JPS6257866B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a shaft seal device that reduces leakage loss of fluid from a rotating shaft penetrating portion that passes through a stationary member of a fluid machine, and particularly to a shaft seal device that employs a honeycomb.

When applying a shaft sealing device using a honeycomb to a rotating shaft penetrating portion of a fluid machine, a structure as shown in FIGS. 1 and 2 has conventionally been adopted.
To explain this, FIGS. 1 and 2 are schematic views of symmetrical halves with respect to the central axis of longitudinal sections of essential parts of the rotating shaft in the direction of the central axis, and the same parts are designated by the same reference numerals. In the figure, 10 is a stationary member (for example, a casing or a seal stand) of the fluid machine, and 20 is a rotating shaft that rotates through the stationary member 10. 11
In the case of FIG. 1, the honeycomb 11 is entirely bonded with adhesive 12 to the surface of the stationary member 10 facing the rotating shaft of the through hole 10'. In addition, in the case of FIG. 2, the honeycomb 11 is the stationary member 1 of the rotating shaft 20.
It is entirely bonded with an adhesive 12 on the circumferential surface facing 0. Therefore, in both the case of FIG. 1 and the case of FIG. 2, only one side of the bonded honeycomb 11 is open, and no fluid flows through the honeycomb 11. In such a structure, the reduction in the amount of fluid leakage depends only on the large fluid resistance when the fluid passes over the opening surface of the honeycomb 11, that is, on the small flow coefficient. In addition, in Fig. 1 and Fig. 2, P ₁ ,
P ₂ indicates the fluid pressure on both sides of the shaft sealing portion by the honeycomb 11, and the figure shows the case where P ₁ >P ₂ . In a shaft sealing device having such a structure, in order to reduce the amount of fluid leakage, measures such as reducing the gap between the honeycomb opening surface and its opposing surface or forming the gap passage in an uneven shape are adopted. However, such means are not only dangerous as they tend to cause a contact accident between the stationary member 10 and the rotating shaft 20, but also prevent the leakage fluid passage gap from being maintained small over a wide range between the stationary member 10 and the rotating shaft 20. Since it is necessary, there is a disadvantage that the construction is troublesome and time-consuming, and the construction cost is high. Note that FIG. 3 is a developed view in the direction of the - cross section in FIGS. 1 and 2, where 10 is the stationary member and 11 is the honeycomb.
The honeycomb 11 is glued with adhesive and the stationary member side is closed, but in the case of FIG. 2, the honeycomb 11 is glued to the rotating shaft 20, so the stationary member 10 side is open, as described above. . Also, the leakage fluid is leaked from the opening side of the honeycomb 11 and the rotating shaft 2 opposite thereto.
It goes without saying that the fluid flows from the P ₁ side to the P ₂ side through the gap formed between the peripheral surface of the rotary shaft 0 or the inner peripheral surface of the rotating shaft through hole provided in the stationary member 10 (the fluid flow direction is (Represented by thick arrows in FIGS. 1 and 2) This invention aims to reduce the amount of fluid leakage in fluid machines by means that can be easily and easily engineered without employing the above-mentioned dangerous and disadvantageous means. The object of the present invention is to provide a shaft sealing device using a honeycomb that can reduce the amount of damage.

The gist of the invention lies in the structure of the shaft sealing device described in the claims above.

