JP5897817B2 - CAND MOTOR PUMP AND MANUFACTURING METHOD THEREOF - Google Patents

Description

  The present invention relates to a canned motor pump, and more particularly to its structure.

  The canned motor pump is an apparatus in which a turbo pump such as a centrifugal pump and an electric motor (hereinafter simply referred to as a motor) that drives the turbo pump are integrated. The rotor of the motor is housed in a cylindrical stator can, and the stator of the motor is arranged outside the stator can so as to surround the rotor. The rotating parts of the motor including the rotor are all contained in the stator can, and the handling liquid of the pump enters the stator can. Since the rotating part is housed in the stator can, a structure such as a packing for sliding with the rotating part and preventing leakage of the handling liquid becomes unnecessary. The stator of the motor is housed in a stator chamber formed by a housing that surrounds the outer periphery of the motor and a stator can. The stator chamber is a sealed space to satisfy explosion-proof standards.

  Since the bearing that supports the motor shaft integrated with the rotor is also accommodated in the stator can, the length of the stator can in the cylindrical axis direction is generally longer than that of the rotor or the stator. That is, the stator can has a portion protruding from the stator outside the stator, that is, in the axial direction. This portion may be provided with a backup sleeve to support the pressure in the stator can. The backup sleeve is also a cylindrical member whose inner peripheral surface is in close contact with the outer peripheral surface of the stator can.

  Patent Document 1 below discloses a canned motor in which a stator chamber formed by a housing surrounding the outer periphery of the stator and a stator can is filled with resin.

Japanese Patent Publication 1-16096

  As described above, the stator can is supported by the backup sleeve from the outer peripheral side in the portion exposed from the stator. However, due to manufacturing reasons, a portion of the stator can that cannot be supported by the backup sleeve has occurred.

  An object of this invention is to provide the support method of the stator can replaced with a backup sleeve.

The canned motor pump of the present invention is surrounded by a metal cylindrical stator can positioned between a rotor and a stator of a motor, a coil wound around the stator, a stator can and a motor housing, and the stator and the coil are A stator chamber, a plurality of spherical inorganic material particles filled in the stator chamber in contact with each other, and a cured resin that is present between the plurality of spherical inorganic particles and fixes the spherical inorganic material particles to each other. And a filler that directly contacts and supports the portion corresponding to the coil of the can. Then, a plurality of spherical inorganic material particles are filled in the stator chamber so as to be in contact with each other, and a resin for fixing the filled plurality of spherical inorganic material particles is injected into the stator chamber and cured. The In the stator chamber, the filler in which the spherical inorganic material particles and the resin are mixed is in direct contact with and supports the portion corresponding to the coil of the stator can, thereby suppressing the deformation of the stator can. The spherical inorganic material particles may be any spherical particles that have a small volume change even with a temperature change when the resin is cured and have a certain mechanical strength, such as alumina (aluminum oxide), zirconia (zirconia dioxide), silicon carbide. Spherical particle sintered body of simple substance or mixture of materials generally called ceramic, such as silicon nitride, and spherical particle sintered body of simple substance or mixture of mainly metal oxide such as silicon dioxide and magnesium oxide Sintered spherical particles of natural minerals or mixtures of natural minerals such as zircon and quartz, and spherical sintered particles or glass beads of ceramics and metal oxides or minerals. The particle | grains comprised by are preferable. The resin to be injected and cured can be selected from the liquid feeding temperature of the canned motor pump, the use environment temperature, etc., and can be a silicone resin or an epoxy resin.

  By filling the stator chamber with the filler, the entire portion of the stator can facing the stator chamber can be supported.

