Sealing device and sealing structure

Abstract

To enable positioning of a sealing device in an axial direction in a state that sealing performance is properly maintained.SOLUTION: A sealing device 30 is installed between a first member 10 in which a first space S1 is formed on a first surface E1 and a second member 20 in which a second space S2 having a diameter larger than that of the first space S1 is formed on a second surface E2 facing the first surface E1. The sealing device 30 includes a tubular elastic body 40. The elastic body 40 includes: a first outer peripheral surface G1 facing an inner peripheral surface F1 of the first space S1; a second outer peripheral surface G2 which faces an inner peripheral surface F2 of the second space S2 and has a diameter larger than that of the first outer peripheral surface G1; a step surface G12 which forms a step between the first outer peripheral surface G1 and the second outer peripheral surface G2 and contacts with the first surface E1; a first annular projection part 41 projecting from the first outer peripheral surface G1; and a second annular projection part 42 projecting from the second outer peripheral surface G2.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a sealing device and a sealing structure. [Background technology]

[0002] Sealing devices have been proposed for use in connecting a first member having a flow path opening at an end surface thereof to a second member having a flow path opening at an end surface thereof opposite to the first member. For example, Patent Document 1 discloses a structure in which a straight pipe joint seal is used to connect piping flow paths. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2012-255470 Summary of the Invention [Problem to be solved by the invention]

[0004] However, in conventional configurations, it is difficult to position the sealing device in the axial direction. For example, in the configuration of Patent Document 1, the position of the joint seal in the axial direction can be determined by abutting each end of the joint seal against a stepped surface in the flow path. However, when the end of the joint seal is pressed against the stepped surface in the flow path, the seal lip at that end may be excessively deformed, making it impossible to maintain the target sealing performance. In consideration of the above circumstances, one aspect of the present disclosure aims to achieve positioning of the sealing device in the axial direction while appropriately maintaining sealing performance. [Means for solving the problem]

[0005] In order to solve the above problems, one aspect of the present disclosure provides a sealing device that is installed between a first member having a first space formed on a first surface and a second member having a second space formed on a second surface facing the first surface, the second space having a larger diameter than the first space, and the sealing device includes a tubular elastic body, the elastic body including a first outer peripheral surface facing the inner peripheral surface of the first space, a second outer peripheral surface facing the inner peripheral surface of the second space and having a larger diameter than the first outer peripheral surface, a step surface that forms a step between the first outer peripheral surface and the second outer peripheral surface and contacts the first surface, a first annular protrusion protruding from the first outer peripheral surface, and a second annular protrusion protruding from the second outer peripheral surface.

[0006] A sealing structure according to one embodiment of the present disclosure comprises a first member having a first space formed on a first surface, a second member having a second space formed on a second surface facing the first surface, the second space having a larger diameter than the first space, and a sealing device installed between the first member and the second member, wherein the sealing device comprises a tubular elastic body, the elastic body including a first outer peripheral surface facing the inner peripheral surface of the first space, a second outer peripheral surface facing the inner peripheral surface of the second space and having a larger diameter than the first outer peripheral surface, a step surface forming a step between the first outer peripheral surface and the second outer peripheral surface and contacting the first surface, a first annular protrusion protruding from the first outer peripheral surface, and a second annular protrusion protruding from the second outer peripheral surface. [Brief explanation of the drawings]

[0007] [Figure 1] FIG. 2 is a cross-sectional view of the sealing structure according to the embodiment. [Figure 2] FIG. [Figure 3] FIG. 10 is a cross-sectional view of a sealing structure in a comparative example. [Figure 4] FIG. 10 is a diagram illustrating the effect of the embodiment. [Figure 5] 10A to 10C are explanatory diagrams of a manufacturing process of the sealed structure. [Figure 6] FIG. 10 is a cross-sectional view of a sealing device according to a modified example. [Figure 7] FIG. 10 is a cross-sectional view of a sealing device according to a modified example. [Figure 8]FIG. 10 is a cross-sectional view of a sealing device according to a modified example. [Figure 9] FIG. 10 is a cross-sectional view of a sealing device according to a modified example. [Figure 10] FIG. 10 is a cross-sectional view of a sealing device according to a modified example. DETAILED DESCRIPTION OF THE INVENTION

[0008] The embodiments for carrying out the present disclosure will be described with reference to the drawings. Note that the dimensions and scale of each element in each drawing may differ from those of the actual product. Furthermore, the embodiment described below is an exemplary embodiment that may be envisioned when carrying out the present disclosure. Therefore, the scope of the present disclosure is not limited to the embodiment exemplified below.

