JPH09324860A - Seal device for high speed rotating operation - Google Patents

Abstract

PROBLEM TO BE SOLVED: To realize a seal device for a high speed rotation having a long life as well as a high anti-pressure characteristic. SOLUTION: There are provided a first seal member 13 positioned at a side opposite to sealing fluid, a side of rotor R, for example, and a second seal user 23 positioned at sealing fluid side, a side of gear G, for example. The first seal member 13 sealingly closes the sealing fluid and at the same time the first seal member 13 is applied as an anti-pressure seal capable of enduring a pressure fed from the side of the rotor R into a closed space S formed between both seal members. The second seal member 23 is constructed such that sealing fluid is fed into the closed space S and at the same time pressure in the closed space S is held and adjusted.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a seal device for high speed rotation, which is used in an automobile, an industrial machine or the like, in which a shaft rotates at a high speed and a positive pressure is applied to a side opposite to a sealing fluid. .

[0002]

2. Description of the Related Art Conventionally, when such a sealing device is provided between a gear that uses oil and a rotor that generates pressure as in a supercharger, the oil on the gear side is sealed and the rotor side is sealed. A pressure resistance function is required to hold the pressure generated at.

FIG. 2 shows an example of a sealing device for a supercharger having such a pressure resistance function. The sealing device 1 includes a metal reinforcing ring 2 having an L-shaped cross section, and a sealing member 3 formed so as to surround the metal reinforcing ring 2. The seal member 3 extends to the gear side G of the housing 8, that is, the side filled with oil, and contacts the shaft 9 with the seal lip 4.
A seal lip 4 and an auxiliary lip 5 that extends to the opposite side, that is, the rotor side R of the housing 8 and contacts the shaft 9, and an attachment portion 6 that is fixed to the metal reinforcing ring 2 and fixed to the housing 8. The waist 7 which is the boundary with the mounting portion 6,
It is thicker and shorter in length than an ordinary sealing device. The waist portion 7 enhances the rigidity of the seal lip 4 and improves the pressure resistance against the pressure from the rotor side R.

[0004]

However, in the above-mentioned conventional sealing device, the rigidity of the sealing member 3 is increased by increasing the thickness of the waist portion 7 of the sealing member 3 to secure the pressure resistance against the pressure generated on the rotor side R. However, on the contrary, there is a problem that the tightening force is increased due to the increased rigidity, and the seal lip 4 and the auxiliary lip 5 generate heat due to the shaft 9 rotating at a high speed to shorten the life of the seal. Therefore, there is a limitation in increasing the rigidity of the seal member 3, and there is a problem that it cannot be used for a supercharger in which the pressure generated on the rotor side R is high.

SUMMARY OF THE INVENTION The present invention is intended to solve such a conventional problem, and an object thereof is to provide a seal device for high speed rotation, which has a long life and is excellent in pressure resistance.

[0006]

In order to achieve the above object, the present invention uses two sealed members arranged in the axial direction to form a sealed space between the two sealed members and utilizes the sealed space. The pressure resistance and the sealing property are ensured.

[0007]

BEST MODE FOR CARRYING OUT THE INVENTION A sealing device according to an embodiment of the present invention comprises a first sealing member located on the side opposite to a sealing fluid and a second sealing member located on the sealing fluid side. The first sealing member is configured to seal the sealing fluid and withstand a positive pressure introduced from the opposite side of the sealing fluid into the sealed space formed between both sealing members, and the second sealing member is the sealing fluid. Is introduced into the closed space between both seal members and the pressure in the closed space is held and adjusted, and the required pressure resistance can be obtained even if the tightening force on the shaft is suppressed to some extent.

Further, in the sealing device of the present invention, the seal lips of the first sealing member and the second sealing member both face the sealing fluid side, and when the pressure in the sealed space between the both sealing members reaches a specified value. The seal lip of the second seal member is pressed to release the pressure to the sealed fluid side, and even if the pressure in the sealed space exceeds the specified value, it is possible to prevent damage in advance. You can

Further, the sealing device of the present invention is used for a device to which positive pressure and negative pressure are applied on the side opposite to the sealing fluid, for example, between a rotor and a gear of a supercharger of an automobile, particularly a Risholum type supercharger. The characteristics can be sufficiently exhibited for these devices.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment in which a seal device for high speed rotation according to the present invention is provided between a rotor and a gear of a Risholm type (screw type) supercharger will be described below with reference to FIG. In FIG. 1, the sealing device is
It comprises a first oil seal 11 on the rotor side R and a second oil seal 21 on the gear side G. The first oil seal 11 is
A metal reinforcing ring 12 having an L-shaped cross section and a rubber first seal member 13 integrally formed with the metal reinforcing ring 12 are provided. The first seal member 13 has a seal lip 14 extending toward the gear side G and is pressed against the shaft 31 by a garter spring 15. In addition, a backup ring 16 is provided on the waist of the seal lip 14 and is configured as a pressure resistant seal as a whole. On the other hand, the second oil seal 21 is similar to the metal reinforcing ring 22 having an L-shaped cross section.
And a rubber second seal member 2 formed integrally therewith
3 is provided. The second seal member 23 has a seal lip 24 extending toward the gear side G and longer than the first seal member 13, and is pressed against the shaft 31 by a garter spring 25. As for the position of the garter spring 25, the garter spring 15 of the first oil seal 11 is located on the right side in the figure with respect to the tip of the seal lip 14, while the garter spring 25 is located at the tip of the seal lip 24. On the other hand, it is located on the left side in the figure. This reverse offset is for maintaining the contact pressure distribution of the tip portion of the seal lip 24 on the shaft 31 appropriately for the object to be sealed. The first oil seal 11 and the second oil seal 21 are axially overlapped and fixed to the housing 41, and the first seal member 13, the second seal member 23, and the shaft 31 form a closed space S.

