JP6011777B2 - Sealing device - Google Patents

Description

  The present invention relates to a sealing device that is interposed between a rotating part and a non-rotating part of a device that generates hydraulic pressure, such as a belt-type continuously variable transmission or a hydraulic device, and seals the hydraulic pressure.

  For example, in a belt type continuously variable transmission of an automobile, an inner peripheral surface of a hollow sheave shaft that rotates a fixed sheave and a movable sheave that can move in the axial direction with respect to the fixed sheave, and a non-insertion inserted into the sheave shaft. A sealing ring made of synthetic resin is interposed between the outer peripheral surface of the cylindrical portion of the rotating retainer as a sealing device for sealing the hydraulic pressure that moves the movable sheave in the axial direction (for example, Patent Documents). 1). However, since this type of seal ring is cut at one place in the circumferential direction, it is unavoidable that leakage occurs, and even a seal having a good sealing property causes leakage of 10 to 40 cc / min.

  Therefore, as a sealing means of such an apparatus, as shown in FIG. 4, a rubber-like elastic material (rubber material or synthetic resin material having rubber-like elasticity) is integrally formed on a metal reinforcing ring, and the reinforcing ring A sealing device 100 having a base 101 vulcanized and bonded, a fixed lip (inner lip) 102 and a sliding lip (outer lip) 103 extending from the base 101 toward the high pressure space (sealed space) A side. Has also been developed. The sealing device 100 has an endless shape, that is, is continuous in the circumferential direction.

  That is, the sealing device 100 is mounted in a state where the inner peripheral side fixed lip 102 is in close contact with the outer peripheral surface of a non-rotating member (not shown), and the outer peripheral sliding lip 103 is attached to the inner peripheral rotating member 200. By being slidably in contact with the peripheral surface, the hydraulic fluid in the sealed space A is prevented from leaking to the atmosphere B side and is continuous in the circumferential direction. Excellent sealing performance compared to a synthetic resin seal ring cut at a location.

JP 2007-078041 A

  However, according to the conventional sealing device 100 described above, when the sealed space A becomes high pressure, the sliding lip 103 strikes against the inner peripheral surface of the outer peripheral rotating member 200 to increase the torque and lubricate. There is a concern that the sliding lip 103 may be worn due to the shortage and the sealing performance thereof may be deteriorated early.

This acts on the pressure receiving area of the hydraulic pressure P ₁ acting on the inner peripheral surface of the sliding lip 103 and on the outer peripheral surface of the sliding lip 102 on the sealed space A side with respect to the intimate sliding portion 103 a of the sliding lip 103. A difference δ from the pressure receiving area of the hydraulic pressure P ₂ is large, that is, the hydraulic pressure P ₁ acting on the inner peripheral surface of the sliding lip 103 in the region indicated by reference numeral δ causes the sliding lip 102 to move to the outer peripheral rotating member 200. because they act to press the inner peripheral surface, the sliding lip 102 when the sealed space a is high is deformed as shown by the broken line in the drawing by the hydraulic pressure P _1, and increase the sliding torque by surface pressure increases, This results in insufficient lubrication due to an increase in sliding area.

  The present invention has been made in view of the above points, and a technical problem thereof is to provide a sealing device that is excellent in seal durability even under high pressure conditions and can maintain a low sliding torque. .

As a means for effectively solving the above technical problem, the sealing device according to the invention of claim 1 has a fixed lip and a sliding lip that extend to the sealed space side and are concentric with each other. Between the lips is a pressure receiving groove that is continuous in the circumferential direction, and a sliding ridge that is continuous in the circumferential direction is formed in the sliding portion of the sliding lip, and the sliding ridge is A first inclined surface extending toward the tip end of the sliding lip is formed with a gentler slope than a second inclined surface extending from the flange portion toward the root side of the sliding lip, and the first inclined surface of the sliding ridge is The moving lip has a gentler slope than the inclined surface on the pressure receiving groove side .

  According to the configuration of the first aspect, the first inclined surface extending from the flange portion of the sliding ridge to the distal end side (sealed space side) of the sliding lip is formed on the root side (anti-sealed space side) of the sliding lip from the flange portion. ) Has a gentler slope than the second inclined surface extending to), the flange portion is unevenly distributed to the anti-sealing space side of the sliding protrusion, and thus acts on the pressure receiving groove between the fixed lip and the sliding lip. Of the pressure in the sealed space, the pressure receiving area corresponding to the pressure imbalance that acts to press the sliding lip against the sliding mating material is reduced, so the sliding lip against the sliding mating material due to the high pressure in the sealed space Since the increase in the surface pressure is suppressed, and the first inclined surface extending from the flange portion of the sliding ridge to the sealed space side has a gentle slope, the liquid to be sealed in the sealed space can easily enter the wedge shape, The buttocks of the sliding ridge are well lubricated.

