rings 5 and 8 perpendicularly to the dividing surface, the divided sealing rings 4 and 7 interpose the elastic seal members 6 and 9. Unlike the first and second conventional seals, unlike the first and second conventional seals, the split seal ring 4 is different from the case where the split seal ring is fastened by tightening in the axial direction using the cam action. , 7 when assembled (tightened), the divided portions 4A, 4B or 7A, 7B will not be displaced in the axial direction. Moreover, the thickness in the binding direction of the first tip portions 61a and 91a and the second tip portions 61b and 91b of the seal members 6 and 9 interposed between the opposed peripheral surfaces of the split seal rings 4 and 7 and the binding rings 5 and 8 ( (Thickness in the radial direction) can be made sufficiently thick (the compression allowance at the time of binding is increased), so that even if the tightening force by the binding rings 5 and 8 is increased, There is no distortion. In the second conventional seal, since the binding force is obtained by the cam action of the tapered surface by the axial movement of the binding ring, as described at the beginning, the thickness of the elastic member is required for the axial movement of the binding ring. Cannot be made thicker than a certain value.

  Therefore, the split-type sealing rings 4 and 7 can be assembled so that the sealing end faces 4a and 7a have an appropriately shaped annular plane without causing distortion, and the sliding operation and the familiar operation as described at the beginning are performed. There is no need. In addition, as described above, the tightening force by the tightening rings 5 and 8 can be increased and the thickness in the tightening direction of the seal members 6 and 9 can be increased. Therefore, even when used under high pressure conditions, the split surface of the split seal ring There will be no leakage.

  Since the third end portions 61c and 91c of the seal members 6 and 9 are filled between the base end face of the seal rings 4 and 7 and the second wall portion 54 of the binding rings 5 and 8, the seal ring 4 , 7 even when an unnecessary axial pressing force is applied, this is absorbed and relaxed (cushion function) by the elasticity of the third tip portions 61c, 91c, so that the contact between the sealed end surfaces 4a, 7a The surface pressure is always properly maintained, and the sealing function by the relative rotational sliding contact action of the sealing end surfaces 4a and 7a is satisfactorily exhibited.

  In the second conventional seal, an elastic member (rubber sheet or O-ring) is loaded on the axially opposed end surfaces of the split seal ring and the holding ring. This elastic member functions as a seal between the two rings. (Secondary sealing function) is exerted, so the pressing force of the split seal ring against the holding ring due to the tightening force of the binding ring is increased, and the elastic member is strongly compressed to exhibit a sufficient sealing function. It is necessary to keep it. On the other hand, when the degree of compression of the elastic member is increased, even when an unnecessary axial pressing force is applied to the sealing ring as described above, a cushion function sufficient to absorb and relax this cannot be exhibited. Therefore, in the second conventional seal, it is necessary to adjust the tightening force of the binding ring to such an extent that the compression degree of the elastic member can be satisfactorily exhibited both the sealing function and the cushion function, but such adjustment is extremely difficult. Yes, often you have to sacrifice one of the functions. In the split mechanical seal according to the present invention, the sealing function between the seal rings 4 and 7 and the seal case 3 is based on the first tip portions 61a and 91a and the second tip portions 61b and 91b of the seal members 6 and 9. Since the end portions 64 and 94 exhibit the cushion function and the third end portions 61c and 91c of the seal members 6 and 9, the above-described problems do not occur.

  Further, since the sealing rings 4 and 7 are strongly bound and fixed by the fastening force of the fastening bolts 51, 83 and 84 in the binding rings 5 and 8 with the seal members 6 and 7 made of an elastic material interposed therebetween, There is no need to provide secondary seal means (O-rings) or relative rotation prevention means (drive pins) between 4, 7 and the binding rings 5, 8, and the sealing rings 4, 7 and the binding rings 5, 8 The connection structure can be simplified or simplified.

  It should be noted that the present invention is not limited to the above-described embodiment, and can be improved and changed as appropriate without departing from the basic principle of the present invention.

