JP2018031400A - Sealing device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a sealing device which is used in an apparatus having relatively-rotating two members, and suppresses a rise of the pressure of an apparatus internal space at the replenishment of a lubricant, and in which the replenished lubricant is held in the apparatus internal space for a long period of time.SOLUTION: A sealing device comprises a sleeve which is fixed to an inside member out of relatively-rotating two members, and a first seal member which is fixed to an inner face of an outside member out of the relatively-rotating two members, and in which an external peripheral face of the sleeve slides. The sealing device seals the apparatus internal space with a lubricant in the apparatus internal space. A lubricant passage communicating with an atmosphere side from the apparatus internal space is formed at the sleeve, and a lip part for permitting the passage of the lubricant in the lubricant passage when the pressure of the apparatus internal space exceeds a constant value is arranged at the sleeve.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a sealing device used in an apparatus having two members that rotate relative to each other.

  Conventionally, as a sealing device of this type, for example, as described in Patent Document 1, one of two relatively rotating members, for example, a rotary seal member called a slinger fixed to a rotating shaft, and two members rotating relatively On the other hand, for example, a sealing structure having a fixed seal member fixed to an inner surface of a shaft hole in which a rotation shaft is disposed is known. Such a sealing device is used to seal a lubricant, for example grease, in the interior space of the device. Normally, the rotary seal member is provided with a flange, and this flange prevents or reduces the intrusion of mud and dust from the atmosphere side into the internal space of the equipment. For example, a railway vehicle carriage, a sintered pallet carriage, a construction machine Such sealing devices are used in equipment used in mud or dusty environments such as truck trunnion suspensions and agricultural machinery.

Japanese Patent No. 4979744

  For equipment having this type of sealing device, it may be necessary to replenish the interior space of the equipment with a lubricant. Reasons for replenishment include the need for replacement due to deterioration of the lubricant and a reduction in the amount due to leakage of the lubricant. In replenishment, care should be taken so that the pressure in the internal space of the device does not become too high due to the injection of the lubricant, and it is desirable that the replenished lubricant be held in the internal space of the device over a long period of time.

  Therefore, the present invention is used in a device having two members that rotate relative to each other, suppresses an increase in pressure in the device internal space when the lubricant is replenished, and the replenished lubricant is held in the device internal space for a long period of time. An object is to provide a sealing device.

  In order to solve the above problems, a sealing device according to the present invention is fixed to a sleeve fixed to an inner member of two relatively rotating members, and to an inner surface of an outer member of the two relatively rotating members, A sealing device that seals the lubricant in the internal space of the device to the internal space of the device, and the sleeve includes an air side from the internal space of the device. A lubricant path leading to the lip portion is provided on the sleeve to allow the lubricant to pass through the lubricant path when the pressure in the device internal space exceeds a certain value. It is characterized by.

  In this sealing device, the lip provided on the sleeve allows the lubricant to pass through the lubricant path when the pressure in the device internal space exceeds a certain value, and in other cases, the lubricant path It functions as a valve that prevents the lubricant from passing through. Therefore, an increase in pressure in the device internal space is suppressed when the lubricant is supplied, and the lubricant is held in the device internal space for a long time after the supply.

  The sleeve includes an inner cylindrical portion formed of an elastic body that is in close contact with the inner member, and an outer cylindrical portion formed of a rigid body fixed to the outer periphery of the inner cylindrical portion. It is preferable that an agent path is provided in the inner cylindrical portion. In this configuration, since the lubricant path is provided in the inner cylindrical portion formed from the elastic body, it is easier to provide the lubricant path compared to providing the lubricant path in the rigid part.

  More preferably, the lubricant path is a groove formed on the inner peripheral surface of the inner cylindrical portion. In this case, the groove can be formed simultaneously with the manufacture of the inner cylindrical portion formed of an elastic body, for example, molding.

  Further, it is preferable that the lip portion is formed at an end portion on the atmosphere side of the sleeve. Since the lip portion is formed at the end of the sleeve on the atmosphere side, the lip portion is disposed on the atmosphere side of the lubricant path, and the lubricant path is extended over a long section of the sleeve even when the pressure inside the device is low. The lubricant can be filled. Therefore, even if mud or dust enters the lubricant path through the lip, it is highly likely that the mud or dust will be trapped in the lubricant path and stay in the lubricant path. Is less likely to reach.

