JP3533847B2 - 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 used for a seal portion of a hydraulic device used for a construction machine or the like, and particularly to a structure of a cut portion of the seal ring.

[0002]

2. Description of the Related Art Conventionally, as a seal ring used in a hydraulic device used in an automobile or the like, a step-cut seal ring as shown in FIGS. . FIG. 3B is a view seen from the arrow B direction in FIG.

The main body of the seal ring 100 is cut at one position in the circumferential direction, and two sets of arc-shaped convex portions and step portions which are fitted to each other are provided between the cut ends facing each other.

The first arcuate convex portion 2 is flush with the end surface 21 formed by the cut surface orthogonal to the circumferential direction, the inner side surface 22 formed by the cut surface orthogonal to the axial direction, and the surface of the main body of the seal ring 100. Is surrounded by an inner peripheral surface 23, an outer peripheral surface 24, and an outer surface 25.

On the other hand, the first step portion 3 is composed of an end face 31 formed by a cut surface orthogonal to the circumferential direction and a side surface 32 formed by a cut surface orthogonal to the axial direction. Here, the side surface 32 of the first step portion 3 is also the inner side surface of the second arc-shaped convex portion 4.

The second arcuate convex portion 4 and the second step portion 5 have the same structures as the first arcuate convex portion 2 and the second step portion 3, respectively.

As shown in FIG. 4, the seal ring 100 seals the annular gap 8 between the shaft hole inner peripheral surface 61 of the housing 6 and the shaft 7, and the main body of the seal ring 100 is the shaft 7.
It is mounted movably in the axial direction in an annular mounting groove 71 which is provided on the outer periphery in contact with the annular gap 8.

In the sealed state, the outer peripheral surface 201 of the seal ring 100 located on the opening side of the mounting groove 71 is attached to the mounting groove 71.
The pressure of the fluid 9 acting on the inner peripheral surface 202 located on the inner side of the shaft crosses the annular gap 8 and presses the shaft hole inner peripheral surface 61 of the housing 6 in a sealed state to form a radial seal portion. Further, one axial side surface 203 of the main body of the seal ring 100 is pressed against one inner wall of the mounting groove 71 in a sealed state by a fluid pressure acting on the other axial side surface 204 to form an axial seal portion.

At this time, at the cut end, the end surface 21 of the first arc-shaped convex portion 2 and the end surface 31 of the first stepped portion 3 are in pressure contact with each other, and the inner side surface 23 of the first arc-shaped convex portion 2 and the first stepped portion. Side 32 of part 3
And are in pressure contact. The same is true between the second arcuate convex portion 4 and the second step portion 5.

[0010]

However, in such a step-cut seal ring, when the cut ends are assembled and mounted, the difference in curvature between the shaft hole inner peripheral surface 61 of the housing 6 and the seal ring 100 main body is caused. As shown in FIG. 5, the first and second arcuate convex portions 2 and 4 project in the outer diameter direction,
There is a problem that a gap is formed in the radial seal portion and the sealing performance is deteriorated.

When the first and second arcuate convex portions 2 and 4 of the seal ring 100 are pushed toward the inner diameter side by the pressing force from the inner peripheral surface 61 of the shaft hole of the housing 6 to eliminate the gap of the radial seal portion. However, as shown in FIG. 6, the contact surface pressure of the first and second arcuate convex portions 2 and 4 with the inner peripheral surface 61 of the shaft hole of the housing 6 has a peak at the tip of the arcuate convex portion, and therefore wear occurs. Was concentrated in this area, shortening the life of the seal ring.

On the other hand, as shown in FIG. 7, the outer peripheral portion 24 of the first and second arcuate convex portions 2 and 4 of the seal ring 100.
It was general to scrape 1,441 as shown by the broken line.

However, when the outer peripheral portion is shaved, a gap may be generated between the outer circumference of the seal ring and the housing depending on the size of the shaved portion, which may increase the amount of leak.

The present invention has been made in order to solve the above-mentioned problems of the prior art. The object of the present invention is to seal a seal ring cut at one position in the circumferential direction and to extend the life of the seal ring. It is to improve the sex.

