JP2006009897A - Seal ring - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a seal ring in which an oil film is largely formed on a side surface of a circular groove that slides to a side wall surface on the counter-seal fluid side, so that direct contact with the side wall surface is eliminated. <P>SOLUTION: In the side surface 12 of the seal ring 1, an oil groove 16 is provided that is gradually widened in the outer diametric direction and the circumferential direction from a depth part 17 on the side of an inner circumferential surface 14 in the rotation direction of a rotary shaft, and gradually narrowed in the outer diameter direction and the circumferential direction from the depth part 17. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a seal ring that is used for a shaft seal of an automatic transmission of an automobile, various hydraulic devices, and a pneumatic device, and seals an annular gap between a rotating shaft and a housing disposed in an annular groove.

  The seal ring is used as a seal for rotation / oscillation. As shown in FIG. 9, the seal ring 1 is disposed in an annular groove 3 provided around the outer peripheral surface of the rotary shaft 2, presses the outer peripheral surface 11 against the inner wall of the housing 4 by hydraulic pressure, and The side surface 12 on the side opposite to the oil is pressed against the side wall surface of the annular groove 3 so as to be sealed. At this time, although the seal ring 1 itself does not rotate but the rotating shaft 2 rotates, the outer peripheral surface 11 of the seal ring 1 does not slide in close contact with the housing 4, but the anti-oil side surface 12 does not slide on the rotating shaft 2. It slides on the side wall surface of the annular groove 3 (sliding portion in FIG. 9). Here, since the side surface 12 on the anti-oil side of the seal ring 1 and the side wall surface of the annular groove 3 slide through the oil film, the seal ring 1 and the side wall surface are in direct contact with each other in a preferable use state. There is not much.

  However, when the high-pressure use conditions and the surface roughness of the side wall surface are rough, as shown in FIG. 10, the unevenness of the roughness becomes larger than the oil film thickness, and the side surface 12 and the annular groove 3 on the anti-oil side of the seal ring 1 are increased. Wear occurs when the side wall surface directly contacts and slides.

  As a countermeasure against direct contact between the side surface 12 of the seal oil 1 opposite to the oil side and the side wall surface of the annular groove 3, as shown in FIG. 11 disclosed in Patent Document 1, when the rotary shaft 2 rotates. It is considered to provide the seal ring 1 with an oil groove 20 capable of introducing an oil film on the surface of the side surface 12 on the anti-oil side. The oil groove 20 shown in FIG. 11 has inclined surface portions 21 and 22 on both sides in the circumferential direction of the deep portion, and the oil introduced into the oil groove 20 is changed from the inclined surface portions 21 and 22 to the side surface 12 by the rotation of the rotating shaft 2. An oil film is delivered and the seal ring 1 is separated from the side wall surface of the annular groove 3 by buoyancy due to the pressure of the oil film.

However, in the thing of patent document 1, when the oil_pressure | hydraulic which presses the seal ring 1 is larger than the buoyancy by the pressure of an oil film, the seal ring 1 contacts with a side wall surface and is not a countermeasure. In detail, in the thing of patent document 1, as shown in FIG. 12, the range of the oil film which produces the buoyancy formed by the oil groove 20 is limited to Y 'part. For this reason, if the hydraulic pressure that presses the seal ring 1 is greater than the buoyancy due to the pressure of the oil film, even if the Y ′ part where the oil film is formed is protected by the oil film, the part other than the Y ′ part (Z ′ part) is due to the oil film There is no protection. Therefore, a portion (Z ′ portion) other than the Y ′ portion on the side surface 12 on the opposite oil side of the seal ring 1 comes into direct contact with the side wall surface of the annular groove 3 of the rotating shaft 2. In this case, the portion other than the Y ′ portion (Z ′ portion) is worn by sliding.
JP 09-210211 A

  The present invention has been made in view of the above circumstances, and its object is to form an oil film widely on the side surface of the annular groove that slides with the side wall surface on the anti-sealing fluid side, and to make direct contact with the side wall surface. It is to provide a seal ring that eliminates the problem.

