JP2010193623A - Squirrel cage rotor for electric motor, electric motor, submersible pump, and method of manufacturing them - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To achieve a squirrel cage rotor for a electric motor in which a rotary shaft is penetrated through a core shaft hole at the center of a laminated core formed by laminating a plurality of thin electromagnetic steel plates, a plurality of conductors are respectively penetrated through each core slot formed on the circumference of the laminated core, an end ring and the conductors are joined to each other, and a high-performance rust-preventing layer is formed by simple treatment on each surface of the laminated core and the rotary shaft without using chemicals or the like in the materials. <P>SOLUTION: The squirrel cage rotor for a electric motor is configured as follows. A laminated core is formed by laminating a plurality of thin electromagnetic steel plates. A plurality of conductors are arranged annularly around the axis of the laminated core. An annular end ring has a plurality of slots connected with the plurality of conductors. The laminated core, the plurality of conductors, and the annular end ring are assembled. Then, a rotary shaft is assembled at the axial center of the core. Subsequently, a rust-preventing layer made of a triiron tetroxide oxide is formed by steam treatment on the surface of the core and the surface of the rotary shaft. <P>COPYRIGHT: (C)2010,JPO&amp;INPIT

Description

  The present invention relates to a squirrel-cage rotor for an electric motor, an electric motor provided with a squirrel-cage rotor, a submersible pump provided with the rotary electric motor, and methods for manufacturing the same.

  Various types of rotary electric motors are being promoted in various ways to improve performance. Among them, the measures for rotors are to improve characteristics by changing the materials of the electromagnetic steel sheets and conductors used as core parts, improve the space factor of the conductors, change the core shape, and improve the magnetic circuit efficiency by improving the flatness of the outer surface of the core. A rust prevention treatment for preventing a short circuit between core iron plates caused by rust generated on the core surface can be mentioned.

  FIG. 11 shows a configuration example of a conventional electric motor rotor. A plurality of cores 1 each having a core shaft hole 12 formed in the center of a thin electromagnetic steel sheet and a plurality of core slots 11 each having a substantially trapezoidal shape on the circumference are laminated so as to have a predetermined height. After the end ring 2 having the substantially same shape is arranged, the shaft 3 is passed through the core shaft hole 12 in the center of the core 1, and the conductor bar 4 is passed through the core slot 11 so as to straddle the core slot 11 of the core 1 and the end ring 2. The end ring 2 and the conductor bar 4 are joined by various methods such as brazing to achieve electrical conduction. Furthermore, by forming an epoxy resin rust prevention layer 52 typified by a baking process of a paint mainly composed of an epoxy resin on the outer peripheral surface of the laminated core 1 or the end ring 2, a cage rotor of an electric motor can be formed. Form.

  In this configuration, the end ring 2 and the conductor bar 4 are prepared as separate parts, and the method of joining them after assembling to the laminated core 1 has been described. However, in the die casting method, the core slot 11 of the laminated core 1 is a cavity. As a method, a molten metal is poured to form the end ring 2 and the conductor bar 4 at a time. Also in this method, since a rust prevention layer is required on the outer peripheral surface of the laminated core 1 or the end ring 2, a baking treatment of a paint mainly composed of an epoxy resin or the like has been performed.

  However, in the baking process of the paint mainly composed of epoxy resin or the like for forming a rust prevention layer on the outer peripheral surface of the laminated core 1 or the end ring 2, in order to obtain a good rust prevention layer, Pre-treatment for cleaning is required, and spray coating and brushing of paint are performed, and then baking is performed in the furnace for temperature control. Depending on the product, in order to exhibit a higher rust prevention effect, there are those in which the coating from coating to baking is repeated twice or more.

  Therefore, as described in the configuration of the first electric motor rotor, a rust prevention layer is required on the outer peripheral surface of the laminated core and end ring. Other methods other than the method of performing the above are being studied. For example, Patent Document 1 proposes a technique for forming a rust-preventing coating film by applying a natural resin-based paint mainly composed of cellulose to the outer surface of a rotor core of a rotor for submerged electric motors or by baking. ing.

  Patent Document 2 proposes a method of insulating the motor core and shaft in a state where the shaft is press-fitted and fixed in the hole in the center of the laminated core for the motor. Examples of treatment, chemical conversion treatment, blackening treatment, and steam treatment are shown, and it is also shown that an oxide film of triiron tetroxide (Fe3O4) is formed on the surface of the laminated iron core by the steam treatment ((paragraph [0111] To [0112]).

