Patent Description:
Conventionally, it is known that a gasket acts as a sealing device that is attached to an annular space such as an annular groove formed between a plurality of members placed face-to-face and immobilized relative to each other, such as a housing and a cover, to seal a gap between the members. The gasket and a component to which the gasket is applied forming the annular space to which the gasket is attached make up a sealing structure. Such a conventional gasket, in some cases, includes a tubular reinforcing ring formed annularly around an axis and extending in a direction of the axis and an elastic body part formed from an elastic body that is attached to the reinforcing ring. The elastic body part includes a pair of lip portions each extending along the axis from both end portions of the reinforcing ring in the direction of the axis (for example, see Patent Literature <NUM>).

In recent years, in response to reductions in size or weight of a component to which the gasket is applied, a cross section of the gasket has been made smaller due to downsizing of the gasket and the component to which the gasket is applied has been developed to be made thinner or to be made of resin. The smaller cross section of the gasket and the development of the component to which the gasket is applied being made thinner or being made of resin decrease a size of the annular space to which the gasket is attached and increase a degree of relative variation in the size of the space caused by manufacturing. As a result, it is conceivable that a gasket cannot provide intended sealing performance because of the variation in the size of the annular space to which the gasket is attached and thus various devices have been made (for example, see Patent Literature <NUM>).

<CIT>, <CIT>, and <CIT> each disclose a sealing device for sealing an annular space formed by a plurality of members, comprising: a reinforcing ring having an annular shape around an axis; and an elastic body part formed from an elastic body, the elastic body part being attached to the reinforcing ring and having an annular shape around the axis, wherein: the elastic body part includes a seal lip that is an annular portion projecting toward one side in a direction of the axis, a secondary lip portion that is an annular portion projecting toward another side in the direction of the axis, and an outer peripheral portion that is a portion covering the reinforcing ring from an outer periphery side; the seal lip projects beyond the reinforcing ring toward the one side in the direction of the axis; and the secondary lip portion projects beyond the reinforcing ring toward the other side in the direction of the axis.

<CIT> discloses a sealing device for sealing an annular space formed by a plurality of members, comprising: a reinforcing ring having an annular shape around an axis; and an elastic body part formed from an elastic body, the elastic body part being attached to the reinforcing ring and having an annular shape around the axis, wherein: the elastic body part includes a seal lip that is an annular portion projecting toward one side in a direction of the axis, a secondary lip portion that is an annular portion projecting toward another side in the direction of the axis, and an outer peripheral portion on an outer periphery side; the seal lip projects beyond the reinforcing ring toward the one side in the direction of the axis; and the secondary lip portion projects beyond the reinforcing ring toward the other side in the direction of the axis.

Even a gasket that can prevent a decrease in sealing performance even despite, as described above, a variation in the size of the annular space in the component to which the gasket is attached may be unable to display intended sealing performance due to a lip of the gasket being detached from the annular space in the component to which the gasket is attached if a direction in which the gasket is attached to the annular space in the component to which the gasket is attached in the direction of the axis is not an intended direction. This necessitates checking that the attached gasket faces in the intended direction. If the gasket does not face in the intended direction, the gasket needs to be properly reattached. This causes a decrease in production efficiency in some cases.

Consequently, the static sealing device like the conventional gasket and the sealing structure have been required to be developed into a sealing device and a sealing structure that enable proper attachment of the sealing device to be able to prevent a decrease in sealing performance even despite a variation in the size of an annular space in a component to which the sealing device is attached.

The present invention has been made in view of the above- described problem, it is an object of the present invention to provide a sealing device and a sealing structure that enable attachment of the sealing device in an intended way.

To achieve the above object, a sealing device according to the present invention is a sealing device for sealing an annular space formed by a plurality of members, characterized in including a reinforcing ring having an annular shape around an axis and an elastic body part formed from an elastic body, the elastic body part being attached to the reinforcing ring and having an annular shape around the axis, wherein the elastic body part includes a seal lip that is an annular portion projecting toward one side in a direction of the axis, a secondary lip portion that is an annular portion projecting toward another side in the direction of the axis, and an outer peripheral portion that is a portion covering the reinforcing ring from an outer periphery side; the seal lip projects beyond the reinforcing ring toward the one side in the direction of the axis; the secondary lip portion projects beyond the reinforcing ring toward the other side in the direction of the axis; and in the outer peripheral portion, a plurality of identification parts are formed further on the one side or the other side than a middle of the outer peripheral portion in the direction of the axis, the plurality of identification parts acting as marks.

