JP2022038898A - Pump device - Google Patents

Abstract

To provide a pump device which has a structure for discharging air gathering near a rotary shaft to the suction side of an impeller and prevents dry operation of a shaft sealing part.SOLUTION: A pump device includes: a rotary shaft 1 to which an impeller 3 is fixed; and a shaft sealing chamber 251 formed by a pump casing 5. The rotary shaft 1 is formed with an air discharge hole 260 which allows the shaft sealing chamber 251 located at a position higher than the impeller 3 and the suction side of the impeller 3 to communicate with each other.SELECTED DRAWING: Figure 1

Description

The present invention relates to a pump device.

A rotating shaft that pressurizes the handling liquid (conveying liquid), an impeller fixed to the rotating shaft, a pump casing that accommodates the impeller, a motor that rotates the rotating shaft, and is arranged between the pump casing and the motor. A pump device including an intermediate bracket is known (see Patent Document 2).

Japanese Unexamined Patent Publication No. 52-9103 Jitsukaisho 60-178391A Gazette

The pump device includes a shaft sealing device that seals the conveyed liquid leaking to the outside through the opening through which the rotating shaft penetrates. When the impeller rotates while the shaft sealing device is not filled with the transport liquid, a part of the handling liquid flows into the shaft sealing chamber in which the shaft sealing device is housed. The handling liquid flowing into the shaft sealing chamber cools and lubricates the shaft sealing device.

However, when the pump is priming, air may be present in the shaft sealing chamber in addition to the handling liquid. When the pump is operated in the presence of air, the density of air is smaller than that of water, so the centrifugal force received by the rotation of the impeller is small, the water is pushed to the outside of the casing, and the air collects near the axis of rotation. If the air collected in the vicinity of the rotating shaft continues to come into contact with the shaft sealing device, the shaft sealing device will not be properly cooled and lubricated, and the shaft sealing device may fail.

In the pump disclosed in Patent Document 2, the air collects in the vicinity of the rotating shaft and is returned to the inside of the impeller from the mechanical seal side through the hole in the main plate. However, since the liquid also returns to the inside of the impeller through the hole in the main plate, the flow in the impeller may be disturbed and the pump efficiency may decrease. Further, if the holes in the main plate are clogged with foreign matter such as slurry, the pump efficiency may change during operation.

Therefore, an object of the present invention is to provide a pump device having a structure for discharging air collected in the vicinity of the rotating shaft to the suction side of the impeller and preventing dry operation of the shaft sealing portion.

In one embodiment, a pump including an impeller for pressurizing a transport liquid, a pump casing for accommodating the impeller, a rotating shaft to which the impeller is fixed, and the pump through an opening through which the rotating shaft penetrates. Provided is a pump device including a shaft sealing device that seals the conveyed liquid leaking to the outside of the casing, and a shaft sealing chamber formed by the pump casing. An air discharge hole for communicating the shaft sealing chamber arranged at a position higher than the impeller and the suction side of the impeller is formed on the rotating shaft.

In one aspect, the air discharge hole is connected to at least one first hole portion extending from the shaft sealing chamber in the axial radial direction of the rotating shaft, and one end thereof is connected to any one of the first hole portions. The other end has at least one second hole extending to the suction side of the impeller.
In one aspect, at least a part of the second hole portion passes through the axis of the rotating shaft, and at least a part of the first hole portion extends in the axial direction of the rotating shaft.
In one aspect, the first hole extends perpendicularly or diagonally to the second hole.

In one aspect, one end of a rotating shaft is arranged on the suction side of the impeller with which the air exhaust hole communicates, and the air exhaust hole extends to one end of the rotating shaft.
In one aspect, the pump is a vertical pump in which the rotating shaft extends in the vertical direction, the shaft sealing chamber communicates with the shaft sealing device, and the air discharge hole is an upper portion of the shaft sealing chamber and the shaft sealing chamber. / Or connected to the bottom.
In one aspect, the pump is a vertical pump in which the rotating shaft extends in the vertical direction, the shaft sealing chamber accommodates the shaft sealing device, and the air discharge hole slides the shaft sealing device. It is formed below the portion.

