JP6650742B2 - Sealing device - Google Patents

Description

  The present invention relates to a sealing device that suppresses leakage of a sealed fluid inside a machine in an automobile, a general machine, an industrial machine, or the like. The sealing device of the present invention is used, for example, as a rotating oil seal for sealing in-machine oil in the field of automobiles.

  Conventionally, as shown in FIG. 5A, a seal is provided between a housing 520 and a rotating shaft 530 inserted into a shaft hole 521 provided in the housing 520 so that the sealed fluid inside the machine A does not leak to the machine outside B. Combination of a sealing device 510 with a slinger 550 mounted on the outer periphery of a rotating shaft 530 and a lip seal member 540 mounted on the outer periphery B of the slinger 550 and mounted on the inner periphery of a shaft hole 521 of the housing 520. A sealing device 510 is known.

  The slinger 550 is made of a rigid material such as metal, and integrally has a sleeve 551 fitted on the outer peripheral surface of the rotating shaft 530 and a seal flange 552 provided at one end of the sleeve 551. A thread groove 553 that exerts a fluid pumping action by centrifugal force when the rotation shaft 530 rotates is provided on the outside end surface 552a of the machine 552.

  On the other hand, the lip seal member 540 has a mounting ring 541 fitted to the inner peripheral surface of the shaft hole 521 of the housing 520, and a rubber-like elastic body 542 attached to the mounting ring 541. The body 542 provides a seal lip 546 that slidably contacts the outer end surface 552a of the seal flange 552 of the slinger 550.

  The sealing device 510 having the above configuration seals the sealing fluid by the slidable contact of the seal lip 546 with the outer end surface 552 a of the seal flange 552, and the screw groove 553 provided on the outer end surface 552 a of the seal flange 552. Exerts a fluid pumping action by centrifugal force when the rotating shaft 530 rotates, and pushes the sealed fluid back to the inside A of the machine, so that an excellent sealing effect can be exhibited.

Japanese Utility Model Laid-Open No. 3-57563 Japanese Utility Model Laid-Open No. 2-113173 JP 2014-129837 A

  However, the sealing device 510 is required to have further improved functions in the following points.

  That is, the seal flange 552 of the slinger 550 with which the seal lip 546 slidably contacts should be originally arranged in a direction orthogonal to the center axis of the rotating shaft 530. However, when the slinger 550 is metal-fitted to the rotating shaft 530, the seal flange 552 may be inclined with respect to the center axis of the rotating shaft 530. In particular, the seal flange 552 is fitted so as to be inclined toward the inside A of the machine. When the seal lip 546 is joined (so-called surface run-out), the interference of the seal lip 546 varies on the circumference, so that the followability of the seal lip 546 to the seal flange 552 is reduced. There is a risk of fluid leakage.

  Further, the slinger 550 exerts a swing-off action by the seal flange 552 and a fluid pumping action by the screw groove 553 due to the centrifugal force generated by the rotation of the rotary shaft 530. However, when the rotation of the rotary shaft 530 stops, the centrifugal force disappears. There is a possibility that a so-called stationary leak occurs in which the sealing fluid passes through the seal lip 546 along the screw groove 553 and leaks to the outside B of the machine.

  Further, since the swing-off action by the seal flange 552 and the fluid pumping action by the screw groove 553 return the sealing fluid that has entered the sealing device 510 to the inside A of the machine, the inner peripheral side of the seal lip 546 in the sealing device 510. The space becomes negative pressure. Therefore, the sealing device 510 according to the related art is in an environment where dust from the outside B is easily sucked.

The technical problem of the present onset bright improves the followability of the seal lip against the sealing flange is to suppress wear and sealed fluid leak of the sealing lip.