[0009] A: Embodiment FIG. 1 is a cross-sectional view of a sealing structure 100 according to one embodiment of the present disclosure. The sealing structure 100 of this embodiment is a structure used in a cooling unit mounted on a moving body such as an automobile. The cooling unit is a heat transport mechanism for efficiently utilizing exhaust heat radiated from a power source such as an internal combustion engine or an electric motor. However, the uses of the sealing structure 100 are not limited to the above examples.

[0010] 1, the sealing structure 100 of this embodiment includes a first member 10, a second member 20, and a sealing device 30. The first member 10 and the second member 20 are pipes that are connected to each other to form a refrigerant flow path. The sealing device 30 is a tubular structure installed between the first member 10 and the second member 20, and seals the refrigerant flow path at the boundary between the first member 10 and the second member 20. The first member 10, the second member 20, and the sealing device 30 are arranged concentrically.

[0011] 1 illustrates a central axis Z of the sealing device 30. In the following description, one direction along the central axis Z is referred to as the Z1 direction, and the direction opposite to the Z1 direction is referred to as the Z2 direction. Furthermore, the direction of the circumference of an imaginary circle of any diameter centered on the central axis Z is referred to as the "circumferential direction," and the direction of the radius of the imaginary circle is referred to as the "radial direction." In the radial direction, the direction toward the central axis Z is referred to as the "inner side," and the direction opposite the central axis Z is referred to as the "outer side."

[0012] The first member 10 is a tubular structure having a first surface E1. The first surface E1 is an end surface of the first member 10 facing the Z2 direction. Specifically, the first surface E1 is a flat surface perpendicular to the central axis Z of the sealing device 30.

[0013] A first space S1 and a first flow path P1 are formed inside the first member 10. The first space S1 is a space that opens to the first surface E1. Specifically, the first space S1 is a cylindrical space (i.e., a circular cross section) with an inner diameter Da1. The first flow path P1 is a refrigerant flow path that communicates with the first space S1. The first flow path P1 is located, for example, in the Z1 direction of the first space S1.

[0014] The second member 20 is a tubular structure having a second surface E2. The second surface E2 is an end surface of the second member 20 facing the Z1 direction. Specifically, the second surface E2 is a flat surface perpendicular to the central axis Z of the sealing device 30. The first surface E1 of the first member 10 and the second surface E2 of the second member 20 face each other. Specifically, the first member 10 and the second member 20 are connected with the first surface E1 and the second surface E2 in contact with each other.

[0015] A second space S2 and a second flow path P2 are formed inside the second member 20. The second space S2 is a space that opens to the second surface E2. Specifically, the second space S2 is a cylindrical space (i.e., a circular cross section) with an inner diameter Da2. The second flow path P2 is a refrigerant flow path that communicates with the second space S2. The second flow path P2 is located, for example, in the Z2 direction of the second space S2.

[0016] The inner diameter Da2 of the second space S2 is greater than the inner diameter Da1 of the first space S1 (Da2>Da1). That is, the second space S2 has a larger diameter than the first space S1. Therefore, when the first member 10 and the second member 20 are connected, a step surface X facing the Z2 direction is formed between the first surface E1 and the second surface E2. The step surface X is a region of the first surface E1 that is located inside the second space S2 when viewed from the direction of the central axis Z. That is, the step surface X is a flat surface with an annular shape (width=(Da2-Da1) / 2) that follows the inner circumferential edge of the first surface E1.

[0017] The sealing device 30 is housed in a space S consisting of a first space S1 and a second space S2. The sealing device 30 is a joint seal that seals the space S. Specifically, the sealing device 30 prevents the refrigerant flowing through the first flow path P1, the space S, and the second flow path P2 from leaking from a gap between the first surface E1 and the second surface E2.

[0018] Fig. 2 is a cross-sectional view of the sealing device 30 when it is not housed in the space S. As illustrated in Fig. 2, the sealing device 30 includes an elastic body 40 and a reinforcing body 50. The sealing device 30 is a molded product in which the elastic body 40 and the reinforcing body 50 are integrally formed by, for example, insert molding.

