Motor pump

Abstract

To provide a motor pump having means for surely cooling an entire motor part including an opposite load-side bearing.SOLUTION: A motor pump includes: a main impeller configured to be able to convey water by rotation; a pump casing for storing the main impeller; a main shaft connected to the main impeller; an opposite load-side bearing for rotationally supporting the main shaft on an opposite load side; an opposite load-side bearing bracket for holding the opposite load-side bearing; a motor frame for storing a rotor that rotates integrally with the main shaft and a stator provided on an outer peripheral side of the rotor; and a cooling jacket provided to surround an outer peripheral face of the motor frame and forming an annular space for receiving a cooling liquid between the motor frame and itself. The motor pump further includes at least one heat sink provided in the annular space. The heat sink is provided in a partial contact with the opposite load-side bearing bracket, and to extend to a position below the opposite load-side bearing bracket.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a motor pump, and more particularly to a motor pump for use underwater. [Background technology]

[0002] Submersible motor pumps are generally used to transport sewage, gray water, and other wastewater. For example, sewage generated in the basement of a building is temporarily stored in a drainage tank (pit) installed further below via an inlet pipe. When the water level in the pit reaches a predetermined start-up level, the submersible pump installed in the pit starts up. The sewage is pumped up into a sewage manhole by the submersible pump, and is then drained into the public sewer pipes via the manhole. In submersible pumps, the motor is generally installed above the impeller, so when the water level in the pit drops, the motor is exposed to the air. To prevent temperature increases due to heat generated by the motor, submersible pumps have a predetermined stop water level, and the operation of the submersible pump stops when the stop water level is reached.

[0003] However, to prevent the problem of sewage odor, it is preferable to pump the sewage as close to the bottom of the pit as possible. From this perspective, a jacket is provided around the motor, and the motor is cooled by circulating liquid within the jacket. In such a coolant circulation system, a circulation impeller for circulating the coolant is used separately from the main impeller for transporting sewage, etc. Patent Document 1 describes a coolant circulation structure for a pump using a circulation impeller.

[0004] Patent document 2 also describes a circulation flow path in which cooling liquid is supplied into a cooling jacket covering the motor part of an underwater motor pump by the rotation of a circulation impeller, and is returned to the pump bracket through a tubular member due to the large pressure difference between the upper and lower spaces separated by a partition member.

[0005] However, with the configurations described in Patent Documents 1 and 2, it is difficult to sufficiently cool the non-load side bearing during air operation when the motor section is exposed to air. The non-load side bearing is a bearing that is located above the motor section and supports the rotating shaft connected to the main impeller.

[0006] The non-load side bearing, located above the motor section, is exposed to air during air operation. The non-load side bearing can generate heat due to various factors. One possible cause of heat generation in the non-load side bearing is heat generated by the bearing itself due to sliding. Another possible cause is heat transfer from the stator and rotor sections of the motor section to the non-load side bearing. Therefore, there is a need for a means to reliably cool the entire motor section, including the non-load side bearing. [Prior art documents] [Patent documents]

[0007] [Patent Document 1] Japanese Patent Application Laid-Open No. 2012-57551 [Patent Document 2] Japanese Patent Application Publication No. 2018-059497 Summary of the Invention [Problem to be solved by the invention]

[0008] According to one embodiment of the present invention, it is possible to provide a submersible motor pump that can reliably cool the entire motor section, including the non-load side bearing. [Means for solving the problem]

[0009] According to one embodiment of the present invention, there is provided a motor pump including: a main impeller configured to transport water by rotation; a pump casing that houses the main impeller; a main shaft connected to the main impeller; a non-load side bearing that rotatably supports the main shaft on the non-load side; a non-load side bearing bracket that holds the non-load side bearing; a motor frame that houses a rotor that rotates integrally with the main shaft and a stator that is provided on the outer periphery of the rotor; and a cooling jacket that is disposed to surround the outer periphery of the motor frame and forms an annular space for receiving a coolant between the motor frame and the cooling jacket. The motor pump further includes at least one heat sink disposed in the annular space. The heat sink is disposed partially in contact with the non-load side bearing bracket and extends to a position below the non-load side bearing bracket. [Brief explanation of the drawings]