  Here, it is preferable that the sleeve is provided with a space that extends across the lubricant path and into which the lubricant can enter. In this case, even if mud or dust enters the lubricant path through the lip, it is difficult for a part of the mud or dust to enter the space and reach the device internal space.

  It is preferable that a lubricant introduction port whose cross-sectional area increases toward the device internal space is provided at an end of the lubricant path on the device internal space side. In this case, if the pressure in the device internal space exceeds a certain value when the lubricant is replenished, the lubricant tends to flow into the lubricant path through the lubricant introduction port.

  In the sleeve, it is preferable that a plurality of the lubricant paths having the same dimensions are arranged at equiangular intervals around the inner member. Since the plurality of lubricant paths having the same dimensions are arranged at equiangular intervals in this way, not only the manufacture of the sealing device is facilitated, but also the pressure in the internal space of the device is replenished when the lubricant is replenished. When a certain value is exceeded, the lubricant flows out through these lubricant paths at a substantially uniform flow rate. Therefore, the load applied to the lip portion from each lubricant path is equalized.

  Preferably, the sealing device includes a second seal member having the sleeve and a flange that is integrally connected to an end portion on the atmosphere side of the sleeve and radially spreads outside the sleeve, and the first seal member includes A seal lip portion on which the outer peripheral surface of the sleeve slides and an outer annular body fixed to the inner surface of the outer member, wherein the second seal member is radially outward from the outer edge of the flange. A dust strip part is further provided which slides relative to the inner peripheral surface of the outer annular body of the first seal member. In this configuration, the flange of the second seal member blocks intrusion of mud and dust from the atmosphere side into the equipment internal space. Further, the dust lip portion of the second seal member more reliably prevents intrusion of mud and dust from the atmosphere side into the equipment internal space. As described above, the lip portion provided in the sleeve causes the lubricant to flow out through the lubricant path when the pressure in the device internal space exceeds a certain value, so that the second seal member and the first seal member It is not necessary to reduce the sealing performance (provided at the seal lip and dust lip) between the lubricant spills, the sealing performance to the lubricant by the seal lip and mud and dust from the dust lip It is possible to form the seal lip portion and the dust lip portion firmly so as to improve the sealing performance.

  In the present invention, the lip portion provided in the sleeve functions as a valve that allows the lubricant to pass through the lubricant path when the pressure in the device internal space exceeds a certain value. Therefore, an increase in pressure in the internal space of the device is suppressed when the lubricant is replenished, and an unexpected breakage of the sealing device is prevented, and an increase in rotational torque of the rotating shaft caused by the high-pressure lubricant is also suppressed. Further, after the replenishment, the lip portion prevents the lubricant from passing through the lubricant path, so that the lubricant is held in the device internal space for a long time. Further, since the lubricant path is provided in the sleeve, it is not necessary to increase the size of the sealing device, particularly the length in the axial direction, in order to provide the lubricant path. Furthermore, since the lip portion as a valve is formed on the sealing device, particularly the sleeve, when the lubricant outflow performance or holding performance is reduced, the sealing device is not required to replace other parts of the equipment. Or the sleeve can be easily replaced. Furthermore, the lip portion contacts the inner member, but since the lip portion is provided on the sleeve fixed to the inner member, no other member slides on the lip portion, and there is no wear due to sliding. In addition, the retention performance of the lubricant is difficult to deteriorate.

It is sectional drawing of the sealing device which concerns on 1st Embodiment of this invention. It is sectional drawing of the rotation sealing member of the sealing device of FIG. It is sectional drawing of the fixed sealing member of the sealing device of FIG. FIG. 3 is a development view of an inner peripheral surface of a sleeve of the rotary seal member of FIG. 2. FIG. 5 is a development view of a modified example of the inner peripheral surface of the sleeve of the rotary seal member of FIG. 2. FIG. 5 is a development view of a modified example of the inner peripheral surface of the sleeve of the rotary seal member of FIG. 2. FIG. 5 is a development view of a modified example of the inner peripheral surface of the sleeve of the rotary seal member of FIG. 2. FIG. 3 is an end view of a sleeve of the rotary seal member of FIG. 2. It is an end elevation of the modification of the sleeve of the rotary seal member of FIG. It is sectional drawing of the sealing device which concerns on 2nd Embodiment of this invention. It is sectional drawing of the sealing device which concerns on 3rd Embodiment of this invention. It is sectional drawing of the sealing device which concerns on 4th Embodiment of this invention. It is sectional drawing of the sealing device which concerns on 5th Embodiment of this invention.

