JP3351515B2 - mechanical seal - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a mechanical seal for sealing a shaft by mutually slidingly contacting respective end faces of a seal ring attached to a rotary shaft of a shaft-sealed device and a housing.

[0002]

2. Description of the Related Art An example of such a mechanical seal is described in, for example, Japanese Utility Model Publication No. Hei 8-3765. As shown in FIG. 3 (a), the apparatus is provided with a pair of seal rings of a rotating ring 52 and a fixed ring 53 that are opposed to each other in the axial direction on the outer peripheral surface of a rotating shaft 51 of the sealed device. The rotating ring 52 is inserted and held on the in-machine X side of the rotating ring holder 54.

[0003] The in-machine X
A spring retainer 55 is fixed to the rotating shaft 51 on the side, and the rotating ring holder 54 and the rotating ring 52 are externally mounted by a spring 56 compressed between the spring retainer 55 and the rotating ring holder 54. It is urged toward the Y side.

On the other hand, a fixed-side ring holder 60 is fixed via an O-ring 59 to the inner surface of a flange member 58 attached to a housing 57 of the shaft-sealed device. The fixed ring 53 is inserted into and held by the fixed ring holder 60 from the inside X side. Seal surfaces 53 s and 5 facing each other in the axial direction of the fixed ring 53 and the rotating ring 52.
2s are held in contact with each other by the spring 56, and when the rotating shaft 51 is driven, the seal surfaces 53s and 52s slide in a state in which they are in close contact with each other to seal the shaft.

[0005] Incidentally, the sealing surface 53s
52s gradually wears as the operation time elapses. Therefore, when the wear occurs to a predetermined limit, it is necessary to replace the rotating ring 52 and the fixed ring 53. In order to facilitate such an exchange operation, the above-described device employs a rotating ring 52.
And the fixed ring 53 are divided into two parts, and each of the cylindrical portions 54a and 6 of the rotary side ring holder 54 and the fixed side ring holder 60
A pair of O-rings 61, 61, 62, 6 are respectively provided between the inner peripheral surface of Oa and the outer peripheral surfaces of the rotating ring 52 and the fixed ring 53.
2 and the rotating ring 52 and the fixed ring 53 each having a two-part structure are formed by the radially inward tightening force of these O-rings.
Are each configured to be held in an annular shape.

According to this configuration, as shown in FIG. 1B, the flange member 58 is moved to the outside Y side together with the fixed ring holder 60 and the fixed ring 53, and the rotating ring 52 and the fixed ring 53 are connected to each other. Between these ring holders 54 and 60
If you create a work space that can be pulled out axially from the
The rotary ring 52 and the fixed ring 53 having the split structure can be removed radially outward in the work space area.

That is, in the case where the rotating ring 52 and the fixed ring 53 are integrally formed in an annular shape, it is necessary to move the rotating ring 52 and the fixed ring 53 to the shaft end of the rotating shaft 1 in order to remove them from the rotating shaft 51. This involves dismantling of the shaft-sealed device. On the other hand, in the above, the rotating ring 52 and the fixed ring
3 can be easily replaced. In the case where the O-rings 61 and 62 are also exchanged, the O-rings which have been cut at one place are used, and these O-rings are connected only at the cut surfaces at the time of mounting and assembling. Assembled with

[0008]

However, in the mechanical seal described in the above-mentioned publication, two divided parts, for example, a rotary ring 52 having a two-part structure are not fixed to each other in the axially fixed structure. is not. For this reason, for example, with the progress of wear on the seal surface 52s, the rotating ring 52 is
For example, when it is pushed and displaced in the axial direction, there is a possibility that an axial displacement may occur between the two divided parts. Accompanying this, each seal surface 52s of the rotating ring 52 and the fixed ring 53
The uniform pressing contact state over the entire circumference at 53 s is impaired, and as a result, there is a problem that it is not always possible to sufficiently secure stable sealing performance.

The present invention has been made in view of the above-mentioned conventional problems, and an object of the present invention is to provide a mechanical seal capable of ensuring stable sealing with a simpler configuration.

