JP2013113319A - Sealing device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a structure that achieves both oil resistance and resistance to muddy water in a sealing device 1 that prevents leakage of oil from within a machine and prevents intrusion of muddy water from the machine exterior A.SOLUTION: The sealing device is equipped with: an oil seal 10, which is attached to a stationary side 2, with an oil-resistant seal lip 13 integrally formed on a first metal ring 11, and a second metal ring 15 tightly mated with the first metal ring 11 and facing the machine exterior A; a dust cover 20, which is positioned on the machine exterior A side of the oil seal 10 and is attached to a rotating side 3; and a muddy-water-resistant seal lip 16, which is integrally formed with either the second metal ring 15 or the dust cover 20, and makes contact with the other of the second metal ring 15 or the dust cover 20 so as to be capable of sliding.

Description

  The present invention is a sealing device that seals the shaft periphery of a portion that is easily exposed to muddy water from outside the machine, such as a vehicle transfer device, transmission, and differential gear, and is particularly in close contact with the dust cover on the rotating side. The present invention relates to a structure provided with a structure that prevents muddy water from entering the oil seal lip side by the muddy water seal lip.

  As a sealing device that seals the shaft circumference and the like of a portion that is easily exposed to muddy water from the outside of the machine, a device as shown in FIG. 7 is conventionally known.

  In FIG. 7, reference numeral 2 is a housing such as a vehicle transfer device, and reference numeral 3 is a rotating shaft inserted through the housing 2. The sealing device 100 is a non-rotating oil seal 110 attached to the inner periphery of the housing 2, and is attached to the outer periphery of the rotating shaft 3, located outside the oil seal 110 in the axial direction, and rotates together with the rotating shaft 3. The metal dust cover 120 is provided.

  Specifically, the oil seal 110 includes an oil seal lip 111 extending toward the inside of the machine and an anti-mud seal lip 112 extending toward the opposite side (outside) of the oil seal lip 111. The oil seal lip 111 is slidably in close contact with the outer peripheral surface of the rotary shaft 3 to prevent leakage of oil in the machine, and the mud seal lip 112 slides on the flange portion 121 of the dust cover 120. Due to the close movement, mud water or the like flying from outside the machine A is prevented from entering the oil seal lip 111 side, and the dust cover 120 itself also has a centrifugal force generated in its flange portion 121. Further, the outer cylinder portion 122 formed on the outer diameter of the housing 2 is brought close to the outer peripheral surface of the end portion of the housing 2 to improve the effect of suppressing the intrusion of muddy water (for example, the following) See patent literature).

JP 2009-103209 A

  In this type of sealing device, when more excellent muddy water resistance is required, it is conceivable to increase the number of muddy water sealing lips, but in that case, there is a problem that energy loss due to sliding torque increases. be pointed out.

  In general, acrylic rubber (hereinafter referred to as ACM) is used as the material of the rubber part of the oil seal 110 in consideration of oil resistance and heat resistance. However, ACM is softened by swelling in water. Therefore, there is a problem that sufficient mud water resistance of the anti-mud seal lip 112 cannot be secured in a severe mud environment.

  In contrast, the use of nitrile rubber (hereinafter referred to as NBR) or hydrogenated nitrile rubber (hereinafter referred to as H-NBR) having excellent mud water resistance as a material for the rubber portion of the oil seal 110 provides resistance to mud water. In the case of improving the oil resistance, these NBR and H-NBR have inferior oil resistance and heat resistance to ACM, and therefore there is a problem that the durability of the oil seal lip 111 is lowered.

  The present invention has been made in view of the above points, and its technical problem is to provide a sealing device that prevents leakage of oil in the machine and prevents intrusion of muddy water from outside the machine. It is to make the structure satisfying both of mud water resistance.

  As a means for effectively solving the technical problem described above, the sealing device according to the invention of claim 1 includes an oil seal lip integrally formed on the first metal ring and the first metal ring. An oil seal that faces the outside of the machine and has a second metal ring closely fitted and attached to the stationary side, a dust cover that is located on the outside of the oil seal and attached to the rotating side, and the second metal ring And a muddy water seal lip formed integrally with one of the dust covers and slidably in contact with the other of the second metal ring and the dust cover.

