Sealing structure and support

Abstract

A seal structure for separating a high-pressure side and a low-pressure side, in which a seal groove (1G) has a high-pressure-side groove bottom (1Ga) provided at a position spaced apart from a second seal surface (2a) at a predetermined distance on the high-pressure side, and a low-pressure-side groove bottom (2Gb) that is continuous with the high-pressure-side groove bottom (1Ga) on the low-pressure side and that is provided at a position spaced apart from the second seal surface (2a) at a predetermined distance from the second seal surface (2a) at a predetermined distance from the high-pressure-side groove bottom (1Ga). The seal (10) is disposed between the high-pressure-side groove bottom (1Ga) and the second seal surface (2a) as the seal (10) approaches the second seal surface (2a) side from the high-pressure-side bottom (1Ga) toward the low-pressure side, the support (20) is disposed between the low-pressure-side groove bottom (1Gb) and the second seal surface (2a), and the support (20) has a contact surface (20c) having a shape that follows the low-pressure-side groove bottom (1Gb) on the side facing the low-pressure-side groove bottom (1Gb).

Description

Technical Field

[0001] The present invention relates to a sealing structure and a support. Background Art

[0002] As an example of a sealed structure, as a technology for a sealing structure for public gases (high-pressure hydrogen, etc.), there can be cited the technologies disclosed in International Publication No. WO2004 / 061353 (Patent Document 1), Japanese Patent No. 4636281 (Patent Document 2), Japanese Patent No. 4949492 (Patent Document 3), and Japanese Patent No. 5126462 (Patent Document 4).

[0003] Here, refer to Figures 15 to 17 As an example of a sealing structure, a structure in which an O-ring for sealing is arranged on the high-pressure side of a seal groove and a backup ring is arranged on the low-pressure side will be described. Figure 15 This is an enlarged cross-sectional view showing a conventional sealing structure (before high-pressure operation). Figure 16 This is an enlarged cross-sectional view showing a conventional sealing structure (after high-pressure operation). Figure 17 This is an enlarged cross-sectional view showing the problems of the conventional sealing structure (after high-pressure operation).

[0004] Reference Figure 15 Cylindrical shaft 1A is housed in cylindrical groove 2A. The outer circumference of shaft 1A forms first sealing surface 1a. The inner circumference of cylindrical groove 2A forms second sealing surface 2a. Gas is introduced into cylindrical groove 2A through through-hole 1h in shaft 1A, creating a high pressure inside cylindrical groove 2A.

[0005] An annular seal groove 1G is provided on the outer peripheral surface of the shaft 1A, which is recessed inward from the first seal surface 1a. In the seal groove 1G, an O-ring 10X for sealing is arranged on the high-pressure side, and a support ring 40X for supporting the O-ring 10X is arranged on the low-pressure side. Figure 14 In the cross-sectional view shown, the O-ring 10X and the backup ring 40X are shown in an undeformed state.

[0006] Reference Figure 16 , shows the O-ring 10X and the backup ring 40X housed in the seal groove 1G. In this state, the O-ring 10X is sandwiched between the bottom 1Gs of the seal groove 1G and the second sealing surface 2a, deforming into an elliptical shape. In this figure, gas pressure is not applied to the O-ring 10X from the high-pressure side (the lower side in the figure), so the O-ring 10X does not move toward the backup ring 40X.

[0007] Reference Figure 17, showing the state where gas pressure is applied to O-ring 10X from the high-pressure side (lower side of the figure). When high pressure is applied to O-ring 10X, O-ring 10X moves toward support ring 40X as shown in the figure. At this time, support ring 40X restrains the movement of O-ring 10X from the low-pressure side (upper side of the figure), thereby maintaining the seal structure of O-ring 10X that separates the high-pressure side from the low-pressure side.

[0008] Prior art literature

[0009] Patent Literature

[0010] Patent Document 1: International Publication No. WO2004 / 061353

[0011] Patent Document 2: Japanese Patent No. 4636281

[0012] Patent Document 3: Japanese Patent No. 4949492

[0013] Patent Document 4: Japanese Patent No. 5126462 Summary of the Invention

[0014] Problems to be solved by the invention

[0015] Reference Figure 17 In conventional sealing structures, when high pressure is applied to the O-ring 10X, the O-ring 10X is pressed toward the backup ring 40X. Since the backup ring 40X is made of a harder material than the O-ring 10X, continued application of pressure to the O-ring 10X creates a deformed region 10y, where a portion of the O-ring 10X enters the gap h formed between the backup ring 40X and the bottom 1Gs of the seal groove 1G.

