JPH0573364U - Side lip base shape - Google Patents

Abstract

(57) [Summary] (Correction) [Purpose] To provide a side lip that can obtain an optimum sliding pressure that is not confused by fluctuations in the contact pressure of the lip and can greatly extend its life. [Arrangement] The rounded portion R1 is provided on the base of the side lip 4a made of an elastic body, and the base is made thinner than the front side.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a sealing device that is mounted between members that rotate with respect to each other and seals the inside and the outside between the members, and more particularly, to improving the shape of a side lip shape of the sealing device.

[0002]

[Prior Art]

 Conventionally, the side lip shape of the seal mounted on the rotating portion is often extended from the base portion in the axial direction while gradually tapering or maintaining the same thickness and forming a sharp lip at the tip thereof. In this side lip structure, the tapered portion is elastically deformed to adjust the contact pressure in the axial direction and maintain the contact to ensure long-term sealing.

When an example of such a structure is shown in the drawing, a lip structure as shown in Japanese Patent Laid-Open No. 57-103930 of FIG. 3 can be seen. Here, a side lip (4) that extends in the axial direction while maintaining almost the same thickness and a radial lip (5) that gradually tapers are shown. Due to the deformed structure during mounting, the side lip (4) and the radial lip are shown. It can be seen that the entire lip (5) is bent and deformed by the contact pressure.

[0004]

[Problems to be solved by the device]

 However, in the case of a structure that extends from the base portion of the side lip (4) while keeping the same thickness in the axial direction, the entire side lip (4) is largely curved and deformed to receive the contact pressure, as described above, so that the buffering Although the action itself can be expected to produce good results, the contact shape of the tip of the side lip (4) greatly changes the contact state. In other words, if excessive contact pressure is applied and the tightening margin increases, the size of the side lip (4) becomes large, and the tip of the contact lip is set at a gentle angle with respect to the contact surface. Expand the area.

Naturally, the expansion of the contact area not only causes an excessive sliding torque to be exerted on each part of the engine but also shortens the lip life thereof. On the contrary, if only a small contact pressure is applied to the side lip (4), the elastic repulsion force caused by the bending is not obtained, but the side lip (4) is not suitable for the sealing action. There is a drawback that the sliding pressure cannot be obtained. The present invention eliminates many of these drawbacks, and aims to provide a side lip capable of obtaining an optimum sliding pressure that is not disturbed by fluctuations in the contact pressure of the lip and greatly extending its life.

[0006]

[Means for Solving the Problems]

 The present invention will be described with reference to the drawings. As shown in FIG. 1, the shape of the base of the side lip (4a) in axial contact with the seal for sealing the rotating portion is as follows. Line (1) and line (2) are connected by R (R1), 2. The minimum thickness of the side lip base is achieved in the middle of the radius (R1), 3. The radius (R1) should be 1.5 times or less and 1.0 times or more the minimum wall thickness. 4. The axial width dimension (h1) in which the radius (R1) is provided is greater than the minimum wall thickness and less than twice the minimum thickness. The starting point (f1) of the line (3) is located closer to the tip side than the midpoint between the starting point (d) and the ending point (e) of the width dimension (h1) and is characterized by the above correlation. Further, the base shape of the side lip (4a), The line (1) and the line (2) are connected by the radiuses (R1) and (R2), and the dimension thereof is R2> R1. 2. The minimum wall thickness of the side lip base is fulfilled in the middle of are (R1) and (R2), 3. The length dimension in which the radiuses (R1) and (R2) are added is 1.5 times or less and 1.0 times or more of the minimum meat. 4. The axial width dimension (h2) in which the radiuses (R1) and (R2) are provided is less than twice the minimum wall thickness, and 5. The starting point (f2) of the line (3) is located closer to the tip side than the midpoint between the starting point (d) and the ending point (g) of the width dimension (h2), and is also characterized by the above correlation.

