JP6717728B2 - mechanical seal - Google Patents

Description

The present invention relates to a mechanical seal in which a sleeve is attached to a rotary shaft.

Conventionally, a mechanical seal has been used which seals a fluid to be sealed by sliding contact between the sealed end surface of a rotary ring and the sealed end surface of a stationary ring. For example, a mechanical seal includes a casing attached to a housing of a shaft sealing portion of a rotating device, a rotating shaft that inserts through the casing, a sleeve that is detachably fixed to the rotating shaft, and a sleeve that is axially movable in the sleeve. It mainly comprises a rotating ring, a stationary ring fixed to the casing, and a spring for urging the rotating ring toward the stationary ring. (See Patent Document 1, etc.). The mechanical seal is inspected at the time of maintenance, and parts are replaced if necessary.

JP, 2013-194899, A ([0024], Drawing 1)

Here, the sleeve contacts a fluid to be sealed on the inside of the machine and a fluid different from the fluid to be sealed on the outside of the machine with respect to a sealing portion formed by the sealing end surface of the rotating ring and the sealing end surface of the stationary ring. Atmosphere). Therefore, when a highly corrosive fluid is used as the sealed fluid, it is necessary to employ a sleeve having excellent corrosion resistance. Further, when the sleeve itself is deteriorated due to corrosion or the like, it is necessary to replace the entire sleeve although the outside of the machine is not corroded.

The present invention has been made in view of these problems, and an object thereof is to provide a mechanical seal having excellent workability in maintenance.

In order to solve the above problems, the mechanical seal of the present invention,
A mechanical seal that axially seals the sealed fluid in the machine,
A rotation axis,
A casing through which the rotary shaft is inserted;
A stationary ring retained in the casing,
A sleeve detachably inserted and fixed to the rotating shaft,
A rotary ring retained by the sleeve and forming a seal with the stationary ring;
Equipped with
The sleeve is
A first sleeve arranged on the opposite side of the sealed fluid side with respect to the sealed portion;
A second sleeve partially exposed on the sealed fluid side,
The second sleeve is detachably attached to the first sleeve.
According to this feature, even if the second sleeve arranged on the sealed fluid side needs to be replaced due to corrosion or the like, the first sleeve and the second sleeve are detachably attached, so that the second sleeve is attached. Only need to be replaced. Therefore, the workability of maintenance is excellent. Furthermore, since the first sleeve and the second sleeve are detachably attached, it is possible to use different materials for the first sleeve and the second sleeve.

The one end portion of the first sleeve and the other end portion of the second sleeve are axially fitted to each other by screwing the male screw portion on the outer peripheral side and the female screw portion on the inner peripheral side at the one end portion and the other end portion. It is characterized by
According to this feature, since the first sleeve is attached to the second sleeve by screwing the male screw portion on the outer peripheral side and the female screw portion on the inner peripheral side, not only the number of parts does not increase, but also the axial and radial directions are increased. Easy to position.
Further, in a preferred mode, one end of the first sleeve and the other end of the second sleeve are defined by a female screw portion on the inner peripheral side at one end of the first sleeve and the other end of the second sleeve. The male screw portion on the outer peripheral side of the portion is screwed and fitted in the axial direction. According to this, it is more preferable that the rotary ring is arranged on the inner side of the machine than the stationary ring.
In another preferred embodiment, the one end of the first sleeve and the other end of the second sleeve are different from the male screw portion on the outer peripheral side of the one end of the first sleeve and the other end of the second sleeve. The female screw portion on the inner peripheral side of the end portion is screwed and fitted in the axial direction. According to this, it is more preferable that the rotary ring is arranged outside the stationary ring rather than the stationary ring.

The sleeve has a rotation restricting member that extends in a radial direction and restricts relative rotation between the first sleeve and the second sleeve.
According to this feature, it is possible to reliably prevent relative rotation between the first sleeve and the second sleeve.

The rotation restricting member is a pin or a bolt that radially penetrates the through hole of the first sleeve and the through hole of the second sleeve.
According to this feature, the assembling work is easy.

The pin or the bolt is arranged at a position to be fitted in the radial groove of the rotary ring.
According to this feature, the same pin or bolt can prevent relative rotation of the first sleeve, the second sleeve, and the rotary ring, so that the assembly work is simple.

