JP2017223258A - Seal - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a seal enabled to reduce a slide torque sufficiently by thinning a seal lip.SOLUTION: A seal comprises: a seal lip 12, in which an inner diameter end 123a of a lip head 123 formed on the leading end side of a waist part 122 extending toward a sealed space A is made to contact slidably with the outer peripheral surface of a rotor 2; and a garter spring 13 mounted on a spring installation groove 123b formed on the outer peripheral surface of the lip head 123. On the outer peripheral surface of the waist part 122, a plurality of axially extending ribs 124 are formed at an arbitrary interval of the circumferential direction.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a sealing device that seals an outer periphery of a rotating body in a car, a general machine, an industrial machine, or the like with a seal lip.

  2. Description of the Related Art Conventionally, as a sealing device that seals the outer periphery of a rotating shaft of a device with a sealing lip, a device as shown in FIG. That is, in the sealing device 100, a seal lip 102 made of a rubber elastic body (rubber material or synthetic resin material having rubber-like elasticity) is integrally formed on a metal reinforcing ring 101, and the lip head 102a of the seal lip 102 is formed. The outer peripheral surface is provided with a structure in which a garter spring 103 for compensating the tension force is mounted.

  The sealing device 100 is attached to the inner periphery of the shaft hole of the device with the seal lip 102 facing the sealed space A, and the inner end of the lip head 102a of the seal lip 102 is connected to the outer periphery of the rotation shaft (not shown). By being in close contact with the surface in a slidable manner, the oil to be sealed in the sealed space A is prevented from leaking from the shaft periphery to the atmosphere B (see, for example, Patent Document 1 below).

Japanese Unexamined Patent Publication No. 1-312274

  In recent years, in automobiles, reduction of sliding torque of the sealing lip 102 of the sealing device 100 with respect to the rotating shaft has been demanded for the purpose of improving fuel consumption. Therefore, in order to reduce the sliding torque, the rigidity of the seal lip 102 is reduced by reducing the thickness of the waist portion 102b (the portion where the inner periphery is constricted) between the root of the seal lip 102 and the lip head portion 102a. It is effective to reduce the pressure on the outer peripheral surface of the rotary shaft, but if the thickness of the waist 102b of the seal lip 102 is reduced, the mold used for vulcanization molding of the seal lip 102 is used. Of the cavities, the portion corresponding to the waist portion 102b becomes narrow, and during molding, the flow of shaping of the unvulcanized rubber material in the molding cavity becomes worse, and molding defects due to insufficient filling tend to occur. Therefore, it has been difficult to reduce the thickness of the waist 102b.

  In addition, reducing the radial height of the holder portion 102c holding the garter spring 103 is also effective in reducing the pressing force of the seal lip 102 against the outer peripheral surface of the rotating shaft. There was a possibility that the garter spring 103 would easily fall off from the outer periphery of 102.

  The present invention has been made in view of the above points, and a technical problem thereof is to provide a sealing device capable of sufficiently reducing a sliding torque by thinning a seal lip. .

  In order to solve the above technical problem, the sealing device according to the invention of claim 1 is such that the inner diameter end of the lip head formed on the distal end side of the waist extending toward the sealed space side slides on the outer peripheral surface of the rotating body. A seal lip that is movably brought into close contact with a garter spring mounted in a spring mounting groove formed on the outer peripheral surface of the lip head, and a plurality of ribs extending in the axial direction are provided on the outer peripheral surface of the waist. It is characterized by being formed at arbitrary intervals in the circumferential direction.

  According to a second aspect of the present invention, there is provided the sealing device according to the first aspect, wherein a plurality of spring holding protrusions projecting in the outer diameter direction are provided on the shoulder portion of the spring mounting groove on the tip side of the seal lip in the circumferential direction. It is characterized by being formed at an arbitrary interval.

  According to the sealing device of the present invention, since the rigidity of the waist portion of the seal lip is supplemented by the rib, the waist portion itself can be thinned, and thereby, the tightening force on the outer peripheral surface of the rotating body, and consequently the sliding torque. Reduction can be achieved.

It is principal part sectional drawing which cuts and shows preferable embodiment of the sealing device which concerns on this invention by the plane which passes along an axial center. It is a principal part section perspective view in the state where a garter spring is not installed which shows a preferred embodiment of a sealing device concerning the present invention cut by a plane which passes along an axis. It is principal part sectional drawing which cuts and shows an example of the sealing device by a prior art by the plane which passes along an axial center.

  Hereinafter, a preferred embodiment of a sealing device according to the present invention will be described with reference to FIGS. 1 and 2. The sealing device 1 in the illustrated embodiment includes a seal lip 12 integrally formed of a rubber elastic body (rubber material or synthetic resin material having rubber-like elasticity) on a metal reinforcing ring 11, and a seal lip 12. And a garter spring 13 mounted on the outer periphery of the lip head 123.

  Specifically, the reinforcing ring 11 is manufactured by punching and stamping a steel plate or the like, for example.

