JP6770376B2 - Double mechanical seal device - Google Patents

Description

The present invention relates to a double mechanical sealing device having two pairs of a rotary sealing ring and a static sealing ring.

As the double mechanical sealing device, for example, those shown in Patent Document 1 or Patent Document 2 shown below are known. In the double mechanical sealing device shown in the publications of these documents, a single spring is arranged on the outer circumference of the rotating shaft. One end of a single spring presses one rotary seal ring against one static seal ring, and the other end of the spring presses the other rotary seal ring against the other static seal ring.

However, these conventional double mechanical sealing devices are devised for the purpose of sealing for a rotating shaft having a relatively small outer diameter, and when the outer diameter of the rotating shaft is large, the outer diameter of the spring is increased. This makes it difficult to manufacture the spring and also makes it difficult to install it. There is also a problem that the spring spreads outward due to fluid pressure or the like.

Jikkai Sho 62-2863 Square root extraction No. 3-98368

The present invention has been made in view of such an actual situation, and an object of the present invention is that even when the outer diameter of the rotating shaft is large, it is easy to press each rotating sealing ring against each stationary sealing ring, and the sealing property is improved. It is to provide an excellent double mechanical sealing device.

In order to achieve the above object, the double mechanical seal device according to the present invention is
A first seal located proximal to the cabin and a second seal located distal to the cabin.
A double mechanical sealing device having an intermediate chamber formed between the first sealing portion and the second sealing portion.
The first seal portion is
The first rotating sealing ring, which rotates with the rotating shaft but is movable in the axial direction,
It has a first static sliding surface that is slidable with respect to the first rotating sliding surface of the first rotary sealing ring, and has a first static sealing ring that is supported by a housing and does not rotate.
The second seal portion is
A second rotary sealing ring that rotates with the rotary shaft but is movably arranged in the axial direction.
It has a second static sliding surface that is slidable with respect to the second rotating sliding surface of the second rotary sealing ring, and has a second static sealing ring that is supported by the housing and does not rotate.
On the outer circumference of the rotating shaft located in the intermediate chamber, an intermediate ring that rotates together with the rotating shaft and moves together in the axial direction is arranged.
The intermediate ring is formed with through holes for springs that penetrate in a plurality of axial directions along the circumferential direction.
A spring is mounted along the axial direction in each of the through holes for the spring.
One end of each of the springs is configured to press the first rotary sealing ring toward the first static sealing ring, and the other end of each of the springs presses the second rotary sealing ring. It is configured to press toward the second static sealing ring.

The double mechanical sealing device according to the present invention has an intermediate ring in which through holes for springs penetrating in a plurality of axial directions are formed. A spring is attached to each of the plurality of through holes for springs formed in the intermediate ring, and the elastic force of each spring is a force in the direction of axially separating the first rotation sealing ring and the second rotation sealing ring. Works. As a result, the first rotary sealing ring is pressed against the first static sealing ring, the second rotary sealing ring is pressed against the second static sealing ring, and the sealing performance between them is improved.

In the double mechanical sealing device of the present invention, when the outer diameter of the rotating shaft is large, the inner and outer diameters of the intermediate ring can be increased, and the number of through holes for springs formed intermittently in the circumferential direction of the intermediate ring can be increased. It is sufficient, and it is not necessary to increase the outer diameter of the spring itself. Therefore, it is easy to manufacture the spring, and it is only necessary to prepare a standard size spring, and it is easy to install the spring. Further, since each spring is used by being inserted into the through hole for the spring, the spring does not spread to the outside due to fluid pressure or the like.

Further, in the double mechanical sealing device of the present invention, even if the axis of the rotating shaft moves due to long-term operation, the pair of rotating sealing rings move relative to the rotating shaft in the axial direction, so that the mounting length of the spring is long. Does not change. Therefore, the pressing force on the pair of rotary sealing rings due to the elastic force of the spring is unlikely to change, and the sealing performance can be easily maintained constant for a long period of time. Further, since both the first seal portion and the second seal portion are composed of mechanical seals, it is possible to cope with a high pressure difference, and it is excellent in sealing performance and durability for a long period of time. It is easy to support maintenance-free. Therefore, the double mechanical sealing device according to the present invention can be effectively used as a sealing device for underwater equipment such as a marine propulsion device.

Preferably, the sleeve is fixed to the outer periphery of the rotating shaft so as to rotate together with the rotating shaft and move together along the axial direction.
The intermediate ring is fixed to the outer circumference of the sleeve.
One end of the spring is in contact with the back surface of the first pressure ring, the back surface of the first rotary sealing ring is in contact with the front surface of the first pressure ring, and the elastic force of the spring is the first. It is configured to be transmitted to the first rotary sealing ring via one pressure ring and push the first rotary sealing ring toward the first static sealing ring along the axial direction.
The other end of the spring is in contact with the back surface of the second pressure ring, the back surface of the second rotary sealing ring is in contact with the front surface of the second pressure ring, and the elastic force of the spring is the same. It is configured to be transmitted to the second rotary sealing ring via the second pressure ring and push the second rotary sealing ring toward the second static sealing ring along the axial direction.

With this configuration, the elastic force of each spring acts satisfactorily so as to separate the first rotary sealing ring and the second rotary sealing ring in the axial direction, and the first rotary sealing ring becomes the first static sealing ring. Pressed, the second rotary sealing ring is pressed against the second static sealing ring, improving the sealing performance between them.

Preferably, on the outer circumference of the sleeve, the first pressure ring and the first rotary sealing ring are axially relative to the sleeve at a first predetermined distance along the axial direction from one end of the intermediate ring. It is arranged so that it can be moved.
On the outer circumference of the sleeve, the second pressure ring and the second rotary sealing ring are axially movable with respect to the sleeve at a second predetermined distance along the axial direction from the other end of the intermediate ring. It is placed in.

With this configuration, even if the rotation axis shifts in the axial direction due to long-term operation and the intermediate ring moves in the axial direction together with the rotation axis within the range of the first predetermined distance or the second predetermined distance, the first The intermediate ring does not collide with the one-turn or second-turn sealing ring. Further, even if the intermediate ring is displaced in the axial direction together with the rotation shaft, the axial mounting length of the spring does not change because each spring is only inserted into the spring through hole of the intermediate ring. Therefore, the pressing force on the pair of rotary sealing rings due to the elastic force of the spring is unlikely to change, and the sealing performance can be easily maintained constant for a long period of time.