[0010] [Figure 1] 1 is a vertical cross-sectional view of a motor pump according to an embodiment of the present invention. [Figure 2] FIG. 2 is a partially enlarged view of FIG. 1, illustrating the flow of a cooling liquid. [Figure 3] FIG. 4 is a cross-sectional view of the motor pump showing the arrangement of the heat sink. [Figure 4] FIG. [Figure 5] FIG. 10 is a front view of another example of the heat sink. DETAILED DESCRIPTION OF THE INVENTION

[0011] Hereinafter, an embodiment of the present invention will be described with reference to the drawings. Note that the following description merely shows an example, and is not intended to limit the technical scope of the present invention to the following embodiment. In addition, in the drawings, identical or corresponding components are given the same reference numerals, and redundant description will be omitted. In addition, in the following description, terms indicating directions such as "upper" and "lower" are used with respect to the installation state of the motor pump shown in FIG. 1, etc. In other words, "upper" means the side farther from the main impeller, and "lower" means the side closer to the main impeller.

[0012] Hereinafter, an embodiment of the present invention will be described with reference to Figs. 1 to 5. Fig. 1 is a vertical cross-sectional view of a motor pump according to this embodiment. Fig. 2 is a partially enlarged view of Fig. 1. Fig. 3 is a horizontal cross-sectional view of the motor pump. Fig. 4 is a front view of a heat sink. Fig. 5 is a front view of another example of a heat sink.

[0013] The motor pump 10 of this embodiment is used as a sewage pump for transporting liquids containing impurities and filth, such as sewage, wastewater, or river water (collectively referred to as "water" in this embodiment). As shown in the figure, the motor pump 10 includes a pump portion 20 and a motor portion 30.

[0014] The pump section 20 includes a main impeller 21 that rotates about a vertical axis AL, and a pump casing 22 that houses the main impeller 21. The main impeller 21 is connected to a main shaft 31 of the motor section 30, and rotates as the main shaft 31 rotates. The pump casing 22 has a suction port 22a and a discharge port 22b, and defines a water flow path together with an intermediate casing 23 (specifically, the bottom of the intermediate casing 23), which will be described later.

[0015] The intermediate casing 23 is disposed between the pump section 20 and the motor section 30 in a position covering the back side (upper side in FIG. 1 ) of the main impeller 21. In this embodiment, the bottom of the intermediate casing 23 is formed by a side plate 23b that is separate from the main body 23a of the intermediate casing 23. The side plate 23b is attached to the main body 23a of the intermediate casing 23 with screws or the like. However, in other embodiments, the main body 23a of the intermediate casing 23 and the side plate 23b may be integrally formed with each other. In the pump section 20, water is transferred from the suction port 22a to the discharge port 22b as the main impeller 21 rotates.

[0016] The intermediate casing 23 may be fixed to the pump casing 22 with screws or the like. The intermediate casing 23 is preferably made of a material with high thermal conductivity, such as an aluminum alloy or a copper alloy. A through-hole (reference numeral omitted) is formed in the intermediate casing 23, through which the main shaft 31 of the motor section 30 is inserted. Furthermore, mechanical seals 25, 39 for sealing the main shaft 31 are provided in this through-hole.

[0017] The motor section 30 provides a rotational driving force to the main impeller 21. The motor section 30 includes a main shaft 31 that rotates about an axis AL, a rotor 32 that rotates integrally with the main shaft 31, and a stator 33 that is provided on the outer periphery of the rotor 32. In this embodiment, the motor section 30 is configured as an induction motor, and the rotor 32 has a rotor core 321 and a secondary conductor 322, but other types such as a synchronous motor may also be used. The stator 33 has a stator core 331 and a stator coil 332 wound around the stator core 331. A power line is connected to the stator coil 332, and power is supplied from an external power source (e.g., a commercial power source) via a cable 43.

