JP6446296B2 - Non-contact gas seal - Google Patents

Description

  The present invention relates to a non-contact gas seal. More specifically, for example, the present invention relates to a non-contact type gas seal that seals between a rotating shaft and a casing in a shaft-sealed device such as various industrial pumps, stirrers, compressors, blowers and the like using a gas.

  As a non-contact gas seal that is provided between a rotating shaft of a shaft-sealed device such as a compressor and a casing and seals a fluid, a static pressure gas seal that uses a static pressure of gas (for example, see Patent Document 1) There is a dynamic pressure type gas seal (see, for example, Patent Document 2) that uses the dynamic pressure of gas.

  In the gas seal described in Patent Document 1, as shown in FIG. 10, an annular rotary seal ring 102 is externally attached to the rotary shaft 101 of the non-shaft seal device, and the housing 103 has a seal. An annular stationary seal ring 105 is attached via the case 104. The rotary seal ring 102 and the stationary seal ring 105 are disposed so as to face each other in the axial direction, and the opposing surfaces of the rotary seal ring 102 and the stationary seal ring 105 are defined as a seal surface 102a and a seal surface 105a, respectively.

  On the surface of the stationary seal ring 105 opposite to the seal surface 105 a, a spring 106 that pushes the stationary seal ring 105 in the direction toward the rotary seal ring 102 is disposed. The stationary seal ring 105 is formed with a gas passage 107 that communicates from the outer peripheral surface 105b to the seal surface 105a. A barrier gas G such as nitrogen gas is supplied from the outside to the seal surface 105 a through the gas passage 107.

  The barrier gas G supplied to the seal surface 105a through the gas passage 107 flows from the gap between the seal surface 102a and the seal surface 105a toward the radially inner side and the radially outer side. At this time, the gas pressure generated in the gap acts as a force for pushing the stationary sealing ring 105 in the opening direction (leftward in FIG. 10), and the stationary gas is in a position where the gas pressure and the biasing force of the spring 106 are balanced. The sealing ring 105 is held. Therefore, the rotary seal ring 102 and the stationary seal ring 105 are in a non-contact state, and the fluid on the machine inner side A is on the opposite side of the machine outer side B by the barrier gas G filling the space between the seal surface 102a and the seal surface 105a. To prevent leakage into the space.

International Publication No. 00/75540 Japanese Patent Laid-Open No. 10-54464

  The non-contact type gas seal described above can obtain a good sealing performance while the shaft-sealed device is in a steady operation, but the pressure and temperature fluctuations of the fluid and the rotation speed of the non-shaft seal device When the sealing surface of the rotating ring comes into contact with the sealing surface of the stationary ring due to fluctuations of the friction ring, frictional heat is generated on the sealing surface of the rotating ring, and this seal surface and other parts of the rotating ring, particularly from the rotating ring, There is a temperature difference between the back surface (the surface opposite to the seal surface) that is separated, and there is a risk that thermal distortion occurs in the rotating ring due to this temperature difference.

  In the non-contact type gas seal, a gap is formed between the sealing surfaces by the static pressure or the dynamic pressure of the gas during the operation of the shaft seal device, but the gas is not supplied when the shaft seal device is stopped. The surfaces are in contact with each other. For this reason, since there is a time zone during which the seal surfaces are in contact with each other at the start of operation of the shaft seal device, frictional heat is generated on the seal surface of the rotating ring. In this case as well, a temperature difference occurs between the seal surface and other parts of the rotating ring, particularly the back surface, as described above, and thermal distortion may occur in the rotating ring due to this temperature difference. is there.

Among the dynamic pressure type non-contact type gas seals, there is a so-called double type gas seal in which both side surfaces in the axial direction of an annular rotary ring are used as seal surfaces. In such a double-type gas seal, stationary rings are arranged facing the respective seal surfaces of the rotating ring, and each stationary ring is pushed to the rotating ring side by a closing force generating means such as a spring. In such a double type gas seal, when the pressure inside the machine is higher than the pressure on the atmosphere side, the closing force that pushes the stationary ring inside the machine is set to be larger than that on the atmosphere side. Therefore, although the opening force due to the dynamic pressure of the gas acts on the seal surface, there is a high possibility that the seal surface on the inside of the machine is in contact with the seal surface on the atmosphere side.
Further, with respect to fluid temperature, normally, in this type of non-contact gas seal, the inside of the machine is used in a temperature range of about 5 to 80 degrees. In this case, assuming that the temperature on the atmosphere side is about 25 degrees, the temperature of the in-machine fluid is often higher, and as a result, the temperature of the in-machine seal surface that contacts the high temperature sealing fluid is In many cases, it becomes higher than the temperature.
For this reason, in the double type gas seal, the temperature of the sealing surface inside the rotating ring is higher than the temperature of the sealing surface on the atmosphere side, and there is a possibility that thermal distortion occurs in the rotating ring.

  When thermal distortion occurs in the rotating ring, the parallelism between the sealing surface of the rotating ring and the sealing surface of the stationary ring cannot be maintained, which may lead to abnormal wear and fluid leakage.

  The present invention has been made in view of such circumstances, and provides a non-contact type gas seal that can prevent or suppress thermal distortion generated in a rotating ring due to a temperature difference between parts of the rotating ring. It is intended to provide.

(1) A non-contact gas seal (hereinafter also simply referred to as “gas seal”) according to the first aspect of the present invention includes a rotary ring provided on a rotary shaft, and the rotary ring facing the rotary ring in the axial direction. A closing force generating means for pushing one of the rotating ring and the stationary ring to the other side in a direction to narrow the space between the sealing ring facing the rotating ring and the stationary ring, and between the sealing surfaces And an opening force generating means for expanding the space between the seal surfaces by supplying gas to the non-contact partitioning the first space on the one axial side and the second space on the other axial side across the seal surfaces Gas seal,
The rotating ring is made of a SiC sintered body or cemented carbide,
A diamond film is formed on the sealing surface of the rotating ring facing the stationary ring, and
A diamond film that is continuous with the diamond film on the seal surface is formed on the outer peripheral surface or the inner peripheral surface of the rotary ring and on the back surface that is the surface opposite to the seal surface in the rotary ring.

