JP2918844B2 - Sealing device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a simple sealing device used for a shaft sealing portion of a fluid machine or a pneumatic machine or a secondary seal portion of a mechanical seal provided in the shaft sealing portion. More particularly, the present invention relates to a sealing device for sealing between a first cylindrical surface to be sealed and a second planar surface to be relatively moved perpendicular to the axis thereof.

[0002]

2. Description of the Related Art In a shaft seal portion of a fluid machine or a pneumatic machine or a secondary seal portion of a mechanical seal provided in such a shaft seal portion, a cylindrical or cylindrical first sealed member is fitted or fitted. The relative movement of the two sealed members (the first movement) between the second sealed member having the circular hole or the circular concave portion to be engaged.
The relative movement of the sealed member in the axial or radial direction)
In some cases, it is necessary to make the seal in a state in which is allowed. For example, in a mechanical seal composed of a rotary seal ring on the rotating shaft side and a stationary seal ring on the seal case side, a first sealed member formed of a stationary seal ring as a second sealed member on the seal case. In some cases, the cylindrical wall portion, which is a member, is fitted and held movably in the axial direction. In such a case, the followability between the stationary sealing ring and the cylindrical wall portion to the rotating sealing ring is ensured. In order to allow the stationary seal ring to be displaced in the axial direction as much as possible, it is necessary to perform sealing (secondary seal).

[0003] As a sealing device between the first and second sealed members that move relative to each other, generally, as a sealed surface, opposing surfaces of both sealed members (the outer periphery of the first sealed member). Surface and a hole of the second member to be sealed and an inner peripheral surface of the concave portion with which the member is fitted and engaged, and a ring-shaped seal made of an elastomer material (hereinafter referred to as "elastomer seal") is provided between the surfaces to be sealed. Loaded ones are well known.
For example, in the mechanical seal described above, a rubber O-ring as an elastomer seal is loaded between the inner peripheral surface of the stationary sealing ring and the outer peripheral surface of the cylindrical wall portion, and the stationary sealing ring, the seal case, The space between them is secondary sealed.

According to the sealing device using such an elastomer seal, the elastomer seal follows the displacement of the first or second sealed member by its own elasticity (entropic elasticity), so that the two sealed members are sealed. Can be satisfactorily sealed between the two sealed members while allowing the relative movement of the members.

[0005]

However, such a sealing device has an advantage that the structure can be simply and easily sealed, but on the other hand, the sealing conditions that can be applied are extremely limited due to the properties of the elastomer seal. There's a problem. For example, an elastomer material such as rubber is inferior in heat resistance and is not suitable for sealing under high temperature conditions. In addition, because the elasticity of the elastomer seal itself ensures compliance with the displacement of the surface to be sealed, the fluid to be sealed under high-pressure conditions where fluid pressure acts on the elastomer seal to prevent the deformation following the surface to be sealed. Under the condition where the pressure fluctuates greatly, the followability to the displacement of the surface to be sealed is not sufficiently exhibited, and proper sealing cannot be performed.

According to the present invention, as the surface to be sealed of the second member to be sealed, the surface facing the outer peripheral surface of the first member to be sealed (the inner peripheral surface of the hole of the second member to be sealed and the concave portion) is selected as described above. Focusing on the fact that the side end surface of the second sealed member (for example, the rear end surface of the stationary sealing ring) can be selected,
It is possible to seal the space between the first cylindrical surface to be sealed and the second flat surface to be sealed which moves relatively perpendicular to the axis thereof without causing the above-mentioned problem. It is another object of the present invention to provide a sealing device that can exhibit a proper sealing function according to sealing conditions.

