JP2021055656A - Intermediate casing and submerged pump provided with the same - Google Patents

Abstract

To provide an intermediate casing which enables formation of a submerged pump operable in a transverse-mounted state without causing a leaked liquid from a mechanical seal to enter a motor part.SOLUTION: An intermediate casing is disposed between a motor frame in which a motor for driving a rotary shaft of a submerged pump is disposed and a pump casing in which an impeller driven by the rotary shaft is disposed. An inner surface of the intermediate casing is provided with: a bearing attachment part to which a bearing for the rotary shaft is attached, a seal holding part which holds a mechanical seal which seals the rotary shaft, and at least one projection part projecting to the radial inner side of the intermediate casing between the bearing attachment part and the seal holding part. The intermediate casing further has at least one penetration passage which opens between the projection part and the seal holding part and penetrates through the intermediate casing.SELECTED DRAWING: Figure 1

Description

The present invention relates to an intermediate casing and a submersible pump including the intermediate casing.

In pump facilities such as wastewater treatment facilities, land pumps that are operated in the air are often used. However, there is a problem that the pump facility is flooded and the onshore pump is stopped due to the recent guerrilla rainstorm, tsunami, etc.

As a method of solving this, it is conceivable to use a submersible pump instead of the land pump. However, the installation space of the pump in the pump facility is relatively small, and the height of the pump is generally limited. On the other hand, the submersible pump, which is expected to be used underwater, is designed on the assumption that it is used in the vertical direction (in other words, the vertical direction). The vertical installation facilitates the work of pulling the pump out of the water. In addition, the vertical installation can prevent foreign matter in the water from accumulating on the pump. However, it is difficult for a submersible pump installed in the vertical direction to meet the above height restrictions. Therefore, for example, Patent Document 1 describes an example in which the submersible pump is used horizontally.

By the way, in the submersible pump, a mechanical seal is provided in order to prevent the pressurized handling liquid of the pump portion from entering the motor portion. The mechanical seal is placed in a mechanical seal chamber containing lubricating oil. However, in reality, during the operation of the submersible pump, the mixed liquid of the oil contained in the mechanical seal chamber and the liquid handled by the pump portion always leaks into the motor portion through the mechanical seal, although the amount is small. The submersible pump is equipped with a flood detector to detect the amount of leakage from the mechanical seal.

FIG. 9 shows a specific configuration example of a conventional submersible pump. The illustrated submersible pump is designed on the assumption that it is installed in the vertical direction with respect to the installation surface G, and is composed of a pump unit 1 and a motor unit 2. The pump unit 1 includes a pump casing 3, a mechanical seal cover 4, and an impeller 5, and the impeller 5 is fixed to a rotating shaft 6. A load-side bracket 7 is fixed to the upper portion of the mechanical seal cover 4, and a mechanical seal chamber 8 is formed in the load-side bracket 7. Mechanical seals 9 and 10 are provided in the mechanical seal chamber 8. The mechanical seals 9 and 10 seal the gap between the mechanical seal cover 4 and the load side bracket 7 and the rotating shaft 6.

The motor unit 2 includes a motor frame 11, a stator 12 fixed in the motor frame 11, and a rotor 13 installed in the stator 12 and fixed to the rotating shaft 6. An inundation detector 20 is provided adjacent to the load side bracket 7. A detection unit (float switch in the illustrated example) 21 is arranged in the inundation detector 20. The internal space of the inundation detector 20 communicates with the space slightly above the upper mechanical seal 10 via the communication passage 22.

In the vertical pump, the liquid in the mechanical seal chamber 8 (that is, the mixed liquid of the oil and the handling liquid) leaks and accumulates in the space between the mechanical seal 10 and the load side bracket 7. When the amount of leakage becomes large, the liquid flows into the inundation detector 20 through the communication passage 22 in front of the motor unit 2 and collects there. When a predetermined amount of liquid is accumulated, it is detected by the detection unit 21. Then, the worker performs maintenance such as replacement of the mechanical seals 9 and 10 and discharge of the liquid.

By using the submersible pump horizontally as described in Patent Document 1, the height limitation in the pump facility can be satisfied. However, as shown in FIG. 10, for example, in order to use the submersible pump horizontally, simply arranging the conventional load side bracket sideways causes the mixed liquid from the mechanical seal chamber to be arranged horizontally. It travels along the rotating shaft and invades the motor section. In FIG. 10, the inflow of the pump handling liquid from the inside of the pump casing 32 of the pump unit 30 of the submersible pump installed horizontally with respect to the installation surface G into the mechanical seal chamber 36 of the load side bracket 34, and the mechanical The inflow of the liquid (that is, the mixed liquid of the oil and the handling liquid) from the seal chamber 36 into the motor unit 40 is indicated by an arrow.