  According to the above configuration, since the oil seal lip and the muddy water seal lip are separately formed, a rubber material (for example, ACM) excellent in oil resistance is used for the oil seal lip, and the muddy water seal is used. A rubber material (for example, NBR or H-NBR) excellent in mud water resistance can be used for the lip.

  According to a second aspect of the present invention, in the sealing device according to the first aspect, the other of the second metal ring and the dust cover is made of a low friction material.

  According to the above configuration, even if a plurality of muddy water seal lips are provided, for example, the sliding counterpart is made of a low friction material, so that an increase in energy loss due to the sliding torque is suppressed. For this reason, even if it does not make the rubber material excellent in muddy water resistance for the muddy water seal lip, muddy water resistance can be secured by providing a plurality.

  The sealing device according to the present invention can satisfy both the oil resistance in the oil seal lip and the mud water resistance in the mud seal lip.

1 is a half sectional view of a non-mounted state in which a first embodiment of a sealing device according to the present invention is cut along a plane passing through its axis. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a half sectional view of a mounting state in which a first embodiment of a sealing device according to the present invention is cut along a plane passing through its axis. It is a half sectional view of the unattached state which cuts and shows a 2nd embodiment of a sealing device concerning the present invention by a plane which passes along the axis. It is a half sectional view of the wearing state which cuts and shows a 2nd embodiment of a sealing device concerning the present invention by a plane which passes along the axis. FIG. 10 is a half sectional view of an unmounted state in which a third embodiment of the sealing device according to the present invention is cut along a plane passing through its axis. It is a half sectional view of the wearing state which cuts and shows a 3rd embodiment of a sealing device concerning the present invention by a plane which passes along the axis. It is a half sectional view of the wearing state which cuts and shows an example of the sealing device concerning the prior art by the plane which passes along the axis.

  Hereinafter, preferred embodiments of a sealing device according to the present invention will be described with reference to the drawings. First, FIG. 1 and FIG. 2 show a first embodiment.

  In FIG. 2, reference numeral 2 is a non-rotating housing, reference numeral 3 is a rotating shaft that is inserted through the housing 2 and is rotatable around an axis, and reference numeral 1 is a sealing device according to the present invention. An oil seal 10 attached to the inner peripheral surface of the end 2a and a dust cover 20 attached to the outer peripheral surface of the rotating shaft 3 so as to be positioned on the outside A side of the oil seal 10 are provided. The housing 2 corresponds to the stationary side described in claim 1, and the rotating shaft 3 corresponds to the rotating side described in claim 1.

  The oil seal 10 includes an outer peripheral seal portion 12, an oil seal lip 13 and a dust lip 14 that are integrally formed with a first metal ring 11 with a rubber material, and a surface facing the outside A side of the first metal ring 11. The second metal ring 15 closely fitted to the second metal ring 15 and the muddy water seal lip 16 formed integrally with the second metal ring 15 with a rubber material are provided.

  Specifically, the first metal ring 11 in the oil seal 10 is manufactured by punching and pressing a metal plate, for example, and is press-fitted to the inner peripheral surface of the open end 2a of the housing 2. A cylindrical portion 11a, an outer peripheral seal holding portion 11b extending so as to gradually become smaller in diameter toward the in-machine B side, an inner peripheral cylindrical portion 11c folded back toward the opposite side to the in-machine B, and the inner circumference An inner diameter flange portion 11d bent from the end portion of the cylindrical portion 11c to the inner diameter side, an outer diameter flange portion 11e extending from the end portion on the outside A side of the press-fit cylinder portion 11a to the outer diameter side, and an outer diameter end portion thereof The outer peripheral cylindrical portion 11f extends and bends from the housing 2 to the opposite side to the housing 2.

