JPH0118928Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a gland packing type shaft sealing device suitable for use in pumps, valves, etc.

Conventionally, there is a system that uses a gland packing as a shaft sealing mechanism for a reciprocating and rotating shaft. 1st
The figure shows an example of a shaft sealing mechanism using conventional gland packings, and between the shaft 1 and the casing 2, there are a high-pressure side gland packing 6 and a low-pressure side gland packing 7 inserted in multiple stages. A lantern ring 5 is interposed between the gland packing 6 and the gland packing 7, and these are held from the low pressure side by the holding ring 4 and the bolt 3.
By tightening them, surface pressure is generated between the shaft 1 and the gland packings 6, 7 and between the gland packings 6, 7 and the casing 2, thereby achieving a fluid seal.

However, in such conventional shaft sealing mechanisms, the gland packing is made of a highly elastic material such as rubber or resin that does not damage the shaft when sliding. The frictional force between the packings 6, 7 and the shaft 1 or between the gland packings 6, 7 and the casing 2 is large,
There is a problem in that it is not possible to transmit a pressing force to the gland packing 6 on the high pressure side to generate a uniform surface pressure similar to that of the gland packing 7 on the low pressure side.

In addition, after long-term operation, the stress in the gland packings 6 and 7 decreases due to wear and material changes in the packings, which reduces the surface pressure on the sealing surface and reduces the sealing force. ,
A method is used to retighten the retaining ring 4 with the bolt 3, but there is a limit to the tightening allowance H, and the operator cannot constantly monitor the amount of leakage, making it difficult to maintain a constant sealing performance. There is a problem.

Therefore, in order to solve this problem, there is an idea as seen in Japanese Utility Model Publication No. 39-29493.
This invention is intended to automatically perform the above-mentioned additional tightening, and the gland packing is tightened by the gland via a spring.

Although such means are effective in automating retightening, they are not useful in transmitting a pressing force that produces uniform surface pressure over the entire gland packing.

In addition, an idea as seen in Japanese Utility Model Application Publication No. 58-63456 has also been made. This idea attempts to equalize the surface pressure of the gland packings on both the high-pressure side and the low-pressure side as described above, and for this purpose, a spring is provided in the casing to spring the packings toward the gland.

Using such a method helps to equalize the surface pressure of both the high-pressure side and low-pressure side gaskets during setting, but since the elastic force of the spring always acts from the high-pressure side to the low-pressure side, If the packing wears or deteriorates after long-term operation, the spring of the low-pressure side gland packing may not be tightened enough, and the surface pressure of the low-pressure side gland packing closest to the gland will decrease. The problem is that it is difficult to compensate for the tendency to

The present invention aims to solve these problems by improving the transmission of stress to the gland packing on the high-pressure side during assembly, and also by improving the shape change of the gland packing (due to wear and material changes). ) Gland packing type shaft sealing device that automatically recovers stress in the gland packing on the low pressure side to maintain constant sealing performance on both the high pressure side and low pressure side. The purpose is to provide

Therefore, in the gland packing type shaft sealing device of the present invention, in the shaft sealing part that partitions the high pressure side and the low pressure side along the shaft surface, the gland packing on the high pressure side and the gland packing on the low pressure side that are adjacent to each other, and the gland packing on the high pressure side and a gland packing tightening mechanism for tightening the gland packing on the low pressure side in the axial direction from the low pressure side. a first spring bearing member that presses the low-pressure side gland packing via a spring; and a second spring compressed by the pressure of the low-pressure side gland packing that presses the high-pressure side gland packing. Second
It is characterized in that a spring receiving member is interposed therebetween.

Hereinafter, embodiments of the present invention will be explained with reference to the drawings. Fig. 2 is a vertical sectional view showing a gland packing type shaft sealing device as a first embodiment of the invention, and Fig. 3 is a second embodiment of the invention. FIG. 4 is a longitudinal sectional view showing a gland packing type shaft sealing device as an example, and FIG. 4 is a longitudinal sectional view showing a gland packing type shaft sealing device as a third embodiment of the present invention.

First, to explain the first embodiment of the present invention, as shown in FIG. 2, a gland packing 6 is installed on the high pressure side in the casing 2 in the shaft sealing part that partitions the high pressure side and the low pressure side along the surface of the shaft 1. installed,
A gland packing 7 is attached to the low pressure side.

