JPH08159047A - Shaft sealing device of gear pump - Google Patents

Abstract

PURPOSE: To easily replace a shaft sealing device according to the viscosity, quantity and so on of a handled high viscous fluid or the operating progress. CONSTITUTION: A shaft sealing device of a gear pump is so constructed that a stuffing box 10 having an inside diameter larger than the diameter of a driving shaft 6 is removably inserted in a through hole 3H bored in a side cover 3. A shaft sealing device of a gear pump is characterized in that the space between the stuffing box 10 and the driving shaft 6 is set in such a manner that a sleeve is inserted and removed between the stuffing box 10 and the driving shaft 6, and sealing mechanisms 12, 13 are fitted between the stuffing box 10 and the driving shaft 6, or between the stuffing box 10 and the sleeve.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a gear pump shaft sealing device for transferring a liquid which is easily deteriorated, such as a synthetic fiber or a polymer for producing a film.

[0002]

2. Description of the Related Art Conventionally, in this type of gear pump, a drive side gear and a driven side gear meshing with the drive side gear are housed in a pump chamber formed by joining a casing and covers on both sides, and the drive side gear is rotated by a rotation of a drive shaft. By being rotationally driven, the liquid introduced from the suction port of the casing is transferred to the discharge port. At the same time, in the gear pump,
The drive shaft is configured to pass through the side cover and be connected to an external rotary drive source so that the rotation thereof is input, and the leakage of liquid transferred to the portion where the drive shaft passes through the side cover is prevented. A shaft seal device is installed for this purpose.

By the way, in a shaft seal device of this kind of gear pump, a stuffing box integral with a side cover is projected from the side cover, and a sealing mechanism by a gland packing is provided inside the stuffing box with a drive shaft and a stuffing box. It is inserted and configured between and. In addition, a mechanical seal type or a labyrinth type is adopted as a sealing mechanism, and a method in which these sealing mechanisms are installed in a stuffing box which can be detachably attached to a side cover has also been proposed.

[0004]

However, in this conventional shaft seal device, the shaft seal mechanism is changed from a gland packing type seal mechanism to a mechanical seal type seal mechanism or a labyrinth type seal mechanism depending on the type of the transfer liquid. It will be necessary to change to a sealing mechanism. However, in reality, if you do not install it on the transfer line in the plant and operate it,
In many cases, it is not known which sealing mechanism is most suitable. In some cases, it may be necessary to change to a shaft sealing device having a different sealing mechanism while the shaft sealing device having a desired sealing mechanism is installed and operating. In such a case, for example, since the mechanical seal type and the gland packing type have different surface treatments (surface hardness) of the drive shaft, it is necessary to replace the drive shaft itself in order to replace the shaft sealing device. When the drive shaft is replaced, the gear pump must be disassembled. Under the above circumstances, there is a problem that the shaft sealing device of various sealing mechanisms is prepared so as to cope with various cases, and the number of parts increases. The present invention is to provide a shaft seal device for a gear pump that solves the above problem.

[0005]

In the shaft sealing device for a gear pump provided by the present invention, a stuffing box having an inner diameter larger than that of a drive shaft can be attached to and detached from a through hole formed in a side cover. The stuffing box and the drive shaft, a sleeve is set between the stuffing box and the drive shaft so that the sleeve can be inserted into and removed from the stuffing box and the drive shaft, or between the stuffing box and the drive shaft. A sealing mechanism is fitted between the fing box and the sleeve.

[0006]

With this structure, when replacing a shaft sealing device having a different sealing mechanism, it is possible to replace it by only replacing the stuffing box and the sealing mechanism. When the sealing mechanism is a labyrinth type, a sleeve can be fitted and a seal can be made between the sleeve and the stuffing box, and the surface hardness of the drive shaft does not matter.

[0007]

The present invention will be described below with reference to the illustrated embodiments. FIG. 1 is a vertical cross-sectional view of a gear pump embodying the present invention, in which a drive side gear 8 and a driven side gear 9 meshing with the drive side gear 8 are formed by joining a casing 1, front covers 2 and rear covers 3 on both sides. It is stored in. Four
Is a screw for fixing the cover 3 to the casing 1. The drive shaft gear 8 is rotationally driven by the rotation of the drive shaft 6 to transfer the liquid introduced from the suction port of the casing (not shown) to the discharge port. 5 is a drive shaft 6 and a driven shaft 7
Is a bearing that rotatably supports in the pump chamber. The right end of the drive shaft 6 penetrates the side cover 3 and is connected to a rotary drive source (not shown) to introduce a rotational force. A through hole 3H having a relatively large inner diameter is formed in the right side cover 3 at a penetrating portion of the right side cover 3 of the drive shaft 6. Moreover, the protruding portion of the drive shaft 6 from the right side cover 3 is formed to have a small diameter. Moreover, it is formed without any special surface treatment. A shaft sealing device is installed on the protruding portion of the drive shaft 6, and the present invention is characterized by this shaft sealing device.

