JP2006349147A - Spiral packing and sealing method of rotating shaft using the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a packing excellent in installation and removal characteristics and a sealing method of a rotating shaft using it. <P>SOLUTION: A spiral packing is an annular packing made of a string-like packing material having two inclined ends provided on both ends and individually inclined at a specified equal angle. An annular body is constituted by spirally winding the packing material at least in two layers, and the inclined ends are positioned to correspond with each other in the circumferential direction. The height of the entire packing is approximately given by (the thickness in the radial direction of the packing material)×(the number of the layers). The sealing method of the rotating shaft includes installation of the spiral packing by winding the spiral packing in the direction same as the rotating direction of the rotating shaft so as to advance to the bottom side of a stuffing box as veiwed from the packing gland side. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a spiral packing used for sealing a rotating shaft and a method for sealing a rotating shaft using the spiral packing.

  Conventionally, packing is used to prevent leakage from the valve stem or the rotating shaft. Such packing is a ring molded product (doughnut shape) or braided product with the same dimensions as the shaft diameter and stuffing box inner diameter (cut string shape) cut into a length per ring of the packing (string shape). It is used with several rings mounted depending on the stuffing box depth by shifting 90 to 120 °.

  In such a conventional packing, the number of rings used may be wrong at the time of mounting because the number of packing rings is determined according to the stuffing box depth. It was difficult to take out the packing later, and there was a problem that a special tool was required when taking out the packing behind the stuffing box.

  In order to solve such problems in the prior art, the present inventor has intensively studied, and as a result, according to the depth of the stuffing box, a continuous braided product is integrally formed in a spiral shape, and packing for the required number of rings. By making it the same as the height, it was found that it was possible to obtain a packing with one packing, no need to shift the cut, excellent take-out performance and improved sealing performance, and the present invention was completed. It was.

In addition, although what is used for the plunger seal of a plunger pump etc. is proposed as a spiral packing (refer patent document 1), this spiral packing makes a single packing into a spiral shape, and uses the ring used. This is different from the present invention in which the entire packing is integrally formed as a spiral shape with a single packing material.
JP 2000-329233 A

  An object of the present invention is to provide a packing excellent in mounting property and take-out property and a method of sealing a rotary shaft using the packing.

  The spiral packing according to the present invention is an annular packing made of a string-like packing material having inclined end portions inclined at a predetermined angle equal to both ends thereof, and is wound in a spiral shape of at least two layers. It is configured so that the inclined end portion is located at a corresponding position in the circumferential direction, and the height of the entire packing is substantially (the thickness in the radial direction of the packing material) × (the number of layers). It is characterized by.

  In the sealing method of the rotating shaft according to the present invention, when the spiral packing is mounted on the rotating shaft in the stuffing box, the rotating shaft is moved so that it proceeds to the bottom of the stuffing box when viewed from the packing presser side. It is characterized by being wound and mounted in the same direction as the rotation direction.

The spiral packing according to the present invention does not need to shift the cut end, and can reduce mounting errors such as an incorrect number of rings used. Further, since the spiral packing according to the present invention has a continuous spiral shape, all packing can be easily taken out without using a dedicated tool.

  The sealing method of the rotating shaft according to the present invention is excellent in sealing performance as compared with the conventional method.

  Hereinafter, the spiral packing and the rotating shaft sealing method according to the present invention will be specifically described. 1A and 1B are schematic perspective views showing a spiral packing according to the present invention, and FIG. 2 is a schematic perspective view showing a packing material used for manufacturing the spiral packing according to the present invention.

  As shown in FIG. 1, the spiral packing according to the present invention is an annular packing made of a string-like packing material having inclined end portions inclined at a predetermined angle equal to both ends thereof, and has at least two layers of spiral packing. It is comprised so that the said inclined end part may come to the position corresponding to the circumferential direction.

  The spiral packing according to the present invention has a right-handed winding and a left-handed winding as shown in FIGS.

  The number of layers of the packing (the number of windings) depends on the depth of the stuffing box to be used, and is configured to have the same number of layers as the number of ring-shaped packings usually used for the stuffing box. Therefore, the height of the entire packing of the spiral packing according to the present invention is approximately (the thickness in the radial direction of the packing material) × (the number of layers).

  Such a spiral packing according to the present invention has a predetermined length packing material 5 having inclined end portions obtained by cutting both ends at a predetermined angle (θ), preferably 30 to 60 °, as shown in FIG. Can be manufactured by inserting into a mold in a spiral shape (right-handed or left-handed) so that the inclined end portion is located at a corresponding position in the circumferential direction and integrally forming with a press. The packing material used here is a conventionally known ring-shaped packing material, for example, expanded graphite yarn, carbon fiber, fluororesin fiber, aramid fiber, etc., braided into eight knitting, bag knitting, lattice knitting, etc. The braided body may be impregnated with a lubricant or the like, or may be surface-treated.

  Next, a method for sealing a rotating shaft using the spiral packing according to the present invention will be specifically described. FIG. 3A is a schematic cross-sectional view showing a state where the spiral packing according to the present invention is mounted on a stuffing box, and FIG. 3B is a schematic perspective view showing only the rotating shaft and spiral packing of FIG. .

  The spiral packing 1 is mounted in the stuffing box 3 as shown in FIG. The number of layers of the spiral packing 1 depends on the depth of the stuffing box 3, and one having the same number of layers as the number of ring-shaped packings usually used for the stuffing box 3 is used.

  At this time, the spiral packing 1 is appropriately selected from right-handed or left-handed packing and, as shown in FIG. 3 (B), the rotating shaft so as to advance toward the bottom of the stuffing box 3 when viewed from the packing presser 4 side. Wrapped in the same direction as the direction of rotation (direction indicated by the arrow).

By attaching the spiral packing according to the present invention in a specific direction as described above, when a plurality of ring-shaped packings are used, fluid leakage is less than when the spiral packing is mounted in a direction opposite to the above direction. can do.

  Further, in the sealing method of the rotating shaft according to the present invention, only one spiral packing wound in a spiral shape so as to be the same height as the packing height corresponding to the number of rings required when using the ring packing is used. Therefore, it is not necessary to shift the cut end as in the case of using a ring-shaped packing, and it is excellent in take-out property and excellent sealing performance.

(A), (B) is a schematic perspective view which shows the spiral packing which concerns on this invention. It is a schematic perspective view which shows the packing raw material used for manufacture of the spiral packing which concerns on this invention. (A) is a schematic sectional drawing which shows the state which installed the spiral packing which concerns on this invention in the stuffing box, (B) is a schematic perspective view which showed only the rotating shaft and spiral packing of (A).

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Spiral packing 2 ... Rotating shaft 3 ... Staffing box 4 ... Packing presser 5 ... Packing material

Claims (2)

  An annular packing made of a string-like packing material having inclined end portions inclined at a predetermined angle equal to both ends thereof, which is wound in a spiral shape of at least two layers to form an annular body, and the inclined end portions are A spiral packing characterized in that the height of the entire packing is substantially (the thickness in the radial direction of the packing material) × (the number of layers), which is configured to come to corresponding positions in the circumferential direction.   When the spiral packing according to claim 1 is mounted on the rotary shaft in the stuffing box, the spiral packing is wound in the same direction as the rotational direction of the rotary shaft so as to advance toward the bottom of the stuffing box when viewed from the packing presser side. A method for sealing a rotating shaft, comprising: mounting.

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