JP2004028273A - Seal ring - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To receive no effect of the machining accuracy of a side wall surface of a ring groove for mounting a seal ring, reduce a press-contact force of the seal ring to the side wall surface, minimize the abrasion of the side surface of the seal ring, and stably retain the sealing performance. <P>SOLUTION: The sides 6 and 9 of the seal ring 5 are formed into, at least, two slope surfaces of the slope surface 52 with a small tilt angle in the outer circumferential side and the slope surface 51 with a large tilt angle in the internal circumferential side. The seal effect is secured by the slope surface 52 in the outer circumferential side and the lowering of the abrasion is secured by the slope surface 51 in the internal circumferential side. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a seal ring mounted on a shaft of a device such as an automatic transmission to maintain a hydraulic pressure required for operation of the device.
[0002]
[Prior art]
A seal ring used in a device such as an automatic transmission is mounted in a pair of spaced ring grooves provided on an outer peripheral surface of a shaft. The outer peripheral surface of the seal ring is in sliding contact with the inner peripheral surface of the housing, and receives the hydraulic oil supplied from the oil passage between the two ring grooves at the side surface and the inner peripheral surface of both seal rings. Seals the side surface of the ring groove and the inner peripheral surface of the housing. The seal ring slides relatively between the groove wall surface of the ring groove and the side surface of the seal ring, and appropriately maintains the hydraulic pressure of the hydraulic oil between the seal rings.
[0003]
Under these conditions, the seal ring is required to have a small friction loss and maintain good sealing properties for a long time. When the seal ring is installed, it is necessary that the frictional force between the seal ring side surface and the ring groove wall surface of the shaft is low. The contact area is large and the friction loss increases.
[0004]
In recent years, improvements in vehicle performance and environmental standards have led to improvements in fuel efficiency. Seal rings have also been reduced in friction between the ring and the ring groove wall surface, and have good sealing performance regardless of the processing accuracy of the ring groove. It is desired to improve the characteristics having the above.
[0005]
As a conventional representative solution to the problem, in Japanese Utility Model Laid-Open No. Hei 6-18764, as shown in FIGS. 4 and 5, a seal ring 5 ″ mounted in a ring groove 4 of a shaft 1 is provided on a side surface thereof. It has an annular groove 22 extending in the circumferential direction, and a plurality of grooves 21 provided in the radial direction and spaced apart in the circumferential direction, and the annular groove 22 is formed inside the seal ring through the radial groove 21. It is open to the peripheral surface side 23. The side surface of the seal ring that is in contact with the ring groove wall surface is guided to an annular groove 22 via a radial groove 21. Reference numeral 2 denotes a housing.
[0006]
Japanese Patent Application Laid-Open No. Hei 9-210211 discloses that, as shown in FIG. 6, a plurality of spaced oil grooves 24a opened to the inner peripheral surface side of the seal ring 5 ″, A seal ring extending to the side and having an inclined concave portion 24b as a wedge effect generating surface connected to the oil groove is taught.
In the above two seal rings, the force pressing against the seal ring groove wall surface is reduced by the hydraulic pressure introduced into the radial groove, the circumferential groove, and the concave portion on the seal ring side surface. Is reduced, which is effective in reducing friction and improving the lubrication function.
[0007]
However, as shown in FIG. 4, the groove often opens outward due to variations in the processing accuracy of the seal ring groove wall surface, that is, a tapered ring groove having a small groove bottom width and a large groove opening width. Often it is the wall 7 '. When the seal ring shown in FIGS. 4 and 6 is used for such a ring groove, the seal ring groove wall surface 7 ′ and the inner peripheral corner of the seal ring side face contact each other, and the seal ring outer peripheral side contact part X and the ring groove There is a difficulty that the side walls are separated from each other, and the side seal characteristics are deteriorated.
