JP2587230Y2 - Shaft sealing device - Google Patents

Description

[Detailed description of the invention]

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a shaft sealing device provided with a gland packing used for sealing a rotary shaft in a liquid-tight manner and a gland presser for pressing the gland packing.

[0002]

2. Description of the Related Art Various pumps and valves used for water supply piping, other hydraulic piping, or hydraulic piping include:
In some cases, the rotating shaft is provided through a casing component such as a casing or a cover that closes the casing. It is necessary to provide a liquid-tight seal between such a casing component and the rotating shaft so that the internal pressure liquid does not leak.

[0003] As a liquid-tight means of this kind of pressure liquid, a shaft sealing device using a gland packing has been conventionally known. An example of this type of shaft sealing device will be described for the case of a centrifugal pump shown in FIG.

FIG. 4 is a partial sectional view of a centrifugal pump.
In the figure, 1 is a pump casing, and 2 is a casing cover that covers the back of the pump casing 1. A suction port 3 is opened on the front surface of the pump casing 1, and a discharge port 4 is formed on the upper part. Pipe joints 5 and 6 for connecting the suction pipe and the discharge pipe are attached to the suction port 3 and the discharge port 4, respectively. The back of the pump casing 1 is open, and the opening of the back is closed by the casing cover 2 so as to be openable and closable. A through-hole 7 is formed in the center of the casing cover 2, and a rotating shaft 8 passes through the through-hole 7. An impeller 9 is attached to the front end of the rotating shaft 8 so as to rotate integrally.

The rear end of the rotating shaft 8 is connected to the casing cover 2.
The rotating shaft 8 is rotatably supported by bearings 11 attached to the bearing box 10. The bearing box 10 is formed integrally with or connected to the bearing box 10. The rear end of the rotary shaft 8 is connected to a drive motor (not shown) via a flange joint 12. 13 is a bearing box 1
It is a supporting leg that supports 0.

Accordingly, when the drive shaft drives the rotary shaft 8, the impeller 9 is rotated. Therefore, water is sucked from the front suction port 3 of the pump casing 1, and this water is pressurized by the impeller 9, and this pressurized water is pumped. 1
From the discharge port 4.

In such a pump, the shaft sealing device 2 is provided between the casing cover 2 and the rotating shaft 8 passing therethrough.
0 is provided. A conventional shaft sealing device 20 is shown in FIG. 5 and will be described based on this. The housing cover 2 is formed with a housing cylindrical portion 17 that extends in the axial direction continuously with the through hole 7 through which the rotating shaft 8 passes. Have been. A plurality of gland packings 21 surrounding the rotary shaft 8 are accommodated in the accommodation cylinder 17 so as to overlap in the axial direction.

These gland packings 21 are pressed by a packing presser 22. The packing presser 22
It has a sleeve portion 24 facing the rotary shaft 8 with a gap 23 therebetween, and a pressing portion 25 for pressing the gland packing 21 in the axial direction is formed at one axial end of the sleeve portion 24. At the other end in the axial direction is a casing cover 2
Is formed by forming a flange portion 26 to be fastened via mounting bolts 27 to the flange portion 26. This mounting bolt 2
When the screw 7 is screwed into the casing cover 2 and tightened, the flange portion 26 is pressed, so that the pressing portion 25 presses the gland packing 21 in the axial direction.
Are pressed against the rotating shaft 8 so that these sliding surfaces are sealed. A retightening nut 28 is screwed to the mounting bolt 27.

In the shaft sealing device 20 having such a structure, when used for a long period of time or under severe pressure conditions, the gland packings 21 are worn and the sealing performance deteriorates. The pressurized water inside leaks to the outside, and the amount of this leak gradually increases. In such a case, a countermeasure is taken such that the additional tightening nut 28 is further tightened and the gland packings 21 are further pressed by the packing presser 20.