In the sealing device according to one aspect of the present invention, the plurality of identification parts are recessed parts or protruding parts projecting from a surface of the outer peripheral portion, and provided at intervals around the axis.

In the sealing device according to one aspect of the present invention, the plurality of identification parts are formed on an end portion on the one side of the outer peripheral portion.

In the sealing device according to one aspect of the present invention, a length of the seal lip in a direction of the projection is greater than a length of the secondary lip portion in a direction of the projection.

To achieve the above object, a sealing structure (not claimed) includes an attachment space that is an annular space around an axis formed by a plurality of members, and a sealing device for sealing the attachment space, wherein an engagement portion is formed between the attachment space and the sealing device; and the engagement portion includes a recessed engagement part that is a part formed in the attachment space, the recessed engagement part being recessed to an outer periphery side and a protruding engagement part that is a part formed in the sealing device so as to be housed in the recessed engagement part, the protruding engagement part projecting to the outer periphery side.

In the sealing structure, the sealing device includes a reinforcing ring having an annular shape around an axis and an elastic body part formed from an elastic body, the elastic body part being attached to the reinforcing ring and having an annular shape around the axis; the elastic body part includes a seal lip that is an annular portion projecting toward one side in a direction of the axis and a secondary lip portion that is an annular portion projecting toward another side in the direction of the axis; the seal lip projects beyond the reinforcing ring toward the one side in the direction of the axis; the secondary lip portion projects beyond the reinforcing ring toward the other side in the direction of the axis; and the protruding engagement part is formed between the seal lip and the secondary lip portion in the direction of the axis.

In the sealing structure, the reinforcing ring includes a flange portion in an end portion on the one side, the flange portion projecting annularly to the outer periphery side; and the sealing device protrudes to the outer peripheral side in the flange portion so that the protruding engagement part is formed.

In the sealing structure, the attachment space has sealing surfaces that are a pair of annular surfaces placed face-to-face in the direction of the axis and an outer peripheral wall surface that is a tubular surface extending from one of the pair of the sealing surfaces along the axis; and the recessed engagement part is formed in an end portion of the outer peripheral wall surface on a side opposite to a side of the one of the sealing surfaces.

In the sealing structure, the recessed engagement part is either of a chamfered part and a counterbored part.

According to the sealing device according to the present invention, it is possible to be attached in an intended way.

<FIG> is a perspective view of a sealing device <NUM> according to the embodiment of the present invention. <FIG> is a top view of the sealing device <NUM> according to the embodiment of the present invention. <FIG> is a cross-sectional view of the sealing device <NUM> according to the embodiment of the present invention in a cross section along an axis x. As illustrated in <FIG>, the sealing device <NUM> according to the embodiment of the present invention includes a reinforcing ring <NUM> having an annular shape around the axis x and an elastic body part <NUM> formed from an elastic body, the elastic body part <NUM> being attached to the reinforcing ring <NUM> and having an annular shape around the axis x. The elastic body part <NUM> includes a seal lip <NUM> that is an annular portion projecting toward one side in a direction of the axis x, a secondary lip portion <NUM> that is an annular portion projecting toward another side in the direction of the axis x, and an outer peripheral portion <NUM> that is a portion covering the reinforcing ring <NUM> from an outer periphery side. The seal lip <NUM> projects beyond the reinforcing ring <NUM> toward the one side in the direction of the axis x, and the secondary lip portion <NUM> projects beyond the reinforcing ring <NUM> toward the other side in the direction of the axis x. In the outer peripheral portion <NUM>, a plurality of identification parts <NUM> are formed further on the one side or the other side than a middle of the outer peripheral portion in the direction of the axis x, the plurality of identification parts <NUM> acting as marks. The sealing device <NUM> is a gasket used to seal an annular space formed by a plurality of members. The annular space is, for example, formed between the members, such as a housing and a cover, placed face-to-face and immobilized relative to each other. Hereinafter, the sealing device <NUM> will be described in detail.

Hereinafter, a direction directed by an arrow a (see <FIG> and <FIG>) in the direction of the axis x (the one side in the direction of the axis) represents an outer side, and a direction directed by an arrow b (see <FIG> and <FIG>) in the direction of the axis x (the other side in the direction of the axis) represents an inner side, for convenience of explanation. In a direction perpendicular to the axis x (hereinafter also referred to as a "radial direction"), a direction away from the axis x (a direction directed by an arrow c in <FIG>) represents the outer periphery side, and a direction approaching the axis x (a direction directed by an arrow d in <FIG>) represents an inner periphery side.

