JP5904327B2 - Sealing device - Google Patents

Description

  The present invention relates to a sealing device according to a sealing technique. The sealing device of the present invention is used, for example, in the field of automobiles or in the field of general-purpose machines.

  Conventionally, as shown in FIG. 5, for the purpose of increasing the pumping amount of the seal lip 51, a sealing device is known in which a screw 53 that exerts a pumping action on the sealing fluid is provided on the atmosphere-side slope 52 of the seal lip 51.

  However, in such a sealing device with the screw 53, when the external dust on the atmosphere side Y enters between the screws 53, the intruding dust moves in the circumferential direction as the rotating shaft 55 rotates, and the moved dust Contacts the screw 53, and the contacted dust moves along the screw 53 toward the lip end 54. Therefore, as a result, there is a concern that dust may be caught between the lip end 54 and the shaft 55, and a gap is generated between the lip end 54 and the shaft 55, and a sealing fluid (oil or the like) leaks from this gap.

Japanese Patent No. 3278349

  In view of the above points, the present invention can suppress the entry of atmospheric external dust toward the end of the lip, thereby suppressing the leakage of the sealing fluid due to the biting of the dust, and the screw. It aims at providing the sealing device which can fully exhibit the pump action by.

In order to achieve the above object, a sealing device according to claim 1 of the present invention is a sealing device that suppresses leakage of a sealing fluid inside the machine to the atmosphere side, and contacts the shaft at the lip end of the sealing lip. In addition, in the sealing device in which a plurality of screws on the circumference are provided on the atmosphere-side slope of the seal lip so as to exert a pumping action on the sealing fluid, the atmosphere-side external dust is prevented from entering the lip end. the three-dimensional shape for preventing dust intrusion provided between the screws, the three-dimensional shape consists of protrusions, said protrusions or discontinuous relative to the screw, air flow path is set between the protrusions and the screw, the projection , Consisting of parallel protrusions extending in a direction parallel to the lip end,
The parallel protrusion has a substantially triangular cross-sectional shape with its apex approaching the atmosphere side, and the protrusion includes a vertical protrusion extending in a direction orthogonal to the lip end in addition to the parallel protrusion, The apex has a substantially triangular cross-sectional shape whose direction is opposite to the rotation direction of the shaft .

The sealing device according to claim 2 of the present invention is a sealing device that suppresses leakage of the sealing fluid inside the machine to the atmosphere side, and is in contact with the shaft at the lip end of the seal lip and the seal lip. In a sealing device provided with a plurality of circumferentially provided screws that exert a pumping action on the sealing fluid on the atmosphere side slope, dust intrudes between the screws in order to suppress the outside dust on the atmosphere side from entering the lip end. A three-dimensional shape for prevention is provided, the three-dimensional shape is formed of a protrusion, the protrusion is discontinuous with respect to the screw, an air flow path is set between the protrusion and the screw, and each of the screws has a lip end. A parallel screw with a uniform cross section provided in the vicinity and a boat bottom-shaped screw provided continuously from the parallel screw, and the three-dimensional shape is a first stand provided between the parallel screws adjacent to each other. A parallel projection having a shape, a second solid-shaped vertical projection provided between the adjacent boat-bottom screws, and a third parallel-shaped projection provided between the adjacent boat-bottom screws. The height of the parallel screw is h ₃ , the maximum height of the boat bottom screw is h ₄ , the height of the parallel projection of the first three-dimensional shape is h ₅ , and the height of the vertical projection of the second three-dimensional shape is The height is h ₆ , and the height of the third three-dimensional parallel projection is h ₇ ,
h ₅ <h ₃ ,
h ₆ <h ₄ and
h ₇ ≦ h ₄
It is characterized by satisfying the relationship .

