阅读说明：本技术 潜水泵 (Submersible pump ) 是由 金子智矢 吉田慎吾 鶴田秀典 于 2019-11-28 设计创作，主要内容包括：本发明的潜水泵(100)包括：热交换室(31、431、731、731、831、931)；第一流路(32、432、832),相对于油室(15)设置在驱动轴(10a)的径向外侧,将热交换室和马达冷却室(30)连通,使冷却液从热交换室和马达冷却室中的一者流向另一者；和第二流路(33、433、833),相对于油室设置在径向外侧,将热交换室和马达冷却室连通,使冷却液沿与第一流路相反的方向流动。(The submersible pump (100) of the present invention comprises: heat exchange chambers (31, 431, 731, 831, 931); a first flow path (32, 432, 832) which is provided on the radial outer side of the drive shaft (10a) with respect to the oil chamber (15), communicates the heat exchange chamber with the motor cooling chamber (30), and allows the coolant to flow from one of the heat exchange chamber and the motor cooling chamber to the other; and a second flow path (33, 433, 833) which is provided radially outward of the oil chamber, communicates the heat exchange chamber and the motor cooling chamber, and causes the coolant to flow in a direction opposite to the first flow path.)

1. A submersible pump (100, 200, 300, 400, 500, 600, 700, 800, 900) comprising:

a motor (10) having a drive shaft (10 a);

a pump chamber (12) in which an impeller (14) driven by the motor is disposed, and which is provided with a suction port (13a) and a discharge port (13 b);

an oil chamber (15) provided with a mechanical seal (15a) having a sliding portion, and disposed between the motor and the pump chamber;

a motor cooling chamber (30) disposed adjacent to the motor for cooling the motor by a cooling liquid;

a heat exchange chamber (31, 431, 731, 831, 931) arranged adjacent to the pump chamber and performing heat exchange between the cooling liquid and the liquid in the pump chamber by flowing the cooling liquid;

a first flow path (32, 432, 832) that is provided radially outside the drive shaft with respect to the oil chamber, communicates the heat exchange chamber and the motor cooling chamber, and causes the coolant to flow from one of the heat exchange chamber and the motor cooling chamber to the other; and

and a second flow path (33, 433, 833) that is provided radially outward of the oil chamber, communicates the heat exchange chamber and the motor cooling chamber, and causes the coolant to flow in a direction opposite to the first flow path.

2. A submersible pump according to claim 1, characterized in that the heat exchange chamber is provided with a sealing structure having watertight properties with respect to the outside.

3. The submersible pump according to claim 1, further comprising a coolant circulation pump chamber (34) that is provided with a coolant circulation impeller (34a, 634a) of the coolant driven by the motor, and that is provided between the motor and the oil chamber in the second flow path.

4. The submersible pump of claim 1,

the first and second flow paths extend in the axial direction of the drive shaft along the outer periphery of the oil chamber on the radially outer side of the oil chamber.

5. The submersible pump of claim 1, wherein at least one of the first and second flow paths is formed substantially around the entire circumference of the oil chamber.

6. The submersible pump of claim 3,

the second flow path is configured to: and a cooling fluid circulation impeller disposed radially inward of the first flow path, the cooling fluid circulation impeller causing the cooling fluid from the heat exchange chamber to flow into the cooling fluid circulation pump chamber and causing the cooling fluid flowing out of the cooling fluid circulation pump chamber to flow into the motor cooling chamber.

7. The submersible pump of claim 3,

the second flow path is configured to: and a cooling fluid circulation impeller disposed radially inward of the first flow path, the cooling fluid circulation impeller causing the cooling fluid from the motor cooling chamber to flow into the cooling fluid circulation pump chamber and causing the cooling fluid flowing out of the cooling fluid circulation pump chamber to flow into the heat exchange chamber.

8. A submersible pump according to claim 1, further comprising a first housing part (23, 423) having an oil change hole communicating with the atmosphere and the oil housing chamber and provided with the oil chamber.

9. The submersible pump of claim 8,

the first housing portion is configured such that the oil change hole and the first and second flow paths provided in the first housing portion do not overlap with each other in a plan view.

10. The submersible pump according to claim 1, wherein the first flow passage is provided with at least one, is arranged on the radially outer side of the second flow passage, and is formed in a circular arc shape surrounding the drive shaft in a plan view.

11. The submersible pump of claim 2, further comprising:

a first housing section (23, 423) that is open on the heat exchange chamber side and in which the oil chamber is provided;

a second housing portion (25, 725, 825, 925) open at the first housing portion side and provided with the heat exchange chamber; and

a partition member (24) disposed between the first housing portion and the second housing portion, partitioning the oil casing chamber and the heat exchange chamber,

the seal structure includes a seal member provided between the first housing portion and the partition member, sealing watertight between the oil casing chamber and the heat exchange chamber.

12. The submersible pump of claim 2, further comprising:

a first housing section (23, 423) that is open on the heat exchange chamber side and in which the oil chamber is provided;

a second housing portion (25, 725, 825, 925) open at the first housing portion side and provided with the heat exchange chamber; and

a partition member (24) disposed between the first housing portion and the second housing portion, partitioning the oil chamber and the heat exchange chamber,

the seal structure includes an integral structure in which the second housing portion and the partition member are integrally formed.

13. The submersible pump of claim 3, further comprising:

a first housing section (23, 423) provided with the oil chamber;

a second housing portion (25, 725, 825, 925) provided with the heat exchange chamber;

a third housing section (22) provided with the coolant circulation pump chamber; and

a fourth housing part (21) provided between the third housing part and the motor,

the first flow path and the second flow path are formed by stacking the first housing section, the second housing section, the third housing section, and the fourth housing section in this order with respect to the pump chamber.

14. The submersible pump of claim 13,

the fourth housing portion has a motor-side first opening (21a) for communicating the first flow path with the motor cooling chamber and a motor-side second opening (21a) for communicating the second flow path with the motor cooling chamber,

the motor-side first opening and the motor-side second opening are respectively provided at positions deviated from each other in the circumferential direction of the drive shaft.

15. The submersible pump of claim 13,

the fourth housing portion extends along a lower surface of the motor,

the second flow path includes: a motor lower side flow path (33b) extending in the radial direction along a lower surface of the motor between the third housing portion and the fourth housing portion and connected at one end and the other end to the coolant circulating pump chamber and the motor cooling chamber, respectively.

16. The submersible pump of claim 13,

the second housing portion is configured such that a position of the heat exchange chamber in an axial direction of the drive shaft is formed to overlap a position of the oil chamber in the axial direction.

17. The submersible pump of claim 1,

the heat exchange chamber includes: and a guide member (31a, 431a, 831a, 931a) for restricting the flow of the coolant flowing in from the radially outer side so as to flow along the drive shaft and flow out from the radially outer side.

18. The submersible pump of claim 17,

the guide member includes: and a plurality of ribs (31a) that have a gap at the radially inner end that is a part of the coolant flow path and that radially extend in the radial direction.

19. The submersible pump of claim 1, further comprising:

a reservoir chamber (51, 351) disposed between the motor and the oil chamber, and

a level sensor (52, 352) that detects a predetermined level of liquid flowing into and stored in the storage chamber.

20. The submersible pump of claim 1,

the heat exchange chamber is provided radially outside the pump chamber.

Technical Field

The invention relates to a submersible pump.

Background

Submersible pumps for cooling motors with cooling liquids are known from the prior art. Such a submersible pump is disclosed in, for example, japanese patent No. 5552402.

Japanese patent No. 5552402 discloses a submersible pump including a motor, a coolant circulation flow path for cooling coolant of the motor, and a mechanical seal provided on the coolant circulation flow path. The submersible pump is configured to use the coolant of the motor as a lubricant for the mechanical seal.

Prior art documents

Patent document

Patent document 1: japanese patent No. 5552402

Disclosure of Invention

Problems to be solved by the invention

However, in the submersible pump of japanese patent No. 5552402, since the liquid flowing through the cooling liquid circulation flow path is used for both cooling and lubrication, there is a problem that it is impossible to select an optimum liquid for each application. Further, when the liquid in the pump chamber enters the cooling liquid circulation flow path through the mechanical seal, there is a problem that the cooling liquid is immediately contaminated. If the cooling liquid is contaminated, scum or the like contained in the entering liquid may block the flow path and stop the circulation of the cooling liquid, which is not preferable. That is, it is not preferable because the function of cooling the motor is hindered.

The present invention has been made to solve the above-mentioned problems, and an object of the present invention is to provide a submersible pump which can select an optimum liquid as liquids for cooling a motor and lubricating a mechanical seal, respectively, and can suppress contamination of a cooling liquid.

Means for solving the problems

A submersible pump according to one aspect of the present invention has: a motor including a drive shaft; a pump chamber provided with an impeller driven by a motor and having a suction port and a discharge port; an oil chamber provided with a mechanical seal having a sliding portion and disposed between the motor and the pump chamber; a motor cooling chamber disposed adjacent to the motor for cooling the motor by a cooling liquid; a heat exchange chamber disposed adjacent to the pump chamber, for exchanging heat between the cooling liquid and the liquid in the pump chamber by flowing the cooling liquid; a first flow path which is provided on the radial outer side of the drive shaft with respect to the oil chamber, communicates the heat exchange chamber with the motor cooling chamber, and causes the coolant to flow from one of the heat exchange chamber and the motor cooling chamber to the other; and a second flow path which is provided radially outward of the oil chamber, communicates the heat exchange chamber and the motor cooling chamber, and causes the coolant to flow in a direction opposite to the first flow path.

