KR20090031984A - Sealing device - Google Patents

Abstract

A sealing installation device is provided to prevent the deformation of sealing part, the movement in an annular groove or being shaken. A sealing installation device comprises: a first seal lip(51) which is installed in a first sealing area(O) in which the liquid is sealed up, and which is moving toward the peripheral surface of a piston(32); a second seal lip(52) which is installed in a second sealing area(G) in which the gas is sealed up, and which is moving toward the peripheral surface of piston; and a sealing part(53) sticking to the inner circumference surface of a shaft holes.

Description

Sealing device

The present invention relates to a sealing device that prevents gas from leaking into a first sealed region in which a liquid is sealed and also prevents liquid from leaking into a second sealed region in which a gas is sealed.

For example, in a hydraulic cylinder used for a breaker, there is a sealing region (first sealing region) in which a liquid such as oil is sealed and a sealing region (second sealing region) in which a gas such as nitrogen gas is sealed. Such a hydraulic cylinder is provided with a sealing device for simultaneously sealing the first sealing region and the second sealing region. The conventional example of such a sealing apparatus is demonstrated with reference to FIG.7 and FIG.8. 7 is a schematic cross-sectional view of a sealing device according to a conventional example 1. FIG. 8 is a schematic cross-sectional view of a sealing device according to a conventional example 2;

In order to simultaneously prevent leakage of liquid from the first sealing area to the second sealing area and leakage of gas from the second sealing area to the first sealing area, a seal is provided on each of the first sealing area side and the second sealing area side. It is appropriate to have a seal lip. Therefore, in order to seal two sealing areas simultaneously, as shown in FIG. 7 or FIG. 8, it is common to use the X ring whose cross section is substantially X shape.

The sealing devices 100 and 110 shown in FIG. 7 and FIG. 8, respectively, are provided in the hydraulic cylinder used for the breaker, and the outer peripheral surface of the piston 132 reciprocating at high speed and the shaft hole formed in the cylinder 131 It is arranged in the annular gap between the inner circumferential surface of the. The first sealing region O in which the oil is sealed and the second sealing region G in which the nitrogen gas is sealed are simultaneously sealed by these sealing apparatuses 100 and 110.

The sealing apparatus 100 shown in FIG. 7 has a first seal lip 101 provided on the inner side of the first sealing region O and a second seal region G on the second sealing region G side. The seal lip 102 is provided. These 1st seal lip 101 and the 2nd seal lip 102 are comprised in the shape (curved shape (R shape)) rounded at the lip tip. The first seal lip 101 and the second seal lip 102 slide with respect to the outer circumferential surface of the piston 132.

Moreover, the sealing apparatus 100 has the 3rd seal lip 103 provided in the 1st sealing area | region O side at the outer peripheral side, and the 4th seal lip provided in the 2nd sealing area G side ( 104). These third seal lip 103 and the fourth seal lip 104 come into close contact with the groove bottom surface (inner circumferential surface) of the annular groove 131a formed in the cylinder 131.

The sealing apparatus 110 shown in FIG. 8 also has the 1st seal lip 111 provided in the 1st sealing area | region O side in the inner peripheral side, and the 2nd provided in the 2nd sealing area | region G side. The seal lip 112 is provided. These 1st seal lip 111 and the 2nd seal lip 112 are comprised by the shape (edge shape (sharpened shape)) with a sharp edge of a lip | tip tip. The first seal lip 111 and the second seal lip 112 slide with respect to the outer circumferential surface of the piston 132.

Moreover, the sealing apparatus 110 has the 3rd seal lip 113 provided in the 1st sealing area | region O side at the outer peripheral side, and the 4th seal lip provided in the 2nd sealing area G side ( 114). These third seal lip 113 and the fourth seal lip 114 are brought into close contact with the groove bottom surface (inner circumferential surface) of the annular groove 131a formed in the cylinder 131.

Here, in the breaker, since the piston 132 reciprocates at high speed as described above, minute vibrations are generated in the sealing devices 100 and 110.