Hereinafter, the present invention will be explained in detail with reference to the drawings showing embodiments thereof. FIG. 4 shows a symmetrical half of a longitudinal section in the direction of the central axis of the rotating shaft of a basic embodiment of the shaft sealing device according to the present invention, and FIG. FIG. Identical parts in FIGS. 4 and 5 are designated by the same reference numerals. In FIG. 4, P ₁ is a high pressure fluid inside the fluid machine, and P ₂ is a low pressure fluid outside the machine, which has a relatively low pressure with respect to the pressure of the high pressure fluid P ₁ . Therefore, in the shaft seal portion of a fluid machine, fluid leaks in the direction from _P1 to _P2 .
In FIG. 4, _10a is a stationary member of the fluid machine (for example, a casing or a seal base, etc.),
Reference numeral _20a denotes a rotating shaft passing through the stationary member _10a . Rotating shaft _20a in stationary member _10a
The inner circumferential surface of the through hole and the rotating shaft 20 _a penetrated through it.
A gap sufficient to attach the honeycomb to the outer circumferential surface of the rotating shaft 20 _a is formed between the outer circumferential surface and the outer circumferential surface of the rotary shaft 20 a.
An enlarged diameter portion 20 _b with stepped portions formed at both ends is formed on the high pressure P ₁ fluid side of the portion of the rotating shaft 20 _a that faces the stationary member 10 _a , and a low pressure P ₂ fluid of the enlarged diameter portion 20 _b is formed. A plurality of columnar protrusions 24 having the same height as the stepped portion are provided at radial positions on the circumferential surface perpendicular to the center line of the rotating shaft _20a on the low pressure _P2 fluid side at a predetermined distance from the side end. The distal end thereof is formed in an arc shape that is equal to the circumferential surface of the enlarged diameter portion _20b . 21 and 22 are honeycombs of equal height, and the honeycomb 21 is adhered to the entire outer periphery of the enlarged diameter portion 20 _b of the rotating shaft 20 _a with an adhesive 29, and only one side is open, so that high pressure is not contained in the honeycomb 21.
P ₁ Fluid leakage Fluid is full. honeycomb 21
One end is attached to the low pressure _P2 fluid side of the enlarged diameter portion _20b with adhesive 29, and the other _end is attached to the upper surface of the protrusion 24 with adhesive 29 to surround the rotating shaft _20a. A honeycomb 22 having the same height as the honeycomb 21 is bonded to form a space 23 between the outer periphery of the rotating shaft _20a and the lower surface of the honeycomb 22. The honeycomb 22 in this space 23 is open on both the upper and lower surfaces and communicates with each other. honeycomb 2
A gap with a preset width is formed between the upper surface of 1 and 22 and the inner peripheral surface of the through hole of the rotating shaft _20a in the stationary member _10a , and the gap is filled with high pressure _P1.
It serves as a fluid leakage path. Therefore, the leaked high-pressure _P1 fluid travels in the direction of the low-pressure _P2 fluid through this leakage passage, but when it reaches the honeycomb 22, a part of it fills the honeycomb 22 and flows through the honeycomb 22. The cavity 23 is also filled and communicated with the low pressure P ₂ fluid through a passage 24' shown in FIG. 5 formed by the respective gaps between the protrusions 24 and the outer periphery of the rotating shaft _20a .

FIG. 6 shows a rotating shaft 20 of a modified embodiment of the present invention.
_This figure shows a symmetrical half of the longitudinal section in the central axis direction of the rotating shaft _20a with respect to the central axis of the fourth axis.
Stationary member 10 facing honeycomb 22 in the figure
_A portion a is formed with a stepped portion in the through hole of the rotating shaft _20a , and is expanded in diameter by cutting to the low pressure _P2 fluid side side wall of the stationary member _10a . The impeller-like action in each of the centrifugal fan or centrifugal pump due to the rotation of the rotating shaft 20 _a of the honeycomb 22 is
The larger the height _h2 of the honeycomb 21, the stronger it becomes, so in this case the height can be made larger than the height of the honeycomb 21, but in that case the shape of the leakage passage for the high pressure _P1 fluid will be smaller than in the case shown in FIG. It becomes complicated.

