JP2016200259A - Sealing device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To suppress the occurrence of a curl of a lip at a sub-lip when a shaft is inserted relatively from the sub-lip side with respect to a sealing device, and also when the shaft insertion is performed at large eccentricity, and to make compatible both shaft insertion performance and seal performance in the sealing device comprising a main lip for sealing a sealing fluid in the device and the sub-lip for sealing foreign matters at the outside of the device.SOLUTION: A sealing device has a sealing device main body which comprises a main lip for sealing a sealing fluid in the device, and a sub-lip for sealing foreign matters at the outside of the device, and a structure in which both lips slidably contacts with a peripheral face of a shaft. In the sealing device, a rigid shaft insertion guide for correcting the eccentricity of the shaft with respect to the sub-lip when inserting the shaft into an internal peripheral part of the sealing main body from the sub-lip side is arranged outside the sealing device main body.SELECTED DRAWING: Figure 1

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, to seal bearing lubrication grease in a hub bearing portion in a vehicle such as an automobile. The sealing device of the present invention is used in fields such as general industrial machinery, agricultural machinery, and construction machinery in addition to vehicles.

  Conventionally, as shown in FIG. 3, a sealing device 51 having a main lip (seal lip) 52 for sealing a sealing fluid (such as grease) inside the machine A is known. A secondary lip (dust strip) 53 for sealing foreign matter (dust, muddy water, etc.) is also provided (see FIG. 3 of Patent Document 1).

  The main lip 52 is shaped to face the machine A side when mounted, and the lip end 52a slidably contacts the peripheral surface of the shaft 61 while receiving the pressure of the sealing fluid to seal the sealing fluid. On the other hand, the auxiliary lip 53 is shaped to face the outside B side, and the lip end 53a slidably contacts the peripheral surface of the shaft 61 to seal foreign matter.

JP 2008-267499 A (FIG. 3)

  In addition to the main lip 52 that seals the sealing fluid in the machine A, the sealing device 51 has a dedicated secondary lip 53 that seals the foreign matter outside the machine B. Intrusion can be effectively suppressed, but there is still room for improvement in the following points.

  That is, when the shaft 61 is inserted (assembled) relative to the sealing device 51 from the side of the secondary lip 53 (the outside B side) due to the structure of the actual machine to which the sealing device 51 is mounted (the shaft insertion direction is indicated by an arrow). When the shaft is inserted with a large eccentricity, the shaft 61 largely interferes with the secondary lip 53 at a part of the circumference on the eccentric side when the shaft is inserted. A phenomenon (a phenomenon in which the lip end 53a is reversed) may occur. Therefore, when the turn-up phenomenon occurs in the secondary lip 53 in this way, the contact posture of the secondary lip 53 with respect to the shaft 61 becomes unstable, so that the sealing performance by the secondary lip 53 is deteriorated.

  In order to suppress the occurrence of the turning phenomenon in the sub lip 53, as shown in FIG. 4, the shape of the sub lip 53 is previously set to a shape perpendicular to the axial direction (a shape perpendicular to the axis in the radial direction). Alternatively, as shown in FIG. 5, it is conceivable that the shape of the sub lip 53 is set in advance so as to face the main lip 52 side (the in-machine A side).

  However, in these cases, although the turning phenomenon does not occur in the auxiliary lip 53, the position where the contact pressure peak P is generated in the auxiliary lip 53 is arranged closer to the main lip 52 (closer to the in-machine A) as shown in FIG. Therefore, the sealing performance by the sub lip 53 is lowered.

  Therefore, conventionally, it has been difficult to achieve both the shaft insertion property and the sealing property related to the sub lip 53.

  In view of the above, the present invention aims at achieving both shaft insertion performance and sealing performance of a secondary lip in a sealing device including a primary lip that seals a sealing fluid inside the machine and a secondary lip that seals foreign matter outside the machine. For the purpose.

  In order to achieve the above object, a sealing device according to claim 1 of the present invention has a main body lip for sealing a sealing fluid inside the machine and a sub lip for sealing a foreign matter outside the machine, and both the lips are In a sealing device having a structure that slidably contacts a peripheral surface of a shaft, rigidity for correcting eccentricity of the shaft with respect to the auxiliary lip when the shaft is inserted from the auxiliary lip side into an inner peripheral portion of the sealing device body. The shaft insertion guide is provided outside the sealing device main body.

