JPH0227723Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to an improvement of a mechanical seal for sealing a rotating shaft of a device.

[Conventional technology]

Conventionally, as a type of mechanical seal, as shown in FIG. 3, a stepped portion 1' of the rotating shaft 1,
A mating ring 3 that is airtightly clamped between a sleeve 2 externally mounted on the rotating shaft 1 and rotates together with the rotating shaft 1, and a retainer 5 that is airtightly fixed to the inner periphery of the housing 4 of the device. A packing 7 made of a rubber-like elastic material is placed in the annular recess 6 having a substantially U-shaped cross section.
It is known that seal rings 9, which are airtightly supported via a coil spring 8 and pressed in the axial direction by a coil spring 8, slide closely against each other to prevent leakage of in-machine oil A. ing. The seal ring 9 is prevented from rotating by a notch 10 recessed in its outer circumferential surface and a protrusion 11 protruding from the circumferential surface of the annular recess 6 engaging each other so as to be able to freely slide in the axial direction. and is fixed to the front surface of the retainer 5 to prevent it from falling out of the annular recess 6 by having a disk-shaped adapter ring 12 whose inner circumferential end 12' has a smaller diameter than the outer diameter of the seal ring 9. has been done.

[Problem that the invention attempts to solve]

However, as shown in FIG. 4, the adapter ring 12 has an inner circumferential end 12' having a circular shape and extends over the entire outer circumference of the opening of the annular recess 6. Therefore, the in-machine oil A that has entered the internal space 13 of the annular recess 6 is dammed by the inner circumferential end 12' of the adapter ring 12 and tends to stay there. Therefore, when the ambient temperature rises due to heat generation due to sliding of the mechanical seal, and the in-machine oil A retained in the annular recess 6 deteriorates and generates sludge, the seal ring 9 and retainer 5, for example, and the protrusion 11, resulting in malfunction of the seal ring 9 in the axial direction.In other words, the elastic pressing action and buffering action of the coil spring 8 do not function sufficiently, and the seal ring 9 and the main part become stuck together. There was a problem in that the sealing performance in the sliding portion 14 of the sealing ring 3 became unstable.

In view of the above problems, the present invention aims to maintain the reliability of the seal over a long period of time by eliminating malfunction of the seal ring.

[Means for solving problems]

As a means to achieve this objective, the mechanical seal of the present invention is provided at the inner circumferential end of an adapter ring that is fixedly installed on the opening side of the annular recess in order to prevent the non-rotating seal ring from coming off from the annular recess on the housing side. A required number of notches are formed to allow flow of internal fluid between the inside and outside of the annular recess, and at least one of the notches is located at the lower end of the annular recess and at the outer diameter side of the annular recess. It has a shape that reaches the same diameter part as the opening edge or a larger diameter part than the opening edge.

[Effect]

Therefore, the in-machine fluid that has entered the annular recess during the operation of the equipment does not remain in the annular recess, and the in-machine fluid flows through the notch formed in the adapter ring. As the fluid flows freely inside and outside the annular recess, it is difficult for sludge to form inside the annular recess due to heat.Furthermore, the fluid that enters the annular recess immediately flows back into the inside of the machine from the cutout at the lower end, which prevents the operation of the seal ring. Defects can be avoided.

〔Example〕

Next, one embodiment of the present invention will be described based on FIGS. 1 and 2. In this embodiment, the same reference numerals are given to the parts whose configurations overlap with those of the conventional example shown in FIGS. 3 and 4 described above, and the explanation thereof will be omitted.

That is, in this embodiment, the housing 4
In order to prevent the seal ring 9 from falling off from the annular recess 6 of the retainer 5 fixed to the inner circumference, cutouts 15, 15, . ...is circumferential direction 4
They are equally spaced, and the outer diameter φ of the notches 15 matches the diameter of the outer opening edge 6' of the annular recess 6. Therefore, the in-machine oil A can freely flow through the notch 15 and the space 13 inside the annular recess 6 and the outer space of the adapter ring 12, and the in-machine oil A that has entered the inner space 13 of the annular recess 6 can be removed. Since A does not remain as it is and turn into sludge, the operability of the seal ring 9 is maintained well.

[Effect of idea]

As is clear from the above explanation, the mechanical seal of the present invention has an adapter ring that prevents the seal ring from coming off from the annular recess on the housing side.
By providing a notch that allows free flow of in-machine fluid between the inside and outside of the annular recess, it is possible to prevent the in-machine fluid from remaining in the annular recess and generate sludge, and to prevent the generation of sludge. It is possible to eliminate the malfunction of the seal ring and stabilize the sealing performance over a long period of time, which has an extremely large practical effect.

[Brief explanation of the drawing]

Fig. 1 is a half-cut side sectional view of a mechanical seal according to an embodiment of the present invention, Fig. 2 is a half-cut front view of an adapter ring in the same embodiment, and Fig. 3 is a half-cut side sectional view of a mechanical seal according to a conventional example. , FIG. 4 is a half-cut front view of the adapter ring in the conventional example. 1...Rotating shaft, 3...Mating ring, 4
... Housing, 5 ... Retainer, 6 ... Annular recess, 6' ... Opening edge on outer diameter side, 7 ... Packing,
8...Coil spring, 9...Seal ring,
12...Adapter ring, 12'...Inner peripheral end,
15... Notch.

Claims (1)

[Scope of utility model registration request] A mating ring that is airtightly fixed to the rotating shaft side and rotates together with the rotating shaft, and a non-rotating seal ring that closely slides together, pack the inner circumference of the seal ring in an annular recess formed on the housing side. In the mechanical seal, the annular recess is airtightly supported through the annular recess, is pressed toward the mating ring by a spring, and is prevented from coming off by an adapter ring fixed to the opening side of the annular recess. A required number of notches are formed on the inner circumferential end of the adapter ring that protrudes from the outer diameter side opening edge toward the inner diameter side, and the required number of notches are formed to allow the flow of internal fluid between the inside and outside of the annular recess. A mechanical seal characterized in that at least one of them is located at the lower end of the annular recess and has a shape that extends to the same diameter part as the outer diameter side opening edge or to a larger diameter part than the opening edge.