Sealing device

Abstract

Provided is a sealing device capable of suppressing detachment of a chuck spring from an annular groove. The present invention is characterized by having a suppression section for suppressing the protrusion of a chuck spring (300), which deforms when the sealing device (10) is attached to a shaft (20), from an annular groove (221), the suppression section having a plurality of protruding sections (222) that protrude toward the root side of a seal lip (220) at intervals in the circumferential direction on the lip tip side of the outer peripheral surface of the seal lip (220), the protruding sections (222) protruding toward the root side of the seal lip (220) at intervals in the circumferential direction, and the protruding sections (222) protruding toward the root side of the seal lip (220) at intervals in the circumferential direction on the lip tip side of the outer peripheral surface of the seal lip (220). When viewed in a cross-section in which the seal lip (220) is sectioned in a plane including the central axis of the shaft (20), the base-side surface of the protrusion (222) has a support surface that supports the chuck spring (300) so as to follow the outer peripheral surface of the chuck spring (300).

Description

Technical Field

[0001] The present invention relates to a sealing device. Background Art

[0002] Conventionally, in a sealing device (oil seal) for rotation, in order to maintain the state where the front end on the inner circumferential surface side of the sealing lip is in contact with the shaft, a clamping spring is installed on the outer circumferential surface of the sealing lip. Refer to Figure 6 A description will be given of a sealing device related to the prior art. Figure 6 FIG. (a) is a schematic sectional view of the sealing device, and FIG. (b) is an explanatory view during the manufacture of the sealing device.

[0003] The sealing device 500 is used to seal an annular gap between a relatively rotating shaft and a housing. The sealing device 500 includes a reinforcing ring 510 and a sealing device main body 520 made of a rubber-like elastic body integrally provided with the reinforcing ring 510. The sealing device main body 520 has a sealing lip 521 that slides freely on the outer circumferential surface of the shaft. A clamping spring 530 is installed in an annular groove 521a provided on the outer circumferential surface of the sealing lip 521. Thus, the sealing lip 521 is pressed radially inward, and therefore the state where the front end on the inner circumferential surface side of the sealing lip 521 is in contact with the shaft can be maintained.

[0004] In the sealing device 500 configured as described above, after being transported in a state where the clamping spring 530 is installed, it is assembled to the shaft. If the area (the range where the clamping spring 530 is supported by the annular groove 521a when observing the cross section of the sealing lip 521 cut by a plane including the central axis of the shaft) for supporting the clamping spring 530 by the annular groove 521a is small, the clamping spring 530 is likely to come off from the annular groove 521a. Therefore, during transportation of the sealing device 500 or during assembly to the shaft, the clamping spring 530 sometimes comes off from the annular groove 521a.

[0005] In order to make it difficult for the clamping spring 530 to come off from the annular groove 521a, it is necessary to increase the above-mentioned area (range), but there are limitations in the manufacturing method. Regarding this point, refer to Figure 5 (b) for an explanation.

[0006] In this figure, a sectional view shows a case where the reinforcing ring 510 is used as an insert member and the sealing device main body 520 is formed by insert molding. In this figure, a part of one mold 600 among the molds composed of a plurality of molds used in the insert molding is shown. When the molded product is demolded, the mold 600 moves relative to the molded product in the direction of arrow X in the figure. At this time, a part of the annular groove 521a (the thick line part in the figure) becomes an undercut part U, and so-called forced ejection is required. Therefore, the above-mentioned area (range) is restricted. In the case of acrylic rubber with relatively high flexibility, the above-mentioned range can be set relatively large, but in the case of fluororubber that is difficult to stretch and is prone to cracking, no countermeasure like that of acrylic rubber is taken, and there is a problem that the clamping spring disengages from the annular groove.