As described above, in the submersible pump according to one aspect of the present invention, by providing the first flow path, the second flow path, the motor cooling chamber, and the heat exchange chamber for flowing the cooling liquid separately from the oil chamber, cooling of the motor and lubrication of the mechanical seal can be performed by separate liquids, so that optimum liquids can be selected as various liquids for cooling the motor and lubricating the mechanical seal. Further, even when the liquid in the pump chamber is immersed through the mechanical seal, the liquid (oil) in the oil chamber can be contaminated first, so that contamination of the coolant can be prevented. According to the above, an optimum liquid can be selected as each liquid for cooling the motor and lubricating the mechanical seal, and contamination of the cooling liquid can be suppressed.

In the submersible pump according to the above-described aspect, preferably, the heat exchange chamber is provided with a sealing structure having water-tight property with respect to the outside. With this configuration, it is possible to effectively prevent liquid or air from entering the heat exchange chamber from the outside (e.g., the pump chamber side, the atmosphere side, and the oil chamber side) of the heat exchange chamber by the seal structure. This can further suppress contamination of the coolant.

In the submersible pump according to the above-described aspect, it is preferable that a coolant circulation pump chamber, which is provided with a coolant circulation impeller of the coolant driven by the motor and is provided on the second flow path between the motor and the oil chamber, is further included. With this configuration, the coolant circulation pump chamber can be disposed at a position further from the pump chamber than the oil chamber along the drive shaft, and the immersion target can be the oil chamber even if immersion occurs. This can further suppress contamination of the coolant.

In the submersible pump according to the above-described one aspect, preferably, the first flow path and the second flow path extend in the axial direction of the drive shaft along the outer periphery of the oil chamber on the radially outer side of the drive shaft of the oil chamber. With this configuration, the lengths of the first and second flow paths can be shortened as compared with a case where the first and second flow paths extend in the direction intersecting the axial direction of the drive shaft around the oil chamber, so energy loss in the flow paths can be reduced, and the motor can be cooled efficiently.

In the submersible pump according to the above-described aspect, preferably, at least one of the first flow path and the second flow path is formed substantially around the entire circumference of the oil chamber. With this configuration, the coolant can flow into the heat exchange chamber from substantially the entire circumference of the oil chamber, so that a large heat transfer area between the coolant in the heat exchange chamber and the liquid in the pump chamber can be ensured. This enables efficient heat exchange between the coolant and the liquid in the pump chamber.

In the configuration including the above-described coolant circulation pump chamber, preferably, the second flow path is configured to: the cooling fluid circulating impeller is disposed radially inward of the first flow path, and causes the cooling fluid from the heat exchange chamber to flow into the cooling fluid circulating pump chamber and causes the cooling fluid flowing out of the cooling fluid circulating pump chamber to flow into the motor cooling chamber. With this configuration, the coolant cooled in the heat exchange chamber can flow toward the second flow path closer to the motor than the first flow path in the radial direction of the drive shaft, and the motor can be cooled efficiently.

In the configuration including the above-described coolant circulation pump chamber, preferably, the second flow path is configured to: the cooling fluid circulating impeller is disposed radially inward of the drive shaft of the first flow path, and causes the cooling fluid from the motor cooling chamber to flow into the cooling fluid circulating pump chamber and causes the cooling fluid flowing out of the cooling fluid circulating pump chamber to flow into the heat exchange chamber. With this configuration, the coolant can be made to flow to the heat exchange chamber side on the side opposite to the motor (excluding the drive shaft) by the coolant circulating impeller, and therefore the motor side is set to a negative pressure, and water intrusion into the motor can be effectively suppressed.

In the submersible pump according to the above-described aspect, it is preferable that the first housing portion further includes an oil change hole for communicating the atmosphere with the oil chamber, and is provided with the oil chamber. With this configuration, as compared with a case where the oil change holes are provided astride the plurality of housing portions, it is possible to save the trouble of assembling the plurality of housing portions. In addition, the number of sealing members required to prevent oil leakage can be reduced.

In this case, it is preferable that the first housing portion is configured such that the oil change hole and the first and second flow paths provided in the first housing portion do not overlap with each other in a plan view. With this configuration, the flow of the coolant in the first flow path and the second flow path can be prevented from being obstructed by the oil change hole, and the structure of the first housing portion can be prevented from becoming complicated.

In the submersible pump according to the above-described aspect, it is preferable that the first flow passage is provided with at least one, is arranged radially outward of the drive shaft of the second flow passage, and is formed in an arc shape surrounding the drive shaft in a plan view. With this configuration, the shape of the first flow path can be formed into a shape along the outer periphery of the motor.

In the above-described configuration in which the heat exchange chamber is provided with the seal structure, it is preferable to further include: a first housing section that is open on the heat exchange chamber side and that is provided with an oil chamber; a second housing section that is open on the first housing section side and is provided with a heat exchange chamber; and a partition member disposed between the first housing portion and the second housing portion, and partitioning the oil chamber and the heat exchange chamber, the seal structure including a seal member provided between the first housing portion and the partition member, and sealing watertightly between the oil chamber and the heat exchange chamber. With this configuration, the sealing member can seal the space between the oil chamber and the heat exchange chamber watertight and prevent the oil from contaminating the coolant.

In the above-described configuration in which the heat exchange chamber is provided with the seal structure, it is preferable to further include: a first housing section that is open on the heat exchange chamber side and that is provided with an oil chamber; a second housing section that is open on the first housing section side and is provided with a heat exchange chamber; and a partition member disposed between the first housing portion and the second housing portion, and partitioning the oil chamber and the heat exchange chamber, the seal structure including an integral structure in which the second housing portion and the partition member are integrally formed. With this configuration, the number of places requiring sealing can be reduced, and the water tightness of the heat exchange chamber can be improved. This can further simplify the apparatus configuration.

In the above configuration including the coolant circulation pump chamber, it is preferable that the pump further includes: a first housing section provided with an oil chamber; a second housing portion provided with a heat exchange chamber; a third housing section provided with a coolant circulation pump chamber; and a fourth housing portion between the third housing portion and the motor, the first flow path and the second flow path being formed by sequentially laminating the first housing portion, the second housing portion, the third housing portion, and the fourth housing portion in the order of the second housing portion, the first housing portion, the third housing portion, and the fourth housing portion with respect to the pump chamber. With this configuration, the pump body can be easily assembled by simply stacking the first, second, third, and fourth housing portions in the order of the second, first, third, and third housing portions.

In this case, preferably, the fourth housing portion has a motor-side first opening for communicating the first flow passage with the motor cooling chamber and a motor-side second opening for communicating the second flow passage with the motor cooling chamber, the motor-side first opening and the motor-side second opening being provided at positions offset from each other in the circumferential direction of the drive shaft, respectively. With this configuration, the motor-side first opening and the motor-side second opening can be used as an opening for flowing the coolant to the motor cooling chamber and an opening for flowing the coolant to the heat exchange chamber.

In the above-described configuration in which the second housing portion, the first housing portion, the third housing portion, and the fourth housing portion are stacked in this order, preferably, the fourth housing portion extends along a lower surface of the motor, and the second flow path includes: a motor lower side flow path extending in a radial direction of the drive shaft along a lower surface of the motor between the third housing portion and the fourth housing portion, one end and the other end being connected to the cooling liquid circulation pump chamber and the motor cooling chamber, respectively. With this configuration, the motor can be cooled from the lower side by the coolant flowing through the motor lower side flow path.

In the above-described configuration in which the second housing portion, the first housing portion, the third housing portion, and the fourth housing portion are stacked in this order, it is preferable that the second housing portion is configured such that a position of the heat exchange chamber in the axial direction of the drive shaft is formed to overlap a position of the oil chamber in the axial direction of the drive shaft. With this configuration, the length of the drive shaft can be shortened as compared with a case where the heat exchange chamber and the oil chamber do not overlap in the axial direction of the drive shaft and are arranged along the drive shaft. That is, the apparatus can be downsized in the axial direction.

In the submersible pump according to the above-described aspect, preferably, the heat exchange chamber includes: and a guide member for restricting the flow of the coolant flowing in from the radially outer side of the drive shaft so as to flow along the drive shaft and flow out from the radially outer side. With this configuration, the flow of the cooling liquid is restricted by the guide member so that it flows along the drive shaft (the circumferential direction of the drive shaft) during driving, and the cooling liquid can be made to flow along the pump chamber, and the flow of the cooling liquid in the heat exchange chamber can be rectified.

In this case, preferably, the guide member includes: the end portion on the inner side in the radial direction of the drive shaft is provided with a plurality of ribs which are gaps as a part of the flow path of the cooling liquid and radially extend in the radial direction. With this configuration, the flow path of the coolant in the heat exchange chamber can be given a shape including a fold-back by the rib, so that the flow path of the coolant in the heat exchange chamber can be extended and heat exchange between the coolant and the liquid in the pump chamber can be performed more efficiently.

In the submersible pump according to the above-described aspect, it is preferable that a reservoir chamber is disposed between the motor and the oil chamber, and a liquid level sensor that detects a predetermined level of liquid that flows into and is stored in the reservoir chamber. With this configuration, it is possible to suppress the liquid from rising to the motor side by the reservoir chamber. In addition, the oil rise or water immersion in the oil storage chamber can be detected by the level sensor. Thereby, before oil rise or flooding occurs in the motor, maintenance work can be reliably performed.

