JP6023502B2 - Sealing device - Google Patents

Description

  The present invention relates to a sealing device according to a sealing technique. The sealing device of the present invention is used, for example, as a rotating oil seal in the field of automobiles, or as a rotating oil seal in the field of general-purpose machines.

  Conventionally, as shown in FIG. 5, a slinger 51 mounted on one member (for example, shaft 71) of two members that rotate relative to each other and a lip member mounted on the other member (for example, shaft housing, not shown). 61, the former slinger 51 is integrally provided with a cylindrical portion 52 fitted to one member and a radially extending flange portion 53, and the latter lip member 61 slides on the flange portion 53. An end face lip 62 that is freely in close contact is provided. For example, it is used as an engine seal in the field of automobiles, so that oil in the machine A is prevented from leaking to the machine B and external dust from the machine B enters the machine A. A sealing device (end face lip type oil seal) that suppresses this is known.

  This type of sealing device is used by the combination of the slinger 51 and the lip member 61 as described above. The oil swing-off effect caused by the rotation of the slinger 51 together with one member, the end face lip 62 and the slinger 51 The oil is sealed by having an appropriate repulsive force (contact force).

  However, when used for a long period of time, oil leakage may occur due to a decrease in interference due to sag (deterioration) of the end surface lip 62 and a decrease in repulsive force (contact force) between the end surface lip 62 and the slinger 51 due to decrease in interference. May occur.

Japanese Utility Model Publication No. 63-36759 Japanese Utility Model Publication No. 61-47159

  In view of the above, the present invention provides a sealing device comprising a combination of a slinger and a lip member, and suppresses a reduction in repulsive force (contact force) due to the sag of the end face lip over a long period of time, thereby providing a sealing property. It aims at providing the sealing device which can improve.

  In order to achieve the above object, a sealing device according to claim 1 of the present invention includes a slinger attached to one of two relatively rotating members and a lip member attached to the other member, The slinger integrally includes a cylindrical portion fitted to the one member and a radially extending flange portion, and the lip member has an end surface lip that is slidably in close contact with the flange portion. A backup lip that suppresses a decrease in repulsive force due to the sag of the end surface lip is provided so as to contact the back surface of the end surface lip, and the backup lip is held by a flange portion of the slinger. To do.

Further, the sealing device according to claim 2 of the present invention is the sealing device according to claim 1, wherein the backup lip is formed by the action of a centrifugal force during the high-speed rotation of the one member and the slinger driven by the one member. It is characterized by being separated from the back of the end face lip.

According to a third aspect of the present invention, there is provided the sealing device according to the first or second aspect, wherein the screw portion that pushes back the sealing fluid by a pumping action when the one member and the slinger driven by the member rotate. The end surface lip is provided on the end surface of the flange portion of the slinger.

  Furthermore, a sealing device according to a fourth aspect of the present invention is the sealing device according to the first, second, or third aspect, wherein the backup lip is formed by a plurality of circumferential projections provided at the tip thereof. It contacts the back surface of this.

  In the sealing device of the present invention having the above configuration, since the backup lip that suppresses the reduction in the repulsive force due to the sag of the end face lip is provided so as to contact the back surface of the end face lip, the backup lip is the end face lip. By supporting from the back side, it is possible to maintain a stable repulsive force over a long period of time. Since the backup lip is held by the flange portion of the slinger, it follows the slinger and supports the end lip from the back side while following the slinger.

When one member and the slinger that follows it rotate, the backup lip also rotates at a high speed when they rotate at a high speed, and there is a concern that the friction torque between the backup lip and the end face lip increases. Therefore, by utilizing the fact that the backup lip rotates at a high speed, the backup lip is separated from the back surface of the end face lip by the action of centrifugal force at the time of high speed rotation, thereby suppressing an increase in friction torque. Further, when the backup lip is separated from the end surface lip, the backup lip does not support the end surface lip, so that it is possible to suppress an increase in friction torque between the end surface lip and the slinger.

When one member and the slinger that follows it rotate, the end surface of the flange portion of the slinger where the end surface lip contacts the threaded portion that pushes back the sealing fluid by the pumping action at the time of rotation using the rotation of the slinger This improves the sealing performance against the sealing fluid. Also, as described above, when the backup lip is separated from the back of the end face lip by the action of centrifugal force at high speed rotation, the backup lip does not support the end face lip and the repulsive force is reduced, resulting in a decrease in sealing performance. Can be supplemented by the sealing action of the threaded portion.