  In the gas seal according to the first aspect of the present invention, the outer peripheral surface or the inner peripheral surface of the rotating ring and the back surface that is the surface opposite to the sealing surface in the rotating ring are continuous with the diamond film of the sealing surface. A diamond film is formed. The diamond film has a large thermal conductivity of 1000 to 2000 W / m · k. For this reason, the diamond formed on the back surface of the rotating ring quickly passes through the diamond film formed on the outer peripheral surface or the inner peripheral surface of the rotating ring with the frictional heat generated on the sealing surface that is the sliding surface of the rotating ring. Can tell the membrane. Thereby, the temperature difference between the sealing surface and the back surface of the rotating ring can be relaxed, and thermal strain caused by the temperature difference can be prevented or suppressed from occurring in the rotating ring. As a result, the parallelism between the sealing surface of the rotating ring and the sealing surface of the stationary ring can be maintained, and stable sealing performance can be exhibited over a long period of time.

(2) A non-contact gas seal (hereinafter also simply referred to as “gas seal”) according to a second aspect of the present invention includes a rotary ring provided on a rotary shaft, and the rotary ring facing the rotary ring in the axial direction. A closing force generating means for pushing one of the rotating ring and the stationary ring to the other side in a direction to narrow the space between the sealing ring facing the rotating ring and the stationary ring, and between the sealing surfaces And an opening force generating means for expanding the space between the seal surfaces by supplying gas to the non-contact partitioning the first space on the one axial side and the second space on the other axial side across the seal surfaces Gas seal,
The rotating ring is made of a SiC sintered body or cemented carbide,
A diamond film is formed on the sealing surface of the rotating ring facing the stationary ring, and
A diamond film continuous with the diamond film on the seal surface is formed on the outer peripheral surface and the inner peripheral surface of the rotating ring.

  In the gas seal according to the second aspect of the present invention, a diamond film continuous with the diamond film on the seal surface is formed on the outer peripheral surface and the inner peripheral surface of the rotating ring. The diamond film has a large thermal conductivity of 1000 to 2000 W / m · k. For this reason, the frictional heat generated on the seal surface which is the sliding surface of the rotating ring is quickly passed through the diamond film formed on the outer peripheral surface and inner peripheral surface of the rotating ring, and the inner and outer peripheral sides of the rotating ring. Can tell. Thereby, the temperature difference between each of the sealing surface of the rotating ring, the outer peripheral surface, and the inner peripheral surface can be relaxed, and thermal strain caused by the temperature difference can be prevented or suppressed from occurring in the rotating ring. As a result, the parallelism between the sealing surface of the rotating ring and the sealing surface of the stationary ring can be maintained, and stable sealing performance can be exhibited over a long period of time.

(3) A gas seal according to a third aspect of the present invention includes a rotating ring provided on a rotating shaft, a stationary ring disposed opposite to the rotating ring in the axial direction, and the rotating ring and the stationary ring. And a closing force generating means for pushing one of the rotating ring and stationary ring to the other side in a direction to narrow the space between the sealing surfaces facing each other, and a sealing surface of the rotating ring, and by rotation of the rotating ring A non-contact type that partitions the first space on one side in the axial direction and the second space on the other side in the axial direction across the seal surfaces. A gas seal,
The rotating ring is made of a SiC sintered body or cemented carbide,
A diamond film is formed on the sealing surface of the rotating ring facing the stationary ring, and
A diamond film that is continuous with the diamond film on the seal surface is formed on the outer peripheral surface or the inner peripheral surface of the rotary ring and on the back surface that is the surface opposite to the seal surface in the rotary ring.

  In the gas seal according to the third aspect of the present invention, the outer peripheral surface or inner peripheral surface of the rotating ring and the back surface that is the surface opposite to the sealing surface in the rotating ring are continuous with the diamond film of the sealing surface. A diamond film is formed. The diamond film has a large thermal conductivity of 1000 to 2000 W / m · k. For this reason, the diamond formed on the back surface of the rotating ring quickly passes through the diamond film formed on the outer peripheral surface or the inner peripheral surface of the rotating ring with the frictional heat generated on the sealing surface that is the sliding surface of the rotating ring. Can tell the membrane. Thereby, the temperature difference between the sealing surface and the back surface of the rotating ring can be relaxed, and thermal strain caused by the temperature difference can be prevented or suppressed from occurring in the rotating ring. As a result, the parallelism between the sealing surface of the rotating ring and the sealing surface of the stationary ring can be maintained, and stable sealing performance can be exhibited over a long period of time.

(4) A gas seal according to a fourth aspect of the present invention includes a rotating ring provided on a rotating shaft, a stationary ring disposed opposite to the rotating ring in the axial direction, and the rotating ring and the stationary ring. And a closing force generating means for pushing one of the rotating ring and stationary ring to the other side in a direction to narrow the space between the sealing surfaces facing each other, and a sealing surface of the rotating ring, and by rotation of the rotating ring A non-contact type that partitions the first space on one side in the axial direction and the second space on the other side in the axial direction across the seal surfaces. A gas seal,
The rotating ring is made of a SiC sintered body or cemented carbide,
A diamond film is formed on the sealing surface of the rotating ring facing the stationary ring, and
A diamond film continuous with the diamond film on the seal surface is formed on the outer peripheral surface and the inner peripheral surface of the rotating ring.

  In the gas seal according to the fourth aspect of the present invention, a diamond film continuous with the diamond film on the seal surface is formed on the outer peripheral surface and the inner peripheral surface of the rotating ring. The diamond film has a large thermal conductivity of 1000 to 2000 W / m · k. For this reason, the frictional heat generated on the seal surface which is the sliding surface of the rotating ring is quickly passed through the diamond film formed on the outer peripheral surface and inner peripheral surface of the rotating ring, and the inner and outer peripheral sides of the rotating ring. Can tell. Thereby, the temperature difference between each of the sealing surface of the rotating ring, the outer peripheral surface, and the inner peripheral surface can be relaxed, and thermal strain caused by the temperature difference can be prevented or suppressed from occurring in the rotating ring. As a result, the parallelism between the sealing surface of the rotating ring and the sealing surface of the stationary ring can be maintained, and stable sealing performance can be exhibited over a long period of time.

(5) A gas seal according to a fifth aspect of the present invention includes a rotating ring provided on a rotating shaft, and first and second stationary rings arranged to face both axial side surfaces of the rotating ring. And a closing force generating means for pushing the stationary rings toward the rotating ring in a direction to narrow a space between the sealing surfaces facing the rotating ring and the stationary rings, and formed on both sealing surfaces of the rotating ring, Dynamic pressure generating means for generating dynamic pressure that spreads between the seal surfaces by rotation of a rotary ring, and a first space on one axial side and a second space on the other axial side across the seal surfaces; A non-contact gas seal that partitions
The rotating ring is made of a SiC sintered body or cemented carbide,
Diamond films are formed on both sealing surfaces facing the stationary ring in the rotating ring, and
A diamond film that is continuous with the diamond films on both sealing surfaces is formed on the outer peripheral surface or inner peripheral surface of the rotating ring.