Japanese Utility Model Publication No. 63-176341 JP 2005-57859 A

  However, the invention of the above-mentioned Patent Document 1 only applies a natural resin-based paint mainly composed of cellulose, or is baked to cover the outer surface of the rotor core and the end ring with the natural resin-based paint, When natural resin paint is worn or damaged, there is a problem in that the surface of the components inside the rotor where the natural resin paint is not applied cannot be rusted and the durability is insufficient. .

  Further, in Patent Document 2, an example in which an oxide film of triiron tetroxide (Fe3O4) is formed by steam treatment is described. However, the rotor described in Patent Document 2 is a simple combination of the shaft 4 and the iron core 9. The structure is different from that of a squirrel-cage rotor in which a plurality of core slots are formed in a plurality of thin electromagnetic steel sheets, a plurality of conductor bars are arranged and fixed with an end ring, and an oxide film is also a laminated iron core. However, it has only a problem that its durability is insufficient.

  The problem to be solved by the present invention is to stack a plurality of cores each having a core shaft hole and a plurality of core slots on the circumference in a center of a thin electromagnetic steel sheet so as to have a predetermined height, and cores at both ends in the axial direction. An end ring with the same shape as that of the core is placed, the shaft is passed through the core shaft hole in the center of the core, the conductor is passed through the core and the core slot of the end ring, and the end ring and the conductor are joined. In a method of performing a rust prevention treatment on a cage rotor for an electric motor, the treatment itself is simple, and it is to realize a cage rotor for an electric motor having a high rust prevention layer formed without using chemicals or the like as a material.

  A squirrel-cage rotor for an electric motor according to the present invention includes a core in which a plurality of thin iron plates are stacked, a rotating shaft disposed at the center of the core axis, a plurality of conductor portions disposed annularly around the axis of the rotating shaft, and the plurality A squirrel-cage rotor for an electric motor in which an annular end ring having a plurality of slot portions connected to a conductor portion of the motor is disposed, and a rust prevention layer of triiron tetraoxide is formed on the surface of the core and the rotating shaft. It is characterized by being.

  In addition, the method of manufacturing a squirrel-cage rotor for an electric motor according to the present invention includes a core in which a plurality of thin iron plates are stacked, a rotating shaft arranged at the center of the core axis, and a plurality of conductors arranged annularly around the axis of the rotating shaft. In the method of manufacturing a cage rotor for an electric motor in which an annular end ring having a plurality of slots connected to a plurality of slots and a plurality of slot portions connected to the plurality of conductors is disposed, after the assembly process of the rotating shaft in which the rotating shaft is disposed at the center of the core axis Then, steam treatment with water vapor molecules of nanometer level is performed on the surface of the core and the surface of the rotating shaft at a processing temperature higher than the shrink fitting temperature at the time of the assembly process, and a rust prevention layer of triiron tetraoxide is formed. It is characterized by forming.

  According to the present invention, in the method of performing the rust prevention treatment on the surface of the laminated core or end ring of the cage cage rotor of the electric motor, after assembling the rotor core, the shaft is assembled, and then the steam treatment is performed. By doing so, a rust prevention layer having a thin rust prevention layer thickness, strong adhesion, high thermal conductivity at the interface, and good performance such as penetration not only to the outer peripheral surface of the core but also to the inside can be obtained.

  Moreover, since the rust preventive layer is formed last, it is possible to prevent damage to the rust preventive layer due to handling of members and prevent deterioration of the accuracy of the laminated core due to heating.

FIG. 1 is an explanatory diagram of the structure of a submersible pump according to a first embodiment of the present invention. FIG. 2 is an explanatory view of the structure of a squirrel-cage rotor for an electric motor according to a second embodiment of the present invention. FIG. 3: is the front view (a) and perspective view (b) of the cage rotor for electric motors of Example 3 of this invention. FIG. 4 is an explanatory view of the structure of the laminated core of the squirrel-cage rotor for an electric motor according to the third embodiment of the present invention. FIG. 5 is an explanatory diagram of a method for manufacturing a laminated core of a squirrel-cage rotor for an electric motor according to a third embodiment of the present invention. FIG. 6 is an explanatory diagram of a method for manufacturing a laminated core of a squirrel-cage rotor for an electric motor according to a third embodiment of the present invention. FIG. 7 is an explanatory diagram of an assembly of a rotor laminated core and a rotating shaft according to the third embodiment of the present invention. FIG. 8 is an explanatory diagram of a method for manufacturing a squirrel-cage rotor for an electric motor according to a third embodiment of the present invention. FIG. 9 is an explanatory diagram of a method for manufacturing a squirrel-cage rotor for an electric motor of Reference Example 1. FIG. 10 is an explanatory diagram of a method for manufacturing a squirrel-cage rotor for an electric motor of Reference Example 2. FIG. 11 is an explanatory diagram of a conventional electric motor rotor.

