JP2019065978A - Sealing device and sealing structure - Google Patents

Abstract

To provide a sealing device and a sealing structure, capable of preventing deterioration of workability for attachment due to expansion of a backup ring.SOLUTION: A sealing device comprises: a seal ring 10 made of a rubber elastic body; and resin backup rings 20, 30 arranged on both sides of the seal ring 10 in an axial direction, and configured to prevent the seal ring 10 from projecting to the outside of an installation region (annular space K1). In the backup rings 20, 30, an abutment part is provided in a circumferential direction. On an inner peripheral surface side of the backup ring 20, 30, annular convex part 21, 31 is provided so as to project toward a side where the seal ring 10 is arranged, wherein the annular convex part is fastened radially inward by the seal ring 10.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a sealing device and a sealing structure for sealing an annular gap between two members.

  As a sealing device for sealing an annular gap between two members, a sealing device provided with a seal ring made of a rubber-like elastic body and a backup ring for suppressing the seal ring from protruding from the mounting region is known. Such a sealing device is also used, for example, in a mechanical seal, at an attachment site of a fixed ring or at an attachment site of a rotary ring. A sealing device according to a conventional example will be described with reference to FIG.

  In the illustrated example, a sealing device M0 is provided to seal the annular gap between the annular portion 710 provided on the housing and the fixed ring 110 attached to the annular portion 710. The sealing device M0 is attached to an annular groove 711 provided on the outer peripheral surface of the annular portion 710. The sealing device M0 is a seal ring 10 made of a rubber-like elastic material, and a resin backup ring 50 disposed on both sides in the axial direction of the seal ring 10 to prevent the seal ring 10 from protruding outside the annular groove 711. , 60.

  Here, in the case of the seal ring 10, the seal ring 10 is made of a rubber-like elastic material and can be easily spread outside, so there is no particular problem in the mounting operation to the annular groove 711. On the other hand, in the case of the backup rings 50 and 60, since the backup rings 50 and 60 are made of resin, when the backup rings 50 and 60 are formed of an endless annular member, the mounting operation to the annular groove 711 becomes difficult. Therefore, from the viewpoint of mounting workability, the backup rings 50 and 60 are provided with abutments (not shown). Thereby, the mounting operation of the backup rings 50 and 60 in the annular groove 711 is facilitated by expanding through the abutment.

  However, when the abutment portion is provided, when the backup rings 50 and 60 are attached to the annular groove 711, the backup rings 50 and 60 may expand outward (see the arrow in FIG. 8). As a result, the backup rings 50 and 60 may protrude largely outward in the radial direction from the annular groove 711 (see the dotted line in FIG. 8). In this state, when the fixing ring 110 is to be attached to the annular portion 710, the fixing ring 110 abuts against the backup rings 50 and 60, and the attachment workability is reduced. In addition, the backup rings 50 and 60 may be damaged.

JP-A-11-315925 Patent No. 5939367

  An object of the present invention is to provide a sealing device and a sealing structure capable of suppressing a decrease in mounting workability caused by the expansion of a backup ring.

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

That is, the sealing device of the present invention is
A sealing device disposed in an annular mounting area formed between two members and sealing an annular gap between the two members,
A seal ring made of a rubber-like elastic body in close contact with both the outer peripheral surface of the radially inner first member of the two members and the inner peripheral surface of the radially outer second member of the two members When,
A resin backup ring disposed on at least one of both sides in the axial direction of the seal ring, for suppressing the seal ring from protruding outside the mounting area;
Equipped with
The backup ring is provided with an abutment at one location in the circumferential direction,
The inner peripheral surface side of the backup ring is provided with an annular convex portion that protrudes toward the side where the seal ring is disposed, and is tightened radially inward by the seal ring. .