[0019] The elastic body 40 is a tubular structure that is elastically deformable. The elastic body 40 is formed from an elastic material such as a rubber material. Examples of rubber materials used to manufacture the elastic body 40 include various rubber materials such as chloroprene rubber (CR), silicone rubber (SR), acrylic rubber (ACM), urethane rubber (U), polyurethane rubber (PUR), vinyl methyl silicone rubber (VMQ), ethylene propylene diene rubber (EPDM), and fluororubber (FKM).

[0020] The reinforcing body 50 is a tubular structure having higher rigidity than the elastic body 40, and reinforces the mechanical strength of the sealing device 30. Most of the reinforcing body 50 is covered by the elastic body 40. That is, the reinforcing body 50 is embedded in the elastic body 40. The reinforcing body 50 is formed of, for example, a metal material. Examples of metal materials used to manufacture the reinforcing body 50 include stainless steel, SPCC (Steel Plate Cold Commercial), and SPHC (Steel Plate Hot Commercial). The reinforcing body 50 may be formed of, for example, a resin material having higher rigidity than the elastic body 40. As described above, in this embodiment, the reinforcing body 50 having higher rigidity than the elastic body 40 is installed, and therefore the mechanical strength of the sealing device 30 can be appropriately maintained compared to a configuration in which the sealing device 30 is composed of only the elastic body 40.

[0021] 2, the elastic body 40 includes an outer peripheral surface G and an inner peripheral surface H. The outer peripheral surface G is the outer surface (the surface opposite to the central axis Z) of the elastic body 40. The inner peripheral surface H is the inner surface (the surface on the central axis Z side) of the elastic body 40.

[0022] The outer peripheral surface G of the elastic body 40 includes a first outer peripheral surface G1 and a second outer peripheral surface G2. The first outer peripheral surface G1 is located in the Z1 direction of the second outer peripheral surface G2. As illustrated in FIG. 1 , the first outer peripheral surface G1 is a cylindrical surface that faces the inner peripheral surface F1 of the first space S1 at a predetermined distance from the outer peripheral surface G. The second outer peripheral surface G2 is a cylindrical surface that faces the inner peripheral surface F2 of the second space S2 at a predetermined distance from the outer peripheral surface G.

[0023] The outer diameter Db2 of the second outer peripheral surface G2 is greater than the outer diameter Db1 of the first outer peripheral surface G1 (Db2>Db1). That is, the second outer peripheral surface G2 has a larger diameter than the first outer peripheral surface G1. Therefore, a step surface G12 facing the Z1 direction is formed between the first outer peripheral surface G1 and the second outer peripheral surface G2. The step surface G12 constitutes a step between the first outer peripheral surface G1 and the second outer peripheral surface G2. That is, the step surface G12 is a flat surface with an annular shape (width=(Db2-Db1) / 2) perpendicular to the central axis Z. As can be understood from the above explanation, the region of the outer peripheral surface G that is located in the Z1 direction of the step surface G12 is the first outer peripheral surface G1, and the region of the step surface G12 that is located in the Z2 direction is the second outer peripheral surface G2. As illustrated in FIG. 1, the step surface G12 of the elastic body 40 comes into contact with the step surface X between the first member 10 and the second member 20.

[0024] 2, the elastic body 40 includes a first protrusion 41, a second protrusion 42, and a third protrusion 43. The first protrusion 41 and the third protrusion 43 protrude radially outward from the first outer peripheral surface G1. The second protrusion 42 protrudes radially outward from the second outer peripheral surface G2. That is, the second protrusion 42 is located further in the Z2 direction than the first protrusion 41. The third protrusion 43 is located between the first protrusion 41 and the second protrusion 42.

[0025] The first protrusion 41 is located near the end of the first outer peripheral surface G1 in the Z1 direction. The first protrusion 41 is an annular protrusion that extends around the entire circumference of the first outer peripheral surface G1. Specifically, the first protrusion 41 is a truncated conical seal lip that expands in diameter in the Z1 direction. That is, the outer diameter of the first protrusion 41 at its tip end is greater than the outer diameter of the first protrusion 41 at its base end. The Z1 direction is the direction along the central axis Z away from the step surface G12. Therefore, the first protrusion 41 is an annular protrusion that expands in diameter in the direction (Z2 direction) away from the step surface G12 along the central axis Z.

[0026] 1, when the sealing device 30 is installed in the space S, the first protrusion 41 contacts the inner circumferential surface F1 of the first space S1. The first protrusion 41 is pressed inward by the inner circumferential surface F1 of the first space S1, causing the first protrusion 41 to curve radially inward. The area of ​​the first protrusion 41 that contacts the inner circumferential surface F1 forms a sealing surface.