[0007]

As described above, a sealing device according to the present invention, which has solved the above-mentioned problem, has a first cylindrical surface to be sealed and a second planar surface which is relatively moved perpendicularly to its axis.
It is for sealing between a surface to be sealed and a seal ring, a holding ring, a binding member, and a biasing member as described below. That is, the seal ring has a cylindrical first seal surface that contacts the first seal surface over the entire circumference thereof, and a planar second seal surface that contacts the second seal surface. , in which disconnecting an箇<br/> plants that put in the circumferential direction. Further, the retaining ring is fitted around the seal ring in a state of being in contact with the entire peripheral surface of the seal ring except for the first and second seal surfaces, and is provided at at least one position in the circumferential direction to separate the seal ring. The part which is inconsistent with the part in the circumferential direction is separated. Further, the binding member binds the holding ring in a ring shape, and urges and holds the holding ring and the seal ring fitted therein in a direction in which the cutoff portions are closed. The urging member presses and biases the holding ring in the axial direction so as to press the second sealing surface against the second sealed surface.

According to the sealing device having such a configuration, the seal ring and the holding ring are flexible with at least one portion cut off, and are urged and held by the binding member in the direction in which the cut off portion is closed. The first and second sealing surfaces of the seal ring are kept pressed against the second sealing surface even when the two sealing surfaces move relative to each other in the radial direction, the axial direction, etc. The first and second surfaces to be sealed can be properly contacted while following, and the space between both surfaces to be sealed can be properly sealed. Then, structurally, the material of each constituent member can be arbitrarily selected according to the sealing condition, so that the sealing condition is not restricted from the material like the elastomer seal. For example, even under a high-temperature condition where an elastomer seal cannot be used, a good sealing function can be exhibited by forming each component member with a heat-resistant material.

[0009]

FIG. 1 is a block diagram showing an embodiment of the present invention.
This will be specifically described with reference to FIG.

FIG. 1 shows a non-contact type mechanical seal used in rotating equipment mainly handling gas (nitrogen, argon, hydrogen, natural gas, air, etc.) such as a turbine, a blower, and a centrifugal compressor. This shows a non-contact type mechanical seal for sealing a turbine or a gas turbine. In this mechanical seal, an annular rotary seal ring 2 fixed to a rotary shaft 1 as a turbine shaft and a seal case 3 are used. The high-pressure fluid region (in-machine gas region) H and the low-pressure fluid region (outside-atmosphere region) L are sealed by the relative rotation of the annular stationary sealing ring 4 which is non-rotatable and axially movable. In this example, in particular, the space between the seal case 3 and the stationary sealing ring 4 is secondarily sealed by the seal device 5 according to the present invention. In the following description, for the sake of convenience, front and rear mean left and right in FIG.

The rotary seal ring 2 is made of a super-hard material such as WC or SiC. As shown in FIG. A dynamic pressure generating groove 2b is formed.

As shown in FIG. 1, the seal case 3 has a circular guide surface 3a formed on an inner peripheral portion thereof and an annular wall portion 3b.
And the cylindrical wall portion 3c is integrally formed concentrically. The rotating shaft 1 passes through the annular wall 3b and the cylindrical wall 3c concentrically.

The stationary sealing ring 4 is made of carbon or the like which is relatively softer than the material of the rotating sealing ring 2. As shown in FIGS. 1 and 2, the sealing end face 4 a as a front end face is rotated by the rotating sealing ring 2. In a state of being opposed to the sealing end face 2a of the seal case 3 while being loosely fitted to the cylindrical wall portion 3c of the seal case 3 and having a very small gap in the guide surface 3a of the seal case 3 so as to be freely movable in the axial direction. It is fitted and held. In addition, the rear end surface side region (back side region) of the stationary sealing ring 4 is communicated with the high-pressure fluid region H via a fitting portion with the guide surface 3a.

As shown in FIG. 1, the sealing device 5 includes a cylindrical wall portion 3c of the seal case 3, which is a first member to be sealed, and a second wall.
Secondary sealing is performed between the stationary sealing ring 4 as a member to be sealed, that is, a cylindrical first sealing surface 3d which is the outer peripheral surface of the cylindrical wall portion 3c and a first sealing surface orthogonal to the axis thereof. 3d is intended to secondary seal between the second target sealing surface 4b flat a rear end surface of the relative movable stationary seal ring 4 in the radial direction or the axial direction of, the seal ring 6 and the retaining ring 7 It comprises a binding member 8 and an urging member 9.