Preferably, the inner diameter of the first rotary sealing ring and the inner diameter of the second rotary sealing ring are substantially the same.
The outer diameter of the sleeve corresponding to the position where the first rotary sealing ring is movably mounted in the axial direction, and the sleeve corresponding to the position where the second rotary sealing ring is movably mounted in the axial direction. The outer diameter is substantially the same.

With this configuration, the pressure action diameters acting on the first rotary sealing ring and the second rotary sealing ring based on the fluid in the intermediate chamber are substantially the same, the thrust forces acting on both are canceled out, and the thrust force is unbalanced. The balance can be prevented.

Preferably, a sealing member is movably mounted along the axial direction in the stepped recess between the second rotary sealing ring and the outer peripheral surface of the sleeve.

With this configuration, the second rotary sealing ring can be pressed against the second static sealing ring even when the pressure in the intermediate chamber is higher than the pressure outside the casing and vice versa, and the second seal can be pressed. Good sealing performance of the part can be maintained. In particular, when the outside of the casing is filled with a liquid such as seawater, even if the pressure of the seawater is higher than the internal pressure of the intermediate chamber, the sealing property of the second seal portion is maintained and the seawater is inside the intermediate chamber. It can be effectively prevented from flowing into the casing. The case where the pressure of seawater is higher than the internal pressure of the intermediate chamber is, for example, the case where the oil supply unit that supplies oil to the intermediate chamber is stopped.

Preferably, the housing is provided with a first tubular convex portion located on the inner peripheral side of the first static sealing ring, and a second cylinder located on the inner peripheral side of the second static sealing ring. Convex parts are arranged,
The outer diameter of the first tubular convex portion and the outer diameter of the second tubular convex portion are substantially the same.
The inner diameter of the first rest-sealing ring and the inner diameter of the second rest-sealing ring are substantially the same.

With this configuration, the pressure action diameters acting on the first rest-sealing ring and the second rest-sealing ring are substantially the same, the thrust forces acting on both are canceled out, and the imbalance of the thrust forces can be prevented. it can.

Preferably, a single O-ring is interposed between the first static sealing ring and the first tubular convex portion, and the first static sealing ring is formed on the outer circumference of the first tubular convex portion. Is held in a float type,
A single O-ring is interposed between the second static sealing ring and the second tubular convex portion, and the second static sealing ring is floated on the outer circumference of the second tubular convex portion. Hold in.

With this configuration, the first static sealing ring and the second static sealing ring can be tilted with the O-ring as the center of rotation, and even if the rotation axis is slightly tilted, the first sealed portion and the second static sealing ring 2 The sealing performance of the sealed portion does not deteriorate. From this point of view, the first rotation sealing ring and the second rotation sealing ring are also equipped with a single O-ring on the inner peripheral side thereof, and they are held in a float manner. Is preferable.

Preferably, the housing is cartridge-type mounted on the casing of the equipment.
The first static sealing is performed on the housing so that the fluid inside the casing is located on the inner peripheral side of the first seal portion and the fluid outside the casing is located on the inner peripheral side of the second seal portion. A ring and the second static sealing ring are attached.

The cartridge type configuration in this way facilitates mounting and maintenance of the device on the casing or the like. Further, since the fluid inside the casing is located on the inner peripheral side of the first seal portion and the fluid outside the casing is located on the inner peripheral side of the second seal portion, the pressure action diameter of the first seal portion and the first It is easy to configure the pressure action diameter of the two seal portions to be substantially the same.

FIG. 1 is a schematic semi-cross-sectional view of a double mechanical sealing device according to an embodiment of the present invention. FIG. 2 is an enlarged cross-sectional view of a main part of the double mechanical sealing device shown in FIG. FIG. 3 is an enlarged cross-sectional view of a main part showing a cross section different from that of FIG. 2 of the double mechanical sealing device shown in FIG. FIG. 4 is an exploded perspective view of the intermediate ring shown in FIGS. 2 and 3. FIG. 5 is an enlarged cross-sectional view of the second seal portion shown in FIGS. 2 and 3. FIG. 6 is an enlarged cross-sectional view of the second seal portion when the seawater pressure is higher than the internal pressure of the intermediate chamber. FIG. 7 is an enlarged cross-sectional view of a main part when the rotation axis shown in FIG. 2 is displaced in the axial direction.

Hereinafter, the present invention will be described based on the embodiments shown in the drawings.
The double mechanical sealing device according to the embodiment of the present invention will be described with reference to FIG. FIG. 1 is a semi-cross-sectional view showing the configuration of the double mechanical sealing device 10.

The double mechanical sealing device 10 is a cartridge-type sealing device that is mounted from the outside OS side in the shaft hole portion 3a of the casing 3 through which the rotating shaft (shaft) 2 penetrates. The casing 3 is used as a part of the casing of an underwater device such as a marine thruster.

The double mechanical seal device 10 is a seal device suitable for such applications as a marine propulsion device. A prime mover, a rotor of a generator, or the like may be fixed to the outer periphery of the rotating shaft 2 located on the in-machine IS side of the casing 3. On the side of the rotating shaft 2 opposite to the housing 3, a screw for propulsion and a hub 12 of an impeller that rotates by receiving a water flow are fixed. The hub 12 is fitted to the outer peripheral surface of the rotating shaft 2 by means such as shrink fitting.

The double mechanical sealing device 10 is mounted inside a cartridge-type housing 8 attached to an axial end surface 3b of the casing 3. The housing 8 has a cover plate 6 and a seal case 7. In FIG. 1, the left side of the double mechanical seal device 10 is the in-machine IS side, and the outside of the casing 8 is the outside OS side.

A cover plate 6 is attached to the end surface 3b of the casing 3, and a seal case 7 is attached to the outside (hub 12 side) of the cover plate 6. The cover plate 6 and the seal case 7, which form a part of the housing, are fixed to the end surface 3b by bolts 5a and 5b in this order from the end surface 3b of the casing 3 toward the hub 12.

An O-ring groove is formed on the mounting surface of the cover plate 6 mounted on the end surface 3b of the casing 3, and an O-ring 4 is mounted on the O-ring groove to seal between the end face 3b and the cover plate 6. are doing. In the present embodiment, an O-ring 9 is attached between the seal cover 6 and the seal case 7 to seal the gap between them.

