JP2017089684A - Sealing device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a sealing device capable of suppressing deterioration of service life of a side lip due to movement of a slinger with which the side lip slidably contacts.SOLUTION: A seal member 2 of a sealing device 1 includes a main lip 62 and an auxiliary lip 63 sliding on an outer peripheral surface 81a of a shaft 81, and a side lip 64 extending in an axial direction and sliding on a slide surface 12a of a slinger 10. In the side lip 64, a plurality of open holes 68 penetrating radially is formed with a predetermined interval in a circumferential direction. In each open hole 68, a porous member 71 configured to restrict moisture from permeating while allowing air to permeate is buried so as to block the open hole 68.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a shaft seal portion of various devices, and more particularly to a sealing device used for a differential side of an automobile.

  As shown in FIG. 3, a conventional sealing device used for the differential side of an automobile has a foreign material such as muddy water from the outer side 122 of the housing 210 in an annular space formed between the shaft 200 and the housing 210 that rotate relative to each other. In order to prevent intrusion into the inner side 121, a seal member 100 mounted on the housing 210 and a slinger 110 disposed on the outer side 122 than the seal member 100 and mounted on the shaft 200 are provided. Yes.

  The seal member 100 includes a core bar 101 having a substantially U-shaped cross section that is open to the inner side 121, a main lip 102 and an auxiliary lip 103 that are fixed to the inner side in the radial direction of the core bar 101 and are in sliding contact with the outer peripheral surface of the shaft 200, A side lip 104 that is fixed to the outer side 122 of the cored bar 101 and extends obliquely outward in the radial direction of the outer side 122 is provided. In recent years, this sealing device causes the side lip 104 to come into sliding contact with the slinger 110 with an increase in demand for high sealing (for example, see Patent Document 1).

JP 2007-225064 A

  In the above-described sealing device, the slinger 110 reciprocates (thrusts) in the axial direction between the solid line position and the two-dot chain line position in the drawing with respect to the seal member 100 during operation, whereby the side lip 104 is moved. The volume of the space 123 formed by the slinger 110, the outer peripheral surface of the shaft 200, and the auxiliary lip 103 may vary. In this case, when the volume of the space portion 123 becomes small, the space portion 123 becomes positive pressure, and the air in the space portion 123 flows out from between the tip of the side lip 104 and the slinger 110 to the external side 122. And the space part 123 becomes a negative pressure by the volume of the space part 123 becoming large after that.

  When such a negative pressure is generated, the area of the sliding contact portion of the side lip 104 with the slinger 110 increases, so that the temperature rises with an increase in torque, resulting in insufficient lubrication in the sliding contact portion. Further, as the reaction force of the side lip 104 increases, the torque (temperature) further increases, and the wear of the sliding contact portion of the side lip 104 is promoted. For this reason, when the said negative pressure generate | occur | produced, the lifetime of the side lip 104 fell and there existed a problem that the function which prevents the foreign material penetration | invasion to the space part 123 fell.

  This invention is made in view of such a problem, and provides the sealing device which can suppress that the lifetime of a side lip falls due to the movement of the slinger which a side lip slidably contacts. Objective.

  The sealing device of the present invention is attached to the housing in order to prevent foreign matter from entering the inside from the outside of the housing in the annular space formed between the shaft and the housing that rotate relative to each other. And a slinger that has a sliding contact surface that extends in a radial direction on the outer side of the sealing member and is attached to the shaft. The sealing member is in contact with the outer peripheral surface of the shaft. A sealing device comprising: a lip; an auxiliary lip that slidably contacts the outer peripheral surface of the shaft on the outer side of the main lip; and a side lip that extends in the axial direction and slidably contacts the sliding surface of the slinger. The side lip is formed with a plurality of through-holes penetrating in the radial direction at predetermined intervals in the circumferential direction, and moisture passes through each through-hole while allowing air to permeate. Limited to porous member, characterized in that embedded so as to close the through hole.

  According to the present invention, when the slinger moves to the outside with respect to the seal member, the volume of the space formed by the side lip, the slinger, the outer peripheral surface of the shaft, and the auxiliary lip is increased. Air outside the lip passes through the porous member embedded in each through hole of the side lip and flows into the space. Thereby, since it can prevent that the said air part becomes negative pressure, it can suppress that the sliding contact part with the slinger of a side lip wears. Therefore, it is possible to suppress the life of the side lip from being reduced due to the movement of the slinger that is in sliding contact with the side lip. Further, since the porous member restricts the permeation of moisture such as muddy water on the outside side, the sealing performance of the side lip can be maintained.

The porous member is vulcanized and bonded to one axial end surface of a cylindrical member made of a rubber material, and the cylindrical member to which the porous member is vulcanized and bonded is inserted into the through hole and fixed. preferable.
In this case, with the porous member vulcanized and bonded to one axial end surface of the cylindrical member made of a rubber material, the cylindrical member is inserted and fixed into the through hole of the side lip. Can be embedded easily.

  When the sealing device of the present invention is used for the differential side of an automobile, it is particularly effective because thrust movement of the slinger remarkably occurs.