  The outer peripheral seal portion 12, the oil seal lip 13 and the dust lip 14 in the oil seal 10 are made of a rubber material excellent in oil resistance and heat resistance, for example, ACM. Of these, the outer peripheral seal portion 12 is vulcanized and bonded to the outer peripheral surface of the outer peripheral seal holding portion 11b of the first metal ring 11, and is press-fit into the inner peripheral surface of the open end 2a of the housing 2. The base of the anti-oil seal lip 13 is vulcanized and bonded to the inner diameter flange portion 11d of the first metal ring 11, extends toward the machine B side, and the inner diameter edge portion 13a near the tip of the rotary shaft 3 The dust lip 14 is slidably in close contact with the outer peripheral surface, and the base of the dust lip 14 branches off from the root of the oil seal lip 13 and extends to the opposite side of the oil seal lip 13, and the tip rotates. It is slidably in close contact with the outer peripheral surface of the shaft 3. A garter spring 17 is attached to the oil seal lip 13 to compensate for its tightness and radial followability.

  The second metal ring 15 in the oil seal 10 is manufactured, for example, by punching and pressing a metal plate, and is press-fitted to the inner peripheral surface of the outer peripheral cylindrical portion 11 f of the first metal ring 11. The outer cylindrical portion 15a and the outer cylindrical portion 15a extending from the outer cylindrical portion 15a toward the inner diameter side and having an outer diameter portion in close contact with the outer diameter flange portion 11e of the first metal ring 11 are provided. The distal end of the outer peripheral cylindrical portion 11f of the first metal ring 11 is caulked toward the inner diameter side, thereby firmly fixing the distal end portion of the outer peripheral cylindrical portion 15a of the second metal ring 15.

  The anti-muddy water seal lip 16 in the oil seal 10 is made of a rubber material excellent in muddy water resistance, for example, NBR or H-NBR, and its root is formed on the inner diameter portion of the flange portion 15 b of the second metal ring 15. In the unmounted state shown in FIG. 1, it is vulcanized and bonded, and extends in the shape of a conical cylinder having a gradually increasing diameter toward the side opposite to the oil seal lip 13.

  The dust cover 20 is manufactured, for example, by punching and press-molding a metal plate. The dust cover 20 is press-fitted to the outer peripheral surface of the rotary shaft 3 and the outer diameter direction from the inner diameter cylindrical portion 20a. A seal flange portion 20b that expands in a disk shape and is slidably brought into contact with the muddy water seal lip 16 in the oil seal 10 in an appropriately curved state in the mounted state shown in FIG. 2 to the outer peripheral side of the opening end 2a of the housing 2 in the mounted state of FIG. 2 from the outer peripheral cylindrical part 20c extending so as to surround the outer peripheral side of the outer peripheral cylindrical part 11f of the first metal ring 11 in the oil seal 10. Become.

  In the sealing device 1 according to the first embodiment configured as described above, the oil seal 10 includes an inner peripheral surface of the open end portion 2a of the housing 2 together with the press-fitting cylinder portion 11a of the first metal ring 11 together with the outer peripheral seal portion 12. Then, the outer diameter flange portion 11e of the first metal ring 11 is brought into contact with the tip of the opening end portion 2a, thereby positioning and fixing to the housing 2. Further, the dust cover 20 is positioned and fixed by press-fitting the inner diameter cylindrical portion 20a to the outer peripheral surface of the rotary shaft 3, and by bringing the seal flange portion 20b into contact with the flange portion of the rotary shaft 3, and mounting as shown in the figure. State.

  The oil seal lip 13 of the oil seal 10 is slidably brought into close contact with the outer peripheral surface of the rotary shaft 3 to prevent the oil in the machine from leaking out of the machine A.

  On the other hand, since the outer peripheral cylindrical portion 20c of the dust cover 20 extends so as to cover the outer peripheral side of the anti-mud seal lip 16, muddy water or the like flying from outside the machine A is difficult to enter the vicinity of the anti-muddy water seal lip 16. Further, the muddy water seal lip 16 of the oil seal 10 is closely slid with the seal flange portion 20b of the dust cover 20 that is rotated integrally with the rotary shaft 3, so that muddy water or the like to the inner peripheral side can be obtained. Intrusion is prevented, and the action of swinging off the seal flange portion 20b by centrifugal force also effectively acts to prevent intrusion of muddy water or the like into the inner peripheral side. The dust lip 14 of the oil seal 10 is slidably in close contact with the outer peripheral surface of the rotary shaft 3 on the inner peripheral side of the anti-muddy water seal lip 16, so that muddy water or the like enters the anti-oil seal lip 13 side. It is a deterrent.

