JP4790534B2 - Sealing device - Google Patents

Description

  The present invention relates to a sealing device that is slidable in the axial direction by supplying hydraulic oil to a hydraulic chamber.

Conventionally, in a power connection part of an automatic transmission such as an automobile (AT), as indicated in Patent Document 1, the sealing device of the slidable ring in the axial direction by the supply of hydraulic fluid to the hydraulic chamber (Bo Used). In this power connection portion, a recess is provided in the casing, and the sealing device closes the opening side of the recess to constitute a hydraulic chamber. By supplying the hydraulic oil to the hydraulic chamber, the sealing device can slide in the axial direction according to the hydraulic pressure, and the outer diameter portion of the sealing device that slides in the axial direction presses the multi-plate clutch. Power is transmitted.

JP 2002-139155 A

In such an automatic transmission, when air (bubbles) cannot be removed from the hydraulic oil and the hydraulic oil containing a large amount of air is supplied into the hydraulic chamber, the air is more easily compressed than the hydraulic oil. There is a problem that the responsiveness of the operation of the sealing device that slides in accordance with the hydraulic pressure of the oil is reduced, or the operating pressure of the sealing device according to the hydraulic pressure cannot be obtained. In this case, there is a possibility that the responsiveness of the operation in the power connection portion is lowered, or the power connection portion (multi-plate clutch) slips due to insufficient working pressure.
Therefore, the present invention has been made in view of the above problems, and even if the hydraulic oil supplied to the hydraulic chamber contains air, it is possible to suppress a decrease in the response of the operation, and to reduce the hydraulic pressure in the hydraulic chamber. It is an object of the present invention to provide a sealing device capable of obtaining a corresponding operating pressure.

In order to achieve the above object, a sealing device according to the present invention forms a hydraulic chamber by closing an opening side of a recess provided in a casing, and seals sliding in an axial direction by supplying hydraulic oil to the hydraulic chamber. The apparatus includes a seal lip that contacts a peripheral wall surface of the hydraulic chamber, and the seal lip forms a flow path for allowing air contained in the hydraulic oil in the hydraulic chamber to escape to the outside of the hydraulic chamber. The passage forming means has a contact surface with the peripheral wall surface, and the flow path forming means protrudes from the smooth contact surface, and comes into contact with the peripheral wall surface to the side in the circumferential direction. It is a quadrangular pyramid shaped protrusion that forms a minute gap that communicates from the hydraulic chamber to the outside, and the slope on the lip tip side that is the hydraulic chamber side of the protrusion is the lip base end that is the external side Than the slope on the part side Wherein the tilt angle is large.
According to this configuration, the air contained in the hydraulic oil in the hydraulic chamber can be released to the outside of the hydraulic chamber by the flow path forming means of the seal lip. As a result, the responsiveness of the operation of the sealing device that slides according to the hydraulic pressure in the hydraulic chamber is reduced due to the air contained in the hydraulic oil, or the operating pressure of the sealing device according to the hydraulic pressure cannot be obtained. This can be suppressed.

The front Kiryuro forming means forms a minute gap leading and raised from smooth the contact surface, from the hydraulic chamber on the side of the circumferential direction by contact with the peripheral wall surface to the external four than a protrusion truncated pyramid, the small gap in the circumferential direction of the side of the protruding portion is formed in the protrusion is brought into contact with the peripheral wall surface, the small gap of air contained in the hydraulic fluid Can escape to the outside of the hydraulic chamber. Moreover, the formation of the protrusion is easy, and the sealing device can be manufactured at a low cost.

Moreover, it is preferable that the said sealing device is a piston seal used in the power connection part of an automatic transmission.
As a result, it is possible to prevent the responsiveness of the operation of the sealing device that slides according to the hydraulic pressure in the hydraulic chamber from being reduced, and it is possible to prevent the operating pressure of the sealing device according to the hydraulic pressure from being obtained. Responsiveness of power transmission in the power connection portion can be maintained high, and slipping of the power connection portion due to insufficient operating pressure can be suppressed.

  According to the sealing device of the present invention, even if the hydraulic oil in the hydraulic chamber contains air, the air can be released to the outside of the hydraulic chamber by the flow path forming means of the seal lip. Accordingly, it is possible to suppress a decrease in the responsiveness of the operation of the sealing device that slides according to the pressure, and to obtain an operating pressure of the sealing device according to the hydraulic pressure.

Embodiments of the present invention will be described below with reference to the drawings.
FIG. 1 is a cross-sectional view of an essential part showing an embodiment of a sealing device of the present invention, and shows a case where the sealing device 1 of the present invention is used in a power connection portion of an automatic transmission of an automobile. In FIG. 1, a casing 10, a multi-plate clutch 11, the sealing device (bonded seal) 1 serving as a piston seal, and a spring member 12 attached to the casing 10 are disposed in the power connection portion. Yes.