Next, the operation of the sealing device will be described. When the shaft 31 rotates at high speed and the pressure on the rotor side R becomes high, the seal lip 14 is pushed to form a gap with the shaft 31, and the pressure generated on the rotor side R is introduced into the sealed space S from there. It When the pressure in the closed space S gradually increases, the tightening force on the shaft 31 of the seal lip 14 of the first seal member 13 increases due to the pressure, and when the pressure on the rotor side R is balanced under certain conditions, the rotor side R R is completely sealed. In this state, the pressure in the closed space S is lower than the pressure on the rotor side R. Since the first seal member 13 is a pressure-resistant seal that can withstand the pressure of the closed space S, the pressure does not affect the durability and the sealability. On the other hand, the second seal member 23 is
Since the garter spring 25 is reversely offset, the pressure in the closed space S is maintained and the gear side G
Of the oil is introduced into the closed space S, and the first seal member 1
The seal lip 14 of No. 3 is kept in a good lubricating state.

As described above, according to the above-described embodiment, the pressure on the rotor side R is introduced into the closed space S formed between the first seal member 13 and the second seal member 23 so that the rotor side R Since the pressure is balanced with the above pressure, the pressure resistance against the pressure on the rotor side R can be ensured even if the tightening force of the first seal member 13 on the shaft 31 is suppressed to some extent. Further, the oil on the gear side G is introduced into the closed space S by the second seal member 23 so that the seal lip 14 of the first seal member 13 is kept lubricated and the pressure in the closed space S is kept. Therefore, both pressure resistance and sealing performance can be achieved.

In the above embodiment, the second seal member 2
Since the seal lip 24 of No. 3 faces the gear side G similarly to the seal lip 14 of the first seal member 13, in the unlikely event that the pressure in the closed space S exceeds the specified value due to an increase in atmospheric temperature or the like. In addition, since the seal lip 24 of the second seal member 23 is opened and the pressure is released to the gear side G, it is possible to prevent the seal member from being damaged.

The above embodiment is applied to a supercharger in which the pressure on the rotor side R is positive pressure. However, the equipment on which the pressure on the rotor side R, that is, the opposite side of the sealed fluid becomes positive pressure and negative pressure. Even when the sealing device of the present embodiment is applied to, since the first seal member 13 is a pressure resistant seal, both durability and sealability can be achieved.

[0015]

As described above, according to the present invention, two seal members are arranged side by side in the axial direction to form a hermetically sealed space between the two seal members, and the hermetically sealed space is utilized to achieve pressure resistance and sealing performance. Since they are made compatible with each other, the required pressure resistance can be secured even if the tightening force of the seal lip on the shaft is suppressed to a certain extent, and a seal device for high-speed rotation having a long life can be realized.

[Brief description of drawings]

FIG. 1 is a partial cross-sectional view of a high-speed rotation seal device showing an embodiment of the present invention.

FIG. 2 is a partial cross-sectional view of a conventional high-speed rotation seal device.

[Explanation of symbols]

 11 First Oil Seal 12 Metal Reinforcing Ring 13 First Seal Member 14 Seal Lip 15 Garter Spring 16 Backup Ring 21 Second Oil Seal 22 Metal Reinforcing Ring 23 Second Seal Member 24 Seal Lip 25 Garter Spring 31 Shaft 41 housing

Claims (5)

[Claims] 1. A sealing device used in a device in which a shaft rotates at high speed, comprising a first sealing member located on the opposite side of the sealing fluid and a second sealing member located on the sealing fluid side. The first sealing member is configured to seal the sealing fluid and to withstand a positive pressure introduced from the opposite side of the sealing fluid into the sealed space formed between the sealing members, and the second sealing member is A sealing device for high-speed rotation, characterized in that a sealing fluid is introduced into a sealed space between both seal members and a pressure in the sealed space is held and adjusted. 2. The seal lips of the first seal member and the second seal member both face the sealed fluid side, and when the pressure in the sealed space between both seal members reaches a specified value, the second seal member The seal device for high speed rotation according to claim 1, wherein the seal lip is pressed to release the pressure to the sealed fluid side. 3. The seal device for high speed rotation according to claim 1, which is used in a device to which a positive pressure and a negative pressure are applied on the side opposite to the sealed fluid. 4. The seal device for high speed rotation according to claim 1, which is arranged between a rotor and a gear of a supercharger. 5. The seal device for high speed rotation according to claim 4, wherein the supercharger is a Risholum type.