FIG. 7 shows the rotating shaft 2 of another modified embodiment of the present invention.
_0a shows a symmetrical half of the rotation axis _20a in the central axis direction longitudinal section with respect to the central axis. In this embodiment, the low pressure _P2 fluid side end of the enlarged diameter portion _20b of the rotating shaft _20a in the embodiment shown in FIG. 24 is formed so that the tip thereof is higher than the outer circumferential surface of the enlarged diameter portion 20 _b and the top surface has the same taper as that of the truncated conical body, so that rotation corresponds to the position of the rear end side wall of the stationary member 10 _a . It is erected and fixed radially on the circumferential surface of the shaft 20 _a , and one end is on the truncated conical body and the other end is on the top surface of the plurality of columnar projections 24 so as to surround the rotating shaft 20 _a . The honeycombs 22 are each bonded with an adhesive 29, and the honeycombs 22 are provided so as to be inclined downward in the direction of the high pressure _P1 fluid at a position on the low pressure _P2 fluid side. Therefore, when the rotating shaft _20a rotates, the honeycomb 22 acts like an impeller of a mixed flow fan or a mixed flow pump. In the case of FIG. 7, the inclined honeycomb 22 is housed in the stationary member _10a , and the flow direction of the fluid discharged from the honeycomb ₂₂ must be smoothly changed by the rotation of the rotating shaft 20a.
2 is arranged by forming a stepped portion at the position of the through hole of the rotating shaft _20a in the stationary member _{10a facing the low pressure P of the enlarged diameter portion 20b of} the rotating shaft _20a near the fluid side end _. The enlarged diameter part is the low pressure of the stationary member _10a .
_P2 is formed up to the fluid side side wall, and a suitable rounded portion is attached to the corner of the stepped portion of the enlarged diameter portion. Note that the same parts are indicated by the same reference numerals throughout FIGS. 4 to 7.

Since this invention has the configuration described above, in the structure of the embodiment shown in _FIG . The fluid is discharged, but in order to compensate for this discharged fluid, low pressure is applied on the shaft sealing outlet side.
The protrusion 24 erected on _the rotating shaft _20a ...
It flows into the cavity 23 through the fluid passages 24' between them. On the other hand, the leaked fluid discharged from the honeycomb 22 collided with the inner circumferential wall of the rotating shaft through hole in the stationary member _10a facing the honeycomb 22, and a part of it was bonded to the inner circumferential wall of the through hole and the outer circumference of the rotating shaft _20a . The leakage fluid passages formed by the honeycombs 21 and 22 flow in the direction of the low-pressure _P2 fluid, and a portion flows through the passage in the direction of the high-pressure _P1 fluid, and this latter flow is from the high-pressure _P1 fluid side. The leakage fluid flowing through the passage collides with the leakage fluid to prevent its progress, and the former flow circulates through the honeycomb 22 to form a fluid curtain at the leakage fluid outlet. The flow of this leaked fluid is as shown by the thick line arrow in FIG. 4, FIG. 6, and FIG.
During the rotation of the rotating shaft of _a , the high pressure P ₁ is maintained steadily.
Fluid leakage from the shaft seal is prevented and low pressure P ₂
Fluid side leakage is reduced. In FIG. 6, the through hole of the rotating shaft _20a in the stationary member _10a in the portion facing the honeycomb 22 forms a step and is enlarged in diameter to the side wall on the low pressure _P2 fluid side of the stationary member _10a , so that it rotates. The amount of leakage fluid discharged from the honeycomb 22 as the shaft _20a rotates is larger than that in the embodiment shown in FIG _.
On the fluid side, a stronger fluid curtain is formed as shown by the thick arrow. In addition, the impeller-like action of the centrifugal fan or centrifugal pump of the honeycomb 22 becomes stronger as the height _h2 of the honeycomb increases, so the height
It is also possible for h ₂ to be greater than the height h ₁ of the honeycomb 21. In the embodiment shown in FIG. 7, since the honeycomb 22 is provided at an angle, the honeycomb 22
2 has an implant function as a mixed flow fan or a mixed flow pump by rotating the rotating shaft _20a , and the flow of leakage fluid from the outer periphery of the honeycombs 21 and 22 is controlled by the projections shown in FIGS. 4 and 6, respectively. This becomes smoother than in the case of the example, and the amount of leaked fluid circulating through the honeycomb 22 increases. In addition, a stepped portion is formed in the through hole of the rotating shaft 20 _a in the stationary member 10 _a of the honeycomb 22 portion, and an enlarged diameter portion is formed up to the low pressure P ₂ fluid side side wall of the stationary member 10 _a , so that leakage fluid of the honeycomb 22 is prevented. The pressure on the discharge side of P ₃ can be increased to make P ₃ > P ₂ , and the pressure difference between high pressure P ₁ and fluid pressure P ₁ can be made to be P ₁ − P ₃ < P ₁ − P ₂ , and high pressure The leakage reduction effect of _P1 fluid can be increased.

