JPH11230079A - Submerged pump - Google Patents

Abstract

PROBLEM TO BE SOLVED: To quickly discharge the gas gasified from a handling liquid in a motor chamber to the outside when a pump is stopped by providing a gas vent valve which passes gas from the inside of the motor chamber to the outside and interrupts the flow of the liquid the outside of the motor chamber to the inside. SOLUTION: The outside of a motor chamber 1 is kept at the pressure higher than the pressure inside the motor chamber 1 by the discharge pressure from a pump chamber 2 during the operation of a submerged pump P, and a gas vent valve 4 is closed. The gas vent valve 4 interrupts the flow of a liquid from the outside of the motor chamber 1 to the inside at this time. When the submerged pump P is stopped, the flow of the handling liquid to the inside of the motor chamber 1 is stopped, and a rotor 11 and a stator 12 are not cooled by the flow of the handling liquid and are quickly heated. The handling liquid remaining in the motor chamber 1 is quickly gasified, the pressure in the motor chamber 1 quickly rises, the pressure on the outside of the motor chamber 1 drops, and the gas vent valve 4 is opened. As the gas is released from the gas vent valve 4, the inside of the motor chamber 1 is again filled with the handling liquid.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a submerged pump, and more particularly to a submerged pump for liquefied gas. In particular, the present invention relates to a submerged pump that can prevent the life of a bearing from being significantly shortened even when stop and start are repeated.

[0002]

2. Description of the Related Art A motor chamber, a pump chamber disposed below and adjacent to the motor chamber, and a part of a liquid handled discharged from the pump chamber is stored in the motor chamber. A submerged pump having a handling liquid flowing means for flowing is generally used for cryogenic liquids such as liquefied natural gas, liquefied nitrogen gas, liquefied petroleum gas, liquefied ethylene, liquefied ethane, and liquefied gas such as liquefied propane. Used.

[0003] During operation of the submerged pump,
By allowing a part of the handling liquid discharged from the pump chamber to flow through the motor chamber, the bearing provided in the motor chamber is maintained in a lubricated state, and the motor chamber is maintained at a pressure higher than the suction pressure. .

Here, when the submerged pump is stopped, the total head of the pump becomes zero, and the pressure inside the motor chamber rapidly decreases. Therefore, the handling liquid stored in the motor chamber is rapidly gasified, so that the bearing provided in the motor chamber, particularly the bearing provided in the upper part of the motor chamber, is in a dry state.

[0005] Since an orifice for discharging a gas obtained by gasifying the handling liquid is usually provided at the top of the motor chamber, the gas which has rapidly gasified the handling liquid is supplied from the inside of the motor chamber to the submerged pump. Out through the orifice.

If the submerged pump is operated again after the gas has been sufficiently discharged out of the motor chamber, a part of the handled liquid discharged from the pump chamber is introduced into the motor chamber, whereby the gas is removed. The motor chamber is completely driven out of the motor chamber, and the motor chamber is again filled with the handling liquid. Thus, the bearing in the motor chamber is maintained in a lubricated state again.

However, if the submerged pump is operated in an operation mode in which starting and stopping are frequently repeated, the starting is performed before the gas generated at the time of stopping the operation is not sufficiently discharged out of the motor room. The bearing of
Always remain dry.

Therefore, when the submerged pump is operated in the operation mode, there is a problem that the life of the bearing in the motor chamber is significantly shortened.

According to the present invention, there is provided a submerged pump in which the problem of shortening the life of the bearing does not occur even when the pump is operated in an operation mode in which starting and stopping are frequently repeated.

[0010]

SUMMARY OF THE INVENTION A submerged pump for solving the above-mentioned problems is provided with a motor chamber including a rotor having a rotating shaft, a stator surrounding the rotor, and A pump chamber having a fixed impeller, and performing suction / discharge of a handled liquid by rotating the impeller; a pump chamber disposed below and adjacent to the motor chamber; and a handled liquid discharged from the pump chamber. A handling liquid flowing means for flowing at least a part of the inside of the motor chamber, a gas flows from the inside of the motor chamber to the outside, and shuts off a flow of the liquid from the outside of the motor chamber to the inside,
A submerged pump having a gas vent valve provided in the motor chamber.