  According to the sealing device of the present invention, it is possible to suppress the life of the side lip from being reduced due to the movement of the slinger that is in sliding contact with the side lip.

It is sectional drawing which shows the principal part of the sealing device which concerns on one Embodiment of this invention. It is an expanded sectional view which shows the state before embedding a porous member in the through-hole of a side lip. It is sectional drawing which shows the principal part of the conventional sealing device.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.
FIG. 1 is a cross-sectional view showing a main part of a sealing device according to an embodiment of the present invention. The sealing device 1 is used on the differential side of an automobile, and is mounted in an annular space formed between a shaft 81 and a housing 82 that rotate relative to each other. This prevents foreign matter such as muddy water from entering the door. Note that the sealing device 1 shown in FIG. 1 shows a natural state before deformation, which is before being mounted between the shaft 81 and the housing 82.

The sealing device 1 includes a seal member 2 attached to the inner peripheral surface 82a of the housing 82, and a slinger 10 attached to the outer peripheral surface 81a of the shaft 81 on the outer side B from the seal member 2.
The slinger 10 is made of, for example, a metal such as stainless steel (for example, SUS material), and has a small diameter cylindrical body 11 fitted to the outer peripheral surface 81a of the shaft 81, and a diameter from the inner end in the axial direction of the small diameter cylindrical body 11. And a first annular body 12 extending outward in the direction. The inner side surface 12a of the first annular body 12 is a slidable contact surface with which a distal end portion of a side lip 64 described later is slidably contacted.

  The slinger 10 further includes a medium diameter cylindrical body 13, a second annular body 14, and a large diameter cylindrical body 15. Specifically, an intermediate diameter cylindrical body 13 that is bent to the inner side A and extends to the inner side A is formed at the outer peripheral end of the first annular body 12. A second annular body 14 that is bent radially outward and extends radially outward is formed at the inner end portion in the direction.

  Furthermore, a large-diameter cylindrical body 15 that is bent to the inner side A and extends to the inner side A is formed on the outer peripheral end portion of the second annular body 14 on the outer side in the radial direction from the outer peripheral surface of the housing 82. . A protruding portion 15 a that is bent so as to protrude outward in the radial direction is formed at the inner end portion in the axial direction of the large-diameter cylindrical body 15. A labyrinth gap is formed between the inner peripheral surface of the large-diameter cylindrical body 15 and the outer peripheral surface of the housing 82, and foreign matter such as muddy water is prevented from entering the side lip 64 from between these. .

  The seal member 2 includes a cored bar 3 and a seal main body 6 provided on the cored bar 3. The cored bar 3 has a cylindrical body 31 and an annular body 32, and is formed in a substantially L-shaped cross section by these. The cylindrical body 31 is formed to extend in the axial direction along the inner peripheral surface 82 a of the housing 82. An annular body 32 that is bent radially inward and extends radially inward is formed at the axially outer end of the cylindrical body 31.

The seal body 6 is made of an elastic material such as synthetic rubber, and has a seal portion 61, a main lip 62, an auxiliary lip 63, and a side lip 64 that are vulcanized and bonded to the core metal 3.
The seal part 61 is an annular member as a whole, and is formed in a substantially L-shaped cross section. The seal portion 61 is fixed so as to cover the inner end surface and the outer peripheral surface in the axial direction of the cylindrical body 31 and the side surface and the inner peripheral end portion on the outer side B of the annular body 32. A cylindrical seal portion 61 a that covers the outer peripheral surface of the cylindrical body 31 in the seal portion 61 is fitted and fixed to the inner peripheral surface 82 a of the housing 82.

  An annular seal portion 61c that covers the inner peripheral end portion of the annular body 32 in the seal portion 61 extends from the inner peripheral end portion to the inner side A and radially inward, and is in sliding contact with the outer peripheral surface 81a of the shaft 81. An annular main lip 62 is formed. A circumferential groove 62a is formed on the outer peripheral surface of the main lip 62, and an annular spring member 7 for pressing the main lip 62 from the outer peripheral side is attached to the circumferential groove 62a. The main lip 62 is pressed against the outer peripheral surface 81 a of the shaft 81 by being pressed by the spring member 7, and seals between the outer peripheral surface 81 a and the cored bar 3.

  Further, the annular seal portion 61 c of the seal portion 61 extends from the inner peripheral end portion to the outer side B and radially inward, and is in sliding contact with the outer peripheral surface 81 a of the shaft 81 on the outer side B from the main lip 62. An annular auxiliary lip 63 is formed. Thus, the auxiliary lip 63 prevents foreign matter that has passed through the sliding contact portion between the side lip 64 and the slinger 10 from the outer side B from entering the inner side A.

The side lip 64 is made of an annular member, and is fixed to the annular seal portion 61c. The side lip 64 is formed so as to extend from the inner peripheral end of the annular seal portion 61 c to the outer side B in the axial direction and radially outward, and the tip thereof is the inner side of the first annular body 12 of the slinger 10. By slidably contacting the side surface 12a, foreign matter is prevented from entering the inner side A from the outer side B.
With the above configuration, the annular space C is defined by the side lip 64, the slinger 10, the outer peripheral surface 81a of the shaft 81, and the auxiliary lip 63.

