JP2022167601A - Coolant circulation structure of pump - Google Patents

Abstract

To secure efficiency of a coolant for cooling heat generated by a motor and improve efficiency of the coolant for cooling heat generated by a bearing.SOLUTION: A casing body 20 is provided with a coolant circulation passage 70 for circulating a coolant for cooling a motor 11 and bearings (first and second bearings 13, 14) to peripheries of the motor 11 and the bearings. The casing body 20 includes bearing casings (first and second bearing casings 23, 27) each of which is fitted on the bearing and supports the bearing in the state. The bearing casing is provided with branch passages (first and second branch passages 50, 60) each of which is formed recessed from the coolant circulation passage 70 to the side, where the bearing is located, and branched from the coolant circulation passage 70.SELECTED DRAWING: Figure 1

Description

TECHNICAL FIELD The present disclosure relates to a cooling liquid circulation structure for a pump.

2. Description of the Related Art Conventionally, as a cooling liquid circulation structure for a pump, for example, a cooling liquid circulation structure as disclosed in Patent Document 1 has been proposed. Specifically, Patent Document 1 describes a motor, a shaft rotatable by driving the motor, bearings (bearings) that support upper and lower portions of the shaft, and a casing that houses the motor, the shaft, and the bearings. A coolant circulation structure for a pump comprising a body is disclosed. The casing body is provided with a coolant circulation flow path for circulating a coolant for cooling the motor around the motor. The casing body is mainly composed of a motor casing, an outer casing, a housing, and a lid casing.

JP 2012-057551 A

In the pump coolant circulation structure of Patent Document 1, the coolant flows into a space corresponding to a part of the coolant circulation flow path (that is, the space formed between the outer peripheral surface of the motor casing and the inner peripheral surface of the outer casing). The coolant receives the heat generated by driving the motor. However, in the structure described above, the cooling liquid circulation channel is arranged at a position relatively distant from the bearing, so that heat is not sufficiently conducted between the cooling liquid circulation channel and the bearing. That is, the cooling liquid circulating in the cooling liquid circulation flow path cannot properly receive the heat generated in the bearings that support the shaft.

The present disclosure has been made in view of the above points, and an object thereof is to improve the cooling efficiency of the cooling liquid with respect to the heat generation of the bearing while securing the cooling efficiency of the cooling liquid with respect to the heat generation of the motor.

To achieve the above object, the first disclosure is a cooling liquid circulation structure for a pump, comprising a motor, a shaft rotatable by driving the motor, at least one bearing supporting the shaft, the motor, A shaft and a casing body that accommodates the bearing are provided. The casing body is provided with a coolant circulation flow path for circulating a coolant for cooling the motor and the bearings around the motor and the bearings. The casing body includes a bearing casing configured to support the bearing while fitted over the bearing. Further, the bearing casing is provided with at least one branch flow path that is formed in a concave shape from the coolant circulation flow path toward the side where the bearing is located and that branches off from the coolant circulation flow path.

In the first disclosure, the bearing casing is provided with at least one branch channel that is recessed from the coolant circulation channel toward the side where the bearing is located and branches from the coolant circulation channel. . With such a configuration, part of the cooling liquid circulating in the cooling liquid circulation flow path flows into the branch flow path. The cooling liquid that has flowed into the branch flow path flows from the cooling liquid circulation flow path toward the side where the bearing is located. As a result, the coolant that has flowed into the branch flow path efficiently receives the heat generated in the bearing in the vicinity of the bearing in the branch flow path. That is, due to the branch flow path, the distance between the position where the cooling liquid flows and the bearing is relatively shortened, so that heat is sufficiently conducted between the cooling liquid flowing in the branch flow path and the bearing. The cooling efficiency of the cooling liquid for the heat generated in is enhanced. On the other hand, part of the coolant that has flowed from the coolant circulation channel into the branch channel convects within the branch channel, and then joins again from the branch channel toward the coolant circulation channel. Therefore, the flow rate of the cooling liquid circulating in the cooling liquid circulation passage does not decrease. As a result, the cooling efficiency of the coolant against the heat generated by the motor is ensured. Therefore, in the first disclosure, it is possible to increase the cooling efficiency of the coolant with respect to the heat generated from the bearing while securing the cooling efficiency of the coolant with respect to the heat generated from the motor.

In a second disclosure, in the first disclosure, the branch channel is configured such that the channel width in a vertical cross-sectional view increases from the side where the bearing is located toward the coolant circulation channel.

In the second disclosure, since the width of the branch flow path in a vertical cross-sectional view increases from the side where the bearing is located toward the cooling liquid circulation flow path, part of the cooling liquid flows into the cooling liquid circulation flow. It becomes easier to flow from the channel into the branch channel. In addition, part of the coolant that has flowed from the coolant circulation channel into the branch channel is likely to merge again from the branch channel toward the coolant circulation channel after convection in the branch channel. Thus, in the second disclosure, it is possible to increase the circulation efficiency of the cooling liquid in the branched flow paths.