  In the gas seal according to the fifth aspect of the present invention, a diamond film is formed on the seal surfaces on both sides of the rotating ring, and the diamond films on both the sealing surfaces are formed on the outer peripheral surface or the inner peripheral surface of the rotating ring. A continuous diamond film is formed. The diamond film has a large thermal conductivity of 1000 to 2000 W / m · k. Therefore, the diamond formed on the sealing surface on the atmosphere side of the rotating ring quickly passes through the diamond film formed on the outer peripheral surface or inner peripheral surface of the rotating ring. Can tell the membrane. Thereby, the temperature difference between the sealing surface on the machine inner side of the rotating ring and the sealing surface on the atmosphere side can be relaxed, and thermal strain caused by the temperature difference can be prevented or suppressed from occurring in the rotating ring. As a result, the parallelism between the sealing surface of the rotating ring and the sealing surface of the stationary ring can be maintained, and stable sealing performance can be exhibited over a long period of time.

(6) In the gas seals of the above (1) to (5), the thermal conductivity of the diamond film can be 1000 to 2000 W / m · k.

  According to the gas seal of the present invention, it is possible to prevent or suppress the thermal strain generated in the rotating ring due to the temperature difference between the parts of the rotating ring.

It is a longitudinal cross-sectional explanatory drawing of 1st Embodiment of the gas seal of this invention. It is a principal part expansion explanatory drawing of the modification of the gas seal shown by FIG. It is a principal part expansion explanatory drawing of the other modification of the gas seal shown by FIG. It is a longitudinal cross-sectional explanatory drawing of 2nd Embodiment of the gas seal of this invention. It is a principal part expansion explanatory drawing of the modification of the gas seal shown by FIG. It is a principal part expansion explanatory drawing of the other modification of the gas seal shown by FIG. It is a longitudinal cross-sectional explanatory drawing of 3rd Embodiment of the gas seal of this invention. FIG. 8 is an enlarged explanatory view of main parts of a modification of the gas seal shown in FIG. 7. It is a longitudinal cross-sectional explanatory drawing of 4th Embodiment of the gas seal of this invention. It is a longitudinal cross-sectional explanatory drawing of an example of the conventional gas seal.

Hereinafter, embodiments of the gas seal of the present invention will be described in detail with reference to the accompanying drawings.
[First Embodiment]
FIG. 1 is a longitudinal cross-sectional explanatory view of a gas seal G1 according to the first embodiment of the present invention. In FIG. 1 and FIGS. 2 to 7 described later, the film thickness of the diamond film is exaggerated for easy understanding.

  The gas seal G1 according to the present embodiment can be used for shaft-sealed devices such as various industrial pumps, agitators, compressors, blowers, etc., and is inserted into the casing 1 of the shaft-sealed device and the casing 1. It is arrange | positioned between the rotating shafts 2. The gas seal G1 divides the machine inner side (first space) A on one side in the axial direction and the machine outer side (second space) B on the other end side in the axial direction with a seal surface, which will be described later, between them. This prevents the fluid that leaks from leaking outside the machine.

A gas seal G1 shown in FIG. 1 includes, as a rotation-side unit, an annular rotating ring 3 attached to a rotating shaft, a stopper ring 4 that is externally fitted to the rotating shaft 2, and is fixed to the stopper ring 4. And a sleeve 5 with a flange 5a, which is fixedly fitted on the rotary shaft 2. The rotating ring 3 is fitted on the sleeve 5 and is fixed to the rotating shaft 2 by being sandwiched between the flange 5 a of the sleeve 5 and the stopper ring 4. As a result, the rotary ring 3 can rotate integrally with the rotary shaft 2. The rotary ring 3 is made of a SiC sintered body, and this sintered body can be obtained, for example, by room temperature sintering or reaction sintering of SiC. The rotating ring 3 may be made of cemented carbide (WC).
The sleeve 5 and the stopper ring 4 are fixed by a bolt 6, and the stopper ring 4 is fixed to the rotating shaft 2 by a set screw 7.

  Between the rotary ring 3 and the sleeve 5, an O-ring 8 that seals between the machine inside A and the machine outside B is interposed. An O-ring 9 is interposed between the rotary shaft 2 and the sleeve 5 to seal between the machine inner side A and the machine outer side B. For this reason, the fluid inside the machine inside A does not leak to the machine outside B between the rotary ring 4 and the rotary shaft 2.

  The gas seal G1 includes, as a stationary side unit, an annular stationary ring 10 that faces the rotating ring 3 in the axial direction, an annular seal case 11 for attaching the stationary ring 10 to the casing 1, and the stationary ring 10 as a rotating ring. 3 and a spring 12 that is a closing force generating means that presses toward 3.

  The seal case 11 includes a first case 13 and a second case 14, and both cases 13 and 14 are fixed to the casing 1 with bolts 15. The first case 13 is formed with a gas supply hole 16 penetrating in the radial direction in order to supply a gas to be described later. The second case 14 is an annular member that sandwiches the first case 13 with the casing 1. The second case 14 has a wall portion 17 that faces the stationary ring 10 in the axial direction, and a cylindrical portion 18 that extends in the axial direction (the direction of the machine interior A) on the radially inner side of the wall portion 17. An O-ring 19 is interposed between the inner peripheral surface of the cylindrical portion 18 and the outer peripheral surface of the stationary ring 10.

  The stationary ring 10 is disposed at a position inside the first case 13 in the radial direction and sandwiched between the second case 14 and the rotating ring 3. Between the inner peripheral surface of the first case 13 and the outer peripheral surface of the stationary ring 10, O-rings 20 and 21 are disposed on both sides with the opening 16a of the gas supply hole 16 sandwiched in the axial direction. Between these O-rings 20, 21, an annular space S 1 into which the gas supplied through the gas supply hole 16 flows is formed between the inner peripheral surface of the first case 13 and the outer peripheral surface of the stationary ring 10. .

