JP2007170629A - Sealing ring and sealing ring manufacturing method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a sealing ring capable of providing stable sealing property and reducing friction torque in sliding and to provide a sealing ring manufacturing method. <P>SOLUTION: In this sealing ring 1 mounted in an annular channel 40 provided in either of a housing 3 having a shaft hole and a shaft 4 inserted into the shaft hole to seal an annular clearance 5 between these two members and provided with a sealing face 12 sliding and coming into contact with a side face on a side A of an object to be not sealed of the annular channel 40, an inclined face 13 leaving the side face 41 on the side A of the object to be not sealed of the annular channel 40 gradually when approaching a bottom of the annular channel 40 from a fringe on a channel bottom side of the annular channel 40 on the sealing face 12 is formed on the channel bottom side of the annular channel 40 on the sealing face 12 in advance when molding the sealing ring 1. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a seal ring used as a sealing device for an automatic transmission and a continuously variable transmission for automobiles, various hydraulic devices, pneumatic devices, and the like, and a method for manufacturing the seal ring.

  A sealing ring as shown in FIG. 7 is known as a sealing device used for a shaft seal of an automobile automatic transmission or the like. The seal ring 100 seals the annular gap 400 between the inner peripheral surface of the shaft hole of the housing 200 and the outer peripheral surface of the shaft 300 inserted into the shaft hole.

  The seal ring 100 is mounted in an annular groove 301 provided on the outer peripheral surface of the shaft 300, and the outer peripheral surface 111 thereof is brought into close contact with the inner peripheral surface of the housing 200 by the pressure received from the sealing target side O. The side surface 110 is closely attached to the side surface 310 of the annular groove 301. Thereby, the leakage of the sealing target fluid to the non-sealing target side A is prevented.

  The seal surface that is in close contact with the side surface 310 of the annular groove 301 slides with respect to the side surface 310 of the annular groove 301 by the rotation of the shaft 300.

  Therefore, as shown in FIG. 8, by reducing the contact area by making the cross-sectional shape of the seal ring 100 T-shaped, the pressure received by the seal ring 100 from the side surface 310 of the annular groove 301 is reduced. The thing which aimed at reduction of the friction torque which arises by sliding with 310 is known.

  In addition, in order to increase durability (PV resistance) when used under high pressure and high speed, a method of improving durability by leaking a small amount of oil from the cut part of the seal ring and cooling the sliding surface Etc. are also known.

  In such a seal ring having a sliding seal surface, the edge of the seal surface (the corners of the side surface and the inner peripheral surface) is set as an edge as much as possible even if the seal surface is worn by sliding. The contact area is not changed.

  When the seal ring is manufactured by injection molding, it is necessary to remove burrs generated by mold splitting. However, in the burr removal process such as barrel polishing, not only the burr but also the edge portion of the seal surface edge portion 112 is polished, and a minute R shape is formed discontinuously on the seal surface edge portion 112.

  If a discontinuous minute R shape is formed, the sealing surface becomes non-uniform and stable sealing performance cannot be obtained.

  Further, with the recent improvement in performance of automatic transmissions, the use conditions of the seal ring have become stricter, and use under higher pressure and higher speed and further reduction of friction torque are required.

  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 that exhibits stable sealing performance and can reduce frictional torque due to sliding. It is to provide a method for manufacturing a seal ring.

In order to achieve the above object, the seal ring in the present invention comprises:
A seal ring that is mounted in an annular groove provided in one of a housing having a shaft hole and a shaft inserted into the shaft hole and seals an annular gap between the two members;
In a seal ring comprising a seal surface that is in sliding contact with the side surface of the annular groove on the non-sealing target side,
When forming the seal ring, the non-circular groove is formed in advance toward the groove bottom side of the annular groove of the seal surface from the groove bottom side edge of the annular groove of the seal surface toward the groove bottom of the annular groove. An inclined surface that is gradually separated from the side surface on the sealing target side is formed.

  Thus, since the edge on the groove bottom side of the annular groove of the seal surface is not an edge, it is possible to suppress the occurrence of a discontinuous minute R shape at the edge of the seal surface due to polishing or the like, A stable sealing surface can be obtained.

  In addition, by forming the groove bottom side of the annular groove on the seal surface as an inclined surface, a substantially wedge-shaped space gradually narrowing from the groove bottom side toward the seal surface is formed. The flow of the fluid to be sealed flowing in the direction is generated by relative movement due to the rotation of the shaft, and dynamic pressure is generated in which the seal ring acts in a direction away from the non-sealed side wall of the annular groove (wedge effect).