In one aspect, the shaft sealing device comprises a fixed ring fixed to the pump casing, a rotating ring that rotates with the rotating shaft, and an urging member connected to the rotating ring, and the air is discharged. A hole is opened below the urging member and / or at a position between the rotating ring and the urging member.
In one aspect, the air exhaust hole comprises a plurality of first hole portions arranged along the radius of the rotating shaft, extending from the shaft sealing chamber in the axial direction of the rotating shaft.
In one aspect, the air discharge hole includes a plurality of first hole portions arranged above and below the rotation shaft, extending from the shaft sealing chamber in the axial direction of the rotation shaft.

In one aspect, a shaft sleeve mounted on the outer peripheral surface of the rotating shaft is further provided, and the air exhaust hole has a sleeve hole provided in the shaft sleeve.
In one aspect, the sleeve hole is a plurality of sleeve holes at different height levels branching from the air exhaust hole formed in the rotating shaft.
In one aspect, a motor for driving the rotary shaft arranged above the pump is further provided, and the shaft sealing device seals the transport liquid leaking from the pump to the motor side.

The rotating shaft has an air discharge hole for communicating the shaft sealing chamber arranged at a position higher than the impeller and the suction side of the impeller. Therefore, the air existing in the shaft sealing chamber is discharged to the suction side of the impeller through the air discharge hole due to the pressure difference from the suction side of the impeller. As a result, the pump device can prevent the shaft sealing device from failing due to the air in the shaft sealing chamber coming into contact with the shaft sealing device.

It is a figure which shows one Embodiment of a pump device. It is a figure which shows the further modification example of an air discharge hole. It is a figure which shows the main part of the pump device of one Embodiment. It is a figure which shows the other embodiment of the air discharge hole. It is a figure which shows the detail of the air discharge hole formed in the rotating shaft. It is a figure which shows the deformation example of an air discharge hole. It is a figure which shows the other modification of the air discharge hole. It is a figure which shows the further modification example of an air discharge hole. It is a figure which shows the further modification example of an air discharge hole. It is a horizontal sectional view of FIG. It is a figure which shows the shaft sleeve attached to the rotating shaft.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
(First Embodiment)
FIG. 1 is a diagram showing an embodiment of a pump device. As shown in FIG. 1, the pump device 100 is located between a rotary shaft 1 for pressurizing a handling liquid (conveyed liquid), a pump 2, a motor 7 for driving the rotary shaft 1, and a pump casing 5 and a motor 7. It includes an arranged intermediate bracket 50 and a shaft sealing device 30 for preventing leakage of a high-pressure liquid pressurized by the impeller 3.

The pump 2 includes an impeller 3 fixed to a rotary shaft 1 and a pump casing 5 for accommodating the impeller 3. The rotary shaft 1 of the present embodiment has a large diameter portion 1a and a small diameter portion 1b located on the tip side of the large diameter portion 1a. The small diameter portion 1b of the rotating shaft 1 engages with the impeller 3 via the key. The impeller 3 is fixed to the rotary shaft 1 by the bolt 42 in a state where the small diameter portion 1b of the rotary shaft 1 is inserted into the impeller 3. The impeller 3 has a main plate 3a located on the motor 20 side (mechanical seal 38 side described later), a side plate 3b, and a plurality of blades 3c provided between the main plate 3a and the side plate 3b.

The pump casing 5 includes a suction port 12 and a discharge port 13. When the motor 7 is driven, the rotation of the motor 7 is transmitted to the rotating shaft 1, and the rotating shaft 1 and the impeller 3 rotate. The liquid that has flowed into the pump casing 5 through the suction port 12 is boosted as the impeller 3 rotates. The pressurized liquid is discharged from the discharge port 13. In the embodiment shown in FIG. 1, the impeller 3 is a semi-open type impeller. In one embodiment, the impeller 3 may be a vortex type impeller, a closed type impeller, or an open type impeller.

In the embodiment shown in FIG. 1, the rotating shaft 1 is arranged vertically (see the axis CL direction in FIG. 1). The intermediate bracket 50 has an opening 50a through which the rotating shaft 1 penetrates, and the shaft sealing device 30 seals the transport liquid leaking from the opening 50a through which the rotating shaft 1 penetrates to the outside (where the outside is the motor 7).

