JPH10131872A - Gear pump - Google Patents

Abstract

PROBLEM TO BE SOLVED: To eliminate a viscous fluid, leaking outside from the inside of a casing, efficiently with simple structure. SOLUTION: A cutter 24 is protrusively provided at a front end face 8a of a gland case 8, and a collar 25 rotated integrally with a driving shaft 2 and elastically energized outward in the axial direction of the driving shaft 12 is provided in a position facing a tip cutting edge face 24a of the cutter 24. A leakage 27 of a viscous fluid passing a contactless seal and solidified by a cooling means so as to have stuck to the outer end face 25a of the collar 25 can thereby be chipped off with the tip cutting edge face 24a of the cutter 24 by rotating the driving shaft 12 so as to be eliminated with high efficiency.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a gear pump particularly preferably used when handling a high-viscosity fluid such as a polymer or a chemical.

[0002]

2. Description of the Related Art A gear pump has a rotating shaft extending through the casing from the inside to the outside. Fluid flows from the inside to the outside of the casing through a gap between the inner and outer circumferences of the casing and the rotating shaft. There is a risk of leakage. In order to prevent or limit such leakage, this portion is provided with a shaft sealing mechanism such as a non-contact type seal such as a labyrinth seal, in addition to a contact type seal such as a gland packing or a mechanical seal. .

In such a shaft sealing mechanism, when a fluid to be handled is a high viscosity fluid, it is effective to use a non-contact seal in combination with a cooling means. In other words, utilizing the properties of a high-viscosity fluid that solidifies when cooled, the high-viscosity fluid is cooled by cooling means while passing over a non-contact seal, and solidified into granules or sticks to prevent leakage to the outside of the casing Or have restricted. However, when the gear pump is operated while the high-viscosity fluid is solidified in the vicinity of the casing penetrating end, in a normal gear pump in which the tip of the rotating shaft is connected to the drive motor via the coupling cover, the solidification has occurred. When the high-viscosity fluid contacts the coupling cover or the like while rotating with the shaft, the coupling cover or the like may be deformed. Also, if a solidified high-viscosity fluid is present at such a position, an axial force acts on the shaft, which may cause abrasion due to improper sliding between the side surface of the gear and the side plate, thereby increasing internal leakage and the like. . Therefore, conventionally, a high-viscosity fluid adhering near the casing penetrating end has been artificially shaved and removed using a tool such as a cutter.

[0004]

However, in the case where the removal is artificially performed using a tool such as a cutter,
There is always danger because the work is performed while rotating the rotating shaft. In particular, when handling a low-melting fluid having a high adhesive strength, it has been extremely difficult to remove the fluid. SUMMARY OF THE INVENTION The present invention has been made in view of such a problem, and provides a gear pump capable of extremely effectively removing a leakage of a high-viscosity fluid leaked to the outside of a casing with a simple structure. The purpose is to:

[0005]

In order to achieve the object, the present invention comprises a non-contact seal and a cooling means near a casing penetrating end of a rotating shaft extending through the casing from the inside to the outside, In a gear pump in which a fluid to be leaked through an inner and outer circumferential gap between a rotating shaft and a casing is restricted by a non-contact seal and solidified and sealed by cooling means, a part of the inner and outer circumferential gap is provided between an outer periphery of a shaft and a casing. Are arranged so as to be integrally rotatable and movable in the axial direction, elastically urge the collar outward in the axial direction, fix the base end to the casing, and set the tip blade surface to the outside of the collar. A cutter is provided at a position where the cutter and the collar are in sliding contact with each other, and the solidified fluid leaking from the inner and outer peripheral gaps is guided to the sliding surfaces of the cutter and the collar to break the fluid. Those consisting configured to.

With such a structure, the high-viscosity fluid that has leaked into the gap between the casing and the inner and outer circumferences of the rotating shaft is
After passing through the non-contact seal and being cooled by the cooling means, it leaks from the casing penetrating end and adheres to the outer end surface of the collar and solidifies. When the collar rotates together with the rotating shaft, the leakage of the high-viscosity fluid adhering to the outer end surface comes into contact with the cutter blade effectively slidingly contacting the outer end surface under elastic biasing force and is shaved off. . Therefore, it is possible to easily scrape and remove even a low-melting-point leakage material having particularly high adhesive strength by utilizing the strong rotation force of the rotation shaft.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to FIGS. The gear pump 1 is used for transferring a high-viscosity fluid such as a polymer or a chemical.
As shown in FIG. 1, the casing 2 and the casing 2
And a pair of fluid feed gears 3 and 4 that mesh with each other.

