Method for manufacturing submersible rotary machines and method for manufacturing submersible electric pumps

Abstract

To provide a manufacturing method of an underwater rotary machine capable of simplifying a manufacturing process while securing dimensional accuracy.SOLUTION: A manufacturing method of an underwater electric pump includes the steps of: resin-molding a resin motor frame 11 by using a mold; inserting a stator 13 into the resin motor frame 11 after the resin molding; and fixing the stator 13 to the resin motor frame 11 through shrinkage of the resin motor frame 11.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a method for manufacturing an underwater rotary machine and a method for manufacturing an underwater electric pump, and in particular to a method for manufacturing an underwater rotary machine equipped with a motor including a stator and a motor frame surrounding the outer periphery of the stator, and a method for manufacturing an underwater electric pump. [Background technology]

[0002] BACKGROUND ART Conventionally, there is known an underwater rotary machine provided with a motor including a stator and a motor housing (see, for example, Patent Document 1).

[0003] The motor pump as an underwater rotary machine of Patent Document 1 includes a main shaft, a rotor that rotates integrally with the main shaft, a stator provided on the outer periphery of the rotor, and a metal motor frame. In addition, in the manufacturing method of the motor pump of Patent Document 1, the stator is fixed to the inner periphery of the metal motor frame. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Publication No. 2019-206839 Summary of the Invention [Problem to be solved by the invention]

[0005] Although not explicitly stated in Patent Document 1, in the field of underwater rotating machines including the motor pump of Patent Document 1, it is necessary to use a jig to accurately position and fix the stator to the motor frame so that the rotational center axis of the main shaft does not shift and cause vibration in the main shaft. In this case, the process of fixing the stator to the motor frame becomes complicated, which poses a problem in that the manufacturing process of the underwater rotating machine becomes complicated.

[0006] The present invention has been made to solve the above-mentioned problems, and one object of the present invention is to provide a method for manufacturing an underwater rotary machine that can simplify the manufacturing process while ensuring dimensional accuracy. [Means for solving the problem]

[0007] A manufacturing method of an underwater rotating machine according to a first aspect of the present invention is a manufacturing method of an underwater rotating machine equipped with a motor including a stator and a motor frame surrounding an outer periphery of the stator, the manufacturing method comprising the steps of: resin molding the motor frame made of resin using a mold; inserting the stator into the resin motor frame after resin molding; and fixing the stator to the resin motor frame by shrinkage of the resin motor frame; The process of resin molding the resin motor frame includes a process of forming an inclined surface that is inclined with respect to the direction in which the stator is inserted and a non-inclined surface that extends in the direction in which the stator is inserted as the inner surface of the resin motor frame.

[0008] As described above, a manufacturing method for a submersible rotating machine according to a first aspect of the present invention includes the steps of: resin-molding a resin motor frame using a mold; inserting a stator into the resin-molded motor frame; and fixing the stator to the resin motor frame by shrinking the resin motor frame. This allows the motor frame to shrink while surrounding the outer circumferential surface of the stator. Therefore, a force due to shrinkage can be applied from the motor frame to the stator approximately uniformly in the circumferential direction of the stator, allowing the stator to be fixed to the motor frame by utilizing the shrinkage of the resin without using a jig. This eliminates the need for a step of fixing the stator to the motor frame using a jig. Furthermore, unlike press-fitting using a jig, this simplifies the fixing process to the resin motor frame and ensures the accuracy of the center position of the stator (shaft) without using a jig. As a result, the manufacturing process can be simplified while ensuring dimensional accuracy. Furthermore, utilizing the shrinkage of the motor frame can reduce the occurrence of cracks in the motor frame compared to when the stator is inserted into the motor frame. In addition, the inclined surface allows the resin motor frame molded from resin to be easily removed from the mold, and the non-inclined surface allows the outer surface of the stator and the inner surface of the resin motor frame to be securely fitted together in surface contact.

[0009] In the method for manufacturing an underwater rotary machine according to the first aspect, the step of inserting the stator into the resin motor frame preferably includes the step of inserting the stator into the resin motor frame before shrinkage of the resin-molded resin motor frame is complete. With this configuration, the stator can be inserted into the resin motor frame immediately after resin molding, when the inner diameter of the resin motor frame is larger than the outer diameter of the stator, making it possible to easily insert the stator into the resin motor frame.