[0027] The second protrusion 42 in Fig. 2 is located near the end of the second outer peripheral surface G2 in the Z2 direction. The second protrusion 42 is an annular protrusion that extends around the entire circumference of the second outer peripheral surface G2. Specifically, the second protrusion 42 is a bead that protrudes radially from the second outer peripheral surface G2. For example, the cross-sectional shape of the second protrusion 42 is trapezoidal (specifically, an isosceles trapezoidal).

[0028] 1, when the sealing device 30 is installed in the space S, the second protrusion 42 contacts the inner circumferential surface F2 of the second space S2. The second protrusion 42 is pressed inward by the inner circumferential surface F2 of the second space S2, thereby compressing the second protrusion 42 radially inward. The region of the second protrusion 42 that contacts the inner circumferential surface F2 forms a sealing surface.

[0029] The third protrusion 43 in Fig. 2 is formed on the first outer peripheral surface G1 together with the first protrusion 41. Specifically, the third protrusion 43 is disposed near the base end of the first protrusion 41. That is, the third protrusion 43 protrudes radially outward from the first outer peripheral surface G1 between the first protrusion 41 and the step surface G12. The third protrusion 43 is an annular protrusion that extends around the entire circumference of the first outer peripheral surface G1.

[0030] As illustrated in FIG. 2, the height h3 of the third protrusion 43 is less than the height h1 of the first protrusion 41 (h3

[0031] The inner circumferential surface H of the elastic body 40 includes a first inner circumferential surface H1 and a second inner circumferential surface H2. The first inner circumferential surface H1 is located in the Z1 direction of the second inner circumferential surface H2. Specifically, the first inner circumferential surface H1 is a portion of the inner circumferential surface H that corresponds to the first outer circumferential surface G1. On the other hand, the second inner circumferential surface H2 is a portion of the inner circumferential surface H that corresponds to the second outer circumferential surface G2.

[0032] The inner diameter Dc2 of the second inner circumferential surface H2 is greater than the inner diameter Dc1 of the first inner circumferential surface H1 (Dc2>Dc2). That is, the second inner circumferential surface H2 has a larger diameter than the first inner circumferential surface H1. Therefore, an annular step surface H12 facing in the Z2 direction is formed between the first inner circumferential surface H1 and the second inner circumferential surface H2.

[0033] As described above, in this embodiment, the second inner circumferential surface H2 of the elastic body 40 has a larger diameter than the first inner circumferential surface H1, and therefore the amount of material used for the elastic body 40 can be reduced compared to a configuration in which the second inner circumferential surface H2 of the elastic body 40 has the same diameter as the first inner circumferential surface H1 (for example, the configuration of Figure 8).

[0034] 2, the reinforcing body 50 of the sealing device 30 is a structure in which a first portion 51, a second portion 52, and a step portion 53 are integrally formed. For example, the reinforcing body 50 is manufactured by press working a metal ring.

[0035] ​The first portion 51 is a tubular portion of the reinforcing body 50 located in the Z1 direction. Specifically, the first portion 51 is a cylindrical portion of the reinforcing body 50 that corresponds to the inner circumferential surface F1 of the first member 10. Therefore, the first portion 51 is located inside the first outer circumferential surface G1 of the elastic body 40.

[0036] The second portion 52 is a tubular portion of the reinforcing body 50 located in the Z2 direction. Specifically, the second portion 52 is a cylindrical portion of the reinforcing body 50 that corresponds to the inner circumferential surface F2 of the second member 20. Therefore, the second portion 52 is located inside the second outer circumferential surface G2 of the elastic body 40.

[0037] The step portion 53 is a portion that connects the first portion 51 and the second portion 52. As illustrated in FIG. 2, the second portion 52 has a larger diameter than the first portion 51. The step portion 53 forms a step between the first portion 51 and the second portion 52. In other words, the step portion 53 is an annular flat portion that is perpendicular to the central axis Z. In the direction of the central axis Z, the step portion 53 of the reinforcing body 50 is located between the step surface G12 of the outer peripheral surface G and the step surface H12 of the inner peripheral surface H.