In the present embodiment, the pump 2 and / or the rotary shaft 1 is made of a material (for example, stainless steel) having corrosion resistance to the handling liquid. More specifically, since a slurry liquid containing a slurry or a corrosive liquid is used as the handling liquid, the pump casing 5 is manufactured of a corrosion-resistant material such as stainless steel. For the same reason, the rotary shaft 1 and the impeller 3 are also corrosion-resistant materials such as stainless steel. On the other hand, the intermediate bracket 50 is manufactured of an inexpensive metal material (for example, cast iron) from the viewpoint of cost reduction and ease of manufacturing.

Even when the intermediate bracket 50 is made of the same member as the member on the pump side, when the high temperature handling liquid is transferred, the heat of the handling liquid is transferred to the motor 7 through the intermediate bracket 50, and the motor 7 ( In particular, a bearing (not shown) that rotatably supports the rotary shaft 1 is greatly affected by the heat of the handling liquid. As a result, the motor may fail. Therefore, in the present embodiment, the pump device 100 has a structure for cooling the intermediate bracket 50.

The pump device 100 includes a cooling flow path 200 for cooling the intermediate bracket 50. Specifically, the cooling flow path 200 is formed in the intermediate bracket 50. More specifically, the intermediate bracket 50 includes a pillar portion 205 extending parallel to the axis CL direction of the rotation shaft 1, and the cooling flow path 200 is connected to the lower portion of the pillar portion 205 (that is, the pump casing 5). It is formed in the part).

Further, the pump device 100 is a pump device capable of preventing the dry operation of the shaft sealing portion by discharging the air collected in the vicinity of the rotating shaft to the suction side of the impeller. The effects thereof will be described in detail below.

As shown in FIG. 1, the pump casing 5 includes a casing main body 49 for accommodating the impeller 3 and a cover portion 51 for covering the opening end 49a of the casing main body 49. The cover portion 51 has an opening 51a through which the rotating shaft 1 is inserted. The pump 10 has a shaft sealing device 30 that seals between the cover portion 51 and the rotating shaft 1 between the opening of the cover portion 51 and the rotating shaft 31. That is, the shaft sealing device 30 seals the conveyed liquid leaking to the outside of the pump casing 5 from the opening through which the rotating shaft 1 penetrates. Further, the shaft sealing device 30 is held by the cover portion 51. The pump device 100 of the present embodiment has a shaft sealing chamber 251 communicating with the shaft sealing device 30 formed by the cover portion 51. In the embodiment shown in FIG. 1, the pump is a vertical pump in which the rotary shaft 1 extends in the vertical direction (that is, in the vertical direction). The shaft sealing chamber 251 is formed under the shaft sealing device 30 so as to communicate with the shaft sealing device 30, but may be formed on the shaft sealing device 30 so as to cover the shaft sealing device 30. In one embodiment, the shaft sealing chamber 251 may be formed above and below the shaft sealing device 30.

When the impeller 3 rotates, a part of the handling liquid passes through the gap 51a between the impeller 3 and the cover portion 51, and further passes through the gap 51b between the cover portion 51 and the rotating shaft 1. It flows into the shaft sealing chamber 251. A part of the handling liquid flowing into the shaft sealing chamber 251 cools and lubricates the shaft sealing device 30. However, for example, in the priming water when the pump 2 is first started from the state where the inside of the pump casing 5 is empty, the water level rises only to the height of the upper end of the impeller 3, and the shaft sealing chamber 251 is filled with the handling liquid. There is also air. When the pump 2 is operated in the state where the air is present in the shaft sealing chamber 251, the centrifugal force received by the rotation of the impeller 3 is small because the air has a smaller density than the water, the water is pushed to the outside of the pump casing 5, and the air is released. It gathers in the vicinity of the rotation axis 1. If the pump 2 is further operated in this state, the air may come into contact with the shaft sealing device 30, the shaft sealing device 30 may be in a dry operation, may not be properly cooled and lubricated, and the shaft sealing device 30 may fail. There is. Therefore, in the present embodiment, the pump device 100 has a structure for discharging the air existing in the shaft sealing chamber 251. Hereinafter, the structure for discharging the air existing in the shaft sealing portion 250 will be described with reference to the drawings.