According to the present invention, the stuffing box forming the main part of the shaft sealing device has the small diameter portion 1 at the left end thereof.
0N is configured to be removably inserted into a through hole 3H formed in the right side cover 3. Further, a flange 10F is formed on the stuffing box 10 close to the small diameter portion 10N, and the flange 10F is fixed to the outer surface of the right side cover 3 by a fixing screw 11. That is, a screw hole for screwing the fixing screw 11 is formed on the outer surface of the side cover 3.

The shaft seal device shown in FIG. 1 has a standard single mechanical seal type seal mechanism installed therein. A fixed seal material 12 and a rotary seal material 13 are mechanically provided between the stuffing box 10 and the drive shaft 6. It is joined. The rotary seal material 13 is attached to the spring holding material 15 side fixed to the drive shaft 6 and is elastically contacted with the fixed seal material 12 by the elastic force of the spring 14. In the case of the shaft sealing device having the mechanical seal type seal mechanism internally provided, since the mechanical seal portion performs the sealing function, the surface of the drive shaft 6 does not need to be precision processed. Therefore, the inner diameter of the stuffing box 10 only needs to be large enough to provide a space for internally installing the mechanical seal type sealing mechanism.
In other words, the annular space between the inner peripheral surface of the stuffing box 10 and the outer surface of the drive shaft 6 only needs to have a size sufficient to internally install the mechanical seal type sealing mechanism.
Stuffing box 1 by internal sealing mechanism
An inner diameter of 0 is set. In the illustrated example, the liquid that has leaked to the mechanical seal type sealing mechanism is provided with a return flow passage S in the stuffing box 10, and is returned to the pump side through this flow passage S. ing.

The shaft sealing device shown in FIG. 2 has a labyrinth seal type sealing mechanism internally provided therein.
A sleeve L1 on which a labyrinth 16 is installed is fitted between the drive shaft 6 and the drive shaft 6. The sleeve L1 is fixed to the drive shaft 6 by screwing a fixing screw through a fixing hole provided at the right end of the sleeve L1. In the case of this sealing mechanism, sealing is performed between the labyrinth 16 and the inner peripheral surface of the stuffing box 10, so surface treatment of the inner peripheral surface of the stuffing box 10 is required, but the surface of the drive shaft 6 There is no need to change the process.

The shaft sealing device of FIG. 3 has a packing type sealing mechanism internally provided, and a sleeve L2 having a gland packing 17 inserted therein is fitted between the stuffing box 10P and the drive shaft 6. ing. The sleeve L2 is fixed to the drive shaft 6 by screwing a fixing screw through a fixing hole provided at the right end of the sleeve L2. Reference numeral 18 is a packing retainer that inserts and presses the gland packing 17 between the stuffing box 10P and the sleeve L2. The bolt 19 and the nut 20 planted on the right end surface cause the packing 1 to perform a predetermined action.
Hold down 7. In the case of this sealing mechanism, since the sealing is performed between the gland packing 17 and the sleeve L2, the surface treatment of the inner peripheral surface of the stuffing box 10P is required, but the surface treatment of the drive shaft 6 needs to be changed. There is no.

Further, the shaft sealing device of FIG. 4 has a double mechanical seal type sealing mechanism internally provided, and the stuffing box 10B has a large diameter unlike that of FIG.
Of course, the fixing screw 11 also has a long axis. In the hole 27H for penetrating the drive shaft 6 of the cover 27, which is fixed to the right of the stuffing box 10B via the screw 28, the fixed sealing material 2
1, 22 are fixed, and rotary seal members 23, 24 are attached to the other drive shaft 6 side, and both seal members are mechanically joined to each. The rotary seal members 23 and 24 are attached to the spring holding member 25 side fixed to the drive shaft 6 and are elastically contacted with the fixed seal members 21 and 22 by the elastic force of the spring 26. Reference numeral 29 is a flow path for returning the liquid that has leaked to the mechanical seal type seal mechanism to the pump side. In the case of the shaft sealing device in which the double mechanical seal type sealing mechanism is installed, the mechanical seal portion performs the sealing function, so that the surface of the drive shaft 6 does not need to be highly cured. Therefore, the inner diameter of the stuffing box 10 should be large enough to provide a space for the mechanical seal type seal mechanism. In other words, the annular space between the inner peripheral surface of the stuffing box 10 and the outer surface of the drive shaft 6 only needs to have a size sufficient to internally install the mechanical seal type sealing mechanism. The inner diameter of the stuffing box 10 is set by the sealing mechanism provided inside.

