JP2013224715A - Shaft seal device and pump - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce a leaking quantity in a shaft passing through part of a pump casing by simple improvement applied to a shaft sealing device.SOLUTION: In a shaft seal device of a gland packing system, a packing pushing is formed by providing slope inclined downward from a center side to an outer periphery side of the packing pushing 10 in a under surface of a pushing protrusion 10a contacting an end of the gland packing 9 of the packing pushing 10, and the gland packing 9 is compressed from an outer periphery side to the inner periphery side.

Description

  The present invention relates to a structure of a shaft seal device of a gland packing system provided in a shaft penetration portion of a pump casing.

  As shown in FIG. 5, the most common and widely adopted gland packing method as a shaft seal device for a pump is that a plurality of gland packings 102 are inserted into a packing box 101 through which the pump main shaft 100 penetrates. A gap between the gland packing 102 and the shaft sleeve 100a of the pump main shaft 100 is secured by tightening a nut 104 to a gland bolt 101a protruding from the upper surface of the packing box 101. The amount of leakage of the fluid flowing through is adjusted (for example, see Patent Document 1).

Japanese Utility Model Publication No. 63-78762

The illustrated shaft seal device is inexpensive and simple. However, if the amount of fluid leakage is small, the gland packing 102 will be seized. If the amount of leakage is too large, the drainage will not be in time and the pump will be immersed in water. There is a problem that decreases. Therefore, it is indispensable to adjust the leakage amount by retightening the nut 104. However, even if the adjustment is performed properly, the leakage amount may suddenly increase if the operating point of the pump changes.
In addition, if the slurry is mixed in the internal fluid, the gland packing 102 may be prematurely deteriorated or the shaft sleeve 100a may be worn, and the amount of leakage may increase. Therefore, in a pump with high pressure, the number of steps of the gland packing 102 is increased. It is indispensable to take measures against water leakage such as changing materials and materials.

  An object of the present invention is to make it possible to reduce the amount of leakage in the shaft penetration portion of the pump casing by a simple improvement applied to the shaft seal device in view of such problems of the prior art.

  In the shaft penetration part of the pump casing, the sliding part between the gland packing and the shaft sleeve of the pump main shaft is easily worn by foreign matters mixed in the fluid handled by the pump, and the amount of leakage from the sliding part is on the opposite side ( The amount of leakage from the joint between the gland packing on the outer periphery side of the gland packing and the inner surface of the packing box of the packing box tends to increase. Therefore, in the shaft seal device of the present invention, the packing presser has directivity in the direction in which the gland packing is pressed, and the gland packing is pressed so that the amount of leakage at the sliding portion is reduced, whereby the total amount of leakage is reduced. Was configured to be suppressed.

  That is, in order to solve the above-mentioned problem, the present invention inserts a gland packing into a packing box provided in the shaft penetrating portion of the pump casing, presses the gland packing with a packing presser, and grounds the outer periphery of the pump main shaft. In the shaft seal device for press-contacting the inner surface of the packing, the lower surface of the presser protrusion joined to the end of the gland packing of the packing retainer is projected from the upper surface of the packing retainer between the center side and the outer peripheral side of the packing retainer. And having a configuration provided in a cross-sectional shape in which the protrusion width on the outer peripheral side is larger than the center side.

  According to this, since the presser protrusion of the packing presser is provided with a cross-sectional shape in which the lower surface has a protrusion width on the outer peripheral side larger than the center side, the gland having an end joined to the lower surface of the presser protrusion The packing is compressed by being pressed from the outer peripheral side toward the center side along the lower surface of the presser protrusion, thereby increasing the adhesion of the joint between the inner surface of the gland packing and the outer peripheral surface of the shaft sleeve of the pump spindle. The amount of leakage at the portion is reduced, and the leakage amount of the entire shaft penetrating portion can be reduced.

  In the shaft seal device having the above-described configuration, it is preferable that a slope inclined downward from the center side of the packing presser to the outer peripheral side is provided on the lower surface of the presser protrusion joined to the end of the gland packing of the packing presser.

  According to this, by providing a gradient of a predetermined size on the lower surface of the pressing projection of the packing presser, the entire end portion of the gland packing to be joined to this is uniformly pressed from the outer peripheral side toward the center side, The gland packing is compressed by applying a component force in the center direction to the gland packing, and the adhesion degree of the joint portion between the gland packing inner surface and the shaft sleeve outer peripheral surface of the pump main shaft can be increased.

  In this case, the gradient (α; see FIG. 3) provided on the lower surface of the presser protrusion is preferably provided in the range of 3 to 30 ° from the horizontal direction.

If the lower surface of the presser protrusion is a flat surface with no slope, the amount of leakage from the sliding portion of the gland packing and shaft sleeve cannot be reduced. It is effective in reducing On the other hand, when the gradient exceeds 30 °, the amount of leakage from the joint portion between the gland packing and the packing box inner surface increases, and therefore, the gradient is preferably in a range not exceeding 30 °.
The range of the gradient at which the leakage reduction effect can be obtained varies depending on the inner diameter of the gland packing, the number of gland packings to be inserted into the packing box, the type of gland packing, etc. Preferably, if a gradient of 5 to 20 ° is provided, the amount of leakage can be sufficiently reduced, and more preferably a gradient of 7 to 15 ° provides a significant effect in reducing the amount of leakage.
The pump of the present invention is characterized by including the shaft seal device having the above-described configuration.

  According to the shaft seal device of the present invention, the gland packing is pressed from the outer peripheral side toward the center side along the lower surface of the pressing protrusion of the packing presser, whereby the inner surface of the gland packing and the outer periphery of the shaft sleeve of the pump main shaft. The degree of adhesion of the joint with the surface can be increased, the amount of partial leakage can be reduced, and the amount of leakage of the entire shaft penetrating portion can be reduced.