  In the sealing device having the above-described configuration, a rigid shaft insertion guide is provided as a part of the sealing device on the outside of the sealing device main body including a main lip that seals the sealing fluid inside the machine and a sub lip that seals foreign matter outside the machine. Therefore, when the shaft is inserted, the shaft is inserted using the shaft insertion guide as a guide. Therefore, even if the shaft insertion is started with a large eccentricity, the eccentricity is corrected while the shaft is guided by the shaft insertion guide, so when the shaft reaches the secondary lip, the state of the large eccentricity is already eliminated. Yes. Therefore, it is possible to suppress the occurrence of the turning phenomenon on the secondary lip without canceling the state of large eccentricity.

  Further, in the sealing device having the above-described configuration, in order to suppress the phenomenon of turning of the auxiliary lip by the shaft insertion guide, the phenomenon of turning of the auxiliary lip occurs even if the shape of the auxiliary lip is directed to the outside of the machine. Hateful. As shown in FIG. 2, the shape facing the outside of the machine is arranged such that the contact pressure peak P generation position in the secondary lip is located outside the machine, so the contact pressure peak P occurrence position in the secondary lip is arranged near the machine interior. Compared to the case (FIG. 6), the sealing property against foreign matter is excellent.

  As described above, according to the sealing device having the above-described configuration, it is possible to achieve both the shaft insertion property and the sealing property related to the sub lip.

  According to a second aspect of the present invention, there is provided a sealing device having a main body lip for sealing a sealing fluid inside the machine and a sub lip for sealing a foreign matter outside the machine, wherein both the lips are provided on the peripheral surface of the shaft. In the sealing device having a slidably contacting structure, a cylindrical portion fitted to the outer peripheral side of the sealing device main body, and an integrally formed radially inward from the machine outer end of the cylindrical portion A rigid shaft insertion guide provided integrally with an inward flange portion is assembled to the outside of the sealing device main body.

  In the sealing device having the above-described configuration, a rigid shaft insertion guide is provided as a part of the sealing device on the outside of the sealing device main body including a main lip that seals the sealing fluid inside the machine and a sub lip that seals foreign matter outside the machine. Therefore, when the shaft is inserted, the shaft is inserted using the shaft insertion guide as a guide. Therefore, even if the shaft insertion is started with a large eccentricity, the eccentricity is corrected while the shaft is guided by the shaft insertion guide, so when the shaft reaches the secondary lip, the state of the large eccentricity is already eliminated. Yes. Therefore, it is possible to suppress the occurrence of the turning phenomenon on the secondary lip without canceling the state of large eccentricity.

  Further, in the sealing device having the above-described configuration, in order to suppress the phenomenon of turning of the auxiliary lip by the shaft insertion guide, the phenomenon of turning of the auxiliary lip occurs even if the shape of the auxiliary lip is directed to the outside of the machine. Hateful. As shown in FIG. 2, the shape facing the outside of the machine is arranged such that the contact pressure peak P generation position in the secondary lip is located outside the machine, so the contact pressure peak P occurrence position in the secondary lip is arranged near the machine interior. Compared to the case (FIG. 6), the sealing property against foreign matter is excellent.

  As described above, according to the sealing device having the above-described configuration, it is possible to achieve both the shaft insertion property and the sealing property related to the sub lip.

  A cylindrical portion fitted on the outer peripheral side of the sealing device body, and an inward flange portion integrally formed from the outer end of the cylindrical portion toward the radially inward side. Therefore, it is possible to assemble the shaft insertion guide concentrically with the sealing device body only by fitting the cylindrical portion to the outer peripheral side of the sealing device body. Therefore, for example, as compared with the case where the shaft insertion guide is composed only of the flange portion and is bonded to the end surface in the axial direction of the sealing device body, the assembly workability of the shaft insertion guide to the sealing device body can be improved. It can be done.

  The shaft insertion guide is preferably provided with a guide portion that is disposed on the outer side of the auxiliary lip at the time of shaft insertion and on the outer side in the radial direction of the shaft. The shaft is inserted using the guide portion as a guide. The guide portion may have a shape in which the inner peripheral tip is perpendicular to the axial direction (a shape perpendicular to the radial inward direction), but the auxiliary portion extends from the outer peripheral base end to the inner peripheral tip. It is preferable to have a shape that is inclined in a direction approaching the lip. According to this, a tapered surface is formed in the inclined direction, so that the shaft inserted in an eccentric state is automatically adjusted along the tapered surface. Will be hearted.

  According to the present invention, in the sealing device including the main lip that seals the sealing fluid inside the machine and the sub lip that seals foreign matter outside the machine, it is possible to achieve both the shaft insertion property and the sealing property related to the sub lip.

