JP2009097607A - Oil seal - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an oil seal superior in dust resistance and muddy water resistance. <P>SOLUTION: This oil seal has a main seal lip 13 extending to a machine internal A side and slidably coming into close contact with the outer peripheral surface of a rotary body 2, and a dust seal lip 14 extending to a machine external B side from a root 13a of the main seal lip 13 and slidably coming into close contact with the outer peripheral surface of the rotary body 2. A garter spring 16 is fitted to the outer peripheral surface of a dust seal lip 14, and the required number of lubricating grooves 143a continuing in the circumferential direction are formed on the sliding surface 143 of the dust seal lip 14, and lubricants are held in these lubricating grooves 143a. The bearing pressure of the sliding surface 143 of the dust seal lip 14 to the rotary body 2 is enhanced by the garter spring 16, and sealing performance to the dust and the muddy water is improved by interposing the lubricants on the sliding surface 143, and the abrasion of the sliding surface 143 is suppressed by the lubricants, and superior sealing performance to the dust and the muddy water is maintained over a long period of time. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

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

An oil seal that seals the outer periphery of a rotating body with a seal lip is widely known as described in the following patent documents. FIG. 3 is a half sectional view showing a conventional oil seal of this type cut along a plane passing through its axis O. As shown in FIG.
JP 2002-139156 A JP 2003-343738 A

  An oil seal 100 shown in FIG. 3 is formed in an annular shape from a rubber-like elastic material, and includes a fixed seal portion 101 that is closely fitted to an inner peripheral surface of a shaft hole housing (not shown), and an inner peripheral side thereof. The main seal lip 103 and the dust seal lip 104 that are slidably in close contact with the outer peripheral surface of the rotary shaft 200 inserted through the shaft hole housing are formed continuously with each other through the intermediate radial direction portion 102, A reinforcing metal ring 105 is integrally embedded from the fixed seal portion 101 to the intermediate radial direction portion 102. Further, the outer periphery of the main seal lip 103 is formed in a groove shape that is continuous in the circumferential direction, and compensates for a decrease in the tightening force due to permanent deformation of the main seal lip 103, and ensures the radial followability with respect to the rotating shaft 200. A garter spring 106 is fitted.

  That is, in this oil seal 100, the fixed seal portion 101 is press-fitted into the inner peripheral surface of a shaft hole housing (not shown), and the tip inner peripheral portion 103a of the main seal lip 103 slides on the outer peripheral surface of the rotary shaft 200. By being in close contact with each other, the fluid (oil) to be sealed on the in-machine A side to which the main seal lip 103 faces is prevented from leaking from the shaft periphery to the outside B, and the dust seal lip 104 is provided on the rotating shaft 200. By being slidably brought into close contact with the outer peripheral surface, the intrusion of dust, muddy water, and the like from the outside B side where the dust seal lip 104 faces is prevented.

  In this type of oil seal 100, dust resistance and muddy water resistance are not a problem under general use conditions. For example, in an oil seal that seals the periphery of an input shaft or the like in an automobile power steering, the dust resistance, There is a demand for further improvement in mud water resistance. And in order to improve dust resistance and mud water resistance, the dust seal lip 104 is also attached with a garter spring in the same manner as the main seal lip 103 to increase the pressing force against the outer peripheral surface of the rotary shaft 200, thereby causing dust, muddy water, etc. It is conceivable to improve the sealing performance against

  However, in this case, the wear of the sliding portion of the dust seal lip 104 is promoted by an increase in the tightening force. As a result, the early deterioration of the sealing performance due to the intervention of dust, muddy water or the like on the sliding portion of the main seal lip 103 is caused. Because of concern, it was not put into practical use.

  This invention is made | formed in view of the above points, The place made into the technical subject is to provide the oil seal excellent in dust resistance and muddy water resistance.

  As means for effectively solving the technical problems described above, an oil seal according to the present invention extends to the inside of the machine and is slidably in close contact with the outer peripheral surface of the rotating body, and the main seal lip. A dust seal lip that extends outward from the base of the rotary body and is slidably in close contact with the outer peripheral surface of the rotating body, and a garter spring is fitted on the outer peripheral surface of the dust seal lip, A required number of lubrication grooves continuous in the circumferential direction are formed on the sliding surface of the first and second lubricants, and a lubricant is held in the lubrication grooves.

  According to the oil seal of the present invention, the garter spring increases the pressing force of the dust seal lip against the rotating body to increase the surface pressure of the sliding surface, and lubrication interposed in the sliding portion between the dust seal lip and the rotating body. The agent improves the sealing performance against dust, muddy water, etc., and can effectively prevent the intervention of dust, muddy water, etc. into the sliding part of the main seal lip. In addition, since the wear of the sliding portion of the dust seal lip is suppressed by the lubricant, excellent sealing performance against dust and muddy water is maintained for a long period of time, and as a result, dust resistance and mud water resistance are remarkably improved. be able to.

  Hereinafter, a sealing device according to the present invention will be described in detail with reference to the drawings. First, FIG. 1 is a half sectional view showing a preferred embodiment of an oil seal according to the present invention by cutting along a plane passing through its axis O, and FIG. 2 is a sectional view showing an enlarged main part of FIG. It is.

  The oil seal 1 seals the circumference of an input shaft or the like in a power steering of an automobile, for example, and is selected for the metal ring 11 in consideration of heat resistance, cold resistance, oil resistance, wear resistance, and the like. A fixed seal portion 12, a main seal lip 13 and a dust seal lip 14 formed of a rubber-like elastic material are integrally provided, and garter springs 15 and 16 are fitted on the outer peripheral surfaces of the main seal lip 13 and the dust seal lip 14, respectively. It has been done.

