Seal member and sealing structure

Abstract

Provided is a seal member that maintains the function of a seal member having protruding parts on both an outer peripheral part and an inner peripheral part, and that has improved fitting properties. An annular seal member 40 is provided between an exterior member 30 that has a cylindrical hole part 31 and an interior member 20 that is disposed inside the hole part 31 and extends along the axis of the hole part 31, said seal member 40 having: an inner peripheral part 50 that has first base parts 52 on both end parts in the axial direction which seal between the interior member 20 and the seal member 40, and an annular first protruding part 54 which protrudes further towards the interior member 20 in comparison to the first base parts 52; and an outer peripheral part 60 that has second base parts 62 on both end parts in the axial direction which seal between the structure body 30 and the seal member 40, and an annular second protruding part 64 which protrudes further towards the structure body 30 in comparison to the second base parts 62. The position in the axial direction of the peak of the second protruding part 64 is offset from the peak of the first protruding part 54.

Description

Seal member and sealing structure

[0001] The present invention relates to a seal member and a sealing structure.

[0002] As a sealing member for sealing between a hole formed in a structure such as an inverter of an electric vehicle and a shaft material arranged inside the hole, sealing members such as those described in International Publication No. 2023 / 210627 (hereinafter referred to as Patent Document 1) and Japanese Patent Laid-Open Publication No. 2016-38076 (hereinafter referred to as Patent Document 2) are known.

[0003] The sealing member described in Patent Document 1 seals between the hole of the structure at multiple locations that are different in the axial direction by using first and second large-diameter outer surfaces provided at both axial ends and a third large-diameter outer surface provided between the first and second large-diameter outer surfaces in the axial direction. The sealing member described in Patent Document 1 seals between the hole of the structure and an inner member disposed inside the hole of the structure at multiple locations that are different in the axial direction by using first and second small-diameter inner surfaces provided at both axial ends and a third small-diameter inner surface provided between the first and second small-diameter inner surfaces in the axial direction.

[0004] In the seal member described in Patent Document 1, the third large-diameter outer peripheral surface and the third small-diameter inner peripheral surface are axially positioned to overlap each other, so when the seal member described in Patent Document 1 is assembled to the hole of the structure and the inner member, the elastic force of the third large-diameter outer peripheral surface and the third small-diameter inner peripheral surface increases the resistance (friction) of the seal member against the structure or the inner member, resulting in poor installation ease.

[0005] The sealing member described in Patent Document 2 is spaced axially from both axial ends of the sealing member, and a plurality of protruding outer circumferential seal portions formed on the outer periphery of the cylindrical main body seal at a plurality of different axial positions between the sealing member and the hole of the structure. The sealing member described in Patent Document 2 is spaced axially from both axial ends of the sealing member, and a plurality of lip-shaped inner circumferential seal portions formed on the inner periphery of the cylindrical main body seal at a plurality of different axial positions between the sealing member and the inner member disposed inside the hole of the structure.

[0006] The sealing member described in Patent Document 2 does not have a protruding portion for sealing with the hole of the structure or a lip-shaped portion for sealing with the inner member at both ends of the cylindrical main body, and therefore the sealing member described in Patent Document 2 has poor sealing properties at both ends of the cylindrical main body.

[0007] An object of the present disclosure is to provide a seal member that maintains the functionality of a seal member having protrusions on both the outer and inner peripheries and has improved mountability.

[0008] An aspect of the present disclosure is an annular sealing member provided between an outer member having a cylindrical hole and an inner member disposed inside the hole and extending along the axis of the hole, the sealing member having an inner circumferential portion having a first base portion that seals between the inner member and the inner member at both axial ends, and an annular first protrusion portion that protrudes from the first base toward the inner member and is spaced axially from the first base, the first protrusion portion being spaced axially from the first base, the outer circumferential portion having a second base portion that seals between the outer member and the outer member at both axial ends, and an annular second protrusion portion that protrudes from the second base toward the outer member and is spaced axially from the second base, the second protrusion portion being spaced axially from the second base, and the sealing member having an axial position of an apex of the second protrusion that is offset with respect to the apex of the first protrusion.

[0009] According to the present disclosure, it is possible to provide a seal member that maintains the functionality of a seal member having protrusions on both the outer and inner peripheries and improves mountability.

