JP2005265162A - Sealing device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a sealing device capable of satisfying improvement of sealing performance against muddy water and low torque. <P>SOLUTION: This sealing device 1 comprises a slinger 2 installed at the one of two relatively rotating members, and a seal member 3 installed at the other. The seal member 3 comprises a seal lip 5 freely slidably contacting the slinger. The seal lip 5 is composed of a resin material (PTFE) with wear resistance and low friction characteristic. The sealing device 1 is composed of only three component elements: the slinger 2; a metal ring 4 for mounting in the seal member 3; and a resin seal lip 5 held by the metal ring 4. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a sealing device. The sealing device of the present invention is suitable for being used as a hub bearing seal in an automobile-related field or other general-purpose machines.

  Conventionally, as shown in FIG. 3, a so-called PAC type sealing device 51 is known, and this sealing device 51 is one of two members (for example, an inner ring and an outer ring) 61 and 62 that rotate relative to each other (for example, an inner ring and an outer ring). For example, it is configured by a combination of a slinger 52 attached to an inner ring 61 and a seal member 53 attached to the other (for example, outer ring) 62. The slinger 52 is made of a metal material, and is formed into a substantially L-shaped cross section by integrally forming an annular flat portion 52b at one end in the axial direction of the cylindrical mounting portion 52a, and one member (inner ring) having the mounting portion 52a. 61 is fitted to the outer peripheral surface. The seal member 53 is formed by attaching a rubber-like elastic body 55 to a metal ring 54 having a substantially L-shaped cross section, and a seal lip 56 which is slidably in close contact with the cylindrical attachment portion 53a and the slinger 52. , 57 are integrated with each other, and are fitted to the inner peripheral surface of the other member (outer ring) 62 with an attachment portion 53a.

  The sealing device 51 is required to improve the sealing performance against muddy water as a major purpose, but at the same time, there is also a request for improvement of fuel consumption (lower torque).

  That is, in the sealing device 51, since a rubber material is used as the material of the seal lips 56, 57, sliding wear occurs in the seal lips 56, 57 with use, and muddy water is reduced along with a decrease in interference. There is a phenomenon that the sealing performance with respect to is significantly reduced. As a countermeasure, the sealing device 51 employs a method in which a plurality of seal lips 56 and 57 are provided, but at the same time as the sealing performance against muddy water is improved, an event in which sliding torque increases as a contradictory event occurs. Therefore, it is difficult to satisfy both the improvement in sealing performance against muddy water and the reduction in torque.

  As another prior art for the present application, the applicant of the present application previously described, as shown in FIG. 4, between the radial front end portion 52c of the flat surface portion 52b of the slinger 52 and the mounting portion 53a of the seal member 53 opposed thereto. A labyrinth seal 58 that suppresses intrusion of dust such as muddy water is provided, and a sealing device 51 is proposed in which annular convex portions 59 and concave portions 60 are alternately arranged on the inner peripheral surface of the mounting portion 53a of the labyrinth seal 58. Therefore, according to the sealing device 51, the sealing performance can be enhanced by the “fluid pumping action by the labyrinth structure” of the convex portion 59 and the concave portion 60 (see Patent Document 1).

  However, what is provided in this prior art is also the seal lips 56 and 57 made of rubber-like elastic material, and therefore it is impossible to satisfy both the improvement in sealing performance against muddy water and the reduction in torque.

Japanese Utility Model Publication No. 07-010630

  An object of this invention is to provide the sealing device which can satisfy both the improvement of the sealing performance with respect to muddy water, and torque reduction in view of the above point.

  In order to achieve the above object, a sealing device according to claim 1 of the present invention has a slinger attached to one of two relatively rotating members and a seal member attached to the other, and the seal member is the slinger. The sealing lip having a sealing lip that is slidably in contact with the sealing lip is formed of a resin material having wear resistance and low friction characteristics.

  The sealing device according to claim 2 of the present invention is the sealing device according to claim 1, wherein the sealing device includes a slinger, a mounting metal ring in a seal member, and a resin material held by the mounting metal ring. It is characterized by being composed of only three components consisting of a seal lip made.

  The present invention has the following effects.

  That is, in the sealing device according to the first aspect of the present invention having the above-described configuration, the seal lip provided on the seal member and slidably in close contact with the slinger is not a rubber material that easily causes sliding wear, but wear resistance. It is molded from a resin material with good properties and low friction characteristics. Since this resin material has good wear resistance, it is possible to suppress a decrease in interference due to wear as compared with a conventional rubber lip, and thus it is possible to expect improved sealing performance against muddy water. At the same time, the torque of the seal can be reduced by taking advantage of the low friction characteristic. Therefore, the sealing apparatus which can satisfy both the improvement of the sealing performance with respect to muddy water and the reduction in torque can be provided as intended.

  In addition to this, in the sealing device according to claim 2 of the present invention having the above-mentioned configuration, the sealing device consists only of a slinger, a metal ring, and a seal lip, and therefore the sealing device does not have rubber parts. It is. Therefore, any vulcanization molding process can be omitted from the manufacturing process of the sealing device, and thus the manufacturing of the sealing device can be facilitated.

  As an example of the resin material, polytetrafluoroethylene (PTFE) having wear resistance and low friction characteristics is most suitable.

  Next, embodiments of the present invention will be described with reference to the drawings.

