JP2842211B2 - Non-contact 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 non-contact mechanical seal, and more particularly to a shaft seal device for a fluid device such as a gas turbine, a blower, a centrifugal compressor or the like, which is used at a high peripheral speed and at a high temperature or at a very low temperature. Non-contact mechanical seal.

[0002]

2. Description of the Related Art Conventionally, a non-contact mechanical seal for sealing between a rotating shaft and a casing in a compressor or the like has already been provided. For example, Japanese Patent Application Laid-Open No. HEI 5-164249, filed by the applicant of the present invention, discloses a mating ring hermetically sealed on a rotating shaft and a primary ring hermetically mounted on a seal housing and urged in the axial direction by pressing means. A plurality of spiral grooves having an advancing angle with respect to the relative rotation direction are provided at regular intervals in the circumferential direction on one of the sealing surfaces facing each other, and the sealed fluid is pressure-fed between the sealing surfaces. A non-contact mechanical seal is provided.

[0003] And, this non-contact mechanical seal,
A dynamic pressure toward the center is generated between the sealing surfaces of the primary ring and the mating ring, and this dynamic pressure creates a micron-level gap between both sealing surfaces to maintain a non-contact state and enable high peripheral speed rotation. It was made.

Here, the primary ring follows a minute displacement of the mating ring due to axial runout of the rotating shaft or displacement in the axial direction, and a retainer sleeve for forming a gap due to dynamic pressure between the sealing surfaces. It is necessary to make it possible to displace in the axial direction with respect to, and to seal between them. Therefore, the one described in the above-mentioned publication is characterized in that the O.D.
The ring is interposed. Also, an O-ring is used for sealing between members such as a casing or a seal housing of a fluid device and a retainer, a mating ring and a fixed sleeve, and a rotating shaft and a fixed sleeve.

However, since an O-ring is used for sealing between members, it is not suitable for continuous operation at a high temperature.
Even if a heat-resistant O-ring made of TFE is used, the temperature that can withstand continuous operation is at most 300 ° C. In particular, the O-ring used between the primary ring and the retainer sleeve is exposed to the harshest operating environment in which high-pressure, high-temperature fluid on the process side comes into direct contact and seals while constantly sliding in the axial direction of the retainer sleeve. Since the mechanical strength needs to be sufficiently maintained, the O-ring must be used at a temperature at which the O-ring does not soften. In addition, considering safety in durability, the upper limit of continuous operation is 200 ° C. It is about. Similarly, when used at an extremely low temperature of −100 ° C. or lower, ordinary O-rings become brittle and cannot be used.

[0006] Therefore, in a mechanical seal for high temperature or ultra low temperature, the sealing between the primary ring and the retainer sleeve is performed by a carbon piston ring. As shown in FIGS. 8 and 9, the carbon piston ring 100 has an end face 102 orthogonal to the axial direction of a primary ring 101 and a pressing means 1 comprising a plurality of coil springs.
03, and one side thereof is pressed against the end surface 102, and the retainer sleeve 105
To tightly seal the space between the primary ring 101 and the retainer sleeve 105. The structure is such that a pair of substantially identical inner component rings 106a and 106b are closely contacted in the axial direction, and a pair of substantially identical outer component rings 107a and 107b are closely fitted on the respective outer circumferences. The garter springs 108a and 108b are fitted into the annular grooves provided on the outer periphery of the rim, respectively, and are tightened. Here, each constituent ring 10
6, 107 are splits 1 formed at three places, respectively.
., And all the splits 109 are assembled so as to be shifted from each other so as not to overlap in the axial direction and the radial direction. As a result, the inner peripheral sliding contact surfaces 110a, 110b of the inner constituent rings 106a, 106b are formed by the garter springs 108a, 108b.
Are in close contact with the outer peripheral surface 111 of the retainer sleeve 105.

[0007]

However, the carbon piston ring having the above structure has a large sliding frictional resistance between the sliding surface of the inner ring and the outer peripheral surface of the retainer sleeve. Quick follow-up is impaired. Also, what actually contributes to the seal between the primary ring and the retainer sleeve is the internal component ring 106a on the primary ring side.
The other ring acts as a joint material for preventing leakage from the three splits 109,... Of the inner component ring 106a, but the joint action at the cross-shaped joint in the cross section of FIG. Because of the insufficiency, there is more leakage than the O-ring.

