JPH07305773A - Lip type seal - Google Patents

Abstract

PURPOSE:To prevent the occurrence of leakage through a lip member made of an elastomer by a method wherein the given number of vent parts is formed in the outer diameter cylindrical part of an inner ring consisting of a press part making contact with the back of the outside diameter part of a synthetic resin lip member. CONSTITUTION:A trace amount of a refrigerant permeating a lip member 20 made of an elastomer from the interior of a machine A and entering a gap G is vaporized and discharged in the atmosphere B through a notch 43A of the rear end of the outside diameter cylindrical part 41 of an inner ring 40. Further, in this case, since a permeation amount of a refrigerant at the lip member 20 made of an elastomer is a trace amount, discharge of the refrigerant to the atmosphere B through the notch 43A is hardly worth consideration. Further, since the gap G is released to the atmosphere B through the notch 43A, a pressure in the gap G is not increased. Thereby, a lip member 30 made of synthetic resin is moved to forcibly open the lip member 20 made of an elastomer and a trouble owing to which leakage occurs is effectively prevented from occurring.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a lip-type seal provided to seal the circumference of a rotary shaft of a refrigerator compressor such as a cooling device.

[0002]

2. Description of the Related Art As a typical conventional lip type seal for sealing the periphery of a rotary shaft of a refrigerating machine compressor, as shown in FIG. 3, a metal outer ring 10 and an outer ring 10 as an insert member are used. An elastomeric lip member 20 that is vulcanized and molded in a partially embedded state, and a synthetic resin lip member 30 that is in contact with the back surface of the elastomeric lip member 20;
Further, it is known that the lip member 30 made of synthetic resin is provided with an inner ring 40 made of metal for pressing the back surface of the lip member 30. Outer ring 10
The outer peripheral surface of is covered with a crimp portion 23 made of an elastomer formed continuously with the outer diameter portion 22 of the elastomer lip portion 20, and the inner ring 40 is provided with the elastomer lip member 2
The outer diameter tubular portion 41 whose rear end is in contact with and supported by the caulking portion 11 of the outer ring 10 exposed from 0, and the synthetic resin lip member 30 extending from the outer diameter tubular portion 41 to the inner diameter side. It has a substantially L-shaped cross section, which is composed of the pressing portion 42 abutting on the back surface.

That is, this lip-type seal has an outer ring 10
Is press-fitted into the shaft hole 1a of the shaft-sealing portion housing 1 via a pressure-bonding portion 23 made of an elastomer in a state in which movement in the axial direction is restricted by a step portion 1b formed in the shaft hole 1a and a retaining ring 2. The head 21a formed at the tip of the inner diameter portion 21 of the elastomer lip member 20 that curves and extends toward the in-machine A side, which is the sealed space, is in sliding contact with the outer peripheral surface of the shaft 3 inserted into the shaft hole 1a. By in-flight A
Refrigerant such as CFC-12 or HFC-134a and refrigerating machine oil that are compressed in the atmosphere B, which is an anti-sealing space from the shaft circumference.
It prevents it from leaking in. The synthetic resin lip member 30 has an inner diameter portion 3 that curves and extends toward the in-machine A side.
The tip 31a of No. 1 reaches the vicinity of the head 21a from the inner peripheral side of the inner diameter portion 21 of the elastomer lip member 20 and receives the pressure of the in-machine A. The inner diameter portion 21 of the elastomer lip member 20 is supported from the inner peripheral side. There is.

In the text, the "rear surface" refers to the surface facing away from the inside A, which is a sealed space (atmosphere B side), and the "tip" refers to the end on the inside A side. Furthermore, the "rear end" refers to the end opposite to the in-flight A.

