JP2014020425A - Mechanical seal - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a mechanical seal capable of maintaining high seal performance over a long period and having high durability.SOLUTION: A tandem type mechanical seal 1 comprising a primary side seal mechanism 20 allowed to be slidably rotated, a seal ring 22 allowed to be moved in an axial direction L and a spring 27 for energizing the seal ring 22 to a float seat 21 in the axial direction L using a spring retainer 25 fixed on a rotation shaft 110 as reaction further includes a buffer fluid intrusion mechanism 50 for supplying buffer fluid from a buffer fluid hole 123 to a secondary side seal space S1 of a machine outside Ko by a secondary side seal mechanism 10, and in the secondary side seal space S1, conducting the buffer fluid supplied to the secondary side seal space S1 to the spring retainer 25.

Description

  The present invention relates to a mechanical seal used as a shaft seal device for various rotating devices such as a compressor and a pump.

  Conventionally, for example, in various rotating devices such as a compressor and a pump, a mechanical seal is frequently used as a device for mechanically sealing leakage from a rotating shaft that penetrates a casing. Even if it is simply a mechanical seal, depending on its use, it is compared with a single type and a single type that are sealed with a pair of rotary seal rings and a stationary seal ring (sliding surface) as proposed in Patent Document 1. There are two types of sealing mechanisms, such as a double type that seals with a seal surface (sliding surface) by two sets of rotary seal ring and stationary seal ring, and a tandem type as proposed in Patent Document 2.

  The double-type seal mechanism is a structure in which two pairs of rotary seal rings and stationary seal rings are arranged in opposite directions in the axial direction of the rotary shaft, and is used under higher pressure conditions by dividing the fluid pressure into two. The tandem type sealing mechanism is configured such that two sets of rotary sealing rings and stationary sealing rings are arranged in the same direction in the axial direction.

  Such a mechanical seal is not limited to the type of the seal mechanism, and the seal surface of the rotary seal ring and the seal surface of the static seal ring are slid and sealed. Therefore, one of the rotary seal ring and the static seal ring is used. Is biased in the axial direction by biasing means toward the other side. The urging force of the urging means greatly affects the sealing performance at the sealing surface. That is, in order to ensure the sealing performance under high pressure, the urging force of the urging means is set large, and one sealing surface is strongly pressed against the other sealing surface to ensure high sealing performance.

  Thus, by increasing the urging force to improve the sealing performance, the rotating seal ring and the stationary seal ring sliding in the rotation direction generate heat and become high temperature. When the rotary seal ring and stationary seal ring reach a high temperature, the rotary seal ring and stationary seal ring expand to cause distortion, and wear due to the strain, or the parallelism of the seal surface collapses due to the strain and leaks. The seal performance may be reduced.

JP 2007-2111939 A JP 2006-83889 A

  Accordingly, an object of the present invention is to provide a highly durable mechanical seal that can maintain high sealing performance over a long period of time.

  The present invention provides a seal that forms a sliding seal surface that rotates and slides between a rotation-side seal surface of a rotary seal ring that is rotationally fixed to a rotary shaft and a stationary-side seal surface of a static seal ring that is rotationally fixed to a housing. A mechanism, and one of the rotary seal ring and the stationary seal ring is configured as an axially movable ring movable in the axial direction of the rotary shaft, and the axially movable ring is directed toward the other, A mechanical seal provided with a biasing means for biasing in the axial direction by a reaction force of a reaction force fixing portion fixed to the rotating shaft, wherein the inside of the housing is defined as an interior space from the seal mechanism. The outside of the machine from the seal mechanism is an outside space, and a fluid supply path for supplying fluid to the outside space is formed, and the outside of the machine is opposed to the reaction force fixing portion in the outside space. space Characterized by comprising a fluid-conducting unit that conducts the supplied the fluid.

The reaction force fixing portion fixed to the rotating shaft can be a reaction force fixing portion fixed to the rotating shaft via a sleeve or a reaction force fixing portion directly fixed to the rotating shaft.
The mechanical seal includes a single type having a pair of rotary seal rings and a stationary seal ring, a double type in which two sets of rotary seal rings and a static seal ring are arranged in opposite directions in the axial direction, and two sets of rotary seal rings. And a tandem type in which the stationary seal rings are arranged in the same direction.

The fluid can be, for example, a circulating fluid or cleaning fluid having lubricity such as flushing, quenching, or buffer fluid.
When the inner side or the outer side of the seal mechanism is a seal surface in a direction crossing the axial direction, the space inside or outside the diameter from the seal surface communicating with the space inside the machine in the axial direction from the seal mechanism, Alternatively, a concept including a radially inner side or a radially outer side from a seal surface communicating with a space outside the machine in the axial direction from the seal mechanism is adopted.

According to the present invention, high sealing performance can be maintained over a long period.
Specifically, the fluid is supplied from a fluid supply path formed in an outside space outside the seal mechanism inside the housing, and in the outside space, the fluid conduction portion is provided with respect to the reaction force fixing portion. In order to conduct the fluid, the rotary seal ring and the stationary seal ring that are heated to high temperatures by the frictional heat can be efficiently cooled with the fluid by sliding in the rotation direction. Therefore, it is possible to prevent thermal expansion of the rotary seal ring and stationary seal ring, and the occurrence of distortion due to thermal expansion, so the biasing force of the biasing means is set large and achieved by pressing one seal surface strongly against the other seal surface. High sealing performance can be maintained over a long period of time.

  As an aspect of the present invention, the axially moving ring is the rotary sealing ring, the biasing means is biased in the axial direction, and the fluid conducting portion is the reaction force fixing portion. And the rotary shaft peripheral surface.

  According to the present invention, a fluid can be more efficiently conducted to the fluid conducting portion, and a high cooling effect can be obtained. Specifically, since the fluid conducting portion is formed between the peripheral surface of the rotating rotating shaft and the reaction force fixing portion, the fluid conducting portion also rotates with the rotation of the rotating shaft. A fluid can be conducted to the conduction part. Therefore, it is possible to prevent leakage due to thermal expansion of the rotating seal ring and stationary seal ring, abnormal wear due to distortion due to thermal expansion, and deterioration of sealing performance, so the biasing force of the biasing means is set large, and one seal surface is The high sealing performance achieved by pressing strongly against the other sealing surface can be stably maintained over a long period of time.

  In addition, as an aspect of the present invention, an annular seal member formed in an annular shape in a direction orthogonal to the axial direction is provided on a radially opposing surface of the axial direction moving ring and the reaction force fixing portion that is opposed to the radial direction. be able to.