[0011] In this case, the step of resin-molding the resin motor frame preferably includes a step of forming the resin motor frame so that the gradient surfaces and non-graded surfaces are alternately arranged at approximately equal intervals in the circumferential direction. With this configuration, the non-graded surfaces and the gradient surfaces can be provided approximately evenly on the stator, which ensures reliable fixation when the motor frame shrinks and prevents the stator from becoming misaligned with respect to the resin motor frame.

[0012] In the method for manufacturing the submersible rotary machine according to the first aspect, the step of resin-molding the resin motor frame preferably includes the step of forming gradient surfaces and non-graded surfaces over the entire circumferential direction on the inner surface of the resin motor frame so that the gradient surfaces and non-graded surfaces are continuously formed along the direction of insertion of the stator, and the step of inserting the stator into the resin motor frame includes the step of inserting the stator into the resin motor frame so that the non-graded surfaces formed over the entire circumferential direction come into contact with the outer peripheral surface of the stator. With this configuration, a large contact area between the resin motor frame and the stator can be ensured, thereby more reliably fixing the stator to the resin motor frame and efficiently transferring heat generated by the stator to the resin motor frame.

[0013] In the manufacturing method of the submersible rotating machine according to the first aspect, the step of resin-molding the resin motor frame preferably includes a step of integrally molding the resin motor frame with a resin motor bracket that supports a bearing portion of the rotor. This configuration eliminates the boundary between the motor bracket and the resin motor frame, thereby preventing water from seeping in between the motor bracket and the resin motor frame. Furthermore, compared to when the motor bracket and the resin motor frame are resin-molded separately, this eliminates the need for a step of separately manufacturing and assembling the motor bracket and the resin motor frame, thereby further simplifying the manufacturing process of the submersible rotating machine.

[0014] In this case, the step of resin-molding the resin motor frame preferably includes a step of integrally molding the resin motor frame and the resin motor bracket so that the resin motor frame surrounds the outer periphery of the stator and the resin motor bracket is located on the bottom side of the stator, thereby forming a cylindrical motor frame easily, unlike when the motor bracket and resin motor frame are manufactured separately and then assembled.

[0016] In the manufacturing method of the submersible rotating machine according to the first aspect, the step of molding the resin motor frame preferably includes the step of integrally molding fins on the outer peripheral surface of the resin motor frame. With this configuration, the provision of fins ensures a large heat dissipation area for the resin motor frame, thereby further improving the heat dissipation performance of the motor. Furthermore, if the resin contains a highly thermally conductive filler, the provision of fins allows the highly thermally conductive filler to be oriented in the thickness direction, thereby further improving the heat dissipation performance.

[0017] In the manufacturing method of the submersible rotary machine according to the first aspect, the step of resin-molding the resin motor frame preferably includes a step of forming a step portion that protrudes inward from the inner peripheral surface of the resin motor frame and whose surface on the side of the insertion opening for inserting the stator contacts the stator, and the step of inserting the stator into the resin motor frame includes a step of contacting the stator with the step portion of the resin motor frame when inserting the stator, thereby positioning the stator relative to the resin motor frame. With this configuration, simply contacting the stator with the step portion of the resin motor frame can position the stator relative to the motor frame in the stator insertion direction before the motor frame shrinks, thereby completing the insertion of the stator into the motor frame. This allows for easy and reliable positioning of the stator in the depth direction (axial direction) without performing a press-fitting step using a jig.

[0018] In this case, preferably, the inner diameter of the portion surrounded by the step portion after resin molding in the positioning step is smaller than the outer diameter of the stator, as viewed in the insertion direction of the stator. This configuration allows the stator to be reliably brought into contact with the step portion, making it easy to position the stator relative to the motor frame in the insertion direction.

[0019] A manufacturing method of a submersible electric pump according to a second aspect of the present invention is a manufacturing method of a submersible electric pump equipped with a motor including a stator and a motor frame surrounding an outer periphery of the stator, the method comprising: a step of resin-molding a resin motor frame using a mold; a step of inserting the stator into the resin-molded motor frame; and a step of fixing the stator to the resin motor frame by shrinkage of the resin motor frame; The process of resin molding the resin motor frame includes a process of forming an inclined surface that is inclined with respect to the direction in which the stator is inserted and a non-inclined surface that extends in the direction in which the stator is inserted as the inner surface of the resin motor frame.