[0038] In the above configuration, the first space S1 and the second space S2 may become eccentric due to errors such as manufacturing errors or assembly errors. For example, FIGS. 3 and 4 show a state in which the second space S2 is eccentric to the left relative to the first space S1. When the first space S1 and the second space S2 are eccentric, the central axis Z of the sealing device 30 is inclined with respect to the central axes of the first space S1 and the second space S2. In other words, the sealing device 30 is eccentric with respect to the first space S1.

[0039] FIG. 3 shows an embodiment (hereinafter referred to as the "comparative example") in which the third protrusion 43 is not formed. As illustrated in FIG. 3, in the comparative example, when the sealing device 30 is eccentric with respect to the first space S1, the first outer peripheral surface G1 of the sealing device 30 may come excessively close to the inner peripheral surface F1 of the first space S1. When the first outer peripheral surface G1 comes excessively close to the inner peripheral surface F1, the portion of the first protrusion 41 that comes close to the inner peripheral surface F1 (the portion on the left side in FIG. 3) is pressed by the inner peripheral surface F1 and is excessively deformed, and the portion of the first protrusion 41 opposite to the portion on the right side in FIG. 3 is not deformed enough to maintain sufficient sealing performance. That is, in the comparative example, the eccentricity of the sealing device 30 with respect to the first space S1 may prevent the first protrusion 41 from maintaining an appropriate interference.

[0040] In contrast to the comparative example, in this embodiment, a third protrusion 43 is formed on the first outer peripheral surface G1. When the sealing device 30 is eccentric with respect to the first space S1, as illustrated in FIG. 4 , the third protrusion 43 abuts against the inner peripheral surface F1 of the first space S1, thereby suppressing further eccentricity of the sealing device 30. That is, excessive eccentricity of the sealing device 30 with respect to the first space S1 is suppressed. Therefore, excessive or insufficient deformation of the first protrusion 41 caused by eccentricity of the sealing device 30 is reduced, and as a result, an appropriate interference can be maintained for the first protrusion 41. That is, it is possible to appropriately ensure the sealing performance of the first protrusion 41.

[0041] In particular, in this embodiment, since the third protrusion 43 is formed in an annular shape, even if the sealing device 30 is eccentric relative to the first space S1 in any direction within a plane perpendicular to the central axis Z, excessive approach between the inner circumferential surface F1 of the first space S1 and the first outer circumferential surface G1 is suppressed. Therefore, the above-mentioned effect that an appropriate interference between the first protrusion 41 and the inner circumferential surface F1 of the first space S1 can be maintained is particularly remarkable.

[0042] FIG. 5 is a process diagram illustrating an example of the procedure for assembling the sealing structure 100. As illustrated in FIG. 5, in step Q1, a portion of the sealing device 30 located in the Z1 direction is accommodated in the first space S1 of the first member 10. Specifically, first, the sealing device 30 is moved in the Z1 direction with the first protrusion 41 bent radially inward, thereby causing the first protrusion 41 to enter the first space S1. The sealing device 30 is moved in the Z1 direction until the step surface G12 of the elastic body 40 abuts against the first surface E1 (step surface X) of the first member 10. When the step surface G12 of the elastic body 40 abuts against the first surface E1 (step surface X), the position of the sealing device 30 relative to the first member 10 in the direction of the central axis Z is determined.

[0043] In step Q2 after step Q1, the first member 10 is joined to the second member 20. Specifically, in the process of moving the second member 20 in the Z1 direction to approach the first member 10, the portion of the sealing device 30 located in the Z2 direction is accommodated in the second space S2 of the second member 20. When the second surface E2 of the second member 20 comes into contact with the first surface E1 of the first member 10, the first member 10 and the second member 20 are fixed to each other by fasteners (not shown), such as screws or bolts. The sealing structure 100 is configured by the procedure exemplified above.

[0044] As described above, in this embodiment, the first space S1 and the second space S2 are connected to each other in a sealed state by the contact of the first protrusion 41 with the inner circumferential surface F1 of the first space S1 and the contact of the second protrusion 42 with the inner circumferential surface F2 of the second space S2. Furthermore, the position of the sealing device 30 in the direction of the central axis Z can be determined by the abutment of the step surface G12 of the elastic body 40 with the first surface E1. That is, the sealing device 30 can be positioned in the direction of the central axis Z while maintaining sealing performance by the first protrusion 41 and the second protrusion 42.