[0010]

A mechanical seal according to a first aspect of the present invention includes a pair of seal rings attached to a rotating shaft and a housing of a shaft-sealed device so that sealing surfaces opposing each other in the axial direction are in contact with each other. Along with forming at least one of the specific seal rings in the circumferential direction by dividing the specific seal ring into a plurality in the circumferential direction, a surrounding wall portion surrounding the specific seal ring from the outside in the radial direction, and an end surface of the specific seal ring on the side opposite to the seal surface A ring holder having a bottom wall portion facing in the axial direction is provided, and an elastic body is provided between an inner peripheral surface of the enclosing wall portion of the ring retaining member and an outer peripheral surface of a specific seal ring inserted in the enclosing wall portion. A mechanical seal in which a specific seal ring is held in an annular shape by interposing an annular first seal member. The outer diameter of a large diameter portion than interposed position of the first seal member is provided on the counter-sealing surface, the first
An adapter ring fixed to the open end side of the surrounding wall portion of the ring holding body was provided so that the sealing member was brought into axial contact with the end surface of the large diameter portion and pressed, and the sealing member was passed through the surrounding wall portion of the ring holding body.
Screw the flat head screw onto the adapter ring to
The turring is fixed to the ring holder .

According to this structure, the first seal member abuts the outer peripheral surface of the specific seal ring as well as the end surface of the large-diameter portion from the axial direction over the entire circumference, whereby the first seal member is divided into a plurality of parts. Each of the divided parts of the specific seal ring is held such that the end faces of the first seal member in contact with each other in the axial direction are flush with each other. That is, since the axial position of each divided part is restricted by the first seal member and the deviation in the axial direction is suppressed, more stable sealing performance is maintained.

Further, in the above, the first seal member wound around the outer periphery of the specific seal ring and having the function of holding the ring in an annular shape also has the function of regulating the axial displacement of each divided part. Therefore, there is no need to separately provide a dedicated member for regulating such an axial position.
The overall configuration becomes simpler.

Further, the mechanical seal according to the first aspect of the present invention is provided with an end protruding portion having a smaller outer diameter than the large diameter portion on the side of the specific seal ring opposite to the large diameter portion on the sealing surface side. An annular second seal member made of an elastic body is wound around the outer periphery, and the adapter ring is fixed to the ring holder, so that the second seal member has a step surface between the large diameter portion and the end projecting portion and the ring holding member. It is characterized in that it is formed so as to be pressed in the axial direction with the bottom wall of the body.

According to this structure, the first and second seal members wound on both sides of the large-diameter portion in the axial direction further contact the axial end surfaces on both sides of the large-diameter portion, respectively, to thereby make the axial direction. Since the position is regulated, the axial displacement between the divided parts of the specific seal ring is more reliably suppressed, and as a result,
Further, stable sealing properties can be maintained.

Further, the mechanical seal according to claim 1 is
The end face of the adapter ring opposite to the side in contact with the first seal member is formed with a screw hole into which a drawer for pulling out the adapter ring in the axial direction is screwed.

According to this configuration, even in the case where the ring holder holding the specific seal ring is externally fitted to the rotary shaft at a recessed position surrounded by the housing of the shaft-sealed device, for example. By screwing the tip of a drawer made of, for example, a bolt or the like from the outside of the machine into the screw hole of the adapter ring and pulling, the ring holder together with the adapter ring can be pulled out of the housing to the outside of the machine. Then, by removing the adapter ring from the ring holder at the position outside the machine and then removing the specific seal ring, the specific seal ring can be easily replaced.

[0017]

Next, an embodiment of the present invention will be described in detail with reference to the drawings. FIG. 2 shows the overall configuration of the mechanical seal according to the present embodiment. In FIG. 1, reference numeral 1 denotes a rotation shaft of the shaft-sealed device, and reference numeral 2 denotes a housing. An annular flange member 3 surrounding the rotating shaft 1 is fixed to an end surface of the housing 2 by bolts and nuts 4a and 4b, and a fixed ring 11 described later is attached to an inner peripheral surface of the flange member 3.