The cage rotor of the electric motor to which the present invention is applied is a high-efficiency electric motor that requires the use of a copper material as a conductor, or a submersible pump in which the thickness of the laminated core portion is longer than the core outer diameter and the use of a conductor bar is required It can be used for a squirrel-cage rotor of various electric motors including an electric motor.
Hereinafter, the details of the present invention will be described with reference to the drawings.

  First, as Example 1 of the present invention, an example of a submersible pump in which a laminated bar portion needs to use a conductor bar whose thickness is longer than the core outer diameter will be described with reference to FIG. The submersible pump includes an impeller 9 attached to the rotary shaft 3, an intermediate casing 10 that houses the impeller 9, a pump unit that includes a discharge port provided in a part of the intermediate casing 10, and the pump unit. It consists of the electric motor part arrange | positioned on the opposite side to the discharge port shown by arrow.

  This electric motor section includes a core 1 in which a plurality of thin steel plates are laminated in the axial direction of the rotating shaft 3, end rings 2 disposed at both ends in the axial direction of the core 1, and end rings 2 at both ends via the core 1. A cage rotor is formed from a plurality of conductor bars 4 to be connected. Further, relative to the squirrel-cage rotor, the stator core 7 disposed on the concentric circle of the rotary shaft 3, the stator winding 71 incorporated in the stator core 7 and allowing current to flow, and the rotary shaft 3 are rotated. A smooth bearing 72, a stator core 7 and an outer frame 8 for housing the cage rotor are configured.

  As will be described later, a rust preventive layer 51 of triiron tetraoxide is formed on the surface of the core 1 in which a plurality of thin iron plates of a squirrel-cage rotor for an electric motor of a submersible pump are laminated and the axis of the core 1. Has been.

  Next, a squirrel-cage rotor for an electric motor that is Embodiment 2 of the present invention will be described. This squirrel-cage rotor is applied to an electric motor, and is used as a squirrel-cage rotor for an electric motor of the above-described submersible pump.

  Steam assembly (500-600 ° C.) is performed on the laminated core 1 in which a plurality of thin iron plates of a squirrel-cage rotor for an electric motor and the rotating shaft 3 are fastened, and the outer peripheral surface of the laminated core 1 and the laminated core The entire core surface including a portion between a plurality of thin iron plates, the entire surface including a portion arranged at the center of the laminated core 1 of the rotating shaft 3, the end ring 3 and the conductor bar 4 forming the laminated core 1, etc. A rust preventive layer of triiron tetroxide is formed by steam treatment on the entire surface including the surface of each component. FIG. 2 shows a state in which the steam processing to the rotor core that has completed the shaft assembly is completed.

  2 (a) is a partially sectional external view of a squirrel-cage rotor for an electric motor according to a second embodiment of the present invention, FIG. 2 (b) is an AA sectional view, and FIG. 2 (c) is FIG. ) And FIG. 2 (d) show an enlarged view of FIG. 2 (b).

  In FIG. 2A, the formation position of the rust prevention layer 51 with respect to the outer peripheral surface of the core 1 and the surface of the rotary shaft 3 is shown. A rust prevention layer 51 is also formed on the surface of the end ring 2 and the surface of the conductor bar 4.

  In FIG. 2B, the rust preventive layer 51 can also be formed on the surface of the core shaft hole 12 in which the rotating shaft 3 is disposed and the surface of the core slot 11 into which the plurality of conductor bars 4 are inserted.

  Moreover, in FIG.2 (c), the formation position of the antirust layer 51 with respect to between the lamination | stacking of several thin iron plates of the lamination | stacking core 1 is shown. 2D shows the formation position of the rust prevention layer 51 on the outer peripheral surface of the laminated core 1, the inner surface of the core slot 11 of the laminated core 1, and the outer peripheral surface of the conductor bar 4. FIG. As will be described later, nanometer-level steam fine particles permeate even in a slight gap of μm (micrometer) level to form a rust prevention layer 51.

