JPH08189567A - Rotary sealing device - Google Patents

Abstract

PURPOSE: To provide a rotary sealing device with which a problem is not caused even if a co-rotating phenomenon is presented under a high pressure and high speed rotation condition by installing a synthetic resin-made substancially rectangular cross sectional sealing ring in contact with a motional surface of a mating member and a slip ring on a shaft directional side surface on the pressure receiving side of the sealing ring by combining them with each other. CONSTITUTION: Fluid pressure P enters an installing groove from a clearance between a side surface 13 of a sealing ring 11 and a side surface 5 of the installing groove, and acts on a peripheral surface 15 corresponding to an outer peripheral surface of the sealing ring 11 and the side surface 13 on the pressure side, and brings a motional side peripheral surface 12 of the sealing ring 11 into close contact with a rod surface 2, and acts so as to press a slip ring 21 to a side surface 6 on the pressure receiving side of the installing groove 4. When high pressure is applied, the sealing ring 11 is put in a co rotating condition of rotating together with a rod 1, but at that time, since it becomes relative motion between a side surface 14 on the pressure receiving side of the sealing ring 11 and the slip ring 21, abrasion is hardly caused, and a frictional resistance value between the sealing ring 11 and the slip ring 21 also becomes a small value.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rotary seal device for sealing fluid pressure between two relatively moving cylindrical members found in a rotary member or a rocking member of a fluid pressure machine. In particular, the present invention relates to a sealing device for a rotating member or an oscillating member under high pressure conditions.

[0002]

2. Description of the Related Art Conventionally, mechanical seals have been widely used as sealing devices used for high-pressure, high-speed rotating parts of fluid pressure equipment, but their mounting structure is complicated.
Moreover, the space is large. Also, a swinging motion part such as that found in fluid pressure equipment with a relatively low number of revolutions,
Alternatively, a seal ring made of a synthetic resin such as polytetrafluoroethylene (hereinafter referred to as PTFE) and having a substantially rectangular cross section is used alone as a seal device for the rotary motion unit.

Such a seal ring has been put into practical use as a seal device having a compact structure that is easy to handle for low-speed rotation and rocking motion as described above, and is now in practical use. Widely used for rotor parts such as center swivel joints.

As shown in FIGS. 7 and 8, a conventional sealing device 70 composed of a single seal ring 71 is attached to a mounting groove 4 having a substantially rectangular cross section in a state of being in close contact with a mating movement surface 2 of a mating member 1. The fluid pressure introduced into the mounting structure 4 obtains hermeticity by pressing the seal ring 71 against the groove side surface and the mating movement surface 2, but the fluid pressure of the mating movement surface 2 and the mounting groove 4 is proportional to the fluid pressure. Since the contact force on the side surface becomes high, the frictional force with the mating movement surface may become larger than the frictional force with the side surface of the mounting groove under high pressure conditions. In such a case, a so-called co-rotation phenomenon occurs in which the seal ring rotates integrally with the mating surface, so that the side surface of the seal ring 71 and the side surface of the mounting groove 4 become a relative rotational movement. In particular, during high-speed rotation, abnormal wear occurred on the seal ring side surface and the mounting groove side surface, and durability could not be obtained.

[0005]

SUMMARY OF THE INVENTION It is an object of the present invention to provide a rotary seal device that does not pose a problem even if such a co-rotation phenomenon occurs under high pressure / high speed rotation conditions.

[0006]

DISCLOSURE OF THE INVENTION The inventors of the present invention have made various studies on the use of a seal ring as a member that performs rotary motion or oscillating motion under high pressure conditions (hereinafter, simply referred to as rotary motion and rotary member). As a result, the durability is improved by making the radial dimension of the cross section of the seal ring larger than the axial dimension and improving the surface roughness of the side surface of the mounting groove. Depending on the usage conditions such as number, co-rotation is inevitable,
Further, the roughening of the surface of the side surface of the integral groove was difficult to process, and so a fundamental solution could not be reached.

As a result of further studies under such circumstances, it was found that the co-rotation phenomenon of the seal ring is unavoidable under high-pressure rotation conditions. I got the idea that it should be avoided.

That is, by providing a slip ring, preferably a slip ring made of an elastic material, which is harder than the seal ring, in the contact area between the side surface of the seal ring and the side surface of the mounting groove, which relatively rotate, It is replaced by a rotational movement relative to the slip ring.