A sleeve 5 which extends from the outside A side to the inside B side through the flange member 3 is fitted on the outer peripheral surface of the rotary shaft 1. Outboard A in this sleeve 5
A key 6 is interposed between the inner peripheral surface of the side end and the outer peripheral surface of the rotating shaft 1, and the sleeve 5 rotates integrally with the rotating shaft 1. In addition, on the outer peripheral surface of the rotating shaft 1,
A stopper ring 7 is further screwed to the outside A side of the sleeve 5. The sleeve 5 has an end surface on the outside A side abutting against the stopper ring 7 and the stopper ring 7.
And is fixed by a set screw 8.

An annular bush 9 made of, for example, carbon is fitted to the inner peripheral surface of the end of the flange member 3 on the outside A side. Then, between the inner peripheral surfaces of the flange member 3 and the housing 2 on the in-machine B side of the annular bush 9 and the outer peripheral surface of the sleeve 5, sequentially from the outer A side.
A stationary ring (seal ring) 11, a rotating ring (specific seal ring) 12, a ring retainer (ring holder) 13, a drive collar 14, and a spring retainer 15 are arranged. These are each formed in a ring shape surrounding the sleeve 5, and the fixed ring 11 and the rotating ring 12 are each formed into a ring shape by bringing two semicircular members into contact with each other. It is formed in such a split structure.

Next, the mounting structure of these components will be described with reference to FIG. 2A and 2B are enlarged views of a cross-sectional view on the upper side and a cross-sectional view on the lower side of the rotary shaft 1 in FIG.

As shown in FIG. 1A, the fixed ring 11 is fixed to the inner surface of the flange member 3 via two O-rings 16 and 17. That is, in a state where the O-rings 16 and 17 are mounted on the inner peripheral surface of the flange member 3, the O-rings 16 and 17 are subjected to a predetermined elastic deformation (hereinafter referred to as a "tightening margin").
The fixed ring 11 is attached to the flange member 3 by inserting the fixed ring 11 from the inside of the machine B through the O-rings 16 and 17 while providing the following. As a result, the fixed ring 11 is fixed to the inner surface of the flange member 3 by the interference of the two O-rings 16 and 17, and the fixed ring 11 having the split structure is held in an annularly assembled state as a whole.

The fixed ring 11 is provided at the end on the side A outside the machine.
It is formed by providing a small diameter portion 11b having an outer diameter smaller than that of the main insertion portion 11a on the inside B side. On the other hand, the inner surface of the flange member 3 also has a shape in which the first peripheral surface 3a in which the fitting main portion 11a is fitted and the second peripheral surface 3b in which the small diameter portion 11b is fitted are connected in a stepped manner from the inside B side. Is formed. In the figure, the right O-ring 17 is mounted in an annular groove formed in the first peripheral surface 3a. On the other hand, the O-ring 16 on the left side in the figure is interposed between the first peripheral surface 3a and the outer peripheral surface of the small diameter portion 11b of the fixed ring 11, and the O-ring 1
Reference numeral 6 denotes an assembled state sandwiched between the step surface between the first and second peripheral surfaces 3a and 3b and the step surface between the fitting main portion 11a and the small diameter portion 11b in the axial direction.

In this structure, the stationary ring 11 is
When the fixing ring 11 is inserted into the flange member 3 from the side and assembled, the above-mentioned step surfaces of the fixing ring 11 and the flange member 3 are in contact with each other on both sides in the axial direction of the O-ring 16. The fixed ring 11 is inserted and fixed at this axial position.

The stationary ring 11 is made of, for example, a cemented carbide or silicon carbide. With respect to such a fixed ring 11, an O-ring 16 made of an elastic body is interposed also in the axial direction with respect to the inner surface of the flange member 3, so that the fixed ring 1 is formed.
For example, even when an impact force acts on the outside of the machine 1 toward the outside A, the impact force is reduced by the O-ring 16, thereby preventing the fixed ring 11 from being chipped. An annular groove 11c for taking out a fixed ring is formed on the outer peripheral surface of the main fitting portion 11a of the fixed ring 11 on the inner side B side of the end surface of the flange member 3 where the first peripheral surface 3a is open.