The one end portion of the first sleeve and the other end portion of the second sleeve are screwed with the male screw portion on the outer peripheral side and the female screw portion on the inner peripheral side at the one end portion and the other end portion,
The pin or the bolt is arranged inside the machine with respect to the screwing position of the male screw portion and the female screw portion.
According to this feature, since the screwing position of the male screw portion and the female screw portion does not interfere with the rotary ring, the structure is simple, and the second sleeve is easily assembled to the first sleeve.

The second sleeve has a protruding portion that protrudes in the outer diameter direction, and the rotary ring has a main body portion that is axially clamped by the protruding portion and the pin or bolt.
According to this feature, the sleeve and the rotary ring can be easily and integrally assembled.

FIG. 3 is a cross-sectional view showing the entire mechanical seal in the first embodiment. FIG. 5 is a diagram illustrating the assembly of the sleeve and the rotating ring of the first embodiment. FIG. 5 is a diagram illustrating the assembly of the sleeve and the rotating ring of the first embodiment. 3 is a front view of a rotary ring of Example 1. FIG. FIG. 6 is a cross-sectional view showing a main part of a mechanical seal according to a second embodiment. FIG. 9 is a cross-sectional view showing the main parts of the mechanical seal in the third embodiment.

Modes for carrying out a mechanical seal according to the present invention will be described below based on Examples. The present invention is not construed as being limited to this, and various changes, modifications, and improvements can be made based on the knowledge of those skilled in the art without departing from the scope of the present invention.

The mechanical seal according to the first embodiment will be described with reference to FIGS. 1 to 4.

The mechanical seal 1 is for sealing the sealed fluid L contained on the in-machine M side of the shaft sealing portion of a pump or the like, and is a so-called tandem type using two sets of a rotating ring and a stationary ring. In FIG. 1, from the left side, the region on the outside A side of the atmospheric atmosphere, the intermediate chamber C into which the external liquid for cooling is introduced, and the region on the inside M side that contains the sealed fluid L are shown. Further, the in-machine M side is called one end side, and the outside A side is called the other end side.

The mechanical seal 1 includes a casing 2 attached to a housing of a shaft sealing portion of a rotating device, a rotary shaft 3 which is inserted through the casing 2, a sleeve 10 which is detachably inserted and fixed to the rotary shaft 3, and a sleeve 10 which is fixed to the sleeve 10. The first rotating ring 30 (rotating ring), the first stationary ring 40 (stationary ring) held by the casing 2 so as to be movable in the axial direction, and the first rotating ring 30 interposed between the casing 2 and the first stationary ring 40. The first stationary ring 40 to urge the first stationary ring 40 toward the first rotating ring 30, the second rotating ring 60 held by the sleeve 10 so as to be movable in the axial direction, and the second stationary ring fixed to the casing 2. A ring 61 and a second spring 62 that is interposed between the holder 63 and the second rotary ring 60 and urges the second rotary ring 60 toward the second stationary ring 61 are mainly configured.

The sealing end surface of the first rotary ring 30 and the sealing end surface of the first stationary ring 40 form a first sealing portion S1 that is in sliding contact. The sealed fluid L leaking from the in-machine M side to the intermediate chamber C side is sealed in the first sealing portion. The sealed end surface of the second rotary ring 60 and the sealed end surface of the second stationary ring 61 form a second sealed portion S2 that is in sliding contact. The external liquid E that leaks from the intermediate chamber C side to the outside A side is sealed in the second sealing portion. The rotation of the first stationary ring 40 is restricted by a knock pin 41 fixed to the second casing 2B. Similarly, the rotation of the second stationary ring 61 is restricted by a knock pin 65 fixed to the first casing 2A. An O-ring G10 is interposed between the first stationary ring 40 and the third casing 2C. Similarly, an O-ring G6 is interposed between the second stationary ring 61 and the first casing 2A.

The casing 2 includes, from the outside A side, a first casing 2A provided with a through passage 2D serving as an external liquid outlet, a second casing 2B provided with a through passage 2E serving as an external liquid inlet, and a rotating device (not shown). And a third casing 2C having a mounting flange to be attached to the housing. O-rings G1 and G2 are interposed between the first casing 2A, the second casing 2B, and the third casing 2C, and the first casing 2A, the second casing 2B, and the third casing 2C are liquid-tightly fixed by fastening screws. Has been done.