Therefore, the behavior of the sealing apparatus 100, 110 becomes unstable, and it becomes the cause which adversely affects the sealing property by the 1st seal lip 101,111 and the 2nd seal lip 102,112.

In addition, with the minute vibration, a minute gap is formed between the groove bottom surface of the annular groove 131a formed in the cylinder 131 and the third seal lips 103 and 113 and the fourth seal lips 104 and 114. You will have a slide.

Therefore, the oil of these 3rd seal lips 103 and 113 and the 4th seal lips 104 and 114 is scraped off, and it is a cause which oil leaks to the 2nd sealing area G side.

As described above, in the case of the sealing devices 100 and 110 according to the conventional example, the sealing property was insufficient.

On the other hand, there exists a thing disclosed by patent document 1, 2 as a related technique.

  Patent document 1; JP-A 1-174677

         Patent document 2; Japanese Patent Application Laid-Open No. 9-14451

SUMMARY OF THE INVENTION An object of the present invention is to provide a sealing device which prevents gas from leaking into a first sealed region where liquid is sealed and also more reliably prevents leakage of liquid into a second sealed region where gas is sealed. Is in.

MEANS TO SOLVE THE PROBLEM This invention employ | adopts the following means in order to solve the said subject.

That is, the sealing device of the present invention,

A sealing apparatus disposed in an annular gap between a cylinder having a shaft hole and a piston reciprocating at high speed in the shaft hole,

A first seal lip installed on the side of the first sealing region in which the liquid is sealed, and sliding against the outer circumferential surface of the piston;

A second seal lip installed on the side of the sealed second sealing region and sliding against the outer circumferential surface of the piston;

A seal in close contact with the inner circumferential surface of the shaft hole,

In a sealing device that prevents leakage of gas into a second sealing area while preventing gas leakage into the first sealing area,

The said sealing part is comprised by the cylindrical surface, It is characterized by the above-mentioned.

According to this invention comprised as mentioned above, since the sealing part is comprised by the cylindrical surface, as a piston reciprocates at high speed, even if a sealing apparatus is accompanied by a minute vibration, a sealing part hardly deforms. Therefore, the influence on the 1st seal lip and the 2nd seal lip by the deformation | transformation of the sealing part side can be suppressed. In addition, since the sealing portion is constituted by the cylindrical surface, suction does not occur as in the case of the seal lip. As described above, even when the sealing device is used for the purpose of causing fine vibration, leakage of liquid or gas from the gap between the sealing device and the cylinder can be suppressed. Moreover, the function of a 1st seal lip and a 2nd seal lip can be exhibited stably.

Further, the shape of the lip tip of the first seal lip and the shape of the lip tip of the second seal lip are such that the thickness of the film by the liquid formed in the slide portion when the first sealing lip slides with respect to the outer circumferential surface of the piston It may be comprised so that a 2nd sealing lip may become thinner than the thickness of the film | membrane by the said liquid formed in a slide part when it slides with respect to the outer peripheral surface of the said piston.

If the shape of the lip tip of the first seal lip and the shape of the lip tip of the second seal lip are constituted as described above, a suction phenomenon occurs in which the liquid is sucked into the first sealing region side. Thereby, the liquid leakage to the 2nd sealing area can be prevented more reliably. Since a film of liquid is formed between the lip tip of the first seal lip and the outer circumferential surface of the piston, and the lip tip of the second seal lip and the outer circumferential surface of the piston, the gas is formed in the first sealing region. There is no leakage.

The lip tip of the first seal lip may have a sharp edge, whereas the lip tip of the second seal lip may have a rounded shape.

By doing so, the thickness of the film formed by the liquid formed in the slide portion when the first sealing lip slides with respect to the outer circumferential surface of the piston is formed in the slide portion when the second sealing lip slides with respect to the outer circumferential surface of the piston. It can be made thinner than the film thickness by the said liquid.