  The structure in which the backup lip contacts the back surface of the end surface lip may be a structure in which the tip of the backup lip directly contacts the back surface of the end surface lip, but a plurality of protrusions on the circumference are provided at the tip of the backup lip. It is good also as a structure which contacts the back surface of an end surface lip by this projection part. If the backup lip contacts the end face lip over the entire circumference, the gap between the backup lip and the end face lip is blocked, and there is a concern that the sealing fluid (oil) will not flow easily and the sealing action by the screw part will be reduced. However, if a plurality of circumferential protrusions are provided at the tip of the backup lip so that the protrusions come into contact with the back of the end face lip, the sealing fluid can easily flow between the protrusions. Can be suppressed.

  The present invention has the following effects.

  That is, according to the present invention, as described above, the back-up lip held by the flange portion of the slinger supports the end surface lip from the back side, so that a stable repulsive force can be maintained over a long period of time. It is said. Therefore, since the sealing performance of the end face lip is maintained for a long period of time, the oil leakage suppressing effect by the end face lip can be maintained for a long period of time.

  When the backup lip is separated from the back of the end face lip by the action of centrifugal force, an increase in sliding torque can be suppressed, and when a screw part that exhibits a pumping action is provided on the end face of the flange part of the slinger, this The sealing performance against the sealing fluid can be improved by the pumping action of the screw portion. In addition, when the backup lip is brought into contact with the back surface of the end surface lip by a plurality of circumferential projections provided at the tip thereof, it is possible to suppress a reduction in the sealing action by the screw portion even if the backup lip is provided. .

Sectional drawing of the principal part of the sealing device which concerns on the Example of this invention. Explanatory drawing which shows the state at the time of the assembly of the sealing device Cross-sectional view of the main part showing the state of the sealing device during high-speed rotation of the shaft Explanatory drawing of the screw part with the sealing device Sectional drawing of the principal part of the sealing device which concerns on a prior art example

The present invention includes the following embodiments.
(1) In order to suppress a reduction in the repulsive force (contact force) due to the sag of the end face lip, a backup lip integrated with the slinger is set on the back face of the end face lip. The back-up lip supports the end face lip from the back, so that a stable repulsive force (contact force) can be generated over a long period of time.
(2) When the shaft (slinger) rotates at high speed, the backup lip opens to the outer peripheral side by centrifugal force and is set so as not to contact the end face lip. When the shaft (slinger) rotates at high speed, the oil sealability can be secured by the pumping action by the screw set on the inner surface of the slinger. In addition, an increase in friction torque can be suppressed as much as possible.
(3) The back-up lip comes into contact with the end surface lip when the pumping action by the screw on the inner surface of the slinger is reduced during low rotation and stop, and the end surface lip is set to have an appropriate repulsive force (contact force) with the slinger.
(4) Further, the backup lip has protrusions at equal intervals on the circumference on the contact surface side with the end face lip. This protrusion comes into contact with the end face lip and does not come into full contact. Thereby, the pumping action (flow of oil) by the screw on the inner surface of the slinger during low rotation is not hindered.
(5) According to the technology of the present invention, it is possible to suppress the decrease in the repulsive force due to the sag (deterioration) of the end face lip over a long period of time. As a result, oil leakage can be improved and vehicle life can be improved. Further, the backup lip of the present invention can suppress an increase in friction torque during high-speed rotation.

  Next, embodiments of the present invention will be described with reference to the drawings.

  FIG. 1 shows a cross section of the main part of a sealing device according to an embodiment of the present invention. The sealing device according to the embodiment is used as, for example, an engine seal in a field related to automobiles, and suppresses the oil in the machine A from leaking to the outside (atmosphere side) B and the outside of the outside B. Suppresses dust from entering Aircraft A.

  The sealing device according to this embodiment includes a slinger 11 that is mounted on a shaft 71 that is one of two members that rotate relative to each other, and a lip member that is mounted on a shaft housing (not shown) that is the other member. 21 and is constituted by a combination of these.