The casing 2 includes a cylindrical body 5, a rear cover 6 covered on the rear end side of the body 5, a stuffing box 7 covered on the front end side, and a front end side of the stuffing box 7. The body 5 is formed with a fluid inlet 9 and a fluid outlet 10. The pair of fluid feed gears 3 and 4 are accommodated in eyeglass-shaped holes provided in the body 5, and one of the gears 3 is on the drive side and is fixed to a drive shaft 12 extending in both axial directions. And is supported by a bearing 14 via the drive shaft 12. And the drive shaft 12
Is protruded to the outside of the casing 2 through an axial hole formed in the stuffing box 7 and the ground case 8 so as to extend to one side in the axial direction. It is linked to a drive source such as a motor via an interlock 20.

The other gear 4 is on the driven side, is fixed to a driven shaft 16 extending in both axial directions, and is supported by a bearing 17 via the driven shaft 16. Bearing 1
Reference numerals 4 and 17 each have a cylindrical shape, and are fitted into eyeglass-like holes of the body 5 with their adjacent end faces abutting against each other, and have an inner surface slidingly sealed with a side surface of the gears 3 and 4. It is located at the location. Each of the bearings 14 and 17 has a lubrication groove 18 extending from the surface facing the gears 3 and 4 to the inner peripheral surface, and the radial outer end of the lubrication groove 18 formed on the side surface facing the gears 3 and 4. The portion 18a is formed so as to open to the discharge port 10.

The fluid is confined in a volume space surrounded by the outer peripheral surfaces of the teeth of the gears 3 and 4, the inner peripheral surface of the body 5, and the bearings 14 and 17, and the driving gear 3 is driven to rotate. Thus, the fluid is sucked in from the suction port 9 and is discharged from the discharge port 10 through the volume space. And the discharge port 10
Since the pressure on the side is higher than that on the suction port 9 side, the discharge port 10
A part of the feed fluid that has flowed through the lubrication groove 18 flows into the gap between the opposing side surfaces of the bearings 14 and 17 and the gears 3 and 4, from which the bearings 14 and 17 and the shafts 12 and 16 flow. It flows into the gap between the inner and outer peripheral surfaces of the inner and outer peripheral surfaces, and can reliably perform lubrication.

On the other hand, each gear 3, 4 and each bearing 14,
The fluid used for lubrication of the inner and outer peripheral gaps 1 between the drive shaft 12 and the stuffing box 7 and the ground case 8
In order to limit and prevent leakage to the outside of the casing 2 through the casing 9, a seal mechanism including a non-contact seal 22 and a cooling unit 23 is provided inside the ground case 8. The non-contact seal 22 is a labyrinth formed between the screw groove 21 provided on the outer periphery of the drive shaft 12 and the inner periphery of the ground case 8. In addition to increasing the flow path resistance of the inner and outer circumferential gaps 19, the screw function of pushing back the fluid existing in the inner and outer circumferential gaps 19 toward the inside of the ground case 8 is also performed.

That is, the high-viscosity fluid that is leaking to the outside from the inner and outer peripheral gaps 19 is pushed back toward the inside of the ground case 8 by the screw grooves 21, and is simultaneously solidified by the cooling means 23 while passing through the non-contact seal 22. Thus, leakage to the outside of the casing 2 is restricted and prevented. In such a configuration, in the present embodiment, as shown in FIG. 2, cutters 24 are further provided at two positions on the front end face 8 a of the ground case 8, which is the casing penetrating end of the drive shaft 12, and the tip blade of the cutter 24 is provided. The outer end surface 25a of the collar 25 fitted to the drive shaft 12 is made to be adjacent to the surface 24a.

The collar 25 engages a key 12a projecting from the drive shaft 12 into a groove (not shown) provided therein so that the collar 25 can rotate integrally with the drive shaft 12 and move in the axial direction. An inner / outer peripheral gap which is continuous with the inner / outer peripheral gap 19 is formed between the outer periphery and the ground case 8. Further, the collar 25 has a spring 26 therein, and is elastically biased outward along the drive shaft 12 by the elastic bias of the spring 26.

On the other hand, as shown in FIGS. 2 and 3, the cutter 24 has a distal end surface 24a protruding from a position where the distal end surface 24a is brought into sliding contact with the outer end surface 25a of the collar 25, and a base end of the cutter 24 is grounded. 8 are attached to upper and lower portions of a front end face 8a by bolts or the like. With such a configuration, most of the high-viscosity fluid that has leaked into the inner and outer peripheral gaps 19 is pushed back toward the inside of the ground case 8 by the screw grooves 21 as indicated by arrows in FIG. While being cooled by the cooling means 23 while passing through the contact seal 22, it leaks from the inner and outer circumferential gaps 19 and adheres to the outer end face 25a of the collar 25 as shown in FIG.
When the collar 25 rotates in the direction of the arrow shown in FIG. 3 together with the drive shaft 12, the leaked material 27 attached to the outer end surface 25a is guided to the sliding surface with the cutter 24 as shown in FIG. When the cutter 24
Is shaved off by the tip blade surface 24a.