[0011]

DESCRIPTION OF THE PREFERRED EMBODIMENTS A submerged pump according to the present invention
As described above, (a) a motor chamber, (b) a pump chamber disposed adjacently below the motor chamber, and (c) at least a part of the handling liquid discharged from the pump chamber to the motor chamber. And (d) a gas vent valve that allows gas to flow from inside to outside of the motor chamber and shuts off the flow of liquid from outside to inside of the motor chamber.

1. An example of the submerged pump of the present invention An example of the submerged pump of the present invention is shown in FIG. 1 as a partial cross-sectional view.

The submerged pump P shown in FIG. 1 is housed in a cylindrical column 5 extending in the vertical direction.

In the submerged pump P of FIG. 1, the motor chamber 1 has a substantially cylindrical casing 10 extending in the vertical direction.
And a substantially cylindrical rotor 11 having a rotating shaft 13 extending in a vertical direction, and the housing 1 surrounding the rotor 11.
0 and a substantially hollow cylindrical stator 12 housed inside. The upper end and the lower end of the rotating shaft 13 are held by an upper bearing 14 having a ball bearing and a lower bearing similarly having a ball bearing. In FIG. 1, the lower bearing is omitted.

A pump chamber 2 is provided below and adjacent to the motor chamber 1. At the upper end of the side surface of the pump chamber 2, there is provided a discharge port 22 through which liquid sucked and discharged in the pump chamber 2 (hereinafter referred to as “handling liquid”) is discharged. The suction port 21 through which the liquid is sucked is open. An impeller not shown in FIG. 1 is provided inside the pump chamber 2. The impeller is fixed to a rotating shaft 13 of the rotor 11. Then, as the impeller rotates, the handled liquid is sucked through the suction port 21 and discharged from the discharge port 22.

Between the pump chamber 2 and the motor chamber 1, there is a handled liquid flow path (not shown in FIG. 1) for guiding a part of the handled liquid discharged from the pump chamber 2 into the motor chamber 1. , Provided along the rotating shaft 13. A return pipe 6 that connects the upper end of the motor chamber 1 and the vicinity of the suction port 21 of the pump chamber 2 is provided inside the side wall of the housing 1. The recirculation pipe 6 is used to supply the handling liquid flowing into the motor chamber 1 to the suction port 2.
It has the function of returning to the vicinity of 1.

An upper end cover 3 having a cylindrical side surface and a substantially conical upper end surface is fixed to the upper end of the housing 10.
At a substantially central portion of the upper end cover 3, a substantially cylindrical bearing holding cylinder 31 extending downward is formed. The upper bearing 14 is fitted inside the bearing holding cylinder 31. The side face of the bearing holding cylinder 31 is further provided with a communication hole 32 for communicating the outside and the inside of the bearing holding cylinder 31. At the top of the bearing holding cylinder 31, there is provided an orifice 33 for discharging a gas, which is a gas of the handling liquid retained in the motor chamber 1, to the outside.

A gas vent valve 4 is provided on an upper end surface of the upper end cover 3. In FIG. 1, a portion surrounded by a circle indicates the gas release valve 4.

The gas vent valve 4 has a function of passing gas from the inside of the motor chamber 1 to the outside and blocking the flow of liquid from the outside of the motor chamber 1 to the inside.

FIG. 2 shows the details of the vent valve 4. 2A shows the state of the vent valve 4 when the submerged pump is operating, and FIG. 2B shows the state of the vent valve 4 when the submerged pump is stopped. Hereinafter, the vertical direction, the upper direction, and the lower direction mean the vertical direction, the upper direction, and the lower direction in the drawings of FIG.

The gas vent valve 4 includes a valve element 41 and the valve element 4.
A valve seat 42 for opening and closing the gas flow path in cooperation with the valve seat 1;
2 and a cylindrical valve box 43 for guiding the valve element 41 in the vertical direction.

The valve element 41 includes a valve element body 410 having a substantially cylindrical shape, a cylindrical intermediate portion 413 extending upward from the upper surface of the valve element body 410 and having a smaller diameter than the valve element body 410, And a cylindrical guide member 412 having a smaller diameter and extending upward from the upper surface of the portion 413. A valve seat surface 411 that is a conical surface that decreases downward is formed at the lower end of the valve body 410. Valve body 41
A cylindrical spring insertion portion 414 having a diameter smaller than the diameter of the lower end of the valve body valve seat surface 411 extends downward from the lower surface of the zero. The spring insertion portion 414 is inserted into an upper end of a spring 44 described later, and defines a positional relationship between the valve body 41 and the spring 44.