  The casing 10 includes a shaft portion 13 radially inward, a radial portion 14 extending radially outward from the shaft portion 13, and an axial portion 15 extending from the radial portion 14 in the axial direction on the multi-plate clutch 11 side. In these portions, the concave portion 7 having a substantially U-shaped cross section is formed. A part of the annular sealing device 1 is provided in the recess 7, and the sealing device 1 constitutes a hydraulic chamber 8 by closing the opening side of the recess 7. The peripheral wall surface (inner peripheral surface) 21 of the axial direction portion 15 and the outer peripheral surface 20 of the axial portion 13 are arranged to face each other in the radial direction.

  The sealing device 1 has a metal annular member 2 and an annular seal portion 3 fixed to the annular member 2. The annular member 2 is press-molded into a predetermined shape, and includes a main body portion 2a having a stepped disk shape and a cylindrical outer diameter portion 2b extending in the axial direction from a radially outer portion of the main body portion 2a. Have. The outer flange portion 2c at the tip of the outer diameter portion 2b contacts the multi-plate clutch 11. The seal portion 3 is made of an elastic material, and is made of rubber, for example, and is vulcanized and bonded to the main body portion 2 a of the annular member 2. The seal portion 3 has an inner seal lip 4a as the inner seal portion 4 that contacts the outer peripheral surface 20 of the shaft portion 13 on the inner peripheral side, and an outer surface that contacts the peripheral wall surface 21 of the axial direction portion 15 on the outer peripheral side. It has an outer seal lip 5 a as the seal portion 5. The inner seal lip 4 a extends from the main body 2 a side toward the outer peripheral surface 20 and contacts the outer peripheral surface 20. Further, the outer seal lip 5 a extends from the main body 2 a side toward the peripheral wall surface 21 and contacts the peripheral wall surface 21.

  Thereby, the sealing device 1 can partition between the hydraulic chamber 8 on the high pressure side and the exterior 9 on the low pressure side. Further, the hydraulic chamber 8 communicates with an oil hole (not shown) for supplying hydraulic oil to the hydraulic chamber 8 and discharging the hydraulic oil from the hydraulic chamber 8, and the hydraulic chamber 8 operates to the hydraulic chamber 8 through the oil hole. The sealing device 1 can slide in the axial direction by supplying and discharging oil. That is, the sealing device 1 can function as a piston member.

  The spring member 12 is an annular disc spring. The outer diameter portion of the annular spring member 12 is in contact with the side surface of the outer diameter portion of the main body portion 2 a of the sealing device 1, and the inner diameter portion of the spring member 12 is externally fitted to the shaft portion 13 and fixed to the shaft portion 13. It is in contact with the retaining ring 16. As a result, the spring member 12 is attached to the shaft portion 13 with its position regulated. The spring member 12 can elastically press the sealing device 1 in a direction in which the annular hydraulic chamber 8 is contracted. Therefore, the sealing device 1 is moved in the direction of expanding the hydraulic chamber 8 (the right direction in FIG. 1) against the elastic force of the spring member 12 by supplying hydraulic oil and increasing the hydraulic pressure of the hydraulic chamber 8. By reducing the hydraulic pressure in the hydraulic chamber 8, the sealing device 1 can be moved in the direction in which the hydraulic chamber 8 is contracted (the left direction in FIG. 1) by the elastic force of the spring member 12. Thus, when the sealing device 1 slides in the axial direction, the outer diameter portion 2b presses the multi-plate clutch 11, and power is transmitted.

  2 is a cross-sectional view of the sealing device 1, and FIG. 3 is a cross-sectional view of the main part of the outer seal lip 5a. 4 is a view taken along the arrow IV in FIG. 3, and FIG. 5 is a view taken along the arrow V in FIG. 1 to 5, the outer seal lip 5 a has flow path forming means 6 that forms a flow path for allowing air contained in the hydraulic oil in the hydraulic chamber 8 to escape to the outside 9 of the hydraulic chamber 8. ing. This flow path forming means 6 is a protrusion 17 formed on a contact surface (sliding contact surface) 5b with the peripheral wall surface 21 (see FIG. 1) of the outer seal lip 5a (first embodiment). . It is only necessary that at least one protrusion 17 is provided in the circumferential direction of the contact surface 5b. In FIG. 4, three protrusions 17 are provided at intervals P in the circumferential direction of the contact surface 5b. The protrusion 17 is formed so as to protrude from the smooth circumferential contact surface 5b, and is integrally formed with the outer seal lip 5a.

