JP2827935B2 - Gear pump shaft sealing device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

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

[0002]

2. Description of the Related Art Conventionally, a gear pump of this type has a drive side gear and a driven side gear meshing with the drive side gear housed in a pump chamber formed by joining a casing and covers on both sides, and the drive side gear is driven by rotation of a drive shaft. The liquid introduced from the suction port of the casing is transferred to the discharge port by being driven to rotate. At the same time, in the gear pump,
The drive shaft penetrates the side cover and is connected to an external rotary drive source so that its rotation is input, and the portion where the drive shaft penetrates the side cover prevents leakage of the transferred liquid. A shaft sealing device is provided for the shaft sealing.

In general, a shaft sealing device in this type of gear pump has an integral stuffing box protruding from a side cover, and a sealing mechanism using gland packing is provided inside the stuffing box with a drive shaft and a stuffing box. And is configured to be inserted between them. Further, a system has been proposed in which a mechanical seal type or a labyrinth type is adopted as a seal mechanism, and these seal mechanisms are installed in a stuffing box that is detachable from a side cover.

[0004]

However, in this conventional shaft seal device, the shaft seal mechanism is changed from, for example, a gland packing type seal mechanism to a mechanical seal type seal mechanism depending on the type of the transfer liquid, or a labyrinth type. It is necessary to change to a sealing mechanism. However, if you do not actually install and operate it on the transfer line in the plant,
In many cases, it is difficult to know which seal mechanism is optimal. In some cases, even if a shaft seal device of a desired seal mechanism is installed and operated, it may be necessary to change to a shaft seal device of another type of seal mechanism on the way. In such a case, for example, since the surface treatment (surface hardness) of the drive shaft is different between the mechanical seal type and the gland packing type, it is necessary to replace the drive shaft itself when replacing the shaft sealing device. When the drive shaft is replaced, the gear pump must be disassembled. Under the circumstances described above, shaft seal devices of various seal mechanisms are prepared to deal with various cases, and there is a problem that the number of parts increases. An object of the present invention is to provide a gear pump shaft sealing device that solves the above problem.

[0005]

The shaft sealing device of the gear pump provided by the present invention has a stuffing box having an inner diameter larger than that of the drive shaft with respect to a through hole formed in a side cover. And the distance between the stuffing box and the drive shaft is set to a value that allows the sleeve to be inserted and removed as necessary, and the stuffing box and the drive shaft can be inserted without inserting the sleeve. A mode in which a mechanical seal-type seal mechanism is provided between the inside, a mode in which a labyrinth-type seal mechanism is configured between the stuffing box and the sleeve with the sleeve inserted, and a stuffing box with the sleeve inserted. And a mode in which a gland packing type seal mechanism is configured between the sleeve and the sleeve.

[0006]

With such a configuration, when replacing the shaft sealing device with a different sealing mechanism, the replacement can be performed only by replacing only the stuffing box and the sealing mechanism. When the sealing mechanism is of a labyrinth type, a sleeve can be fitted, and sealing can be performed between the sleeve and the stuffing box, and the surface hardness of the drive shaft does not matter.

[0007]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to the illustrated embodiments. FIG. 1 is a longitudinal sectional view of a gear pump implemented by the present invention. A pump chamber in which a driving gear 8 and a driven gear 9 meshing with the driving gear 8 are formed by joining a casing 1, a front cover 2 on both sides, and a rear cover 3. It is stored in. 4
Is a screw for fixing the cover 3 to the casing 1. The drive shaft gear 8 is rotatably driven by the rotation of the drive shaft 6 to transfer liquid introduced from a suction port (not shown) of a casing to a discharge port. 5 is a drive shaft 6 and a driven shaft 7
Are rotatably supported 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 cover 3 at a penetrating portion of the right cover 3 of the drive shaft 6. 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. The shaft sealing device is installed at 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 constituting the main part of the shaft sealing device has a small diameter portion 1 at the left end thereof.
0N is removably inserted into a through hole 3H formed in the right cover 3. Further, a flange 10F is formed in the stuffing box 10 near the small-diameter portion 10N, and the flange 10F is attached to the outer surface of the right cover 3 and fixed by a fixing screw 11. That is, a screw hole for screwing the fixing screw 11 is formed in the outer surface of the side cover 3.