In order to achieve the above object, the present invention adopts the following configuration. That is,
Mounted in an annular groove provided around the outer peripheral surface of the rotary shaft, the outer peripheral surface is in close contact with the inner wall of the housing through which the rotary shaft is inserted, and the side surface is slidably in close contact with the side wall surface of the annular groove on the anti-sealing fluid side. A seal ring that seals an annular gap between the rotating shaft and the housing,
Opened in the inner peripheral surface on the side surface of the seal ring, and spreads in the outer diameter direction and the circumferential direction from the deepest portion on the inner peripheral surface side as it advances in the rotation direction of the rotary shaft, and from the deepest portion to the outer diameter direction and the circumferential direction. It is a seal ring characterized by providing grooves that gradually become shallower in the direction.

  According to the present invention, an oil film can be widely formed on the side surface of the annular groove that slides with the side wall surface on the anti-sealing fluid side, direct contact with the side wall surface is eliminated, wear can be reduced, and durability is excellent. .

  Embodiments will be described with reference to the drawings. FIG. 1 is a partial perspective view of a seal ring according to an embodiment. FIG. 2 is a side external view of the seal ring according to the embodiment. 3 is a cross-sectional view of the oil groove portion of the seal ring according to the embodiment, and is a cross-sectional view taken along the line AA of FIG. FIG. 4 is an external view of the inner peripheral surface of the seal ring according to the embodiment, and is a view taken in the direction of arrow B in FIG.

  In the present embodiment, the seal ring 1 has a quadrangular cross section, an outer peripheral surface 11 that is in close contact with the inner wall of the housing 4 facing the annular groove 3 of the rotating shaft 2, and the annular groove 3 side of the rotating shaft 2. One side face 12 on the opposite oil side that is in close contact with the wall surface, the side face 13 on the oil side opposite to the one side face 12, and the inner circumference facing the groove bottom side of the annular groove 3 of the rotary shaft 2 And a surface 14.

  As shown in FIG. 9, the seal ring 1 is mounted in an annular groove 3 provided around the outer peripheral surface of the rotary shaft 2, and the outer peripheral surface 11 is formed on the inner wall of the housing 4 through which the rotary shaft 2 is inserted by hydraulic pressure. And the side surface 12 is pressed against the side wall surface on the anti-oil side (anti-sealing fluid side) of the annular groove 3 so as to be slidably in contact with each other to seal the annular gap between the rotating shaft 2 and the housing 4. To do. As will be described later, in the present embodiment, oil leakage is not completely prevented but moderate leakage is allowed.

  Here, the oil as the sealing fluid is, for example, a lubricating oil, and refers to ATF (Automatic Transmission Fluid) when used in an automobile transmission.

  Further, as shown in FIG. 2, the seal ring 1 is provided with a separation portion 15 at one place in the circumferential direction. The separating portion 15 is provided for facilitating the mounting work when the seal ring 1 is mounted. The separation unit 15 is a special step cut. The special step cut is a shape cut into two steps, and step-like cuts appear on both the side surface 12 and the side surface 13. With this special step cut, the amount of leakage can be reduced, and even if the seal ring 1 expands or contracts due to a change in the ambient temperature, the gap can be made not so large correspondingly.

  In such a seal ring 1 of the present embodiment, the side surface 12 is provided with a plurality of oil grooves (grooves) 16 scattered over the entire circumference.

  The oil groove 16 opens in the inner peripheral surface 14, and spreads in the outer diameter direction and the circumferential direction from the deepest portion 17 on the inner peripheral surface 14 side as it advances in the rotation direction of the rotary shaft 2, and from the deepest portion 17 to the outer diameter direction. And it gradually becomes shallower in the circumferential direction.

