Mechanical seal

Abstract

The invention provides a mechanical seal capable of making the surface pressure between sliding surfaces appropriate. A mechanical seal (1) having a seal ring (21) held by a housing (20) via an elastic body (22), the housing (20) being provided with: an axial wall (20a) extending in the axial direction along the circumferential surface of the seal ring (21); and a radial wall (20b) extending in the radial direction along the rear surface (21f) of the seal ring (21), the elastic body (22) being provided with: an axial portion (221) sandwiched between the circumferential surface of the seal ring (21) and the axial wall (20a) of the housing (20); and a radial portion (222) sandwiched between the rear surface (21f) of the seal ring (21) and the radial wall (20b) of the housing (20), and a taper (223) is formed on the elastic body (22) from the circumferential surface of the axial portion (221) to the rear surface (222a) of the radial portion (222) to the rear surface of the seal ring (21).

Description

Technical Field

[0001] The present invention relates to a mechanical seal, for example, a mechanical seal for sealing a rotating shaft. Background Art

[0002] A mechanical seal is installed between a housing of a fluid device and a rotating shaft arranged to penetrate the housing, and has the following functions: a sliding surface of a stationary sealing ring fixed to a stationary side housing mounted on the housing and a sliding surface of a rotating sealing ring fixed to a rotating side housing mounted on the rotating shaft and rotating are brought into sliding contact in the circumferential direction, thereby reducing friction generated on the sliding surfaces and preventing leakage of the sealed fluid.

[0003] A general mechanical seal, for example, as shown in Patent Document 1, has a sealing member disposed between a stationary seal ring and a stationary housing to ensure sealing between the stationary seal ring and the stationary housing. The stationary seal ring is disposed to be movable in the axial direction relative to the stationary housing and is urged toward the rotating seal ring by an urging unit.

[0004] In addition, the rotating seal ring is pressed into the rotating side housing via the stationary ring sleeve. Specifically, the rotating side housing comprises: an axial wall extending in a cylindrical shape in the axial direction; a radial wall extending in a ring shape from the back side end of the axial wall to the inner diameter direction; and a fixed wall extending in the axial direction from the inner diameter end of the radial wall and fixed to the rotating shaft. The stationary ring sleeve comprises: an axial portion clamped between the outer peripheral surface of the rotating seal ring and the inner peripheral surface of the axial wall of the rotating side housing; and a radial portion clamped between the back side of the rotating seal ring and the front side of the radial wall of the rotating side housing. In this way, the sealing performance and fixing force of the rotating side housing and the rotating seal ring are ensured.

[0005] Prior art literature

[0006] Patent Literature

[0007] Patent Document 1: International Publication No. 2019 / 163726 (page 5, Figure 1 ) Summary of the invention

[0008] Problems to be solved by the invention

[0009] In the mechanical seal of Patent Document 1, since the axial part and radial part of the stationary ring sleeve are arranged in a compressed state between the rotating side housing and the rotating seal ring, the sealing and fixation are excellent. However, for example, when ensuring higher sealing and fixation, when the rotating seal ring is pressed into the rotating side housing, the axial part of the elastomer is radially compressed between the outer peripheral surface of the rotating seal ring and the inner peripheral surface of the axial wall of the housing, and the axial part bulges toward the back side compared with the radial part of the elastomer. The bulged axial part first abuts against the radial wall of the housing, and the radial part may be axially separated from the radial wall. Therefore, when assembling the mechanical seal, the elastic force of the stationary ring sleeve overcomes the force of the force-applying unit on the stationary seal ring side and exerts its effect, and there is a problem that it is difficult to properly set the surface pressure between the sliding surfaces of the stationary seal ring and the rotating seal ring.

[0010] The present invention has been made in view of such problems, and an object of the present invention is to provide a mechanical seal capable of making the surface pressure between sliding surfaces appropriate.