  A sealing device according to a second aspect of the invention is characterized in that, in the configuration of the first aspect, the flange portion of the sliding ridge is located on the root side from the intermediate position in the axial direction of the sliding lip. It is.

  According to the configuration of the second aspect, of the pressure in the sealed space acting on the pressure receiving groove between the fixed lip and the sliding lip, the unbalanced portion of the pressure acting to press the sliding lip against the sliding counterpart material Since the pressure receiving area is sufficiently small, an increase in the surface pressure of the sliding lip can be more effectively suppressed.

  According to a third aspect of the present invention, in the sealing device according to the first or second aspect, the sliding protrusion extends in the circumferential direction while meandering repeatedly in the axial direction.

  According to the configuration of the third aspect, since the sliding ridge repeatedly meanders in the axial direction, the liquid to be sealed that rotates together with the rotation of the sliding counterpart material is Since it is easy to enter the wedge shape between the moving counterparts, the sliding surface is lubricated better.

According to the sealing device of the present invention, the pressure receiving area of the pressure acting to press the sliding lip against the sliding partner material is reduced, and a lubricating liquid film is easily formed on the sliding portion by the liquid to be sealed. In addition, the increase in the surface pressure of the sliding lip due to the high pressure in the sealed space is suppressed and a good lubrication state is secured, and the first inclined surface of the sliding ridge is on the pressure receiving groove side of the sliding lip. Due to the gentler slope than the slope, the radial component of the hydraulic pressure acting on the first slope of the sliding ridge that lifts the sliding lip from the sliding material is the slope on the pressure receiving groove side of the sliding lip. Of the fluid pressure acting on the sliding surface is larger than the radial component that presses the sliding lip against the sliding mating member, so that the liquid to be sealed in the sealed space can easily enter the wedge shape, and the sliding surface is even better lubricated. Is done. Therefore, even under high pressure conditions, the seal durability is excellent and a low torque can be maintained.

1 is a half sectional view showing a preferred embodiment of a sealing device according to the present invention by cutting along a plane passing through an axis. It is the figure which looked at preferable embodiment of the sealing device which concerns on this invention from the outer peripheral side. It is explanatory drawing which shows the effect | action of preferable embodiment of the sealing device which concerns on this invention. It is explanatory drawing which shows the effect | action of the sealing device by a prior art.

  Hereinafter, preferred embodiments of a sealing device according to the present invention will be described with reference to the drawings.

  As shown in FIG. 1, the sealing device 1 is integrally formed of a rubber-like elastic material (rubber material or a synthetic resin material having rubber-like elasticity) on a metal-made reinforcing ring 15, and includes the reinforcing ring. 15 has a base portion 11 vulcanized and bonded, a fixed lip (inner lip) 12 and a sliding lip (outer lip) 13 extending from the base 11 toward the sealed space A in the mounted state. Between the fixed lip 12 and the sliding lip 13, a pressure receiving groove 14 having a substantially V-shaped cross section and continuous in the circumferential direction is formed. A plurality of support protrusions 11a are formed on the inner peripheral surface of the base 11 at predetermined intervals in the circumferential direction.

  On the outer peripheral surface which is the sliding side of the sliding lip 13, a sliding protrusion 131 continuous in the circumferential direction is formed. As shown in FIG. 2, the sliding protrusion 131 extends in the circumferential direction while meandering repeatedly in the axial direction.

Also, as shown in FIG. 3, the sliding protrusion 131 has a first inclined surface 131b extending from the flange 131a to the distal end side (sealed space A side) of the sliding lip 13, and the sliding lip 13 from the flange 131a. Is formed at a gentler slope (θ ₁ <θ ₂ ) than the second inclined surface 131c extending to the base side (anti-sealed space B side), and the first inclined surface 131b is on the pressure receiving groove 14 side of the sliding lip 13 The slope (θ ₁ <θ ₃ ) is gentler than that of the slope (inner peripheral surface) 132.

  For this reason, the flange 131a of the sliding ridge 131 is unevenly distributed to the anti-sealing space B side of the sliding ridge 131, and the base side (anti-sealing space B) from the intermediate position in the axial direction of the sliding lip 13. Even in the portion where the sliding protrusion 131 is most unevenly distributed on the tip end side of the sliding lip 13 due to meandering, the flange 131a is located on the root side from the intermediate position in the axial direction of the sliding lip 13. Yes.

  The sealing device 1 of the embodiment configured as described above includes, for example, a cylindrical shape of a hollow sheave shaft in a continuously variable transmission of an automobile and a non-rotating retainer inserted in the sheave shaft. The inner peripheral fixed lip 12 is mounted in close contact with the outer peripheral surface of an inner peripheral non-rotating member (not shown) (for example, the cylindrical portion of the retainer). As shown in FIG. 2, the sliding lip 13 on the outer peripheral side is slidably brought into close contact with the inner peripheral surface of the outer cylindrical rotating member (for example, the sheave shaft 2), thereby rotating. The liquid to be sealed (hydraulic oil) in the sealed space A on the inner periphery of the member 2 is prevented from leaking into the anti-sealed space B. And since this sealing device 1 is continuous in the circumferential direction, it has better sealing performance than a seal ring cut in one circumferential direction, and the leakage amount should be 1 cc / min or less. Can do.