[0020] A manufacturing method for a submersible electric pump according to a second aspect of the present invention includes the steps of: resin-molding a resin motor frame using a mold; inserting a stator into the resin-molded motor frame; and fixing the stator to the resin motor frame by shrinking the resin motor frame. This allows the motor frame to shrink while surrounding the outer circumferential surface of the stator. Therefore, a force due to shrinkage can be applied from the motor frame to the stator approximately uniformly in the circumferential direction of the stator, allowing the stator to be fixed to the motor frame by utilizing the shrinkage of the resin without using a jig. This eliminates the need for a step of fixing the stator to the motor frame using a jig. Furthermore, unlike press-fitting using a jig, this simplifies the fixing process to the resin motor frame and ensures the accuracy of the center position of the stator (shaft) without using a jig. As a result, the manufacturing process for a submersible electric pump can be simplified while ensuring dimensional accuracy. Furthermore, utilizing the shrinkage of the motor frame can reduce the occurrence of cracks in the motor frame compared to when the stator is inserted into the motor frame. In addition, the inclined surface allows the resin motor frame molded from resin to be easily removed from the mold, and the non-inclined surface allows the outer surface of the stator and the inner surface of the resin motor frame to be securely fitted together in surface contact. [Effects of the Invention]

[0021] According to the present invention, as described above, it is possible to provide a method for manufacturing an underwater rotary machine that can simplify the manufacturing process while ensuring dimensional accuracy. [Brief explanation of the drawings]

[0022] [Figure 1] FIG. 1 is a side view showing the overall configuration of a submersible pump. [Figure 2] FIG. 2 is a perspective view of a resin motor frame. [Figure 3] FIG. 2 is a bottom view showing a state in which a stator is attached to a resin motor frame. [Figure 4] 10A and 10B are diagrams illustrating a process of inserting the stator into a resin motor frame. [Figure 5] 10A to 10C are diagrams showing a process of fixing the starter to a resin motor frame. [Figure 6] FIG. 10 is a bottom view showing a state in which a stator is attached to a resin motor frame according to a first modified example. [Figure 7] FIG. 10 is a side view showing a state in which fins are provided on a motor frame according to a second modified example. [Figure 8] FIG. 10 is a bottom view showing a state in which a stator is attached to a motor frame according to a modified example. DETAILED DESCRIPTION OF THE INVENTION

[0023] The present embodiment will be described below with reference to FIGS.

[0024] [Present embodiment] (Configuration of underwater rotating machines) The submersible electric pump 100 will be described with reference to Figure 1. The "submersible electric pump" is an example of the "submersible rotary machine" set forth in the claims.

[0025] The submersible electric pump 100 includes a motor 1, a pump chamber 2, and an oil chamber 3.

[0026] The motor 1 includes a motor frame 11, a motor bracket 12, a stator 13, a rotor 14, a bearing 15, and a shaft (rotating shaft) 16. One end of the shaft 16 is rotatably supported by the bearing 15 attached to the motor bracket 12, and the impeller 4 is attached to the other end of the shaft 16. The shaft 16 is disposed to extend in the vertical direction. In this specification, the direction in which the shaft 16 extends is referred to as the Z direction. The side on which the motor bracket 12 is located is referred to as the Z1 side, and the side on which the impeller 4 is attached is referred to as the Z2 side.

[0027] As shown in Figures 1 and 2, motor frame 11 houses stator 13 and rotor 14. Motor frame 11 is cylindrical. Motor frame 11 is made of resin. Resin motor frame 11 is preferably molded using a highly thermally conductive resin with a thermal conductivity of 1.0 W / mK or higher. Highly thermally conductive resins include, for example, general-purpose plastics, engineering plastics with improved strength or heat resistance compared to general-purpose plastics, or super engineering plastics with improved heat resistance compared to engineering plastics.