[0016] If such a deformed region 10 y is formed in the O-ring 10X, there is a possibility that damage such as cracks will occur in the O-ring 10X starting from the deformed region 10 y.

[0017] The present invention is made to solve the above-mentioned problems, and its purpose is to provide a sealing structure and a support member, in which, even when high pressure is applied to the seal, damage such as cracks can be suppressed in the seal.

[0018] Means for solving problems

[0019] [1]: In the sealing structure disclosed herein, it is a sealing structure for separating the high-pressure side and the low-pressure side, wherein, when observed in a longitudinal cross-sectional structure, the sealing structure comprises: a component having a first sealing surface; a sealing groove provided on the first sealing surface; a sealing member installed in the sealing groove and arranged on the high-pressure side; a supporting member installed in the sealing groove and arranged on the low-pressure side; and another component arranged opposite to the one component and having a second sealing surface that forms the sealing structure by abutting against the sealing member. The sealing structure has the following structure.

[0020] The above-mentioned sealing groove comprises: a high-pressure side groove bottom, which is arranged at a position separated from the above-mentioned second sealing surface on the high-pressure side; and a low-pressure side groove bottom, which is continuous with the above-mentioned high-pressure side groove bottom on the low-pressure side, and approaches the above-mentioned second sealing surface side as it moves from the above-mentioned high-pressure side groove bottom toward the low-pressure side. The above-mentioned sealing member is arranged between the above-mentioned high-pressure side groove bottom and the above-mentioned second sealing surface, and the above-mentioned supporting member is arranged between the above-mentioned low-pressure side groove bottom and the above-mentioned second sealing surface. The above-mentioned supporting member has a contact surface along the shape of the above-mentioned low-pressure side groove bottom on the side opposite to the above-mentioned low-pressure side groove bottom.

[0021] [2] The sealing structure according to [1], wherein the support member has an inclined surface on the side opposite to the second sealing surface that is inclined away from the second sealing surface toward the low-pressure side.

[0022] [3] The sealing structure according to [1] or [2], wherein the bottom of the low-pressure side groove is formed by a portion of a circular arc.

[0023] [4] A sealing structure according to any one of [1] to [3], wherein the first sealing surface is the outer peripheral surface of the cylindrical member, the second sealing surface is a cylindrical inner peripheral surface with a bottom provided in the housing and accommodating the cylindrical member and in contact with the first sealing surface, the sealing groove is an annular groove provided on the outer peripheral surface of the cylindrical member, and the sealing member and the supporting member have an annular shape.

[0024] [5]: In the support member disclosed in the present invention, it has an annular shape and is used together with a seal member in a sealing groove of a sealing structure provided in a separation between a high-pressure side and a low-pressure side, wherein the cross section of the support member when observed in the longitudinal cross section structure includes: a first surface; a second surface, which stands up from the radially outer end of the above-mentioned first surface; a third surface, which stands up from the radially inner end of the above-mentioned first surface and is opposite to the above-mentioned second surface; and a fourth surface, which connects the above-mentioned second surface and the above-mentioned third surface and is opposite to the above-mentioned first surface, and the above-mentioned third surface is inclined in a manner approaching the above-mentioned second surface side as it moves toward the above-mentioned fourth surface side.

[0025] [6] The support member according to [5], wherein the third surface includes a curved surface bulging inward.

[0026] [7] The support member according to [5] or [6], wherein the second surface is inclined so as to approach the third surface side as it goes toward the fourth surface side.

[0027] Effects of the Invention

[0028] According to this sealing structure and support member, it is possible to provide a sealing structure and support member comprising a sealing member and a support member, wherein even when a high pressure is applied to the sealing member, damage such as cracks can be suppressed from occurring in the sealing member. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 It is a cross-sectional view showing the sealed structure of the first embodiment.

[0030] Figure 2 It is a partially enlarged cross-sectional view showing the sealing structure of the first embodiment.

[0031] Figure 3 This is a partially enlarged cross-sectional view showing a seal groove used in the seal structure of the first embodiment.

[0032] Figure 4 This is a plan view of the support ring according to the first embodiment.

[0033] Figure 5 yes Figure 4 Sectional view along line VV.

[0034] Figure 6 It is a partially enlarged cross-sectional view showing the sealing state of the sealing structure according to the first embodiment.

[0035] Figure 7 It is a schematic diagram showing changes in the sealing state of the sealing structure of the first embodiment.