[0018] The motor section 30 further includes a motor frame 34. In this embodiment, the motor frame 34 includes a cylindrical motor frame main body 34a and an upper cover 34b disposed on the upper portion of the motor frame main body 34a. However, the specific shape of the motor frame 34 is not limited to that shown in the figure. In this embodiment, a stator core 331 is fixed to the inner peripheral surface of the cylindrical motor frame main body 34a of the motor frame 34. The upper cover 34b includes an opening (reference numeral omitted) through which the cable 43 is passed. The motor frame 34 may be formed of stainless steel, or a resin such as polypropylene resin (PP resin), polyphenylene sulfide resin (PPS resin), or polyamide resin, or a metal such as an aluminum alloy or copper alloy. Hereinafter, the pump section 20 side of the motor section 30 (lower side in FIG. 1) will be referred to as the "load side," and the opposite side (upper side in FIG. 1) will be referred to as the "anti-load side." A load-side bearing bracket 37 is fixed to the lower end of the motor frame main body 34a. The load side bearing bracket 37 holds a load side bearing 38 for supporting the main shaft 31 of the motor section 30 .

[0019] A non-load side bearing bracket 40 can be disposed between the motor frame main body 34a and the upper cover 34b. The non-load side bearing bracket 40 holds a non-load side bearing 41 for supporting the main shaft 31 of the motor section 30. In this embodiment, the outer peripheral end of the non-load side bearing bracket 40 is sandwiched between the motor frame main body 34a and the upper cover 34b. The non-load side bearing bracket 40 is hermetically fixed to the inner surfaces of the motor frame main body 34a and the upper cover 34b via fixing parts 40-1. This configuration improves the water resistance of the motor pump 10, achieving water resistance of, for example, about IP68 (JIS C 0920).

[0020] A cylindrical cooling jacket 57 is disposed to surround the outer peripheral surface of the motor frame 34 of the motor section 30. This forms an annular space 59 for receiving the coolant 27 between the motor frame 34 and the cooling jacket 57. As shown in FIG. 1 , the non-load side bearing bracket 40 has a surface (in this embodiment, the outer peripheral end surface 42) exposed within the annular space 59 between the motor frame main body 34a and the upper cover 34b. The cooling jacket 57 is disposed so that the upper end of the annular space 59 is positioned above the outer peripheral end surface 42 of the non-load side bearing bracket 40. The opening at the upper end of the cooling jacket 57 is closed by a non-load side jacket side plate 56. Note that in this embodiment, the non-load side jacket side plate 56 is configured as a separate member from the cooling jacket 57. However, in other embodiments, the non-load side jacket side plate 56 may be formed integrally with the cooling jacket 57.

[0021] The annular space 59 between the inner peripheral surface of the cooling jacket 57 and the outer peripheral surface of the motor frame 34 is filled with the coolant 27, leaving an air layer 70 at the top. The cooling jacket 57 is used to cool the generated heat. The cooling liquid 27 may be, for example, an antifreeze solution such as a propylene glycol solution or an ethylene glycol solution. The air layer 70 may be provided to absorb volume changes in the cooling liquid 27 caused by temperature changes. However, depending on the pressure resistance of the cooling jacket 57, the air layer 70 may not necessarily be provided. The lower end of the cooling jacket 57 may be attached to the intermediate casing 23.

[0022] The motor pump 10 has an intermediate casing 23 disposed between the pump section 20 and the motor section 30, which forms a flow path 24 capable of receiving the flow of coolant 27 within an annular space 59. A circulation impeller 60 disposed within the flow path 24 of the intermediate casing 23 generates the flow of coolant 27. FIG. 1 shows openings 371 and 373 formed in the upper surface 23a-1 of the intermediate casing 23. The coolant 27 within the annular space 59 can flow from the opening 373 of the intermediate casing 23 through the flow path 24 to the suction port 60a (see FIG. 2) of the circulation impeller 60. The coolant 27 from the discharge port 60b (see FIG. 2) of the circulation impeller 60 can flow through the flow path 24 and into the annular space 59 via the opening 371. In this embodiment, the openings 371 and 373 are formed in the upper surface 23a-1 of the intermediate casing 23 (specifically, the main body 23a) so as to face the annular space 59. Therefore, the upper surface 23a-1 of the intermediate casing 23 extends laterally (in other words, radially outward) beyond the motor frame 34. However, in other embodiments, the specific locations of the openings 371, 373 are not particularly limited as long as they can communicate with the annular space 59. For example, the openings 371, 373 may be formed in the side wall of the intermediate casing 23.

