JP2011153664A - Seal ring - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a seal ring capable of more effectively reducing torque. <P>SOLUTION: This seal ring 1 is mounted in an annular groove 30 provided on an outer peripheral surface of a shaft 3, and is pressed on each of a side surface 31 of the annular groove 30 and an inner peripheral surface 21 of a shaft hole 20 of a housing 2 by an action of pressure P in a region on an axial direction one side of an annular gap 4. The seal ring 1 includes an inclined surface 14 inclined to abut on the side surface 31 of the annular groove 30 by a wider contact surface than a contact surface with the inner peripheral surface 21 so that sliding with the inner peripheral surface 21 may be allowed and sliding with the annular groove 30 may be suppressed during relative rotation of the shaft 3 and the housing 2 and to generate component force (P<SB>3</SB>) for canceling a part (P<SB>2</SB>) of force (P<SB>1</SB>+P<SB>2</SB>) acting in a direction for pressing the seal ring 1 on the inner peripheral surface 21 and component force acting in a direction for pressing the seal ring 1 on the side surface 31 of the annular groove 30 by applying the pressure P. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a seal ring that seals an annular gap between two members that are rotatable relative to each other.

  When an annular gap between two members that can rotate relative to each other is sealed by a seal ring, sliding between the seal ring and the two members during relative rotation of the two members becomes a problem. In order to reduce the torque generated by such sliding, seal rings having various configurations have been proposed so far. FIG. 8 to FIG. 11 are schematic cross-sectional views showing a state in which the seal ring according to the conventional example is mounted.

  As a cross-sectional shape of a conventional seal ring, for example, a substantially T-shaped one as shown in FIG. 8 and a substantially trapezoidal one as shown in FIG. 9 are known. Further, as disclosed in Patent Document 1, a polygonal shape such as a hexagon shown in FIG. 10 or a pentagon shown in FIG. 11 is also known.

As shown in FIG. 8, the T-shaped seal ring 100a has a configuration in which a contact area with the side surface 31 of the annular groove 30 is reduced by providing a step on the side surface 101a as compared with a seal ring having a rectangular cross section. Yes. In addition, a force (P ₁₀ ) acting in a direction in which the seal ring 100 a is separated from the side surface 31 of the annular groove 30 is received at a portion of the side surface 101 a of the seal ring 100 a on the inner peripheral side away from the side surface 31 of the annular groove 30. Thus, a part (P ₁₂ ) of the force (P ₁₁ + P ₁₂ ) acting in the direction of pressing the seal ring 100 a against the side surface 31 of the annular groove 30 is canceled. That is, the pressure receiving area of the side surface 101a of the seal ring 100a (the area that can generate a force for pressing the seal ring 100a against the side surface 31 of the annular groove 30 without being canceled out of the surfaces receiving pressure) is reduced. It is configured.

Further, as shown in FIG. 9, the trapezoidal seal ring 100 b is configured such that the inclined side surface 101 b is in contact with the corner of the opening edge of the annular groove 30, thereby reducing the contact area with the side surface 31 of the annular groove 30. In addition, the seal ring 100b is pressed against the side surface 31 of the annular groove 30 by receiving a force (P ₂₀ ) that acts on the inner peripheral side of the contact portion in a direction separating the seal ring 100b from the side surface 31 of the annular groove 30. A part (P ₂₂ ) of the force (P ₂₁ + P ₂₂ ) acting in the direction is canceled.

  Also, as shown in FIGS. 10 and 11, the polygonal seal rings 100c and 100d are configured to contact the side surface 31 of the annular groove 30 at the polygonal corners 102c and 102d, thereby forming a lubricating film. Further, the contact area with the side surface 31 of the annular groove 30 is reduced to reduce the pressure receiving area, and a surface that receives a force acting in a direction in which the seal rings 100c and 100d are separated from the inner peripheral surface 21 of the shaft hole 20. 103c and 103d are formed, and the pressure receiving areas of the outer peripheral surfaces 104c and 104d of the seal rings 100c and 100d (the force that presses the seal rings 100c and 100d against the inner peripheral surface 21 of the shaft hole 20 without canceling the pressure receiving surfaces) Is also reduced.

