JP2560805Y2 - Seal ring - Google Patents

Description

[Detailed description of the invention]

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a seal ring made of synthetic resin, and more particularly to a seal ring in which the sliding frictional resistance and the amount of abrasion on a seal surface are reduced.

[0002]

2. Description of the Related Art As shown in FIG. 13, a seal ring 1 is generally mounted in a circumferential groove 3 of a shaft 2 and an outer peripheral surface of the seal ring 1 is pressed against an inner peripheral surface of a cylinder 4 to seal the pressed surface. At the same time, the pressure difference of the liquid to be sealed is pressed against the inner wall of the peripheral groove 3 on the low pressure side, and the peripheral surface 3 is sealed by the sealing surface 5 on the low pressure side.

Further, in the case of a device in which the shaft 2 rotates, sliding frictional resistance and wear occur between the sealing surface 5 and the inner wall of the circumferential groove 3.
It has been proposed to use a seal ring 1 as shown in JP-A-3-88062.

In these seal rings 1, lubrication grooves 6, 7 are formed on the seal surface 5, and a liquid to be sealed is introduced into the lubrication grooves 6, 7, so that a lubricating film is easily formed.

[0005]

[Problems to be solved by the invention] However, FIG.
In the case where the lubrication groove 6 is formed as a thin groove as described above, the liquid to be sealed is difficult to freely enter and exit the lubrication groove 6, and often accumulates therein. For this reason, when the liquid to be sealed is oil and used at a high temperature, the oil accumulated in the lubrication groove 6 gradually deteriorates, and finally changes into a tar-like state and closes the lubrication groove 6. There is a problem.

In the case of FIG. 15, since the lubrication grooves 7 are continuous in the circumferential direction, the liquid to be sealed does not accumulate as described above. However, in this case, when stress that deforms the seal ring 1 is generated due to the pressure difference between the high pressure side and the low pressure side of the liquid to be sealed, the stress concentrates on the edge 8 of the lubrication groove 7 as shown in FIG. There is a problem that this portion is easily worn.

Therefore, the present invention solves the above-mentioned problem by improving the shape of the lubrication groove in a synthetic resin seal ring, and has an object to provide a seal ring having a small sliding frictional resistance and a small amount of wear. .

[0008]

In order to solve the above-mentioned problems, a first invention according to the present application is to make a constant interval over the entire length of both side surfaces of the seal ring 11 as shown in FIGS. A seal ring made of a synthetic resin in which a number of lubrication grooves 12 are provided on both side surfaces of the ring, and a sealing surface 13 is formed on the side surface of the ring other than the lubrication grooves 12. In the illustrated case, the lubrication groove 12 is provided at the same position on both side surfaces of the ring, but may be provided at a position shifted in the circumferential direction.

The above-mentioned lubrication groove 12 is formed on both end walls 1 having a required depth which reaches the center of the ring side surface in the radial direction from the inner peripheral edge of the ring.
4 and a circumferentially long recess 16 surrounded by a groove outer peripheral wall 15 formed between both end walls 14.

In the second invention, as shown in FIGS. 4 to 6, a land 17 having a height corresponding to the sealing surface 13 is provided in the recess 16 described above.

The third invention is an improvement of the first and second inventions as shown in FIGS. 7 to 12, wherein both of the space between the both end walls 14 of the lubrication groove 12 and the inner peripheral surface of the ring are provided. Corner 1 of
8 and a corner 19 between both end walls 14 and the outer peripheral wall 15 is rounded, and an edge 20 between both end walls 14 and the seal surface 13 and an edge between the outer peripheral wall 15 and the seal surface 13 are provided. The part 21 is crowned.

In the fourth invention, in each of the above-mentioned inventions, the area ratio of the lubrication groove 12 to the side surface of the ring is set to 20 to 70%.

[0013]

In the seal ring 11 according to the first invention, the lubrication groove 12 is formed to be long in the circumferential direction, and the lubrication groove 12 is opened to the ring inner peripheral surface side in a sealed state.
The liquid to be sealed can freely enter and exit the lubrication groove 12 and does not accumulate. Further, even when a force that deforms the seal ring 11 is generated due to the pressure difference between the high pressure side and the low pressure side of the liquid to be sealed, and stress concentrates on the edge of the groove outer peripheral wall 15, the columnar portion 22 between the lubrication grooves 12 is formed. , The stress concentration described above can be reduced, and wear is reduced.

In the second invention, since the lubricating groove 12 is formed around the land portion 17, it does not hinder the inflow and outflow of the liquid to be sealed. The presence of the lands 17 in addition to the pillars 22 between the lubricating grooves 12 alleviates stress concentration and reduces wear when the seal ring 11 is deformed.

[0015] The third idea is that each corner 18 of the lubrication groove 12 is
By adding a radius to 19, the liquid to be sealed easily enters and exits the lubrication groove 12, and the edge portion 20 between the both end walls 14 and the sealing surface 13 and the edge portion 20 between the groove outer peripheral wall 15 and the sealing surface 13. When the edge portion 21 is crowned, a lubricating film is easily formed on the seal surface 13 and stress is less likely to be concentrated on the edge portions 20 and 21, thereby reducing abrasion.

In the fourth invention, the area ratio of the lubrication groove 12 to the side surface of the ring is set to 20 to 70%.
If it is less than 20%, the sliding friction resistance and wear are not sufficiently reduced, and if it is 70% or more, the wear becomes large, and the original purpose cannot be achieved.

It is preferable that the above numerical value is set to 20 to 50%.