[0023] FIG. 2 is a partially enlarged view of FIG. 1 showing the configuration of the flow path 24 of the intermediate casing 23. In this embodiment, the flow path 24 of the intermediate casing 23 is separated into a suction flow path 24a and a discharge flow path 24b by an inner casing 26 disposed within the intermediate casing 23. The inner casing 26 may be disposed so as to partially contact the inner wall of the intermediate casing 23 to prevent leakage of the coolant 27 from the discharge flow path 24b (high-pressure side) to the suction flow path 24a (low-pressure side). The inner casing 26 may be fixed to the intermediate casing 23 with screws or the like. The provision of the inner casing 26 can increase the flow velocity of the coolant 27 in the flow path 24 (particularly the discharge flow path 24b), thereby improving the efficiency of heat exchange between the water in the pump casing 22 and the coolant 27.

[0024] The suction flow passage 24a and the discharge flow passage 24b of the intermediate casing 23 are filled with coolant 27. The circulation impeller 60 is attached to the main shaft 31 between the mechanical seals 25, 39. The circulation impeller 60 rotates integrally with the main shaft 31. As shown by the arrows in FIG. 2 , as the circulation impeller 60 rotates, the coolant 27 in the annular space 59 of the cooling jacket 57 is sucked from the opening 373 of the intermediate casing 23 through the suction flow passage 24a into the suction port 60a of the circulation impeller 60. Meanwhile, the coolant 27 discharged from the discharge port 60b of the circulation impeller 60 passes through the discharge flow passage 24b of the intermediate casing 23 and is discharged into the annular space 59 of the cooling jacket 57 through the opening 371.

[0025] FIG. 1 shows one opening 371 and one opening 373. In this embodiment, the opening 373 is an inlet opening for the coolant 27 from the annular space 59 to the flow path 24 of the intermediate casing 23 and is also referred to as a first opening. In contrast, the opening 371 is an outlet opening for the coolant 27 from the flow path 24 of the intermediate casing 23 to the annular space 59 and is also referred to as a second opening. In this embodiment, the number and arrangement of the first openings and second openings are not particularly limited. The specific dimensions of the first openings and second openings are also not particularly limited. In this embodiment, it is sufficient that at least one first opening and at least one second opening are provided in the intermediate casing 23.

[0026] In this embodiment, the circulation impeller 60 is a centrifugal impeller. Therefore, the circulation impeller 60 does not have to be a centrifugal impeller, and may be, for example, an axial flow impeller.

[0027] Furthermore, although the motor pump 10 of this embodiment is configured to circulate the coolant 27 using the circulation impeller 60, other coolant circulation methods may be employed for the motor pump 10. It is sufficient that the motor pump 10 forms an annular space 59 for receiving the coolant 27 between itself and the motor frame 34.

[0028] 1, the motor pump 10 includes at least one heat sink 80 disposed within the annular space 59. The heat sink 80 can be formed from a material with high thermal conductivity, such as an aluminum alloy or a copper alloy. The heat sink 80 extends vertically within the annular space 59 so as to have a portion in contact with the non-load side bearing bracket 40 and at least a portion in contact with the coolant 27 during operation of the motor pump 10. In other words, the heat sink 80 is disposed so as to be partially in contact with the non-load side bearing bracket and to extend to a position below the non-load side bearing bracket.