Each of the seal rings basically comes into static contact with the inner peripheral surface 21 of the shaft hole 20 and slides into contact with the side surface 31 of the annular groove 30 when the shaft 3 and the housing 2 rotate relative to each other. It is designed on the assumption. Therefore, in order to reduce the torque, it is important to reduce the contact area with the side surface 31 of the annular groove 30 and the pressure receiving area of the seal ring side surface 101. However, in the above-described seal rings that slide the side surface 101, there is a limit to their reduction.

In the case of a side-sliding seal ring, the side surface 31 of the annular groove 30 is taken into consideration in order to prevent the annular gap 4 from protruding into the ring ring and considering the case where the width of the annular gap changes due to the eccentricity of the shaft 3 or the housing 2. It is necessary to secure the contact area to the inner side to some extent or set the contact position to the inner side to some extent. Therefore, the range in which the surface for receiving the force (P ₁₀ , P ₂₀ , P ₃₀ , P ₄₀ ) for canceling the force pressing the seal ring against the side surface 31 of the annular groove 30 can be formed is limited.

  Further, for reducing the pressure receiving areas of the outer peripheral surfaces 104c and 104d, as in the case of the seal rings 101c and 101d in FIGS. The range in which the surfaces 103c and 103d for receiving the force for canceling the force pressing the 101c and 101d against the inner peripheral surface 21 of the shaft hole 20 is limited, and the pressure receiving area is only about half of the seal ring width W at the maximum. Can not be reduced.

  Further, by reducing the pressure receiving area of the outer peripheral surfaces 104c and 104d, the torque when the seal rings 101c and 101d slide with the inner peripheral surface 21 of the shaft hole 20 can be reduced. Or, in most cases, the rotation occurs with either of the housings 2. That is, a behavior in which the seal rings 101c and 101d continue to slide with respect to both at the same time is not normally considered. Therefore, even if both the pressure receiving area on the side surface and the pressure receiving area on the outer peripheral surface are reduced, this does not mean that a synergistic torque reduction effect can be obtained.

  Patent Document 2 discloses a seal ring that reduces both the contact surface with the side surface of the annular groove and the contact surface with the inner peripheral surface of the shaft hole by making both the outer peripheral surface and the side surface inclined. Has been. FIG. 12 shows a schematic cross-sectional view thereof.

  Patent Document 2 describes that according to the seal ring 100e shown in FIG. 12, the shaft groove wear amount and torque are reduced as compared with the seal ring 100a shown in FIG. However, this is considered to be an effect of positively sliding the seal ring not only with the shaft but also with the housing.

  The seal ring 100e has a configuration in which the pressure receiving areas of the outer peripheral surface 104e and the side surface 101e are approximated, and sliding with the housing is likely to occur more frequently than the seal ring 100a of FIG. Needless to say, the progress of wear of the shaft groove is suppressed while sliding with the housing. That is, the seal ring 100e shown in FIG. 12 is considered to have a relatively low frequency of sliding with the shaft due to an increase in the frequency of sliding with the housing 2, thereby reducing the wear of the shaft groove. . Further, it is considered that the torque itself when the seal ring 100e shown in FIG. 12 slides on the shaft is equivalent to the seal ring of FIG. As described above, the seal ring in which the side surface slide and the outer surface slide occur at the same frequency becomes unstable in behavior, and therefore, the torque generated by the sliding of the seal ring becomes unstable.

  Further, as shown in FIGS. 13 and 14, a leakage path (black arrow in the figure) is formed in the cut portion of the seal ring in the seal ring in which the side surface contacting the side surface of the annular groove is inclined. There is a problem. Therefore, it is difficult to cope with applications in which reduction of oil leakage is important.

  In addition, as a technique related to the side-sliding type seal ring, there are those disclosed in Patent Documents 3 to 5.