  And according to the said structure, the outer peripheral seal part 12 integral with the 1st metal ring 11, the anti-oil seal lip 13, and the dust lip 14 and the anti-mud seal lip 16 integral with the 2nd metal ring 15 are shape | molded separately. Therefore, a rubber material such as ACM having excellent oil resistance and heat resistance is used for the oil seal lip 13, and NBR or H-NBR having excellent muddy water resistance is used for the mud seal lip 16. Therefore, it is possible to satisfy both of oil resistance and mud water resistance without providing a plurality of anti-mud seal lips 16.

  If the oil seal lip 13 is made of ACM, the muddy water seal lip 16 is made of fluorine rubber (FKM), or the oil seal lip 13 is FKM, and the muddy water seal lip is made of FKM. Various combinations of materials can be employed depending on the use conditions, such as 16 made of NBR.

  Next, FIG.3 and FIG.4 shows 2nd embodiment of the sealing device based on this invention.

  This second embodiment also basically has the same configuration as that of the first embodiment described above, and the first metal ring 11 in the oil seal 10 has a structure shown in FIGS. The outer diameter flange portion 11e and the outer peripheral cylinder portion 11f do not exist, and the outer peripheral cylinder portion 15a of the second metal ring 15 is press-fitted to the inner peripheral surface of the press-fit cylinder portion 11a of the first metal ring 11. The outer diameter portion of the seal flange portion 20b of the dust cover 20 is close to the opening end portion 2a of the housing 2, and the outer peripheral cylindrical portion 20c of the dust cover 20 extends so as to surround the outer periphery of the opening end portion 2a. This is different from the first embodiment.

  According to this configuration, a labyrinth-shaped gap L is formed between the opening end 2a of the housing 2 and the seal flange portion 20b and the outer peripheral cylindrical portion 20c of the dust cover 20 on the outer peripheral side of the mud seal lip 16. Due to the labyrinth sealing action, muddy water or the like flying from outside the machine A becomes more difficult to enter the muddy water seal lip 16 side.

  5 and 6 show a third embodiment of the sealing device according to the present invention.

  In the third embodiment, the oil seal 10 includes an outer peripheral seal portion 12, an oil seal lip 13, a dust lip 14, and a muddy water receiver 18 that are integrally formed with a first metal ring 11 with a rubber material, The second metal ring 15 is closely fitted to the first metal ring 11 so as to face the outside A side.

  Specifically, as in the first embodiment, the first metal ring 11 in the oil seal 10 is a press-fit cylinder part 11a that is press-fitted to the inner peripheral surface of the opening end part 2a of the housing 2, and the in-machine B The outer peripheral seal holding portion 11b extending so as to gradually become smaller in diameter toward the side, the inner peripheral cylindrical portion 11c folded back toward the opposite side to the interior B, and the inner peripheral side from the end of the inner peripheral cylindrical portion 11c The inner flange portion 11d bent to the outer side, the outer diameter flange portion 11e extending from the end on the machine outside A side of the press-fitted cylinder portion 11a to the outer diameter side, and the housing 2 in the mounted state of FIG. It consists of the outer peripheral cylinder part 11f extended and bent to the opposite side.

  The outer peripheral seal portion 12 of the oil seal 10 is vulcanized and bonded to the outer peripheral surface of the outer peripheral seal holding portion 11b of the first metal ring 11, and is press-fitted to the inner peripheral surface of the open end 2a of the housing 2. The base of the anti-oil seal lip 13 is vulcanized and bonded to the inner diameter flange portion 11d of the first metal ring 11, extends toward the machine B side, and the inner diameter edge portion 13a near the tip of the rotary shaft 3 The dust lip 14 is slidably in close contact with the outer peripheral surface, and the base of the dust lip 14 branches off from the root of the oil seal lip 13 and extends to the opposite side of the oil seal lip 13, and the tip rotates. The muddy water receiver 18 is slidably in contact with the outer peripheral surface of the shaft 3, and the muddy water receiver 18 is located on the outer peripheral side of the dust lip 14 and is vulcanized and bonded to the inner diameter flange portion 11 d of the first metal ring 11. And oil seal lip 13 Toward the opposite side is obtained by projecting the shape gradually becomes large. A garter spring 17 is attached to the oil seal lip 13 to compensate for its tightness and radial followability.