[0029] In this embodiment, the heat sink 80 is arranged in contact with the counter-load side bearing bracket 40 at an upper end 80-1, and is configured to come into contact with at least the coolant 27 at a lower end 80-2 during operation of the motor pump 10. This allows heat exchange between the coolant 27 and the counter-load side bearing bracket 40 via the heat sink 80 (i.e., heat from the counter-load side bearing bracket 40 can be dissipated into the coolant 27). Furthermore, as will be described later, the heat sink 80 of this embodiment includes a fin-shaped portion 82 on which a plurality of fins 82-1 are formed.

[0030] The motor pump 10 of this embodiment is equipped with multiple heat sinks 80. FIG. 3 is a cross-sectional view of the motor pump 10 showing the arrangement of the multiple heat sinks 80. In the illustrated example, four heat sinks 80 are arranged at equal intervals around the circumferential direction of the motor pump 10. However, the number of heat sinks 80 provided on the motor pump 10 is not particularly limited. For example, the heat sink 80 may be a single plate-shaped member extending around the entire circumference of the motor frame 34. Furthermore, when multiple heat sinks 80 are arranged, the heat sinks 80 do not necessarily have to be arranged at equal intervals. Furthermore, in the example shown in FIG. 3, the heat sink 80 has a generally curved shape that follows the circumferential curvature of the motor frame 34. However, the heat sink 80 does not necessarily have to be curved. The specific number, shape, and dimensions of the heat sinks 80 can be determined based on the motor diameter, heat generation amount, etc. of the motor pump 10. 3, the upper end 80-1 of each heat sink 80 can be fixed to the motor frame 34 via fixing members 84 such as screws. However, in this embodiment, the heat sink 80 only needs to be fixed so that it is in partial contact with the anti-load side bearing bracket 40, and the specific fixing method is not particularly limited. For example, it is also possible to fix the heat sink 80 to the anti-load side bearing bracket 40 via the fixing members 84.

[0031] 1, in this embodiment, the heat sink 80 has a fin-shaped portion 82, which will be described later, extending substantially vertically at a position spaced apart from the outer circumferential surface of the motor frame 34 and the inner circumferential surface of the cooling jacket 57. However, the heat sink 80 does not necessarily have to extend vertically, and may extend at an angle to the vertical (for example, diagonally in FIG. 1). For example, the fin-shaped portion 82 of the heat sink 80 may be disposed so as to partially contact the inner circumferential surface of the cooling jacket 57. In this case, heat from the non-load side bearing bracket 40 can be released to the outside air through the heat sink 80 and the cooling jacket 57.

[0032] As described above, the heat sink 80 can at least partially have the fin-shaped portion 82. The fin-shaped portion 82 includes a plurality of fins 82-1. This can increase the heat dissipation area of ​​the heat sink 80. As shown in FIG. 1, in this embodiment, the fin-shaped portion Fins 82 have a wave shape with a substantially triangular cross section. However, fins 82 may also have a wave shape with a rectangular cross section. Fins 82 may also have a curved cross section, such as a semicircular cross section.

[0033] FIG. 4 is a front view of the heat sink 80 alone, as viewed from the right in FIG. 1. As shown in FIG. 4, in this embodiment, the fin-shaped portion 82 of the heat sink 80 includes multiple fins 82-1 formed in the circumferential direction of the motor frame 34. FIG. 5 shows another example of the fin-shaped portion 82. In the example of FIG. 5, the heat sink 80 includes multiple fins 82-1 formed in a substantially vertical direction (in other words, in the direction of the axis AL of the motor pump 10). However, the direction in which the fins 82-1 of the heat sink 80 are formed is not particularly limited. The fins 82-1 can also be formed in any direction intersecting the direction of the axis AL of the motor pump 10, such as a diagonal direction in FIG. 4. Furthermore, the multiple fins 82-1 do not have to be parallel to each other. For example, the fin-shaped portion 82 may be formed with at least one circumferential fin and at least one vertical fin. Furthermore, the number of fins 82-1 is not particularly limited.