Hereinafter, various embodiments according to the present invention will be described with reference to the accompanying drawings.
First Embodiment FIG. 1 is a diagram according to a first embodiment of the present invention, and shows a sealing device used in a device having two members that rotate relative to each other.

  The sealing device 1 seals the space between the rotating shaft (inner member) 4 and the inner surface of the shaft hole 6 of the housing (outer member) in which the rotating shaft 4 is inserted and disposed, thereby providing a device internal space S. Prevents or reduces fluid leakage from the atmosphere to the atmosphere A side. The rotating shaft 4 has a cylindrical shape, the shaft hole 6 has a circular cross section, and the sealing device 1 has a substantially annular shape, but only the left side portion thereof is shown in FIG.

  The sealing device 1 is an assembly that is a combination of a rotary seal member 8 called a slinger that is fixed to the rotary shaft 4 and rotates integrally with the rotary shaft 4 and a fixed seal member 10 that is fixed to the shaft hole. The rotary seal member 8 and the fixed seal member 10 cooperate to seal the lubricant in the device internal space S. The rotary seal member 8 is fitted to the fixed seal member 10. When a large force is applied along the axial direction of the sealing device 1, the fitting is released and can be removed.

  The rotary seal member 8 includes a sleeve 12 fixed to the rotary shaft 4, and a flange 14 that is integrally connected to the end of the sleeve 12 on the atmosphere A side and radially spreads outside thereof. The method of fixing the rotating shaft 4 and the sleeve 12 is not limited, but may be an interference fit, for example. The rotary seal member 8 has a double structure, and includes an elastic ring 16 formed of an elastic body, for example, an elastomer, and a rigid body, for example, a metal reinforcing ring 18, which closely contacts the elastic ring 16 and reinforces the elastic ring 16. .

  As shown in FIG. 2, the sleeve 12 is a part of the elastic ring 16 and is fixed to the outer periphery of the inner cylindrical part 16 a that is a part of the inner cylindrical part 16 a that is in close contact with the rotating shaft 4 and a reinforcing ring 18. The outer cylindrical portion 18a. The flange 14 is a part of the elastic ring 16 and is disposed on the atmosphere A side, and the flange 14 is a part of the reinforcing ring 18 and is disposed on the equipment internal space S side and is fixed to the elastic flange part 16b. And a rigid flange portion 18b. In this embodiment, a circumferential groove 20 is formed on the inner circumferential surface of the inner cylindrical portion 16a. The function of this circumferential groove 20 will be described later.

  As shown in FIG. 3, the fixed seal member 10 includes an outer annular body 22, an intermediate annular body 24 disposed coaxially with the outer annular body 22 on the radially inner side of the outer annular body 22, and a radius of the intermediate annular body 24. The inner annular body 26 is disposed coaxially with the intermediate annular body 24 on the inner side in the direction. The outer annular body 22 and the intermediate annular body 24 are connected by an outer flange 23 in the device internal space S, and the intermediate annular body 24 and the inner annular body 26 are connected by an inner flange 25 on the atmosphere A side.

  The fixed seal member 10 also has a double structure, and has an elastic ring 28 formed of an elastic body, for example, an elastomer, and a rigid body that reinforces the elastic ring 28, for example, a metal reinforcing ring 30. A part of the reinforcing ring 30 is embedded in the elastic ring 28 and is in close contact with the elastic ring 28.

  As shown in FIG. 1, the outer annular body 22 of the fixed seal member 10 is an outer seal portion fixed to the shaft hole 6. The fixing method is not limited, but may be an interference fit, for example. The reinforcing ring 30 applies a force toward the radially outer side to the elastic body portion of the outer annular body 22, and firmly presses the elastic body portion of the outer annular body 22 against the shaft hole 6. However, the reinforcing ring 30 is not necessarily indispensable. A garter spring 32 for compressing the inner annular body 26 radially inward is wound around the inner annular body 26. As shown in FIG. 3, the inner annular body 26 is formed with a receiving groove 34 that receives the garter spring 32.

