JP3166062B2 - Lip type seal - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a lip seal provided for sealing the periphery of a rotating shaft of a refrigerator compressor such as a cooling device.

[0002]

2. Description of the Related Art As a typical conventional example of this type of lip seal, as shown in FIG. 3, an lip member 10 made of an elastomer, an inward flange 21 at a front end, and a caulked portion 22 at a rear end are respectively provided on the inner diameter side. Metal outer ring 20 embedded in the outer diameter portion 11 of the elastomer lip member 10
And a lip member 30 made of synthetic resin such as PTFE in which the outer diameter portion 31 is in contact with the back surface of the outer diameter portion 11 of the elastomer lip member 10, and a lip member 30 made of synthetic resin which is in contact with the caulking portion 22. One having a metal inner ring 40 for holding the back surface is well known. The outer peripheral surface of the outer ring 20 is covered with a crimping portion 12 integrally extending from the outer diameter portion 11 of the elastomer lip member 10. On the back surface of the outer diameter portion 11 of the elastomer lip member 10, an annular protrusion 11a indicated by a broken line in the figure is formed, and this annular protrusion 11a is crushed against the front surface of the outer diameter portion 31 of the synthetic resin lip member 30. It is pressed in a state where it is pressed.

[0003] That is, this lip type seal is provided with an outer ring 20.
The crimping portion 12 made of an elastomer on the outer periphery of the shaft is press-fitted into the shaft hole 1a of the shaft sealing portion housing 1 in a state where the axial movement is regulated by the step portion 1b formed in the shaft hole 1a and the retaining ring 2. The head 13a formed at the distal end portion 13 of the elastomer lip member 10 extending to the inside A of the machine, which is a sealed space, slides on the outer peripheral surface of the shaft 3 inserted into the shaft hole 1a. This prevents the refrigerant and refrigerating machine oil compressed in the machine A from leaking from the shaft circumference into the atmosphere B, which is an anti-sealed space. The synthetic resin lip member 30 has a distal end portion 32 that curves and extends toward the in-machine A side, and supports the distal end portion 13 of the elastomer lip member 10 that receives the pressure of the in-machine A from the inner peripheral side.

[0004] In the description, "front" means a surface facing the interior A side which is a sealed space, and "back" means a surface facing the atmosphere B side which is a non-sealed space.
The “front end” refers to the end on the inboard A side, and the “rear end” refers to the end on the atmosphere B side.

[0005]

This type of lip seal has a synthetic resin lip member 30 and an inner ring 40 on the inner periphery of an outer ring 20 in which an elastomer lip member 10 is integrated.
Are sequentially inserted, and the rear end of the outer ring 20 is swaged to assemble the outer end 20 of the synthetic resin lip member 30 via the inner ring 40 due to the formation of the swaged portion 22. The outer diameter portion 11 of the elastomer lip member 10 and the synthetic resin lip member 30 are pressed by the repulsive force against the compression at this time.
A mutual frictional force is applied between the outer diameter portion 31 and the inner ring 40, and the synthetic resin lip member 30 is held. However, when the elastomer is used for a long time at a high temperature, stress is reduced by heat in the elastomer, and the holding force on the synthetic resin lip member 30 is significantly reduced. 30 may slip (co-rotate) in the circumferential direction with respect to the elastomeric lip member 10. When such co-rotation occurs, the outer diameter portion 31 of the synthetic resin lip member 30 or the annular projection 11a on the side of the elastomer lip member 10 which is pressed against the lip member 30 is worn to hold the synthetic resin lip member 30 with respect to the synthetic resin lip member 30. The speed of co-rotation is increased because the decrease in force is accelerated. Therefore, abrasion of the inner peripheral surface 13b of the distal end portion 13 of the elastomer lip member 10 supported on the outer peripheral surface of the distal end portion 32 of the synthetic resin lip member 30 occurs,
There is a problem in that the contact state of the head 13a of the lip member 10 made of the elastomer with the rotating shaft 3 becomes unstable and leakage occurs.

The present invention has been made in view of the above circumstances, and a technical problem thereof is to prevent the sealing performance of an elastomer lip member from deteriorating due to co-rotation of a synthetic resin lip member. Is to do.