It is the external view which fractured | ruptured the principal part of the pump provided with the shaft seal apparatus of this invention. It is an expanded sectional view of the shaft seal device of one embodiment of the present invention. It is a principal part expanded sectional view of the packing presser in FIG. (A), (B) is a member cutting | disconnection end elevation for demonstrating the state which presses a gland packing with a packing presser. It is a principal part expanded sectional view of the conventional shaft seal apparatus.

A preferred embodiment of the present invention will be described with reference to the drawings.
FIG. 1 shows a pump provided with a shaft seal device according to an embodiment of the present invention.
A pump 1 shown in the figure is a vertical shaft pump, and a pump main shaft 3 having an impeller 4 fixed to a lower end portion is disposed inside a vertically long tube body 2 and is installed on an upper portion of the tube body 2. By rotating the pump main shaft 3 with the prime mover 5, fluid is sucked from a suction port 2 a provided at the lower part of the tube body 2, and is discharged from a discharge port 2 b provided at the upper part of the tube body 2. The shaft seal device 7 is provided in the shaft penetrating portion of the pump casing 6 in the tube body 2.

  FIG. 2 shows an enlarged cross section of the shaft seal device 7. As shown in FIG. 2, the shaft seal device 7 includes a packing box 8, a gland packing 9, and a packing presser 10.

  The packing box 8 is installed so as to surround the periphery of the pump main shaft 3 penetrating the pump casing 6, and a plurality of gland packings 9 are loaded in a packing box 8 a provided at the center thereof, and the inner surface of each gland packing 9 is filled with the packing box 8. The shaft sleeve 3 a fitted on the outer periphery of the pump main shaft 3 is pressed against the outer peripheral surface. Further, four guide bolts 8b are provided on the upper surface of the packing box 8 so as to protrude upward at equal intervals along the circumferential direction.

The packing presser 10 has a ring shape having an opening through which the pump main shaft 3 penetrates in the center, and is formed by surrounding a presser protrusion 10a projecting downward and joined to the end of the gland packing 9 on the lower surface of the center. It is.
More specifically, as shown in FIG. 3, the pressing protrusion 10 a of the packing presser 10 has a protruding width from the upper surface 10 b of the packing presser 10 on the lower surface, and a protruding width (d1) on the center side of the packing presser 10. In addition, the bottom surface of the pressing projection 10a is formed as a tapered surface inclined downward with a gradient (α) from the central side to the outer peripheral side.
Further, on the surface of the packing retainer 10, four locking holes 10c having a size through which each guide bolt 8b passes are formed in correspondence with the protruding position of the guide bolt 8b.

  The shaft seal device 7 according to the present embodiment, which is composed of these members, engages the locking holes 10c of the packing presser 10 with the guide bolts 8b protruding upward from the upper surface of the packing box 8 so that the packing presser 8 is held in the packing box 8. 10, nuts 11 are screwed into the guide bolts 8 b projecting upward through the packing presser 10, and the pressing projection 10 a of the packing presser 10 presses the end of the gland packing 9 with an appropriate urging force. In this manner, the nut 11 is tightened and fixed.

  According to the shaft seal device 7 of this embodiment configured as described above, the lower surface of the pressing projection 10a of the packing presser 10 is joined to the end of the gland packing 9 inserted into the packing box 8a, and this is moved downward. The inner surface of the gland packing 9 is pressed against the outer peripheral surface of the shaft sleeve 3a of the pump main shaft 3 to seal the gap between the shaft sleeve 2a and the gland packing 9.

  And, as shown in FIG. 4, the gland packing 9 pressed downward by the packing presser 10 is joined to the lower end thereof, which is inclined downward from the center side of the pressing projection 10a to the outer peripheral side, as shown in FIG. A component force Fc in the center direction of the urging force applied from the packing presser 10 acts and compresses from the outer peripheral side toward the central side, and accordingly, the inner surface of the gland packing 9 and the outer periphery of the shaft sleeve 3a of the pump main shaft 3 are compressed. The degree of adhesion of the joint with the surface is increased, the amount of fluid leaking through this portion can be reduced, and the amount of leakage in the entire shaft penetrating portion can be suppressed.

  Note that the illustrated pump 1 and shaft seal device 7 are examples of the embodiment of the present invention, and the present invention is not limited to this, and can be configured in other appropriate forms. The shaft seal device of the present invention can be applied to other appropriate pumps in addition to the vertical shaft pump.

1 Vertical shaft pump, 3 pump main shaft, 3a shaft sleeve, 7 shaft seal device, 8 packing box, 9 gland packing, 10 packing presser, 10a presser projection, 11 nut

Claims (4)

In a shaft seal device in which a gland packing is inserted into a packing box provided in the shaft penetration part of the pump casing, the gland packing is pressed with a packing press, and the inner surface of the gland packing is pressed against the outer peripheral surface of the pump main shaft.
The lower surface of the presser protrusion that is joined to the end of the gland packing of the packing retainer has different protrusion widths from the upper surface of the packing retainer at the center side and the outer peripheral side of the packing retainer, and the outer peripheral side of the center side. A shaft seal device having a configuration provided in a cross-sectional shape in which the protruding width of the shaft is increased.   The slope (α) inclined downward from the center side of the packing presser to the outer peripheral side is provided on the lower surface of the presser protrusion joined to the end of the gland packing of the packing presser. Shaft seal device.   The shaft seal device according to claim 3, wherein a slope of 3 to 30 ° is provided on a lower surface of the presser protrusion of the packing presser.   The pump provided with the shaft seal device in any one of Claims 1-4.

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