At this time, the slip ring also rotates due to the friction with the seal ring, but the friction force between the slip ring and the side surface of the mounting groove becomes larger than the friction force between the slip ring and the seal ring. The combination of the seal ring with the slip ring and the side surface of the mounting groove regulates the rotation of the slip ring (including swinging, the same applies below), and the surface of the slip ring has better surface roughness than the side surface of the mounting groove. Therefore, it has been found that friction and wear between the seal ring and the slip ring are reduced, and sufficient durability can be obtained even in high-pressure / high-speed rotary motion.

Here, the gist of the present invention is that an annular mounting groove having a substantially rectangular cross section is provided on one of opposing surfaces of two cylindrical members that relatively rotate or swing. A seal device mounted on the seal ring, the seal ring having a substantially rectangular cross section made of a synthetic resin that abuts on a moving surface of a mating member, and a slip ring preferably made of an elastic material on an axial side surface of the seal ring on the pressure receiving side. The sealing device for rotation is characterized by being mounted in combination with and.

According to a preferred aspect of the present invention, the slip ring is made of a material harder than the material of the seal ring. According to still another preferred embodiment, an elastic imparting ring for axially pressing the seal ring is further provided between the pressure side surface or the pressure side slip ring and the mounting groove side surface of the seal ring. Good.

[0012]

As described above, in the present invention, the conventional co-rotation is considered to be inevitable, and the slip ring is further combined. By considering the materials of the seal ring, the slip ring, and the mounting groove, respectively. In particular, if the rotating contact surface is formed between the seal ring side surface and the slip ring side surface even under high pressure conditions, abnormal wear on the rotating contact surface can be effectively prevented.

Examples of the synthetic resin material for the seal ring used in the present invention include thermoplastic resins such as fluororesin, polyethylene resin, polyamide resin, polyacetal resin, polyphenene sulfide resin, phenol resin, polyimide resin and polyether ether ketone resin. Various synthetic resins such as thermosetting resins can be used, and these resins are filled with liquid or solid lubricant, synthetic resin fiber or powder, carbon fiber, metal powder, inorganic fiber or powder, Those with improved physical properties can be used.

The material of the slip ring includes the materials shown above as the material of the seal ring. Among them, the elastic material is particularly preferable, and a metal material softer than the material forming the mounting groove (eg, aluminum alloy) is also preferable. Can be used.

As described above, the combination of the materials forming the seal ring, the slip ring, and the mounting groove, whichever material is used, is determined by the hardness of the material of the slip ring. Is harder than the material of the seal ring and softer than the material forming the mounting groove, and more preferably, the frictional force between the seal ring and the slip ring is smaller than the frictional force between the slip ring and the mounting groove. It should be configured to.

The slip ring preferably has a substantially flat cross section, and the width dimension of the slip ring may be narrow if the pressure resistance of the material of the seal ring is sufficiently higher, but it is usually the width dimension in the radial direction of the seal ring. It is desirable that they are equivalent or higher.

A plurality of axial notches may be provided on the fixed peripheral surface on the bottom surface side of the mounting groove of the slip ring. Such a notch allows fluid pressure to be easily introduced into the mounting groove when pressure is applied from both directions of the sealing device, and ensures that fluid pressure acts on the fixed side peripheral surface of the seal ring. It is effective as a means for maintaining the hermeticity.

R-faces or C-faces may be provided at the corners of the substantially rectangular cross section of the seal ring, and the surface of the seal ring that contacts the slip ring may be a pressure receiving surface that is opposite to the contact peripheral surface that contacts the mating motion surface. A plurality of radial grooves or one or a plurality of annular grooves which have an open end and which do not communicate with the contact peripheral surface side;
It is possible to provide a contact surface pressure reducing means having an opening end on the pressure receiving surface and a pressure introducing groove for introducing a fluid pressure up to the annular groove.

By providing such contact surface pressure reducing means, the fluid pressure is introduced between the seal ring and the slip ring, so that the contact surface pressure of the seal ring with respect to the slip ring is reduced and a lubricating effect is obtained. Therefore, the durability is improved and the frictional force is reduced.

The adhesion of the seal ring to the side surface of the mounting groove depends on the fluid pressure introduced into the mounting groove. Therefore, when the fluid pressure is low, almost no force is generated to press the seal ring against the slip ring, and contact between the seal ring and the slip ring and between the slip ring and the groove side surface becomes unstable, which may cause leakage. is there.
In order to prevent such leakage, it is preferable to further combine an elasticity imparting ring that presses the seal ring against the pressure-side side surface of the seal ring on the pressure-side side surface. Such a configuration eliminates such leakage problems.