In the submersible pump according to the above-described aspect, preferably, the heat exchange chamber is disposed radially outside the pump chamber. With this configuration, a large heat transfer area between the heat exchange chamber and the pump chamber can be ensured by using substantially the entire circumference of the outer circumference of the pump housing, so that heat exchange can be efficiently performed. In addition, heat exchange can be efficiently performed between the coolant in the heat exchange chamber and the fluid outside the submersible pump. In addition, in the case of a vertical submersible pump, the heat exchange chamber may be disposed at a relatively low position, so that heat exchange may be more effectively performed between the cooling liquid of the heat exchange chamber and the fluid outside the submersible pump even if the water level outside the submersible pump is low. Further, the length of the drive shaft can be shortened as compared with a case where the heat exchange chamber and the pump chamber are arranged along the drive shaft without overlapping in the axial direction of the drive shaft. That is, the apparatus can be downsized in the axial direction.

Effects of the invention

According to the present invention, as above, the following submersible pump may be provided: an optimum liquid can be selected as each liquid for cooling the motor and lubricating the mechanical seal, and contamination of the cooling liquid can be suppressed.

Drawings

Fig. 1 is a schematic view showing a submersible pump according to a first embodiment of the present invention.

Fig. 2 is an exploded perspective view showing a cross section of a housing portion of a submersible pump according to a first embodiment of the present invention.

Fig. 3 is a side view showing an oil casing chamber of the submersible pump according to the first embodiment of the present invention.

Fig. 4 is a cross-sectional view taken along line 1000-1000 of fig. 3.

Fig. 5 is a plan view illustrating a cooling jacket of a submersible pump according to a first embodiment of the present invention.

Fig. 6 is a schematic view illustrating a submersible pump according to a second embodiment of the present invention.

Fig. 7 is a schematic view illustrating a submersible pump according to a third embodiment of the present invention.

Fig. 8 is a schematic view illustrating a submersible pump according to a fourth embodiment of the present invention.

Fig. 9 is a sectional view of an oil casing chamber of a submersible pump according to embodiment 3 of the present invention, and corresponds to fig. 4.

Fig. 10 is a schematic view showing a submersible pump according to a fifth embodiment of the present invention.

Fig. 11 is a partially enlarged schematic view illustrating a submersible pump according to a sixth embodiment of the present invention.

Fig. 12 is a schematic view showing a submersible pump according to a seventh embodiment of the present invention.

Fig. 13 is a plan view of a cooling jacket of a submersible pump according to a seventh embodiment of the present invention, which corresponds to fig. 5.

Fig. 14 is a schematic view showing a submersible pump according to an eighth embodiment of the present invention.

Fig. 15 is a plan view of a cooling jacket of a submersible pump according to an eighth embodiment of the present invention, which corresponds to fig. 5.

Fig. 16 is a schematic view showing a submersible pump according to a ninth embodiment of the present invention.

Fig. 17 is a sectional view taken along line 1100 of fig. 16.

Fig. 18 is a cross-sectional view taken along line 1200-1200 of fig. 16.

Detailed Description

Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings.

First embodiment

(construction of submersible pump)

A first embodiment of the present invention will be described with reference to fig. 1 to 5. As shown in fig. 1, the submersible pump 100 according to the first embodiment includes a motor 10 (electric motor), a top cover 11, a pump chamber 12, a pump housing sleeve 13, an impeller 14, an oil chamber 15, a housing portion 2, a coolant circulation portion 3 provided in the housing portion 2, and a seal member 4.

The seal member 4 is provided in a heat exchange chamber 31 described later of the coolant circulation unit 3. The seal member 4 has a watertight structure with respect to the outside, preventing liquid from entering from the pump chamber 12 side. That is, the seal member 4 prevents the coolant from being contaminated by water entering from the pump chamber 12 side.

The submersible pump 100 is an internally cooled pump. Specifically, the submersible pump 100 is configured to cool the motor 10 with the coolant circulated by the coolant circulation portion 3. The submersible pump 100 is configured to perform heat exchange between the coolant and the liquid in the pump chamber 12 in the heat exchange chamber 31. That is, the submersible pump 100 is configured to cool the coolant in the heat exchange chamber 31. The coolant is, for example, water to which ethylene glycol is added.

Therefore, according to circumstances, the submersible pump 100 may be used even in an environment in which the submersible pump 100 is exposed due to a drop in the level of liquid around the submersible pump 100. Additionally, the submersible pump 100 may be used even in environments similar to surface pumps that are always exposed. The submersible pump 100 is a vertical pump in which a drive shaft 10a of the motor 10 extends in the vertical direction.

Here, in the following description, the axial direction of the drive shaft 10a of the motor 10 is assumed to be the Z direction (vertical direction). In the Z direction, the upper direction is the Z1 direction, and the lower direction is the Z2 direction. Further, the radial direction of the drive shaft 10a is defined as the a direction. Among the a directions, a direction provided radially facing the outside of the drive shaft 10a is the a1 direction, and a direction opposite to the a1 direction is the a2 direction.

The motor 10 is sealed so that liquid from the outside does not enter. The motor 10 includes: a drive shaft 10a, a stator 10b, a rotor 10c and a motor frame 10 d. The motor 10 is configured to rotationally drive an impeller 14 connected to a drive shaft 10a via the drive shaft 10 a. Specifically, the motor 10 is an inner rotor motor in which the stator 10b is arranged on the radially outer side (a1 direction side) of the rotor 10c and attached to the inner side of the motor frame 10 d. The rotor 10c is mounted on the driving shaft 10a and rotates together with the driving shaft 10a by the magnetic field from the stator 10 b. The rotor 10c is configured to rotationally drive the impeller 14 via the drive shaft 10 a.

The drive shaft 10a is rotatably supported by bearings 16a, 16 b. The bearing 16a is supported by a later-described top cover 11 of the housing portion 2 on the Z1 direction side of the motor 10. The bearing 16b is supported by a bearing cover 21, described later, of the housing portion 2 on the Z2 direction side of the motor 10. The motor 10, a coolant circulation pump chamber 34, an oil chamber 15, a heat exchange chamber 31, and a pump chamber 12 of the coolant circulation unit 3, which will be described later, are arranged in this order from the side of the drive shaft 10a (Z direction) in the Z1 direction.

An impeller 14 driven by the motor 10 is disposed in the pump chamber 12. The pump chamber 12 is provided in a pump housing 13. The pump housing 13 is provided with a suction port 13a and a discharge port 13b for liquid (sewage or the like). The pump housing 13 is disposed below the housing 2 (on the Z2 direction side).

The impeller 14 rotates to suck water in the drain region where the submersible pump 100 is disposed into the pump housing 13 (pump chamber 12) from the suction port 13a, and sends the sucked water to the discharge port 13b (substantially in the a1 direction).

The oil chamber 15 is disposed between the motor 10 and the pump chamber 12, and is filled with oil. The oil chamber 15 includes a mechanical seal 15a and an electrode type sensor 15 b.

The mechanical seal 15a has sliding portions on the load side (the pump chamber 12 side, i.e., the Z2 direction side) and the counter load side (the opposite side to the pump chamber 12, i.e., the Z1 direction side), respectively. The load-side sliding portion has a function of suppressing the pressure water of the pump chamber 12 from flowing into the oil chamber 15. The sliding portion on the counter load side has a function of suppressing the oil-containing liquid in the oil chamber 15 from flowing into the coolant circulation pump chamber 34. The sliding portions are lubricated with oil filled in the oil chamber 15 and cooled without seizure. Since the mechanical seal 15a forms a slight gap between the stationary ring and the rotating ring constituting the mechanical seal 15a, even if the mechanical seal is operating normally, liquid will enter the oil chamber 15 from the pump chamber 12, albeit rarely.

The electrode sensor 15b is configured to be able to detect entry of liquid from the pump chamber 12 into the oil chamber 15. The electrode type sensor 15b is configured to detect the entry of liquid by being energized between the oil housing chamber 23 by the liquid entering the oil chamber 15.

(construction of Cooling liquid circulating section and case section)

As shown in fig. 1, the coolant circulation section 3 is configured to circulate coolant in the pump body between the pump chamber 12 and the head cover 11 to cool the motor 10. The coolant circulation portion 3 is configured such that oil in the oil chamber 15 is not mixed into the coolant.

The coolant circulation unit 3 includes: a motor cooling chamber 30, a heat exchange chamber 31 (a space for cooling the coolant), a first flow path 32, a second flow path 33, and a coolant circulation pump chamber 34 provided in the second flow path 33.

The coolant circulation unit 3 is configured to circulate the coolant in the coolant circulation pump chamber 34, a flow path on the downstream side of the coolant circulation pump chamber 34 of the second flow path 33 (a motor lower side flow path 33b described later), the motor cooling chamber 30, the first flow path 32, the heat exchange chamber 31, and a flow path on the upstream side of the coolant circulation pump chamber 34 of the second flow path 33 (a flow path 33a described later) in this order, and return the coolant to the coolant circulation pump chamber 34 again.

The housing part 2 includes a water jacket 20, a bearing cap 21, a cooling case 22, an oil case 23, an oil case 24, and a cooling case 25. The bearing cover 21 is an example of the "fourth housing portion" of the claims. The cooling shell chamber 22 is an example of the "third shell portion" of the claims. The oil casing 24 is an example of the "partition member" of the claims. The oil casing chamber 23 is an example of the "first casing portion" of the claims. The cooling jacket 25 is an example of the "second housing portion" of the claims.