  According to the present invention, the sealing property can be improved. Specifically, since the sealability between the axial direction moving ring that moves in the axial direction and the reaction force fixing portion can be secured, and the axial direction moving ring is cooled by the fluid that conducts the fluid conducting portion, The annular seal member can be prevented from being thermally deteriorated. Therefore, high sealing performance can be maintained.

As an aspect of the present invention, the fluid conducting portion can be provided with a concavo-convex shape portion having a concavo-convex shape that enlarges the surface area.
The concavo-convex shape of the concavo-convex shape portion described above can be a concavo-convex shape in the cross-sectional direction or a concavo-convex shape in the circumferential direction.

  According to the present invention, the surface area of the fluid conducting portion can be enlarged. Therefore, the heat exchange between the fluid that conducts the fluid conducting part and the axially moving ring is improved, and the cooling effect of the axially moving ring caused by the fluid that conducts the fluid conducting part is improved.

As an aspect of the present invention, the uneven portion can be formed in a spiral shape along the axial direction.
By this invention, the electrical conductivity of the fluid to the fluid conducting part is improved. Specifically, since the fluid conducting portion having the concavo-convex shape portion formed in a spiral shape rotates with the rotation of the rotating shaft, the conductivity of the fluid to the fluid conducting portion is improved by the spiral screw effect. Therefore, the cooling effect of the axial direction moving ring by the fluid can be further improved.

  Further, as an aspect of the present invention, two sets of rotary sealing rings and stationary sealing rings are arranged in series in the axial direction, and the sealing mechanism is composed of an inner sealing mechanism inside the aircraft and an outer sealing mechanism outside the aircraft. And the interior space is defined as the interior side from the interior seal mechanism, the exterior space is defined as a first exterior space outside the exterior seal mechanism, the exterior seal mechanism, and the It is constituted by a second machine outer space between the machine inner seal mechanisms, and the fluid supply path can be configured to supply the fluid to the second machine outer space.

  According to the present invention, even in the so-called double type or tandem type, it is possible to obtain high durability and high sealing performance due to the cooling effect by the fluid conducted to the fluid conducting portion.

  Further, as an aspect of the present invention, a sleeve that is long in the axial direction along the outer peripheral surface of the rotary shaft and is fixed to the rotary shaft is provided, and the rotary sealing ring on the outside of the machine is located near the center in the axial direction of the sleeve. A large-diameter large-diameter portion is mounted, and the reaction force fixing portion is fixed in the vicinity of the machine inner end portion of the sleeve, and the fluid conducting portion is provided. The sleeve may be formed between the sleeve and the reaction force fixing portion.

According to the present invention, it is possible to improve the assembling property of a so-called double type or tandem type mechanical seal that can maintain high sealing performance over a long period of time.
Specifically, of the in-machine seal mechanism and the out-of-machine seal mechanism composed of two sets of rotary seal ring and stationary seal ring, the out-of-machine seal mechanism is assembled from the outside of the sleeve and mounted on the large diameter portion, and the in-machine seal mechanism Can be assembled from the inner side of the sleeve, and the reaction force fixing portion can be fixedly mounted near the inner end of the sleeve. In other words, since two sets of seal mechanisms can be assembled from both the outside and inside of the machine, high sealing performance can be maintained over a long period of time, and the so-called double or tandem type has a more complex structure than the single type. Even so, it can be easily assembled.

  According to the present invention, it is possible to provide a highly durable mechanical seal that can maintain high sealing performance over a long period of time.

Sectional drawing of a tandem type mechanical seal. The a section expanded sectional view of a tandem type mechanical seal. The front view of a tandem type mechanical seal. Explanatory drawing about the buffer fluid penetration | invasion mechanism in a tandem type mechanical seal.

An embodiment of the present invention will be described below with reference to FIGS.
1 shows a cross-sectional view of a tandem mechanical seal 1, FIG. 2 shows an enlarged cross-sectional view of a portion of the tandem mechanical seal 1, FIG. 3 shows a front view of the tandem mechanical seal 1, and FIG. The explanatory view about buffer fluid penetration mechanism 50 in mechanical seal 1 is shown.

  4A is a partial cross-sectional perspective view showing a state in which the sleeve 140 and the spring retainer 25 are assembled to the rotating shaft 110, and FIG. 4B is a diagram illustrating the rotating shaft 110 in which the sleeve 140 is assembled. The partial cross-sectional perspective view of the state which the spring retainer 25 isolate | separated from FIG.

The tandem mechanical seal 1 is a device that seals leakage of liquid to be sealed inside the machine from the rotary shaft 110 that penetrates the casing 100 and the flanges 120 and 130 in various rotary devices such as a compressor and a pump. And float sheets 11 and 21 that are non-rotatably locked to the second flange 130 and function as a stationary seal ring, and a seal ring 12 that is fixed to the rotation shaft 110 and rotates together with the rotation shaft 110 and functions as a rotation seal ring. And sealing mechanisms 10 and 20 are provided. The tandem mechanical seal 1 includes a secondary side seal mechanism 10 on the outboard side Ko (left side in FIG. 1) and a primary side seal mechanism 20 on the inside side Ki (right side in FIG. 1). This is a tandem mechanical seal in which the float sheet and the seal ring are arranged in the same positional relationship with respect to the center direction L.
That is, the tandem mechanical seal 1 is disposed between the rotating shaft 110 that passes through the casing 100 and rotates, and the casing 100 and the flanges 120 and 130.

  The tandem mechanical seal 1 includes a sleeve 140 that is mounted along the outer peripheral surface of the rotating shaft 110 that passes through the casing 100 and the flanges 120 and 130, and a shaft 140 that extends along the outer periphery of the sleeve 140 that is long in the axial direction L. The two seal mechanisms 10 and 20 are arranged in the center direction L at a predetermined interval.

  In the main body case of various rotating devices, the casing 100, which is a portion through which the rotating shaft 110 passes, has a through hole 101 that allows the rotating shaft 110 to pass through the substantially cylindrical shape, and the inner side of the tandem mechanical seal 1. A mounting recess 102 that allows the mounting of the part is formed to have a larger diameter than the inner diameter of the through hole 101 so as to be a concave shape from the outboard side Ko toward the inboard side Ki.

  Further, as shown in FIGS. 1 to 3, the casing 100 is provided with a flushing oil hole 103 for supplying and discharging flushing oil to a primary side seal space S2, which will be described later, at a predetermined interval in the circumferential direction between the supply side and the discharge side. They are separated.