  Here, the hydraulic pressure in the sealed space A acts to press against the outer peripheral surface of the inner non-rotating member against the fixed lip 12, but against the outer peripheral rotating member 2 against the sliding lip 13. It does not act as a significant pressing force.

This will be described in detail. As described above, the first inclined surface 131b of the sliding ridge 131 of the sliding lip 13 has a gentle slope and the second inclined surface 131c has a steep slope. 131a is unevenly distributed to the anti-sealing space B side of the sliding protrusion 131, and the flange 131a is located closer to the root side (anti-sealing space B side) than the intermediate position in the axial direction of the sliding lip 13. From the pressure receiving area of the hydraulic pressure P ₁ acting on the inclined surface (inner peripheral surface) 132 on the pressure receiving groove 14 side in the sliding lip 13, and the flange 131 a of the sliding protrusion 131 serving as a sliding surface with the rotating member 2. Further, the difference δ from the pressure receiving area of the hydraulic pressure P ₂ acting on the outer peripheral surface of the sliding lip 13 on the sealed space A side is smaller.

That is, the hydraulic pressure P ₁ acting so as to press the sliding lip 13 against the inner peripheral surface of the rotating member 2 substantially acts only on the region indicated by the symbol δ in FIG. 3, and the sliding lip 13 is larger than this region δ. The hydraulic pressures P ₁ and P ₂ are canceled out in the radial direction between the inner peripheral side and the outer peripheral side. In other words, since the area of the region δ that receives the unbalanced pressure acting to press the sliding lip 13 against the rotating member 2 is small, the surface of the sliding lip 13 (sliding protrusion 131) with respect to the rotating member 2 Increase in pressure is suppressed.

Moreover, in addition to the above-described surface pressure increase suppression action, the first inclined surface 131b of the sliding protrusion 131 has a gentle gradient (θ ₁ <θ ₂ ), so that the liquid to be sealed in the sealed space A is in contact with the sliding protrusion 131. It becomes easy to enter the wedge shape between the sliding surfaces with the rotating member 2. Further, by satisfying θ ₁ <θ ₃ , the radial component that lifts the sliding lip 13 from the rotating member 2 out of the hydraulic pressure P ₂ acting on the first inclined surface 131 _b of the sliding protrusion 131 is the sliding lip. 13, the hydraulic pressure P ₁ acting on the inclined surface 132 on the pressure receiving groove 14 side is larger than the radial component pressing the sliding lip 13 against the rotating member 2.

  Furthermore, since the sliding protrusion 131 meanders repeatedly in the axial direction, the liquid to be sealed that rotates together with the rotation of the rotating member 2 causes the flange 131a of the sliding protrusion 131 and the rotating member 2 to rotate. It becomes easy to enter between the sliding surfaces in a wedge shape.

  According to the sealing device 1, because of these actions, a good lubricating liquid film is formed between the sliding surfaces even when the sealed space A becomes high pressure. For example, the rotational speed is 3,000 rpm, and the sealed space A Even under a pressure of 3.5 MPa, it is possible to suppress sliding heat generation, suppress wear, and reduce sliding torque, and as a result, seal durability is improved.

  In the embodiment described above, the fixed lip 12 is formed on the inner peripheral side and the sliding lip 13 is formed on the outer peripheral side. However, the reverse relationship, that is, the fixed lip 12 is formed on the outer peripheral side and the sliding lip 13 is formed on the inner side. By being present on the peripheral side, the present invention can be applied to a device in which the outer peripheral member is not rotated and the inner peripheral member is rotated.

DESCRIPTION OF SYMBOLS 1 Sealing device 11 Base 12 Fixed lip 13 Sliding lip 131 Sliding ridge 131a Saddle 131b First slope 131c Second slope 14 Pressure receiving groove 2 Outer peripheral member A Sealing space B Anti-sealing space

Claims (3)

It has a fixed lip and a sliding lip that are concentric with each other and extend toward the sealed space. A pressure receiving groove is formed between the fixed lip and the sliding lip in the circumferential direction. A sliding ridge that is continuous in a direction is formed, and the sliding ridge has a first inclined surface that extends from the collar portion toward the distal end side of the sliding lip, and extends from the collar portion to the root side of the sliding lip. The sealing device is formed with a gentler slope than the second slope , and the first slope of the sliding ridge has a gentler slope than the slope of the sliding lip on the pressure receiving groove side .   2. The sealing device according to claim 1, wherein the flange portion of the sliding ridge is located closer to the root side than the intermediate position in the axial direction of the sliding lip.   The sealing device according to claim 1 or 2, wherein the sliding protrusion extends in the circumferential direction while repetitively meandering in the axial direction.

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