JPS63158364A - Seal device for air rotary joint - Google Patents

Abstract

PURPOSE:To aim at improvement in the durability of an air seal, by cooling sealing oil inside the lubricating oil chamber formed in space between internal and external air seals, in the case of an air rotary joint which feeds pneumatic equipment including an air clutch or the like with compressed air. CONSTITUTION:Sealing oil 70 is sealed in oil chambers 62 and 62', and lubricating oil is fed to oil chambers 64 and 64'. The sealing oil 70 inside these oil chambers 62 and 62' is pressurized with the same pressure as that in a chamber 38. The sealing oil in these oil chambers 62 and 62' cools air seals S2-S5 and thereby it comes to high temperature, but since these oil chambers 62 and 62' are in succession to an oil chamber 65, the hot sealing oil 70 flows into this oil chamber 65, thus it is colled by cooling water in a cooling chamber 75 at the oil chamber 65 via a pressure interruptive heat exchanger plate 74.

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. 4 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 force generated by the annular pneumatic actuator 14 (pneumatic device) of the clutch cover 12 is transmitted to the pressure plate 16, and the pressure plate 16 and the flywheel 10 are A clutch disc 18 is sandwiched between them.

The clutch disc 18 is spline-fitted to an input shaft 20 of a transmission (not shown) disposed after the air clutch. A cylindrical shaft 24 is fitted onto the outer periphery of the input shaft 20 via a bushing 22. 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.
308 to 30b are interposed, and air leakage is prevented by air seals 308 to 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 has an inlet hole 40 and a 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. .

However, at high rotations, the circumferential speed of the lip increases, and as the air pressure increases, the pressure contact force of the lip increases, and the pv value (
P゛: pressure, V: circumferential speed) increases, and there is a risk that the air seal will eventually be damaged due to FJ friction heat.

(Object of the Invention) An object of the present invention is to provide a sealing device for an air rotary joint that can improve the durability of the air seal by cooling the lip portion of the rubber air seal.

(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. The f! This is a sealing device for an air rotary joint, characterized in that a compressed air passage that applies the same pressure as the compressed air is connected to the lubricating oil chamber, and a cooling mechanism is provided to cool the sealed oil in the lubricating oil chamber.

(2) Function The oil sealed between both air seals is cooled by a cooling mechanism to prevent the air seal from being damaged by frictional heat.

(Embodiments) (1) First Embodiment An air seal device for an air clutch for an automobile, which is a first embodiment of the present invention, will be explained with reference to FIG.

FIG. 1 is an enlarged view of the construction part in FIG. 4, and since other parts have substantially the same structure, they are designated by the same reference numerals in FIG. 1 as in FIG. 4.

In FIG. 1, three rubber air seals with a total weight of 6 gI are arranged at intervals in the axial direction on the outer peripheral surface of the cylindrical shaft 24 (rotating shaft), three on each side of the left and right sides of the chamber 38. 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 supplied to the air clutch from a passage 42 (FIG. 3) of the cylinder shaft 24. .

The rubber annular air seal S1 is arranged with the lip portion 61 open toward the chamber 38, and the same is true of the air seal S2. 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). A lubricating oil chamber 62 is formed between the air seal S3 and the air seal S2. Further, an oil chamber 64 is also formed between the air seal S1 and the air seal S2, and lubricating oil is supplied to the oil chamber 64 from a lubricating oil passage 66 at a predetermined pressure.

To the right of the air 38 in the figure, air seals 84 to S6 are arranged symmetrically with air seals 81 to S3, and similarly to the air seals 84 to S6, the oil 'J'
62-164- is formed.

A fourth air seal is located radially outward of the above air seals 81 to S6.
It is surrounded by a cover 26 similar to the figure.

An annular oil chamber 65 is formed radially outward of the oil chambers 62 and 62-. The oil chamber 65 is partitioned by a sealed oil surface 68 , and a passage 72 branched and connected to the compressed air passage 60 communicates with the oil chamber 62 , and the sealed oil 70 sealed in the oil chamber 62 is heated by the pressure from the compressed air passage 60 . It is designed to be pressurized.

The right side of the oil chamber 65 in the figure is a pressure cutoff heat transfer plate 74 made of a material with good thermal conductivity such as a copper plate, and the oil chamber 65 is connected to the oil chamber 65 through the pressure cutoff heat transfer plate 74. An annular cooling chamber 75 (cooling water circulation chamber) is adjacent thereto. The cooling chamber 75 is connected to a passage 76 that connects to, for example, a radiator of the vehicle, and relatively low-temperature cooling water is supplied from the passage 76 to the cooling chamber 75.
The sealed oil 70 in the oil chamber 65 is cooled.

Next, the effect will be explained. In the device of the first embodiment shown in FIG.
′ is supplied with lubricating oil, an oil film is formed at the tip of each lip portion 61, and this oil film prevents the compressed air in the chamber 38 from leaking and reduces the frictional force of the lip portion 61. reduce

In addition, a passage 72 is provided for the sealed oil 70 in the oil chamber 62, 62'.
Since compressed air at the same pressure as in the chamber 38 is supplied from the oil chamber 62, 62-, the sealed oil 70 in the oil chamber 62, 62- is pressurized at the same pressure as in the chamber 38. Therefore, the lip portions 61 of the air seals S3 and S4 are 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 the air 38, and the lips of the air seals S3 and S4 are pressed against the cylinder shaft 24 by the pressure of the sealed oil 70. Part 61
This prevents the cylinder from being pressed strongly against the cylinder shaft 24.

Therefore, the binding force of the lip portion 61 of the air seals S3 and S4 to the cylinder shaft 24 is reduced to only the tightening force of the wire 63 built in the lip portion 61 and the lip portion 61, and the gap between the lip portion 61 and the cylinder shaft 24 is reduced. The frictional force of decreases and occurs 11! Friction 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 53S4 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 constant pressure.