[0028] Examples of general-purpose plastics are ABS (acrylonitrile butadiene styrene) or PP (polypropylene). Examples of engineering plastics are PC (polycarbonate), PA (polyamide or nylon), PBT (polybutylene terephthalate), PPE (polyphenylene ether), and m-PPE (modified polyphenylene ether or Noryl). Examples of super engineering plastics are PPS (polyphenylene sulfide), PSU (polysulfone), PAI (polyamide imide), PEI (polyether imide), PEEK (polyether ether ketone), or LCP (liquid crystal polyester or liquid crystal polymer).

[0029] Resin motor frame 11 is formed integrally with motor bracket 12. Resin motor frame 11 has a cylindrical shape in which resin motor frame 11 surrounds the outer periphery of stator 13 and motor bracket 12 is located on the bottom side (Z1 side) of stator 13. Note that stator 13 is inserted into resin motor frame 11 from the Z2 side toward the Z1 side. The thickness of resin motor frame 11 is not particularly limited, but from the viewpoint of heat dissipation and strength, it may be set to, for example, 3.0 mm or more, preferably 3.5 mm to 5 mm, and more preferably 3.5 mm to 4 mm.

[0030] As shown in Fig. 2, the resin motor frame 11 has an insertion opening 11a for inserting the stator 13. The insertion opening 11a is provided on the opposite side (Z2 side) from the side (Z1 side) on which the motor bracket 12 is provided. After the components including the stator 13 and rotor 14 are attached to the resin motor frame 11, a cover member 17 (see Fig. 1) is attached to the insertion opening 11a.

[0031] As shown in FIGS. 2 and 3 , the resin motor frame 11 has, as its inner surface, a sloped surface 11b that slopes with respect to the insertion direction (Z direction) of the stator 13 so that the size of the slope in a direction (X direction or Y direction) perpendicular to the insertion direction (Z direction) of the stator 13 increases toward the insertion opening 11a for inserting the stator 13, and a non-slope surface 11c that extends in the insertion direction of the stator 13. The angle of the sloped surface 11b is set to, for example, 2 degrees. The non-slope surface 11c functions as a fitting surface when the stator 13 is fitted into the resin motor frame 11. The non-slope surface 11c has a slope of approximately 0 degrees. In this embodiment, the sloped surfaces 11b and the non-slope surfaces 11c are alternately arranged at approximately equal intervals in the circumferential direction (R direction). In this embodiment, the sloped surfaces 11b are provided at four locations in the circumferential direction.

[0032] As shown in Figures 3 and 4, the resin motor frame 11 has a step 11d on its inner circumferential surface. When viewed in the direction in which the stator 13 is inserted, the size of the inner diameter D1 of the portion surrounded by the step 11d is smaller than the size of the outer diameter D3 of the stator 13. The step 11d is formed in a continuous circular shape along the inner circumferential surface of the resin motor frame 11. The step 11d is provided to position the stator 13 in the depth direction (axial direction) relative to the resin motor frame 11.

[0033] As shown in FIG. 1, the motor bracket 12 is configured to support the bearing portion 15 of the rotor 14 from above.

[0034] 3, the motor bracket 12 has a circular shape when viewed from above. The motor bracket 12 is provided with a hole 12a into which the bearing 15 is inserted.

[0035] As shown in Fig. 1, the stator 13 is configured to generate a magnetic field to rotate the rotor 14. The stator 13 is fitted to a non-inclined surface 11c of the resin motor frame 11 (see Fig. 3). The non-inclined surface 11c is in contact with the outer peripheral surface 13b of the stator 13 over substantially the entire surface.

[0036] A shaft 16 is attached to the rotor 14. The rotor 14 functions as an electromagnet when electricity is passed through it. The rotor 14 is configured to rotate together with the shaft 16 by generating a magnetic field by the stator 13.

[0037] One end of the rotor 14 on the Z1 side is attached to the bearing portion 15. The bearing portion 15 is attached to the motor bracket 12.

[0038] The shaft 16 has a cylindrical shape that extends generally in the vertical direction (Z direction). The impeller 4 is fixed to the Z2 side of the shaft 16. The motor 1 is configured to rotate the impeller 4 via the shaft 16. The rotation axis center line α of the shaft 16 is precisely positioned relative to the motor frame 11.

