JP5346527B2 - Rotor for induction machine, method for manufacturing the same, and induction machine - Google Patents

Description

  The present invention relates to a high-efficiency induction machine, a squirrel cage rotor used in the induction machine, and a method of manufacturing the same.

In order to obtain a highly efficient squirrel-cage induction machine, for example, an induction motor, it is important to ensure electrical insulation between the rotor core and the rotor conductor provided in the outer peripheral slot of the rotor core. Become.
Therefore, a first layer made of a phosphate coating or triiron tetroxide and a second layer of ceramic paint are provided between the rotor core and the rotor conductor, and the rotor core and the rotor conductor are attached. There is an example of electrical insulation (see Patent Document 1).
JP-A-5-316699

In the above-described invention, when the rotor conductor is formed in the slot of the rotor core, two layers of insulating films (layers) must be covered in advance so as to cover the inner peripheral surface of the slot. The nature was bad.
The present invention has been made in view of the above circumstances, and its purpose is to ensure electrical insulation between the rotor core and the rotor conductor without performing complicated work, and to achieve high efficiency. It is providing the rotor for induction machines, its manufacturing method, and an induction machine.

In order to achieve the above object, a rotor for an induction machine according to claim 1 includes a rotor core having a plurality of slots formed in an outer peripheral portion and oxygen ions formed so as to cover the inner peripheral surface of the slots. Between the contained layer, the plurality of rotor conductors formed by supplying a conductor molten metal to the slot, and between the rotor core and the rotor conductor; ions possess an insulating layer made of a metal oxide produced is transferred, the containing layer, iron rust layer consisting of triiron tetraoxide film containing oxygen ions which can produce the insulating layer by the transfer It is characterized by being .
The method for manufacturing a rotor for an induction machine according to claim 6 is a rotor for an induction machine having a rotor core having a plurality of slots formed on an outer peripheral portion thereof, so that the inner peripheral surface of the slot is covered with oxygen. An ion-containing layer is formed, a molten metal is poured into the slot to form a rotor conductor, and oxygen ions are transferred from the containing layer to the molten metal so that the gap between the rotor core and the rotor conductor An insulating layer made of a metal oxide is formed, and the containing layer is an iron rust layer made of a triiron tetroxide film containing oxygen ions capable of generating the insulating layer by the transfer .

  According to the present invention, since the oxygen ion containing layer is formed on the inner peripheral surface of the slot of the rotor core so as to cover it, the molten metal is poured into the slot during the process of forming the rotor conductor. The oxygen ions in the containing layer are transferred to the conductor molten metal, and an insulating layer made of a metal oxide is generated between the rotor core and the rotor conductor. By this insulating layer made of a metal oxide, insulation between the rotor core and the rotor conductor is ensured, and a highly efficient induction machine rotor can be easily obtained. In other words, when the molten metal is poured into the inner peripheral surface of the slot, only one oxygen ion-containing layer needs to be formed in advance, and no further complicated work is required.

(First embodiment)
Hereinafter, a first embodiment of the present invention will be described with reference to FIGS.
FIG. 5 shows a squirrel-cage induction motor 1 according to the present embodiment, which includes a stator 2 and a rotor 3 that is located on the inner peripheral side of the stator 2 via a gap.
The stator 2 is configured by mounting a plurality of coils 5 on a stator core 2a. The stator core 2a is formed in a cylindrical shape by laminating a large number of annular silicon steel plates, and the lamination direction is integrally bound by a rivet or the like (not shown). Further, slots 6 for accommodating the coils 5 are formed at a plurality of locations, for example, 12 locations on the inner peripheral surface of the stator core 2a.

  As shown in FIGS. 4 and 5, the rotor 3 has a rotor core 7 formed by laminating a large number of annular silicon steel plates, and a rotary shaft 9 provided on the inner peripheral portion of the rotor core 7. In addition, aluminum short-circuiting rings 10 and 10 each having an annular shape are provided at both axial ends 8 and 8 of the rotor core 7. A plurality of aluminum cooling fins 11 projecting outward in the axial direction are integrally formed on the axial surface of the short-circuit ring 10 as shown in FIG.

As shown in FIG. 5, the rotor core 7 is formed with a shaft hole portion 12 through which the rotation shaft 9 is inserted in the center portion, and circular slots 13 in the outer peripheral portion at a predetermined interval in the circumferential direction, for example, constant. A plurality are formed with an interval of.
FIG. 2 is a partially enlarged view of the outer peripheral portion of the rotor core 7. On the inner peripheral surface of the slot 13, a containing layer 14 of triiron tetroxide (Fe ₃ O ₄ ) containing oxygen ions is formed so as to cover it. Triiron tetroxide is a kind of iron rust.

  The triiron tetraoxide containing layer 14 is formed on the inner peripheral surface of the slot 13 of the rotor core 7 by the following method. First, the oil and rust adhering to the inner peripheral surface of the slot 13 are washed by degreasing and removing oxide scale. Thereafter, the rotor core 7 is immersed in an aqueous solution of caustic soda to form a triiron tetraoxide containing layer 14 on the surface of the slot 13. In addition, since the surface of the silicon steel plate 7a constituting the rotor iron core 7 is covered with an electrically insulating coating material, triiron tetroxide is not formed in portions other than the slot 13. After the formation of the ferrous tetraoxide containing layer 14, the rotor core 7 is washed with water and washed with hot water to wash away the aqueous solution of caustic soda and dried to enter the aluminum die casting process.