[0010] 1 is a cross-sectional view of the periphery of a seal member of a structure according to a first embodiment; FIG. 1 is a cross-sectional view of a seal member alone according to the first embodiment in an unassembled state; FIG. 2 is a cross-sectional view of a seal member alone according to a comparative embodiment in an unassembled state; FIG. 3 is a cross-sectional view of a seal member according to a second embodiment in an unassembled state; FIG. 4 is a cross-sectional view of an outer member being assembled to a seal member assembled to an inner member according to the first embodiment; FIG. 5 is a cross-sectional view of an outer member being assembled to a seal member assembled to an inner member according to the first embodiment; FIG. 6 is a graph showing an insertion load applied to an outer member when assembling the outer member to a seal member assembled to an inner member according to a comparative embodiment; FIG. 7 is a graph showing an insertion load applied to an outer member when assembling the outer member to a seal member assembled to an inner member according to the first embodiment;

[0011] Hereinafter, embodiments of the present disclosure will be described with reference to the drawings. The drawings are not necessarily drawn to scale, and some features may be exaggerated or omitted.

[0012] In the following description, the direction along the axial direction of the shaft member inserted into the hole of the structure is referred to as the X direction. The direction in which the abutment portion formed on the shaft member faces is referred to as the -X direction. The direction opposite to the -X direction is referred to as the +X direction. Furthermore, in the radial direction relative to the axial direction, the direction away from the central axis of the hole of the structure is referred to as the radially outward direction. In the radial direction relative to the axial direction, the direction toward the central axis of the hole of the structure is referred to as the radially inward direction.

[0013] First Embodiment A seal member 40 according to a first embodiment of the present disclosure is applied to an electric device (not shown) disposed in an electric vehicle, etc. The electric device is, for example, an inverter.

[0014] 1, the electric device according to the first embodiment includes a structure 30, a shaft member 20, and a seal member 40. The structure 30, the shaft member 20, and the seal member 40 form a sealed structure.

[0015] As shown in FIG. 1 , the structure 30 has a hole 31. The hole 31 is formed so as to open on the outer surface of the structure 30 (see FIG. 5 ). The hole 31 is cylindrical and extends in the X-axis direction. The hole 31 has an inner circumferential surface 32 and an opening edge 33. The inner circumferential surface 32 is the cylindrical surface of the hole 31. As shown in FIG. 5 , the opening edge 33 is the edge of the hole 31 formed on the outer surface of the structure 30. The structure 30 is disposed radially outward from the shaft member 20 described below. The structure 30 is an example of an outer member. The hole 31 has an axis XC. The axis XC is an imaginary central axis extending in the axial direction of the hole 31.

[0016] As shown in Fig. 1 , the shaft member 20 is coaxially arranged inside the hole 31 of the structure 30. The shaft member 20 has a cylindrical shape extending along the X-axis direction. The shaft member 20 is an example of an inner member. The shaft member 20 has a reference portion 21 and an abutment portion 24.

[0017] The cylindrical surface of the reference portion 21 is an outer peripheral surface 22. The outer peripheral surface 22 of the reference portion 21 forms a cylindrical gap G0 between itself and an inner peripheral surface 32 of the hole portion 31.

[0018] The abutting portion 24 protrudes radially outward beyond the outer circumferential surface 22 of the reference portion 21. The abutting portion 24 has an abutting surface 25 facing the −X direction. The abutting surface 25 comes into contact with an end surface 42 of the seal member 40, which will be described later.

[0019] The shaft member 20 has an insertion end (not shown) provided at the end on the side where the seal member 40 is disposed relative to the abutment portion 24. The insertion end can be inserted into the hole 31 from the opening edge 33 of the structure 30 (see FIG. 6 ). The shaft member 20 can be positioned inside the hole 31 of the structure 30 by being inserted relatively from the insertion end toward the hole 31 along the axis X.

[0020] The shaft member 20 and the structure 30 are made of an aluminum-based metal material, which includes pure aluminum-based materials and aluminum-based alloys.

[0021] The structure 30 is used in an environment with a lot of moisture (salt water) containing chlorides such as sodium chloride and / or calcium chloride. Therefore, salt water can easily enter the gap G0 formed between the structure 30 and the shaft member 20 through the opening edge 33 of the hole 31 of the structure 30, etc.

[0022] <Sealing member 40> As shown in Fig. 1 , the sealing member 40 is disposed in the gap G0 formed between the structure 30 and the shaft member 20, and has a hollow cylindrical shape extending along the X-axis direction. The sealing member 40 is annular and coaxial with the structure 30 and the shaft member 20. The sealing member 40 can be assembled between the structure 30 and the shaft member 20 in an elastically deformed state. The state in which the sealing member 40 is assembled between the structure 30 and the shaft member 20 is referred to as an assembled state. The state in which the sealing member 40 is not assembled between the structure 30 and the shaft member 20 is referred to as a non-assembled state. In the assembled state, the sealing member 40 seals between the structure 30 and the shaft member 20.