A third disclosure is, in the first or second disclosure, wherein the branch channel is configured such that the channel width in a cross-sectional view increases from the side where the bearing is located toward the cooling liquid circulation channel. there is

In the third disclosure, since the width of the branched flow path in a cross-sectional view increases from the side where the bearing is located toward the cooling liquid circulation flow path, part of the cooling liquid flows into the cooling liquid circulation flow. It becomes easier to flow from the channel into the branch channel. In addition, part of the coolant that has flowed from the coolant circulation channel into the branch channel is likely to merge again from the branch channel toward the coolant circulation channel after convection in the branch channel. Thus, in the third disclosure, it is possible to increase the circulation efficiency of the cooling liquid in the branch flow path.

A fourth disclosure is that in any one of the first to third disclosures, a plurality of branched flow paths are provided, and the plurality of branched flow paths are in a non-communication state independently of each other.

In the fourth disclosure, the coolant flows into the plurality of branched flow paths, so that the cooling efficiency of the coolant against the heat generated in the bearing can be enhanced. In addition, since the plurality of branch channels are independent of each other and are in a non-communication state, part of the coolant that has flowed into the branch channels from the coolant circulation channel does not continue to convect within the branch channels. The coolant quickly flows out from the branch channel toward the coolant circulation channel. As a result, the flow rate of the cooling liquid circulating in the cooling liquid circulation passage does not decrease, and the cooling efficiency of the cooling liquid against heat generated by the motor can be ensured.

A fifth disclosure is any one of the first to third disclosures, wherein a plurality of branched flow passages are provided, and the plurality of branched flow passages are arranged at intervals in the circumferential direction of the bearing casing. . The bearing casing is provided with an inner peripheral flow path that is arranged near the inner periphery in the vicinity of the bearing and communicates the mutually adjacent branched flow paths.

In the fifth disclosure, the coolant flows into the plurality of branch flow paths, so that the cooling efficiency of the coolant against the heat generated in the bearing can be enhanced. In addition, the cooling liquid that has flowed into the branch flow path also flows into the inner peripheral flow path that is arranged near the inner periphery of the bearing casing near the bearing. That is, the surface area of the cooling liquid flowing near the bearing is relatively increased. As a result, the efficiency of cooling the cooling liquid against heat generated by the bearing can be further enhanced.

A sixth disclosure is the first disclosure, wherein the bearing includes an upper bearing that supports the shaft above the motor.

In a seventh disclosure, in the first disclosure, the bearing includes a lower bearing that supports the shaft below the motor, and a bearing casing that supports the lower bearing extends vertically through the bearing casing. A through hole is formed to form a part of the coolant circulation flow path, and the branch flow path is formed on a side surface of the through hole.

In the seventh disclosure, since the bearing casing is formed with both the through hole forming part of the coolant circulation channel and the branch channel, the coolant circulation structure of the pump can be reduced in number of parts. can be realized by

As described above, according to the present disclosure, it is possible to increase the cooling efficiency of the coolant with respect to the heat generated from the bearing while securing the cooling efficiency of the coolant with respect to the heat generated from the motor.

FIG. 1 is a vertical cross-sectional view of a submersible pump to which a pump coolant circulation structure according to an embodiment of the present disclosure is applied. FIG. 2 is a perspective view schematically showing a part of the internal structure of the coolant circulation structure of the pump. FIG. 3 is a plan view illustrating the configuration of the first bearing casing. FIG. 4 is a cross-sectional view illustrating the cross-sectional configuration of a portion of the coolant circulation structure of the pump where the second branch flow path of the second bearing casing is located. FIG. 5 is a partially enlarged cross-sectional view showing an enlarged lower portion of the coolant circulation structure of the pump. FIG. 6 is a vertical cross-sectional view illustrating a cross-sectional structure of a portion of the coolant circulation structure of the pump where the water level detector is located. FIG. 7 is a partially enlarged cross-sectional view schematically showing the flow of coolant in the first branch channel of the coolant circulation structure of the pump. FIG. 8 is a view equivalent to FIG. 7 showing Modification 1 of the embodiment of the present disclosure. FIG. 9 is a view equivalent to FIG. 3 showing Modification 2 of the embodiment of the present disclosure.

Hereinafter, embodiments of the present disclosure will be described in detail based on the drawings. The following description of the embodiments is merely exemplary in nature and is not intended to limit the present disclosure, its applications or uses.

(underwater pump)
FIG. 1 shows a vertical cross-sectional structure of a submersible pump 1 to which a pump coolant circulation structure 10 according to an embodiment of the present disclosure is applied. This submersible pump 1 can be used, for example, as a water pump in a sewage system. The submersible pump 1 comprises a pump section 2 and a coolant circulation structure 10 for the pump. A cooling liquid circulation structure 10 of the pump is arranged above the pump section 2 .

(pump section)
As shown in FIG. 1 , the pump section 2 includes an impeller 3 attached to the lower end of the shaft 12 and a pump casing 4 that houses the impeller 3 . This submersible pump 1 is a centrifugal pump provided with a centrifugal impeller 3 . In addition, the impeller 3 is not limited to the illustrated example, and various types of impellers can be adopted.