WO01 / 084024 Japanese Patent No. 3800355 Japanese Patent Laid-Open No. 08-121603 Japanese Patent Laid-Open No. 10-318375 JP 2002-195417 A

  The present invention has been made to solve the above-described problems of the prior art, and an object of the present invention is to provide a seal ring capable of reducing torque more effectively.

In order to achieve the above object, the seal ring in the present invention comprises:
A seal ring that seals an annular gap between a housing provided to be rotatable relative to each other and a shaft inserted through a shaft hole of the housing;
Attached to an annular groove provided on one surface of the housing or the shaft, the side surface of the annular groove and the shaft hole or the A seal ring configured to be pressed against each other surface of the shaft;
During relative rotation of the shaft and the housing, the sliding with the other surface is allowed, and the sliding with the annular groove is suppressed,
Abutting on the side surface of the annular groove at a contact surface wider than the contact surface with the other surface;
When the pressure acts, a component force that cancels a part of the force acting in the direction of pressing the seal ring against the other surface and a component force acting in the direction of pressing the seal ring against the side surface of the annular groove are generated. It is provided with the inclined surface inclined so.

  According to the present invention, the contact surface with the side surface of the annular groove is relatively larger than the contact surface with the other surface, and the force that presses the seal ring against the side surface of the annular groove by the force generated by the inclined surface. However, the force is relatively greater than the force pressing the seal ring against the other surface. Thus, during relative rotation of the shaft and the housing, sliding with the other surface is allowed, and sliding with the annular groove is suppressed.

  In this way, by configuring the seal ring to slide with the other surface during relative rotation of the shaft and the housing, it becomes possible to reduce the pressure receiving area on the peripheral surface in contact with the other surface as much as possible. . That is, it is possible to reduce the sliding resistance without being subjected to design restrictions in consideration of the protrusion to the annular gap as in the case of sliding the side surface of the seal ring as in the conventional technique described above. Thereby, the torque can be further reduced.

  Further, the behavior of the seal ring during the relative rotation of the shaft and the housing is almost sliding with the other surface, so that the sliding portion does not change frequently. Therefore, the torque generated by the sliding of the seal ring can be stabilized.

  Furthermore, wear of the annular groove can be suppressed by reducing the sliding frequency with the annular groove. Therefore, it is possible to use a soft material as a material for the member provided with the annular groove.

  In addition, since it is in surface contact with the side surface of the annular groove, a leakage path is not formed by using line contact as in the prior art, which is advantageous in reducing the amount of leakage.

  The inclined surface may be a tapered surface that is provided on one side in the axial direction of the peripheral surface facing the other surface and gradually separates from the other surface toward the one side in the axial direction.

  By configuring the peripheral surface facing the other surface in this way, it is possible to easily realize a configuration including a reduced contact surface with the other surface and an inclined surface for obtaining the reaction force. Moreover, according to this structure, the improvement of the lubricity of the sliding surface by the wedge effect can also be expected. That is, the introduction of the fluid to be sealed (for example, hydraulic oil) to the contact surface that slides on the other surface is facilitated by the gap having a wedge-shaped cross section formed between the tapered surface and the other surface. This makes it easy to form a lubricating film (oil film).

  According to the present invention, more effective torque reduction is possible.

The schematic diagram which looked at the seal ring which concerns on the Example of this invention from the axial direction. The A arrow directional view of FIG. The typical sectional view in the wearing state of the seal ring concerning the example of the present invention. The typical perspective view of the isolation | separation part of the seal ring which concerns on the Example of this invention. The typical sectional view of the separation part of the seal ring concerning the example of the present invention. The typical perspective view of the isolation | separation part of the seal ring which concerns on a modification. The typical perspective view of the isolation | separation part of the seal ring which concerns on a modification. The typical sectional view in the wearing state of the seal ring concerning a conventional example. The typical sectional view in the wearing state of the seal ring concerning a conventional example. The typical sectional view in the wearing state of the seal ring concerning a conventional example. The typical sectional view in the wearing state of the seal ring concerning a conventional example. The typical sectional view in the wearing state of the seal ring concerning a conventional example. The typical perspective view which shows a leak path | route. The typical sectional view showing a leak course.