[0023] The seal member 40 is made of an elastomer. The elastomer preferably has excellent water resistance and / or salt resistance. The elastomer is preferably, for example, ethylene propylene diene rubber (EPDM), acrylic rubber (ACM), nitrile rubber (NBR), or fluororubber (FKM). The seal member 40 is more preferably made of EPDM or fluororubber, which have excellent water resistance and / or salt resistance.

[0024] The sealing member 40 has an end face 42, an inner periphery 50, and an outer periphery 60. The end faces 42 are faces facing the X-axis direction and are provided on both ends of the sealing member 40. As shown in FIG. 1 , the sealing member 40 is assembled to the structure 30 and the shaft member 20 such that the end faces 42 facing the +X side are in contact with the abutment surface 25 of the shaft member 20.

[0025] 2, the inner circumferential portion 50 faces radially inward of the seal member 40. The inner circumferential portion 50 has a first base portion 52, a first protruding portion 54, and a first recessed portion 56.

[0026] The first base portions 52 have a cylindrical surface shape and are provided on each end side in the axial direction of the inner peripheral portion 50. As shown in Fig. 1, when assembled, the first base portions 52 contact the outer peripheral surface 22 of the shaft material 20 in an elastically deformed state to seal the space between them and the shaft material 20. When assembled, each first base portion 52 contacts the outer peripheral surface 22 of the shaft material 20 over a length of 0.1 mm or more in the axial direction.

[0027] The inner diameter of the first base portion 52 is preferably smaller than the outer diameter of the outer peripheral surface 22 of the shaft material 20. In other words, the first base portion 52 preferably has an interference fit with the outer peripheral surface 22 of the shaft material 20. Note that the interference fit of the first base portion 52 with the shaft material 20 at room temperature (e.g., 20 degrees Celsius) may be 0 mm.

[0028] As shown in FIG. 2 , the first protrusion 54 is provided between the first base portions 52 on both sides in the axial direction so as to be spaced apart from the first base portions 52. The first protrusion 54 is annular and protrudes radially inward (toward the axis XC) from the first base portions 52. That is, the first protrusion 54 protrudes toward the shaft 20 relative to the first base portions 52. The cross-sectional shape of the first protrusion 54 in the unassembled state is an isosceles triangle with a rounded apex. The cross-sectional shape of the first protrusion 54 in the unassembled state may also be approximately semicircular.

[0029] 1, in an assembled state, the first protrusion 54 comes into contact with the outer peripheral surface 22 of the shaft material 20 in an elastically deformed state to form a seal between the shaft material 20 and the first protrusion 54. The inner diameter of the first protrusion 54 is preferably smaller than the inner diameter of the first base 52. In other words, the first protrusion 54 preferably has an interference fit with the outer peripheral surface 22 of the shaft material 20. The interference fit between the first protrusion 54 and the outer peripheral surface 22 of the shaft material 20 is preferably 0.05 mm or more.

[0030] 2, the first recesses 56 are provided between the first protrusions 54 and the respective first base portions 52 in the axial direction. The first recesses 56 are annular and recessed radially outward relative to the first base portions 52. The first recesses 56 are groove-shaped and open radially inward (toward the axis XC).

[0031] The first recess 56 has a first inclined portion 56a and a first groove bottom 56b. The first inclined portion 56a smoothly connects with the first base portion 52. In a cross section in the unassembled state, the first inclined portion 56a is linear and inclined radially outward from the first base portion 52 and with respect to the axis XC. The first groove bottom 56b smoothly connects the end of the first inclined portion 56a on the first protruding portion 54 side with the first protruding portion 54. The first groove bottom 56b is arc-shaped in a cross section in the unassembled state.

[0032] As shown in FIG. 1 , when the first recess 56 is in an assembled state, it forms a first gap G1 between itself and the outer peripheral surface 22 of the shaft 20 in an elastically deformed state. The maximum radial length of the first gap G1 is preferably 0.05 mm or more. The maximum radial length of the first gap G1 is preferably half or less of the thickness of the seal member 40 when not assembled. The thickness of the seal member 40 is the length between the first base 52 and a second base 62 (described later) when not assembled. It is more preferable that the maximum radial length of the first gap G1 be less than half of the radial length of the gap G0 formed between the structure 30 and the shaft 20.

[0033] 2, the outer circumferential portion 60 faces radially outward of the seal member 40. The outer circumferential portion 60 has a second base portion 62, a second protruding portion 64, and a second recessed portion 66.

[0034] The second bases 62 have cylindrical surfaces provided on the respective end sides of the outer peripheral portion 60 in the axial direction. As shown in FIG. 1 , the second bases 62, when assembled, contact the inner peripheral surface 32 of the structure 30 in an elastically deformed state to seal the structure 30. When assembled, each second base 62 contacts the inner peripheral surface 32 of the structure 30 over a length of 0.1 mm or more in the axial direction. The second base 62 on the -X side has a corner A1. The corner A1 is the boundary between the second base 62 on the -X side and the end face 42 on the -X side.