Sectional drawing of the principal part of the sealing device which concerns on the Example of this invention. Explanatory drawing of the contact pressure distribution in the sub lip provided in the sealing device Sectional drawing of the principal part of the sealing device which concerns on a 1st prior art example Sectional drawing of the principal part of the sealing device which concerns on a 2nd prior art example Sectional drawing of the principal part of the sealing device which concerns on a 3rd prior art example Explanatory drawing of the contact pressure distribution in the sub lip provided in the sealing device

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

  FIG. 1 shows a cross section of a main part of a sealing device 11 according to an embodiment of the present invention. The sealing device 11 according to the embodiment suppresses leakage of the sealing fluid (grease etc.) in the machine (inside the equipment) A to the outside (outside the equipment) B and foreign matter (dust, muddy water, etc.) outside the machine B. Is used as an inner seal in a hub bearing portion of a truck or the like that suppresses intrusion into the aircraft A.

  The sealing device 11 includes a sealing device main body 21 including a metal ring 22 and a rubber-like elastic body 23 attached (vulcanized and bonded) to the metal ring 22. A main lip (seal lip) 24 that seals the sealing fluid and a secondary lip (dust strip) 25 that seals foreign matter outside the machine B are integrally formed.

  The main lip 24 has a shape in which the lip end 24a faces the in-machine A side when the sealing device 11 is mounted on the shaft peripheral portion of the device, and the lip end 24a receives the pressure of the sealing fluid and the peripheral surface of the shaft 61. The sealing fluid is sealed by slidably contacting the fluid. A garter spring 26 is fitted to the main lip 24.

  The auxiliary lip 25 is shaped so that the lip end 25a faces the outside B of the machine when the sealing device 11 is attached to the shaft peripheral part of the device, and the lip end 25a is slidably in contact with the peripheral surface of the shaft 61. To seal foreign matter.

  In the above-described configuration, when the shaft 61 is inserted (assembled) relative to the sealing device 11 from the side of the secondary lip 25 (the outside B side) due to the structure of the actual machine to which the sealing device 11 is attached (shaft insertion direction) Is indicated by an arrow C) and the shaft is inserted with a large eccentricity, there is a concern that the turning phenomenon may occur in the auxiliary lip 25 due to the shaft insertion.

  Therefore, as a countermeasure, the following configuration is added to the sealing device 11.

  That is, the shaft insertion guide 31 is assembled to the sealing device main body 21 at the outer side B side of the sealing device main body 21, and the shaft 61 is moved to the sub lip 25 side (outside B side) by the shaft insertion guide 31. ) To the inner peripheral portion of the sealing device body 21, the eccentricity of the shaft 61 with respect to the sub lip 25 is corrected.

  The shaft insertion guide 31 is configured as follows.

(1) The shaft insertion guide 31 is formed separately from the sealing device body 21 and can be retrofitted. Further, the shaft insertion guide 31 is formed of a material having rigidity such as metal so that the shaft insertion guide 31 is not deformed even if it contacts the shaft 61.

(2) The shaft insertion guide 31 is formed in an annular shape, and is assembled to the sealing device body 21 so as to be concentric with the sealing device body 21, particularly the sub lip 25.

(3) The shaft insertion guide 31 is formed integrally with a cylindrical portion 31a fitted to the outer peripheral side of the sealing device main body 21, and from the outer end of the cylindrical portion 31a toward the radially inner side. The facing flange portion 31b and an annular guide portion 31c integrally formed at the inner peripheral end of the flange portion 31b as a part of the inward flange portion 31b are integrally provided.

(4) When the shaft insertion guide 31 is assembled to the sealing device main body 21, the guide portion 31c is arranged on the outside B side of the sub lip 25, and a predetermined interval is set between the guide portion 31c and the sub lip 25. The

(5) When the shaft is inserted, the shaft 61 passes through the inner peripheral side of the shaft insertion guide 31, and it is better that the shaft insertion guide 31 does not contact the shaft 61 after the shaft is inserted. Therefore, the inner diameter dimension of the shaft insertion guide 31 is set slightly larger than the outer diameter dimension of the shaft 61. However, since the shaft insertion guide 31 is provided to exert the aligning function of the shaft 61 with respect to the sub lip 25, the difference in the inner diameter dimension of the shaft insertion guide 31 and the outer diameter dimension of the shaft 61 is as much as possible. Small is desirable. Further, the shaft insertion guide 31 is preferably not in contact with the shaft 61, whereas the sub lip 25 is in contact with the shaft 61. Therefore, the inner diameter dimension of the shaft insertion guide 31 is d ₁ and the outer diameter dimension of the shaft 61 is d _2. The inner lip dimension of the sub lip 25 is d ₃ , and d ₁ > d ₂ > d ₃ .