  The rotating shaft 110 is composed of a large-diameter portion 111 penetrating the tandem mechanical seal 1 and a meridian portion 112 whose diameter is reduced at the in-machine ki of the tandem mechanical seal 1. The diameter of the shaft 110 is not limited to this. 1 and 4, only a part of the rotating shaft 110 in the axial direction L is cut out and illustrated.

  The sleeve 140 has a cylindrical shape that is attached so as to be in close contact with the outer peripheral surface of the large-diameter portion 111 of the rotating shaft 110, and a set plate 127 that fixes the position of the first flange 120, which will be described later, in the axial direction L. A fitting groove 141 that allows fitting (shown by a broken line in FIG. 1), a first seal mounting portion 142 that is formed near the middle of the axial direction L and that mounts the secondary-side seal mechanism 10, and an axial direction L And a spiral groove 143 formed on the outer peripheral surface at a portion where the primary side seal mechanism 20 which is the machine inner side Ki is mounted (see FIG. 4).

  In addition, in the sleeve 140, an inner diameter locking projection 25aa of a spring retainer 25, which will be described later, is locked from the inner side Ki at the end of the machine inner side Ki where the primary side seal mechanism 20 is mounted. A locking step 140a that restricts the position in the center direction L is formed (see FIG. 2).

  The first seal mounting portion 142 is formed to be thicker than the other portions of the sleeve 140 so as to protrude radially outward, and the outer diameter corner 142a at the end of the machine exterior Ko of the first seal mounting portion 142. Is provided with a radial convex portion 142b that restricts movement of the mounted secondary-side seal mechanism 10 to the inboard side Ki at the end of the inboard side Ki of the first seal mounting portion 142.

  The spiral groove 143 is a spiral groove having a rectangular cross section spiraling along the axial direction L, as shown in the enlarged view of portion b in FIG. 4B, and is a spring retainer 25 of the primary-side seal mechanism 20 described later. A buffer fluid guide groove 52, which will be described later, is configured together with the spiral groove 25f formed on the inner peripheral surface of the inner surface.

In this specification, both the spiral groove 143 and the spiral groove 25f are illustrated, but the same action can be obtained even if any one of the spiral grooves is formed.
The sleeve 140 is fixed to the rotating shaft 110 by a set screw 144 in the vicinity of the end of the machine exterior Ko.

  As shown in FIGS. 1 to 3, the second flange 130 that is mounted on the casing 100 so as to cover the outboard side Ko of the mounting recess 102 is formed in a flange body 131 that is circular when viewed from the front, and in the inboard side Ki of the flange body 131. The insertion ring portion 132 is inserted into the mounting recess 102 along the inner peripheral surface of the mounting recess 102.

  In addition, the flange body 131 includes a through hole 133 that allows the rotation shaft 110 to pass through the outside Ko, and on the inner diameter side, the flange body 131 straddles the insertion ring portion 132 and communicates with the through hole 133. An arrangement space H <b> 2 that allows the arrangement of the primary side seal mechanism 20 is formed.

  More specifically, an arrangement space H2 formed by an outboard arrangement space H2o formed inside the flange main body 131 and an inside arrangement space H2i formed inside the diameter of the insertion ring portion 132 is an outboard Ko. The through-hole 133, the arrangement space H2, the mounting recess 102, and the through-hole 101 communicate in this order from the machine interior Ki toward the machine interior Ki, and the primary-side seal mechanism 20 is arranged in the arrangement space H2 and the mounting recess 102.

  In addition, as shown in FIG. 2, which is an enlarged view of the part a in FIG. 1, the float sheet 21 of the primary side seal mechanism 20 is arranged in the outboard arrangement space H2o, and the outboard arrangement space H2o and the inboard arrangement space A stainless steel annular plate 134 for preventing the float sheet 21 arranged in the outboard arrangement space H2o from protruding in the axial direction L is fixed to the snap ring 134a. Further, the float sheet 21 is non-rotatably locked to the flange main body 131 by a fixing pin 135.

In addition, a circumferential groove 136 having a rectangular cross section formed in the circumferential direction is formed along the outer circumferential surface of the machine interior Ki from the plate 134 in the insertion ring portion 132.
The circumferential groove 136 corresponds to the position of the flushing oil hole 103 formed in the casing 100 described above in the axial direction L, and communicates with the flushing oil hole 103. Further, the circumferential groove 136 is formed with a plurality of communication holes 136a that communicate the circumferential groove 136 with the machine-side arrangement space H2i that is inside the diameter of the insertion ring portion 132 with a predetermined interval in the circumferential direction. doing.

  As shown in FIGS. 1 and 3, the first flange 120 attached to the outboard side Ko of the second flange 130 is formed in a substantially cylindrical shape, and allows a through hole 121 that allows the rotation shaft 110 to pass through the outboard side Ko. And an arrangement space H1 that communicates with the through-hole 121 and allows the secondary seal mechanism 10 to be arranged.

More specifically, the bush B1a disposed on the inner circumference of the end face of the machine exterior Ko of the first flange 120, the plate B1b for pressing and fixing the bush B1a in the axial direction, and the plate B1b are attached and fixed to the first flange 120. The bush seal B1 is formed on the inner peripheral portion of the end face of the machine outside Ko of the first flange 120 by the bolt B1c. The bush seal B1 allows the rotation shaft 110 to pass therethrough, and a slight gap is formed between the bush seal B1 and the sleeve 140. A through hole 121 to be formed is formed. The arrangement space H1 communicates with the through hole 121, and allows the arrangement of the first arrangement space H1o, the seal ring 12, and the seal ring retainer 13 that allow the arrangement of the float sheet 11 of the secondary-side seal mechanism 10 described later. The second arrangement space H1m and the third arrangement space H1i allowing the arrangement of the spring retainer 15 are arranged in this order from the outboard side Ko.
Further, the first arrangement space H1o, the second arrangement space H1m, and the third arrangement space H1i are formed so that their diameters increase in this order.

  The first flange 120 includes a quench supply hole 122a that supplies a quench fluid (hereinafter referred to as a quench) from the outside to the first arrangement space H1o, a quench discharge hole 122b that discharges the quench to the outside, and a bush that seals the supplied quench. The seal B1, the buffer fluid supply hole 123a for supplying the buffer fluid from the outside to the second arrangement space H1m, and the buffer fluid discharge hole 123b for discharging the buffer fluid to the outside are provided.