[0036] Figure 8 It is a top view of the support ring of Embodiment 2.

[0037] Figure 9 yes Figure 8 Sectional view along line IX-IX.

[0038] Figure 10 It is a top view of the support ring of Embodiment 3.

[0039] Figure 11 yes Figure 10 Sectional view along line XI-XI.

[0040] Figure 12 It is a top view of the support ring of Embodiment 4.

[0041] Figure 13 yes Figure 10 Cross-sectional view along line XIII-XIII.

[0042] Figure 14 It is a cross-sectional view showing the sealed structure of embodiment 5.

[0043] Figure 15 This is an enlarged cross-sectional view showing a conventional sealing structure (before high-pressure operation).

[0044] Figure 16 This is an enlarged cross-sectional view showing a conventional sealing structure (after high-pressure operation).

[0045] Figure 17 This is an enlarged cross-sectional view showing the problems of the conventional sealing structure (after high-pressure operation). DETAILED DESCRIPTION

[0046] Hereinafter, the sealing structure of each embodiment will be described with reference to the accompanying drawings. In the embodiments described below, when the number, amount, etc. are mentioned, the scope of the present invention is not necessarily limited to the number, amount, etc., unless otherwise specified. In addition, the same reference numerals are marked on the same parts and equivalent parts, and repeated descriptions are sometimes not repeated. In the following description, for the sake of convenience, the upper and lower statements are used to express the positional relationship, but this does not exclude the upper and lower configurations from being reversed or left-right configurations.

[0047] (Implementation 1)

[0048] Reference Figures 1 to 5 , the sealing structure of this embodiment is described. Figure 1 1 is a cross-sectional view showing a sealed structure 1000 using the sealing structure 100. Figure 2 is a partially enlarged cross-sectional view showing the sealing structure 100. Figure 3 FIG. 1 is a partially enlarged cross-sectional view showing a seal groove used in the seal structure 100. Figure 4 is a top view of the support ring, Figure 5 yes Figure 4 Sectional view along line VV.

[0049] (Sealed structure 1000)

[0050] Reference Figure 1 The sealed structure 1000 of this embodiment is a gas (high-pressure hydrogen, etc.) sealed structure, and comprises a head 1 and a housing 2. The head 1 is provided with a cylindrical shaft 1A extending toward the housing 2. A through hole 1h for introducing gas is provided in the center of the shaft 1A.

[0051] The housing 2 is provided with a bottomed cylindrical groove 2A that accommodates the shaft 1A. The outer circumferential surface of the shaft 1A constitutes a first sealing surface 1a, provided on one component side. The inner circumferential surface of the cylindrical groove 2A constitutes a second sealing surface 2a, provided on the other component side. Gas is introduced into the cylindrical groove 2A through a through-hole 1h in the shaft 1A, creating a high pressure state within the cylindrical groove 2A.

[0052] The head 1 and the housing 2 are fastened together by bolts 3 via an O-ring 30. This maintains the airtightness of the sealing structure 100 described below.

[0053] (Sealing structure 100)

[0054] Reference Figure 2 , the details of the sealing structure 100 will be described. An annular sealing groove 1G that is recessed from the first sealing surface 1a toward the inside is provided on the outer peripheral surface of the shaft 1A. A sealing ring is provided as a sealing member on the high-pressure side of the sealing groove 1G. In this embodiment, an O-ring 10 is provided. A support ring 20 is provided as a support member on the low-pressure side of the sealing groove 1G. Figure 2 In the cross-sectional view shown, the O-ring 10 and the backup ring 20 are shown in an undeformed state.

[0055] The O-ring 10 has a generally circular cross-section, and a commercially available O-ring can be used. It should be noted that a fixed-use seal such as a U-shaped seal can be used as a sealing ring instead of a commercially available O-ring. The support ring 20 can be made of a material that is harder than the O-ring 10 but softer than the shaft 1A, such as PTFE (polytetrafluoroethylene), POM (polyoxymethylene), or PEEK (polyetheretherketone). Details of the cross-section of the support ring 20 and the function of the sealing structure 100 will be described later.

[0056] (Cross-sectional shape of seal groove 1G)

[0057] Reference Figure 3 , the cross-sectional shape of the sealing groove 1G will be described. Figure 3 The cross section represents a cross section of one groove when viewed in a longitudinal section obtained by cutting along a plane including the axis line, with the axial direction of the shaft 1A being the longitudinal direction.