The sleeve 10 is mainly composed of a first sleeve 11 on the outside A side and a second sleeve 21 on the inside M side.

With reference to FIG. 2, the first sleeve 11 is made of stainless steel, and a female screw portion 13 is formed on the inner circumference of an end portion 12 (one end portion) on one end side (inside the machine M side) of the first sleeve 11. Through holes 14 that are equally arranged in the circumferential direction and penetrate through in the radial direction are formed on the M side in the axial direction.

The second sleeve 21 is formed of a titanium alloy having excellent corrosion resistance, and has a small diameter portion 21A from the other end side (outside the machine A side), a first step portion 21B having a larger outer diameter than the small diameter portion 21A, and a first step portion. The second step portion 21C having an outer diameter larger than that of 21B and the large diameter portion 21D having an outer diameter larger than that of the second step portion 21C are formed in a stepped cross section.

A male thread portion 23 is formed on the outer circumference of the end portion 22 (the other end portion) on the other end side of the small diameter portion 21A, and is provided with a step that is equidistantly arranged in the circumferential direction on the axial direction inside M side of the male thread portion 23 and penetrates in the radial direction. Through holes 24 are formed. The upper surface of the first step portion 21B serves as a mounting portion for the O-ring G22, and the upper surface of the second step portion 21C has an inner peripheral surface 32a on one end side (in-machine M side) of the main body portion 32 of the first rotary ring 30. It is a mating surface for mating. The large diameter portion 21D is a flange portion (projection portion) extending outward in the radial direction, and the side surface 28b on the other end side is in contact with the side surface 32b on one end side of the main body portion 32 of the first rotating ring 30 so that the first rotating ring 30 is formed. Are positioned in the axial direction.

The outer diameter of the small diameter portion 21A is formed to have substantially the same size as the inner diameter of the end portion 12 of the first sleeve 11, and the first sleeve 11 and the second sleeve 21 are so-called spigot joints. It is like this.

Here, the assembly of the first sleeve 11 and the second sleeve 21 will be described. The O-ring G21 is arranged on the inner circumference of the second sleeve 21, the O-ring G22 is axially inserted and mounted to the first step portion 21B, and the first rotary ring 30 is axially inserted to the second step portion 21C. And put it on. Further, the cap 33 (rotation restricting member) having a concave portion inside is arranged in the fitting groove 31 (radial groove) of the first rotating ring 30. As shown in FIG. 4, fitting grooves 31 extending in the radial direction from the inner peripheral side are arranged in the first rotary ring 30 at equal intervals in the circumferential direction. The outer diameter of the cap 33 is formed to have substantially the same size as the inner diameter of the fitting groove 31. Note that the number of fitting grooves 31 arranged is not limited to four.

Next, by fitting the end portion 22 of the second sleeve 21 into the end portion 12 of the first sleeve 11 and rotating the second sleeve 21, the male screw portion 23 is screwed into the female screw portion 13. In this state, as shown in FIGS. 2 and 3, the outer peripheral surface 12a of the end portion 12 of the first sleeve 11 on the other end side in the axial direction of the through hole 14 is fitted to the inner peripheral surface 32a of the first rotating ring 30. At the same time, the side end surface 12b of the end portion 12 on the other end side in the axial direction contacts the side surface 29 on the one end side of the first step portion 21B of the second sleeve 21. By the contact between the side end surface 12b and the side surface 29, the relative assembly position of the first sleeve 11 and the second sleeve 21 in the axial direction is determined. In this way, the first rotating ring 30 is fitted to the second step portion 21C of the second sleeve 21 and the end portion 12 of the first sleeve 11 over the axial direction of the inner peripheral surface 32a thereof, and thus is stable. Then installed.

Next, as shown in FIG. 3, the small-diameter body portion 27B of the pin 27 (rotation restricting member) is inserted into the through hole 24 and the through hole 14 from the inside in the radial direction, and the tip portion of the body portion 27B is press-fitted into the cap 33. Fix it. As a result, the pin 27 is prevented from coming off, and the first sleeve 11 and the second sleeve 21 are more firmly fixed. The inner diameters of the through hole 14 and the through hole 24 are formed to have substantially the same dimensions as the outer diameter of the body portion 27B of the pin 27, and are formed to be smaller than the outer diameter of the head portion 27A of the pin 27. There is. Therefore, the head portion 27A of the pin 27 is housed in the large diameter portion 25 (FIG. 2) of the stepped through hole 24. Further, the main body portion 32 of the first rotary ring 30 is sandwiched and fixed by the body portion 27B of the pin 27 and the flange portion 28 of the second sleeve 21 via the cap 33 in the axial direction.