  As shown in FIG. 1 or FIG. 3, the quench hole 122 (122a, 122b) communicates with the first arrangement space H1o of the outboard side Ko in the arrangement space H1, and the quench supply hole 122a is arranged on the upper half side to quench. The discharge hole 122b is arranged downward.

  As shown in FIG. 1, the buffer fluid discharge hole 123b of the buffer fluid holes 123 (123a, 123b) communicates with the second arrangement space H1m, and the buffer fluid supply hole 123a communicates with the third arrangement space H1i. As shown in FIG. 3, the buffer fluid supply hole 123a is arranged upward, and the buffer fluid discharge hole 123b is arranged downward.

Further, a concave groove 124 that is recessed radially outward is formed on the inner peripheral surface of the first flange 120 that constitutes the third arrangement space H1i, and the buffer fluid supply hole 123a communicates therewith.
Furthermore, the inner surface of the 1st flange 120 is provided with the pin 125 which latches the float sheet 11 arrange | positioned in the 1st arrangement space H1o so that rotation is impossible.

  In addition, set plates 127 that can be fitted into the fitting grooves 141 of the sleeve 140 are mounted at two opposing positions of the through-hole 121 on the end face of the first flange 120 on the outboard side Ko (see FIGS. 1 and 3). .

  In the tandem seal configured as described above, first, the rotation side seal members 12, 13, 14, 15, and 16 constituting the secondary seal mechanism 10 are mounted at predetermined positions of the sleeve 140, and the inner periphery of the first flange 120 is mounted. After mounting the float sheet 11 on the side, the sleeve 140 mounted with the secondary seal mechanism 10 is inserted into the first flange 120, and the bush seal B1 is mounted on the inner peripheral side of the first flange 120. Then, the outer periphery of the set plate 127 is fitted into the fitting groove 141 of the sleeve 140, and the first flange 120 is engaged with the sleeve 140.

  Further, the second flange 130 is inserted into the sleeve 140 from the spring retainer 15 side of the secondary seal mechanism 10, and the first flange 120 and the second flange 130 are fixed by a plurality of fixing bolts (not shown). After the float sheet 21 constituting the primary side seal mechanism 20 is attached to the inner peripheral side of the second flange 130, the seal ring 22 to the spring 27 constituting the primary side seal mechanism 20 are attached and fixed to the sleeve 140.

In this way, the primary side seal mechanism 20 and the secondary side seal mechanism 10 are fixed to the casing 100 by the plurality of fixing bolts 104 in the seal space S formed by the first flange 120, the second flange 130, and the sleeve 140. To do. Thereafter, the set plate 127 is removed, and installation of a desired tandem seal is completed.
Further, an O-ring 130 a is disposed at an appropriate position on the boundary surface between the rotating shaft 110 and the second flange 130 and on the boundary surface between the second flange 130 and the first flange 120.

  Next, the seal mechanisms 10 and 20 arranged in series in the axial direction L between the first flange 120, the second flange 130, the casing 100, and the rotating shaft 110 will be described in detail.

The secondary side seal mechanism 10 arranged in the arrangement space H1 includes a float sheet 11 arranged in the first arrangement space H1o, a seal ring 12 arranged in the second arrangement space H1m, a seal ring retainer 13 and a collar in this order from the outboard side Ko. 14 and a spring retainer 15 disposed in the third disposition space H1i, and a spring 17 disposed between the collar 14 and the spring retainer 15 (shown by a broken line in FIG. 1).
The float sheet 11, the seal ring 12, the seal ring retainer 13, the collar 14 and the spring retainer 15 are formed in a ring shape.

More specifically, the float sheet 11 is made of carbon and protrudes from the first seal mounting portion 142 into the machine inner side Ki near the inner peripheral edge of the ring main body 11a and the ring main body 11a that can be inserted into the sleeve 140 on the outer side Ko. The end face of the machine inner side Ki is composed of a convex seal portion 11b that constitutes the seal facing surface 11ba.
As described above, the float sheet 11 is arranged in the first arrangement space H1o and is non-rotatably locked to the first flange 120 by the pins 125.

The seal ring 12 is made of silicon carbide (SiC), and is disposed in front of the outboard side Ko from the first seal mounting portion 142 in the second arrangement space H1m.
The seal ring 12 includes a ring main body 12a that is ring-shaped when viewed from the front, and an inboard side protruding portion 12b that protrudes toward the inboard side Ki on the outer peripheral side of the ring main body 12a.

  The end face of the machine body Ko of the ring body 12a is a seal facing surface 12aa that faces the seal facing surface 11ba in the float sheet 11 and is slidable in the circumferential direction. In addition, the seal ring 12 is mounted so as to be movable in the axial direction so that the in-machine protrusion 12b is related to the radially outer corner 142a that is the out-of-machine Ko of the first seal mounting part 142.

  The seal ring retainer 13 is made of, for example, titanium or stainless steel, and is a ring body that is mounted on the outer periphery of the first seal mounting portion 142. The seal ring retainer 13 protrudes toward the outboard side Ko, and the inboard side protruding portion 12b of the seal ring 12 described above. The outer peripheral protrusion 13a for shrink-fitting and fixing the side peripheral surface of the inner peripheral surface and an insertion groove 13b for allowing the O-ring (balance line O-ring) 16 to be inserted are provided on the inner peripheral surface.

  The collar 14 is a flat ring body formed with substantially the same diameter as the seal ring retainer 13, and is engaged with a spring retainer 15 described later by a drive pin 15e so as to be axially movable and non-rotatable. The end face of the collar 14 on the outboard side Ko is in surface contact with the end face of the seal ring retainer 13 on the inboard side Ki.

  The spring retainer 15 is a retainer main body 15a disposed on the inner side Ki of the first seal mounting portion 142, and an inner side Ki of the retainer main body 15a, and the retainer main body via a flange portion 15b that abuts on the radial protrusion 142b. The outer ring portion 15c is formed at a predetermined interval in the radially outward direction from 15a.

  The spring retainer 15 is fixed to the first seal mounting portion 142 by a set screw 15d, and the seal ring 12, the seal ring retainer 13, and the collar 14 are movable in the axial direction L with respect to the spring retainer 15. The first seal mounting portion 142 and the first seal mounting portion 142 are rotatably fixed by a drive pin (detent) 15e arranged in parallel with the axial direction L.

  Further, the seal ring 12, the seal ring retainer 13 and the collar 14 are connected via a spring retainer 15 in which the position toward the machine inner side Ki in the axial direction L with respect to the first seal mounting portion 142 is restricted by the radial convex portion 142b. The spring 17 is biased toward the outboard side Ko in the axial direction L by the reaction force of the spring 17.