As illustrated in <FIG>, the reinforcing ring <NUM> is a tubular member extending along the axis x and is, for example, a cylindrical or substantially cylindrical member centered about or substantially centered about the axis x. The reinforcing ring <NUM> has an inner side end <NUM> which is an end portion on the inner side and an outer side end <NUM> which is an end portion on the outer side. The reinforcing ring <NUM> is a part for reinforcing the elastic body part <NUM>. The reinforcing ring <NUM> is, for example, made of a metal material, the metal material is, for example, stainless steel or SPCC (a cold rolled steel sheet). If the reinforcing ring <NUM> is made of a resin material, the resin material is, for example, nylon <NUM> (PA66) or a polyphenylene sulfide (PPS) resin.

The elastic body part <NUM> is formed so as to cover the reinforcing ring <NUM> and includes, as described above, the seal lip <NUM>, the secondary lip portion <NUM>, and the outer peripheral portion <NUM>. The elastic body part <NUM> also includes a base portion <NUM> that is a portion on the inner periphery side. The base portion <NUM>, as illustrated in <FIG>, is a portion covering the reinforcing ring <NUM> from the inner periphery side. The seal lip <NUM> and the secondary lip portion <NUM> each extend from the base portion <NUM>. Specifically, the seal lip <NUM> extends from an end portion (an outer side end 24a) on the outer side of the base portion <NUM>, whereas the secondary lip portion <NUM> extends from an end portion (an inner side end 24b) on the inner side of the base portion <NUM>.

The seal lip <NUM>, as illustrated in <FIG>, projects diagonally from the outer side end 24a of the base portion <NUM> toward the outer side (the arrow a direction) and the inner periphery side (the arrow d direction). The seal lip <NUM> is, for example, a portion that decreases in diameter toward the outer side in the direction of the axis x and is a conical cylindrical or substantially conical cylindrical portion centered about or substantially centered about the axis x. The seal lip <NUM> projects further to the outer side than the outer side end <NUM> of the reinforcing ring <NUM>, and a distal end 21a that is an end portion on the outer side of the seal lip <NUM> is positioned further on the outer side than the outer side end <NUM> of the reinforcing ring <NUM> in the direction of the axis x. Of the seal lip <NUM>, the distal end 21a is thinner than a root 21b that is a portion joined to the base portion <NUM>. The seal lip <NUM>, for example, decreases in thickness from the root 21b toward the distal end 21a. The seal lip <NUM> has a length so as to be in contact with a sealing surface on the outer side with a predetermined interference in a usage state described later. Note that the length of the seal lip <NUM> is a width in a direction of extension (projection) of the seal lip <NUM>.

As illustrated in <FIG>, the secondary lip portion <NUM>, for example, projects diagonally from the inner side end 24b of the base portion <NUM> toward the inner side (the arrow b direction) and the inner periphery side (the arrow d direction). Specifically, the secondary lip portion <NUM> is a portion that decreases in diameter toward the inner side in the direction of the axis x and is a conical cylindrical or substantially conical cylindrical portion centered about or substantially centered about the axis x. The secondary lip portion <NUM> projects further to the inner side than the inner side end <NUM> of the reinforcing ring <NUM>, and a distal end 22a that is an end portion on the inner side of the secondary lip portion <NUM> is positioned further on the inner side than the inner side end <NUM> of the reinforcing ring <NUM> in the direction of the axis x. Of the secondary lip portion <NUM>, the distal end 22a is thinner than a root 22b that is a portion joined to the base portion <NUM>. The secondary lip portion <NUM>, for example, decreases in thickness from the root 22b toward the distal end 22a. The secondary lip portion <NUM> has a length so as to be in contact with a sealing surface on the inner side with a predetermined interference.

The secondary lip portion <NUM> may be an annular protruding part projecting from the inner side end 24a of the base portion <NUM> to the inner side. Specifically, the secondary lip portion <NUM> is a circular ring shaped or substantially circular ring shaped protruding part centered about or substantially centered about the axis x. In this case as well, the secondary lip portion <NUM> projects further to the inner side than the inner side end <NUM> of the reinforcing ring <NUM>, and the distal end 22a that is an end portion on the inner side of the secondary lip portion <NUM> is positioned further on the inner side than the inner side end <NUM> of the reinforcing ring <NUM> in the direction of the axis x. The secondary lip portion <NUM> is formed so as to be in contact with the sealing surface on the inner side with a predetermined crush allowance in the usage state described later.