  In FIG. 3, the external view of the cage rotor for electric motors of Example 3 of this invention is shown. 3A is a front view, and FIG. 3B is a perspective view. A plurality of mechanical and electrical connection portions 23 are formed at positions corresponding to the plurality of conductor bars 4 of the end ring 2 by press molding.

  In the squirrel-cage rotor for electric motors of Example 3, as with the squirrel-cage rotor for electric motors of Example 2, the entire core surface including the outer peripheral surface of the laminated core 1 and the plurality of thin iron plates of the laminated core 1 The entire surface including the portion arranged at the center of the laminated core 1 of the rotating shaft 3 and the entire surface including the surfaces of the respective constituent elements such as the end ring 3 and the conductor bar 4 forming the laminated core 1 are subjected to steam treatment. In addition to the formation of a rust prevention layer of triiron oxide, the surface of a plurality of mechanical and electrical connection portions 23 formed at positions corresponding to the plurality of conductor bars 4 of the end ring 2 by press molding, A rust preventive layer of triiron tetraoxide is formed.

  FIG. 4 shows the structure of the laminated core of the squirrel-cage rotor for an electric motor according to the third embodiment of the present invention. Similar to FIG. 2, FIG. 4A shows a partially sectional external view, and FIG. 4B shows an AA sectional view. A plurality of cores 1 each having a core shaft hole 12 formed in the center of a thin electromagnetic steel sheet and a plurality of core slots 11 each having a substantially trapezoidal shape on the circumference are laminated so as to have a predetermined height. An end ring 2 having a substantially identical shape is disposed, and the conductor bar 4 is passed through the core 1 and the core slot 11 of the end ring 2.

  In the laminated core of the squirrel-cage rotor for the motor shown in FIG. 4, the mechanical and electrical connection between the end ring 2 and the conductor bar 4 is formed by a pressing method as shown in the manufacturing method of FIGS. .

[Press molding]
In FIG. 5, the example of the manufacturing method of the laminated core of the cage rotor for electric motors of this invention is shown. This is a view of the end faces of the end ring 2 and the conductor bar 4 from the axial direction of the shaft 3. FIG. 5A shows a state in which the pressing member 5 stands by at a distance where it does not come into contact with the outer periphery of the end ring 2 disposed at both axial ends of the stacked cores 1.

  The end faces of the conductor bars 4 are arranged so as to roughly match the end faces of the end rings 2 arranged at both ends in the axial direction of the laminated cores 1 and not in contact with the core 1. The width of the pressing member 5 is approximately equal to or greater than the width of the end ring 2, and the axial direction position of the shaft 3 of the pressing member 5 is a position that does not contact the end surface extension surface of the laminated core 1.

  From these positional relationships, the pressing member moving mechanism (not shown) moves the pressing member 5 toward the outer periphery of the end ring 2 as shown in FIG. By moving even after the contact, the thin-walled portion 22 that is thin due to the hole through which the conductor bar 4 passes is deformed near the outer peripheral surface of the end ring 2.

  Due to this deformation, the gap between the thin portion 22 of the end ring 2 and the conductor bar 4 is reduced, and the movement of the pressing member moving mechanism (not shown) continues even after the gap is eliminated, so that the thin portion 22 of the end ring 2 alone or the end Since the thin portion 22 of the ring 2 and the conductor bar 4 are plastically deformed with each other, the connection between the end ring 2 and the conductor bar 4 becomes strong and stable.

  6A shows a standby state, FIG. 6B shows a state in which the connecting portion 23 is formed, and FIG. 6C shows a state in which the brazing material 24 is added. The end position of the movement of the pressing member moving mechanism shown in FIG. 6B is detected by detecting the amount of movement and the generated force, and ending with the set value. As shown in FIG. 6B, the end ring 2 and the conductor bar 4 are electrically connected in this state. As shown in FIG. 6 (c), a brazing material (silver brazing, phosphor copper brazing, etc.) is attached to the end faces of the end ring 2 and the conductor bar 4 and the gaps formed by plastic deformation. By heating to the material melting temperature, the electrical continuity between the end ring 2 and the conductor bar 4 is further strengthened and stable performance is obtained.

[Rotating shaft shrink fit]
By performing the above-described steps, the rotor core is assembled as shown in FIG. Next, the rotating shaft 3 is arranged at the center of the core axis. As a fixing method at this time, there is a shrink fit method. The shrink-fit used for this shaft assembly is heating only the core (200 to 300) against a product shaft having an outer diameter slightly larger (0 to 20 μm) than the core hole diameter at room temperature (around 20 ° C.). This is a method in which the diameter of the hole is enlarged by expanding it, and the product shaft is inserted and positioned therein, and then the whole is cooled to firmly fasten the product shaft and the core. FIG. 7 shows a state where the shaft is assembled to the rotor core.