The valve seat 42 has a substantially columnar shape as a whole. A frusto-conical shape that is screwed downward from the lower end surface of the valve seat 42 into a gas vent valve mounting hole (not shown) provided in the upper end cover 3 and contracts downward. Mounting leg 424 extends while the valve seat 4
A spring accommodating chamber 423, which is a cylindrical recessed portion, for accommodating the spring 44, is formed on the upper end surface of 2. In addition, a screw that is screwed into the gas vent valve mounting hole is provided on an outer surface of the mounting leg 424. A valve seat surface 421, which is a conical surface that opens upward, is formed at the upper end of the side wall of the spring housing chamber 423, and extends downward from the center of the bottom surface of the spring housing chamber 423. A communicating vent hole 422 extends.

When the vent valve 4 is closed, the valve seat surface 421 has a valve body valve seat surface 41 that the valve body 41 has.
1 is formed so as to be in close contact therewith. Spring accommodation room 423
Accommodates the spring 44 as described above. A spring insertion portion 414 of the valve body 41 is provided at an upper end of the spring 44.
Is inserted. The valve body 41 is urged upward by the spring 44.

The valve box 43 has a cylindrical shape having an opening below. A circular guide hole 432 into which the guide member 412 is slidably inserted is provided at the center of the top surface of the valve box 43. The top surface of the valve box 43 is further provided with four gas flow holes 431 communicating with the inside and the outside of the valve box 43 on a circumference concentric with the guide hole 432. When the guide member 412 slides while being fitted into the guide hole 432 of the valve box 43, the valve body 41 is guided in the up-down direction.

The valve seat 42 and the valve box 43 are connected to each other by four bolts 45 arranged on the circumference concentric with the guide hole 432 outside the gas flow hole 431. I have.

In the submerged pump P of FIG. 1, the motor chamber 1 corresponds to the motor chamber of the submerged pump according to the present invention, and the rotating shaft 13 and the rotor 11 are connected to the rotating shaft of the submerged pump according to the present invention. And a rotor. The stator 12 corresponds to a stator in the submerged pump of the present invention.

The pump chamber 2 corresponds to the pump chamber in the submerged pump of the present invention, and the impeller fixed to the rotating shaft 13 and not shown in FIG. 1 corresponds to the impeller in the submerged pump of the present invention. . The handled liquid flow path and the reflux pipe 6 correspond to a handled liquid flowing means in the submerged pump according to the present invention, and the gas vent valve 4 corresponds to a gas vent valve in the submerged pump according to the present invention.

The operation of the submerged pump P shown in FIG. 1 will be described below.

During operation of the submerged pump P, the pressure outside the motor chamber 1 is maintained at a higher pressure than the inside of the motor chamber 1 due to the discharge pressure from the pump chamber 2. Therefore, the valve element 41 of the gas release valve 4 is pressed downward as shown in FIG. 2A and pressed against the valve seat 42. Therefore, the valve body valve seat surface 411 of the valve body 41 is
1, whereby the vent valve 4 closes. Therefore, the handled liquid discharged from the discharge port 22 is supplied to the degassing valve 4.
The liquid is discharged from the upper end opening of the column 5 without flowing into the motor chamber 1 through the motor.

When the submerged pump P stops, the discharge pressure from the pump chamber 2 becomes zero, so that the flow of the liquid to be processed into the motor chamber 1 is stopped. It is not cooled by the flow and generates heat rapidly. Therefore, the handling liquid remaining in the motor chamber 1 is rapidly gasified, and the pressure in the motor chamber 1 is rapidly increased. On the other hand, since the discharge pressure from the submerged pump P is not applied to the liquid handled outside the motor chamber 1, the pressure decreases outside the motor chamber 1. Therefore, the valve body 41 is lifted by the spring 44 that urges the valve body 41 upward, as shown in FIG. 2B, and the valve body valve seat surface 411 and the valve seat surface 421 of the valve body 41 There is a gap between them. The gas inside the motor chamber 1 passes through the gas vent hole 422 in the gas vent valve 4, and escapes from the gap formed between the valve body valve seat surface 411 and the valve seat surface 421 to the outside. As the gas escapes from the vent valve 4, the inside of the motor chamber 1 is filled with the handling liquid again.