As illustrated in <FIG>, the outer peripheral portion <NUM> is a portion covering the reinforcing ring <NUM> from the outer periphery side, and the outer peripheral portion <NUM> is joined to the seal lip <NUM> in an outer side end 23a that is an end portion on the outer side. The outer peripheral portion <NUM>, in the outer side end 23a, has a shoulder 23b where an edge (a corner) is formed on the outer periphery side. The shoulder <NUM> is a portion defined by an annular surface facing the outer side and a tubular surface facing the outer periphery side.

As illustrated in <FIG>, the elastic body part <NUM> does not cover the inner side end <NUM> of the reinforcing ring <NUM>. The elastic body part <NUM> may be flush with or may not be flush with the inner side end <NUM> of the reinforcing ring <NUM> in the radial direction. The elastic body part <NUM> may cover the inner side end <NUM> of the reinforcing ring <NUM>. In this case, the elastic body part <NUM> is formed such that the distal end 22a of the secondary lip portion <NUM> is positioned further on the inner side than a part of the elastic body part <NUM> covering the inner side end <NUM> of the reinforcing ring <NUM> in the direction of the axis x.

The identification part <NUM> is a part that enables identification of an orientation of the sealing device <NUM> and is a part designed to ensure that a direction in which the sealing device <NUM> is attached to an attachment space is an intended proper direction by allowing a worker to certainly know the orientation of the sealing device <NUM> when the worker attaches the sealing device <NUM> to the attachment space to put the sealing device <NUM> in the usage state described later. Specifically, the identification part <NUM> is a part that makes it possible to identify on which side in the direction of the axis x the seal lip <NUM> is present in the sealing device <NUM>. The identification part <NUM> is, for example, formed in the outer peripheral portion <NUM> of the elastic body part <NUM> and is formed further on an side of the seal lip <NUM> than the middle of the outer peripheral portion <NUM> in the direction of the axis x. The identification part <NUM> is, for example, formed in the end portion (the outer side end 23a) on the outer side (the one side) of the outer peripheral portion <NUM>, and specifically, the identification part <NUM> is, as illustrated in <FIG>, formed in the shoulder 23b of the outer peripheral portion <NUM>. The identification part <NUM> is a recessed part that is recessed inward from a surface of the shoulder 23b. The identification part <NUM> allows the worker to identify presence of the seal lip <NUM> in the vicinity of the identification part <NUM> and properly attach the sealing device <NUM> to the attachment space. In the present embodiment, as illustrated in <FIG>, a plurality of the identification parts <NUM> are provided and the identification parts <NUM> are formed at equal angle intervals around the axis x.

The identification part <NUM> may be formed in an area further on a side of the secondary lip portion <NUM> than the middle of the outer peripheral portion <NUM> in the direction of the axis x. In this case as well, the identification part <NUM> allows the worker to identify presence of the secondary lip portion <NUM> in the vicinity of the identification part <NUM> and properly attach the sealing device <NUM> to the attachment space. In the present embodiment, as illustrated in <FIG> and <FIG>, eight identification parts <NUM> are provided. However, the number of the identification parts <NUM> should not be limited to this example. In the sealing device <NUM>, only one identification part <NUM> may be formed. The identification parts <NUM> may not be provided at equal angle intervals around the axis x. The identification part <NUM> may not be a recessed part that is recessed from the surface of the outer peripheral portion <NUM> but may be a protruding part projecting from the surface of the outer peripheral portion <NUM>, for example. However, the shape of the identification part <NUM> does not have an influence on sealing performance of the sealing device <NUM>.

Examples of the elastic body of the elastic body part <NUM> include various rubber materials. The various rubber materials are, for example, synthetic rubber such as nitrile rubber (NBR), hydrogenated nitrile rubber (H-NBR), acrylic rubber (ACM), and fluororubber (FKM).

The reinforcing ring <NUM> is manufactured by press working or forging, for example, and the elastic body part <NUM> is molded with a mold by cross-linking (vulcanization). During the cross-linking, the reinforcing ring <NUM> is placed in the mold, the elastic body part <NUM> is bonded to the reinforcing ring <NUM> by cross-linking bonding, and the elastic body part <NUM> is integrally molded with the reinforcing ring <NUM>.