The shaft sealing device shown in FIG. 1 is provided with a standard single mechanical seal type sealing mechanism therein. A fixed sealing material 12 and a rotary sealing material 13 are mechanically provided between a stuffing box 10 and a driving shaft 6. Are joined. The rotary seal 13 is attached to the spring holding member 15 fixed to the drive shaft 6 and is elastically contacted with the fixed seal 12 by the elastic force of the spring 14. In the case of a shaft sealing device in which the mechanical seal type sealing mechanism is provided, the sealing function is performed at the mechanical seal portion, so that the surface of the drive shaft 6 does not need to be precisely machined. Therefore, the inside diameter of the stuffing box 10 only needs to be large enough to provide a space in which the mechanical seal type sealing mechanism is provided.
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 be large enough to accommodate 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 path S in the stuffing box 10 and returns to the pump side through this flow path S. ing.

The shaft sealing device shown in FIG. 2 has a labyrinth seal-type sealing mechanism provided therein.
A sleeve L <b> 1 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 thereof. In the case of this sealing mechanism, since the sealing is performed between the labyrinth 16 and the inner peripheral surface of the stuffing box 10, the inner peripheral surface of the stuffing box 10 needs to be surface-treated. There is no need to change the processing.

The shaft sealing device shown in FIG. 3 has a packing type sealing mechanism provided therein. A sleeve L2 in which a gland packing 17 is inserted 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 thereof. Reference numeral 18 denotes a packing press for inserting and pressing the gland packing 17 between the stuffing box 10P and the sleeve L2, and the packing 1 is provided with a predetermined action by a bolt 19 and a nut 20 planted on the right end face.
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 inner peripheral surface of the stuffing box 10P needs to be surface-treated, but the surface treatment of the drive shaft 6 needs to be changed. There is no.

Further, the shaft sealing device shown in FIG. 4 has a double mechanical seal type sealing mechanism therein, and the stuffing box 10B is set to have a large diameter unlike FIG.
Of course, the fixing screw 11 is also a long axis. A fixed sealing material 2 is provided in a hole 27H for penetrating the drive shaft 6 of the cover 27 fixed to the right side of the stuffing box 10B via a screw 28.
Rotational seals 23 and 24 are attached to the drive shaft 6 side, and both seals are mechanically joined to each other. The rotary seal members 23 and 24 are attached to the side of the spring holding member 25 fixed to the drive shaft 6 and elastically contact the fixed seal members 21 and 22 by the elastic force of the spring 26. Reference numeral 29 denotes a flow path for returning the liquid leaking to the mechanical seal type seal mechanism to the pump side. In the case of a shaft sealing device in which the double mechanical seal type sealing mechanism is provided, since the sealing function is performed at the mechanical seal portion, the surface of the drive shaft 6 does not need to be subjected to advanced hardening treatment. Therefore, the inside diameter of the stuffing box 10 only needs to be large enough to provide a space in which the mechanical seal type sealing mechanism is provided. 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 be large enough to accommodate the mechanical seal type sealing mechanism. The inner diameter of the stuffing box 10 is set by a seal mechanism provided inside.

When the stuffing boxes 10 each having a single mechanical seal type, a double mechanical seal type, a packing type, and a labyrinth seal type as a seal mechanism are prepared, the transfer liquid is transferred. Depending on the type or when the optimum sealing mechanism is installed and operated on the transfer line and the optimum sealing mechanism is found, or when it is necessary to change to a different type of sealing mechanism on the way, various types of sealing mechanisms are used each time. The shaft sealing device having an appropriate sealing mechanism can be selected from among the shaft sealing devices, and can be installed immediately.

Although the present invention has been described in detail above, there can be mentioned modifications incorporating the features of the present invention. For example, in the embodiments shown in FIGS. 1 and 4, a 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, the liquid leaks to the position of the seal mechanism, so that it is usually necessary.
If it is necessary to cool the shaft sealing device, a cooling jacket or the like may be provided 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. The spacing 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 seal mechanisms can be installed between the stuffing box and the drive shaft. Even if the specifications differ depending on the viscosity and amount of the high-viscosity liquid to be handled, a shaft sealing device with an appropriate sealing mechanism can be realized correspondingly, and the performance of the gear pump can be improved. There is no need for special surface treatment of the drive shaft, and there is no need to replace the drive shaft when exchanging the shaft sealing device, and the replacement operation is easy. further,
There is an advantage that the number of parts of the shaft sealing device to be prepared can be reduced.

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

1) A driving gear and a driven gear meshing with the driving gear are housed in a pump chamber formed by joining the casing and the covers on both sides, and the driving gear is rotated by the rotation of the driving shaft, thereby rotating the casing. A gear pump is configured to transfer the liquid introduced from the suction port to the discharge port, and the drive shaft is installed at a portion penetrating the side cover, and the liquid leaks from between the drive shaft and the side cover. A shaft sealing device that prevents a stuffing box having an inner diameter larger than the drive shaft into a through hole formed in the side cover and is detachably inserted. The distance between the drive shaft and the stuffing box is set 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 the box and the sleeve.