[0058] Seal groove 1G includes a high-pressure side groove bottom 1Ga, which is located a certain distance from second sealing surface 2a on the high-pressure side; and a low-pressure side groove bottom 1Gb, which is continuous with high-pressure side groove bottom 1Ga on the low-pressure side and approaches second sealing surface 2a as it moves from high-pressure side bottom 1Ga toward the low-pressure side. The low-pressure side end of low-pressure side groove bottom 1Gb intersects first sealing surface 1a.

[0059] The low-pressure side groove bottom 1Gb is formed by a portion of an arc having a radius Ra. When the depth of the high-pressure side groove bottom 1Ga is set to W, the radius Ra only needs to satisfy Ra>W.

[0060] (Shape of Support Ring 20)

[0061] Reference Figure 4 and Figure 5 The overall shape and cross-sectional shape of the support ring 20 will be described. The support ring 20 has an annular shape. The support ring 20 is provided with a cut surface 20k in order to be mounted in the seal groove 1G of the cylindrical shaft 1A.

[0062] The longitudinal cross-sectional shape of the support ring 20 is a roughly rectangular shape having a bottom surface 20a located on the high-pressure side (O-ring 10 side), a side surface 20b located on the second sealing surface 2a side, an abutment surface 20c along the shape of the low-pressure side groove bottom 1Gb on the side opposite to the low-pressure side groove bottom 1Gb, and an upper surface 20d located on the low-pressure side.

[0063] The shape of the contact surface 20c along the low-pressure side groove bottom 1Gb is described later, including the case where a small gap is generated between the contact surface 20c and the low-pressure side groove bottom 1Gb. Figure 3 In the case where the radius Ra of the low-pressure side groove bottom 1Gb is set to R2.6 mm, the radius Rb of the abutting surface 20 c is set to a curved surface of R2.4 mm.

[0064] The bottom surface 20a corresponds to the first surface, and the side surface 20b corresponds to the second surface rising from the radially outer end of the bottom surface 20a. The contact surface 20c corresponds to the third surface rising from the radially inner end of the bottom surface 20a and opposing the side surface 20b. The top surface 20d connects the side surface 20b and the contact surface 20c and corresponds to the fourth surface opposing the bottom surface 20a. The contact surface 20c is inclined so as to approach the side surface 20b as it approaches the top surface 20d. Specifically, the contact surface 20c includes a curved surface that bulges inward.

[0065] According to the support ring 20 of this embodiment, the side surface 20b located on the second sealing surface 2a side is inclined radially inward from the bottom surface 20a toward the upper surface 20d. Specifically, the side surface 20b is inclined so as to approach the contact surface 20c side as it moves toward the upper surface 20d.

[0066] In this embodiment, the angle (α) between the second sealing surface 2a and the side surface 20b is approximately 85 degrees. As a result, the diameter φA on the bottom surface 20a side of the support ring 20 and the diameter φB on the upper surface 20d side have a relationship of diameter φA>diameter φB.

[0067] (Function of Sealing Structure 100)

[0068] Next, refer to Figure 6 and Figure 7 The function of the sealing structure 100 will be described. Figure 6 is a partially enlarged cross-sectional view showing the sealing state of the sealing structure 100. Figure 7 Schematic diagram showing changes in the sealing state of the sealing structure 100 .

[0069] Reference Figure 6 , shows the O-ring 10 and backup ring 20 housed in the seal groove 1G. In this state, the O-ring 10 is sandwiched between the bottom 1Gs of the seal groove 1G and the second sealing surface 2a, deforming into an elliptical shape. In this figure, gas pressure is not applied to the O-ring 10 from the high-pressure side (the lower side of the figure), so the O-ring 10 does not move toward the backup ring 20.

[0070] Reference Figure 7 , the state where the pressure of the gas in the O-ring 10X gradually increases is represented as state I, state II and state III. Figure 6 State III shows the state where the pressure applied to the support ring 20 is the highest.

[0071] In the state I, no large pressure is applied to the backup ring 20 from the O-ring 10. Therefore, a gap exists between the side surface 20b and the first sealing surface 1a, and the line L1 of the bottom surface 20a does not move (rotate).

[0072] In state II, pressure begins to be applied to the backup ring 20 from the O-ring 10. As a result, the contact surface 20c is shaped to follow the low-pressure side groove bottom 1Gb, and the backup ring 20 begins to move (rotate) along the low-pressure side groove bottom 1Gb. As a result, the gap between the side surface 20b and the first sealing surface 1a decreases, and the line L1 of the bottom surface 20a begins to move (clockwise) in the figure.