  A plurality of holes 22 that are recessed in the axial direction are formed at equal intervals in the circumferential direction on the outboard side B of the stationary ring 10. A spring 12 is disposed in each hole 22. One end of the spring 12 is in contact with the bottom surface of the hole 22, and the other end is in contact with the wall surface 17 a on the machine inner side A of the wall portion 17 of the second case 14. The stationary ring 10 can be pushed in the axial direction toward the rotating ring 3 by the elastic restoring force of the spring 12.

  The stationary ring 10 is supported in the radial direction by the O-ring and the O-rings 20 and 21 on the inner and outer peripheral surfaces thereof. The stationary ring 10 is movable in the axial direction against the elastic force of the spring 12.

  A plurality of gas holes 23 are formed in the stationary ring 10 at equal intervals in the circumferential direction. The plurality of gas holes 23 communicate with the annular space S <b> 1 and the seal surface 10 a that is the end surface of the stationary ring 10 on the machine inner side A. A groove 24 is formed in the seal surface 10 a of the stationary ring 10, and the gas hole 23 is opened in the groove 24. In addition, an orifice 25 that restricts the passage area (flow rate) of the gas is disposed in the gas hole 23. In the present embodiment, the gas hole 23, the groove 24, and the orifice 25 constitute an opening force generating means that supplies gas between the seal surfaces to widen the seal surfaces.

  In the present embodiment, nitrogen gas is supplied from the gas supply hole 16 of the seal case 11 to the annular space S1. The gas supplied to the annular space S <b> 1 flows into each gas hole 23 and is supplied to the groove 24 through these gas holes 23. The gas supplied to the groove 24 is called a barrier gas, and the pressure (static pressure) of the barrier gas generated in the groove 24 is superimposed on the pressure of the fluid filled in the machine interior A. As a result, the stationary ring 10 moves to the outer side B against the resultant force of the elastic force of the spring 12 and the pressure of the fluid (for example, the atmosphere) on the outer side B, and the sealing surface 10a of the stationary ring 10 is moved. However, it is separated from the seal surface 3a which is the end surface of the rotating ring 3 facing this. As a result, the barrier gas supplied to the groove 24 flows out radially inward and radially outward through the gap between the seal surfaces 3a, 10a, that is, the seal surface gap.

  And it stops to the position where the resultant force of the gas pressure (static pressure) of the barrier gas in the clearance between the seal surfaces and the pressure of the fluid inside the machine A and the resultant force of the elastic force of the spring 12 and the pressure of the fluid outside the machine B antagonize. After the ring 10 moves to the outboard side B, it is held in that position. Then, a sealing state in which the stationary ring 10 and the rotating ring 3 are not in contact with each other is obtained by the barrier gas filled in the gap between the sealing surfaces, and the rotating shaft 2 and the rotating ring 3 rotate while this state is maintained.

  In the present embodiment, the labyrinth seal portion 26 is provided between the stationary unit and the rotating unit. On the inner peripheral surface of the machine inner side A of the first case 13, an uneven portion 27 in which unevenness is continuous in the axial direction is formed. The uneven portion 27 and the outer peripheral surface of the rotary ring 3 and the flange 5a are opposed to each other in the radial direction with a gap, and the labyrinth seal portion 26 is configured by the uneven portion 27 and the outer peripheral surface.

  In the present embodiment, diamond films d1, d2, and d3 are respectively formed on the seal surface 3a, the outer peripheral surface 3b, and the back surface 3c that is the surface opposite to the seal surface 3a in the rotary ring 3. Yes. The diamond films d1, d2, and d3 are formed so as to be continuous with each other. The diamond film has a large thermal conductivity of 1000 to 2000 W / m · k. For this reason, the frictional heat generated on the seal surface 3a which is the sliding surface of the rotating ring 3 is quickly formed on the back surface 3c of the rotating ring 3 via the diamond film d2 formed on the outer peripheral surface 3b of the rotating ring 3. Can be transmitted to the diamond film d3. As a result, the temperature difference between the seal surface 3a and the back surface 3c, which are both side surfaces in the axial direction of the rotating ring 3, is relaxed, and thermal distortion caused by the temperature difference is prevented or suppressed from occurring in the rotating ring 3. Can do. As a result, the parallelism between the sealing surface 3a of the rotating ring 3 and the sealing surface 10a of the stationary ring 10 can be maintained, and a stable sealing performance can be exhibited over a long period of time.

  The diamond film can be manufactured using a general manufacturing technique such as a microwave CVD method or a hot filament CVD method. The thickness of the diamond film is not particularly limited in the present invention, but is usually 3 to 20 μm, preferably 3 to 10 μm. From the viewpoint that the frictional heat generated on the seal surface 5a of the rotating ring 5 is moved to the diamond film d2 on the outer peripheral surface 5b before moving to the SiC sintered body that is the base material of the rotating ring 5, the thickness is 3 μm or more. It is desirable that it is. In addition, the thicker the diamond film, the larger the surface roughness of the film, making it difficult to use as a sealing surface for mechanical seals, which are precision mechanical parts. In addition, the residual stress of the diamond film is minimized. From the viewpoint, it is desirably 10 μm or less.

  The diamond film d1 and the diamond films d2 and d3 may have the same thickness, but may have different thicknesses. From the viewpoint of quickly moving the frictional heat generated on the seal surface 3a of the rotating ring 3 to the diamond film d2 on the outer peripheral surface 3b, the film thickness of the diamond film d2 on the outer peripheral surface 3b is the film of the diamond film d1 on the seal surface 3a. It is desirable that the thickness is greater than or equal to.

  FIG. 2 is an enlarged explanatory view of a main part of a modification of the first embodiment shown in FIG. This modification differs from the gas seal G1 according to the first embodiment in that a diamond film d4 is formed on the inner peripheral surface 3d of the rotary ring 3 instead of the outer peripheral surface 3b of the rotary ring 3. Therefore, the same reference numerals are given to the same components as those in the first embodiment, and the description thereof will be omitted for simplicity.

  In this modification, diamond films d1, d4, and d3 are respectively formed on the seal surface 3a, the inner peripheral surface 3d of the rotating ring 3, and the back surface 3c that is the surface opposite to the sealing surface 3a in the rotating ring 3. ing. The diamond films d1, d4, d3 are formed so as to be continuous with each other. The frictional heat generated on the seal surface 3a that is the sliding surface of the rotating ring 3 is quickly formed on the back surface 3c of the rotating ring 3 via the diamond film d4 formed on the inner peripheral surface 3d of the rotating ring 3. It can be transmitted to the diamond film d3. As a result, the temperature difference between the seal surface 3a and the back surface 3c, which are both side surfaces in the axial direction of the rotating ring 3, is relaxed, and thermal distortion caused by the temperature difference is prevented or suppressed from occurring in the rotating ring 3. Can do. As a result, the parallelism between the sealing surface 3a of the rotating ring 3 and the sealing surface 10a of the stationary ring 10 can be maintained, and a stable sealing performance can be exhibited over a long period of time.