2) The driving gear and the driven gear meshing with the driving gear are housed in a pump chamber formed by joining the casing and the covers on both sides, and the driving gear is rotated by the rotation of the driving shaft to rotate the casing. A gear pump is configured to transfer the liquid introduced from the suction port to the discharge port, and the drive shaft is installed at a portion penetrating the side cover, and the liquid leaks from between the drive shaft and the side cover. A shaft sealing device that prevents a stuffing box having an inner diameter larger than the drive shaft into a through hole formed in the side cover and is detachably inserted. The distance between the drive shaft and the stuffing box is set so that the sleeve can be inserted and removed between the stuffing box and the drive shaft. There shaft seal of the gear pump, characterized in that it is inlaid.

3) The driving gear and the driven gear meshing with the driving gear are housed in a pump chamber formed by joining the casing and the covers on both sides, and the driving gear is driven to rotate by the rotation of the driving shaft, so that the casing of the casing is rotated. A gear pump is configured to transfer the liquid introduced from the suction port to the discharge port, and the drive shaft is installed at a portion penetrating the side cover, and the liquid leaks from between the drive shaft and the side cover. A shaft sealing device that prevents a stuffing box having an inner diameter larger than the drive shaft into a through hole formed in the side cover and is detachably inserted. The distance between the drive shaft and the stuffing box is set so that the sleeve can be inserted and removed between the stuffing box and the drive shaft, and the 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 driving gear and the driven gear meshing with the driving gear are housed in a pump chamber formed by joining the casing and the covers on both sides, and the driving gear is rotated by the rotation of the driving shaft to rotate the casing. A gear pump is configured to transfer the liquid introduced from the suction port to the discharge port, and the drive shaft is installed at a portion penetrating the side cover, and the liquid leaks from between the drive shaft and the side cover. A shaft sealing device that prevents a stuffing box having an inner diameter larger than the drive shaft into a through hole formed in the side cover and is detachably inserted. The distance between the drive shaft and the stuffing box is set so that the sleeve can be inserted and removed between the stuffing box and the drive shaft. There shaft seal of the gear pump, characterized in that it is inlaid.

5) The driving gear and the driven gear meshing with the driving gear are housed in a pump chamber formed by joining the casing and the covers on both sides, and the driving gear is rotated by the rotation of the driving shaft, so that the casing of the casing is rotated. A gear pump is configured to transfer the liquid introduced from the suction port to the discharge port, and the drive shaft is installed at a portion penetrating the side cover, and the liquid leaks from between the drive shaft and the side cover. A stuffing box having an inner diameter larger than the drive shaft for a through hole formed in the side cover, and a flange portion of the stuffing box attached to and detached from the side cover. Means for surface joining and fixing as much as possible, the distance 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. 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. The spacing 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 seal mechanisms can be installed between the stuffing box and the drive shaft. Even if the specifications differ depending on the viscosity and volume of the high-viscosity liquid to be handled, a shaft sealing device with an appropriate sealing mechanism can be realized correspondingly, and it can be used even for liquids with no proven track record, easy maintenance, and gear pump Performance can be improved. There is no need to specially treat the surface of the drive shaft, and it is not necessary to replace the drive shaft 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 cost can be reduced.

[Brief description of the drawings]

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

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

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

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

[Explanation of symbols]

 DESCRIPTION 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 DESCRIPTION OF SYMBOLS 11 ... Fixing screw 12, 21, 22 ... Fixed sealing material 13, 23, 24 ... Rotary sealing material 16 ... Labyrinth 1 17 ... Gland packing 18 ... Packing holding material L1, L2 ... Sleeve

Claims (1)

(57) [Claims] A drive-side gear and a driven-side gear engaged 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 rotationally driven by rotation of a drive shaft to form a casing. A gear pump for transferring the liquid introduced from the suction port to the discharge port is configured,
And a shaft sealing device provided at a portion where the drive shaft penetrates the side cover to prevent the liquid from leaking from between the drive shaft and the side cover. A stuffing box having an inner diameter larger than the drive shaft can be removably inserted into the hole, and the space between the stuffing box and the drive shaft can be inserted and removed as necessary. Value, the mechanical seal type seal mechanism is installed between the stuffing box and the drive shaft without inserting the sleeve, and the labyrinth type between the stuffing box and the sleeve with the sleeve inserted. An embodiment constituting a sealing mechanism;
A shaft sealing device for a gear pump, wherein a gland packing type sealing mechanism can be selected between the stuffing box and the sleeve with the sleeve inserted.