JPH054548B2 - - Google Patents

Description

Detailed Description of the Invention (Field of Industrial Application) The present invention relates to a gland packing box constituting a shaft sealing part of a fluid machine, and more specifically, it improves the lubrication function and cooling function of the sealing part to reduce power loss. Concerning the structure of the Grand Packing Box, which is permanently kept small.

(Prior Art) As a conventional general gland packing structure, the one shown in FIG. 6 is known. In the figure, 20 is, for example, a packing box formed at one end of the pump casing, 21 is a neck bushing,
22A and 22B are gland packings, 23 is a packing holder, and 24 is a rotating shaft. The fitted packing retainer 23 is clamped in the axial direction with a predetermined tightening pressure to ensure sealing performance against the rotating shaft 24.

By the way, the structure of the gland packing box is such that the outer peripheral surface of the rotating shaft 24 and the gland packing box 22
A small amount of fluid leaks from the seal portion 25 with the inner peripheral surface of A, 22B, and this leaked fluid has a lubricating and cooling function to prevent abnormal wear of the rotating shaft 24 or seizure of the seal portion 25 due to dry operation. is configured to do so.

(Problems to be Solved by the Invention) However, in the structure of the conventional packing box, the gland packing clamping surfaces 21A, 23A of the neck bushing 21 and the packing presser 23, which come into contact with the gland packings 22A, 22B, respectively,
These gasket clamping surfaces 21 are formed in a shape perpendicular to and uniformly intersecting the axis of the rotating shaft 24.
A, 23A by ground packing 22A, 2
Since it is holding 2B, it is Grand Patsukin 22.
The axial end faces of A and 22B naturally intersect perpendicularly and uniformly with the axis of the rotating shaft 24.

Therefore, the small annular gap 26 formed between the inner circumferential surface of the neck bushing 21 and the outer circumferential surface of the rotary shaft 24 has an axial inner end that is connected to the gland packing 2.
2A, and does not overlap with the inner peripheral surface of the clamp packing 22A in the circumferential direction.

Therefore, leakage fluid that functions as a lubricant and a coolant is fed into the seal portion 25 only from the axially inner end of the small annular gap 26. However, by tightening the packing holder 23 in the direction of the neck bushing 21 with a predetermined tightening pressure, the inner circumferential surfaces of the clamp packings 22A and 22B are brought into pressure contact with the outer circumferential surface of the rotating shaft 24, thereby achieving suitable sealing performance. Therefore, the inner circumferential surfaces of the gland packings 22A, 22B forming the seal portion 25 and the outer circumferential surface of the rotating shaft 24 are in close contact with each other.
On the other hand, it is practically difficult to feed the leakage fluid only by the fluid pressure within the casing, and the leakage flow rate is limited to a small value, making it impossible to effectively perform the lubrication and cooling functions.

Moreover, if the tightening pressure of the gland packing holder 23 is excessive, or due to the influence of internal stress of the gland packing 22A, 22B, the gland packing 22
When the inner circumferential edge of A protrudes into the small annular gap 26, this protruding portion becomes locally dense, which significantly limits the leakage flow to the seal portion 25, further reducing the lubrication and cooling functions. However, there are problems in that this may lead to problems such as abnormal wear of the rotating shaft or seizure of the seal portion due to dry operation.

Incidentally, such a problem also occurs in the small annular gap 27 formed between the inner circumferential surface of the packing holder 23 and the outer circumferential surface of the rotating shaft 24 in FIG.

Therefore, a cooling jacket 28 is formed on the peripheral wall of the packing box 20 to circulate, for example, cooling water, and a passage 29 communicating with the small annular gap 27 is formed in the packing foot 23, and through this passage 29, for example, cooling can be carried out. A small annular gap for water 2
However, since the cooling jacket 28 only indirectly cools the gland packings 22A and 22B, it cannot be expected to have much of a cooling effect on the seal portion 25. , no lubrication effect can be expected.

Furthermore, even if the cooling water is introduced into the small annular gap 27 through the passage 29, the cooling water will directly damage only a small portion of the gland packing 22B corresponding to the small annular gap 27 or a protruding portion. Because it is only cooled,
Similar to the cooling jacket 28, the cooling effect and lubrication effect on the seal portion 25 cannot be expected.

The present invention has been made to solve these problems in the prior art, and by simply adding a simple configuration, fluid can be effectively sent to the seal part to improve the lubrication and cooling functions of the rotating shaft. We have developed a gland packing box structure that can prevent abnormal wear or seizure of the seal part due to dry operation, keep power loss as low as possible, and can be easily installed on existing equipment. The purpose is to provide.