Moreover, the sealing structure of the present invention is
2 members,
A sealing device disposed in an annular mounting area formed between the two members and sealing an annular gap between the two members;
The sealing device
A seal ring made of a rubber-like elastic body in close contact with both the outer peripheral surface of the radially inner first member of the two members and the inner peripheral surface of the radially outer second member of the two members When,
A resin backup ring disposed on at least one of both sides in the axial direction of the seal ring, for suppressing the seal ring from protruding outside the mounting area;
Equipped with
The backup ring is provided with an abutment at one location in the circumferential direction,
The inner peripheral surface side of the backup ring is provided with an annular convex portion that protrudes toward the side where the seal ring is disposed, and is tightened radially inward by the seal ring. .

  According to these inventions, the annular convex portion provided on the inner peripheral surface side of the backup ring is tightened radially inward by the seal ring. Therefore, although the backup ring is provided with the abutment, it is suppressed that the backup ring is spread outside in the state of being attached to the attachment area.

Assuming that the maximum width in the axial direction of the seal ring is WS, the sum of the widths in the axial direction on the inner peripheral surface side of the backup ring is WB, and the width of the mounting region in the axial direction is W0.
WS + WB> WO
It is good to meet

  Thus, the annular convex portion provided on the inner peripheral surface side of the backup ring is more securely tightened by the seal ring.

  As described above, according to the present invention, it is possible to suppress a decrease in mounting workability caused by the expansion of the backup ring.

FIG. 1 is a schematic cross-sectional view of a mechanical seal to which a sealing device and a sealing structure according to an embodiment of the present invention are applied. FIG. 2 is a schematic cross-sectional view of the sealing structure according to the first embodiment of the present invention. FIG. 3 is a front view of a backup ring according to an embodiment of the present invention. FIG. 4 is a schematic cross-sectional view of a backup ring according to an embodiment of the present invention. FIG. 5 is a schematic cross-sectional view showing how the sealing device according to the first embodiment of the present invention is attached. FIG. 6 is a schematic cross-sectional view of a sealing structure according to a second embodiment of the present invention. FIG. 7 is a schematic cross-sectional view of a sealing structure according to a conventional example. FIG. 8 is a schematic cross-sectional view showing how the sealing device according to the prior art is mounted.

  Hereinafter, with reference to the drawings, modes for carrying out the present invention will be exemplarily described in detail based on examples. However, the dimensions, materials, shapes, relative positions, etc. of the components described in this embodiment are not intended to limit the scope of the present invention to them unless otherwise specified. .

Example 1
<Example of application of sealing device and sealing structure>
An application of the sealing device and the sealing structure according to the embodiment of the present invention will be described with reference to FIG. The sealing device and the sealing structure according to the present embodiment can be used, for example, in a mechanical seal, at an attachment site of a fixed ring or at an attachment site of a rotary ring. FIG. 1 is a schematic cross-sectional view of a mechanical seal to which a sealing device and a sealing structure according to an embodiment of the present invention are applied. Hereinafter, the "axial direction" means the direction in which the central axes of the various annular members extend.

  The mechanical seal 100 is used to seal an annular gap between the rotating shaft 500 and the housing 700. The mechanical seal 100 further includes a fixed ring 110, a rotary ring 120 slidably provided to the fixed ring 110, and a spring 130 biasing the rotary ring 120 toward the fixed ring 110. The fixed ring 110 is attached to an annular portion 710 provided on the housing 700. The fixed ring 110 is allowed to move slightly in the axial direction with respect to the annular portion 710, and is locked. The rotating ring 120 is attached to an annular member 600 attached to the rotating shaft 500. The rotary ring 120 is allowed to move slightly in the axial direction with respect to the annular member 600, and is locked.

  According to the mechanical seal 100 configured as described above, the annular member 600 and the rotary ring 120 rotate together with the rotary shaft 500 and slide between the rotary ring 120 and the fixed ring 110. The rotary ring 120 is biased toward the fixed ring 110 by the spring 130, so that the rotary ring 120 and the fixed ring 110 are kept in contact with each other. Accordingly, the annular gap between the rotating shaft 500 and the housing 700 is sealed.