Next, the above described sealing device <NUM> in the usage state will be described. <FIG> is a cross-sectional view illustrating the sealing device <NUM> in the usage state. As illustrated in <FIG>, the sealing device <NUM> gets into the usage state when the sealing device <NUM> is attached to an attachment space S which is an annular space. The attachment space S is, for example, a circular ring shaped or substantially circular ring shaped space around an axis x1, and the attachment space S is formed by a cover <NUM> in which a through-hole <NUM> is formed and a housing <NUM> to which the cover <NUM> is fixed and in which a through-hole <NUM> is formed. In a surface <NUM> of the housing <NUM>, a groove portion <NUM> is formed to form an annular groove around the through-hole <NUM>. The groove portion <NUM> is defined by an outer peripheral wall surface 113a extending in a shape of a cylinder or a substantial cylinder in a direction of the axis x1 and an inner-side sealing surface 113b that is an annular plane extending from an end portion on the inner side of the outer peripheral wall surface 113a to the through-hole <NUM> toward the inner periphery side. The cover <NUM> is fixed to the housing <NUM> such that a surface <NUM> of the cover <NUM> faces the surface <NUM> of the housing <NUM>. The cover <NUM> is fixed to the housing <NUM> such that the through-hole <NUM> of the cover <NUM> is coaxial or substantially coaxial with respect to the through-hole <NUM> of the housing <NUM>. The through-hole <NUM> and the through-hole <NUM> communicate to form a single through-tube <NUM>. In the surface <NUM> of the cover <NUM>, an annular plane that faces the inner-side sealing surface 113b of the housing <NUM> in the direction of the axis x1 is an outer-side sealing surface 102a. The attachment space S is an annular space defined by the above-described outer-side sealing surface 102a, the outer peripheral wall surface 113a, and the inner-side sealing surface 113b. The sealing device <NUM> is attached to the attachment space S to seal the attachment space S and thus seals the through-tube <NUM> formed by the through-hole <NUM> and the through-hole <NUM>.

In the usage state, the sealing device <NUM> is attached to the attachment space S coaxially or substantially coaxially with respect to the attachment space S. In other words, in the usage state, the axis x and the axis x1 coincide with or slightly diverge from each other. As illustrated in <FIG>, the sealing device <NUM> is put between and compressed by the cover <NUM> and the housing <NUM> in the usage state. Specifically, the seal lip <NUM> is pressed by the outer-side sealing surface 102a toward the inner side, and the seal lip <NUM> is in contact with the outer-side sealing surface 102a with an interference of a predetermined range extending from the distal end 21a. Meanwhile, the inner side end <NUM> of the reinforcing ring <NUM> is in contact with the inner-side sealing surface 113b, and the secondary lip portion <NUM> is pressed to the inner-side sealing surface 113b and is in contact with the inner-side sealing surface 113b with a predetermined interference or crush allowance.

The seal lip <NUM> is longer than the secondary lip portion <NUM> and is, as illustrated in <FIG>, allowed to be in contact with the outer-side sealing surface 102a with a relatively large interference in the usage state. As a result, even if there is a variation in a size of the attachment space S, for example, a variation in a width size (a distance between the inner- and the outer- side sealing surfaces 113b and 102a) in the direction of the axis x1, the seal lip <NUM> is able to offset the variation to be kept in a state of contact with the outer-side sealing surface 102a. This enables also the secondary lip portion <NUM> to be kept in a state of being pressed to the inner-side sealing surface 113b, and thus the secondary lip portion <NUM> is able to be kept in a state of contact with the inner-side sealing surface 113b.

In this way, when the sealing device <NUM> is attached to the attachment space S in an intended direction, the sealing device <NUM> is able to seal the attachment space S and properly seal the attachment space S even with a variation in the size of the attachment space S.

Meanwhile, if the sealing device <NUM> is not attached to the attachment space S in an intended way, for example, when the sealing device <NUM> is attached to the attachment space S in a opposite direction in the direction of the axis x1, the seal lip <NUM> is pressed to the inner-side sealing surface 113b and the secondary lip portion <NUM> is pressed to the outer-side sealing surface 102a. As illustrated in <FIG>, an inside diameter of the inner-side sealing surface 113b is larger than an inside diameter of the outer-side sealing surface 102a and a width of the inner-side sealing surface 113b extending in an inner peripheral direction is smaller than a width of the outer-side sealing surface 102a extending in the inner peripheral direction in some cases. In such a case, when the sealing device <NUM> is attached to the attachment space S in a direction opposite the intended direction in the direction of the axis x1, a part of the seal lip <NUM> on a side of the distal end 21a sticks out of the inner-side sealing surface 113b, causing a decrease in sealing performance or damage to the seal lip <NUM>.