[0007] Prior Art Documents

[0008] Patent Documents

[0009] Patent Document 1: Japanese Unexamined Patent Application Publication No. 2017-223258

[0010] Patent Document 2: Japanese Unexamined Patent Application Publication No. 2012-117611

[0011] Patent Document 3: Japanese Unexamined Patent Application Publication No. 2009-103177

[0012] Patent Document 4: Japanese Utility Model Publication No. 7-42461. Summary of the Invention

[0013] Problems to be Solved by the Invention

[0014] The present invention provides a sealing device capable of suppressing the detachment of a clamping spring from an annular groove.

[0015] Means for Solving the Problems

[0016] The present invention adopts the following means to solve the above problems.

[0017] That is, the sealing device of the present invention seals the gap between a relatively rotating shaft and a housing, and the sealing device has: a reinforcing ring; a sealing device main body, which is integrally provided with the reinforcing ring and is made of fluororubber; and a clamping spring, which is installed in an annular groove provided on the outer peripheral surface of a sealing lip in the sealing device main body. The sealing device is characterized by having:

[0018] a restraining portion that restrains the clamping spring deformed when the sealing device is installed on the shaft from protruding from the annular groove,

[0019] The restraining portion has a plurality of protruding portions that protrude toward the root side of the sealing lip at intervals in the circumferential direction on the lip front end side of the outer peripheral surface of the sealing lip.

[0020] In a cross-sectional view of the sealing lip cut along a plane including the central axis of the shaft, the surface on the root side of the protruding portion has a support surface that supports the clamping spring along the outer peripheral surface of the clamping spring.

[0021] According to the present invention, even if the clamping spring tends to come out of the annular groove due to the deformation of the clamping spring caused by the shaft, the clamping spring will be pressed into by the protruding portion having a support surface for supporting the clamping spring. In addition, a plurality of protruding portions are provided at intervals in the circumferential direction, so that an excessive increase in the area that becomes an undercut portion can be suppressed, and thus breakage of the sealing lip during demolding can be suppressed.

[0022] In addition, in a sealing device of another invention, a gap between a relatively rotating shaft and a housing is sealed. The sealing device includes: a reinforcing ring; a sealing device main body that is integrally provided with the reinforcing ring and is made of fluororubber; and a clamping spring that is installed in an annular groove provided on the outer peripheral surface of a sealing lip in the sealing device main body. The sealing device is characterized by having:

[0023] a restraining portion that restrains the clamping spring deformed when the sealing device is installed on the shaft from protruding from the annular groove,

[0024] The restraining portion has a relief groove provided on the groove bottom surface of the annular groove.

[0025] According to the present invention, during demolding, the undercut portion is easily deformed, and breakage of the sealing lip can be suppressed. In addition, in the sealing lip, when deforming from the inner peripheral surface toward the outer peripheral surface, the deformed portion is displaced into the relief groove, thereby suppressing the clamping spring from detaching from the annular groove.

[0026] In addition, in a sealing device of another invention, a gap between a relatively rotating shaft and a housing is sealed. The sealing device includes: a reinforcing ring; a sealing device main body that is integrally provided with the reinforcing ring and is made of fluororubber; and a clamping spring that is installed in an annular groove provided on the outer peripheral surface of a sealing lip in the sealing device main body. The sealing device is characterized by having:

[0027] a restraining portion that restrains the clamping spring deformed when the sealing device is installed on the shaft from protruding from the annular groove,

[0028] The restraining portion has:

[0029] a relief groove provided on the groove bottom surface of the annular groove; and

[0030] A plurality of protrusions project toward the root side of the sealing lip at intervals in the circumferential direction on the lip front end side of the outer circumferential surface of the sealing lip.

[0031] When observing a cross section of the sealing lip cut by a plane including the central axis of the shaft, the surface on the root side of the protrusion has a support surface that supports the clamping spring along the outer circumferential surface of the clamping spring.