However, if the stuffing boxes 10 each having a sealing mechanism such as a single mechanical seal type, a double mechanical seal type, a packing type, and a labyrinth seal type are prepared, the stuffing box 10 Depending on the type, or if the optimum sealing mechanism installed in the transfer line is found, or if it is necessary to change to a shaft sealing device of another type in the middle of the process, various sealing mechanisms will be used each time. It is possible to select a shaft sealing device having an appropriate sealing mechanism from among the shaft sealing devices described above, and to install it immediately.

Although the present invention has been described above in detail, there can be mentioned modified examples including the features of the invention. For example, in the embodiment of FIGS. 1 and 4, the flow path for circulating the leaked liquid is provided, but this return flow path is not always necessary. However, in the case of the mechanical seal type, liquid is normally leaked to this sealing mechanism position, so that it is usually necessary.
When it is necessary to cool the shaft sealing device, a cooling jacket or the like can be installed in the stuffing box. The present invention includes all of these.

[0015]

According to the shaft sealing device for a gear pump of the present invention, a stuffing box having an inner diameter larger than that of a drive shaft is detachably inserted into a through hole formed in a side cover, and The distance between the stuffing box and the drive shaft is set so that the sleeve can be inserted and removed between the stuffing box and the drive shaft, so various sealing mechanisms can be installed between the stuffing box and the drive shaft. Even if the specifications vary depending on the viscosity and amount of the high-viscosity liquid to be handled, it is possible to realize a shaft seal device having an appropriate seal mechanism corresponding to the specification and improve the performance of the gear pump. The surface of the drive shaft does not need to be specially treated, and the drive shaft does not need to be replaced when replacing the shaft sealing device, which facilitates the replacement work. further,
There is an advantage that the number of parts of the shaft sealing device to be prepared can be small.

The shaft sealing device for the gear pump of the present invention is summarized as follows.

1) The drive-side gear and the driven-side gear meshing with the drive-side gear are housed in a pump chamber formed by joining the casing and the covers on both sides, and the drive-side gear is rotatably driven by the rotation of the drive shaft. A gear pump is configured to transfer the liquid introduced from the suction port to the discharge port, and the drive shaft is installed in a portion penetrating the side cover, and the liquid leaks from between the drive shaft and the side cover. In the shaft sealing device for preventing the above, a stuffing box having an inner diameter larger than that of the drive shaft is removably inserted into a through hole formed in the side cover. The distance between the stuffing box and the drive shaft is set so that the sleeve can be inserted and removed between the stuffing box and the drive shaft, and the gap between the stuffing box and the drive shaft or the stuffing Shaft seal of the gear pump seal mechanism is characterized in that it is inlaid between the box and the sleeve.

2) The drive-side gear and the driven-side gear meshing with the drive-side gear are housed in a pump chamber formed by joining the casing and the covers on both sides, and the drive-side gear is rotatably driven by the rotation of the drive shaft. A gear pump is configured to transfer the liquid introduced from the suction port to the discharge port, and the drive shaft is installed in a portion penetrating the side cover, and the liquid leaks from between the drive shaft and the side cover. In the shaft sealing device for preventing the above, a stuffing box having an inner diameter larger than that of the drive shaft is removably inserted into a through hole formed in the side cover. A gap between the stuffing box and the drive shaft is set such that a sleeve can be inserted and removed between the stuffing box and the drive shaft, and a mechanical seal machine is provided between the stuffing box and the drive shaft. There shaft seal of the gear pump, characterized in that it is inlaid.

3) The drive-side gear and the driven-side gear meshing with the drive-side gear are housed in a pump chamber formed by joining the casing and the covers on both sides, and the drive-side gear is rotatably driven by the rotation of the drive shaft. A gear pump is configured to transfer the liquid introduced from the suction port to the discharge port, and the drive shaft is installed in a portion penetrating the side cover, and the liquid leaks from between the drive shaft and the side cover. In the shaft sealing device for preventing the above, a stuffing box having an inner diameter larger than that of the drive shaft is removably inserted into a through hole formed in the side cover. A gap between the stuffing box and the drive shaft is set so that the sleeve can be inserted and removed between the stuffing box and the drive shaft, and a labyrinth seal is provided between the stuffing box and the sleeve. Shaft seal of the gear pump, characterized in that structure is inlaid.

