JP2504076B2 - Pump shaft sealing device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION A. Object of the Invention (1) Field of Industrial Application The present invention relates to a shaft sealing device for a rotary shaft such as a gear pump,
In particular, the present invention relates to a shaft sealing device for a pump that facilitates replacement work of the gland packing.

(2) Related Art As shown in FIG. 4, a conventional external gear pump has a pair of drive gears 02 inside a hollow cylindrical casing 01.
And the driven gear 03 mesh with each other, and these gears 02,0
A drive shaft 06 and a driven shaft 07 are rotatably supported by bearings 04 and 05 arranged on both sides of the shaft 3. The rear end of this casing 01 is closed by a rear cover 08, and its front end is the drive shaft.
One end of 06 is blocked by a stuffing box 09 that penetrates. The stuffing box 09 has a liquid groove 010 and a packing support hole 011 which is open to the outside and covers the outer peripheral surface of the drive shaft 06. Inside the packing support hole 011 is a gland packing 013 for sliding contact with a sleeve 012 fixed to the drive shaft 06 to prevent liquid leakage from the inside of the pump.
Is installed. And this gland packing 013
Is externally pressed and held by a packing presser 015 which is detachably fixed to the stuffing box 09 by a screw 014. Further, a storage chamber 016 is formed inside the gland packing 013 of the stuffing box 09, and the storage chamber 016 of the pump is provided via a reflux passage (not shown) formed in the stuffing box 09 and the casing 01. It communicates with a suction side channel (not shown). In this way, the drive shaft can be
The liquid that has leaked into the storage chamber 016 from the gap between the 06 and the driven shaft 07 and the bearing 04 is returned to the suction-side flow path through the above-described reflux passage.

(3) Problems to be Solved by the Invention In the above-described conventional external gear pump, when replacing the deteriorated gland packing 013, loosen the screw 014, remove the packing retainer 015, remove the old gland packing 013, and replace it with a new one. This is done by inserting a gland packing 013. At this time, since the solidified liquid residue or the like is often attached to the inner surface of the packing support hole 011 of the stuffing box 09, a new gland packing 013 can be smoothly inserted and assembled unless it is cleaned. I can't. However, gland packing 013
If removed, the liquid remaining in the suction side flow passage of the pump flows into the packing support hole 011 through the above-mentioned reflux passage (not shown) and the storage chamber 016, which makes replacement work of the gland packing 013 difficult. Was there. Then, when the liquid tank is installed at a position higher than the pump, the liquid in the tank flows out indefinitely, and this tendency becomes more remarkable.

The present invention has been made in view of the above circumstances, and when replacing the gland packing of the shaft sealing device of the pump,
The purpose is to prevent the liquid accumulated in the pump from flowing out from the stuffing box, and to smoothly clean the packing support holes and replace the gland packing.

B. Structure of the Invention (1) Means for Solving the Problems In order to achieve the above object, the pump shaft sealing device of the present invention has an opening on the inner surface of a stuffing box through which a drive shaft of the pump penetrates. A packing support hole is formed, and a ring-shaped storage chamber that surrounds the outer periphery of the drive shaft is formed inside the packing support hole, and the storage chamber is connected to the suction side flow path of the pump through the return path. In the shaft sealing device, a ring formed on a drive shaft located in the storage chamber, a seal surface for closing a gap between the drive shaft and the stuffing box to prevent liquid leakage from the storage chamber to the packing support hole. It is characterized by loosely fitting a ring-shaped collar.

(2) Action In the shaft seal device for a pump of the present invention having the above-mentioned configuration, when the deteriorated gland packing is removed from the packing support hole of the stuffing box for replacement, the liquid retained in the storage chamber acts as a drive shaft. Attempts to flow through the gap in the stuffing box into the packing support hole. Then, the collar slidably fitted on the drive shaft in the storage chamber is
This liquid pressure slides and the sealing surface closes the gap, and blocks the outflow of liquid from the storage chamber to the packing support hole. Therefore, no liquid leakage occurs in the packing support hole during the cleaning work of the liquid residue attached to the inner surface of the packing support hole or the outer circumference of the drive shaft and the mounting work of the new gland packing.