The first flow path 32 and the second flow path 33 are formed by stacking the bearing cap 21, the cooling case chamber 22, the oil case chamber 23, the oil case sleeve 24, and the cooling case sleeve 25 in this order from the Z2 direction side to the Z1 direction side with respect to the pump chamber 12 (pump case sleeve 13) in the order of the cooling case sleeve 25, the oil case sleeve 24, the oil case chamber 23, the cooling case chamber 22, and the bearing cap 21. The housing portion 2 is provided with a seal member (e.g., an O-ring or the like) in each portion so that the coolant, the oil and the air in the oil chamber 15, and the liquid in the pump chamber 12 do not mix with each other.

Each of the portions (the water jacket 20, the bearing cover 21, the cooling case 22, the oil case 23, the cooling case 25) constituting the housing portion 2 is formed to have substantially the same outer diameter (dimension in the a direction) except the oil case 24. The bearing cover 21 extends in the radial direction (direction a) of the drive shaft 10a along the lower surface of the motor 10 (excluding the drive shaft 10 a).

The oil casing chamber 23 is open on the heat exchange chamber 31 side (Z2 direction side) and is provided with an oil chamber 15. The cooling jacket 25 is open on the oil casing chamber 23 side (the Z1 direction side) and is provided with a heat exchange chamber 31. The oil jacket 24 is disposed between the oil jacket chamber 23 and the cooling jacket 25, and partitions the oil jacket chamber 23 and the cooling jacket 25. That is, the oil jacket 24 prevents the oil in the oil chamber 15 from being mixed with the coolant in the heat exchange chamber 31.

The motor cooling chamber 30 is provided in the water jacket 20, and is disposed adjacent to the motor 10 so as to cover the motor 10 from the outer peripheral side (a1 direction side). That is, the motor cooling chamber 30 is a cylindrical space portion.

The motor cooling chamber 30 includes a partition wall portion 30a, an inner cooling chamber 30b, and an outer cooling chamber 30 c.

Partition wall portion 30a has a cylindrical shape extending upward from a lower end (end portion on the Z2 direction side), and is a plate-like wall that divides motor cooling chamber 30 into inner cooling chamber 30b and outer cooling chamber 30 c. The partition wall 30a has a gap at an upper end (end on the Z1 direction side). The inner cooling chamber 30b is disposed inside (on the side in the a2 direction) the partition wall 30 a. The outer cooling chamber 30c is disposed outside (a direction of a 1) the partition wall portion 30 a. The inside cooling chamber 30b and the outside cooling chamber 30c communicate with each other through a gap at the upper end of the partition wall portion 30 a. The upper end of the partition wall 30a is located on the Z1 direction side of the stator 10b and the rotor 10c of the motor 10.

The lower end (end on the Z2 direction side) of the inner cooling chamber 30b communicates with a second flow path 33 (a motor lower side flow path 33b described later) (an inlet 21a described later provided in the bearing cap 21). Therefore, the inside cooling chamber 30b is configured to be able to effectively cool the motor 10 by flowing the coolant from the heat exchange chamber 31 along the motor 10.

The outer cooling chamber 30c communicates at a lower end with a first flow passage 32 (an outlet port 21b provided in the bearing cap 21, which will be described later). Therefore, the outside cooling chamber 30c is configured to be efficiently cooled by the liquid or the atmosphere around the submersible pump 100 before the cooling liquid heated by taking heat from the motor 10 is delivered to the heat exchange chamber 31.

The bearing cap 21 disposed adjacent to the Z2 direction side of the water jacket 20 is provided with a plurality of (three) inflow ports 21a and a plurality of (three) outflow ports 21 b. The inflow port 21a is an example of the "motor-side first opening" of the claims. The outflow port 21b is an example of the "motor-side second opening" of the claims.

The inlet 21a is configured to communicate the second channel 33 with the motor cooling chamber 30 (inner cooling chamber 30b) and to allow the coolant to flow from the second channel 33 into the motor cooling chamber 30 (inner cooling chamber 30 b). The outlet 21b is configured to communicate the first flow path 32 with the motor cooling chamber 30 (outer cooling chamber 30c) and to cause the coolant to flow out from the motor cooling chamber 30 (outer cooling chamber 30c) to the first flow path 32.

As shown in fig. 2, the inlet port 21a and the outlet port 21b are circular arc-shaped and are arranged at positions shifted from each other in the a direction. That is, the inlet 21a is disposed on the side of the outlet 21b in the direction a 2. The plurality of inflow ports 21a and the plurality of outflow ports 21b are alternately arranged in parallel at substantially equal angular intervals in the circumferential direction of the drive shaft 10a (see fig. 1) while being shifted from each other in the a direction. That is, the motor cooling chamber 30 (see fig. 1) is configured to unevenly cool the motor 10 (see fig. 1) by the coolant flowing in and out from the plurality of inlet ports 21a and the plurality of outlet ports 21b in the circumferential direction of the drive shaft 10 a. Fig. 2 shows only one side configuration of the longitudinal sectional shapes of the cooling liquid circulating portion 3 and the housing portion 2, but the other side configuration (not shown) of the longitudinal sectional shape has the same shape as the one side configuration (it has a symmetrical shape with respect to the cross section).

The heat exchange chamber 31 is provided in the cooling jacket 25. The heat exchange chamber 31 is disposed adjacent to the side of the pump chamber 12 in the direction Z1. The heat exchange chamber 31 is disposed adjacent to the Z2 direction side of the oil chamber 15. The heat exchange chamber 31 is configured to exchange heat between the cooling liquid and the liquid in the pump chamber 12 by flowing the cooling liquid.

As shown in fig. 4 and 5, the oil casing chamber 23 is provided with a plurality of (three) inflow ports 23a and a plurality of (three) outflow ports 23 b.

The inflow port 23a is configured to communicate the first flow path 32 with the heat exchange chamber 31, thereby causing the coolant to flow from the first flow path 32 into the heat exchange chamber 31 (see fig. 1). The outlet port 23b is configured such that the second flow path 33 communicates with the heat exchange chamber 31, thereby causing the coolant to flow out from the heat exchange chamber 31 to the second flow path 33.

The inflow port 23a and the outflow port 23b have circular arc shapes, and are arranged at positions corresponding to each other in the a direction without being offset from each other in the a direction. The inlet 23a and the outlet 23b are disposed near the outer ends of the heat exchange chamber 31 in the a1 direction. The plurality of inflow ports 23a and the plurality of outflow ports 23b are alternately arranged at substantially equal angular intervals in the circumferential direction of the drive shaft 10 a.

As shown in fig. 2 and 5, the heat exchange chamber 31 includes a plurality of ribs 31 a.

The plurality of ribs 31a are configured to restrict the flow of the coolant flowing in from the inflow port 23a on the outer side in the radial direction (direction a) to flow along the drive shaft 10a (circumferential direction of the drive shaft 10a) and to flow out from the outflow port 23b on the outer side in the radial direction.

Specifically, the plurality of ribs 31a have, at the inner end in the radial direction, a gap that becomes a part of the flow path of the coolant in the heat exchange chamber 31, and extend radially in the radial direction. That is, the plurality of ribs 31a divide the heat exchange chamber 31 into a plurality of spaces arranged in the circumferential direction in a fan shape in plan view. Thus, the coolant flowing into the heat exchange chamber 31 from the inlet 23a (the first flow path 32) flows radially inward (toward the a2 direction) in the fan-shaped space, passes through the gap at the inner end of the rib 31a, flows into another adjacent fan-shaped space, flows radially outward (toward the a1 direction), and flows out from the outlet 23b to the second flow path 33. The plurality of ribs 31a can efficiently circulate the coolant by rectifying (restricting) the flow of the coolant in the heat exchange chamber 31. Thereby, the heat exchange chamber 31 can efficiently cool the coolant.

As shown in fig. 2, a plurality of (three) first flow passages 32 are provided on the outside of the oil chamber 15 in the radial direction (a direction) of the drive shaft 10a (see fig. 1). The first flow path 32 communicates the heat exchange chamber 31 with the motor cooling chamber 30 (see fig. 1). Specifically, one end (end on the Z2 direction side) of the first flow path 32 communicates with the heat exchange chamber 31 via the inlet 23a, and the other end (end on the Z1 direction side) communicates with the motor cooling chamber 30 via the outlet 21 b. Thus, the first flow path 32 is configured to allow the coolant to flow from the motor cooling chamber 30 to the heat exchange chamber 31.

The first flow passage 32 extends in the axial direction (Z direction) of the drive shaft 10a along the outer periphery of the oil chamber 15 radially outside the oil chamber 15. The first flow path 32 is provided astride the bearing cover 21, the cooling case chamber 22, and the oil case chamber 23. The first flow path 32 linearly extends along the axial direction (Z direction) of the drive shaft 10 a.

Therefore, although not shown, the first flow path 32, the outflow port 21b, and the inflow port 23a are arranged at positions corresponding to each other in a plan view. The plurality of first flow paths 32 are arranged in the vicinity of the outer ends of the bearing cover 21, the cooling case chamber 22, and the oil case chamber 23 in the a1 direction, respectively, and are arranged side by side at substantially equal angular intervals in the circumferential direction of the drive shaft 10 a.

The plurality of (three) second flow paths 33 are provided on the outside of the oil chamber 15 in the radial direction (a direction) of the drive shaft 10a (see fig. 4). The second flow channel 33 is disposed radially inward (in the a direction) of the first flow channel 32. The second flow path 33 communicates the heat exchange chamber 31 and the motor cooling chamber 30. Specifically, one end (end on the Z2 direction side) of the second flow path 33 communicates with the heat exchange chamber 31 via the outlet 23b, and the other end (end on the Z1 direction side) communicates with the motor cooling chamber 30 via the inlet 21 a. Thereby, the second flow path 33 is configured to flow the coolant in the opposite direction (from the heat exchange chamber 31 to the motor cooling chamber 30) to the first flow path 32.