[0007]

Means for Solving the Problems The technical problems described above are:
This can be effectively solved by the present invention. That is, in the lip seal according to the present invention, the inner ring has an outer diameter of the elastomer lip member on the pressure contact surface with the synthetic resin lip member.
Corresponding to the radial position of the annular protrusion formed on the back of the part,
And a plurality of projections formed at predetermined intervals in the circumferential direction, and a plurality of undulations formed at predetermined intervals in the circumferential direction on the outer peripheral surface, and the outer peripheral surface of the inner ring is a rear portion of the outer ring. It has a configuration in which it is pressed against the elastomer layer formed on the inner peripheral surface. In addition, the undulating portion referred to here is a general term for ridges, grooves, irregularities, and the like.

The press-contact surface of the inner ring against the synthetic resin lip member is pressed against the back surface of the outer diameter portion of the synthetic resin lip member in a state where a plurality of projections formed on the press-contact surface bite into each other.
This prevents relative rotation between the synthetic resin lip member and the inner ring. Also, the outer peripheral surface of the inner ring has a plurality of undulating portions formed on the outer peripheral surface biting into the elastomer layer formed on the rear inner peripheral surface of the outer ring embedded in the outer diameter portion of the elastomer lip member. To prevent relative rotation between the inner ring, the outer ring, and the lip member made of elastomer. Therefore, even if stress relaxation due to heat occurs in the elastomer material of the elastomer lip member, the relative rotation of both lip members is caused by the circumferential engagement force of the inner ring on both the elastomer lip member and the synthetic resin lip member. Is prevented.

[0009]

FIG. 1 is a half sectional view showing an embodiment of a lip seal according to the present invention, and FIG. 2 is a sectional perspective view partially showing an inner ring 40 in the lip seal. . That is, according to this embodiment, the inner ring 40 is
A disk-shaped flange portion 41 and a cylindrical portion 42 extending rearward from an outer peripheral end of the flange portion 41, that is, a cross-sectional shape cut along a plane passing through an axial center has a substantially L-shape; A plurality of projections 43 projecting toward the front side are formed at predetermined intervals in the circumferential direction at the portion 41 in correspondence with the radial position of the annular projection 11 a formed on the back surface of the outer diameter portion 11 of the elastomer lip member 10. A plurality of grooves 44 extending in the axial direction are formed on the outer peripheral surface of the cylindrical portion 42 at predetermined circumferential intervals. The protrusion 43 is provided on the inner ring 4.
The groove 44 is formed by cutting the cylindrical portion 42 by stamping out from the back side of the flange portion 41 at the time of press forming of No. 0.

The inner ring 40 has a cylindrical portion 42 having a rear end formed by the outer ring 20.
The flange portion 41 is pressed against the rear surface of the outer diameter portion 31 of the lip member 30 made of synthetic resin, and each projection 43 is in a state of being bitten. The outer diameter portion 31 of the synthetic resin lip member 30 has an annular projection 11a formed on the back surface of the outer diameter portion 11 of the elastomer lip member 10 by a pressing force from the flange portion 41 of the inner ring 40. Pressed in a crushed state. On the inner peripheral surface of the outer ring 20 integral with the lip member 10 made of elastomer, an elastomer layer 11 of an appropriate thickness which is a part of the outer diameter portion 11 of the lip member 10 made of elastomer is provided.
b is formed, and the cylindrical portion 42 of the inner ring 40 is press-fitted into the inner periphery of the elastomer layer 11b.
2 is in a state of being cut into each groove 44 formed on the outer peripheral surface.

The other parts of the structure are almost the same as those of the lip-type seal shown in FIG.