(Means for Solving the Problems) In order to achieve the above object, the structure of the gland packing box according to the present invention includes a gland packing externally fitted around the rotating shaft within the packing box, and
Between the clamping surface of the gland packing member that clamps this gland packing from both sides in the axial direction,
A ring-shaped plate member having at least one displacement portion formed in the circumferential direction that partially displaces the inner circumferential surface of the gland packing in the axial direction is disposed, and the inner circumferential surface of the gland packing is partially displaced in the axial direction. Accordingly, a part of the annular cavity formed by the inner circumferential surface of the gland packing fixing member and the outer circumferential surface of the rotating shaft expands to the inner circumferential surface of the gland packing.

(Function) In the present invention, by clamping the gland packing from both sides in the axial direction by the gland packing clamping members, the inner peripheral surface portion of the gland packing is axially moved through the displacement part of the ring-shaped plate. As a result, a part of the annular cavity formed by the inner circumferential surface of the gland packing attachment member and the outer circumferential surface of the rotating shaft expands to the inner circumferential surface of the gland packing. . Therefore, as the rotating shaft rotates, the leaked fluid is forcibly fed into the inner circumferential surface of the gland packing, thereby lubricating and cooling the inner circumferential surface of the gland packing. Further, since the gland packing is partially displaced in the axial direction by a plate-shaped member, it can be easily installed in an existing one, and furthermore, the plate-shaped member can be easily manufactured.

(Embodiment) FIG. 1 is a longitudinal cross-sectional view showing an embodiment of the structure of a gland packing box according to the present invention. In the figure, 1 is a packing box, which is formed, for example, at one end of a pump casing. Reference numeral 2 denotes a gland packing attachment member, and in this embodiment, a gland packing attachment member 2A is inserted into the inner part of the packing box 1.
and a packing presser 2B whose tip is fitted into the opening of the packing box 1, and the gland fittings 3A and 3B are placed inside the packing box 1.
It is clamped in the axial direction via ring-shaped plates 10, 10 by the neck bush 2A and the seal presser 2B, and is externally fitted onto the rotating shaft 4.

That is, one end surface in the axial direction of the gland packing 3A contacts the clamping surface 10a of the plate-shaped body 10 disposed on the clamping surface 2a of the neck bushing 2A, and the other end surface in the axial direction of the gland packing 3B contacts the clamping surface 2a of the gland packing 3B.
The clamping surface 10 of the plate-shaped body 10 arranged on the clamping surface 2b of
It is in contact with a. Then, by tightening the seal retainer 2B in the direction of the neck bushing 2A with a predetermined tightening pressure using a tightening machine (not shown), the inner circumferential surfaces of the gland seals 3A and 3B are brought into close contact with the outer circumferential surface of the rotating shaft 4, and the gland A seal portion 5 is formed by the inner circumferential surfaces of the gaskets 3A, 3B and the outer circumferential surface of the rotating shaft 4.

By the way, the plate-like body 10 is made of a sheet metal material,
As shown in detail in FIG. 2, the inner circumferential edge on the clamping surface 10a side has a plurality of (four in this embodiment) circumferential portions that displace the inner circumferential surfaces of the gland packings 3A, 3B in the axial direction. ) are formed at predetermined intervals by press molding.

Therefore, Grand Packins 3A and 3B are
A pair of plate-like bodies 10 provided with the displacement portion 10ax,
10, the inner circumferential surface portion 3 of the gland packing 3A, 3B corresponding to the displacement portion 10ax of the plate-like body 10
a, 3b are partially displaced in the axial direction by the amount of protrusion of each displacement portion 10ax.

Therefore, a small annular gap 6 formed between the inner circumferential surface of the neck bush 2A and the outer circumferential surface of the rotating shaft 4 is formed.
is expanded to the inner circumferential surface portion 3a displaced in the axial direction, and this expanded portion 6a of the air 6,
Gland packing 3A that was not displaced in the axial direction
The inner circumferential surface of the inner circumferential surface overlaps in the circumferential direction. Therefore, as the rotary shaft 4 rotates, the fluid in the gap 6 is transferred to the seal portion 5 formed by the inner circumferential surface of the gland packing 3A, which is not displaced in the axial direction, and the outer circumferential surface of the rotary shaft 4. Since it is forcibly fed, the lubrication and cooling functions are improved.

On the other hand, a small annular gap 7 formed between the inner circumferential surface of the gland packing holder 2B and the outer circumferential surface of the rotating shaft 4 is formed by the inner circumferential surface portion 3b of the gland packing 3B due to the displacement portion 10ax of the plate-shaped body 10. The expanded portion 7a of the gap 7 and the inner circumferential surface of the gland packing 3B that has not been displaced in the axial direction overlap in the circumferential direction. Therefore, as the rotary shaft 4 rotates, the fluid leaking from the neck bushing 2A side through the seal portion 5 into the small annular gap 7 is transferred to the inner circumferential surface of the gland packing 3A, which was not displaced in the axial direction. was forcibly sent to
This will effectively lubricate and cool this part.