In view of the above situation, the present invention is to solve the problem that a non-contact mechanical seal uses a carbon piston ring having excellent heat resistance to seal between a primary ring and a retainer sleeve. It is an object of the present invention to provide a non-contact mechanical seal capable of reducing the leakage of process fluid while reducing the sliding frictional resistance to the sleeve and ensuring the followability of the primary ring to the mating ring.

[0009]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the present invention provides a mating ring which is hermetically fixed to a rotating shaft, a sealing housing which is axially movable in a seal housing, and is provided on a retainer. A number of spiral grooves having an advancing angle with respect to the relative rotation direction are formed in the circumferential direction on at least one of the two sealing surfaces with the primary ring biased toward the mating ring side by means. A non-contact mechanical seal, wherein a carbon piston ring slidably fitted tightly on a retainer sleeve is interposed between an end surface of the pressing means and a disc perpendicular to the axial direction of the primary ring, and the retainer sleeve is
With a coefficient of thermal expansion close to that of a carbon piston ring
In addition, the carbon piston ring tightly fits a plurality of constituent rings forming a split in one place with each other, tightens the outer periphery with a garter spring, and forms an annular concave portion on the inner and outer edges in the axial direction that contacts the retainer sleeve. Ru a configuration of becoming.

Furthermore, the non-contact mechanical seal of the present invention
As the carbon piston ring, a pair of inner component rings tightly fitted to a retainer sleeve are axially closely contacted, one outer component ring is closely fitted over the outer periphery of both inner component rings, and the outer The outer component ring is closely fitted to the outer periphery of the inner component ring which is tightly fitted to the retainer sleeve, and the retainer is provided on both sides of one side of the inner and outer component ring and on the disk side of the pressing means. closely side structure ring which closely fitted to the sleeve, the outer configuration ring and the side structure ring in which each comprise a structure formed by tension in the garter spring.

Here, it is preferable that an expanded graphite sheet is interposed between the end face of the carbon piston ring and the disk of the pressing means.

Further, the retainer sleeve may be made of tungsten carbide or silicon carbide having a coefficient of thermal expansion close to that of a carbon piston ring, or a retainer sleeve formed of ceramics having a hardness and a coefficient of thermal expansion equivalent to those. preferable.

The members between the rotating shaft and the mating ring, the seal housing and the retainer, and between the retainer and the retainer sleeve are sealed with a graphite gasket.

[0014]

According to the non-contact mechanical seal of the present invention having the above-described contents, the sealed fluid is pressure-fed between the sealing surfaces by the spiral groove formed on at least one of the sealing surfaces of the mating ring and the primary ring. A dynamic pressure is generated, and a gap is formed between the sealing surfaces by the pressure of the sealed fluid pumped between the sealing surfaces by this fluid transport action, so that the mating ring and the primary ring do not contact each other. High peripheral speed rotation, and the space between the primary ring and the retainer sleeve is sealed with a carbon piston ring.
Continuous operation at a high temperature of about 500 ° C. is possible. Since only one split is formed in each of the constituent rings of the carbon piston ring, the carbon piston ring has structural elasticity enough to be elastically deformed by the tension of the garter spring and prevents leakage of the sealed fluid through the split. Since the annular concave portion is formed on the inner and outer edges in the axial direction that contacts the retainer sleeve of the carbon piston ring, the contact area with the outer peripheral surface of the retainer sleeve is reduced, and the sliding friction resistance in the axial direction is reduced. Smaller,
This ensures the ability of the primary ring to follow the mating ring.

[0015] As the carbon piston ring, a pair of inner component rings closely fitted to the retainer sleeve are closely contacted in the axial direction, and one outer component ring is closely fitted over the outer periphery of both inner component rings. A structure in which the outer periphery of the ring is tightened by a garter spring, or an outer constituent ring is closely fitted to the outer periphery of an inner constituent ring closely fitted to a retainer sleeve, and both side end faces on one side of the inner and outer constituent rings and a pressing means The side component ring that closely fits the retainer sleeve on the disk side of
When the outer component ring and the side component ring are each configured to be tightened by a garter spring, a joining portion in a cross section of each component ring becomes T-shaped, and the inner component ring located on the primary ring side is formed. The joint effect of the other component rings is sufficient to minimize leakage. Also, the carbon piston ring having the former structure has one garter spring, so that the number of parts is reduced.

