JP3185997U - Sealing device - Google Patents

Abstract

Provided is a sealing device that improves sealing performance against external foreign matters by dust lip and does not increase sliding torque.
A plurality of concave and convex strips 32 extending in the circumferential direction are formed on an inner peripheral surface of a dust lip 3 extending toward the outer space B side, and are substantially V-shaped and open toward the outer space B side. A plurality of recesses 33 are formed at predetermined intervals in the circumferential direction so as to divide the projections and depressions 32 in the circumferential direction, and the projections and depressions 32 form a cylindrical shape that is concentric with the rotating body 200. It is characterized by being arranged in the axial direction.
[Selection] Figure 1

Description

  The present invention relates to a sealing device that seals the outer periphery of a rotating body in an automobile, a general machine, an industrial machine, and the like, and more particularly, to a device having a dust strip for preventing intrusion of dust and the like from the outside.

  2. Description of the Related Art Conventionally, some sealing devices that seal the outer periphery of a rotating body with a seal lip include a dust lip for preventing intrusion of dust, muddy water, and the like from the outside. 5 and 6 show a typical prior art of this type of sealing device 100. An outer diameter portion 101 that is tightly fitted and fixed to an inner peripheral surface of a shaft hole of a housing (not shown), A main seal lip 102 extending from the periphery to the in-machine space A side, and a dust lip 103 positioned on the outer space B side of the main seal lip 102 and provided on the inner periphery of the outer diameter portion 101 and extending to the outer space B side. The main seal lip 102 is slidably brought into close contact with the outer peripheral surface of the rotary shaft 200 inserted through the shaft hole, thereby sealing oil and the like in the in-machine space A, and the dust lip 103 is provided with the rotary shaft. By being slidably in close contact with the outer peripheral surface of 200, entry of foreign matter such as dust from the external space B is prevented.

  Further, as shown in FIG. 5, the dust lip 102 is not in contact with the outer peripheral surface of the rotating shaft 200 (see, for example, Patent Document 1 below), and as shown in FIG. There is a configuration in which a plurality of protrusions (or recesses) 103a are provided on the inner peripheral surface and are brought into contact with the outer peripheral surface of the rotating shaft 200 with a tightening margin (for example, see Patent Document 2 below).

JP 2008-75679 A JP-A-8-61512

  However, if the dust lip 103 is not in contact with the rotating shaft 200, the sealing performance against foreign matter in the external space B is inevitably deteriorated. There is a concern that the power loss is increased by the sliding torque.

  The present invention has been made in view of the above points, and its technical problem is to improve the sealing performance against external foreign matters by dust lip and to prevent the sealing torque from increasing. To provide an apparatus.

  As means for effectively solving the technical problem described above, the sealing device according to claim 1 is directed to the inner peripheral surface of the dust strip extending toward the outer space and facing the outer peripheral surface of the rotating body. A plurality of concave and convex strips extending in the circumferential direction are formed, and a plurality of substantially V-shaped concave portions opened toward the external space are formed at predetermined intervals in the circumferential direction so as to divide the concave and convex strips in the circumferential direction. And the said uneven | corrugated strip is located in a line in the axial direction so that the virtual surface which passes through each peak part may make the concentric cylinder shape with the said rotary body.

  A sealing device according to a second aspect of the invention is characterized in that, in the configuration described in the first aspect, the inner diameter of the dust lip is equal to or larger than the outer diameter of the rotating body on the inner peripheral side.

  According to a third aspect of the present invention, in the sealing device according to the first or second aspect, a cylindrical surface having the same diameter as the inner diameter of the ridges is formed on the inner peripheral surface of the dust strip.

  According to the sealing device of the first aspect of the invention, the V-shaped concave portion formed on the inner peripheral surface of the dust lip has the effect of discharging air to the external space side with the rotation of the rotating body, and the unevenness. Since the flow of the air in the circumferential direction is caused along the strip, the sealing performance against foreign matter entering from the external space together with the air can be improved.