The pump casing 4 has a volute 5 in which the impeller 3 is accommodated. The volute 5 communicates with a suction port 4a opening at the bottom of the pump casing 4. As shown in FIG. The volute 5 also communicates with a laterally projecting outlet 4b of the pump casing 4. As shown in FIG. The discharge port 4b is connected to a discharge pipe (not shown).

The upper end of the pump casing 4 is open. A peripheral edge portion of the upper end opening of the pump casing 4 is fixed to a lower end portion of a lower casing 24 which will be described later.

(Pump coolant circulation structure)
As shown in FIG. 1 , a pump coolant circulation structure 10 is mainly composed of a motor 11 , a shaft 12 , a first bearing 13 , a second bearing 14 and a casing body 20 .

(motor and shaft)
The motor 11 has a stator 11a and a rotor 11b. A shaft 12 is provided integrally with the rotor 11b. The shaft 12 extends along the vertical direction. A lower end portion of the shaft 12 is positioned below a lower portion of the casing body 20 (a partition wall portion 25 and a bottom cover 26 to be described later). The shaft 12 is rotatably supported by a first bearing 13 and a second bearing 14 .

(first bearing)
The first bearing 13 (bearing) is composed of, for example, two bearings. The first bearing 13 is attached to an intermediate portion of the shaft 12 located below the motor 11 . The first bearing 13 rotatably supports the vicinity of the lower end of the shaft 12 .

(Second bearing)
The second bearing 14 (bearing) is composed of, for example, one bearing. A second bearing 14 is attached to the upper end of the shaft 12 . The second bearing 14 rotatably supports the upper end of the shaft 12 .

(casing body)
As shown in FIG. 1, the casing body 20 mainly includes a motor casing 21, an outer casing 22, a first bearing casing 23, a lower casing 24, a partition wall portion 25, a bottom cover 26, a second bearing casing 27, and a motor cover. 28 and a head cover 29 .

(motor casing)
As shown in FIG. 1, the motor casing 21 has a substantially cylindrical shape whose longitudinal direction extends along the vertical direction. Upper and lower ends of the motor casing 21 are opened vertically. A motor 11 and a shaft 12 are housed inside the motor casing 21 .

As also shown in FIG. 5 , a plurality of forward pass through holes 31 and a plurality of return pass through holes 32 are formed in the lower end portion of the motor casing 21 . In this embodiment, two outbound through holes 31 and two inbound through holes 32 are provided at the lower end of the motor casing 21 . 1 and 5, only one outward through-hole 31 and one return through-hole 32 are shown, and illustration of the other outward through-hole 31 and the other return through-hole 32 is omitted. ing.

Each forward pass through-hole 31 and each return pass through-hole 32 are positioned radially outside the outer peripheral surface of the motor casing 21 . Each outbound through-hole 31 functions as a part of an outbound flow path 71 to be described later. Each return pass through-hole 32 functions as a part of a return pass channel 72 to be described later.

(rib)
As shown in FIG. 4, the outer peripheral surface of the motor casing 21 is provided with ribs 33a to 33d. The ribs 33a and 33b and the ribs 33c and 33d face each other with the shaft 12 interposed therebetween. Each of ribs 33a to 33d protrudes radially outward of motor casing . Each of the ribs 33a to 33d is formed in a substantially plate shape along the vertical direction and extends from the lower end to the upper end of the motor casing 21 (see FIGS. 1 and 2).

The ribs 33a and 33b are arranged on the outer peripheral surface of the motor casing 21 on the lower side of the paper surface of FIG. The ribs 33a and 33b are spaced apart from each other in the circumferential direction of the outer peripheral surface of the motor casing 21 .

The ribs 33c and 33d are arranged on the outer peripheral surface of the motor casing 21 on the upper side of the paper surface of FIG. The ribs 33 c and 33 d are spaced apart from each other in the circumferential direction of the outer peripheral surface of the motor casing 21 .

(outer casing)
As shown in FIGS. 1, 2, and 4, the outer casing 22 is arranged to surround the outer peripheral surface of the motor casing 21. As shown in FIGS. The outer casing 22 is arranged outside the outer peripheral surface of the motor casing 21 with a predetermined gap therebetween. The outer casing 22 has a substantially cylindrical shape whose longitudinal direction extends along the vertical direction. The upper and lower ends of the outer casing 22 are opened vertically.

(First bearing casing)
As shown in FIG. 1 , the first bearing casing 23 (bearing casing) is attached to the lower end of the motor casing 21 . The first bearing casing 23 is configured to support the first bearing 13 while fitted onto the first bearing 13 .

As shown in FIG. 3 , the first bearing casing 23 has a first bearing support portion 34 for supporting the first bearing 13 . The first bearing support portion 34 has an annular shape surrounding the outer peripheral surface of the first bearing 13 from the outside.