[Steam processing]
Next, steam processing (500 to 600 ° C.) is performed on the assembly in which the rotor core and the shaft are fastened, and the entire core surface including the core outer peripheral surface and between the core laminations, or the surface of the shaft, Form a rust prevention layer of triiron tetroxide. FIG. 7 corresponds to a state in which the steam processing to the rotor core that has completed the shaft assembly is completed.

  With respect to the contents of the manufacturing process described above, the difference between the baking process and the steam process that have been conventionally performed for forming the rust-preventing layer will be described.

First, regarding the difference in the rust prevention layer formed on the core surface,
(1) For the heat resistance (100 to 250 ° C.) of epoxy resin, which is a representative material for baking coating, the steam treatment is not the adhesion of the paint but the modification of the surface of the base material that becomes triiron tetroxide. Therefore, since it conforms to the heat resistance of the iron material as the base material, it has very high heat resistance. For the same reason, the adhering force is also increased, so that it is possible to prevent problems due to the rust-proof layer falling off during operation of the electric motor.

(2) In baking coating, since a material different from the base material is applied to the surface, the heat conductivity changes at the interface, so that there is a possibility that loss on the heat radiation surface may occur. In the steam treatment, since the surface of the base material that becomes triiron tetroxide is modified, there is little change at the interface, and loss on the heat radiating surface hardly occurs.

(3) In the steam treatment, the thickness of the rust prevention layer can be set to 0 to 5 μm after satisfying the rust prevention performance, and the thickness is extremely thin, so that the core thickness accuracy is improved. Thus, an outer peripheral surface cutting step is not required. Moreover, since another material is not attached like baking coating, generation | occurrence | production of the imbalance regarding rotation can be suppressed.

(4) The size of the water vapor molecules used in the steam treatment is on the nm level, and the normal surface roughness and gaps due to tightening between the members performed on the core stack are on the μm level. Easy to penetrate. Unlike spraying and brushing used in baking coating, the rust-proof layer is less likely to be uneven because it has less directionality.

(5) In baked coating, rust prevention performance is ensured only on the outer peripheral surface of the rotor, so even if part of the rust prevention layer is broken, wraparound to the back surface occurs, which has an effect on rust prevention performance. large. In the steam treatment, not only the rotor outer peripheral surface, but also the outer peripheral surface of the core that is the member, the front and back of the end surface, the entire surface reaching the outer peripheral surface of the shaft, so even if some damage occurs, The effect on other parts is extremely small.

(6) In baking coating, the thickness of the rust-preventing layer, which has been 30-50 μm, can be reduced to 5 μm or less by steam treatment, so the distance between the rotor and stator that forms the magnetic circuit of the motor As a result, improvement in motor efficiency can be expected.

About difference of process to form rust prevention layer,
(7) Bake coating requires a uniform surface roughness to some extent as compared with mirror finish to increase the adhesion of the paint, but the steam treatment is a modification of the surface of the base material due to the modification of the base material surface. The degree does not matter. In baking painting, pretreatment such as phosphoric acid cleaning is required to increase the adhesion of the paint. Steam treatment is not necessary depending on the cleanliness of the surface.

(8) Sub-materials such as coating materials required for baking coating are only moisture in the steam treatment, so the cost can be reduced. In addition, since no solvent is used in the steam treatment, it is not necessary to dispose of waste or to maintain an exhaust environment.

Next, the difference between the process until the rotor is completed and the order of the steam process is
(1) After assembling the rotor core, when the steam treatment is performed first and the shaft assembly is performed later, the shaft comes into contact with the rust preventive layer of the steam-treated ferrous oxide. There is a possibility of damaging the rust prevention layer. Further, in handling the rotor core, it is necessary to contact the outer or inner rust preventive layer, which may also damage the rust preventive layer. For these problems, after assembling the rotor core, the shaft is assembled first, and when the steam treatment is performed later, as a whole, grip the end of the shaft that does not require rust prevention performance. It is not necessary to contact the outer periphery of the rotor core, where rust prevention performance is important.

(2) When a member subjected to steam treatment is used for the core material before lamination, there is a possibility that the rust preventive layer may be damaged in the assembly process of the rotor core starting from the core lamination. Further, in the case where the rotor core cannot be used due to a defect that occurs in the middle of the process, it is not necessary to perform the steam process wastefully, so that the production yield is improved.