The sealing device may be configured to be mounted in an annular groove formed in the cylinder, and may have at least one protrusion in close contact with at least one side of both sides of the annular groove.

By doing this, it is possible to suppress the sealing device from moving or vibrating in the annular groove. Therefore, the occurrence of a slide between the sealing portion and the bottom of the groove of the annular groove can be further suppressed, and the deformation of the sealing portion can be suppressed more reliably.

In addition, each said structure can be employ | adopted in combination as much as possible.

As described above, according to the present invention, it is possible to prevent the gas from leaking into the first sealing region in which the liquid is sealed, and more reliably prevent the liquid from leaking into the second sealing region in which the gas is sealed.

Best Mode for Carrying Out the Invention The best mode for carrying out the present invention will be described in detail below with reference to the drawings. However, the dimensions, materials, shapes, relative arrangements, and the like of the component parts described in this embodiment are not intended to limit the scope of the present invention only to them unless otherwise specified.

(Example 1)

With reference to FIGS. 1-3, the sealing apparatus which concerns on Example 1 of this invention, and the hydraulic cylinder to which this sealing apparatus is applied are demonstrated.

<Hydraulic Cylinder>

With reference to FIG. 1, the structure of the hydraulic cylinder which concerns on embodiment of this invention is demonstrated. In addition, the case where a hydraulic cylinder is applied to a breaker as an example here is demonstrated. 1 is a schematic cross-sectional view of a breaker to which a hydraulic cylinder according to an embodiment of the present invention is applied.

The breaker 30 is provided with the cylindrical cylinder 31 which has an axial hole, and the piston 32 inserted in the axial hole of this cylinder 31 with clearance with respect to the inner peripheral surface of the axial hole. At the distal end of the piston 32, a tooth gel (rod) 33 for crushing concrete or rock is provided.

And the cylindrical front head 34 is coaxially fixed to the front end side of the cylinder 31. As shown in FIG. In the inside of the front head 34, a chisel 33 is provided so as to be able to reciprocate freely, and in the inside of the front head 34, a shock from the tooth gel 33 is applied. The thrust bush is assembled. Further, a cylindrical back head 35 having a bottom is fixed coaxially to the rear end side of the cylinder 31. In the back head 35, a hydraulic blow-out or gas intake valve is assembled, and nitrogen gas is filled inside (hereinafter, the region in which the nitrogen gas is sealed is referred to as a second sealing region G). ).

Moreover, the breaker 30 performs pressure compensation and pulsation prevention of the control valve 36 for controlling the reciprocating movement of the piston 32, and the hydraulic circuit provided in the cylinder 31, and internally pressurizes nitrogen of high pressure. A gas filled accumulator 37 is also provided.

And in order to seal the annular clearance between the axial hole formed in the cylinder 31, and the piston 32, the 1st sealing ring system 10 and the 2nd sealing ring system 20 are provided in the rear end side and the front end side, respectively. It is installed. In addition, in FIG. 1, these 1st sealing ring system 10 and the 2nd sealing ring system 20 are shown briefly. And oil is enclosed between these 1st sealing ring system 10 and the 2nd sealing ring system 20 (Hereinafter, the area | region in which this oil is sealed is called 1st sealing area | region O). The 1st sealing ring system 10 prevents the leakage of this oil, and plays the role of preventing the leakage of nitrogen gas mentioned above. In addition, the second seal ring system 20 serves to prevent leakage of oil and to prevent dust from invading from the outside.

In the breaker 30 configured as described above, the pile-shaped chisel 33 is reciprocated at a high speed in the axial direction together with the piston 32 by hydraulic pressure and gas pressure, and the tip of the tooth gel 33 is destroyed. The object to be broken can be crushed by embedding in a rock or the like). On the other hand, by compressing the gas by hydraulic pressure and using the repulsive force of the gas, the piston 32 and the chisel 33 can be moved at high speed (for example, 10 m / s) toward the destruction target.

