JPH0614628U - Shaft seal device - Google Patents

Abstract

(57) [Abstract] [Purpose] To provide a shaft sealing device that prevents liquid leaking from between a gland packing and a rotary shaft from being transmitted through the rotary shaft and being scattered by centrifugal force. In a shaft sealing device including a gland packing 21 and a packing retainer 22 for pressing the casing component 2 and the rotating shaft 8 penetrating the casing component 2, a packing retainer is provided with a rotating shaft. The sleeve portion 24 facing each other with a gap 23 between is provided with a pressing portion 25 for pressing the gland packing at one end and a flange portion 26 at the other end.
And a seal wall 29 for closing the other end is provided, a drain port 30 is formed in this sleeve portion, and a draining portion 40 is projectingly provided on the inner surface of this sleeve portion. [Operation] The water draining portion protruding from the inner surface of the sleeve prevents rotation of the leaking liquid traveling along the rotating shaft, thereby preventing the leaking liquid from flowing to the rotating shaft and making it difficult for the leaking liquid to flow. Reduce.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a shaft seal device including a gland packing used for liquid-tightly sealing a rotating shaft and a gland packing for pressing the gland packing.

[0002]

[Prior art]

 For various pumps and various types of valves used for water supply pipes, other hydraulic pipes, or hydraulic pipes, there are cases where the rotary shaft is penetrated through a casing component such as a casing or a cover that closes the casing. is there. A liquid-tight seal must be provided between the casing component and the rotary shaft so that the pressurized liquid inside does not leak.

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

FIG. 5 is a partial cross-sectional view of a centrifugal pump, in which 1 is a pump casing and 2 is a casing cover that covers the back surface 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 portion. Pipe fittings 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 surface of the pump casing 1 is open, and the back surface opening 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 rotary shaft 8 penetrates through the through hole 7. An impeller 9 is attached to the front end of the rotary shaft 8 so as to rotate integrally therewith.

A rear end of the rotary shaft 8 is inserted with a bearing box 10 formed integrally with or connected to the casing cover 2, and the rotary shaft 8 is a bearing attached to the bearing box 10. It is rotatably supported by 11, 11. The rear end of the rotating shaft 8 is connected to a drive motor (not shown) via a flange joint 12. Incidentally, 13 is a supporting leg for supporting the bearing box 10.

Therefore, when the rotating shaft 8 is driven by the drive motor, the impeller 9 is rotated, so that water is sucked from the front inlet 3 of the pump casing 1, the water is pressurized by the impeller 9, and the pressurized water is pumped. It is designed to discharge from the discharge port 4 of 1.

In such a pump, a shaft sealing device 20 is provided between the casing cover 2 and the rotary shaft 8 penetrating the casing cover 2. A conventional shaft sealing device 20 is shown in FIG. 6, and will be described based on this. The casing cover 2 has an accommodating cylinder portion 17 that extends in the axial direction continuously from a through hole 7 through which a rotating shaft 8 penetrates. Has been formed. A plurality of gland packings 21 surrounding the rotary shaft 8 are housed in the storage cylinder portion 17 so as to be stacked in the axial direction.

These gland packings 21 ... Are pressed by a packing retainer 22. The packing retainer 22 has a sleeve portion 24 facing the rotary shaft 8 with a gap 23 therebetween, and an axially one end of the sleeve portion 24 is provided with a pressing portion 25 for axially pressing the gland packing 21. At the other end in the axial direction, a flange portion 26 that is fastened to the casing cover 2 via a mounting bolt 27 is formed. When the mounting bolt 27 is screwed into the casing cover 2 and tightened, the flange portion 26 is pushed, so that the pushing portion 25 pushes the gland packing 21 in the axial direction, so that the inner surface of each gland packing 21 is pressed against the rotating shaft 8. Therefore, these sliding surfaces are sealed. An additional tightening nut 28 is screwed onto 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 is deteriorated. Therefore, the pump casing 1 Pressurized water inside leaks to the outside, and the amount of this leak gradually increases. In such a case, the additional tightening nut 28 is further tightened to further press the gland packings 21 ... With the packing retainer 20.

However, even if the retightening nut 28 is retightened, leakage will occur again when it is used further. When the amount of leaked water is small, this leaked water drops from the other end opening of the packing retainer 22 as shown by the arrow a, collects in a water collecting portion (not shown) below, and is discharged through a discharge hole or the like.