Therefore, even when the operation is restarted immediately after the submerged pump P is stopped, the upper bearing 1
4 and the lower bearing are kept lubricated with the handling liquid. When the operation of the submerged pump P is restarted, the pressure outside the motor chamber 1 increases, and the degassing valve 2 closes again against the urging force of the spring 44.

2. Hereinafter, the motor chamber, the pump chamber, the liquid handling means, and the gas vent valve in the submerged pump of the present invention will be described in detail.

2.1 Motor Chamber In the canned motor pump of the present invention, the motor chamber comprises:
It has a function of rotating an impeller provided in a pump chamber described later.

[0035] The motor chamber may include a rotor having a rotating shaft, a stator surrounding the rotor, and a housing accommodating the stator. In the housing,
A bearing for supporting the rotating shaft may be provided. Then, by flowing at least a part of the handling liquid discharged from a pump chamber to a space formed between the rotor and the stator, the stator and the rotor are cooled, and The bearing holding the rotating shaft can be lubricated.

In the present invention, the handling liquid is
For example, liquefied natural gas, liquefied ethane gas, liquefied petroleum gas, liquefied propane gas, liquefied ethylene gas, liquefied propylene gas, liquefied nitrogen gas, liquefied carbon dioxide gas, liquefied ammonia gas, liquefied oxygen gas, liquefied hydrogen gas, liquefied helium gas, etc. Of various liquefied gases.

Therefore, when the handling liquid is a flammable liquefied gas, it is particularly preferable that the rotor does not have a commutator, so that the motor composed of the rotor and the stator is Motors without commutators, such as induction motors, synchronous motors, and commutatorless DC motors, are preferred.

The rotor may be configured such that neither the iron core nor the winding or the conductor (hereinafter abbreviated as “iron core or the like”) does not come into contact with the handling liquid. In particular, in a submerged pump in which a highly corrosive liquefied gas such as liquid ammonia is used as a handling liquid, it is preferable that the iron core and the like be configured so as not to contact the handling liquid. This is the same for the stator.

As the rotor, for example, a rotor having a substantially cylindrical shape and having an outer peripheral surface covered with a rotor-side cover that does not allow liquid to pass through can be given. On the other hand, examples of the stator include a stator whose inner peripheral surface is covered with a stator-side cover that does not allow liquid to pass through.

In the submerged pump, the stator-side cover and the rotor-side cover may be any type of cover as long as the cover does not allow the handling liquid to pass through. Examples of the rotor-side cover and the stator-side cover include, for example, a high-corrosion-resistant metal material such as stainless steel, a synthetic resin, a glass fiber-reinforced resin, or a thin plate of an aramid fiber-reinforced resin or the like. Can and rotor side can. Note that a jacket made of a thin plate of a highly corrosion-resistant metal material, a synthetic resin, a glass fiber reinforced resin, an aramid fiber reinforced resin, or the like, which is impermeable to the handling liquid, may be inserted inside the stator. In this case, the inner peripheral surface of the mantle forms the stator side cover.

The rotor enclosed in the synthetic resin and the stator enclosed in the synthetic resin are also included in the rotor and the stator in the motor chamber of the present invention. In the case where the rotor and the stator are sealed in a synthetic resin, the rotor-side cover and the stator-side cover are unnecessary.

As a method of enclosing the rotor and the stator in the synthetic resin, for example, a reaction injection molding method, an injection molding method,
Various methods such as a liquid injection molding method, a resin transfer molding method, and a reaction casting method can be exemplified. Among these methods, the reaction injection molding method is particularly preferred. The resin used to encapsulate the rotor and the stator is not particularly limited, and various thermoplastic resins and thermosetting resins are used. Among these thermoplastic resins and thermosetting resins,
Polydicyclopentadiene is particularly preferred because it is tough, has excellent heat resistance and chemical resistance, and has the property of increasing strength when repeatedly heated.

2.2 Pump Chamber In the submerged pump of the present invention, the pump chamber comprises:
An impeller is provided below and adjacent to the motor chamber and fixed to a rotating shaft of the rotor, and has a function of sucking and discharging the handled liquid by rotating the impeller.

In the pump chamber, a suction port for sucking the handling liquid may be provided at a lower end portion, and a discharge port for discharging the handling liquid may be provided on a side surface.

In the pump chamber, a single-stage pump having only one impeller may be provided, or a multi-stage pump having two or more impellers may be provided.

