JP4076626B2 - mechanical seal - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a mechanical seal, and more particularly, to a bellows type mechanical seal that can be used both as a rotary type in which a seal ring, a bellows and a collar are attached to a rotary shaft side, and a stationary type in which they are attached to a housing side.
[0002]
[Prior art and its problems]
There are two types of bellows-type mechanical seals: a rotary type and a static type. The rotary type is configured so that the collar, bellows and seal ring are attached to the rotary shaft side, and the static type is to attach them to the housing side. It is configured.
[0003]
In the case of the rotary type, the seal end surface of the seal ring attached to the rotary shaft side and the seal end surface of the mating ring attached to the housing side are brought into contact with each other, thereby sealing between the rotary shaft and the housing. In the case of the stationary type, the seal end surface of the seal ring attached to the housing side and the seal end surface of the mating ring attached to the rotary shaft side are brought into contact with each other, thereby sealing between the rotary shaft and the housing. It can be done.
[0004]
An example of a static mechanical seal is shown in FIG. The mechanical seal 31 includes a metal cylindrical collar 32 attached to the housing 53 side, a metal bellows 36 connected to the collar 32 by welding or the like, and a metal bellows 36 connected to the bellows 36 by welding or the like. An adapter 37, a carbon seal ring 39 fitted to the adapter 37, a metal adapter 43 attached to the rotating shaft 52 side, and a carbon mating ring 41 fitted to the adapter 43 It is.
[0005]
Then, the seal end face 40 of the seal ring 39 attached to the housing 53 side is brought into contact with the seal end face 42 of the mating ring 41 attached to the rotating shaft 52 side, and the sealing ring 39 is moved by the urging force of the bellows 36. The seal end surface 42 of the mating ring 41 and the seal end surface 40 of the seal ring 39 are in sliding contact with each other by rotating the rotating shaft 52 in this state. The space between the two is sealed.
[0006]
However, the mechanical seal 31 configured as described above has no particular problem when used in a rotary form, but when used in a stationary form, a cylindrical protrusion that protrudes in the axial direction on the housing 53. Since the portion 54 is provided and the collar 32 must be attached to the outer peripheral side of the protruding portion 54, the thickness of the housing 53 is increased. Further, the protrusion 54 of the housing 53 needs to have a predetermined thickness in order to ensure strength, and a predetermined clearance is required to avoid interference between the inner peripheral surface of the protrusion 54 and the rotating shaft 52. Therefore, a large space is required in the radial direction, and the whole size is increased.
[0007]
The present invention solves the problems of the prior art as described above, and when used for both the rotary type and the stationary type, the thickness of the housing does not increase and is large in the radial direction. An object of the present invention is to provide a mechanical seal that does not require a space and can be used both as a rotary type and a static type without changing the structure.
[0008]
[Means for solving problems]
In order to solve the above problems, the present invention provides a mechanical seal provided between a rotating shaft and a housing and sealing between the two, and a seal ring having a seal end surface perpendicular to the axis of the rotating shaft. A collar attached to the seal ring via a bellows, and a mating ring having a seal end surface perpendicular to the axis of the rotary shaft that contacts the seal end surface of the seal ring, the seal ring, the bellows and the color come together, the provided inner circumferential surface and each O-ring groove on the outer peripheral surface of the collar, configured to be shared in both rotary and static, when used as a rotary, the inner periphery of the collar When the O-ring is installed in the O-ring groove on the side to seal between the collar and the rotating shaft, and used as a stationary type, the O-ring on the outer peripheral side of the collar It is obtained by employing the structure for sealing between the collar and the housing by mounting the O-ring in the groove. Further, a screw hole penetrating between the inner and outer peripheral surfaces is provided in a part of the collar, and means configured to be able to be tightened by screwing a set screw from the outer peripheral side or the inner peripheral side is adopted.
[0009]
[Action]
Since the present invention employs the above-described means, when used as a rotary type, the O-ring is mounted in the O-ring groove on the inner peripheral side of the collar, and in this state, the collar is attached to the rotating shaft side. As a result, the space between the collar and the rotating shaft is sealed. When used as a stationary type, an O-ring is mounted in an O-ring groove on the outer peripheral side of the collar, and the collar is attached to the housing in this state to seal the housing.
[0010]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention shown in the drawings will be described.
FIG. 1 shows an embodiment of a mechanical seal according to the present invention. A mechanical seal 1 according to this embodiment is mounted between a rotary shaft and a housing and seals between the two. 1, a collar 2, a bellows 6 coupled to the collar 2, an adapter 7 coupled to the bellows 6, a seal ring 9 fitted to the adapter 7, and a mating ring 11. It is.