However, even if the tightening nut 28 is further tightened, leakage will occur again when the nut is further used. When the amount of leaked water is small, the leaked water falls from the other end opening of the packing presser 22 as shown by an arrow a, collects in a lower water collecting portion (not shown), and is eliminated through a discharge hole or the like.

However, when the amount of leaked water increases, a large amount of water flows out along the rotating shaft 8, and the leaked water does not fall from the other end opening of the packing presser 22 as shown by the arrow a, but travels along the rotating shaft 8 to move along the rotating shaft 8. This water leaks along with the rotation of the rotating shaft 8 and is scattered by the centrifugal force as shown by the arrow b. Such splash of water scatters water droplets and splashes, so that it not only wets surrounding parts, but also scatters outside of the pump from an opening 18 formed between the casing cover 2 and the bearing box 10 and the like. The area around the pump may be flooded.

In order to prevent such a problem, as shown in FIG. 6, a device has been proposed in which a seal wall 29 is provided at the other end opening of the packing presser 22. This seal wall 29
Is to prevent the water from flowing along the rotating shaft 8 and flowing out in the axial direction when a large amount of water leaks. The water leakage prevented by the seal wall 29 is reduced by the drain port 3 opened at the lower part.
It is rejected downward from zero. For this reason, a large amount of water leakage is prevented from scattering around by centrifugal force.

[0013]

However, even in the packing presser 20 provided with such a seal wall 29, the seal wall 29 cannot slide on the rotary shaft 8, so that the seal wall 29 and the rotary shaft 8 cannot be slid. When a large amount of leaked water is transmitted to the minute clearance 31 formed between them, the leaked water leaks out in the axial direction through the clearance 31. Therefore, there is a case where the minute amount of the leaking water scatters to wet or stain the surrounding members.

The present invention has been made in view of such circumstances, and the purpose of the present invention is to allow the liquid leaking from between the gland packing and the rotating shaft to travel along the rotating shaft to remove the liquid from the sealing wall from the seal wall. It is an object of the present invention to provide a shaft sealing device which can prevent the shaft from flowing out.

[0015]

In order to achieve the above object, the present invention provides a gland packing for sealing between a casing member and a rotating shaft penetrating the casing member, and the gland packing is disposed in an axial direction. The packing gland is formed at one axial end of the sleeve with a gap between the gland packing and the sleeve. A pressing portion that presses in the axial direction;
A flange portion formed at the other end in the axial direction of the sleeve portion and fixed to the casing member; a seal wall closing an opening at the other end in the axial direction of the sleeve portion; and a drain formed at a lower portion of the sleeve portion. A drain, a drain portion located downstream of the drain port in the rotational direction of the rotary shaft and projecting from the inner surface of the sleeve portion and having a leading end approaching the outer peripheral surface of the rotary shaft; And a volute portion formed on the inner surface of the sleeve portion along the rotation direction of the rotary shaft.

[0016]

In the above construction, since the leaking liquid transmitted through the rotating shaft is scraped off by the draining portion protruding from the inner surface of the sleeve portion, the amount of leaked liquid flowing in the axial direction of the rotating shaft is reduced. I do. Also, at this time, the leaked liquid separated from the rotating shaft and directed in the rotating direction is swirled along the inner surface of the sleeve portion by the rectifying action of the volute portion. Guided to the mouth.

Accordingly, even if the amount of leaking liquid leaking from between the gland packing and the rotating shaft is large, the amount of leaking liquid flowing toward the seal wall is kept at a small amount. This prevents the leakage liquid from leaking from the seal wall, that is, from leaking out of the packing presser.

