JP2002295692A - Sealing ring - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a sealing ring, capable of reducing torque, while suppressing the leakage and reducing the wear of a side surface of the seal ring and a groove side surface of a shaft. SOLUTION: A side surface 8 of a sealing ring body is protruded and a ridge part 8 of the protruded part in contact with the side surface 9 of a ring groove 2 is offset from the outer circumferential surface 4 of the body of the sealing ring.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a resin seal ring used for, for example, an automatic transmission of an automobile or various hydraulic devices.

[0002]

2. Description of the Related Art FIG.
As shown in FIG. 1A, a resin seal ring body 101 is formed.
Into the ring groove 103 formed on the outer periphery of the shaft 102,
When the pressure of the lubricating oil 106 as a fluid to be sealed is exerted, the outer peripheral surface 104 of the seal ring main body 101 is pressed against the inner peripheral surface 107 of the housing 105 which is rotatably fitted to the outer periphery of the shaft 102, and the seal ring main body 101 is pressed. The lubricating oil 106 is sealed by pressing one side surface 108 of the ring groove 103 against one groove side surface 109 of the ring groove 103. here,
The lubricating oil 106 corresponds to an ATF in the case of a transmission for an automobile.

[0003]

However, in such a conventional seal ring, when an aluminum alloy or a spheroidal graphite cast iron material is used for the shaft 102, the seal ring main body 101 and the shaft 102 are worn out in a short time. In the transmission of an automobile, problems such as a failure to shift gears occur.

[0004] Here, it is known that the strength of an aluminum alloy at a high temperature is reduced, and it is known that a spheroidal graphite of a spheroidal graphite cast iron material drops at a high temperature. Therefore, one of the causes of the abrasion is an increase in the temperature of the groove side surface due to the heat generated by sliding between the seal ring main body side surface 108 and the groove side surface 109.

In order to solve the above problem, Japanese Patent Laid-Open No.
In Japanese Patent Publication No. 17836, as shown in FIG. 5B, there is a method of tapering the seal ring main body side surface 108 to reduce the pressing pressure acting on the seal ring main body side surface 108, thereby reducing loss torque and wear. Proposed.

However, in the case of this form, as shown in FIG. 5 (C), even if a special step cut having a relatively small leak amount in the entire temperature range is adopted for the cut shape of the seal ring main body 101, as shown in FIG. A flow path T that penetrates the high pressure side and the low pressure side beyond the contact portion S,
Is formed, so that the leak characteristics deteriorate.

In order to improve the leak characteristics, the applicant of the present invention has disclosed in Japanese Patent Application No. 2000-130689 the FIG.
As shown in (A), (B) and (C), the outer and inner slopes 108A, 108A,
8B, and a method was proposed in which a ridge 108C that comes into contact with the groove side surface is installed so as to overlap the cut side 108D of the special step cut.

However, since the seal ring main body side surface 108 and the groove side surface of the shaft continue to contact and slide in a concentrated manner on the same circumference (ridge portion 108C), the temperature of the contact portion is significantly increased due to the heat generated by the sliding. Wear of the seal ring and the shaft is apt to progress.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems of the prior art. It is an object of the present invention to reduce the torque while suppressing the amount of leakage, and to provide a seal ring side surface and a shaft groove side surface. It is an object of the present invention to provide a seal ring capable of reducing the amount of wear of the seal ring.

[0010]

In order to achieve the above object, according to the present invention, in order to achieve the above object, according to the present invention, a resin seal ring main body is formed around the shaft. When the pressure of the fluid to be sealed is applied, the outer peripheral surface of the seal ring main body is pressed against the inner peripheral surface of the housing which is relatively rotatably fitted to the outer periphery of the shaft,
In a seal ring in which one side surface of the seal ring main body is pressed into contact with one groove side surface of a ring groove, the side surface of the seal ring main body has a convex shape, and a ridge portion of a convex portion that comes into contact with the groove side surface of the ring groove is a seal ring main body. It is characterized by being eccentric with respect to the outer peripheral surface.

[0011] The side surface of the seal ring main body is characterized in that it is an inclined surface inclined in a direction away from the groove side surface from the center ridge line toward both ends in the radial direction.

The convex portion on the side surface of the sheeting main body is characterized in that a part of the side surface of the seal ring main body has a convex shape.