[0011]
The collar 2 has a cylindrical shape made of metal, and annular O-ring grooves 3 and 4 are formed at predetermined depths on the inner and outer peripheral surfaces of one end in the axial direction. At the other end in the axial direction, a screw hole 5 penetrating between the inner and outer peripheral surfaces is screwed in at least one place.
[0012]
The bellows 6 is formed by arranging a plurality of metal diaphragm plates formed in a corrugated ring shape by punching or the like, and alternately connecting the outer diameter portions and the inner diameter portions of adjacent diaphragm plates by gas welding or the like. Are formed in a bellows cylinder shape, and one end is integrally connected to the collar 2 side by gas welding or the like.
[0013]
The adapter 7 has a cylindrical shape formed of metal, and an annular step 8 is formed on the inner peripheral surface of one end, and the outer periphery of the seal ring 9 is fitted into the step 8. It is like that. The other end of the bellows 6 is integrally connected to the adapter 7 by gas welding or the like.
[0014]
The seal ring 9 has a cylindrical shape made of carbon, and is fitted to the adapter 7 by fitting the outer peripheral side into the step portion 8 of the adapter 7. One end surface of the seal ring 9 in the axial direction is formed on a seal end surface 10 that is perpendicular to the axis of the rotation shaft.
[0015]
The mating ring 11 has a cylindrical shape made of carbon, and one end face in the axial direction is formed on a seal end face 12 perpendicular to the axis of the rotating shaft. The mating ring 11 is attached to the housing alone when used as a rotary type, and is attached to the rotary shaft side via a collar, an adapter or the like when used as a stationary type. .
[0016]
And when using the mechanical seal 1 comprised as mentioned above as a rotary form, as shown in FIG. 2, the mating ring 11 is fixed to the housing 23 side with a set screw (not shown). In this case, an O-ring 13 is interposed between the outer peripheral surface of the mating ring 11 and the inner peripheral surface of the housing 23.
[0017]
Next, an O-ring 14 is mounted in the O-ring groove 3 on the inner peripheral side of the collar 2, and in this state, the rotary shaft 22 is inserted through the inner peripheral side of the collar 2, bellows 6, adapter 7 and seal ring 9, The collar 2 is moved in the direction of the mating ring 11, the seal end face 10 of the seal ring 9 is brought into contact with the seal end face 12 of the mating ring 11, and the seal ring 9 is moved to the mating ring 11 by the urging force of the bellows 6. Press in the direction. In this state, the set screw 15 is screwed into the screw hole 5 of the collar 2 from the outer peripheral side and tightened to fix the collar 2 to the rotary shaft 22.
[0018]
In this way, when the collar 2, the bellows 6, the adapter 7 and the seal ring 9 are attached to the rotating shaft 22 side, the mating ring 11 is attached to the housing 23 side, and the rotating shaft 22 is rotated in this state, the seal ring 9 The seal end face 10 and the seal end face 12 of the mating ring 11 are in sliding contact with each other, and the space between the rotary shaft 22 and the housing 23 is sealed.
[0019]
In this case, the bellows 6 and the O-ring 14 function as a secondary seal to seal between the rotary shaft 22, and the O-ring 13 functions as a secondary seal to seal between the housing 23.
[0020]
Next, when the mechanical seal 1 configured as described above is used as a stationary type, the mating ring 11 is attached to the rotary shaft 22 side via the collar 16 and the adapter 19 as shown in FIG. The collar 16 has a cylindrical shape made of metal, and is fixed to the rotating shaft 22 side by a set screw 17. An O-ring 18 is interposed between the collar 16 and the rotating shaft 22. The adapter 19 has a cylindrical shape made of metal, and is fixed to the outer peripheral side of the collar 16 via a knock pin 20. An O-ring 21 is interposed between the collar 16 and the adapter 19. The mating ring 11 is configured such that the outer peripheral side is fitted to the inner peripheral side of the adapter 19.
[0021]
Next, an O-ring 14 is mounted in the O-ring groove 4 on the outer peripheral surface side of the collar 2, and in this state, the rotary shaft 22 is inserted through the inner peripheral side of the collar 2, bellows 6, adapter 7 and seal ring 9, The collar 2 is fitted to the housing 23 side, the set screw 15 is screwed into the screw hole 5 of the collar 2 from the inner peripheral side and tightened to fix the collar 2 to the housing 23 side, and the seal end face of the seal ring 9 10 is brought into contact with the seal end surface 12 of the mating ring 11, and the seal ring 9 is pressed in the direction of the mating ring 11 by the urging force of the bellows 6.
[0022]
In this way, when the collar 2, the bellows 6, the adapter 7, and the seal ring 9 are attached to the housing 23 side, the mating ring 11 is attached to the rotary shaft 22 side, and the rotary shaft 22 is rotated in this state, the seal ring 9 The seal end surface 10 and the seal end surface 12 of the mating ring 11 are in sliding contact with each other to seal between the rotary shaft 22 and the housing 23.