  A sealing device M1 is provided to seal the annular gap between the annular portion 710 and the fixed ring 110 in the housing 700. That is, a sealing structure is configured by the two members (the housing 700 and the fixed ring 110) and the sealing device M1 that seals the annular gap between the two members. More specifically, the sealing device M1 is disposed in an annular space (mounting area) K1 having a rectangular cross section formed by the annular groove 711 formed on the outer peripheral surface of the annular portion 710 of the housing 700 and the inner peripheral surface of the fixed ring 110. It is attached. Thus, the first member (corresponding to the annular portion 710 of the housing 700) on the radially inner side of the two members and the second member (corresponding to the fixed ring 110) on the radially outer side of the two members The annular gap is sealed.

In addition, a sealing device M2 is provided to seal the annular gap between the annular member 600 and the rotary ring 120. That is, a sealing structure is provided by the two members (the annular member 600 and the rotary ring 120) and the sealing device M2 for sealing the annular gap between these two members. More specifically, an annular space having a rectangular cross section formed by an annular notch 610 formed on the outer circumferential surface of the annular member 600 and an annular notch 121 formed on the inner circumferential surface of the rotary ring 120 ( Mounting region) A sealing device M2 is mounted on K2. Thus, an annular gap between the radially inner first member (corresponding to the annular member 600) of the two members and the radially outer second member (corresponding to the rotary ring 120) of the two members is It is sealed.

<Sealing device and sealing structure>
The sealing device according to the present embodiment is applicable as the sealing device M1 in the mechanical seal described above, and is also applicable as the sealing device M2. Hereinafter, the sealing device and the sealing structure according to the present embodiment will be described in more detail with reference to FIGS. 2 to 5 by taking the case of the sealing device M1 as an example. FIG. 2 is a schematic cross-sectional view of the sealing structure according to the first embodiment of the present invention. The sealing device according to the present embodiment has a substantially rotationally symmetrical shape, and FIG. 2 shows a cross-sectional view of the sealing structure cut along a plane including the central axis of the sealing device. FIG. 3 is a front view of a backup ring according to an embodiment of the present invention. FIG. 4 is a schematic cross-sectional view of a backup ring according to an embodiment of the present invention, and is a cross-sectional view taken along line AA in FIG. FIG. 5 is a schematic cross-sectional view showing how the sealing device according to the first embodiment of the present invention is attached.

  The sealing device M1 according to this embodiment includes a seal ring 10 made of a rubber-like elastic material, and a pair of backup rings 20 and 30 made of resin disposed on both sides in the axial direction of the seal ring 10. The seal ring 10 according to the present embodiment is an endless seal ring (so-called O-ring) having a circular cross section in a state in which no external force is applied. The seal ring 10 is configured to be in intimate contact with both the outer peripheral surface of the first member (the annular portion 710 of the housing 700) and the inner peripheral surface of the second member (the fixed ring 110).

  The backup rings 20 and 30 are provided to prevent the seal ring 10 from protruding outside the mounting area (annular space K1). And these backup rings 20 and 30 are provided with the abutment part (refer the abutment part 22 in FIG.3, 4) in one place of the circumferential direction. As a result, the mountability of the backup rings 20 and 30 is enhanced. In the present embodiment, although the joint 22 shown in FIGS. 3 and 4 shows the case of the bias cut which is cut obliquely, the joint is not limited to the bias cut. For example, a straight cut cut straight in a plane including the central axis, a step cut cut in a step shape, or the like may be employed. Further, on the inner peripheral surface side of the backup rings 20 and 30, annular convex portions 21 and 31 that protrude toward the side where the seal ring 10 is disposed, and are tightened radially inward by the seal ring 10 are provided. ing.