By contrast, the sealing device <NUM>, as described above, has the identification part <NUM> and allows the worker to identify a side of the sealing device <NUM> in the direction of the axis, where the seal lip <NUM> is present. This can prevent the sealing device <NUM> from being attached to the attachment space S in a direction other than the intended direction.

Thus, the sealing device <NUM> according to the embodiment of the present invention is allowed to be attached in an intended way.

Next, a sealing structure <NUM> (not claimed) will be described. <FIG> is a cross-sectional view of a sealing device <NUM> included in the sealing structure <NUM> in a cross section along the axis x. <FIG> is a cross-sectional view of an attachment space <NUM> included in the sealing structure <NUM> in a cross section along the axis x. <FIG> is a cross-sectional view of the sealing structure <NUM> in a usage state in which the sealing device <NUM> is attached to the attachment space <NUM>.

As illustrated in <FIG>, the sealing structure <NUM> includes the attachment space <NUM> that is an annular space around the axis x formed by a plurality of members and the sealing device <NUM> for sealing the attachment space <NUM>. In the sealing structure <NUM>, an engagement portion <NUM> is provided between the attachment space <NUM> and the sealing device <NUM>. The engagement portion <NUM> includes a recessed engagement part 5b that is a part formed in the attachment space <NUM> and recessed to the outer periphery side and an engagement part 5a that is a part formed in the sealing device <NUM> and projecting to the outer periphery side so as to be housed in the recessed engagement part 5b. Hereinafter, the sealing structure <NUM> will be described in detail.

The sealing device <NUM> included in the sealing structure <NUM> differs from the sealing device <NUM> described above in forms of the reinforcing ring and the outer peripheral portion of the elastic body part. The sealing device <NUM> includes a reinforcing ring <NUM> different from the reinforcing ring <NUM> of the sealing device <NUM> and an elastic body part <NUM> different from the elastic body part <NUM> of the sealing device <NUM>. Hereinafter, components of the sealing device <NUM> that are identical or similar in function to those of the sealing device <NUM> are assigned the same reference signs, and descriptions thereof are omitted. Components that differ between the sealing devices will be described.

As illustrated in <FIG>, the sealing device <NUM> includes the reinforcing ring <NUM> and the elastic body part <NUM> that is formed from an elastic body and formed so as to cover the reinforcing ring <NUM>. The sealing device <NUM> also includes the protruding engagement part 5a projecting to the outer periphery side.

As illustrated in <FIG>, the reinforcing ring <NUM> includes a tubular portion <NUM> and a flange portion <NUM> on an end portion on the outer side (the one side) of the reinforcing ring <NUM>. The tubular portion <NUM> is a tubular member extending along the axis x and is, for example, a cylindrical or substantially cylindrical member centered about or substantially centered about the axis x. The tubular portion <NUM> has an inner side end 14a which is an end portion on the inner side and an outer side end 14b which is an end portion on the outer side. The flange portion <NUM> is a portion projecting annularly to the outer periphery side from the outer end portion 14b of the tubular portion <NUM>. The reinforcing ring <NUM> is a part for reinforcing the elastic body part <NUM> and is, for example, made of a metal or resin material in a similar way to the reinforcing ring <NUM>.

As illustrated in <FIG>, the elastic body part <NUM> includes a seal lip <NUM> and a secondary lip portion <NUM> each projecting from a base portion <NUM> and an outer peripheral portion <NUM> covering the reinforcing ring <NUM> from the outer periphery side. In the outer peripheral portion <NUM>, a part covering the flange portion <NUM> of the reinforcing ring 13projects to the outer periphery side, the outer peripheral portion <NUM> has an annular projecting part 26a. In a similar way to the elastic body part <NUM>, the elastic body part <NUM> is formed from a elastic body.

In the sealing device <NUM>, the reinforcing ring <NUM> includes the flange portion <NUM> projecting to the outer periphery side, and the outer peripheral portion <NUM> of the elastic body part <NUM>, in which the part covering the flange portion <NUM> projects to the outer periphery side, has the projecting part 26a. In this way, in the sealing device <NUM>, the outer peripheral portion <NUM> projects to the outer periphery side (the projecting part 26a) in the flange portion <NUM>, and the protruding engagement part 5a is formed by the flange portion <NUM> and the projecting part 26a.

Note that the flange portion <NUM> may be made up of a plurality of arcs formed at intervals between the arcs in an intermittently annular shape rather than an endless annular shape as described above. Alternatively, the flange portion <NUM> may be a single arc extending in a circumference around the axis x. In this case, the projecting part 26a also has a shape corresponding to that of the flange portion <NUM> and thus the protruding engagement part 5a has a shape corresponding to that of the flange portion <NUM>.

