JPH0451255Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention applies an axial pressing force to the gland packing in the stuff-in box that constitutes the shaft seal of a fluid device to rotate it. This article relates to a pressurizing component for a gland packing that applies appropriate tightening surface pressure to the shaft.

[Prior Art] A gland packing in a stuff-in box that constitutes a shaft seal of a fluid device is pressed in the axial direction by a packing holder, so that its outer periphery comes into pressure contact with the inner periphery of the stuff-in box. In addition, the inner periphery is in pressure contact with the rotating shaft to ensure sealing.

However, if stress relaxation occurs in the gland packing over time or abrasion occurs on the sliding surface with respect to the rotating shaft, the tightening surface pressure against the rotating shaft decreases and the sealing performance is impaired. In addition, if the gland packing is pressed against the rotating shaft only by the pressing force of the packing holder, the tightening surface pressure of the gland packing against the rotating shaft decreases as it goes deeper into the stuff-in box, and uniform sealing performance is ensured. There was also the problem of not being able to get it.

To achieve this, the gland packing inside the stuff-in box is pressed axially by a spring to bulge radially inward, thereby relieving stress and absorbing wear on the sliding surfaces to ensure uniform sealing at all times. Various pressurizing devices have been proposed for this purpose. A typical example thereof is disclosed in Japanese Utility Model Publication No. 31-17326. The pressurizing device disclosed in the publication divides a previously formed annular hollow case into two in the axial direction and has an outer diameter that matches the diameter of the inside of the stuff-in box. The two hollow case halves are fitted to be slidable relative to each other in the axial direction, and a plurality of springs are interposed within the two split hollow case bodies at appropriate intervals in the circumferential direction.

[Problem to be solved by the invention] However, in the conventional pressurizing device as described above, the case that holds the spring is formed in advance into an annular shape corresponding to the diameter of the lid-in box and the outer diameter of the rotating shaft. Therefore, the size of the shaft seal that can be used when one pressurizing device is inserted into a stuff-in box is naturally limited, and shaft seals with different stuff-in-box diameters and rotating shaft diameters may be used. Therefore, for example, if one device has multiple shaft seals with different diameters, it is necessary to use multiple shaft seals with different sizes to correspond to the number of shaft seals. The problem is that a pressurizing device must be used, which increases costs accordingly. In addition, the spring specifications (for example, spring constant) must be changed in response to the tightening surface pressure that varies depending on the shaft diameter and the winding diameter of the gland packing, and it is difficult to remove the spring during maintenance and inspection. However, there are drawbacks such as a complicated structure and high price.

The present invention was developed in view of these circumstances, and can be applied regardless of variations in the diameter of the stuff-in box and the shaft diameter of the rotating shaft, and avoids changing spring specifications.
The purpose of this product is to provide a pressurizing component for a gland packing that has improved versatility, facilitates attachment/detachment work, and simplifies the structure.

[Means for Solving the Problems] In order to achieve the above object, the pressurizing part of the gland packing according to the present invention has flexibility and elasticity that can be formed into an annular shape, and has a shape that can be formed to fit the diameter of the stuff-in box. a long belt-shaped main body made of a material that can be cut to a length that closely fits the inner peripheral surface;
The main body includes a plurality of spring retainers provided at predetermined intervals on the inner surface thereof, and a plurality of springs held by each of these spring retainers to press and bias the gland packing in the axial direction. .

[Function] According to the present invention, a long strip-shaped main body is cut into a length that fits closely to the inner peripheral surface of the stuff-in box according to the diameter of the stuff-in-box, and the cut strip-shaped main body is cut into a length that fits tightly into the inner peripheral surface of the stuff-in box. By inserting it into an inbox and winding it around the outer circumference of the rotating shaft, an appropriate number of springs provided at predetermined intervals on the band-shaped main body are brought into contact with one end surface in the axial direction of the gland packing. Then, the gland packing is pressed from both sides in the axial direction in cooperation with the packing holder, thereby causing the inner and outer circumferences of the gland packing to contact the outer circumferential surface of the rotating shaft and the inner circumferential surface of the stuff-in box, respectively. Sealing performance can be achieved by applying uniform surface pressure.

[Example] Hereinafter, an example of the present invention will be described based on the drawings.

Figures 1 and 2 show an embodiment of the present invention, and in these figures, a long belt-shaped main body 1 has flexibility and elasticity that can be formed into an annular shape, and constitutes a shaft sealing part. It is a band-shaped material made of a material such as a stainless steel plate that can be cut to a length that closely fits the inner circumferential surface of the lid-in box (described later), and has a spring retainer with a roughly T-shaped cross section on the inner surface. 2 are attached by welding at predetermined intervals, and a coil spring 3 is held by these spring retainers 2.

The spring retainer 2 includes a base portion 2a attached orthogonally to one end of the inner surface of the elongated main body portion 1;
The base portion 2a has a cylindrical protrusion 2b extending from the approximate center to the other end in parallel with the main body 1, and the axial length of the cylindrical protrusion 2b is set equal to the width of the main body 1. It has been done.

The coil spring 3 is held with one axial end in contact with the base portion 2a of the spring retainer 2 and fitted onto the protruding portion 2b, and in a natural state, the other axial end, that is, the tip portion is in contact with the protruding portion 2b. It has a length that protrudes slightly forward.