According to a third aspect of the present invention , there is provided a sealing device for suppressing sealing fluid inside the machine from leaking to the atmosphere side, contacting the shaft at the lip end of the seal lip and In a sealing device provided with a plurality of circumferentially provided screws that exert a pumping action on the sealing fluid on the atmosphere side slope, dust intrudes between the screws in order to suppress the outside dust on the atmosphere side from entering the lip end. A three-dimensional shape for prevention is provided, the three-dimensional shape is formed of a protrusion, the protrusion is discontinuous with respect to the screw, and an air flow path is set between the protrusion and the screw. The parallel protrusions extend in parallel directions, and each of the parallel protrusions has a substantially triangular cross-sectional shape with its apex toward the atmosphere, and each of the screws is a parallel screw with a uniform cross-section provided in the vicinity of the lip end. And a boat bottom-shaped screw provided continuously from the parallel screw, wherein the three-dimensional shape includes a first three-dimensional parallel protrusion provided between the parallel screws adjacent to each other and the boat adjacent to each other. A vertical projection of a second three-dimensional shape provided between the bottom-shaped screws and a parallel projection of a third three-dimensional shape provided between the adjacent boat-bottomed screws, and the height of the parallel screws is h _3. The maximum height of the boat bottom-shaped screw is h ₄ , the height of the parallel projection of the first three-dimensional shape is h ₅ , the height of the vertical projection of the second three-dimensional shape is h ₆ , the third three-dimensional shape as h ₇ the height of the parallel projections,
h ₅ <h ₃ ,
h ₆ <h ₄ and
h ₇ ≦ h ₄
It is characterized by satisfying the relationship .

Furthermore, a sealing device according to a fourth aspect of the present invention is a sealing device that suppresses leakage of a sealing fluid inside the machine to the atmosphere side, and contacts the shaft at the lip end of the seal lip and the seal lip. A sealing device having a plurality of circumferentially provided screws that exert a pumping action on the sealing fluid on the atmosphere-side slope of the dust, and the dust between the screws is suppressed to prevent the atmospheric dust from entering the lip end. A three-dimensional shape for preventing intrusion is provided, the three-dimensional shape is formed of a protrusion, the protrusion is discontinuous with respect to the screw, and an air flow path is set between the protrusion and the screw. The parallel protrusions have a substantially triangular cross-sectional shape with the apexes approaching the atmosphere side, and the protrusions are perpendicular to the lip ends in addition to the parallel protrusions. Extending it from the vertical projection, the vertical projections are substantially triangular cross-sectional shape that vertex is closer to the direction opposite to the rotational direction of the shaft, each of said screws, parallel cross-section uniformly provided on the lip end near The three-dimensional shape is a first protrusion of the three-dimensional shape provided between the parallel screws adjacent to each other, and the adjacent one of the parallel protrusions. A vertical projection of a second three-dimensional shape provided between the boat bottom-shaped screws and a third projection of a third solid shape provided between the boat-shaped screws that are adjacent to each other, and the height of the parallel screws is h ₃ , the maximum height of the boat bottom-shaped screw is h ₄ , the height of the parallel projection of the first three-dimensional shape is h ₅ , the height of the vertical projection of the second three-dimensional shape is h ₆ , the third three-dimensional shape the height of the parallel projection shape as h _7,
h ₅ <h ₃ ,
h ₆ <h ₄ and h ₇ ≦ h ₄
It is characterized by satisfying the relationship.

  In the sealing device of the present invention having the above-described configuration, since a three-dimensional shape for preventing dust intrusion is provided between the plurality of screws to suppress external dust on the air side from entering the lip end, This three-dimensional shape exhibits a function of suppressing the dust on the atmosphere side from entering the lip end. The three-dimensional shape is composed of protrusions, and the protrusions dam up the dust, so that the dust can be prevented from entering the lip end. On the other hand, since the protrusion is discontinuous with respect to the screw and the air flow path is set between the protrusion and the screw, even if the protrusion is provided between the screws, the air flows through the air flow path due to the screw. It is possible to sufficiently exhibit the pumping action.

