JPH0736211Y2 - Lip seal - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial application] The present invention relates to a lip seal having a lip ring sandwiched between an outer retaining ring and an inner retaining ring.

[Prior Art] A lip seal of this type is disclosed in Japanese Utility Model Publication No. 56-113262. The inner peripheral part of the lip part (lip ring) projects in the axial direction and is joined to the peripheral surface of the rotating shaft. The outer peripheral part of the lip part is the outer ring (outer retaining ring) and the inner ring (inner retaining ring). ) And is sandwiched by. With this configuration, the high-pressure fluid on the inner ring side is prevented from leaking from the peripheral surface of the rotating shaft. The inner peripheral edge of the outer ring that holds the outer peripheral portion of the lip extends to near the inner peripheral portion of the lip, and the pressure on the inner ring acting on the lip is effectively received by the outer ring, and the sealing performance is improved. It is intended to prevent the lip portion from being deformed improperly, which leads to a decrease in temperature.

[Problems to be Solved by the Invention] However, the inner peripheral end of the inner ring is located near the outer peripheral portion of the lip portion, and the fitting action direction at the time of fitting the lip seal onto the rotating shaft is uniform in the axial direction of the rotating shaft. If this is not done, there will be partial contact between the inner peripheral seal of the lip and the peripheral surface of the rotating shaft, and the sliding resistance due to this partial contact will not affect the inner peripheral part of the lip that is not suppressed by the inner ring. Bring it up. If this rise occurs, the joining region between the lip portion and the peripheral surface of the rotating shaft becomes shorter in the width direction in the rotating shaft direction, and there is a problem that the required sealing performance cannot be secured.

Further, in the structure in which the vicinity of the inner peripheral portion of the lip portion is not restrained by the inner ring, the inner peripheral portion of the lip portion still floats up even when the inner ring side has a negative pressure, and the necessary sealing performance cannot be secured.

An object of the present invention is to provide a lip seal having improved sealing performance on the peripheral surface of a rotating shaft.

[Means for Solving the Problems] Therefore, in the present invention, in a lip seal in which a single lip ring is sandwiched between an outer retaining ring and an inner retaining ring, the lip ring protruding in a curved shape in the axial direction of the lip seal The inner circumference of the outer retaining ring is curved so that it projects along the convex side of the lip ring to the vicinity of the inner periphery of the inner ring, and the inner periphery of the inner retaining ring is curved so as to contact the concave side of the lip ring. Then, the inner circumferential edge of the inner restraining ring extends to near the inner circumferential seal portion so as to correspond to the inner circumferential edge of the outer restraining ring, and the lip ring is sandwiched by both inner circumferential edges.

[Operation] The pressure on the inner retaining ring side acting on the lip ring is effectively received by the outer retaining ring extending to the vicinity of the inner seal portion of the lip ring. Further, since the tip of the inner holding ring extends to the vicinity of the inner peripheral seal portion in alignment with the tip of the outer holding ring, when the lip seal is fitted on the rotary shaft, the rotation shaft and the inner peripheral seal portion of the lip ring are separated from each other. Even if a one-sided sliding resistance occurs between them, the sliding resistance prevents the inner circumference seal part from rising from the peripheral surface of the rotating shaft, and the inner circumference is prevented even when negative pressure is applied to the inner holding ring side. The seal part does not float above the peripheral surface of the rotating shaft.

[Embodiment] An embodiment in which the present invention is embodied in a lip seal of a compressor will be described below with reference to the drawings.

The compressor shown in FIG. 1 is an oscillating swash plate compressor, in which a swash plate 3 swingably supported by a shaft pin 2a of a slidable sleeve 2 on a rotary shaft 1 rotates together with the rotary shaft 1. It is rocked by the driving body 4 without rotating, and the piston 5 is reciprocally driven. The tilt angle of the swash plate 3 depends on the difference between the pressure in the crank chamber C and the suction pressure via the piston 5, and the pressure in the crank chamber C is controlled by the supply of the discharge refrigerant gas via the electromagnetic control valve mechanism 6. .

A lip seal 8 is interposed between the front housing 7 forming the crank chamber C and the rotary shaft 1 to prevent leakage of high-pressure refrigerant gas in the crank chamber C.
The lip seal 8 includes a fixed ring 9, a rubber seal ring 10 fitted on the outer circumference thereof, and a PTFE (poly-tetra-fluoro-ethylene) lip ring 11 fitted on the inner circumference of the fixed ring 9. , A pair of inner and outer retaining rings 12 and 13 made of metal fitted in the inner periphery of the fixed ring 9 so as to sandwich the lip ring 11, and the lip ring 11, the inner retaining ring 12 and the outer retaining ring 13 are bundled and clamped. A rubber seal member 14 interposed between the fixed ring 9 and the outer retaining ring 13 and a seal member for covering the inner retaining ring 12.
It consists of 15 and.