(Communication flow path)
As shown in FIGS. 1, 3, and 5, the first bearing casing 23 has a plurality of communication channels 35. As shown in FIGS. Each communication flow path 35 penetrates through the first bearing casing 23 in the thickness direction (vertical direction).

As shown in FIG. 3 , the plurality of communication passages 35 are arranged near the outer circumference of the first bearing casing 23 . The plurality of communication channels 35 are arranged at regular intervals in the circumferential direction of the first bearing casing 23 . Each communication flow path 35 is formed in the shape of an elongated hole extending along the circumferential direction of the first bearing casing 23 .

The plurality of communication channels 35 are composed of two outgoing communication channels 35a and two return communication channels 35b. The two outbound communication channels 35a located on the upper side and the lower side of the paper surface of FIG. 3 function as part of the outbound channel 71 described later. The two return path communication flow paths 35b located on the left side and the right side of the paper surface of FIG. 3 function as part of the return path flow path 72 to be described later.

(lower casing)
As shown in FIGS. 1 and 5, the lower casing 24 is attached to the first bearing casing 23 . The lower casing 24 is arranged closer to the lower end of the shaft 12 than the first bearing casing 23 is. The lower end of the lower casing 24 is open. A substantially circular opening 36 is provided at the center of the lower portion of the lower casing 24 at the boundary between an outward flow path 71 (to be described later) and a return path 72 (to be described later).

(partition and bottom cover)
As shown in FIGS. 1 and 5, the partition wall 25 is attached to the lower portion of the lower casing 24 . The bottom cover 26 is attached to the partition wall portion 25 . The partition wall portion 25 and the bottom cover 26 are configured to separate the pump portion 2 and the casing body 20 .

(Circulation vane)
As shown in FIGS. 1 and 5, a circulation vane 37 is attached to the middle portion of the shaft 12 near the lower end. The circulation vanes 37 are positioned in the openings 36 of the lower casing 24 . In other words, the circulation vane 37 is positioned at the boundary between an outward flow path 71 and a return flow path 72, which will be described later. The circulation blades 37 are configured to rotate as the shaft 12 rotates.

When the circulation blades 37 rotate, the cooling liquid is forced to flow from the below-described fifth flow path 85 toward the below-described first flow path 81 . As a result, the coolant can be circulated along the coolant circulation flow path 70 as indicated by the thick arrows in FIGS. 1 and 5 .

(flood pool room)
As shown in FIG. 1, the casing body 20 is provided with a water accumulating chamber 38 . As shown in FIGS. 5 and 6, the flooded chamber 38 is a space surrounded by the first bearing casing 23 and the lower casing 24, and is between the space in which the motor is accommodated and the pump section 2. are placed in The flooded water pool chamber 38 is in a state separated from a coolant circulation flow path 70, which will be described later. The water accumulating chamber 38 functions as a space for accumulating the submerged liquid when water intrudes toward the motor 11 side from the cooling liquid circulation flow path 70 (especially the fifth flow path 85). As shown in FIG. 6, the water pool chamber 38 is provided with a water level detector 39 for detecting the water level of the liquid (water) pooled in the water pool chamber 38 .

(Second bearing casing)
As shown in FIG. 1 , the second bearing casing 27 (bearing casing) is attached to the upper end of the motor casing 21 . The second bearing casing 27 is configured to support the second bearing 14 while being fitted onto the second bearing 14 .

As shown in FIG. 4 , the second bearing casing 27 has a second bearing support portion 40 for supporting the second bearing 14 . The second bearing support portion 40 has an annular shape that surrounds the outer peripheral surface of the second bearing 14 from the outside in a cross-sectional view.

As shown in FIGS. 2 and 4, the second bearing casing 27 has a plurality of (two in the illustrated example) central wall portions 62 . Each central wall portion 62 protrudes radially outward of the second bearing casing 27 from the inner peripheral side of the second bearing casing 27 (the side where the second bearing support portion 40 is located). Each central wall portion 62 is formed in a substantially plate shape in a cross-sectional view. The central wall portion 62 located on the lower side of the paper surface of FIG. 4 is arranged so as to be located between the ribs 33a and 33b in plan view. On the other hand, the central wall portion 62 located on the upper side of the paper surface of FIG. 4 is arranged so as to be located between the ribs 33c and 33d in plan view.

(motor cover and head cover)
As shown in FIG. 1 , a motor cover 28 is attached to the upper end of the second bearing casing 27 . A head cover 29 is attached to the upper end of the motor cover 28 . A space surrounded by the second bearing casing 27 , the motor cover 28 , and the head cover 29 accommodates a drive control unit 15 for controlling the drive of the motor 11 . The second bearing casing 27 is provided with wiring holes 41 for wiring lead wires (not shown) that electrically connect the motor 11 and the drive controller 15 .

(Cooling liquid circulation channel)
As shown in FIG. 1, the casing body 20 is provided with a coolant circulation flow path 70 . The coolant circulation flow path 70 is arranged at a position surrounding the motor 11, the first bearing 13, and the second bearing 14 in the internal space of the casing body 20 from the outside. The coolant circulation flow path 70 is divided into an outward flow path 71 and a return flow path 72 .