  By this projecting portion 17 coming into contact with the peripheral wall surface 21 of the axial portion 15 of the casing 10, a minute gap 22 communicating from the hydraulic chamber 8 to the outside 9 can be formed on the lateral side of the projecting portion 17. it can. That is, the contact surface 5b on which the protrusions 17 are formed is slightly floated from the peripheral wall surface 21 locally, and the minute gap 22 between the peripheral wall surface 21 and the contact surface 5b is used as a flow path for venting air. Thereby, the air contained in the hydraulic oil in the hydraulic chamber 8 can be released to the outside 9 through the minute gap 22 by the internal pressure in the hydraulic chamber 8. Although the cross-sectional area of the minute gap 22 is small and air can pass through the minute gap 22, the hydraulic oil is higher in viscosity than air, so that passage of the hydraulic oil is suppressed. In addition, as shown in FIG. 1, the operation connecting portion is configured such that the axial center (not shown) of the sealing device 1 is substantially horizontal, so that the hydraulic oil in the annular hydraulic chamber 8 is Since the contained air naturally gathers at the upper position of the hydraulic chamber 8, the protrusion 17 is formed at the upper position of the contact surface 5 b of the annular outer seal lip 5 a so that the air can be efficiently released to the outside 9. Can do. Further, since the protrusion 17 can be formed integrally with the outer seal lip 5a and the mold, the sealing device 1 can be manufactured at a low cost.

  The shape of the protrusion 17 in FIGS. 3, 4 and 5 is a quadrangular pyramid, and its height h is set to 0.2 mm to 0.4 mm, for example. The width dimension b in the circumferential direction of the protrusion 17 and the interval P between the protrusions 17 are substantially the same, for example, set to 1.0 mm to 2.0 mm. In FIG. 3, the protrusion 17 has a slope 17 a on the lip tip side that has a larger inclination angle than the slope 17 b on the lip base end side, and the protrusion 17 includes the contact surface 5 b on which the protrusion 17 is formed. The hydraulic chamber 8 side is more easily separated from the peripheral wall surface 21 than the outside 9 side. Thereby, it becomes easy to discharge air to the outside 9.

FIG. 6 is a cross-sectional view showing a main part of another sealing device 1 . The sealing device 1 is the same as the first embodiment except for the flow path forming means 6 and the other parts are the same. This flow path forming means 6 is a notch groove 18 formed in the contact surface (sliding contact surface) 5b from the lip tip of the outer seal lip 5a. In a state where the contact surface 5 b of the outer seal lip 5 a is in contact with the peripheral wall surface 21 of the axial portion 15 of the casing 10, the notch groove 18 has a groove length that leads from the hydraulic chamber 8 to the outside 9. Further, at least one notch groove 18 may be provided in the circumferential direction of the contact surface 5b of the outer seal lip 5a. When a plurality of the cutout grooves 18 are provided, the cutout grooves 18 may be provided at intervals in a part of the circumferential direction of the contact surface 5b. (Not shown).

  According to the notch groove 18, air is vented from the hydraulic chamber 8 to the outside 9 between the peripheral wall surface 21 of the axial portion 15 of the casing 10 and the contact surface 5 b of the outer seal lip 5 a that is in contact with the peripheral wall surface 21. A flow path for is formed. Thereby, the air contained in the hydraulic oil in the hydraulic chamber 8 can be released to the outside 8 through the notch groove 18 by the internal pressure in the hydraulic chamber 8. Further, the formation of the notch groove 18 is easy because it can be integrally formed with the outer seal lip 5a and a mold, and the sealing device 1 can be manufactured at low cost.

  Further, in a state where the contact surface 5b of the outer seal lip 5a is in contact with the peripheral wall surface 21, the cross-sectional area of the notch groove 18 is small, and air can pass through the notch groove 18, but the hydraulic oil is more viscous than air. Its passage is suppressed due to its high height. The cross-sectional shape of the notch groove 18 is an arc shape, and the radius can be set to 0.5 mm to 1 mm, for example. Similarly to the first embodiment, the operation connecting portion is configured in such a posture that the axial center (not shown) of the sealing device 1 is substantially horizontal (see FIG. 1), and the outer seal lip 5a. In the contact surface 5 b, a notch groove 18 is formed at a position corresponding to the upper position of the hydraulic chamber 8. Thereby, the air collected at the upper position of the hydraulic chamber 8 can be efficiently released to the outside 9.

FIG. 7 is a cross-sectional view showing a main part of another sealing device 1 . This sealing device 1 is different from the sealing device of the first and FIG. 6 in the flow path forming means 6, and the others are the same. This flow path forming means 6 is a minute through hole 19 that penetrates the outer seal lip 5 a from the hydraulic chamber 8 to the outside 9. The through holes 19 are opened on both sides of the middle portion between the distal end portion of the outer seal lip 5a that contacts the peripheral wall surface 21 and the base end portion on the main body portion 2a side. Even when the contact surface 5 b of the seal lip 5 a is in contact, the hydraulic chamber 8 and the outside 9 are communicated with each other through the through hole 19. Further, at least one through hole 19 may be provided in the circumferential direction of the outer seal lip 5a, and when a plurality of through holes 19 are provided, they may be provided with a gap in a part of the circumferential direction (not shown).