(3) In a normal processing order considering temperature change, a method is adopted in which deformation by heating is generated at an early stage, and new processing is performed while correcting the deformation of the previous process on the subsequent process side. That is, the process temperature on the front process side is set high, and the process temperature on the back process side is set lower than that of the front process.

  At this time, the core fastening condition according to the heating order was confirmed. Here, the processing temperature of each process is assumed as follows. The rotor core assembly is at room temperature (around 20 ° C.), the steam treatment is 520 ° C., the shrink fitting as the shaft assembly is 270 ° C., and the typical linear expansion coefficient (/ ° K) of iron, copper, and aluminum is 12 × 10-6, 18 × 10-6, and 24 × 10-6. The deformation due to heating when the core thickness is 100 mm is as follows.

  In the assembly of the rotor core, in order to reduce the dispersion of the core stacking interval, the end rings arranged at both ends of the stacked core and the conductor portions penetrating in the axial direction are provided with pressure applied in the core stacking direction. The pressure is maintained by fixing. When the rotor core is assembled at room temperature (around 20 ° C.) and heated from this state to 520 ° C. for steam treatment, a temperature difference ΔT is generated.

  By multiplying this temperature difference by the core stack thickness of 100 mm and the linear expansion coefficient, a change in the length of each material is obtained. As a matter of fact, for iron, the increase of 0.6 mm is 0.9 mm for copper and 1.2 mm for aluminum. Thereby, the applied pressure is released when the rotor core is assembled.

(4) Shrink fitting as a shaft assembly is performed by heating and expanding only the core of a product shaft having an outer diameter slightly larger (0 to 20 μm) than the core hole diameter at room temperature. In this method, the product shaft and the core are firmly fastened by expanding the diameter, inserting and positioning the product shaft therein, and then cooling the whole.

  On the other hand, the method of temporarily assembling using the assembly shaft improves the coaxiality of the laminated core inner diameters, but ultimately, it is necessary to pull out, so that the outer diameter is slightly smaller than the core hole diameter. It is necessary to make the diameter. For this reason, a gap is required between the inner diameter of the core and the outer diameter of the assembly shaft, and the workability when the core is laminated on the assembly shaft is 20 to 60 μm.

(5) When the laminated core, the end ring, and the conductor portion are assembled and steam-treated without the assembly shaft, the pressure on the laminated core is released from the difference in the linear expansion coefficient described above, There is a possibility that the stacking accuracy of the core is lost, and the clearance between the slot of the stacked core that is restraining in the axial direction and the clearance of the conductor portion (wider than the clearance of the core inner diameter is about 0.1 to 0.4 mm). Further, since the shrink fitting as the shaft assembly to be performed thereafter is 200 to 300 ° C., it is lower than the previous steam processing temperature (500 to 600 ° C.), so that the pressure release to the laminated core is insufficient, and the product The accuracy of the shaft cannot be imitated, and there is a possibility that the bending and lamination accuracy may remain poor.

FIGS. 8 to 10 show the process sequence and the processing temperature transition in each process.
FIG. 8 is an example of the present invention, in the case where steam processing is performed to form a rust-preventing layer on the outer peripheral surface of the core, the shaft temperature is assembled after the core is assembled, and then the processing temperature transition when the steam processing is performed is shown. Show. The rotor core is assembled at room temperature (around 20 ° C.), and after shrink fitting (200 to 300 ° C.) on the shaft assembly, steam treatment (500 to 600 ° C.) is performed to form a rust-proof layer on the outer peripheral surface of the core. It is a rough process temperature transition when it was given.

  FIG. 9 shows the transition of the processing temperature when the conventional baking coating is performed for forming the rust-preventing layer on the outer peripheral surface of the core, which is Reference Example 1. The rotor core is assembled at room temperature (around 20 ° C), and the shaft assembly is shrink-fitted (200-300 ° C) and then baked (200-300 ° C) to form a rust-proof layer on the outer peripheral surface of the core. It is a rough process temperature transition when it was given.

  FIG. 10 shows the transition of the treatment temperature when the steam treatment is performed for forming the rust-proof layer on the outer peripheral surface of the core, which is Reference Example 2, when the heat treatment step is performed in order from the highest temperature step. The rotor core is assembled at room temperature (around 20 ° C), and after steaming (500 to 600 ° C) to form a rust-preventing layer on the outer peripheral surface of the core, the shaft assembly is shrink-fitted (200 to 300 ° C). It is a rough process temperature transition when it was given.