[0011] Means for solving problems

[0012] In order to solve the above problems, the mechanical seal of the present invention is:

[0013] It has a sealing ring held to the housing via an elastomer, wherein

[0014] The housing includes: an axial wall extending in the axial direction along the peripheral surface of the seal ring; and a radial wall extending in the radial direction along the back surface of the seal ring.

[0015] The elastic body comprises: an axial portion which is clamped between the peripheral surface of the seal ring and the axial wall of the housing; and a radial portion which is clamped between the back surface of the seal ring and the radial wall of the housing.

[0016] The elastic body is formed with a taper from the peripheral surface of the axial portion to the back surface of the radial portion to the back surface position of the seal ring.

[0017] Thus, when the seal ring is press-fitted into the housing, the elastic body retreats into the gap between the taper and the housing, so that the back surface of the radial portion is properly disposed in contact with the radial wall, and the surface pressure between the sliding surfaces can be made appropriate.

[0018] Alternatively, the cone may be a flat surface.

[0019] Thus, the taper easily abuts smoothly against the radial wall of the housing.

[0020] Alternatively, the cone is formed by two cone surfaces.

[0021] Thus, the gap between the housing and the elastic body can be reduced, and the elastic body can be elastically deformed efficiently in the gap.

[0022] The tapered shape may extend to a rear surface position of the seal ring that is closer to the axial portion than the radial center.

[0023] This can reduce the gap between the housing and the elastic body.

[0024] The corners of the seal ring surrounded by the elastic body may be chamfered.

[0025] As a result, a portion of the elastic body that has been elastically deformed is disposed in a gap between the corner portion of the seal ring and the elastic body.

[0026] The corner portion may be chamfered more greatly than other corner portions of the seal ring.

[0027] This ensures that a large gap is provided for arranging a part of the elastic body that has been elastically deformed.

[0028] A notch portion may be formed at a front end portion of a peripheral surface of the axial portion.

[0029] Thus, a part of the elastic body that has been elastically deformed is arranged in the gap between the notch and the housing. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 is a cross-sectional view showing a mechanical seal according to Embodiment 1 of the present invention;

[0031] Figure 2 is a cross-sectional view showing a stationary ring sleeve before assembling the mechanical seal;

[0032] Figure 3 is a cross-sectional view showing a state where the stationary ring sleeve is fitted into the rotating side housing, and is a view for explaining the dimensions of the rotating side housing and the stationary ring sleeve;

[0033] Figure 4 is a cross-sectional view showing a state in which a rotary seal ring with a stationary ring sleeve fitted thereon is pressed into a rotating side housing;

[0034] Figure 5 is a cross-sectional view showing a state in which a rotary seal ring with a stationary ring sleeve embedded therein is pressed into a rotary side housing;

[0035] Figure 6 1 is a cross-sectional view showing a stationary ring sleeve according to a second embodiment of the present invention. DETAILED DESCRIPTION

[0036] Hereinafter, a mode for implementing the mechanical seal of the present invention will be described based on examples.

[0037] [Example 1]

[0038] Reference Figures 1 to 5 The mechanical seal of Example 1 is described below. Figure 1 The description is given with the left side of the paper as the left side and the right side of the paper as the right side.

[0039] like Figure 1 As shown, the mechanical seal 1 is an inner type mechanical seal that seals the sealed fluid F that leaks from the outer diameter side to the inner diameter side. In addition, the space on the inner diameter side of the stationary seal ring 11 and the rotating seal ring 21 is the atmosphere A side, and the space on the outer diameter side of the stationary seal ring 11 and the rotating seal ring 21 is the sealed fluid F side.

[0040] The mechanical seal 1 of the present embodiment is composed of a stationary-side element S and a rotating-side element R.

[0041] The stationary side element S is mainly composed of the following components: a stationary side housing 10, which is fixed to the housing 3; an annular stationary sealing ring 11, which is arranged in the housing 10 in a non-rotating state and can move in the axial direction; a bellows 12, which seals between the housing 10 and the stationary sealing ring 11; and a spring 13, which applies force to the stationary sealing ring 11 toward the rotating sealing ring 21 described later.