[0032] According to the present invention, even if the clamping spring tends to come out of the annular groove due to the deformation of the clamping spring caused by the shaft, the clamping spring will be pressed into by the protrusion having a support surface for supporting the clamping spring. In addition, a plurality of protrusions are provided at intervals in the circumferential direction, so that an excessive increase in the area of the undercut portion can be suppressed, and thus breakage of the sealing lip during demolding can be suppressed. In addition, by providing the relief groove, the undercut portion is easily deformed during demolding, and breakage of the sealing lip can be suppressed. In addition, in the sealing lip, when deforming from the inner circumferential surface toward the outer circumferential surface, the deformed portion is displaced into the relief groove, thereby suppressing the detachment of the clamping spring from the annular groove.

[0033] It may be that the clamping spring is supported by the support surface of the protrusion and the bottom surface of the annular groove.

[0034] It may be that a plurality of the relief grooves are provided at intervals in the circumferential direction.

[0035] It may be that a plurality of the relief grooves are provided, and the plurality of protrusions and the relief grooves are respectively provided at different positions in the circumferential direction.

[0036] Thereby, the function of the protrusion for holding the clamping spring and the function of the relief groove for facilitating the deformation of the sealing lip are effectively exerted respectively.

[0037] It may be that the protrusions and the relief grooves are alternately provided in the circumferential direction.

[0038] In addition, the above-described respective structures can be combined and adopted as much as possible.

[0039] Effect of the Invention

[0040] As described above, according to the present invention, detachment of the clamping spring from the annular groove can be suppressed. Description of the Drawings

[0041] Figure 1 It is a schematic cross-sectional view of a sealing structure of a sealing device according to an embodiment of the present invention.

[0042] Figure 2 It is a front view of a sealing device according to an embodiment of the invention.

[0043] Figure 3It is a schematic cross-sectional view of the sealing device related to the embodiment of the invention.

[0044] Figure 4 It is a schematic cross-sectional view of the sealing device related to the embodiment of the invention.

[0045] Figure 5 It is a partial enlarged cross-sectional view of the sealing device related to the embodiment of the present invention.

[0046] Figure 6 It is an explanatory diagram of the sealing device related to the prior art. Detailed Description of the Invention

[0047] Hereinafter, embodiments for implementing the present invention will be illustratively and detailedly described with reference to the accompanying drawings. However, as long as there is no specific description of the dimensions, materials, shapes, relative configurations, etc. of the constituent parts described in this embodiment, it is not intended to limit the scope of the present invention only to them.

[0048] (Embodiment)

[0049] Refer to Figures 1 to 4 The sealing device related to the embodiment of the present invention will be described. Figure 1 It is a schematic cross-sectional view of the sealing structure of the sealing device related to the embodiment of the present invention. In addition, in Figure 1 a cross-sectional view of the sealing device cut along a plane including the central axis of the shaft 20 is shown. Figure 2 It is a front view of the sealing device related to the embodiment of the invention. In Figure 2 for the plurality of protrusions 222 and the plurality of relief grooves 221a, they are perspectively shown by dotted lines. Figure 1 The cross-sectional view of the sealing device in Figure 2 corresponds to the AA cross-sectional view in Figure 3 It is a schematic cross-sectional view of the sealing device related to the embodiment of the invention, and it is the Figure 2 AA cross-sectional view in Figure 4 It is a schematic cross-sectional view of the sealing device related to the embodiment of the invention, and it is the Figure 2 BB cross-sectional view in Figure 4 In addition, the clamping spring is omitted in Figure 5 It is a partial enlarged cross-sectional view of the sealing device related to the embodiment of the present invention, and it is a cross-sectional view of the vicinity of the sealing lip enlarged. In addition, in Figure 5 the depth lines are omitted and only the cross-sectional plane is shown.

