JP5088075B2 - Seal ring - Google Patents

Description

  The present invention relates to a seal ring.

  In various types of hydraulic equipment, resin seal rings are frequently used to maintain hydraulic pressure. Such a seal ring is generally provided with a separating portion at one place in the circumferential direction so that it can be easily mounted in an annular groove provided on a shaft.

  Further, the seal ring is generally required to have improved wear resistance. Therefore, in recent years, a highly elastic material such as polyether ether ketone (PEEK) has been used as a material for the seal ring in order to improve the wear resistance.

  However, although a seal ring made of a highly elastic material is excellent in wear resistance, it has a drawback that it has a strong restoring force and part of the seal ring is easily damaged when the seal ring is mounted. This point will be described with reference to FIGS.

  FIG. 12 is a part of a schematic cross-sectional view showing a state of a seal ring mounting operation. FIG. 13 is a schematic plan view showing how the shape of the seal ring is restored.

  The seal ring 100 shown in this figure is mounted in an annular groove 201 provided on the shaft 200. When the seal ring 100 is mounted, a jig 400 is used. This jig 400 has a cylindrical surface 401 having a diameter smaller than the inner diameter of the seal ring 100 on the front end side, a cylindrical surface 402 having a diameter larger than the outer diameter of the shaft 200 on the rear end side, and a front end side in the center. A taper surface 403 that expands from the rear end side toward the rear end side. Further, a fitting hole 404 that fits at the tip of the shaft 200 is provided at the rear end of the jig 400.

  When the seal ring 100 is mounted, the tip of the shaft 200 is fitted into the fitting hole 404 provided in the jig 400 as shown in FIG. Then, the seal ring 100 is fitted from the front end side of the jig 400, and the seal ring 100 is slid toward the rear end side. In the seal ring 100, in the process of sliding the tapered surface 403 of the jig 400 (see arrow A), the distance between the tips of the separation portion gradually increases. Then, in the process in which the seal ring 100 passes through the jig 400 and is attached to the annular groove 201 provided in the shaft 200 (see the arrow B to the arrow C), the seal ring 100 is restored to the original shape. That is, the tips at the separation part come into contact again.

  FIG. 13 shows a state when the seal ring 100 is restored and returned to its original shape. As shown in the figure, the separating portion 101 of the seal ring 100 has a predetermined gap when sliding near the rear end of the jig 400. Then, the seal ring 100 is restored to the original shape in the process of passing through the jig 400 and being attached to the annular groove 201. That is, the tip of the separation unit 101 is deformed so as to move in the arrow R direction.

  Here, as described above, when a highly elastic material such as PEEK is used as the material of the seal ring 100, the restoring force of the seal ring 100 is increased. Therefore, when the seal ring 100 is restored to the original shape, the leading ends of the separation unit 101 collide violently. Thereby, a part of tip may be damaged.

As described above, when a highly elastic material such as PEEK is used as a material for the seal ring, although it has excellent wear resistance, the restoring force is strong, and part of the seal ring is damaged in the work of installing the seal ring. There is a drawback that it is easy to do.

In addition, there exists a thing disclosed by patent document 1, 2 as a related technique.
Japanese Patent No. 3576642 JP 2004-353760 A

  An object of the present invention is to provide a seal ring that is not easily damaged during the mounting operation even when a highly elastic material having excellent wear resistance is used as the material of the seal ring.

  The present invention employs the following means in order to solve the above problems.

That is, the seal ring of the present invention is
These two members are attached to an annular groove provided in one of the two members that are assembled so as to be relatively movable, and are in contact with the side wall surface of the annular groove and the peripheral surface of the other member, respectively. In the seal ring which seals the annular gap between them and is provided with a separation part separated at one place in the circumferential direction,
An axially thin portion with a small axial thickness is provided over the entire circumference so as not to contact the side wall surface of the annular groove,
A radially thin portion having a small radial thickness is configured such that a portion of the axial thin portion is configured to have a partially thin radial thickness at a position symmetrical to the separation portion with respect to the axial center. Is provided.