[0034] 4 and 5, the upper end 80-1 of the heat sink 80 forms a fixing portion that is attached to the motor frame 34, and has holes 82-2 for passing fixing members 84, such as screws. As shown in FIG. 1, the upper end 80-1 is disposed in direct contact with the outer peripheral end surface 42 of the non-load side bearing bracket 40. The upper end 80-1 is fixed to the motor frame 34 by fixing members 84 at the upper and lower hole portions 82-2 of the outer peripheral end surface 42.

[0035] However, according to other embodiments, the heat sink 80 in the annular space 59 does not necessarily have to be in direct contact with the outer peripheral end surface 42 of the non-load side bearing bracket 40. The heat sink 80 may be in indirect contact with, for example, a portion of the non-load side bearing bracket 40 located inside the motor frame 34, for example, via an appropriate thermally conductive member.

[0036] Furthermore, fins 82-1 may be formed on the upper end portion 80-1 serving as a fixing portion.

[0037] As shown in FIG. 4, the lower end 80-2 of the heat sink 80 also forms a fixing portion for attachment to the motor frame 34 and has holes 82-3 for passing through fixing members 84, such as screws. The lower end 80-2 can be fixed to a protrusion 35 formed on the motor frame main body 34a by the fixing member 84. However, the lower end 80-2 does not have to be fixed, and the motor frame 34 does not have to have a protrusion 35. In other words, the heat sink 80 may be fixed to the motor frame 34 only at the upper end 80-1 and simply suspended from the motor frame 34. In this case, fins 82-1 can be formed on the lower end 80-2.

[0038] Fins 82-1 may be formed on the lower end portion 80-2 serving as a fixing portion. In the illustrated example, the number of holes 82-2 on the upper end portion 80-1 is different from the number of holes 82-3 on the lower end portion 80-2, but this embodiment is not limited to this. The specific numbers and arrangements of the holes 82-2 and 82-3 are not particularly limited.

[0039] The vertical length of the heat sink 80 may be determined so that at least the lower end 80-2 is in contact with the coolant 27 during operation of the motor pump 10. However, as shown in Fig. 1, the vertical length of the heat sink 80 is preferably determined so that almost the entire fin-shaped portion 82 is immersed in the coolant 27 (i.e., is located within the coolant 27). This allows heat from the non-load side bearing bracket 40 to be efficiently dissipated into the coolant 27.

[0040] The upper end portion 80-1 and the lower end portion 80-2 as the fixing portion and the fin-shaped portion 82 may be integrally formed with each other, or may be formed separately and then joined together. In this embodiment, the heat sink 80 is provided as a separate member from the motor frame 34 and is attached using a fixing member 84. However, according to other embodiments, the heat sink 80 can be formed as a part of the motor frame 34, that is, integrally molded with the motor frame 34 (for example, either the motor frame main body 34a or the upper cover 34b). It is also conceivable to mold the heat sink 80 integrally with the non-load side bearing bracket 40.

[0041] Thus, in this embodiment, the heat sink 80, which is disposed within the annular space 59, is disposed in contact with the counter-load side bearing bracket 40 (specifically, the outer peripheral end surface 42). The heat sink 80 also extends to a position below the counter-load side bearing bracket 40 so that the lower end 80-2 is in contact with at least the coolant 27. Therefore, heat can be exchanged between the coolant 27 and the counter-load side bearing bracket 40 (and therefore the counter-load side bearing 41) via the heat sink 80.

[0042] As described above, the volume of the coolant 27 changes due to temperature changes and other factors. The level of the coolant 27 in the cooling jacket 57 may also decrease over time. For example, if an aqueous solution such as a propylene glycol solution is used as the coolant 27, the water content of the coolant 27 may react with cast iron, a common material used in the wetted parts of the motor pump 10, generating gases such as hydrogen gas. The resulting reactive gases cause the coolant 27 to lose water, lowering the level of the coolant 27. Furthermore, deterioration of components such as the mechanical seals 25 and 39 may cause the coolant 27 to leak, lowering the level of the coolant 27. In this case, during air operation of the motor pump 10, a portion of the upper part of the motor frame 34 may not be surrounded by the coolant 27.