JP-A-2018-115570

An object of the present invention is to provide an intermediate casing such as a load-side bracket that enables a submersible pump to be operated horizontally without allowing a liquid leak from a mechanical seal to enter the motor portion. Another object of the present invention is to provide an intermediate casing that can be easily applied to a conventional submersible pump and enables the submersible pump to be operated horizontally. Another object of the present invention is to provide an intermediate casing that can be shared by a plurality of horizontally placed submersible pumps arranged in parallel.

According to one embodiment of the present invention, an intermediate casing arranged between a motor frame in which a motor for driving a rotating shaft of a submersible pump is arranged and a pump casing in which an impeller driven by the rotating shaft is arranged is provided. Provided. On the inner surface of the intermediate casing, there is a bearing mounting portion on which a bearing for the rotating shaft is mounted, a seal holding portion that holds a mechanical seal that seals the rotating shaft, and an intermediate casing between the bearing mounting portion and the seal holding portion. At least one protrusion that protrudes inward in the radial direction of the bearing is formed. The intermediate casing further has at least one through passage that opens between the protrusion and the seal holding portion and penetrates the intermediate casing.

It is sectional drawing of the submersible pump provided with the intermediate casing by one Embodiment of this invention. It is an end view which shows the example of the intermediate casing by one Embodiment of this invention. It is sectional drawing of the intermediate casing along the XX direction of FIG. It is sectional drawing of the intermediate casing along the YY direction of FIG. It is a partially enlarged explanatory view of FIG. It is sectional drawing which shows the inundation detector together with the mounting cover. It is a cross-sectional view of the intermediate casing to which the inundation detector is attached. It is a figure which shows the intermediate casing of two submersible pumps arranged in parallel. It is sectional drawing which shows the example of the conventional submersible pump. It is a figure explaining the conventional submersible pump placed horizontally.

Hereinafter, embodiments of the present invention will be described with reference to the drawings. The following description is merely an example, and does not mean that the technical scope of the present invention is limited to the following embodiments.

FIG. 1 shows an example of a submersible pump provided with an intermediate casing according to an embodiment of the present invention.
The illustrated submersible pump is designed on the assumption that it is installed horizontally on the installation surface G. In the present embodiment, "horizontal placement" means a direction in which the rotation axis of the submersible pump is maintained in a substantially horizontal direction. Hereinafter, in the description of the present embodiment, terms indicating directions such as "up" and "down" are used with respect to the state of the submersible pump installed horizontally unless otherwise specified.

The submersible pump 100 includes a pump unit 101 and a motor unit 102. The pump portion 101 includes a pump casing 103, a mechanical seal cover 104, and an impeller 105, and the impeller 105 is fixed to a rotating shaft 106. A load-side bracket (in other words, an intermediate casing) 107 is fixed to the mechanical seal cover 104. The mechanical seal chamber 108 is formed by the mechanical seal cover 104 and the load side bracket 107. A mechanical seal 110 is provided in the mechanical seal chamber 108. The mechanical seal 110 seals the gap between the load side bracket 107 and the rotating shaft 106. The mechanical seal 110 also seals the gap between the mechanical seal cover 104 and the rotating shaft 106.

The load-side bracket 107 and the mechanical seal cover 104 have insertion holes 114 and 116 through which the rotating shaft 106 for driving the impeller 105 is passed, respectively. The mechanical seal cover 104 has a seal holding portion 118 for holding the mechanical seal 110 on the outside of the insertion hole 116. Further, the load-side bracket 107 has a seal holding portion 120 for holding the mechanical seal 110 and a bearing mounting portion 124 for mounting the load-side bearing 122 that pivotally supports the rotating shaft 106 on the outside of the insertion hole 114.

The motor unit 102 includes a motor frame 111, a stator 112 fixed in the motor frame 111, and a rotor 113 installed in the stator 112 and fixed to the rotating shaft 106. A water immersion detector 202 (not shown), which will be described later, is attached to the load side bracket 107.

During the operation of the submersible pump 100, the handling liquid in the pump casing 103 enters the mechanical seal chamber 108 through the mechanical seal 110. The handling liquid is mixed with the lubricating oil in the mechanical seal chamber 108. The mixed liquid passes through the mechanical seal 110 and leaks from the mechanical seal chamber 108 to the outside of the seal holding portion 120. The flow of the handling liquid and the mixed liquid is shown by arrows in FIG.