The rotating shaft 1 is formed with an air discharge hole 260 for communicating the shaft sealing chamber 251 arranged at a position higher than the impeller 3 and the suction side of the impeller 3. The air discharge hole 260 has at least one first hole portion 260a extending in the axial radial direction of the rotary shaft 1 from the shaft sealing chamber 251 and one end connected to the first hole portion 260a and the other end of the impeller 3. It has at least one second hole portion 260b extending to the suction side. As one embodiment, when the shaft sleeve is mounted on the outer periphery of the rotary shaft 1, the first hole portion 260a penetrates the sleeve and extends in the axial radial direction of the rotary shaft 1. Further, as one embodiment, when the lower end of the impeller 3 is covered with the bolt 42, the second hole portion 260b penetrates the bolt and extends to the suction side of the impeller 3.

In this embodiment, a slurry liquid containing a slurry may be used as the handling liquid. Therefore, the diameter of the air discharge hole 260 is larger than the diameter of the slurry. More specifically, the diameter of the air discharge hole 260 is preferably 10 to 100 times the diameter of the slurry. The diameter of the slurry is, for example, about 0.05 mm.

The end portion 1c of the rotary shaft 1 is arranged on the suction side of the impeller 3, and the air discharge hole 260 including the axis of the rotary shaft 1 extends to the end portion of the rotary shaft 1. More specifically, the first hole portion 260a is opened on the outer peripheral surface of the rotating shaft 1, and the opening is arranged in contact with the shaft sealing chamber 251. The second hole portion 260b extending along the axial direction of the rotating shaft 1 is opened at the end of the rotating shaft 1, and the opening is arranged in contact with the suction side of the impeller 3. With such a configuration, the air existing in the shaft sealing chamber 251 is discharged to the suction side of the impeller 3 through the air discharge hole 260. When the bolt 42 covers the axis of the end 1c of the rotating shaft 1, the air discharge hole 260 penetrates the bolt 42.

Since the handling liquid flowing into the pump casing 5 is pressurized by the rotation of the impeller 3, the pressure on the discharge side of the impeller 3 is higher than the pressure on the suction side of the impeller 3. Therefore, the air existing in the shaft sealing chamber 251 located on the discharge side of the impeller 3 is discharged to the suction side of the impeller 3 through the air discharge hole 260 due to the pressure difference from the suction side of the impeller 3.

Further, when the pump is operated, the air having a specific gravity smaller than that of the liquid collects in the axial direction of the rotating shaft 1, while the handling liquid moves to the inner peripheral wall side of the shaft sealing chamber 251. Therefore, the air in the shaft sealing chamber 251 positively flows into the first hole portion 260a extending in the shaft radial direction.

As a result, the pump device can prevent the shaft sealing device 30 from failing due to the air in the shaft sealing chamber 251 coming into contact with the shaft sealing device 30. Further, after the air in the shaft sealing chamber 251 is released, the conveyed liquid flows through the air discharge hole 260. Even if foreign matter such as slurry is clogged when the conveyed liquid flows through the air discharge hole 260, there is an advantage that the influence on the pump efficiency is small.

(Variation example of the first embodiment)
FIG. 2 is a diagram showing still another modification of the air exhaust hole. In the embodiment shown in FIG. 1, the first hole portion 260a of the air discharge hole 260 is connected to the upper part of the shaft sealing chamber 251. However, as shown in FIG. 2, the first hole portion 260a is the shaft sealing chamber 251. It may be connected to the bottom. In other words, the first hole portion 260a is connected to the entrance of the shaft sealing chamber 251. Further, in one embodiment, the first hole portion 260a may be connected to the upper part and the lower part of the shaft sealing chamber 251.

(Second embodiment)
FIG. 3 is a diagram showing a main part of the pump device of one embodiment. In the pump device 101 of the present embodiment, a mechanical seal as shown below is used as the shaft sealing device 30. The shaft sealing device 30 includes a fixed ring 30a fixed to the cover portion 51 and a rotating ring 30b that rotates together with the rotating shaft 1. A urging member 31 (more specifically, a spring) is connected to the rotary ring 30b. The urging member 31 urges the rotary ring 30b until the rotary ring 30b comes into contact with the fixed ring 30a. In the present embodiment, the shaft sealing device 30 is housed in the shaft sealing chamber 251 formed by the cover portion 51 to which the fixing ring 30a is fixed.