  According to the sealing device M1 configured as described above, the annular gap between the first member and the second member is sealed by the seal ring 10. Further, the backup rings 20 and 30 prevent the seal ring 10 from protruding outside the mounting region (annular space K1). As a result, the seal ring 10 is prevented from protruding into the annular minute gap between the first member and the second member and being damaged. In addition, the backup ring 20 and the backup ring 30 can use the same components. That is, it is only necessary to change the direction of placement.

FIG. 5 shows a state in which the sealing device M1 is attached to an annular groove 711 formed on the outer peripheral surface of the annular portion 710 of the housing 700. As shown, the maximum axial width (corresponding to the diameter of the O-ring in the case of this embodiment) of the seal ring 10 is WS. Further, the sum of the widths in the axial direction on the inner peripheral surface side of the backup rings 20 and 30 is taken as WB. In the case of the present embodiment, assuming that the width in the axial direction of the inner peripheral surface side of the backup ring 20 is WB1 and the width in the axial direction of the inner peripheral surface side of the backup ring 30 is WB2, as shown in FIG. It becomes WB1 + WB2. Furthermore, the axial width of the mounting area (annular space K1) (corresponding to the groove width of the annular groove 711)
Let W0 be.

  Then, it is configured to satisfy WS + WB> WO. As a result, even when backup ring 20 is disposed at a position deviated to the first side in the mounting area and backup ring 30 is disposed at the position deviated to the other side in the mounting area, the inner peripheral surface of seal ring 10 Is in contact with the annular convex portions 21 and 31 of the backup rings 20 and 30.

  In the above description, although the case of the sealing device M1 in the mechanical seal 100 shown in FIG. 1 has been described as an example, the same configuration can be adopted in the sealing device M2.

<Superior points of the sealing device and the sealing structure according to the present embodiment>
According to the sealing device and the sealing structure according to the present embodiment, the annular convex portions 21 and 31 provided on the inner peripheral surface side of the backup rings 20 and 30 are tightened radially inward by the seal ring 10. Therefore, although the backup rings 20 and 30 are provided with abutments, the backup rings 20 and 30 can be prevented from spreading outward in the state of being attached to the attachment area. Therefore, in the case of the sealing device M1, when the fixed ring 110 is attached, it is suppressed that the fixed ring 110 collides with the backup rings 20 and 30. Further, in the case of the sealing device M2, when the rotary ring 120 is attached, the rotary ring 120 is prevented from abutting against the backup rings 20 and 30. Therefore, according to the sealing device and the sealing structure according to the present embodiment, it is possible to suppress a decrease in mounting workability caused by the expansion of the backup rings 20 and 30.

  Further, in the sealing structure according to the present embodiment, the maximum width in the axial direction of the seal ring 10 is WS, and the sum of the widths in the axial direction on the inner peripheral surface side of the backup rings 20 and 30 is WB, the axis of the mounting region Assuming that the width of the direction is W0, WS + WB> WO is satisfied. Thereby, the annular convex portions 21 and 31 provided on the inner peripheral surface side of the backup rings 20 and 30 are more securely tightened by the seal ring 10.

(Example 2)
The sealing structure based on Example 2 of this invention is shown by FIG. In the first embodiment, the configuration in which the backup rings are disposed on both sides in the axial direction of the seal ring has been described. However, as described above, the backup ring is provided to prevent the seal ring from protruding outside the mounting area. Therefore, although there is a possibility that the seal ring may protrude on one side in the axial direction, it is not necessary to arrange the backup ring on the other side if there is almost no possibility of the seal ring protruding on the other side. So, in a present Example, the structure in case a backup ring is arrange | positioned only in the one side of the axial direction in a seal ring is demonstrated. The basic configuration and operation are the same as in the first embodiment, and therefore the same components are denoted by the same reference numerals and the description thereof is omitted.