<First Sealing System>

With reference to FIG. 2, the 1st sealing ring system 10 is demonstrated. 2 is a partially enlarged cross-sectional view (an enlarged cross-sectional view of a side of the first seal ring system) of the hydraulic cylinder according to the first embodiment of the present invention.

The 1st sealing ring system 10 is comprised from the sealing unit 40 provided in the 1st sealing area | region O side, and the sealing apparatus 50 provided in the 2nd sealing area | region G side. The first annular groove 31a and the second annular groove 31b are formed on the inner circumferential surface of the shaft hole of the cylinder 31. And the sealing unit 40 is provided in the 1st annular groove 31a, and the sealing apparatus 50 is provided in the 2nd annular groove 31b.

The sealing unit 40 is comprised from the resin ring 41 installed so that it can slide freely with respect to the outer peripheral surface of the piston 32, and the rubber ring 42 fitted in the outer periphery of the resin ring 41. FIG. It is. While the rubber ring 42 is in close contact with the groove bottom of the first annular groove 31a, the resin ring 41 is pressed against the outer circumferential surface of the piston 32 by magnetic elastic repulsion. . The sealing unit 40 comprised in this way exhibits the function which buffers the oil pressure which became the high pressure mainly.

The sealing device 50 is a seal ring made of a rubber-like elastic body, in which oil leaks from the first sealing region O to the second sealing region G, and the first sealing region from the second sealing region G. This is to prevent nitrogen gas from leaking at the same time as (O). This sealing device 50 is demonstrated in detail below.

<Sealing Device>

In particular, with reference to FIG. 3, the sealing apparatus 50 which concerns on Example 1 of this invention is demonstrated in detail. 3 is a schematic cross-sectional view showing a mounting state of the sealing apparatus according to the first embodiment of the present invention.

The sealing device 50 includes a first seal lip 51 and a second seal lip 52 which slide with respect to the outer circumferential surface of the piston 32, and a second annular groove provided on the inner circumference of the shaft hole of the cylinder 31 ( The sealing part 53 which adheres to the groove bottom surface (inner circumferential surface) of 31b) is provided.

The first seal lip 51 is provided on the first sealing region O side, and the second seal lip 52 is provided on the second sealing region G side. And the lip tip of the 1st seal lip 51 and the lip tip of the 2nd seal lip 52 are comprised in the shape (edge shape (sharp shape)) with a sharp edge.

And in the sealing apparatus 50 which concerns on a present Example, the sealing part 53 is comprised by the cylindrical surface. That is, when the sealing part 53 is seen from the cross section, as shown in FIG. 2 and FIG. 3, it is comprised in linear form. Thus, the sealing device 50 which concerns on a present Example is a K ring whose cross-sectional shape by which the sealing on the outer peripheral side consists of a cylindrical surface is substantially K-shaped.

As mentioned above, in the present Example, the structure of the sealing of the side which does not slide (the side attached to the 2nd annular groove 31b provided in the cylinder 31) was comprised by the cylindrical surface which is hard to deform | transform.

<Excellent point of this embodiment (function of sealing device)>

By the configuration as described above, in the sealing device 50 according to the present embodiment, as the piston 32 reciprocates at a high speed, the sealing part 53 is formed even under an environment involving the fine vibration of the sealing device 50. Almost no deformation.

Therefore, it can suppress that the 1st seal lip 51 and the 2nd seal lip 52 are affected by the deformation | transformation of the sealing part 53 side. Moreover, since the sealing part 53 is comprised by the cylindrical surface, the suction phenomenon will not generate | occur | produce like the case where it is comprised by a seal lip.

In view of the above, even when the sealing device 50 is used for a fine vibration, the gap between the sealing device 50 and the groove bottom surface of the second annular groove 31b provided in the cylinder 31 is obtained. The leakage of a liquid or gas can be suppressed. Moreover, the function of the 1st seal lip 51 and the 2nd seal lip 52 can be exhibited stably.