[0008]
As seal rings intended to solve the above-mentioned disadvantages, those described in JP-A-8-219292 and JP-A-9-217736 are known. In this case, as shown in FIG. 7, the side surface of the seal ring is a tapered surface having a width of 2 to 10 degrees such that the width on the inner peripheral side is smaller than the width on the outer peripheral side. Since the seal ring has a tapered seal ring side surface 57, the seal groove also has a tapered ring groove wall surface 7 'like an outward opening due to variation in processing accuracy of the ring groove side wall surface. In addition, the contact between the side surface of the ring and the side surface of the ring groove is not separated from each other, so that there is an effect that a deterioration phenomenon does not occur in the sealing characteristics.
Further, since the seal ring side surface is formed by a tapered surface inclined inward in the radial direction, a wedge-shaped gap 56 that opens radially inward is formed between the seal ring side surface and the seal ring groove side wall surface. The pressure applied between the seal ring 5 ″ and the seal ring groove side wall surface is reduced by the action of the hydraulic pressure introduced into the gap 56, and the friction is reduced.
[0009]
However, in this seal ring, while the effect of the low friction is obtained, on the other hand, the gap between the end portion 50 of the projecting portion piece of the abutment structure and the end face of the ring groove wall surface 7 ′ opposed to the end portion 50 is obtained. The gap forms a hydraulic path for releasing the internal oil pressure to the outside through the wedge-shaped gap, which presents a drawback that the original sealing effect of this kind of special fitting structure cannot be sufficiently exhibited.
Also, the groove often opens outward due to variations in the processing accuracy of the seal ring groove wall surface, but the contact between the ring side surface and the ring groove side wall surface is not separated, and the deterioration of the seal characteristics does not occur. However, a wedge-shaped gap that opens radially inward between the seal ring side surface and the seal ring groove side wall surface disappears, and the effect of the hydraulic pressure introduced into the gap cannot be sufficiently obtained, thereby reducing friction. There is a disadvantage that the effect is not exhibited.
[0010]
[Problems to be solved by the invention]
The present invention has been made in order to solve the problem that was difficult to cope with the conventional technology as described above, and the purpose thereof is not affected by the processing accuracy of the seal ring groove side wall surface, An object of the present invention is to provide a seal ring in which the frictional contact between the seal ring and the ring groove side wall surface is reduced and the sealing performance is maintained.
[0011]
[Means for Solving the Problems]
In order to solve the above-mentioned problem, the present invention basically uses a technical means for making the side surface of the seal ring a tapered surface having a two-step angle as shown in FIG.
[0012]
Specifically, the present invention is mounted on a pair of spaced ring grooves provided on the outer peripheral surface of a shaft, and receives hydraulic pressure supplied to the ring groove from between the pair of ring grooves on its side surface and inner peripheral surface. A seal ring for sealing between an opposite side surface and an outer peripheral surface, wherein the seal ring is formed on a tapered surface such that an inner peripheral width between both side surfaces of the seal ring is smaller than an outer peripheral width. The tapered surface on both sides of the ring is formed in two steps, and the tapered surface has a larger inclination angle β of the tapered surface on the inner peripheral surface side than the inclination angle α of the tapered surface on the outer peripheral surface side. A seal ring is provided.
[0013]
The seal ring according to the present invention has a function of the gentle inclination angle α on the outer peripheral surface side of the side surface. This is to ensure sealing performance. On the other hand, the function of the steep inclination angle β on the inner peripheral surface side of the side surface is that due to this inclination angle, a wedge-shaped gap formed between the ring groove wall side surface and the seal ring causes In this case, the pressing force due to the hydraulic pressure is canceled, the wear loss torque generated between the seal ring side surface and the groove wall is reduced, and the fuel efficiency of a product using the seal ring can be improved.
[0014]
Further, according to the present invention, the oil pressure is mounted on the pair of spaced ring grooves provided on the outer peripheral surface of the shaft, and receives the hydraulic pressure supplied to the ring groove from between the pair of ring grooves on its side surface and the inner peripheral surface, A seal ring that seals with the opposite side surface and the outer peripheral surface, wherein a seal ring having a tapered surface formed on at least one side surface of the seal ring, wherein the tapered surface of the seal ring side surface is formed in a plurality of stages, There is provided a seal ring characterized in that the tapered surface has a portion in which the inclination angle of the tapered surface on the inner peripheral surface side is larger than the inclination angle of the tapered surface on the outer peripheral surface side.