[0015]

In order to achieve the above-mentioned object, the present invention provides a housing that is concentrically and relatively movable, and a shaft that is inserted into a shaft hole of the housing.
When mounted in a groove provided on the outer periphery of the shaft of the body
Is pressed against the inner peripheral surface of the shaft hole of the housing,
In the seal ring that seals the annular gap with the ring , cut the ring body at one location in the circumferential direction, and provide an arcuate convex portion that projects in the circumferential direction at one cutting end and cut the other A step portion that fits the arcuate convex portion is provided at the end portion, and the step portion has a normal line in the axial direction of the ring body.
A first side surface, a second side surface having a radial normal, and a circumference
Consisting of an end face having a normal to the direction of the arc-shaped convex portion
Notched inner diameter side, characterized in that reduced the flexural rigidity of <br/> the arc-shaped convex portions by molding a thin-walled in the radial direction.

Further , in order to achieve the above-mentioned object,
Ming is a housing that is concentrically and relatively movable.
And a shaft body inserted into the shaft hole of the housing,
A seal ring that is mounted in a groove provided on the outer circumference of the shaft.
And a fluid acting on the inner peripheral surface of the seal ring.
Pressure is applied to the inner peripheral surface of the shaft hole of the housing,
A seal ring that seals the annular gap with the ging
The ring body at one point in the circumferential direction,
Providing a first arcuate protrusion protruding in the circumferential direction at the cut end
At the same time, the other cut end is fitted with the first arcuate convex portion.
The first stepped part that
A second arc-shaped convex portion that protrudes in the
A second step portion that fits with the second arcuate convex portion is provided at the cut end.
Provided in the first arc-shaped convex portion and the second arc-shaped convex portion
Notch on the perimeter side to form thin wall in the radial direction
And the bending rigidity of the arcuate convex portion is reduced by
In the sealed state, the ring body and the first arcuate convex
Pressure acting on the inner peripheral surface side of the projection and the second arcuate convex portion
The ring body, the first arc-shaped convex portion and the front
The outer peripheral surface of the second arcuate convex portion is the inner peripheral surface of the shaft hole of the housing.
It is characterized in that it is pressed against the surface in a sealed state.

With this arrangement , when the seal ring is attached
Between the fitting part of the arcuate convex part and the step part and the other member.
The radial gap that occurs in the
This is solved by the deformation of the arcuate convex part on the pressure receiving side.
There is no deterioration of the sealability due to the gap.

Further, the bending rigidity of the arcuate convex portion is lowered.
By doing so, the arc-shaped convex portion projecting to the outer diameter side is formed on the other member.
This occurs when the radial clearance is eliminated by pressing force from
The peak of contact surface pressure that had been
Absolute value is small, so seal ring wear is uniform
It gets smaller as you do. Therefore, the longevity of the seal ring
Can be destined.

Further , the pressure contact portion of the arcuate convex portion with the other member
There is a gap between the other member and
On the other hand, the sealing property does not deteriorate.

In order to reduce the bending rigidity, arc-shaped convex
The pressure receiving side may be cut out, or a material with low bending rigidity may be used.
You may make it shape an arcuate convex part. Also, arc shape
A slit in the axial direction may be formed in the convex portion.

Here, the seal ring is on the outer diameter side.
Not only when pressing the other member to seal it,
Alternatively, the case may be a case where the mating member is pressed against and sealed.

Here, the cutout is not limited to the case where the cutout is provided after the molding, but the cutout may be provided in advance during the molding.

With this configuration, the bending rigidity of the arcuate convex portion can be easily reduced by molding or cutting. Therefore, there is no radial gap between the fitting portion between the arcuate convex portion and the step portion and the inner peripheral surface of the shaft hole of the housing, and the sealing performance is improved.

Further, the inner diameter side of the arcuate convex portion is cut out to form a thin wall in the radial direction to reduce the bending rigidity, so that the arcuate convex portion protruding to the outer diameter side is formed on the inner peripheral surface of the shaft hole of the housing. Since the peak of the contact surface pressure that occurs when the radial gap is eliminated by the pressing force from is eliminated and the absolute value of the contact surface pressure is also reduced, the wear of the seal ring is uniformed and reduced. Therefore, the life of the seal ring can be extended.