On the other hand, the fixed ring 11 fixed as described above
The spring retainer 15 is fixed to the outer periphery of the sleeve 5 by a set screw 21 at a position separated from the inside by a predetermined dimension toward the machine B side. Between the spring retainer 15 and the fixed ring 11, the rotating ring 12, the ring retainer 13, and the drive collar 14
Are disposed so as to be movable in the axial direction. The rotating shaft 1 is provided between the drive collar 14 and the spring retainer 15.
, A plurality of compression coil springs (biasing means) 22 are compressed in the axial direction.

With the spring force of these coil springs 22,
The rotary ring 12 is pressed to the outside A side via the drive collar 14 and the ring retainer 13, whereby the seal between the outside A side end face of the rotary ring 12 and the inside B side end face of the fixed ring 11 is formed. The surfaces 12s and 11s are configured to be held in a state where they are in close contact with each other.

The drive collar 14 has an engagement hole 14a into which an engagement pin 23 implanted in the in-machine B side end surface of the ring retainer 13 is inserted, and a spring retainer 15 as shown in FIG. And a female screw 14b to which the outside end of the drive pin 24 on the outside A side of the drive pin 24 is screwed. Thus, when the rotating shaft 1 is driven, the rotational force is sequentially transmitted from the spring retainer 15 that rotates integrally with the rotating shaft 1 to the ring retainer 13 via the drive pin 24, the drive collar 14, and the engaging pin 23. The drive collar 14 and the ring retainer 13 also rotate integrally with the rotating shaft 1.

It should be noted that the drive pin 24 has
A slightly larger head 24a is provided at the end on the side.
As will be described later, when the rotating shaft 1 is rotationally driven in a state where the sealing surfaces 11 s and 12 s of the fixed ring 11 and the rotating ring 12 are in sliding contact with each other, the rotating ring 12 The seal surface 12s gradually wears, and the axial length of the rotary ring 12 decreases according to the amount of the wear. Along with this, the drive collar 14 pressed to the outside A side by the compression coil spring 22 moves to the outside A side together with the drive pin 24. And the seal surface 12s of the rotating ring 12
When the amount of wear of the drive collar 14 reaches a predetermined limit, the head 14a of the drive collar 14 comes into contact with the stopper seat 15a of the spring retainer 15, thereby the rotating ring 12, the ring retainer 13, and the drive collar 14 outside the machine. No further movement to the side takes place.

As shown in FIG. 2A, the ring retainer 13 has a circular outer peripheral bottom wall 13a on which the drive collar 14 is in close contact with the inside B side, and a radially outer end of the bottom wall 13a. And has a cylindrical surrounding wall portion 13b extending to the outside A side from the outside. The rotating ring 12 has a fitting portion (large-diameter portion) 12 a having an outer diameter dimensioned to be fitted inside the surrounding wall portion 13 b of the ring retainer 13 over a predetermined axial length on the in-machine B side. ing.

Further, on both sides in the axial direction of the fitting portion 12a, a first O-ring (first sealing member) 26 and a second O-ring (second sealing member) 27, which will be described later, than the fitting portion 12a.
The first and second O-ring windings whose outer diameters are made smaller in accordance with the respective thickness dimensions of the O-rings and whose axial length is formed to a length commensurate with the thickness dimensions of the respective O-rings 26 and 27. The mounting parts 12b and 12c are provided. Further, on the outside A side of the left side of the 1-O-ring winding portion 12b in the figure, a seal portion 12d whose outer diameter is further reduced is provided. An end face is formed as the seal surface 12s.

On the other hand, the surrounding wall 13b of the ring retainer 13
The adapter ring 2
5 is further mounted. The rotating ring 12 includes the fitting portion 1.
A first O-ring winding portion 12b on the outside A side with the 2a interposed therebetween;
The first O-ring 26 and the second O-ring 27 are wound around the second O-ring winding portion (end protruding portion) 12c, respectively.
The O-ring 27 is inserted into the surrounding wall portion 13b from the outside A side until the O-ring 27 comes into contact with the bottom wall portion 13 of the ring retainer 13, whereby the O-ring 27 is assembled to the ring retainer 13. afterwards,
The adapter ring 25 is inserted into the surrounding wall portion 13b of the ring retainer 13 from the outside A side, and the end surface of the adapter ring 25 on the outside A side is substantially flush with the end surface of the ring retainer 13. A flat head screw 28 is screwed to the adapter ring 25 through the surrounding wall portion 13b, and the adapter ring 25 is fixed to the ring retainer 13.