When the air present in the shaft sealing chamber 251 acts on the sliding portion between the fixed ring 30a and the rotating ring 30b, the shaft sealing device 30 is not properly cooled and lubricated. In the embodiment shown in FIG. 2, the first hole portion 260a of the air discharge hole 260 is opened at a position below the urging member 31. Therefore, the air around the shaft sealing device 30 is discharged to the outside of the shaft sealing chamber 251 through the first hole portion 260a that opens at a position below the urging member 31. That is, the shaft sealing chamber 251 accommodates the shaft sealing device 30, and the air discharge hole 260 is formed below the sliding portion of the shaft sealing device 30.

(Modified example of the second embodiment)
FIG. 4 is a diagram showing another embodiment of the air exhaust hole 260. As shown in FIG. 4, the air discharge hole 260 may include a first hole portion 260a that opens at a position between the rotary ring 30b and the urging member 31. Even with such a configuration, the air around the shaft sealing device 30 is discharged to the outside of the shaft sealing chamber 251 through the first hole portion 260a that opens at the position between the rotary ring 30b and the urging member 31. ..

Hereinafter, the air discharge holes will be described in detail with reference to FIGS. 5 to 11. FIG. 5 is a diagram showing details of an air discharge hole formed in the rotating shaft. The air discharge hole 260 according to the above-described embodiment has at least one first hole portion 260a extending from the shaft sealing chamber 251 in the axial direction of the rotary shaft, and one end connected to the first hole portion 260a and the other end. Has at least one second hole 260b, which extends to the suction side of the impeller 3.

The air discharge hole shown in FIG. 5 is provided with one first hole portion 260a and one second hole portion 260b. At least a part of the second hole portion 260b passes through the axis CL of the rotating shaft 1, and at least a part of the first hole portion 260a extends in the axial direction of the rotating shaft 1.

FIG. 6 is a diagram showing a modified example of the air discharge hole. FIG. 7 is a diagram showing another modification of the air exhaust hole. As shown in FIGS. 6 and 7, the second hole portion 260b extends in the vertical direction about the axis, and the first hole portion 260a extends in a direction perpendicular to or diagonally to the second hole portion 260b. There is. In FIG. 7, the first hole portion 260a extends diagonally upward, but may extend diagonally downward.

FIG. 8 is a diagram showing still another modification of the air exhaust hole. FIG. 9 is a diagram showing still another modification of the air exhaust hole. FIG. 10 is a horizontal cross-sectional view of FIG.

As shown in FIGS. 8 and 10, the air discharge hole 260 may include a plurality of first hole portions 260a arranged along the radius of the rotating shaft 1. In the embodiment shown in FIGS. 8 and 10, two first hole portions 260a extending from the center of the rotation shaft 1 are provided, but the number of the first hole portions 260a is not limited to this embodiment. In one embodiment, three or more first hole portions 260a may be provided. As shown in FIG. 10, the two first hole portions 260a are arranged symmetrically with respect to the axis CL, but the arrangement of the first hole portion 260a is not limited to the embodiment shown in FIG.

As shown in FIG. 9, the air discharge hole 260 may include a plurality of first hole portions 260a arranged vertically. In the embodiment shown in FIG. 9, three first hole portions 260a are provided, and an opening communicating with the shaft sealing chamber 251 is formed in the same direction (right side of the paper surface) of the rotating shaft 1. The number of holes 260a and the direction of the opening are not limited to this embodiment. In one embodiment, two or more first hole portions 260a may be provided, and in the plurality of first hole portions 260, for example, in FIG. 8, the opening of the first hole portion 260 is on the right side of the paper surface of the rotation axis 1. The direction of the opening on the shaft sealing chamber 251 side may be different as shown on the left side. All the first hole portions 260a arranged along the axis CL direction are opened by the shaft sealing portion 250. As shown in FIGS. 8 and 9, by providing the plurality of holes 260a, the air in the shaft sealing portion 250 is more positively discharged to the suction side of the pump casing 5.