Specifically, the shape of the opening of the oil groove 16 with respect to the side surface 12 of the seal ring 1 is a substantially curved parallelogram, as shown in FIG. The oil groove 16 opens to the inner peripheral surface 14 as shown in FIGS. 1 to 4, and reaches the deepest portion as it advances in the rotation direction of the rotary shaft 2 with the deepest portion 17 on the inner peripheral surface 14 side as a base point. The oil groove side wall 18 is extended in the outer diameter direction while curving from 17, and the opening on the inner peripheral surface 14 side is widened in the circumferential direction. In addition, the oil groove bottom surface 19 of the oil groove 16 is an inclined surface that becomes shallower as it is farther from the deepest portion 17 (either in the outer diameter direction or in the circumferential direction).

  Moreover, the corner | angular part (C, D, E part of FIG. 2) of the oil groove 16 with the side surface 12 of the seal ring 1 and the boundary (F part of FIG. ) Is rounded to R. Thus, the oil can be smoothly introduced into the side 12 on the side opposite to the oil of the seal ring 1 without scraping oil at the corners.

  In the side surface 12 having such an oil groove 16, oil is introduced from the opening on the inner peripheral surface 14 side of the oil groove 16 when the rotary shaft 2 rotates. This oil flows up from the deepest part 17 side of the oil groove 16 by the rotation of the rotating shaft 2 to the shallow part of the oil groove 16 and spreads in the outer diameter direction and the circumferential direction. Then, oil is not scraped off from the shallow part of the oil groove 16 to the peripheral edge part (C, D, E part) of the oil groove 16 which becomes R, and spreads to the surface of the side surface 12 to form an oil film.

  FIG. 5 is a diagram showing an oil film formation range of the seal ring 1 according to the embodiment. As shown in FIG. 5, an oil film is formed between the sliding side surface 12 and the side wall surface of the annular groove 3 in the outer diameter side of the oil groove 16 and in a wide range (Y portion) in the circumferential direction. In particular, the angle of the portion where oil is introduced from the oil groove 16 to the side surface 12 is R, and the oil groove bottom surface 19 of the oil groove 16 has a slope that becomes gradually shallower with respect to the oil entering direction. The following movement due to the viscosity of the oil when rotating is better performed, and a thick oil film can be easily formed in a wide range of the side surface 12. In this oil film, in the outer diameter side region of the side surface 12 of the seal ring 1, the side wall surface of the annular groove 3 is lost, and the gap between the rotating shaft 2 and the housing 4 is reached. However, this leakage is acceptable.

  Here, as the dimensions of the oil groove 16, in the AT seal ring 1 of a passenger car, the depth of the deepest portion 17 of the oil groove 16: 0.02 mm to 1.0 mm, and the oil groove bottom surface 19 of the oil groove 16. The inclination angle is set in the range of 1 ° to 45 °, the circumferential length of the oil groove 16: 0.2 mm to 5.0 mm, and the peripheral edge R of the oil groove 16: R 0.1 mm to R5.0 mm. The number of the oil grooves 16 is provided so that an oil film is formed over the entire circumference of the side surface 12 of the seal ring 1 in consideration of the circumferential length of the seal ring 1, the operating pressure, and the sliding speed.

  In order to form such an oil groove 16, the seal ring 1 is injected using a resin material such as ultra-high molecular weight polyethylene, PPS, or PEEK, or a resin material containing a filler as necessary. Manufactured by molding.

  In the embodiment described above, the oil groove 16 is provided on the side surface 12 of the seal ring 1, so that the oil in the oil groove 16 moves widely and thickly to the side surface 12 of the seal ring 1 when the rotary shaft 2 rotates. Let As a result, an oil film can be formed on almost the entire circumference of the side surface 12 on the opposite oil side of the seal ring 1, direct contact with the side wall surface of the annular groove 3 on the side surface 12 can be eliminated, and wear can be reduced. The seal ring 1 can be excellent in durability.

  Further, since the corner of the boundary between the oil groove 16 and the side surface 12 and the inner peripheral surface 14 is rounded to R, oil can be introduced from the oil groove 16 to the side surface 12 without scraping oil at the corner. A wide and thick oil film can be formed on the side surface 12.