[0035] The outer diameter of the second base 62 is preferably larger than the inner diameter of the inner circumferential surface 32 of the structure 30. In other words, the second base 62 preferably has an interference with the inner circumferential surface 32 of the structure 30. Note that the interference of the second base 62 with the structure 30 at room temperature (e.g., 20 degrees Celsius) may be 0 mm.

[0036] 2, a portion of the second base 62 on the +X side overlaps in the axial direction with a portion of the first recess 56 on the +X side. In other words, the position in the axial direction of at least a portion of the first recess 56 on the +X side overlaps with the second base 62 on the +X side.

[0037] As shown in FIG. 2 , the second protrusion 64 is provided between the second bases 62 on both sides in the axial direction so as to be spaced apart from the second bases 62. The second protrusion 64 is annular and protrudes radially outward from the second bases 62. That is, the second protrusion 64 protrudes toward the structure 30 relative to the second bases 62. The cross-sectional shape of the second protrusion 64 in the unassembled state is an isosceles triangle shape having a rounded apex B1. The cross-sectional shape of the second protrusion 64 in the unassembled state may also be approximately semicircular.

[0038] 1 , in an assembled state, the second protrusion 64 comes into contact with the inner circumferential surface 32 of the structure 30 in an elastically deformed state to provide a seal between the structure 30 and the second protrusion 64. The outer diameter of the second protrusion 64 is preferably larger than the outer diameter of the second base 62. That is, the second protrusion 64 preferably has an interference with the inner circumferential surface 32 of the structure 30. The interference of the second protrusion 64 with the inner circumferential surface 32 of the structure 30 is preferably 0.05 mm or more.

[0039] 2, the axial position of the second protrusion 64 is shifted toward the −X side relative to the first protrusion 54. In particular, the axial position of the apex B1 of the second protrusion 64 is shifted toward the −X side relative to the apex of the first protrusion 54. The axial position of the second protrusion 64 overlaps with the first recess 56 on the −X side. It is preferable that the axial position of the apex B1 of the second protrusion 64 overlaps with the first recess 56 on the −X side.

[0040] 2, the second recesses 66 are provided between the second protrusions 64 and the respective second base portions 62 in the axial direction. The second recesses 66 are annular and recessed radially inward (toward the axis XC) relative to the second base portions 62. The second recesses 66 are groove-shaped and open radially outward.

[0041] The second recess 66 has a second inclined portion 66a and a second groove bottom 66b. The second inclined portion 66a smoothly connects to the second base 62 at a boundary C1. In a cross section in the unassembled state, the second inclined portion 66a is linearly oriented radially inward (toward the axis XC) with respect to the second base 62 and inclined with respect to the axis XC. The second groove bottom 66b smoothly connects the end of the second inclined portion 66a on the second protruding portion 64 side to the second protruding portion 64. The second groove bottom 66b is arc-shaped in a cross section in the unassembled state.

[0042] 1 , in the assembled state, the second recess 66 forms a second gap G2 between itself and the inner circumferential surface 32 of the structure 30 in an elastically deformed state. The maximum radial length of the second gap G2 is preferably 0.05 mm or more. The maximum radial length of the second gap G2 is preferably half or less of the thickness of the sealing member 40 in the unassembled state. It is more preferable that the maximum radial length of the second gap G2 is less than half the radial length of the gap G0 formed between the structure 30 and the shaft member 20.

[0043] 2, the second recess 66 on the +X side is shifted toward the −X side with respect to the first recess 56 on the +X side. The position of the second recess 66 on the +X side in the axial direction overlaps with the first protrusion 54. It is preferable that the position of the second recess 66 on the +X side in the axial direction overlaps with the top of the first protrusion 54.

[0044] The second recess 66 on the -X side is shifted toward the -X side with respect to the first recess 56 on the -X side. At least a portion of the second recess 66 on the -X side is positioned in the axial direction so as to overlap with the first base 52 on the -X side. In other words, a portion of the first base 52 on the -X side overlaps with a portion of the second recess 66 on the -X side in the axial direction.

[0045] <Method of Assembling Seal Member 40> Next, a method of assembling the seal member 40 in the sealed structure will be described. First, as shown in Fig. 5 , the seal member 40 is inserted relatively to the shaft member 20 from the insertion end (not shown) of the shaft member 20 so that the inner peripheral portion 50 of the seal member 40 contacts the outer peripheral surface 22 of the shaft member 20. Thereafter, the seal member 40 is further inserted relatively toward the abutment portion 24 while elastically deforming the inner peripheral portion 50 until the +X side end face 42 of the seal member 40 contacts the abutment surface 25, thereby assembling the seal member 40 to the shaft member 20.