It is sectional drawing of the canned motor pump of this embodiment. It is explanatory drawing regarding the support of the stator can by a backup sleeve.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a cross-sectional view showing a schematic configuration of the canned motor pump 10. The canned motor pump 10 includes a pump unit 12 having a centrifugal pump configuration and a motor unit 14 for driving the centrifugal pump. The pump unit 12 is not limited to a centrifugal pump, and may be configured as a turbo pump such as a mixed flow pump or an axial flow pump. In the pump unit 12, the impeller 16 is housed in the impeller chamber of the casing 18 and is coupled to the end of the motor shaft 20. A connecting plate 22 is fixedly coupled to the casing 18 on the rear surface side of the impeller by bolts.

  The motor unit 14 includes a rotor 24 that is coupled to be integrated with the motor shaft 20, and a motor 28 that includes a stator 26 that is disposed so as to surround the rotor 24. The stator 26 includes a stator core 30 having magnetic poles arranged in a circumferential direction on a substantially cylindrical inner peripheral surface, and a coil 32 formed by winding a conductive wire around the magnetic poles of the stator core. The end of the conducting wire of the coil 32 extends to the terminal box 34 and is connected to a terminal (not shown) provided in the terminal box. At least one axial groove 36 extending along the motor axial direction is provided on the outer peripheral surface of the stator core.

  A cylindrical stator can 38 is disposed inside the stator core 30 and outside the rotor 24. The stator can 38 is a cylinder having a uniform thickness. The stator can 38 is in contact with the inner peripheral surface of the stator core 30, that is, the tip end surface of the magnetic pole, and is disposed with a certain distance from the outer peripheral surface of the rotor 24.

  A cylindrical stator band 44 is provided along the outer peripheral surface of the stator core 30. The stator can 38 and the stator band 44 are doubly and concentrically arranged, and their axial lengths are substantially equal. At the both ends of the stator can 38 and the stator band 44, annular plate-shaped end bells 46 and 48 are arranged to block the end of the cylindrical space between the stator can 38 and the stator band 44. The end bell 46 on the pump unit 12 side is coupled to the connecting plate 22 by a bolt. In addition, a disk end plate 50 that closes the end of the space inside the stator can 38 is coupled to the end bell 48 on the side opposite to the pump unit 12 by bolts. The stator band 44, the two end bells 46, 48, and the disc end plate 50 can be viewed as a motor housing that houses the motor 28. The stator 26 is housed in a space surrounded or formed by a motor housing, in particular, a stator band 44 and two end bells 46 and 48, and a stator can 38. This space is hereinafter referred to as a stator chamber 52.

  The motor shaft 20 integrated with the rotor 24 is supported at both ends by bearings 54 and 56. The bearing 54 on the pump unit 12 side is held by a bearing housing 58 extending from the casing 18 of the pump unit 12. On the other hand, the bearing 56 at the opposite end is held by a bearing housing 60 extending from the disk end plate 50. The liquid inside the pump portion 12 sucks and discharges enters the space inside the cylindrical stator can 38, that is, the rotor chamber 62 in which the rotor 24 is accommodated. The handling liquid enters the rotor chamber 62 from the back side of the impeller 16, passes through the bearing 54 or the periphery thereof, passes through the gap between the rotor 24 and the stator can 38, and reaches the space opposite to the pump unit 12. From there, it passes through a center hole (not shown) penetrating along the axis to the center of the motor shaft 20 and returned to the suction side of the impeller 16.

  The canned motor pump 10 is entirely supported by legs 64 fixed to the end bells 46 and 48.