[0018]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below based on a first embodiment shown in FIGS. This embodiment shows an example in which the present invention is applied to the centrifugal pump shown in FIG. 4, and the overall structure of the pump may be the same as that of FIG. In this embodiment, the packing gland 20 shown in FIG. 6 is modified, and the same parts as those in FIG. 6 are denoted by the same reference numerals and description thereof will be omitted. In addition, a draining part 40 and a volute part 41 continuous from the draining part 40 are provided. That is, the packing retainer 20 of the present embodiment is formed on the inner surface of the sleeve portion 24 so as to be located on the downstream side in the rotation direction of the drain port 30 and to integrally project the draining portion 40. The tip of the drainer 40 is close to the outer peripheral surface of the rotating shaft 8. On the inner surface of the sleeve portion 24 continuously from the rotation direction downstream side of the draining portion 40, the volute portion 41 is provided along the rotation direction of the rotating shaft 8.
Is formed. The volute part 41 is formed so as to increase the diameter smoothly, and the downstream side of the draining part 40 is rectified from the change in the diameter of the volute part 41.

In such a structure, when the pressure water leaks from between the rotating shaft 8 and the gland packings 21 and tries to flow out along the rotating shaft 8, the leakage water tends to be transmitted along the rotating shaft 8. The water tends to travel along the rotating shaft 8 by rotating with the rotating shaft 8.

Here, since the tip of the draining portion 40 provided on the inner surface of the sleeve portion 24 is close to the peripheral surface of the rotary shaft 8, the drainage portion 40 is attached to the periphery of the rotary shaft 8 to scrape the leaking water that rotates. Drop it. As a result, the amount of leaked water flowing in the axial direction of the rotating shaft 8 decreases. In addition, the leaked water leaked is guided to the drain port 30.

Further, the leakage water separated from the rotating shaft 8 and riding on the turbulent flow around the rotating shaft 8 is prevented from being transmitted to the rotating shaft 8 again by the volute portion 41 continuous from the draining portion 40.

To explain this point, a turbulent flow occurs downstream of the draining section 40. In this state, the leaked water separated from the rotating shaft 8 rides on the turbulent flow, adheres to the rotating shaft 8 again, and is rotated along with the axial direction.
Turbulence generated on the downstream side of the draining part 40 is
Part 4 extending along the direction of rotation of rotary shaft 8 from
1 rectifies the flow in the rotational direction toward the inner surface of the sleeve portion 24, so that the separated leaked water becomes a stable circumferential flow along the inner surface of the sleeve portion 24 and is guided to the drain port 30. . Then, the water is discharged downward from the drain port 30 together with the leaked water that has been scraped off.

As a result, even if the amount of leaking liquid leaking from between the gland packing 21 and the rotating shaft 8 is large, the amount of leaking liquid flowing toward the seal wall 29 is kept small.

As a result, the sealing performance of the seal wall 29 prevents the leakage liquid from leaking from the seal wall 29, that is, from leaking out of the packing presser. Therefore, the scattering due to the centrifugal force is greatly reduced, and it is possible to prevent the surrounding members from being wet or stained by the leakage water.

The present invention is not limited to the first embodiment shown in FIGS. That is, FIG. 3 shows a second embodiment of the present invention. The first embodiment shown in FIG.
The draining part 40 and the volute part 41 are formed so as to extend over the entire length of the sleeve part 24 in the axial direction as shown in FIG. 2B, but the second embodiment shown in FIG. )
As shown in the figure, the draining part 40 and the volute part 41 are formed halfway in the axial direction of the sleeve part 24 avoiding the opening area of the drain port 30.

The draining section 40 and the volute section 41
Is adopted, it is possible to prevent the leakage water swirling along the inner surface of the sleeve portion 24 from leaking from the clearance 31 even if there is a momentum in the axial direction.

That is, the leakage water separated from the rotating shaft 8 and flowing along the inner surface of the sleeve portion 24 and swirling may leak from the clearance 31 due to the momentum in the axial direction. When the drainage portion 40 and the volute portion 41 are formed to escape from the extension of the opening area of the opening 30, the flow along the inner surface of the sleeve portion 24 passes through the portion where the drainage portion 40 and the volute portion 41 are present, and the drainage portion is formed. When reaching an expanded space without the 40 and the volute 41, the flow is weakened. At this time, the momentum in the axial direction is also weakened, so that a minute leak from the clearance 31, that is, even a minute leak outside the packing presser 22 can be prevented.