In the present embodiment, an intermediate chamber 70 is formed inside the housing 8, and a double mechanical sealing device 10 is arranged inside the intermediate chamber 70. The double mechanical seal device 10 has a first seal portion 30 arranged on the in-flight IS side (proximal side) and a second seal arranged on the hub 12 side (distal side) along the axial direction of the rotating shaft 2. It has a portion 50 and an intermediate ring 80 located between them. The first seal portion 30, the intermediate ring 80, and the second seal portion 50 are arranged inside the housing 8 along the axial direction of the rotating shaft 2.

The intermediate chamber 70 is formed inside the housing 8 (inner peripheral side) so as to surround the outer periphery of the first seal portion 30, the intermediate ring 70, and the second seal portion 50, and the mechanical seals 30 and 50 function appropriately. In this state, the space on the outside OS side is sealed, and the space on the inside IS side is also sealed.

The inside of the casing 3 (the gap between the shaft hole portion 3a and the rotating shaft 2) is set to atmospheric pressure so as to maintain the environment such as the prime mover and the generator, and the intermediate chamber 70 is set by the first seal portion 30. Is sealed between the aircraft and the in-flight IS. The second seal portion 50 prevents seawater or the like existing in the external OS from entering the inside of the intermediate chamber 70. In the present embodiment, the seal cover 6 is formed with an oil supply port 72 leading to the intermediate chamber 70, from which oil is supplied to the inside of the intermediate chamber 70. The illustration of the oil discharge port is omitted.

On the inner peripheral side of the housing 8, the sleeve 20 is fixed to the outer circumference of the rotating shaft 2 by a sleeve collar 14 or the like, and can rotate around the axis of the rotating shaft 2 together with the rotating shaft 2. The sleeve 20 includes a relatively thick sleeve body 21, a relatively thin first extension tube 26a extending integrally from the end of the sleeve body 21 toward the in-flight IS, and the sleeve body 21. It has a relatively thin second extension tube portion 26a that integrally extends from the end toward the hub 12.

On the outer peripheral surface of the end portion of the second extension cylinder portion 26b on the hub 12 side, a tapered surface 22 whose outer diameter becomes smaller toward the in-machine IS side and O-ring grooves located on both sides in the axial direction thereof are formed. .. An O-ring 24 is attached to each of the O-ring grooves, and seals between the sleeve collar 14 and the extension cylinder portion 26b of the sleeve 20.

The sleeve collar 14 is fixed to the hub 12 with bolts 16 and the like. At least one, preferably a plurality of bolts 18, are attached to the sleeve collar 14 at an angle so that their tips are pressed against the tapered surface 22 substantially perpendicularly. When the tip of the bolt 18 is pressed against the tapered surface 22 of the sleeve 20, the sleeve 20 has a force that fits on the outer periphery of the rotating shaft 2 and a direction opposite to the in-machine IS side along the axial direction of the rotating shaft 2. A directing force acts. As a result, it is possible to resist the thrust force generated in the sleeve 20 toward the in-flight IS based on the pressure of the seawater located in the outside OS.

The sleeve body 21 of the sleeve 20 is positioned and attached to the rotating shaft 2 so as to be located inside the intermediate chamber 70 of the housing 8. On the inner peripheral surface of the sleeve body 21, for example, O-ring grooves are formed at a plurality of positions along the axial direction, and by mounting the O-ring 25 on each O-ring groove, the sleeve 20 and the rotating shaft 2 are formed. The gap between them is sealed.

A large diameter portion 23 having a larger outer diameter than the first outer peripheral surface 21a and the second outer peripheral surface 21b is formed between the first outer peripheral surface 21a and the second outer peripheral surface 21b of the sleeve body 21 so as to project in the radial direction. There is. The outer diameter of the first outer peripheral surface 21a and the outer diameter of the second outer peripheral surface 21b are substantially the same.

The first outer peripheral surface 21a is formed so that the inner end of the intermediate ring 80 on the anti-machine IS side (opposite to the in-machine IS) engages with the stepped portion between the large diameter portion 23 and the first outer peripheral surface 21a. The intermediate ring 80 is fixed. As shown in FIG. 3, for example, the intermediate ring 80 is fixed to the sleeve 20 by using a bolt 81 or the like, rotates together with the rotating shaft 2 and the sleeve 20, and moves in the axial direction together with the rotating shaft 2. There is.

As shown in FIG. 2, the first sealing portion 30 has a first rotary sealing ring 31 and a first static sealing ring 41. Similarly, the second sealing portion 50 has a second rotary sealing ring 51 and a second static sealing ring 61. The material of these sealing rings 31, 41, 51, 61 is not particularly limited, but silicon carbide, carbon, ceramic, and the like are exemplified, and silicon carbide is preferable. The materials of these sealing rings 31, 41, 51, 61 may all be the same or different. In particular, since the materials of the sealing rings 51 and 61 in contact with seawater are made of silicon carbide, even if solids in seawater or marine organisms are caught between the sliding surfaces, the sliding surfaces are less worn.

In the present embodiment, the first rotary sealing ring 31 and the second rotary sealing ring 51 have substantially the same shape, and the first static sealing ring 41 and the second static sealing ring 61 have substantially the same shape, and the rotation The shapes of the sealing rings 31, 51 and the static sealing rings 41, 61 are also similar. Therefore, when manufacturing these sealed rings 31, 41, 51, 61, it is possible to share the material molding mold, and the shrinkage amount at the time of sintering can be made the same, so that these can be easily manufactured. There is also a cost reduction.

First, the first seal portion 30 will be described. As described above, the first sealing portion 30 has at least a first rotary sealing ring 31 and a first static sealing ring 41. The first rotary sealing ring 31 and the first static sealing ring 41 have opposite end faces facing each other in the axial direction of the rotary shaft 2 at the outer peripheral position of the rotary shaft 2. On the facing surface of the first rotary sealing ring 31, a first rotary sliding surface 31a that protrudes in the axial direction at a position on the inner peripheral side thereof is formed. A first stationary sliding surface 41a projecting in the axial direction is formed on the facing surface of the first static sealing ring 41 corresponding to the first rotating sliding surface 31a.

In the present embodiment, the first rotating sliding surface 31a having a relatively narrow radial width slides on the first stationary sliding surface 41a having a relatively wide radial width. Yes, but vice versa.