Further, unlike the case where the pressure contact portion of the arcuate convex portion with the inner peripheral surface of the shaft hole of the housing is shaved, a gap is not generated between the arcuate convex portion and the counterpart member and the sealing performance is not deteriorated.

[0026]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention will now be described based on the illustrated embodiments.

(First Embodiment) FIG. 1 shows a first embodiment of the present invention.
1 shows a seal ring 1 according to the embodiment.

Portions having the same construction as the seal ring 100 according to the prior art are designated by the same reference numerals and the description thereof will be omitted.

In the present embodiment, a cut is formed on the inner peripheral side of the first and second arcuate convex portions 25, 40 of the step-cut seal ring 1 so that the thickness in the radial direction decreases toward the tip in the protruding direction. The notches 25 and 45 are provided.

If the notches 25 and 45 are provided on the inner peripheral side in this way, the first and second arcuate convex portions 20 and 40 are formed.
It is possible to easily reduce the bending rigidity of the. Therefore, when the seal ring is mounted, it is provided between the fitting portion between the first and second arcuate convex portions 20 and 40 and the first and second step portions 3 and 5 and the shaft hole inner peripheral surface 61 of the housing 6. The generated radial clearance is eliminated by bending deformation of the first and second arcuate convex portions 20 and 40 to the inner diameter side due to the pressing force from the shaft hole inner peripheral surface 61 of the housing 6, so that the sealing performance is improved. .

Further, unlike the case where the outer peripheral side of the arcuate convex portion is shaved, a gap is not generated between the convex portion and the housing, and the sealing performance is not deteriorated.

Further, there is no peak (see FIG. 6) of the contact surface pressure between the outer peripheral surfaces of the first arcuate convex portions 20 and 40 and the inner peripheral surface 61 of the shaft hole of the housing 6 contacting each other, and the contact surface pressure is almost uniform. Therefore, there is no place where the wear of the seal ring 1 is concentrated, and the wear is uniformized and reduced. Therefore, the life of the seal ring 1 can be extended.

The notches 25 and 45 may be formed beforehand by molding when the seal ring 1 main body is molded, or may be formed by cutting the inner diameter side after molding.

The relationship between the curvature of the shaft hole inner peripheral surface 61 of the housing 6 and the curvature of the seal ring 1 determines how much the bending rigidity of the first and second arcuate convex portions 20 and 40 needs to be weakened. Therefore, the cutouts 25, 45 in the broken line portion of FIG.
The shapes of the first and second arcuate convex portions 20 and 40 are set based on the above-mentioned relationship of curvatures.

In the present embodiment, the notch has a triangular prism shape as shown in FIG. 1, and the arcuate convex portion has a tapered shape that becomes thinner in the radial direction toward the tip portion. The shape of the arcuate convex portion is not limited to these.

(Second Embodiment) FIG. 2 shows the periphery of a cut end portion of a seal ring according to a second embodiment.

The seal ring 10 according to the present embodiment is specially step cut, and has a first arcuate convex portion 12 at one cutting end and a first step portion at the other cutting end. 13 is provided so that the first arcuate convex portion 12 and the first step portion 13 are fitted to each other.

The first step portion 13 has a first side surface 131 having an axial normal line and a second side surface 13 having a radial normal line.
2, an end surface 133 having a normal line in the circumferential direction.

The first arcuate convex portion 12 has an inner surface 121 having a normal line in the axial direction, an inner peripheral surface 122 having a tapered surface inclined with respect to the circumferential direction, and an end face 1 having a normal line in the circumferential direction.
23, and an outer peripheral surface 124 and an outer surface 125 that are flush with the surface of the seal ring body.

At the cut end of the seal ring 10, a second arcuate convex portion 14 is provided axially adjacent to the first step portion 13, and the first side surface of the first step portion 13 is the second side. The same surface as the inner surface of the arcuate convex portion 14 is formed.