[0042] The stationary housing 10 is an annular member with a substantially U-shaped cross section opened to the left, and is formed by punching and bending a metal sheet. The material and processing method of the stationary housing 10 are not limited, and it may be a resin molded product, for example.

[0043] The stationary side housing 10 mainly comprises: a cylindrical first portion 10a extending axially along the inner circumferential surface of the housing 3; an annular second portion 10b extending inwardly from the right end of the first portion 10a; and a cylindrical third portion 10c extending to the left from the inner diameter end of the second portion 10b.

[0044] The stationary seal ring 11 includes a base 11a, an annular convex portion 11b that protrudes axially from the inner diameter side and the left surface side of the base 11a, and an annular convex portion 11c that protrudes axially from the inner diameter side and the right surface side of the base 11a. The left surface of the convex portion 11b, that is, the surface facing the rotating seal ring 21, serves as a sliding surface 11d.

[0045] The bellows 12 includes a cylindrical portion 12a that is expandable and contractible in the axial direction, a flange portion 12b that extends from the left end of the cylindrical portion 12a in the outer diameter direction, and a flange portion 12c that extends from the right end of the cylindrical portion 12a in the outer diameter direction. The flange portion 12b is arranged at a step portion formed by the base portion 11a and the convex portion 11c of the stationary seal ring 11. In addition, the flange portion 12c is arranged at a corner portion formed by the second portion 10b and the third portion 10c of the stationary side housing 10.

[0046] The spring 13 is a compression spring, and is disposed on the outer diameter side of the cylindrical portion 12a of the bellows 12. The left end of the spring 13 presses the right surface of the base 11a of the stationary seal ring 11 via the flange portion 12b of the bellows 12, and the right end of the spring 13 presses the second portion 10b of the housing 10 via the flange portion 12c of the bellows 12.

[0047] The rotating side element R is mainly composed of the following components: a rotating side housing 20, which is fixed to the rotating shaft 2; a rotating seal ring 21, which is arranged in the housing 20; and a stationary ring sleeve 22 as an elastic body, which is arranged in a compressed state between the housing 20 and the rotating seal ring 21.

[0048] The rotating side housing 20 is an annular member with a substantially J-shaped cross section opened toward the right surface side, and is formed by punching and bending a metal thin plate. The material and processing method of the rotating side housing 20 are not limited, and it may be a resin molded product, for example.

[0049] The rotating side housing 20 includes: a cylindrical first portion 20a as an axial wall extending in the axial direction; an annular second portion 20b as a radial wall extending from the left end of the first portion 20a in the inner diameter direction; and a cylindrical third portion 20c extending from the inner diameter end of the second portion 20b to the right along the rotating shaft 2. In this embodiment, the first portion 20a and the second portion 20b form a substantially 90-degree angle.

[0050] The rotary seal ring 21 has a rectangular cross section, and its right surface, that is, the front surface of the rotary seal ring 21 is a flat sliding surface 21a. In the following, the right side of the rotary seal ring 21 is sometimes referred to as the front side, and the left side is sometimes referred to as the back side.

[0051] Reference Figure 5 The left surface of the rotary seal ring 21, i.e., the corner 21b on the back outer diameter side, the corner 21c on the front outer diameter side, the corner 21d on the front inner diameter side, and the corner 21e on the back inner diameter side of the rotary seal ring 21 are chamfered. The corner 21b on the back outer diameter side is chamfered more than the other corners 21c to 21e. In addition, the back side 21f of the rotary seal ring 21 is the surface on the back side except the corners 21b and 21e, and is a flat surface in this embodiment.

[0052] like Figure 2 As shown, the stationary ring sleeve 22 is an annular component made of elastically deformable synthetic resin, has an L-shaped cross-section, and has a cylindrical axial portion 221 extending axially and a circular annular radial portion 222 extending from the back side end of the axial portion 221 in the inner diameter direction.