On the inner peripheral surface of the first rotary sealing ring 31, a stepped recess 36 is formed at a position opposite to that of the first rotary sliding surface 31a in the axial direction, and an O-ring 32 as a sealing member is formed therein. It is attached and seals the gap between the inner peripheral surface of the first rotary sealing ring 31 and the first outer peripheral surface 21a of the sleeve 20. The inner diameter R1a of the inner peripheral surface of the first rotary sealing ring 31 at the position where the stepped recess 36 is not formed is slightly larger than the outer diameter of the first outer peripheral surface 21a, and the O-ring 32 seals the gap. ing.

The stepped recess 36 is open to the intermediate chamber 70, and the O-ring 32 is a first static sealing ring inside the stepped recess 36 due to the pressure of a fluid such as oil introduced into the intermediate chamber 70. It is pressed in the direction of 41. The axial width of the stepped recess 36 is about 1.5 times or more, preferably about 2 times or more the wire diameter of the O-ring 32, but is narrower than the axial width of the first rotary sealing ring 31.

A stepped recess 46 is formed on the inner peripheral surface of the first static sealing ring 41 at a position opposite to that of the first static sliding surface 41a in the axial direction, and an O-ring 42 as a sealing member is formed therein. It is attached and seals the gap between the inner peripheral surface of the second static sealing ring 41 and the outer peripheral surface of the first tubular convex portion 6a of the seal cover 6. The inner diameter R1b of the inner peripheral surface of the first static sealing ring 41 at the position where the stepped concave portion 46 is not formed is slightly larger than the outer diameter of the outer peripheral surface of the first tubular convex portion 6a, and the gap is O. The ring 42 is hermetically sealed.

The first tubular convex portion 6a is formed on the inner peripheral surface of the seal cover 6 constituting the housing 8 so as to project axially toward the center of the intermediate chamber 70. As shown in FIG. 7, the axially tip portion of the first tubular convex portion 6a is configured to maintain a first predetermined gap C1 along the axial direction with the sleeve main body 21.

As shown in FIG. 2, the stepped recess 46 is open to the intermediate chamber 70, and an adapter 48 is mounted between the O-ring 42 and the first axial end surface 6b of the intermediate chamber 70. is there. One end in the axial direction of the adapter 48 enters the inside of the stepped recess 46 and abuts on the O-ring 42, and the other end in the axial direction abuts on the end surface 6b in the first axial direction. By arranging the adapter 48 between the O-ring 42 and the first axial end surface 6b, a predetermined shaft is formed between the anti-sliding surface side end surface of the first static sealing ring 41 and the first axial end surface 6b. A directional gap can be formed.

The O-rings 32 and 42 are made of a material such as nitrile rubber, fluororubber, silicone rubber, and VMQ, and the adapter 48 is made of a metal material such as stainless steel or nickel alloy. The axial width of the stepped recess 46 is about 1.1 to 1.5 times the wire diameter of the O-ring 32, but is narrower than the axial width of the first static sealing ring 41.

The ring-shaped axial recess formed by the first axial end surface 6b is formed on the inner peripheral side of the seal cover 6 and on the outer peripheral side of the first tubular convex portion 6a, and is formed on the outer peripheral side of the seal case 7. It communicates with the intermediate chamber 70 formed in the portion. A plurality of knock pins 43 are fixed to the first axial end surface 6b at predetermined intervals along the circumferential direction so as to project axially from the end surface 6b.

These knock pins 43 are inserted into engaging holes 44 that penetrate a plurality of axial directions along the circumferential direction on the outer peripheral side of the first static sealing ring 41, and the first static sealing ring 41 is provided with respect to the seal cover 6. It prevents it from rotating relatively. However, since the knock pin 43 is only inserted into the engagement hole 44, the first static sealing ring 41 is allowed to move along the axial direction with respect to the seal cover 6.

The front surface 40a of the first pressure ring 40 is in contact with the end surface of the first rotary sealing ring 31 on the side opposite to the first sliding surface 31a in the axial direction on the inner peripheral side. On the front surface of the first pressure ring 40, on the outer peripheral side, a plurality of knock pins 33 are fixed so as to project axially toward the first rotary sealing ring 31 at predetermined intervals along the circumferential direction. These knock pins 33 are each inserted into engagement holes 34 penetrating in a plurality of axial directions along the circumferential direction on the outer peripheral side of the first rotary sealing ring 31, and the first rotary sealing ring 31 is the first pressure ring 40. It prevents it from rotating relative to the relative. However, since the knock pin 33 is only inserted into the engagement hole 34, the first rotary sealing ring 31 is allowed to move along the axial direction with respect to the first pressure ring 40.

Next, the second seal portion 50 will be described. As described above, the second sealing portion 50 has at least a second rotary sealing ring 51 and a second static sealing ring 61. The second rotary sealing ring 51 and the second static sealing ring 61 have opposite end faces facing each other in the axial direction of the rotary shaft 2 at the outer peripheral position of the rotary shaft 2. On the facing surface of the second rotation sealing ring 51, a second rotation sliding surface 51a that protrudes in the axial direction at a position on the inner peripheral side thereof is formed. A second static sliding surface 61a protruding in the axial direction is formed on the facing surface of the second static sealing ring 61 corresponding to the second rotating sliding surface 51a.

In the present embodiment, the second rotating sliding surface 51a having a relatively narrow radial width slides on the second stationary sliding surface 61a having a relatively wide radial width. Yes, but vice versa.

On the inner peripheral surface of the second rotation sealing ring 51, a stepped recess 56 is formed at a position opposite to the second rotation sliding surface 51a in the axial direction, and an O-ring 52 as a sealing member is formed therein. It is attached and seals the gap between the inner peripheral surface of the second rotary sealing ring 51 and the second outer peripheral surface 21b of the sleeve 20. The inner diameter R2a of the inner peripheral surface of the second rotary sealing ring 51 at the position where the stepped recess 56 is not formed is slightly larger than the outer diameter of the second outer peripheral surface 21b, and the O-ring 52 seals the gap. ing.

The stepped recess 56 is open to the intermediate chamber 70, and the O-ring 52 is located inside the stepped recess 56 due to the pressure of a fluid such as oil introduced into the intermediate chamber 70 in a normal operation state. 2 It is pressed in the direction of the static sealing ring 51. The axial width of the stepped recess 56 is about 1.5 times or more, preferably about 2 times or more the wire diameter of the O-ring 52, but is narrower than the axial width of the second rotary sealing ring 51.