  Further, the outer ring portion 15c of the spring retainer 15 is spaced apart by a predetermined interval in the circumferential direction and communicates with the concave groove 124 formed on the inner peripheral surface of the first flange 120, so that the outer ring portion 15c is radially arranged. A plurality of penetrating through holes 15ca are formed.

  Furthermore, the O-ring 16 is disposed in the fitting groove 13b, which is the radially opposing portion between the first seal mounting portion 142 and the seal ring retainer 13, and the outer periphery of the first seal mounting portion 142 moves in the axial direction L. The sealing property between the seal ring retainer 13 and the first seal mounting portion 142 is ensured.

  The secondary side sealing mechanism 10 configured in this way is regulated by the radial convex portion 142b of the first seal mounting portion 142 with respect to the seal facing surface 11ba of the float sheet 11 fixed to the second flange 130. Since the seal facing surface 12aa of the seal ring 12 urged toward the machine exterior Ko by the reaction force of the spring 17 is pressed through the spring retainer 15, the second flange 130 is brought into contact with the rotation of the rotary shaft 110. The float sheet 11 that is locked so as not to rotate can be sealed while sliding in the rotational direction.

  As shown in FIG. 2, the primary-side sealing mechanism 20 arranged in the arrangement space H2 includes, in order from the outboard side Ko, a float sheet 21 arranged in the outboard side arrangement space H2o, a seal ring 22 arranged in the inboard side arrangement space H2i, The seal ring retainer 23, the collar 24, and the spring retainer 25, and the spring 27 (shown by a broken line in FIGS. 1 and 2) disposed between the collar 24 and the spring retainer 25 are configured.

The float sheet 21, the seal ring 22, the seal ring retainer 23, the collar 24, and the spring retainer 25 are formed in a ring shape or a cylindrical shape.
More specifically, the float sheet 21 is made of carbon and protrudes toward the machine inner side Ki near the inner peripheral edge of the ring main body 21a through the ring main body 21a. It is comprised with the convex-shaped seal part 21b which comprises 21ba.
As described above, the float sheet 21 is disposed in the outboard arrangement space H2o, and is non-rotatably locked to the second flange 130 by the fixing pin 135.

  The seal ring 22 is made of silicon carbide (SiC), and includes a ring main body 22a having a ring shape when viewed from the front and an inner projecting portion 22b projecting from the outer peripheral side of the ring main body 22a toward the inboard side Ki. It is arranged in front of the outboard side Ko in the space H2i.

  The end surface of the machine body Ko of the ring body 22a is a seal facing surface 22aa that faces the seal facing surface 21ba in the float sheet 21 and can slide in the circumferential direction. Further, the seal ring 22 is mounted so that the in-machine protruding portion 22b can move in the axial direction so as to be related to the tip of the reduced diameter fitting insertion portion 25c which is the outboard side Ko of the spring retainer 25 described later.

  The seal ring retainer 23 is made of, for example, titanium or stainless steel. The retainer main body 23a is mounted on an outboard side Ko of a spring retainer 25, which will be described later, and projects out of the outboard side Ko. The side peripheral surface of 22b is comprised with the machine outer side protrusion part 23b which carries out shrink fitting.

  Drive pins 23d are arranged at equal intervals in the circumferential direction on the end surface 23c of the inboard side Ki of the seal ring retainer 23, and engage with the holes 24a formed in the collar 24 corresponding to the drive pins 23d in a non-rotatable manner. Has been.

  The collar 24 is a plate-like ring body formed with substantially the same outer diameter as the retainer main body 23a, and is engaged with a spring retainer 25 described later by a drive pin 25e so as to be axially movable and non-rotatable. The end face of the outer side Ko of the collar 24 is in surface contact with the end face of the inner side Ki of the retainer body 23a.

The spring retainer 25 is formed with an outer diameter substantially the same as that of the retainer main body 23a from the inner side Ki toward the outer side Ko, and a fixing flange 25a that allows mounting of a set screw 25d that is fixed to the sleeve 140, and the retainer main body A ring main body 25b that allows the axial movement of the inner peripheral surface of 23a, and an O-ring (balance line O-ring) 26 on the outer periphery are allowed to be attached, and the in-machine protrusion 22b of the seal ring 22 The inner peripheral surface of the inner peripheral surface is configured with a reduced-diameter fitting insertion portion 25c that allows fitting in the axial direction and is arranged in this order.
In addition, an in-diameter engaging convex portion 25aa that engages with the engaging step portion 140a of the sleeve 140 described above is provided on the inner side of the fixed flange 25a on the inner side Ki.

  The spring retainer 25 is attached to the sleeve 140 from the machine inner side Ki, and the in-diameter engaging protrusion 25aa of the fixing flange 25a is engaged with the engaging step 140a of the sleeve 140, so that the position in the axial direction L with respect to the sleeve 140 is reached. Is fixed to the sleeve 140 by a set screw 25d screwed into the fixing flange 25a. Further, the seal ring 22, the seal ring retainer 23, and the collar 24 are not rotatable with respect to the sleeve 140 by the set screw 25 e that is movable in the axial direction L with respect to the spring retainer 25 and arranged parallel to the axial direction L. It is locked to.

  The primary side sealing mechanism 20 configured as described above is biased toward the machine exterior Ko by the reaction force of the spring 27 via the spring retainer 25 against the seal facing surface 21ba of the float sheet 21 fixed to the second flange 130. Since the seal facing surface 22aa of the seal ring 22 thus pressed is pressed against the float sheet 21 that is non-rotatably locked to the second flange 130 in accordance with the rotation of the rotating shaft 110, the slide ring 22 rotates in the circumferential direction. Can be sealed while moving.

  In addition, an O-ring 26 is disposed in a radially opposing portion between the reduced diameter insertion portion 25c of the spring retainer 25 and the seal ring retainer 23, and the seal ring moves in the axial direction L on the outer periphery of the reduced diameter insertion portion 25c. The sealing property between the retainer 23 and the spring retainer 25 is ensured.

  Furthermore, the inner circumferences of the reduced diameter fitting portion 25c and the ring main body 25b are formed slightly larger than the outer circumference of the sleeve 140, and when the sleeve 140 is mounted, the reduced diameter fitting insertion portion 25c and the ring main body 25b. An intrusion clearance 51 that allows buffer fluid to enter is formed between the inner peripheral surface of the sleeve 140 and the outer peripheral surface of the sleeve 140.