[0015]
According to this seal ring, the contact between the seal ring groove side wall surface and the seal ring side surface secures the seal, and the hydraulic action direction of the other side surface is set to the axial direction of the seal ring.
[0016]
BEST MODE FOR CARRYING OUT THE INVENTION
As shown in FIGS. 1 and 2A and 2B, the present invention is mounted on a pair of spaced ring grooves 4 provided on the outer peripheral surface of the shaft 1, and is provided with a ring from between the pair of ring grooves. The seal ring 5 receives the hydraulic oil 8 supplied to the groove 4 on its side surface 9 and the inner peripheral surface 23, and seals the ring groove side wall surface and the inner peripheral surface of the housing 2 with the opposite side surface 6 and the outer peripheral surface 55. In the seal ring 5, the side surface of the seal ring 5 is formed such that the width on the inner peripheral side is smaller than the width on the outer peripheral side, and both side surfaces of the seal ring 5 are inclined on the outer peripheral surface side. The seal ring is characterized in that the angle α is small and the inclination angle β on the inner peripheral surface side is larger than the inclination angle α.
[0017]
Further, as shown in FIG. 2 (b), the present invention determines the angle of the seal ring 5 with respect to a plane perpendicular to the outer peripheral surface 55, that is, a plane perpendicular to the axis of the seal ring 5. On the outer peripheral surface side of the side surface, the inclination angle α is set to be gentle, that is, the inclination angle is more than 0 and 8 degrees or less, preferably 0.5 or more and 3 degrees or less. As a result, the area for forming a hydraulic path for releasing the internal hydraulic pressure from the abutting portion to the outside through the wedge-shaped gap 54 is reduced, so that the deterioration of the sealing characteristics does not occur.
[0018]
In addition, the steep inclination angle β on the inner peripheral surface side of the seal ring side surfaces 6 and 9 with respect to the aforementioned surface, that is, the taper angle is formed to be more than 8 degrees and 45 degrees or less, preferably 9 degrees or more and 11 degrees or less. Is done. As a result, a wedge-shaped gap 53 is formed between the seal ring side faces 6 and 9 and the seal ring groove side wall face 7 and is opened inward in the radial direction. The pressing force between the seal ring groove side wall surface and the seal ring groove is reduced, and the friction is reduced.
[0019]
Further, even in the case where the ring groove 4 is inclined to open outward due to the variation in processing accuracy of the seal ring groove wall surface 7, the gap 53 having the inclination angle on the inner peripheral side of the seal ring side surface is maintained because the seal ring 5 and the ring Oil can intervene between the groove 4 and the side wall surface 7 to constitute a seal ring in which a sudden increase in friction and prevention of deterioration of sealing characteristics are compatible.
[0020]
Here, with respect to the inclination angle of the side surface of the seal ring, the inclination angle α of the outer peripheral surface side 52 is set to more than 0 ° and 8 ° or less, but if the inclination angle is larger than 8 °, sufficient effect is obtained for the leak property. It will not be possible.
The inclination angle β of the inner peripheral surface 51 is more than 8 degrees and not more than 45 degrees, but when it is 8 degrees or less, the inclination angle β is radially inward between the seal ring side surface and the seal ring groove side wall surface. A wedge-shaped gap that opens is less likely to be formed, which leads to an increase in friction. Also, when it is larger than 45 degrees, no wedge-shaped gap is formed, and no cancel pressure is generated, which leads to an increase in friction.
[0021]
Further, FIG. 3 shows a special joint of the present seal ring. The boundary line 58 of the two-side taper having the different angles is located at the radial thickness L of the protrusion of the joint structure. The ring is formed annularly in the range of 0.4 to 1.2 mm from the outer circumference of the thickness a1 of the seal ring in the radial direction, and the radial length of the inner peripheral surface side taper is at least 1/4 of the a1 dimension. It is characterized by the following.