  As a result, the surface pressure between the sealing surface and the non-sealed side wall of the annular groove is reduced, and the sliding friction force generated on the sealing surface is reduced. Therefore, an appropriate oil film can be interposed between the seal surface and the annular groove side wall, and sliding friction can be reduced.

  The sealing surface and the inclined surface may be formed by injection molding.

  Therefore, even when burrs generated by injection molding are removed by polishing such as barrel polishing, it is possible to suppress the occurrence of a minute R shape at the edge of the seal surface, and a stable seal surface can be obtained.

In order to achieve the above object, the seal ring manufacturing method in the present invention is:
A manufacturing method of a seal ring that is mounted in an annular groove provided in one member of a housing having a shaft hole and a shaft inserted into the shaft hole, and seals an annular gap between the two members,
In a manufacturing method of a seal ring comprising a seal surface that is in sliding contact with a side surface on the non-sealing target side of the annular groove,
When forming the seal ring, the non-circular groove is formed in advance toward the groove bottom side of the annular groove of the seal surface from the groove bottom side edge of the annular groove of the seal surface toward the groove bottom of the annular groove. An inclined surface that is gradually separated from the side surface on the sealing target side is formed.

  The sealing surface and the inclined surface may be formed by injection molding.

  As described above, according to the present invention, it is possible to exhibit stable sealing performance and reduce frictional torque due to sliding.

The best mode for carrying out the present invention will be exemplarily described in detail below 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. .

  A seal ring and a seal ring manufacturing method according to a first embodiment of the present invention will be described with reference to FIGS. FIG. 1 is a diagram showing an entire seal ring 1 according to the present embodiment, and shows a state in which the seal ring 1 is viewed from the axial direction. FIG. 2 is a cross-sectional view showing a use state of the seal ring 1 according to the present embodiment, and corresponds to the AA cross section of FIG. FIG. 3 is a cross-sectional view showing a usage state of the seal ring 1 according to a modification of the present embodiment.

  The seal ring 1 is a sealing device that seals an annular gap between two members that are assembled so as to be relatively rotatable. Here, as shown in FIG. 2, the outer peripheral surface of the shaft 4 is sealed in order to seal the annular gap 5 between the inner peripheral surface of the shaft hole of the housing 3 and the outer peripheral surface of the shaft 4 inserted into the shaft hole. The seal ring 1 is mounted in an annular groove 40 provided in the.

  The seal ring 1 is made of a resin material that can be injection-molded. For example, polyether ether ketone (PEEK), polyphenylene sulfide (PPS), or the like is used.

  Further, the seal ring 1 has a substantially annular shape in which a cross section along the radial direction passing through the central axis has a rectangular shape, and is separated at one place on the circumference (separation part S).

  By providing such a separation portion S, mounting to the annular groove 40 is facilitated. As the separation part S, for example, a special step cut that can absorb a change in the circumference of the seal ring 1 due to a temperature change or the like can be appropriately employed.

  The seal ring 1 is mounted in an annular groove 40 provided on the outer peripheral surface of the shaft 4, and when pressure acts in the direction of arrow P from the sealing target side O (left side in FIG. 2), the seal ring 1 is unsealed target side A. (Right side in FIG. 2).

  The side surface 10 of the seal ring 1 on the non-sealing target side is in close contact with the side wall 41 of the annular groove 40, and the outer peripheral surface 11 is in close contact with the inner peripheral surface of the housing 3. Thereby, the leakage to the non-sealing target side A of the sealing target fluid is suppressed.

  The fluid to be sealed is, for example, lubricating oil, and particularly ATF in the case of an automatic transmission of an automobile.

  The side surface 10 on the non-sealing target side A of the seal ring 1 according to the present embodiment is provided on the groove bottom side of the annular groove 40 with respect to the seal surface 12 that is in close contact with the side wall 41 of the annular groove 40 and sealed. And the inclined surface 13 to be formed.

  The inclined surface 13 is a surface inclined so as to be gradually separated from the side wall 41 of the annular groove 40 from the edge on the groove bottom side of the annular groove 40 of the seal surface 12 toward the groove bottom of the annular groove 40. It is a surface that does not adhere to the side wall 41.

  More specifically, the inclined surface 13 increases the degree of inclination with respect to the side wall 41 of the annular groove 40 from the edge on the groove bottom side of the annular groove 40 of the seal surface 12 while gradually sealing the inner peripheral surface of the seal ring 1. It is a surface that extends gently to the edge on the object side, and has a shape in which R is provided at the corner between the seal surface 12 and the inner peripheral surface.