  For example, the protrusion is a parallel protrusion extending in a direction parallel to the lip end. Although the cross-sectional shape of the parallel protrusion is not particularly limited, for example, a substantially triangular cross-sectional shape is used. In this case, the triangle may be an equilateral triangle or an isosceles triangle. However, if the apex of the triangle is an unequal triangle with the apex approaching the atmosphere side, the elevation angle of the atmosphere side surface is set large. Hateful.

  In addition to the parallel protrusions, the protrusions are vertical protrusions extending in a direction perpendicular to the lip end. Although the cross-sectional shape of the vertical protrusion is not particularly limited, for example, it has a substantially triangular cross-sectional shape. In this case, the triangle may be an equilateral triangle or an isosceles triangle, but if the apex is an unequal triangle whose direction is opposite to the axis rotation direction, the elevation angle of the surface on the rear side in the axis rotation direction is set large. It is difficult for dust to get over the rear surface in the axial direction. The vertical protrusions can also block the dust that moves in the circumferential direction as the shaft rotates.

The screw is a spiral protrusion, and is composed of, for example, a parallel screw having a uniform cross section provided in the vicinity of the lip end and a boat bottom-shaped screw provided continuously from the parallel screw. Also, the three-dimensional shape is a first three-dimensional parallel projection provided between adjacent parallel screws, a second three-dimensional vertical projection provided between adjacent boat bottom screws, and a boat that is also adjacent to each other. Suppose that it consists of a parallel projection of the 3rd solid shape provided between bottom-shaped screws. In this case, the height of the parallel screw is h ₃ , the maximum height of the boat bottom-shaped screw is h ₄ , the height of the parallel projection of the first three-dimensional shape is h ₅ , and the height of the vertical projection of the second three-dimensional shape is h ₆ , the height of the parallel projection of the third three-dimensional shape is h ₇ ,
h ₅ <h ₃ ... (a) Formula h ₆ <h ₄ ... (b) and h ₇ ≦ h _4. Since the screw at the height is higher than the protrusion, the pumping action by the screw can be sufficiently sustained. The boat-bottomed screw has a shape such that its height and width are the largest in the central portion in the longitudinal direction and are gradually reduced toward both ends.

  The present invention has the following effects.

  That is, in the present invention, as described above, a three-dimensional shape for preventing dust intrusion is provided between a plurality of screws so as to prevent the dust on the air side from entering the lip end. However, it exerts a function of suppressing the dust on the atmosphere side from entering the lip end. The three-dimensional shape is a protrusion, and the protrusion dams up the dust, so that the dust is prevented from entering the lip end. On the other hand, since the protrusion is discontinuous with respect to the screw and the air flow path is set between the protrusion and the screw, even if the protrusion is provided between the screws, the pump is driven by the screw by the air flowing through the air flow path. Demonstrate the effect sufficiently. Therefore, according to the intended purpose of the present invention, the external dust on the atmosphere side is prevented from entering the lip end, so that the leakage of the sealing fluid due to the biting of the dust is suppressed, and the pump action by the screw It is possible to provide a sealing device that sufficiently exhibits the above.

  Also, by making the three-dimensional parallel protrusions into a substantially triangular cross-sectional shape with the apex approaching the atmosphere side, it is possible to make it difficult for dust to get over the air-side surface of the parallel protrusion. By adopting a substantially triangular cross-sectional shape close to the direction opposite to the rotation direction, it is possible to make it difficult for dust to get over the rear surface of the vertical protrusion in the axial rotation direction.

  Further, the heights of the parallel screw, the boat bottom screw, the first three-dimensional parallel protrusion, the second three-dimensional vertical protrusion, and the third three-dimensional parallel protrusion are determined in accordance with the above formulas (a) to (c). By setting, it is possible to achieve both of the pump action by the screw and the suppression of dust intrusion by the protrusion.