Like the first flow path 32, the second flow path 33 extends in the axial direction (Z direction) of the drive shaft 10a along the outer periphery of the oil chamber 15 on the radially outer side (a1 direction side) of the oil chamber 15.

A coolant circulation pump chamber 34 is provided in the second flow path 33 at a midpoint of the flow path, and a coolant circulation impeller 34a for generating a flow of coolant in the coolant circulation unit 3 is disposed in the coolant circulation pump chamber 34.

The coolant circulation impeller 34a is mounted to a drive shaft 10a of the motor 10 (see fig. 1), and is configured to be driven (rotated) by the motor 10. The coolant circulation impeller 34a is configured to generate a flow in the direction Z1 along the drive shaft 10a by being driven. The coolant circulation pump chamber 34 (coolant circulation impeller 34a) is disposed between the motor 10 (excluding the drive shaft 10a) and the oil chamber 15. The coolant circulation impeller 34a is an axial flow impeller that allows the coolant to flow in and out in the axial direction (Z direction) of the drive shaft 10 a.

As shown in fig. 1, the second flow path 33 includes: a flow path 33a provided upstream of the coolant circulation pump chamber 34; and a motor lower flow path 33b provided on the downstream side of the coolant circulation pump chamber 34.

The second flow path 33 is configured to send the coolant from the heat exchange chamber 31 to the motor cooling chamber 30 by flowing the coolant through the flow path 33a, the coolant circulation pump chamber 34, and the motor lower side flow path 33b in this order.

The flow path 33a includes: a first portion 133a extending in the axial direction (Z direction) of the drive shaft 10 a; and a second portion 133b extending from the end of the first portion 133a in the direction Z1 toward the radially inner side (the side in the direction a 2) of the drive shaft 10 a. The first portion 133a is provided in the oil casing chamber 23 in the shape of a through hole. The second portion 133b is disposed between the oil casing chamber 23 and the cooling casing chamber 22.

The motor lower side flow path 33b extends radially outward (a1 direction side) of the drive shaft 10a along the lower surface of the motor 10 (the portion excluding the drive shaft 10 a). The motor lower flow path 33b is provided between the bearing cover 21 and the cooling case chamber 22. One end of the motor lower flow path 33b on the upstream side is connected to the coolant circulation pump chamber 34. The other end of the motor lower flow path 33b on the downstream side is connected to the motor cooling chamber 30 (inner cooling chamber 30 b).

The second flow path 33 is configured to allow the coolant from the heat exchange chamber 31 to flow through the second portion 133b along the oil chamber 15 (the upper portion of the oil chamber 15) to the radially inner side (the a2 direction side) of the drive shaft 10a, flowing into the coolant circulation pump chamber 34. Further, the second flow path 33 is configured to allow the coolant flowing out from the coolant circulation pump chamber 34 to flow radially outward (a1 direction side) of the drive shaft 10a along the lower surface of the motor 10 (the portion excluding the drive shaft 10a) by the coolant circulation impeller 34 a.

As a result, the coolant flows into the motor cooling chamber 30. That is, the second flow path 33 is configured to flow the coolant in opposite directions in the radial direction (a direction) on the upstream side and the downstream side of the coolant circulation impeller 34 a.

(Structure of oil change hole)

As shown in fig. 3 and 4, the oil casing chamber 23 includes an oil change hole 23c for changing oil.

The oil change hole 23c communicates the atmosphere (outside the submersible pump 100) with the oil chamber 15. Specifically, the oil casing chamber 23 is configured such that the oil change hole 23c does not overlap with the first flow path 32 and the second flow path 33 provided in the oil casing chamber 23 in a plan view (as viewed from the Z direction). The oil change hole 23c extends in a direction (direction a) orthogonal to the axial direction of the drive shaft 10 a. The oil change hole 23c is disposed at a substantially middle position of the oil case chamber 23 in the Z direction. One oil change hole 23c is provided on each side of the drive shaft 10a with the drive shaft 10a interposed therebetween.

(Structure of sealing Member)

As shown in fig. 1 and 2, the oil jacket 24 includes a cylindrical boss portion 24a protruding in the Z2 direction along the drive shaft 10a (see fig. 1). The convex portion 24a is formed with an annular groove portion 24b that is concave toward the radially inner side (the side in the a2 direction) and surrounds the periphery of the drive shaft 10 a. The sealing member 4 is attached to the groove portion 24 b. A heat exchange chamber 31 (coolant) is disposed on one side of the seal member 4, and a pump chamber 12 (liquid such as sewage) is disposed on the other side of the seal member 4. The sealing member 4 is formed of, for example, an O-ring.

The cooling jacket 25 includes an annular recessed portion 25a, and the annular recessed portion 25a engages with the protruding portion 24a of the oil jacket 24 from the Z2 direction side and surrounds the drive shaft 10 a. The sealing member 4 is in contact with the inner surface of the convex portion 24a in a state of being attached to the groove portion 24b, thereby sealing the space between the pump chamber 12 and the heat exchange chamber 31.

Since the seal member 4 is disposed between the cooling jacket 25 and the oil jacket 24 which are relatively stationary with respect to each other, unlike the mechanical seal 15a provided on the drive shaft 10a which is driven to rotate, it is possible to substantially reliably prevent the liquid from entering the heat exchange chamber 31 from the pump chamber 12.

Further, a seal member 4a is provided between the oil casing chamber 23 and the oil casing 24. The sealing member 4a seals watertightly between the oil chamber 15 and the heat exchange chamber 31. Thereby, the sealing member 4a prevents the oil in the oil chamber 15 from entering the heat exchange chamber 31. The sealing member 4a is formed of, for example, an O-ring. The seal member 4a is an example of the "seal structure" of the claims.

Further, a seal member 4b is provided between the oil casing chamber 23 and the cooling casing 25. The sealing member 4b seals watertight between the atmosphere and the heat exchange chamber 31. The sealing member 4b is formed of, for example, an O-ring. The seal member 4b is an example of the "seal structure" of the claims.

Further, an oil seal (not shown) may also be provided on the top of the Z1 direction side of the pump chamber 12 along the lower face of the drive shaft 10a and the cooling jacket 25 in the Z2 direction. The oil seal can suppress the rise of the liquid from the pump chamber 12 toward the Z1 direction side.

(Effect of the first embodiment)

The following describes the effects of the first embodiment.

In the first embodiment, as described above, by providing the first flow path 32, the second flow path 33, the motor cooling chamber 30, and the heat exchange chamber 31 for flowing the coolant separately from the oil chamber 15, the cooling of the motor 10 and the lubrication of the mechanical seal 15a can be performed by separate liquids, and thus, it is possible to select optimum liquids for cooling the motor 10 and lubricating the mechanical seal 15a, respectively. Further, even when the liquid in the pump chamber 12 seeps in through the mechanical seal 15a, it can be made to contaminate the liquid (oil) in the oil chamber 15 first, so that the coolant can be prevented from being contaminated. As described above, an optimum liquid can be selected as each liquid for cooling the motor 10 and lubricating the mechanical seal 15a, and contamination of the cooling liquid can be suppressed.

As described above, in the first embodiment, the heat exchange chamber 31 is provided with a watertight sealing structure (the sealing members 4, 4a, 4b) against the outside. Thereby, it is possible to effectively prevent liquid or air from outside the heat exchange chamber 31, for example, the pump chamber 12 side, the atmosphere side, the oil chamber 15 side, and the like, from entering the heat exchange chamber 31 by the seal structure (seal member 4, 4a, 4 b). This can further suppress contamination of the coolant.

As described above, in the first embodiment, the coolant circulation pump chamber 34 provided with the second flow path 33 between the motor 10 and the oil chamber 15 is further provided, and the coolant circulation impeller 34a for the coolant driven by the motor 10 is disposed therein. Thus, the coolant circulation pump chamber 34 can be disposed at a position further from the pump chamber 12 than the oil chamber 15 along the drive shaft 10a, and the sewage entry destination at the time of just the immersion can be set as the oil chamber 15. This can further suppress contamination of the coolant.

In the first embodiment, as described above, the first flow passage 32 and the second flow passage 33 extend in the axial direction of the drive shaft 10a along the outer periphery of the oil chamber 15 on the radially outer side of the drive shaft 10a of the oil chamber 15. Thus, compared to the case where the first flow path 32 and the second flow path 33 extend around the oil chamber 15 in the direction intersecting the axial direction of the drive shaft 10a, the flow path lengths of the first flow path 32 and the second flow path 33 can be shortened, so that energy loss in the flow paths can be reduced, and the motor 10 can be cooled efficiently.

As described above, in the first embodiment, the second flow path 33 is arranged radially inside the drive shaft 10a of the first flow path 32, and is configured such that the coolant from the heat exchange chamber 31 flows into the coolant circulation pump chamber 34 by the coolant circulation impeller 34a, and the coolant flowing out of the coolant circulation pump chamber 34 flows into the motor cooling chamber 30. Thereby, the coolant cooled in the heat exchange chamber 31 can be caused to flow to the second flow passage 33 which is closer to the motor 10 than the first flow passage 32 in the radial direction of the drive shaft 10a, and the motor 10 can be cooled efficiently.

In the first embodiment, as described above, there is also provided one oil case chamber 23, the oil case chamber 23 including the oil change hole 23c for communicating the atmosphere with the oil chamber 15, and the oil chamber 15. Thus, the trouble of assembling the plurality of housing portions can be reduced as compared with the case where the replacement oil holes are provided across the plurality of housing portions. In addition, the number of sealing members required to prevent oil leakage can be reduced.