[0039] As shown in Figure 1, an impeller 4 is disposed in the pump chamber 2. The pump chamber 2 also has an inlet 21 and a discharge port 22. The submersible electric pump 100 is disposed in a drainage area (not shown) and draws water into the pump chamber 2 through the inlet 21. The rotation of the impeller 4 imparts velocity energy to the water drawn into the pump chamber 2, and the velocity energy of the water is converted into pressure energy within the pump chamber 2 and discharged from the discharge port 22.

[0040] The oil chamber 3 is disposed between the motor 1 and the pump chamber 2, and is filled with oil. A mechanical seal 31 is provided in the oil chamber 3.

[0041] (Submersible electric pump manufacturing method) A method for manufacturing the submersible electric pump 100 will be described with reference to FIGS.

[0042] The resin motor frame 11 is resin-molded using a mold. For example, injection molding is used to mold the resin by preparing a mold consisting of a core and a cavity, fitting the core and the cavity together, and pouring the resin into the mold. The mold is designed so that the inner circumferential surface of the resin motor frame 11 has a sloped surface 11b and a non-sloped surface 11c.

[0043] The mold is set so that the inner diameter D2 of the resin motor frame 11 immediately after resin molding is larger than the outer diameter D3 of the stator 13. The resin motor frame 11 is adjusted so that the inner diameter D2 after shrinkage is complete without the stator 13 attached will be smaller than the outer diameter D3 of the stator 13. As a result, the resin motor frame 11 does not fully shrink to the specified inner diameter size when the stator 13 is inserted, so a shrinking force is applied to the stator 13, and the stator 13 is firmly fixed to the resin motor frame 11.

[0044] As shown in FIG. 4, after the resin-molded resin motor frame 11 is removed from the mold, the stator 13 is inserted into the resin motor frame 11 before the resin motor frame 11 has completely shrunk. The insertion direction is from the Z2 direction to the Z1 direction. At this time, the bottom surface 13a of the stator 13 contacts the stepped portion 11d of the resin motor frame 11, thereby positioning the stator 13 relative to the resin motor frame 11. The timing for inserting the stator 13 into the resin motor frame 11 is set, for example, within one cycle of molding the motor frame 11 in the injection molding process. One cycle is set appropriately depending on conditions such as the shrinkage rate of the resin used and the size of the motor frame 11. For example, one cycle is set to be 2 minutes and 30 seconds starting 2 minutes after removal from the mold.

[0045] When viewed in the direction of inserting the stator 13, the inner diameter D2 of a portion of the resin motor frame 11 that is not provided with the step portion 11d when the stator 13 is attached is larger than the outer diameter D3 of the stator 13. When viewed in the direction of inserting the stator 13, the inner diameter D1 of a portion of the resin motor frame 11 that is surrounded by the step portion 11d when the stator 13 is attached is smaller than the outer diameter D3 of the stator 13. Note that a process for shaping the resin motor frame 11 may be included after the resin motor frame 11 is removed from the mold and before the stator 13 is inserted.

[0046] As shown in FIG. 5 , the stator 13 is inserted into the resin motor frame 11, and then the resin motor frame 11 is shrunk to fix the stator 13 to the resin motor frame 11. Specifically, the inner diameter D2 of the fully shrunk resin motor frame 11 is set to be slightly smaller than the outer diameter D3 of the stator 13. However, due to the constraints of the outer diameter D3 of the stator 13, the inner diameter D2 of the resin motor frame 11 and the outer diameter D3 of the stator 13 become approximately the same size. As a result, the outer peripheral surface 13b of the stator 13 fits into the non-graded surface 11c of the resin motor frame 11, and the stator 13 is fixed to the inner surface of the resin motor frame 11. After the stator 13 is fixed to the resin motor frame 11, the rotor 14 is placed inside the stator, and the bearing portion 15 of the rotor 14 is brought into contact with the motor bracket 12. A cover member 17 is then attached to the insertion opening 11a of the resin motor frame 11, completing the motor 1.

[0047] The completed motor 1 has the impeller 4 attached to the shaft 16. Thereafter, the oil chamber 3 and the pump chamber 2 are attached to the motor 1, thereby completing the submersible electric pump 100.

[0048] (Effects of this embodiment) In this embodiment, the following effects can be obtained.