As an assembling procedure, in FIGS. 2 and 3, an example in which the second sleeve 21 is assembled to the first sleeve 11 and then the sleeve 10 is assembled to the casing 2 is described, but the first sleeve 11 is assembled to the casing 2. After mounting, the second sleeve 21 may be assembled to the first sleeve 11.

Referring to FIG. 1, the first sleeve 11 has O-rings G3 and G4 arranged on the inner periphery thereof, and is detachably fixed to the rotary shaft 3 using a shaft fixing member 16. The shaft fixing member 16 is composed of a tapered belt member, a pair of rings, and a tightening screw, and fixes the first sleeve 11 to the rotating shaft 3 with a torque according to the tightening amount of the tightening screw. The first sleeve 11 may be fixed to the rotary shaft 3 by another means, for example, a means using a set screw.

The holder 63 is fixed to the first sleeve 11 by a set screw 66. The holder 63 accommodates the second spring 62, holds the second rotary ring 60 so as to be movable in the axial direction, and engages with the protrusion of the second rotary ring 60 in the outer diameter direction to rotate the second rotary ring 60. It has a restricting claw 64 for restricting. An O-ring G5 is arranged between the second rotary ring 60 and the first sleeve 11.

The first casing 2A and the first sleeve 11 are positioned at the same time by fitting the convex portion on the inner diameter side of the set plate 19 attached to the first casing 2A via the attachment screw 18 into the positioning groove 17 of the first sleeve 11. Can be assembled. The set plate 19 is removed after assembly and before use of the mechanical seal 1. In this way, before removing the set plate 19, the casing 2, the sleeve 10, the first rotating ring 30, the first stationary ring 40, the second rotating ring 60, and the second stationary ring 61 are unitized.

As described above, it has the following advantages.
Since the first sleeve 11 is arranged on the side of the intermediate chamber C and the outside A side opposite to the sealed fluid L side with respect to the first sealed portion S1, the first sleeve 11 contacts the sealed fluid L. It does not corrode and does not easily corrode.
Although the second sleeve 21 is partially exposed on the side of the sealed fluid L, the second sleeve 21 is made of a titanium alloy and is therefore unlikely to be corroded.
Furthermore, since the second sleeve 21 is detachably attached to the first sleeve 11, only the second sleeve 21 can be replaced when it is corroded. Therefore, the workability of maintenance is excellent.

Further, the end portion 22 of the second sleeve 21 is axially fitted inside the end portion 12 of the first sleeve 11 in the axial direction, and in this state, the male screw portion 23 on the outer peripheral side of the end portion 22 and the end portion 12 are The female screw portion 13 on the peripheral side is screwed. Therefore, a separate fixing screw is not required to attach the second sleeve 21 to the first sleeve 11, and the number of parts does not increase. In addition, the axial and radial directions of the first sleeve 11 and the second sleeve 21 are not increased. Easy to position.
Further, since the male screw portion 23 and the female screw portion 13 are fixed by screwing, the screwed portion is relatively excellent in liquid tightness.
In addition, since the male screw portion 23 and the female screw portion 13 are fixed by screwing, even a material such as titanium alloy that is difficult to weld can be used as a constituent member of the sleeve 10.
Further, the first rotary ring 30 is located closer to the inboard M side than the first stationary ring 40, the second sleeve 21 is fitted inside the first sleeve 11, and the second sleeve 21 on the inboard M side makes a first rotation. The ring 30 is attached and supported. Since the first rotary ring 30 is mounted and supported on the second sleeve 21 on the M side in the machine, the length in the axial direction can be shortened.

Further, since the end portion 22 of the second sleeve 21 is axially fitted inside the end portion 12 of the first sleeve 11 in the radial direction, the inner peripheral side of the intermediate chamber C is defined by the first sleeve 11. The 2 sleeve 21 is not exposed in the intermediate chamber C. Therefore, a long continuous surface is formed by the first sleeve 11 on the inner peripheral side of the intermediate chamber C, and the flow of the external liquid E supplied to the intermediate chamber C can be made smooth.

