JPS63158365A - Seal device for air rotary joint - Google Patents

Abstract

PURPOSE:To improve reliability in a seal device, by installing an exhaust valve mechanism which discharges lubricating oil in a storage chamber by means of air pressure variations in a compressed air passage, in case of an air rotary joint feeding pneumatic equipment including an air clutch or the like with compressed air. CONSTITUTION:Inside rubber air seals S3 and S4 facing to an air chamber 38 feeding the inside of a turning shaft 24 with compressed air and outside rubber air seals S2 and S5 separating an axial interval to these inside air seals S3 and S4 are combined together and installed herein. A lubricating oil chamber, sealing lubricating oil, is formed in space between both these air seals S2 and S3, and a passage 72, imposing the same pressure as the compressed air, is connected to this lubricating oil chamber 62. Lubricating oil flowing into the chamber 38 from a projection strip T formed in each lip part 61 of these air seals S2 and S5 is dischargeable to the outside with an exhaust valve mechanism 76 to be opened or closed by means of pressure variations in a compressed air passage 60.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a sealing device for an air rotary joint that supplies compressed air to pneumatic equipment such as an air clutch.

(Prior art and its problems) This type of air rotary joint is constructed as shown in FIG.

In FIG. 3 showing an automobile air clutch which is a type of pneumatic equipment, 10 is a flywheel on the engine side. A clutch cover 12 is fixed to the flywheel 10, and the pressure contact force generated by the annular pneumatic AC unit 14 (pneumatic equipment) of the clutch cover 12 is transmitted to the pressure plate 16. A clutch disc 18 is sandwiched between the flywheel 10 and the flywheel 10.

The clutch disc 18 is splined to an input @20 of a transmission (not shown) located after the air clutch. 1 on the outer periphery of the input shaft 20 via a bushing 22.
Fiq11124 is fitted. The clutch cover 12 is fitted to the right end of the cylindrical shaft 24 in the drawing.

The left end portion of the cylinder shaft 24 is surrounded by a cover 26, and a chamber 28 is formed inside the cover 26.

There are two air seals 30a between the cover 26 and the cylinder shaft 24.
30b are interposed, and air leaks are prevented by air seals 30a and 30b, which will be described in detail later.

On the other hand, a control valve 32 operated by a clutch pedal 31 is connected to the cover 26, and the control valve 32 allows compressed air flowing from a compressor 34 via a pressure regulating valve 36 to a chamber 38 between an air seal 30a and an air seal 30b. The cylinder shaft 24 passes through the inlet hole 4o to flow into the passage 42.

Further, an outlet hole 44 is connected to the left end of the passage 42, and the outlet hole 44 is connected to an air chamber 48 of the pneumatic actuator 14 through a passage 46 formed within the thickness of the clutch cover 12. .

In such a conventional example, the circumferential speed of the lip part increases at high rotations, and the pressure contact force of the lip part increases due to the high air pressure, causing the PV
The value (P: pressure, ■= peripheral speed increases, and there is a risk that the air seal will eventually be damaged due to frictional heat.

On the other hand, if a large amount of lubricant is supplied to prevent damage to the lip, the lubricant may flow into the air clutch.
There is a problem that it ends up in ν.

Therefore, the applicant has developed a prior art technique in which a screw-like protrusion is formed on the lip of the air seal, and this protrusion pushes the lubricating oil on the surface of the tube@24 into the interior of the air seal. (Jitsugan 61-1724)
No. 15).

In this prior art, the air seal is sufficiently lubricated and the lubricating oil can be prevented from entering the air clutch, but the problem remains that the lubricating oil that has flowed into the air seal cannot be discharged to the outside.

(Object of the Invention) The present invention provides a sealing device for an air rotary joint that can discharge lubricating oil stored inside the air seal to the outside when using an air seal that feeds lubricating oil into the inside of the air seal. The purpose is

(Structure of the Invention) (1) Technical Means The present invention provides an air rotary joint that supplies compressed air from the outside to a pneumatic device through a rotating shaft. A lubricating oil chamber is formed by filling the space between both air seals with lubricating oil. A compressed air passage that applies the same J mocha as the compressed air is connected to the sliding surface of either one or both of the air seals and the rotating shaft, and the lubricant that adheres to the surface of the rotating shaft due to the rotation of the rotating shaft is connected. A slanted protrusion is formed so as to send oil into the lubricating oil chamber, and a storage chamber is connected to the lubricating oil chamber by the protruding ridge and has a capacity set to be large enough to store the lubricating oil flowing into the lubricating oil chamber. A sealing device for an air rotary joint is characterized in that the sealing device is formed of a gasket, and is provided with a discharge valve mechanism for discharging lubricating oil in the storage chamber by fluctuations in air pressure in the compressed air passage.

(2) Operation The discharge valve mechanism opens and closes due to pressure fluctuations in the compressed air passage, and the lubricating oil in the storage chamber is discharged to the outside.