In such an assembled state, the inner and outer surfaces of the respective O-rings 26 and 27 are in close contact with the outer surfaces of the respective O-ring winding portions 12b and 12c of the rotary ring 12 and the inner surface of the surrounding wall portion 13b. Also in the direction, the first O-ring 26 is attached to each end face of the adapter ring 25 and the fitting portion 12a.
Reference numeral 7 is in an interposed state in which a predetermined interference is provided in both the radial direction and the axial direction, in close contact with the respective end surfaces of the fitting portion 12a and the bottom wall portion 13a.

As a result, the rotating ring 12 is held in an annular shape by the interference of the O-rings 26 and 27 and is fixed in the ring retainer 13. When the ring retainer 13 rotates together with the rotating shaft 1 as described above, This rotating ring 12 also rotates integrally. The above adapter ring 2
5, as shown in FIG. 5B, a screw hole (engaging portion) 25 a for extraction extending in the axial direction from the end surface on the side of the outside of the machine A is provided.
A plurality of holes are formed at appropriate intervals in the circumferential direction.

The rotating ring 12 is made of, for example, SiC, cemented carbide or carbon. The rotating ring 12 is fixed to the fixed ring 11 made of cemented carbide or silicon carbide by a compression coil spring 22.
And the hydraulic pressure of the fluid introduced into the shaft-sealed device acts strongly, and the two seal surfaces 11 s and 12 s are in close contact with each other even when the rotating shaft 1 is driven to rotate. The shaft sealing is achieved by holding the respective sealing surfaces 11s and 12s in relative sliding contact with each other.

In addition to the above-mentioned O-rings 16, 17, 26, and 27, a secondary seal between the rotary shaft 1 and the sleeve 5, a bottom wall of the sleeve 5 and the ring retainer 13, as a secondary seal on the in-machine B side. O-rings 31 to 33 are interposed between the inner surface of the housing 13a and the housing 2 and the flange member 3, respectively.

As shown in a sectional view below the rotary shaft 1 in FIG. 2, the flange member 3 has a third surface extending from the outer peripheral surface to a space between the annular bush 9 and the fixed ring 11. One cooling fluid passage 3c is formed. The cooling liquid is circulated through the passage 3c to cool the stationary ring 11 and the rotating ring 12. Further, as shown in the sectional view above the rotary shaft 1 in the figure, a second cooling fluid passage 3 d communicating with a space outside the fixed ring 11 and the rotary ring 12 is formed in the flange member 3. Further provided. The fluid supplied into the apparatus is circulated through the passage 3d, so that the stationary ring 11 and the rotating ring 12 can be cooled.

The mechanical seal having the above-described structure is composed of the rotating shaft 1
, The sealing surfaces 11 s and 12 s of the fixed ring 11 and the rotating ring 12 gradually wear. In particular, in the above description, the stationary ring 11 is made of cemented carbide or silicon carbide, and the rotating ring 12 is made of carbon. In such a combination, the wear of the seal surface 12s of the rotating ring 12 selectively progresses. Before the amount of wear of the rotating ring 12 reaches the above-mentioned limit amount, an operation of replacing the rotating ring 12 is performed. The procedure of the replacement work will be described.

First, the set screw 8 for fixing the sleeve 5 to the stopper ring 7 is removed, and then the stopper ring 7 screwed to the rotary shaft 1 is loosened and removed from the rotary shaft 1. It is moved along the rotation axis 1 to the outside A side. Next, by removing the nut 4b fixing the flange member 3 to the housing 2, the flange member 3 is removed.
Is also moved along the rotation axis 1 to the outside A side. At this time, the fixed ring 11 also moves integrally with the flange member 3.
Thereby, the fixed ring 11 is separated from the rotating ring 12,
Between the two, the rotating ring 12 is moved from the ring retainer 13 to the outside A
Form a working space that can be drawn axially to the side.