[0045] In this embodiment, the first protrusion 41 is configured by a seal lip, and the second protrusion 42 is configured by a bead. Generally, a seal lip is more easily deformed in the radial direction than a bead. In step Q1 of accommodating the portion of the elastic body 40 corresponding to the first outer peripheral surface G1 in the first space S1, the elastic body 40 can be easily inserted into the first space S1 by deforming the first protrusion 41 (seal lip), and the step surface G12 of the elastic body 40 abuts against the first surface E1, thereby determining the position of the sealing device 30 in the direction of the central axis Z.

[0046] Furthermore, in this embodiment, the reinforcing body 50 is installed so as to extend over both the portion of the elastic body 40 corresponding to the first outer peripheral surface G1 and the portion of the elastic body 40 corresponding to the second outer peripheral surface G2. Therefore, compared to a configuration in which the reinforcing body 50 is installed only in one of the portion of the elastic body 40 corresponding to the first outer peripheral surface G1 and the portion of the elastic body 40 corresponding to the second outer peripheral surface G2, or a configuration in which the first portion 51 and the second portion 52 are separate members (e.g., the configuration of FIG. 10 ), the mechanical strength of the entire sealing device 30 can be appropriately maintained. For example, since the mechanical strength is ensured also in the portion of the elastic body 40 near the stepped surface G12, the sealing device 30 can be appropriately positioned by the stepped surface G12 abutting against the first surface E1. In particular, in this embodiment, since the reinforcing body 50 includes the stepped portion 53, the mechanical strength of the portion of the elastic body 40 near the stepped surface G12 can be easily ensured. Therefore, the sealing device 30 can be easily and reliably positioned by the stepped surface G12 abutting against the first surface E1.

[0047] B: Modified example Specific modified embodiments that can be added to the embodiments exemplified above are shown below. Two or more embodiments arbitrarily selected from the following examples may be combined as appropriate within the scope of not being mutually contradictory.

[0048] (1) In the embodiment, the second protrusion 42 is a bead, but the form of the second protrusion 42 is not limited to the above example. For example, as illustrated in FIG. 6, the second protrusion 42 may be a seal lip. The second protrusion 42 in FIG. 6 is a truncated cone-shaped seal lip whose diameter increases in the Z2 direction. Furthermore, in the embodiment, the first protrusion 41 is a seal lip, but the first protrusion 41 may be a bead.

[0049] (2) In the embodiment, the elastic body 40 includes the third protrusion 43, but the third protrusion 43 may be omitted as shown in Fig. 7. That is, the comparative example shown in Fig. 3 is also included in the scope of the present disclosure.

[0050] (3) In the embodiment, a configuration is illustrated in which, in a standard state in which the sealing device 30 is arranged concentrically with the first member 10, the third protrusion portion 43 faces the inner surface F1 at a distance, but in the standard state, the third protrusion portion 43 may also contact the inner surface F1 of the first member 10.

[0051] (4) In the embodiment, a configuration in which a step is formed between the first inner circumferential surface H1 and the second inner circumferential surface H2 that constitute the inner circumferential surface H of the elastic body 40 has been exemplified, but the step may be omitted from the inner circumferential surface H. For example, as illustrated in Fig. 8, the inner circumferential surface H of the elastic body 40 may be a simple cylindrical surface with a substantially constant inner diameter.

[0052] (5) In the embodiment, the sealing device 30 includes the elastic body 40 and the reinforcing body 50. However, as shown in Fig. 9, the reinforcing body 50 may be omitted. That is, the sealing device 30 may be configured with only the elastic body 40.

[0053] (6) In the embodiment, an example of an integrated reinforcing body 50 in which the first portion 51 and the second portion 52 are connected via the step portion 53 is shown, but the form of the reinforcing body 50 is not limited to the above example. For example, as shown in Fig. 10, the first portion 51 and the second portion 52 of the reinforcing body 50 may be configured as separate bodies. Also, one of the first portion 51 and the second portion 52 in Fig. 10 may be omitted.

[0054] (7) In the embodiment, the third protrusion 43 is formed in an annular shape, but the shape of the third protrusion 43 is not limited to the above example. For example, the third protrusion 43 may be formed by a plurality of protrusions arranged at intervals along the circumferential direction of the first outer peripheral surface G1. However, according to the configuration of the embodiment in which the third protrusion 43 is formed in an annular shape, as described above, excessive proximity between the inner peripheral surface F1 of the first space S1 and the first outer peripheral surface G1 can be suppressed, regardless of the direction of eccentricity of the sealing device 30 with respect to the first space S1.

