JP6000845B2 - 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, in the field of automobiles or in the field of general-purpose machines.

  Conventionally, as shown in FIG. 4, a slinger 52 that is fixed to the outer periphery of the rotating shaft 51 and rotates with the rotating shaft 51 is provided, and the end surface lip 53 is slidably in close contact with the axial end surface 52 a of the slinger 52. Therefore, a sealing device having a structure that suppresses leakage of a sealing fluid (oil) existing in the machine A to the outside B is known.

  Conventionally, a screw seal is known as a kind of sealing structure, and this screw seal seals a sealing fluid by a pumping action exerted by a screw portion provided on a rotating body during rotation.

  Assuming that the screw seal is combined with the sealing device, the configuration is as follows, for example.

  That is, as a comparative example for the present invention, as shown in FIGS. 5 and 6, a slinger 52 is provided which is fixed to the outer periphery of a rotating shaft (not shown) and rotates together with the rotating shaft. On the other hand, the end face lip 53 is slidably brought into close contact with the sealing fluid. Further, a threaded portion 54 (FIG. 6) is provided on the axial end surface 52a of the slinger 52, and the threaded portion 54 exhibits a pumping action when rotating, thereby sealing the sealing fluid.

  However, according to this combination technique, the following problems are pointed out.

That is, in the combination technique shown in FIGS. 5 and 6, the screw portion 54 is an annular region (screw) having a predetermined radial width d ₀ from the radial center portion to the outer peripheral end portion 52b of the axial end surface 52a of the slinger 52. Part formation region). The screw portion 54 is specifically provided as a spiral groove.

  Accordingly, as the positional relationship of such a threaded portion 54 with respect to the lip end 53a of the end face lip 53, the spiral groove is disposed so as to pass from the radially outer side to the lip end 53a. A gap corresponding to the cross section of the groove is formed between the end face lip 53 and the slinger 51 at a position where the lip-shaped groove and the lip end 53 a intersect. Therefore, when the rotation of the rotating shaft 51 stops and the centrifugal force disappears, the sealing fluid passes through this gap (spiral groove) and passes through the lip end 53a and enters the internal space 55 of the sealing device (static leakage). Occurrence), the sealing performance of the sealing device may be impaired due to this.

JP-A-10-115375 JP-A-7-208610

  In view of the above points, the present invention does not cause static leakage even if a threaded portion is provided on the axial end surface of the slinger in which the end surface lip is slidably in close contact, and thus can exhibit excellent sealing performance. An object is to provide an apparatus.

  To achieve the above object, the sealing device according to claim 1 of the present invention is such that the end face lip is slidably in close contact with the axial end face of the slinger that is fixed to the outer periphery of the rotary shaft and rotates together with the rotary shaft. In the sealing device that seals the sealing fluid by sealing the sealing fluid by sealing the sealing fluid by causing the screw portion provided on the axial end surface of the slinger to exhibit a pumping action when rotating, the slinger includes the screw portion provided with the screw portion Provided on the outer peripheral side of the forming region is a screw portion non-existing region in which no screw portion is provided, and the end lip is slidably in close contact with the screw portion forming region, and the tip of the end surface lip The lip end of the auxiliary lip integrally formed with the slidable contact with the region where the screw portion is absent is slidable.

  The sealing device according to claim 2 of the present invention is the sealing device according to claim 1, wherein an annular recess is provided between the lip end of the end surface lip and the lip end of the auxiliary lip. The lip is thinner than the end face lip.

  In the sealing device of the present invention having the above-described configuration, a screw portion non-existing region not provided with a screw portion is provided on the outer peripheral side of the screw portion forming region provided with the screw portion on the axial end surface of the slinger, and the tip of the end face lip The auxiliary lip is formed integrally with the lip portion, and the lip end of the auxiliary lip is slidably in close contact with the non-threaded region. The tight leakage path closes the leak path for static leakage and seals the sealing fluid. That is, when the rotating shaft is stopped, the sealing fluid is sealed by the auxiliary lip and does not reach the threaded portion, so that it is possible to suppress the occurrence of stationary leakage along the threaded portion.