  For example, in the above-described split type mechanical seal, the second binding ring 8 is separated into the binding body 81 and the fixed body 82. However, instead of the second binding ring 8, as shown in FIGS. A second binding ring 80 of the structure can be used. As shown in FIGS. 7 and 8, the second binding ring 80 is made of a metal having the same annular shape as the shape obtained by integrating the two bodies 81 and 82, and is linear on the circumferential direction. It is divided into two parts, and the divided parts 80 </ b> A and 80 </ b> B are fastened in an annular shape with a pair of fastening bolts 87 and fixed to the rotary shaft 2 with a plurality of set screws 88. The seal receiving portion 80a that abuts the proximal end surface (front end surface) of the distal end portion 91 of the second seal member 9 in the fitting portion of the second seal member 9 to the second seal ring 7 in the second binding ring 80 is the fixed body. It has the same shape as the tip portion 82a of 82. The configuration of the split type mechanical seal shown in FIGS. 7 and 8 is the same as the split type mechanical seal shown in FIGS. 1 to 6 except for the configuration of the second binding ring 80 described above. 7 and 8 are denoted by the same reference numerals as in FIGS. 1 to 6, and the description thereof is omitted.

  In addition, as described above, the number of used snap rings 41 and 71 can be set as appropriate according to the shape of the split seal rings 4 and 7 in consideration of workability and necessary binding force. It can also be 1 or 3 or more. Further, the groove widths of the annular grooves 44a and 74a into which the inner peripheral portions of the snap rings 41 and 71 are fitted are set in accordance with the number of use.

  In the case where the mechanical seal mounting portion 1a is configured as a separate member from the main body portion 1A of the device housing 1, the mechanical seal mounting portion 1a is divided into two on the diameter line in the circumferential direction in the same manner as the seal case 3, It is also possible to fasten the ring in an annular shape with a fastening bolt.

  Further, as shown in FIG. 1 or FIG. 7, the first binding ring 5 is configured to directly fit and hold the holding portion 55 to the flange portion 3a of the seal case 3, but the fitting portions of both the portions 3a and 55 are fitted. An elastic material O-ring may be interposed in the joint portion. In this way, the alignment function by the O-ring is exhibited, and the concentricity of the first binding ring 5, that is, the first sealing ring 4 with respect to the rotating shaft 2 is effectively maintained even when the apparatus vibration is intense. There is. The O-ring is different from the O-ring loaded in the fitting portion between the retaining ring and the seal case in the first and second conventional seals, and has a sealing function (secondary sealing function) between the two parts 3a and 55. ) Is not intended.

  Further, in the seal case 3, the first binding ring 5, the second binding ring 8 (the binding body 81, the fixed body 82), and the second binding ring 80, in the vicinity of each fastening bolt 31, 51, 83, 84, 87. In addition, a taper hole for inserting a taper pin for alignment at the time of abutting each divided surface may be provided.