On the inner peripheral surface of the second static sealing ring 61, a stepped recess 66 is formed at a position opposite to the second static sliding surface 61a in the axial direction, and an O-ring 62 as a sealing member is formed therein. It is attached and seals the gap between the inner peripheral surface of the second static sealing ring 61 and the outer peripheral surface of the second tubular convex portion 7a of the seal case 7. The inner diameter R2b of the inner peripheral surface of the second static sealing ring 61 at the position where the stepped concave portion 66 is not formed is slightly larger than the outer diameter of the outer peripheral surface of the second tubular convex portion 7a, and the gap is O. The ring 62 is hermetically sealed.

The second tubular convex portion 7a is formed on the inner peripheral surface of the seal case 7 constituting the housing 8 so as to project axially toward the center of the intermediate chamber 70. As shown in FIG. 7, the axial tip portion of the second tubular convex portion 7a is configured to maintain a second predetermined gap C2 along the axial direction with the sleeve main body 21.

As shown in FIG. 2, the stepped recess 66 is open to the intermediate chamber 70, and an adapter 68 is mounted between the O-ring 62 and the seventh axial end surface 7b of the intermediate chamber 70. is there. One end in the axial direction of the adapter 68 enters the inside of the stepped recess 66 and abuts on the O-ring 62, and the other end in the axial direction thereof abuts on the end surface 7b in the second axial direction. By arranging the adapter 68 between the O-ring 62 and the second axial end surface 6b, a predetermined shaft is formed between the anti-sliding surface side end surface of the second static sealing ring 61 and the second axial end surface 7b. A directional gap can be formed.

The O-rings 52 and 62 are manufactured of the same material as the O-rings 32 and 42, for example, but do not necessarily have to be the same. Further, the adapter 68 is manufactured of the same material as the adapter 48, for example, but does not necessarily have to be the same. The axial width of the stepped recess 66 is about 1.1 to 1.5 times the wire diameter of the O-ring 62, but is narrower than the axial width of the second static sealing ring 61.

The ring-shaped axial recess formed by the second axial end surface 7b is formed on the inner peripheral side of the seal case 7 and on the outer peripheral side of the second tubular convex portion 7a, and is formed on the outer peripheral side of the seal case 7. It communicates with the intermediate chamber 70 formed in the portion. A plurality of knock pins 63 are fixed to the end surface 7b in the second axial direction at predetermined intervals along the circumferential direction so as to project axially from the end surface 7b.

These knock pins 63 are each inserted into engagement holes 64 penetrating in a plurality of axial directions along the circumferential direction on the outer peripheral side of the second static sealing ring 61, and the first static sealing ring 61 is provided with respect to the seal case 7. It prevents it from rotating relatively. However, since the knock pin 63 is only inserted into the engagement hole 64, the second static sealing ring 61 is allowed to move along the axial direction with respect to the sealing case 7.

The front surface 60a of the second pressure ring 60 is in contact with the end surface of the second rotary sealing ring 51 on the side opposite to the second sliding surface 51a in the axial direction on the inner peripheral side. On the front surface of the second pressurizing ring 60, on the outer peripheral side, a plurality of knock pins 53 are fixed so as to project axially toward the second rotary sealing ring 51 at predetermined intervals along the circumferential direction.

These knock pins 53 are inserted into engaging holes 54 penetrating in a plurality of axial directions along the circumferential direction on the outer peripheral side of the second rotary sealing ring 51, and the second rotary sealing ring 51 is inserted into the second pressure ring 60. It prevents it from rotating relative to the relative. However, since the knock pin 53 is only inserted into the engagement hole 54, the second rotary sealing ring 51 is allowed to move along the axial direction with respect to the second pressure ring 60.

The second pressurizing ring 60 is a component corresponding to the first pressurizing ring 40 and has substantially the same shape, but the first pressurizing ring 40 has a shape that matches the outer diameter of the large diameter portion 23 of the sleeve 20. It is larger than the inner diameter. The materials of these pressure rings 40 and 60 are preferably the same, but may be different, and are made of a metal such as stainless steel or nickel alloy.

Next, the intermediate ring 80 will be described. As shown in FIG. 4, the intermediate ring 80 has a plurality of through holes 82 for springs at predetermined intervals along the circumferential direction. The through hole 82 for the spring penetrates the intermediate ring 80 in the axial direction. A coiled spring 86 is inserted into each spring through hole 82 so that both ends protrude from the through hole 82 in the axial direction.

As shown in FIG. 7, the free length in the axial direction of each spring 86 before mounting is the mounting length L3 obtained by adding the first predetermined distance L1 and the second predetermined distance L2 to the axial thickness L0 of the intermediate ring 80. Greater than As shown in FIG. 2, in the mounted state of the spring 86, a compressive force is applied to the spring 86, and one end of the spring 86 pushes the back surface 40b of the first pressure ring 40 toward the first rotary sealing ring 31, and the spring The other end of the 86 pushes the back surface 60b of the second pressure ring 60 toward the second rotary sealing ring 51.

It should be noted that one end of the spring 86 may be in pressure contact with the back surface 40b of the first pressure ring 40, and may not necessarily be fixed. Similarly, the other end of the spring 86 may be in pressure contact with the back surface 60b of the second pressure ring 60, and may not necessarily be fixed.

As shown in FIG. 4, in the intermediate ring 80, another pair of drive holes 84 and 85 are arranged at predetermined intervals in the circumferential direction between the spring through holes 82 arranged at predetermined intervals in the circumferential direction. Will be done. The heads of the drive bolts 88, which are attached and fixed at predetermined intervals along the circumferential direction, are inserted and fitted into the back surfaces 40b of the first pressure ring 40, respectively, in the drive holes 84. The heads of the drive bolts 89, which are attached and fixed at predetermined intervals along the circumferential direction, are inserted into the other drive holes 85 and fitted to the back surface 60b of the second pressure ring 60, respectively.

The first pressure ring 40 is formed with an operation hole 85a at a position corresponding to the drive hole 85 of the intermediate ring 80, and the second pressure ring 60 corresponds to the drive hole 84 of the intermediate ring 80. Operation holes 84a are formed at each of the positions. The operation hole 85a is a hole for operating the attachment / detachment of the drive bolt 89 inserted into the drive hole 85 through the operation hole 85a, and the operation hole 84a is inserted into the drive hole 84 through the operation hole 84a. It is a hole for operating the attachment / detachment of the drive bolt 88.

