JP2012047260A - Plane seal structure - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a long life plane seal structure stably exhibiting superior sealing performance.SOLUTION: In the plane seal structure for hermetically sealing between the first plane part 1 and the second plane part 2 carrying out relative planar movement, the annular seal groove 3 is recessedly arranged in the second plane part 2. The elastic rubber seal 4 is installed in the seal groove 3 and the low friction material 5 with a crosssectional L shape arranged along the back pressure side face and the groove opening of the low pressure side of the seal groove 3 is installed in the seal groove 3 in the covering shape of the elastic rubber seal 4.

Description

  The present invention relates to a planar seal structure.

  Conventionally, in order to prevent fluid from leaking from the clearance between the shaft hole and the rotation shaft, or the clearance between the cylinder and the piston, an annular seal groove has been provided in the rotation shaft or piston, and an elastic rubber seal has been provided in the annular seal groove. However, in order to reduce sliding frictional resistance and improve sealing performance, there is a rubber seal provided with a resin ring having a single letter cross section on the outer peripheral side (see, for example, Patent Document 1).

  However, as shown in FIG. 19, an annular seal groove 32 and an elastic rubber seal are provided at the place where the two planes 30 and 31 are in relative plane motion (the two planes 30 and 31 are relatively in motion) as in the above-described seal structure. (O-ring) 33, when the low-friction material 34 having a single cross section is provided, there is no problem if the low-friction material 34 is always disposed directly above the O-ring 33 as shown in FIG. If the two planes 30 and 31 move relative to each other immediately after mounting the seal in the seal groove 32 due to the dimensional accuracy (tolerance) of the seal groove 32, rubber seal 33 and low friction material 34, The low friction material 34 tilts toward the inner diameter side as shown in FIG. 21 or tilts toward the outer diameter side as shown in FIG. And the rubber seal 33 and the low friction material 34 have the disadvantage of causing excessive wear locally, the life is not stable, For Kunar, 19, as shown in FIG. 20 was difficult to apply to flat seal.

Japanese Patent Laid-Open No. 11-248003

  The problem to be solved is that the sealing surface pressure becomes unstable when sealing between two planes that perform relative plane motion. In addition, the sliding torque varies. And it is a point which produces local abrasion in a constituent material and the life becomes unstable and becomes short.

Therefore, the planar seal structure according to the present invention is a planar seal structure that seals between the first planar portion and the second planar portion that perform relative planar motion, and an annular seal groove is provided in the second planar portion. An elastic rubber seal is embedded in the seal groove, and a low friction material having an L-shaped cross section disposed along the back pressure side surface and the groove opening on the low pressure side of the seal groove is covered with the elastic rubber seal as a cover. It is built in the groove.
Further, in the planar seal structure that seals between the first planar portion and the second planar portion that perform relative planar motion, an annular seal groove is provided in the second planar portion, and an elastic rubber seal is provided in the seal groove. In addition, a low friction material having a U-shaped cross section disposed along the groove bottom surface of the seal groove, the back pressure side surface on the low pressure side, and the groove opening portion is enclosed in an elastic rubber seal and is embedded in the seal groove. is there.

Further, the back pressure side surface is the inner diameter side surface of the seal groove and is used for external pressure.
The back pressure side surface is the outer diameter side surface of the seal groove and is used for internal pressure.

  According to the flat seal structure of the present invention, the posture of the low friction material in the seal groove is stable, the local friction of the low friction material and the rubber seal is prevented, the sliding torque is stabilized, the sealing performance is improved, and the long Life can be extended.