  The seal lip 12 has a root 121 integrally vulcanized and bonded to the inner diameter end 11a of the reinforcing ring 11, and a conical cylindrical shape extending from the root 121 toward the sealed space A and having a relatively large diameter on the root 121 side. The inner peripheral surface 122a is constricted and the inner peripheral surface 122a is formed on the distal end side of the waist 122, and the inner peripheral surface 123a having a substantially V-shaped cross-sectional shape is formed on the outer peripheral surface of the rotary shaft 2. A lip head 123 that is slidably in contact with the outer periphery of the lip head 123, and a spring mounting groove 123b that extends endlessly in the circumferential direction for mounting the garter spring 13 is formed on the outer peripheral surface of the lip head 123. Yes. The rotating shaft 2 corresponds to the rotating body described in claim 1.

  The garter spring 13 is formed by connecting a metal coil spring in an annular shape, and is fitted into the spring mounting groove 123 b of the lip head 123 of the seal lip 12 so that the seal lip 12 is pressed against the outer peripheral surface of the rotating shaft 2. Compensates for force.

  A large number of ribs 124 extending in the axial direction from the end portion on the base 121 side to the end portion on the spring mounting groove 123b side are formed on the outer peripheral surface of the waist portion 122 in the seal lip 12 at equal intervals in the circumferential direction.

  A plurality of spring holding projections 125 projecting in the outer diameter direction are formed at predetermined intervals in the circumferential direction on a shoulder portion 123c located on the distal end side of the seal lip 12 among the shoulder portions of the spring mounting groove 123b in the seal lip 12. . The radial height h of the spring holding projection 125 is preferably larger than the outer diameter d of the garter spring 13 mounted in the spring mounting groove 123b.

  From the root 121 of the seal lip 12, a dust lip 14 is formed which extends in a conical cylindrical shape facing the side opposite to the seal lip 12, that is, the atmosphere B side in the mounted state and having a small diameter at the tip side.

  Of the inner peripheral surface of the lip head 123 in the seal lip 12, the inner surface 123 a of the lip head 123 and the outer periphery of the rotary shaft 2 are located on the inclined surface 123 d on the atmosphere B side (dust strip 14 side) from the inner diameter end 123 a. Forming a number of screw ridges that express the screw pump action that pushes oil that tries to leak the sliding part with the surface from the sealed space A side to the atmosphere B side by rotating the rotary shaft 2 to the sealed space A side. Also good.

  The sealing device 1 having the above configuration is mounted on the inner peripheral surface of a housing (not shown) so that the seal lip 12 faces the sealed space A, and the inner diameter end 123a of the lip head 123 in the seal lip 12 is The oil to be sealed in the sealed space A is prevented from leaking from the shaft periphery to the atmosphere B side by being slidably in close contact with the outer peripheral surface of the rotary shaft 2 inserted through the inner periphery of the housing. . The dust lip 14 prevents dust on the atmosphere B side from entering the seal lip 12 side.

  Here, in the automobile, for the purpose of improving the fuel efficiency, it is required to further reduce the sliding torque of the seal lip 12 with respect to the outer peripheral surface of the rotating shaft 2. It is effective to reduce the rigidity of the seal lip 12 by reducing the thickness of the waist 122 of the lip 12 and to reduce the pressing force on the outer peripheral surface of the rotating shaft 2.

  According to the sealing device 1 according to the present invention, a large number of ribs 124 extending from the end on the base 121 side to the end on the spring mounting groove 123b side are formed on the outer peripheral surface of the waist 122. The thickness of 122 can be made sufficiently thin, and as a result, the tightening force can be effectively reduced. The reason is that if the thickness of the waist portion 122 of the seal lip 12 is reduced, the portion corresponding to the waist portion 122 of the mold forming cavity used for vulcanization molding of the seal lip 12 becomes narrow, but the rib 124 This is because the flow of the unvulcanized rubber material in the molding cavity is compensated by the corresponding part, and molding defects due to insufficient filling are prevented.

  Further, in addition to the thinning of the waist portion 122 as described above, the lip head 123 is also thinner than the conventional one, and the spring holding projection 125 is not continuous in the circumferential direction. The rigidity of the seal lip 12 can also be reduced by being formed at a predetermined interval.

  Therefore, according to the sealing device 1 having the above configuration, it is possible to reduce the tightening force of the seal lip 12 with respect to the outer peripheral surface of the rotating shaft 2 and reduce the sliding torque, thereby contributing to the improvement of fuel consumption.

  Further, since the spring holding projection 125 is not continuous in the circumferential direction, even if the axial thickness or the radial height h of the spring holding projection 125 is increased, the seal lip with respect to the outer peripheral surface of the rotary shaft 2 is increased. Therefore, the garter spring 13 is larger than the outer diameter d of the garter spring 13 mounted in the spring mounting groove 123b and has a required axial thickness. Can be effectively prevented from falling off.

DESCRIPTION OF SYMBOLS 1 Sealing device 12 Seal lip 121 Base 122 Lumbar part 123 Lip head part 123c Shoulder part 124 Rib 125 Spring holding protrusion 13 Gutter spring

Claims (2)

  A seal lip formed on the outer circumferential surface of the lip head, and an inner diameter end of the lip head formed on the distal end side of the waist portion extending toward the sealed space side is slidably in contact with the outer circumferential surface of the rotating body. And a garter spring mounted in the spring mounting groove, wherein a plurality of ribs extending in the axial direction are formed on the outer peripheral surface of the waist portion at arbitrary intervals in the circumferential direction.   2. The sealing device according to claim 1, wherein a plurality of spring holding protrusions projecting in an outer diameter direction are formed at an interval in the circumferential direction on a shoulder portion on a tip end side of the seal lip of the spring mounting groove.

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