[0023]
In this case, the O-ring 14 functions as a secondary seal to seal between the housing 23, and the O-ring 18 functions as a secondary seal to seal between the rotary shaft 22.
[0024]
In the mechanical seal 1 according to this embodiment configured as described above, the O-ring grooves 3 and 4 are provided on the inner and outer peripheral surfaces of the collar 2 on the seal ring 9 side, and the collar 2 penetrates between the inner and outer peripheral surfaces. Since the screw hole 5 to be screwed is provided, when used as a rotary type, the O-ring 14 is mounted in the O-ring groove 3 on the inner peripheral side, and the set screw 15 is screwed into the screw hole 5 from the outer peripheral side. When the collar 2 is fixed to the rotary shaft 22 side by tightening together and used as a stationary type, an O-ring 14 is mounted in the O-ring groove 4 on the outer peripheral side, and the screw hole 5 has an inner peripheral side. Then, the collar 2 may be fixed to the housing 23 side by screwing and tightening the set screw 15.
[0025]
Therefore, it can be used for both the rotary type and the static type without changing the structure, and when used as a static type, there is no need to provide a protrusion on the housing 23, and the protrusion and the rotary shaft Therefore, it is not necessary to provide a clearance between the two and the space in the radial direction.
[0026]
In the above description, the bellows-type mechanical seal is targeted, but it goes without saying that the same effect can be obtained even if the configuration according to this embodiment is used for other types of mechanical seals. .
[0027]
【The invention's effect】
The present invention is configured as described above, and the O-ring grooves are provided on the inner peripheral surface and the outer peripheral surface of the collar, respectively. By mounting the O-ring and attaching the collar to the rotating shaft side in this state, the O-ring functions as a secondary seal to seal between the rotating shaft and the collar, and the seal of the sealing ring on the rotating shaft side The end surface and the sealing end surface of the housing-side mating ring are in sliding contact with each other, thereby sealing between the rotating shaft and the housing. Also, when used as a stationary type, an O-ring is mounted in the O-ring groove on the outer peripheral side of the collar, and the collar is attached to the housing in this state, so that the O-ring functions as a secondary seal and the housing The seal end surface of the seal ring on the housing side and the seal end surface of the mating ring on the rotary shaft side are in sliding contact with each other, so that the seal between the rotary shaft and the housing is sealed. Will be. Therefore, both the rotary type and the stationary type can be used without changing the structure. In addition, when used as a stationary type, there is no need to provide a protrusion on the housing side, so the thickness of the housing can be reduced, and there is no need to provide a clearance between the protrusion and the rotating shaft. Therefore, a small space in the radial direction is sufficient, and the whole can be downsized.
[Brief description of the drawings]
FIG. 1 is a schematic cross-sectional view showing an embodiment of a mechanical seal according to the present invention.
FIG. 2 is a schematic cross-sectional view when the one shown in FIG. 1 is used in a rotary form.
FIG. 3 is a schematic cross-sectional view when the one shown in FIG. 1 is used in a static form.
FIG. 4 is a schematic sectional view showing an example of a conventional mechanical seal.
[Explanation of symbols]
1, 31 ... Mechanical seal 2, 16, 32 ... Collar 3, 4 ... O-ring groove 5 ... Screw hole 6, 36 ... Bellows 7, 19, 37, 43 ... Adapter 8 ... Step 9 , 39... Seal ring 10, 12, 40, 42... Seal end face 11, 41... Mating ring 13, 14, 18, 21. ... Rotating shafts 23, 53 ... Housing 54 ... Protrusions

Claims (1)

A mechanical seal provided between the rotating shaft and the housing and sealing between the two, a seal ring having a seal end surface perpendicular to the axis of the rotating shaft, and a collar attached to the seal ring via a bellows A mating ring having a seal end surface perpendicular to the axis of the rotating shaft that contacts the seal end surface of the seal ring,
The seal ring, the bellows, and the collar are integrated, and an O-ring groove is provided on each of the inner peripheral surface and the outer peripheral surface of the collar so that both the rotary type and the stationary type can be used.
When used as a rotary type, an O-ring is installed in the O-ring groove on the inner circumference side of the collar to seal between the collar and the rotating shaft.
When used as a stationary type, the O-ring is installed in the O-ring groove on the outer peripheral side of the collar to seal between the collar and the housing .
A mechanical seal characterized in that a screw hole penetrating between the inner and outer peripheral surfaces is provided in a part of the collar and can be tightened by screwing a set screw from the outer peripheral side or the inner peripheral side .

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