On the side of the first arcuate convex portion 12, a second step portion 15 that is fitted in the second arcuate convex portion 14 is formed adjacent to the first arcuate convex portion 12 in the axial direction. And the second step portion 1
A second end face 16 is formed adjacent to the inner diameter direction of No. 5.

The third stepped portion 13 and the second arcuate convex portion 14 are adjacent to each other in the inner diameter direction and have a normal line in the circumferential direction.
The end face 17 is formed.

Such a special step cut is formed by molding, total cutting or partial molding and then cutting.

The seal ring 10 according to the present embodiment is provided on the outer periphery of the shaft 7 which is coaxially and relatively movably inserted into the shaft hole 61 of the housing 6 similarly to the seal ring 1 according to the first embodiment. The fluid is sealed by the radial and axial sealing portions that are mounted in the groove 71 formed by the fluid pressure. In the state where the fluid pressure is applied, the end surface 123, the inner side surface 121, and the inner peripheral surface 12 of the first arc-shaped convex portion 12
2 and the end surface 133 of the first step portion 13, the first side surface 131, and the second side surface 132 are in pressure contact with each other. At this time, another set of the second arcuate convex portion 14 and the second step portion 15 are similarly pressed, and the second end surface 16 and the third end surface 17 are also pressed.

In the present embodiment, the inner diameter side of the first arcuate convex portion 12 is cut out as shown by the broken line, and is formed in a taper shape which becomes thinner in the radial direction toward the tip.

By forming the first arcuate convex portion 12 in this way, the bending rigidity of the first arcuate convex portion 12 is reduced, and the end surface 123 of the first arcuate convex portion 12 and the end surface of the first step portion 13 are reduced. 133
In a state in which the and are in pressure contact with each other, a radial gap generated between the fitting portion of the first arcuate convex portion 12 and the first step portion 14 and the inner peripheral surface 61 of the shaft hole of the housing 6 is a shaft of the housing 6. Inner surface of hole 6
Since it is eliminated by bending deformation of the first arc-shaped convex portion 12 toward the inner diameter side due to the pressing force from 1, the sealing property is improved.

Further, the seal ring 1 according to the first embodiment.
Similarly, the peak of the contact surface pressure on the inner peripheral surface 61 of the shaft hole of the housing 6 with which the outer peripheral surface of the first arcuate convex portion 12 comes into contact disappears and becomes substantially uniform, so that the wear of the seal ring 10 is concentrated. Disappears and wear becomes uniform and becomes smaller. Therefore, the life of the seal ring 10 can be extended.

Similarly to the seal ring 1 according to the first embodiment, the notch 126 in this embodiment is also formed by molding the seal ring main body or by cutting after forming the seal ring main body.

The relationship between the curvature of the shaft hole inner peripheral surface 61 of the housing 6 and the curvature of the seal ring 10 determines how much the bending rigidity of the first arcuate convex portion 12 needs to be weakened. The shapes of the notch 126 and the first arcuate convex portion 12 in the broken line portion are set based on the above-described relationship of curvatures.

In this embodiment, the notch 126 is formed as shown in FIG.
As described above, the shape of the first arcuate convex portion 12 is a taper shape in which the thickness of the first arcuate convex portion 12 is reduced in the radial direction toward the tip end. However, the shape of the notch 126 and the shape of the first arcuate convex portion 12 are It is not limited to these.

Although the first arcuate convex portion 12 has been described,
Since the second arcuate convex portion 14 is also formed with a notch 146 on the inner diameter side and formed in a taper shape that becomes thin in the radial direction toward the tip, fitting of the second arcuate convex portion 14 and the second step portion 15 is performed. Similarly, the sealing property is improved in the part. The above description regarding the first arcuate convex portion 12 also applies to the second arcuate convex portion 14.

[0052]

As described above, according to the first aspect of the invention, the bending rigidity of the arcuate convex portion is lowered, and the arcuate convex portion is bent and deformed toward the pressure receiving side against the pressing force from the other member. Therefore, when the seal ring is attached, the radial gap between the fitting part between the arcuate convex part and the step part and the other member is the arcuate convex part due to the pressing force from the other member. Is deformed to the pressure receiving side, and the sealing property is improved.