As shown in FIG. 3, the intermediate ring 80 is fixed to the sleeve 20 by using a bolt 81 or the like, rotates together with the rotating shaft 2 and the sleeve 20, and moves in the axial direction together with the rotating shaft 2. .. Drive bolts 88 and 89 are inserted and engaged with the drive holes 84 and 85 of the intermediate ring 80, respectively. Therefore, when the intermediate ring 80 rotates together with the rotating shaft 2 and the sleeve 20, the rotational force is transmitted to the first pressure ring 40 and the second pressure ring 60 via the drive bolts 88 and 89. Therefore, the first pressure ring 40 and the second pressure ring 60 also rotate together with the rotation shaft 2.

As shown in FIG. 2, the knock pin 33 of the first pressure ring 40 is engaged with the engagement hole 34 of the first rotary sealing ring 31. Further, the knock pin 53 of the second pressure ring 60 is engaged with the engagement hole 64 of the second rotary sealing ring 51. Further, these pressure rings 40 and 60 are pressed by the elastic force (compressive force) of the spring 86 in the direction of axially separating the first rotary sealing ring 31 and the second rotary sealing ring 51, respectively. The first static sealing ring 41 and the second static sealing ring 61 are located outside the first rotary sealing ring 31 and the second rotary sealing ring 51 in the axial direction, respectively.

Therefore, the first pressurizing ring 40 and the second pressurizing ring 60 rotate together with the first rotary sealing ring 31 and the second rotary sealing ring 51 while pressing them in the axially separating directions, respectively. As a result, the first rotary sealing ring 31 is pressed against the first static sealing ring 41, and the second rotary sealing ring 51 is pressed against the second static sealing ring 61, so that the sealing performance between them is improved.

In the double mechanical sealing device 10 of the present embodiment, when the outer diameter of the rotating shaft 2 is large, the inner and outer diameters of the intermediate ring 80 are increased to intermittently form the intermediate ring 80 in the circumferential direction. The number of through holes 82 may be increased, and it is not necessary to increase the outer diameter of the spring 86 itself. Therefore, the spring 86 can be easily manufactured, and it is only necessary to prepare a standard size spring 86, and the mounting thereof is also easy. Further, since each spring 86 is used by being inserted into the through hole 82 for the spring, the spring 86 does not spread to the outside due to fluid pressure or the like. The double mechanical sealing device 10 of the present embodiment can handle even if the outer diameter of the rotating shaft 2 is 500 to 1000 mm or more.

Further, in the double mechanical sealing device 10 of the present embodiment, even if the rotating shaft 2 is moved by the axis due to long-term operation, the pair of rotating sealing rings 31 and 51 move in the axial direction with respect to the rotating shaft 2. , The mounting length L3 of the spring 86 shown in FIG. 7 does not change. Therefore, the pressing force on the pair of rotary sealing rings 31 and 51 due to the elastic force of the spring 86 is unlikely to change, and the sealing performance can be easily maintained constant for a long period of time.

Further, since both the first seal portion 30 and the second seal portion 50 are composed of mechanical seals, it is possible to cope with a high pressure difference, and the sealability and durability are excellent. It is easy to support maintenance-free for a period (for example, about 10 years). Therefore, the double mechanical sealing device 10 according to the present embodiment can be effectively used as a sealing device for underwater equipment such as a marine propulsion device.

Further, in the present embodiment, as shown in FIG. 2, one end of the spring 86 is in contact with the back surface 40b of the first pressure ring 40, and the front surface 40a of the first pressure ring 40 is sealed by the first rotation. The back surface of the ring 30 comes into contact. Therefore, the elastic force of the spring 86 is transmitted to the first rotary sealing ring 31 via the first pressure ring 40, and pushes the first rotary sealing ring 31 toward the first static sealing ring 41 in the axial direction. The other end of the spring 86 is in contact with the back surface 60b of the second pressure ring 60, and the back surface of the second rotary sealing ring 51 is in contact with the front surface 60a of the second pressure ring 60. Therefore, the elastic force of the spring 86 is transmitted to the second rotary sealing ring 51 via the second pressure ring 60, and pushes the second rotary sealing ring 51 toward the second static sealing ring 61 along the axial direction.

With this configuration, the elastic force of each spring 86 acts well so as to pull the first rotary sealing ring 31 and the second rotary sealing ring 51 apart in the axial direction, and the first rotary sealing ring 31 is the first. Pressed against the static sealing ring 41, the second rotary sealing ring 51 is pressed against the second static sealing ring 61, and the sealing performance between them is improved.

Further, in the present embodiment, as shown in FIG. 7, the first pressure ring 40 and the first rotation sealing are separated from one end of the intermediate ring 80 by a first predetermined distance L1 along the axial direction on the outer circumference of the sleeve 20. The ring 31 is arranged so as to be movable in the axial direction with respect to the sleeve 20. Similarly, on the outer circumference of the sleeve 20, the second pressure ring 60 and the second rotary sealing ring 51 are axially separated from the other end of the intermediate ring 80 along the axial direction by a second predetermined distance L2. It is arranged so that it can move in any direction. These predetermined distances L1 and L2 can be varied, for example, in the range of 0 to 15 mm, preferably several mm to 10 mm, respectively. However, since the mounting length L3 does not change, if one of the predetermined distances L1 and L2 becomes larger, the other becomes smaller.

Further, the axial tip portion of the first tubular convex portion 6a is configured to maintain a first predetermined gap C1 with the sleeve main body 21 along the axial direction. Further, the axial tip portion of the second tubular convex portion 7a is configured to maintain a second predetermined gap C2 with the sleeve main body 21 along the axial direction. These predetermined gaps C1 and C2 can be changed in the range of, for example, 0 to 12 mm, preferably several mm to 10 mm, respectively. However, the axial distance C3 between the tip of the first tubular convex portion 6a and the tip of the second tubular convex portion 7a does not change, and the axial length of the sleeve body 21 does not change. If either one of the gaps C1 and C2 becomes larger, the other becomes smaller.

With this configuration, the rotating shaft 2 and the sleeve 20 are displaced in the axial direction due to long-term operation, and the intermediate ring 80 is shafted together with the rotating shaft 2 within the range of the first predetermined distance L1 or the second predetermined distance L2. Even if it moves in the direction, the intermediate ring 80 does not collide with the first rotary sealing ring 31 or the second rotary sealing ring 51. Further, even if the intermediate ring 80 is displaced in the axial direction together with the rotating shaft 2, each spring 86 is only inserted into the spring through hole 82 of the intermediate ring 80, so that the axial mounting length of the spring 86 is long. L3 does not change. Therefore, the pressing force on the pair of rotary sealing rings 31 and 51 due to the elastic force of the spring 86 is unlikely to change, and the sealing performance can be easily maintained constant for a long period of time.