  FIG. 3 is an enlarged explanatory view of a main part of another modification of the first embodiment shown in FIG. This modification differs from the gas seal G1 according to the first embodiment in that diamond films d2 and d4 are formed on the outer peripheral surface 3b and the inner peripheral surface 3d of the rotary ring 3 except for the back surface 3c of the rotary ring 3. ing. Therefore, the same reference numerals are given to the same components as those in the first embodiment, and the description thereof will be omitted for simplicity.

  In this modification, diamond films d1, d2, and d4 are formed on the seal surface 3a, the outer peripheral surface 3b, and the inner peripheral surface 3d of the rotating ring 3, respectively. The diamond films d1, d2, and d4 are formed so as to be continuous with each other. The frictional heat generated on the seal surface 3a, which is the sliding surface of the rotating ring 3, quickly passes through the diamond films d2 and d4 formed on the outer peripheral surface 3b and the inner peripheral surface 3d of the rotating ring 3, and It can be transmitted to the inner peripheral side and the outer peripheral side. As a result, the temperature differences among the seal surface 3a, the outer peripheral surface 3b, and the inner peripheral surface 3d of the rotating ring 3 are alleviated, and thermal strain caused by the temperature difference is prevented or suppressed from occurring in the rotating ring 3. be able to. As a result, the parallelism between the sealing surface 3a of the rotating ring 3 and the sealing surface 10a of the stationary ring 10 can be maintained, and a stable sealing performance can be exhibited over a long period of time.

[Second Embodiment]
FIG. 4 is a longitudinal cross-sectional explanatory view of a gas seal G2 according to the second embodiment of the present invention. The gas seal G1 according to the first embodiment described above uses the static pressure of the gas to widen the seal surface gap, whereas the gas seal G2 according to the second embodiment uses the dynamic pressure of the gas to seal. The surface gap is widened. For this reason, in this embodiment, the structure of the rotary ring 31, the stationary ring 32, and the first case 33 involved in gas supply and generation of dynamic pressure is the same as that of the gas seal G2 according to the first embodiment shown in FIG. Is different. Therefore, common components are denoted by the same reference numerals, and description thereof is omitted for simplicity.

  In the rotating ring 31, a dynamic pressure generating groove 34 that opens to the outer peripheral surface 31 b of the rotating ring 31 is formed on the sealing surface 31 a that faces the sealing surface 32 a of the stationary ring 32 in the axial direction. A force (opening force) that separates the seal surfaces 31a and 32a from each other is generated by the dynamic pressure generated when the gas flowing into the dynamic pressure generating groove 34 rotates when the rotary ring 31 rotates.

  The first case 33 is formed with a gas supply hole 35 penetrating in the radial direction to supply gas. The gas supplied through the gas supply hole 35 flows into an annular space S2 defined by the inner peripheral surface of the first case 31, the outer peripheral surface of the rotating ring 31, and the outer peripheral surface of the stationary ring 32, and further generates the dynamic pressure. It flows into the groove 34.

  Also in the present embodiment, as in the first embodiment, the diamond film d1 is formed on the sealing surface 31a, the outer peripheral surface 31b of the rotating ring 31, and the back surface 31c which is the surface of the rotating ring 31 opposite to the sealing surface 31a. , D2 and d3 are formed. The diamond films d1, d2, and d3 are formed so as to be continuous with each other. The diamond film has a large thermal conductivity of 1000 to 2000 W / m · k. For this reason, the frictional heat generated on the seal surface 31a which is the sliding surface of the rotating ring 31 is quickly formed on the back surface 31c of the rotating ring 31 via the diamond film d2 formed on the outer peripheral surface 31b of the rotating ring 31. Can be transmitted to the diamond film d3. Thereby, the temperature difference between the seal surface 31a and the back surface 31c, which are both side surfaces in the axial direction of the rotating ring 31, is relaxed, and thermal strain caused by the temperature difference is prevented or suppressed from occurring in the rotating ring 31. Can do. As a result, the parallelism between the sealing surface 31a of the rotating ring 31 and the sealing surface 32a of the stationary ring 32 can be maintained, and a stable sealing performance can be exhibited over a long period of time.

  FIG. 5 is an enlarged explanatory view of a main part of a modification of the second embodiment shown in FIG. This modification differs from the gas seal G2 according to the second embodiment in that a diamond film d4 is formed on the inner peripheral surface 31d of the rotary ring 31 instead of the outer peripheral surface 31b of the rotary ring 31. Therefore, the same reference numerals are given to the same components as those in the second embodiment, and description thereof will be omitted for simplicity.

  In this modification, diamond films d1, d4, and d3 are respectively formed on the seal surface 31a, the inner peripheral surface 31d of the rotating ring 31, and the back surface 31c on the rotating ring 31 opposite to the sealing surface 31a. ing. The diamond films d1, d4, d3 are formed so as to be continuous with each other. The frictional heat generated on the seal surface 31a which is the sliding surface of the rotating ring 31 is quickly formed on the back surface 31c of the rotating ring 31 via the diamond film d4 formed on the inner peripheral surface 31d of the rotating ring 31. It can be transmitted to the diamond film d3. Thereby, the temperature difference between the seal surface 31a and the back surface 31c, which are both side surfaces in the axial direction of the rotating ring 31, is relaxed, and thermal strain caused by the temperature difference is prevented or suppressed from occurring in the rotating ring 31. Can do. As a result, the parallelism between the sealing surface 31a of the rotating ring 31 and the sealing surface 32a of the stationary ring 32 can be maintained, and a stable sealing performance can be exhibited over a long period of time.

  FIG. 6 is an enlarged explanatory view of a main part of another modification of the second embodiment shown in FIG. This modification differs from the gas seal G2 according to the second embodiment in that diamond films d2 and d4 are formed on the outer peripheral surface 31b and the inner peripheral surface 31d of the rotary ring 31 except for the back surface 31c of the rotary ring 31. ing. Therefore, the same reference numerals are given to the same components as those in the second embodiment, and description thereof will be omitted for simplicity.