  As described above, the assembly process such as shrink fitting that assembles the product shaft is first performed on the assembly of the laminated core, end ring, and conductor, and then the nanometer level at a temperature higher than the shrink fitting temperature. The above-mentioned various problems can be solved by forming a rust preventive layer by performing a steam treatment with fine water vapor particles.

  In the description of the present invention, an example in which the conductor bar and the end ring are connected in the rotor core assembly has been shown. However, as in the die-cast method, the slot portion of the stacked core is regarded as a cavity, and the molten metal is A rotor core formed by an injection method may be used. In addition, although a method of shrink fitting is shown for assembling the rotor core and the rotating shaft, a configuration using a keyway may be used.

DESCRIPTION OF SYMBOLS 1 Laminated core 2 End ring 3 Rotating shaft 4 Conductor bar 5 Press member 7 Stator core 8 Outer frame 9 Impeller 10 Intermediate casing 11 Core slot 12 Core shaft hole 21 End ring slot 22 Thin part 23 Connection part 24 Brazing material 51 Four Triiron oxide rust prevention layer 52 Epoxy resin rust prevention layer 71 Stator winding 72 Bearing

Claims (10)

  A laminated core in which a plurality of thin iron plates are laminated, a rotating shaft arranged at the center of the core axis, a plurality of conductor portions arranged annularly around the axis of the rotating shaft, and a plurality of slot portions connected to the plurality of conductor portions A squirrel-cage rotor for an electric motor in which an annular end ring is disposed, wherein an anticorrosive layer of triiron tetraoxide is formed on the surface of the laminated core and the surface of the rotary shaft. A cage rotor.   A laminated core in which a plurality of thin iron plates are laminated, a rotating shaft arranged at the center of the core axis, a plurality of conductor portions arranged annularly around the axis of the rotating shaft, and a plurality of slot portions connected to the plurality of conductor portions A squirrel-cage rotor for an electric motor having a ring-shaped end ring having the entire surface of the laminated core including the surfaces of the plurality of thin iron plates and a portion disposed at the center of the core axis. A squirrel-cage rotor for electric motors characterized in that a rust prevention layer of triiron tetraoxide is formed on the entire surface.   A core in which a plurality of thin iron plates are laminated, a rotating shaft arranged at the center of the core axis, a conductor part arranged in an annular shape around the axis of the rotating shaft, and an annular end ring having a slot part connected to the conductor part A squirrel-cage rotation for a motor in which mechanical and electrical connection portions are formed by pressing and molding at positions corresponding to conductors on the outer surface of the end ring using means for placing and pressing from the outer surface of the end ring Mechanical and formed by pressing the entire surface of the laminated core including the surfaces of the plurality of thin iron plates and the entire surface of the rotating shaft including a portion disposed at the center of the core axis. A squirrel-cage rotor for a motor, wherein a rust prevention layer of triiron tetraoxide is formed on a surface of a squirrel-cage rotor for an electric motor including a surface of an electrical connection portion.   A laminated core in which a plurality of thin iron plates are laminated, a rotating shaft arranged at the center of the core axis, a plurality of conductor portions arranged annularly around the axis of the rotating shaft, and a plurality of slot portions connected to the plurality of conductor portions A squirrel-cage rotor having a ring-shaped end ring, a stator core disposed on a concentric circle of the rotary shaft relative to the squirrel-cage rotor, and an electric current incorporated in the stator core. An electric motor comprising a stator winding for flowing and a bearing for smooth rotation of the rotating shaft, wherein the surface of the laminated core of the squirrel-cage rotor and the surface of the rotating shaft are rust-proofed with ferric oxide. An electric motor characterized by forming a layer.   A laminated core in which a plurality of thin iron plates are laminated, a rotating shaft arranged at the center of the core axis, a plurality of conductor portions arranged annularly around the axis of the rotating shaft, and a plurality of slot portions connected to the plurality of conductor portions A squirrel-cage rotor having a ring-shaped end ring, a stator core disposed on a concentric circle of the rotary shaft relative to the squirrel-cage rotor, and an electric current incorporated in the stator core. An electric motor provided with a stator winding to be flown and a bearing for smooth rotation of the rotary shaft, an impeller attached to the rotary shaft, an intermediate casing for storing the impeller, and a part of the intermediate casing A submersible pump comprising a discharge port, and a rust preventive layer of triiron tetraoxide on the surface of the laminated core and the surface of the rotary shaft of the squirrel-cage rotor for an electric motor. Formation Water pump, characterized in that the.   