[0043] In this embodiment, the upper end 80-1 of the heat sink 80 is in contact with the non-load side bearing bracket 40, and the lower end 80-2 is in contact with the coolant 27. Therefore, even if the level of the coolant 27 drops, heat from the non-load side bearing bracket 40 can be released to the coolant 27 via the heat sink 80.

[0044] As described above, the intermediate casing 23, together with the pump casing 22, defines the flow path of water transported by the main impeller 21. Therefore, the intermediate casing 23, particularly the side plate 23b forming the bottom of the intermediate casing 23, is constantly cooled by water, and the coolant 27 is cooled by water through the intermediate casing 23. The coolant 27, which has been heated by heat exchange, is drawn into the suction port 60a of the circulation impeller 60 by the centrifugal force of the circulation impeller 60 from the cooling jacket 57 through the suction flow path 24a between the intermediate casing 23 and the inner casing 26, and then discharged from the discharge port 60b into the discharge flow path 24b. The discharged coolant 27 is cooled in the discharge flow path 24b between the inner casing 26 and the side plate 23b, and flows into the annular space 59 through the opening 371. As the coolant 27 rises within the annular space 59, it exchanges heat with the heated stator coil 332 via the motor frame 34, thereby cooling the stator coil 332. Furthermore, since the heat sink 80, which is in partial contact with the non-load side bearing bracket 40, is in contact with the coolant 27, heat exchange with the non-load side bearing bracket 40 via the heat sink 80 ensures that the non-load side bearing bracket 40 (and therefore the non-load side bearing 41) is cooled. The coolant 27 itself expands as it is heated, but the volume change due to the expansion of the coolant 27 can be absorbed by the air layer 70. The coolant 27 flows from the cooling jacket 57 through the opening 373 of the intermediate casing 23 and the suction passage 24a and returns to the suction port 60a. Thus, the coolant 27 circulates within the motor pump 10.

[0045] Thus, according to this embodiment, the cooling jacket 57, the circulation impeller 60, the intermediate casing 23, and the heat sink 80 form a cooling mechanism for cooling the motor portion 30. This makes it possible to provide a motor pump 10 that can be operated in air. Unlike conventional techniques, this is a simple method for dissipating heat from the non-load side bearing bracket 40 to the coolant 27. Therefore, the cooling effect of the entire motor section 30, including the non-load side bearing bracket 40, can be improved.

[0046] Although the embodiments of the present invention have been described above, the above-described embodiments are intended to facilitate understanding of the present invention and are not intended to limit the present invention. The present invention may be modified or improved without departing from the spirit thereof, and the present invention includes equivalents thereof. Furthermore, any combination or omission of the components described in the claims and specification is possible within the scope of solving at least part of the above-described problems or achieving at least part of the effects.

[0047] The present invention includes the following aspects. 1. A main impeller configured to be able to transport water by rotating; a pump casing that houses the main impeller; a main shaft connected to the main impeller; a counter-load side bearing that supports the rotation of the main shaft on the counter-load side; a counter-load side bearing bracket for holding a counter-load side bearing; a motor frame that houses a rotor that rotates integrally with the main shaft and a stator that is provided on the outer periphery of the rotor; a cooling jacket disposed so as to surround an outer peripheral surface of the motor frame, and forming an annular space for receiving a coolant between the cooling jacket and the motor frame, The motor pump further includes at least one heat sink disposed within the annular space; the heat sink is arranged in partial contact with the anti-load side bearing bracket and extends to a position below the anti-load side bearing bracket; Motor pump. 2. The motor pump according to 1. above, a counter-load side bearing bracket attached to the motor frame such that the counter-load side bearing bracket has a surface partially exposed within the annular space; A motor pump, wherein the heat sink is placed in direct contact with the exposed surface. 3. The motor pump according to 1. or 2. above, The heat sink is disposed in partial contact with the cooling jacket of the motor pump. 4. The motor pump according to any one of 1. to 3. above, A motor pump, wherein the heat sink includes a fin-shaped portion on which a plurality of fins are formed. 5. The motor pump according to 4 above, A motor pump, wherein the plurality of fins are formed in the circumferential direction of the motor frame. 6. The motor pump according to any one of 1. to 5. above, The motor pump further comprises a fixing member for fixing the heat sink in contact with the anti-load side bearing bracket. 7. The motor pump according to item 6 above, The motor pump, wherein the heat sink includes a fixing portion to which a fixing member is attached. 8. The motor pump according to any one of 1. to 7. above, The heat sink is a single heat sink that extends around the entire periphery of the motor frame, motor pump. 9. The motor pump according to any one of 1. to 8. above, A motor pump comprising: an intermediate casing disposed between a pump casing and a motor frame, forming a flow path for a coolant; and a circulation impeller attached to a main shaft within the flow path. [Industrial Applicability]