As will be described later, in the present embodiment, the protrusion 126 is formed between the bearing mounting portion 124 and the seal holding portion 120.

FIG. 2 is an end view of the load-side bracket 107, which is a view of the load-side bracket 107 from the right side of FIG. 1 (in other words, the pump casing 103 side). FIG. 3 is a cross-sectional view of the load-side bracket 107 along the XX line of FIG. 2, and FIG. 4 is a cross-sectional view of the load-side bracket 107 along the YY line of FIG. For ease of understanding, FIGS. 2 to 4 also show a rotating shaft 106 (including a small diameter portion 106a at the tip and a large diameter portion 106b adjacent thereto) passing through the insertion hole 114 of the load side bracket 107. ..

The load-side bracket 107 has a substantially cylindrical outer shape, and is configured to be fixed to the mechanical seal cover 104 via a fastening portion 109. As described above, the load side bracket 107 is formed with an insertion hole 114 through which the rotating shaft 106 is inserted, and a seal holding portion for holding the mechanical seal 110 provided around the rotating shaft 106 on the outside of the insertion hole 114. 120 is formed. The seal holding portion 120 includes a peripheral surface portion 120a that faces the rotation shaft 106 and extends in the circumferential direction thereof, and an end surface portion 120b that is adjacent to the peripheral surface portion 120a and is arranged so as to intersect the peripheral surface portion 120a. Further, a bearing mounting portion 124 for the load side bearing 122 that pivotally supports the rotating shaft 106 is formed at a position separated from the seal holding portion 120. A protrusion 126 is formed between the bearing mounting portion 124 and the seal holding portion 120. Specifically, the protrusion 126 projects radially inward from the load-side bracket 107 from the inner surface 128 of the load-side bracket 107. The protrusion length of the protrusion 126 is determined so that the protrusion 126 does not come into contact with the rotation shaft 106.

FIG. 5 is a partially enlarged view of FIG. 1 showing the configuration around the protrusion 126. As described above, the protrusion 126 projects radially inward from the inner surface 128 of the load-side bracket 107 with a protrusion length between the bearing mounting portion 124 and the seal holding portion 120 so as not to contact the rotating shaft 106. .. As a result, while the submersible pump 100 is in operation, the protrusion 126 acts as a weir for the leaked liquid from the mechanical seal 110. The leaked liquid is blocked by the protrusion 126, collects in the recess or groove 130 formed between the protrusion 126 and the seal holding portion 120, and does not reach the load side bearing 122. As a result, it is possible to eliminate the risk of leaked liquid entering the motor portion when the conventional submersible pump is placed horizontally.

The length and number of the protrusions 126 in the circumferential direction are not particularly limited. The protrusion 126 may be provided only on a part of the inner surface 128 of the load-side bracket 107 in the circumferential direction, or may have a single annular shape that extends continuously in the entire circumferential direction. When the protrusion 126 is provided in a part in the circumferential direction, the protrusion 126 is located at a position facing each other in the radial direction of the load side bracket 107 (in other words, the load side bracket as shown by the broken line in FIG. 2). It is preferably formed at a position substantially 180 degrees off about the central axis C of 107). Further, the load-side bracket 107 is installed so that at least one protrusion 126 (126a in FIG. 2) is located at the lower portion in the vertical direction so that the leaked liquid flows into the recess 130.

Further, in the present embodiment, the load side bracket 107 has a through passage 134 (134a, 134b) penetrating the wall portion 132 (see FIG. 2). The through passage 134 opens inside the load-side bracket 107 between the protrusion 126 and the seal holding portion 120. The openings 136 (136a, 136b) are shown by solid lines in FIGS. 3 and 4. Further, the through passage 134 is opened at the outer surface 138 of the load side bracket 107 so as to extend to the outside of the load side bracket 107. For the reason described later, in the present embodiment, the two through passages 134a and 134b are formed in a parallel state as shown in FIG. However, the number of through passages 134 is not limited, and a single through passage 134 may be provided.

Further, in the present embodiment, the inundation detector 202 is provided on the outside of the load side bracket 107. FIG. 6 is a vertical sectional view showing the inundation detector 202 as a single unit. FIG. 7 is a diagram showing a cross section of the load side bracket 107 to which the inundation detector 202 is attached (in other words, a cross section intersecting the rotation axis 106 of the submersible pump 100). FIG. 8 shows a load-side bracket 107 and an inundation detector 202 of two submersible pumps 100 arranged in parallel with each other.