[0005]

The following problems are pointed out in the above-mentioned conventional lip type seal. That is,
CFC-12 or HFC-13 compressed in cabin A
The refrigerant such as 4a swells the elastomer lip member 20 and slightly permeates. However, the amount of permeation is extremely small, and although it is not recognized as a problematic leak itself, a part of the permeated refrigerant is part of the outer ring 10.
And the outer diameter portion 22 of the elastomer lip member 20, the outer diameter portion 32 of the synthetic resin lip member 30, and the outer diameter tubular portion 41 of the inner ring 40 collect in a gap G, so that high speed operation is possible. When the ambient temperature of the lip-type seal becomes relatively high due to the above reasons, the pressure in the gap G sharply rises due to vaporization or expansion of the refrigerant. Therefore, as shown in FIG. 4, the pressure in the gap G causes the synthetic resin lip member 30 to move.
Of the synthetic resin lip member 30 is moved toward the in-machine A side, and the tip 31a of the synthetic resin lip member 30 moves inside the head 21a of the elastomer lip member 20. Since the pressure is widened from the circumference, the close contact force of the head 21a with respect to the outer peripheral surface of the shaft 3 is reduced or brought into a non-contact state, which may lead to leakage.

The present invention has been made under the circumstances as described above, and the technical problems thereof are, from the elastomer lip member to the outer ring, the outer diameter portion of the elastomer lip member, and the synthetic resin. The leakage of pressure caused by the synthetic resin lip member spreading the elastomer lip member by the pressure of the refrigerant that has permeated into the gap between the outer diameter portion of the lip member made of plastic and the outer cylindrical portion of the inner ring is prevented. Especially.

[0007]

The above-mentioned technical problems are as follows.
The present invention can effectively solve the problem. That is, the present invention is an outer ring formed with a caulking portion bent to the inner diameter side at the rear end, and an elastomer lip member in which the outer diameter portion is held at the tip of the outer ring and the inner diameter portion extends to the sealed space side. A synthetic resin lip having an outer diameter portion abutting on a rear surface of the outer diameter portion of the elastomer lip member and an inner diameter portion extending toward the sealed space to support the inner diameter portion of the elastomer lip member from an inner peripheral side. A member, an outer diameter cylindrical portion whose rear end is in contact with and supported by the caulking portion of the outer ring, and an outer diameter portion rear surface of the synthetic resin lip member that extends from the outer diameter cylindrical portion toward the inner diameter side. A lip-type seal having an inner ring made up of abutting pressing parts, wherein a required number of ventilation parts are provided in the outer diameter tubular part of the inner ring.

[0008]

The gap surrounded by the outer ring, the outer diameter portion of the elastomer lip member, the outer diameter portion of the synthetic resin lip member, and the outer diameter tubular portion of the inner ring is the outer diameter tubular portion of the inner ring. Since it is opened to the anti-sealing space by the provided ventilation part, the refrigerant that has permeated the elastomer lip member and entered the gap is discharged through the ventilation part, and the atmosphere of this lip-type seal is generated by the high speed operation of the equipment. Even if the temperature becomes relatively high, the pressure in the gap does not rise, and this pressure does not move the synthetic resin lip member so as to spread the elastomer lip member.

[0009]

1 shows a first embodiment of a lip-type seal according to the present invention, in which a pressing portion 42 is brought into contact with the rear surface of an outer diameter portion 32 of a synthetic resin lip member 30 to have an outer diameter The inner ring 40 that presses the portion 32 toward the outer diameter portion 22 side of the elastomer lip member 20 has the crimped portion 11 of the outer ring 10.
The required number of notches 4 are provided at the rear end of the outer diameter tubular portion 41 abutted against
3A is formed, and by this notch 43, the outer ring 1
0, the outer diameter portion 22 of the elastomer lip member 20, the outer diameter portion 32 of the synthetic resin lip member 30, and the outer diameter tubular portion 41 of the inner ring 40 are opened to the atmosphere B. The ventilation part 43 is provided. The configuration of the other parts is almost the same as that of the lip-type seal of FIG. 3 described above, and therefore the description thereof is omitted.