[0073] In state III, further pressure is applied to the backup ring 20 from the O-ring 10X. Consequently, the backup ring 20 moves further along the low-pressure side groove bottom 1Gb (clockwise). As a result, the gap between the side surface 20b and the first sealing surface 1a disappears, and the line L1 of the bottom surface 20a moves further (clockwise) in the figure.

[0074] In this manner, when pressure is applied to the support ring 20 from the O-ring 10, the support ring 20 moves (rotates) along the low-pressure side groove bottom 1Gb. As a result, no gap, as in conventional structures, is created between the support ring 20 and the low-pressure side groove bottom 1Gb, and no deformed region is formed in the support ring 20. Consequently, damage to the support ring 20 can be suppressed.

[0075] As described above, according to this embodiment, the bottom portion of the low-pressure side of the seal groove 1G that accommodates the backup ring 20 (low-pressure groove bottom portion 1Gb) is formed into an R-shape, and the contact surface 20c of the backup ring 20, which faces this bottom portion, is formed to conform to the shape of the low-pressure groove bottom portion 1Gb. This eliminates the need for a gap between the backup ring 20 and the seal groove 1G. As a result, even when high pressure is applied to the O-ring 10, deformation of the O-ring 10 can be suppressed.

[0076] In each of the embodiments shown below, other aspects of the cross-sectional shape of the support ring will be described.

[0077] (Embodiment 2: Support Ring 20A)

[0078] Reference Figure 8 and Figure 9 , the overall shape and cross-sectional shape of another type of support ring 20A will be described. Figure 8 is a top view of the support ring 20A, Figure 9 yes Figure 8 The basic structure is the same as that of the support ring 20, so only the differences will be described below.

[0079] When viewed in cross-section, the support ring 20 is a generally rectangular shape having a bottom surface 20a, a side surface 20b, a contact surface 20c, and an upper surface 20d, but the support ring 20A is a generally triangular shape in which the upper surface 20d is not provided and the curved contact surface 20c intersects with the side surface 20b.

[0080] The support ring 20A having this cross-sectional shape can also achieve the same effects as those of the support ring 20 described above.

[0081] (Embodiment 3: Support Ring 20B)

[0082] Reference Figure 10 and Figure 11 , the overall shape and cross-sectional shape of another embodiment of the support ring 20B will be described. Figure 10 is a top view of the support ring 20B, Figure 11 yes Figure 10 The basic structure is the same as that of the support ring 20A, so only the differences will be described below.

[0083] The curved contact surface 20c of the support ring 20A intersects the side surface 20b. However, the contact surface 20c of this embodiment has a curved portion 20c1 on the high-pressure side and a straight portion 20c2 on the low-pressure side.

[0084] Even with this structure, the curved surface portion 20c1 can move (rotate) along the low-pressure side groove bottom portion 1Gb, and thus the same operational effects as those of the support ring 20A can be obtained.

[0085] (Embodiment 4: Support Ring 20C)

[0086] Reference Figure 12 and Figure 13 , the overall shape and cross-sectional shape of another embodiment of the support ring 20C will be described. Figure 12 is a top view of the support ring 20C, Figure 13 yes Figure 12 The basic structure is the same as that of the support ring 20A, so only the differences will be described below.

[0087] The contact surface 20 c of the support ring 20C of the present embodiment includes a curved surface portion 20 c 1 (radius Ra) and a curved surface portion 20 c 3 (radius Rb) having different curvatures.

[0088] Even with this structure, the contact surface 20c can move (rotate) along the low-pressure side groove bottom 1Gb, and thus the same operational effects as those of the support ring 20A can be obtained.

[0089] In the above embodiments, a structure in which a sealing groove 1G is provided on the shaft 1A and a seal and a support are provided on the sealing groove 1G is described. However, when a sealing structure of the above structure is adopted between a sliding rod and a housing, a sealing groove may also be provided on the housing side.

[0090] (Embodiment 5: Sealed Structure 1000A)

[0091] Reference Figure 14 , a case where the above-mentioned sealing structure 100 is applied to a sealing structure 1000A which is different from the above-mentioned sealing structure 1000 will be described. Figure 14 1000A is a cross-sectional view showing the sealed structure. Figure 14 In the cross-sectional view shown, the O-ring 10 and the backup ring 20 are shown in an undeformed state.