  Further, according to the sealing device of the second aspect of the present invention, since the allowance of the dust strip to the rotating body is not provided, in addition to the effect of the first aspect, the power loss of the rotating body due to the sliding torque of the dust strip is increased. Can be prevented.

  According to the sealing device of the third aspect of the invention, in addition to the effect of the first or second aspect, the cylindrical surface formed on the inner peripheral surface of the dust lip serves as a bearing surface for the outer peripheral surface of the rotating body. Further, it is possible to prevent the uneven stripes from being worn by contact with the outer peripheral surface of the rotating body.

1 is a half sectional view showing a first preferred embodiment of a sealing device according to the present invention by cutting along a plane passing through an axis O; FIG. It is a principal part enlarged view of FIG. FIG. 5 is a half sectional view showing another preferred embodiment of the sealing device according to the present invention by cutting along a plane passing through an axis O. It is a principal part enlarged view of FIG. FIG. 6 is a half cross-sectional view showing an example of a sealing device according to the prior art cut along a plane passing through an axis O. FIG. 10 is a half cross-sectional view showing another example of a sealing device according to the prior art cut by a plane passing through an axis O.

  Hereinafter, preferred embodiments of a sealing device according to the present invention will be described with reference to the drawings. First, FIG. 1 and FIG. 2 show a first embodiment.

  In the sealing device shown in FIG. 1, a main seal lip 2, a dust lip 3 and a fixed seal portion 4 are integrally provided on a metal reinforcing ring 1. The main seal lip 2, the dust lip 3 and the fixed seal portion 4 on the outer peripheral side thereof are made of rubber-like elastic material (rubber material or synthetic resin material having rubber-like elasticity) and are continuous with each other. A garter spring 5 is attached to the outer peripheral surface near the tip of the main seal lip 2.

  The reinforcing ring 1 is manufactured by punching and stamping a steel plate or the like, and is formed from an outer diameter cylindrical portion 11 and an end portion of the outer diameter cylindrical portion 11 which is the outer space B side in the mounted state from the end portion to the inner diameter side. It consists of an inward flange 12 that extends.

  The main seal lip 2 extends from the position on the inner peripheral side of the inward flange portion 12 of the reinforcing ring 1 in the direction toward the in-machine space A in the mounted state, and on the inner periphery in the vicinity of the tip thereof, the rotation shaft shown in FIG. 200 has a lip edge portion 2a having a mountain-shaped cross section that is slidably in close contact with the outer peripheral surface of 200. The rotating shaft 200 corresponds to the rotating body described in claim 1.

  The dust lip 3 extends in a conical cylindrical shape from a position on the inner peripheral side of the inward flange portion 12 of the reinforcing ring 1 to a side opposite to the main seal lip 2 (a direction toward the external space B in the mounted state). The portion 31 has a cylindrical shape concentric with the outer peripheral surface of the rotary shaft 200 and faces the outer peripheral surface of the rotary shaft 200 in the radial direction.

  A plurality of concave and convex strips 32 extending in the circumferential direction are formed on the inner peripheral surface of the cylindrical tip portion 31 in the dust lip 3, and a plurality of substantially V-shaped concave portions 33 opened toward the outer space B side. Are formed at predetermined intervals in the circumferential direction so as to divide the ridges 32 in the circumferential direction. Further, as shown in the enlarged view of FIG. 2, the concave and convex strips 32 are arranged in the axial direction so that a virtual plane i passing through each peak portion is concentric with the rotation shaft 200. Further, the inner diameter of the cylindrical tip 31 of the dust lip 3, in other words, the diameter D of the virtual surface i is equal to or slightly larger than the outer peripheral surface of the rotating shaft 200.

  The fixed seal portion 4 is formed by a rubber-like elastic material continuous with the main seal lip 2 and the dust lip 3 wrapping around the outer peripheral side of the outer diameter cylindrical portion 11, and is formed on the inner peripheral surface of a housing (not shown). These are fixedly fitted and fixed in an appropriately compressed state in the radial direction.