[0046] Next, the insertion end of the shaft member 20 with the seal member 40 assembled thereto is inserted relative to the opening edge 33 of the structure 30 into the hole 31 of the structure 30. Thereafter, as shown in the order of FIGS. 5 , 6 , and 1 , the shaft member 20 with the seal member 40 assembled thereto is further inserted relative to the structure 30, thereby assembling the seal member 40 to the structure 30. Specifically, the seal member 40 is assembled to the structure 30 while being elastically deformed by contacting it with the inner circumferential surface 32 of the structure 30 in the order of the corner A1, the apex B1, the boundary C1, and the end on the +X side. At this time, an elastic force is applied to the structure 30 from the seal member 40 as the seal member 40 elastically deforms. Furthermore, due to the application of the elastic force from the seal member 40, an insertion load acting in the same direction as the direction in which the abutment surface 25 faces (the −X direction) is applied to the structure 30.

[0047] (Functions and Effects) Next, the functions and effects of the seal member 40 of the first embodiment will be described. In this description, a seal member H40 as a comparative example to the first embodiment will be described with reference to Fig. 3. In describing the seal member H40, when the same parts as those of the seal member 40 of the first embodiment are used, the reference numerals and names of those parts will be used as they are.

[0048] As shown in FIG. 3 , the comparative seal member H40 has an outer peripheral portion H60 instead of the outer peripheral portion 60 of the seal member 40. The outer peripheral portion H60 has a second base H62, a second protruding portion H64, and a second recessed portion H66. The outer peripheral portion H60 has a corner HA, an apex HB, and a boundary portion HC instead of the corner A1, apex B1, and boundary portion C1 of the outer peripheral portion 60 of the seal member 40. The first protruding portion 54 and the second protruding portion H64 are positioned to overlap each other in the axial direction. In particular, the apex of the first protruding portion 54 and the apex HB of the second protruding portion H64 are positioned to overlap each other in the axial direction. The first recessed portion 56 on the +X side and the second recessed portion H66 on the +X side are positioned to overlap each other in the axial direction. The first recess 56 on the -X side and the second recess H66 on the -X side are positioned to overlap each other in the axial direction. The first base 52 on the +X side and the second base H62 on the +X side are positioned to overlap each other in the axial direction. The first base 52 on the -X side and the second base H62 on the -X side are positioned to overlap each other in the axial direction. Other than the above, the structure and assembly method of the seal member H40 are the same as those of the seal member 40.

[0049] In the comparative sealing member H40, the axial positions of the first protrusion 54 and the second protrusion H64 overlap each other. In this case, when assembling the sealing member H40 to the structure 30 and the shaft member 20, the elastic force applied from the sealing member H40 to the structure 30 when the structure 30 passes through contacting the apex HB of the second protrusion H64 is greater than that of the sealing member 40. Therefore, the sealing member H40 increases the insertion load applied to the structure 30 when assembling it to the structure 30 and the shaft member 20, resulting in poor installation properties.

[0050] On the other hand, in the seal member 40, the axial position of the apex B1 of the second protrusion 64 is shifted toward the −X side relative to the apex of the first protrusion 54. Therefore, when assembling the seal member 40 to the structure 30 and the shaft member 20, the elastic force applied from the seal member 40 to the structure 30 when the structure 30 contacts and passes through the apex B1 of the second protrusion 64 is smaller than that of the seal member H40 of the comparative embodiment. In other words, the insertion load applied to the structure 30 when assembling the seal member 40 to the structure 30 and the shaft member 20 is smaller than that of the seal member H40 of the comparative embodiment. Therefore, the seal member 40 can maintain the function as a seal member and improve the mountability of a seal member having protrusions 54, 64 on both the outer periphery 60 and the inner periphery 50. In other words, a sealed structure including the seal member 40 can improve the mountability of the sealed structure.

[0051] The seal member 40 has the first recess 56. Therefore, the contact area of ​​the seal member 40 with the outer circumferential surface 22 of the shaft material 20 is smaller than when the seal member 40 does not have the first recess 56. Therefore, the seal member 40 can be easily attached to the shaft material 20.

[0052] The axial position of the first recess 56 on the -X side overlaps with the top of the second protrusion 64. In this case, when the relatively inserted structure 30 comes into contact with the second protrusion 64 during assembly of the seal member 40, the seal member 40 is likely to elastically deform while escaping into the first gap G1 formed by the first recess 56. Therefore, the elastic force applied from the seal member 40 to the structure 30 when the relatively inserted structure 30 comes into contact with the second protrusion 64 is smaller than that of the seal member H40 of the comparative embodiment. Therefore, the seal member 40 can maintain its function as a seal member and improve its mountability, even when the seal member has protrusions 54, 64 and recesses 56, 66 on both the outer circumferential portion 60 and the inner circumferential portion 50.