A coolant for cooling the motor 11 , the first bearing 13 , and the second bearing 14 circulates through the coolant circulation flow path 70 . As this cooling liquid, for example, cooling water containing water as a main component and an additive for preventing corrosion is suitable. The cooling liquid is not limited to cooling water and may be cooling oil.

(Forward flow path)
The outward flow path 71 is configured by a flow path communicating from a first flow path 81 to a third flow path 83, which will be described later. Specifically, the forward flow path 71 includes a first flow path 81, a second flow path 82, a forward communication flow path 35a of the first bearing casing 23, a forward through hole 31 of the motor casing 21, and a third It is configured to communicate in the order of the flow path 83 .

(Return flow path)
The return path flow path 72 is configured by a flow path that communicates from a fourth flow path 84 to a fifth flow path 85, which will be described later. Specifically, the return passage 72 is arranged in the order of the fourth passage 84, the return passage through hole 32 of the motor casing 21, the return passage communication passage 35b of the first bearing casing 23, and the fifth passage 85. configured to communicate.

(First flow path)
As shown in FIGS. 1, 5 and 6, the first flow path 81 is mainly configured as a space surrounded by the lower casing 24, partition wall 25 and bottom cover 26. As shown in FIG. The first flow path 81 is configured such that the coolant flows from the fifth flow path 85 by the circulation vanes 37 . Specifically, the high-temperature coolant that has absorbed the heat of the motor 11 flows into the first flow path 81 from the fifth flow path 85 .

The first flow path 81 is vertically adjacent to the spiral chamber 5 of the pump casing 4 . Therefore, the cooling liquid that has flowed into the first flow path 81 is heat-exchanged with the relatively low-temperature liquid flowing in the spiral chamber 5 via the partition wall portion 25 and the bottom cover 26 . That is, the coolant circulating in the coolant circulation flow path 70 is cooled in the first flow path 81 . Thus, the first flow path 81 functions as a heat exchange chamber for the cooling liquid circulating in the cooling liquid circulation flow path 70 .

(Second flow path)
As shown in FIGS. 1, 5 and 6, the second flow path 82 is provided inside the lower casing 24 . The second flow path 82 functions as part of the outward flow path 71 . The second flow path 82 communicates with the first flow path 81 . In addition, the second flow path 82 communicates with the outward communication flow path 35 a of the first bearing casing 23 .

(Third flow path)
As shown in FIGS. 1 , 5 and 6 , the third flow path 83 is provided between the outer peripheral surface of the motor casing 21 and the inner peripheral surface of the outer casing 22 . The third flow path 83 functions as part of the outward flow path 71 .

As shown in FIG. 4, in this embodiment, two third flow paths 83 are provided. One third flow path 83 is a space surrounded by the outer peripheral surface of the motor casing 21, the inner peripheral surface of the outer casing 22, the ribs 33a, and the ribs 33b. The other third flow path 83 is a space surrounded by the outer peripheral surface of the motor casing 21, the inner peripheral surface of the outer casing 22, the ribs 33c, and the ribs 33d.

(Fourth flow path)
As shown in FIG. 4 , the fourth flow path 84 is configured as a space formed between the outer peripheral surface of the motor casing 21 and the inner peripheral surface of the outer casing 22 excluding the third flow paths 83 . ing. Each fourth channel 84 functions as part of the return channel 72 (see FIGS. 1, 5 and 6).

In this embodiment, two fourth flow paths 84 are provided. One fourth flow path 84 is a space surrounded by the outer peripheral surface of the motor casing 21, the inner peripheral surface of the outer casing 22, the ribs 33a, and the ribs 33c. The other fourth flow path 84 is a space surrounded by the outer peripheral surface of the motor casing 21, the inner peripheral surface of the outer casing 22, the ribs 33b, and the ribs 33d.

(Fifth flow path)
As shown in FIGS. 1, 5 and 6, the fifth flow path 85 is provided inside the lower casing 24 . The fifth flow path 85 functions as part of the return flow path 72 . The fifth flow path 85 communicates with the return path communication flow path 35 b of the first bearing casing 23 . Also, the fifth flow path 85 communicates with the first flow path 81 via the circulation vane 37 .

(First branch channel)
As shown in FIG. 1, the first bearing casing 23 is provided with a plurality of first branch flow paths 50 (branch flow paths). Each first branch channel 50 is configured to branch from the coolant circulation channel 70 .

As shown in FIG. 3, in this embodiment, four first branch channels 50 are provided. These first branch flow paths 50 are arranged at regular intervals in the circumferential direction of the first bearing casing 23 . The plurality of first branch channels 50 are in a non-communication state independently of each other.

Each of the two first branch flow paths 50 located on the upper side and the lower side of the paper surface of FIG. 3 communicates with each forward communication flow path 35a. On the other hand, each of the two first branch flow paths 50 located on the left side and the right side of the paper surface of FIG. 3 communicates with each return path communication flow path 35b.