The inundation detector 202 has a space 206 defined by the housing portion 204, in which the liquid to be detected is stored, and in which the detection unit 208 is arranged. Any known inundation detector configuration can be used in this embodiment.

As shown in FIG. 7, the rear surface (load side bracket 107 side) of the housing portion 204 is partially opened through the opening 210, and the inundation detector 202 is mounted on the load side bracket around the opening 210. It has a mounting cover 212 as shown in FIG. 6 for fixing to 107. The mounting cover 212 has mounting holes 214 capable of accepting fasteners.

The through passages 134 (134a, 134b) communicate with the space 206 through the opening 210. The leaked liquid in the recess 130 flows into the space 206 of the inundation detector 202 through the through passage 134a in the lower part in the vertical direction. In the present embodiment, in the cross section of the load side bracket 107, the protrusion 126a at the lower portion in the vertical direction acts as a weir for the leaked liquid, and the leaked liquid flows into the space 206 through the lower through passage 134a. The upper through passage 134b can function as a ventilation passage for discharging a gas such as air in the space 206 in response to the inflow of the leaked liquid.

The detected water level of the inundation detector 202 can be set at a position below the height of the protrusion 126 (126a in FIG. 7) at the lower part in the vertical direction. As a result, it is possible to prevent the leaked liquid from entering the motor portion 102 beyond the protrusion 126.

As described above, the load-side bracket 107 of the present embodiment is positioned in parallel with the protrusions 126 (126a, 126b) positioned vertically in the vertical direction and the protrusions 126 in the vertical direction. It has two through passages 134 (134a, 134b). As a result, when the submersible pump 100 is installed, one set of the protrusion 126 and the through passage 134 is arranged in the lower part in the vertical direction, and the other set of the protrusion 126 and the through passage 134 is arranged in the upper part in the vertical direction. can do. The pump facility may employ, for example, a unit structure including two submersible pumps 100. In that case, the load-side bracket 107 of the present embodiment can be installed at a symmetrical position with respect to the two submersible pumps 100 by reversing left and right as shown in FIG. For example, assume that the load side bracket 107 has a single protrusion 126 and a single through passage 134 (eg, only 126a and 134a in FIG. 7). In this case, if the load side bracket 107 is inverted left and right, the single protrusion 126a and the single through passage 134a are located at the upper part in the vertical direction, so that the leaked liquid is blocked by the protrusion 126a to prevent the inundation detector. It cannot be sent to 202. On the other hand, in the configuration of the present embodiment, when the load side bracket 107 of FIG. 7 is flipped left and right like the load side bracket 107 on the right side of FIG. 8, the load side bracket 107 on the right side is moved downward in the vertical direction. There is a protruding portion 126b and a through passage 134b that are located. Therefore, the leaked liquid can be blocked by the protrusion 126b and flowed to the inundation detector 202. Further, the through passage 134a at the upper part in the vertical direction can be used as a ventilation passage through which the air discharged from the space 206 passes when the leaked liquid flows into the space 206. As described above, the load side bracket 107 of the present embodiment can be shared by a plurality of submersible pumps 100 arranged in parallel.

Although the embodiments of the present invention have been described above, the above-described embodiments of the invention are for facilitating the understanding of the present invention and do not limit the present invention. In the above embodiment, the load side bracket 107 has been described as an example of the intermediate casing, but the intermediate casing is not limited to the load side bracket 107. The intermediate casing may be a casing member arranged between the motor frame in which the motor of the submersible pump is arranged and the pump casing in which the impeller is arranged.

The present invention can be modified and improved without departing from the spirit thereof, and it goes without saying that the present invention includes an equivalent thereof. In addition, any combination or omission of the claims and the components described in the specification is possible within the range in which at least a part of the above-mentioned problems can be solved, or in the range in which at least a part of the effect is exhibited. Is.