As shown in FIGS. 1 and 2, the seal ring 6 is an annular body having a rectangular cross section obtained by cutting off one location 6a in the circumferential direction, and its inner peripheral surface can contact the first sealed surface 3d. It forms the first sealing surface 6b and forms the front end surface as the second sealing surface 6c which can contact the second sealed surface 4b.
In the case where the separation portion 6a is closed (when the separation end surfaces are brought into contact with each other), the first seal surface 6b is in close contact with the first sealed surface 3d over the entire circumference thereof. It is formed in a shape that can be used.

As shown in FIGS. 1 and 2, the retaining ring 7 includes first and second sealing surfaces 6b and 6c of the sealing ring 6.
This is an annular body having an L-shaped cross section that can be fitted onto the seal ring 6 in a state of contacting the entire peripheral surface portion (that is, the outer peripheral surface and the rear end surface of the seal ring 6) except for. Thus, the holding ring 7 has a portion 7a in the circumferential direction cut away in the same manner as the seal ring 6, and in this example, in particular, the minimum diameter inner peripheral surface is set to the first sealed surface 3d. A first auxiliary sealing surface 7b that can be in contact with the first sealing surface 7b and a front end surface of the second auxiliary sealing surface 7b
And a second auxiliary seal surface 7c which can contact the second auxiliary seal surface 7c. A first auxiliary sealing surface 7b and a second auxiliary sealing surface that can be in contact with the first and second sealed surfaces 3d, 4b by making the inner diameter surface and the front end surface flush with the first and second sealing surfaces 6b, 6c. 7c. That is, the holding ring 7 has a state in which the separation portion 7a is inconsistent in the circumferential direction with the separation portion 6a of the seal ring 6 (see FIG. 2), and has the first auxiliary sealing surface 7b and the minimum diameter inner peripheral surface. The second auxiliary sealing surface 7c which is the front end surface is the first and second sealing surfaces 6b of the seal ring 6,
Similarly to 6c, it is tightly fitted to the seal ring 6 in a state of contacting the first and second sealed surfaces 3d and 4b (see FIG. 1). When the separation portion 7a is closed (when the separation end surfaces are brought into contact with each other), the first auxiliary sealing surface 7b is in close contact with the first sealed surface 3d over the entire circumference thereof. It is formed into a shape that can be used.

The binding member 8 is, as shown in FIGS.
An annular garter spring engaged with an annular concave portion 7d formed on the outer peripheral surface of the holding ring 7. The garter spring 8 serving as a binding member binds the retaining ring 7 in a ring shape while pressing the retaining ring 7 in the diameter reducing direction, so that the detached portion 7a of the retaining ring 7 is not opened, that is, the detached end faces are in close contact with each other. It is used to keep it in a state of collision. As a result, the holding ring 7 is tightened by the garter spring 8, so that the seal ring 6 is also tightened in the diameter-reducing direction via the holding ring 7, and the cut-off portion 6 a is urged and held in a closed state. Will be.

The components of the seal ring 6 and the holding ring 7 can be arbitrarily selected according to the conditions of use. For example, when used under high temperature conditions, a material having high heat resistance is selected. However, even when the rings 6 and 7 are complete annular bodies having no cut-off portions, an elastomer such as rubber which is easily deformed by pressure fluctuation in the high-pressure fluid region H or vibration accompanying rotation of the rotating shaft 1 is used. Flexible materials such as materials and soft plastics are excluded. In the case where the rings 6 and 7 are cut off at only one location 6a and 7a in the circumferential direction as in this example, the rings 6 and 7 have elasticity (energy elasticity) to the extent that the binding effect by the garter spring 8 can be obtained. (Eg, carbon, engineering plastic, etc.) must be selected. In this example, the rings 6, 7 are made of carbon in consideration of the slidability with the surfaces 3d, 4b to be sealed.

