JPS6322376Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a mechanical seal, and more particularly, to a mechanical seal that has both the sealing action of a mechanical seal and a visco seal.

[Prior Art] As shown in FIG. 3, a mechanical seal includes a rotating ring 2 provided on a rotating portion 1 and a stationary portion 4 that slides against the rotating ring 2 provided on a base body 3.
It performs a sealing action with. The sliding surface is wrapped so that the necessary pressing load is applied by the pressure of the spring 5 and the sealing fluid. By the way, when the outer circumferential side of the mechanical seal is the high pressure side A and the inner circumferential side is the low pressure side B, the leakage fluid flowing inward is extremely small at low speeds, and sufficient sealing performance can be obtained. However, at high speeds, it becomes impossible to keep the sealing surface 6 of the mechanical seal in a narrow gap, or vibration occurs and the behavior of the sealing surface 6 becomes unstable, resulting in an increase in leakage. . Additionally, the sealing surfaces are often in contact and are easily damaged and have a shorter lifespan than non-contact seals. Another problem is that the gap between the sealing surfaces is narrow, resulting in large losses.

[Purpose of the invention] This invention was created in view of the above-mentioned problems, and its purpose is to create a mechanical seal that improves sealing performance at high speeds, extends service life, and reduces loss. Our goal is to provide the following.

[Configuration of the invention] The mechanical seal according to the invention forms a visco seal with the low-pressure side of the stationary part of the mechanical seal and a part of the rotating part opposing this, and the stationary part and the pressing load are formed in a part of the visco seal. A pressure chamber is provided to counter the

[Operations and Effects of the Invention] Since the present invention is configured as described above, leakage fluid at high speed is sealed by the Visco seal provided on the low pressure side, and as a result, sealing performance is improved.
Also, at this time, the pressure in the pressure chamber increases and the sealing surface is pushed apart, creating a non-contact state and preventing damage to the sealing surface, thereby extending the service life. Also, losses are reduced because the gap between the sealing surfaces becomes larger.

[Examples] Examples of the present invention will be described below with reference to the drawings. In these drawings, parts corresponding to those in FIG. 3 are designated by the same reference numerals and redundant explanation will be omitted.

In FIG. 1, a thread groove 9 whose twist direction is opposite to the rotation direction is formed on the outer periphery of a part 8 of the rotating part that faces the low-pressure side part 7 of the stationary part 4. A visco seal 10 is formed with the low pressure side portion 7 of the lower pressure side portion. Also Visco Seal 10
A pressure chamber 15 is formed on the side of the sealing surface 6 by the end surface 11 and inner circumference 12 of the stationary part 4, the end surface 13 of the rotating ring 2, and the outer circumference 14 of the end part 8 of the rotating part 4.
is formed to counter the pressing load of the stationary part 4 due to the spring 5 and the fluid pressure on the high pressure side A.

With this configuration, leakage fluid at high speeds is sealed by the visco seal 10, and as a result, sealing performance is improved. Furthermore, when this sealing action becomes effective, pressure is generated by the pumping action of the reverse screw and the flow resistance determined by the gap between the sealing surfaces, so that the pressure in the pressure chamber 15 increases. Then, when the pressure becomes larger than the pressing load on the stationary part 4 due to the fluid pressure of the spring 5 and the high pressure side A, the stationary part 4 is pushed back, thereby opening the sealing surface 6 and putting it in a non-contact state. Damage to the sealing surface 6 is thereby prevented, so that the service life is extended and losses at the sealing surface are reduced. In this way, the sealing surface of the mechanical seal works effectively at low speeds, and the Visco seal works effectively at high speeds, and the sealing surfaces are in a non-contact state, preventing damage and extending service life.

Fig. 2 shows another embodiment of the present invention, in which the outer peripheral side of the mechanical seal is the low pressure side B, and the inner peripheral side is the high pressure side A.
This is an example of the case where In this example, the inner periphery 8' of the rotating ring 2' facing the low pressure side portion 7' of the stationary part 4
A thread groove 9 is formed in the screw groove 9, and a visco seal 10 is formed by the thread groove 9 and the stationary part low pressure side portion 7,
A pressure chamber 1 is located on the sealing surface 6 side of the visco seal 10.
5'. This embodiment also has the same effects as in FIG. 1.

[Summary] As explained above, since the Visco seal is formed on the low pressure side of the mechanical seal and a pressure chamber is provided in a part of the Visco seal, the sealing performance at high speeds is improved and the life is extended.

[Brief explanation of the drawing]

FIGS. 1 and 2 are sectional views showing different embodiments of the present invention, and FIG. 3 is a sectional view showing a conventional mechanical seal. 1... Rotating part, 2... Rotating ring, 4... Stationary part, 7, 7'... Low pressure side part of stationary part, 8, 8'...
... Part of the rotating part, 10 ... Visco seal, 15,
15'...pressure chamber.

Claims (1)

[Scope of utility model registration request] A Visco seal is formed by the low pressure side of the stationary part of the mechanical seal and a part of the rotating part facing it,
A mechanical seal characterized by having a pressure chamber provided in a part of the visco seal to counter the pressing load of the stationary part.