FIG. 11 is a diagram showing a shaft sleeve 270 mounted on the rotating shaft 1. As shown in FIG. 11, a shaft sleeve 270 may be mounted on the outer peripheral surface of the rotating shaft 1. The air discharge hole 260 has sleeve holes 270a to 270d provided in the shaft sleeve 270. More specifically, the plurality of sleeve holes 270a to 270d communicate with the first hole portion 260a of the air discharge hole 260, branch from the first hole portion 260a, and extend toward the outer periphery of the shaft sleeve 270. There is.

In the embodiment shown in FIG. 11, a plurality of sleeve holes 270a to 270d are provided, but the number of sleeve holes may be one. As shown in FIG. 11, the shaft sleeve 270 includes a plurality of sleeve holes 270a-270d in which openings on the shaft sealing chamber 251 side are arranged at different levels in order to collect air from a wide range of height levels. There is. That is, the sleeve holes of the present embodiment are a plurality of sleeve holes 270a to branch from the first hole portion 260a of the air discharge hole 260 formed in the rotary shaft 1 and capable of discharging air having different height levels. It is 270d.

More specifically, the shaft sleeve 270 includes a first sleeve hole 270a extending parallel to the axis CL direction of the rotating shaft 1, and a second sleeve hole 270b extending diagonally upward with respect to the axis CL direction of the rotating shaft 1. It has a third sleeve hole 270c extending perpendicularly to the axis CL direction of the rotation axis 1 and a fourth sleeve hole 270d extending diagonally downward with respect to the axis CL direction of the rotation axis 1. In this way, by having the air discharge holes 260 having sleeve holes 270a to 270d having different height levels, the air in the shaft sealing chamber 251 is discharged to the outside even when the level at which the air stays is high or low. be able to.

According to the present embodiment, by providing the shaft sleeve 270 with a plurality of sleeve holes 270a to 270d, it is possible to prevent a decrease in the strength of the rotating shaft 1. That is, there is a possibility that the strength of the rotating shaft 1 is lowered by forming a plurality of holes in the rotating shaft 1, but in the present embodiment, the strength of the rotating shaft 1 is maintained by providing the shaft sleeve 270. At the same time, the air in the shaft sealing chamber 251 can be discharged to the outside more effectively.

In the above-described embodiment, the pump device 100 includes both a structure for cooling the intermediate bracket 50 (intermediate bracket cooling structure) and a structure for discharging air existing in the shaft sealing portion 250 (air discharge structure). The pump device 100 may include only one of these structures. That is, when using a high-temperature handling liquid, the pump device 100 may have an intermediate bracket cooling structure, and does not necessarily have to have an air discharge structure. On the contrary, when the high temperature handling liquid is not used, the pump device 100 does not necessarily have to include the intermediate bracket cooling structure.

The pump device 100 of the present embodiment is particularly suitable when a slurry liquid is used. In the present embodiment, since the air discharge hole 260 is formed in the rotary shaft 1, in addition to the above-mentioned effect, the pump device 100 operates without any problem even if the air discharge hole 260 is clogged with foreign matter or eroded. The effect of being able to continue can also be expected. This is because, normally, priming is performed at the time of installation, and after the air is discharged from the air discharge hole 260 during the priming operation, the shaft sealing chamber 251 is usually filled with water and the shaft sealing device 30 is operated dry. This is because there is little risk. Further, if the hole for discharging air to the suction side is eroded and the amount of water returned to the suction side increases, the pump efficiency may decrease. However, in the case of the air discharge hole 260 formed in the rotating shaft 1, even if the first hole portion 260a is eroded, the amount of water returned to the suction side is almost the same as before the erosion until the second hole portion 260b is eroded. Can be maintained. Therefore, this embodiment can also be applied to a pump device in which there is a concern about erosion of the flow path returned from the shaft sealing chamber 251 to the suction side, such as transporting a slurry liquid. On the other hand, when the pump device having a structure that returns the air collected in the vicinity of the rotating shaft from the mechanical seal side to the inside of the impeller through the hole of the main plate as shown in the prior art, the slurry liquid is conveyed to the main plate. Holes have a short lifespan against erosion. Further, in general, the conventional structure of returning the air collected in the vicinity of the rotating shaft from the mechanical seal side to the inside of the impeller through the hole of the main plate is applied to the pump device of the closed blade. In contrast, the embodiments of the present invention are not limited in the shape of the blades and can be applied to various types of pumps.