  DESCRIPTION OF EMBODIMENTS Hereinafter, embodiments for carrying out the present invention will be exemplarily described in detail with reference to the drawings. However, the dimensions, materials, shapes, relative arrangements, and the like of the components described in this embodiment are not intended to limit the scope of the present invention only to those unless otherwise specified. .

(Example)
FIG. 1 is a schematic view (plan view) of a seal ring according to an embodiment of the present invention viewed from the axial direction. FIG. 2 is a view taken in the direction of arrow A in FIG. 1 and partially shows a cross section. FIG. 3 is a schematic cross-sectional view of the seal ring according to the embodiment of the present invention in a mounted state. FIG. 4 is a schematic perspective view of the separation portion of the seal ring according to the embodiment of the present invention. FIG. 5 is a schematic cross-sectional view of the separation portion of the seal ring according to the embodiment of the present invention.

<Schematic configuration of seal ring>
As shown in FIGS. 1 and 2, the seal ring 1 is an annular member provided with a separation portion S at one place on the circumference, such as tetrafluoroethylene (PTFE), polyetheretherketone (PEEK), etc. It is comprised from the resin material of.

As shown in FIG. 3, the seal ring 1 seals the annular gap 4 between the shaft hole 20 of the housing 2 and the shaft 3 inserted into the shaft hole 20. The seal ring 1 is mounted in an annular groove 30 provided on the outer peripheral surface of the shaft 3, and the side surface 10 on the anti-sealing target region side A is formed on the side surface 31 of the annular groove 30 by the action of the pressure P on the sealing target region side O. The outer peripheral surface 11 is in close contact with the inner peripheral surface 21 of the shaft hole 20. Further, when the housing 2 and the shaft 3 are relatively rotated, the outer peripheral surface 11 slides with respect to the inner peripheral surface 21 of the shaft hole 20. This prevents leakage of the sealing target fluid existing on the sealing target region side O to the anti-sealing target region A. The fluid to be sealed is, for example, lubricating oil, and in particular, an ATF in the case of an automatic transmission of an automobile.

  As shown in FIG. 3, the seal ring 1 according to the present embodiment has side surfaces 10 and 12 perpendicular to the axis, and an outer peripheral surface 11 and an inner peripheral surface 13 parallel to the axis. Moreover, the cross-sectional width of the outer peripheral surface 11 is set smaller than the inner peripheral surface 13, the cross-sectional width of the side surface 12 on the sealing target region side O is set smaller than the side surface 10 on the anti-sealing target region side A, A large inclined surface (tapered surface) 14 is formed between the outer peripheral surface 11 and the inner peripheral surface 12. That is, when a seal ring having a rectangular cross section is assumed, a substantially triangular shape (substantially right-angled isosceles triangle shape) in which a corner portion between the outer peripheral surface 11 and the side surface 12 on the sealing target region side O is greatly cut out. Has a cross section.

  As shown in FIGS. 4 and 5, a special step cut that is a conventional technique is employed as the shape of the separation portion S of the seal ring 1. Since the configuration of the separation unit S is a conventional technique, it will be briefly described.

  The separating part S is provided with a convex part 5 at one end part and a concave part 6 combined with the convex part 5 at the other end part. The separation part S is joined by the fitting of the convex part 5 and the concave part 6, and the annular seal ring 1 is formed. Sliding seal surfaces 7a and 7b that are slidable in the circumferential direction are formed in the fitting portion of the separation portion S by contacting the side surfaces 5a and 5b of the convex portion 5 with the side surfaces 6a and 6b of the concave portion 6. . In addition, a gap 8 that can absorb a change in the circumferential length of the seal ring is formed between the front end surface 5 c of the convex portion 5 and the bottom surface 6 c of the concave portion 6.