[0013]

Preferred embodiments of the present invention will be described in detail below with reference to the accompanying drawings. However, the dimensions of the components described in this embodiment,
The materials, shapes, relative arrangements, and the like are not intended to limit the scope of the present invention only to them unless otherwise specified.

FIG. 1 shows a sectional shape of a seal ring according to an embodiment of the present invention.

In this seal ring, a resin-made seal ring main body 1 formed in an annular shape is mounted in a ring groove 3 formed on the outer periphery of a shaft 2, and when a pressure of a lubricating oil 6 to be sealed is applied, the seal ring main body 1 is formed. 1 is pressed against an inner peripheral surface 7 of a housing 5 rotatably fitted to the outer periphery of the shaft 2, and one side surface 8 of the seal ring main body 1 is joined to one groove side surface 9 of the ring groove 3. Is to be pressed against. The groove side surface 9 of the ring groove 3 is an orthogonal surface orthogonal to the central axis of the shaft 2.

Materials applied to the seal ring include:
A resin composition comprising a heat-resistant resin and a filler is used.

Examples of the heat resistant resin include aromatic polyether ketone resins such as polycyano aryl ether resin (PEN) and polyether ether ketone (PEEK) resin, aromatic thermoplastic polyimide resin, polyamide 4-
Resin materials having excellent heat resistance, viscosity resistance, and chemical resistance, and exhibiting excellent mechanical properties, such as a 6-series resin, a polyphenylene sulfide-based resin, and a polytetrafluoroethylene-based resin.

The filler improves the mechanical strength of the resin material,
It is incorporated for the purpose of improving abrasion resistance and imparting low friction characteristics, and is not particularly limited.

The side surface 8 of the seal ring main body has a convex shape as a whole, and a ridge portion 8C in contact with the groove side surface 9 of the ring groove 3 is eccentric with respect to the outer peripheral surface 4 of the seal ring main body. That is, the ridge portion 8C is also a circle having a diameter smaller than the outer diameter of the seal ring main body 1 and larger than the inner diameter of the seal ring main body 1, and its center O1 is a predetermined amount Δ with respect to the center O of the outer peripheral surface 4 of the seal ring main body 4. Eccentric.

The shape of the other side surface of the seal ring main body 1 is symmetrical in the left and right directions, and a description thereof will be omitted.

Therefore, the ridge 8C is located 180 degrees apart at the center of the radial width of the seal ring body 1 at two positions (see FIGS. 1B and 1D), and the position closest to the inner diameter is 1 point. 1 (see FIG. 1C), and one position closest to the outer diameter exists (see FIG. 1E).

The shape of the side surface 8 of the seal ring main body is such that inclined surfaces 8A (outer diameter side) and 8B (inner diameter side) are inclined from the central ridge 8C toward both ends in the radial direction in a direction away from the groove side surface.
It has become.

The outer and inner inclined surfaces 8A, 8A
The angles θA and θB of B are at least 1 degree and less than 90 degrees, preferably 5 degrees with respect to an orthogonal plane orthogonal to the central axis of the axis 2.
Degrees or more and less than 45 degrees.

The ridge portion 8C has a triangular shape in FIG. 1 and is configured to make line contact with the groove side surface 9. A flat portion 8E may be provided as shown in FIG. 2 (A), or a rounded portion 8R having a rounded tip may be provided as shown in FIG. 2 (B).

The seal ring body 1 is cut at one place. In this embodiment, the cut portion is formed as shown in FIG.
As shown in the figure, the ridge line portion 8C is provided at a portion located at the center position of the radial width of the seal ring main body 1.

As shown in FIG. 2 (C), the cut portion 10 has a concave portion 10a and a convex portion 10b which are slidably fitted to each cut end of the ring along the circumferential direction.
Is provided, and the joint surface between the concave portion 10a and the convex portion 10b is pressed in the axial direction and the radial direction by the hydraulic pressure to be sealed.

The concave portion 10a has a shape in which an end of the seal ring main body is cut by a predetermined length, and a part of the outer peripheral surface and a slant surface on the outer peripheral side of the side surface are cut off at a right angle. The concave first side surface 10a1 extending by a predetermined dimension in parallel with the central axis O along the ridge line portion 8C of the side surface 8, and is orthogonal to the central axis O from the axial middle position of the outer peripheral surface 4 of the seal ring main body 1. A second side surface 10a2 extending in the direction by a predetermined dimension.