Here, if the position of the boundary line is 0.4 mm or less from the outer periphery, there is a high probability that the boundary line 58 of the seal ring is displaced from the seal ring groove side wall surface 7 in consideration of the runout of the rotation axis of the housing or the shaft. There is deterioration of characteristics. When the distance in the radial direction is larger than 1.2 mm or the taper on the inner peripheral surface side and the distance in the radial direction is 1/4 or less of the a1 dimension, the distance between the seal ring side surface and the seal ring groove side wall surface toward the radial center. The formation of a wedge-shaped gap that opens is small, so that no cancel pressure is generated and the effect of reducing friction is lost.
The "cancellation pressure" means "reduce the pressing pressure by the hydraulic pressure on the opposite side surface".
[0022]
In the above-described example, two inclined surfaces 51, 52 are formed on both the seal ring side surfaces 6, 9, but these inclined surfaces 51, 52 are formed only on the side of the seal ring that is in contact with the side wall surface 7 of the seal ring groove 4. You may.
The number of the inclined surfaces 51 and 52 is preferably two, but may be three or more. These inclined surfaces gradually increase the inclination angle toward the inner peripheral side.
[0023]
【Example】
An example of the embodiment of the present invention will be described below. The main features of this seal ring are low leakage and low friction irrespective of the manufacturing accuracy of the ring groove wall side surface 7. FIG. 2 is a cross-sectional view when the seal ring 5 is mounted in the groove 4 of the shaft. The shaft 1 and the housing 2 are made of steel, and the groove 1 of the shaft 1 is inclined outwardly to 0 to 2 ° due to variation in processing accuracy of the groove wall surface 7.
[0024]
The seal ring 5 is made of a synthetic resin material in which carbon fibers are added to polyetheretherketone (PEEK), and has an outer diameter φ50, an axial width of 2.35 mm, a radial thickness of 2.0 mm, a two-step tapered side surface 51, 52, the outer peripheral side α is 1.5 ° ± 1 °, and the inner peripheral side β is 10 ° ± 1 °. The radial thickness L of the protrusion 50 of the abutment structure is set to 1.0 mm from the outer peripheral surface, and this is set as a change point of the taper angle.
[0025]
Further, as Comparative Examples 1 and 2, 1: a conventional grooved ring having a flat side surface and 2: a single-stage tapered ring having a uniform side surface having a uniform inclination angle were tested. It was the same, and the side taper surface was 3 ° ± 1 °.
FIG. 9 shows the results of oil leakage and friction tests performed on the sealing device equipped with each of the above seal rings under the conditions of a housing rotation speed of 3000 rpm, a hydraulic pressure of 1.27 MPa, and an oil temperature of 120 ° C. As shown in FIG. 9, when the seal ring according to the embodiment of the present invention is used, the friction is reduced as compared with the seal ring of Comparative Example 1, the amount of oil leakage is reduced as compared with Comparative Example 2, and the ring groove side wall surface is reduced. It can be seen that the effect of improving low oil leak can be obtained irrespective of the processing accuracy of the steel.
Thus, according to the present invention, as shown in FIG. 9, the effect of achieving both low friction and low leakage can be obtained regardless of the processing accuracy of the ring groove wall surface of the shaft.
[0026]
The seal ring of the present invention has an advantageous effect of achieving both low friction and low leakage irrespective of the processing accuracy of the ring groove wall surface of the shaft due to its two-stage tapered side surface. It can improve fuel efficiency.
[Brief description of the drawings]
FIG. 1 is a sectional view showing an example of a method for using a seal ring of the present invention.
2A is a cross-sectional view illustrating a seal ring mounting portion of the seal device of the present invention, and FIG. 2B is a cross-sectional view illustrating main dimensions of the seal ring.
FIG. 3 is a perspective view showing a mating structure of the seal ring of the present invention.
FIG. 4 is a sectional view showing a seal ring mounting portion of a conventional side groove sealing device.
FIG. 5 is a partial plan view of the conventional seal ring shown in FIG.
FIG. 6 is a sectional view showing a seal ring mounting portion of a conventional side oil groove sealing device.