  In this modification, diamond films d1, d2, and d4 are formed on the seal surface 31a, the outer peripheral surface 31b, and the inner peripheral surface 31d of the rotating ring 31, respectively. The diamond films d1, d2, and d4 are formed so as to be continuous with each other. The frictional heat generated on the seal surface 31a, which is the sliding surface of the rotating ring 31, quickly passes through the diamond films d2 and d4 formed on the outer peripheral surface 31b and the inner peripheral surface 31d of the rotating ring 31. It can be transmitted to the outer peripheral side and the inner peripheral side. Thereby, the temperature difference between the seal surface 31a of the rotating ring 31 and each of the outer peripheral surface and the inner peripheral surface is relaxed, and the thermal strain caused by the temperature difference is prevented or suppressed from occurring in the rotating ring 31. it can. As a result, the parallelism between the sealing surface 31a of the rotating ring 31 and the sealing surface 32a of the stationary ring 32 can be maintained, and a stable sealing performance can be exhibited over a long period of time.

[Third Embodiment]
FIG. 7 is a longitudinal cross-sectional explanatory view of a gas seal G3 according to the third embodiment of the present invention. The gas seal G3 according to the present embodiment is the same as the gas seal G2 according to the second embodiment in that the gap between the seal surfaces is widened using the dynamic pressure of the gas, but both side surfaces of the rotating ring 41 are the same. The sealing surfaces 41a and 41c are different from the gas seal G2. For this reason, the gas seal G3 is provided with a pair of stationary rings 42 and 43 whose seal surfaces face each other.

  A gas seal G3 shown in FIG. 7 includes, as a rotation-side unit, an annular rotation ring 41 attached to a rotation shaft, a stopper ring 45 that is externally fixed to the rotation shaft 44, and a stopper ring 45. And a sleeve 46 that is fixedly fitted on the rotary shaft 44. The rotating ring 41 is fitted on the sleeve 46, and the head of the pin 48 press-fitted into a hole formed on the outer peripheral surface of the sleeve 46 is inserted into a recess 47 formed on the inner peripheral surface of the rotating ring 41. It protrudes. Thereby, the rotation ring 41 is prevented from rotating. The rotary ring 41 can rotate integrally with the rotary shaft 44. The rotating ring 41 is made of a SiC sintered body, and this sintered body can be obtained, for example, by room temperature sintering or reactive sintering of SiC. The rotating ring 41 may be made of cemented carbide (WC).

The sleeve 46 and the stopper ring 45 are fixed by bolts 49, and the stopper ring 45 is fixed to the rotating shaft 44 by a set screw 50.
An O-ring 50 that seals between the machine inner side A and the machine outer side B is interposed between the rotary shaft 44 and the sleeve 46. For this reason, the fluid inside the machine inside A does not leak to the machine outside B between the rotating shaft 44 and the sleeve 46.

  The gas seal G3, as a stationary side unit, is a pair of annular stationary rings 42 and 43 that are opposed to the rotating ring 41 in the axial direction, and an annular seal case 53 and a seal for attaching the stationary rings 42 and 43 to the casing 52. A flange 54 and springs 55 and 56 which are closing force generating means for pressing the stationary rings 42 and 43 toward the rotating ring 41 are provided.

  The seal flange 54 is fixed to the seal case 53 with bolts 57, and the seal flange 54 and the seal case 53 are fixed to the casing 52 with bolts 58. The seal case 53 is formed with a gas supply hole 59 penetrating in the radial direction in order to supply a gas to be described later.

  The stationary ring 42 on the outer side B is disposed between the seal flange 54 and the rotating ring 41, and the stationary ring 43 on the inner side A is disposed between the rotating ring 41 and the seal case 53. ing. The gas supply hole 59 is opened in an annular space S3 defined by the outer peripheral surfaces of the stationary rings 42 and 43 and the rotary ring 41 and the inner peripheral surfaces of the seal flange 54 and the seal case 53.

  On both side surfaces of the rotary ring 41, that is, the seal surface 41a that faces the seal surface 42a of one stationary ring 42 in the axial direction, and the seal surface 41c that faces the seal surface 43a of the other stationary ring 43 in the axial direction, Dynamic pressure generating grooves 60a and 60b are formed in the outer peripheral surface 41b of the rotating ring 41, respectively. The gas supplied through the gas supply hole 59 flows into the annular space S3 and further flows into the dynamic pressure generating grooves 60a and 60b. A force (opening force) that separates the seal surface 41a and the seal surface 42a and the seal surface 41c and the seal surface 43a from each other by the dynamic pressure generated when the gas flowing into the dynamic pressure generating grooves 60a and 60b rotates when the rotating ring 41 rotates. Arise.

  In the present embodiment, diamond films d1, d2, and d3 are formed on the seal surface 41a, the outer peripheral surface 41b, and the seal surface 41c of the rotating ring 41, respectively. The diamond films d1, d2, and d3 are formed so as to be continuous with each other. The diamond film has a large thermal conductivity of 1000 to 2000 W / m · k.

In the double-type gas seal G3 as shown in FIG. 7, when the pressure inside the machine inside A is higher than the pressure outside the machine outside B, the closing force that presses the stationary ring 43 on the machine inside A is larger than that of the machine outside B. Therefore, although the opening force due to the dynamic pressure of the gas acts on the seal surface, there is a high possibility that the seal surface on the machine inner side A comes into contact with the seal surface on the machine outer side B.
Furthermore, regarding the fluid temperature, normally, in this type of non-contact type gas seal, the machine interior A is used in a temperature range of about 5 to 80 degrees. In this case, assuming that the temperature on the atmosphere side is about 25 degrees In many cases, the temperature of the in-machine fluid is higher, and as a result, the temperature of the sealing surface on the inner side A that contacts the high-temperature sealed fluid is higher than the temperature of the sealing surface on the outer side B.

  Thus, in the double-type gas seal, the temperature of the sealing surface 41c on the machine inner side A of the rotating ring 41 becomes higher than the temperature of the sealing surface 41a on the outer side B, and thermal distortion may occur in the rotating ring 41. However, in this embodiment, since the diamond film as described above is formed, the heat of the sealing surface 41c on the machine inner side A of the rotating ring 41 is quickly formed on the outer peripheral surface 41b of the rotating ring 41. It can be transmitted to the diamond film d3 formed on the sealing surface 41a on the outside of the rotary ring 41 via the diamond film d2. As a result, the temperature difference between the sealing surface 41c on the machine inner side A and the sealing surface 41a on the machine outer side B of the rotating ring 41 is relaxed, and thermal distortion caused by the temperature difference is prevented or suppressed from occurring in the rotating ring 41. can do. As a result, the parallelism between the sealing surfaces 41a and 41c of the rotating ring 41 and the sealing surfaces 42a and 43a of the stationary ring can be maintained, and stable sealing performance can be exhibited over a long period of time.