As illustrated in <FIG>, the attachment space <NUM> is an annular space formed in a component to which the sealing device <NUM> is attached. The attachment space <NUM> is, for example, a circular ring shaped or substantially circular ring shaped space around the axis x formed by a cover <NUM> in which a through-hole <NUM> is formed and a housing <NUM> to which the cover <NUM> is fixed and in which a through-hole <NUM> is formed. In a surface <NUM> of the housing <NUM>, a groove portion <NUM> is formed to form an annular groove around the through-hole <NUM>. The groove portion <NUM> is defined by an outer peripheral wall surface <NUM> extending in a shape of a cylinder or a substantial cylinder in a direction of the axis x and an inner-side sealing surface <NUM> that is an annular plane extending from an end portion (an inner side end 42a) on the inner side of the outer peripheral wall surface <NUM> to the through-hole <NUM> toward the inner periphery side. The cover <NUM> is fixed to the housing <NUM> such that a surface <NUM> of the cover <NUM> faces the surface <NUM> of the housing <NUM>. The cover <NUM> is fixed to the housing <NUM> such that the through-hole <NUM> of the cover <NUM> is coaxial or substantially coaxial with respect to the through-hole <NUM> of the housing <NUM>. The through-hole <NUM> and the through-hole <NUM> communicate to form a single through-tube <NUM>. In the surface <NUM> of the cover <NUM>, an annular plane that faces the inner-side sealing surface <NUM> of the housing <NUM> in the direction of the axis x is an outer-side sealing surface <NUM>.

The attachment space <NUM> is an annular space defined by the above-described outer-side sealing surface <NUM>, the outer peripheral wall surface <NUM>, and the inner-side sealing surface <NUM>. As illustrated in <FIG>, the outer peripheral wall surface <NUM> of the attachment space <NUM> has a counterbored part <NUM> that is recessed in a shape of a counterbore toward the outer periphery side. The counterbored part <NUM> is formed in an end portion (an outer side end 42b) on the outer side of the outer peripheral wall surface <NUM> opposite the end portion (the inner side end 42a) on a side of the inner-side sealing surface <NUM>. Specifically, the counterbored part <NUM> is defined by a tubular surface 45a that is a tubular surface extending along the axis x and an annular surface 45b that is an annular surface extending from an end portion on the inner side of the tubular surface 45a toward the inner periphery. In the sealing structure <NUM> in a usage state described later, the counterbored part <NUM> is formed so as to house the protruding engagement part 5a of the sealing device <NUM>. Thus, in the attachment space <NUM>, the counterbored part <NUM> forms the recessed engagement part 5b.

In the usage state of the sealing structure <NUM>, the sealing device <NUM> is attached to the attachment space <NUM> to seal the attachment space <NUM> in a similar way to the sealing device <NUM> described above. In other words, the seal lip <NUM> and the secondary lip portion <NUM> of the sealing device <NUM> are in contact with the outer-side sealing surface <NUM> and the inner-side sealing surface <NUM>, respectively. The protruding engagement part 5a of the sealing device <NUM> is housed in the recessed engagement part 5b of the attachment space <NUM>. In this way, in the sealing structure <NUM>, when the sealing device <NUM> is attached to the attachment space <NUM> in an intended proper direction, the protruding engagement part 5a is housed in the recessed engagement part 5b. In this state, the seal lip <NUM> is in contact with the outer-side sealing surface <NUM> with a desired interference, and the secondary lip portion <NUM> is in contact with the inner-side sealing surface <NUM> with a desired interference or crush allowance. Meanwhile, in the sealing structure <NUM>, if the sealing device <NUM> is to be attached in an improper direction and a direction different from the intended direction, i.e., when the sealing device <NUM> is to be attached to an interior of the groove portion <NUM> of the attachment space <NUM> from the seal lip <NUM> side, the protruding engagement part 5a is housed in the recessed engagement part 5b but the protruding engagement part 5a is caught in the recessed engagement part 5b such that the sealing device <NUM> is stopped from advancing into the attachment space <NUM> further. This can prevent the sealing device <NUM> from being attached to the attachment space <NUM> in a direction other than the intended direction.

Thus, according to the sealing structure <NUM>, it is possible to be attached in an intended way.