  Further, as shown in the enlarged view of the portion c in FIG. 4B, the inner peripheral surface of the reduced diameter insertion portion 25c and the ring body 25b is provided with a spiral groove 25f that spirals along the axial direction L. The buffer fluid guide groove 52 is configured together with the spiral groove 143 formed on the outer peripheral surface of the sleeve 140 described above. Various spiral shapes can be selected for the spiral grooves 25f and 143. Here, the spiral grooves 25f and 143 have a rectangular cross section.

  The buffer fluid guide groove 52 is formed on both sides of the intrusion clearance 51 in the radial direction so as to sandwich the intrusion clearance 51 from both sides in the radial direction. The intrusion clearance 51 and the buffer fluid guide groove 52 are described later from the buffer fluid supply hole 123a. A buffer fluid intrusion mechanism 50 that allows intrusion of the buffer fluid supplied to the secondary seal space S1 is configured.

  The tandem mechanical seal 1 configured as described above includes a machine seat Ko of the float sheet 11, a radially inner side of the sliding seal surface by the seal facing surface 11ba of the float sheet 11 and the seal facing surface 12aa of the seal ring 12, A bush B1a disposed on the inner periphery of the end face of the machine exterior Ko of the one flange 120, a plate B1b for pressing and fixing the bush B1a in the axial direction, and a bolt B1c for fixing the plate B1b to the first flange 120, A bush seal B1 is formed on the inner peripheral portion of the end face of the machine outside Ko of the flange 120, and the bush seal B1 allows the rotation shaft 110 to pass therethrough and has a through hole 121 that forms a slight gap with the sleeve 140. The tip sheet is formed by the float sheet 11 and the seal ring 12 and the facing surface portion of the sleeve 140. A quench that protects the sliding seal surfaces of the seal facing surface 11ba and the seal facing surface 12aa is supplied from the quench supply hole 122a to the space S0 and sealed in the distal end side seal space S0. . The quench sealed in the tip side seal space S0 can be discharged from the quench discharge hole 122b.

  Further, the tandem type mechanical seal 1 includes a second arrangement space H1m outside the diameter of the sliding seal surface by the seal facing surface 11ba of the float sheet 11 and the seal facing surface 12aa of the seal ring 12 in the inboard side Ki of the float sheet 11. , Through the third arrangement space H1i, the through hole 133, the inside diameter of the sliding seal surface by the seal facing surface 21ba of the float sheet 21 and the seal facing surface 22aa of the seal ring 22, the float sheet 21, the seal ring 22 and the sleeve The secondary surface seal space S <b> 1 is configured by the surface portion facing 140 and the buffer fluid intrusion mechanism 50.

  Then, buffer fluid that protects the sliding seal surface between the seal facing surface 21ba and the seal facing surface 22aa is supplied to the secondary seal space S1 from the buffer fluid supply hole 123a through the through hole 15ca. Can be encapsulated. The buffer fluid sealed in the secondary side seal space S1 can be discharged from the buffer buffer fluid discharge hole 123b.

Here, the pressure Pb of the buffer fluid sealed in the secondary side seal space S1 is Po when the atmospheric pressure is Po and the fluid pressure of the machine interior Ki is Pi.
Po ≦ Pc ≦ Pb ≦ Pi
Is set to be Here, Pc is the pressure of the quench fluid.

  Further, the tandem type mechanical seal 1 includes an in-machine arrangement space H2i outside the sliding seal surface by the seal facing surface 21ba of the float sheet 21 and the seal facing surface 22aa of the seal ring 22 in the in-machine Ki of the float sheet 21. The mounting recess 102 constitutes a primary side seal space S2.

  Then, flushing oil for cleaning and cooling the sliding seal surface by the seal facing surface 21ba and the seal facing surface 22aa is supplied from the flushing oil hole 103 to the primary side seal space S2 through the circumferential groove 136. it can.

  The tandem mechanical seal 1 configured in this manner is provided by enclosing quench in the front end side seal space S0, enclosing buffer fluid in the secondary side seal space S1, and supplying flushing oil to the primary side seal space S2. High sealing performance can be ensured.

  Further, since the buffer fluid sealed in the secondary side seal space S1 can enter the buffer fluid intrusion mechanism 50, the buffer fluid is emitted by rotational sliding between the seal facing surface 21ba and the seal facing surface 22aa in the primary side seal mechanism 20. The primary side sealing mechanism 20 heated by heat can be cooled. Further, since the heated primary side sealing mechanism 20 can be cooled by the buffer fluid that has entered the buffer fluid intrusion mechanism 50, thermal deterioration of the O-ring 26, which may be cured by heat, is prevented, and reliable sealing performance is maintained. can do. Even if the flushing oil in the primary side seal space S2 is at a high temperature, it can be cooled by the buffer fluid sealed in the secondary side seal space S1.

  Further, since the spiral grooves 25f and 143 constituting the buffer fluid guide groove 52 are formed on both sides of the penetration clearance 51 constituting the buffer fluid penetration mechanism 50 into which the buffer fluid enters, the buffer fluid penetration into which the buffer fluid enters. The surface area of the mechanism 50 can be enlarged, and the cooling effect by the buffer fluid can be improved.

  Furthermore, the buffer fluid guide groove 52 constituting the buffer fluid intrusion mechanism 50 is formed in a spiral shape along the axial direction L, and the buffer fluid intrusion mechanism 50 becomes a secondary side seal space as the rotary shaft 110 rotates. Since it rotates in S1, the penetration | invasion of the buffer fluid to the buffer fluid penetration | invasion mechanism 50 is accelerated | stimulated by the screw effect of the buffer fluid guide groove | channel 52, and a higher cooling effect can be acquired.

Below, the effect of the tandem type mechanical seal 1 of this invention is demonstrated in detail.
Specifically, the seal sliding surface 22aa of the seal ring 22 fixed to the rotating shaft 110 so as to be movable in the axial direction and the seal facing surface 21ba of the float sheet 21 locked to the second flange 130 so as not to rotate can be rotated. The primary seal mechanism 20 having a movable sliding seal surface is configured, the seal ring 22 is configured to be movable in the axial direction L of the rotary shaft 110, and the seal ring 22 is rotated toward the float seat 21. In the tandem mechanical seal 1 provided with a spring 27 that presses and urges in the axial direction L via a spring retainer 25 fixed to the shaft 110, the primary side seal mechanism 20 is provided inside the second flange 130 and the casing 100. The inboard side Ki is used as the primary side seal space S2, and the outboard side Ko is secondary from the primary side seal mechanism 20. A buffer fluid hole 123 for supplying buffer fluid to the secondary side seal space S1 is formed as the seal space S1, and the secondary side seal space S1 is supplied to the secondary side seal space S1 with respect to the spring retainer 25 in the secondary side seal space S1. By providing the buffer fluid intrusion mechanism 50 that conducts the buffer fluid, high sealing performance can be maintained over a long period of time.