As shown in FIG. 1, the urging member 9 comprises a plurality of coil springs 9a (only one is shown) interposed between the holding ring 7 and the annular wall 3b of the seal case 3. The holding ring 7 is pressed and urged to the stationary sealing ring 4 via a spring receiver 9b, which is a metal annular plate loosely fitted on the cylindrical wall portion 3c of the seal case 3, and further via the holding ring 7. Replace the stationary sealing ring 4 with the rotating sealing ring 2
Is pressed and urged. The coil springs 9a are arranged at equal intervals in the circumferential direction in an annular area surrounding the cylindrical wall 3c of the seal case 3.

In the non-contact type mechanical seal configured as described above, with the relative rotation of the two sealing rings 2 and 4 due to the rotation of the rotating shaft 1, the action of the dynamic pressure generating groove 2b causes the sealing end faces 2a and 2a. A dynamic pressure is generated between 4a. as a result,
This dynamic pressure, the back pressure acting on the stationary sealing ring 4 (due to the fluid pressure in the high-pressure fluid region H), and the urging force of the coil springs 9a are balanced to form a fluid film between the sealing end faces 2a, 4a. The high pressure fluid region H and the low pressure fluid region L
And seal.

At this time, the seal case 3 (cylindrical wall 3
Between the c) and the stationary sealing ring 4, the secondary sealing is favorably performed by the sealing device 5 while allowing the displacement of the stationary sealing ring 4.

That is, the seal ring 6 and the holding ring 7 are flexible with one portion 6a, 7a separated, and are separated by the garter spring 8.
Because a is bound in a closed ring shape,
The first seal surface 6b of the seal ring 6 and the first auxiliary seal surface 7b of the holding ring 7 allow a relative movement in the axial direction, and a first sealed surface 3d on the seal case 3 side.
The entire circumference of the ring 6,
7 and the seal case 3 are sealed well. Also,
The second seal surface 6c of the seal ring 6 and the second auxiliary seal surface 7c of the holding ring 7 are moved along the axial direction of the stationary seal ring 4 by the spring 9a so that the second seal surface 6c on the stationary seal ring 4 side.
The rings 6 and 7 are brought into close contact with the surface 4b to be sealed.
And the stationary sealing ring 4 are sealed well. by the way,
The seal ring 6 has a smaller cross-sectional area and a higher deformability (conformability) in the radial and axial directions than the holding ring 7. For this reason, even when the spring force of the garter spring 8 and the coil spring 9a acting on the holding ring 7 is not uniform, the spring force acts evenly and uniformly and appropriately on the sealed surfaces 3d and 4b. Pressing contact will be made. Therefore, the surfaces 3d and 4b to be sealed are substantially properly sealed substantially by the contact of the first and second sealing surfaces 6b and 6c, and the first and second auxiliary sealing surfaces 7b and 7c are It merely performs an auxiliary sealing function. First and second auxiliary sealing surfaces 7b, 7c
Is a fluid formed between the separation portion 6a and the surfaces 3d and 4b to be sealed when the separation portion 6a of the seal ring 6 is opened, together with the surface of the holding ring 7 that is fitted and adhered to the seal ring 6. It functions to block the leak passage.

Incidentally, each of the rings 6 and 7 is provided at one location 6a,
Since the flexible member 7a is detached, it can follow the stationary sealing ring 4 well and can cope with vibrations and pressure fluctuations of the device, but instantaneously disconnect the parts 6a, 7a.
a may open to cause fluid leakage (gas leakage).
However, since the cut-off portions 6a and 7a of the two rings 6 and 7 are inconsistent in the circumferential direction, the fitting portion of the two rings 6 and 7 has the binding action of the garter spring 8 and the coil spring 9
a, a series of fluid passages passing through both rings 6, 7 are formed even when the cut-off portions 6a, 7a are opened. Therefore, there is no possibility that the above-described fluid leakage will occur. That is, even if the high-pressure fluid in the high-pressure fluid region H tries to enter the separation portion 6a of the seal ring 6 from the separation portion 7a of the holding ring 7 through the fitting portion of the two rings 6, 7, such a detour path is formed. Since the pressure is reduced during tracing, there is no danger that the pressure will leak to the low-pressure fluid region L through the separation points 6a and 7a of the rings 6 and 7.