[0053] The seal member 40 has the second recess 66. Therefore, the contact area of ​​the seal member 40 with the inner circumferential surface 32 of the structure 30 is smaller than when the seal member 40 does not have the second recess 66. Therefore, the seal member 40 can improve the attachment property to the structure 30.

[0054] The axial position of the second recess 66 on the +X side overlaps with the top of the first protrusion 54. A sealing member having a first protrusion on its inner periphery is likely to deform radially outward at the portion of its outer periphery that overlaps with the first protrusion in the axial direction when assembled to the shaft material 20. In the sealing member 40, the second recess 66 on the +X side overlaps with the top of the first protrusion 54 in the axial direction, so that when assembled to the shaft material 20, the amount of deformation of the outer periphery 60 at the position that overlaps with the top of the first protrusion 54 in the axial direction is small. Therefore, the sealing member 40 can further improve the mountability to the structure 30.

[0055] The first recess 56 forms a first gap G1 between the shaft member 20 and the first recess 56. When saltwater enters the hole 31 from the opening edge 33 on the +X side of the structure 30 and reaches the end face 42 on the +X side of the seal member 40, the saltwater slowly enters a minute gap (not shown) between the seal member 40 and the shaft member 20 or the hole 31 by capillary action. That is, the saltwater that enters the seal member 40 from the +X side slowly enters a minute gap formed between the outer peripheral surface 22 of the shaft member 20 and the first base 52 of the seal member 40 and / or between the inner peripheral surface 32 of the structure 30 and the second base 62 of the seal member 40, and proceeds toward the -X side. The saltwater that enters the minute gap accelerates corrosion of the outer peripheral surface 22 of the shaft member 20 and / or the inner peripheral surface 32 of the structure 30, which are made of an aluminum-based metal material. When the seal member 40 has the first recess 56, saltwater that has entered between the outer circumferential surface 22 of the shaft material 20 and the first base portion 52 of the seal member 40 remains in the first gap G1 formed by the first recess 56. The saltwater that remains in the first gap G1 is less likely to corrode the outer circumferential surface 22 of the shaft material 20 than saltwater that has entered the small gap between the outer circumferential surface 22 of the shaft material 20 and the first base portion 52 of the seal member 40. Therefore, the seal member 40 can delay the intrusion of saltwater between the seal member 40 and the shaft material 20. In particular, the maximum radial length of the first gap G1 is 0.05 mm or more. Therefore, the seal member 40 can further delay the intrusion of saltwater between the seal member 40 and the shaft material 20.

[0056] The first protrusion 54 has an interference of 0.05 mm or more with respect to the shaft material 20. In this case, saltwater that has accumulated in the first gap G1 is less likely to penetrate into the minute gap between the outer peripheral surface 22 of the shaft material 20 and the first protrusion 54. Therefore, the seal member 40 can more effectively delay the penetration of saltwater toward the gap between the seal member 40 and the shaft material 20.

[0057] In addition, in the seal member 40, saltwater that has entered between the inner circumferential surface 32 of the structure 30 and the second base 62 of the seal member 40 remains in the second gap G2 formed by the second recess 66. The saltwater that remains in the second gap G2 is less likely to corrode the inner circumferential surface 32 of the structure 30 than saltwater that has entered the small gap between the inner circumferential surface 32 of the structure 30 and the second base 62 of the seal member 40. Therefore, the seal member 40 can delay the intrusion of saltwater toward between the seal member 40 and the structure 30. In particular, the maximum radial length of the second gap G2 is 0.05 mm or more. Therefore, the seal member 40 can further delay the intrusion of saltwater toward between the seal member 40 and the structure 30.

[0058] Furthermore, the second protrusion 64 has an interference of 0.05 mm or more with respect to the structure 30. In this case, saltwater that has accumulated in the second gap G2 is less likely to infiltrate into the minute gap between the inner circumferential surface 32 of the structure 30 and the second protrusion 64. Therefore, the seal member 40 can more effectively delay the infiltration of saltwater toward the gap between the seal member 40 and the structure 30.

[0059] The maximum radial length of the first gap G1 is equal to or less than half the thickness between the first base 52 and the second base 62. When the sealing member has a first recess on the inner periphery, if a portion of the first recess overlaps with the second base 62 in the axial direction, the sealing ability of the second base 62 with respect to the structure 30 is likely to be reduced. In particular, when the maximum radial length of the first gap formed by the first recess is greater than half the thickness between the first base 52 and the second base 62, the sealing ability of the second base 62 with respect to the structure 30 is more likely to be reduced. Because the maximum radial length of the first gap G1 according to the present disclosure is less than half the thickness between the first base 52 and the second base 62, the sealing member 40 can maintain the sealing ability of the second base 62 on the +X side with respect to the hole 31 of the structure 30.