Thereafter, by removing the flat head screw 28 and removing the adapter ring 25 from the ring retainer 13, the rotating ring 12 can be pulled out from the ring retainer 13 in the axial direction. Therefore, hereinafter, FIG.
In substantially the same manner as in the conventional example described with reference to FIG.
If the 27 is removed, the rotary ring 12 having the split structure can be removed radially outward from the rotary shaft 1 in the area of the working space.

Next, the rotating ring 12 having a new split structure is
Is fitted around the rotation shaft 1. Then, new O-rings 26 and 27 cut at one location in the circumferential direction are wound around the respective O-ring winding portions 12 b and 12 c of the rotating ring 12, and the rotating ring 12 is attached to the ring retainer 1.
3 and inserted in the axial direction. Then, as described above, the adapter ring 25 is fitted into the opening end of the ring retainer 13, the adapter ring 25 is pushed into a predetermined position, and the adapter ring 25 is screwed with the flat head screw 28 to the opening end side of the ring retainer 13. Fixed to a new rotating ring 1
Assembly of the second ring retainer 13 to the ring retainer 13 is completed.

As shown in FIGS. 1A and 1B, the present embodiment has a structure in which the flat head screw 28 is located near the end face of the housing 2. In this case, a bolt (not shown) is screwed into the draw-out screw hole 25a of the adapter ring 25, and the bolt is pulled to the outside A side, so that the ring retainer 13 and the rotary ring 12 are moved together with the adapter ring 25. It can be moved from inside the housing 2 to the outside A side. Accordingly, when the driver is engaged with the flathead screw 28 from the outside in the radial direction to remove or attach the adapter ring 25, the operation can be easily performed without interference with the housing 2.

Further, even when the entire ring retainer 13 and the rotary ring 12 are located on the inside B side of the end face of the housing 2, the flange member 3 is detached from the housing 2 and the outside A is removed. Side to form a working space with the housing 2, and then screw a bolt or the like into the drawing screw hole 25a of the adapter ring 25 in the same manner as described above, and pull it out of the machine. Since the rotating ring 12 and the rotating ring 12 can be drawn out into the working space, the replacement of the rotating ring 12 can be easily performed in this case as well.

Moreover, the screw hole 25a as described above can be easily formed in the adapter ring 25 made of, for example, stainless steel, and the bolt or the like can be used as a drawer as described above. In addition, since it is not necessary to separately manufacture a drawer having a special shape, the overall manufacturing cost can be reduced.

When the rotating ring 12 is replaced as described above, the fixed ring 11 is also replaced as necessary. In the present embodiment, the fixed ring 11 is fixed at a position deeper than the in-machine B end face of the flange member 3, so that, for example, a pull-out tool (not shown) having a hook-shaped tip. And the pulling tool is fixed to the fixing ring 11.
Annular groove 11c formed on the outer periphery of the in-machine B side end
And pulled out in the axial direction.

When the replacement with the new fixed ring 11 is completed, the flange member 3 is fixed to the housing 2 of the shaft-sealed device, and the stopper ring is attached to the male screw portion of the rotary shaft 1 in the reverse order. By successively tightening the sleeve 7 and fixing the sleeve 5 to the stopper ring 7 with the set screw 8, the assembled state shown in FIG. 1 is restored.

In such an assembled state, as described above, each of the sealing surfaces 11 s
When the rotating shaft 1 is driven, the sealing surfaces 11 s and 12 s come into sliding contact with each other to obtain a shaft seal. Is a pair of O-rings 26 for applying a clamping force from the outer periphery to the radially inward to maintain the ring in an annular shape.
27 is configured to press the insertion portion 12a of the rotating ring 12 from both sides in the axial direction.

That is, the rotating ring 12 having the split structure has
Adapter ring 25 and bottom wall 13 of ring retainer 13
O-rings 26 and 27 between axially opposed end faces
, The seal surface 12s of the rotating ring 12 wears and the rotating ring 1
Even if 2 moves in the axial direction together with the ring retainer 13, there is no danger that axial displacement will occur between the divided parts, and as a result, the stationary ring 11 is not formed on the seal surface 12 s.
The state of the action of the pressing force on the side of the sealing surface 11s is maintained uniform over the entire circumference, and a stable shaft sealing state is ensured.