Further, since the sleeve body 21 of the sleeve 20 also has a first predetermined gap C1 and a second predetermined gap C2, even if the sleeve 20 moves in the axial direction together with the intermediate ring 80, the sleeve body 21 has a first tubular shape. It does not collide with the convex portion 6a or the second tubular convex portion 7a.

Furthermore, in the present embodiment, as shown in FIG. 2, the inner diameter R1a of the first rotary sealing ring 31 and the inner diameter R2a of the second rotary sealing ring 41 are substantially the same. Further, the outer diameter of the first outer peripheral surface 21a of the sleeve 20 corresponding to the position where the first rotary sealing ring 31 is movably mounted in the axial direction and the second rotary sealing ring 51 are movably mounted in the axial direction. The outer diameter of the second outer peripheral surface 21b of the sleeve 20 corresponding to the position is substantially the same.

With this configuration, the pressure acting diameters acting on the first rotary sealing ring 31 and the second rotary sealing ring 51 based on the fluid in the intermediate chamber 70 are substantially the same, and the thrust force acting on both is offset. It is possible to prevent the imbalance of the thrust force.

Further, in the present embodiment, the O-ring 52 is movably mounted along the axial direction in the stepped recess 56 between the second rotary sealing ring 51 and the outer peripheral surface of the sleeve 20. With this configuration, the second rotary sealing ring 51 is pressed against the second static sealing ring 61 even when the pressure of the intermediate chamber 70 is higher than the seawater pressure of the external OS outside the casing 8 or vice versa. This makes it possible to maintain the sealing performance of the second sealing portion 50.

As shown in FIG. 5, for example, when the oil supply unit that supplies oil into the intermediate chamber 70 is normal, the internal pressure of the intermediate chamber 70 is 0.1, rather than the pressure of seawater located in the external OS. It can be increased to about 0.2 MPa. In that case, the internal pressure of the intermediate chamber 70 acts on the stepped recess 56 to move the O-ring 52 in the stepped recess 56 in the direction of the second rotating sliding surface 51a. As a result, the internal pressure of the intermediate chamber 70 presses the second rotary sealing ring 51 against the second static sealing ring 61.

Further, as shown in FIG. 6, the pressure of seawater located in the external OS may be higher than the internal pressure of the intermediate chamber 70, for example, when the oil supply unit that supplies oil to the intermediate chamber is stopped. is there. In such a case, the seawater passing through the second predetermined gap C2 passes through the gap between the inner peripheral surface of the second rotary sealing ring 51 and the second outer peripheral surface 21b of the sleeve 20, and reaches the stepped recess 56. Be guided. As a result, the O-ring 52 is moved inside the stepped recess 56 in a direction away from the second rotating sliding surface 51a. As a result, the pressure of the seawater introduced into the stepped recess 56 presses the second rotary sealing ring 51 against the second static sealing ring 61.

In this way, in any case, the second rotary sealing ring 51 can be pressed against the second static sealing ring 61, and the sealing property of the second sealing portion 50 can be maintained.

Furthermore, as shown in FIG. 2, in the present embodiment, the outer diameter of the first tubular convex portion 6a and the outer diameter of the second tubular convex portion 7a are substantially the same, and the first static sealing ring The inner diameter R1b of 41 and the inner diameter R2b of the second static sealing ring 61 are substantially the same. With this configuration, the pressure action diameters acting on the first rest-sealing ring 41 and the second rest-sealing ring 61 are substantially the same, the thrust forces acting on both are canceled out, and the imbalance of the thrust forces is prevented. be able to. Further, in the present embodiment, the inner diameters R1a and R2a are substantially the same as the inner diameters R1b and R2b, and from this point as well, the imbalance of the thrust force can be prevented.

Further, in the present embodiment, a single O-ring 42 is interposed between the first static sealing ring 41 and the first tubular convex portion 6a, and the first outer circumference of the first tubular convex portion 6a is the first. The static sealing ring 41 is held in a float type. A single O-ring 62 is also interposed between the second static sealing ring 61 and the second tubular convex portion 7a, and the second static sealing ring 61 is formed on the outer periphery of the second tubular convex portion 7a. It is held in a float type.

With this configuration, the first static sealing ring 41 and the second static sealing ring 61 can be tilted about the O-rings 42 and 62, respectively, and the rotating shaft 2 is slightly tilted or eccentric. Even if this happens, the sealing performance of the first sealing portion 30 and the second sealing portion 50 does not deteriorate. From this point of view, the first rotary sealing ring 31 and the second rotary sealing ring 51 are also provided with single O-rings 32 and 52 on their inner peripheral sides, respectively, and are held in a float manner. It is done.

Further, in the present embodiment, as shown in FIG. 1, the housing 8 includes a seal cover 6 and a seal case 7, and is attached to the casing 3 of the device in a cartridge manner. Further, the air inside the casing 3 is located on the inner peripheral side of the first seal portion 30, and the seawater outside the casing 8 is located on the inner peripheral side of the second seal portion 50. A static sealing ring 41 and a second static sealing ring 61 are attached.

With the cartridge type configuration in this way, the installation and maintenance of the double mechanical sealing device 10 on the casing 3 of the device or the like becomes easy. Further, since the air inside the casing 8 is located on the inner peripheral side of the first seal portion 30 and the seawater outside the casing 8 is located on the inner peripheral side of the second seal portion 50, the pressure of the first seal portion 30 is increased. It is easy to configure the working diameter and the pressure working diameter of the second seal portion 50 to be substantially the same.

The present invention is not limited to the above-described embodiment, and can be variously modified within the scope of the present invention. For example, the fluid existing in the external OS is not limited to seawater, but may be other liquid or gas. The fluid existing in the in-flight IS is not limited to air, but may be other gas. Further, in the above-described embodiment, the double mechanical seal device used when the pressure of the in-flight IS is lower than that of the out-of-machine OS has been described, but the reverse may be true.