A gland packing tightening mechanism is provided on the low pressure side, which tightens the gland packings 6 and 7 to each other in the axial direction using the holding ring 4 and the tightening bolt 3.

Further, a lantern ring 5 is interposed between the gland packing 6 and the gland packing 7, and a plurality of spring insertion holes 5c are provided in the circumferential direction on the end surfaces of the high pressure side and low pressure side of the lantern ring 5. A compression spring 10a is attached to each of the spring insertion holes 5c.

Then, the spring 10a and the ground packing 6, 7
Slide rings 8, 8 as spring bearing members are provided between the two. The slide rings 8, 8 can slide on the inner peripheral surface of the lantern ring 5. On the other hand, a sleeve 9 as a first spring receiving member is provided between the presser ring 4 and the slide ring 8 attached to the low pressure side of the lantern ring 5. An O-ring 11 provides a fluid seal between the sleeve 9 and the shaft 1 with a gland packing 7. Also, sleeve 9
is always pushed in by the reaction force of a compression spring 10b as a first spring attached to a plurality of holes 4a formed in the circumferential direction of the end face of the gland packing 7 in the holding ring 4, At the time of assembly, by pressing down the retaining ring 4 with the tightening bolt 3, a predetermined surface pressure can be applied to the gland packings 6, 7.

In other words, the gland packing 6 on the high pressure side has
Holder ring 4, sleeve 9, lantern ring 5, and slide ring 8 as a second spring receiving member
The tightening force of the tightening bolt 3 is transmitted through the tightening bolt 3, and the adjacent gland packings 6 are tightened together by this tightening force.

Further, the gland packing 6 is pressed by the spring 10a via the slide ring 8, so that even when the gland packing 6 is worn out or deformed, the mutually tightened state of the adjacent gland packing 6 is maintained. It's becoming like that.

Further, the tightening force of the bolt 3 is transmitted to the gland packing 7 on the low pressure side via the retaining ring 4 and the sleeve 9, and this tightening force causes the adjacent gland packings 7 to mutually move. It is designed to be tightened.

The gland packing 7 is pressed by a spring 10a and a spring 10b via a slide ring 8 and a sleeve 9, so that even when the gland packing 7 is worn out or deformed, adjacent gland packing 7 are tightened together. State is preserved.

Since the gland packing type shaft sealing device as the first embodiment of the present invention is constructed as described above,
When assembling the device, the tightening force of the bolt 3 acts on the gland packing 6 through the sleeve 9, and since it does not go through the gland packing 7, it is subjected to the same surface pressure as the gland packing 7 on the low pressure side. Be able to load. By making the free lengths of the springs 10a and 10b sufficiently longer than the holes 5c and 4a, the spring constant of the object to be tightened with the bolt 3 (packets 6, 7 + springs 10a, 10b) can be reduced, and the bolt 3 can be tightened. The force can be transmitted without any problem.

After driving for a long time, Grand Packkin 6,
7 is worn or deformed and the surface pressure is about to decrease due to stress relaxation, the slide ring 8 and sleeve 9 are pushed toward the gland packings 6 and 7 by the reaction force of the springs 10a and 10b, and the gland packings 6, 7 is prevented from decreasing in surface pressure. As mentioned above, if the compression allowance of the springs 10a, 10b is made sufficiently large relative to the amount of deformation of the gland packings 6, 7, the change in spring force will be small even if the gland packings 6, 7 are deformed, and the above-mentioned A drop in surface pressure can be prevented without any problem.

Next, a second embodiment of the present invention will be described. As shown in FIG. 3, a gland packing 6,
7. A lantern ring 5, a tightening bolt 3, and a holding ring 4 are installed in the same manner as in the first embodiment.

In this embodiment, the lantern ring 5 has two
It is composed of divided lantern ring parts 5a and 5b, and the lantern ring parts 5a and 5b are
Holes 5a' and 5b' are formed in the center thereof, and a spring 10a as a second spring is loaded into these holes 5a' and 5b'.

That is, the spring 10a urges both end surfaces of the lantern ring 5 to spread in the axial direction, thereby tightening the gland packings 6 together.

The gland packing 7 also includes a spring 10b serving as a first spring and a first spring loaded with the spring 10b.
The tightening force of the tightening bolt 3 is transmitted through the spring receiving ring 12 as a spring receiving member and the retaining ring 4, and the spring force of the spring 10a is transmitted through the lantern ring portion 5b. It's getting old.