Further, in the above description, the rotating ring 12 is
A so-called detent for rotating together with the ring retainer 13 without rotating together with the O-ring 26
27 contact surface with the ring retainer 13 and the rotating ring 1
2, the frictional force is applied to each of the radial contact surfaces of the O-rings 26 and 27 with the ring retainer 13 and the rotating ring 12, respectively.
Since it is also generated on the contact surface in the axial direction, the fixed holding force of the rotating ring 12 to the ring retainer 13 becomes larger.

As a result, the rotating ring 12 and the ring retainer 1
3, the rotating state of the rotating ring 12 and the ring retainer 13 can be ensured without using a configuration in which a detent such as an engaging pin that engages in the circumferential direction is separately provided and connected. This makes it possible to further simplify the overall configuration. Further, in the configuration in which the engagement pin is provided to prevent the rotation as described above, the circumferential force from the fixed ring 11 acting on the seal surface 12s acts on each divided part as a rotational moment around the engagement pin. As a result, a behavior may occur in which the split portions of the respective divided parts open mutually, which may lead to a reduction in sealing performance. On the other hand, in this embodiment, since the two O-rings 26 and 27 apply a uniform detent force over the entire circumference as described above, a behavior that the divided parts open mutually also occurs. This also maintains a stable sealing property.

Although the specific embodiments of the present invention have been described above, the present invention is not limited to the above embodiments, and various modifications can be made within the scope of the present invention. For example, in the above-described embodiment, a stationary ring 11 made of cemented carbide or silicon carbide and a rotating ring 12 made of carbon are provided. In this case, the rotating ring 12 in which abrasion progresses selectively is used as a specific seal ring. The configuration is such that the axial displacement of the divided parts is suppressed by holding and fixing the ring in the ring retainer 13 to which the adapter ring 25 is attached at the open end.
In the case of a combination of materials in which abrasion selectively progresses to one side, it is also possible to configure the fixed ring 11 as a specific seal ring in the same manner as described above. In the case where the rotating ring 12 and the fixed ring 11 are worn equally, for example, both of them are used as specific seal rings, and each of them is held and fixed to a ring retainer to which an adapter ring is attached. It is also possible to adopt such a configuration.

In the above-described embodiment, the rotary mechanical seal in which the compression coil spring 22 is provided on the rotary ring 12 side and the rotary ring 12 can be moved in the axial direction has been described as an example. The present invention can be applied to other types of mechanical seals such as a static mechanical seal configured as possible.

In the above description, an example has been given in which the rotary ring 12 as the specific seal ring is divided into two parts. However, it is also possible to provide a seal ring divided into three or more parts. Further, although the example in which the seal member wound around the outer periphery of the rotary ring 12 is formed by the O-rings 26 and 27 has been described, the seal member may be configured by using another elastic seal member such as a V-ring.

Further, in the above description, O-rings 26 and 27 are interposed on both sides in the axial direction of the insertion portion (large-diameter portion) 12a of the rotary ring 12, and the O-rings 26 and 27 are used to pivot the insertion portion 12a. Although the configuration in which the sheet is sandwiched in the direction is described as an example, in the scope of claim 1, for example, the end surface of the rotating ring 12 on the side opposite to the sealing surface is brought into direct contact with the bottom wall portion 13a of the sealing ring 13 or a sheet made of an elastic body. It is also possible to adopt a configuration in which the seal member is pressed in the axial direction only between the end surface of the large-diameter portion 12a on the open end side and the adapter ring 25 only.

[0054]

As described above, in the mechanical seal according to the first aspect of the present invention, the specific seal ring divided into a plurality in the circumferential direction is provided with a large diameter portion, and is wound around the outer periphery of the specific seal ring. An adapter ring fixed to the open end side of the ring holding body is provided so that the first seal member to be pressed against the end surface of the large diameter portion in the axial direction is pressed.
Screw the flat head screw through the wall of the holding body onto the adapter ring
The adapter ring to the ring holder.
As a result, it is possible to suppress the occurrence of an axial displacement in each of the divided parts of the specific seal ring, thereby maintaining a more stable sealing property. In addition, the first seal member has a function of holding the divided parts of the specific seal ring in an annular shape and a function of restricting the axial displacement, so that such an axial position is restricted. It is not necessary to separately provide a dedicated member for performing the operation, and thereby the overall configuration can be simplified.