[0053] A tapered portion 223 is formed at a corner portion on the rear outer diameter side of the stationary ring sleeve 22 so as to gradually become thinner toward the rear side.

[0054] The conical portion 223 is composed of the following parts: a first inclined surface 223a as a flat conical surface, which gradually tapers from the outer peripheral surface 221a of the axial portion 221 toward the back side; and a second inclined surface 223b as a flat conical surface, which further gradually tapers from the back side end of the first inclined surface 223a toward the back side 222a of the radial portion 222.

[0055] The boundary portion 225 between the second inclined surface 223 b and the back surface 222 a of the radial portion 222 is arranged on the inner diameter side of the inner peripheral surface 221 b of the axial portion 221 .

[0056] In addition, if Figure 5 As shown in FIG. 1 , the second inclined surface 223b extends to the rear position of the rear surface 21f of the rotary seal ring 21, that is, to the position overlapping the rear surface 21f of the rotary seal ring 21 in the axial direction. In addition, the boundary portion 225 is arranged at the rear position of the rear surface 21f of the rotary seal ring 21 at the outer diameter side (that is, the axial portion 221 side) of the radial center 21g of the rotary seal ring 21. In addition, hereinafter, the portion of the rear surface 21f of the rotary seal ring 21 located on the axis passing through the radial center 21g of the rotary seal ring 21 is sometimes described simply as "the radial center of the rear surface 21f of the rotary seal ring 21".

[0057] In addition, a notch 224 is formed at the front end of the front side of the axial portion 221. The notch 224 is formed in an annular shape in a manner opening toward the outer diameter side and the front side. In addition, the notch 224 is not limited to an annular shape, and can also be provided at multiple locations along the circumferential direction.

[0058] Reference Figure 3 , the dimensional relationship between the rotating side housing 20 and the stationary ring sleeve 22 is described. Among them, the inner diameter of the rotating side housing 20 and the outer diameter of the stationary ring sleeve 22 are substantially the same.

[0059] When the stationary ring sleeve 22 is embedded in the rotating side housing 20 alone, the outer peripheral surface 221a of the axial portion 221 abuts against the inner peripheral surface of the first portion 20a of the rotating side housing 20, and the back surface 222a of the radial portion 222 abuts against the front surface of the second portion 20b of the rotating side housing 20.

[0060] In addition, a gap S1 is formed between the tapered portion 223 and the inner diameter side corner portion of the rotating-side housing 20. In addition, a gap S2 is formed between the notch portion 224 and the first portion 20a.

[0061] Next, use Figure 4 and Figure 5 The actual assembly of the rotating side element R will be described. Here, the outer diameter of the rotating seal ring 21 is slightly larger than the inner diameter of the stationary ring sleeve 22 .

[0062] like Figure 4 As shown, first, the stationary ring sleeve 22 is pressed from the front side to the back side of the rotating side housing 20 while being externally fitted on the rotating seal ring 21. The axial portion 221 is clamped and pressed radially between the rotating seal ring 21 and the first portion 20a of the rotating side housing 20, and thus elastically deforms in a manner of bulging in the axial direction.

[0063] Specifically, the tapered portion 223 of the axial portion 221 bulges toward the back side. At this time, the second inclined surface 223b is located closer to the front side than the back side 222a of the radial portion 222 and the boundary portion 225. In addition, the first inclined surface 223a of the tapered portion 223 bulges toward the outer diameter direction, but is located closer to the inner diameter side than the inner peripheral surface of the first portion 20a of the rotating side housing 20.

[0064] In addition, the corner 21b of the rotary seal ring 21 surrounded by the stationary ring sleeve 22 is chamfered, so that in a state not shown in the figure before the stationary ring sleeve 22 is externally fitted on the rotary seal ring 21 and pressed into the rotating side housing 20, a gap S3 is formed between the corner on the inner diameter side of the axial portion 221 and the radial portion 222 that form approximately 90 degrees and the corner 21b of the rotary seal ring 21. In this gap S3, a part of the elastically deformed stationary ring sleeve 22 can be retracted, and the gap S3 is smaller than before being pressed into the rotating side housing 20.