  Due to the configuration of the separating portion S as described above, the side surfaces 5a and 5b of the convex portion 5 and the side surfaces 6a and 6b of the concave portion 6 slide in the circumferential direction even when the circumferential length of the seal ring 100 changes due to a temperature change or the like. Then, the separation portion S expands and contracts in the circumferential direction (the arrow direction in FIG. 4), so that the change in the circumferential length of the seal ring 100 can be absorbed. Further, even if the circumferential length changes, the state where the side surfaces 5a, 5b of the convex portion 5 and the side surfaces 6a, 6b of the concave portion 6 are in contact (the state where the sliding seal surfaces 7a, 7b are formed) is maintained. There is no gap in the separation portion S such that the sealing target region side O and the anti-sealing target region side A communicate with each other.

<Characteristics of seal ring according to this embodiment>
The seal ring 1 according to the present embodiment is provided with the inclined surface 14 so that sliding between the outer peripheral surface 11 and the inner peripheral surface 21 of the shaft hole 20 is allowed when the housing 2 and the shaft 3 rotate relative to each other. The sliding between the side surface 10 and the side surface 31 of the annular groove 30 is configured to be suppressed.

  Forces due to pressure P act in different directions on the side surface 12, the inner peripheral surface 13, and the inclined surface 14 of the surface of the seal ring 1 facing the region to be sealed O. The seal ring 1 receives a force acting on the side surface 12 in the axial direction toward the anti-sealing target region side A. Further, the inner peripheral surface 13 receives a force acting in the outer diameter direction (a force acting in a direction of pressing the seal ring 1 against the inner peripheral surface 21 of the shaft hole 20). Further, the inclined surface 14 receives a force acting in a direction inclined with respect to the axial direction and the radial direction. By the action of these forces, the seal ring 1 is pressed against the inner peripheral surface 21 of the shaft hole 20 and the side surface 31 of the annular groove 30 to seal the annular gap 4.

In the seal ring 1 according to this embodiment, the force received by the inclined surface 14 cancels a part of the force acting in the direction of pressing the seal ring 1 against the inner peripheral surface 21 of the shaft hole 20, and the seal ring 1. A component force is generated that acts in a direction in which the is pressed against the side surface 31 of the annular groove 30. Thus, the force acting in the direction of pressing the seal ring 1 against the inner peripheral surface 21 of the shaft hole 20 is reduced.

  In the seal ring 1 according to the present embodiment, the radial width WR and the axial width WL in the cross section are set to be approximately equal (see FIG. 2). That is, the width of the region receiving the force pressing the seal ring 1 against the inner peripheral surface 21 of the shaft hole 20 is substantially equal to the width of the region receiving the force pressing the seal ring 1 against the side surface 31 of the annular groove 30. Of the component forces generated by the force received by the inclined surface 14, when the component force that cancels a part of the force pressing the seal ring 1 against the inner peripheral surface 21 of the shaft hole 20 is ignored, the seal ring 1 The inner peripheral surface 21 and the side surface 31 of the annular groove 30 are pressed with substantially the same force. Accordingly, a part of the force that presses the seal ring 1 against the inner peripheral surface 21 of the shaft hole 20 due to the component of the force received by the inclined surface 14 is canceled, so that the force that presses the seal ring 1 against the side surface 31 of the annular groove 30. However, it is comprised so that it may become relatively larger than the force which presses the seal ring 1 to the internal peripheral surface 21 of the axial hole 20. FIG.

The force acting on the inclined surface 14 by the pressure P can be regarded as a force that is a combination of two component forces in the axial direction and the radial direction. That is, the axial component force acting in the direction of pressing the seal ring 1 against the side wall 31 of the annular groove 30 and the radial direction (inner diameter direction) acting in the direction separating the seal ring 1 from the inner peripheral surface 21 of the shaft hole 20. The component force (P ₁ ). Of these two component forces, the radial component force (P ₁ ) cancels a part (P ₂ ) of the force (P ₂ + P ₃ ) acting on the inner peripheral surface 13. Thereby, the force (P ₃ ) that is not canceled by the radial component force (P ₁ ) acts on the seal ring 1 in the outer diameter direction.