Further, in addition to fixing by screwing the male screw portion 23 and the female screw portion 13, the pin 27 is inserted into the through hole 24 and the through hole 14, so that the relative rotation between the first sleeve 11 and the second sleeve 21 is ensured. Can be regulated. The tip portion of the body portion 27B of the pin 27 may be used as a portion/member for preventing rotation of the first rotary ring 30 without using the cap 33. Further, although the pin 27 is described as an example having no threaded portion, it may be a bolt having a threaded portion on the body portion. In the case of using a bolt, a cap having a female screw portion may be used as the cap 33 and the bolt may be screwed into the cap.

Further, since the pin 27 penetrates the through hole 14 of the first sleeve 11 and the through hole 24 of the second sleeve 21 in the radial direction, the structure is simple and the assembling work is simple.

Further, since the pin 27 is arranged at a position to be fitted into the fitting groove 31 of the first rotary ring 30, the relative rotation of the first sleeve 11, the second sleeve 21, and the first rotary ring 30 is performed by the same pin 27. Can be prevented. Therefore, the number of parts is small and the assembling work is easy.

Further, since the pin 27 is arranged on the in-machine M side of the male screw portion 23, the male screw portion 23 does not interfere with the first rotary ring 30. Therefore, the structure is simple and the second sleeve 21 is easily assembled to the first sleeve 11.

Further, since the main body portion 32 of the first rotating ring 30 is axially sandwiched by the flange portion 28 of the second sleeve 21 and the pin 27, the second sleeve 21 and the first rotating ring 30 can be easily and integrally formed. Can be assembled. In other words, since the first rotating ring 30 is fixed to the second sleeve 21 by the pin 27, the number of parts for fixing the first rotating ring 30 can be reduced.

A mechanical seal according to the second embodiment will be described with reference to FIG. The description of the same configuration as the first embodiment will be omitted. The mechanical seal 101 of the second embodiment is a so-called double type that uses two sets of a rotating ring and a stationary ring, and the end portion 122 of the second sleeve 121 is axially arranged on the outer peripheral side of the end portion 112 of the first sleeve 111. The configuration in which they are fitted together differs from the mechanical seal 1 of the first embodiment.

Referring to FIG. 5, the sealing end surface of the first rotary ring 130A and the sealing end surface of the first stationary ring 140 form a first sealing portion S1 (sealing portion) that is in sliding contact. The sealing end surface of the second rotary ring 130B and the sealing end surface of the second stationary ring (not shown) form a second sealing portion that makes sliding contact.

A holder 132 is attached to the first sleeve 111 so as not to rotate relative to it. The holder 132 has a first rotary ring 130A and a second rotary ring 130B arranged and held in opposite directions. The first rotary ring 130A is movable in the axial direction and the rotational force is transmitted by the drive pin 136. The first rotary ring 130A is biased toward the first stationary ring 140 by a spring (not shown). The second rotary ring 130B is movable in the axial direction, and the rotational force is transmitted by a drive pin (not shown). The second rotating ring 130B is biased by a spring 150B toward a second stationary ring (not shown). The first stationary ring 140 is fitted into the inner circumference of the first casing 102A and is restricted from moving in the axial direction from the other end side by the mounting member 102B.

Next, the sleeve 110 will be described. The sleeve 110 is mainly composed of a first sleeve 111 and a second sleeve 121.
The first sleeve 111 is formed of stainless steel, and has a male thread portion 113 formed on the outer periphery of an end portion 112 (one end portion) on one end side (in-machine M side) of the first sleeve 111. A through hole 114 is formed so as to penetrate in the direction.
The second sleeve 121 is formed of a titanium alloy having excellent corrosion resistance, and has a female screw portion 123 formed on the inner circumference of the end portion 122 (the other end portion) on the other end side.

The female screw portion 123 of the second sleeve 121 is screwed onto the male screw portion 113 of the first sleeve 111, and the second sleeve 121 is attached to the first sleeve 111. After that, a set screw 115 (rotation restricting member) is screwed into the through hole 114 to fix the second sleeve 121 to the first sleeve 111 in a non-rotatable manner.