As shown in FIGS. 1 and 5, each first branch flow path 50 extends from the cooling liquid circulation flow path 70 (each communication flow path 35) in the first bearing casing 23 toward the side where the first bearing 13 is located. It is formed in a concave shape. In addition, in the present embodiment, the outer peripheral surface of the lower wall portion 52 and the outer peripheral surface of the upper wall portion 53 forming each of the first branch flow paths 50 are substantially flush with each other in a vertical cross-sectional view.

A back wall portion 51 is formed on the back side of each first branch flow path 50 (the side where the first bearing 13 is located). The inner wall portion 51 is located near the first bearing 13 with the first bearing support portion 34 interposed therebetween. The inner wall portion 51 is formed in a substantially arc shape along the outer circumference of the first bearing support portion 34 in plan view (see FIG. 3).

As shown in FIGS. 3 and 7 , the coolant flows from the coolant circulation channel 70 toward each first branch channel 50 . Specifically, the coolant flows from each communication channel 35 of the first bearing casing 23 toward the opening of each first branch channel 50 . The coolant that has flowed into the opening flows along the lower wall portion 52 toward the inner wall portion 51 . Then, the cooling liquid flows from the inner wall portion 51 along the upper wall portion 53 and flows toward the opening of the first branch flow path 50 again. Thus, the coolant convects within each first branch channel 50 . The coolant that has returned to the opening of the first branch channel 50 flows out to each communication channel 35 again. In addition, in FIG. 3, portions where the coolant circulates are clearly indicated by dot hatching.

(Second branch flow path)
As shown in FIG. 1, the second bearing casing 27 is provided with a plurality of second branch flow paths 60 (branch flow paths). Each second branch channel 60 is configured to branch from the coolant circulation channel 70 . Each of the second branch flow paths 60 is formed in a concave shape in the second bearing casing 27 from the coolant circulation flow path 70 toward the side where the second bearing 14 is located.

As shown in FIG. 4, in this embodiment, four second branch flow paths 60 are provided. Each of the second branch flow paths 60 is configured such that, in a cross-sectional view, the interval between the inner walls (flow path width) widens from the side where the second bearing 14 is located toward the coolant circulation flow path 70. .

A back wall portion 61 is formed on the back side of each second branch channel 60 (the side where the second bearing 14 is located). The inner wall portion 61 is located near the second bearing 14 with the second bearing support portion 40 interposed therebetween.

As shown in FIGS. 2 and 4, the pair of second branch flow paths 60 are arranged in the circumferential direction of the second bearing casing 27 with the central wall portion 62 therebetween. The pair of second branch flow paths 60 located on the lower side of the paper surface of FIG. 4 and the pair of second branch flow paths 60 located on the upper side of the paper surface of FIG. Each second branch channel 60 is configured to communicate with each of the third channel 83 and the fourth channel 84 .

The coolant flows from the coolant circulation channel 70 toward the second branch channel 60 . Specifically, as shown in FIG. 4 , the cooling liquid flows from the third flow path 83 toward the opening of the second branch flow path 60 and flows along the central wall portion 62 to the back wall of the second branch flow path 60 . It flows into part 61 . Furthermore, the cooling liquid that has flowed into the inner wall portion 61 flows out from the inner wall portion 61 toward the opening of the second branch channel 60 along the inner wall facing the central wall portion 62 . That is, the coolant convects within the second branch channel 60 . Then, the cooling liquid flowing out of the opening of the second branch channel 60 flows out toward the fourth channel 84 (return channel 72). In addition, in FIG. 4, portions where the cooling liquid circulates are clearly indicated by dot hatching.

[Action and effect of the embodiment]
As shown in FIG. 7, the first bearing casing 23 (bearing casing) is formed in a concave shape from the coolant circulation channel 70 toward the side where the first bearing 13 is located. A branched first branch flow path 50 is provided. With this configuration, part of the cooling liquid circulating in the cooling liquid circulation flow path 70 flows toward the first branch flow path 50 as indicated by the arrows schematically showing the flow of the cooling liquid in FIG. Become. The coolant that has flowed into the first branch channel 50 flows from the communication channel 35 that is part of the coolant circulation channel 70 toward the side where the first bearing 13 is located. As a result, the coolant that has flowed into the first branch flow path 50 efficiently receives the heat generated in the first bearing 13 in the vicinity of the first bearing 13 inside the first branch flow path 50 . That is, by providing the first branch flow path 50, the distance between the position where the coolant flows and the first bearing 13 is relatively shortened. The heat is sufficiently conducted between the and the first bearing 13, and the cooling efficiency of the coolant for the heat generated in the first bearing 13 is enhanced. On the other hand, part of the coolant that has flowed from the coolant circulation channel 70 into the first branch channel 50 convects within the first branch channel 50, and then flows from the first branch channel 50 to the coolant circulation channel 70. merge again towards Therefore, the flow rate of the coolant circulating in the coolant circulation channel 70 (especially the coolant flowing through the third channel 83 and the fourth channel 84) does not decrease. As a result, the cooling efficiency of the coolant against the heat generated by the motor 11 is ensured. Therefore, in the pump cooling liquid circulation structure 10 according to the embodiment of the present disclosure, it is possible to increase the cooling efficiency of the cooling liquid with respect to the heat generation of the first bearing 13 while ensuring the cooling efficiency of the cooling liquid with respect to the heat generation of the motor 11. . In addition, in the cooling liquid circulation structure 10 for a pump according to the embodiment of the present disclosure, the structure of the first branch flow path 50 is relatively simple, so the manufacturability is also excellent.