    FIG. 8 is an enlarged explanatory view of a main part of a modification of the third embodiment shown in FIG. This modification differs from the gas seal G3 according to the third embodiment in that a diamond film d4 is formed on the inner peripheral surface 41d of the rotating ring 41 instead of the outer peripheral surface 41b of the rotating ring 41. Therefore, the same reference numerals are given to the same components as those in the third embodiment, and the description thereof will be omitted for simplicity.

  In this modification, diamond films d1, d3, and d4 are formed on both the seal surfaces 41a and 41c and the inner peripheral surface 41d of the rotating ring 41, respectively. The diamond films d1, d3, d4 are formed so as to be continuous with each other. Of the sliding surface of the rotating ring 41, the frictional heat generated on the sealing surface 41c inside the machine, which is likely to become a higher temperature, quickly passes through the diamond film d4 formed on the inner peripheral surface 41d of the rotating ring 41. Thus, the rotation can be transmitted to the diamond film d1 formed on the sealing surface 41a on the outside B of the rotating ring 41. As a result, the temperature difference between the seal surface 41a and the seal surface 41c, which are both side surfaces in the axial direction of the rotary ring 41, is alleviated, and thermal strain caused by the temperature difference is prevented or suppressed from occurring in the rotary ring 41. be able to. As a result, the parallelism between the sealing surfaces 41a and 41c of the rotating ring 41 and the sealing surfaces 42a and 43a of the stationary ring can be maintained, and stable sealing performance can be exhibited over a long period of time.

[Fourth Embodiment]
FIG. 9 is a longitudinal cross-sectional explanatory view of a gas seal G4 according to the fourth embodiment of the present invention. The gas seal G4 according to the present embodiment is the same as the gas seal G1 according to the first embodiment shown in FIG. 1 in that the gap between the seal surfaces is widened by utilizing the static pressure of the gas. In the seal G1, the stationary ring that is one of the stationary ring and the rotating ring is pressed against the other rotating ring by the spring, whereas in the gas seal G4 according to this embodiment, the stationary ring and the rotating ring The difference is that one of the rotary rings is pressed against the other stationary ring by a spring.

  In the gas seal G4, the fluid existing on one side in the axial direction (machine inner side A) is sealed between the casing 71 and the rotating shaft 72 inserted into the casing 71. The gas seal G4 includes an annular rotary ring 73 attached to the rotary shaft 72, an annular stationary ring 74 facing the rotary ring 73 in the axial direction, and an annular seal case for attaching the stationary ring 74 to the casing 71. 75.

  The gas seal G4 includes a sleeve 76 that is fixed to the rotating shaft 72, and a spring 77 that is a closing force generating means is disposed between the sleeve 76 and the rotating ring 73. The spring 77 pushes the rotating ring 72 in the axial direction toward the stationary ring 74. As described above, in the present invention according to the first and second aspects, the spring which is the closing force generating means for applying the elastic force in the direction of narrowing the space between the sealing surfaces facing the stationary ring and the rotating ring is stationary. Any one that elastically pushes one of the ring and the rotating ring to the other side may be used.

  The stationary ring 74 has a plurality of gas holes 78 opened at the sealing surface 74 a of the abutting stationary ring 74 in order to supply gas between the sealing surfaces 74 a and 73 a facing the stationary ring 74 and the rotating ring 73. Are formed at equal intervals along the circumferential direction. A gas supply hole 79 for supplying gas to the gas hole 78 is formed in the seal case 75. The gas supply hole 79 is continuous with an annular space S <b> 4 formed between the stationary ring 74 and the seal case 75.

  In the present embodiment, diamond films d1, d2, and d3 are formed on the seal surface 73a, the outer peripheral surface 73b of the rotating ring 73, and the back surface 73c that is the surface opposite to the sealing surface 73a in the rotating ring 73, respectively. Yes. The diamond films d1, d2, and d3 are formed so as to be continuous with each other. The diamond film has a large thermal conductivity of 1000 to 2000 W / m · k. Therefore, the frictional heat generated on the seal surface 73a that is the sliding surface of the rotating ring 73 is quickly formed on the back surface 73c of the rotating ring 73 via the diamond film d2 formed on the outer peripheral surface 73b of the rotating ring 73. Can be transmitted to the diamond film d3. Thereby, the temperature difference between the seal surface 73a and the back surface 73c, which are both side surfaces in the axial direction of the rotating ring 73, is relaxed, and the thermal strain caused by the temperature difference is prevented or suppressed from occurring in the rotating ring 73. Can do. As a result, the parallelism between the seal surface 73a of the rotating ring 73 and the seal surface 74a of the stationary ring 74 can be maintained, and a stable sealing performance can be exhibited over a long period of time.

[Other variations]
In addition, the gas seal of this invention is not limited to embodiment mentioned above, A various change is possible.
For example, in the embodiment described above, a spring is used as a means for generating a closing force that narrows the seal surface of the stationary ring and the seal surface of the rotating ring. However, for example, it is disclosed in Japanese Patent Application Laid-Open No. 2014-173700. As shown, a sealed back pressure chamber is formed on the back side of the stationary ring, and a gas introduction path communicating with the back pressure chamber is formed in the stationary ring, and the gas is introduced into the back pressure chamber through the gas introduction path. It is also possible to adopt a configuration in which the stationary ring is pushed toward the rotating ring by the high pressure gas inside the machine.

  Further, in the embodiment according to FIGS. 4 to 8 described above, the diamond film is not formed in the dynamic pressure generating groove. However, the embodiment according to FIGS. The same operations and effects as the embodiment can be achieved. Furthermore, by forming the diamond film up to the inside of the groove, the temperature distribution of the entire rotary ring of the gas seal can be made more uniform, and the rotational speed can be 1 to 20,000 while maintaining a few microns as the gap between the seal faces. The optimum effect can be obtained as a precision gas seal used in an ultra-high speed rotating device such as a compressor for a liquefied gas that reaches rpm.