The present invention includes the following aspects.
1. 1. An intermediate casing arranged between the motor frame in which the motor for driving the rotating shaft of the submersible pump is arranged and the pump casing in which the impeller driven by the rotating shaft is arranged.
On the inner surface of the intermediate casing,
Bearing mounting part where bearings for rotating shafts are mounted,
A seal holder that holds the mechanical seal that seals the rotating shaft,
At least one protrusion protruding inward in the radial direction of the intermediate casing is formed between the bearing mounting portion and the seal holding portion.
The intermediate casing is further
It has at least one through passage that opens between the protrusion and the seal holder and penetrates the intermediate casing.
Intermediate casing.
2. Above 1. The intermediate casing described in
The submersible pump is a horizontal axis pump that is installed horizontally.
The protrusion is an intermediate casing formed at a position where the liquid leaked from the mechanical seal during the operation of the submersible pump can be received in the space between the protrusion and the seal holder.
3. 3. Above 1. Or 2. The intermediate casing described in
An intermediate casing having two protrusions, the two protrusions being formed at positions facing each other in the radial direction of the intermediate casing.
4. Above 1. Or 2. The intermediate casing described in
The protrusion is an intermediate casing, which is a single protrusion that extends continuously in the circumferential direction of the intermediate casing.
5. Above 3. Or 4. The intermediate casing described in
An intermediate casing having two through passages and having the two through passages arranged substantially in parallel in the cross section of the intermediate casing.
6. Above 1. ~ 5. A submersible pump with the intermediate casing described in any of.
7. 6. Above. The submersible pump described in
The submersible pump is further equipped with an inundation detector, which is positioned relative to the intermediate casing so that the through passage communicates with the liquid storage space of the inundation detector.
A submersible pump in which the water level detected by the inundation detector is set in association with the protrusion length of the protrusion.
8. 5. Above. A submersible pump with an intermediate casing as described in.
The submersible pump is further equipped with an inundation detector, both of which communicate with the liquid storage space of the inundation detector, one of the two through passages used as a liquid passage and the other as a ventilation passage. Submersible pump that can be used.

The present invention can be widely applied to submersible pumps.

C Central axis G Installation surface 1 Pump part 2 Motor part 3 Pump casing 4 Mechanical seal cover 5 Impeller 6 Rotating shaft 7 Load side bracket 8 Mechanical seal chamber 9, 10 Mechanical seal 11 Motor frame 12 stator 13 Rotor 20 Flood detector 21 Detection part 22 Continuous passage 100 Submersible pump 101 Pump part 102 Motor part 103 Pump casing 104 Mechanical seal cover 105 Impeller 106 Rotating shaft 106a Small diameter part 106b Large diameter part 108 Mechanical seal chamber 109 Fastening part 110 Mechanical seal 111 Motor frame 112 stator 113 Rotor 114 Insertion hole 116 Insertion hole 118 Seal holding part 120 Seal holding part 120a Peripheral surface part 120b End face part 122 Load side bearing 124 Bearing mounting part 126, 126a, 126b Projection part 128 Inner surface 130 Recession 132 Wall part 134, 134a, 134b Penetration Passage 136, 136a, 136b Opening 138 Outer surface 202 Inundation detector 204 Housing part 206 Space 208 Detection part 210 Opening 212 Mounting cover 214 Mounting hole

Claims (8)

An intermediate casing arranged between a motor frame in which a motor for driving a rotating shaft of a submersible pump is arranged and a pump casing in which an impeller driven by the rotating shaft is arranged.
On the inner surface of the intermediate casing,
The bearing mounting part to which the bearing for the rotating shaft is mounted and
A seal holder that holds the mechanical seal that seals the rotating shaft,
At least one protrusion protruding inward in the radial direction of the intermediate casing is formed between the bearing mounting portion and the seal holding portion.
The intermediate casing further
It has at least one through passage that opens between the protrusion and the seal holding portion and penetrates the intermediate casing.
Intermediate casing. The intermediate casing according to claim 1.
The submersible pump is a horizontal axis pump installed horizontally.
The protrusion is an intermediate casing formed at a position where the liquid leaked from the mechanical seal during the operation of the submersible pump can be received in the space between the protrusion and the seal holding portion. The intermediate casing according to claim 1 or 2.
An intermediate casing having two protrusions, the two protrusions being formed at positions facing each other in the radial direction of the intermediate casing. The intermediate casing according to claim 1 or 2.
The protrusion is an intermediate casing which is a single protrusion continuously extending in the circumferential direction of the intermediate casing. The intermediate casing according to claim 3 or 4.
An intermediate casing having two through passages and having the two through passages arranged substantially in parallel in a cross section of the intermediate casing. A submersible pump comprising the intermediate casing according to any one of claims 1 to 5. The submersible pump according to claim 6.
The submersible pump further comprises an inundation detector, which is positioned relative to the intermediate casing such that the through passage communicates with the liquid storage space of the inundation detector.
A submersible pump in which the detected water level of the inundation detector is set in association with the protruding length of the protrusion. A submersible pump comprising the intermediate casing according to claim 5.
The submersible pump further comprises an inundation detector, both of which communicate with the liquid storage space of the inundation detector, one of the two through passages being used as the liquid passage and the other. Is a submersible pump that can be used as a vent.

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