JP2016001061A - Sealing device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a structure which satisfies both oil resistance and slurry resistance, in a sealing device which prevents the leakage of an in-machine oil and the intrusion of slurry from the outside of a machine.SOLUTION: A sealing device comprises: an oil seal 10 in which an oil-resistance seal lip 13 is integrally molded at a first metal ring 11 which is pressure-inserted into an internal peripheral face of an opening end part 2a of a static-side housing 2, and a second metal ring 15 is sealingly fit to the first metal ring 11 while facing the machine outside A; a dust cover 20 which is positioned at the machine outside A of the oil seal 10, and attached to a rotation side; and a slurry resistance seal lip 16 which is integrally molded at the second metal ring 15, and slidably brought into tight contact with the dust cover 20. An external peripheral cylinder part 20c formed at the dust cover 20 extends so as to surround an external peripheral side of an external peripheral cylinder part 11f formed at the first metal ring 11 of the oil seal 10.

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.

  2. Description of the Related Art Conventionally, as shown in FIG. 5, a sealing device that seals a shaft periphery of a portion that is easily exposed to muddy water from the outside of the machine is known.

  In FIG. 5, reference numeral 2 is a housing of a vehicle transfer device or the like, 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 first aspect of the present invention provides an oil solution to the first metal ring press-fitted into the inner peripheral surface of the opening end of the stationary housing. An oil seal in which a seal lip is integrally formed and the second metal ring is closely fitted to the first metal ring so as to face the outside of the machine. A dust cover to be attached; and a muddy water seal lip formed integrally with the second metal ring and slidably in contact with the dust cover, and an outer peripheral cylindrical portion formed on the dust cover includes the oil cover It extends so as to surround the outer peripheral side of the outer peripheral cylindrical portion formed in the first metal ring of the seal.

  According to a second aspect of the present invention, an oil seal lip is integrally formed on a first metal ring that is press-fitted into an inner peripheral surface of an opening end of a stationary housing. An oil seal in which a second metal ring is closely fitted to the metal ring facing the outside of the machine, a dust cover that is located on the outside of the oil seal and is attached to the rotating side, and the second metal ring A muddy water seal lip formed integrally and slidably in close contact with the dust cover is provided, and an outer peripheral cylindrical portion formed on the dust cover extends so as to surround the outer peripheral side of the housing.

  According to the sealing device of the present invention, various materials can be combined with the oil seal lip and the muddy water seal lip according to the use conditions. As a result, the oil resistance and the muddy water seal lip with the oil seal lip can be combined. Both of the mud water resistance can be satisfied.

FIG. 3 is a half cross-sectional view of an unmounted state in which the first embodiment of the sealing device according to the present invention is cut along a plane passing through its axis. 1 is a half cross-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. FIG. 5 is a half cross-sectional view of a second embodiment of the sealing device according to the present invention in a non-mounted state shown by cutting along a plane passing through its axis. FIG. 6 is a half cross-sectional view of a mounting state in which the second embodiment of the sealing device according to the present invention is cut along a plane passing through its axis. FIG. 10 is a half cross-sectional view of an installed state in which an example of a sealing device according to the prior art is cut along a plane passing through its 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 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.

DESCRIPTION OF SYMBOLS 1 Sealing device 10 Oil seal 11 1st metal ring 12 Peripheral seal part 13 Oil seal lip 14 Dustrip 15 2nd metal ring 16 Muddy water seal lip 20 Dust cover 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 with the first metal ring press-fitted into the inner peripheral surface of the opening end of the stationary housing, and the second metal faces the first metal ring toward the outside of the machine. An oil seal in which the ring is closely fitted, a dust cover that is located on the outer side of the oil seal and attached to the rotating side, and is integrally formed with the second metal ring and is slidable on the dust cover A muddy water seal lip that is in close contact with the outer periphery, and the outer peripheral cylindrical portion formed on the dust cover extends so as to surround the outer peripheral side of the outer peripheral cylindrical portion formed on the first metal ring of the oil seal. Sealing device.   An oil seal lip is integrally formed with the first metal ring press-fitted into the inner peripheral surface of the opening end of the stationary housing, and the second metal faces the first metal ring toward the outside of the machine. An oil seal in which the ring is closely fitted, a dust cover that is located on the outer side of the oil seal and attached to the rotating side, and is integrally formed with the second metal ring and is slidable on the dust cover A sealing device comprising an anti-muddy water sealing lip that is in close contact with the outer periphery, and an outer peripheral cylindrical portion formed on the dust cover extending so as to surround the outer peripheral side of the housing.

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