It is a section front view showing a 1st embodiment of the present invention. It is an expanded sectional view which shows a seal groove. It is a principal part expanded sectional front view of FIG. It is a cross-sectional enlarged view which shows the free state of an elastic rubber seal. It is a cross-sectional enlarged view showing a state where an elastic rubber seal is externally fitted to a low friction material. It is a principal part expanded sectional front view which shows 2nd Embodiment. It is a cross-sectional enlarged view showing a state where an elastic rubber seal is externally fitted to a low friction material. It is a section front view showing a 3rd embodiment. It is an expanded sectional view which shows a seal groove. It is a principal part expanded sectional front view of FIG. It is an expanded sectional view which shows the state which made the low-friction material fit the elastic rubber seal. It is a principal part expanded sectional front view which shows 4th Embodiment. It is an expanded sectional view which shows the state which made the low-friction material fit the elastic rubber seal. It is a section front view showing a 5th embodiment. It is a section front view showing a 6th embodiment. It is a principal part sectional end view which shows 7th Embodiment. It is a principal part sectional end view which shows 8th Embodiment. It is a principal part sectional end view which shows 9th Embodiment. It is a sectional front view showing a conventional example. It is a principal part expanded sectional view of a prior art example. It is a principal part expanded sectional view of a prior art example. It is a principal part expanded sectional view of a prior art example.

  FIG. 1 shows a first embodiment of the present invention. This flat seal structure is used, for example, for a rotating disk portion of a machine tool. That is, the present invention relates to a planar seal structure that seals between the first planar portion 1 and the second planar portion 2 that perform relative planar motion. A case where the rotating disk Y rotates (or swings) around the axis L with respect to the base X will be exemplified. That is, the case where the lower surface of the rotating disk Y is the first flat surface portion 1 and the upper surface of the base X is the second flat surface portion 2 is illustrated. The flat seal (structure) is also called a face seal (structure) or an end face seal (structure).

  The back pressure side surface 3A (see FIG. 2) is the inner diameter side surface of the seal groove 3, and is used for external pressure (that is, when the inner diameter side is lower than the seal groove 3 and the outer diameter side is high pressure). The flat seal structure of the present invention is used at a location where the pressure is low to about 3 MPa.

  As shown in FIGS. 1 to 3, an annular seal groove 3 is formed in the second flat surface portion 2. An elastic rubber seal 4 is housed in the seal groove 3, and a low friction material 5 having an L-shaped cross section disposed along the low pressure side back pressure side surface 3 </ b> A and the groove opening 3 </ b> B of the seal groove 3 is a seal groove. The elastic rubber seal 4 within the cover 3 is covered with the seal groove 3. The elastic rubber seal 4 is made of, for example, fluorine rubber or nitrile rubber. The low friction material 5 is made of PTFE, for example.

The elastic rubber seal 4 and the low friction material 5 are configured to be in pressure contact with the mating surface on the inner diameter side. Specifically, the inner diameter D ₄ of the elastic rubber seal 4 in a free state shown in FIG. ₄ and the inner diameter D ₃ of the elastic rubber seal 4 in a state where the elastic rubber seal 4 is externally fitted to the low friction material 5 as shown in FIG. Is set to D ₄ <D ₃ . Further, the elastic rubber seal 4 and the inner diameter D ₂ of the low friction material 5 in fitted state of the low friction material 5, the sealing groove 3 inside diameter of the sealing groove 3 (i.e. the resilient rubber seal 4 a low friction material 5 shown in FIG. 3 the inside diameter) _{D 1} of low friction material 5 in a state of being furnished _to, set to _D 2 <D _1.

When the inner diameter D ₁ , the inner diameter D ₂ , the inner diameter D ₃ , and the inner diameter D ₄ are in the above ranges, the elastic rubber seal 4 and the low friction material 5 are in close contact with each other and do not slide between them. The friction material 5 and the first plane portion 1 (of the base X) slide in close contact with each other. Therefore, when the rotating disk Y rotates, the low friction material 5 does not rotate together, and it is possible to prevent the elastic rubber seal 4 and the low friction material 5 from being excessively worn locally. When the inner diameter D ₁ , the inner diameter D ₂ , the inner diameter D ₃ , and the inner diameter D ₄ are outside the above ranges, sliding between the elastic rubber seal 4 and the low friction material 5 or between the low friction material 5 and the base X is possible. The elastic rubber seal 4 or the low friction material 5 may move locally and excessively wear.