[0065] In addition, Figure 4 In the illustrated state, the boundary portion 225 is disposed at a rear surface position of the rear surface 21 f of the rotary seal ring 21 that is closer to the axial portion 221 than the radial center.

[0066] like Figure 5 As shown, when the stationary ring sleeve 22 and the rotating seal ring 21 are further pressed into the rotating side housing 20, the back side 222a of the radial portion 222, the boundary portion 225, and a portion of the inner diameter side of the second inclined surface 223b of the tapered portion 223 abut against the second portion 20b of the rotating side housing 20.

[0067] On the other hand, the outer diameter side of the second inclined surface 223 b of the tapered portion 223 is slightly separated from the second portion 20 b of the rotating-side housing 20 toward the front side.

[0068] In addition, the first inclined surface 223 a of the tapered portion 223 is slightly separated from the inner diameter side of the first portion 20 a of the rotating-side housing 20 .

[0069] In addition, Figure 5 In the state, the axial portion 221 elastically deforms in a manner of bulging in the axial direction, so Figure 3 In addition, the vicinity of the notch portion 224 of the axial portion 221 bulges toward the outer diameter side in a manner that fills the gap S2.

[0070] Next, the assembly of the mechanical seal 1 will be described. After the stationary element S is assembled to the housing 3, Figure 5 The rotating side element R shown is fixed to the rotating shaft 2 at a predetermined position in the axial direction to complete the assembly. Figure 1 Status shown.

[0071] As described above, the tapered portion 223 is formed on the stationary ring sleeve 22 from the outer peripheral surface 221a of the axial portion 221 to the back surface 222a of the radial portion 222 until the back surface of the rotary seal ring 21. Therefore, when the rotary seal ring 21 is pressed into the rotary side housing 20, the tapered portion 223 can be retracted into the gap S1 between the tapered portion 223 and the rotary side housing 20, so that the back surface 222a of the radial portion 222 can be properly set in a state of abutting against the second portion 20b. Therefore, the elastic force of the stationary ring sleeve 22 is not applied to the surface pressure between the sliding surfaces 11d and 21a, and the surface pressure can be made appropriate by the force of the spring 13.

[0072] In addition, since the second inclined surface 223 b of the tapered portion 223 is a flat surface, it is easy to smoothly contact the second portion 20 b of the rotating-side housing 20 .

[0073] In addition, the tapered portion 223 is composed of the first inclined surface 223a and the second inclined surface 223b. Thus, the tapered portion 223 can be elastically deformed in a manner of bulging in the axial direction and the radial direction, so that compared with the case where only the second inclined surface 223b is provided, the stationary ring sleeve 22 can be elastically deformed efficiently in a smaller gap S1.

[0074] In addition, the stationary ring sleeve 22 gradually tapers toward the back side due to the first inclined surface 223 a , so it is easy to press-fit the stationary ring sleeve 22 into the rotating-side housing 20 .

[0075] In addition, the boundary portion 225 is arranged on the back surface 21f of the rotary seal ring 21 closer to the axial portion 221 than the radial center, so that the back surface 222a of the radial portion 222 abutting against the second portion 20b of the rotary housing 20 can be ensured to be larger. That is, the gap S1 can be reduced.

[0076] Furthermore, since the corner 21 b of the rotary seal ring 21 surrounded by the stationary ring sleeve 22 is chamfered, a part of the elastically deformed stationary ring sleeve 22 can be retracted into the gap S3 formed between the stationary ring sleeve 22 and the corner 21 b of the rotary seal ring 21 .

[0077] Furthermore, since the corner 21 b of the rotary seal ring 21 is chamfered more greatly than the other corners 21 c to 21 e , a larger gap S3 in which a part of the elastically deformable stationary ring sleeve 22 is arranged can be ensured.