On the other hand, the protruding portion 10b is a portion that partially protrudes from the ring end face, and is one side face 8 of the seal ring main body 1.
The first protrusion protruding side surface 10b1 extends by a predetermined dimension parallel to the central axis O along an extension of the ridge line portion 8C, and from the axially intermediate position of the outer peripheral surface 4 of the seal ring main body 1 to the central axis O. Protruding portion second side surface 10b2 extending in a direction orthogonal to
And

By setting the ridge line portion 8C so as to overlap the joining surface on the side surface side of the cut portion, that is, to overlap the first concave side surface 10a1 and the first convex side surface 10b1, a normal special step cut seal is provided. It can exhibit the same leak characteristics as a ring.

Further, for convenience of molding, the ridge line portion 8 of the cut portion is formed.
Even if the radial width F on the outer diameter side is larger than the radial width G on the inner diameter side, the eccentricity of the ridge 8C as shown in FIG. 2D reduces the pressure receiving area. And lower torque can be achieved.

(Other Embodiments) In the above embodiment,
Although the side surface of the seal ring main body is made to protrude in a triangular shape as a whole to form a convex portion, as shown in FIG. 3, a convex portion 28 which protrudes a part of the flat side surface 8 of the seal ring main body is provided. The ridge line portion 28C of the seal ring 28 may be eccentric with respect to the outer peripheral surface 4 of the seal ring main body. Also in this case, the left and right side surfaces 8, 8 of the seal ring main body 1 have a left-right symmetric shape.

The convex portion 28 has a triangular shape, and the angles θA and θB of the inclined surfaces 28A and 28B on the outer diameter side and the inner diameter side with the ridge 28C therebetween are 1 ° or more and less than 90 °, preferably 30 ° or more and 80 ° or less. Less than degrees.

The protrusion Hs of the projection 28 is 0.2 m.
m and 0.5 mm or less are desirable.

In addition, a flat portion may be provided at the tip of the convex portion 28, or the tip may have an R-shape for reasons of manufacturing and stabilization of leak characteristics.

Other structures and operations are the same as those in the first embodiment, and therefore, the same components are denoted by the same reference numerals and description thereof will be omitted.

[0036]

Next, more specific embodiments of the present invention will be described.

In this example, a seal ring injection molded using polyetheretherketone (PEEK) was subjected to additional processing to obtain a seal ring according to the embodiment shown in FIG. The outer diameter D: 47.5m of the seal ring
m, wall thickness: 1.9 mm, height: 2.0 mm, θA, θ
B: 20 °, eccentricity Δ: 0.6 mm.

As a comparative example, a seal ring shown in FIGS. 6A and 6B was used (the outer diameter of the seal ring was 4 mm).
7.5 mm), and the temperature of the shaft side surface was measured by a tester shown in FIG.

The testing machine 200 includes a testing machine case 201,
A shaft 202 fixed to the tester case 201 and a shaft 20 inside the tester case 201 and on the outer peripheral side of the shaft 202.
Housing 203 provided rotatably concentrically with 2
And A ring groove 204 for mounting a seal ring sample S is provided on the outer periphery of the shaft 202, and a space between the housing 203 and the shaft 202 serves as an oil chamber 205 into which test oil is introduced. The hydraulic pressure is introduced from the hydraulic pressure inlet 206 into the oil chamber 205.

In the vicinity of the side surface of the ring groove 204,
A temperature sensor 207 such as a thermocouple for detecting heat generated by sliding between the seal ring and the side surface of the ring groove is provided.

When the seal ring sample S is mounted in the ring groove 204 of the shaft 202 and hydraulic pressure is applied, the side surface of the seal ring sample S is pressed against the groove side surface, and the outer peripheral surface is pressed against the inner peripheral surface of the housing 203 to seal the oil.

The hydraulic pressure is 1.3 MPa and the housing rotation speed is:
With respect to 1000, 2000, 3000, and 4000 rpm, the respective shaft side temperatures were detected. The oil type was ATF.

FIG. 4B shows the test results.

As shown in FIG. 4B, it was confirmed that the shaft side temperature of the example was kept 15 to 20% lower than that of the comparative example.