[0049] As described above, this embodiment includes the steps of resin-molding the resin motor frame 11 using a mold, inserting the stator 13 into the resin-molded motor frame 11, and fixing the stator 13 to the resin motor frame 11 by shrinking the resin motor frame 11. This allows the motor frame 11 to shrink while surrounding the outer peripheral surface 13b of the stator 13. Therefore, the force associated with shrinkage can be applied from the motor frame 11 to the stator 13 approximately uniformly in the circumferential direction of the stator 13, allowing the stator 13 to be fixed to the motor frame 11 by utilizing the shrinkage of the resin without using a jig. This eliminates the need for a step of fixing the stator 13 to the motor frame 11 using a jig. Furthermore, unlike press-fitting using a jig, this simplifies the fixing process to the resin motor frame 11 and ensures the accuracy of the center position of the stator 13 (shaft 16) without using a jig. As a result, the manufacturing process can be simplified while ensuring dimensional accuracy. Furthermore, by utilizing the contraction of the motor frame 11, it is possible to suppress the occurrence of cracks in the motor frame 11 compared to when the stator 13 is inserted into the motor frame 11.

[0050] In this embodiment, as described above, the step of inserting the stator 13 into the resin motor frame 11 includes the step of inserting the stator 13 into the resin motor frame 11 before complete shrinkage of the resin-molded resin motor frame 11. This allows the stator 13 to be inserted into the resin motor frame 11 immediately after resin molding, when the inner diameter D2 of the resin motor frame 11 is larger than the outer diameter D3 of the stator 13, making it easy to insert the stator 13 into the resin motor frame 11.

[0051] In this embodiment, as described above, the process of resin-molding the resin motor frame 11 includes a process of forming, as the inner surface of the resin motor frame 11, a sloped surface 11b that is sloped with respect to the insertion direction of the stator 13 so that the size of the direction perpendicular to the direction of insertion of the stator 13 increases toward the insertion opening 11a for inserting the stator 13, and a non-sloped surface 11c that extends in the insertion direction of the stator 13. As a result, the sloped surface 11b makes it easy to remove the resin-molded resin motor frame 11 from the mold, and the non-sloped surface 11c makes it possible to reliably fit the outer peripheral surface 13b of the stator 13 and the inner peripheral surface of the resin motor frame 11 in surface contact with each other.

[0052] In this embodiment, as described above, the step of resin-molding the resin motor frame 11 includes a step of forming the resin motor frame 11 so that the inclined surfaces 11b and the non-inclined surfaces 11c are alternately arranged at approximately equal intervals in the circumferential direction. This allows the non-inclined surfaces 11c and the inclined surfaces 11b to be provided approximately evenly on the stator 13, which ensures reliable fixation when the motor frame 11 shrinks and prevents the stator 13 from becoming misaligned with respect to the resin motor frame 11.

[0053] In this embodiment, the process of resin molding the resin motor frame 11 includes a process of integrally molding the resin motor frame 11 and the resin motor bracket 12 that supports the bearing portion 15 of the rotor 14. This eliminates the boundary between the motor bracket 12 and the resin motor frame 11, thereby preventing water from seeping in between the motor bracket 12 and the resin motor frame 11. Furthermore, compared to when the motor bracket 12 and the resin motor frame 11 are resin molded separately, this eliminates the need for the process of individually manufacturing and assembling the motor bracket 12 and the resin motor frame 11, thereby further simplifying the manufacturing process of the submersible electric pump 100.

[0054] In this embodiment, the process of resin molding the resin motor frame 11 includes a process of integrally molding the resin motor frame 11 and the resin motor bracket 12 so that the resin motor frame 11 surrounds the outer periphery of the stator 13 and the resin motor bracket 12 has a cylindrical shape located on the bottom side of the stator 13. This makes it possible to easily manufacture the cylindrical motor frame 11, unlike when the motor bracket 12 and the resin motor frame 11 are manufactured separately and then assembled.

[0055] In this embodiment, the process of resin molding the resin motor frame 11 includes a process of molding the resin motor frame 11 using a highly thermally conductive resin with a thermal conductivity of 1.0 W / mK or higher. By using a highly thermally conductive resin, the resin motor frame 11 can more easily dissipate heat transmitted from the stator 13, thereby improving the heat dissipation performance of the motor 1.