Further, by disposing an expanded graphite sheet between the end face of the carbon piston ring and the disk of the pressing means, the distortion of the end face of the carbon piston ring is absorbed.

If the retainer sleeve is made of tungsten carbide or silicon carbide having a coefficient of thermal expansion close to that of a carbon piston ring or a ceramic having the same hardness and coefficient of thermal expansion as those of a carbon piston ring, it can be used at high temperatures. The difference between the inner diameter of the carbon piston ring and the outer diameter of the retainer sleeve is small, and good sealing performance can be ensured.

Further, the rotating shaft and a mating ring,
By sealing between the seal housing and the retainer and between the retainer and the retainer sleeve with a graphite gasket, the sealing performance can be maintained even during continuous high-temperature operation.

[0019]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a block diagram showing a first embodiment of the present invention; In this embodiment, a non-contact mechanical seal used for a high-temperature gas seal will be mainly described, but the same applies to a liquid seal.

FIG. 1 shows the entire structure of a non-contact mechanical seal M according to the present invention. The non-contact mechanical seal M is provided between a casing 1 which is a sealed container of a fluid device and a rotary shaft 2 penetrating an open end of the casing 1. I have. Here, in the figure, A indicates the atmospheric pressure (low pressure) side, and B indicates the process (high pressure) side.

The non-contact mechanical seal M of this embodiment is
The casing 1 includes a seal housing 3 and a retainer 4.
In a sealing space formed by sequentially tightening bolts, a mating ring 5 hermetically fixed to the rotating shaft 2 and a primary ring 7 hermetically mounted in a retainer sleeve 6 fixed to the retainer 4 and projected into the sealing space. And the sealing surfaces 8, 9 of the mating ring 5 and the primary ring 7 are brought into contact with each other, and the primary ring 7 is non-rotatable and axially movable between the retainer 4 and the retainer sleeve 6 so as to be retained. 6 and the pressing means 1 held by the retainer 4
At 0, the seal surfaces 8 and 9 are urged in the approaching direction. Here, the pressing means 10 is composed of a plurality of coil springs 12,... Supported by a holder 11 disposed between the retainer 4 and the retainer sleeve 6, and a ring-shaped disk 13 disposed inward in the axial direction. ing. And
A carbon piston ring 15 slidably fitted to the retainer sleeve 6 is interposed between the disk 13 and an end surface 14 orthogonal to the axial direction of the primary ring 7,
The space between the primary ring 7 and the retainer sleeve 6 is sealed.

As shown in FIG. 2, the sealing surface 8 of the mating ring 5 has a spiral groove 16 extending inward starting from the outer peripheral edge thereof and having an advancing angle with respect to the rotation direction R. Many are provided at regular intervals in the direction. As a result, the mating ring 5 rotates relative to the primary ring 7 (rotation direction R) in the presence of the process gas, thereby generating a dynamic pressure between the sealing surfaces 8 and 9 toward the center in the radial direction by the spiral groove 16. Then, the process gas is fed under pressure to form a minute gap between the two sealing surfaces 8 and 9, and a sealing pressure higher than the pressure on the process side is formed for sealing. On the other hand, although not shown, a similar spiral groove 17 is also formed on the seal surface 9 of the primary ring 7, and even if this spiral groove 17 has an advancing angle with respect to the relative rotation direction, the backward angle is reduced. When it has an advancing angle, it has the same effect as the spiral groove 16, and when it has a backward angle, it partially reverses the process gas pumped by the spiral groove 16, and It has the effect of reducing In this embodiment,
The material of the mating ring 5 is tungsten carbide, and the material of the primary ring 7 is carbon.