The sealed oil 70 in the oil chamber 62, 62' is filled with air seals S2 and S.
3. S4 and S5 are cooled and become high temperature, but the oil chamber 62.
62' is continuous with the oil chamber 65, so the high temperature sealed oil 70 flows into the oil chamber 65, and the pressure cutoff heat exchanger plate 7 is connected to the oil chamber 65.
4 and is cooled by cooling water in the cooling chamber 75.

The sealed oil 70 cooled by this cooling action returns to the oil chamber 62.
Return to step 62' and cool air seals S2, S3, S4, and S5. Therefore, the frictional heat of the lip portions 61 of the air seals S3, S4 is cooled by the low-temperature sealed oil 70, extending the life of the air seals S2, S3, S4, S5.

In addition, when implementing the present invention, air seals 81 to S
6 is not necessarily necessary, and if there is an oil film attached to the outer peripheral surface of the cylinder shaft 24, the lip portion 61 of the air seal S2, $4 can be lubricated with the oil film attached to the cylinder @24, so the air seal S1, $4 6 can also be reduced.

(2) Second Embodiment In FIG. 2 showing a second embodiment of the present invention, a check valve 77 is interposed in a passage 72 connected to the oil chamber 65. A cooling chamber 75 (llll
Relatively low-temperature lubricating oil flows into the lubricating oil passage 66 (a lubricating oil distribution chamber), and the fl18N oil in the cooling chamber 75 cools the high-temperature sealed oil 70 in the oil chamber 65. There is.

(3) Third Embodiment In FIG. 3 showing the third embodiment of the present invention, the oil chamber 62, 62-
The outer periphery of the oil chamber 65 connected to the oil chamber 65 passes through the cover 26 to form a substantially annular air cooling chamber 80. Outer wall 81 of air cooling room 80
is made of a material with good thermal conductivity, such as a copper plate, and is in contact with the surrounding atmosphere.

Therefore, the sealed oil 70 in the air cooling chamber 80 is cooled by air cooling in the air cooling chamber 80.

In this embodiment, a drain passage 82 is formed in the oil chamber 64, 64'. Note that cooling fins may be formed on the outer wall 81 to further increase cooling efficiency.

(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, the cylindrical shaft 24).
A lubricating oil chamber 62 is provided by combining an inner air seal S3 and an outer rubber air seal S4 spaced apart from each other in the axial direction, and sealing lubricating oil in the space between both air seals S3 and S4.
A compressed air passage 72 that applies the same pressure as the compressed air to the lubricating oil 9!62 is connected to the oil chamber 62.62.
Since a cooling mechanism (for example, cooling chamber 75 and air cooling chamber 80) for cooling the sealed oil 70 in 62' is provided, the following effects are achieved.

The lip portions 61 of the air seals S3 and S4 are 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 the chamber 38, and the air seals S
3. The lip portion 61 of S4 can be prevented from being strongly pressed against the cylinder shaft 24, and the lip portion 61 of air seals S3 and S4 can be prevented from being pressed strongly against the cylinder shaft 24.
The binding force on the cylinder shaft 24 of the cylinder 1 is reduced, the frictional force between the lip portion 61 and the cylinder shaft 24 is reduced, and the generated frictional heat can be reduced.

Furthermore, the sealed oil 70 in the oil chamber 65 can be cooled in the cooling chamber 75 in FIGS. 1 and 2, or the oil chamber 65 can be cooled in the air cooling chamber 80 in FIG.
Since the sealed oil 70 in the oil chamber 62, 62' can be cooled, the sealed oil 70 in the oil chamber 62, 62' can be maintained at a low temperature, and the lips 61 of the air seals S2, S3, S4, and S5 that come into contact with the sealed oil 70 can be cooled. The lifespan of S2, S3, S4, and S5 can be extended.

Therefore, even if the PV values of the lip portions 61 of the air seals S2, S3, S4, and S5 are increased, the lip portions 61 are not damaged, and the durability of the air seals S2, S3, S4, and S5 is improved.

(Another Embodiment) (1) The present invention is not limited to air clutches for automobiles as shown in FIGS. 1 and 2, but can be applied to general pneumatic equipment.

[Brief explanation of the drawing]

FIG. 1 is a structural diagram showing a first embodiment according to the present invention;
The figure is a schematic structural diagram showing the second embodiment, FIG. 3 is a structural schematic diagram showing the third embodiment, and FIG. 4 is a vertical sectional view showing the conventional example. 24...Cylinder shaft, 81-S6...Air seal, 61.
...Lip part, 62.62', 65...Oil chamber, 72.
...Passage, 74...Pressure isolation heat exchanger plate, 75...Cooling chamber, 80...Air cooling chamber Patent applicant: Daikin Seisakusho Co., Ltd. Figure 1 L---Yo' -Ryoichi No. 2 Figure 1 - - - Figure 3

Claims (4)

[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. A sealing device for an air rotary joint, characterized in that a cooling mechanism is connected to the lubricating oil chamber and cools sealed oil in the lubricating oil chamber. (2) The sealing device for an air rotary joint according to claim 1, wherein the cooling mechanism is a cooling water circulation chamber formed to cool the sealed oil via a pressure cutoff heat transfer plate. (3) The sealing device for an air rotary joint according to claim 1, wherein the cooling mechanism is a lubricating oil circulation chamber formed to cool the sealed oil via a pressure cutoff heat transfer plate. (4) The sealing device for an air rotary joint according to claim 1, wherein the cooling mechanism is an annular air cooling chamber extending radially outward and continuous with the lubricating oil chamber.