Sectional drawing of the principal part of the sealing device which concerns on 1st Example of this invention. (A) is explanatory drawing of the screw and three-dimensional shape in the same sealing device, (B) is explanatory drawing of three-dimensional shape Sectional drawing of the principal part of the sealing device which concerns on 2nd Example of this invention. (A) is explanatory drawing of screw and three-dimensional shape in the same sealing device, (B) and (C) are explanatory drawings of three-dimensional shape Sectional drawing of the principal part of the sealing device which concerns on a prior art example

The present invention includes the following embodiments.
(1-1) Configuration (1-1-1) A projection parallel to the surface of the lip tip is provided between the screws on the atmosphere side of the boat bottom screw.
(1-1-2) The parallel protrusions have a substantially triangular cross-sectional shape with apexes close to the atmosphere, and the height is lower than the boat bottom screw or the same height.
(1-1-3) Install an obstacle that allows air to pass between the screws (there is a gap between them) but makes it difficult for external dust to reach the tip of the lip (changes the flow).
(1-2) Effects (1-2-1) The amount of intrusion between the lips is reduced by damming up dust or the like that has entered from the outside on the atmosphere side with parallel protrusions.
(1-2-2) Since the apex of the protrusion has a substantially triangular cross-sectional shape that is close to the atmosphere, dust or the like is difficult to get over the protrusion.
(1-2-3) Since the protrusion and the ship bottom screw are not in contact with each other, an air flow path is secured and the pump amount is maintained.

(2-1) Configuration (2-1-1) A plurality of protrusions parallel to and perpendicular to the surface of the lip tip are provided between the screws.
(2-1-2) The parallel protrusion is a substantially triangular cross-sectional shape whose apex is close to the atmosphere side, and the vertical protrusion is a substantially triangular cross-sectional shape whose apex is close to the rotation direction of the rotation shaft, and the height is lower than that of the screw.
(2-1-3) The parallel protrusion of the parallel screw portion is lower than the parallel screw, the vertical protrusion of the boat bottom screw portion is lower than the boat bottom screw, and the parallel protrusion of the boat bottom screw portion is lower than the top of the boat bottom screw. To do.
(2-2) Effect (2-2-1) The amount of dust entering between the lips is reduced by damming up dust or the like entering from the outside on the atmosphere side with parallel protrusions.
(2-2-2) Dust and the like that are rotated along with the rotation of the rotating shaft are dammed up by vertical protrusions, thereby reducing the contact of dust with screws.
(2-2-3) The parallel projections serve to block the dust flow in the axial direction, and the vertical projections serve to block the dust that is rotated in the circumferential direction by the rotation of the shaft.
(2-2-4) Since the apex of the projection has a substantially triangular cross-sectional shape that is close to the atmosphere, dust or the like is difficult to get over the projection.
(2-2-5) Since the protrusion and the ship bottom screw are not in contact with each other, an air flow path is secured and the pump amount is maintained.

  Next, embodiments of the present invention will be described with reference to the drawings.

  1 and 2 show a sealing device according to a first embodiment of the present invention. The sealing device according to this embodiment is mounted on the inner peripheral surface of a shaft hole of a device (not shown) and slidably comes into close contact with the peripheral surface of the shaft (not shown). X leakage fluid (not shown) is prevented from leaking to the atmosphere side Y. The shaft rotates in the direction of arrow Z. The sealing device is sometimes called a rotating oil seal because of its function or use.

  The seal lip 11 is slidably in close contact with the peripheral surface of the shaft at the lip end 12, and an inboard side slope 13 is provided on the inboard side X of the lip end 12 and the atmosphere side Y of the lip end 12. Atmosphere side slope 14 is provided. A plurality of screws 15 on the circumference are provided on the latter air-side slope 14 for exerting a pumping action on the sealing fluid when the shaft rotates to push the sealing fluid back to the machine interior X.

