JPH02209675A - Gland packing and manufacture thereof - Google Patents

Abstract

PURPOSE:To obtain stable sealing function in a long period and facilitate assembling operation by piercing a second knitting yarn through a passage exposed on each side other than four corners of a gland packing while piercing a first knitting yarn through a passage circulating each of four corners thereof, and braiding them. CONSTITUTION:A second knitting yarn 3 is pierced through a passage exposed on each side other than four corners of a gland packing 1, while a first knitting yarn 2 is pierced through a passage circulating the four corners, and braiding them. In this construction, a gland 10 is engaged with an atmospheric side opening of a packing case 7 and a gland packing 4 is compressed to uniformly pressurize the side central part of the second knitting yarn 3 circularing each corner thereof. The knitting yarn 3 is composed of a plurality of bundles of high strength fiber having 5g/d or more of tensile strength, so that pressure resistance and automorphic ability are excellent. Tensile stress for inward direction is applied to the bent parts of the knitting yarn 3 corresponding to the corners, thereby the bent parts are positively prevented from biting in the gaps between a rotational shaft 8 and the gland 10.

Description

DETAILED DESCRIPTION OF THE INVENTION (a) Field of Industrial Application The present invention relates to a gland packing used for shaft sealing of various types of equipment such as agitators, blowers, mixers, etc., and a method for manufacturing the same.

(B) Prior Art Conventionally, as the above-mentioned gland packing and its manufacturing method, for example, as shown in FIG.
(See Publication No.).

This ground packing 11 has a first path 13 and a second path 14 that connect each corner of the ground packing 11 in a diagonal direction. The knitting yarn 15 made of a large number of normal strength fibers is passed through the ground packing 11 through a third path 16 that goes around the center of the upper and lower surfaces and the center of both sides.
This manufacturing method involves braiding the fibers into a lattice shape.

(C) Problems to be Solved by the Invention However, each knitting yarn 12° 12 of the first path 13 and second path 14 constituting the above-mentioned ground packing 11 has an angle close to 180 degrees at each corner. Because it is bent into
As shown in FIG. 7, when the gland packing 11 is used as a shaft sealing means, after the gland packing 11 is press-fitted into the packing housing 9 inside the packing case 7, the gland packing 11 is inserted into the atmosphere side opening of the packing case 7. The gland packing 11 is compressed by fitting the presser foot 10, and during compression, the bent portion of the knitting yarn 12 corresponding to the atmospheric side corner of the gland packing 11 is connected to the rotating shaft 8 and the gland packing presser 10.
This biting causes the bent part of the knitting yarn 12 to be bent in two, so the residual stress generated at the time of bending and the stress generated by the biting phenomenon cause This has a problem in that the durability of the bent portion of the knitting yarn 12 is reduced.

Furthermore, since the atmosphere-side corner of the gland packing 11 is caught in the gap between the rotating shaft 8 and the packing holder 10, the contact surface pressure of the gland packing 11 with respect to the rotating shaft 8 is partially increased. The problem is that only the biting part with high surface pressure wears abnormally and the sealing function deteriorates, so in order to prevent biting, it is necessary to increase the proportion of high-strength fibers that make up the knitting yarn 12. It also has

An object of the present invention is to provide a gland packing and gland packing that can reliably prevent deterioration of the sealing function due to the jamming phenomenon, provide a stable sealing function for a long period of time, and facilitate braiding work to reduce manufacturing costs. The purpose is to provide a manufacturing method.

(d) Means for Solving the Problems The ground packing according to the first means of the present invention includes a first knitting yarn formed by bundling a large number of ordinary strength fibers, and a high strength having a tensile strength of 5 g/d or more. A ground packing made of a rectangular braid using a plurality of second knitting yarns formed by bundling a large number of fibers, wherein the second knitting yarn is arranged in a path exposed on each side other than the four corners of the ground packing. The structure is such that the first knitting yarn is passed through a path that goes around each of the four corners.

The method for manufacturing a gland packing according to the second means of the present invention is as follows:
The first connecting the corners of the gland packing in the diagonal direction.
The first knitting yarn is passed through the route and the second route, and the second knitting yarn is passed through the third route that goes around the center of the upper and lower surfaces and the center of both sides of the gland packing and is braided in a lattice shape. The corners are compressed in the diagonal direction, and the first knitting yarn is reversed to a first path side that vertically connects the center portions of the top and bottom surfaces of the ground packing, and a second path side that connects the center portions of both sides horizontally. At the same time, the second knitting yarn is inverted and formed on the third path side that goes around each corner of the gland packing.

(E) Function This invention provides a ground that is pre-braided as in the first means so that the second knitting yarn is exposed on each side other than the four corners and the first knitting yarn goes around each of the four corners. When a gland packing or a compression-molded gland packing as in the second method is used for the shaft seal, after press-fitting it into the packing housing inside the packing case, fit the packing holder into the atmosphere side opening of the packing case. By compressing the ground packing, the central part of the side surface of the second knitting yarn that goes around each corner of the ground packing is pressurized in a plane, and this knitting yarn has a high tensile strength of 5 g/d or more. Because it is made of a large number of strong fibers bundled together, it has extremely good pressure resistance and shape retention, and an inward tensile force acts on each corner and the corresponding bent part of the silk thread, allowing it to rotate. To actively prevent a bent part from getting caught in the gap between a shaft and a packing holder.