Moreover, since the sealing device 50 which concerns on a present Example has a simple cylindrical shape on the outer peripheral side, the mold release property at the time of shaping | molding by a metal mold | die becomes excellent. Therefore, the side effect of being excellent in manufacture (molding) also exists.

(Example 2)

In FIG. 4, Example 2 of this invention is shown. In the first embodiment, the lip front ends of the first seal lip and the second seal lip are all configured in a sharp edge shape (edge shape (sharpened shape)). The case where all this is comprised by round shape (curved shape (R shape)) is demonstrated.

Since other structures and operations are the same as those in the first embodiment, the same components are denoted by the same reference numerals, and the description thereof is omitted.

4 is a schematic cross-sectional view showing a mounting state of a sealing device according to a second embodiment of the present invention. Also in the sealing apparatus 50a which concerns on a present Example, the 1st seal lip 51a and the 2nd seal lip 52a which slide with respect to the outer peripheral surface of the piston 32 are provided.

In this embodiment, the lip front ends of these 1st seal lip 51a and the 2nd seal lip 52a are comprised in round shape (curved shape (R shape)). Other configurations are the same as those of the first embodiment.

Also in this embodiment, needless to say, the same effects as in the first embodiment can be obtained.

(Example 3)

In FIG. 5, Example 3 of this invention is shown. In the present embodiment, the lip tip of the first seal lip is configured with a sharp edge (edge shape (sharpened shape)), and the lip tip of the second seal lip is rounded (curved shape (R shape). The case where it consists of)) is demonstrated.

Since other structures and operations are the same as those in the first embodiment, the same components are denoted by the same reference numerals, and the description thereof is omitted.

5 is a schematic cross-sectional view showing a mounting state of a sealing device according to a third embodiment of the present invention. Also in the sealing device 50b which concerns on a present Example, the 1st seal lip 51b and the 2nd seal lip 52b which slide with respect to the outer peripheral surface of the piston 32 are provided.

In this embodiment, the lip tip of the first seal lip 51b has a sharp edge shape (edge shape (sharpened shape)), and the lip tip of the second seal lip 52b has a round shape ( Curved shape (R shape). About other structure, it is the same as that of the said Example 1.

Thus, the reason which made the shape of the lip tip of each seal lip into another shape is demonstrated in detail below.

The sealing mechanism in the reciprocating sealing device is generally based on the thickness of the sealing object fluid formed in the slide portion. For example, a case of a general reciprocating sealing device disposed in an annular gap between a relatively reciprocating shaft and a housing and preventing oil from leaking to the atmosphere will be described as an example. In this case, when the sealing device moves to the air side with respect to the shaft (pull step), the oil film formed at the portion where the sealing device slides on the shaft surface moves to the sealing region side with respect to the shaft. It is comprised so that thickness may become thicker than the oil film formed in the said part in a (pressing process). With such a configuration, since a suction phenomenon occurs in which oil is sucked into the sealing fluid side, it is possible to prevent the oil from leaking to the atmosphere side.

In the case of the sealing devices 50 and 50a of the first and second embodiments, the slides are moved when the sealing devices 50 and 50a move toward the first sealing region O with respect to the piston 32. The film thickness of the fluid to be sealed formed in the portion and the film thickness of the fluid to be formed in the slide portion when moved to the second sealing region G side are set to be equal in theory.

This is because the consideration of the sealing mechanism in the reciprocating seal is that the fluid to be sealed is considered to be liquid or gaseous, i.e. oil leakage into the second sealing region G and the first sealing region O. In order to prevent nitrogen gas leakage at the same time, it is based on the design idea that suction should not occur on either side. On the other hand, in the sealing devices 50 and 50a, the suction phenomenon is prevented from occurring in any of them by being symmetrical with respect to the center C of the axial width.