Of course, the material of each component can be selected according to the sealing conditions (for example, a heat-resistant material is selected under high-temperature conditions). Therefore, the elastomer seal described at the beginning is used. Conditions that are not possible (for example,
Under high temperature conditions), it can be suitably used,
A good sealing function can be exhibited.

It should be noted that the present invention is not limited to the above-described embodiment, and can be appropriately changed and improved without departing from the basic principle of the present invention.

[0026] For example, the switching of the holding ring 7 Hanare箇office 7
The number of “a” is arbitrary, and as shown in FIG. 3 , the holding ring 7 can be cut off at two or more locations and divided into a plurality of arc-shaped portions. In this case,
The ring 7 has a separation portion 7a at which the seal ring 6 is separated.
In order to make a discrepancy in the circumferential direction with the point 6a,
Need to be fitted to the outer ring 6. Also, the retaining ring 7
When the material is divided into arc-shaped parts, the material is not limited to the energy elastic material required when one part is cut off, but depends on the sealing conditions. Can be arbitrarily selected.

The shape of each of the rings 6 and 7 is such that the holding ring 7 is closely fitted to the seal ring 6 in a state of being in contact with the entire peripheral surface except the first and second seal surfaces 6b and 6c. A first cylindrical surface 3d to be sealed and a second planar surface
It can be arbitrarily set on condition that the two surfaces 3d and 4b can be sealed by contacting the surface 4b to be sealed. For example, as shown in FIG.
May have a triangular cross section, and the holding ring 7 may have a trapezoidal cross section. Even in the case of such a shape, the sealing function between the surfaces to be sealed 3d and 4b is exerted similarly to the above-described example. In this case, the tightening force of the retaining ring 7 by the garter spring 8 causes the pressing force of the seal ring 6 in the direction of the stationary sealing ring 4 (the axis of the radial force (tightening force) acting on the fitting surfaces of both rings 6 and 7). (Component force in the direction).

Further, the sealing device 5 according to the present invention comprises a cylindrical first surface to be sealed and a planar second surface which can be moved relative to the first surface to be sealed in a radial or axial direction perpendicular to the axis thereof. The mechanical seal provided on the shaft sealing portion of a fluid machine or a pneumatic machine or the mechanical seal provided on the shaft sealing portion (provided that the above-mentioned non-contact surface is provided), provided that the two sealed surfaces exist and it is necessary to seal between the two sealed surfaces. It can be used for a secondary seal portion of a mechanical seal or a contact mechanical seal), and the components of each of the rings 6 and 7 and the surfaces to be sealed are appropriately selected according to the sealing conditions. be able to. For example, as shown in FIG. 5, the sealing device 5 can be suitably used for sealing between the seal case 3 and the rotating shaft 1 passing therethrough. That is, FIG.
In the sealing device 5 shown in FIG. 1, the space between the first sealed surface 1a, which is the outer peripheral surface of the rotating shaft 1, and the second sealed surface 3e, which is the wall surface of the seal case 3, is formed by the seal ring 6 and the holding ring 7. It is configured to seal (primary seal). In this case, the rings 6 and 7 are held by the appropriate rotation preventing means (drive pins and the like) on the seal case side so that they cannot rotate relative to each other, and the first seal surface 6b and the first auxiliary seal surface 7b are connected to the first cover. The seal surface 1a is designed so as to relatively slide in the circumferential direction. The biasing member 9 includes a plurality of coil springs 9a (only one is shown) interposed between a spring retainer 3f provided on the seal case 3 and the holding ring 7, and the holding ring 7 is provided with a second cover. The pressure is applied to the sealing surface 3e.