  The elastic ring 28 of the fixed seal member 10 further includes a seal lip portion 36, a dust lip portion 38, and a dust lip portion 40. The seal lip portion 36 is a protrusion that protrudes inward from the inner annular body 26 and is continuous in the circumferential direction, and has two inclined surfaces. The seal lip portion 36 is in sealing contact with the outer peripheral surface of the sleeve 12 of the rotary seal member 8 to prevent or reduce fluid leakage from the device internal space S to the atmosphere A side. When the rotary seal member 8 rotates together with the rotary shaft 4, the outer peripheral surface of the sleeve 12 slides with respect to the seal lip portion 36. The garter spring 32 applies a force for pressing the seal lip portion 36 against the rotating shaft 4 to the seal lip portion 36.

  The dust lip 38 extends obliquely from the connecting portion of the inner annular body 26 and the inner flange 25 to the atmosphere A side and to the inside. The dust lip 40 extends from the inner flange 25 to the atmosphere A side and is bent. The tip of the dust lip portion 38 is in sealing contact with the outer peripheral surface of the sleeve 12 of the rotary seal member 8, and when the rotary seal member 8 rotates with the rotary shaft 4, the outer peripheral surface of the sleeve 12 slides against the dust lip portion 38. Move. The tip of the dust lip 40 contacts the rigid flange 18b of the flange 14 of the rotary seal member 8. When the rotary seal 8 rotates with the rotary shaft 4, the rigid flange 18b slides against the dust lip 40. Move.

  The rotary seal member 8 further includes a dust lip portion 42 that extends radially outward from the outer edge of the flange 14. The dust lip 42 extends obliquely from the outer edge of the flange 14 to the atmosphere A side and to the outside. The tip of the dust lip portion 42 is in sealing contact with the inner peripheral surface of the rigid portion of the outer annular body 22, and when the rotary seal member 8 rotates together with the rotary shaft 4, the dust lip portion 42 becomes the outer annular body of the stationary seal member 10. 22 slides against the inner peripheral surface of the rigid body portion.

  The dust strips 38, 40, and 42 mainly play a role of preventing entry of foreign matter (mud and dust) from the atmosphere A side to the equipment internal space S side. However, the dust lip portions 38, 40, 42 may prevent the lubricant from flowing out from the device internal space S side to the atmosphere A side. As is clear from comparison between FIG. 1 and FIG. 2 or FIG. 3, the seal lip portion 36 and the dust lip portions 38 and 40 are deformed by contacting the rotary seal member 8, and the dust lip portion 42 is fixed to the fixed seal. It is deformed by contacting the member 10.

  The sealing device 1 has a rotary seal member 8 having a flange 14, and the flange 14 prevents or reduces entry of foreign matter from the atmosphere A side into the device internal space S. The dust strips 38, 40, and 42 further reduce the risk of foreign material intrusion. Therefore, the sealing device 1 is a mud or dusty environment such as a railcar bogie, a sintered pallet bogie, a construction machine, a truck trunnion suspension, an agricultural machine (cultivator, tractor, rice transplanter, etc.). Even in the equipment used in the above, the sealing function is suitably exhibited. However, the application of the sealing device 1 is not limited to such a device, and may be another device.

  As for the device having the sealing device 1, it may be necessary to replenish the device internal space S with a lubricant. At the time of replenishment, care should be taken so that the pressure in the device internal space S does not become too high due to the injection of the lubricant. Therefore, in the sealing device 1, at least one lubricant path 50 through which the lubricant can flow out from the device internal space S to the atmosphere A side is provided in the sleeve 12 of the rotary seal member 8.

  In this embodiment, the lubricant path 50 is provided in the inner cylindrical portion 16 a of the sleeve 12. Since the lubricant path 50 is provided in the inner cylindrical portion 16a made of an elastic body, for example, an elastomer, it is easier to provide the lubricant path 50 compared to providing the lubricant path in a rigid body, for example, a metal part. More specifically, the lubricant path 50 is a groove formed on the inner peripheral surface of the inner cylindrical portion 16a. Therefore, the lubricant path 50 that is a groove can be formed simultaneously with the manufacture of the inner cylindrical portion 16a formed of an elastic body, for example, molding, and the manufacturing cost can be suppressed. However, the lubricant path 50 may be formed in the inner cylindrical portion 16a by cutting. A lubricant introduction port 51 whose cross-sectional area increases toward the device internal space S is provided at the end of the lubricant path 50 on the device internal space S side. Therefore, the lubricant easily flows into the lubricant path 50 through the lubricant introduction port 51.