  According to the seal ring of the present invention, since the axially thin portion that does not contact the side wall surface of the annular groove is provided over the entire circumference, the sliding resistance between the seal ring and the side wall surface of the annular groove can be reduced. it can. And since the radial direction thin part is provided in the position symmetrical to the separation part with respect to the axial center, the restoring force when restoring the original shape from the state where the tips of the separation part are separated is reduced. Can do. Thereby, when the seal ring is mounted in the annular groove, the collision force between the tips of the separation portion can be reduced. Therefore, even when a highly elastic material having excellent wear resistance is used as the material for the seal ring, it is possible to suppress damage during the mounting operation. However, the material of the seal ring of the present invention is not limited to a highly elastic material. In addition, since the radial thin portion is configured such that a part of the axial thin portion has a small radial thickness, the sealing performance is not affected.

  In addition, the radial thickness of the thin portion in the axial direction is reduced at a position different from the position symmetrical to the separation portion with respect to the axial center. A plurality of directional thin portions may be provided.

  Thereby, the restoring force can be further reduced.

  Further, the axially thin portion may be provided with a plurality of through holes penetrating in the axial direction.

  Thereby, the restoring force can be further reduced.

As described above, according to the present invention, even when a highly elastic material having excellent wear resistance is used as the material of the seal ring, it is possible to suppress damage during the mounting operation.

  The best mode for carrying out the present invention will be exemplarily described in detail below with reference to the drawings. However, the dimensions, materials, shapes, relative arrangements, and the like of the components described in this embodiment are not intended to limit the scope of the present invention only to those unless otherwise specified. .

Example 1
With reference to FIGS. 1-5, the seal ring which concerns on Example 1 of this invention is demonstrated. 1 is a partially broken side view of a seal ring according to Embodiment 1 of the present invention. FIG. 2 is a plan view of the seal ring according to the first embodiment of the present invention. FIG. 3 is a schematic cross-sectional view showing a mounting state of the seal ring according to the first embodiment of the present invention. FIG. 4 is a positional relationship diagram showing the positional relationship between the seal ring and the annular groove according to the first embodiment of the present invention. FIG. 5 is a positional relationship diagram showing the positional relationship between the seal ring and the annular groove according to the virtual technology.

<Seal ring>
In particular, the configuration of the seal ring according to the first embodiment of the present invention will be described with reference to FIGS. 1 and 2. The seal ring 10 according to the present embodiment uses a highly elastic material such as PEEK having excellent wear resistance as a material (material).

  The seal ring 10 according to the present embodiment is provided with a separation portion 11 separated at one place in the circumferential direction. In the present embodiment, the separation portion 11 is configured by a so-called special step cut (the outer peripheral surface side and both side surfaces are cut in a step shape). Since this special step cut is a known technique, detailed description thereof will be omitted. However, when the special step cut is adopted for the separating portion, the sealing performance does not change even if the seal ring expands or contracts due to heat. It has the characteristic.

  And the seal ring 10 which concerns on a present Example is provided with the axial direction thin part 14 with thin thickness of an axial direction over the perimeter at the inner peripheral side. Further, in the seal ring 10 according to the present embodiment, the radial thickness of a part of the axially thin portion 14 is configured to be thin at a position symmetrical to the separation portion 11 with respect to the axis. A radially thin portion 15 having a small thickness in the direction is provided.

<Use condition of seal ring>
In particular, a state in which the seal ring 10 according to the first embodiment of the present invention is used will be described with reference to FIG. The seal ring 10 according to the present embodiment is mounted in an annular groove 21 provided on the shaft 20 of two members (the shaft 20 and the housing 30) that are assembled to be relatively rotatable.

  Then, a part of the side surface 13 in the axially thick portion on the outer peripheral side of the seal ring 10 is slidably in contact with the side wall surface 21a of the annular groove 21 over the entire circumference. Further, the entire outer peripheral surface 12 of the seal ring 10 is slidably in contact with the housing 30 (the inner peripheral surface of the shaft hole). Thereby, the annular gap between the shaft 20 and the housing 30 is sealed by the seal ring 10. A gap is formed between the inner peripheral surface 16 of the seal ring 10 and the groove bottom surface 21 b of the annular groove 21.

In the example shown in FIG. 3, the left side is the high pressure side (H), and the right side is the low pressure side (L). Note that the high pressure side (H) is a region where the oil to be sealed is sealed, and the low pressure side (L) is exposed to the atmosphere, or the oil is both on the high pressure side (H) and the low pressure side (L). There may be a sealed area.