Since this invention has the structure and operation described above,
According to the present invention, in a shaft seal device in which a honeycomb is adopted as a rotating shaft penetrating portion that penetrates a stationary member in a fluid machine, a simple structure at the shaft seal device outlet portion prevents leakage high-pressure fluid that enters from the shaft seal device inlet portion. While the rotating shaft is rotating, the effective flow area is effectively reduced by the liquid curtain formed by the circulating flow generated on the shaft sealing device outlet side, and the flow path resistance of high-pressure fluid entering the shaft sealing portion is also effectively increased. As a result, the intrusion of high-pressure leakage fluid into the shaft sealing device is effectively reduced, and in order to reduce the passage area of high-pressure fluid in the shaft sealing part, the gap is reduced over a wide range. This eliminates the need for troublesome and complicated operations such as forming irregularities on the honeycomb openings constituting the shaft sealing portion to increase flow path resistance, so the industrial and economical effects are extremely significant.

[Brief explanation of the drawing]

1 and 2 are schematic diagrams of a symmetrical half of a vertical cross section of a main part of a shaft sealing device of a rotating shaft penetrating part in a conventional fluid machine employing a honeycomb, with respect to the central axis of the rotating shaft. In Figures and Figure 2 -
4 is a schematic diagram of a symmetrical half of a longitudinal section in the direction of the rotating shaft center axis of the basic embodiment of the present invention with respect to the rotating shaft center axis, and FIG. 5 is a cross-sectional view in the direction of the arrows in FIG. FIGS. 6, 7, and 7 are schematic views of symmetrical halves of longitudinal sections in the direction of the center axis of the rotating shaft of modified embodiments of the present invention, respectively, with respect to the center axis of the rotating shaft. DESCRIPTION OF SYMBOLS _10a ...Stationary member of fluid machine, _20a ...Rotating shaft, _20b ...Rotating shaft enlarged diameter part, 21, 22...Honeycomb, 23...Vacancy, 24...Columnar projection, 2
4'...Fluid passage, 29...Adhesive, _h1 , _h2 ...
Honeycomb height, P ₁ ... high pressure fluid, P ₂ ... low pressure fluid with respect to P ₁ , P ₃ ... pressure fluid with pressure lower than P ₁ and higher than P ₂ .

Claims (1)

[Claims] 1. One end surface is adhered with adhesive in a closed state to the outer circumferential surface of the portion of the rotating shaft that is disposed through the through hole drilled in the stationary member of the fluid machine and faces the inner circumferential surface of the through hole. the honeycomb 21 and the honeycomb 2
A cavity 23 is formed at the base of the leakage fluid outlet side of 1 to communicate with the leakage space of the fluid, and surrounding the cavity 23, one end is on the outer circumferential surface of the rotating shaft, and the other end is on the central axis of the rotating shaft. The top and bottom surfaces of the columnar projections are respectively adhered with adhesive to the top surfaces of a plurality of columnar projections arranged and fixed at radial positions on the outer circumferential surface in a direction perpendicular to the space 23, so that the upper and lower surfaces thereof are each left open at the position of the space 23. The low-pressure P ₂ fluid discharged from the honeycomb 22 collides with the upper surface of the honeycomb 21 to form an axial gap with a preset width, and the rotating shaft is rotated in the direction of the gap. 1. A shaft sealing device, characterized in that the shaft sealing device is disposed in a through hole formed with an inner circumferential surface that branches into a leakage fluid exit direction and causes the leakage fluid to flow.