  Also in this embodiment, a sealing device M3 for sealing an annular gap between the annular portion 710X and the fixed ring 110 in the housing will be described as an example. That is, a sealing structure is configured by the two members (the housing and the fixed ring 110) and the sealing device M3 that seals the annular gap between the two members. More specifically, the sealing device M3 is mounted in an annular space (mounting area) K3 having a rectangular cross section formed by the annular groove 711X formed on the outer peripheral surface of the annular portion 710X and the inner peripheral surface of the fixed ring 110. . Thus, an annular gap between the radially inner first member (corresponding to the annular portion 710X) of the two members and the radially outer second member (corresponding to the fixed ring 110) of the two members is It is sealed.

The sealing device M3 according to the present embodiment includes a seal ring 10 made of a rubber-like elastic material, and a resin backup ring 20 disposed on one side in the axial direction of the seal ring 10. The configurations and operations of the seal ring 10 and the backup ring 20 according to the present embodiment are as described in the first embodiment.

  The present embodiment is different from the sealing structure shown in the first embodiment in that the backup ring 30 is not provided. Then, the maximum width in the axial direction of the seal ring 10 (corresponding to the diameter of the O ring in the case of this embodiment) is WS. Further, the sum of the widths in the axial direction of the inner peripheral surface side of the backup ring 20 is taken as WB. In the case of the present embodiment, only one backup ring 20 is provided. Therefore, assuming the width WB1 in the axial direction of the inner peripheral surface side of the backup ring 20, WB = WB1. Further, the axial width (corresponding to the groove width of the annular groove 711) of the mounting region (annular space K3) is set to W0.

  Then, it is configured to satisfy WS + WB> WO. As a result, even when the backup ring 20 is disposed at a position biased to one side in the mounting area and the seal ring 10 is disposed at a position biased to the other side in the mounting area, the inner circumferential surface of the seal ring 10 Is in contact with the annular convex portion 21 of the backup ring 20.

  According to the configuration as described above, in the sealing device M3 and the sealing structure according to the present embodiment, the same effect as in the case of the first embodiment can be obtained.

DESCRIPTION OF SYMBOLS 10 seal ring 20, 30 backup ring 21, 31 annular convex part 22 joint part 100 mechanical seal 110 fixed ring 120 rotary ring 130 spring 500 rotary shaft 600 annular member 700 housing 710, 710X annular part 711, 711X annular groove K1, K2, K3 annular space M1, M2, M3 sealing device

Claims (3)

A sealing device disposed in an annular mounting area formed between two members and sealing an annular gap between the two members,
A seal ring made of a rubber-like elastic body in close contact with both the outer peripheral surface of the radially inner first member of the two members and the inner peripheral surface of the radially outer second member of the two members When,
A resin backup ring disposed on at least one of both sides in the axial direction of the seal ring, for suppressing the seal ring from protruding outside the mounting area;
Equipped with
The backup ring is provided with an abutment at one location in the circumferential direction,
The inner peripheral surface side of the backup ring is provided with an annular convex portion that protrudes toward the side where the seal ring is disposed, and is tightened radially inward by the seal ring. Sealing device. 2 members,
A sealing device disposed in an annular mounting area formed between the two members and sealing an annular gap between the two members;
The sealing device
A seal ring made of a rubber-like elastic body in close contact with both the outer peripheral surface of the radially inner first member of the two members and the inner peripheral surface of the radially outer second member of the two members When,
A resin backup ring disposed on at least one of both sides in the axial direction of the seal ring, for suppressing the seal ring from protruding outside the mounting area;
Equipped with
The backup ring is provided with an abutment at one location in the circumferential direction,
The inner peripheral surface side of the backup ring is provided with an annular convex portion that protrudes toward the side where the seal ring is disposed, and is tightened radially inward by the seal ring. Sealed structure. Assuming that the maximum width in the axial direction of the seal ring is WS, the sum of the widths in the axial direction on the inner peripheral surface side of the backup ring is WB, and the width of the mounting region in the axial direction is W0.
WS + WB> WO
The sealing structure according to claim 2, characterized in that:

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