The stator chamber 52 is filled with a filler 66 and hardened. A coil end 68 that is a portion of the coil 32 that protrudes from the stator core 30 is also embedded in the filler 66. Further, the filler 66 is in contact with the entire surface of the stator can 38 that faces the stator chamber 52. The filler 66 is a mixed material of spherical inorganic material particles and a resin, particularly a silicone resin. The spherical inorganic material particles need only be spherical particles that are non-conductive and have some mechanical strength, and spherical ceramic particles can be used. As the spherical ceramic particles, for example, Niiga Cera Beads 60 (registered trademark) manufactured by ITOCHU CERATECH Co., Ltd. can be used. The particles do not need to be true spheres, and may be particles that are round as a whole and have no corners. The main components are aluminum oxide (Al ₂ O ₃ ) and silicon dioxide (SiO ₂ ). As the resin, a component used as a binder can be used. In addition, when the temperature of the liquid to be fed is high, the resin is preferably excellent in heat resistance. For example, a silicone resin KR-242R made of Shin-Etsu silicone can be used. In addition, an epoxy resin can be used instead of the silicone resin depending on the environmental conditions in use, such as temperature and humidity. A mixed material of glass beads and epoxy resin can also be used. As the glass beads, for example, general purpose glass beads GB301S manufactured by Potters Barotini can be used. The selection of the material of the spherical inorganic material particles and the type of resin can be appropriately selected depending on the temperature of the fluid handled by the pump.

  For filling with the filler 66, first, spherical inorganic material particles in a dry state are poured into the stator chamber 52, for example, from the terminal box 34. When spherical inorganic material particles are poured from the terminal box 34, the spherical inorganic material particles first flow into the stator chamber 52 b adjacent to the terminal box 34, and then pass through the portion between the magnetic poles of the stator core 30 and the axial groove 36. The stator chamber 52a on the side is reached. At this time, if necessary, the stator chamber (stator chamber 52a) on the side far from the inlet side (terminal box 34) is lowered. In addition, the packing density can be increased by applying vibration. The spherical inorganic material particles have good fluidity because the surface of the particles is smooth, and can be closely packed in every corner of the stator chamber because the particle diameter is small. After filling the spherical inorganic material particles, the silicone resin is filled. An opening for sucking up resin is provided in the lower part of the stator chamber 52, for example, the annular end plate 46, and the spherical inorganic material is formed by vacuuming the stator chamber 52 from the terminal box 34, for example, from the opposite side of the opening. Suction is performed so that the resin enters between the particles. In order to increase the fluidity of the resin at this time, the resin may be diluted with an appropriate solvent to reduce the viscosity. Then, the resin is cured by heating and drying. By using spherical inorganic material particles, it can be injected into the stator chamber separately from the resin, filling work can be performed without using a large-scale facility such as injection molding, and manufacturing effort is not required.

  As described above, the filler 66 using the spherical inorganic material particles as the filler is filled to every corner of the stator chamber 52. Therefore, the filler 66 can also enter and support the portion of the stator can 38 that could not be supported by the backup sleeve conventionally.

  FIG. 2 is a view showing a main part of a type of canned motor pump having a backup sleeve. About the structure similar to the canned motor pump 10 of this invention of FIG. 1, the same code | symbol is attached | subjected and the description is abbreviate | omitted. A backup sleeve 70 is provided in close contact with the outer peripheral surface of the stator can 38 at a portion of the stator can 38 that extends outward in the axial direction from the stator core 30. In FIG. 2, only the periphery of the stator chamber 52a on the motor side is shown, but the stator chamber 52b on the opposite side also has the same configuration. Clearances 72 and 74 are formed between the backup sleeve 70 and the stator core 30 and between the backup sleeve 70 and the end bell 46. In the gaps 72 and 74, there is no one that supports the stator can 38 from the outside, and the stator can 38 may not be sufficiently supported when an internal pressure is applied.

  The gaps 72 and 74 are caused by the attachment process of the stator can 38. Before attaching the stator can 38 to the motor unit 12, the stator band 44 is welded to the stator 30 and the end bells 46 and 48 are fixed to the stator band 44 with the backup sleeve 70 inserted. In this state, the stator can 38 is inserted into the inner diameters of the backup sleeve 70 and the stator 30 from the axial direction of the motor. At this time, if the backup sleeve 70 is restrained by the stator 30 and the end bells 46 and 48 and does not move, the stator can 38 cannot be inserted satisfactorily. Therefore, the gaps 72 and 74 are provided at both ends of the backup sleeve 70 in the axial direction so that the backup sleeve 70 can move slightly without being restrained, so that the stator 30 and the end bells 46 and 48 can be moved. Easy centering. Since the centering can be easily performed, the stator can 38 can be easily inserted.