  On the other hand, since the role of the sealing device 1 is to keep the lubricant sealed in the device internal space S, it is desirable that the replenished lubricant is held in the device internal space S over a long period of time. Therefore, in the sealing device 1, when the pressure in the device internal space S exceeds a certain value, the lubricant is allowed to pass through the lubricant path 50. In other cases, the lubricant passes through the lubricant path 50. At least one lip portion 52 that functions as a valve for preventing this is formed integrally with the elastic ring 16 of the sleeve 12 of the rotary seal member 8.

  The lip 52 is formed at the end of the sleeve 12 on the atmosphere A side, and is a thin plate extending obliquely inward and inward from the connection between the inner cylindrical portion 16a of the elastic ring 16 and the elastic flange portion 16b. And can be regarded as a cantilever with the connecting portion as a fulcrum. The tip of the lip 52 is in sealing contact with the outer peripheral surface of the rotating shaft 4.

  Since the lip portion 52 formed integrally with the sleeve 12 extends obliquely from the connecting portion of the inner cylindrical portion 16a and the elastic flange portion 16b to the atmosphere A side and to the inner side, the pressure in the device internal space S has a constant value. If exceeded, it functions as a valve that allows the lubricant to pass through the lubricant path 50. Therefore, even if an excessive replenishment force is applied at the time of replenishment of the lubricant, an increase in the pressure in the device internal space S is suppressed, and unexpected damage to the sealing device 1 is prevented, and also due to the high-pressure lubricant. An increase in rotational torque of the rotating shaft 4 is also suppressed. Further, after the replenishment, the lip portion 52 prevents the lubricant from passing through the lubricant path 50, so that the lubricant is held in the device internal space S over a long period of time. In addition, since the lubricant path 50 is provided in the sleeve 12, it is not necessary to increase the size of the sealing device 1, particularly the length in the axial direction, in order to provide the lubricant path 50. Furthermore, since the lip portion 52 as a valve is formed in the sealing device 1, particularly the sleeve 12, when the outflow performance or the retention performance of the lubricant is deteriorated, there is no need to replace other parts of the device. The sealing device 1 or the sleeve 12 can be easily replaced. Furthermore, the lip portion 52 is in contact with the rotating shaft 4 but is provided on the sleeve 12 that rotates together with the rotating shaft 4, so that other members do not slide on the lip portion 52 and wear due to sliding. And the performance of retaining the lubricant is unlikely to deteriorate.

  Further, since the lip portion 52 extends obliquely from the connecting portion between the inner cylindrical portion 16a and the elastic flange portion 16b to the atmosphere A side and to the inside, the fluid flow from the device internal space S to the atmosphere A side is allowed. Also, it functions as a check valve that prevents the flow of fluid from the atmosphere A side to the equipment internal space S, and can be regarded as a dust lip section. Therefore, the lubricant can flow out from the lubricant path 50 to the atmosphere A side, but there is a low risk of foreign matter entering the lubricant path 50 from the atmosphere A side.

  Since the lip portion 52 is formed at the end of the sleeve 12 on the atmosphere A side, the lip portion 52 is disposed on the atmosphere A side with respect to the lubricant path 50, and even when the pressure in the device internal space S is low, the sleeve The lubricant path 50 can be filled with lubricant over twelve long sections. Therefore, even if a foreign object passes through the lip 52 and enters the lubricant path 50, the foreign object is likely to be captured by the lubricant and stay in the lubricant path 50, and the foreign object reaches the device internal space S. Is less likely to occur.

  In particular, the sealing device 1 has a circumferential groove 20 formed on the inner circumferential surface of the inner cylindrical portion 16a. The circumferential groove 20 extends across the lubricant path 50, and the lubricant can enter from the lubricant path 50. Therefore, even if the foreign matter passes through the lip 52 and enters the lubricant path 50, a part of the foreign matter enters the circumferential groove 20 and hardly reaches the device internal space S. However, instead of the circumferential groove 20, another space may be provided in the sleeve 12 that extends across the lubricant path 50 and allows the lubricant to enter from the lubricant path 50. Specifically, such a space may not extend continuously in the circumferential direction of the sleeve 12. Further, the circumferential groove 20 or such a space is not necessarily indispensable.