  Specifically, inside the second flange 130 and the casing 100, the buffer fluid is supplied from the buffer fluid supply hole 123a formed in the secondary side seal space S1 which is the outboard side Ko from the primary side seal mechanism 20, and the secondary side seal is provided. In the space S1, the buffer retainer 25 fixed to the rotating shaft 110 is brought into conduction with the buffer fluid intrusion mechanism 50, so that the frictional heat of the spring retainer 50 becomes high due to rotation and sliding in the circumferential direction. The seal ring 22 and the float sheet 21 can be efficiently cooled with buffer fluid.

  Therefore, since the thermal expansion of the seal ring 22 and the float sheet 21 and the occurrence of distortion due to the thermal expansion can be prevented, the biasing force of the spring 27 is set to be large, and the seal facing surface 22aa of the seal ring 22 is opposed to the seal of the float sheet 21. The high sealing performance achieved by pressing strongly against the surface 21ba can be maintained over a long period of time.

  Further, the spring 27 urges the seal ring 22 in the axial direction L, and the buffer fluid intrusion mechanism 50 is formed between the outer peripheral surface of the sleeve 140 attached to the rotating shaft 110 and the spring retainer 25, so that The buffer fluid can be efficiently conducted to the buffer fluid intrusion mechanism 50 to obtain a high cooling effect on the primary side seal mechanism 20.

  Specifically, since the buffer fluid intrusion mechanism 50 is formed between the outer peripheral surface of the sleeve 140 attached to the rotating shaft 110 and the spring retainer 25, the buffer fluid intrusion mechanism 50 is rotated with the rotation of the rotating shaft 110. And the buffer fluid can be conducted to the buffer fluid intrusion mechanism 50 more efficiently.

  Therefore, since the thermal expansion of the seal ring 22 and the float sheet 21 and the occurrence of distortion due to the thermal expansion can be prevented, the biasing force of the spring 27 is set to be large, and the seal facing surface 22aa of the seal ring 22 is opposed to the seal of the float sheet 21. High sealing performance achieved by pressing strongly against the surface 21ba can be stably maintained over a long period of time.

  Further, since the seal ring 22 and the spring retainer 25 are provided with an O-ring 26 formed in an annular shape in a direction perpendicular to the axial direction L in a radially opposed portion opposed to the radial direction of the spring retainer 25, the sealing performance is improved. Can do. Specifically, the seal ring 22 that moves in the axial direction L and the spring retainer 25 can be secured, and the seal ring 22 is cooled by the buffer fluid that conducts the buffer fluid intrusion mechanism 50. Can be prevented from being thermally deteriorated. Therefore, high sealing performance can be maintained.

  Further, since the buffer fluid intrusion mechanism 50 is provided with the buffer fluid guide groove 52 formed by the spiral groove 25f or 143 formed in a concave shape having a rectangular cross section, the surface area of the buffer fluid intrusion mechanism 50 can be increased. Therefore, the heat exchange between the buffer fluid that conducts the buffer fluid intrusion mechanism 50 and the seal ring 22 is improved, and the cooling effect of the seal ring 22 by the buffer fluid that conducts the buffer fluid intrusion mechanism 50 is improved.

  Further, the buffer fluid guide groove 52 formed by the spiral groove 25f or 143 formed in a concave shape having a rectangular cross section is formed in a spiral shape along the axial direction L, so that the buffer fluid is connected to the buffer fluid intrusion mechanism 50. Improves.

  Specifically, since the buffer fluid intrusion mechanism 50 in which the spiral buffer fluid guide groove 52 is formed rotates with the rotation of the rotating shaft 110, the screw effect by the spiral buffer fluid guide groove 52 causes the buffer fluid intrusion mechanism 50 to enter. The conductivity of the buffer fluid is improved. Therefore, the cooling effect of the seal ring 22 by the buffer fluid can be further improved.

  Further, a secondary side sealing mechanism 10 constituted by the float sheet 11 and the seal ring 12 and a primary side sealing mechanism 20 constituted by the float sheet 21 and the seal ring 22 are arranged in series in the axial direction L, and two Cooling by buffer fluid conducted to the buffer fluid intrusion mechanism 50 by supplying buffer fluid from the buffer fluid supply hole 123a to the secondary seal space S1 between the secondary seal mechanism 10 and the primary seal mechanism 20. Due to the effect, it is possible to obtain high durability and high sealing performance.

  In addition, a sleeve 140 that is long in the axial direction L is attached along the outer peripheral surface of the rotating shaft 110, the spring retainer 25 is fixed to the sleeve 140, and the buffer fluid intrusion mechanism 50 is disposed between the sleeve 140 and the spring retainer 25. In the vicinity of the center L of the sleeve 140 in the axial direction L, the first seal mounting portion 142 having a large diameter is provided as a reaction force of the spring 17 that urges the seal ring 12 of the outboard side Ko in the axial direction L. By forming and fixing the spring retainer 25 in the vicinity of the end portion Ki of the machine interior Ki, the assembling property of the tandem mechanical seal 1 can be improved.

  Specifically, of the primary side seal mechanism 20 and the secondary side seal mechanism 10 constituted by the float sheets 11, 21 and the seal rings 12, 22, the secondary side seal mechanism 10 is assembled from the outboard side Ko of the sleeve 140 to form the first seal. The primary seal mechanism 20 can be mounted from the machine inner side Ki of the sleeve 140 and the spring retainer 25 can be fixedly mounted near the machine inner Ki end of the sleeve 140, that is, the secondary side. Since the seal mechanism 10 and the primary side seal mechanism 20 can be assembled from both the outer side Ko and the inner side Ki, high sealing performance can be maintained over a long period of time, and the tandem type mechanical structure is more complicated than the single type. The seal 1 can be easily assembled.