  On the other hand, the axial force that presses the seal ring 1 against the side surface 31 of the annular groove 30 is configured not to generate a force acting in the opposite direction to cancel the axial force. That is, the seal ring 1 according to the present embodiment does not include a surface that receives a force acting in a direction in which the seal ring 1 is separated from the side surface 31 of the annular groove 30.

  Further, the seal ring 1 according to the present embodiment is configured to contact the side surface 31 of the annular groove 30 with a contact surface wider than the contact surface with the inner peripheral surface 21 of the shaft hole 20. That is, the position where the inclined surface 14 is formed so that the contact width of the outer peripheral surface 11 reduced by forming the inclined surface 14 is smaller than the width of the region where the side surface 10 contacts the side surface 31 of the annular groove 30. The size, angle, etc. are set as appropriate.

  As a specific example of dimension setting, the width (outer peripheral contact width) in which the inner peripheral surface 21 of the shaft hole 20 and the outer peripheral surface 11 of the seal ring 1 are in contact is 0.1 mm to 1.0 mm, preferably 0. It is preferable to set in the range of 2 mm to 0.5 mm. When the outer peripheral contact width is smaller than 0.1 mm, stable sealing performance cannot be ensured, and the surface pressure increases and wear tends to proceed. On the other hand, if the outer peripheral contact surface is larger than 1.0 mm, the pressure receiving area is increased, and the effect of low torque is reduced.

  With the configuration as described above, the seal ring 1 according to the present embodiment slides between the outer peripheral surface 11 and the inner peripheral surface 21 of the shaft hole 20 during relative rotation of the housing 2 and the shaft 3, and the side surface 10 and the annular groove. The sliding with the side surface 31 of 30 is suppressed.

<Excellent points of this embodiment>
According to the seal ring 1 according to the present embodiment, the shaft 3 and the housing 2 are configured to slide with the inner peripheral surface 21 of the shaft hole 20 when the shaft 3 and the housing 2 are rotated relative to each other, thereby contacting the inner peripheral surface 21 of the shaft hole 20. It is possible to reduce the pressure receiving area on the outer peripheral surface 11 as much as possible. That is, the size of the contact surface can be set without being restricted by design in consideration of the protrusion to the annular gap as in the case of sliding the side surface of the seal ring as in the prior art. As a result, it is possible to further reduce the sliding resistance, that is, further reduce the torque.

  In addition, the behavior of the seal ring 1 during the relative rotation of the shaft 3 and the housing 2 is almost sliding with the inner peripheral surface 21 of the shaft hole 20, and the sliding portion is not frequently switched. The torque generated by the sliding of 1 can be stabilized.

  Furthermore, wear of the annular groove 30 can be suppressed by reducing the sliding frequency with the annular groove 30. Therefore, it is possible to use a soft material as the material of the shaft 3 in which the annular groove 30 is provided.

  Further, since it is in surface contact with the side surface 31 of the annular groove 30, there is no formation of a leakage path with a line contact structure as shown in FIGS. 13 and 14, which is advantageous in reducing the amount of leakage.

  In addition, the inclined surface 14 provided on the sealing target region side O (one axial direction side) of the outer peripheral surface 11 gradually becomes the inner peripheral surface 21 of the shaft hole 20 toward the sealing target region side O (one axial direction side). As a result, a gap having a wedge-shaped cross section is formed between the inclined surface 14 and the inner peripheral surface 21 of the shaft hole 20. Due to the wedge effect due to the wedge-shaped gap, introduction of hydraulic oil into the sliding portion of the housing 2 and the seal ring 1 (between the outer peripheral surface 11 and the inner peripheral surface 21 of the shaft hole 20) is promoted, and the housing 2 and the seal are sealed. Formation of the oil film at the sliding portion of the ring 1 is promoted.

  That is, according to the present embodiment, more effective torque reduction can be achieved.

  In the present embodiment, the shape of the inclined surface 14 is a linear tapered surface shape, but is not limited to this shape as long as the behavior of the seal ring 1 described above can be realized. For example, it may have a curved surface shape, or may be formed by a plurality of tapered surfaces having different taper angles.