  The screw 15 is a projection provided in a spiral shape, and includes a parallel screw 16 having a uniform cross-section provided so as to reach the lip end 12 and a boat bottom-shaped screw 17 provided continuously from the parallel screw 16. It is formed by a combination. The screw 15 is formed so as to incline backward in the axial rotation direction Z from the base end portion on the lip end side to the tip end portion on the atmosphere side Y. The parallel screw 16 is, for example, a protrusion having a substantially triangular cross section, and the cross section is formed in a uniform shape over the entire length. The boat bottom-shaped screw 17 is, for example, a protrusion having a substantially triangular cross-sectional shape, and has a height and width that are the largest at the center in the longitudinal direction and gradually reduced toward both ends. In FIG. 1, for convenience of drawing, only three screws 15 are depicted, but many screws 15 are provided over the entire circumference.

  Further, in the sealing device according to the embodiment, the following configuration is provided so that external dust (not shown) on the atmosphere side Y does not enter the lip end 12. The dust is, for example, sand particles contained in muddy water.

  That is, on the atmosphere-side inclined surface 14 of the seal lip 11, the external dust on the atmosphere-side Y does not enter the lip end 12 through the gap between the adjacent screws 15. A three-dimensional shape 21 for preventing dust intrusion is provided.

  The three-dimensional shape 21 is composed of linear parallel protrusions 22 provided so as to extend in a direction parallel to the lip end 12, that is, in the circumferential direction, between adjacent boat bottom-shaped screws 17. Both end portions 22 a and 22 b are discontinuous with respect to the screw 15, and air flow paths 23 are respectively provided between the longitudinal end portions 22 a and 22 b of the parallel protrusion 22 and the screw 15. The air flow path 23 flows air from the atmosphere side Y toward the lip end side, and promotes the pumping action by the screw 15.

Although the cross-sectional shape of the parallel protrusion 22 is not particularly limited, in this embodiment, it is a substantially triangular cross-sectional shape as shown in FIG. Triangle is the vertex 22c is a scalene triangle closer to the atmosphere side Y, elevation theta ₁ atmosphere-side surface 22d is set to be larger than the elevation theta ₂ surface 22e of the lip end (θ _1> θ ₂ ). The height h ₁ of the protrusion 22 is set to be equal to or less than the maximum height h ₂ of the boat bottom screw 17 (h ₁ ≦ h ₂ ).

In the sealing device configured as described above, the three-dimensional shape 21 for preventing dust intrusion is provided between the screws 15 adjacent to each other in order to prevent the external dust on the atmosphere side Y from entering the lip end 12. This three-dimensional shape 21 exhibits a function of suppressing the dust on the atmosphere side Y from entering the lip end 12. The three-dimensional shape 21 includes parallel protrusions 22 extending in a direction parallel to the lip end 12, and the parallel protrusions 22 dam the dust, so that the dust is prevented from entering the lip end 12. Because protrusion 22 is the elevation angle theta ₁ of the atmosphere-side surface 22d while being substantially triangular cross-section is set larger, the dust is difficult to overcome the surface 22d of the atmosphere. Therefore, from the above, it is possible to suppress the dust on the atmosphere side Y from entering the lip end 12, and thus it is possible to suppress the leakage of the sealing fluid due to the biting of the dust.

On the other hand, since the parallel protrusion 22 is discontinuous with respect to the screw 15 and the air flow path 23 is set between the parallel protrusion 22 and the screw 15, even if the parallel protrusion 22 is provided between the screws 15, The pumping action by the screw 15 is sufficiently exhibited by the air flowing through the air flow path 23. Further, since the height h ₁ of the parallel protrusion 22 is set to be equal to or less than the maximum height h ₂ of the boat bottom screw 17, the parallel protrusion 22 does not hinder the pumping action by the screw 15. Therefore, even if the parallel protrusion 22 for preventing dust intrusion is provided, the pump action by the screw 15 is sufficiently exhibited.

  The sealing device according to the first embodiment may have the following configuration.