(6) The flange portion 31b and the guide portion 31c continuous with the flange portion 31b may have a shape perpendicular to the axial direction (a shape perpendicular to the axial direction facing inward in the radial direction). As shown in the figure, the shape is inclined from the outer peripheral side base end portion 31ca to the inner peripheral side distal end portion 31cb in a direction approaching the sub lip 25, that is, the guide portion 31c is tapered as a whole (funnel shape). Is formed.

  In the sealing device 11 having the above-described configuration, the main body lip 24 for sealing the sealing fluid in the in-machine A and the auxiliary lip 25 for sealing foreign matter in the outside B are made of a rigid material on the outside B side of the sealing device body 21. Since the shaft insertion guide 31 is assembled as a part of the sealing device 11, the shaft 61 is inserted using the shaft insertion guide 31 as a guide during shaft insertion, and insertion of the shaft 61 is started with a large eccentricity. Even when the shaft 61 is guided by the shaft insertion guide 31, the eccentricity is corrected, and when the shaft 61 reaches the sub lip 25, the state of large eccentricity is already eliminated. Therefore, it is possible to prevent the turning phenomenon from occurring in the auxiliary lip 25 without the large eccentricity being eliminated.

  Further, in the sealing device 11 having the above-described configuration, since the turning phenomenon of the auxiliary lip 25 is suppressed by the shaft insertion guide 31 as described above, the shape of the auxiliary lip 25 causes the lip end 25a to be connected to the outside B side. Even if the shape is directed toward the top, it is difficult for the secondary lip 25 to turn over. As shown in FIG. 2, the shape of the lip end 25a facing the outside B side is located near the outside B of the auxiliary lip 25, so that the sealability against foreign matter is excellent. is there.

  Therefore, according to the sealing device 11 having the above-described structure, the secondary lip 25 is less likely to be turned up, so that the shaft insertion property can be improved. In addition, the secondary lip 25 exhibits an excellent sealing property, so that the sealing property is improved. Therefore, both the shaft insertion property and the sealing property of the sub lip 25 can be achieved.

  Further, since the guide portion 31c is inclined from the outer peripheral base end portion 31ca to the inner peripheral tip portion 31cb in a direction approaching the sub lip 25, the shaft 61 inserted in an eccentric state is automatically operated. Can be aligned. Therefore, the insertion operation of the shaft 61 can be facilitated as compared with the case where alignment is performed manually.

  Further, since the shaft insertion guide 31 disposed on the outside B side of the auxiliary lip 25 also functions as a protective cover for guarding the auxiliary lip 25, the auxiliary lip 25 is caused by foreign matter (for example, stepping stones) outside the aircraft. Damage can be suppressed. Further, since the labyrinth is formed between the shaft insertion guide 31 and the shaft 61 as the seal, foreign matter (dust, muddy water, etc.) outside the machine B hardly passes through the labyrinth. Therefore, for example, sand particles contained in the muddy water can be prevented from reaching the sub lip 25 and being bitten, and thus the seal life can be improved.

DESCRIPTION OF SYMBOLS 11 Sealing device 21 Sealing device main body 22 Metal ring 23 Rubber-like elastic body 24 Main lip 24a, 25a Lip end 25 Sub lip 26 Gutter spring 31 Shaft insertion guide 31a Cylindrical part 31b Flange part 31c Guide part 31ca Outer peripheral side base end part 31cb Inner peripheral tip 61 Axis A Inside B B Outside

Claims (3)

A sealing device having a main body lip for sealing a sealing fluid inside the machine and a sub lip for sealing a foreign matter outside the machine, wherein both the lips are slidably in contact with the peripheral surface of the shaft;
A rigid shaft insertion guide for correcting eccentricity of the shaft relative to the sub lip when the shaft is inserted from the sub lip side into the inner peripheral portion of the sealing device main body is provided on the outside of the sealing device main body. Sealing device characterized. A sealing device having a main body lip for sealing a sealing fluid inside the machine and a sub lip for sealing a foreign matter outside the machine, wherein both the lips are slidably in contact with the peripheral surface of the shaft;
A rigid portion integrally including a cylindrical portion fitted to the outer peripheral side of the sealing device main body and an inward flange portion integrally formed radially inward from an outer end of the cylindrical portion. A sealing device, wherein a shaft insertion guide is assembled to the outside of the sealing device main body. The sealing device according to claim 1 or 2,
The shaft insertion guide includes a guide portion that is disposed on the outer side of the auxiliary lip when the shaft is inserted and radially outward of the shaft,
The sealing device according to claim 1, wherein the guide portion has a shape inclined in a direction approaching the sub lip from an outer peripheral base end portion to an inner peripheral front end portion.

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