[0078] In addition, a notch portion 224 is formed at the front end portion of the axial portion 221 on the front side, so that a part of the elastically deformed stationary ring sleeve 22 can be retracted into the gap S2 between the notch portion 224 and the rotating-side housing 20 .

[0079] In addition, in this embodiment, if Figure 4 As shown in FIG. 1 , a method of pressing a rotating seal ring 21 with a stationary ring sleeve 22 embedded therein into a rotating side housing 20 is illustrated, but the method is not limited thereto. Figure 3 As shown, the rotating seal ring 21 is pressed into the stationary ring sleeve 22 when the stationary ring sleeve 22 is installed on the rotating side housing 20. Even in this case, the tapered portion 223 does not extend further to the back side than the back side 222a of the radial portion 222 and the boundary portion 225, so the elastic force of the stationary ring sleeve 22 acting on the rotating seal ring 21 can be suppressed.

[0080] In addition, since the second inclined surface 223b of the stationary ring sleeve 22 is inclined by approximately 10 degrees relative to the back surface 222a of the radial portion 222, the gap S1 can be reduced, and the sealing and fixation between the rotary seal ring 21 and the rotating side housing 20 are excellent. In addition, from the perspective of retaining the gap S1 and ensuring excellent sealing and fixation, the second inclined surface 223b can be inclined by 1 to 30 degrees in the axial direction relative to the back surface 222a of the radial portion 222, preferably by 2 to 10 degrees.

[0081] Furthermore, in the above description, the following example is described: Figure 5 In the press-fitting completed state shown, the back surface 222a of the radial portion 222, the boundary portion 225, and a portion of the inner diameter side of the second inclined surface 223b of the tapered portion 223 are in contact with the second portion 20b of the rotating-side housing 20. However, only the boundary portion 225 and its radial vicinity may be in contact with the second portion 20b of the rotating-side housing 20, and most of the back surface 222a of the radial portion 222 is very slightly separated from the second portion 20b of the rotating-side housing 20. In this case, since only a very small gap is generated, the rotating-side element R is fixedly assembled to the rotating shaft 2 at a predetermined position in the axial direction, and the biasing force of the spring 13 of the stationary-side element S is not greatly affected.

[0082] In addition, in this embodiment, the example is given in which the inner diameter of the rotating side housing 20 is approximately the same as the outer diameter of the stationary ring sleeve 22, and the outer diameter of the rotating sealing ring 21 is slightly larger than the inner diameter of the stationary ring sleeve 22, but it may also be that the outer diameter of the stationary ring sleeve 22 is slightly larger than the inner diameter of the rotating side housing 20, and the outer diameter of the rotating sealing ring 21 is approximately the same as the inner diameter of the stationary ring sleeve 22.

[0083] [Example 2]

[0084] Next, refer to Figure 6 A mechanical seal of Example 2 will be described. Note that the same structures as those of the above-described embodiment and the repeated descriptions thereof will be omitted.

[0085] The stationary ring sleeve 122 of the second embodiment includes an axial portion 122A and a radial portion 122B, and a tapered portion 122C is formed at a corner portion on the outer diameter side of the back surface of the stationary ring sleeve 122 .

[0086] The tapered portion 122C is formed in a stepped shape so as to gradually taper from the outer peripheral surface 123 of the axial portion 122A toward the back surface 124 of the radial portion 122B. The boundary 125 between the tapered portion 122C and the back surface 124 of the radial portion 122B is arranged on the inner diameter side of the inner peripheral surface 126 of the axial portion 122A.

[0087] Thus, when the rotary seal ring 21 is pressed into the rotating side housing 20, the tapered portion 122C can be retracted to the axial back side, so that the back side 124 of the radial portion 122B can be properly disposed in a state of contact with the second portion 20b of the rotating side housing 20 (see Figure 5 ).