(I)
In the first embodiment, although the elevation angle theta ₁ of the atmosphere-side surface 22d is set larger than the elevation theta ₂ surface 22e of the lip end of the parallel projections 22, the surface 22d of the atmosphere side is perpendicular to the axis (theta It is preferable to set the angle within a range of ₁ > 90 °) or a right angle (θ ₁ = 90 °) with respect to the atmosphere-side slope 14 because dust can be easily dammed. Θ ₁ may be larger than 90 ° (θ ₁ > 90 °).

(B)
In the first embodiment, the projection of the three-dimensional shape 21 is provided at one location between the screws 15. Alternatively, the projection of the three-dimensional configuration 21 may be provided at a plurality of locations between the screws 15.

  3 and 4 shown as the second embodiment, the three-dimensional shape 21 is provided between the first three-dimensional parallel projections 24 provided between the parallel screws 16 adjacent to each other and the boat bottom-type screws 17 adjacent to each other. It is formed by a combination of the second solid-shaped vertical protrusion 25 and a third solid-shaped parallel protrusion 26 provided between adjacent boat bottom-shaped screws 17. The vertical protrusion 25 is a linear protrusion extending in a direction orthogonal to the lip end 12, that is, in the axial direction.

  The first three-dimensional parallel protrusion 24 is disposed on the lip end side of the second three-dimensional vertical protrusion 25, and the second three-dimensional vertical protrusion 25 is disposed on the atmosphere side Y of the first three-dimensional parallel protrusion 24, Both protrusions 24 and 25 are disposed with an axial interval therebetween. The second three-dimensional vertical protrusion 25 is arranged on the lip end side of the third three-dimensional parallel protrusion 26, the third three-dimensional parallel protrusion 26 is arranged on the atmosphere side Y of the second three-dimensional vertical protrusion 25, Both protrusions 25 and 26 are arranged with an axial interval therebetween.

  The first three-dimensional parallel projection 24 has both longitudinal ends 24 a and 24 b discontinuous with respect to the screw 15, and an air flow path between the longitudinal ends 24 a and 24 b of the parallel projection 24 and the screw 15, respectively. 27 is provided. The longitudinal projections 25 of the second three-dimensional shape have their longitudinal ends 25a and 25b discontinuous with respect to the screws 15, respectively, and the air flow paths between the longitudinal ends 25a and 25b of the vertical projections 25 and the screws 15, respectively. 28 is provided. The parallel projections 26 of the third three-dimensional shape have their longitudinal ends 26 a and 26 b discontinuous with respect to the screws 15, respectively, and air flow paths between the longitudinal ends 26 a and 26 b of the parallel projections 26 and the screws 15, respectively. 29 is provided.

Although the cross-sectional shape of the parallel protrusions 24 and 26 is not particularly limited, in this embodiment, it is a substantially triangular cross-sectional shape as shown in FIG. It triangles the vertex 24c, 26c is a scalene triangle closer to the atmosphere side Y, the air-side surface 24d, elevation theta ₁ of 26d is set to be larger than the surface 24e, 26e of the elevation theta ₂ of the lip end (Θ ₁ > θ ₂ ). Although the cross-sectional shape of the vertical protrusion 25 is not particularly limited, in this embodiment, it has a substantially triangular cross-sectional shape as shown in FIG. Triangle is the vertex 25c is a scalene triangle closer to a direction opposite to the rotating direction Z of the shaft, the elevation angle theta ₃ surface 25d of the rotation direction rear side than the elevation theta ₄ surface 25e of the rotation direction front side It is set large (θ ₃ > θ ₄ ).

Further, the height of the parallel screw 16 is h ₃ , the maximum height of the boat bottom-shaped screw 17 is h ₄ , the height of the parallel projection 24 of the first three-dimensional shape is h ₅ , and the height of the vertical projection 25 of the second three-dimensional shape The height is h ₆ , and the height of the third three-dimensional parallel protrusion 26 is h ₇ .
h ₅ <h ₃ ... (a) Formula h ₆ <h ₄ ... (b) and h ₇ ≦ h _4. Yes.