Therefore, the strong rotating force of the drive shaft 12 can be used to easily scrape and remove even the low-melting-point leaking material 27 having a particularly high adhesive force, as in the prior art. There is no danger of removing the object 27. Further, in the case of the gear pump 1 in which the tip of the drive shaft 12 is connected to the drive motor via the coupling cover 20 as in the present embodiment, the leaked material 27 can be driven because the leaked material 27 can be reliably removed. Shaft 12 and coupling cover 20
The coupling cover 20 is pushed in the direction of the drive shaft 12 to prevent the internal gear 3 from being worn by contact with the side surface of the bearing 14, and the deteriorated polymer adheres to the drive shaft 12 and the coupling cover 20. There is an excellent effect that the deformation of the coupling cover 20 due to the contact rotation while keeping it can be prevented. Further, in this embodiment, the effective effect is maintained even if the rotary shaft 12 is displaced in the radial direction based on the tolerance with respect to the bearing 14. Therefore, for example, the tip blade surface of the cutter is applied to the outer periphery of the rotary shaft 12. It may be more suitable for this type of gear pump as compared to a configuration in which it is in contact. Furthermore, it is possible to prevent the leaked material 27 from invading the heat insulating material and cause a fire, and since the leaked material 27 is completely removed, the appearance does not give any discomfort.

The cutter 24 may be provided at three or more positions to prevent the collar 25 from tilting. It is also effective to make the tip blade surface 24a slightly more inclined than that shown in the figure so that the leaked material 27 is easily broken. If necessary, the collar 25 can be hardened and hardened to have durability.

In addition, the specific configuration of each part is not limited to the above-described embodiment, and various modifications can be made without departing from the spirit of the present invention.

[0018]

The present invention is embodied in the form described above and has the following effects. That is, in the gear pump of the present invention, the collar is disposed at the end of the inner and outer circumferential gap between the shaft and the casing, and the solidified fluid leaked from the inner and outer circumferential gap is brought into sliding contact with the outer end face of the collar and the outer end face. Since the cutting surface is configured to break on the sliding surface with the cutter provided with the tip blade surface, there is no danger of removing leaks artificially as in the past, and the strong rotating force of the rotating shaft is reduced. Utilizing the same, it is possible to easily scrape and remove even a low-melting-point leak having particularly high adhesive strength.
Therefore, in the case of a gear pump in which the tip of the drive shaft is connected to the drive motor via the coupling, the leaked material enters between the drive shaft and the coupling, the coupling is pushed in the drive shaft direction, and the internal gear is placed on the bearing side. In addition, the present invention has an excellent effect of preventing the contact cover from being worn and preventing the coupling cover from being deformed due to the contact rotation of the deteriorated polymer while being adhered to the drive shaft and the coupling. Further, it is possible to prevent the leaked material from entering the heat insulating material and to cause a fire, and the leaked material is completely removed, so that the appearance is not uncomfortable.

[Brief description of the drawings]

FIG. 1 is an overall vertical sectional view showing one embodiment of the present invention.

FIG. 2 is a partially enlarged view of FIG.

FIG. 3 is a sectional view taken along line AA in FIG. 1;

FIG. 4 is a partial plan view of the same.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Gear pump 2 ... Casing 12 ... Rotating shaft (drive shaft) 19 ... Shaft hole 22 ... Non-contact seal 23 ... Cooling means 24 ... Cutter 24a ... Tip blade surface 25 ... Collar 25a ... Outer end surface

Claims (1)

[Claims] A non-contact seal and cooling means are provided near a casing penetrating end of a rotating shaft extending from the inside to the outside through the casing, and a fluid to be leaked through an inner and outer circumferential gap between the rotating shaft and the casing is provided. A gear pump which is limited by a non-contact seal and is solidified and sealed by a cooling means, wherein a collar which constitutes a part of the inner and outer circumferential clearance is integrally rotatably and axially movable between the outer circumference of the shaft and a casing. A cutter is provided that elastically urges the collar outward in the axial direction, and that has a base end fixed to the casing and a tip blade surface disposed at a position in sliding contact with the outer end surface of the collar. A gear pump configured to guide the solidified fluid leaked from the inner and outer peripheral gaps to the sliding surfaces of the cutter and the collar to break the fluid.