  The second metal ring 15 is a low-friction material such as a metal plate coated with a solid lubricating material such as PTFE (polytetrafluoroethylene) or carbon on the surface opposite to the first metal ring 11 or a mirror-finished metal plate. An outer peripheral cylindrical portion 15a that is manufactured by press fitting into the inner peripheral surface of the outer peripheral cylindrical portion 11f of the first metal ring 11, and extends from the outer peripheral cylindrical portion 15a to the inner diameter side. The diameter portion is composed of a flange portion 15 b in close contact with the outer diameter flange portion 11 e of the first metal ring 11.

  The dust cover 20 is manufactured, for example, by punching and press-molding a metal plate. The dust cover 20 is press-fitted to the outer peripheral surface of the rotary shaft 3 and the outer diameter direction from the inner diameter cylindrical portion 20a. An inner diameter flange portion 20d developed in a disk shape, and a folded portion 20e folded from the outer diameter portion so as to be convex toward the inner circumferential space of the outer peripheral cylindrical portion 15a of the second metal ring 15 in the oil seal 10. And an outer diameter flange portion 20f developed in a disk shape from the folded portion 20e toward the outer diameter direction, and further from the outer diameter end portion toward the outer peripheral side of the opening end portion 2a of the housing 2 in the mounted state of FIG. The oil seal 10 includes an outer peripheral cylindrical portion 20c extending so as to surround the outer peripheral side of the outer peripheral cylindrical portion 11f of the first metal ring 11.

  The dust cover 20 is integrally formed with two-stage mud seal lips 21 and 22 made of a rubber material on the surface facing the oil seal 10 side. Further, the rubber layer 23 extending from the base of the muddy water seal lips 21 and 22 is vulcanized and bonded so as to cover almost the entire surface of the dust cover 20 facing the oil seal 10 side.

  Of the two-stage muddy water seal lips 21, 22, the muddy water seal lip 21 on the inner peripheral side is bonded to the inner diameter flange portion 20 d of the dust cover 20 via the rubber layer 23, and is not shown in FIG. In the mounted state, it has a conical cylinder shape that gradually increases in diameter toward the oil seal 10 side. In the mounted state shown in FIG. 6, the second metal ring 15 in the oil seal 10 is curved and deformed appropriately. The flange portion 15b is in close contact with the flange portion 15b.

  On the other hand, the base of the outer peripheral mud seal lip 22 is vulcanized and bonded to the vicinity of the top of the folded portion 20e of the dust cover 20 via the rubber layer 23, and gradually goes from the root to the oil seal 10 side. It has a large diameter and is formed into a shape bent from there to the outer diameter side. In the mounted state shown in FIG. 6, the oil seal 10 is slidably in close contact with the inner peripheral surface of the outer peripheral cylindrical portion 15a of the second metal ring 15 in a state where it is appropriately curved and the front end faces the outside A side. It is what is done.

  Further, in the mounted state shown in FIG. 6, the outer peripheral cylindrical portions 11 f and 15 a of the first and second metal rings 11 and 15 of the oil seal 10 are close to and opposed to the outer diameter flange portion 20 f of the dust cover 20. Therefore, a labyrinth-like gap L bent in a lateral “J” shape is formed between the outer peripheral cylindrical portions 11f and 15a and the folded portion 20e of the dust cover 20, the outer diameter flange portion 20f, and the outer peripheral cylindrical portion 20c. ing.

  In the sealing device 1 according to the third embodiment configured as described above, the oil seal 10 includes an inner peripheral surface of the open end portion 2a of the housing 2 together with the press-fit cylinder portion 11a of the first metal ring 11 together with the outer peripheral seal portion 12. Then, the outer diameter flange portion 11e of the first metal ring 11 is brought into contact with the tip of the opening end portion 2a, thereby positioning and fixing to the housing 2. The dust cover 20 is positioned by press-fitting the inner diameter cylindrical portion 20 a to the outer peripheral surface of the rotary shaft 3 and bringing the inner diameter flange portion 20 d and the outer diameter flange portion 20 f into contact with the flange portion of the rotary shaft 3. Fix and set to the mounted state shown in the figure.