According to the through hole 19, air contained in the hydraulic oil in the hydraulic chamber 8 can be released to the outside 8 through the through hole 19 by the internal pressure in the hydraulic chamber 8. Moreover, although the cross-sectional area of the through-hole 19 is small and air can pass through this through-hole 19, since the hydraulic oil is higher in viscosity than air, its passage is suppressed. The through hole 19 has a circular cross section, and the diameter can be set to 1 mm to 2 mm, for example. Similarly to the sealing device of the first and FIG. 6, the operation connecting portion is configured such that the axial center (not shown) of the sealing device 1 is substantially horizontal (see FIG. 1), and the outer seal In the lip 5a, a through hole 19 is formed at a position corresponding to the upper position of the hydraulic chamber 8. Thereby, the air collected at the upper position of the hydraulic chamber 8 can be efficiently released to the outside 9.

  Further, since the through hole 19 is not formed on the contact surface 5b of the outer seal lip 5a, that is, is formed in the middle part away from the contact surface 5b, the tightening margin between the peripheral wall surface 21 and the outer seal lip 5a changes. Even so, the influence of the change in the cross-sectional area of the through hole 19 for air venting is small. For this reason, even if the outer seal lip 5a is greatly deformed and the tightening margin is increased, it is possible to prevent the cross-sectional area of the flow path (through hole 19) through which air is released from becoming too small. As a result, it is possible to prevent the air from being difficult to escape from the through hole 19.

According to the following, the hydraulic oil in the hydraulic chamber 8, be included compressed easily air than the hydraulic oil (gas) is the protrusion of the channel forming unit 6 formed on the outer seal lip 5a 17, the notch groove 18, and the through hole 19 can release air contained in the hydraulic oil to the outside 9 of the hydraulic chamber 8. For this reason, the sealing device 1 can be slid in the axial direction according to the hydraulic pressure in the hydraulic chamber 8, and a decrease in the responsiveness of the operation of the sealing device 1 can be suppressed, and the sealing device according to the hydraulic pressure A working pressure of 1 can be obtained. Therefore, by using the sealing device 1 as a piston seal used in the power connection portion of the automatic transmission, the power transmission responsiveness in the power connection portion can be increased, and the power connection portion (multiple The slippage of the plate clutch 11) can be suppressed.

Further, the sealing device of the invention, but it may also be of other forms within the scope of the invention is not limited to the embodiments shown. The cross-sectional shape of the cutout groove 18 may be V-shaped or rectangular in addition to the arc shape, and the cross-sectional shape of the through hole 19 may be rectangular or oval other than circular. Further, the inner seal portion 4 of the sealing device 1 may have another form. For example, referring to FIG. 1, a cylindrical portion (not shown) that fits around the shaft portion 13 is formed on the inner peripheral side of the annular member 2 a, and this cylindrical portion is used as the inner seal portion 4. The hydraulic oil may be sealed between the surface and the outer peripheral surface of the shaft portion 13, and in this case, an O-ring may be used for the shaft portion 13.

It is sectional drawing of the principal part which shows one Embodiment of the sealing device of this invention. It is sectional drawing of a sealing device. It is principal part sectional drawing of the outer seal lip part of a sealing device. It is IV arrow line view in FIG. FIG. 4 is a view taken in the direction of arrow V in FIG. 3. It is principal part sectional drawing of another sealing device . It is principal part sectional drawing of another sealing device .

DESCRIPTION OF SYMBOLS 1 Sealing device 4 Inner seal part 5a Outer seal lip 5b Contact surface 6 Flow path formation means 7 Recessed part 8 Hydraulic chamber 9 External 13 Shaft part 15 Axial part 17 Protrusion part 18 Notch groove 19 Through-hole 20 Outer peripheral surface 21 Peripheral wall surface

Claims (2)

In the sealing device that closes the opening side of the recess provided in the casing to constitute the hydraulic chamber, and slides in the axial direction by supplying hydraulic oil to the hydraulic chamber,
A flow path forming means for forming a flow path for allowing the air contained in the hydraulic oil in the hydraulic chamber to escape to the outside of the hydraulic chamber; On the contact surface with the peripheral wall surface ,
The flow path forming means protrudes from the smooth contact surface, and forms a small gap that forms a minute gap that leads from the hydraulic chamber to the outside on the side in the circumferential direction by contacting the peripheral wall surface. A protrusion of
The sealing device according to claim 1 , wherein the inclined surface on the lip distal end side, which is the hydraulic chamber side, has a larger inclination angle with respect to the contact surface than the inclined surface on the lip base end side, which is the external side. . The sealing device according to claim 1 , which is a piston seal used in a power connection part of an automatic transmission.

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