In order to fix the mating ring 5 to the rotating shaft 2, first, a drive collar 19 tightly fitted to an assembly sleeve 18 extrapolated and fixed to the rotating shaft 2 is bolted, and the drive collar 19 is attached to the inside of the drive collar 19. Side, i.e., in the sealing space, the shaft sleeve 20 externally fitted to the assembly sleeve 18 is axially tightened and fixed with a bolt, and further positioned on the shaft sleeve 20 on the inner side thereof.
At the same time, the locking sleeve 21 externally fitted to the assembly sleeve 18 is axially tightened and fixed with a bolt, and at the same time, the mating ring 5 externally fitted to the annular step 22 provided on the shaft sleeve 20 with the tolerance ring 23 interposed therebetween. It is clamped and fixed between the radial wall surface of the annular step portion 22 and the flange 24 of the locking sleeve 21. The assembly sleeve 18 is used for arranging a plurality of non-contact mechanical seals M in tandem in the axial direction. In the case of a single assembly sleeve, the assembly sleeve 18 is omitted and the above-described members are directly rotated. It is attached to the shaft 2.

The assembly sleeve 18 and the shaft sleeve 20 are sealed by a cylindrical pressing portion 25 extending along the shaft sleeve 20 on the inner side of the drive collar 19 and on the outer side of the shaft sleeve 20. An annular space 2 formed along the assembly sleeve 18
6 is compressed and a trapezoidal gasket 27 made of graphite tightly fitted in the annular space 26 at the tip of the pressing portion 25 is compressed, and the gasket 27 is fitted to the wall surface of the annular space 26 of the shaft sleeve 20 and the assembly sleeve 18. In close contact with the outer peripheral surface of. The sealing between the mating ring 5 and the shaft sleeve 20 is performed by fitting a gasket 28 made of graphite into an annular seal groove formed on a radial wall surface of the annular step portion 22 of the shaft sleeve 20. The gasket 28 is pressed against the mating ring 5 by using a fastening force for fixing the shaft 21 to the shaft sleeve 20. Also,
In order to integrate the locking sleeve 21 and the mating ring 5 for rotation, the locking sleeve 2
A pin 29 protruding from the first flange 24 is embedded in the mating ring 5.

The casing 1 and the seal housing 3
Is sealed with a gasket 30 made of graphite on the joint surface of both members, and the seal between the seal housing 3 and the retainer 4 is made with a gasket 31 made of graphite on the joint surface of both members. I have. Further, the retainer 4 and the retainer sleeve 6 are radially aligned via the tolerance ring 23a, to prevent concentric misalignment due to a difference in thermal expansion therebetween, and to seal between them.
As described above, the gasket 32 made of graphite is interposed between the joining surfaces of the two members.

Next, the assembling structure of the primary ring 7 will be described. The balance diameter portion of the primary ring 7 is externally fitted to the outer peripheral surface of the retainer sleeve 6 so as to be movable in the axial direction, and protruded from the outer periphery. The rotation restricting portion 33 is axially movably fitted into the spline groove 34 formed in the inner peripheral surface of the retainer 4 in the axial direction so as to maintain the non-rotational state of the primary ring 7. Here, it is preferable to provide a small gap between the primary ring 7 and the retainer sleeve 6 in order to ensure quick following of the primary ring 7 with respect to the mating ring 5.

As shown in FIGS. 3 to 5, the carbon piston ring 15 of the present embodiment has a pair of inner component rings 36, which are closely fitted to the outer peripheral surface 35 of the retainer sleeve 6.
37 are arranged side by side in the axial direction and are in close contact with each other, one outer component ring 38 is closely fitted over the outer periphery of both inner component rings 36 and 37, and a garter is The spring 40 is fitted in tension, and the inner component rings 36,
37 is pressed against the outer peripheral surface 35 of the retainer sleeve 6, and each of the constituent rings 36, 37, 38 is provided with a split 41 at one location to provide structural elasticity. Here, both inner constituent rings 36,
The sum of the axial widths of the outer ring 37 and the axial width of the outer component ring 38 is made to match. Further, a pair of both inner constituent rings 36, 3
As shown in FIG. 5, annular recesses 42, 42 are formed on each outer edge of the retainer sleeve 6 in contact with the retainer sleeve 6, that is, on the inner inner and outer edges of the retainer sleeve 6 when both inner constituent rings 36, 37 are assembled. Then, the axial width of the sliding contact surfaces 43, 43 in contact with the retainer sleeve 6 is narrowed, and the sliding frictional resistance to the retainer sleeve 6 is reduced. In addition, both inner constituent rings 36 and 37 may have completely the same shape, and the cost can be reduced by inverting and using one of them.