According to this embodiment, the inner ring 40 has a frictional force due to the pressing of the cylindrical portion 42 against the elastomer layer 11b, and the engagement between each groove 44 formed in the cylindrical portion 42 and a part of the elastomer layer 11b. As a result, the outer ring 20 and the lip member 10 made of elastomer are prevented from rotating. In addition, the synthetic resin lip member 30 is formed on the flange portion 41 of the inner ring 40 and the frictional force caused by the pressure contact between the outer diameter portion 31 and the back surface (the annular protrusion 11 a) of the outer diameter portion 11 of the elastomer lip member 10. The engagement with each of the projections 43 prevents the inner ring 40 and the lip member 10 made of elastomer from rotating. Therefore, even if the frictional force between the elastomeric lip member 10 and the synthetic resin lip member 30 is reduced by the relaxation of the stress of the elastomer due to heat, the synthetic resin lip member 30 is formed by the friction torque with the rotating shaft 3. There is no slippage in the circumferential direction with respect to the lip member 10, and the occurrence of leakage due to instability of the support of the synthetic resin lip member 30 with respect to the head 13a of the tip portion 13 of the elastomer lip member 10 is effectively prevented. Is prevented.

The lip seal according to this embodiment has a crimping portion 12 integrally extending from an outer diameter portion 11 of an elastomer lip member 10 and vulcanized and bonded to an outer peripheral surface of an outer ring 20. The lip members 10 and 30 are attached to the hole 1 a in a state of being pressed against the outer circumferential surface of the rotary shaft 3. Since the frictional force is sufficiently large compared to the axial width and sufficiently large compared to the sliding torque, the lip member 10 made of the elastomer does not rotate together with the shaft. The entire seal does not rotate.

The projection 43 formed on the flange portion 41 of the inner ring 40 may have various shapes other than the shape shown in FIG. 2, and the undulation of the cylindrical portion 42 for engaging with the elastomer layer 11b is as follows. In addition to the grooves 44 formed by cutting,
Various types are conceivable, such as a projected ridge or a depression as in the case of 3.

[0015]

According to the lip seal of the present invention, the frictional force between the outer diameter portions of the elastomer lip member and the synthetic resin lip member is reduced by stress relaxation of the elastomer when used at a high temperature for a long time. However, the synthetic resin lip member does not slip in the circumferential direction with respect to the elastomer lip member due to the friction torque with the rotating shaft, and is therefore supported on the outer peripheral surface of the distal end portion of the synthetic resin lip member. The problem that the tip of the elastomer lip member becomes unstable and leaks can be effectively solved.

[Brief description of the drawings]

FIG. 1 shows an embodiment of a lip seal according to the present invention;
FIG. 4 is a half sectional view of a use state shown cut along a plane passing through an axis.

FIG. 2 is a sectional perspective view partially showing an inner ring in the embodiment.

FIG. 3 is a half sectional view showing an example of a lip-type seal according to the related art, cut along a plane passing through an axis.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Elastomer lip member 11b Elastomer layer 20 Outer ring 30 Synthetic resin lip member 40 Inner ring 43 Projection 44 Groove (undulating portion)

──────────────────────────────────────────────────続 き Continuation of front page (56) References JP-A-8-219295 (JP, A) JP-A 63-20569 (JP, U) JP-A 3-121270 (JP, U) JP-A 62-219 181759 (JP, U) (58) Field surveyed (Int. Cl. ⁷ , DB name) F16J 15/32 311

Claims (1)

(57) [Claims] 1. An elastomeric lip member having a tip end slidingly contacting an outer peripheral surface of a rotating shaft facing the sealed space, an outer ring embedded in an outer diameter portion of the elastomeric lip member, and an outer diameter portion comprising: A synthetic resin lip member which abuts against the back surface of the outer diameter portion of the elastomer lip member and faces the sealed space side and supports the tip portion of the elastomer lip member from the inner peripheral side; An inner ring supported by an end caulking portion and pressed against the back surface of the outer diameter portion of the synthetic resin lip member, wherein the inner ring has a pressure contact surface with the synthetic resin lip member ,
Formed on the back surface of the outer diameter portion of the elastomer lip member
It has a plurality of projections corresponding to the radial position of the annular projection and formed at predetermined intervals in the circumferential direction , and has a plurality of undulating portions formed at predetermined intervals in the circumferential direction on the outer peripheral surface. A lip seal wherein an outer peripheral surface of the ring is pressed against an elastomer layer formed on a rear inner peripheral surface of the outer ring.