When the shaft 4 rotates, the seal ring 1 itself basically does not rotate, so that the outer peripheral surface 11 and the inner peripheral surface of the housing 3 do not slide closely to each other. On the other hand, the sealing surface 12 of the side surface 10 on the non-sealing target side A and the side wall 41 of the annular groove 40 of the shaft 4 slide.

  An oil film is formed between the sealing surface 12 and the side wall 41 by, for example, hydraulic fluid that is a sealing target. Therefore, the seal surface 12 and the side wall 41 slide through the oil film, and the seal surface 12 and the side wall 41 hardly slide in direct contact with each other.

  Further, the groove bottom side of the annular groove 40 with respect to the seal surface 12 has a substantially wedge-shaped cross section in which the gap between the seal ring 1 and the side wall 41 gradually narrows from the groove bottom side toward the seal surface 12 due to the inclined surface 13. A space is formed.

  When the shaft 4 rotates with respect to the housing 3, a flow of the fluid to be sealed (arrow a in the figure) is generated in the space from the groove bottom side toward the seal surface 12 due to the relative movement of the fluid to be sealed. This flow generates a dynamic pressure (arrow b in the figure) that acts in a direction in which the seal ring 1 is separated from the side wall 41 of the annular groove 40.

  As a result, the surface pressure between the seal surface 12 and the side wall 41 is reduced, more oil can be interposed between the seal surface 12 and the side wall 41, and the sliding frictional force generated on the seal surface 12 is reduced. Further reduced.

  Therefore, the friction torque due to the sliding of the seal surface 12 can be reduced, and durability (PV resistance) for use under high pressure and high speed can be improved.

  Next, a method for manufacturing the seal ring 1 according to this embodiment will be described.

  First, the seal ring 1 having the shape shown in FIGS. 1 and 2 such as the side surface 10, the outer peripheral surface 11, and the separation portion S is injection-molded using a molding die. The sealing surface 12 and the inclined surface 13 constituting the side surface 10 are also injection-molded by a molding die.

  When a seal ring is manufactured by injection molding, burrs are generated in the parting line of the mold. By removing this burr, the seal ring is completed as a final product.

  As a method for removing burrs, in general, a seal ring after injection molding and a polishing material such as a grindstone are rotated for a predetermined time in a tank using a fluid barrel, and both rub against each other to remove burrs (for example, Fluid type barrel polishing) is known.

  In the case of such a burr removing method, not only the burr but also the edge portion of the seal ring is polished. Since a minute R shape with a radius of curvature of about 0.1 mm is formed discontinuously on the polished edge portion, as shown in FIG. 7, when the seal surface is formed up to the side edge, By polishing, a discontinuous R shape is also formed at the edge portion of the seal surface edge, and the seal surface becomes non-uniform.

  On the other hand, in the case of the seal ring 1 according to the present embodiment, the inclined surface 13 is formed in advance at the corner between the seal surface 12 and the inner peripheral surface by injection molding, and the edge of the seal surface 12 becomes an edge. Not. Therefore, even if the edge portion of the edge portion of the seal surface 12 of the seal ring 1 hits the abrasive material and is polished in the burr removing process, the seal surface 12 is not uneven and a stable sealing property can be obtained. it can.

  In addition, the inclined surface 13 is provided so that a curvature radius may be set to 0.1-0.5 mm. That is, a discontinuous R-shaped portion is formed at the edge of the seal surface 12 by setting the radius of curvature to be equal to or greater than that of the R-shaped portion generated by polishing the edge of the edge of the seal surface 12. Is prevented.

  Here, as the shape of the inclined surface 13, as shown in FIG. 3, the curvature radius may be larger than that of the inclined surface 13 of FIG. .

  In this case, as shown in FIG. 3, the inclined surface 13 is formed more gently with respect to the seal surface 12 so as to extend substantially parallel to the side wall 41. It becomes easy to receive the dynamic pressure (arrow b in FIG. 3) which acts in the direction which separates the seal ring 1 from the side wall 41 from the fluid to be sealed flowing between the side 41 and the surface pressure between the seal surface 12 and the side wall. It can be effectively reduced.

  In the first embodiment, the cross section of the seal ring 1 is rectangular, whereas in the second embodiment, the cross section is T-shaped, and the side surface of the seal ring 1 is in contact with the side wall 41 of the annular groove 40. , And the non-seal surface 14 which does not contact is different. Since other configurations are substantially the same, different points are mainly described here, and the same portions are denoted by the same reference numerals, and detailed description thereof is omitted.