The load per unit length of the main body 1 generated when the coil spring 3 is compressed is the tightening (axial pressure) of the gland packing described later.
(e.g. 2.5Kg/cm ² or 5.0Kg/
cm ² ), the spring constant of the coil spring 3 and the mounting interval of the spring retainer 2 are set in advance.

Next, the state of use of the above configuration will be explained.

First, a long main body 1 is cut to a length that can be formed into an annular shape that matches the diameter of the stuff-in box 4 shown in FIG. Next, this cut main body portion 1 is bent to form a perfect circular annular shape as shown in FIG. Next, as shown in FIG. 3, attach the other end of the coil spring 3 to the stuff-in box 4.
After inserting the annularly formed elongated main body 1 into the deepest part of the stuff-in box 4, and sequentially inserting a sheet packing 5 and a plurality of gland packings 6, with the main body 1 oriented toward the opening of Insert the rotating shaft 7, then fit the tip of the packing holder 8 into the opening of the stuff-in box 4, and then tighten it with a tightening member such as a bolt (not shown) to a predetermined tightening pressure. Therefore, the gland packing 6 is clamped and pressed in the axial direction. As a result, the gland packing 6 is brought into pressure contact with the inner periphery of the stuff-in box 4 and the outer periphery of the rotating shaft 7 with an appropriate surface pressure to form a seal.

In this case, the coil spring 3 is compressed,
A spring force is generated. Therefore, even if the gland packing 6 undergoes stress relaxation over time or wear occurs on its sliding surface with the rotating shaft 7, the spring force of the coil spring 7 is biased against the gland packing 6 via the seat packing 5. Therefore, due to this bias, the gland packing 6 bulges in the radial direction to relieve stress or absorb wear on the sliding surface, and to apply an appropriate tightening surface pressure to the rotating shaft 7. Sealing performance can be ensured. In addition, it is possible to avoid uneven sealing performance that would occur when the gland packing 6 is brought into pressure contact with the rotating shaft 7 using only the pressing force of the packing presser 8.

5 and 6 show a second embodiment of the present invention, in which the elongated main body 1 is formed of a rubber bar with a square cross section, and the spring retainer 2 is formed by a blind through hole. A coil spring 3 is fitted and held in this spring retainer 2. Even with this configuration,
The same effects as in the embodiment described above are achieved.

[Effects of the invention] As explained above, according to the invention, it has flexibility and elasticity that can be formed into an annular shape, and
A plurality of spring retainers and gland packings are pressed in the axial direction at predetermined intervals on a long strip-shaped main body made of material that can be cut to a length that fits closely to the inner peripheral surface of the stuff-in box to fit the diameter of the stuff-in box. Since it is equipped with a biasing spring, in actual use, the main body of the pressurizing part can be arbitrarily cut to a length that matches the diameter of the stuff-in box that constitutes the shaft seal part. By inserting the cut main body into a stuff-in box and wrapping it around the outer circumference of the rotating shaft, the gland packing is pressed from both sides in the axial direction in cooperation with the packing holder, and the rotating shaft is Uniform tightening surface pressure can be applied over almost the entire area. Therefore, just by preparing a kind of pressurized part,
It can be applied to a shaft seal made of a stuff-in box of any diameter and a rotating shaft of any shaft diameter, and the versatility can be significantly improved. Moreover, since the main body can always be kept in close contact with the inner circumferential surface of the stuff-in box when it is installed, there is no possibility that the pressurized parts will be accidentally displaced due to vibrations caused by rotation or uneven wear of the gland packing. This makes it possible to always apply a uniform pressing force to the gland packing and ensure a predetermined sealing performance.
Also, set the spring constant of the spring and the installation interval of the spring retainer in advance so that the load per unit length of the long main body when the spring is compressed is the load required to tighten the gland packing. By doing so, versatility is also improved by making it possible to avoid the troublesome changes in spring specifications that were conventionally required in response to changes in the diameter of the stuff-in box and the shaft diameter of the rotating shaft. Further, it has the advantage that it can be easily attached to and detached from the stuff-in box and has a simple structure.

[Brief explanation of the drawing]

1 to 6 show embodiments of the present invention,
FIG. 1 is a front view showing a part of the state before cutting of the first embodiment, FIG. 2 is a sectional view taken along the - line in FIG. 1,
Fig. 3 is a cross-sectional view showing an example of the same usage state, Fig. 4 is a front view showing the circular ring-shaped state after cutting, and Fig. 5 is a front view showing a part of the state before cutting of the second embodiment. , FIG. 6 is a sectional view taken along the - line in FIG. 5. DESCRIPTION OF SYMBOLS 1... Long strip-shaped main body part, 2... Spring retainer, 3... Spring, 4... Stuff-in box, 6... Grand packing, 7... Rotating shaft.

Claims (1)

[Scope of utility model registration request] A pressurizing part for a gland packing that presses the gland packing packed in a stuff-in box in the axial direction so as to oppose the pressing force of the packing holder to apply a tightening surface pressure to the rotating shaft,
A long belt-shaped main body made of a material that has flexibility and elasticity and can be formed into an annular shape and can be cut to a length that fits closely to the inner peripheral surface of the stuff-in box according to the diameter of the stuff-in box; It is characterized by comprising a plurality of spring retainers provided on the inner surface at predetermined intervals, and a plurality of springs held by each of these spring retainers to press and bias the gland packing in the axial direction. Pressurized parts of Grand Packkin.