Further, as described above, the surfaces 7b and 7c of the holding ring 7 facing the surface to be sealed are coupled with the surface in close contact with the seal ring 6, and the fluid from the cut-off portion 6a of the seal ring 6 is formed. The first and second sealing surfaces 6 of the seal ring 6 only need to function so as to prevent leakage.
It is not necessary to provide a sealing function as in b and 6c, but it is also possible to have a structure in which the first and second sealing surfaces 6b and 6c come into contact with the surface to be sealed in order to perform a sealing action. It is.

The binding member 8 is preferably a garter spring, but is not limited to this. Of course, the location to be bound by the binding member 8 such as a garter spring may be either one location in the axial direction of the holding ring 7 or a plurality of locations (using a plurality of garter springs or the like). Separation point 6 of seal ring 6
It is desirable to set the condition that a can be maintained in a proper closed ring shape.

[0031]

As can be easily understood from the above description, according to the present invention, the first sealed surface having a cylindrical surface and the second sealed surface which is relatively moved perpendicularly to the axis thereof. Can be satisfactorily sealed, and a practical and simple sealing device for a secondary seal portion or the like of a mechanical seal can be provided. Moreover, unlike the case where a general elastomer seal is used, the material of the constituent members can be arbitrarily selected according to the sealing conditions, so that an appropriate sealing function can be exerted under any sealing conditions. .

[Brief description of the drawings]

FIG. 1 is a half cut longitudinal side view showing an example of a sealing device according to the present invention.

FIG. 2 is a vertical sectional front view taken along the line II-II of FIG.

FIG. 3 is a longitudinal sectional front view showing a modification and corresponding to FIG. 2;

FIG. 4 is a half sectional vertical side view showing another modified example.

FIG. 5 is a half sectional vertical side view showing still another modified example.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Rotating shaft, 1a, 3d ... 1st to-be-sealed surface, 2 ... Rotary sealing ring, 3 ... Seal case, 3c ... Cylindrical wall part, 3e, 4
b: second sealed surface, 4: stationary sealing ring, 5: sealing device, 6: seal ring, 6a, 7a: cut-off point, 6b ...
First sealing surface, 6c: second sealing surface, 7: retaining ring,
7b: first auxiliary seal surface, 7c: second auxiliary seal surface, 8
... Garter spring (binding member), 9 ... Biasing member, 9a
…coil spring.

Continuation of front page (56) References JP-A-6-101765 (JP, A) JP-A-2-271003 (JP, A) JP-A-55-6067 (JP, A) JP-A-52-144560 (JP) , A) Shokai 58-16463 (JP, U) Shokai Hei 3-39664 (JP, U) Japanese Patent Publication No.43-21457 (JP, B1) Shogun 36-21457 (JP, Y1) Shoko Shoji 47-7551 (JP, Y1) (58) Field surveyed (Int. Cl. ⁶ , DB name) F16J 15/34

Claims (1)

(57) [Claims] 1. A sealing device for sealing between a first cylindrical surface to be sealed and a second planar surface to be moved relative to the axis perpendicular to the first sealed surface, wherein the first sealed surface is provided. The first sealing surface in contact with the entire surface of the first sealing surface and the second sealing surface in contact with the second sealing surface.
It has a sealing surface, and the seal ring disconnecting one part that put in a circumferential direction, Shi fitted to the seal ring in contact with the entire peripheral surface portion excluding the first and second sealing surfaces of the sealing ring And
A retaining ring in which at least one location in the circumferential direction that is inconsistent with the separation location of the seal ring in the circumferential direction is separated, and the retaining ring is tightly bound in a ring shape, and the retaining ring and a seal fitted therein. A binding member for urging and holding the rings in a direction to close the cutoff portions; and an urging member for urging the holding ring in the axial direction so as to press the second sealing surface against the second sealed surface. And a sealing device.