Further, unlike the case where the pressure-contacting portion of the arcuate convex portion with the counterpart member is shaved, a gap is not created between the other member and the sealing property, and the sealing performance is not deteriorated.

According to the second aspect of the present invention, by molding or cutting, the arcuate convex portion is notched on the inner diameter side of the pressure contact portion with the inner peripheral surface of the shaft hole of the housing to form a thin wall in the radial direction. It is possible to easily reduce the bending rigidity and improve the sealing property.

[Brief description of drawings]

FIG. 1 is a perspective view schematically showing a cut end portion of a seal ring according to a first embodiment of the present invention.

FIG. 2A is a perspective view schematically showing a cut end portion of a seal ring according to a second embodiment of the present invention. FIG. 2B is a perspective view seen from the arrow A direction in FIG.

FIG. 3A is a perspective view schematically showing a cut end portion of a conventional step-cut-shaped seal ring. Figure 3
FIG. 3B is a perspective view seen from the arrow B direction in FIG.

FIG. 4 is a sectional view showing a schematic structure of a seal portion of a conventional seal ring.

FIG. 5 is a diagram showing a fitted state of a cut end portion when a conventional seal ring is attached.

FIG. 6 is a graph showing a contact surface pressure near the tip of an arcuate convex portion of a conventional seal ring.

FIG. 7 is a diagram showing an outline of a cut end portion when a countermeasure is applied to a conventional step-cut type seal ring.

[Explanation of symbols]

1,10 seal ring 12, 20 1st arcuate convex part 3,13 First step 14,40 Second arc-shaped convex portion 5,15 Second step 25,45,126,146 Notch 6 housing 61 Inner peripheral surface of shaft hole 7 axes 71 groove 8 annular gap

Claims (2)

(57) [Claims] 1. A concentric relative movement assembly is possible.
Housing and shaft inserted into shaft hole of the housing
While being mounted in a groove provided on the outer periphery of the shaft body,
In a seal ring that is in pressure contact with the inner peripheral surface of the shaft hole of the housing and seals the annular gap with the housing , the ring body is cut at one position in the circumferential direction, and one of the cut ends is circumferentially cut. In addition to providing a protruding arcuate convex part,
A step portion that fits the arcuate convex portion is provided on the other cut end, and the step portion has a normal line in the axial direction of the ring body.
One side surface, a second side surface having a radial normal, and a circumferential direction
The end surface having the normal line is cut out on the inner diameter side of the arc-shaped convex portion to form a thin wall in the radial direction.
Reduce the flexural rigidity of the arc-shaped convex portions by the form
A seal ring characterized by that. 2. Assembled concentrically so as to be movable relative to each other.
Housing and shaft inserted into shaft hole of the housing
Body and a seal ring mounted in a groove provided on the outer periphery of the shaft body
And a fluid pressure acting on the inner peripheral surface of the seal ring.
It comes into pressure contact with the inner peripheral surface of the shaft hole of the housing, and
In a seal ring for sealing a ring-shaped gap, the ring body is cut at one location in the circumferential direction, and one cut end is provided with a first arc-shaped convex portion projecting in the circumferential direction.
The first arcuate convex portion is provided on the other cut end while being provided.
A first stepped portion that fits with the second arcuate shape that projects in the circumferential direction at the other cut end is further provided.
A convex portion is provided, and the second arc is formed on one cutting end.
A second step portion that fits with the convex protrusion is provided, and the inner peripheral sides of the first circular convex portion and the second circular convex portion are provided.
By notching each and forming thinly in the radial direction
The bending rigidity of the arc-shaped convex portion is reduced, and in the sealed state, the ring body, the first arc-shaped convex portion, and
And the fluid pressure acting on the inner peripheral surface side of the second arcuate convex portion.
The ring body, the first arcuate convex portion, and the first
2 The outer peripheral surface of the arc-shaped convex portion is the inner peripheral surface of the shaft hole of the housing.
A seal ring, which is pressed into a sealed state.