The axial position of the second sleeve 121 is determined by the side end surface 122a of the end 122 on the in-machine M side of the second sleeve 121 contacting the side end surface 112a of the first sleeve 111. The axial position may have a dimensional relationship that is determined by the contact between the side end surface 122b of the end portion 122 of the second sleeve 121 and the outer diameter side end surface 112b of the first sleeve 111.

With the second sleeve 121 attached to the first sleeve 111, the side end surface 122b of the end portion 122 of the second sleeve 121 contacts the side end 132b of the holder 132. The holder 132 has its axial position determined by the second sleeve 121.

Since it is as above, it has the same advantage as Example 1, for example, the following advantages.
Since the first sleeve 111 is arranged on the side of the intermediate chamber C and the outside A side of the sealed fluid L side opposite to the sealed fluid L side, the first sleeve 111 contacts the sealed fluid L. It does not corrode and does not easily corrode.
Further, although the second sleeve 121 is partially exposed on the sealed fluid L side, the second sleeve 121 is made of a titanium alloy and is therefore unlikely to be corroded.
Further, since the second sleeve 121 is detachably attached to the first sleeve 111, only the second sleeve 121 can be replaced when it is corroded. Therefore, the workability of maintenance is excellent.

Further, the end portion 122 of the second sleeve 121 is fitted in the outer side in the radial direction of the end portion 112 of the first sleeve 111 from the axial direction, and the female screw portion 123 on the inner peripheral side of the end portion 122 and the outer peripheral side of the end portion 112. The male screw portion 113 is screwed. Therefore, a separate fixing screw is not required to attach the second sleeve 121 to the first sleeve 111, and the number of components does not increase. In addition, the axial and radial directions of the first sleeve 111 and the second sleeve 121 are not increased. Easy to position.
Further, the first rotary ring 130A is located closer to the outside A side than the first stationary ring 140, the second sleeve 121 is fitted to the outside of the first sleeve 111, and the first sleeve ring A is attached to the second sleeve 121 on the inside M side. The rotating ring 130A can be mounted and supported. Since the first rotary ring 130A is mounted and supported on the second sleeve 121 on the M side in the machine, the structure can be simplified.

A mechanical seal according to the third embodiment will be described with reference to FIG. The description of the same configuration as the first embodiment will be omitted. The mechanical seal 201 of the third embodiment is mainly different from the mechanical seal 1 of the first embodiment in that the first sleeve 211 and the second sleeve 221 are tapered together.

The sleeve 210 will be described. The sleeve 210 is mainly composed of a first sleeve 211 and a second sleeve 221.
The first sleeve 211 is made of stainless steel, and a taper portion 213 is formed on the inner periphery of an end portion 212 (one end portion) on one end side (inside the machine M side) of the first sleeve 211. Through holes 14 that are equally arranged in the circumferential direction and penetrate through in the radial direction are formed.

The second sleeve 221 is formed of a titanium alloy having excellent corrosion resistance, and a taper portion 223 is formed on the outer circumference of the end portion 222 (one end portion) on the other end side (outside the machine A side). A stepped through hole 24 is formed on the inner side of the direction machine M so as to be evenly arranged in the circumferential direction and penetrate in the radial direction.

The second sleeve 221 is inserted into the first sleeve 211 from the axial direction, and the tapered portion 223 is engaged with the tapered portion 213 to position the first sleeve 211 and the second sleeve 221 in the axial direction. Since the engagement is made by the taper, the assembly is easy and the positioning accuracy is good.

Although the embodiments of the present invention have been described above with reference to the drawings, the specific configurations are not limited to these embodiments, and any modifications or additions within the scope of the present invention are included in the present invention. Be done.

Although the first sleeve is made of stainless steel and the second sleeve is made of titanium alloy having excellent corrosion resistance in Examples 1 to 3, the present invention is not limited to these materials. The material of the first sleeve and the second sleeve may be a material suitable for the application, and for example, iron material, stainless material, titanium material, zirconium material can be used.

Further, the tandem mechanical seals 1 and 201 in the first and third embodiments and the double mechanical seal 101 in the second embodiment have been described, but the mechanical seal may be of any type. For example, a single type mechanical seal may be used.