[0060] The maximum radial length of the second gap G2 is less than half the thickness between the first base 52 and the second base 62. When the sealing member has a second recess on the outer periphery, if a portion of the second recess overlaps with the first base 52 in the axial direction, the sealing ability of the first base 52 with respect to the shaft material 20 is likely to be reduced. In particular, when the maximum radial length of the second gap formed by the second recess is greater than half the thickness between the first base 52 and the second base 62, the sealing ability of the first base 52 with respect to the shaft material 20 is more likely to be reduced. Because the maximum radial length of the second gap G2 according to the present disclosure is less than half the thickness between the first base 52 and the second base 62, the sealing ability of the first base 52 on the −X side with respect to the shaft material 20 can be maintained by the sealing member 40.

[0061] The first base portion 52 contacts the shaft material 20 over a length of 0.1 mm or more in the axial direction. Therefore, the seal member 40 can improve the sealing performance between the shaft material 20 and the seal member 40. Furthermore, when the seal member 40 forms the first gap G1 in the assembled state, the shape of the first gap G1 is easily formed so that the maximum radial length is 0.05 mm or more.

[0062] The second base 62 contacts the hole 31 of the structure 30 over a length of 0.1 mm or more in the axial direction. Therefore, the sealing member 40 can improve the sealing performance between the hole 31 of the structure 30. Furthermore, when the sealing member 40 forms the second gap G2 in the assembled state, the shape of the second gap G2 is easily formed so that the maximum length in the radial direction is 0.05 mm or more.

[0063] As described above, an embodiment of the present invention has been described as an example, but the present invention is not limited to the above embodiment, and various modifications, changes, and improvements are possible within the scope of the technical concept of the present invention.

[0064] The seal member 40 of the first embodiment has a first recess 56 and a second recess 66. However, the seal member according to the present disclosure may have either the first recess or the second recess. Furthermore, the seal member according to the present disclosure may have neither the first recess nor the second recess, as in the seal member 240 shown in FIG. 4 . The seal member 240 is an example of a seal member according to the second embodiment of the present disclosure. The seal member 240 has the same configuration as the seal member 40 except that, unlike the seal member 40, the seal member 240 does not have the first recess 56 or the second recess 66. That is, the seal member 240 has an inner periphery 250 and an outer periphery 260 instead of the inner periphery 50 and the outer periphery 60 of the seal member 40. The seal member 240 has a corner A2 and an apex B2 instead of the corner A1 and the apex B1 of the seal member 40. The seal member 240 does not have a boundary between the second base and the second recess.

[0065] In the above-described embodiment, the seal member 40 is applied to an electric device such as an inverter disposed in an electric vehicle, etc. However, the application of the seal member according to the present disclosure is not limited to electric devices disposed in an electric vehicle, etc. The seal member according to the present disclosure may also be applied to vehicle accessories, general industrial machinery, construction machinery, and other general-purpose machinery.

[0066] To verify the effectiveness of the seal member according to the present disclosure, an evaluation was conducted of the insertion load applied to the structure 30 when the seal member 40 of the first embodiment, the seal member 240 of the second embodiment, and the seal member H40 of the comparative embodiment were assembled. The assembly method of the seal members conformed to the method described above, and the same conditions were applied to each embodiment. The insertion load was calculated by numerical analysis using the finite element method.

[0067] 7, 8, and 9 are graphs showing the insertion load applied to the structure 30 when the seal members H40, 40, and 240 are assembled. The horizontal axis of the graphs indicates the axial position of the opening edge 33 of the structure 30 that is inserted relatively. The vertical axis of the graphs indicates the value of the dimensionless number RW obtained by dividing the insertion load applied to the structure 30 at each axial position by the maximum value of the insertion load in the comparative form. In other words, the vertical axis of the graphs indicates the ratio RW of the insertion load applied to the structure 30 at each axial position to the maximum value of the insertion load in the comparative form.

[0068] 7 , in the comparative sealing member H40, the insertion load applied to the structure 30 is maximized when the opening edge 33 comes into contact with the top HB of the second protrusion H64. The insertion load at this time is used as the reference value for evaluation. That is, the dimensionless number RW of the insertion load applied to the structure 30 when the opening edge 33 comes into contact with the top HB of the second protrusion 64 is set to 1.0.