(3) Example Hereinafter, a first example of a pump shaft sealing device according to the present invention will be described with reference to the drawings. In the present embodiment, the same members as those in the conventional example are designated by the same reference numerals except zero "0".

As is clear from FIG. 1 and FIG. 2, the entire structure of the external gear pump has substantially the same structure as the conventional example. That is, the drive shaft 6 and the driven shaft 7 are rotatably supported by bearings 4 and 5 arranged on both side surfaces of a pair of the drive gear 2 and the driven gear 3 which mesh with each other inside the casing 1, and both end faces of the casing 1 are provided with a rear cover. 8 and the stuffing box 9 are closed. The stuffing box 9 is formed with a through hole for guiding the drive shaft 6 to the outside of the pump. The through hole has a protrusion 17 formed on an inner wall of an intermediate portion thereof to support the inner storage chamber 16 and the outer packing. Separated into holes 11. A sleeve 12 fitted through an O-ring 18 is integrally fixed to the outer periphery of the drive shaft 6 by a pin 19. The end face of the sleeve 12 and the protrusion
A gap 20 is formed by 17 and. The storage chamber 16 is communicated with the suction side flow passage 22 of the pump through the return passage 21 (see FIG. 2), the packing support hole 11 is provided with the gland packing 13, and the stuffing box 9 is provided with the gland packing 13. It is held from the outside by a packing retainer 15 fixed with a screw 14.

An annular collar 23 is slidably fitted into the storage chamber 16 so as to be slidable with respect to the drive shaft 6. The collar 23 has a cross-sectional outer periphery extending into a gap 20 as shown in FIG. Protrusion
23a, a taper-shaped sealing surface 23b capable of contacting the end of the sleeve 12, an upright wall-shaped sealing surface 23C capable of contacting the protrusion 17.
It has a hydraulic pressure receiving surface 23d. And this color 23
And the gland packing 13 between the gland packing 13 and the gland packing 13, the projecting portion 24a (second
An annular bush 24 (see the drawing) is slidably attached to the drive shaft 6.

Next, the operation of the embodiment of the pump shaft sealing device according to the present invention having the above-described structure will be described.

During normal pump operation, the liquid leaked from the high-pressure side of the pump reaches the storage chamber 16 through the gap between the bearing 4 and the drive shaft 6 and the driven shaft 7 and the like, from which the liquid is leaked to the suction side. It is returned to the flow path 22. And the storage chamber
The liquid inside 16 is prevented from leaking to the outside of the pump by the action of the gland packing 13 which is in sliding contact with the outer periphery of the sleeve 12 fixed to the drive shaft 6. At this time, the protruding part of the collar 23
23a is a bush 2 inserted in the innermost part of the packing support hole 11.
The seal surface 23 of the collar 23 is pressed by the protruding portion 24a of 4
b is separated from the end of the sleeve 12. Therefore,
Wear on the collar 23 due to contact with the end of the rotating sleeve 12 during operation of the pump is prevented.

To replace the worn gland packing 13, screw 14
Loosen and remove packing retainer 15, then remove the packing support hole.
Remove gland packing 13 and bush 24 from 11. Then, as shown in FIG. 2, the collar 23 engaged with the protruding portion 24a of the bush 24 is pressed toward the gap 20 by the hydraulic pressure acting on the pressure receiving surface 23d, and the sealing surface 23b of the collar 23 is pressed.
And 23c abut the ends of the sleeve 12 and the protrusion 17, respectively. At this time, since the sealing surface 23b is tapered in the direction of the packing support hole 11, the collar 23 is pushed into the gap 20 like a wedge, and the sealing effect is further enhanced. In this way, when the gap 20 is sealed by the collar 23, the liquid in the storage chamber 16 is prevented from flowing out to the packing support hole 11, and the inside of the packing support hole 11 is cleaned and a new gland packing 13 is attached. Work can be performed easily.