In addition, since the second branch flow path 60 provided in the second bearing casing 27 also has the same configuration as the first branch flow path 50, the cooling efficiency of the cooling liquid against the heat generated by the motor 11 is ensured. It is possible to increase the cooling efficiency of the coolant with respect to the heat generated by the second bearing 14 .

Further, the first branch flow path 50 is configured such that the width of the flow path when viewed in longitudinal section increases from the side where the first bearing 13 is located toward the coolant circulation flow path 70 . Such a configuration makes it easier for part of the coolant to flow from the coolant circulation channel 70 into the first branch channel 50 . In addition, after a part of the coolant that has flowed from the coolant circulation channel 70 into the first branch channel 50 convects within the first branch channel 50, the cooling liquid flows from the first branch channel 50 to the coolant circulation channel 70. It becomes easier to merge again toward Therefore, the circulation efficiency of the cooling liquid in the first branch channel 50 can be enhanced. In addition, since the second branch flow path 60 is also configured such that the width of the flow path when viewed in longitudinal section increases toward the cooling liquid circulation flow path 70 from the side where the second bearing 14 is located, The circulation efficiency of the cooling liquid in the two-branch flow path 60 can be enhanced.

Moreover, the plurality of first branch flow paths 50 are in a non-communication state independently of each other. With such a configuration, the cooling liquid flows into the plurality of first branch flow paths 50, so that the cooling efficiency of the cooling liquid with respect to the heat generation of the first bearing 13 can be enhanced. In addition, since the plurality of first branch channels 50 are independent of each other and are in a non-communication state, part of the cooling liquid that has flowed from the cooling liquid circulation channel 70 into the first branch channels 50 is transferred to the third flow channel. The cooling liquid flows out quickly from the first branch channel 50 toward the coolant circulation channel 70 without passing through the channel 83 and the fourth channel 84 and circulating through the communicating portion of the first branch channel 50 . become. As a result, the flow rate of the cooling liquid circulating in the cooling liquid circulation flow path 70 (especially the third flow path 83 and the fourth flow path 84) does not decrease, and the cooling efficiency of the cooling liquid against heat generated by the motor 11 can be ensured. can.

On the other hand, as shown in FIG. 4, the second branch channel 60 is configured such that the channel width in a cross-sectional view increases from the side where the second bearing 14 is located toward the coolant circulation channel 70. ing. Such a configuration makes it easier for part of the coolant to flow from the coolant circulation channel 70 into the second branch channel 60 . Further, part of the coolant that has flowed from the coolant circulation flow path 70 into the second branch flow path 60 convects within the second branch flow path 60, and then flows from the second branch flow path 60 to the cooling liquid circulation flow path 70. It becomes easier to merge again toward Therefore, the circulation efficiency of the cooling liquid in the second branch channel 60 can be enhanced.

[Modification 1 of Embodiment]
In the above-described embodiment, the outer peripheral surface of the lower wall portion 52 and the outer peripheral surface of the upper wall portion 53 constituting each first branch flow channel 50 are substantially flush with each other in a vertical cross-sectional view (for example, FIGS. 5 and 5). 7) is shown, but it is not limited to this form. That is, the outer peripheral surface of the lower wall portion 52 and the outer peripheral surface of the upper wall portion 53 do not have to be flush with each other when viewed in a vertical cross section.

For example, as shown in Modification 1 of FIG. It is configured to protrude radially outward (left side of the paper surface of FIG. 8) of the bearing casing 23 . With such a configuration, the width of the upper portion of the outward communication passage 35a is narrower than the width of the lower portion of the outward communication passage 35a. Therefore, the flow velocity of the coolant flowing from the second flow path 82 to the third flow path 83 can be increased. Also, due to the difference between the flow velocity of the cooling liquid flowing through the second flow path 82 and the flow velocity of the cooling liquid flowing through the third flow path 83, the cooling speed from the second flow path 82 to the third flow path 83 increases. A part of the liquid becomes easier to flow toward the first branch channel 50 . Therefore, in this modified example, it is possible to promote the flow of the cooling liquid from the outward communication channel 35a toward the first branch channel 50 .

[Modification 2 of Embodiment]
In the above-described embodiment, the form (see FIG. 3) in which the plurality of first branch flow paths 50 are independent of each other and are in a non-communication state is shown, but the present invention is not limited to this form. For example, as in Modified Example 2 shown in FIG. 9, the first branch flow paths 50, 50 adjacent to each other may be communicated with each other. Specifically, in the first bearing casing 23 of Modification 2, an inner peripheral flow path 54 is provided. The inner peripheral flow path 54 is arranged near the inner periphery of the first bearing casing 23 near the first bearing 13 . The inner peripheral flow path 54 is configured to allow the adjacent first branch flow paths 50, 50 to communicate with each other.