However, when the amount of leaked water increases, a large amount of water flows out along the rotary shaft 8, and this leaked water does not drop from the other end opening of the packing retainer 22 as indicated by the arrow a, but travels along the rotary shaft 8 and the shaft. The water flows in a direction, and this water leakage is accompanied by the rotation of the rotating shaft 8 and is scattered by the centrifugal force as shown by an arrow b. Such splashes of water will not only wet the surrounding parts, but also splash out of the pump through the opening 18 formed between the casing cover 2 and the bearing box 10 as water droplets and splashes will be scattered. , The area around the pump may be submerged.

In order to prevent such a problem, as shown in FIG. 7, it has been proposed to provide a seal wall 29 at the other end opening of the packing retainer 22. The seal wall 29 prevents the water from flowing along the rotary shaft 8 in the axial direction when a large amount of water leaks, and the water leak blocked by the seal wall 29 is drained to the bottom. Are eliminated from below. For this reason, a large amount of water leakage is prevented from scattering around due to centrifugal force.

[0013]

[Problems to be solved by the device]

 However, even in the packing retainer 20 provided with such a seal wall 29, the seal wall 29 cannot be brought into sliding contact with the rotary shaft 8, so that a minute clearance 31 is formed between the seal wall 29 and the rotary shaft 8. The water is generated and leaks in the axial direction through the clearance 31 along the rotary shaft 8. Therefore, this minute amount of leaked water may scatter to wet or stain surrounding members.

The present invention has been made in view of the above circumstances. The purpose of the present invention is that the liquid leaking from between the gland packing and the rotary shaft is transmitted through the rotary shaft and flows out in the axial direction. It is an object of the present invention to provide a shaft sealing device capable of preventing scattering by force and preventing wetting and contamination of surrounding members due to leaked liquid.

[0015]

[Means for Solving the Problems]

 In order to achieve the above-mentioned object, the present invention comprises a gland packing for sealing between a casing constituent member and a rotary shaft penetrating the casing constituent member, and a packing retainer for axially pressing the ground packing. In the shaft sealing device described above, the packing retainer includes a sleeve portion that faces the rotary shaft with a gap, and a pressing portion that is formed at one axial end of the sleeve portion and presses the gland packing in the axial direction. A flange portion formed at the other axial end of the sleeve portion and fixed to the casing constituent member, a seal wall closing the opening at the other axial end of the sleeve portion, and a flange wall formed on the sleeve portion. It is characterized in that it is provided with a drain port and a water draining portion formed so as to project on the inner surface of the sleeve portion.

[0016]

[Action]

 In the above configuration, the water draining portion projecting on the inner surface of the sleeve portion prevents the leaked liquid traveling along the rotating shaft from rotating together, which makes it difficult for the leaked liquid to reach the rotating shaft and flow. The rate of centrifugal force is also reduced, which prevents leakage along the axis of rotation through the clearance in the seal wall.

[0017]

【Example】

 The present invention will be described below based on the first embodiment shown in FIGS. This embodiment shows an example applied to the centrifugal pump shown in FIG. 5, and since the entire structure of the pump may be the same as that in FIG. 5, the description thereof will be omitted. In this embodiment, the packing presser 20 shown in FIG. 7 is modified, and the same parts as those in FIG. 7 are designated by the same reference numerals and the description thereof will be omitted. The difference from FIG. 7 is that the inner surface of the sleeve portion 24 is different. The point is that the drainer 40 is provided. That is, the packing retainer 20 of this embodiment is formed on the inner surface of the sleeve portion 24 at the downstream side in the rotation direction of the drain port 30 and integrally formed with the water draining portion 40. Are projected from the inner surface of the sleeve portion 24 so as to approach the rotary shaft 8.

In such a configuration, when the pressure water leaks from between the rotary shaft 8 and the gland packing 21 and tries to flow out through the rotary shaft 8, it tries to travel through the rotary shaft 8 in this way. The leaked water tries to travel along the rotary shaft 8 by rotating together with the rotary shaft 8. On the other hand, since the tip of the water draining portion 40 provided on the inner surface of the sleeve portion 24 is close to the peripheral surface of the rotating shaft 8, the leaking water adhering to the periphery of the rotating shaft 8 and rotating along with it is scraped off. Act. The water scraped from the rotary shaft 8 by the water draining section 40 is discharged downward from the drain port 30.