Further, in the first and third embodiments, an example in which the end portions of the second sleeves 21 and 221 are fitted inside the end portions 12 and 222 of the first sleeves 11 and 211 in the radial direction has been described. The end of the second sleeve may be fitted to the outer side of the end in the radial direction. Similarly, in the second embodiment, an example in which the end portion 122 of the second sleeve 121 is fitted to the outer side in the radial direction of the end portion 112 of the first sleeve 111 has been described, but the inner side in the radial direction of the end portion of the first sleeve is described. Alternatively, the end portion of the second sleeve may be fitted in.

In addition, in the first to third embodiments, the example in which the first sleeve is configured by one member has been described, but the first sleeve may be configured to be dividable in the axial direction. Similarly, the second sleeve may also be configured to be axially separable. At least a part of the first sleeve is exposed to the sealed fluid side, and the second sleeve is not exposed to the sealed fluid side.

Further, the materials of the rotary ring and the stationary ring in Examples 1 to 3 can be appropriately selected from well-known ceramic materials and metal materials. For example, it is manufactured from SiC by a special conversion method (the carbon surface is partially made into SiC so as to reinforce the surface strength so as to have both the wear resistance of SiC and the self-lubricating property of carbon). It may also be made of diamond-coated SiC.

Further, in the first to third embodiments, each O-ring described with reference numeral G is a so-called secondary seal, and a well-known one can be appropriately selected. For example, it is formed in a ring shape with rubber as a main component.

1 Mechanical Seal 2 Casing 3 Rotating Shaft 10 Sleeve 11 First Sleeve 12 End (One End)
13 Female thread portion 14 Through hole 21 Second sleeve 22 End portion 23 Male thread portion 24 Through hole 27 Pin (rotation restricting member)
28 Flange (projection)
30 first rotary ring 31 fitting groove (radial groove)
33 Cap (rotation restriction member)
40 first stationary ring 101 mechanical seal 102 casing 110 sleeve 111 first sleeve 112 end 113 male thread 114 through hole 115 set screw (rotation restricting member)
121 2nd sleeve 122 End part 123 Female screw part 130A 1st rotary ring 130B 2nd rotary ring 201 Mechanical seal 210 Sleeve 211 1st sleeve 212 End part 213 Tapered part 221 2nd sleeve 222 End part 223 Taper part A Outside M Inside machine C Intermediate chamber L Sealed fluid S1 First sealed portion S2 Second sealed portion

Claims (6)

A mechanical seal that axially seals the sealed fluid in the machine,
A rotation axis,
A casing through which the rotary shaft is inserted;
A stationary ring retained in the casing,
A sleeve detachably inserted and fixed to the rotating shaft,
A rotary ring retained by the sleeve and forming a seal with the stationary ring;
Equipped with
The sleeve is
A first sleeve arranged on the opposite side of the sealed fluid side with respect to the sealed portion;
A second sleeve partially exposed on the sealed fluid side,
The second sleeve is removably attached to the first sleeve, and one end portion of the first sleeve and the other end portion of the second sleeve are externally threaded male thread portions at the one end portion and the other end portion. A mechanical seal characterized in that the female screw portion on the inner peripheral side is screwed and fitted in the axial direction . The mechanical seal according to claim 1 , wherein the sleeve has a rotation restricting member that extends in a radial direction and restricts relative rotation between the first sleeve and the second sleeve. The mechanical seal according to claim 2 , wherein the rotation restricting member is a pin or a bolt that radially penetrates the through hole of the first sleeve and the through hole of the second sleeve. The mechanical seal according to claim 3 , wherein the pin or the bolt is arranged at a position to be fitted into the radial groove of the rotary ring. The one end portion of the first sleeve and the other end portion of the second sleeve are screwed with the male screw portion on the outer peripheral side and the female screw portion on the inner peripheral side at the one end portion and the other end portion,
The mechanical seal according to claim 3 or 4 , wherein the pin or the bolt is arranged on the inner side of the machine with respect to a screwing position of the male screw portion and the female screw portion. The said 2nd sleeve has a protrusion part which protrudes in an outer radial direction, The main body part of the said rotating ring is pinched|interposed by the said protrusion part and the said pin or a bolt in the axial direction, The said 3 thru|or 3 characterized by the above-mentioned. 5. The mechanical seal according to any one of 5 .

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