  The garter spring 5 is formed by connecting metal coil springs in an annular shape, and is fitted into an annular groove 25 formed on the outer peripheral surface of the main seal lip 2 in the vicinity of the tip of the lip edge portion 2a. It is worn.

  In the sealing device having the above configuration, the fixed seal portion 4 is press-fitted and attached to the inner peripheral surface of the housing (not shown) so that the main seal lip 2 faces the interior space A side, and the lip edge of the main seal lip 2 The portion 21 is slidably brought into close contact with the outer peripheral surface of the rotary shaft 200, thereby preventing oil in the in-machine space A from leaking from the shaft periphery to the outer space B side.

  Further, since the inner diameter D of the distal end portion 31 of the dust lip 3 is equal to or larger than the outer peripheral surface of the rotating shaft 200, there is no allowance for the outer peripheral surface of the rotating shaft 200. For this reason, the power loss of the rotating shaft 200 due to the sliding torque is not increased, and the dust strip 3 is not worn. In addition, the plurality of concavo-convex ridges 32 formed on the inner peripheral surface of the cylindrical tip 31 of the dust lip 3 has an axial direction such that a virtual plane i passing through each peak is concentric with the rotary shaft 200. As a result, the labyrinth seal function is triggered.

  As the rotary shaft 200 rotates, the air in contact with the outer peripheral surface thereof is dragged and rotationally flows, so that it enters the V-shaped recess 33 formed on the inner peripheral surface of the cylindrical tip 31 of the dust lip 3. The air collides with the oblique edge of the concave portion 33 on the downstream side of the flow, and is discharged to the external space B side as indicated by an arrow F or F ′ in FIG. Further, part of the air that has entered the concave portion 33 flows in the circumferential direction along the concave / convex strip 32 through the gap between the concave / convex strip 32 and the outer peripheral surface of the rotating shaft 200. And, by these actions, the sealing performance against foreign matter entering from the external space B can be improved.

  3 and 4 show another preferred embodiment of the sealing device according to the present invention. In this embodiment, the difference from the first embodiment shown in FIGS. 3 on the inner side (main seal lip 2 side) of the concavo-convex ridge 32, the same diameter as the inner diameter of the concavo-convex ridge 32, that is, the same diameter as the diameter D of the imaginary plane i passing through each peak of the concavo-convex ridge 32 The cylindrical surface 34 is formed.

  According to the sealing device shown in FIGS. 3 and 4, in addition to the effects of the first embodiment described above, the cylindrical surface 34 formed on the inner peripheral surface of the tip 31 of the dust lip 3 has a rotational axis. Since it becomes a bearing surface with respect to the outer peripheral surface of 200, the abrasion of the uneven | corrugated strip 32 by sliding with the outer peripheral surface of the rotating shaft 200 can be suppressed, and an initial stage performance can be maintained over a long term.

DESCRIPTION OF SYMBOLS 1 Reinforcement ring 2 Main seal lip 3 Dustrip 31 Tip part 32 Concavity and convexity 33 Concavity 200 Rotating shaft
A In-flight space B External space i Virtual plane

Claims (3)

  A plurality of concave and convex strips extending in the circumferential direction are formed on the inner peripheral surface of the dust lip that extends toward the outer space and faces the outer peripheral surface of the rotating body, and is substantially V-shaped that opens toward the outer space. Are formed at predetermined intervals in the circumferential direction so as to divide the concavo-convex portion in the circumferential direction, and the concavo-convex portion forms a cylindrical shape concentric with the rotating body. A sealing device characterized by being aligned in the axial direction.   2. The sealing device according to claim 1, wherein an inner diameter of the dust lip is equal to or larger than an outer diameter of a rotating body on an inner peripheral side thereof.   The sealing device according to claim 1, wherein a cylindrical surface having the same diameter as the inner diameter of the uneven strip is formed on the inner peripheral surface of the dust strip.

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