  The oil seal lip 13 of the oil seal 10 is slidably brought into close contact with the outer peripheral surface of the rotary shaft 3 to prevent the oil in the machine from leaking out of the machine A.

  On the other hand, a labyrinth-shaped gap L is formed on the outer peripheral side of the anti-mud seal lips 21 and 22, so that muddy water flying from outside the machine A enters the sealing sliding portion by the anti-mud seal lips 21 and 22 The muddy water seal lips 21, 22 provided on the dust cover 20 are difficult to rotate, and the second metal of the non-rotating oil seal 10 while rotating together with the dust cover 20 rotated integrally with the rotating shaft 3. By being closely slid with the ring 15, the intrusion of muddy water and the like from outside the machine A is prevented. The muddy water that has passed once is received and allowed to flow down along the circumferential groove 18 a by the muddy water receiver 18. The muddy water flowing down along the muddy water receptacle 18 is dropped on the rotating muddy water seal lip 21 and shaken off by the centrifugal force, and pushed back to the outer peripheral side. The dust lip 14 is slidably in contact with the outer peripheral surface of the rotary shaft 3 on the inner peripheral side of the anti-muddy water seal lip 21 to prevent the intrusion of muddy water or the like into the anti-oil seal lip 13 side. is there.

  And according to the said structure, the 2nd metal ring 15 of the oil seal 10 with which the anti-mud seal lips 21 and 22 are slidably contacted consists of a low friction material or a mirror surface material such as a metal plate coated with a solid lubricating material. Therefore, in spite of the provision of a plurality (two stages in the illustrated example) of the muddy water seal lips 21 and 22, an increase in energy loss due to the sliding torque is suppressed.

  Moreover, in this embodiment, since the mud water resistance is secured by a plurality (two stages in the illustrated example) of the mud water seal lips 21, 22, the mud water seal lips 21, 22 are not necessarily excellent in mud water resistance. The material is not required, and therefore, it can be made of the same material (for example, ACM) as the oil seal lip 13, but it is needless to say that NBR having excellent mud water resistance may be used.

  When the second metal ring 15 of the oil seal 10 is formed by coating a solid lubricating material on a metal plate as described above, it has a rust prevention effect in addition to reducing sliding torque. Steel), plated steel plate, aluminum metal plate, etc. can be used to prevent rust.

  Also in the first embodiment shown in FIGS. 1 and 2 or the second embodiment shown in FIGS. 3 and 4, for example, the oil seal 10 is provided with a plurality of anti-muddy water seal lips 16, and the anti-muddy water seal lip is provided. The dust cover 20 with which the sliding contact is made of 16 is made of a low friction material such as a metal plate coated with a solid lubricating material or a mirror-finished metal plate, thereby ensuring muddy water resistance and energy loss due to sliding torque. Rust prevention can be achieved by adopting a configuration in which the increase is suppressed, or by using SUS, a plated steel plate, an aluminum metal plate, or the like.

DESCRIPTION OF SYMBOLS 1 Sealing device 10 Oil seal 11 1st metal ring 12 Perimeter seal part 13 Oil seal lip 14 Dustrip 15 2nd metal ring 16 Muddy water seal lip 20 Dust cover 21, 22 Muddy water seal lip 2 Housing (stationary side) )
3 Rotating shaft (Rotating side)
A Outside the machine B Inside the machine

Claims (2)

  An oil seal lip is integrally formed on the first metal ring, and the oil seal is attached to the stationary side by closely fitting the second metal ring so as to face the outside of the first metal ring. A dust cover that is located on the outer side of the oil seal and is attached to the rotating side, and is integrally formed with one of the second metal ring and the dust cover, and of the second metal ring and the dust cover. A sealing device comprising a muddy water sealing lip slidably in contact with the other.   The sealing device according to claim 1, wherein the other of the second metal ring and the dust cover is made of a low friction material.

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