FIG. 7 is a cross-sectional view showing a conventional improved sealing device and a seal ring mounting portion having a tapered side surface.
FIG. 8 is a graph showing comparison test results between a sealing device according to the present invention and a conventional sealing device.
FIG. 9 is a graph showing comparison test results between a sealing device according to the present invention and a conventional sealing device.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Shaft 2 Housing 3 Hydraulic passage 4 Seal ring groove 5, 5 ', 5 ", 5'" Seal ring 6 Atmospheric side seal ring side surface 7 Ring groove side surface 8 Hydraulic oil 9 Hydraulic side seal ring side surface 21 Groove 22 Radial groove 23 Seal ring inner circumferential surface 24 Oil groove 50 Projecting piece 51 Seal ring side inner circumferential slope 52 Seal ring side outer circumferential slope 53 Between seal ring side inner circumferential slope and ring groove wall surface Wedge-shaped gap 54 Wedge-shaped gap 55 between the outer peripheral side slope of the seal ring side surface and the ring groove wall surface Seal ring outer peripheral surface 56 Wedge-shaped gap 57 between the seal ring side surface and the ring groove wall surface 57 Seal ring side surface inclined surface 58 Seal Ring side inclination angle boundary line X Seal ring outer peripheral side contact part L Radial thickness α of the protrusion of the joint structure α Seal ring side outer peripheral side inclination angle β Luling side inner circumferential side tilt angle

Claims (8)

The side surface and the inner peripheral surface are attached to the pair of spaced ring grooves provided on the outer peripheral surface of the shaft, and receive the hydraulic pressure supplied to the ring groove from between the pair of ring grooves to the opposite side surface and the outer peripheral surface. A seal ring formed on a taper surface such that the width on the inner peripheral side between both side surfaces of the seal ring is smaller than the width on the outer peripheral side, wherein the tapered surfaces on both side surfaces of the seal ring are removed. A seal ring wherein the taper surface is formed in two stages, and the inclination angle of the taper surface on the inner peripheral surface side is larger than the inclination angle of the taper surface on the outer peripheral surface side. The inclination angle of the taper surface on the outer peripheral side of the seal ring is an angle with respect to a plane perpendicular to the axial direction of the seal ring, and is formed to be more than 0 degree and 8 degrees or less, and the inclination angle of the taper surface on the inner peripheral side is 8 degrees. The seal ring according to claim 1, wherein the seal ring is formed to have a shape of more than 45 degrees and less than 45 degrees, and the side surface has a two-step taper. A boundary line 58 of the tapered surface is formed in an annular shape in a range of 0.4 mm or more and 1.2 mm or less from the outer periphery of the seal ring, and the dimension between the boundary line 58 and the inner peripheral surface is in the radial direction of the seal ring. The seal ring according to claim 1 or 2, wherein the thickness is at least 1/4 of the thickness a1. The seal ring according to claim 2, wherein the inclination angle of the tapered surface on the outer peripheral side of the seal ring is 0.5 degrees or more and 3 degrees or less, and the inclination angle of the tapered surface on the inner peripheral side is 9 degrees or more and 11 degrees or less. The side surface and the inner peripheral surface are attached to the pair of spaced ring grooves provided on the outer peripheral surface of the shaft, and receive the hydraulic pressure supplied to the ring groove from between the pair of ring grooves to the opposite side surface and the outer peripheral surface. A seal ring having a tapered surface formed on at least one side surface of the seal ring, wherein the tapered surface of the seal ring side surface is formed in a plurality of steps, and the tapered surface is formed on the outer peripheral surface side. A seal ring having a portion in which the inclination angle of the tapered surface on the inner peripheral surface side is increased with respect to the inclination angle of the tapered surface. The seal ring according to claim 5, wherein the tapered surfaces are formed on both side surfaces of the seal ring. The seal ring according to claim 5, wherein the tapered surface has a portion having an inclination angle of 0.5 ° or more and 3 ° or less and a portion having a tilt angle of 9 ° or more and 11 ° or less. A hydraulic seal device incorporating the seal ring according to claim 1.

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