A plurality of circular through holes 68 penetrating in the radial direction are formed at predetermined intervals in the circumferential direction in the central portion of the side lip 64 in the axial direction. The through hole 68 may be formed in a shape other than a circle.
In each through hole 68, a porous member 71 that allows air such as muddy water to permeate while allowing air to pass therethrough is embedded so as to close the opening on the outer side B of the through hole 68. Yes. For example, Gore-Tex (registered trademark) is preferably used as the porous member 71.

  FIG. 2 is an enlarged cross-sectional view showing a state before the porous member 71 is embedded in the through hole 68 of the side lip 64. In FIG. 2, the porous member 71 is formed in a disk shape, for example, and one surface thereof is vulcanized and bonded to one axial end surface (upper end surface in the figure) of a cylindrical member 72 made of a rubber material. . The outer diameter of the porous member 71 is set to be substantially the same as the outer diameter of the cylindrical member 72, and the porous member 71 is arranged on the upper end surface of the cylindrical member 72 in a state of being concentrically arranged with the cylindrical member 72. It is glued.

  The outer diameter of the porous member 71 and the outer diameter of the cylindrical member 72 are set slightly smaller than the hole diameter of the through hole 68. Further, the overall length L1 in the axial direction in a state where the porous member 71 is fixed to the cylindrical member 72 is set to be substantially the same as the length L2 of the through hole 68 in the axial direction. The cylindrical member 72 to which the porous member 71 is bonded is inserted into the through hole 68, and the outer peripheral surface of the cylindrical member 72 is fixed to the inner peripheral surface of the through hole 68 by bonding (see FIG. 1). The outer peripheral surface of the cylindrical member 72 may be fitted and fixed to the inner peripheral surface of the through hole 68.

  As described above, according to the sealing device 1 of the present embodiment, the volume of the space C is large when the slinger 10 moves to the outer side B with respect to the seal member 2 as indicated by the white arrow in FIG. Thus, the air on the outer side B from the side lip 64 passes through the porous member 71 embedded in each through hole 68 of the side lip 64 and flows into the space C. Thereby, since it can prevent that the air part C becomes negative pressure, it can suppress that the sliding contact part with the slinger 10 of the side lip 64 wears.

Therefore, it is possible to suppress the life of the side lip 64 from being reduced due to the side lip 64 being in sliding contact with the slinger 10. In particular, when the sealing device 1 is used on the differential side of an automobile, the above-described thrust movement of the slinger 10 occurs remarkably, which is effective.
Moreover, since the porous member 71 restrict | limits the permeation | transmission of the muddy water etc. of the external side B, the sealing performance of the side lip 64 can be maintained.

  Further, since the cylindrical member 72 is inserted into the through hole 68 of the side lip 64 and fixed in a state where the porous member 71 is vulcanized and bonded to one axial end surface of the cylindrical member 72 made of a rubber material, the porous member 71 is porous. The member 71 can be easily embedded in the through hole 68.

  Note that the present invention is not limited to the above-described embodiment, and can be implemented with appropriate modifications. For example, the sealing device 1 of the present invention may be applied to a shaft seal portion of various devices other than the differential side of an automobile. In addition, the porous member 71 of the above embodiment is embedded in the through hole 68 of the side lip 64 while being vulcanized and bonded to the cylindrical member 72, but directly added to the through hole 68 without using the cylindrical member 72. It may be fixed by sulfur bonding. At that time, the porous member 71 may block the entire axial direction of the through hole 68.

  1: sealing device, 2: sealing member, 10: slinger, 12a: sliding contact surface, 62: main lip, 63: auxiliary lip, 64: side lip, 68: through hole, 71: porous member, 72: cylindrical member , 81: shaft, 81a: outer peripheral surface, 82: housing, A: inner side, B: outer side

Claims (3)

In an annular space formed between a shaft and a housing that rotate relative to each other, a seal member that is mounted on the housing and the seal to prevent foreign matter from entering from the outside to the inside of the housing A slinger having a sliding contact surface extending in the radial direction on the outer side of the member and attached to the shaft,
The seal member includes a main lip that slidably contacts the outer peripheral surface of the shaft, an auxiliary lip that slidably contacts the outer peripheral surface of the shaft on the outer side of the main lip, and an axially extending and slidable contact surface of the slinger. A side lip in sliding contact with the sealing device,
In the side lip, a plurality of through-holes penetrating in the radial direction are formed at predetermined intervals in the circumferential direction,
A sealing device, wherein a porous member that allows air to pass therethrough and restricts moisture from passing therethrough is embedded in each through-hole so as to close the through-hole. The porous member is vulcanized and bonded to one axial end surface of a cylindrical member made of a rubber material,
The sealing device according to claim 1, wherein the cylindrical member to which the porous member is bonded by vulcanization is inserted into the through hole and fixed.   The sealing device according to claim 1, wherein the sealing device is used for a differential side of an automobile.

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