[0048] The present invention can be widely applied to motor pumps. [Explanation of symbols]

[0049] AL axis 10 Motor pump 20 Pump part 21 Main impeller 22 Pump casing 22a Intake port 22b Discharge port 23 Intermediate casing 23a Main body 23a-1 Top surface 23b Side plate 24 flow paths 24a Suction channel 24b Discharge flow path 25 Mechanical seal 26 Inner casing 27 Coolant 30 Motor part 31 Main shaft 32 rotor 33 Stator 34 Motor frame 34a Motor frame body 34b Top cover 35 Convex part 37 Load side bearing bracket 38 Load side bearing 39 Mechanical seal 40 Anti-load side bearing bracket 40-1 Fixed part 41 Anti-load side bearing 42 Outer peripheral end face 43 Cable 56 Anti-load side jacket side plate 57 Cooling jacket 59 Annular Space 60 Circulation impeller 60a Intake port 60b outlet 70 Air Layer 80 Heat sink 80-1 Upper end (fixed part) 80-2 Lower end (fixed part) 82 Fin-shaped section 82-1 Finn 82-2, 82-3 Hole 84 Fixing member 321 rotor core 322 Secondary Conductor 331 Stator Core 332 stator coil 371 Second Opening 373 First Opening

Claims

1. a main impeller configured to be able to transport water by rotating; a pump casing that houses the main impeller; a main shaft connected to the main impeller; a counter-load side bearing that supports the main shaft for rotation on the counter-load side; a counter-load side bearing bracket for holding the counter-load side bearing; a motor frame that accommodates a rotor that rotates integrally with the main shaft and a stator that is provided on the outer periphery of the rotor; a cooling jacket disposed to surround an outer peripheral surface of the motor frame and defining an annular space for receiving a coolant between the cooling jacket and the motor frame, the motor pump further includes at least one heat sink disposed within the annular space; the heat sink is disposed in partial contact with the counter-load side bearing bracket and extends to a position below the counter-load side bearing bracket. Motor pump.

2. 2. The motor pump according to claim 1, the counter-load side bearing bracket is attached to the motor frame so as to have a surface partially exposed within the annular space; The heat sink is positioned in direct contact with the exposed surface.

3. 3. The motor pump according to claim 1 or 2, The heat sink is arranged in partial contact with the cooling jacket.

4. 3. The motor pump according to claim 1 or 2, The motor pump, wherein the heat sink includes a fin-shaped portion on which a plurality of fins are formed.

5. 5. The motor pump according to claim 4, The motor pump, wherein the plurality of fins are formed in a circumferential direction of the motor frame.

6. 3. The motor pump according to claim 1 or 2, The motor pump further comprises a fixing member for fixing the heat sink in contact with the anti-load side bearing bracket.

7. 7. The motor pump according to claim 6, The heat sink includes a fixing portion to which the fixing member is attached.

8. 3. The motor pump according to claim 1 or 2, A motor pump, wherein the heat sink is a single heat sink extending around the entire periphery of the motor frame.

9. 3. The motor pump according to claim 1 or 2, A motor pump comprising: an intermediate casing disposed between the pump casing and the motor frame and forming a flow path for the coolant; and a circulation impeller attached to the main shaft within the flow path.

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