  An end face lip having a lip end and an auxiliary lip integrally formed at the tip portion has a lip end. Therefore, one lip has a multi-stage lip end structure having two lip ends. An annular recess is provided between the lip end and the lip end of the auxiliary lip. Therefore, since the auxiliary lip is made thinner than the end face lip, the auxiliary lip is relatively soft and easily elastically deformed. Therefore, the auxiliary lip can be easily separated from the axial end surface of the slinger by centrifugal force acting at the time of rotation or / and by the pressure of the radially outward pumping action exerted by the screw portion. The auxiliary lip does not hinder the pumping action (sealing action) of the threaded portion.

  The present invention has the following effects.

  In other words, in the present invention, as described above, a screw portion non-existing region not provided with a screw portion is provided on the outer peripheral side of the screw portion forming region provided with a screw portion on the axial end surface of the slinger, and the tip portion of the end face lip The auxiliary lip is integrally formed with the lip end of the auxiliary lip so that the lip end of the auxiliary lip is slidably in contact with the non-threaded region, so that the lip end of the auxiliary lip is in close contact with the flat non-threaded region. As a result, the leakage path of the stationary leak is closed and the sealing fluid is sealed. Therefore, according to the intended purpose of the present invention, even if a thread portion is provided on the axial end face of the slinger where the end face lip is slidably in contact, no static leakage occurs, and thus a sealing device that exhibits excellent sealing performance is provided. can do. Further, since the auxiliary lip is easily separated from the axial end surface of the slinger, the auxiliary lip does not hinder the pumping action (seal action) of the screw portion.

Sectional drawing of the principal part of the sealing device which concerns on the Example of this invention. It is an E direction arrow directional view in Drawing 1, and is an explanatory view of a screw part in the sealing device Sectional drawing of the principal part which shows the state before combining the lip seal member in the sealing device with a slinger Sectional drawing of the principal part of the sealing device which concerns on a prior art example Sectional drawing of the principal part of the sealing device which concerns on a comparative example FIG. 6 is a view taken in the direction of the arrow C in FIG.

The present invention includes the following embodiments.
(1) Problem (1-1) The conventional sealing device (end face lip type oil seal) is used as a set with a slinger, and the oil swing-off effect by the slinger rotating together with the shaft and the inner surface of the slinger are set. The oil is sealed by the oil pumping action by the thread groove.
(1-2) In the prior art, there is a problem that oil enters the seal through the thread groove on the inner surface of the slinger when stationary.
(2) Configuration (2-1) In order to prevent oil leakage at rest, an auxiliary lip is set, and a flat portion not provided with a thread groove is set on the inner surface of the slinger.
(2-2) Prevent stationary leakage by bringing the auxiliary lip into contact with the flat part.
(3) Effect (3-1) According to the present invention, it is possible to prevent oil leakage at rest while maintaining the oil pumping action by the thread groove. Further, according to the present invention, it is possible to prevent oil leakage at rest in a non-thread groove portion (flat portion) while maintaining an oil pumping action (pump action) with the thread groove of the slinger.
(3-2) As a result, stable sealability can be ensured over a long period of time, and the seal life can be improved.

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

  As shown in FIG. 1, a sealing device (end face lip type oil seal) 1 according to this embodiment is fixed to the outer periphery of a rotary shaft (not shown) and rotates in the axial direction of a slinger (metal ring) 21 that rotates together with the rotary shaft. The end surface lip 14 is slidably brought into close contact with the end surface 21c to seal the sealing fluid in the machine A, and the screw portion 23 (FIG. 2) provided on the axial end surface 21c of the slinger 21 exhibits a pumping action when rotating. By doing so, the sealing fluid in the machine A is sealed. Further, the sealing device 1 according to the embodiment includes a lip seal member 11 fixed to the inner periphery of a shaft hole of a housing (not shown), and a slinger 21 fixed to the outer periphery of a rotating shaft that is inserted through the shaft hole. It consists of a combination and exhibits a sealing function so as to suppress the leakage of the sealing fluid in the machine A to the outside B and to suppress the dust in the machine B from entering the machine A.