[0050] <Sealing Structure>

[0051] The sealing structure involved in this embodiment includes a shaft 20, a housing 30, and a sealing device 10 that seals the annular gap between the shaft 20 and the shaft hole of the housing 30 (the shaft hole of the housing 30). The shaft 20 and the housing 30 are configured to rotate relative to each other. The sealing device 10 is a so-called rotary seal, and in addition to the oil seal for an automobile engine, it can also be used for a speed reducer for a robot, etc. In addition, Figure 1 On the right side of the sealing device 10 is a sealing area O (an area where a sealing object fluid such as oil exists), and on the left side of the sealing device 10 is an atmospheric area A.

[0052] <Sealing device>

[0053] The sealing device 10 includes a metal reinforcing ring 100, a sealing device main body 200 integrally provided with the reinforcing ring 100 and made of fluororubber, and a clamping spring 300. In addition, by using the reinforcing ring 100 as an insert part and performing insert molding to form the sealing device main body 200, the reinforcing ring 100 and the sealing device main body 200 are integrally provided. The reinforcing ring 100 includes a cylindrical portion 110 and an inward flange portion 120 provided at the front end of the cylindrical portion 110. The sealing device main body 200 includes: an outer peripheral sealing portion 210 that abuts against the inner peripheral surface 31 of the shaft hole of the housing 30; and a sealing lip 220 and a dust-proof lip 230 that extend radially inward from the waist portion 215 near the inner peripheral end of the inward flange portion 120 and can slide freely on the outer peripheral surface of the shaft 20. The sealing lip 220 is configured to extend radially inward and toward the sealing area O side from the waist portion 215 and slide on the outer peripheral surface of the shaft 20, mainly functioning to suppress the leakage of the sealing object fluid. The dust-proof lip 230 is configured to extend radially inward and toward the atmospheric area A side from the waist portion 215 and slide on the outer peripheral surface of the shaft 20, mainly functioning to suppress the intrusion of foreign matters such as dust in the atmosphere into the sealing area O.

[0054] A ring-shaped groove 221 is provided on the outer peripheral surface of the sealing lip 220. The clamping spring 300 is installed in the ring-shaped groove 221. In the sealing device 10 involved in this embodiment, a restraining portion is provided, and the restraining portion restrains the clamping spring 300 deformed when the sealing device 10 is installed on the shaft 20 from protruding from the ring-shaped groove 221. The restraining portion involved in this embodiment has a protruding portion 222 and an avoidance groove 221a described below.

[0055] That is, on the outer peripheral surface of the sealing lip 220, at a position axially closer to the lip front end side than the ring-shaped groove 221 (on the right side in Figure 1 、 Figure 3 ), a plurality of protruding portions 222 are provided at intervals in the circumferential direction. These plurality of protruding portions 222 are configured to protrude toward the root side of the sealing lip 220 (the opposite side of the axially lip front end side (on the left side in Figure 1 、 Figure 3 ).

[0056] On the surface on the root side of the sealing lip 220 in the protrusion 222, a support surface 222X for supporting the clamping spring 300 is provided so as to follow the outer circumferential surface of the clamping spring 300 (see Figure 5 ). When observing the cross-section of the sealing lip 220 cut along the plane including the central axis of the shaft 20, in the portion where the protrusion 222 is not provided, the range R1 where the clamping spring 300 is supported by the groove bottom surface 221X of the annular groove 221 is 180° or less (see Figure 3 ). In contrast, when observing from this cross-section, in the portion where the protrusion 222 is provided, the range R2 where the clamping spring 300 is supported by the groove bottom surface 221X of the annular groove 221 and the support surface 222X of the protrusion 222 is configured to exceed 180°. In addition, in the circumferential direction, the total of the ranges where a plurality of protrusions 222 are provided is preferably set to 30% or more of the entire circumference.

[0057] In addition, on the groove bottom surface 221X of the annular groove 221 provided on the outer circumferential surface of the sealing lip 220, a plurality of relief grooves 221a are provided at intervals in the circumferential direction. The protrusions 222 and the relief grooves 221a are respectively provided at different positions in the circumferential direction (see Figure 2 ). In the present embodiment, a structure in which the protrusions 222 and the relief grooves 221a are alternately arranged in the circumferential direction is adopted. It is not necessarily required to arrange them alternately, but in order to fully exert their functions, it is preferable to arrange them alternately.