And in this 2nd Example, since the parallel protrusions 24 and 26 of the three-dimensional shape 21, and the vertical protrusion 25 are provided over several places between the screws 15, while being effective in suppressing dust penetration | invasion, a parallel protrusion 24, 26 and the vertical protrusion 25 and the screw 15 are provided with the air flow paths 27, 28, 29, respectively, so that the pumping action by the screw 15 is sufficiently performed by the air flowing through the air flow paths 27, 28, 29. Demonstrated. The height h _{5 of} the first three-dimensional parallel protrusion 24 is set to be smaller than the height h ₃ of the parallel screw 16 provided at the corresponding position, and the height h _{6 of} the second three-dimensional vertical protrusion 25 is is set smaller than the maximum height h ₄ of the corresponding boat bottom shaped provided at a position screw 17, the height h7 parallel projections 26 of the third three-dimensional shape, the corresponding boat bottom shaped screw provided at a position 17 since it is set to the maximum below the height h ₄ equivalent, parallel projections 24, 26 and vertical projection 25 does not inhibit pumping action by the screw 15 either. Therefore, the pump action by the screw 15 is sufficiently exhibited also by this.

11 Seal lip 12 Lip end 13 Aircraft inside slope 14 Atmosphere side slope 15 Screw 16 Parallel screw 17 Ship bottom screw 21 Three-dimensional shape 22, 24, 26 Parallel protrusion 22a, 22b, 24a, 24b, 25a, 25b, 26a, 26b Long Direction end 22c, 24c, 25c, 26c Vertex 22d, 24d, 26d Air side surface 22e, 24e, 26e Lip end side surface 23, 27, 28, 29 Air flow path 25 Vertical projection 25d Axial rotation direction rear side Surface 25e Front surface in the direction of shaft rotation X Aircraft inside Y Air side

Claims (4)