[0055] (8) The term "nth" (n is a natural number) in this application is used only as a formal and convenient label to distinguish each element in the description and does not have any substantive meaning. Therefore, there is no room for restrictive interpretation of the position of each element or the order of manufacture, etc., based on the term "nth."

[0056] C: Notes From the above-described exemplary embodiments, the following configurations can be understood, for example.

[0057] A sealing device according to one aspect (Aspect 1) of the present disclosure is a sealing device installed between a first member having a first space formed in a first surface and a second member having a second space formed in a second surface facing the first surface, the second space having a larger diameter than the first space. The sealing device includes a tubular elastic body. The elastic body includes a first outer surface facing the inner surface of the first space, a second outer surface facing the inner surface of the second space and having a larger diameter than the first outer surface, a step surface that forms a step between the first outer surface and the second outer surface and contacts the first surface, a first annular protrusion protruding from the first outer surface, and a second annular protrusion protruding from the second outer surface. In the above aspect, the first space and the second space are connected to each other in a sealed state by the contact of the first protrusion with the inner surface of the first space and the contact of the second protrusion with the inner surface of the second space. Furthermore, the position of the sealing device in the axial direction can be determined by the contact of the step surface of the elastic body with the first surface. That is, the first protrusion and the second protrusion can achieve positioning of the sealing device in the axial direction while maintaining sealing performance.

[0058] In a specific example (Aspect 2) of Aspect 1, the first protrusion is a seal lip that expands in diameter along the central axis of the elastic body in a direction away from the stepped surface, and the second protrusion is a bead that protrudes radially from the second outer peripheral surface. In the above aspect, the seal lip is more easily deformed radially than the bead. In the step of accommodating the portion of the elastic body corresponding to the first outer peripheral surface in the first space, the elastic body can be easily inserted into the first space by deforming the seal lip, and the stepped surface of the elastic body abuts against the first surface, thereby determining the position of the sealing device in the axial direction.

[0059] In a specific example (Aspect 3) of Aspect 1 or Aspect 2, a third protrusion protruding from the first outer peripheral surface between the first protrusion and the step surface is further provided, and the height of the third protrusion is less than the height of the first protrusion. In the above aspect, when the sealing device is eccentric with respect to the first space, the third protrusion contacts the inner peripheral surface of the first space, thereby preventing the inner peripheral surface and the first outer peripheral surface from coming too close to each other. In other words, the possibility of the first protrusion being pressed by the inner peripheral surface of the first space and causing excessive deformation of the first protrusion is reduced. Therefore, an appropriate interference between the first protrusion and the inner peripheral surface of the first space can be maintained.

[0060] In a specific example (Aspect 4) of Aspect 3, the third protrusion is formed in an annular shape around the entire circumference of the first outer peripheral surface. In the above aspect, since the third protrusion is formed in an annular shape, even if the sealing device is eccentric relative to the first space in any direction within a plane perpendicular to the central axis, excessive approach between the inner peripheral surface of the first space and the first outer peripheral surface is suppressed. Therefore, the aforementioned effect of being able to maintain an appropriate interference between the first protrusion and the inner peripheral surface of the first space is particularly remarkable.

[0061] In a specific example (Aspect 5) of any one of Aspects 1 to 4, a tubular reinforcing body having higher rigidity than the elastic body is further provided. In the above aspects, a reinforcing body having higher rigidity than the elastic body is provided, so that the mechanical strength of the sealing device can be appropriately maintained compared to an aspect in which the sealing device is composed of only an elastic body.

[0062] In a specific example (Aspect 6) of Aspect 5, the reinforcing body is an integral member including a tubular first portion located inside the first outer peripheral surface and a tubular second portion located inside the second outer peripheral surface. In the above aspects, the reinforcing body is installed so as to extend over both the portion of the elastic body corresponding to the first outer peripheral surface and the portion of the elastic body corresponding to the second outer peripheral surface. Therefore, compared to an aspect in which the reinforcing body is installed only in the portion of the elastic body corresponding to the first outer peripheral surface or the portion of the elastic body corresponding to the second outer peripheral surface, or an aspect in which the first portion and the second portion are separate members, the mechanical strength of the sealing device can be appropriately maintained throughout. In particular, because the mechanical strength is ensured even in the portion of the elastic body near the stepped surface, the sealing device can be appropriately positioned by abutting the stepped surface against the first surface.