  FIG. 1 shows a cross section of a main part of a sealing device 1 according to an embodiment of the present invention. The sealing device 1 according to this embodiment is used as a hub bearing seal in the field of automobiles and is configured as follows.

  That is, first, the sealing device 1 includes a slinger 2 attached to one member (inner ring) of two members (inner ring and outer ring of a bearing) that rotate relative to each other, and a seal member 3 attached to the other member (outer ring). It is comprised by the combination of.

  The slinger 2 is made of a metal material such as a sheet metal, and is integrally formed from a cylindrical mounting portion 2a and one axial end (upper end in the drawing) of the mounting portion 2a outward in the radial direction (left in the drawing). The annular flat surface portion 2b is integrally formed to have a substantially L-shaped cross section, and the mounting portion 2a is fitted to the outer peripheral surface of one member (inner ring).

  The seal member 3 includes a metal ring 4 made of a metal material such as a sheet metal, and a seal lip 5 held by the metal ring 4.

  The metal ring 4 includes a cylindrical mounting portion 4a and an annular flat portion 4b integrally formed from one axial end (the lower end in the drawing) toward the radially inner side (the right side in the drawing) of the mounting portion 4a. A cylindrical seal lip holding portion 4c integrally formed from the inner peripheral edge of the flat surface portion 4b toward one side in the axial direction (upward in the figure) is integrally formed to have a substantially U-shaped cross section (however, the seal lip holding The axial length of the portion 4c is formed to be shorter than the axial length of the mounting portion 4a), and the mounting portion 4a is fitted to the inner peripheral surface of the other member (outer ring).

  The seal lip 5 has a cylindrical mounting portion 5a fixed to the inner peripheral surface of the seal lip holding portion 4c in the metal ring 4 by means of adhesion or the like, and an annular molded integrally with one end portion in the axial direction of the mounting portion 5a. The lip portion 5b is integrally provided, and the tip of the lip portion 5b is slidably in close contact with the inner end surface 2c of the flat surface portion 2b of the slinger 2. The seal lip 5 is not a rubber material that easily generates sliding wear as in the prior art, but is integrally formed of a resin material having wear resistance and low friction characteristics, specifically, PTFE. Further, as shown in the drawing, the lip portion 5b is formed in a trumpet shape from the mounting portion 5a side to the tip end side. This trumpet shape is formed in this way from the beginning of the molding. Alternatively, it may be formed into a cylindrical shape at the beginning of molding, and the cylinder may be expanded into a trumpet shape by assembling with the slinger 2.

  In the sealing device 1 having the above-described configuration, the seal lip 5 provided on the seal member 3 and slidably in close contact with the slinger 2 is not a rubber material that easily generates sliding wear, but has wear resistance and low friction characteristics. The resin material provided, specifically, is integrally molded with PTFE. Since PTFE has good wear resistance, it is possible to suppress a decrease in interference due to wear as compared with a conventional rubber lip, and thus improve sealing performance against muddy water. At the same time, the torque of the seal can be reduced by taking advantage of the low friction characteristic. Therefore, the hub bearing seal which can satisfy both the improvement of sealing performance against muddy water and the reduction of torque can be provided as intended.

  In addition, the sealing device 1 having the above-described configuration is configured by only three components, that is, the slinger 2, the metal ring 3, and the seal lip 4, and does not have rubber parts. Therefore, any vulcanization molding process can be omitted from the manufacturing process of the sealing device 1, and thus the manufacturing of the sealing device 1 can be facilitated.

  Further, in the sealing device 1 having the above-described configuration, the seal lip holding portion 4c of the metal ring 4 is formed in a cylindrical shape, and a resin-made seal lip 5 is provided on the inner peripheral side of the cylindrical seal lip holding portion 4c. By being fixed, the seal lip 5 exhibits a cross-sectional arc shape in which the inner end surface 2c of the flat surface portion 2b of the slinger 2 is tangent and deforms relatively smoothly. Therefore, as shown in FIG. 2 as a comparative example, the fixing posture is stabilized and the fixing force is not weakened as compared with the case where the seal lip 5 is fixed to the end face of the flat portion 4b of the metal ring 4. Therefore, it is possible to provide the sealing device 1 that is excellent in stability of fixation and, in turn, excellent in durability. In the case of FIG. 2, the seal lip 5 is forced to undergo a substantially unreasonable deformation as shown in the figure.

Sectional drawing of the principal part of the sealing device which concerns on the Example of this invention. Sectional drawing of the principal part of the sealing device which concerns on a comparative example Half-cut sectional view showing the mounting state of the sealing device according to the conventional example Sectional drawing of the principal part of the sealing device which concerns on another prior art example

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Sealing device 2 Slinger 2a, 4a, 5a Mounting part 2b, 4b Plane part 2c Inner end surface 3 Seal member 4 Metal ring 4c Seal lip holding part 5 Seal lip 5b Lip part

Claims (2)

A seal lip having a slinger (2) attached to one of the two relatively rotating members and a seal member (3) attached to the other, the seal member (3) being slidably in close contact with the slinger In a sealing device (1) having (5),
The sealing device according to claim 1, wherein the seal lip (5) is formed of a resin material having wear resistance and low friction characteristics. The sealing device of claim 1.
The sealing device (1) includes a slinger (2), a mounting metal ring (4) in the sealing member (3), and a resin seal lip (5) held by the mounting metal ring (4). The sealing device characterized by comprising only three components.

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