In the first embodiment shown in FIGS. 1 to 5, the length dimension W _{5 of} the portion corresponding to the back pressure side surface 3 </ b> A of the seal groove 3 of the low friction material 5 (back pressure side surface corresponding portion 5 a) and The diameter dimension W ₄ of the elastic rubber seal 5 in the free state is set to W ₄ × 0.5 <W ₅ . When the length dimension W ₅ and the diameter dimension W ₄ are within the above ranges, the low friction material 5 can be reliably prevented from being tilted, the seal surface pressure and the sliding torque are stabilized, and the life of the flat seal is increased. Can be long. If the length W ₅ and diameter dimension W ₄ is outside the above range, the sealing surface pressure to tilt the low-friction material 5, variation sliding torque, there is a possibility that the life is shortened.

The crushing allowance of the elastic rubber seal 4 is set to 5% to 30%. That is, the distance W ₇ between the lower surface of the opening corresponding portion 5b of the low friction material 5 in use and the groove bottom surface 3C and the diameter W ₄ of the elastic rubber seal 4 in the free state are expressed as W ₄ × 0.7. ≦ W ₇ ≦ W ₄ × 0.95 is set. When the distance W ₇ is in the above range, the elastic rubber sealing material 4 can press the first flat portion 1 with an appropriate elastic force to obtain an appropriate sealing property. When W ₇ <W ₄ × 0.7, the elastic rubber seal 4 may be damaged. In the case of W ₄ × 0.95 <W ₇ , the elastic force of the elastic rubber seal 4 is small, and the sealing performance may be insufficient.

  6 and 7 show a second embodiment. A low friction material 5 having a U-shaped cross section disposed along the groove bottom surface 3C of the seal groove 3, the back pressure side surface 3A on the low pressure side, and the groove opening 3B is covered with the elastic rubber seal 4 (enclosed). The seal groove 3 is internally provided.

The crushing allowance of the elastic rubber seal 4 is set to 5% to 30%. That is, the distance between the portion corresponding to the groove opening 3B (opening corresponding portion 5b) in the low friction material 5 and the portion corresponding to the groove bottom surface 3C in the low friction material 5 (that is, the elastic rubber seal 4 is used as the low friction material). and height) W ₆ of the elastic rubber seal 4 in a state of being fitted to 5, diameter W ₄ in the elastic rubber sealing material 4 in the free state _(refer to FIG. _{4), W 4 × 0.7 ≦} W 6 ≤W ₄ × 0.95 is set. When the distance W ₆ is in the above range, the elastic rubber sealing material 4 can press the first flat portion 1 with an appropriate elastic force to obtain an appropriate sealing property. If W ₆ <W ₄ × 0.7, the elastic rubber seal 4 or the low friction material 5 may be damaged. In the case of W ₄ × 0.95 <W ₆ , the elastic force of the elastic rubber seal 4 is small, and the sealing performance may be insufficient. Other configurations are the same as those of the first embodiment.

8 to 11 show a third embodiment. The back pressure side surface 3A is the outer diameter side surface of the seal groove 3, and is used for internal pressure (that is, when the inner diameter side is higher than the seal groove 3 and the outer diameter side is lower pressure). The elastic rubber seal 4 and the low friction material 5 are configured to be pressed against the outer diameter side. Specifically, the outer diameter D ₈ in the free state of the elastic rubber seal 4 shown in FIG. 4 and the outer diameter D ₇ of the elastic rubber seal 4 in a state in which the elastic rubber seal 4 shown in FIG. Is set to D ₇ <D ₈ . Further, the outer diameter D ₆ of the low friction material 5 with the elastic rubber seal 4 fitted in the low friction material 5 and the outer diameter of the seal groove 3 (that is, the elastic rubber seal 4 and the low friction material 5 are installed in the seal groove 3. the outer diameter) _{D 5} of the low friction material 5 in a _state, is set to D 5 _{<D 6.}