[0069] On the other hand, as shown in FIG. 8 , in the seal member 40 of the first embodiment, the insertion load applied to the structure 30 reaches its maximum when the opening edge 33 contacts the apex B1 of the second protrusion 64. The insertion load at this time is smaller than the maximum insertion load of the seal member H40 of the comparative embodiment. Specifically, the ratio RW of the maximum insertion load of the seal member 40 of the first embodiment to the maximum insertion load of the seal member H40 of the comparative embodiment is 0.88. That is, the maximum insertion load of the seal member 40 of the first embodiment is 88% of the maximum insertion load of the seal member H40 of the comparative embodiment. From these evaluation results, it can be confirmed that the seal member 40 of the first embodiment has superior wearability to the seal member H40 of the comparative embodiment.

[0070] Furthermore, as shown in FIG. 9 , in the seal member 240 of the second embodiment, the insertion load applied to the structure 30 reaches its maximum when the opening edge 33 contacts the apex B2 of the second protrusion 264. The insertion load at this time is smaller than the maximum insertion load of the seal member H40 of the comparative embodiment. Specifically, the ratio RW of the maximum insertion load of the seal member 240 of the second embodiment to the maximum insertion load of the seal member H40 of the comparative embodiment is 0.88. That is, the maximum insertion load of the seal member 240 of the second embodiment is 88% of the maximum insertion load of the seal member H40 of the comparative embodiment. These evaluation results confirm that the seal member 240 of the second embodiment has superior wearability to the seal member H40 of the comparative embodiment.

[0071] 20 Shaft member (an example of an inner member) 30 Structure (an example of an outer member) 40 Sealing member 50 Inner peripheral portion 52 First base portion 54 First protruding portion 56 First recessed portion 60 Outer peripheral portion 62 Second base portion 64 Second protruding portion 66 Second recessed portion 240 Sealing member 250 Inner peripheral portion 260 Outer peripheral portion 262 Second base portion 264 Second protruding portion B1 Top portion B2 Top portion G1 First gap G2 Second gap XC Axis

Claims

1. An annular sealing member provided between an outer member having a cylindrical hole and an inner member disposed inside the hole and extending along the axis of the hole, the sealing member having: an inner circumferential portion having a first base portion that seals between the inner member and the inner member at both axial ends; and an annular first protrusion portion that protrudes from the first base toward the inner member, the first protrusion portion being axially spaced apart from the first base; an outer circumferential portion having a second base portion that seals between the outer member and the outer member at both axial ends; and an annular second protrusion portion that protrudes from the second base toward the outer member, the second protrusion portion being axially spaced apart from the second base; and the axial position of the apex of the second protrusion is offset from the apex of the first protrusion.

2. The seal member according to claim 1, wherein the inner peripheral portion has a first annular recess provided between the first base portion and the first protrusion portion and recessed relative to the first base portion.

3. The seal member according to claim 2, wherein the first recess is axially positioned so as to overlap the top of the second protrusion.

4. A sealing member according to any one of claims 1 to 3, wherein the outer peripheral portion has a second annular recess provided between the second base portion and the second protrusion portion and recessed relative to the second base portion.

5. The seal member according to claim 4, wherein the second recess is axially positioned so as to overlap the top of the first protrusion.

6. A sealing member according to any one of claims 2 to 5, wherein the inner member is formed from an aluminum-based metallic material, the first recess forms a first gap between itself and the inner member, and the maximum radial length of the first gap is 0.05 mm or more.

7. A sealing member as described in claim 6, wherein at least a portion of the first recess is axially positioned to overlap with the second base, and the maximum radial length of the first gap is equal to or less than half the thickness between the first base and the second base.

8. A sealing member according to any one of claims 1 to 7, wherein the first protrusion has an interference of 0.05 mm or more with respect to the inner member.

9. A seal member according to any one of claims 1 to 8, wherein the first base portion contacts the inner member over a length of 0.1 mm or more in the axial direction.

10. A sealing member according to any one of claims 4 to 9, wherein the outer member is formed of an aluminum-based metallic material, the second recess forms a second gap between itself and the outer member, and the maximum radial length of the second gap is 0.05 mm or more.

11. A sealing member according to claim 10, wherein at least a portion of the second recess is axially positioned to overlap with the first base, and the maximum radial length of the second gap is equal to or less than half the thickness between the first base and the second base.

12. A sealing member according to any one of claims 1 to 11, wherein the second protrusion has an interference of 0.05 mm or more with respect to the outer member.

13. A seal member according to any one of claims 1 to 12, wherein the second base portion contacts the outer member over a length of 0.1 mm or more in the axial direction.

14. A sealing structure comprising: an outer member having a cylindrical hole; an inner member disposed inside the hole and extending along the axis of the hole; and a seal member according to any one of claims 1 to 13 provided between the outer member and the inner member.

Images