The elasticity imparting ring may be, for example, a washer ring shape made of metal, synthetic resin, or elastomer material formed in a wave shape in the radial direction, and may be used between the seal ring and the mounting groove or the slip ring. It is provided between the mounting grooves.

The combined use of such elasticity imparting ring is effective in not only pressing the seal ring but also smoothly introducing the fluid pressure into the mounting groove to improve the sealing performance.

[0023]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, embodiments will be described with reference to the drawings. FIG.
[Fig. 2] is a one-sided cross-sectional view of the rotary seal device according to the present invention, and Fig. 2 is a partial cross-sectional view of the same when it is mounted in a mounting groove.

As can be seen from FIG. 1, the rotary seal device 10 according to the present invention is preferably provided by combining a seal ring 11 made of a synthetic resin and having a substantially rectangular cross section, and the axial side surface on the pressure receiving side of the seal ring. Is composed of a slip ring 21 made of an elastic material. The seal ring 11 includes a movement side peripheral surface 12, a mounting groove side peripheral surface 15, a pressure side surface 13 and a pressure receiving side surface 14. The slip ring 21 is provided in contact with this side surface 14, and the inner diameter is a seal ring.
It is preferable to make it substantially the same as that of No. 11 and to make the outer diameter slightly larger. For example, a shaft diameter of 70 mm is about 0.3 mm.

As shown in FIG. 2, a rotary seal device 10 according to the present invention is a seal that is attached to a mounting groove 4 of a substantially rectangular cross section provided in a rotary shaft 1 and an outer peripheral housing 3 thereof and is in contact with a rod surface 2. A slip ring 21 is provided between a side surface 14 on the pressure receiving side opposite to the side surface 13 on the pressure side on which the pressure of the ring 11 acts and a side surface 6 on the pressure receiving side of the mounting groove 4.

By adopting such a configuration, the fluid pressure indicated by P in the figure is the pressure side surface 1 of the seal ring 11.
3 and the side surface 5 of the mounting groove enter the mounting groove, and the peripheral surface 15 corresponding to the outer peripheral surface of the seal ring 11 and the side surface 13 on the pressure side.
Of the seal ring 11, the peripheral surface 12 on the moving side of the seal ring 11 is brought into close contact with the rod surface 2, and the slip ring 21 is attached to the mounting groove 4.
It acts so as to press the side surface 6 on the pressure receiving side of.

At this time, the fluid pressure is the contact surface between the peripheral surface 12 on the moving side of the seal ring 11 and the surface 2 of the rotary shaft, and the seal ring.
Sealing is performed on the contact surface between the side surface 14 of the pressure receiving side 11 and the slip ring 21 and the contact surface between the slip ring 21 and the side surface 6 of the mounting groove.

Here, when a high pressure is applied to the sealing device 10, the seal ring 11 is in a so-called co-rotating state in which the seal ring 11 rotates together with the rod 1. At that time, the seal ring 11 is rotated.
Since there is relative motion between the side 14 on the pressure receiving side and the slip ring 21, there is almost no wear, and the seal ring 11
Also, the frictional resistance of the slip ring 21 is smaller than the direct frictional resistance between the side surface 14 of the seal ring 11 and the mounting groove side surface 6.

FIG. 3 shows an example of the rotary sealing device 40 according to the present invention when it is attached to the piston portion and fluid pressure is applied alternately from both sides in the axial direction, and FIG. Indicate the case. In this example, the slip rings 51, 51
Is provided on each of the pressure side and the pressure receiving side.

As can be seen from FIGS. 3 and 4, both axial side surfaces 43 and 44 of the seal ring 41 and side surfaces 65 and 66 on the mounting groove side.
It is a figure which shows the state which provided the slip rings 51 and 51 between them. In the illustrated example, such a sealing device is used as the pressure supply passage 69.
It is provided in the lower two steps across. Reference numeral 68 indicates a port of the rotor section.

FIG. 5 shows a side surface 13 of the seal ring 11 on the pressure side.
In one side cross-sectional view showing a state in which the elasticity imparting ring 31 is provided,
FIG. 6 is a cross-sectional view showing a state in which this is mounted in the mounting groove, and the seal ring 11 is brought into close contact with the slip ring 21 by the elasticity imparting ring 31, and further the slip ring 21 is brought into close contact with the side surface 6 of the mounting groove 4. It is possible to ensure the sealing performance under pressure or low pressure. Reference numerals 8 and 9 represent a drain port and an oil seal housing, respectively.