In the first embodiment, as described above, the oil casing chamber 23 is configured such that the oil change hole 23c and the first flow path 32 and the second flow path 33 provided in the oil casing chamber 23 do not overlap with each other in plan view. Thereby, the flow of the coolant in the first flow path 32 and the second flow path 33 can be prevented from being blocked by the oil change hole 23c, and the structure of the oil casing chamber 23 can be prevented from becoming complicated.

In the first embodiment, as described above, at least one first flow path 32 is provided, is disposed radially outward of the drive shaft 10a of the second flow path 33, and is formed in an arc shape surrounding the drive shaft 10a in plan view. Thereby, the first flow path 32 can be formed in a shape along the outer periphery of the motor 10.

In the first embodiment, as described above, the present invention further includes: an oil case chamber 23 open on the heat exchange chamber 31 side and provided with an oil chamber 15; a cooling jacket 25 open on the oil case chamber 23 side and provided with a heat exchange chamber 31; an oil jacket 24 disposed between the oil jacket chamber 23 and the cooling jacket 25 and partitioning the oil chamber 15 and the heat exchange chamber 31, and the seal structure includes: and a sealing member 4a provided between the oil casing 24 and the oil casing chamber 23 for watertight sealing between the pump chamber 12 and the heat exchange chamber 31. Thereby, the space between the oil chamber 15 and the heat exchange chamber 31 can be watertight sealed by the sealing member 4a to prevent the coolant from being contaminated by the oil.

In the first embodiment, as described above, the present invention further includes: an oil case chamber 23 provided with an oil chamber 15; a cooling jacket 25 provided with a heat exchange chamber 31; the cooling casing chamber 22 provided with the coolant circulation pump chamber 34, and the bearing cap 21 provided between the cooling casing chamber 22 and the motor 10, and the first flow path 32 and the second flow path 33 are formed by stacking the oil casing chamber 23, the cooling casing 25, the cooling casing chamber 22, and the bearing cap 21 with respect to the pump chamber 12 in the order of the cooling casing 25, the oil casing chamber 23 to which the oil casing 24 is attached, the cooling casing chamber 22, and the bearing cap 21. Thus, the pump body can be easily assembled by stacking the case 23, the cooling jacket 25, the cooling jacket chamber 22, and the bearing cap 21 in this order of the cooling jacket 25, the oil jacket chamber 23, the cooling jacket chamber 22, and the bearing cap 21.

In the first embodiment, as described above, the bearing cap 21 includes: an inlet 21a that communicates the second flow path 33 with the motor cooling chamber 30; the outlet 21b, the inlet 21a, and the outlet 21b, which communicate the first flow path 32 with the motor cooling chamber 30, are provided at positions shifted from each other in the circumferential direction of the drive shaft 10 a. Thus, the inflow port 21a and the outflow port 21b can be used as an opening for flowing the coolant to the motor cooling chamber 30 and an opening for flowing the coolant to the heat exchange chamber 31.

In the first embodiment, as described above, the bearing cap 21 extends along the lower surface of the motor 10, and the second flow path 33 includes: a motor lower side flow path 33b which extends in the radial direction of the drive shaft 10a along the lower surface of the motor 10 between the cooling case chamber 22 and the bearing cover 21 and whose one end and the other end are connected to the coolant circulation pump chamber 34 and the motor cooling chamber 30, respectively. Thereby, the motor 10 can be cooled from below by the coolant flowing through the motor lower flow path 33 b.

In the first embodiment, as described above, the heat exchange chamber 31 includes: and a rib 31a that restricts the flow of the coolant flowing in from the radially outer side of the drive shaft 10a so as to flow along the drive shaft 10a and flow out from the radially outer side. Since the flow of the cooling liquid can be restricted by the rib 31a so that it can flow along the drive shaft 10a (the circumferential direction of the drive shaft 10a) at the time of driving and can flow the cooling liquid along the pump chamber 12, the flow of the cooling liquid in the heat exchange chamber 31 can be rectified.

In the first embodiment, as described above, the plurality of ribs 31a are provided so as to radially extend in the radial direction with a gap that becomes a part of the flow path of the coolant at the radially inner end of the drive shaft 10 a. Since the flow path of the coolant in the heat exchange chamber 31 can be given a shape including a fold by the rib 31a, the flow path of the coolant in the heat exchange chamber 31 can be extended, and heat exchange between the coolant and the liquid in the pump chamber 12 can be performed more efficiently.

Second embodiment

Next, a second embodiment will be explained with reference to fig. 6. In the second embodiment, an example will be described in which a reserve chamber 51 is provided between the coolant circulation pump chamber 34 and the oil chamber 15, in addition to the structure of the first embodiment described above. The same constituents as those of the first embodiment described above are denoted by the same reference numerals as those of the first embodiment, and the illustration will be omitted.

As shown in fig. 6, the submersible pump 200 according to the second embodiment includes a reservoir chamber 51 and a level sensor 52 provided in the reservoir chamber 51.

The reservoir chamber 51 is disposed between the motor 10 (excluding the drive shaft 10a) and the oil chamber 15. Specifically, the reservoir chamber 51 is disposed between the coolant circulation pump chamber 34 and the oil chamber 15. The submersible pump 200 includes a cover member 53 mounted to the sump chamber 23 from above to form the reservoir chamber 51.

The liquid level sensor 52 is a float-type sensor configured to detect a predetermined liquid level of the liquid (oil and liquid from the pump chamber 12) that has flowed into and stored in the reservoir chamber 51. On the Z1 direction side of the reservoir chamber 51, a second portion 133b of the flow path 33a of the second flow path 33 is disposed adjacent.

The submersible pump 200 is configured to be able to stop the motor 10, notify a user, or the like when a predetermined liquid level in the reservoir chamber 51 is detected by the liquid level sensor 52. This makes it possible to prevent the submersible pump 200 from mixing with the coolant in the coolant circulation unit 3.

The other configurations of the second embodiment are the same as those of the first embodiment.

(Effect of the second embodiment)

The effects of the second embodiment will be explained below.

In the second embodiment, as described above, there are further provided: a reserve chamber 51 disposed between the motor 10 and the oil chamber 15; a liquid level sensor 52 that detects a predetermined level of the liquid flowing into and stored in the reservoir chamber 51. This prevents the liquid from rising to the motor 10 side through the reservoir chamber 51. In addition, the oil rising or dipping into the reservoir chamber 51 can be detected by the level sensor 52. Thereby, before the oil rises or soaks into the motor 10, the maintenance work can be reliably performed. Further, by providing the liquid level sensor 52 on the upper side of the oil chamber 15, it is possible to detect not only the intrusion of water into the oil chamber 15 from the pump chamber 12 but also the rising of oil from the oil chamber 15 to the upper side at an early stage.

Other effects of the second embodiment are the same as those of the first embodiment described above.

Third embodiment

Next, a third embodiment will be explained with reference to fig. 7. In the third embodiment, unlike the configuration of the above-described second embodiment, an example including the reservoir chamber 351 disposed between the coolant circulation pump chamber 34 and the motor 10 (except for the drive shaft 10a) will be described. The same components as those of the second embodiment are denoted by the same reference numerals as those of the second embodiment, and descriptions thereof are omitted.

As shown in fig. 7, the submersible pump 300 according to the third embodiment includes a storage chamber 351 and a liquid level sensor 352 disposed in the storage chamber 351.

The reservoir chamber 351 is disposed between the motor 10 (excluding the drive shaft 10a) and the oil chamber 15. Specifically, the reservoir chamber 351 is disposed between the motor 10 (excluding the drive shaft 10a) and the coolant circulation pump chamber 34. The submersible pump 300 includes a cover member 353 mounted to the bearing cover 21 from below to form the reservoir chamber 351.

The liquid level sensor 352 is a float-type sensor configured to detect a predetermined level of liquid (coolant, oil, and liquid from the pump chamber 12) that has flowed into and stored in the reservoir chamber 351. The motor lower side flow passage 33b of the second flow passage 33 is disposed adjacent to the reservoir chamber 351 in the Z2 direction.

The submersible pump 300 is configured to stop the motor 10, notify a user, or the like when a predetermined liquid level in the storage chamber 351 is detected by the liquid level sensor 352. Thereby, the submersible pump 300 can suppress the liquid from entering the motor 10 (the inside of the motor frame 10 d).

The other configurations of the third embodiment are the same as those of the second embodiment.

(Effect of the third embodiment)

The effects of the third embodiment will be explained below.

In the third embodiment, as described above, the reservoir chamber 351 and the liquid level sensor 352 are provided immediately below the motor 10 (excluding the drive shaft 10 a). Thus, the most important oil rise or water inflow into the motor 10 can be detected immediately before.

Other effects of the third embodiment are the same as those of the second embodiment described above.

Fourth embodiment

Next, a fourth embodiment will be explained with reference to fig. 8 and 9. In the fourth embodiment, unlike the above-described first embodiment in which a plurality of first flow paths 32 are provided, an example in which one first flow path 432 is provided will be described. The same components as those of the first embodiment are denoted by the same reference numerals as those of the first embodiment, and descriptions thereof are omitted.

As shown in fig. 8, the submersible pump 400 according to the fourth embodiment includes a first flow path 432, a second flow path 433, a heat exchange chamber 431, and an oil housing 423.