In reality, however, oil leakage occurs to the second sealing region G side. For this reason, first, in the case where the sealing devices 50, 50a reciprocate with respect to the piston 32, the thickness of the oil film made in the air path and the thickness of the oil film made in the return path are theoretically the same. Even if, in fact, due to some influence (external disturbance such as eccentricity or various dimensional errors, etc.), it is impossible to always make the thickness of the oil film the same as the design. Secondly, since an oil film is formed at the lip tip and the portion where the piston 32 slides, it is conceivable that gas (nitrogen gas) hardly leaks into the first sealing region O.

Therefore, in the sealing device 50b which concerns on a present Example, when the 1st seal lip 51b slides with respect to the surface of the piston 32, the thickness of the oil film formed in a slide part will be 2nd lip 52b. ) Is made thinner than the thickness of the oil film formed on the slide when the slide is made against the surface of the piston 32.

As described above, in the sealing device 50b according to the present embodiment, the lip tip of the first seal lip 51b is configured to have a sharp corner, and the lip tip of the second seal lip 52b is It is by having a rounded shape.

Therefore, when the sealing device 50b moves to the 1st sealing area O side with respect to the piston 32, the thickness of the oil film formed by the sealing device 50b on the surface of the piston 32, When the sealing device 50b moves to the second sealing region G side with respect to the piston 32, the sealing device 50b becomes thinner than the thickness of the oil film formed by the sealing device 50b on the surface of the piston 32.

As a result, a suction phenomenon occurs in which oil is sucked into the first sealing region O side. Therefore, oil leakage to the 2nd sealing area G can be prevented more reliably.

Here, the suction phenomenon in which the sealing object fluid is sucked into the first sealing region O side occurs, so that the nitrogen gas on the second sealing region G side leaks into the first sealing region O. Can be. However, in reality, the lip tip of the first seal lip 51b and the surface of the piston 32 are sliding, and the lip tip of the second seal lip 52b and the surface of the piston 32 are also sliding, An oil film is formed in these slide parts. Therefore, nitrogen gas does not leak into the first sealing region O.

On the other hand, in the present embodiment, the lip tip of the first seal lip 51b is configured with a sharp edge, whereas the lip tip of the second seal lip 52b has a rounded shape. Indicated.

In short, however, the thickness of the oil film formed on the slide portion when the first seal lip 51b slides against the surface of the piston 32 is greater than the surface of the piston 32 of the second seal lip 52b. It is good to make it thinner than the thickness of the oil film formed in a slide part at the time of a slide.

To realize this, for example, the lip front end of the first seal lip 51b and the lip front end of the second seal lip 52b are rounded, so that the radius of curvature becomes smaller toward the first seal lip 51b. You may also do it. In this case, the radius of curvature R of the lip tip of the second seal lip 52b may be increased as long as the space of the second annular groove 31b allows.

On the other hand, it is also conceivable to make the thickness of the oil film different by having a difference in the compression amount (tightening value) of the lip. However, in the case where the compression amount of the lip is different, the surface pressure at the tip of the lip is different, but the difference in pressure gradient is less likely to occur, so that the thickness of the oil film is hardly different. Therefore, it is hardly practical to make the thickness of the oil film different by making a difference in the compression amount of the lip as described above.

(Example 4)

6, Embodiment 4 of the present invention is shown. In this embodiment, in addition to the configuration of the third embodiment, the projections are added in the axial direction. Since other structures and operations are the same as those in the third embodiment, the same components are denoted by the same reference numerals, and the description thereof is omitted.

6 is a schematic sectional view showing a mounting state of a sealing device according to a fourth embodiment of the present invention. The sealing apparatus 50c which concerns on a present Example is provided with the projection 54 on both sides of an axial direction, respectively. These projections 54 are configured to be in close contact with each other in a compressed state with respect to both side surfaces of the second annular groove 31b provided on the inner circumferential surface of the shaft hole of the cylinder 31.