A sealing device inboard of sealing fluid seals to prevent leakage to the outboard side between the rotary shaft is inserted into a shaft hole provided in said the housings housing, seal flange mounted on the outer periphery of the rotary shaft On the other hand, in a sealing device in which a seal lip attached to a mounting ring mounted on an inner periphery of a shaft hole of the housing slidably contacts, the seal lip has a lip length from the mounting ring toward the inside of the machine. a connecting portion provided in the middle of the direction to, and extend toward the obliquely outward from the connecting portion, and a main lip which contacts the outboard end face of the seal flange, branches the main lip from the connecting portion Te extend toward the obliquely inwardly and a sub lip in contact with the outboard end face of the seal flange, the connecting portion is elastically deformed portion becomes thin in the radial direction as a lever fulcrum, Each serial main lip and said sub lip is displaced to said outboard and said machine inside.

Even in a situation where the surface vibration to sheet Rufuranji occurs, to improve the capability of the seal lip against the sealing flange, it is possible to suppress abrasion and sealed fluid leak of the sealing lip.

It is a fragmentary cross-sectional view of a sealing device according to the first embodiment. It is an explanatory view of the thread groove of the sealing device according to the first embodiment. Slinger of the sealing device according to the first embodiment is a sectional view showing a state in which the fitted inclined to the rotation axis. It is a fragmentary cross-sectional view of a sealing device according to the second embodiment. (A) is sectional drawing of the principal part of the sealing device which concerns on a prior art, (B) is explanatory drawing of a screw groove.

The sealing device 10 according to the first embodiment will be described in detail with reference to the drawings. Figure 1 is a fragmentary cross-sectional view of a sealing device 10 according to the first embodiment, FIG. 2 is an explanatory view of the thread groove 53 of the sealing device 10 according to the first embodiment, FIG. 3, the first It is a sectional view showing the state where slinger 50 of sealing device 10 concerning an embodiment was inclined and fitted to rotation axis 30.

  The sealing device 10 according to the present embodiment includes a sealed fluid (oil) on the inside (oil side) A between a housing (seal housing) 20 and a rotary shaft 30 inserted into a shaft hole 21 provided in the housing 20. ) Is a sealing device (oil seal for engine) 10 for sealing so as not to leak to the outside (atmosphere side) B, wherein a slinger 50 mounted on the outer periphery of the rotating shaft 30 and an inner periphery of the shaft hole 21 of the housing 20 are provided. And a lip seal member 40 mounted on the lip seal member 40.

  The slinger 50 is made of a rigid material such as metal, and has a sleeve 51 fixed (fitted) to the outer peripheral surface of the rotating shaft 30 and a radially outer portion provided at one end (inboard end) of the sleeve 51. The seal flange (flange portion) 52 is integrally formed, and a sealing effect is exerted on the outer end face 52a of the seal flange 52 by exerting a fluid pumping action by centrifugal force when the rotating shaft 30 rotates as shown in FIG. A helical thread groove 53 is formed which exerts an action of pushing back the fluid toward the outer peripheral side (the inner side A). The arrow e indicates the rotation direction of the rotation shaft 30.

  An annular thread groove forming area 53a having a thread groove 53 formed therein is provided on the outer end face 52a of the seal flange 52, and an annular thread groove having no thread groove 53 is formed on the inner peripheral side thereof. The non-formation region 53b is provided. Since the screw groove 53 is not formed in the non-thread groove forming region 53b, it is provided as a flat surface perpendicular to the axial direction.

  On the other hand, the lip seal member 40 is fixed (fitted) to the inner peripheral surface of the shaft hole 21 of the housing 20, and is attached (vulcanized) to the attachment ring 41 made of a rigid material such as metal. An outer peripheral seal portion 43 that seals between the housing 20 and the mounting ring 41 by contacting the inner peripheral surface of the shaft hole 21 of the housing 20 by the rubber elastic body 42; An end surface attachment portion 44 attached to the end surface portion of the mounting ring 41, a seal lip 46 slidably in contact with the outer end surface 52 a of the seal flange 52 of the slinger 50, and an inner peripheral end of the lip seal member 40. And an oil recovery lip 47 formed at the portion are provided integrally. A dust lip 45 is mounted on the inner peripheral side of the end face covering portion 44, and the dust lip 45 is made of fabric, but is integrally provided by the rubber-like elastic body 42. It may be.