  A seal ring and a seal ring manufacturing method according to a second embodiment of the present invention will be described with reference to FIGS. FIG. 4 is a diagram illustrating the entirety of the seal ring 1a according to the present embodiment, and illustrates a state in which the seal ring 1a is viewed from the axial direction. FIG. 5 is a cross-sectional view showing a use state of the seal ring 1a according to the present embodiment, and corresponds to the AA cross section of FIG. FIG. 5 is a cross-sectional view showing a usage state of the seal ring 1a according to a modification of the present embodiment.

  The seal ring 1a has a generally annular shape in which the cross section along the radial direction passing through the central axis has a substantially T shape, and is separated at one place on the circumference (separation part Sa).

  The side surface 10 a of the seal ring 1 a is provided on the seal surface 12 a that contacts the side wall 41 of the annular groove 40, and on the groove bottom side of the annular groove 40 relative to the seal surface 12 a, and a gap is formed between the side surface 10 a. And a non-seal surface 14 provided so as to be provided.

  On the outer peripheral side of the non-seal surface 14, a step portion 15 extending concentrically with the central axis of the seal ring 1a is provided, and an inclined surface 13a is formed at a corner between the seal surface 12a and the step portion 15. Is provided.

  The inclined surface 13 a is a surface that is inclined so as to gradually move away from the side wall 41 of the annular groove 40 toward the step portion 15 from the groove bottom side edge of the annular groove 40 of the seal surface 12 a. It is a surface that does not adhere.

  The shape of the inclined surface 13a may be a shape in which R is provided at the corner between the seal surface 12a and the step portion 15 as shown in FIG. 5, or as shown in FIG. The shape which made the curve of an inclined surface gentler may be sufficient.

  In the seal ring 1a according to the present embodiment, the cross section is T-shaped, and the side surface is configured by the seal surface 10a that contacts the side wall 41 of the annular groove 40 and the non-seal surface 14 that does not contact, The sliding area can be reduced while ensuring the minimum sealing surface necessary for sealing, and the friction torque generated by sliding is reduced.

  Further, due to the dynamic pressure effect of the inclined surface 13a, the surface pressure between the seal surface 12a and the side wall 41 is reduced, and more oil can be interposed between the seal surface 12a and the side wall 41. The sliding frictional force generated on the surface 12a is reduced.

  That is, according to the seal ring according to the present embodiment, the friction ring can be reduced by reducing the area of the sliding surface with a T-shaped cross section of the seal ring, and further, the sliding surface can generate dynamic pressure. Due to the effect of reducing the friction torque by lowering the surface pressure, it is possible to further improve the low torque property.

It is a figure showing the whole seal ring concerning the 1st example of the present invention. It is typical sectional drawing which shows the use condition of the seal ring of FIG. It is typical sectional drawing which shows the use condition of the seal ring which concerns on the modification of a 1st Example. It is a figure which shows the whole seal ring which concerns on the 2nd Example of this invention. It is typical sectional drawing which shows the use condition of the seal ring of FIG. It is typical sectional drawing which shows the use condition of the seal ring which concerns on the modification of a 2nd Example. It is typical sectional drawing of the seal ring which concerns on a prior art. It is typical sectional drawing of the seal ring which concerns on a prior art.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Seal ring 10 Side surface 11 Outer peripheral surface 12 Seal surface 13 Inclined surface 3 Housing 4 Shaft 40 Annular groove 41 Side wall 5 Annular gap

Claims (4)

A seal ring that is mounted in an annular groove provided in one of a housing having a shaft hole and a shaft inserted into the shaft hole and seals an annular gap between the two members;
In a seal ring comprising a seal surface that is in sliding contact with the side surface of the annular groove on the non-sealing target side,
When forming the seal ring, the non-circular groove is formed in advance toward the groove bottom side of the annular groove of the seal surface from the groove bottom side edge of the annular groove of the seal surface toward the groove bottom of the annular groove. A seal ring, characterized in that an inclined surface that is gradually separated from a side surface on a sealing target side is formed.   The seal ring according to claim 1, wherein the seal surface and the inclined surface are formed by injection molding. A manufacturing method of a seal ring that is mounted in an annular groove provided in one member of a housing having a shaft hole and a shaft inserted into the shaft hole, and seals an annular gap between the two members,
In a manufacturing method of a seal ring comprising a seal surface that is in sliding contact with a side surface on the non-sealing target side of the annular groove,
When forming the seal ring, the non-circular groove is formed in advance toward the groove bottom side of the annular groove of the seal surface from the groove bottom side edge of the annular groove of the seal surface toward the groove bottom of the annular groove. A method of manufacturing a seal ring, comprising forming an inclined surface that is gradually separated from a side surface on a sealing target side.   The seal ring manufacturing method according to claim 3, wherein the seal surface and the inclined surface are formed by injection molding.

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