It should be noted that the present invention is not limited to the shaft sealing device of the centrifugal pump, and the rotary shaft guided through the casing member, such as other pumps or other valves, is liquid-tight. The present invention can be applied to various types of shaft sealing devices.

[0029]

[Effect of the Invention] As described above, according to the present invention, since the leaked liquid transmitted through the rotating shaft is scraped off by the draining portion protruding from the inner surface of the sleeve portion, the amount of water flowing along the rotating shaft is reduced. Can be reduced. In addition, the leaked liquid separated from the rotating shaft and traveling in the rotating direction is rectified by the rectifying action of the volute portion and rectified, and turns along the inner surface of the sleeve portion. There is no.

Therefore, even if the amount of leaking liquid leaking from between the gland packing and the rotating shaft is large, the amount of leaking liquid flowing toward the sealing wall is kept small, and the sealing performance of the sealing wall is reduced by the sealing performance of the sealing wall. It is possible to prevent the leaked liquid from leaking out of the wall, that is, to leak out of the packing presser, and to prevent the surrounding members from being wet or stained by the leaked liquid.

[Brief description of the drawings]

FIG. 1 is a sectional view of a shaft sealing device showing a first embodiment of the present invention.

2 (A) is a side view, FIG. 2 (B) is a sectional view taken along line BB in FIG. 2 (A), and FIG.
The figure is a sectional view taken along line CC in FIG.

FIG. 3 shows a packing press according to a second embodiment of the present invention;
(A) is a side view, (B) is a cross-sectional view taken along line BB in (A), and (C) is a cross-sectional view taken along line CC in (B).

FIG. 4 is a partially sectional side view showing a centrifugal pump to which the shaft sealing device is applied.

FIG. 5 is a sectional view of a conventional shaft sealing device.

FIG. 6 is a cross-sectional view of another conventional shaft sealing device.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Pump casing, 2 ... Casing cover, 7 ... Through-hole, 8 ... Rotating shaft, 9 ... Impeller, 17 ... Housing cylinder part, 2
0: shaft sealing device, 21: gland packing, 22: packing retainer, 23: gap, 24: sleeve portion, 25: pressing portion, 26: flange portion, 29: sealing wall, 30: drain port, 40: draining portion, 41 ... Volute part.

──────────────────────────────────────────────────続 き Continuation of the front page (56) References Japanese Utility Model Sho 53-78366 (JP, U) Japanese Utility Model Sho 54-174611 (JP, U) Japanese Utility Model Sho 58-22562 (JP, U) Japanese Utility Model Hei 2 109075 (JP, U) Jiko 45-31962 (JP, Y1) (58) Field surveyed (Int. Cl. ⁶ , DB name) F16J 15/24

Claims (1)

(57) [Scope of request for utility model registration] 1. A shaft sealing device comprising a gland packing for sealing between a casing constituent member and a rotating shaft penetrating the casing constituent member, and a packing presser for pressing the gland packing in an axial direction. The packing presser includes a sleeve portion facing the rotary shaft with a gap therebetween, a pressing portion formed at one axial end of the sleeve portion to press the gland packing in the axial direction, and a sleeve portion of the sleeve portion. A flange portion formed at the other end in the axial direction and fixed to the casing constituent member, a seal wall closing an opening at the other end in the axial direction of the sleeve portion, a drain port formed at a lower portion of the sleeve portion, A draining portion which is located downstream of the drain port in the rotation direction of the rotary shaft and protrudes from the inner surface of the sleeve portion and whose tip is close to the outer peripheral surface of the rotary shaft. , Volume formed along the rotation direction of the rotating shaft on the inner surface of the sleeve portion continuously from the draining unit - the shaft seal device characterized by comprising a preparative portion.