[0058] In the present embodiment, when observing the cross-section of the sealing lip 220 cut along the plane including the central axis of the shaft 20, both the groove bottom surface 221X of the annular groove 221 and the relief groove 221a are arc-shaped, and the curvature radius of the latter is configured to be smaller than that of the former. Thus, except when the sealing lip 220 is greatly deformed, the inner wall surface of the relief groove 221a does not contact the clamping spring 300. That is, even in the state where the clamping spring 300 is installed, a space or a state filled with the fluid to be sealed is formed inside the relief groove 221a.

[0059] In addition, as described above, in the present embodiment, when observing the cross-section of the sealing lip 220 cut along the plane including the central axis of the shaft 20, the relief groove 221a is arc-shaped. However, the shape of the relief groove 221a when observing the cross-section of the sealing lip 220 cut along the plane including the central axis of the shaft 20 is not limited to arc-shaped, and various shapes such as elliptical arc-shaped and rectangular-shaped can be adopted. In addition, in the present embodiment, when observing the relief groove 221a from the radially outer side toward the inner side ( Figure 4 in the direction of the arrow P), the outer shape of the relief groove 221a is elliptical (see Figure 4The part surrounded by a circle in the figure). However, regarding this outer shape, it is not limited to an ellipse. In addition to an oval shape other than an ellipse, a circular shape, a rectangular shape, or the like can also be adopted.

[0060] <Advantages of the sealing device according to this embodiment>

[0061] According to the sealing device 10 according to this embodiment, even if the clamping spring 300 is about to come out of the annular groove 221 due to the deformation of the clamping spring 300 caused by the shaft 20, the clamping spring 300 will be pressed into the annular groove 221 by the protrusion 222 having the support surface 222X for supporting the clamping spring 300. Thus, even when the sealing device 10 is mounted on the shaft 20, or when the sealing device 10 vibrates or is impacted, the detachment of the clamping spring 300 from the annular groove 221 can be suppressed.

[0062] In addition, since a plurality of protrusions 222 are provided at intervals in the circumferential direction, the excessive increase in the area that becomes an undercut portion can be suppressed during insert molding. Therefore, breakage of the sealing lip 220 during demolding can be suppressed. In addition, regarding the area that becomes an undercut portion during insert molding, refer to Figure 6 (b) as described in the prior art.

[0063] In addition, in this embodiment, when observing a cross-section of the sealing lip 220 cut along a plane including the central axis of the shaft 20, in the portion where the protrusion 222 is not provided, the range R1 of the annular groove 221 supporting the clamping spring 300 is 180° or less. Thus, the increase in the area that becomes an undercut portion can be more reliably suppressed.

[0064] In this embodiment, a plurality of relief grooves 221a are provided at intervals in the circumferential direction on the groove bottom surface of the annular groove 221. Thus, during demolding, the undercut portion is easily deformed, and breakage of the sealing lip 220 can be suppressed. In addition, in the sealing lip 220, when deforming from the inner circumferential surface toward the outer circumferential surface, the deformed portion is displaced into the relief groove 221a, thereby suppressing the clamping spring 300 from being pushed out radially outward. Therefore, the detachment of the clamping spring 300 from the annular groove 221 can be further suppressed.

[0065] In addition, the above-mentioned protrusion 222 and the relief groove 221a are provided at circumferentially offset positions. Thus, the function of the protrusion 222 for holding the clamping spring 300 and the function of the relief groove 221a for facilitating the deformation of the sealing lip 220 can be effectively exerted respectively.