(Embodiment) An air seal device for an air clutch for an automobile, which is an embodiment of the present invention, will be described with reference to FIG. Figure 1 is an enlarged view of part ■ in Figure 2, and the other parts have almost the same structure, so
In FIG. 1, the same reference numerals as in FIG. 2 are used. Note that FIG. 1 shows only the upper half across the center line 0.

In FIG. 1, a total of six rubber air seals, three on each side of the left and right sides of the chamber 38, are arranged on the outer peripheral surface of the cylindrical shaft 24 (rotating shaft) at intervals in the axial direction. A compressed air passage 60 is connected to the chamber 38, and the compressed air flowing into the chamber 38 from the compressed air passage 60 is passed through the passage 42 (the third
(Fig.) is supplied to the air clutch.

A rubber annular air seal S1 is arranged with the lip portion 61 facing the chamber 38 side.
The same applies to 2. On the contrary, the air seal S3 has a lip portion 61 open toward the opposite side of the chamber 38 (left side in the figure). aI lubricant between this air seal S3 and air seal S2! i! 62 is formed. In addition, air seal S1
An oil chamber 64 is also formed between the air seal S2 and the air seal S2.
4 is supplied with rIU lubricating oil from a lubricating oil passage 66 at a predetermined pressure.

On the right side of the chamber 38 in the figure, air seals 84 to S6 are arranged symmetrically to the air seals 81 to S3, and similarly to the oil chamber 6.
2", 64- is formed.

On the inner surface of the lip portion 61 of the air seals $2 and S5, protrusions T are formed at approximately equal intervals over the entire circumference. This protrusion T is inclined so that as the cylinder shaft 24 rotates, the lubricating oil in the oil chamber 64, which is attached to the surface of the cylinder shaft 24, is sent into the chamber 38 by a viscous pumping action.

In FIG. 1, the protrusions T are formed only on the air seals S2 and S5, but the protrusions T may also be formed on the air seals S3 and $4. Regarding this protrusion T, the present applicant's U.S. Pat.
-172415@ is described in detail.

A substantially annular oil chamber 62a is formed radially outward of the oil chamber 62'. oil'? The right side surface of 62a in the figure is in contact with the cooling chamber 67 via a pressure-blocking heat transfer plate 65 made of, for example, a steel plate. The cooling chamber 67 is connected to the lubricating oil passage 66,
Relatively low-temperature f1 lubricating oil flows through the cooling chamber 67.

A sealed oil tank 68 communicates with the further outside of the oil chamber 62a. A passage 72 is connected to the sealed oil tank 68,
The oil level of the sealed oil 70, which fluctuates between the sealed oil standard oil level 68a and the sealed oil increased oil level 68b, is pressurized by the pressure of the compressed air supplied from the passage 72.

There is a liquid level difference H between the standard filled oil level 68a and the increased filled oil level 68b.
2. The capacity is set such that the lubricating oil flowing into the chamber 38 can be sufficiently stored by the protrusion T of S5.

A communication pipe 74 is connected to communicate the upper part of the oil chamber 62a and the vicinity of the sealed oil reference oil level 68a, and a discharge valve mechanism 76 is interposed in the middle of the communication pipe 74. The discharge valve mechanism 76 consists of a diaphragm 78 and a check ball 80, and the diaphragm 78 is moved by pressure fluctuations in the compressed air passage 60 transmitted to the diaphragm 78 via the communication pipe 74, and the check ball 80 is controlled to open and close. Communication pipe 7
A discharge passage 82 is connected to the transmission passage 4, and the lubricating oil is discharged from the discharge passage 82 to the transmission chamber 52 (FIG. 2). The discharge passage 82 is a passage 84 and a lubricating oil passage 66.
It is also connected to

On the radially outward side of the air seals 81 to S6, there is
It is surrounded by a cover 26 similar to the figure.

Next, the effect will be explained. In the device of the first embodiment shown in FIG.
Since lubricating oil is supplied to r! of lip part 61, an oil film is formed at the tip of each lip part 61. This oil film prevents the compressed air in v38 from leaking, and also prevents the r! of lip part 61 from leaking. Reduce AyA force.

Further, compressed air having the same pressure as that in the chamber 38 is supplied from the passage passage 72 to the sealed oil 70 in the oil chamber 62.62', so that the sealed oil 70 in the oil chamber 62.62- is supplied to the sealed oil 70 in the chamber 38. is pressurized with the same pressure. Therefore, air seals S3, S
The lip portion 61 of air seal $3, S4 is pressed against the cylinder shaft 24 by the pressure of the sealed oil 70, but the pressure of the sealed oil 70 is in pressure balance with the compression pressure of v38, and the lip portion 61 of the air seal $3, S4 is pressed against the cylinder shaft 24. 24 to prevent it from being pressed too hard.