  The slinger 11 is made of a metal material, and is formed by integrally molding a flange portion (outward flange portion) 13 outwardly in the radial direction at one axial end (in-machine A side) of the cylindrical portion 12. The inner peripheral surface of the cylindrical portion 12 is fitted to the outer peripheral surface of the shaft 71. The cylindrical portion 12 and the flange portion 13 may each include stepped portions 14 and 15 as shown in the figure.

  The lip member 21 has an attachment ring 22 and a rubber-like elastic body 31 attached to the attachment ring. The mounting ring 22 is made of a metal material, and is formed by integrally forming a flange portion (inward flange portion) 24 inward in the radial direction at an end portion on the other axial side (external side B) of the cylindrical portion 23. Then, the outer peripheral surface of the cylindrical portion 23 is fitted to the inner peripheral surface of the shaft housing. The cylindrical portion 23 may include a stepped portion 25 as illustrated, and the flange portion 24 may include a tapered surface 26 as illustrated.

  The rubber-like elastic body 31 is slidable on the other end surface 13a in the axial direction of the flange portion 13 of the slinger 11 supported by the attached rubber portion 32 and 22 attached to the mounting ring. An intimate end lip (side lip) 33 and a sub lip 34 which is also supported by the adherend rubber part 32 and provided on the inner peripheral side of the end face lip 33 are integrally provided. A step 35 for mounting is provided on the other end surface in the direction, and a radial lip 36 made of a synthetic resin that is slidably in close contact with the outer peripheral surface of the cylindrical portion 12 of the slinger 11 is assembled to the step 35. Yes. The end surface lip 33 mainly seals the oil in the machine A. In order to perform this function, the lip end is directed to the machine A side and obliquely outward in the radial direction. The sub lip 34 is not in contact with the slinger 11. The radial lip 36 mainly seals the external dust outside the machine B. In order to perform this function, the lip end of the radial lip 36 is on the machine B side and is directed to the other side in the axial direction when combined with the slinger 11. ing. The radial lip 36 may not be a single lip made of synthetic resin, but may be integral with the end face lip 33 formed by the rubber-like elastic body 31.

  Moreover, the sealing device according to the embodiment has the following configuration as a further feature.

  That is, a backup lip 37 for suppressing a decrease in the repulsive force due to the sag of the end surface lip 33 is provided so as to contact the back surface (the other surface in the axial direction) 33a of the end surface lip 33. The backup lip 37 is positioned on the outer peripheral side of the lip end of the end face lip 33 and is held by the flange portion 13 of the slinger 11. That is, the backup lip 37 is made of a predetermined rubber-like elastic body, and is attached (vulcanized and bonded) to the other end surface 13a in the axial direction of the flange portion 13 of the slinger 11 at the base end portion 37a. 37b is provided on the outside B side and obliquely inward in the radial direction, and the lip end 37b is provided so as to contact the back surface 33a of the end surface lip 33.

  Further, as shown in FIG. 2, when the shaft 71 and the slinger 11 driven by the backup lip 37 rotate at a high speed, the lip end 37b swings radially outward by the action of centrifugal force ( The swinging direction is indicated by an arrow x), whereby the structure separates from the back surface 33a of the end surface lip 33.

  Further, a threaded portion 16 that pushes back the sealing fluid by a pumping action when the shaft 71 and the slinger 11 driven by the shaft 71 rotate is provided on the other end surface 13a in the axial direction of the flange portion 13 of the slinger 11 with which the end surface lip 33 contacts. ing. As shown in part of FIG. 3, the screw portion 16 is provided as a spiral protrusion or groove, and pushes back the sealing fluid radially outward by a pumping action accompanying the rotation. An arrow y indicates the rotation direction of the shaft 71 at this time.

  Further, as shown in FIG. 4, a plurality of protrusions 38 are provided on the circumference of the lip end 37 b of the backup lip 37, and the backup lip 37 is structured to contact the back surface 33 a of the end face lip 33 with the protrusions 38. Yes. Since a plurality of protrusions 38 are provided on the circumference, a gap 39 is provided between the protrusions 38 adjacent to each other. Thus, a gap 39 is provided, and the sealed fluid passes therethrough. Therefore, even if the backup lip 37 is in contact with the back surface 33a of the end surface lip 33 with the protrusion 38, the sealing effect by the pumping action of the screw portion 16 is exhibited.