A balance disk ("balance"), which is a disk-shaped member for reducing the axial force acting on the shaft, is provided between the pump chamber and the motor chamber on the shaft on which the impeller is mounted. Drum ").

2.3 Handling Liquid Distribution Means In the present invention, the handling liquid distribution means has a function of distributing at least a part of the handling liquid discharged from the pump chamber into the motor chamber.

Examples of the liquid handling means include, for example, a liquid handling channel that connects the inside of the pump chamber and the inside of the motor chamber.

The handling liquid flow path may be provided along the axis of the rotor of the motor chamber, or may be provided at a portion near the axis of the impeller of the pump chamber.

In addition, the handling liquid flowing means may include the handling liquid flow path and the handling liquid flowing through the motor chamber, the suction port of the pump chamber, the first stage impeller outlet, the intermediate stage impeller outlet, and the intermediate pressure. A handling liquid circulation flow path including a handling liquid return flow path such as a reflux pipe returning to any of the chambers.

2.4 Degassing Valve In the submerged pump according to the present invention, the degassing valve allows gas to flow from the inside to the outside of the motor chamber, and controls the flow of liquid from the outside to the inside of the motor chamber. Has the function of shutting off.

The valves that can be used as the vent valve include:
A swing-type check valve that opens and closes when a disc-shaped valve body swings like a pendulum about a point on a valve body, a lift-type check valve that opens and closes when a disc-shaped valve body moves up and down, and Various check valves such as a ball type check valve having a spherical valve body can be given. In these check valves, an urging member for urging the valve body to open the valve can be provided. Examples of such a biasing member include various springs such as a plate spring and a coil spring. Preferred valves as the gas release valve include a lift type check valve and a ball type check valve,
Particularly preferable valves include a lift check valve and a ball check valve in which the urging member is provided on a valve body.

In the lift valve, the shape of the valve body valve seat surface and the shape of the valve seat surface are not particularly limited. As the shape of the valve body valve seat surface, for example, a conical convex surface such as the gas vent valve shown in FIG. 2 can be mentioned. Other examples of the shape of the valve seat surface include a spherical convex surface, a conical concave surface, and a spherical concave surface.

The location where the gas vent valve is provided may be any location on the housing of the motor chamber. The submerged pump usually has a substantially columnar shape, and is installed in a state of being suspended inside a column extending in the vertical direction. Parts are most preferred.

3. Another Example of the Present Invention Another example of the vent valve that can be used in the submerged pump of FIG. 1 is shown in FIG. 3 as a cross-sectional view.

In FIG. 3, (A) shows the state of the vent valve 4 when the submerged pump is operating,
(B) shows the state of the gas release valve 4 when the submerged pump is stopped.

As in the case of the gas vent valve shown in FIG. 2, the gas vent valve 4 of FIG. 3 also has a valve element 41, a valve seat 42 which cooperates with the valve element 41 to open and close a gas flow path, and And a cylindrical valve box 43 mounted on an upper part of the valve seat 42 for guiding the valve element 41 in the vertical direction.

The valve body 41 has a disk shape, and
3, a disc-shaped valve body guide member 415 that slides up and down, and a cylindrical valve that extends downward from the lower surface of the valve body guide member 415 and has a smaller diameter than the valve body guide member 415. And a body body 410. The valve body 4
A valve body valve seat surface 411, which is a conical surface that decreases downward, is formed at the lower end of 10. Note that a portion of the valve body guide member 415 outside the valve body body 410 includes:
A gas flow passage 416 communicating in the up-down direction is provided.

The valve seat 42 has a substantially columnar shape as a whole, and is formed at its lower end with a mounting leg 424 having a truncated conical shape that is reduced downward. Screws to be screwed into gas vent valve mounting holes (not shown) provided in the upper end cover 3 are also provided on the outer side surfaces of the mounting legs 424. At the center of the valve seat 42, a valve seat flange portion 42a extending outward is formed, and the valve seat 4
2 has a vent hole 422 communicating vertically.
Are formed. At the upper end of the inner wall of the gas vent hole 422, a valve seat surface 421 that is a conical surface that opens upward is formed. The valve seat surface 421 is formed so as to be in close contact with the valve body valve seat surface 411 of the valve body 41 when the gas vent valve 4 is closed.

On the upper surface of the valve seat flange 42a, the valve body 4
The lower end of the coil spring 44 that urges 1 upward is in contact.
The upper end of the coil spring 44 is connected to the valve guide member 415.
Abuts the lower surface of.