As the elasticity imparting ring 31, a spring washer-shaped member made of synthetic resin, metal or the like and corrugated in the circumferential direction is used. When it is made of a synthetic resin material, it is attached so as to be in direct contact with the seal ring, but when it is made of a metal material, it is preferable to sandwich a slip ring or a flat washer-like spacer ring between them.

Next, in order to evaluate the sealing characteristics of each sealing device as described above, a performance test was conducted under the conditions shown in Tables 1 and 2, and the sealing characteristics were evaluated by the leakage of hydraulic oil at that time. evaluated.

FIG. 10 is an explanatory view showing the outline of the test apparatus. A seal device 101 is installed on a shaft 100, and a predetermined pressure is applied to a pressure chamber 102 from a pressure port in the central portion, and the seal device 101 is placed outside the seal device at that time. The amount of hydraulic oil that leaks to the outside through the provided recovery passage 104 is received by the tray 106, and the amount is measured.

As shown in the results in FIG. 9, in the conventional seal ring device (see FIG. 7), wear of the seal ring progresses in about 36 hours, and damage is also seen and damage is not observed. On the other hand, the sealing device according to the present invention (see FIG. 1, FIG. 5 and Table 2) is
Even at the time of durability 168 hours, it was about 1 cc or less per minute, and neither the seal ring nor the slip ring had abnormal wear.

As described above, the sealing device for rotation according to the present invention may cause a small amount of leakage, but when it is used for a rod portion where slight leakage is disliked, the sealing device of the present invention is used. By combining an oil seal 9 and the like on the outer side as shown in FIG. 6 and providing a drain circuit 8 between them, it can be used as a sealing device for a rod portion of a hydraulic motor or the like.

[0037]

[Table 1]

[0038]

[Table 2]

[0039]

As described above, the sealing device according to the present invention has a simple structure in which a slip ring made of an elastic material such as synthetic resin is combined between the seal ring and the side surface of the mounting groove. As a sealing device for high-pressure rotating parts, it has excellent durability and sealing performance.
Moreover, it is easy to handle and low cost, and it is also economical.

[Brief description of drawings]

FIG. 1 is a side cross-sectional view of a rotary sealing device according to the present invention.

FIG. 2 is a one-sided cross section showing a state in which the sealing device of FIG. 1 is attached to a mounting groove of a rod portion.

FIG. 3 is a one-sided sectional view showing an example in which the rotary sealing device according to the present invention is used for both pressures in which fluid pressure is alternately applied from both sides in the groove direction.

FIG. 4 is a one-sided cross-section showing a state in which the sealing device of FIG. 3 is attached to a piston portion.

FIG. 5 is a one-sided cross-sectional view showing an example in which a wave spring-like elasticity imparting ring is also used.

6 is a schematic cross-sectional view showing a state in which the sealing device of FIG. 5 is attached to a rod portion.

FIG. 7 is a one-sided cross section of a conventional sealing device used with a single seal ring.

8 is a schematic cross-sectional view showing a state in which the sealing device of FIG. 7 is attached to a rod portion.

FIG. 9 is a graph showing the performance of a seal device using the seal device of the present invention and a conventional seal ring alone.

FIG. 10 is a schematic explanatory diagram of a leak test device for a sealing device used in an example.

[Explanation of symbols]

1: Rod 3: Rod housing
4: Mounting groove 5: Pressure side groove side surface 6: Pressure receiving side groove side surface
7: Bottom of groove 10: Sealing device for rotation 11: Seal ring 1
2: Movement side peripheral surface 13: Pressure side side surface 14: Pressure receiving side surface 1
5: Fixed side peripheral surface 21: Slip ring 31: Elasticity imparting ring 4
1: Seal ring 51: Slip ring 61: Rotor 6
2: Body 71: Seal ring

Claims (3)

[Claims] 1. A sealing device which is mounted in an annular mounting groove having a substantially rectangular cross section, which is provided on one of opposing surfaces of two cylindrical members which relatively rotate or swing. A rotary seal device comprising a seal ring made of a synthetic resin and having a substantially rectangular cross section, which comes into contact with a moving surface of a mating member, and a slip ring, which is mounted on the axial side surface on the pressure receiving side of the seal ring in combination. 2. The rotary seal device according to claim 1, wherein the slip ring is made of a material harder than the material of the seal ring. 3. An elasticity imparting ring for pressing the seal ring in the axial direction is further provided in combination between the pressure side surface of the seal ring or between the pressure side slip ring and the mounting groove side surface. The sealing device for rotation according to 2.