  FIG. 4 is a development view of the inner peripheral surface of the sleeve 12 of the rotary seal member 8 (that is, the inner peripheral surface of the inner cylindrical portion 16a). As indicated by phantom lines in FIG. 4, the lip portion 52 may cover at least the lubricant path 50 and may be formed as a tongue piece that prevents the lubricant from flowing out from the lubricant path 50. However, as shown by a solid line in FIG. 4, the lip portion 52 may be a ring extending continuously in the circumferential direction so as to be in contact with the rotating shaft 4 over its entire circumference.

  As shown in FIG. 4, the lubricant path 50 may be formed on a straight line that extends perpendicularly to both end edges of the sleeve 12 (that is, extends parallel to the axial direction of the sleeve 12). However, as shown in FIGS. 5 and 6, the lubricant path 50 may be inclined with respect to the axial direction of the sleeve 12. Furthermore, the lubricant path 50 may have a bent or curved shape. FIG. 7 shows an example of a bent zigzag lubricant path 50. Since the slanted lubricant path 50 and the bent or curved lubricant path 50 are longer than the lubricant path 50 shown in FIG. 4, the possibility of foreign matter reaching the device internal space S is further reduced. Can do.

  The width, depth, and cross-sectional area of the lubricant path 50 are not limited, and the cross-sectional shape of the lubricant path 50 is not limited. Further, the number of lubricant paths 50 is not limited. FIG. 8 is an end view of the sleeve 12 of the rotary seal member 8. As shown in FIG. 8, a single lubricant path 50 may be provided in the sleeve 12. However, a plurality of lubricant paths 50 may be provided in the sleeve 12.

  When a plurality of lubricant paths 50 are provided in the sleeve 12, as shown in FIG. 9, it is preferable that these lubricant paths 50 have the same dimensions and are equiangularly spaced from each other. . As a result, not only is the sealing device 1 easy to manufacture, but when the pressure in the device internal space S exceeds a certain value when the lubricant is replenished, the lubricant is supplied at a substantially uniform flow rate through these lubricant paths 50. leak. Therefore, the load applied to the lip portion 52 from each lubricant path 50 is equalized.

  In the sealing device 1, the flange 14 of the rotary seal member 8 repels intrusion of foreign matter from the atmosphere A side into the device internal space S. Further, the dust lip portion 42 of the rotary seal member 8 and the dust lip portions 38 and 40 of the fixed seal member 10 more reliably prevent foreign matters from entering the device internal space S from the atmosphere A side. As described above, since the lip portion 52 formed integrally with the sleeve 12 causes the lubricant to flow out through the lubricant path 50 when the pressure in the device internal space S exceeds a certain value, the rotary seal member 8 and the fixed seal It is not necessary to reduce the sealing performance with the member 10 (provided by the seal lip portion 36 and the dust lip portions 38, 40, and 42) due to the outflow of the lubricant. The sealing lip portion 36 and the dust lip portions 38, 40, 42 can be firmly formed so as to enhance the sealing performance and the sealing performance against foreign matters by the dust lip portions 38, 40, 42.

Second Embodiment FIG. 10 shows a sealing device 61 according to a second embodiment of the present invention. In the drawings subsequent to FIG. 10, the same reference numerals are used to indicate the same components as those in the first embodiment, and those components will not be described in detail.

  In addition to the lip portion 52, the sealing device 61 includes a further lip portion 64 formed integrally with the sleeve 12. The lip portion 64 is a thin tongue piece disposed inside the lubricant path 50, and is a piece extending obliquely inward and inward from the surface corresponding to the bottom surface of the lubricant path 50 of the inner cylindrical portion 16a. It is a holding beam. The tip of the lip portion 64 is in sealing contact with the outer peripheral surface of the rotating shaft 4.