  When the stator can 38 is supported by the backup sleeve 70, the thickness of the stator can 38 needs to be determined so as not to be deformed in the gaps 72 and 74 even when a force such as an internal pressure is applied. On the other hand, if the stator can 38 is supported by the filler 66 without using the backup sleeve as in this embodiment, the entire surface of the stator can 38 facing the stator chamber 52 can be supported. Since the weak portions such as the positions of the gaps 72 and 74 when the backup sleeve 70 is employed are eliminated, the stator can 38 can be made thin.

  In addition, when using irregularly shaped particles as the filler, the corners may be crushed or broken, and the particles that are hooked at the corners may be displaced from each other, reducing the volume when the resin is cured. There are things to do. However, since the particles of this embodiment are spherical, the particles are close to each other close to a cubic close-packed state, and there are few gaps that cause displacement between the particles, so that the entire volume is hardly reduced. Therefore, since the stator can 38 is not deformed by the deformation at the time of hardening of the filler, the stator can 38 from this surface can be made thin. Further, since the resin enters and fills between the magnetic pole tip of the stator core 30 and the stator can 38, the deformation of the stator can 38 at this portion can be suppressed.

  In addition, the spherical inorganic material particles contact the coil 32 when the particles are poured into the stator chamber 52 and after curing, but at this time, since there are no corners like the irregular particles, an insulating coating on the coil conductor is formed. It will not hurt.

  In the canned motor pump, it is known that the motor efficiency deteriorates due to the eddy current generated in the metal plate of the stator can. Thinning the stator can reduces the amount of eddy current generation, and is expected to improve motor efficiency.

  10 Canned motor pump, 12 Pump part, 14 Motor part, 24 Rotor, 26 Stator, 28 Motor, 30 Stator core, 38 Stator can, 52 Stator chamber, 66 Filling material.

Claims (10)

A metal cylindrical stator can located between the rotor and stator of the motor;
A coil wound around a stator;
A stator chamber surrounded by a stator can and a motor housing and containing a stator and a coil;
Compatible with stator can coils, including multiple spherical inorganic material particles filled in the stator chamber in contact with each other and cured resin that is present between the multiple spherical inorganic particles and fixes the spherical inorganic material particles together. A filler that is in direct contact with and supports the part,
A canned motor pump.   The canned motor pump according to claim 1, wherein the spherical inorganic material particles are spherical ceramic particles.   The canned motor pump according to claim 1, wherein the spherical inorganic material particles are glass beads.   The canned motor pump according to any one of claims 1 to 3, wherein the resin is a silicone resin.   The canned motor pump according to any one of claims 1 to 3, wherein the resin is an epoxy resin. Manufacture of a canned motor pump having a metal cylindrical stator can located between a rotor and a stator of a motor, a motor housing that forms a stator chamber for housing the stator together with the stator can, and a coil wound around the stator A method,
Filling the stator chamber with a plurality of spherical inorganic material particles in contact with each other,
A resin for fixing the filled spherical inorganic material particles is injected into the stator chamber and cured,
In the stator chamber, the filler mixed with the spherical inorganic material particles and the resin supports the portion directly in contact with the portion corresponding to the coil of the stator can and suppresses deformation of the stator can.
A method for manufacturing a canned motor pump . The method for manufacturing a canned motor pump according to claim 6, wherein the spherical inorganic material particles are spherical ceramic particles. The method for manufacturing a canned motor pump according to claim 6, wherein the spherical inorganic material particles are glass beads. It is a manufacturing method of the canned motor pump of any one of Claims 6-8, Comprising: The manufacturing method of the canned motor pump whose said resin is a silicone resin. It is a manufacturing method of the canned motor pump of any one of Claims 6-8, Comprising: The manufacturing method of the canned motor pump whose said resin is an epoxy resin.

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