The inner peripheral seal portion 11a of the lip ring 11 is formed to be curved and protruded toward the crank chamber C in the axial direction, and the convex side of the inner peripheral seal portion 11a is joined to the peripheral surface of the rotary shaft 1. The outer retaining ring 13 is curved so as to follow the convex surface side of the lip ring 11, and the tip of the outer retaining ring 13 reaches the vicinity of the inner peripheral seal portion 11a. The inner holding ring 12 is curved so as to come into contact with the concave surface side of the lip ring 11, and the tip of the inner holding ring 12 reaches the vicinity of the inner peripheral seal portion 11a. That is, the inner peripheral edge of the inner side retaining ring 12 and the inner peripheral edge of the outer side retaining ring 13 are aligned at positions where the lip ring 11 is sandwiched in the thickness direction.

According to the configuration in which the inner peripheral ends of the both restraining rings 12 and 13 are aligned at the positions sandwiching the lip ring 11 in the thickness direction of the lip ring 11, the leakage of the high pressure refrigerant gas along the peripheral surface of the rotating shaft 1 can be surely prevented. That is, when the lip seal 8 is fitted into the rotary shaft 1, the fitting action direction does not coincide with the axial direction of the rotary shaft 1, and there is a gap between the peripheral surface of the rotary shaft 1 and the inner peripheral seal portion 11a of the lip ring 11. Even when a hitting sliding resistance occurs, the lifting action of the inner circumferential seal portion 11a due to this sliding resistance is suppressed by the inner holding ring 2 reaching near the inner circumferential seal portion 11a. As a result, the inner peripheral seal portion 11a does not float up from the peripheral surface of the rotary shaft 1. When the lip seal 8 is fitted on the rotary shaft 1 and the air in the compressor is evacuated to be filled with the refrigerant gas, the crank chamber C has a negative pressure, but when the crank chamber C has a negative pressure. Inner circumference seal part
The inner peripheral seal portion 11a does not float up from the peripheral surface of the rotating shaft 1 due to the restraining action of the inner restraining ring 12 reaching near 11a. Therefore, the joint area between the inner peripheral seal portion 11a and the rotary shaft 1 is sufficiently secured in the width direction in the rotary shaft direction, and the pressure leak along the peripheral surface of the rotary shaft 1 after the refrigerant gas is filled with the inner peripheral seal portion 11a. The joint with the rotating shaft 1 and the refrigerant gas pressure receiving action of the outer restraining ring 13 reliably prevent it.

Of course, the present invention is not limited to the above embodiment, and for example, a lip seal in which the fixing ring 9 and the outer retaining ring 13 in the above embodiment are integrated or the fixing ring 9 and the inner retaining ring 12 are integrated. It is also possible to apply the present invention to a lip seal.

[Advantages of the Invention] As described in detail above, in the present invention, the lip ring is sandwiched in the thickness direction by the inner peripheral edge of the inner / outer restraining ring in the vicinity of the inner peripheral seal portion of the lip ring. Even if one-sided fitting of the lip seal or negative pressure occurs, it does not lift up from the peripheral surface of the rotating shaft of the inner seal part, and it is possible to reliably prevent pressure leak along the peripheral surface of the rotating shaft. Produce the effect.

[Brief description of drawings]

FIG. 1 is a side sectional view showing an embodiment embodying the present invention,
FIG. 2 is an enlarged sectional view of a main part. Lip seal 8, lip ring 11, inner peripheral seal portion 11a,
Inner retaining ring 12, outer retaining ring 13.

Front page continued (72) Inventor Tatsuya Nakai, 2-chome, Toyota-cho, Kariya city, Aichi Stock company Toyota Industries Corporation (72) Inventor Yoshiharu Nakamura, Miyanedai, Chikusa-ku, Nagoya, Aichi prefecture 3-21 ( 56) References JP-A-63-312569 (JP, A) JP-A-2-8565 (JP, A) Actual development 61-49164 (JP, U) JP-B 41-15847 (JP, B1)

Claims (1)

[Scope of utility model registration request] 1. A lip seal in which a single lip ring is sandwiched between an outer retaining ring and an inner retaining ring,
The inner retaining portion of the outer retaining ring is curved and protrudes along the convex side of the lip ring to the vicinity of the inner peripheral sealing portion of the lip ring that protrudes in a curved shape in the axial direction of the lip seal. The inner peripheral portion is curved and protrudes so as to contact the concave surface side of the lip ring, and further the inner peripheral end of the inner retaining ring is extended to the vicinity of the inner peripheral seal portion so as to correspond to the inner peripheral end of the outer retaining ring, Lip seal with a lip ring sandwiched between both inner peripheral edges.