As described above, in the present embodiment, by providing the projections 54 in close contact with both sides of the second annular groove 31b in the compressed state, the sealing device 50c is provided within the second annular groove 31b. It can suppress moving or vibrating. In addition, with this, it can further suppress that a slide generate | occur | produces between the sealing part 53 and the groove bottom surface of the 2nd annular groove 31b, and it can reliably suppress the deformation of the sealing part 53 more reliably. It can be suppressed. Therefore, compared with each said embodiment, the function of the 1st seal lip 51b and the 2nd seal lip 52b can be exhibited more stably.

On the other hand, these projections 54 may be constituted by annular projections continuously provided over the entire circumference, or may be constituted by projections independently provided at appropriate intervals in the circumferential direction. In addition, although the example which employ | adopted the structure which provides a processus | protrusion respectively in both axial directions was shown in the example shown, you may employ | adopt the structure which provides a processus | protrusion only in either one. Even in this case, it is a matter of course that both sides (one of the projections) in the axial direction can be configured to be in contact with both sides of the second annular groove 31b.

That is, the projection is provided to suppress the sealing device from moving or vibrating in the second annular groove 31b. On the other hand, the higher the compressive force of the projections, the lower the workability when the sealing device is attached to the second annular groove 31b. Therefore, considering the balance between the effect of suppressing the movement and vibration of the sealing device and the workability when the sealing device is mounted, should the projection be an annular projection or an independent projection, or will the projection be installed in both axial directions? You only have to choose whether to install on one side. The same applies to the size (width dimension and protrusion amount) of the projection.

1 is a schematic cross-sectional view of a breaker to which a hydraulic cylinder according to an embodiment of the present invention is applied;

2 is a partially enlarged cross-sectional view of a hydraulic cylinder according to Embodiment 1 of the present invention;

3 is a schematic cross-sectional view showing a mounting state of a sealing device according to a first embodiment of the present invention;

4 is a schematic cross-sectional view showing a mounting state of a sealing device according to a second embodiment of the present invention;

5 is a schematic cross-sectional view showing a mounting state of a sealing device according to a third embodiment of the present invention;

6 is a schematic cross-sectional view showing a mounting state of a sealing device according to a fourth embodiment of the present invention;

7 is a schematic cross-sectional view of a sealing device according to a conventional example 1;

8 is a schematic cross-sectional view of a sealing device according to a conventional example 2. FIG.

(Explanation of the sign)

10---First Sealing System

20---Second Sealing System

30---Breaker

31---Cylinder

31a---First Fantasy Home

31b---Second Fantasy Home

32---Piston

33---Chisel

34---Front Head

35---Back Head

36---Control Valve

37---Accumulator

40---Sealing Unit

41---Ring made of resin

42---Rubber Ring

50, 50a, 50b, 50c---Sealing device

51, 51a, 51b---First Seal Lip

52, 52a, 52b---Second Seal Lip

53---Seal

54---Turning

O---first sealing area

G---Second sealing area

Claims (4)

A sealing apparatus disposed in an annular gap between a cylinder having a shaft hole and a piston reciprocating at high speed in the shaft hole, A first seal lip installed on the side of the first sealing region in which the liquid is sealed, and sliding against the outer circumferential surface of the piston; A second seal lip installed on the side of the sealed second sealing region and sliding against the outer circumferential surface of the piston; A seal in close contact with the inner circumferential surface of the shaft hole, In a sealing device that prevents leakage of gas into the second sealing region while preventing gas from leaking into the first sealing region, Sealing device characterized in that the sealing portion is composed of a cylindrical surface. The shape of the lip tip of the first seal lip and the shape of the lip tip of the second seal lip, The thickness of the film formed by the liquid formed in the slide portion when the first sealing lip slides against the outer circumferential surface of the piston; Sealing device, characterized in that configured to become thinner than the thickness of the film. The sealing device according to claim 2, wherein the lip tip of the first seal lip has a sharp edge, and the lip tip of the second seal lip has a rounded shape. The sealing device according to any one of claims 1 to 3, wherein the sealing device is configured to be mounted in an annular groove formed in the cylinder. Sealing device characterized in that it has at least one projection in close contact with at least one side of both sides of the annular groove in a compressed state.

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