Oil seal

Abstract

To enhance holding property of a lubricant.SOLUTION: An oil seal 1 has a side lip 14 extending in an axis line direction and is brought into contact with a face along a radial direction in a rotation body (rotary shaft 2). On the face with which the rotation body 2 is brought into contact in the side lip 14, a plurality of recessions 16 are provided while separated in a circumferential direction and a radial direction respectively. A lubricant is blocked at an opening edge of each of the recessions 16 because each of the plurality of recessions 16 becomes discontinuous, and thereby the lubricant hardly flows through each of the plurality of recessions 16.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to an oil seal. [Background technology]

[0002] For example, Patent Document 1 describes that "parallel grooves are formed on the side surface of the side lip of the sealing device." [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent No. 4280903 (JP 2004-263797) Summary of the Invention [Problem to be solved by the invention]

[0004] In the above Patent Document 1, the parallel grooves are continuous in the circumferential direction of the side lip, and therefore there is a concern that as the shaft rotates, the lubricant such as grease applied in the parallel grooves may be pulled in the circumferential direction and may flow out of the parallel grooves.

[0005] In view of the above circumstances, an object of the present invention is to provide an oil seal with improved lubricant retention. [Means for solving the problem]

[0006] The present invention is an oil seal having a side lip that extends in the axial direction and contacts a surface of a rotating body that is radially aligned, and is characterized in that the surface of the side lip that contacts the rotating body has a plurality of recesses that are spaced apart in the circumferential and radial directions.

[0007] With this configuration, the lubricant applied and filled into the multiple recesses on the inner surface of the side lip is pulled as the rotating body rotates, but because the multiple recesses are spaced apart, the lubricant is blocked by the opening edges of each recess, making it difficult for the lubricant to flow out of each of the multiple recesses.

[0008] This improves the lubricant retention ability of each of the multiple recesses, thereby reducing the frictional resistance of the surface of the side lip that slides against the rotating body (also called the sliding surface) and improving the wear resistance of the sliding surface. [Effects of the Invention]

[0009] According to the present invention, an oil seal with improved lubricant retention can be provided. [Brief explanation of the drawings]

[0010] [Figure 1] 1 is a cross-sectional view of an upper side showing an embodiment of an oil seal according to the present invention. FIG. [Figure 2] FIG. 2 is a front view showing the inner peripheral surface of the side lip. [Figure 3] FIG. 4 is an enlarged view showing a contact portion between a side lip and a rising wall surface of the rotating shaft. DETAILED DESCRIPTION OF THE INVENTION

[0011] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will now be described in detail with reference to the accompanying drawings.

[0012] One embodiment of the present invention is shown in Figures 1 to 3. The oil seal 1 shown in the figures is attached in a non-rotating state to a fixed ring body (not shown) that is arranged on the outer periphery of a rotating shaft 2 without contacting it, and is configured such that a main lip 12, a sub-lip 13, and a side lip 14 are integrally provided on a body 11.

[0013] The rotary shaft 2 is provided at a predetermined position in the axial direction with a large diameter portion 21 extending radially outward.

[0014] The body 11 has a shape in which an annular plate portion 11b extending radially inward from one axial end of a cylindrical portion 11a is integrally connected to the cylindrical portion 11a. Although not shown in detail, the body 11 is configured, for example, by vulcanization bonding a rubber-like elastic material to a metal core.

[0015] The main lip 12, the sub-lip 13 and the side lip 14 are formed of a rubber-like elastic material.

[0016] The main lip 12 is arranged to extend diagonally inward from the inner diameter side of the annular plate portion 11b of the body 11, and suppresses or prevents the lubricant (grease, oil, etc., not shown) present in the space sealed by the oil seal 1 (called the sealed space) from leaking out to the sub-lip 13 and side lip 14 side, and ultimately to the outer space.

[0017] The cross-sectional shape of the tip portion of this main lip 12 is formed into a triangular shape that becomes sharper toward the inner diameter side, and a spring ring 15 is attached to its outer surface to press the tip portion against the outer surface of the rotating shaft 2.

[0018] The side lip 14 and the sub-lip 13 are formed so as to slope diagonally outward from the inner diameter side of the body 11, suppressing or preventing foreign matter such as moisture and dust from entering the main lip 12 side and, ultimately, the sealed space.

[0019] The main lip 12 and the sub-lip 13 are in a bent state because they come into contact with the outer circumferential surface of the rotating shaft 2 while applying a predetermined pressure. The side lip 14 is in a bent state because it comes into contact with the rising wall surface that rises radially outward in the large diameter portion 21 of the rotating shaft 2 while applying a predetermined pressure.

[0020] As shown in FIG. 2, the side lip 14 has a plurality of recesses 16 formed on its inner peripheral surface.

[0021] The recesses 16 are each formed in a diamond shape and are arranged at regular intervals in the circumferential and radial directions on the inner peripheral surface, and are arranged in a staggered pattern in the circumferential and radial directions.

[0022] When the oil seal 1 is shipped after manufacture, a lubricant such as grease is applied to the surfaces of the main lip 12, sub-lip 13, and side lip 14, so that the lubricant fills the recess 16.

[0023] When the oil seal 1 having such a configuration is assembled in an area where it is actually used, the main lip 12 and the sub-lip 13 come into contact with the outer peripheral surface of the rotating shaft 2 at a predetermined pressure, and the inner peripheral surface of the side lip 14 comes into contact with the rising wall surface of the rotating shaft 2 at a predetermined pressure.

[0024] When the rotating shaft 2 is rotated in this state, as shown in Figure 3, the lubricant that has been applied and filled into the multiple recesses 16 on the inner surface of the side lip 14 is pulled by the rotating shaft 2. However, since the multiple recesses 16 are spaced apart from each other, the lubricant is blocked by the opening edges of each recess 16, making it difficult for the lubricant to flow out of each of the multiple recesses 16.

[0025] As described above, according to the embodiment to which the present invention is applied, the lubricant retention ability of each of the multiple recesses 16 in the side lip 14 of the oil seal 1 is improved, thereby reducing the frictional resistance of the inner surface of the side lip 14 sliding against the raised wall surface of the large diameter portion 21 of the rotating shaft 2 and improving the wear resistance of the inner surface.

[0026] As a result, it becomes possible to maintain the sealing performance of the oil seal 1 for a long period of time, thereby contributing to improved reliability.

[0027] The present invention is not limited to the above-described embodiments, but can be modified as appropriate within the scope of the claims and the equivalents thereof.

[0028] (1) In the above embodiment, the sub-lip 13 may be omitted.

[0029] (2) In the above embodiment, the shapes of the body 11 and the main lip 12 are not particularly limited.

[0030] (3) In the above embodiment, the shape of the recess 16 is not particularly limited, and it may be round, square, or the like. [Industrial Applicability]

[0031] The present invention can be suitably used in oil seals. [Explanation of symbols]

[0032] 1 Oil seal 11 Body 11a Cylindrical part 11b Annular plate portion 12 Main Lip 13 Sublip 14 Side lip 15 spring ring 16 Dent 2 rotation axes 21 Large diameter section

Claims

[Claim 1] An oil seal having a side lip that extends in the axial direction and contacts a surface of a rotating body along the radial direction, An oil seal characterized in that a plurality of recesses are provided on the surface of the side lip that comes into contact with the rotating body, the recesses being spaced apart in the circumferential direction and the radial direction.

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