  The method of attaching the seal ring 10 to the annular groove 21 can be performed using a jig as described in the background art. The mounting method is not limited to the method described in the background art, but in any case, in the mounting operation, the seal ring 10 is deformed so as to separate the tips of the separating portion 11 (see FIG. 2 (deformation in the direction of arrow P in FIG. 2), followed by an operation to restore the original shape (operation of deformation in the direction of arrow Q in FIG. 2).

<Excellent points of this embodiment>
According to the seal ring 10 according to the present embodiment, a highly elastic material such as PEEK having excellent wear resistance is used as the material (material). Therefore, deterioration due to wear can be suppressed, and durability can be enhanced. And since the axial thin part 14 which does not contact | abut to the side wall surface 21a of the annular groove 21 is provided over a perimeter, the sliding resistance between the seal ring 10 and the side wall surface 21a of the annular groove 21 can be reduced. . Thereby, deterioration by wear can be suppressed synergistically.

  Further, the seal ring 10 according to the present embodiment is provided with a radially thin portion 15 at a position symmetrical to the separation portion 11 with respect to the axial center. For this reason, when the seal ring 10 is deformed so as to separate the distal ends of the separating portion 11, the rigidity of the portion where the elastic repulsion force is greatest (the portion that is symmetrical with the separating portion 11 with respect to the axis) is reduced. Can be made. Thereby, the restoring force at the time of decompress | restoring to the original shape from the state which isolate | separated the front-end | tips in the isolation | separation part 11 can be reduced. Therefore, when the seal ring 10 is attached to the annular groove 21, the collision force between the tips of the separating portion 11 can be reduced.

  Further, since the radial thin portion 15 is configured such that a portion of the axial thin portion 14 that is not a portion to be sealed has a small radial thickness, the sealing performance is not affected. In addition, when the pressure on the high pressure side (H) increases due to the reduction of the restoring force, the seal ring 10 is easily deformed so as to expand its diameter, and an effect that the sealing performance on the outer peripheral surface side can be improved. Demonstrate.

  Here, from the viewpoint of reducing the restoring force, it can be considered that the thickness in the radial direction of the entire thin axial portion 14 that does not affect the sealing performance may be reduced. However, when such a configuration is adopted, it is not desirable from the viewpoint of wearability. This point will be described with reference to FIGS.

  FIG. 4 shows the positional relationship between the outer peripheral surface 12 and the inner peripheral surface 16 of the seal ring 10 according to the present embodiment, and the outer peripheral surface of the shaft 20 and the groove bottom surface 21 b of the annular groove 21. In this figure, the position of the outer peripheral surface of the shaft 20 and the position of the groove bottom surface 21b of the annular groove 21 are indicated by dotted lines for convenience.

  In the case of the seal ring 10 according to the present embodiment, only the radial thin portion 15 is partially thin in the radial direction, and the other portions are thick. Therefore, as shown in FIG. 4, in the other portion, the gap between the inner peripheral surface 16 of the seal ring 10 and the groove bottom surface 21 b of the annular groove 21 is narrow. Therefore, it is possible to suppress the positional deviation between the shaft center of the shaft 20 and the shaft center (center) of the seal ring 10, and the outer peripheral surface 12 of the seal ring 10 protrudes greatly from the outer peripheral surface of the shaft 20. Can be prevented.

From the above, in the case of the seal ring 10 according to the present embodiment, the arrangement position when mounted in the annular groove 21 is stable, and the outer peripheral surface 12 of the seal ring 10 is relative to the outer peripheral surface of the shaft 20. Never jump out. Therefore, when the shaft 20 is inserted into the shaft hole provided in the housing 30 with the seal ring 10 mounted in the annular groove 21, the side surface of the seal ring 10 is located near the edge of the shaft hole opening of the housing 30. A problem such as hitting can be suppressed.

  On the other hand, FIG. 5 shows a virtual technique in the case where the radial thickness is reduced on the entire circumference of the thin axial portion in the seal ring. FIG. 5 shows the positional relationship between the outer peripheral surface 12X and the inner peripheral surface 16X in the seal ring according to the virtual technology, and the outer peripheral surface of the shaft 20 and the groove bottom surface 21b of the annular groove 21. In this figure, the position of the outer peripheral surface of the shaft 20 and the position of the groove bottom surface 21b of the annular groove 21 are indicated by dotted lines for convenience.