According to this embodiment, a small amount of the refrigerant (CFC-12 or HFC-134a) which has penetrated the elastomer lip member 20 from the inside A into the gap G is evaporated and the outer diameter of the inner ring 40 is reduced. It is released into the atmosphere B through the notch 43A at the rear end of the tubular portion 41. As mentioned earlier,
Since the amount of refrigerant permeating through the elastomer lip member 20 is extremely small, the refrigerant discharge from the notch 43A into the atmosphere B is of no problem. Further, even if the ambient temperature of the lip-type seal becomes relatively high due to high-speed operation or the like, the pressure in the gap G does not rise because the gap G is opened to the atmosphere B by the notch 43A. Therefore, the pressure in the gap G causes the synthetic resin lip member 30 to move.
Moves as shown in FIG. 4 to move the elastomer lip member 2
It is possible to effectively prevent a problem that 0 is opened and a leak occurs.

The ventilation part 43 may be a small hole 43B formed in the outer diameter cylindrical part 41 of the inner ring 40, as shown in FIG. 2 of the second embodiment of the present invention.

The lip-type seals according to the illustrated first and second embodiments are both made of an elastomer lip member 20.
Is integrally vulcanized and molded on the outer ring 10, but in the present invention, the elastomer lip member 20 and the synthetic resin lip member 30 are sandwiched between the outer ring 10 and the pressing portion 42 of the inner ring 40. The outer ring 10 can be similarly applied to a lip-type seal in which the outer ring 10 is press-fitted into the shaft hole 1a of the housing 1 through a packing such as an O-ring.

[0013]

According to the present invention, the pressure in the gap between the outer ring, the outer diameter portion of the elastomer lip member, the outer diameter portion of the synthetic resin lip member, and the outer diameter cylindrical portion of the inner ring increases. Since this does not occur, the synthetic resin lip member does not move so as to push the elastomer lip member open from the outer peripheral surface of the shaft due to this pressure, and the occurrence of leakage due to this can be effectively prevented.

[Brief description of drawings]

FIG. 1 is a half cross-sectional view showing a usage state of a first embodiment of a lip type seal according to the present invention by cutting along a plane passing through an axis.

FIG. 2 is a half sectional view showing a usage state of a second embodiment of the lip-type seal according to the present invention by cutting along a plane passing through an axis.

FIG. 3 is a half cross-sectional view showing a usage state of an example of a conventional lip-type seal, taken along a plane passing through an axis.

FIG. 4 is a half cross-sectional view of a situation in which leakage occurs in the lip type seal, taken along a plane passing through an axis.

[Explanation of symbols]

 1 Housing 3 Shaft 10 Outer Ring 11 Caulking Section 20 Elastomer Lip Member 30 Synthetic Resin Lip Member 40 Inner Ring 41 Outer Diameter Cylindrical Section 42 Pressing Section 43 Ventilation Section

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Takayuki Kato, 2-chome, Toyota-cho, Kariya city, Aichi Stock company, Toyota Industries Corporation (72) Inventor, Kenji Yamada 2-chome, Toyota-cho, Kariya-shi, Aichi Stock Company Toyota Industries Corporation (72) Inventor Koichiro Oreyama 1212 Abe, Ochiai-cho, Takahashi-shi, Okayama Eagle Industry Co., Ltd. Okayama factory

Claims (1)

[Claims] 1. An outer ring having a rear end formed with a caulked portion bent toward the inner diameter side, and an elastomer lip member having the outer diameter portion held at the tip of the outer ring and the inner diameter portion extending toward the sealed space. A synthetic resin lip having an outer diameter portion abutting on a rear surface of the outer diameter portion of the elastomer lip member and an inner diameter portion extending toward the sealed space to support the inner diameter portion of the elastomer lip member from an inner peripheral side. A member, an outer diameter cylindrical portion whose rear end is in contact with and supported by the caulking portion of the outer ring, and a rear surface of the outer diameter portion of the synthetic resin lip member extending from the outer diameter cylindrical portion to the inner diameter side. A lip-type seal, comprising: an inner ring composed of a pressing portion in contact with the inner ring, and a required number of ventilation parts being provided in an outer diameter cylindrical portion of the inner ring.