[0007]

[Action]

 The present invention has the above-described structure and has the following excellent effects. That is, the function of each dimension and relationship specified in the present invention is that the minimum thickness of the side lip base portion is located at the formation portion of the radius (R1) or (R2), so that the starting point of bending of the side lip (3a). Is determined in the minimum thickness portion regardless of the interference, and the starting point (d) where the radius (R1) starts is located near the points (f1) and (f2) where the diameter increases toward the tip of the lip. It further contributes to the stabilization of the starting point. If the bending start point is kept constant, the side lip (4a) on the other side having a sufficient thickness rigidity contacts the tip of the side lip (4a) without making a large deformation and keeps the area of the contact portion constant. Therefore, the change in the contact load has no effect on the lip contact portion.

Further, the radius (R1) is set to 1.5 times or less and 1.0 times or more of the minimum wall thickness, and the axial width dimension (h1) in which the radius (R1) is provided is set to the minimum wall thickness. By defining it to be larger than less than twice, the deformation point can be fixed inside the points (f1) and (f2) where the diameter is expanded toward the tip of the lip, and stable bending is provided. Here, Table 1 shows changes in the contact load with respect to the interference of the side lip (4a) of the present invention and the conventional side lip (4).

Table 1

[0010]

【Example】

 In implementing the present invention, as shown in FIG. 2, the radius to be provided can be composed of radiuses (R1) and (R2) having different radii. It is possible to obtain the effect of forming the portion and strengthening the bendability thereof and, at the same time, having a small radius of curvature (R1), clearly fixing the bend portion.

[0011]

[Effect of the device]

 According to the present invention, by defining the base portion of the side lip (4a) as the minimum thickness and finely defining each portion in the vicinity thereof, the bending start point of the side lip (4a) is made constant, and thus there is an appropriate degree not related to the tightening margin. A wide lip contact load is obtained, and the seal shape that does not change the load greatly reduces the seal torque as compared with the conventional lip shape, and provides stable sealing performance.

[0012]

[Brief description of drawings]

FIG. 1 is an enlarged sectional view showing an embodiment of the present invention.

FIG. 2 is an enlarged cross-sectional view showing another embodiment of the present invention.

FIG. 3 is a sectional view showing a lip shape of a sealing device without using the present invention.

[0013]

[Explanation of symbols]

1 line 2 line 3 line 4a Side lip R1 R1 R2 R1 h1 A1 (R1) provided axial width dimension h2 A2 (R1) and (R2) provided axial width dimension f1 point f2 point d width dimension (h1) ) Start point e End point of width dimension (h1) g End point of width dimension (h2)

Claims (2)

[Scope of utility model registration request] 1. A base shape of a side lip (4a) contacting in an axial direction in a seal for sealing a rotating portion, comprising: 1. Line (1) and line (2) are connected by R (R1), 2. The minimum thickness of the side lip base is fulfilled in the middle of the round (R1), 3. The radius (R1) should be 1.5 times or less and 1.0 times or more the minimum wall thickness. Axial width dimension (h1) where R (R1) is provided
Is greater than the minimum wall thickness and less than twice, The starting point (f1) of the line (3) is located closer to the tip side than the midpoint of the starting point (d) and the ending point (e) of the width dimension (h1), and has the above-mentioned correlation. Base shape. 2. The base shape of the side lip (4a), wherein: The line (1) and the line (2) are connected by the ares (R1) and (R2), and the dimensions are (R2)> (R1), and 2. The minimum thickness of the side lip base is achieved in the middle of the rounds (R1) and (R2), 3. The length dimension including the radiuses (R1) and (R2) is 1.5 times or more and 1.0 times or more of the minimum wall thickness. 4. The axial width dimension (h2) in which the radiuses (R1) and (R2) are provided is greater than the minimum wall thickness and less than twice the minimum thickness. The starting point (f2) of the line (3) is located closer to the tip side than the midpoint of the starting point (d) and the ending point (g) of the width dimension (h2), and has the above-mentioned correlation. Base shape.