  The seal lip 46 is provided so as to protrude from the vicinity of the inner diameter end of the mounting ring 41 toward the inside of the machine A, and a connecting portion 46a is provided midway in the protruding direction (lip length direction). A main lip 46b is provided extending from the connecting portion 46a obliquely outward (in the radial direction and toward the inboard side A), and is provided diagonally inward (inner diameter direction and the inboard side A). ) Are provided. In other words, the seal lip 46 has a shape in which one seal lip bifurcates in the middle of the lip length.

  More specifically, the main lip 46b and the sub lip 46c extend from the common connecting portion 46a toward the inboard side A, and the main lip 46b has a large diameter at the front end, and has a thread groove on the outer side end face 52a of the seal flange 52. The sub-lip 46c is formed to have a small diameter toward the opposite side of the main lip 46b, while being slidably in contact with the formation region 53a with a predetermined interference. The non-groove forming area 53b is slidably contacted with a predetermined interference.

  In the sealing device 10 configured as described above, when the rotating shaft 30 rotates, the sealing flange 52 of the slinger 50 exerts an action of shaking off the sealing fluid that comes into contact with the sealing flange 52 in the outer radial direction by centrifugal force. In addition, even if a part of the sealing fluid existing in the space inside the machine inside A tries to pass from the sliding portion between the seal lip 46 and the seal flange 52 to the inner peripheral side, there is a gap between the seal lip 46 and the seal flange 52. The thread groove 53 causes a fluid pumping action of sending the sealing fluid to the outer peripheral side by rotation. Therefore, the present sealing device 10 has an excellent sealing function.

In a state where the slinger 50 is stopped by the stop of the rotating shaft 30, the dynamic pressure due to the above-mentioned swinging-off action and screw pump action is lost, so that the sealed fluid tends to leak to the outside B of the machine through the screw groove 53. However, tight sealing device 10, the sub-lip 46c is positioned on the inner peripheral side of the main lip 46b, and the sub-lip 46c is closely slidably with a screw groove formed area 53b at the outboard end face 52a of the sealing flange 52 Therefore, no leakage path is formed. Therefore, even when the rotating shaft 30 is stopped, it is possible to effectively prevent the sealed fluid from passing through the seal lip 46 and leaking into the space on the inner peripheral side of the seal lip 46.

  In the process of fitting the slinger 50 to the rotating shaft 30, the seal flange 52 is fitted to the inside A of the machine as shown by the dotted line in FIG. 3 with respect to the center axis O of the rotating shaft 30. It is feared that the interference of the main lip 46b is reduced. However, in the present embodiment, when the sub lip 46c is pressed in the axial direction by the seal flange 52 (arrow V2), the seal lip 46 is elastically deformed as a whole by using the connecting portion 46a as a fulcrum of the lever, and the main lip 46b is turned into Displaced toward the inside A (arrow V1).

  Therefore, the axial followability of the seal lip 46 with respect to the surface fluctuation of the slinger 50 is excellent, and the interference of the main lip 46b and the tightening of the sub lip 46c with respect to the thread groove forming region 53a and the thread groove non-forming region 53b in the seal flange 52 are achieved. The margin is suppressed from decreasing in a part of the circumferential direction. Therefore, it is possible to suppress the occurrence of local wear on the seal lip 46 and the leakage of the sealing fluid.

Shi Rurippu 46 for contacting the sealing flange 52 in the slinger 50 can be compared to the sealing apparatus of the general radial lip structure to realize low torque.

A sealing device 10 according to a second embodiment will be described in detail with reference to the drawings. Figure 4 is a fragmentary cross-sectional view of a sealing device 10 according to the second embodiment.