A sealing device that suppresses leakage of the sealing fluid inside the machine to the atmosphere side,
In the sealing device provided with a plurality of screws on the circumference that contact the shaft at the lip end of the seal lip and that exert a pumping action on the sealing fluid on the atmosphere-side slope of the seal lip,
In order to suppress external dust on the air side from entering the lip end, a three-dimensional shape for preventing dust intrusion is provided between the screws,
The three-dimensional shape is a protrusion, the protrusion is discontinuous with respect to the screw, and an air flow path is set between the protrusion and the screw ,
The protrusion comprises a parallel protrusion extending in a direction parallel to the lip end,
The parallel protrusion has a substantially triangular cross-sectional shape with its apex approaching the atmosphere side,
In addition to the parallel protrusion, the protrusion includes a vertical protrusion extending in a direction orthogonal to the lip end,
The sealing device according to claim 1, wherein the vertical protrusion has a substantially triangular cross-sectional shape with a vertex thereof in a direction opposite to a rotation direction of the shaft . A sealing device that suppresses leakage of the sealing fluid inside the machine to the atmosphere side,
In the sealing device provided with a plurality of screws on the circumference that contact the shaft at the lip end of the seal lip and that exert a pumping action on the sealing fluid on the atmosphere-side slope of the seal lip,
In order to suppress external dust on the air side from entering the lip end, a three-dimensional shape for preventing dust intrusion is provided between the screws,
The three-dimensional shape is a protrusion, the protrusion is discontinuous with respect to the screw, and an air flow path is set between the protrusion and the screw,
Each of the screws consists of a parallel screw having a uniform cross section provided near the lip end and a boat bottom screw provided continuously from the parallel screw,
The three-dimensional shape is also adjacent to the first three-dimensional parallel protrusion provided between the parallel screws adjacent to each other and the second three-dimensional vertical protrusion provided between the adjacent boat bottom-shaped screws. It consists of parallel projections of a third three-dimensional shape provided between the matching ship bottom shaped screws,
The height of the parallel screw is h ₃ , the maximum height of the boat bottom screw is h ₄ , the height of the parallel projection of the first three-dimensional shape is h ₅ , and the height of the vertical projection of the second three-dimensional shape is h ₆ , the height of the third three-dimensional parallel projection is h ₇ ,
h ₅ <h ₃ ,
h ₆ <h ₄ and
h ₇ ≦ h ₄
The sealing device characterized by satisfying the relationship . A sealing device that suppresses leakage of the sealing fluid inside the machine to the atmosphere side,
In the sealing device provided with a plurality of screws on the circumference that contact the shaft at the lip end of the seal lip and that exert a pumping action on the sealing fluid on the atmosphere-side slope of the seal lip,
In order to suppress external dust on the air side from entering the lip end, a three-dimensional shape for preventing dust intrusion is provided between the screws,
The three-dimensional shape is a protrusion, the protrusion is discontinuous with respect to the screw, and an air flow path is set between the protrusion and the screw,
The protrusion comprises a parallel protrusion extending in a direction parallel to the lip end,
The parallel protrusion has a substantially triangular cross-sectional shape with its apex approaching the atmosphere side,
Each of the screws consists of a parallel screw having a uniform cross section provided near the lip end and a boat bottom screw provided continuously from the parallel screw,
The three-dimensional shape is also adjacent to the first three-dimensional parallel protrusion provided between the parallel screws adjacent to each other and the second three-dimensional vertical protrusion provided between the adjacent boat bottom-shaped screws. It consists of parallel projections of a third three-dimensional shape provided between the matching ship bottom shaped screws,
The height of the parallel screw is h ₃ , the maximum height of the boat bottom screw is h ₄ , the height of the parallel projection of the first three-dimensional shape is h ₅ , and the height of the vertical projection of the second three-dimensional shape is h ₆ , the height of the third three-dimensional parallel projection is h ₇ ,
h ₅ <h ₃ ,
h ₆ <h ₄ and
h ₇ ≦ h ₄
The sealing device characterized by satisfying the relationship . A sealing device that suppresses leakage of the sealing fluid inside the machine to the atmosphere side,
In the sealing device provided with a plurality of screws on the circumference that contact the shaft at the lip end of the seal lip and that exert a pumping action on the sealing fluid on the atmosphere-side slope of the seal lip,
In order to suppress external dust on the air side from entering the lip end, a three-dimensional shape for preventing dust intrusion is provided between the screws,
The three-dimensional shape is a protrusion, the protrusion is discontinuous with respect to the screw, and an air flow path is set between the protrusion and the screw,
The protrusion comprises a parallel protrusion extending in a direction parallel to the lip end,
The parallel protrusion has a substantially triangular cross-sectional shape with its apex approaching the atmosphere side,
In addition to the parallel protrusion, the protrusion includes a vertical protrusion extending in a direction orthogonal to the lip end,
The vertical protrusion has a substantially triangular cross-sectional shape whose apex is in a direction opposite to the rotation direction of the shaft,
Each of the screws consists of a parallel screw having a uniform cross section provided near the lip end and a boat bottom screw provided continuously from the parallel screw,
The three-dimensional shape is also adjacent to the first three-dimensional parallel protrusion provided between the parallel screws adjacent to each other and the second three-dimensional vertical protrusion provided between the adjacent boat bottom-shaped screws. It consists of parallel projections of a third three-dimensional shape provided between the matching ship bottom shaped screws,
The height of the parallel screw is h ₃ , the maximum height of the boat bottom screw is h ₄ , the height of the parallel projection of the first three-dimensional shape is h ₅ , and the height of the vertical projection of the second three-dimensional shape is h ₆ , the height of the third three-dimensional parallel projection is h ₇ ,
h ₅ <h ₃ ,
h ₆ <h ₄ and h ₇ ≦ h ₄
The sealing device characterized by satisfying the relationship.

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