4) The drive-side gear and the driven-side gear meshing with the drive-side gear are housed in a pump chamber formed by joining the casing and the covers on both sides, and the drive-side gear is rotatably driven by the rotation of the drive shaft. A gear pump is configured to transfer the liquid introduced from the suction port to the discharge port, and the drive shaft is installed in a portion penetrating the side cover, and the liquid leaks from between the drive shaft and the side cover. In the shaft sealing device for preventing the above, a stuffing box having an inner diameter larger than that of the drive shaft is removably inserted into a through hole formed in the side cover. A gap between the stuffing box and the drive shaft is set such that a sleeve can be inserted and removed between the stuffing box and the drive shaft, and a packing seal machine is provided between the stuffing box and the sleeve. There shaft seal of the gear pump, characterized in that it is inlaid.

5) The drive-side gear and the driven-side gear that meshes with the drive-side gear are housed in a pump chamber formed by joining the casing and the covers on both sides, and the drive-side gear is rotatably driven by the rotation of the drive shaft. A gear pump is configured to transfer the liquid introduced from the suction port to the discharge port, and the drive shaft is installed in a portion penetrating the side cover, and the liquid leaks from between the drive shaft and the side cover. And a stuffing box having an inner diameter larger than that of the drive shaft with respect to a through hole formed in the side cover, and a flange portion of the stuffing box is attached to or detached from the side cover. A means for fixing the stuffing box and the drive shaft is provided so that the sleeve can be inserted and removed between the stuffing box and the drive shaft. Shaft seal of the gear pump seal mechanism is characterized in that it is inlaid between or between stuffing box and the sleeve of the stuffing box and the drive shaft together with.

[0022]

According to the shaft sealing device for a gear pump of the present invention, a stuffing box having an inner diameter larger than that of a drive shaft is detachably inserted into a through hole formed in a side cover, and The distance between the stuffing box and the drive shaft is set so that the sleeve can be inserted and removed between the stuffing box and the drive shaft, so various sealing mechanisms can be installed between the stuffing box and the drive shaft. It is possible to realize a shaft seal device with a suitable seal mechanism even if the specifications vary depending on the viscosity and amount of the high-viscosity liquid to be handled, and it can be used even for liquids with no proven record, and maintenance is easy and gear pump The performance of can be improved. The drive shaft does not need to be specially surface-treated, and the drive shaft does not need to be replaced even when replacing the shaft sealing device, and the replacement work is easy, and the shaft parts of the shaft sealing device to be prepared can be shared, There is an advantage that the number of parts is small and the cost can be reduced.

[Brief description of drawings]

FIG. 1 is a vertical sectional view showing a shaft sealing device for a gear pump according to the present invention.

FIG. 2 is a vertical sectional view showing the configuration of another shaft sealing device according to the present invention.

FIG. 3 is a vertical sectional view showing the configuration of another shaft sealing device according to the present invention.

FIG. 4 is a vertical sectional view showing the configuration of another shaft sealing device according to the present invention.

[Explanation of symbols]

 1 ... Casing 2, 3 ... Cover 4 ... Fixing bolt 6 ... Drive shaft 7 ... Driven shaft 8 ... Drive side gear 9 ... Driven side gear 3H ... Through hole 10, 10P, 10B ... Stuffing box 10F ... Stuffing box flange 11 ... Fixing screw 12, 21, 22 ... Fixed sealing material 13, 23, 24 ... Rotating sealing material 16 ... Labyrinth 1 17 ... Gland packing 18 ... Packing holding material L1, L2 ... Sleeve

Claims (1)

[Claims] 1. A drive-side gear and a driven-side gear meshing with the drive-side gear are housed in a pump chamber formed by joining a casing and covers on both sides, and the drive-side gear is rotatably driven by rotation of a drive shaft. A gear pump is configured to transfer the liquid introduced from the suction port to the discharge port,
A shaft sealing device which is installed at a portion where the drive shaft penetrates the side cover and prevents the liquid from leaking between the drive shaft and the side cover. A stuffing box having an inner diameter larger than that of the drive shaft is removably inserted into the hole, and the distance between the stuffing box and the drive shaft is determined by a sleeve between the stuffing box and the drive shaft. A shaft seal device for a gear pump, which is set to be insertable and removable and has a seal mechanism fitted between the stuffing box and a drive shaft or between the stuffing box and a sleeve.