[0066] <Details of the sealing lip>

[0067] Refer to Figure 5The detailed structure of the sealing lip 220 is described. In the sealing structure, the sealing area O is arranged in the direction parallel to the shaft 20 in the direction from the dust lip 230 to the sealing lip 220. The sealing lip 220 includes a lip outer peripheral surface 220O on the radial outer side (the side of the cylindrical portion 110 of the reinforcement ring 100) and a lip inner peripheral surface 220I on the radial inner side (the opposite side of the cylindrical portion 110).

[0068] The front end of the sealing area O side of the sealing lip 220 is composed of a planar lip front end surface 224 connecting the lip outer peripheral surface 220O and the lip inner peripheral surface 220I. The lip outer peripheral surface 220O can also be said to be a surface that is continuous from the waist portion 215 to the lip front end surface 224 on the radial outer side. Similarly, the lip inner peripheral surface 220I can also be said to be a surface that is continuous from the waist portion 215 to the lip front end surface 224 on the radial inner side.

[0069] The annular groove 221 is provided on the lip outer peripheral surface 220O of the sealing lip 220. In addition, the protrusion 222 is provided intermittently in the direction along the circumferential direction of the shaft 20. The portion where the protrusion 222 is not provided intermittently can also be referred to as a cutout portion 222a. It can also be said that the protrusion outer peripheral surface 225 is provided on the radial outer side of the protrusion 222, and the cutout outer peripheral surface 225a is also provided on the radial outer side of the cutout portion 222a.

[0070] In this embodiment, the end surface of the protrusion 222 on the sealing region O side and the end surface of the cutout portion 222a on the sealing region O side are arranged on the same plane, thereby forming the lip front end surface 224. However, they do not necessarily need to be arranged on the same plane.

[0071] The surface of the protrusion 222 on the opposite side to the sealing region O is the above-mentioned support surface 222X. In addition, the surface of the cutout portion 222 a on the opposite side to the sealing region O does not contact the clamp spring 300 .

[0072] In this embodiment, the groove bottom surface 221X and the support surface 222X of the annular groove 221 are configured to have substantially the same curvature radius when the seal lip 220 is cut along a plane including the central axis of the shaft 20. However, the latter may be configured to have a smaller curvature radius.

[0073] The lip inner peripheral surface 220I includes a first inclined surface 223a that expands in diameter from the atmosphere region A side toward the sealing region O side and a second inclined surface 223b that expands in diameter from the sealing region O side toward the atmosphere region A side. An inner peripheral lip front end portion 223 is provided at a portion where the first inclined surface 223a and the second inclined surface 223b intersect. The vicinity of the inner peripheral lip front end portion 223 is in slidable contact with the shaft 20 over the entire circumference, thereby performing a sealing function.

[0074] (other)

[0075] In the above-described embodiment, a structure is shown in which a plurality of relief grooves 221a are provided at intervals in the circumferential direction on the groove bottom surface of the annular groove 221. However, depending on the dimensions of each part, the properties of the material, etc., when breakage of the sealing lip 220 during demolding and detachment of the clamping spring 300 from the annular groove 221 are not likely to be problems, a structure in which the relief grooves 221a are not provided may also be employed.

[0076] In addition, when breakage of the sealing lip 220 during demolding and detachment of the clamping spring 300 from the annular groove 221 are not likely to be problems only by providing the relief grooves 221a, a structure in which the protrusion 222 is not provided may also be employed.

[0077] In addition, in the above-described embodiment, a structure is shown in which the sealing device main body 200 has the outer peripheral sealing portion 210. However, in the present invention, it can also be applied to a sealing device in which a cylindrical portion configured as a reinforcing ring is directly fitted to the inner peripheral surface of the shaft hole of the housing without having the outer peripheral sealing portion. In addition, the present invention can also be applied to a sealing device without a dust-proof lip. And the present invention can also be applied to a sealing device having a side lip that slides on an outward flange portion provided on the shaft or the like. Thus, in the present invention, as long as the sealing device main body has a sealing lip, it can be applied to various sealing devices.