  In the case of the seal ring according to this virtual technology, the radial thickness is reduced over the entire circumference. Therefore, the clearance S between the inner peripheral surface 16X of the seal ring and the groove bottom surface 21b of the annular groove 21 is wide as shown in the figure. Therefore, the shaft center of the shaft 20 and the shaft center (center) of the seal ring are greatly displaced.

  In the figure, the thick dotted line indicates the position of the outer peripheral surface 12Y of the seal ring when the position of the seal ring is most greatly displaced (see arrow T). Thus, in the case of the seal ring according to the virtual technology, the outer peripheral surface 12X (12Y) of the seal ring greatly protrudes from the outer peripheral surface of the shaft 20.

  Therefore, in the case of the seal ring according to the virtual technology, in the operation of inserting the shaft 20 into the shaft hole provided in the housing 30 with the seal ring mounted in the annular groove 21, the side surface of the seal ring is the side of the housing 30. Problems that hit the vicinity of the edge of the opening of the shaft hole are likely to occur. In this case, a part of the seal ring may be damaged.

  As described above, it is not desirable to adopt a configuration in which the thickness in the radial direction is thin for the entire thin axial portion 14 that does not affect the sealing performance from the viewpoint of mounting properties.

  Further, the separation part 11 in the seal ring 10 has a complicated shape compared to other parts, and it is difficult to reduce the radial thickness of the separation part 11 from the viewpoint of molding. . Along with this, by reducing the thickness of the entire seal ring 10 and reducing the depth of the annular groove 21, the outer peripheral surface of the seal ring greatly protrudes from the outer peripheral surface of the shaft 20. It is difficult to take measures to prevent it.

(Example 2)
6 and 7 show the second embodiment of the present invention. In the first embodiment, the configuration in the case where the radially thin portion is provided only at a position that is symmetrical to the separation portion with respect to the axial center has been described. However, in this embodiment, the diameter may be different from the position. The structure in the case of providing a direction thin part is demonstrated.

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

  FIG. 6 is a partially broken side view of a seal ring according to Embodiment 2 of the present invention. FIG. 7 is a plan view of a seal ring according to Embodiment 2 of the present invention.

  In the case of the seal ring 10a according to the present embodiment, four radial thin portions 17 are provided in addition to the radial thin portions 15 provided at positions symmetrical to the separation portion 11 with respect to the axis. Yes. These four radial thin portions 17 are also provided in the axial thin portion 14 that does not affect the sealing performance.

  According to the seal ring 10a according to the present embodiment, the restoring force can be further reduced by the amount of the radially thin portions that is greater than that of the seal ring 10 according to the first embodiment. Therefore, when the seal ring 10a is attached to the annular groove 21, the collision force between the tips of the separating portion 11 can be further reduced.

  Also in the case of the present embodiment, since the thick portions in the radial direction are provided at predetermined intervals in the circumferential direction, the shaft center of the shaft 20 and the shaft center (center) of the seal ring 10a are provided. Misalignment can be suppressed, and the outer peripheral surface 12 of the seal ring 10a can be prevented from greatly protruding from the outer peripheral surface of the shaft 20.

(Example 3)
8 and 9 show a third embodiment of the present invention. In the present embodiment, the configuration in the case where the number of radially thin portions is further increased than in the case of the second embodiment will be described.

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

  FIG. 8 is a partially broken side view of a seal ring according to Embodiment 3 of the present invention. FIG. 9 is a plan view of a seal ring according to Embodiment 3 of the present invention.

  In the case of the seal ring 10b according to the present embodiment, in addition to the radial thin portions 15 provided at positions symmetrical to the separation portion 11 with respect to the axial center, a large number (12 pieces) of the radial thin portions 17 are provided. Is provided. These radial thin portions 17 are also provided in the axial thin portion 14 which does not affect the sealing performance. In this embodiment, thin portions and thick portions are alternately provided with substantially the same width.

  According to the seal ring 10b according to the present embodiment, the restoring force can be further reduced by the amount of the radially thin portions that is greater than that of the seal rings according to the first and second embodiments. Therefore, when the seal ring 10b is mounted in the annular groove 21, the collision force between the tips of the separating portion 11 can be further reduced.