In such a modified example, the cooling liquid that has flowed into the first branch flow paths 50 , 50 also flows into the inner peripheral flow path 54 located near the first bearing 13 . That is, the surface area of the coolant flowing near the first bearing 13 is relatively increased. As a result, the efficiency of cooling the coolant against the heat generated by the first bearing 13 can be further enhanced.

[Other embodiments]
In the above-described embodiment, a mode in which a plurality of first branch flow paths 50 are provided has been shown, but the present invention is not limited to this mode. That is, as long as at least one first branch flow path 50 is provided in the first bearing casing 23, the effects of the above-described embodiment can be obtained. In such a case, considering that the cooling liquid cooled in the first flow path 81 functioning as a heat exchange chamber circulates in the outward flow path 71, one first branch flow path 50 is provided in the outward flow path 71. The communicating form is more advantageous than the form in which one first branch flow path 50 communicates with the return flow path 72 in terms of increasing the cooling efficiency of the cooling liquid with respect to heat generation of the first bearing 13. .

In the above-described embodiment, the width of the first branch flow path 50 in the vertical cross-sectional view increases from the side where the first bearing 13 is located toward the cooling liquid circulation flow path 70. Not limited. For example, the width of the first branch flow path 50 in a vertical cross section may be configured to have a constant size from the side where the first bearing 13 is located toward the coolant circulation flow path 70 . The same applies to the second branch channel 60 as well.

Although the embodiments of the present disclosure have been described above, the present disclosure is not limited to the above-described embodiments, and various modifications are possible within the scope of the present disclosure.

INDUSTRIAL APPLICABILITY The present disclosure can be industrially applied as a pump cooling liquid circulation structure applied to, for example, a sewage pump (submersible pump).

1: submersible pump 10: coolant circulation structure 11: motor 12: shaft 13: first bearing (bearing, lower bearing)
14: Second bearing (bearing, upper bearing)
20: Casing body 21: Motor casing 22: Outer casing 23: First bearing casing (bearing casing)
24: Lower casing 25: Partition wall 26: Bottom cover 27: Second bearing casing (bearing casing)
28: Motor cover 29: Head cover 31: Outgoing through hole 32: Incoming through hole 33a to 33d: Rib 34: First bearing support 35: Communication flow path (through hole)
37: Circulation vane 40: Second bearing support 50: First branch flow path (branch flow path)
54: Inner peripheral channel 60: Second branch channel (branch channel)
70: Cooling liquid circulation flow path 71: Forward flow path 72: Return flow path 81: First flow path 82: Second flow path 83: Third flow path 84: Fourth flow path 85: Fifth flow path

Claims (7)

a motor;
a shaft rotatable by driving the motor;
at least one bearing supporting the shaft;
a casing body that houses the motor, the shaft, and the bearing;
The casing body is provided with a cooling liquid circulation flow path for circulating a cooling liquid for cooling the motor and the bearing around the motor and the bearing,
The casing body includes a bearing casing configured to support the bearing while being fitted onto the bearing,
The bearing casing is provided with at least one branch channel that is recessed from the coolant circulation channel toward the side where the bearing is located and that branches off from the coolant circulation channel. cooling liquid circulation structure. In the cooling liquid circulation structure for the pump according to claim 1,
The coolant circulation structure of a pump, wherein the branch channel is configured such that a channel width in a vertical cross-sectional view increases from a side where the bearing is located toward the coolant circulation channel. In the pump cooling liquid circulation structure according to claim 1 or 2,
The coolant circulation structure of a pump, wherein the branch channel is configured such that a channel width in a cross-sectional view increases from a side where the bearing is located toward the coolant circulation channel. In the pump coolant circulation structure according to any one of claims 1 to 3,
A plurality of the branch flow paths are provided,
The cooling liquid circulation structure of the pump, wherein the plurality of branched flow paths are in a non-communication state independently of each other. In the pump coolant circulation structure according to any one of claims 1 to 3,
A plurality of the branch flow paths are provided,
The plurality of branched flow paths are arranged at intervals in the circumferential direction of the bearing casing,
The cooling liquid circulation structure for a pump, wherein the bearing casing is provided with an inner peripheral flow path that is arranged near the inner periphery in the vicinity of the bearing and that communicates the branch flow paths that are adjacent to each other. In the cooling liquid circulation structure for the pump according to claim 1,
A coolant circulation structure for a pump, wherein the bearings include an upper bearing that supports the shaft above the motor. In the cooling liquid circulation structure for the pump according to claim 1,
the bearing includes a lower bearing that supports the shaft below the motor;
A bearing casing that supports the lower bearing is provided with a through hole that vertically penetrates the bearing casing and forms a part of the coolant circulation flow path, and the branch flow path is formed on the side surface of the through hole. The cooling liquid circulation structure of the pump.

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