Therefore, the binding force of the lip portions 61 of the air seals S3 and S4 on the cylinder shaft 24 is reduced to only the tightening force of the one-wheel 63 built in the lip portion 61 and the lip portion 61,
The S vibration force between the lip portion 61 and the cylinder shaft 24 is reduced, and the generated frictional heat is also reduced.

Since the pressures in the chamber 38 and the oil chamber 62.62- are balanced as described above, even if the binding force of the lip portion 61 of the air seal 5384 is light, the sealed oil in the oil chamber 62.62- 70 will not flow out into the chamber 38.

The same applies to the oil chambers 64 and 64', since lubricating oil is supplied at a predetermined pressure.

Since the air seals S2 and S5 are provided with protrusions T, the lubricating oil in the oil chambers 64 and 64' flows into the chamber 38 little by little while lubricating the lip portions 61 of the air seals S2 and S5. Therefore, the oil level in the oil chamber 62a rises from the standard filled oil level 68a to the increased filled oil level 68b. Since the setting corresponds to the amount of lubricating oil flowing into the chamber 38 by
There is no risk of it exceeding 8b.

When disengaging the air clutch, use valve 3 in Figure 2.
The pressure in the compressed air passage 60 connected to the compressor 2 becomes low, and this pressure is transmitted from the oil chamber 62a and the communication pipe 74 to the diaphragm 78, and moves the diaphragm 78 to the right in FIG.

When the diaphragm 78 moves to the right, the check ball 80 also moves together, and the discharge valve mechanism 76 opens. When the discharge valve mechanism 76 opens, the sealed oil 70 in the oil chamber 62a flows to the discharge passage 82, and the oil level in the oil chamber 62a reaches the sealed oil standard oil level 6.
It drops to 8a.

In addition, when carrying out the present invention, 1A seal 81 to S
6 is not necessarily necessary, and if an oil film is attached to the outer peripheral surface of the cylinder shaft 24, the lips 61 of the air seals S2 and S4 can be lubricated by the oil film attached to the cylinder shaft 24, so F-seals S1 and S6 are It can also be reduced.

(Effects of the Invention) As explained above, the sealing device for the air rotary joint according to the present invention includes a rubber inner air seal S facing the air chamber 38 that supplies compressed air to the inside of the rotating shaft (for example, cylinder @24).
3. A lubricating oil chamber 62 which is provided by combining S4 and outer rubber air seals S2 and S5 spaced apart from each other in the axial direction by the inner air seal S3.84, and seals lubricating oil in the space between both air seals 82. A passage 72 that applies the same pressure as the compressed air is connected to this lubricating oil chamber 62, and a passage 72 that applies the same pressure as the compressed air is attached to the sliding surface of one or both of the air seals 82 to S5 to prevent the rotation of the rotary shaft. A slanted protrusion T is formed so as to send the lubricating oil adhering to the surface of the rotating shaft into the lubricating oil chamber, and the lubricating oil chamber 62 is formed by this protruding ridge T.
Eight storage chambers (lubricating oil tanks 68) are formed in series with the lubricating oil chamber 62 to store the lubricating oil flowing into the lubricating oil chamber 62. Since the discharge valve mechanism 76 for discharging the ra lubricating oil is provided, the following effects are achieved.

The lubricating oil flowing into the chamber 38 from the protrusions T formed on the lip portions 61 of the air seals S2 and S5 can be discharged to the outside by a discharge valve mechanism 76 that opens and closes according to pressure fluctuations in the compressed air passage 60, and has a protrusion T. The reliability of a sealing device using air seals S2 and S5 can be improved.

(Another Embodiment) (1') The present invention is not limited to air clutches for automobiles as shown in FIG. 1, but can be applied to general pneumatic equipment.

[Brief explanation of the drawing]

Claims (2)

[Claims] (1) In an air rotary joint that supplies compressed air from the outside to pneumatic equipment through a rotating shaft, there is a rubber inner air seal facing the air chamber that supplies compressed air inside the rotating shaft, and an axial direction on the inner air seal. A lubricating oil chamber is formed by sealing lubricating oil in the space between both air seals, and a compressed air passage is provided to apply the same pressure as the compressed air to this lubricating oil chamber. connected, and on the sliding contact surface of one or both of the air seals with the rotating shaft, an inclined protrusion is provided so as to feed the lubricating oil adhering to the surface of the rotating shaft into the lubricating oil chamber by rotation of the rotating shaft. A storage chamber is continuously formed in the lubricating oil chamber, and the storage chamber is set to have a capacity that can store the lubricating oil flowing into the lubricating oil chamber by the protruding stripes, and the storage chamber is continuously formed in the lubricating oil chamber, and A sealing device for an air rotary joint, characterized by being provided with a discharge valve mechanism for discharging lubricating oil from a storage chamber. (2) The sealing device for an air rotary joint according to claim 1, wherein the discharge valve mechanism is comprised of a diaphragm that moves according to air pressure fluctuations, and a check ball connected to the diaphragm.