Therefore, the amount of leaked water that is rotated by the rotating shaft 8 is reduced, and thus the amount of leaked water that is transmitted along the rotating shaft 8 and tends to flow in the axial direction is also reduced. As a result, the amount of water passing through the clearance 31 of the seal wall 29 is reduced, and the scattering due to the centrifugal force can be significantly reduced.

The present invention is not limited to the first embodiment shown in FIGS. 1 and 2. That is, FIG. 3 shows a second embodiment of the present invention, in which, in this case, a volute portion 41 is formed continuously on the downstream side of the draining portion 40 in the rotational direction so as to smoothly increase the diameter. In the case of such a structure, when the water draining section 40 scrapes water running along the rotary shaft 8 in the same manner as described above, the scraped water swirls along the inner surface of the sleeve section 24. While entering the drain port 30, it can be removed downward from the drain port 30. In this case, the scraped water may generate a turbulent flow on the downstream side in the rotation direction of the water draining part 40, but in the case of this embodiment, the volute part 41 can prevent the generation of the turbulent flow. The action is smoothed, the scraping effect is increased, and the leaked water can be reliably guided to the drain port 30.

In the case of the embodiment shown in FIG. 3, the draining portion 40 and the volute portion 41 are formed so as to extend over the entire axial length of the sleeve portion 24 as shown in FIG. 3B. In the case of the second embodiment, as shown in FIG. 4 (B), the water draining portion 40 and the volute portion 41 are formed in the axial direction of the sleeve portion 24 while avoiding the opening region of the drain port 30. Is.

As described above, the water scraped off by the water draining portion 40 swirls along the inner surface of the sleeve portion 24. In this case, if there is axial momentum, the water leaks from the clearance 31, but as described above, If the water draining portion 40 and the volute portion 41 are not formed in the extension portion of the opening area of the drain port 30, the water swirling along the inner surface of the sleeve portion 24 will not flow toward the drain port 30 before the water draining portion 40 and the volute portion. Since it is not obstructed by the portion 41, the momentum in the axial direction is not generated, and the flow toward the drain port 30 is smooth and reliable.

The present invention is not limited to the shaft seal device of the centrifugal pump, and other pumps as well as other valves, in other words, the rotary shaft that is guided through the casing constituent member is guided by the liquid. It can be applied to various shaft sealing devices when tightly sealing.

[0024]

[Effect of device]

 As described above, according to the present invention, the draining portion projecting on the inner surface of the sleeve portion prevents the leaked liquid traveling along the rotating shaft from rotating along with it, so that the leaked liquid flows along the rotating shaft. It becomes more difficult and less susceptible to centrifugal forces, which prevents leakage through the seal wall clearance along the axis of rotation. As a result, the leaked liquid is prevented from scattering due to the centrifugal force, and it is possible to prevent the surrounding members from getting wet and dirty by the leaked liquid.

[Brief description of drawings]

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

2A and 2B show a packing retainer of the same embodiment, wherein FIG. 2A is a side view, FIG. 2B is a sectional view taken along line BB in FIG. 2A, and FIG.
The figure is a cross-sectional view taken along the line CC in FIG.

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

FIG. 4 shows a packing holder according to a third embodiment of the present invention,
(A) is a side view, (B) is a sectional view taken along line BB in (A), and (C) is a sectional view taken along line CC in (B).

FIG. 5 is a partially sectional side view showing a centrifugal pump to which a shaft sealing device is applied.

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

FIG. 7 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 ... Storage cylinder part, 2
0 ... Shaft sealing device, 21 ... Gland packing, 22 ... Packing retainer, 23 ... Gap, 24 ... Sleeve part, 25 ... Pressing part, 26 ... Flange part, 29 ... Seal wall, 30 ... Drain port, 40 ... Draining part, 41 ... Volute part.

Claims (2)

[Scope of utility model registration request] 1. A shaft sealing device comprising a gland packing for sealing between a casing constituent member and a rotary shaft penetrating the casing constituent member, and a packing retainer for axially pressing the gland packing, The packing retainer includes a sleeve portion that faces the rotary shaft with a gap, a pressing portion that is 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 component member, a seal wall closing an opening at the other end in the axial direction of the sleeve portion, a drain port formed in the sleeve portion, and the sleeve portion And a drainer formed to project from the inner surface of the shaft. 2. The packing presser is provided with a volute part continuously from the draining part.
The shaft sealing device described in.