In the above-described embodiment, the opening shape from the side surface 12 side of the oil groove 16 is a substantially curved parallelogram shape. However, the shape is not limited to this, and the inner circumferential surface 14 increases as the rotation axis 2 rotates. As long as it spreads from the deepest portion 17 on the outer side in the outer diameter direction and the circumferential direction, and gradually becomes shallower from the deepest portion 17 in the outer diameter direction and the circumferential direction, a triangular shape or a figure as shown in FIG. A fan shape as shown in FIG. 7 is also included in the scope of the present invention.

  Further, in the seal ring 1 of the above embodiment, the rotation direction of the rotation shaft 2 is limited to one direction. However, in the case of the rotation shaft 2 whose rotation direction is reversely rotated, FIG. As shown, the oil groove 16 and a second oil groove (second groove) 16 ′ that is a mirror image may be provided. The second oil groove 16 ′ extends in the outer diameter direction and the circumferential direction from the deepest portion on the inner peripheral surface 14 side as it proceeds in the reverse rotation direction of the rotary shaft 2, and gradually from the deepest portion in the outer diameter direction and the circumferential direction. It is shallow. As described above, when the oil groove 16 is provided with the second oil groove 16 ′ which is a mirror image, the seal ring to which the present invention is applied can be used even when the rotation direction of the rotating shaft 2 is rotated forward or reverse.

  Further, these seal rings 1 are preferably provided with an oil groove 16 and a second oil groove 16 ′ on both of the two side surfaces 12 and 13 of the seal ring 1 so that they can be reversed. . As a result, it is possible to prevent erroneous assembly of the seal ring 1.

It is a fragmentary perspective view of the seal ring which concerns on embodiment. It is a side appearance figure of a seal ring concerning an embodiment. It is sectional drawing of the oil groove part of the seal ring which concerns on embodiment. It is an internal peripheral surface external view of the oil groove part of the seal ring which concerns on embodiment. It is a figure which shows the oil groove formation range of the seal ring which concerns on embodiment. It is a fragmentary perspective view of the seal ring which concerns on the other example of embodiment. It is a fragmentary perspective view of the seal ring which concerns on the other example of embodiment. It is a side external view of the seal ring which concerns on the other example of embodiment. It is a half cross-sectional view showing a mounting state of the seal ring. It is a half sectional view showing the case where there is unevenness on the surface of the annular groove on which the seal ring is mounted. It is a figure of the oil groove part of the seal ring of a prior art, (a) is an arrow view, (b) is sectional drawing. It is a figure which shows the oil groove formation range of the seal ring of a prior art.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Seal ring 2 Rotating shaft 3 Annular groove 4 Housing 11 Outer peripheral surface 12 Anti-oil side surface 13 Oil side side surface 14 Inner peripheral surface 15 Separation part 16 Oil groove 16 'Second oil groove 17 Deepest part 18 Oil groove side wall 19 Oil Groove bottom

Claims (3)

Mounted in an annular groove provided around the outer peripheral surface of the rotary shaft, the outer peripheral surface is in close contact with the inner wall of the housing through which the rotary shaft is inserted, and the side surface is slidably in close contact with the side wall surface of the annular groove on the anti-sealing fluid side. A seal ring that seals an annular gap between the rotating shaft and the housing,
Opened in the inner peripheral surface on the side surface of the seal ring, and spreads in the outer diameter direction and the circumferential direction from the deepest portion on the inner peripheral surface side as it advances in the rotation direction of the rotary shaft, and from the deepest portion to the outer diameter direction and the circumferential direction. A seal ring characterized by a groove that gradually becomes shallower in the direction.   2. The seal ring according to claim 1, wherein corners of a peripheral portion of the groove with a side surface of the seal ring and corners of a boundary between the side surface of the seal ring and the inner peripheral surface are rounded.   The seal ring according to claim 1, wherein the groove and a second groove having a mirror image are provided on a side surface of the seal ring.

Images