[0056] In this embodiment, the process of resin-molding the resin motor frame 11 includes a process of forming a step 11d on the inner peripheral surface of the resin motor frame 11, the step 11d protruding inward and having a surface on the side of the insertion opening 11a for inserting the stator 13 come into contact with the stator 13, and the process of inserting the stator 13 into the resin motor frame 11 includes a process of positioning the stator 13 relative to the resin motor frame 11 by bringing the stator 13 into contact with the step 11d of the resin motor frame 11 when inserting the stator 13. Thus, simply by bringing the stator 13 into contact with the step 11d of the resin motor frame 11, the stator 13 can be positioned relative to the motor frame 11 in the insertion direction before the motor frame 11 shrinks, and insertion of the stator 13 into the motor frame 11 can be completed. This makes it possible to easily and reliably position the stator 13 in the depth direction (axial direction) without performing a press-fit process using a jig.

[0057] In this embodiment, when viewed in the direction in which the stator 13 is inserted, the size of the inner diameter D1 of the portion surrounded by the step portion 11d after resin molding in the positioning step is smaller than the size of the outer diameter D3 of the stator 13. This allows the stator 13 to be reliably brought into contact with the step portion 11d, making it easy to position the stator 13 relative to the motor frame 11 in the direction in which the stator 13 is inserted.

[0058] [First Modification of the Present Embodiment] Next, a first modified example of this embodiment will be described with reference to Fig. 6. In this first modified example, a non-graded surface 11c is provided over the entire inner circumferential surface of a resin motor frame 211. In the figure, parts with the same configuration as in the above embodiment are denoted by the same reference numerals.

[0059] In a first modified example of this embodiment, the step of resin-molding the resin motor frame 211 includes a step of forming gradient surface 11b and non-graded surface 11c over the entire circumferential direction as the inner surface of the resin motor frame 211 so that gradient surface 11b and non-graded surface 11c are continuously formed along the direction of insertion of the stator 13. Specifically, the non-graded surface 11c is formed on the insertion opening 11a side of the resin motor frame 211, and the gradient surface 11b is formed on the motor bracket 12 side. Furthermore, the step of inserting the stator 13 into the resin motor frame 211 includes a step of inserting the stator 13 into the resin motor frame 211 so that the non-graded surface 11c formed over the entire circumferential direction and the outer peripheral surface 13b of the stator 13 come into contact with each other.

[0060] In the first modified example of this embodiment, a large contact area can be secured between the resin motor frame 211 and the stator 13, so that heat generated from the stator 13 can be efficiently transferred to the resin motor frame 211. The other configurations and effects of the first modified example of this embodiment are the same as those of the above embodiment.

[0061] [Second Modification of the Present Embodiment] Next, a second modified example of this embodiment will be described with reference to Fig. 7. In this second modified example, fin portions 18 are formed on the outer peripheral surface 13b of a resin motor frame 311. In the figure, parts having the same configuration as those in the above embodiment are given the same reference numerals.

[0062] In the second modified example of this embodiment, the process of molding the resin motor frame 311 includes a process of integrally molding the fin portions 18 on the outer peripheral surface 13b of the resin motor frame 311. The shape, orientation (direction), and number of the fin portions 18 are not particularly limited. For example, the fin portions 18 may be arranged to extend along the Z direction, or along the X direction or Y direction.

[0063] In the second modification of this embodiment, by providing fins 18 on the outer peripheral surface 13b of the resin motor frame 311, it is possible to ensure a large heat dissipation area of ​​the resin motor frame 311, thereby further improving the heat dissipation of the motor 1. Furthermore, by providing fins 18, if the resin contains a highly thermally conductive filler, the highly thermally conductive filler can be oriented in the thickness direction, thereby further improving heat dissipation. The other configurations and effects of the second modification of this embodiment are the same as those of the above embodiment.

[0064] (Variation) The embodiments disclosed herein should be considered to be illustrative and not restrictive in all respects. The scope of the present invention is defined by the claims rather than the above description of the embodiments, and further includes all modifications (variations) within the meaning and scope of the claims.

[0065] For example, in the above embodiment, the submersible rotary machine is an electric submersible pump, but the present invention is not limited to this. The submersible rotary machine is not particularly limited as long as it is a device that is placed underwater, such as an aeration device or a submersible mixer.