[0088] As mentioned above, although the embodiment of the present invention is described based on the drawings, the specific structure is not limited to these embodiments, and even if there are changes and additions within the scope that does not depart from the gist of the present invention, they are also included in the present invention.

[0089] For example, in the above-mentioned first and second embodiments, the rotating seal ring 21 is press-fitted into the rotating side housing 20 via the stationary ring sleeve, but the stationary seal ring 11 may be press-fitted into the stationary side housing 10 via the stationary ring sleeve.

[0090] In addition, in the above-mentioned embodiments 1 and 2, a method of providing a sealing ring embedded in the static ring sleeve, that is, a method of providing a sealing ring on the inner diameter side of the static ring sleeve is illustrated, but it is also possible to provide a sealing ring embedded in the static ring sleeve, that is, a sealing ring is provided on the outer diameter side of the static ring sleeve.

[0091] In the first embodiment, the tapered portion 223 is constituted by two surfaces, the first inclined surface 223 a and the second inclined surface 223 b , but may be constituted by only the second inclined surface.

[0092] In addition, regarding the taper, although the first embodiment described above exemplifies a flat surface, and the second embodiment described above exemplifies a stepped surface, the taper may also be a curved surface.

[0093] In the above-mentioned first and second embodiments, the tapered portion extends to a back position of the back surface 21f of the rotary seal ring 21 which is closer to the axial portion than the radial center. However, the tapered portion may extend to a back position of the radial center or beyond the radial center of the back surface 21f of the rotary seal ring 21.

[0094] In addition, in the above-mentioned embodiments 1 and 2, the inner side type mechanical seal is described as an example, but the invention is not limited to this, and an outer side type mechanical seal may also be used.

[0095] The sealed fluid F may be any of gas, liquid, or a mixture of gas and liquid. The fluid on the leakage side is not limited to the atmosphere A, but may be any of gas, liquid, or a mixture of gas and liquid.

[0096] Explanation of symbols

[0097] 1: Mechanical seal; 2: Rotating shaft; 3: Housing; 10: Stationary side housing; 11: Stationary sealing ring; 11d: Sliding surface; 13: Spring; 20: Rotating side housing; 20a: First part (axial wall); 20b: Second part (radial wall); 21: Rotating sealing ring; 21a: Sliding surface; 21b~21e: Corner; 21f: Back; 22: Stationary ring sleeve (elastomer); 122: Stationary ring sleeve (elastomer); 122A: Axial part; 122B: Radial part; 122C: Conical part; 125: Boundary part; 221: Axial part; 222: Radial part; 223: Conical part; 223a: First inclined surface; 223b: Second inclined surface; 224: Notch part; 225: Boundary part; R: Rotating side element; S: Stationary side element; S1~S3: Gap.

Claims

1. A mechanical seal having a sealing ring held in a housing via an elastic body, wherein: The housing includes: an axial wall extending in the axial direction along the peripheral surface of the seal ring; and a radial wall extending in the radial direction along the back surface of the seal ring. The elastic body comprises: an axial portion which is clamped between the peripheral surface of the seal ring and the axial wall of the housing; and a radial portion which is clamped between the back surface of the seal ring and the radial wall of the housing. The elastic body is formed with a taper from the peripheral surface of the axial portion to the back surface of the radial portion to the back surface position of the seal ring.

2. The mechanical seal according to claim 1, wherein: The cone is a flat surface.

3. The mechanical seal according to claim 1, wherein: The cone is composed of two cone surfaces.

4. The mechanical seal according to any one of claims 1 to 3, wherein: The tapered shape extends to a rear surface position of the seal ring that is closer to the axial portion than the radial center.

5. The mechanical seal according to claim 1, wherein: Corners of the sealing ring surrounded by the elastic body are chamfered.

6. The mechanical seal according to claim 5, wherein: The corner is chamfered more greatly than other corners of the sealing ring.

7. The mechanical seal according to claim 1, wherein: A notch portion is formed at a front end portion of a peripheral surface of the axial portion.

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