  Further, when the backup lip 37 is assembled from the state shown in FIG. 4 to the state shown in FIG. 1, the projection 38 is pressed by the end face lip 33 and elastically deforms so that the inclination angle of the slinger 11 with respect to the flange 13 is increased. . Therefore, in this process, the backup lip 37 is provided with an elastic restoring force in one axial direction for pressing the end lip 33 toward the flange portion 13 of the slinger 11.

  In the sealing device having the above-described configuration, the backup lip 37 is provided so as to be in contact with the back surface 33a of the end surface lip 33 so as to suppress a decrease in the repulsive force due to the sag of the end surface lip 33. However, by pressing and supporting the end face lip 33 from the back face 33a side, it is possible to maintain a stable repulsive force over a long period of time. Therefore, since the sealing performance of the end surface lip 33 is maintained over a long period of time, the oil leakage suppressing effect by the end surface lip 33 can be maintained over a long period of time, and the sealing performance against the sealing fluid can be improved. it can.

  Further, the backup lip 37 and the end surface lip 33 are separated from the back surface 33a of the end surface lip 33 by the action of centrifugal force when the shaft 71 and the slinger 11 driven thereby rotate at high speed. It is possible to suppress an increase in the friction torque generated between the end face lip 33 and the slinger 11.

  Further, a threaded portion 16 that pushes back the sealing fluid by a pumping action when the shaft 71 and the slinger 11 driven by the shaft 71 rotate is provided on the other end surface 13a in the axial direction of the flange portion 13 of the slinger 11 with which the end surface lip 33 contacts. Therefore, the sealing performance against the sealing fluid can be improved by the pumping action of the screw portion 16. Further, as described above, the sealing effect by the screw portion 16 compensates for the deterioration of the sealing performance due to the reduction of the repulsive force when the backup lip 37 is separated from the back surface 33a of the end face lip 33 by the action of centrifugal force during high-speed rotation. Can do.

  Further, a plurality of circumferential protrusions 38 are provided on the lip end 37 b of the backup lip 37, and the backup lip 37 is configured to contact the back surface 33 a of the end face lip 33 with the protrusions 38. Even when 37 is in contact with the end surface lip 33, the sealing fluid can flow between the backup lip 37 and the end surface lip 33. Accordingly, since the sealing effect by the pumping action of the screw portion 16 is always exhibited even when the backup lip 37 is in contact with the end surface lip 33 or away from the end surface lip 33, this also provides a seal against the sealing fluid. Can be improved.

DESCRIPTION OF SYMBOLS 11 Slinger 12, 23 Cylindrical part 13,24 Flange part 13a Flange part end surface 14,15,25 Step part 16 Screw part 21 Lip member 22 Mounting ring 26 Tapered surface 31 Rubber-like elastic body 32 Adhered rubber part 33 End surface lip 33a Back 34 Sub lip 36 Radial lip 37 Backup lip 37a Base end 37b Lip end 38 Projection 39 Gap

Claims (4)

The slinger has a slinger attached to one of the two members that rotate relative to each other and a lip member attached to the other member, and the slinger has a cylindrical portion fitted to the one member and a radial direction. A sealing device having an end surface lip that is slidably in close contact with the flange portion.
A backup lip that suppresses a decrease in repulsive force due to the sag of the end surface lip is provided so as to contact the back surface of the end surface lip,
The sealing device, wherein the backup lip is held by a flange portion of the slinger. The sealing device according to claim 1.
The sealing device according to claim 1, wherein the backup lip is separated from the back surface of the end face lip by the action of centrifugal force when the one member and the slinger driven by the one member are rotated at a high speed. The sealing device according to claim 1 or 2,
2. A sealing device according to claim 1, wherein a screw portion for pushing back the sealing fluid by a pumping action when the one member and the slinger driven by the one member rotate is provided on an end surface of the flange portion of the slinger where the end surface lip contacts. The sealing device according to claim 1, 2 or 3,
The sealing device according to claim 1, wherein the backup lip contacts the back surface of the end surface lip by a plurality of circumferential projections provided at a tip thereof.

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