Then, the inner rings 36, 37 and the outer ring 38 are fitted into the retainer sleeve 6 one after another by shifting the positions of the splits 41,... By a rotation angle of about 120 °. I am nervous at 40. In this assembled state, as shown in FIG. 5, the joint of the constituent rings 36, 37 and 38 has a T-shape in cross section, and the radius of the inner constituent ring 36 and the outer constituent ring 38 located inward in the axial direction. Directional sealing surfaces 44,44
Are exactly flush and in close contact with the radial end face 14 of the primary ring 7. On the other hand, the radial side surfaces 4 of the inner component ring 37 and the outer component ring 38 located axially outward.
Although it is preferable to set exactly the same as 5, 45,
Even if there is some dimensional error, the disc 13 of the pressing means 10
The expanded graphite sheet 46 is interposed between the internal component ring 3 and the internal component ring 37 via the internal component ring 37 to absorb the dimensional error and make the pressing force of the coil spring 12 substantially uniform.
6 to the outer component ring 38 so that the surface pressures of the end face 14 and the sealing faces 44, 44 can be balanced. Of course, if the side surfaces 45, 45 of the inner component ring 37 and the outer component ring 38 are exactly flush, the expanded graphite sheet 46 can be omitted.

FIG. 6 shows another embodiment of the carbon piston ring 15, which is composed of three constituent rings in which splits 41,. Are the same in basic configuration. Carbon piston ring 15 of the present embodiment
The outer component ring 48 is tightly fitted to the outer periphery of the inner component ring 47 that closely fits the outer peripheral surface 35 of the retainer sleeve 6, and the disc 13 of the pressing means 10 A side component ring 49 closely fitted to the retainer sleeve 6 is closely attached to the side, and the outer component ring 48 and the side component ring 49 are tightened by garter springs 50, 50, respectively. Here, the axial widths of the inner component ring 47 and the outer component ring 48 are exactly matched, and the shape of the inner component ring 47 with the outer component ring 48 fitted externally and the shape of the side component ring 49 are antisymmetric. And that. Further, similarly to the above, at the outer edges of the inner component ring 47 and the side component ring 49 which come into contact with the retainer sleeve 6, that is, at the inner and outer edges in the axial direction when both the component rings 47, 49 are assembled to the retainer sleeve 6. As shown in FIG. 6, annular concave portions 51, 51 are formed to reduce the axial width of the sliding contact surfaces 52, 52 that come into contact with the retainer sleeve 6, thereby reducing the sliding frictional resistance to the retainer sleeve 6. Then, the inner component ring 47 located inward in the axial direction
And the radial sealing surfaces 53 of the outer component ring 48 are exactly flush and in close contact with the radial end surface 14 of the primary ring 7. On the other hand, the radial side surface 54 of the side component ring 49 located outward in the axial direction is pressed against the disk 13 of the pressing means 10. It should be noted that the expanded graphite sheet 46 may be interposed between the side surface 54 and the disk 13 so that the pressing force of the coil spring 12 can be applied evenly to the entire surface of the side surface 54. However, in the case of this embodiment, Need not use the expanded graphite sheet 46 in particular.

Next, a brief description will be given of the process gas sealing effect when such a carbon piston ring 15 is employed. First, the internal structure ring 3 located on the primary ring 7 side has the structure shown in FIG.
6 is closed and sealed by the radial joining surface of the inner component ring 37 and the axial inner peripheral joining surface of the outer component ring 38, and the inner component ring 37 and the outer component ring 38 have a sealing effect. It acts as a joint. In the structure shown in FIG. 6, the split 41 of the inner component ring 47 located on the primary ring 7 side in the same manner as described above, It is sealed by closing with the directional joining surface.