[0018]

EXAMPLE 1 A seal ring 11 having the shape shown in FIGS. 7 to 9 was injected by using a material in which a polyether ether ketone resin was used as a main material and carbon fiber and a tetrafluoroethylene resin were used as a filler. Obtained by molding. The sectional area of the pillar portion 22 of the seal ring 11 in the ring width direction is substantially rectangular,
Outer diameter 59mm, ring width 1.95mm, ring thickness 2.1
5 mm, lubrication grooves 12 are provided at regular intervals over the entire circumference of both sides of the ring, the area ratio of these lubrication grooves 12 to the side surface of the ring is 40%, and the corners 18 and 19 of each lubrication groove 12 are Attach the edges 20 and 2
1 was crowned.

The seal ring 11 thus obtained
Using an automatic transmission oil for automobiles (manufactured by Showa Shell Sekiyu KK: Dexilon II), a hydraulic pressure of 15 kgf / cm ² , a shaft rotation speed of 7,500 rpm, and an oil temperature of 1
A 100-hour durability test was performed at 40 ° C., and the rotational torque, that is, the sliding friction resistance, and the amount of wear on the side surface of the ring were measured. Table 1 shows the results.

Example 2 Using a material having the same composition as in Example 1, a seal ring 11 having the shape shown in FIGS. 10 to 12 was obtained by injection molding.
The step area in the ring width direction of the pillar portion 22 of the seal ring 11 is substantially rectangular, and has an outer diameter of 59 mm, a ring width of 1.95 mm, a ring thickness of 2.15 mm, and is constant over the entire circumference of both sides of the ring. The lubrication groove 12 having the land portion 17 at the center is provided at intervals, and the area ratio of the lubrication groove 12 to the side surface of the ring is set to 30%.

Table 1 shows the results of a durability test performed under the same conditions as in Example 1.

[0022]

[Table 1]

[Comparative Example] A seal ring made of the same material as in Examples 1 and 2 and injection-molded without providing a lubricating groove on the side surface of the ring is referred to as Comparative Example 1.

A lubrication groove similar to that of the first embodiment is provided on the side surface of the ring, and the area ratio of the lubrication groove to the side surface of the ring is 15%.
The seal ring described above is referred to as Comparative Example 2.

Comparative Example 3 is a seal ring in which the lubrication groove on the side surface of the ring has the shape shown in FIG.

A seal ring having a lubrication groove on the side surface of the ring as shown in FIG.

Each of the above comparative examples was subjected to an endurance test under the same conditions as in each of the examples. Table 1 shows the results.

[Consideration] As shown in Table 1, Examples 1 and 2 have smaller rotational torque, that is, sliding friction resistance, and a smaller amount of wear on the ring side surface than Comparative Examples 1 to 3. Further, as compared with Comparative Example 4, the rotation torque is almost the same, but the amount of wear on the side surface of the ring is small.

[0029]

In the seal ring according to the first invention of the present application, a lubricating film is easily formed on the side surface of the seal ring by the liquid to be sealed, the liquid to be sealed does not accumulate in the lubricating groove, and the edge of the lubricating groove is formed. Concentration of stress on the portion can be prevented. As a result, there is an effect that sliding friction resistance and wear are reduced.

According to the second to fourth inventions, the above effects can be more remarkably exhibited.

[Brief description of the drawings]

FIG. 1 is a partially enlarged front view of the first invention.

FIG. 2 is a sectional view taken along line II-II of FIG.

FIG. 3 is a sectional view taken along the line III-III in FIG. 1;

FIG. 4 is a partially enlarged sectional view of the second device.

FIG. 5 is a sectional view taken along line VV in FIG. 4;

FIG. 6 is a sectional view taken along line VI-VI of FIG. 4;

FIG. 7 is a partially enlarged front view of the third device.

8 is a sectional view taken along line VIII-VIII in FIG. 7;

9 is a sectional view taken along line IX-IX of FIG.

FIG. 10 is a partially enlarged front view of the fourth device.

11 is a sectional view taken along line XI-XI in FIG.

12 is a sectional view taken along line XII-XII in FIG.

FIG. 13 is an enlarged sectional view of a use state of the seal ring.

14A is a partially enlarged sectional view of a conventional example, and FIG. 14B is a sectional view of the same.

FIG. 15A is a partially enlarged cross-sectional view of another conventional example,
(B) is a sectional view of the above.

FIG. 16 is an enlarged cross-sectional view of the conventional example in use in FIG.

[Description of Signs] 1 seal ring 2 shaft 3 peripheral groove 4 cylinder 5 sealing surface 6, 7 lubrication groove 11 seal ring 12 lubrication groove 13 sealing surface 14 end wall 15 groove outer peripheral wall 16 concave portion 17 land portion 18, 19 corner portion 20, 21 Edge part 22 Column part

Claims (4)

(57) [Scope of request for utility model registration] 1. A synthetic resin seal ring in which a number of lubrication grooves are provided on both sides of the ring at regular intervals over the entire length of both sides of the ring, and a sealing surface is formed on the side of the ring other than the lubrication grooves. Both end walls of a required depth reaching the middle of the ring side surface in the radial direction from the inner peripheral edge of the ring,
A seal ring formed by a circumferentially long recess surrounded by a groove outer peripheral wall formed between both end walls. 2. A seal ring according to claim 1, wherein a land portion having a height corresponding to a sealing surface is provided at a central portion of said recess. 3. A corner portion between both end walls of the lubrication groove and a ring inner peripheral surface and a corner portion between both end wall and the groove outer peripheral wall, and an edge portion between both end wall and the sealing surface; 3. The seal ring according to claim 1, wherein an edge portion between the groove outer peripheral wall and the seal surface is crowned. 4. An apparatus according to claim 1, wherein an area ratio of the lubrication groove to the side surface of the ring is set to 20 to 70%.
4. The seal ring according to 2 or 3.