FIG. 3 shows a second embodiment of the shaft sealing device for a pump according to the present invention.

In this embodiment, instead of the bush 24 of the first embodiment,
It is characterized in that a tubular packing case 25 is used. This packing case 25 is a stuffing box 9
A flange formed on the front end of the stuffing box 9 is fixed to the stuffing box 9 with a screw 26.
The gland packing 13 is attached to the inside of the packing case 25, and the protrusion 25a is attached to the tip of the gland packing 13.
Is formed, and the protrusion 23a of the collar 23 is pressed to release the engagement of the seal faces 23b and 23c with the collar 12 and the protrusion 17.

In the second embodiment, the screws 26 are loosened and the packing case
It is possible to remove the gland packing 13 at the same time by pulling out 25, and the stuffing box 9
Since the diameter of the through hole is large, the cleaning work can be performed more easily.

According to the first and second embodiments described above, the sealing effect can be enhanced by forming the sealing surface of the collar 23 in a tapered shape. Further, by using the bush 24 having the protruding portion 24a or the packing case 25 having the protruding portion 25a, it is possible to prevent the collar 23 from coming into contact with the drive shaft and abrading during the pump operation, and to enhance the durability thereof. it can.

Although the embodiment of the shaft sealing device for a pump according to the present invention has been described above in detail, the present invention is not limited to the above embodiment, and does not deviate from the present invention described in the scope of claims, It is possible to make various small design changes.

For example, instead of abutting the collar 23 on the end of the sleeve 12 fixed to the drive shaft 6, it is possible to directly form a step on the drive shaft 6 and abut the collar 23 on the step.
Further, the cross-sectional shape of the collar 23 is not limited to that of the embodiment, and an appropriate shape can be adopted.

Further, the shaft sealing device of the present invention can be applied to shaft sealing devices for various pumps such as an internal gear pump and a vane pump, in addition to the external gear pump.

A packing case having the bush 24 and the protruding portion
Although 25 is effective for improving the durability of the collar 23, it is not always necessary and can be omitted.

C. Effect of the Invention According to the pump shaft sealing device of the present invention described above, a collar is disposed in the storage chamber formed in the stuffing box of the pump, and the collar closes the gap leading to the packing support hole. Therefore, even if the old gland packing is removed from the support hole, the liquid staying in the pump does not flow out into the packing support hole. Therefore, not only can the cleaning work of the liquid residue attached to the packing support hole be easily performed, but also the solidified liquid residue can be completely removed, so that a new gland packing can be securely attached. It becomes possible and the durability can be greatly improved.

[Brief description of drawings]

1 is a sectional view of a first embodiment of a pump shaft sealing device according to the present invention, FIG. 2 is a sectional view taken along line II-II of FIG. 1, FIG. 3 is an explanatory view of a second embodiment, and FIG. The figure is an illustration of a conventional shaft seal device for a pump. 6 ... Drive shaft, 9 ... Stuffing box, 11 ... Packing support hole, 12 ... Sleeve, 13 ... Gland packing, 16 ... Storage chamber, 17 ... Projection, 20 ... Gap, 21 ... Return path, 22 …… Suction side flow path, 23 …… Color, 23b, 23c ……
Seal surface

Claims (2)

(57) [Claims] 1. A packing support hole that opens to the outside is formed on the inner surface of a stuffing box through which a drive shaft of a pump penetrates, and an annular storage chamber that surrounds the outer periphery of the drive shaft is formed inside the packing support hole. In a pump shaft sealing device that communicates this storage chamber with a suction side flow path of a pump via a return path, a gap between the drive shaft and a stuffing box is closed on a drive shaft located in the storage chamber. A shaft sealing device for a pump, wherein a ring-shaped collar having a sealing surface for preventing liquid leakage from the storage chamber to the packing support hole is slidably loosely fitted. 2. The gap between the drive shaft and the stuffing box is
The shaft sealing device for a pump according to claim 1, which is formed by an end portion of a sleeve fixed to the drive shaft and a projection of a stuffing box.