As described above, in the correspondence between the configuration of the present invention and the above-described embodiment,
The rotary seal ring and the axially movable ring of the present embodiment correspond to the seal ring 22,
Similarly,
The rotation side seal surface corresponds to the seal facing surface 22aa,
The housing corresponds to the second flange 130 and the casing 100,
The stationary sealing ring corresponds to the float sheet 21,
The stationary side seal surface corresponds to the seal facing surface 21ba,
The seal mechanism corresponds to the primary-side seal mechanism 20,
The reaction force fixing part corresponds to the spring retainer 25,
The biasing means corresponds to the spring 27,
The mechanical seal corresponds to the tandem type mechanical seal 1,
The interior space corresponds to the primary seal space S2,
The outside space corresponds to the secondary seal space S1,
The fluid corresponds to buffer fluid,
The fluid supply path corresponds to the buffer fluid supply hole 123a,
The fluid conducting portion corresponds to the buffer fluid intrusion mechanism 50,
The rotating shaft peripheral surface corresponds to the outer peripheral surface of the sleeve 140 attached to the rotating shaft 110,
The annular seal member corresponds to the balance line O-ring 26,
The concavo-convex shape corresponds to the spiral groove 25f or 143 formed in a concave shape having a rectangular cross section, which constitutes the buffer fluid guide groove 52,
Two sets of rotary seal ring and stationary seal ring correspond to the float sheets 11 and 21 and the seal rings 12 and 22,
The first machine outer space corresponds to the tip side seal space S0,
The space outside the second machine corresponds to the secondary seal space S1,
The large diameter portion corresponds to the first seal mounting portion 142, but is not limited to the above embodiment.

  For example, even if it is a single type having a pair of seal mechanisms composed of a seal ring and a float sheet, or a double type mechanical seal in which two sets of seal mechanisms are mounted opposite to the axial direction L, the buffer By providing the fluid intrusion mechanism 50, the same effect as the buffer fluid intrusion mechanism 50 in the tandem mechanical seal 1 described above can be obtained.

  Further, although the buffer fluid has been conducted to the buffer fluid intrusion mechanism 50, quenching and flushing may be conducted to the buffer fluid intrusion mechanism 50 when only the cooling effect is assumed.

  Further, the buffer fluid intrusion mechanism 50 is formed with the buffer fluid guide groove 52 in such a manner that the intrusion clearance 51 is sandwiched on both sides. However, the buffer fluid intrusion mechanism 50 may be configured by only the intrusion clearance 51. On the other hand, the buffer fluid guide groove 52 may be configured by only one of the spiral groove 25f and the spiral groove 143.

Specifically, the spiral groove 143 is formed on the outer peripheral surface of the sleeve 140, and the inner peripheral surface of the reduced-diameter insertion portion 25c is formed in a cylindrical shape having a diameter larger than the inner diameter of the spring retainer 25, thereby entering the buffer fluid. It is possible to smoothly enter and discharge the buffer fluid from the mechanism 50.
On the contrary, even if the spiral groove 25f is formed only on the inner peripheral surface of the reduced diameter insertion portion 25c of the spring retainer 25 to form the buffer fluid guide groove 52, the same effect can be obtained.

  Furthermore, in the above description, the spiral groove 25f and the spiral groove 143 are formed in the same spiral shape at the same position in the axial direction L, but the positions of the spiral groove 25f and the spiral groove 143 in the axial direction L are shifted. The spiral shapes such as the spiral angle and the spiral direction may be formed in different shapes.

DESCRIPTION OF SYMBOLS 1 ... Tandem type mechanical seal 10 ... Secondary side seal mechanism 11 ... Float sheet 12 ... Seal ring 20 ... Primary side seal mechanism 21 ... Float sheet 21ba ... Seal opposing surface 22 ... Seal ring 22aa ... Seal opposing surface 25 ... Spring retainer 25f ... spiral groove 26 ... balance line O-ring 27 ... spring 50 ... buffer fluid intrusion mechanism 52 ... buffer fluid guide groove 110 ... rotating shaft 123 ... buffer fluid hole 130 ... second flange 140 ... sleeve 142 ... first seal mounting portion 143 ... Spiral groove L ... axial direction S1 ... secondary side seal space S2 ... primary side seal space

Claims (7)

A rotation-side seal surface of a rotation seal ring fixed to the rotation shaft;
A seal mechanism that constitutes a sliding seal surface that rotates and slides with a stationary seal surface of a stationary seal ring that is rotationally fixed to the housing, and
One of the rotary seal ring and the stationary seal ring is constituted by an axially movable ring that is movable in the axial direction of the rotary shaft,
A mechanical seal provided with a biasing means for biasing the axially moving ring toward the other side in the axial direction by a reaction force of a reaction force fixing portion fixed to the rotating shaft,
Inside the housing, the inside of the machine from the sealing mechanism is an inside space, and the outside of the machine from the sealing mechanism is an outside space,
Forming a fluid supply path for supplying fluid to the outer space of the machine,
The mechanical seal provided with the fluid conduction | electrical_connection part which conducts the said fluid supplied to the said machine outer side space with respect to the said reaction force fixing | fixed part in the said machine outside space. The axially moving ring is the rotary sealing ring,
Urging means for urging the rotary sealing ring in the axial direction;
The mechanical seal according to claim 1, wherein the fluid conducting portion is formed between the reaction force fixing portion and the rotary shaft peripheral surface. On the radial direction facing surface that faces the radial direction of the axial direction moving ring and the reaction force fixing portion,
The mechanical seal according to claim 1, further comprising an annular seal member formed in an annular shape in a direction orthogonal to the axial direction. The fluid conducting portion;
The mechanical seal in any one of Claims 1 thru | or 3 provided with the uneven | corrugated shaped part which has the uneven | corrugated shape which expands a surface area. The uneven shape portion is
The mechanical seal according to claim 1, wherein the mechanical seal is formed in a spiral shape along the axial direction. Two sets of rotary seal ring and stationary seal ring are arranged in series in the axial direction,
The seal mechanism is composed of an in-machine seal mechanism inside the machine and an out-of-machine seal mechanism outside the machine,
The inside space is set to the inside from the inside seal mechanism,
The outside space is composed of a first outside space outside the outside sealing mechanism, and a second outside space between the outside sealing mechanism and the inside sealing mechanism.
The mechanical seal according to any one of claims 2 to 5, wherein the fluid supply path is configured to supply the fluid to the space outside the second machine. A sleeve that is long in the axial direction along the outer peripheral surface of the rotating shaft and is fixed to the rotating shaft,
In the vicinity of the center in the axial direction of the sleeve, a biasing means for biasing the rotary sealing ring on the outside of the machine in the axial direction is mounted, and a large diameter large portion is formed.
The reaction force fixing part is fixed near the machine inner end of the sleeve,
The mechanical seal according to claim 6, wherein the fluid conducting portion is formed between the sleeve and the reaction force fixing portion.

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