The non-contact mechanical seal M of the present embodiment is provided between the seal surfaces 8 and 9 and the carbon piston ring 15.
The sliding contact surface 43 is designed so that dust and the like do not enter. One of them is to arrange a split labyrinth 55 coaxially around the outer periphery of the drive collar 19 and
And a small gap between the inner peripheral surface of the split labyrinth 55 and a plurality of ridges 56, which are continuous in the circumferential direction and project at equal intervals in the axial direction, and the outer peripheral surface of the drive collar 19. Are formed to prevent dust from entering the seal space from outside with the ridges 56,.
Even if dust adheres to the surface, the process gas that leaks to the outside is blown off at a small gap with an increased flow velocity. The second is an outer peripheral surface of the cylindrical portion of the locking sleeve 21 which is continuous in the circumferential direction and is arranged at equal intervals in the axial direction.
, And a minute gap is formed between the ridges 57,... And the inner peripheral surface of the bushing 58 fixed coaxially to the outer periphery of the cylindrical portion and fixed to the seal housing 3. In order to prevent dust from entering the sealing space from the side by the ridges 57,... Even if dust adheres to the ridges 57,. Alternatively, a nitrogen gas is injected, and the gas is blown toward the process side at an increased flow rate in the minute gap.

As shown in FIG. 7, the primary ring 7, the pressing means 10 and the carbon piston ring 15 are bolted to the seal housing 3 in a state where they are temporarily assembled to the retainer 4 and the retainer sleeve 6.
In this case, a set plate 60 is fixed to the connecting surface side of the retainer 4 to the seal housing 3 with bolts 61 so that each member does not fall off from the retainer 4, and an inner edge of the set plate 60 defines the spline groove 34. The rotation restricting portion 33 of the primary ring 7 is stopped by closing the open end. Then, in this state, after extrapolating to the shaft sleeve 20, the set plate 60 is removed, and the sealing surface 9 of the primary ring 7 is joined to the sealing surface 8 of the mating ring 5.

[0033]

According to the above-described non-contact mechanical seal of the present invention, the following effects can be obtained.

According to the present invention , when the rotating shaft rotates, the mating ring fixed to the rotating shaft rotates to generate a dynamic pressure between the sealing surface with the primary ring, thereby sealing the process gas in a non-contact state. In addition to the primary ring, the primary ring can be used for mating even if the mating ring is subject to axial runout or small axial displacement during rotation of the rotating shaft. Since it is not in contact with the ring, it does not follow the shaft runout, but it has a structure with an annular concave part with little sliding friction resistance to the retainer sleeve, and through a heat-resistant carbon piston ring, it is pushed to the mating ring side by pressing means. As it is pressed, it quickly follows minute displacements in the axial direction, thereby ensuring stable sealing even at high peripheral speeds and high temperatures. Than it can be achieved. Further, since the split is formed only at one position of each of the constituent rings of the carbon piston ring, the leakage of the process fluid through the split can be reduced.

Further, according to the first aspect of the present invention , the joint between the constituent rings in the cross section has a T-shape, and in addition to the above-described effect of one split, it has a structural sealing property. Fluid leakage can be suppressed to a minimum, and only one garter spring is required, so that the number of parts is reduced and cost can be reduced.

Further, according to claim 2, wherein become joint T-shaped constituent rings in the same manner in section, in addition to the one place of the split of the above effects, it has the structural sealability Therefore, leakage of the process fluid can be suppressed to a minimum.

According to the third aspect of the present invention, even when the axially outer end face of the carbon piston ring is not exactly flush, the elasticity of the expanded graphite sheet causes the pressing force of the pressing means to uniformly act on each component ring. It is possible,
Further, the sealing performance can be improved.

According to the fourth aspect , since the coefficient of thermal expansion between the carbon piston ring and the retainer sleeve is similar,
Good sealability can be maintained from extremely low to high temperatures.

According to the fifth aspect , all the gaskets to be sealed between the members are made of graphite, so that the gaskets have heat resistance and corrosion resistance to the process fluid.

[Brief description of the drawings]

FIG. 1 is a sectional view of a main part in a state where a non-contact mechanical seal of the present invention is mounted between a rotating shaft and a casing.

FIG. 2 is a side view showing an example of a spiral groove pattern formed on a sealing surface of a mating ring.

FIG. 3 is an exploded perspective view of a carbon piston ring.

FIG. 4 is a side view of the assembled state of the carbon piston ring.

FIG. 5 is a simplified cross-sectional view showing a state where a carbon piston ring is similarly assembled.

FIG. 6 is a simplified sectional view showing a state where a carbon piston ring of another embodiment is assembled.

FIG. 7 is a sectional view showing a temporary assembly state around a primary ring.

FIG. 8 is a side view of a conventional carbon piston ring in an assembled state.

FIG. 9 is a simplified cross-sectional view showing a state where a carbon piston ring is also attached.