  In the present embodiment, the configuration in which the seal ring 1 is mounted on the annular groove 30 provided on the outer peripheral surface of the shaft 3 has been described. However, the annular groove provided on the inner peripheral surface 21 of the shaft hole 20 of the housing 2 is described. The ring gap 4 may be sealed by sliding on the outer peripheral surface of the shaft 3.

<Modification>
As shown in FIGS. 4 and 5, the cross-sectional shape of the seal ring 1 changes from the substantially triangular shape shown in FIG. 3 to the substantially rectangular shape shown in FIG. The sliding surface (contact surface) with the inner peripheral surface 21 of the shaft hole 20 expands at the separation portion S, and the protruding corner portion at the boundary between the separation portion S and the other portions as shown in FIG. C is formed. There is a concern that the corner portion C may be damaged when sliding with the inner peripheral surface 21 of the shaft hole 20.

  Moreover, as shown in FIG. 1, the range in which the cross section is formed in a substantially rectangular shape is a relatively narrow range for the seal ring 1 as a whole. However, if the cross-sectional shape is different, the way in which pressure is applied to the seal ring 1 will also be different, and such a change in the cross-sectional shape may affect the behavior of the seal ring 1 when the shaft 3 and the housing 2 are rotated relative to each other. Concerned.

  Therefore, as shown in FIG. 6 and FIG. 7, the angle at the time of sliding can be reduced by gently introducing the lubricating oil into the sliding surface and eliminating the protrusion of the corner portion C, by gently changing the cross-sectional shape. It is conceivable to attempt to stabilize the behavior of the seal ring 1 or damage to the part C. Here, FIG.6 and FIG.7 is a typical perspective view of the isolation | separation part of the seal ring which concerns on a modification, respectively.

  In the modification shown in FIG. 6, the end surface formed at the boundary between the triangular cross section and the rectangular cross section in the seal ring 1 is the inclined surface 9 a, and the gap between the inner peripheral surface 21 of the shaft hole 20 is the circumference of the seal ring 1. It is comprised so that it may become narrow gradually toward the direction (direction opposite to the relative rotation direction with respect to the housing 2). Thereby, a wedge effect is generated in the lubricating oil existing between the inclined surface 9a and the inner peripheral surface 21 of the shaft hole 20, and a sliding surface (contact surface) with the inner peripheral surface 21 of the shaft hole 20 in the separation portion S is generated. ) Will be actively introduced into the lubricant. Thus, it becomes possible to prevent the damage in the separation part S, etc. by improving lubricity.

  Further, the modification shown in FIG. 7 is configured such that the inclined surface 9b is formed at the boundary between the triangular cross section and the rectangular cross section by cutting out the corner C shown in FIG. Similar to the modification shown in FIG. 6, the lubricity is enhanced by the wedge effect, and damage or the like in the separation portion S can be prevented.

DESCRIPTION OF SYMBOLS 1 Seal ring 10 Side surface 11 Outer peripheral surface 12 Side surface 13 Inner peripheral surface 14 Inclined surface (taper surface)
2 housing 20 shaft hole 21 inner peripheral surface 3 shaft 30 annular groove 31 side surface 4 annular gap

Claims (2)

A seal ring that seals an annular gap between a housing provided to be rotatable relative to each other and a shaft inserted through a shaft hole of the housing;
Attached to an annular groove provided on one surface of the housing or the shaft, the side surface of the annular groove and the shaft hole or the A seal ring configured to be pressed against each other surface of the shaft;
During relative rotation of the shaft and the housing, sliding with the other surface is allowed, and sliding with the side surface of the annular groove is suppressed,
Abutting on the side surface of the annular groove at a contact surface wider than the contact surface with the other surface;
When the pressure acts, a component force that cancels a part of the force acting in the direction of pressing the seal ring against the other surface and a component force acting in the direction of pressing the seal ring against the side surface of the annular groove are generated. A seal ring comprising an inclined surface inclined so as to perform.   The inclined surface is a tapered surface that is provided on one axial side of a peripheral surface facing the other surface and gradually separates from the other surface toward the one axial side. Item 2. The seal ring according to Item 1.

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