When the inner diameter D ₄ , the inner diameter D ₅ , the inner diameter D ₆ , and the inner diameter D ₇ are in the above ranges, the elastic rubber seal 4 and the low friction material 5 are in close contact with each other and do not slide between the two. The friction material 5 and the base X are in close contact with each other and do not slide between them. Therefore, when the rotating disk Y rotates, the low friction material 5 does not rotate together, and it is possible to prevent the elastic rubber seal 4 and the low friction material 5 from being excessively worn locally. When the inner diameter D ₄ , the inner diameter D ₅ , the inner diameter D ₆ , and the inner diameter D ₇ are outside the above ranges, sliding between the elastic rubber seal 4 and the low friction material 5 or between the low friction material 5 and the base X is possible. The elastic rubber seal 4 or the low friction material 5 may move locally and excessively wear. Other configurations are the same as those of the first embodiment.

  12 and 13 show a fourth embodiment. The back pressure side surface 3A is the outer diameter side surface of the seal groove 3 and is used for internal pressure. A low friction material 5 having a U-shaped cross section disposed along the groove bottom surface 3C of the seal groove 3, the back pressure side surface 3A on the low pressure side, and the groove opening 3B forms the elastic rubber seal 4 as a cover (enclosed shape). The seal groove 3 is internally provided. About each dimension, the same code | symbol as what was shown in 2nd Embodiment and 3rd Embodiment is set to the same range as the above-mentioned thing.

  FIG. 14 shows a fifth embodiment. The low friction material 5 has a thin boundary portion 6 between the back pressure side corresponding portion 5a and the opening corresponding portion 5b. That is, the low-friction material 5 has a tapered surface 7 having an enlarged diameter on the inner surface (or can be said to be chamfered 7). The rebound resilience (upward in FIG. 14) of the elastic rubber seal 4 (see FIG. 4) can be sufficiently exerted. Other configurations are the same as those of the first embodiment.

  FIG. 15 shows a sixth embodiment. The low friction material 5 has a radial cut 8 on the outer peripheral surface of the back pressure side face corresponding portion 5a. Specifically, the notch 8 is provided between the back pressure side corresponding part 5a and the opening corresponding part 5b and between the back pressure side corresponding part 5a and the groove bottom corresponding part 5c. The rebound resilience (upward in FIG. 14) of the elastic rubber seal 4 (see FIG. 4) can be sufficiently exerted. Other configurations are the same as those of the second embodiment.

  FIG. 16 shows a seventh embodiment. The low friction material 5 has a plurality of triangular lip portions 10 on the upper surface (sliding surface with the first flat surface portion 1) 9 of the opening corresponding portion 5b. A sufficient contact surface pressure can be generated in the lip portion 10 to improve the initial sealing performance. Other configurations are the same as those of the second embodiment.

  FIG. 17 shows an eighth embodiment. A plurality of square-shaped grease grooves 11 (oil retaining grooves for lubrication) are formed on the upper surface 9 of the opening corresponding portion 5b of the low friction material 5. Long life can be achieved. The grease groove 11 preferably has a smaller radial width and a deeper width. Other configurations are the same as those of the second embodiment.

  FIG. 18 shows a ninth embodiment. A plurality of pentagonal-shaped grease grooves 11 are formed on the upper surface 9 of the opening corresponding portion 5b of the low friction material 5. Long life can be achieved. Other configurations are the same as those in the eighth embodiment.

  The design of the present invention can be changed. For example, the elastic rubber seal 4 is not limited to an O-ring, and the cross-sectional shape may be a rectangle, a pentagon, an X-ring, or the like. Further, only one lip portion 10 of the seventh embodiment shown in FIG. 16 may be formed. In this case, the lip portion 10 is formed at the central portion in the radial direction. Further, the embodiments may be combined. For example, the lip portion 10 may be provided in the fifth embodiment. Also, the grease groove 11 may be provided in the sixth embodiment. Further, both the lip portion 10 and the grease groove 11 may be provided. In the planar seal structure of the present invention, the relative planar motion of the first planar portion 1 and the second planar portion 2 is not only a circular motion but a relative curve that draws a complex curve such as an eccentric rotational motion such as a scroll. It can also be used for devices that perform planar motion.