  The metal ring 11 is formed by stamping and pressing a steel plate such as SPCC, and has a substantially L-shaped cross section including a cylindrical portion 11a and an inward flange portion 11b bent from one end thereof to the inner peripheral side.

  The fixed seal portion 12 is integrally bonded so as to cover the outer peripheral surface of the cylindrical portion 11a in the metal ring 11, and is appropriately compressed in the radial direction on the inner peripheral surface of a shaft hole housing (not shown). It is fixed tightly.

  The main seal lip 13 is continuous with the fixed seal portion 12 via a rubber layer 12 a that wraps around from the fixed seal portion 12 to the inner peripheral surface of the cylindrical portion 11 a of the metal ring 11. It extends from the base 13a integrally bonded to the portion 11b in the direction toward the in-machine A side in the mounted state. On the inner peripheral surface near the tip of the main seal lip 13 is a main edge 13b having a chevron cross section that is in close contact with the outer peripheral surface of the rotary shaft 2 inserted through the inner periphery of the shaft hole housing with an appropriate tightening margin. A secondary edge 13c located on the outer B side is formed. The rotating shaft 2 is an input shaft in the above-described power steering, for example, and corresponds to the rotating body described in claim 1.

  The dust seal lip 14 is connected to the inward flange portion 11b of the metal ring 11 continuously from the base 13a of the main seal lip 13, and is connected to the opposite side of the main seal lip 13, that is, outside the machine in the mounted state. It extends in the direction of the B side.

  The inner peripheral surface in the vicinity of the tip of the dust seal lip 14 has a tip-side conical surface 141 having a large diameter toward the tip, and a root-side conical surface 142 having a large diameter toward the root 14a on the root 14a side. And a sliding surface 143 that is between the conical surfaces 141 and 142 and is in close contact with the outer peripheral surface of the rotating shaft 2 with an appropriate margin, as shown in FIG. 2 in an enlarged manner. In addition, a plurality of lubricating grooves 143a that are parallel to each other and continuous in the circumferential direction are formed. Further, grease (not shown) is applied to the sliding surface 143 as a lubricant, and this grease is held between the outer peripheral surface of the rotating shaft 2 by a lubricating groove 143a.

  The garter springs 15 and 16 are formed by connecting metal coil springs in an annular shape, and are fitted into annular grooves 13 d and 14 b formed on the outer peripheral surfaces of the main seal lip 13 and the dust seal lip 14.

  In the oil seal 1 configured as described above, the fixed seal portion 12 is press-fitted into the inner peripheral surface of the shaft hole housing so that the main seal lip 13 faces the machine A side, and the main edge 13b in the main seal lip 13 is fitted. However, depending on the internal pressure in the machine A, the secondary edge 13c is also slidably brought into contact with the outer circumference of the rotary shaft 2, so that the oil to be sealed in the machine A is sealed. This prevents leakage from the shaft circumference to the outside B side.

  On the other hand, the dust seal lip 14 has a sliding surface 143 slidably in contact with the outer peripheral surface of the rotary shaft 2, so that dust and muddy water in the atmosphere outside the machine B can be moved to the main edge 13 b of the main seal lip 13. This prevents the main seal lip 13 from being worn by preventing it from intervening in the sliding portion between the (and sub edge 13c) and the outer peripheral surface of the rotary shaft 2. The dust seal lip 14 has a pressing force against the outer peripheral surface of the rotating shaft 2, in other words, a surface pressure of the sliding surface 143 is increased by the garter spring 16, and the lubrication formed on the sliding surface 143 is also performed. Since the grease interposed between the outer peripheral surface of the rotating shaft 2 by the groove 143a functions as a sealant (sealant) that blocks passage of dust and muddy water, excellent sealing performance against dust and muddy water is exhibited.

  Further, since the grease held by the lubricating groove 143a is interposed as a lubricating film between the sliding surface 143 of the dust seal lip 14 and the outer peripheral surface of the rotary shaft 2, the sliding resistance of the dust seal lip 14 is remarkably reduced. Wear is also significantly suppressed. For this reason, the excellent sealing performance with respect to dust, muddy water, etc. is maintained over a long period of time. As a result, wear of the main seal lip 13 is also suppressed over a long period of time, and the dust resistance and mud water resistance can be remarkably improved.

1 is a half sectional view showing a preferred embodiment of an oil seal according to the present invention by cutting along a plane passing through its axis O. FIG. It is sectional drawing which expands and shows the principal part of FIG. FIG. 5 is a half sectional view showing a conventional oil seal cut along a plane passing through its axis O.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Oil seal 11 Metal ring 12 Fixed seal part 13 Main seal lip 14 Dust seal lip 143 Sliding surface 143a Lubrication groove | channels 15 and 16 Garter spring 2 Rotating shaft (rotating body)
A In-flight B Out-of-flight

Claims (1)

  A main seal lip extending inward of the machine and slidably in contact with the outer peripheral surface of the rotating body, and a dust seal extending from the base of the main seal lip to the outer side of the machine and slidably in contact with the outer peripheral surface of the rotating body A garter spring is fitted on the outer peripheral surface of the dust seal lip, and a required number of lubricating grooves continuous in the circumferential direction are formed on the sliding surface of the dust seal lip with the rotating body. An oil seal characterized in that a lubricant is retained on the surface.

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