[Explanation of symbols]

 M Non-contact mechanical seal 1 Casing 2 Rotating shaft 3 Seal housing 4 Retainer 5 Mating ring 6 Retainer sleeve 7 Primary ring 8, 9 Seal face 10 Pressing means 11 Holder 12 Coil spring 13 Disk 14 End face 15 Carbon piston ring 16, 17 spiral Groove 18 Assembly sleeve 19 Drive collar 20 Shaft sleeve 21 Locking sleeve 22 Annular step 23, 23a Tolerance ring 24 Flange 25 Pressing part 26 Annular space 27, 28, 30, 31, 31, 32 Gasket 29 Pin 33 Rotation regulating part 34 Spline groove 35 outer peripheral surface 36 inner constituent ring 37 inner constituent ring 38 outer constituent ring 39 annular groove 40 garter spring 41 split 42 annular concave portion 43 sliding contact surface 44 Surface 45 side surface 46 expanded graphite sheet 47 inner constituent ring 48 outer constituent ring 49 side constituent ring 50 garter spring 51 annular concave part 52 sliding contact surface 53 sealing surface 54 side surface 55 split labyrinth 56 ridge 57 ridge 58 bushing 59 gas inlet 60 Set plate 61 Bolt

──────────────────────────────────────────────────続 き Continued on front page (58) Field surveyed (Int.Cl. ⁶ , DB name) F16J 15/34

Claims (5)

(57) [Claims] 1. A mating ring which is hermetically fixed to a rotating shaft and a primary ring which is axially movable and is hermetically mounted on a seal housing and is urged toward the mating ring by a pressing means provided on a retainer. A non-contact mechanical seal in which a number of spiral grooves having an advancing angle with respect to a relative rotation direction are formed in at least one of the two sealing surfaces in a circumferential direction, wherein the disk and the primary A carbon piston ring closely slidably fitted to the retainer sleeve is interposed between end faces orthogonal to the axial direction of the ring, and the retainer sleeve is attached to the carbon piston ring.
It has an approximate thermal expansion coefficient, the carbon piston rings, the retainer sleeve
A pair of internal components that are closely fitted to form a split at one location
Ring in the axial direction, and
One external component phosphorus with split formed in one place
A non-contact mechanical seal characterized in that the outer ring is tightly fitted with a garter spring to tightly fit the outer ring, and an annular concave portion is formed at an inner and outer edge in the axial direction in contact with the retainer sleeve. 2. A mating ring which is hermetically fixed to a rotating shaft and a primary ring which is axially movable and is hermetically mounted on a seal housing and is urged toward the mating ring by a pressing means provided on a retainer. A non-contact mechanical seal in which a number of spiral grooves having an advancing angle with respect to a relative rotation direction are formed in at least one of the two sealing surfaces in a circumferential direction, wherein the disk and the primary A carbon piston ring closely slidably fitted to the retainer sleeve is interposed between end faces orthogonal to the axial direction of the ring, and the retainer sleeve is attached to the carbon piston ring.
It has an approximate thermal expansion coefficient, the carbon piston rings, the retainer sleeve
Outside the inner component ring that is tightly fitted to form one split
Closely fitted outer component ring with split formed in one place around the circumference
And both end faces on one side of the inner and outer constituent rings,
A side component ring that fits tightly on the retainer sleeve on the disk side
The outer ring and the side ring.
A non-contact mechanical seal characterized in that it is tightened by a garter spring and has an annular concave portion formed on the inner and outer edges in the axial direction in contact with the retainer sleeve. 3. An end face and a front face of said carbon piston ring.
The expanded graphite sheet is placed between the disc and the pressing means.
The non-contact mechanical seal according to claim 1, wherein the mechanical seal is interposed . 4. A carburetor as the retainer sleeve.
Tungs with a coefficient of thermal expansion approximating a piston ring
Ten carbide, silicon carbide or equivalent
Retes made of ceramics with hardness and coefficient of thermal expansion
3. The non-contact mechanical seal according to claim 1, wherein the mechanical seal comprises an inner sleeve . 5. The rotating shaft, a mating ring and a sheet
Housing and retainer and retainer and retainer
Seal between graphite sleeves with graphite gaskets
The non-contact mechanical seal according to claim 1 or 2, wherein