The first flow path 432 is disposed radially outward (a1 direction side) of the drive shaft 10a of the second flow path 433. The first flow path 432 is formed in an arc shape (C shape) surrounding the drive shaft 10a in a plan view (as viewed from the Z1 direction side) (see fig. 9). An oil change hole 23C is disposed in the C-shaped opening of the first flow path 432. The second flow path 433 is also formed in an arc shape (C shape) similar to the first flow path 432 in a plan view (as viewed from the Z1 direction side) (see fig. 9). Therefore, the first flow path 432 and the second flow path 433 are formed around substantially the entire circumference of the oil chamber 15.

The heat exchange chamber 431 includes a flat plate-like horizontal rib 431a extending in a direction (horizontal direction) intersecting the axial direction (Z direction) of the drive shaft 10 a. The horizontal rib 431a has a gap at the end on the a2 direction side, and forms a flow path of the coolant folded back in the up-down direction at the end on the a2 direction side. The horizontal rib 431a is an example of the "guide member" of the claims.

The other configurations of the fourth embodiment are the same as those of the first embodiment.

(Effect of the fourth embodiment)

The effects of the fourth embodiment will be explained below.

In the fourth embodiment, as described above, the first flow path 432 and the second flow path 433 are formed around substantially the entire circumference of the oil chamber 15. Thereby, the coolant can flow into the heat exchange chamber 431 from substantially the entire circumference of the oil chamber 15, and a large heat transfer area between the coolant in the heat exchange chamber 431 and the liquid in the pump chamber 12 can be ensured. Thereby, heat exchange between the coolant and the liquid in the pump chamber 12 can be efficiently performed.

In the fourth embodiment, as described above, at least one first flow path 432 is provided on the second flow path 433 radially outward of the drive shaft 10a, and the first flow path 432 is formed in an arc shape (C shape) surrounding the drive shaft 10a in plan view. This makes it possible to simplify the configuration of the first flow path 432.

Other effects of the fourth embodiment are the same as those of the first embodiment described above.

Fifth embodiment

Next, a fifth embodiment will be explained with reference to fig. 10. In the fifth embodiment, unlike the above-described first embodiment having one oil jacket 24 and one cooling jacket 25, respectively (i.e., the oil jacket 24 and the cooling jacket 25 are separate), an example will be described in which the oil jacket 24 and the cooling jacket 25 are integrally formed. The same components as those of the first embodiment are denoted by the same reference numerals as those of the first embodiment, and descriptions thereof are omitted.

As shown in fig. 10, the submersible pump 500 according to the fifth embodiment has a shell 525, and the shell 525 is configured by integrally forming (a part of) the oil shell 24 and (a part of) the cooling shell 25. Jacket 525 is an example of the "seal structure" and "unitary structure" of the claims.

The submersible pump 500 has no gap between (a part of) the oil jacket 24 and (a part of) the cooling jacket 25, and is not provided with the seal member 4 like the submersible pump 100 of the first embodiment.

The other configurations of the fifth embodiment are the same as those of the first embodiment.

(Effect of the fifth embodiment)

The effect of the fifth embodiment will be described below.

In the fifth embodiment, as described above, there are further provided: an oil case chamber 23 open on the heat exchange chamber 31 side and provided with an oil chamber 15; a cooling jacket 25 open on the oil casing chamber 23 side and provided with a heat exchange chamber 31; an oil jacket 24 disposed between the oil jacket chamber 23 and the cooling jacket 25 and partitioning the oil chamber 15 and the heat exchange chamber 31, and the seal structure includes a jacket 525 in which the cooling jacket 25 and the oil jacket 24 are integrally formed. This makes it possible to reduce the locations where sealing is required and to improve the water-tightness of the heat exchange chamber 31. This can further simplify the device structure.

Other effects of the fifth embodiment are the same as those of the first embodiment described above.

Sixth embodiment

Next, a sixth embodiment will be explained with reference to fig. 11. The sixth embodiment illustrates an example in which the coolant flows in the opposite direction to the first embodiment. The same components as those of the first embodiment are denoted by the same reference numerals as those of the first embodiment, and descriptions thereof are omitted.

As shown in fig. 11, the submersible pump 600 according to the sixth embodiment includes a coolant circulation impeller 634 a.

The coolant circulation impeller 634a is mounted to a drive shaft 10a of the motor 10, and is configured to be driven (rotated) by the motor 10. The coolant circulation impeller 634a has the same shape and is disposed at the same position as the coolant circulation impeller 34a (see fig. 1) of the first embodiment described above, but is attached to the drive shaft 10a in an upside-down orientation as the coolant circulation impeller 34 a. Therefore, the coolant circulation impeller 634a is configured to be driven to generate a flow in the Z2 direction (oil chamber 15) along the drive shaft 10 a.

The other configurations of the sixth embodiment are the same as those of the first embodiment.

(Effect of the sixth embodiment)

The effects of the sixth embodiment will be explained below.

As described above, in the sixth embodiment, the second flow path 33 is arranged radially inward of the drive shaft 10a of the first flow path 32, and is configured to cause the coolant from the motor cooling chamber 30 to flow into the coolant circulation pump chamber 34 by the coolant circulation impeller 634a, and cause the coolant flowing out of the coolant circulation pump chamber 34 to flow into the heat exchange chamber 31. Thus, the coolant is caused to flow to the heat exchange chamber 31 side opposite to the motor 10 (except for the drive shaft 10a) by the coolant circulation impeller 634a, and the motor 10 side is brought into a negative pressure. Therefore, the water can be effectively inhibited from infiltrating into the motor 10.

Other effects of the sixth embodiment are the same as those of the first embodiment described above.

Seventh embodiment

Next, a seventh embodiment will be explained with reference to fig. 12 and 13. The seventh embodiment differs from the first embodiment in which the oil chamber 15 and the heat exchange chamber 31 are arranged to be aligned in the axial direction (Z direction) of the drive shaft 10a, and an example in which the oil chamber 15 and the heat exchange chamber 731 are arranged to be aligned in the radial direction (a direction) of the drive shaft 10a will be described. The same components as those of the first embodiment are denoted by the same reference numerals as those of the first embodiment, and descriptions thereof are omitted.

As shown in fig. 12, the submersible pump 700 according to the seventh embodiment includes a cooling jacket 725 and a heat exchange chamber 731.

The cooling jacket 725 has a circular opening 725a on the radially inner side (a2 direction side) of the drive shaft 10a, and the oil jacket 24 is fitted in the opening. Therefore, the heat exchange chamber 731 is disposed radially outward (a direction a1 side) of the drive shaft 10 a. The cooling jacket 725 is formed such that the position of the heat exchange chamber 731 in the axial direction (Z direction) of the drive shaft 10a overlaps with the position of the oil chamber 15 in the axial direction of the drive shaft 10 a. That is, the heat exchange chamber 731 and the oil chamber 15 are arranged side by side.

The other configurations of the seventh embodiment are the same as those of the first embodiment.

(Effect of the seventh embodiment)

The effects of the seventh embodiment will be explained below.

As described above, in the seventh embodiment, the cooling jacket 725 is formed such that the axial position of the heat exchange chamber 731 overlaps with the axial position of the oil chamber 15. Thus, the length of the drive shaft 10a can be shortened as compared with a case where the heat exchange chamber 731 and the oil chamber 15 are not overlapped in the axial direction of the drive shaft 10a but arranged along the drive shaft 10 a. That is, the apparatus can be downsized in the axial direction.

Other effects of the seventh embodiment are the same as those of the first embodiment described above.

Eighth embodiment

Next, an eighth embodiment will be explained with reference to fig. 14 and 15. The eighth embodiment is different from the seventh embodiment described above, and as with the fourth embodiment described above, an example in which one first flow path 832 is provided will be described. The same components as those of the seventh embodiment are denoted by the same reference numerals as those of the seventh embodiment, and descriptions thereof are omitted.

As shown in fig. 14, the submersible pump 800 according to the eighth embodiment includes a first flow path 832, a heat exchange chamber 831, and a cooling jacket 825.

The first flow path 832 is disposed radially outward (a1 direction side) of the drive shaft 10a of the second flow path 833. The first flow path 832 is formed in an arc shape (C shape) surrounding the drive shaft 10a in a plan view (as viewed from the Z1 direction side) (see fig. 9). An oil change hole 23C is disposed at the C-shaped opening portion of the first flow path 832 (see fig. 9).

The heat exchange chamber 831 includes a flat plate-like horizontal rib portion 831a extending in a direction (horizontal direction) intersecting the axial direction (Z direction) of the drive shaft 10 a. The horizontal rib 831a has a gap at the end on the a2 direction side, and forms a flow path of the coolant folded back in the up-down direction at the end on the a2 direction side. The horizontal rib portion 831a is an example of a "guide member" of the claims.

As shown in fig. 15, in an upper portion of the cooling jacket 825, a plurality of (six) openings 825a are provided which are aligned in the circumferential direction of the drive shaft 10a and are connected to the first flow path 832. Further, by combining the cooling jacket 825 and the oil jacket 24, a plurality of (six) openings 826 arranged in the circumferential direction of the drive shaft 10a and connected to the second flow path 833 are formed at the radially inner side (the side in the a2 direction) of the opening 825a at the upper portion of the cooling jacket 825. Further, an opening 825b is provided in the middle of the flow path forming the heat exchange chamber 831, and the opening 825b is disposed downstream of the opening 825a and communicates with the opening 825 a.

The other configurations of the eighth embodiment are the same as those of the first embodiment.

(Effect of the eighth embodiment)

The effect of the eighth embodiment is the same as the effect of the fourth and seventh embodiments described above.