  The slinger 21 is made of a metal material, and is formed by integrally forming a flange portion 21b outwardly in the radial direction at the inner end of the tubular portion 21a fitted to the outer peripheral surface of the rotating shaft. A screw portion 23 (see FIG. 2) that exhibits a pumping action radially outward is provided on the axial end surface 21c on the machine outside of the portion 21b.

As shown in FIG. 2, the screw portion 23 is formed of a spiral groove, and specifically, four equally spaced grooves (four right-hand strips) that are rotated clockwise from the inner side (inner diameter side) to the outer side (outer diameter side). And the screw portion 23 has an annular shape having a predetermined radial width d ₁ set at the center portion in the radial direction of the axial end surface 21c of the flange portion 21b. It is provided in the screw portion forming region 22.

Further, in the axial end face 21c of the flange portion 21b, the outer peripheral side of the threaded portion formation region 22, an annular threaded portion absence region 24 threaded portion 23 is not provided over a predetermined radial width d ₂ Is set. Since the screw part 23 is not provided in the screw part non-existing region 24, the axial end face 21c remains a flat surface perpendicular to the axis in this region 24. The screw portion non-existing region 24 is set between the screw portion forming region 22 and the outer peripheral end portion 21d of the flange portion 21b. The screw part non-existing region 24 is disposed on the outer peripheral side of the screw part forming region 22, and the screw part forming region 22 is disposed on the inner peripheral side of the screw part non-existing region 24.

  The lip seal member 11 includes an attachment ring 12 and a rubber-like elastic body 13 adhered (vulcanized and bonded) to the attachment ring 12, and further a dust lip 16 made of fabric is assembled. The mounting ring 12 is made of a metal material, and is formed by integrally forming a flange portion 12b radially inward at the outer end of the tubular portion 12a fitted to the inner peripheral surface of the shaft hole of the housing. The rubber-like elastic body 13 is integrally provided with an outer peripheral rubber portion (outer peripheral seal portion) 13a, an end surface rubber portion 13b and an inner peripheral rubber portion 13c attached to the mounting ring 12, and is further supported by the inner peripheral rubber portion 13c. An end lip (main lip) 14 slidably in close contact with the axial end surface 21c of the flange portion 21b of the slinger 21 and a grease lip 15 which is supported by the inner peripheral rubber portion 13c and holds grease. And are integrally molded. Further, a dust lip (sub lip) 16 made of the above fabric is assembled to the step portion 13d at the outer side of the grease lip 15, and the dust lip 16 slides on the outer peripheral surface of the cylindrical portion 21a of the slinger 21. Seal dust as closely as possible.

  The end surface lip 14 is provided obliquely outward in the radial direction so as to gradually increase in diameter from the base end portion 14a to the tip end portion 14b. The tip end portion 14b includes a lip end (sliding end) 14c. The lip end 14c is slidably in close contact with the former screw portion forming region 22 among the screw portion forming region 22 and the screw portion non-existing region 24 set on the axial end surface 21c of the flange portion 21b.

  Further, an auxiliary lip 17 is formed integrally with the tip portion 14 b of the end face lip 14. The auxiliary lip 17 is provided obliquely outward in the radial direction so as to gradually increase in diameter from the base end portion 17a to the tip end portion 17b. The tip end portion 17b is provided with a lip end (sliding end) 17c. The lip end 17c is slidably brought into close contact with the latter screw portion absence region 24 among the screw portion formation region 22 and the screw portion absence region 24 set on the axial end surface 21c of the flange portion 21b.

  As shown in FIG. 3, the auxiliary lip 17 is provided on the extension line of the end face lip 14. The outer peripheral surface 17 d of the auxiliary lip 17 is provided on an extension line of the outer peripheral surface 14 d of the end surface lip 14. The inner peripheral surface 17e of the auxiliary lip 17 is provided in parallel or substantially in parallel with the outer peripheral surface 17d of the auxiliary lip 17. The lip end 17 c of the auxiliary lip 17 is provided on the outer peripheral side of the lip end 14 c of the end face lip 14. Between the lip end 14c of the end lip 14 and the lip end 17c of the auxiliary lip 17, an annular recess 18 having a triangular or substantially triangular cross section is provided. Accordingly, since the recess 18 is provided, the auxiliary lip 17 is formed thinner than the end surface lip 14, and therefore, the auxiliary lip 17 is more flexible than the end surface lip 14 and is easily elastically deformed. Yes.