(F) Effects of the Invention According to this invention, the ground packing of the first means is arranged such that the second knitting yarn is exposed on each side other than the four corners, and the first knitting yarn goes around each of the four corners. It is pre-braided, and the second means of ground packing is braided into a lattice shape, compression molded, and the second knitting yarn of high-strength fiber is reversed on the third path side that goes around each corner. , conventional ground packing 11
Compared to , the bending angle of the second knitting yarn going around each corner is 1
The angle becomes a gentle angle of /2 or less, and by compressing this with a packing presser, etc., an inward tensile force acts on the second knitting yarn that goes around each corner, and the gap between the packing presser and the rotating shaft is It is possible to actively prevent the bent portion of the silk thread from getting caught.

As a result, the corners of the gland packing are prevented from being partially abnormally worn and the sliding properties are impaired due to biting, and the stress generated in the bent portions is reduced, improving durability and increasing the durability. It is possible to obtain a stable sealing function over a period of time, and moreover, the use ratio of high-strength fibers constituting the second knitting yarn for corners is reduced compared to the conventional ground packing 11, increasing flexibility and making braiding work easier. It is possible to facilitate the process and reduce manufacturing costs.

(g) Examples of the invention An embodiment of the present invention will be described in detail below based on the drawings.

The drawings show a ring-shaped gland packing used for shaft sealing and a method for manufacturing the same. After braiding each of the first knitting yarns 2.2 and a plurality of second knitting yarns 3 made of a large number of high-strength fibers into a lattice shape, the ground packing 1 is folded in vertical and horizontal directions. It is compressed into a rectangular cross-sectional shape.

The braiding paths of each of these first knitting yarns 2, 2 and second knitting yarn 3 are as follows:
First knitting yarns 2. of normal strength fibers are connected to a first path 4 vertically connecting the center portions of the upper and lower surfaces of the rectangular ground packing 1 and a second path 5 horizontally connecting the center portions of both sides. 2
A second knitting yarn 3 made of high-strength fiber is passed through a third path 6 that goes around each corner of the gland packing 1 to form a lattice-like braid.

Each of the first knitting yarns 2 passing through the first path 4 and second path 5 described above.
No. 2 is formed by, for example, mixing a filler such as graphite particles with PTFE particles to form fibers, and tightly bunching a large number of the resulting filler-containing PTFE fibers.

Each of the first knitting yarns 2, 2 has excellent properties inherent to filler-containing PTFE fibers, such as abrasion resistance, elasticity, sliding properties, thermal conductivity, heat resistance, and chemical resistance. There is.

The second knitting yarn 3 passing through the third path 6 described above is made by tightly gathering a large number of high-strength fibers having a tensile strength of 5 g/d or more, such as aramid fibers, glass fibers, carbon fibers, metal fibers, etc. At the same time, it is impregnated with a lubricant such as PTFE fine particles or graphite fine particles.

This second knitting yarn 3 is harder than each of the first knitting yarns 2, 2 described above, and is excellent in stress resistance and shape retention, as well as resistance to stress distortion.

The illustrated embodiment is constructed as described above, and the gland packing 1 and its manufacturing method will be described below.

First, as shown in FIGS. 3 and 4, two first knitting yarns 2.2 made of a large number of normal strength fibers are tied diagonally at each corner of the ground packing 1. 1st route 4
and second path 5, and each of these first knitting yarns 2.2
is bent 180 degrees at each corner and reversed, and the first knitting yarns 2.2 are orthogonal to each other at the center of the axis of the gland packing 1.

On the other hand, a second knitting yarn 3 formed by bundling a large number of high-strength fibers is passed through a third path 6 that goes around the center of the upper and lower surfaces and the center of both sides of the ground packing 1, and the second knitting yarn 3 is 3 alternately through each first knitting yarn 2.2.
2 and the second knitting yarn 3 are braided in a grid pattern.

Next, each corner of the ground packing 1 braided in a grid pattern,
That is, by compressing the bent portions of each first knitting yarn 2.2 in the diagonal direction (in the direction of the arrow shown in FIG. 3), as shown in FIG. Each first knitting yarn 2.2 is reversed to the side of the first path 4 that connects to the center part of both sides and the side of the second path 5 that horizontally connects the central part of both sides, and goes around each corner of the ground packing 1. The second knitting yarn 3 is reversed to the third path 6 side to form a rectangular cross-sectional shape.

When the compression-molded gland packing 1 as described above is used as a shaft seal, as shown in FIG. After press-fitting the gland packing 1 into the part 9,
A packing presser 1 is attached to the atmosphere side opening of this packing case 7.
0 is fitted.