FIG. 3 shows a second embodiment of the present invention, in which four gland packings 3A, 3B, 3
C, 3D is used, and ground packing 3B, 3
A lantern ring 8 is interposed between C, and the gland packing member 2 is constituted by the neck bushing 2A, the packing presser 2B, and the lantern ring 8, and the clamping surface 2b of the packing presser 2B and the lantern ring 8 are both clamped. Plate bodies 10, 10, 10 are arranged on the surfaces 8a, 8b, respectively, and the gland packings 3B, 3C,
The 3D inner peripheral surface portions 3b, 3c, and 3d are partially displaced in the axial direction. With this configuration, the sealing liquid injected into the lantern ring 8 from the injection passage 11 is prevented from being displaced in the axial direction for the same reason as in the previous embodiment.
It is forcibly sent to the inner circumferential surfaces of B, 3C, and 3D, and even if the entire length of the seal portion 5 is long, the lubricating function and cooling function can be effectively exhibited.

FIG. 4 shows a modified usage example of the present invention, in which a coil spring 12 is interposed between the neck bush 2A and the rear end of the packing box 1, and the spring force is constantly transmitted through the neck bush 2A and the plate-like body 10. The gland packings 3A, 3B, and 3C are biased in the axial direction.

Therefore, ground packing 3A, 3B, 3
Since the stress relaxation occurring in C over time can be compensated for by the spring force of the coil spring 12, deterioration of the seal portion 5 can be effectively prevented and life extension can be realized.

FIG. 5 is a longitudinal sectional view when the embodiment shown in FIG. 1 is applied to equipment having a horizontal axis (for example, a horizontal pump).

In the case of the horizontal axis, the fluid leaked from the seal portion 5 does not stay in the gap 7 but is discharged to the outside. Therefore, an auxiliary seal 13 is provided as a means to prevent this.

The auxiliary seal 13 used here may be a lip seal or a gland packing as shown.

Further, this embodiment can be similarly applied to the case where the embodiments shown in FIGS. 3 and 4 are used in horizontal axis equipment.

Incidentally, in the above embodiment, a case has been described in which the plate-like body 10 is formed of a sheet metal material, but of course, this plate-like body may be integrally formed of synthetic resin or the like.

(Effects of the Invention) As explained above, according to the present invention, the gland packing is fitted around the rotating shaft in the packing box, and the gland packing clamping member that clamps the gland packing from both sides in the axial direction. A plate-shaped body forming at least one displacement part for partially displacing the gland packing in the axial direction is disposed between the clamping surface and the gland packing from both sides in the axial direction by the gland packing clamping member. When clamped, a part of the annular cavity formed by the inner peripheral surface of the gland packing clamping member and the outer peripheral surface of the rotating shaft,
Since it is configured to expand to the inner circumferential surface of the gland packing, as the rotating shaft rotates, the fluid is forcibly and reliably and sufficiently fed from the enlarged empty part to the inner circumferential surface of the gland packing and then to the sealing part. Therefore, the lubrication function and cooling function of the seal portion can be significantly improved. Therefore, by simply adding a ring-shaped plate, an extremely simple and low-cost improvement can prevent abnormal wear of the rotating shaft or seizure of seals due to dry operation, thereby reducing power loss. can be kept as small as possible.

Moreover, since the part that partially displaces the gland packing in the axial direction is a plate-shaped member, it can be easily installed in existing equipment, which is a very excellent practical effect.

[Brief explanation of the drawing]

FIG. 1 is a longitudinal sectional front view showing a first embodiment of the structure of a gland packing box according to the present invention, FIG. 2 is a perspective view of a plate-like body, FIG. 3 is a longitudinal sectional front view of the second embodiment, and FIG. 5 is a vertical sectional view showing a modified example of the embodiment shown in FIG. 1, and FIG. 6 is a structure of a conventional gland packing box. DESCRIPTION OF SYMBOLS 1... Packing box, 2... Grand packing attachment member, 3A, 3B, 3C, 3D... Grand packing, 4... Rotating shaft, 10... Plate-shaped body,
10ax...displacement part.

Claims (1)

[Claims] 1. The inner circumferential surface of the gland packing is placed between the gland packing externally fitted around the rotating shaft in the packing box and the clamping surfaces of the gland packing clamping members that sandwich the gland packing from both sides in the axial direction. at least 1 in the circumferential direction to partially displace the
A ring-shaped plate member is provided in which two displacement parts are formed, and the ring-shaped plate member is formed by the inner peripheral surface of the gland packing clamping member and the outer peripheral surface of the rotating shaft by the axial displacement of the inner peripheral surface portion of the gland packing. The structure of the gland packing box is characterized in that a part of the annular space is expanded to the inner circumferential surface of the gland packing box.