Next, a modification example of the sealing device <NUM> in the sealing structure <NUM> described above will be described. <FIG> is a cross-sectional view of a sealing device <NUM> according to a modification example of the sealing device <NUM> in a cross section along the axis x. The sealing device <NUM> according to the present modification example differs from the sealing device <NUM> described above in a form of the outer peripheral portion <NUM> of the elastic body part. In the sealing device <NUM> according to the modification example, an outer peripheral portion <NUM> of an elastic body part <NUM> does not cover the flange portion <NUM> of the reinforcing ring <NUM>, the flange portion <NUM> passes through the outer peripheral portion <NUM> and projects from a surface 26b of the outer peripheral portion <NUM>. In this way, the sealing device <NUM> does not include the projecting part 26a in the outer peripheral portion <NUM> of the elastic body part <NUM>. In the sealing device <NUM>, a protruding engagement part 5a is formed by the flange portion <NUM> of the reinforcing ring <NUM> sticking out from the outer peripheral portion <NUM>. This protruding engagement part 5a, in a similar way to the protruding engagement part 5a described above, is designed to be capable of being housed in the recessed engagement part 5b of the attachment space <NUM> in the usage state of the sealing structure <NUM>. The sealing structure <NUM> can prevent the sealing device <NUM> from being attached to the attachment space <NUM> in a way that differs from the intended way.

Next, a modification example of the attachment space <NUM> in the sealing structure <NUM> described above will be described. <FIG> is a cross-sectional view of a sealing structure <NUM> including an attachment space <NUM> according to a modification example of the attachment space <NUM>. In <FIG>, the attachment space <NUM> according to the modification example is illustrated in a usage state in which the sealing device <NUM> described above is attached to the attachment space <NUM>. As illustrated in <FIG>, the attachment space <NUM> according to the modification example includes a chamfered part <NUM> recessed to the outer periphery side as a recessed engagement part 5b in place of the counterbored part <NUM>. The chamfered part <NUM> is designed in such a manner that the flange portion <NUM> of the sealing device <NUM> can be housed in the chamfered part <NUM>. Specifically, as illustrated in <FIG>, the chamfered part <NUM> has a chamfered surface 46a in an outer side end 42b of an outer peripheral wall surface <NUM>. The chamfered surface 46a is an annular surface that increases in diameter toward the outer side (the arrow a direction) in the direction of the axis x and is, for example, a conical or substantially conical surface centered or substantially centered about the axis x. The chamfered part <NUM> is a recessed part forming an annular space that is defined by the chamfered surface 46a, and thus the space extends further to the outer periphery side toward the outer side in the direction of the axis x. Note that the chamfered part <NUM> may be in any other form, and the chamfered part <NUM>, for example, may have a portion in which the chamfered part <NUM> does not continuously extend to the outer periphery side toward the outer side in the direction of the axis x.

In the usage state of the sealing structure <NUM>, in the attachment space <NUM> according to the modification example, the protruding engagement part 5a is, as described above, allowed to be housed in the recessed engagement part 5b. In the sealing structure <NUM>, it is possible to prevent the sealing device <NUM> from being attached to the attachment space <NUM> in a way that differs from the intended way. Note that the attachment space <NUM> acts similarly for the sealing device <NUM>, and in the sealing structure <NUM>, it is possible to prevent the sealing device <NUM> from being attached to the attachment space <NUM> in a way that differs from the intended way.

Claim 1:
A sealing device (<NUM>) for sealing an annular space formed by a plurality of members (<NUM>, <NUM>), comprising:
a reinforcing ring (<NUM>) having an annular shape around an axis (x); and
an elastic body part (<NUM>) formed from an elastic body, the elastic body part being attached to the reinforcing ring and having an annular shape around the axis,
wherein:
the elastic body part includes a seal lip (<NUM>) that is an annular portion projecting toward one side in a direction of the axis, a secondary lip portion (<NUM>) that is an annular portion projecting toward another side in the direction of the axis, and an outer peripheral portion (<NUM>) that is a portion covering the reinforcing ring from an outer periphery side;
the seal lip projects beyond the reinforcing ring toward the one side in the direction of the axis; and
the secondary lip portion projects beyond the reinforcing ring toward the other side in the direction of the axis,
characterized in that,
in the outer peripheral portion, a plurality of identification parts (<NUM>) are formed further on the one side or the other side than a middle of the outer peripheral portion in the direction of the axis, the plurality of identification parts acting as marks,
wherein
the plurality of identification parts are recessed parts or protruding parts projecting from a surface of the outer peripheral portion, and provided at intervals around the axis