The above-described embodiments have been described for the purpose of allowing a person having ordinary knowledge in the technical field to which the present invention belongs to carry out the present invention. Various modifications of the above embodiment can be naturally made by those skilled in the art, and the technical idea of the present invention can be applied to other embodiments. Accordingly, the invention is not limited to the described embodiments, but is to be construed in the broadest range in accordance with the technical ideas defined by the claims.

1 Rotating shaft 1a Large diameter part 1b Small diameter part 1c End part 2 Pump 3 Impeller 3a Main plate 3b Side plate 3c Flange 5 Pump casing 7 Motor 12 Suction port 13 Discharge port 30 Shaft sealing device 30a Fixed ring 30b Rotating ring 31 Bouncer 42 Bolt 49 Casing body 49a Opening end 50 Intermediate bracket 50a Opening 50b End face 50b-1 First part 50b-2 Second part 51 Cover member 100 Pumping device 200 Cooling flow path 200a Inlet 200b Outlet 202 Pump casing side flange 202a Thick part 203 Motor side flange 205 Pillar part 206 Recess 207 Lid part 210 Gap 215 Inlet piping 216 Outlet piping 250 Shaft sealing part 251 Shaft sealing chamber 260 Air discharge hole 260a 1st hole 260b 2nd hole

Claims (13)

A pump provided with an impeller that pressurizes the transport liquid and a pump casing that accommodates the impeller.
The rotating shaft to which the impeller is fixed and
A shaft sealing device that seals the conveyed liquid leaking to the outside of the pump casing from the opening through which the rotating shaft penetrates, and a shaft sealing device.
The shaft sealing chamber formed by the pump casing is provided.
A pump device in which an air discharge hole for communicating the shaft sealing chamber arranged at a position higher than the impeller and the suction side of the impeller is formed on the rotating shaft. The air exhaust hole is
At least one first hole extending from the shaft sealing chamber in the axial direction of the rotating shaft, and
The pump device of claim 1, wherein one end is connected to any of the first holes and the other end has at least one second hole extending to the suction side of the impeller. .. The pump device according to claim 2, wherein at least a part of the second hole portion passes through the axis of the rotating shaft, and at least a part of the first hole portion extends in the axial direction of the rotating shaft. The pump device according to claim 2 or 3, wherein the first hole portion extends in a direction perpendicular to or an oblique direction with respect to the second hole portion. 1. The pump device described. The pump is a vertical pump in which the rotation axis extends in the vertical direction.
The shaft sealing chamber communicates with the shaft sealing device, and the shaft sealing chamber is communicated with the shaft sealing device.
The pump device according to any one of claims 1 to 5, wherein the air discharge hole is connected to an upper portion and / or a lower portion of the shaft sealing chamber. The pump is a vertical pump in which the rotation axis extends in the vertical direction.
The shaft sealing chamber houses the shaft sealing device.
The pump device according to any one of claims 1 to 5, wherein the air discharge hole is formed below the sliding portion of the shaft sealing device. The shaft sealing device is
A fixed ring fixed to the pump casing and
A rotating ring that rotates with the axis of rotation,
With an urging member connected to the rotating ring,
The pump device according to claim 7, wherein the air discharge hole is opened at a position below the urging member and / or at a position between the rotating ring and the urging member. Any of claims 1 to 8, wherein the air discharge hole includes a plurality of first holes arranged along the radius of the rotating shaft and extending from the shaft sealing chamber in the axial direction of the rotating shaft. The pump device according to one item. One of claims 1 to 9, wherein the air discharge hole includes a plurality of first holes arranged above and below the rotation shaft and extending from the shaft sealing chamber in the axial direction of the rotation shaft. Pumping device as described in the section. Further provided with a shaft sleeve mounted on the outer peripheral surface of the rotating shaft,
The pump device according to any one of claims 1 to 10, wherein the air discharge hole has a sleeve hole provided in the shaft sleeve. 11. The pump device according to claim 11, wherein the sleeve holes are a plurality of sleeve holes having different height levels, branching from the air exhaust holes formed in the rotating shaft. Further comprising a motor for driving the rotating shaft located above the pump.
The pump device according to any one of claims 1 to 12, wherein the shaft sealing device seals the transport liquid leaking from the pump to the motor side.

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