The valve box 43 has a cylindrical shape whose lower end is open. On the top surface of the valve box 43, four gas vent holes 431 are provided on a circumference centered on the center point of the top surface. The gas vent hole 431 is a communication hole that communicates the inside and the outside of the valve box 43.

The valve body 41 is guided up and down by sliding the outer surface of the valve body guide member 415 against the inner surface of the valve box 43.

Incidentally, similarly to the gas vent valve shown in FIG.
In the degassing valve shown in FIG. 3 as well, the valve seat 42 and the valve box 43 are connected to the outside of the gas flow hole 431 by four bolts 45 arranged on the circumference.

The operation of the gas vent valve during operation and stoppage of the submerged pump shown in FIG. 1 with the gas vent valve shown in FIG. 3 will be described below.

During operation of the submerged pump, the pressure outside the motor chamber 1 is maintained at a higher pressure than the inside of the motor chamber 1 due to the discharge pressure from the pump chamber 2. Therefore, the valve element 41 of the gas release valve 4 is pressed downward in FIG. 3 and pressed against the valve seat 42 as shown in FIG. Therefore,
The valve body valve seat surface 411 of the valve body 41 is in close contact with the valve seat surface 421 of the valve seat 42. Thereby, the vent valve 4
Closes.

When the submerged pump stops, as described above, the handling liquid remaining in the motor chamber 1 rapidly gasifies, and the pressure in the motor chamber 1 rapidly increases, while the motor chamber 1 rapidly increases in pressure. Outside of 1, the pressure drops. Therefore, the valve body 41 is lifted by the spring 44 that urges the valve body 41 upward as shown in FIG. 3B, and the valve body valve seat surface 411 and the valve seat surface 421 of the valve body 41 There is a gap between them, and the vent valve 4 opens. As the gas escapes from the vent valve 4, the inside of the motor chamber 1 is filled with the handling liquid again.

Therefore, even when the operation is restarted immediately after the submerged pump P is stopped, the upper bearing 1
4 and the lower bearing are kept lubricated with the handling liquid. When the operation of the submerged pump P is restarted, the pressure outside the motor chamber 1 increases, and the degassing valve 2 closes again against the urging force of the spring 44.

[0068]

According to the present invention, there is provided a submerged pump in which a gas which is a gas of a liquid handled in a motor chamber is quickly discharged to the outside when the motor is stopped.

Therefore, in the submerged pump provided by the present invention, the bearing in the motor chamber is kept in a lubricated state even when the pump is operated in the operation mode in which start and stop are frequently repeated.

Therefore, in the submerged pump provided by the present invention, the problem that the life of the bearing in the motor chamber is shortened hardly occurs even when the operation is performed in the operation mode.

[Brief description of the drawings]

FIG. 1 is a partial sectional view showing an example of a submerged pump according to the present invention.

FIG. 2 is a cross-sectional view showing a vertical cross section of the vent valve.

FIG. 3 is a cross-sectional view showing another example of the gas vent valve that can be used in the submerged pump shown in FIG.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Motor room, 11 ... Rotor, 12 ... Stator, 13 ... Rotating shaft, 14 ... Bearing, 2 ... Pump room, 21 ... Suction port, 22 ..Discharge ports, 3
· Top cover, 31 ··· Bearing holding part, 32 ··· Communication hole, 4 ··· Gas release valve, 41 ··· Valve body, 411 ···
.Valve valve seat surface, 412 ... guide member, 413 ...
Intermediate portion, 414: Spring insertion portion, 415: Valve guide member, 416: Gas flow hole, 42: Valve seat, 4
21 ... valve seat surface, 422 ... gas inlet, 43 ...
・ Valve box, 431: gas flow hole, 432: guide hole, 44: spring

Claims (1)

[Claims] 1. A motor chamber having a rotor having a rotating shaft, a stator surrounding the rotor, an impeller fixed to the rotating shaft, and the rotation of the impeller for the handling of liquid. A pump chamber that performs suction / discharge and is disposed adjacent to and below the motor chamber; a handling liquid distribution unit that allows at least a part of a handling liquid discharged from the pump chamber to flow into the motor chamber; A gas vent valve provided in the motor chamber for passing a gas from the inside to the outside and blocking a flow of a liquid from the outside to the inside of the motor chamber.