  Even in the case of the present embodiment, since the thick portions in the radial direction are provided at predetermined intervals in the circumferential direction, the axis center of the shaft 20 and the axis center (center) of the seal ring 10b are provided. Misalignment can be suppressed, and the outer peripheral surface 12 of the seal ring 10b can be prevented from greatly protruding from the outer peripheral surface of the shaft 20.

Example 4
10 and 11 show Embodiment 4 of the present invention. In the present embodiment, a configuration in the case where a plurality of through holes penetrating in the axial direction is provided in the thin axial portion will be described.

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

  FIG. 10 is a partially broken side view of a seal ring according to Embodiment 4 of the present invention. FIG. 11 is a plan view of a seal ring according to Embodiment 4 of the present invention.

  In the case of the seal ring 10c according to the present embodiment, a plurality of through holes 18 are provided in the thin axial portion 14 that does not affect the sealing performance.

  According to the seal ring 10 c according to the present embodiment, the rigidity of the axial thin portion 14 can be reduced by providing the plurality of through holes 18 in the axial thin portion 14. Thereby, compared with the case of Example 1, a restoring force can be reduced further. Therefore, when the seal ring 10c is mounted in the annular groove 21, the collision force between the tips of the separating portion 11 can be further reduced.

1 is a partially broken side view of a seal ring according to Embodiment 1 of the present invention. FIG. 2 is a plan view of the seal ring according to the first embodiment of the present invention. FIG. 3 is a schematic cross-sectional view showing a mounting state of the seal ring according to the first embodiment of the present invention. FIG. 4 is a positional relationship diagram showing the positional relationship between the seal ring and the annular groove according to the first embodiment of the present invention. FIG. 5 is a positional relationship diagram showing the positional relationship between the seal ring and the annular groove according to the virtual technology. FIG. 6 is a partially broken side view of a seal ring according to Embodiment 2 of the present invention. FIG. 7 is a plan view of a seal ring according to Embodiment 2 of the present invention. FIG. 8 is a partially broken side view of a seal ring according to Embodiment 3 of the present invention. FIG. 9 is a plan view of a seal ring according to Embodiment 3 of the present invention. FIG. 10 is a partially broken side view of a seal ring according to Embodiment 4 of the present invention. FIG. 11 is a plan view of a seal ring according to Embodiment 4 of the present invention. FIG. 12 is a part of a schematic cross-sectional view showing a state of a seal ring mounting operation. FIG. 13 is a schematic plan view showing how the shape of the seal ring is restored.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10, 10a, 10b, 10c Seal ring 11 Separation part 12 Outer peripheral surface 13 Side surface 14 Axial thin part 15 Radial thin part 16 Inner peripheral surface 17 Radial thin part 18 Through-hole 20 Axis 21 Annular groove 21a Side wall surface 21b Groove bottom face 30 Housing

Claims (3)

These two members are attached to an annular groove provided in one of the two members that are assembled so as to be relatively movable, and are in contact with the side wall surface of the annular groove and the peripheral surface of the other member, respectively. In the seal ring which seals the annular gap between them and is provided with a separation part separated at one place in the circumferential direction,
An axially thin portion with a small axial thickness is provided over the entire circumference so as not to contact the side wall surface of the annular groove,
A radially thin portion having a small radial thickness is configured such that a portion of the axial thin portion is configured to have a partially thin radial thickness at a position symmetrical to the separation portion with respect to the axial center. A seal ring is provided. These two members are attached to an annular groove provided in one of the two members that are assembled so as to be relatively movable, and are in contact with the side wall surface of the annular groove and the peripheral surface of the other member, respectively. In the seal ring which seals the annular gap between them and is provided with a separation part separated at one place in the circumferential direction,
An axially thin portion with a small axial thickness is provided over the entire circumference so as not to contact the side wall surface of the annular groove,
A radially thin portion with a small radial thickness is provided at a position symmetrical to the separation portion with respect to the axial center by forming a thin radial portion of the axial thin portion. And
The axially thin wall portion is provided with a plurality of through holes penetrating in the axial direction . A radial thin wall having a small radial thickness is formed by forming a thin radial thickness at a part of the axial thin wall portion at a position different from the position symmetrical to the separation portion with respect to the axial center. seal ring according to claim 1 or 2 parts is characterized in that provided in plural.

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