A laminated core in which a plurality of thin iron plates are laminated, a rotating shaft arranged at the center of the core axis, a plurality of conductor portions arranged annularly around the axis of the rotating shaft, and a plurality of slot portions connected to the plurality of conductor portions In a method for manufacturing a squirrel-cage rotor having a ring-shaped end ring, the processing is higher than the shrink-fit temperature during the assembly process after the assembly process of the rotary shaft in which the rotary shaft is disposed in the center of the core axis. A squirrel-cage rotor for an electric motor characterized in that a steam treatment with water vapor molecules having a nanometer level is applied to the surface of the core and the surface of the rotary shaft to form a rust prevention layer of ferric oxide. Manufacturing method.   The method of manufacturing a cage rotor for an electric motor according to claim 6, wherein the laminated core, a plurality of conductor portions arranged annularly around an axis of the laminated core, and a plurality of slot portions connected to the plurality of conductor portions. After assembling the annular end ring, the rotary shaft is assembled at the core axis center, and then the rotation including the entire surface of the laminated core including the surfaces of the plurality of thin steel plates and the portion disposed at the core axis center A method of manufacturing a squirrel-cage rotor for an electric motor, wherein a rust prevention layer of ferric oxide is formed on the entire surface of the shaft.   7. The method of manufacturing a squirrel-cage rotor for an electric motor according to claim 6, wherein a core obtained by laminating a plurality of the thin iron plates, a rotating shaft arranged at the center of the core axis, and a conductor portion arranged annularly around the axis of the rotating shaft. And an outer surface of the end ring using means for pressing from the outer surface of the end ring in a method for manufacturing a cage rotor for an electric motor in which an annular end ring having a slot portion connected to the conductor portion is disposed. After forming a mechanical and electrical connection portion by pressing at a position corresponding to the conductor of the assembly, a rotary shaft is assembled at the center of the core axis, and then the entire laminated core including the surfaces of the plurality of thin iron plates is assembled. A squirrel-cage rotor for an electric motor including a surface, the entire surface of the rotating shaft including a portion disposed at the center of the core axis, and a surface of a mechanical and electrical connection portion formed by pressing. On the surface, a manufacturing method of an electric motor for cage rotor and forming a rust-preventive layer of triiron tetroxide.   A laminated core in which a plurality of thin iron plates are laminated, a rotating shaft arranged at the center of the core axis, a plurality of conductor portions arranged annularly around the axis of the rotating shaft, and a plurality of slot portions connected to the plurality of conductor portions A squirrel-cage rotor having a ring-shaped end ring, a stator core disposed on a concentric circle of the rotary shaft relative to the squirrel-cage rotor, and an electric current incorporated in the stator core. A method of manufacturing an electric motor having a stator winding to be flown and a bearing for smooth rotation of the rotating shaft, wherein the rotating shaft is arranged at the center of the core axis of the cage rotor. The surface of the core and the surface of the rotary shaft are subjected to a steam treatment with water vapor molecules of a nanometer level at a treatment temperature higher than the shrink-fit temperature during the assembly process, and tetraoxidation is performed. Method for manufacturing a motor and forming a rust-preventive layer of iron.   A laminated core in which a plurality of thin iron plates are laminated, a rotating shaft arranged at the center of the core axis, a plurality of conductor portions arranged annularly around the axis of the rotating shaft, and a plurality of slot portions connected to the plurality of conductor portions A squirrel-cage rotor having a ring-shaped end ring, a stator core disposed on a concentric circle of the rotary shaft relative to the squirrel-cage rotor, and an electric current incorporated in the stator core. An electric motor provided with a stator winding to be flown and a bearing for smooth rotation of the rotary shaft, an impeller attached to the rotary shaft, an intermediate casing for storing the impeller, and a part of the intermediate casing A submersible pump manufacturing method comprising: a pump unit configured with a discharge port, wherein the rotary shaft is arranged in the center of the core axis of the cage rotor for electric motor After that, the surface of the core and the surface of the rotating shaft are subjected to steam treatment with water vapor molecules of a nanometer level at a processing temperature higher than the shrink fitting temperature at the time of the assembly process, and the anticorrosion of triiron tetraoxide is performed. A method of manufacturing a submersible pump, characterized by forming a layer.

Images