Ninth embodiment

Next, a ninth embodiment will be explained with reference to fig. 16 to 18. The ninth embodiment differs from the first embodiment in which the heat exchange chamber 31 is disposed between the pump chamber 12 and the oil chamber 15 in the Z direction, and an example in which the heat exchange chamber 931 is disposed radially outward (a1 direction side) of the pump chamber 12 will be described. The same components as those of the first embodiment are denoted by the same reference numerals as those of the first embodiment, and descriptions thereof are omitted.

As shown in fig. 16, the submersible pump 900 according to the ninth embodiment includes a cooling jacket 925, a heat exchange chamber 931, and a pump casing jacket 913.

Cooling jacket 925 includes an upper cooling jacket 925a and a lower cooling jacket 925 b.

The upper cooling jacket 925a is disposed radially outward (a1 direction side) of the pump casing sleeve 913 and surrounds an upper portion of the pump casing sleeve 913. The lower cooling jacket 925b is disposed radially outward (a1 direction side) of the pump casing sleeve 913 and surrounds a lower portion of the pump casing sleeve 913. The pump housing sleeve 913 is comprised of two components: a body member 913a surrounding the impeller 14 and a pipe member 913b forming a discharge flow path of the liquid.

The heat exchange chamber 931 is provided around substantially the entire circumference of the pump chamber 12 on the radially outer side (a1 direction side) of the pump chamber 12. Specifically, a heat exchange chamber 931 is provided between the pump shell sleeve 913 and the cooling shell sleeve 925. In fig. 17, the impeller 14 is omitted from illustration.

As shown in fig. 18, the heat exchange chamber 931 has a plurality of ribs 931a extending radially in a plan view and a plurality of (six) regions arranged in the circumferential direction. Specifically, the heat exchange chamber 931 includes a plurality of (three) regions 931b and a plurality of (three) regions 931 c. The rib 931a is an example of the "guide member" of the claims.

The region 931b is configured such that the coolant flows in from the first flow path 32 and flows downward (Z2 direction). The region 931c is configured such that the coolant flows in from the region 931b at the end in the Z2 direction, flows upward (in the Z1 direction), and flows out to the second flow path 33. The regions 931b and the regions 931c are partitioned by the ribs 931a and are alternately arranged in the circumferential direction. The rib 931a is provided on the outer periphery of each of the pump case sleeve 913 and the oil case sleeve 24.

As shown in fig. 16, a plurality of (two) seal members 4c are provided between the pump casing sleeve 913 and the cooling casing sleeve 925. The sealing member 4c seals watertight between the atmosphere and the heat exchange chamber 931. The sealing member 4c is formed of, for example, an O-ring. The seal member 4c is an example of the "seal structure" of the claims.

The seal member 4d is disposed between the pump case sleeve 913 and the oil case sleeve 24. The seal member 4d seals watertight between the pump chamber 12 and the heat exchange chamber 931. The sealing member 4d is formed of, for example, an O-ring. The seal member 4d is an example of the "seal structure" of the claims.

The seal member 4e is disposed between the body member 913a and the tube member 913 b. The seal member 4e seals watertight between the pump chamber 12 and the heat exchange chamber 931. The sealing member 4e is formed of, for example, an O-ring. The seal member 4e is an example of the "seal structure" of the claims.

The seal member 4f is provided between the upper cooling jacket 925a and the lower cooling jacket 925 b. The sealing member 4f is watertight sealed between the atmosphere and the heat exchange chamber 931. The sealing member 4f is made of, for example, a packing. The seal member 4f is an example of the "seal structure" of the claims.

The other configurations of the eighth embodiment are the same as those of the first embodiment.

(Effect of the ninth embodiment)

The effects of the ninth embodiment will be explained below.

In the ninth embodiment, as described above, the heat exchange chamber 931 is provided radially outward (a1 direction side) of the pump chamber 12 so as to surround the pump chamber 12. Thus, by using substantially the entire outer circumference of the pump housing sleeve 913, a large heat transfer area between the heat exchange chamber 931 and the pump chamber 12 can be ensured, and heat exchange can be performed efficiently. In addition, heat exchange between the cooling liquid in the heat exchange chamber 931 and the fluid outside the submersible pump 900 can be efficiently performed. Further, since heat exchange chamber 931 can be disposed at a relatively low position, heat exchange can be performed more efficiently between the coolant in heat exchange chamber 931 and the fluid outside submersible pump 900 even when the water level outside submersible pump 900 is low. Further, the length of the drive shaft 10a can be shortened as compared with the case where the heat exchange chamber 931 and the pump chamber 12 do not overlap in the axial direction of the drive shaft 10a and the heat exchange chamber and the pump chamber are arranged along the drive shaft. That is, the apparatus can be downsized in the axial direction.

Other effects of the ninth embodiment are the same as those of the first embodiment.

Modification example

It should be noted that the embodiments disclosed herein are exemplary in all respects and are not to be considered as limiting. The scope of the present invention is indicated by the patent claims rather than the description of the above embodiments, and all changes (modifications) within the meaning and range equivalent to the patent claims are also included.

For example, in the first to ninth embodiments described above, the submersible pump is shown as an example of a vertical pump, but the present invention is not limited thereto. In the present invention, the submersible pump may be a horizontal pump.

In the first to ninth embodiments, the example in which the number of the first flow paths (second flow paths) is one or three is shown, but the present invention is not limited thereto. In the present invention, the number of the first flow paths (second flow paths) may be two or four or more.

In the first to ninth embodiments, the example in which the coolant circulation pump chamber (coolant circulation impeller) is provided between the motor (excluding the drive shaft) and the oil chamber is shown. However, the present invention is not limited thereto. In the present invention, the coolant circulation pump chamber (coolant circulation impeller) may be provided, for example, between the oil chamber and the pump chamber.

In addition, in the first to ninth embodiments, the example in which the first flow passage is formed to extend linearly in the axial direction of the drive shaft is shown, but the present invention is not limited thereto. In the present invention, the first flow path may be bent between the heat exchange chamber and the motor cooling chamber, rather than linearly extending in the axial direction of the drive shaft.

In the first to fifth embodiments and the seventh to ninth embodiments described above, the example in which the coolant flows from the inside of the motor cooling chamber is shown, but the present invention is not limited to this. In the present invention, the cooling liquid may flow in from the outside of the motor cooling chamber.

In addition, in the first to eighth embodiments described above, examples are shown which include all configurations corresponding to the first, second, third, and fourth case portions of the present invention. However, the present invention is not limited thereto. In the present invention, only a part of the first, second, third, and fourth housing portions of the present invention may be included.

In the first to ninth embodiments, the electrode type sensor is provided in the oil chamber, but the present invention is not limited to this. In the present invention, the electrode type sensor may not be provided in the oil chamber. Further, in the present invention, it may be configured that an electrode type sensor or a float type liquid level sensor is provided in the motor to detect whether water is immersed in the motor.

In addition, in the above-described first to ninth embodiments, an example is shown in which an axial flow type impeller is provided as the coolant circulating impeller, but the present invention is not limited thereto. In the present invention, as the coolant circulating impeller, an impeller other than the axial flow type, such as a centrifugal impeller or the like, may be provided.

Further, in the first to third and fifth to seventh embodiments described above, an example in which the rib portions are formed radially in a plan view is shown, but the present invention is not limited thereto. In the present invention, for example, the rib portion may be formed in a zigzag shape, a circular arc shape, or the like in a plan view.

In addition, in the first to ninth embodiments described above, an example in which an O-ring is used as the sealing member is shown, but the present invention is not limited thereto. In the present invention, an elastic member or the like other than the O-ring may be used as the sealing member.

Further, although an example is shown in which the heat exchange chamber is disposed on the upper side of the pump chamber in the above-described first to eighth embodiments, and the heat exchange chamber is disposed radially outward of the pump chamber in the ninth embodiment, the present invention is not limited thereto. In the present invention, the heat exchange chamber may be disposed above the pump chamber, or may be disposed radially outward of the pump chamber.

In the ninth embodiment, the heat exchange chamber is provided substantially over the entire circumference of the outer periphery of the pump housing cover, but the present invention is not limited to this. In the present invention, the heat exchange chamber may be provided so as to partially overlap with the outer periphery of the pump casing sleeve.

Further, in the above-described ninth embodiment, an example is shown in which the pump housing is constituted by two members of the main body member surrounding the impeller and the pipe member forming the discharge flow path of the liquid, but the present invention is not limited thereto. In the present invention, the body member surrounding the impeller and the pipe member forming the discharge flow path of the liquid may be integrally configured.

Description of the reference numerals

4. 4a, 4b, 4c, 4d, 4e, 4 f: sealing component (sealing structure)

10: motor with a stator having a stator core

10 a: drive shaft

12: pump chamber

13 a: suction inlet

13 b: discharge port

14: impeller

15: oil chamber

15 a: mechanical seal (mechanical seal, mechanical shaft seal)

21: bearing cap (fourth casing)

21 a: inflow (first opening of motor side)

21 b: outflow (second opening of motor side)

22: cooling shell (third shell)

23. 423: oil casing (first casing part)

24: oil casing (clapboard component)

25. 725, 825, 925: cooling jacket (second casing part)

30: motor cooling chamber

31. 431, 731, 831, 931: heat exchange chamber

31 a: rib (guide member)

32. 432, 832: first flow path

33. 433, 833: second flow path

33 b: flow passage at lower side of motor

34: cooling liquid circulating pump chamber

34a, 634 a: cooling liquid circulating impeller

51. 351, the method comprises the following steps: storage chamber

52. 352: liquid level sensor

100. 200, 300, 400, 500, 600, 700, 800, 900: submersible pump

431a, 831 a: horizontal rib (guide member)

525: shell (sealing structure, integral structure)

931 a: ribs (guide members).