  The oil seal 1 having the above-described configuration is used, for example, to seal around the axis of a crankshaft in an automobile engine, and suppresses leakage of the sealing fluid (oil) in the machine A to the outside B as described above. The seal function is exhibited so as to prevent the dust from outside B from entering the machine interior A, and the above-described configuration has the following effects.

  That is, in the sealing device 1 having the above-described configuration, the screw portion absence region 24 in which the screw portion 23 is not provided on the outer peripheral side of the screw portion forming region 22 in which the screw portion 23 is provided on the axial end surface 21c of the flange portion 21b of the slinger 21. The auxiliary lip 17 is integrally formed at the tip of the end surface lip 14, and the lip end 17 c of the auxiliary lip 17 is configured to be slidably in close contact with the thread portion absence region 24. Since the lip end 17c of the lip 17 is in close contact with the flat screw portion non-existing region 24, the leakage path of stationary leakage through which the sealing fluid on the machine A side leaks through the screw portion 23 when the rotary shaft is stopped is closed. The fluid is sealed. Therefore, even if the screw portion 23 is provided on the axial end surface 21c of the flange portion 21b of the slinger 21 in which the end surface lip 14 is slidably in close contact, no static leakage occurs, and thus a sealing device that exhibits excellent sealing performance is provided. can do.

  An annular recess 18 having a triangular or substantially triangular cross section is provided between the lip end 14 c of the end lip 14 and the lip end 17 c of the auxiliary lip 17, and the auxiliary lip 17 is formed thinner than the end lip 14. Therefore, the auxiliary lip 17 is more flexible than the end face lip 14 and is easily elastically deformed. Therefore, the auxiliary lip 17 is easily separated from the axial end surface 21c of the flange portion 21b of the slinger 21 by centrifugal force acting at the time of rotation or / and by the pressure of the pumping action toward the radially outward exerted by the screw portion 23. Therefore, the auxiliary lip 17 does not hinder the pumping action (sealing action) of the screw part 23, and the screw part 23 can fulfill its pumping action (sealing action).

DESCRIPTION OF SYMBOLS 1 Sealing device 11 Lip seal member 12 Mounting ring 12a, 21a Tubular part 12b, 21b Flange part 13 Rubber-like elastic body 13a Outer rubber part 13b End surface rubber part 13c Inner peripheral rubber part 13d Step part 14 End face lip 14a, 17a Base end Portions 14b and 17b Tip portions 14c and 18c Lip ends 14d and 17d Outer peripheral surface 15 Grease lip 16 Dustrip 17 Auxiliary lip 17e Inner peripheral surface 18 Recess 21 Slinger 21c Axial end surface 21d Outer peripheral end 22 Threaded portion forming region 23 Screw portion 24 Area without screw part A In-machine B Out-of-machine

Claims (2)

The threaded portion provided on the axial end surface of the slinger while sealing the sealing fluid by slidably coming into contact with the axial end surface of the slinger that is fixed to the outer periphery of the rotary shaft and rotates with the rotary shaft. In a sealing device that seals the sealing fluid by exerting a pumping action when rotating,
The slinger is provided with a screw part non-existing region not provided with a screw part on the outer peripheral side of the screw part forming region provided with the screw part,
The end surface lip is slidably in close contact with the screw portion forming region, and the auxiliary lip end integrally formed with the end portion of the end surface lip is slidable in the screw portion non-existing region. A sealing device characterized by close contact. The sealing device according to claim 1.
The sealing device according to claim 1, wherein an annular recess is provided between a lip end of the end surface lip and a lip end of the auxiliary lip so that the auxiliary lip is thinner than the end surface lip.

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