[0063] In a specific example (Aspect 7) of Aspect 6, the second portion has a larger diameter than the first portion, and the reinforcing body further includes a stepped portion that defines a step between the first portion and the second portion. In the above aspect, since the reinforcing body includes the stepped portion, it is easy to ensure mechanical strength for the portion of the elastic body near the stepped surface. Therefore, it is possible to easily and reliably position the sealing device by abutting the stepped surface against the first surface.

[0064] In a specific example (Aspect 8) of any of Aspects 1 to 7, the elastic body further includes a first inner circumferential surface corresponding to the first outer circumferential surface, and a second inner circumferential surface corresponding to the second outer circumferential surface and having a larger diameter than the first inner circumferential surface. In the above aspects, since the second inner circumferential surface of the elastic body has a larger diameter than the first inner circumferential surface, the amount of material used for the elastic body can be reduced compared to an aspect in which the second inner circumferential surface of the elastic body has the same diameter as the first inner circumferential surface.

[0065] A sealing structure according to one aspect (aspect 9) of the present disclosure comprises a first member having a first space formed on a first surface, a second member having a second space formed on a second surface opposite the first surface, the second space having a larger diameter than the first space, and a sealing device installed between the first member and the second member, wherein the sealing device comprises a tubular elastic body, the elastic body including a first outer peripheral surface facing the inner peripheral surface of the first space, a second outer peripheral surface facing the inner peripheral surface of the second space and having a larger diameter than the first outer peripheral surface, a step surface forming a step between the first outer peripheral surface and the second outer peripheral surface and contacting the first surface, a first annular protrusion protruding from the first outer peripheral surface, and a second annular protrusion protruding from the second outer peripheral surface. [Explanation of symbols]

[0066] 100...sealing structure, 10...first member, 20...second member, 30...sealing device, 40...elastic body, 41...first protrusion, 42...second protrusion, 43...third protrusion, 50...reinforcing body, 51...first part, 52...second part, 53...step part.

Claims

1. A sealing device installed between a first member having a first space formed in a first surface and a second member having a second space formed in a second surface facing the first surface, the second space having a larger diameter than the first space, A tubular elastic body is provided. The elastic body is a first outer peripheral surface facing an inner peripheral surface of the first space; a second outer peripheral surface facing an inner peripheral surface of the second space and having a larger diameter than the first outer peripheral surface; a step surface that forms a step between the first outer peripheral surface and the second outer peripheral surface and is in contact with the first surface; a first annular protrusion protruding from the first outer peripheral surface; a second annular protrusion protruding from the second outer circumferential surface Sealing device.

2. the first protrusion is a seal lip whose diameter increases in a direction away from the step surface along a central axis of the elastic body, The second protrusion is a bead that protrudes radially from the second outer circumferential surface. The sealing device of claim 1.

3. a third protrusion protruding from the first outer peripheral surface between the first protrusion and the step surface, The height of the third protrusion is less than the height of the first protrusion. The sealing device according to claim 1 or 2.

4. The third protrusion is formed in an annular shape over the entire circumference of the first outer peripheral surface. The sealing device of claim 3.

5. a tubular reinforcing member having higher rigidity than the elastic member; The sealing device of claim 1 further comprising:

6. The reinforcing body is a tubular first portion located inside the first outer circumferential surface; a tubular second portion located inside the second outer circumferential surface; The sealing device of claim 5.

7. the second portion has a larger diameter than the first portion; The reinforcing body is The step portion further includes a step portion that forms a step between the first portion and the second portion. The sealing device of claim 6.

8. The elastic body is a first inner peripheral surface corresponding to the first outer peripheral surface; a second inner circumferential surface corresponding to the second outer circumferential surface and having a larger diameter than the first inner circumferential surface. The sealing device of claim 1.

9. a first member having a first space formed in a first surface; a second member having a second space formed in a second surface facing the first surface, the second space having a larger diameter than the first space; a sealing device disposed between the first member and the second member, The sealing device includes a tubular elastic body, The elastic body is a first outer peripheral surface facing an inner peripheral surface of the first space; a second outer peripheral surface facing an inner peripheral surface of the second space and having a larger diameter than the first outer peripheral surface; a step surface that forms a step between the first outer peripheral surface and the second outer peripheral surface and is in contact with the first surface; a first annular protrusion protruding from the first outer peripheral surface; a second annular protrusion protruding from the second outer circumferential surface Sealed structure.

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