  Since the lip portion 64 formed integrally with the sleeve 12 extends obliquely toward the atmosphere A side and inward, the lubricant passes through the lubricant path 50 when the pressure in the device internal space S exceeds a certain value. In other cases, it functions as a valve that prevents the lubricant from passing through the lubricant path 50. In this embodiment, the lip portion 52 at the end of the sleeve 12 allows the lubricant to pass when the pressure in the space between the lip portions 52 and 64 exceeds a certain value, and in other cases the lubricant. It functions as a valve that prevents the lubricant from passing through the path 50.

  Further, since the lip portion 64 extends obliquely inward to the atmosphere A side, fluid flow from the device internal space S to the atmosphere A side is permitted, but fluid flow from the atmosphere A side to the device internal space S is allowed. It functions as a check valve for preventing flow and can be regarded as a dust lip. As described above, by providing the plurality of lip portions 52 and 64 for the lubricant path 50, the lubricant can flow out from the lubricant path 50 to the atmosphere A side, but from the atmosphere A side to the lubricant path 50. It is possible to further reduce the risk of intrusion of foreign matter. The number of lip portions in the lubricant path 50 is not limited.

Third Embodiment FIG. 11 shows a sealing device 71 according to a third embodiment of the present invention. In the sealing device 71, the lubricant path 72 of the lubricant from the device internal space S to the atmosphere A side is a through hole that penetrates the inner cylindrical portion 16 a formed of an elastic body in the sleeve 12.

  At the end of the lubricant path 72 on the equipment internal space S side, a lubricant introduction port 74 whose cross-sectional area increases toward the equipment internal space S is provided. Therefore, the lubricant easily flows into the lubricant path 72 through the lubricant introduction port 74.

  In this embodiment, the circumferential groove 20 may be formed on the inner circumferential surface of the inner cylindrical portion 16a, but it may not be formed. Even when the circumferential groove 20 is formed, the circumferential groove 20 and the lubricant path 72 may not be communicated with each other. In these cases, the lubricant flows out as it is toward the atmosphere side A through the lubricant path 72 which is a through hole penetrating the inner cylindrical portion 16a formed of an elastic body in the sleeve 12, and therefore the inner cylinder. It becomes difficult for the lubricant to flow between the portion 16 a and the rotating shaft 4. Therefore, the fixed state of the sleeve 12 and the rotating shaft 4 can be stably maintained.

Fourth Embodiment FIG. 12 shows a sealing device 81 according to a fourth embodiment of the present invention. In the sealing device 81, the lubricant path 82 of the lubricant from the device internal space S to the atmosphere A side is a through hole that penetrates the sleeve 12. Most of the lubricant path 82 is a groove formed in the inner peripheral surface of the outer cylindrical portion 18 a formed of a rigid body in the sleeve 12, but the end 83 of the lubricant path 82 is an elastic body in the sleeve 12. It is a through-hole which penetrates the inner cylindrical part 16a formed from. When the elastic ring 16 and the reinforcing ring 18 are joined to manufacture the rotary seal member 8, the groove is covered with the inner cylindrical portion 16a to form a through hole.

  A lubricant introduction port 84 whose cross-sectional area increases toward the device internal space S is provided at the end of the lubricant path 82 on the device internal space S side. Therefore, the lubricant easily flows into the lubricant passage 82 through the lubricant introduction port 84. The lubricant introduction port 84 has an inclined surface formed on the outer peripheral surface of the end portion of the inner cylindrical portion 16a, and thereby spreads toward the device internal space S.

  In this embodiment, the sleeve 12 may be formed with a circumferential groove corresponding to the circumferential groove 20 described above, but may not be formed. Even when the circumferential groove is formed, the circumferential groove and the lubricant path 82 may not be communicated with each other. In these cases, the lubricant flows out as it is toward the atmosphere side A through the lubricant passage 82 which is a groove formed in the inner peripheral surface of the outer cylindrical portion 18a formed of a rigid body in the sleeve 12. The lubricant is less likely to flow between the inner cylindrical portion 16a and the rotating shaft 4. Therefore, the fixed state of the sleeve 12 and the rotating shaft 4 can be stably maintained.

Fifth Embodiment FIG. 13 shows a sealing device 91 according to a fourth embodiment of the present invention. In the sealing device 91, the rotary seal member 8 does not have the flange 14 but has only the sleeve 12. Therefore, the dust lip 42 is not provided. The fixed seal member 10 does not have the dust lip 40. Even in such a sealing device 91, the lubricant path 50 and the lip 52 function as described above.

