JPH0138374Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to an improvement of a shaft sealing device related to shaft sealing technology.

[Conventional technology]

As a type of shaft sealing device conventionally used in automobile superchargers, seal rings c and c are fixed to a body a via a retainer b, as shown in Fig. 2.
It is known that these are loosely inserted into annular grooves f and f provided on the outer diameter surface of a sleeve e that is externally fitted onto the shaft d, and two sets of labyrinth seals g and g are provided in the grooves f and f, respectively. There is.

[Problem that the invention attempts to solve]

The above-mentioned shaft sealing device is equipped with oil o
The labyrinth seals g have the function of sealing this so that it does not leak to the blower i side, but the seal ring c and the annular groove f
Due to the characteristics of the labyrinth seal g that sets axial and radial clearances between the two, there is a risk that a large amount of oil o may leak when the blower i side becomes negative pressure. In order to suppress this leakage, measures such as narrowing the clearance of the labyrinth seal g to improve the performance of the seal g can be considered, but with the operation of the supercharger, a relatively large vibration in the shaft d...
Therefore, there is a problem in that the clearance cannot be narrowed and leakage of oil cannot be reduced.

[Means for solving problems]

In view of the above points, the present invention aims to provide a shaft seal device that also uses a labyrinth seal but improves sealing performance by narrowing the clearance of the seal. A mechanism is provided for the labyrinth seal that seals the liquid to be sealed by packing made of a rubber-like elastic material to suppress vibration of the shaft. The structure was such that a drain hole was opened at the bottom.

[Effect]

The shaft sealing device with the above configuration uses the elasticity of the packing to suppress vibration of the shaft.
This system narrows the clearance of the labyrinth seal to improve its sealing performance, and in addition, the drain hole opened between the shaft support mechanism and the labyrinth seal collects much of the liquid to be sealed that leaks from the former mechanism and transfers it to the latter seal. Since the sealing force is prevented from reaching this level, the sealing force can be further improved dramatically.

〔Example〕

Next, one embodiment of the present invention will be described with reference to the drawings.

In FIG. 1, reference numeral 1 indicates the body of an automobile supercharger, a part of which is shown, 2 indicates a shaft inserted into the shaft hole of the body 1, and the shaft seal device is sealed in the in-machine thrust bearing 3 side. This is sealed so that oil O does not leak to the side of the blower 4 screwed to the shaft 2.

Reference numeral 5 indicates a sleeve that is clamped and fixed together with a mating ring 6 between the stepped portion 2a of the shaft 2 and the blower 4, and is inserted into an annular groove 7 provided on the outer diameter surface of the sleeve 5 via a retainer 8. A seal ring 9 fixed to the body 1 is loosely inserted to form a set of labyrinth seals 10. It is fitted into the opening edge of the shaft hole of the body 1 together with the thrust bearing 3,
The retainer 8, which is prevented from coming off by the snap ring 11, includes a first member 12 into which the seal ring 9 is inserted, and a second member 13 which is held between the member 12 and the bearing 3. A shaft support mechanism 14 consisting of a support ring 15 and an O-ring 16 made of a rubber-like elastic material is provided on the inner periphery of the second member 13. The inner diameter of the support ring 15 is set to be slightly larger than the outer diameter of the sleeve 5 located on the inner periphery of the support ring 15. Further, a drain hole 18 is provided at a lower position in the circumferential direction of the retainer 8 along the joint surface of the first and second members 12 and 13 and opens into the space 17 between the shaft support mechanism 14 and the labyrinth seal 10. It is being This drain hole 18 is connected to a notch 3 formed in the thrust bearing 3.
It communicates with an oil reservoir (not shown) via a. The lower part of the thrust bearing 3 side where the oil reservoir is provided is connected to an oil pan via a thick pipe.

In the shaft sealing device configured as described above, when the shaft 2 starts to shake due to the operation of the supercharger, the shaft 2 comes into contact with the support ring 15 via the sleeve 5, and the shaft 2 is placed behind (outer circumference of) the ring 15. Vibration is suppressed by the elasticity of the provided O-ring 16. As a result, the radial clearance of the labyrinth seal 10, which was conventionally set wide assuming a large amount of vibration of the shaft 2, can be set narrower in accordance with the reduction of the vibration. It becomes possible to improve the sealing force and reduce the amount of oil leakage. The seal ring 9 made of metal or resin is partially cut in the circumferential direction so that it has a C-shape in its free state, and is reduced in diameter to form the retainer 8,
It will fit into 12. Further, the packing made of rubber-like elastic material using the O-ring 16 can be replaced with an X-ring or a ripple ring made of the same material. Although the number of labyrinth seals 10 can be reduced by improving their performance, the number is not particularly limited. Also support ring 1
5 and the sleeve 5 to the labyrinth seal 10 side, most of it is collected from the drain hole 18, and the labyrinth seal 10
reduce the burden on The oil o collected in the drain hole 18 is immediately sent from the oil reservoir to the oil pan, and does not flow back even if the blower 4 side becomes negative pressure. When the blower 4 side becomes negative pressure, the space 1 between the shaft support mechanism 14 and the labyrinth seal 10
Air flows into the space 17 from the thrust bearing 3 side through the drain hole 18 to maintain the space 17 at approximately atmospheric pressure, so that the amount of leakage from between the support ring 15 and the sleeve 5 can be suppressed.

[Effect of idea]

As explained above, the shaft sealing device of the present invention is provided with a shaft support mechanism equipped with packing made of rubber-like elastic material to suppress vibration of the shaft, and correspondingly narrow the clearance of the labyrinth seal. In addition, a drain hole is provided between the mechanism and the seal, which improves the sealing performance of the labyrinth seal itself while reducing its burden, and has the feature of dramatically improving the overall sealing force. .

[Brief explanation of the drawing]

FIG. 1 is a cross-sectional view of an embodiment of the shaft sealing device of the present invention, and FIG. 2 is a cross-sectional view showing an example of a conventional shaft sealing device. 1...Body, 2...Shaft, 3...In-machine thrust bearing, 4...Blower, 5...Sleeve, 7
... Annular groove, 8 ... Retainer, 9 ... Seal ring, 10 ... Labyrinth seal, 14 ... Shaft support mechanism, 15 ... Support ring, 16 ... O ring, 17 ... Space, 18 ... Drain Hole.

Claims (1)

[Scope of utility model registration request] In shaft sealing devices used in automotive superchargers, etc., a labyrinth seal that seals oil and other liquids to be sealed is equipped with packing made of rubber-like elastic material to suppress shaft vibration. A shaft sealing device characterized in that a clearance of a labyrinth seal is narrowed and a drain hole is provided between the mechanism and the labyrinth seal.