[0078] Explanation of Reference Numerals

[0079] 10: Sealing device

[0080] 100: Reinforcing ring

[0081] 110: Cylindrical portion

[0082] 120: Inward flange portion

[0083] 200: Sealing device main body

[0084] 210: Outer peripheral sealing portion

[0085] 215: Waist portion

[0086] 220: Sealing lip

[0087] 220I: Inner peripheral surface of lip

[0088] 220O: Outer peripheral surface of lip

[0089] 221: Annular groove

[0090] 221a: Relief groove

[0091] 222: Protrusion

[0092] 222X: Support surface

[0093] 222a: Cut portion

[0094] 223: Front end portion of inner peripheral lip

[0095] 223a: First inclined surface

[0096] 223b: Second inclined surface

[0097] 224: Front end surface of lip

[0098] 225: Outer peripheral surface of protruding portion

[0099] 225a: Outer peripheral surface of cut portion

[0100] 230: Dust lip

[0101] 300: Clamping spring

[0102] 20: Shaft

[0103] 30: Housing

[0104] 31: Inner peripheral surface

[0105] A: Atmosphere region

[0106] O: Sealing region.

Claims

1. A sealing device for sealing a gap between a relatively rotating shaft and a housing, the sealing device comprising: a reinforcement ring; a sealing device body integrally provided with the reinforcement ring and made of fluororubber; and a clamp spring mounted in an annular groove provided on the outer peripheral surface of a sealing lip in the sealing device body, wherein the sealing device is characterized in that: a suppressing portion that suppresses the garter spring that is deformed when the sealing device is mounted on the shaft from protruding from the annular groove, The suppressing portion includes a plurality of protrusions, the protrusions protruding toward the root side of the seal lip at intervals in the circumferential direction on the lip tip side of the outer peripheral surface of the seal lip, When the seal lip is viewed in cross section along a plane including the central axis of the shaft, a surface of the protruding portion on the root side has a support surface that supports the garter spring along an outer peripheral surface of the garter spring.

2. A sealing device for sealing a gap between a relatively rotating shaft and a housing, the sealing device comprising: a reinforcement ring; a sealing device body integrally provided with the reinforcement ring and made of fluororubber; and a clamping spring mounted in an annular groove provided on the outer peripheral surface of a sealing lip in the sealing device body, the sealing device being characterized in that: a suppressing portion that suppresses the garter spring that is deformed when the sealing device is mounted on the shaft from protruding from the annular groove, The suppressing portion includes a relief groove provided on a groove bottom surface of the annular groove.

3. A sealing device for sealing a gap between a relatively rotating shaft and a housing, the sealing device comprising: a reinforcement ring; a sealing device body integrally provided with the reinforcement ring and made of fluororubber; and a clamping spring mounted in an annular groove provided on the outer peripheral surface of a sealing lip in the sealing device body, the sealing device being characterized in that: a suppressing portion that suppresses the garter spring that is deformed when the sealing device is mounted on the shaft from protruding from the annular groove, The suppression unit has: An avoidance groove is provided on the bottom surface of the annular groove; and A plurality of protrusions protrude toward the root side of the seal lip at intervals in the circumferential direction on the lip tip side of the outer peripheral surface of the seal lip, When the seal lip is viewed in cross section along a plane including the central axis of the shaft, a surface of the protruding portion on the root side has a support surface that supports the garter spring along an outer peripheral surface of the garter spring.

4. The sealing device according to claim 1 or 3, characterized in that: The garter spring is supported by the supporting surface of the protruding portion and the groove bottom surface of the annular groove.

5. The sealing device according to claim 2 or 3, characterized in that: A plurality of the avoidance grooves are provided at intervals along the circumferential direction.

6. The sealing device according to claim 3, characterized in that: A plurality of the avoidance grooves are provided, and the plurality of protrusions and the avoidance grooves are respectively provided at different positions in the circumferential direction.

7. The sealing device according to claim 6, characterized in that: The protrusions and the avoidance grooves are alternately arranged in the circumferential direction.

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