Since the gland packing type shaft sealing device as the second embodiment of the present invention is constructed as described above,
The gland packings 6 and 7 are worn or deformed,
When the surface pressure is about to decrease, the springs 10a, 1
The lantern ring portions 5a, 5b and the spring receiving ring 12 are pressed by the lantern ring portions 5a, 5b, and the gland packings 6, 7 are pressed, thereby preventing a decrease in the surface pressure of the gland packings 6, 7 against the shaft 1.

Furthermore, to explain the third embodiment of the present invention, in FIG. 4, the same reference numerals as in FIG. 2 indicate almost the same parts.

In this embodiment, a high-pressure side gland packing 6 and a low-pressure side gland packing 7 are arranged adjacent to the center of the device, and a lantern ring portion divided into two is provided at both ends of the gland packings 6 and 7. 5a and 5b are provided.

And, in the lantern ring parts 5a and 5b,
Holes 5a', 5b' opening in the opposite direction to the gland packings 6, 7 are formed, and springs 10a, 10b are loaded into the holes 5a', 5b'.

Therefore, in this embodiment, the first and second spring bearing members are comprised of lantern ring portions 5b and 5a.

Since the gland packing type shaft sealing device as the third embodiment of the present invention is constructed as described above,
If the device is operated for a long time, the gland packing 6,7
When the lantern ring portions 5a, 5b press the gland packings 6, 7 due to the spring force of the springs 10a, 10b, and the gland packings 6, 7 This prevents a decrease in the surface pressure on the shaft 1.

As described in detail above, according to the gland packing type shaft sealing device of the present invention, in the shaft sealing part that partitions the high pressure side and the low pressure side along the shaft surface, the gland packing on the high pressure side and the gland on the low pressure side that are adjacent to each other. The gland packing is provided with a gland packing and a gland packing tightening mechanism that tightens the gland packing on the high pressure side and the low pressure side in the axial direction from the low pressure side. a first spring bearing member that presses the gland packing on the low-pressure side via a first spring compressed by the spring; and a second spring compressed by the pressure of the gland packing on the low-pressure side With a simple structure in which a second spring receiving member that presses the gland packing is interposed, the following effects and advantages can be obtained.

(1) The same surface pressure as the gland packing on the low-pressure side can be transmitted to the gland packing on the high-pressure side, and the distribution of surface pressure across the packing can be made almost uniform, so the initial tightening force of the bolt can be reduced. , it becomes easier to manage the tightening force.

(2) Even when the gland packing is worn or deformed, the surface pressure on the sliding surface between the shaft and gland packing can be automatically restored to match the actual wear and deformation, and the surface is always kept constant. Pressure is maintained across the entire sliding surface, resulting in stable sealing performance, and damage to the packing and mating shaft is greatly reduced.

[Brief explanation of the drawing]

FIG. 1 is a longitudinal sectional view showing a conventional gland packing type shaft sealing device, FIG. 2 is a longitudinal sectional view showing a gland packing type shaft sealing device as a first embodiment of the present invention, and FIG. 4 is a longitudinal sectional view showing a gland packing type shaft sealing device as a second embodiment of the present invention, and FIG. 4 is a longitudinal sectional view showing a gland packing type shaft sealing device as a third embodiment of the invention. . 1... Shaft, 2... Casing, 3... Tightening bolt, 4... Holding ring, 4a... Hole, 5... Lantern ring, 5a, 5b... Lantern ring part, 5a', 5b'... Hole, 5c... Spring insertion hole,
6, 7...Gland packing, 8...Slide ring, 9...Sleeve, 10a, 10b...Spring, 11...O ring, 12...Spring receiving ring.

Claims (1)

[Scope of utility model registration request] At the shaft sealing part that partitions the high-pressure side and low-pressure side along the shaft surface, tighten the adjacent high-pressure side gland packing and low-pressure side gland packing, and these high-pressure side and low-pressure side gland packings in the axial direction from the low-pressure side. A gland packing tightening mechanism is provided, and the gland packing on the low pressure side is pressed via a first spring compressed by the gland packing tightening mechanism in order to evenly tighten the gland packing on the high pressure side and the low pressure side. A first spring receiving member and a second spring receiving member that presses the gland packing on the high pressure side via a second spring compressed by the pressure of the gland packing on the low pressure side are interposed. Features a gland packing type shaft sealing device.