[0045]

As described above, according to the present invention, the side surface of the seal ring main body is formed in a convex shape, and the ridge portion of the convex portion in contact with the groove side surface of the ring groove is eccentric with respect to the outer peripheral surface of the seal ring main body. This prevents the contact portion between the seal ring main body side surface and the shaft groove side surface from being limited on the same circumference, thereby suppressing a local temperature increase of the shaft groove side surface temperature and the groove side surface. Is prevented from concentrating and receiving the sliding load, and the durability can be improved.

Further, if the side surface of the seal ring main body is formed as an inclined surface inclined in a direction away from the groove side surface from the center ridge portion toward both ends in the radial direction, the product can be easily removed from the mold when the seal ring is injection-molded. The effect is also obtained.

Further, the protrusion on the side surface of the seal ring main body is
If a part of the side surface of the seal ring main body is formed in a convex shape, even if the tip of the convex shape is slightly worn, the initial contact state is maintained, so that the effect is maintained.

[Brief description of the drawings]

FIGS. 1A and 1B show a seal ring according to a first embodiment of the present invention, wherein FIG. 1A is a front view, and FIG.
-B line enlarged sectional view, (C) is the CC line enlarged sectional view of (A), (D) is the DD line enlarged sectional view of (A), (E) is EE of (A) It is a line expanded sectional view.

2A is a cross-sectional view showing a modification in which the side ridges of the seal ring in FIG. 1 are flattened, and FIG. 2B shows a modification in which the side ridges of the seal ring in FIG. 1 are R-shaped; Sectional view,
(C) is a partial perspective view showing an example of a cut portion, and (D) is a front view showing a modification of the cut portion position in (C).

FIGS. 3A and 3B show a seal ring according to a second embodiment of the present invention, wherein FIG. 3A is a front view, and FIG.
-B line enlarged sectional view, (C) is the CC line enlarged sectional view of (A), (D) is the DD line enlarged sectional view of (A), (E) is EE of (A) It is a line expanded sectional view.

FIG. 4A is a cross-sectional view of a testing machine used in a comparative experiment,
(B) is a graph showing test results.

FIG. 5A is a cross-sectional view of a conventional seal ring, and FIG.
Is a cross-sectional view of another conventional seal ring, and (C) is a partial perspective view of an abutment portion of (B).

6A is a front view of another conventional seal ring, FIG. 6B is an enlarged sectional view taken along line WW of FIG. 6A, and FIG. 6C is a partial perspective view of a cut portion of FIG. is there.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 seal ring main body 2 shaft 3 ring groove 4 ring outer peripheral surface 5 housing 7 housing inner peripheral surface 8 ring side surface 8A, 8B inclined surface 8C ridge line portion 9 groove side surface 10 cut portion 10a concave portion 10a1 concave first side surface 10a2 concave second side surface 10b Projection 10b1 Projection first side surface 10b2 Projection second side surface 28 Projection 28A, 28B Inclined surface 28C Edge line θA, θB Incline angle O Center of seal ring body outer peripheral surface O1 Center of edge line portion Δ Eccentricity 200 Test machine 201 Test machine case 202 Shaft 203 Housing 204 Ring groove 205 Oil chamber 206 Hydraulic inlet 206 207 Temperature sensor S Seal ring sample

Claims (3)

[Claims] 1. A seal ring body made of resin is mounted in a ring groove formed on the outer periphery of a shaft, and the outer peripheral surface of the seal ring body is relatively rotatably fitted on the outer periphery of the shaft when a pressure of a fluid to be sealed is applied. To the inner surface of the housing
In a seal ring in which one side surface of the seal ring main body is pressed into contact with one groove side surface of a ring groove, the seal ring main body side surface is formed in a convex shape, and a ridge portion of a convex portion in contact with the groove side surface of the ring groove is formed in the seal ring main body. A seal ring characterized by being eccentric with respect to an outer peripheral surface. 2. The seal ring according to claim 1, wherein the side surface of the seal ring main body is an inclined surface inclined in a direction away from the groove side surface from the center ridge portion toward both ends in the radial direction. 3. The seal ring according to claim 1, wherein the convex portion on the side surface of the seal ring main body is formed by forming a part of the side surface of the seal ring main body into a convex shape.