Further, an end protruding portion having a smaller outer diameter than the large diameter portion is provided on the side of the specific seal ring opposite to the large diameter portion on the sealing surface side, and a second portion wound around the outer periphery of the end protruding portion is provided.
Since the seal member is also configured to be pressed in the axial direction between the step surface between the large-diameter portion and the end projecting portion and the bottom wall portion of the ring holding body, the seal member is disposed between the divided parts of the specific seal ring. In the axial direction is more reliably suppressed, and thereby more stable sealing performance can be maintained.

Further, a screw hole into which a drawer for pulling out the adapter ring in the axial direction is formed on the end face of the adapter ring opposite to the side in contact with the first seal member. Even in the case where the holding body is externally fitted to the rotary shaft at a recessed position surrounded by the housing of the shaft-sealed device, it is possible to pull the tip of a screw or the like into the screw hole from the outside of the machine by pulling it. In addition, the ring holder can be pulled out of the housing to the outside of the machine together with the adapter ring, so that the specific seal ring can be easily replaced.

[Brief description of the drawings]

1A and 1B show a mechanical seal according to an embodiment of the present invention, in which FIG. 1A is a half-sectional view, and FIG. 1B is a half-sectional view at a circumferential position different from FIG. It is.

FIG. 2 is a cross-sectional view showing the overall configuration of the mechanical seal.

3A and 3B show a conventional mechanical seal. FIG. 3A is a half sectional view, and FIG. 3B is a diagram in which a flange member is moved along a rotation axis when a rotating ring or a fixed ring is replaced. It is a half sectional view showing a state.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Rotation shaft 2 Housing 11 Fixed ring (seal ring) 11s Seal surface 12 Rotation ring (specific seal ring) 12a Fitting part (large diameter part) 12c O-ring winding part (projecting end part) 12s Seal surface 13 Ring retainer (Ring holder) 13a Bottom wall 13b Surrounding wall 25 Adapter ring 25a Screw hole for removal 26 1-O-ring (first sealing member) 27 2-O-ring (second sealing member)

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁷ , DB name) F16J 15/34-15/38

Claims (1)

(57) [Claims] 1. A pair of seal rings respectively attached to a rotating shaft of a device to be sealed and a housing such that axially opposed seal surfaces are in contact with each other, and at least one of these seal rings has a specific seal ring. Is formed in the circumferential direction into a plurality of parts, and a wall holding the specific seal ring from the outside in the radial direction, and a bottom wall part axially facing the end face of the specific seal ring on the side opposite to the sealing surface. A body is provided, and an annular first seal member made of an elastic body is interposed between an inner peripheral surface of the enclosing wall of the ring holding body and an outer peripheral surface of a specific seal ring inserted in the enclosing wall. A mechanical seal formed by holding a seal ring in an annular shape, wherein a large-diameter portion having an outer diameter larger than an inner diameter of a first seal member is provided on a specific seal ring from an interposition position of the first seal member. Is provided on the counter-sealing surface, the first sealing member is provided an adapter ring secured to the open end of the enclosure portion of the ring holder so as to press is brought into contact with the axially end surface of the large diameter portion, Li
Adapter screw with a flat head screw through the surrounding wall of the ring holder
Screwing the adapter ring into the ring holder
It is fixed, and the sealing surface is larger than the large diameter part of the specified seal ring.
An end projection with an outer diameter smaller than the large diameter part is provided on the side
An annular second seal portion made of an elastic body on the outer periphery of the end projection
Wrap the material and fix the adapter ring to the ring holder
By doing so, the second seal member is formed with the large diameter portion and the end portion
The axial direction between the step surface between the protrusions and the bottom wall of the ring holder
Is formed so as to be pressed toward the first seal member.
Pull out this adapter ring on the opposite end face in the axial direction.
To form a screw hole into which a drawer is screwed
Mechanical seal, characterized in that.