[0092] This sealed structure 1000A includes an annular sealing groove 1G on the upper surface of an annular flange 200f provided on a housing 200, which has a centrally located pipe 200h. The upper surface of the annular flange 200f constitutes a first sealing surface 200a, while the lower surface of the plate 300 constitutes a second sealing surface 300a. The plate 300 is fixed to the annular flange 200f at a position not shown.

[0093] Since pipe 200h is on the high-pressure side, a high-pressure side groove bottom 1Ga is provided on the pipe 200h side of the seal groove 1G, and a low-pressure side groove bottom 1Gb is provided outside of the high-pressure side groove bottom 1Ga. An O-ring 10 is provided on the pipe 200h side, and a support ring 20 is provided outside of the O-ring 10. The shape of the support ring 20 can also be the same as the support ring 20A, support ring 20B, and support ring 20C described in the second to fourth embodiments above.

[0094] In the sealed structure 1000A of this embodiment, the same operational effects as those of the sealed structure 1000 of the first embodiment can be obtained.

[0095] The embodiments disclosed herein are to be considered in all respects as illustrative and non-restrictive. The scope of the present invention is indicated by the claims rather than the above description, and is intended to include all modifications within the meaning and scope of the claims and equivalents thereof.

[0096] Description of Reference Numerals

[0097] 1. Head; 1A, Shaft; 1G, Seal Groove; 1Ga, High-Pressure Side Groove Bottom; 1Gb, Low-Pressure Side Groove Bottom; 1Gs, 20a, Bottom; 1a, 200a, First Seal Surface; 1h, Through-Hole; 2, 200, Housing; 2A, Cylindrical Groove; 2a, 300a, Second Seal Surface; 3, Bolt; 10, 10X, 30, O-Ring; 10y, Deformation Area; 20, 20A, 20B, 20C, 40X, support ring; 20b, side surface; 20c, abutment surface; 20c1, 20c3, curved surface portion; 20c2, straight portion; 20d, upper surface; 20k, cutting surface; 50, 300, plate; 200h, pipeline; 200f, annular flange; 100, sealing structure; 200h, pipeline; 1000, 1000A, closed structure.

Claims

1. A sealing structure for separating a high-pressure side from a low-pressure side, wherein: When observing in longitudinal section, The sealing structure has: A component having a first sealing surface, A sealing groove provided on the first sealing surface, A seal is installed in the sealing groove and is arranged on the high pressure side. a support member installed in the sealing groove and arranged on the low-pressure side, and another component, which is arranged opposite to the one component and has a second sealing surface that forms the sealing structure by abutting against the sealing member, The sealing groove has: a high-pressure side groove bottom, which is arranged at a position spaced a certain distance from the second sealing surface on the high-pressure side, and a low-pressure side groove bottom portion which is continuous with the high-pressure side groove bottom portion on the low-pressure side and approaches the second sealing surface side as it moves from the high-pressure side groove bottom portion toward the low-pressure side; The sealing member is arranged between the bottom of the high-pressure side groove and the second sealing surface. The support member is arranged between the bottom of the low-pressure side groove and the second sealing surface. The support member has an abutment surface along the shape of the low-pressure side groove bottom on a side opposite to the low-pressure side groove bottom.

2. The sealing structure according to claim 1, wherein: The support member has an inclined surface on a side facing the second sealing surface that is inclined away from the second sealing surface toward the low-pressure side.

3. The sealing structure according to claim 1, wherein: The bottom of the low-pressure side groove is formed by a part of a circular arc.

4. The sealing structure according to claim 1, wherein: The first sealing surface is the outer peripheral surface of the cylindrical member, The second sealing surface is a cylindrical inner peripheral surface with a bottom provided in the housing and accommodating the cylindrical member and in contact with the first sealing surface. The sealing groove is an annular groove provided on the outer peripheral surface of the cylindrical member. The sealing member and the supporting member have an annular shape.

5. A support member having an annular shape and used together with a seal member in a seal groove provided in a seal structure for separating a high-pressure side and a low-pressure side, wherein: The cross section when observing the longitudinal cross section structure of the support member includes: Page 1; a second surface rising from the radially outer end of the first surface; a third surface rising from the radially inner end of the first surface and facing the second surface; and a fourth surface connecting the second surface and the third surface and facing the first surface, The third surface is inclined so as to approach the second surface side as it goes toward the fourth surface side.

6. The support member according to claim 5, wherein The third surface includes a curved surface that bulges inward.

7. The support member according to claim 5, wherein: The second surface is inclined so as to approach the third surface side as it goes toward the fourth surface side.

Images