1: Casing 2: Rotating shaft
3: Rotating ring 3a: Sealing surface 3b: Outer peripheral surface 3c: Back surface 4: Stopper ring 5: Sleeve 5a: Flange
6: Bolt 6a: Pressing surface 7: Set screw 8: O-ring
9: O-ring
10: stationary ring 10a: seal surface
11: Seal case
12: Spring
13: First case
14: Second case
15: Bolt 16: Gas supply hole 16a: Opening
17: Wall portion 17a: Wall surface
18: Cylindrical part
19: O-ring 20: O-ring 21: O-ring 22: Hole 23: Gas hole
24: Groove 25: Orifice
26: Labyrinth seal portion 27: Concavity and convexity
31: Rotating ring 31a: Sealing surface 31b: Outer peripheral surface 31c: Back surface
32: stationary ring
33: First case 34: Dynamic pressure generating groove
35: Gas supply hole 41: Rotating ring 42: Stationary ring 43: Stationary ring 44: Rotating shaft 45: Stopper ring 46: Sleeve 47: Recess 48: Pin 49: Bolt 50: Set screw 51: O-ring 52: Casing 53 : Seal case 54: Seal flange 55: Spring 56: Spring 57: Bolt 58: Bolt 59: Gas supply hole 60a: Dynamic pressure generation groove 60b: Dynamic pressure generation groove 71: Casing 72: Rotating shaft 73: Rotating ring 74: Stationary Ring 75: Seal case 76: Sleeve 77: Spring 78: Gas hole 79: Gas supply path G1: Gas seal G2: Gas seal G3: Gas seal G4: Gas seal S1: Annular space S2: Annular space S4: Annular space d1: Diamond film d2: Diamond film d 3: Diamond film d4: Diamond film

Claims (6)

A rotating ring provided on a rotating shaft, a stationary ring disposed opposite to the rotating ring in an axial direction, and the rotating ring and the stationary ring in a direction to narrow a space between seal surfaces facing the rotating ring and the stationary ring. A closing force generating means for pushing one of the rings to the other side, and an opening force generating means for supplying a gas between the seal surfaces to widen the seal surfaces, and axially sandwiching the seal surfaces A non-contact gas seal that partitions the first space on one side and the second space on the other side in the axial direction,
The rotating ring is made of a SiC sintered body or cemented carbide,
A diamond film is formed on the sealing surface of the rotating ring facing the stationary ring, and
The outer peripheral surface or inner peripheral surface of the rotating ring and the back surface that is the surface opposite to the sealing surface in the rotating ring are continuous with the diamond film of the sealing surface, and heat generated on the sealing surface is generated. diamond film Ru transmitted to the rear is formed, a non-contact gas seal. A rotating ring provided on a rotating shaft, a stationary ring disposed opposite to the rotating ring in an axial direction, and the rotating ring and the stationary ring in a direction to narrow a space between seal surfaces facing the rotating ring and the stationary ring. A closing force generating means for pushing one of the rings to the other side, and an opening force generating means for supplying a gas between the seal surfaces to widen the seal surfaces, and axially sandwiching the seal surfaces A non-contact gas seal that partitions the first space on one side and the second space on the other side in the axial direction,
The rotating ring is made of a SiC sintered body or cemented carbide,
A diamond film is formed on the sealing surface of the rotating ring facing the stationary ring, and
Wherein the whole entire outer peripheral surface and inner peripheral surface of the rotating ring, the diamond film which is continuous with the diamond film of the sealing surface is formed, a non-contact gas seal. A rotating ring provided on a rotating shaft, a stationary ring disposed opposite to the rotating ring in an axial direction, and the rotating ring and the stationary ring in a direction to narrow a space between seal surfaces facing the rotating ring and the stationary ring. A closing force generating means that pushes one of the rings to the other side, and a dynamic pressure generating means that is formed on a seal surface of the rotating ring and generates a dynamic pressure that spreads between the sealing surfaces by rotation of the rotating ring; A non-contact gas seal that partitions the first space on one side in the axial direction and the second space on the other side in the axial direction across the seal surface,
The rotating ring is made of a SiC sintered body or cemented carbide,
A diamond film is formed on the sealing surface of the rotating ring facing the stationary ring, and
The outer peripheral surface or inner peripheral surface of the rotating ring and the back surface that is the surface opposite to the sealing surface in the rotating ring are continuous with the diamond film of the sealing surface, and heat generated on the sealing surface is generated. diamond film Ru transmitted to the rear is formed, a non-contact gas seal. A rotating ring provided on a rotating shaft, a stationary ring disposed opposite to the rotating ring in an axial direction, and the rotating ring and the stationary ring in a direction to narrow a space between seal surfaces facing the rotating ring and the stationary ring. A closing force generating means that pushes one of the rings to the other side, and a dynamic pressure generating means that is formed on a seal surface of the rotating ring and generates a dynamic pressure that spreads between the sealing surfaces by rotation of the rotating ring; A non-contact gas seal that partitions the first space on one side in the axial direction and the second space on the other side in the axial direction across the seal surface,
The rotating ring is made of a SiC sintered body or cemented carbide,
A diamond film is formed on the sealing surface of the rotating ring facing the stationary ring, and
Wherein the whole entire outer peripheral surface and inner peripheral surface of the rotating ring, the diamond film which is continuous with the diamond film of the sealing surface is formed, a non-contact gas seal. Between the rotating ring provided on the rotating shaft, the first and second stationary rings disposed opposite to both axial side surfaces of the rotating ring, and the sealing surfaces facing the rotating ring and both stationary rings, respectively. A closing force generating means for pushing both stationary rings toward the rotating ring in a direction to narrow the width of the rotating ring, and a dynamic pressure that is formed on both seal surfaces of the rotating ring and expands between the sealing surfaces by the rotation of the rotating ring. A non-contact type gas seal that partitions the first space on one side in the axial direction and the second space on the other side in the axial direction across the seal surface,
The rotating ring is made of a SiC sintered body or cemented carbide,
Diamond films are formed on both sealing surfaces facing the stationary ring in the rotating ring, and
Wherein the outer peripheral surface or inner peripheral surface of the rotating ring, wherein is continuous with the diamond film of both sealing surfaces, the diamond film Ru convey the heat generated in one of the sealing surface on the other sealing surface is formed, the non Contact gas seal.   The non-contact type gas seal according to any one of claims 1 to 5, wherein the diamond film has a thermal conductivity of 1000 to 2000 W / m · k.

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