  That is, in addition to the configuration of the above-described first embodiment, the sealing device 10 according to the present embodiment has an annular shape having a stepped cross section between the sleeve 51 and the seal flange 52 on the inner peripheral side of the seal flange 52. Are formed integrally with each other.

More specifically, the stepped portion 60 is formed in an axial direction from an end surface 61 formed in an outer radial direction from an end of the inside 51 of the sleeve 51 and an outer end of the end surface 61, A cylindrical surface 62 is formed integrally with the inner side A and is connected to an inner diameter end of the seal flange 52. The outer diameter (d ₁ ) of the step portion 60 (cylindrical surface 62) is set to be equal to or larger than the inner diameter (d ₂ ) of the oil recovery lip 47 in the lip seal member 40. That is, both diameter dimensions have a relationship of d ₁ ≧ d ₂ .

  According to the sealing device 10 of the present embodiment, the following operation and effect can be obtained.

  That is, when the dust on the outer side B passes through the dust lip 45 and enters through the inner peripheral side of the oil recovery lip 47, the end face 61 of the step portion 60 becomes a weir, and the dust is transferred to the outer periphery of the sleeve 51. On the outside side B of the step portion 60 on the side. Further, a so-called labyrinth effect is produced by forming a minute radial gap between the seal lip 46 and the stepped portion 60, so that intrusion of dust can be prevented. Therefore, it is possible to prevent the dust that has entered from the outside side B from entering the sub lip 46c, and thus to suppress the dust from entering the space inside the inside A of the sealing device 10.

Therefore, tight sealing device 10, dust can be prevented damage to the sub-lip 46c by chewing crowded is that between the outboard end surface 52a of the sub-lip 46c and the sealing flange 52.

DESCRIPTION OF SYMBOLS 10 Sealing device 20 Housing 21 Shaft hole 30 Rotating shaft 40 Lip seal member 41 Mounting ring 42 Rubber-like elastic body 43 Outer peripheral seal part 44 End face covering part 45 Dustrip 46 Seal lip 46a Connecting part 46b Main lip 46c Sub lip 47 Oil recovery lip Reference Signs List 50 slinger 51 sleeve 52 seal flange 52a machine outer end face 53 screw groove 53a screw groove forming area 53b screw groove non-forming area 60 stepped portion 61 end face 62 cylindrical surface A machine side B machine side

Claims (3)

A sealing device for sealing between a housing and a rotating shaft inserted into a shaft hole provided in the housing so that sealing fluid inside the machine does not leak to the outside of the machine,
A sealing device in which a seal lip attached to a mounting ring attached to an inner periphery of a shaft hole of the housing slidably contacts a seal flange attached to an outer periphery of the rotating shaft.
The seal lip,
A connecting portion provided in the middle of the lip length direction from the mounting ring toward the inside of the machine ,
A main lip extend, contacts the outboard end face of the sealing flange directed towards obliquely out from said connection portion,
A sub lip which extend toward the obliquely inwardly into contact with the outboard end face of the seal flange branches with the main lip from the connecting portion,
With
The connecting portion is elastically deformed by using a radially thin portion as a fulcrum of a lever, and displaces each of the main lip and the sub lip to the inside and outside of the machine.
A sealing device characterized by the above-mentioned. The sealing device according to claim 1,
Wherein the said outboard end face of the seal flange, said with a screw groove formed region screw groove is provided with the rotary shaft exerts a fluid pumping action when rotated is formed, not provided the screw groove A thread groove non-forming region is provided on the inner peripheral side of the thread groove forming region,
The sealing device according to claim 1, wherein the main lip is slidably in contact with the thread groove forming region, and the sub lip is in slidable contact with the non-thread groove forming region. The sealing device according to claim 1 or 2,
A sealing device, wherein a stepped portion is formed on an inner peripheral side of the seal flange to reduce a radial distance from an inner peripheral surface of the seal lip to suppress intrusion of dust from outside. .

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