2 ... Rotating shaft (shaft)
3 ... Casing 3a ... Shaft hole 3b ... End face 4 ... O-ring 5a, 5b ... Bolt 6 ... Cover plate (part of housing)
6a ... 1st tubular convex portion 6b ... 1st axial end surface 7 ... Seal case (part of housing)
7a ... 2nd tubular convex portion 7b ... 2nd axial end surface 8 ... Housing 9 ... O-ring 10 ... Double mechanical sealing device 12 ... Hub 14 ... Sleeve collar 16, 18 ... Bolt 20 ... Sleeve 21 ... Sleeve body 21a ... No. 1 Outer peripheral surface 21b ... Second outer peripheral surface 22 ... Tapered surface 23 ... Large diameter portion 24, 25 ... O-ring 26a, 26b ... Extension cylinder portion 30 ... First seal portion 31 ... First rotary sealing ring 31a ... First rotary slide Moving surface 32 ... O-ring 33 ... Knock pin 34 ... Engagement hole 36 ... Stepped recess 40 ... First pressurizing ring 40a ... Front surface 40b ... Back surface 41 ... First static sealing ring 41a ... First static sliding surface 42 ... O Ring 43 ... Knock pin 44 ... Engagement hole 46 ... Stepped recess 48 ... Adapter 50 ... Second seal part 51 ... Second rotation sealing ring 51a ... Second rotation sliding surface 52 ... O-ring 53 ... Knock pin 54 ... Engagement hole 56 ... Stepped recess 60 ... Second pressure ring 60a ... Front surface 60b ... Back surface 61 ... Second static sealing ring 61a ... Second static sliding surface 62 ... O-ring 63 ... Knock pin 64 ... Engagement hole 66 ... Stepped recess 68 ... Adapter 70 ... Intermediate chamber 72 ... Oil supply port 80 ... Intermediate ring 81 ... Bolt 82 ... Spring through hole 84, 85 ... Drive hole 84a, 85a ... Operation hole 86 ... Spring 88 ... Drive bolt 89 ... Drive bolt IS ... Inside OS ... Outside

Claims (7)

A first seal located proximal to the cabin and a second seal located distal to the cabin.
A double mechanical sealing device having an intermediate chamber formed between the first sealing portion and the second sealing portion.
The first seal portion is
The first rotating sealing ring, which rotates with the rotating shaft but is movable in the axial direction,
It has a first static sliding surface that is slidable with respect to the first rotating sliding surface of the first rotary sealing ring, and has a first static sealing ring that is supported by a housing and does not rotate.
The second seal portion is
A second rotary sealing ring that rotates with the rotary shaft but is movably arranged in the axial direction.
It has a second static sliding surface that is slidable with respect to the second rotating sliding surface of the second rotary sealing ring, and has a second static sealing ring that is supported by the housing and does not rotate.
On the outer circumference of the rotating shaft located in the intermediate chamber, an intermediate ring that rotates together with the rotating shaft and moves together in the axial direction is arranged.
The intermediate ring is formed with through holes for springs that penetrate in a plurality of axial directions along the circumferential direction.
A spring is mounted along the axial direction in each of the through holes for the spring.
One end of each of the springs is configured to press the first rotary sealing ring toward the first static sealing ring, and the other end of each of the springs presses the second rotary sealing ring. configured tear to press toward the second stationary seal ring is,
On the outer circumference of the rotating shaft, a sleeve rotates together with the rotating shaft and along the axial direction.
It is fixed so that it can move together
The intermediate ring is fixed to the outer circumference of the sleeve.
One end of the spring is in contact with the back surface of the first pressure ring and is in front of the first pressure ring.
The back surface of the first rotary sealing ring is in contact with the surface, and the elastic force of the spring is applied to the first pressurization.
The first rotation is transmitted to the first rotation sealing ring through the ring and toward the first rest sealing ring.
The sealing ring is configured to be pushed along the axial direction.
The other end of the spring is in contact with the back surface of the second pressure ring and is in front of the second pressure ring.
The back surface of the second rotary sealing ring is in contact with the surface, and the elastic force of the spring is applied to the second pressurization.
The second rotation is transmitted to the second rotation sealing ring through the ring and toward the second rest sealing ring.
The sealing ring is configured to be pushed along the axial direction.
In the intermediate ring, a pair of drive holes are spaced apart from each other through the spring through holes in the circumferential direction.
In one of the drive holes, respectively, on the back surface of the first pressure ring.
Drive members that are mounted and fixed at predetermined intervals along the circumferential direction are fitted, and the other drive hole is
Are attached and fixed to the back surface of the second pressure ring at predetermined intervals along the circumferential direction.
That the drive member is fitted Oh Ru double mechanical seal device. On the outer circumference of the sleeve, the first pressure ring and the first rotary sealing ring are axially movable with respect to the sleeve at a distance of a first predetermined distance along the axial direction from one end of the intermediate ring. Have been placed
On the outer circumference of the sleeve, the second pressure ring and the second rotary sealing ring are axially movable with respect to the sleeve at a second predetermined distance along the axial direction from the other end of the intermediate ring. The double mechanical seal device according to claim 1 , which is arranged in. The inner diameter of the first rotary sealing ring and the inner diameter of the second rotary sealing ring are substantially the same.
The outer diameter of the sleeve corresponding to the position where the first rotary sealing ring is movably mounted in the axial direction, and the sleeve corresponding to the position where the second rotary sealing ring is movably mounted in the axial direction. The double mechanical sealing device according to claim 1 or 2 , wherein the outer diameter is substantially the same. The double according to any one of claims 1 to 3 , wherein a sealing member is movably mounted along the axial direction in the stepped recess between the second rotary sealing ring and the outer peripheral surface of the sleeve. Mechanical seal device. The housing is provided with a first tubular convex portion located on the inner peripheral side of the first static sealing ring, and a second tubular convex portion located on the inner peripheral side of the second static sealing ring. Is placed,
The outer diameter of the first tubular convex portion and the outer diameter of the second tubular convex portion are substantially the same.
Claims 1 to 1 in which the inner diameter of the first static sealing ring and the inner diameter of the second static sealing ring are substantially the same .
The double mechanical sealing device according to any one of 4 . A single O-ring is interposed between the first static sealing ring and the first tubular convex portion.
The first static sealing ring is held in a float manner on the outer circumference of the first tubular convex portion.
A single O-ring is interposed between the second static sealing ring and the second tubular convex portion, and the second static sealing ring is floated on the outer circumference of the second tubular convex portion. The double mechanical sealing device according to claim 5 , which is held in. The housing is cartridge-type mounted on the casing of the equipment.
The first static sealing is performed on the housing so that the fluid inside the casing is located on the inner peripheral side of the first seal portion and the fluid outside the casing is located on the inner peripheral side of the second seal portion. The double mechanical sealing device according to any one of claims 1 to 6 , wherein the ring and the second static sealing ring are attached.

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