1. Equipment housing (rotary equipment housing)
DESCRIPTION OF SYMBOLS 1A Main body part 1a Mechanical seal attaching part 1b Annular convex part 1c Flushing path 1d Baffle 1e Annular path 1f Annular protrusion 2 Rotating shaft 3 Seal case 3A Divided part 3B Divided part 3a Flange part 3b Recessed part 4A Sealing ring 4A Divided part 4B Divided Part 4a Sealed end face 5 First binding ring 5A Split part 5B Split part 6 First seal member 6a Separated part 7 Second seal ring 7A Split part 7B Split part 7a Sealed end face 8 Second binding ring 9 Second seal member 9a Cut Separation part 10 Spring member 10a Coil spring 10b Adjustment plate 31 Fastening bolt 32 Mounting bolt 33 Drive pin 41 First snap ring 41a Operation hole 42 Tip part 43 Intermediate part 44 Base end part 44a Annular groove 51 Fastening bolt 52 Main body part 53 First Wall part 54 Second wall part 55 Holding Part 56 Annular collar part 56a Notch part 56b Recessed part (through hole)
57 Drive collar 57a Engaging recess 58 Diffusion prevention cover 59 Mounting bolt 61 Tip portion 61a First tip portion 61b Second tip portion 61c Third tip portion 62 First intermediate portion 63 Second intermediate portion 64 Base end portion 71 Second snap Ring 71a Operation hole 72 Tip portion 73 Intermediate portion 74 Base end portion 74a Annular groove 80 Second binding ring 80A Split portion 80B Split portion 80a Seal receiving portion 81 Tightened body 81A Split portion 81B Split portion 81a Wall portion 82 Fixed body 82A Split portion 82B Divided portion 82a Tip portion 82b Base end portion 82c Flange portion 82d Annular recess 83 Fastening bolt 84 Fastening bolt 85 Connection bolt 86 Set screw 87 Fastening bolt 88 Set screw 91 Tip portion 91a First tip portion 91b Second tip portion 91c Third tip portion 92 Base end portion F Flushing liquid H Sealed fluid region (in-machine region)
L Unsealed fluid region (atmosphere region)

Claims (6)

A seal case which is divided into two in the circumferential direction and is attached to the housing of the rotating device in a state of being fastened in an annular shape;
A first binding ring which is divided into two in the circumferential direction and is held in a seal case so as to be axially movable in a state of being fastened in an annular shape;
A second binding ring which is divided into two in the circumferential direction and is fastened in an annular shape and fixed to the rotating shaft of the rotating device;
First and second sealing members made of an elastic material that are formed in a cylindrical body by adhering a cut-off portion that is one place in the circumferential direction and separated over the entire length with an adhesive;
A split-type sealing ring that is divided into two in the circumferential direction, comprising a tip end portion having a sealed end face, an intermediate portion having a constant outer diameter connected thereto, and a base end portion having a constant outer diameter having a smaller outer diameter. First and second sealing rings,
A snap ring that is externally fitted to the proximal end portion of each split seal ring and holds the split seal ring in an annular shape;
The base end portion of the first seal member is clamped and fixed between the axially opposed end surfaces of the housing and the seal case, and the intermediate portion of the first seal ring and the base end portion on which the snap ring is fitted are first sealed. With the first binding ring in an annular state with the tip of the member interposed,
An intermediate portion of the second sealing ring and a proximal end portion on which the snap ring is fitted are fastened and fixed in an annular shape by the second binding ring with the second seal member interposed;
By the relative rotational sliding contact action of the sealing end faces of both sealing rings, the sealed fluid region that is the inner peripheral side region of the relative rotational sliding contact portion and the non-sealed fluid region that is the outer peripheral side region are configured to be shield-sealed. A split-type mechanical seal characterized by that.   The seal case is attached to a mechanical seal attachment portion of the housing, and the mechanical seal attachment portion is formed of a separate member from the main body portion of the housing and is attached to the main body portion. 1. A split type mechanical seal described in 1.   The second binding ring is divided into a binding body and a fixed body that are each divided into two in the circumferential direction and fastened in an annular shape, and the second sealing ring is connected to the first seal by connecting both bodies together. 3. The split mechanical seal according to claim 1, wherein the split mechanical seal is configured to be fixed to a rotating shaft with a member interposed therebetween.  The split mechanical according to any one of claims 1 to 3, wherein an annular groove into which an inner peripheral portion of the snap ring is fitted is formed on an outer peripheral surface of a base end portion of each sealing ring. seal.   The base end portion of each sealing ring is fitted with a plurality of snap rings of the same shape and the same material that are closely aligned in the axial direction. Split type mechanical seal to be described. The front end portion of each seal member has a cylindrical shape that is in pressure contact with the outer peripheral surface of the intermediate portion of the split seal ring and the base end portion with which the snap ring is fitted, and the base end surface of the seal ring. The split-type mechanical seal according to any one of claims 1 to 5.

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