  As described above, according to the present invention, in the planar seal structure that seals between the first planar portion 1 and the second planar portion 2 that perform relative planar motion, the annular seal groove 3 is recessed in the second planar portion 2. And installing an elastic rubber seal 4 in the seal groove 3, and a low friction material 5 having an L-shaped cross section disposed along the low pressure side back pressure side surface 3A and the groove opening 3B of the seal groove 3, Since the elastic rubber seal 4 in the seal groove 3 is covered and built in the seal groove 3, the low friction material 5 having an L-shaped cross section is in stable contact (sliding contact) with the first flat portion 1, The low friction material 5 is not in an unstable posture as shown in FIG. 21 and FIG. 22 (conventional example), smoothly slides against the first flat surface portion 1, does not rotate together, and causes local wear. The low friction material 5 itself and the elastic rubber seal 4 are not generated, and the durability (life) is stably extended. As described above, for the planar motion, the conventional problems shown in FIGS. 19 to 22 can be solved, a long life and stable high sealing performance (sealing performance) can be exhibited, and a low sliding resistance sealing structure can be obtained.

  Further, in the planar seal structure that seals between the first planar portion 1 and the second planar portion 2 that perform relative planar movement, an annular seal groove 3 is provided in the second planar portion 2, and the seal groove 3 is An elastic rubber seal 4 is housed, and a low friction material 5 having a U-shaped cross section disposed along the groove bottom surface 3C of the seal groove 3, the back pressure side surface 3A on the low pressure side, and the groove opening 3B is provided in the seal groove 3 Since the inner elastic rubber seal 4 is covered and installed in the seal groove 3, the low friction material 5 having a U-shaped cross section stably contacts (slidably contacts) the first flat surface portion 1. 21 is not in an unstable posture as in FIGS. 21 and 22 (conventional example), smoothly slides against the first flat surface portion 1 and does not rotate together, and local wear is reduced with low friction. The material 5 itself and the elastic rubber seal 4 are not generated, and the durability (life) is stably extended. As described above, for the planar motion, the conventional problems shown in FIGS. 19 to 22 can be solved, a long life and stable high sealing performance (sealing performance) can be exhibited, and a low sliding resistance sealing structure can be obtained.

Further, the back pressure side surface 3A is an inner diameter side surface of the seal groove 3, and is suitable as a flat seal for external pressure.
Further, the back pressure side surface 3A is the outer diameter side surface of the seal groove 3, and is suitable as a flat seal for internal pressure.

DESCRIPTION OF SYMBOLS 1 1st plane part 2 2nd plane part 3 (annular) seal groove 3A back pressure side surface 3B groove opening part 3C groove bottom face 4 elastic rubber seal 5 low friction material

Claims (4)

In a plane sealing structure for sealing between the first plane part (1) and the second plane part (2) that perform relative plane movement,
An annular seal groove (3) is recessed in the second flat portion (2), and an elastic rubber seal (4) is provided in the seal groove (3), and a back pressure side surface on the low pressure side of the seal groove (3). (3A) and a low friction material (5) having an L-shaped cross section disposed along the groove opening (3B) is covered with the elastic rubber seal (4) and provided in the seal groove (3). A flat seal structure characterized by that. In a plane sealing structure for sealing between the first plane part (1) and the second plane part (2) that perform relative plane movement,
An annular seal groove (3) is recessed in the second flat portion (2), and an elastic rubber seal (4) is provided in the seal groove (3), and a groove bottom surface (3C) of the seal groove (3) and A low friction material (5) having a U-shaped cross section disposed along the back pressure side surface (3A) and the groove opening (3B) on the low pressure side is surrounded by the elastic rubber seal (4). A flat seal structure characterized by being installed in the groove (3).   The flat seal structure according to claim 1 or 2, wherein the back pressure side surface (3A) is an inner diameter side surface of the seal groove (3) and is used for external pressure.   The flat seal structure according to claim 1 or 2, wherein the back pressure side surface (3A) is an outer diameter side surface of the seal groove (3) and is used for internal pressure.

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