Next, a plurality of tightening bolts (not shown) are screwed into the atmosphere side plane of the packing case 7 via the packing holder 10, and the gland packing 1 is compressed by the packing case 7 and the packing holder 10. Then, the central part of the side surface of the second knitting yarn 3 made of high-strength fiber that goes around each corner of the ground packing 1 is pressurized in a plane, and as shown by the arrow in FIG. An inward tensile force acts on the bent portion of the second knitting yarn 3 to actively prevent the bent portion of the second knitting yarn 3 from getting caught in the gap between the packing presser 10 and the rotating shaft 8. do.

At the same time, the outer circumferential surface of the gland packing 1 is brought into pressure contact with the inner circumferential surface of the packing housing part 9 by the radial pressing force exerted by the compression of the packing retainer 10, and the inner circumferential surface of the gland packing 1 is brought into contact with the inner circumferential surface of the gland packing 1 by the rotation shaft 8. The shaft is sealed by pressing against the outer peripheral surface of the shaft.

The gland packing 1 braided in a lattice pattern is compression-molded and the second knitting yarn 3 made of high-strength fibers is reversed on the 8th third path 6 side that goes around each corner, so that the gland packing 11 of the conventional example is Compared to the above, the bending angle of the second knitting yarn 3 that goes around each corner becomes a gentle angle of 1/2 or less, and by compressing the ground packing 1 with the packing presser 10, the second knitting yarn 3 that goes around each corner An inward tensile force acts on the second knitting yarn 3 in the third path 6 to actively prevent the bent portion of the second knitting yarn 3 from getting caught in the gap between the packing presser 10 and the rotating shaft 8. do.

That is, at the corner of the ground packing 1, a second fiber is formed by converging a large number of high-strength fibers having a tensile strength of 5 g/d or more.
Since the knitting yarn 3 is used, the pressure resistance and shape retention are extremely good, and even when used for shaft sealing under conditions of fluid pressure of 20 kg/d or more, no jamming phenomenon occurs.

As a result, the corners of the gland packing 1 are prevented from being partially abnormally worn and the sliding properties are impaired due to the jamming phenomenon, and the stress generated in the bent portions is reduced to improve durability. Improved sealing performance and stable sealing performance over a long period of time.

Furthermore, compared to the conventional ground packing 11, the use ratio of high-strength fibers constituting the second knitting yarn 3 for the corners is reduced to increase flexibility, and after braiding in a lattice shape, compression molding is performed. Since the second knitting yarn 3 is reversed to the third path 6 that goes around the corner, it is possible to facilitate the braiding work and reduce manufacturing costs.

Note that the present invention is not limited to the configuration of the above-described embodiment.

For example, by combining a plurality of the gland packings 1 described above and press-fitting them into the packing storage part 9, it is possible to prevent the corners from getting caught in the gap between the rotating shaft 8 and the packing holder 10, as in the above-described embodiment. .

[Brief explanation of the drawing]

The drawings show one embodiment of the present invention; FIG. 1 is a braiding route diagram of the gland packing after compression molding; FIG. 2 is a side view of the gland packing shown in FIG. 1;
The figure is a braiding route diagram of the gland packing that is braided in a lattice pattern. Figure 4 is a side view of the gland packing shown in Figure 3.
The figure is an enlarged vertical cross-sectional side view of the shaft seal part showing the gland packing in use. Figure 6 is a braiding route diagram of the gland packing showing a conventional example. Figure 7 is an enlarged longitudinal cross-section of the shaft seal part showing the gland packing in use. FIG. 1... Ground packing 2... First knitting yarn 3... Second knitting yarn 4... First route 5... Second route
6... 3rd route Figure 1 Figure 2 5...lt2 route 6... Certain 31 & Step 1-ri〉Sitpatzkin 6-・Tei 3 route Figure 5

Claims (2)

[Claims] (1) A plurality of first knitting yarns made by bundling a large number of normal strength fibers and a second knitting yarn made by bundling a large number of high strength fibers having a tensile strength of 5 g/d or more are used. The gland packing is braided into a rectangular shape, and the second knitting yarn is passed through a path exposed on each side other than the four corners of the gland packing, and the first knitting yarn is passed through a path going around each of the four corners. Gland packing. (2) A plurality of first knitting yarns made by bundling a large number of normal strength fibers and a second knitting yarn made by bundling a large number of high strength fibers having a tensile strength of 5 g/d or more are used. The gland packing is braided in a rectangular shape, and a first knitting thread is passed through a first path and a second path connecting each corner of the gland packing in a diagonal direction, and a first knitting yarn is passed through a first path and a second path connecting each corner of the gland packing in a diagonal direction. After passing the second knitting yarn through the third path that goes around the section and braiding it in a lattice shape, each corner of the gland packing is compressed diagonally, and the first The first knitting yarn is reversed to the path side and the second path side that horizontally connects the center portions of both sides, and the second knitting yarn is reversed to the third path side that goes around each corner of the gland packing. A manufacturing method for gland packing molded using