[0066] In addition, although the above embodiment shows an example in which four inclined surfaces are provided, the present invention is not limited to this. In the present invention, the number of inclined surfaces is not particularly limited, and as long as it is one or more, it may be eight as shown in FIG.

[0067] Furthermore, in the above embodiment, an example in which the step portion is provided continuously has been shown, but the present invention is not limited to this, and in the present invention, the step portion may be provided intermittently. [Explanation of symbols]

[0068] 1 motor 11, 211, 311 motor frame 11a Insertion opening 11b Sloped surface 11c Non-sloped surface 11d Step 12 Motor bracket 13 Stator 13a (Stator) bottom 13b (stator) outer surface 14 rotors 15 Bearing section 18 Fin section 100 Submersible electric pump

Claims

1. A method for manufacturing an underwater rotary machine including a motor including a stator and a motor frame surrounding an outer periphery of the stator, a step of resin-molding the motor frame using a mold; a step of inserting the stator into the resin motor frame after resin molding; and fixing the stator to the resin motor frame by shrinking the resin motor frame, The method for manufacturing an underwater rotating machine includes a step of forming an inclined surface that is inclined with respect to the direction in which the stator is inserted and a non-inclined surface that extends in the direction in which the stator is inserted as an inner surface of the resin motor frame.

2. 2. The method for manufacturing an underwater rotating machine according to claim 1, wherein the step of inserting the stator into the resin motor frame includes the step of inserting the stator into the resin motor frame before shrinkage of the resin-molded resin motor frame is completed.

3. 2. The method for manufacturing an underwater rotating machine according to claim 1, wherein the step of resin molding the resin motor frame includes a step of forming the resin motor frame so that the inclined surfaces and the non-inclined surfaces are alternately arranged at approximately equal intervals in the circumferential direction.

4. the step of resin-molding the resin motor frame includes a step of forming the inclined surface and the non-inclined surface over the entire circumferential direction as an inner surface of the resin motor frame such that the inclined surface and the non-inclined surface are formed continuously along a direction in which the stator is inserted, 2. The method for manufacturing an underwater rotating machine according to claim 1, wherein the step of inserting the stator into the resin motor frame includes the step of inserting the stator into the resin motor frame so that the non-graded surface formed over the entire circumferential direction comes into contact with an outer peripheral surface of the stator.

5. 5. The method for manufacturing an underwater rotating machine according to claim 1, wherein the step of resin molding the resin motor frame includes a step of integrally molding the resin motor frame and the resin motor bracket that supports a bearing portion of a rotor.

6. 6. The method for manufacturing an underwater rotating machine according to claim 5, wherein the step of resin molding the resin motor frame includes a step of integrally molding the resin motor frame and the resin motor bracket so that the resin motor frame surrounds an outer periphery of the stator and the resin motor bracket has a cylindrical shape located on a bottom surface side of the stator.

7. 7. The method for manufacturing an underwater rotary machine according to claim 1, wherein the step of molding the resin motor frame includes a step of integrally molding a fin portion on an outer peripheral surface of the resin motor frame.

8. the step of resin-molding the resin motor frame includes a step of forming a step portion that protrudes inward on an inner peripheral surface of the resin motor frame and whose surface on an insertion opening side for inserting the stator comes into contact with the stator, 8. The method for manufacturing an underwater rotating machine according to claim 1, wherein the step of inserting the stator into the resin motor frame includes a step of contacting the stepped portion of the resin motor frame with the stator when inserting the stator, thereby positioning the stator relative to the resin motor frame.

9. 9. The method for manufacturing an underwater rotating machine according to claim 8, wherein an inner diameter of a portion surrounded by the step portion after resin molding in the positioning step is smaller than an outer diameter of the stator when viewed in a direction in which the stator is inserted.

10. A method for manufacturing a submersible electric pump equipped with a motor including a stator and a motor frame surrounding an outer periphery of the stator, a step of resin-molding the motor frame using a mold; a step of inserting the stator into the resin motor frame after resin molding; and fixing the stator to the resin motor frame by shrinking the resin motor frame, The method for manufacturing a submersible electric pump includes a step of forming an inclined surface that is inclined with respect to the insertion direction of the stator and a non-inclined surface that extends in the insertion direction of the stator as an inner surface of the resin motor frame, wherein the resin motor frame is resin-molded.

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