  Although various embodiments of the present invention have been described above, the above description is not intended to limit the present invention, and various modifications including deletion, addition, and replacement of components are included in the technical scope of the present invention. Conceivable.

  The several embodiments and variations described above may be combined as long as they are not contradictory. For example, the modification described above with respect to the first embodiment can be applied to other embodiments.

  Further, the shape and number of the lip portions of the fixed seal member 10 are not limited to those described above.

  In the above embodiment, the lubricant paths 50, 72, and 82 are grooves or through holes formed in the sleeve 12, but the lubricant paths may be provided by embedding a pipe in the sleeve 12.

  In the above embodiment, the lip portions 52 and 64 are formed integrally with the elastic ring 16 of the sleeve 12, and therefore can be formed simultaneously with the manufacture of the sleeve 12. However, the lip portions 52 and 64 may be attached to the sleeve 12.

  In the said embodiment, the axis | shaft 4 is a rotating shaft and the housing which has the axial hole 6 is a stationary member. However, the present invention is not limited to the above embodiment, and can be applied to sealing between two members that rotate relative to each other. For example, the shaft 4 (and the seal member 8) may be stationary, the housing (and the seal member 10) may rotate around it, and the shaft 4 and the housing may also rotate.

1, 61, 71, 81, 91 Sealing device 4 Rotating shaft (inner member)
6 Shaft hole (shaft hole of outside member)
8 Rotating seal member (second seal member)
10 Fixed seal member (first seal member)
12 Sleeve 14 Flange 16 Elastic ring 18 Reinforcement ring 16a Inner cylindrical part 18a Outer cylindrical part 16b Elastic flange part 18b Rigid flange part 20 Circumferential groove (space)
22 Outer annular body 23 Outer flange 24 Intermediate annular body 25 Inner flange 26 Inner annular body 28 Elastic ring 30 Reinforcement ring 32 Garter spring 34 Receiving groove 36 Seal lip part 38, 40 Dustrip part 42 Dustrip part 50, 72, 82 Lubrication Agent path 51, 74, 84 Lubricant inlet 52, 64 Lip part 83 End part

Claims (8)

A sleeve fixed to the inner member of the two members that rotate relative to each other;
A first seal member that is fixed to the inner surface of the outer member of the two members that rotate relative to each other, and on which the outer peripheral surface of the sleeve slides;
A sealing device that seals the lubricant in the internal space of the device to the internal space of the device,
The sleeve is provided with a lubricant path that leads from the internal space of the device to the atmosphere side,
The sealing device according to claim 1, wherein a lip portion that allows the lubricant to pass through the lubricant path when a pressure in the device internal space exceeds a certain value is provided in the sleeve.   The sleeve includes an inner cylindrical portion formed of an elastic body that is in close contact with the inner member, and an outer cylindrical portion formed of a rigid body fixed to the outer periphery of the inner cylindrical portion. The sealing device according to claim 1, wherein an agent path is provided in the inner cylindrical portion.   The sealing device according to claim 2, wherein the lubricant path is a groove formed on an inner peripheral surface of the inner cylindrical portion.   The sealing device according to any one of claims 1 to 3, wherein the lip portion is formed at an end portion on an atmosphere side of the sleeve.   The sealing device according to claim 4, wherein the sleeve is provided with a space that extends across the lubricant path and into which the lubricant can enter.   6. The lubricant introduction port according to claim 1, wherein a lubricant introduction port having a cross-sectional area that increases toward the device internal space is provided at an end of the lubricant path on the device internal space side. A sealing device according to claim 1.   7. The sleeve according to any one of claims 1 to 6, wherein a plurality of the lubricant paths having the same dimensions are arranged at equiangular intervals around the inner member. The sealing device according to item. A second seal member having the sleeve and a flange that is integrally connected to an end portion on the atmosphere side of the sleeve and radially spreads outside the sleeve;
The first seal member includes a seal lip portion on which an outer peripheral surface of the sleeve slides, and an outer annular body fixed to the inner surface of the outer member,
The second seal member further includes a dust lip that extends radially outward from an outer edge of the flange and slides with respect to an inner peripheral surface of the outer annular body of the first seal member. The sealing device according to any one of claims 1 to 7.

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