  Next, a method for manufacturing the rotor 3 from the rotor core 7 by aluminum die casting will be described. The rotor conductor 15, the short-circuit ring 10 and the cooling fin 11 of the rotor 3 are integrally formed by aluminum die casting. FIG. 3 shows a mold 16 used for aluminum die casting. The mold 16 includes a space for accommodating the rotor core 7 in the mold 16 and includes plates 17 and 17 that open in the axial direction of the rotor core 7. Cavities 18 and 18 for forming the short-circuit ring 10 and the cooling fins 11 in the rotor core 7 are formed in the plates 17 and 17. The plates 17 and 17 are formed with gates 19 and 19 for sending molten aluminum (not shown) from the outside to the cavities 18 and 18, respectively.

Next, the rotor core 7 is placed at a predetermined position of the mold 16, and molten aluminum is supplied to the cavities 18 and 18 to perform aluminum die casting. The molten aluminum is slotted in the rotor core 7. 13 and the rotor conductor 15 is formed, and the short-circuit rings 10 and 10 and the plurality of cooling fins 11 are formed at both axial ends 8 and 8 of the rotor core 7.
After the aluminum die casting, the mold 16 is opened, and the rotor core 7 on which the rotor conductor 15, the short-circuit ring 10 and the cooling fins 11 are formed is removed. After the rotor core 7 is removed from the mold 16, the rotary shaft 9 is inserted into the shaft hole portion 12 to complete the rotor 3.

FIG. 1 is an enlarged partial vertical cross-sectional view of the rotor 3. The rotor core 7 has a slot 13 on the outer periphery thereof. When the slot 13 is punched and formed in the rotor core 7, a return portion 20 of the silicon steel plate 7a is generated on the outer periphery of the slot 13 as shown in FIG. Due to the return portion 20, a gap 21 with a minute interval is generated between the laminated silicon steel plates 7a.
A triiron tetroxide containing layer 14 containing oxygen ions is formed on the inner peripheral surface of the slot 13, and an aluminum oxide (Al) as an insulating layer is interposed between the rotor conductor 15 and the triiron tetroxide containing layer 14. ₂ O ₃ ) layer 22 is formed. This is because the oxygen ions are transferred from the triiron tetroxide to the molten aluminum filled in the slots 13 during the aluminum die casting process to form aluminum oxide. Transfer means that electrons and ions move from a metal.

As described above, the rotor 3 according to the first embodiment includes an aluminum oxide layer having a very high resistivity of 10 ¹⁵ Ω · cm or more between the rotor core 7 and the rotor conductor 15. 22 and a triiron tetroxide containing layer 14 which is iron rust having a volume resistivity of about 10 ⁶ Ω · cm. For this reason, the induced current flowing through the rotor conductor 15 does not leak into the rotor core 7 and high efficiency can be obtained.
In addition, since the iron tetraoxide-containing layer 14 is formed by corroding the iron base on the inner peripheral surface of the slot 13 as iron rust, it is firmly adhered to the inner peripheral surface of the slot 13. For this reason, the ferrous tetraoxide-containing layer 14 is not peeled off from the inner peripheral surface of the slot 13 by the molten aluminum injected into the slot 13 at high pressure and high speed in the aluminum die casting process. For this reason, since the rotor 3 can form the aluminum oxide layer 22 so as to cover the entire inner peripheral surface of the slot 13, the electrical insulation between the rotor core 7 and the rotor conductor 15 is ensured. Can do.

Furthermore, when the ferrous tetroxide containing layer 14 is formed on the inner peripheral surface of the slot 13, the iron base on the inner peripheral surface of the slot 13 is corroded and expanded as iron rust, so that the space between the silicon steel plates 7 a of the rotor core 7 is increased. It works to fill the gap 21. For this reason, molten aluminum does not enter the gaps 21 between the silicon steel plates 7a, and the deformation of the rotor core 7 and electrical conduction between the silicon steel plates 7a can be prevented. It is possible to prevent the electrical insulation between the silicon steel plates 7a by breaking the coating of the steel plate 7a with the electrically insulating coating material.
Further, triiron tetroxide is iron rust, and the melting point of iron rust is about 1500 ° C., whereas the melting point of aluminum is about 700 ° C. Therefore, in the aluminum die-casting process, the triiron tetroxide containing layer 14 Can form the aluminum oxide layer 22 over the entire inner peripheral surface of the slot 13 without being broken by molten aluminum.

  Moreover, since the aluminum oxide layer 22 produced | generated by an aluminum die-casting process is produced | generated densely, even if the thickness of the aluminum oxide layer 22 is several nanometers, the electricity between the rotor core 7 and the rotor conductor 15 is produced. Mechanical insulation is maintained. For this reason, the aluminum as the rotor conductor 15 can maintain a low resistivity. Furthermore, since the induced current becomes a large current, the rotor conductor 15 becomes high temperature, but since the melting point of aluminum oxide exceeds 2000 ° C., the heat resistance of the aluminum oxide layer 22 is sufficiently secured.

(Second embodiment)
Next, a second embodiment of the present invention will be described with reference to FIG. In addition, the same code | symbol is attached | subjected to the same part as said 1st embodiment, and the detailed description is abbreviate | omitted. The second embodiment is different from the first embodiment in that the inner peripheral surface of the slot 13 is covered with iron rust of FeO and Fe ₂ O ₃ .
FIG. 6 is a partial vertical cross-sectional enlarged view of the rotor 3. The containing layer 23 of FeO and Fe ₂ O ₃ iron rust (hereinafter simply referred to as iron rust) is formed on the inner peripheral surface of the slot 13 by placing the rotor core 7 in a mixed gas of water vapor and oxygen.

In the rotor for a cage induction motor 1 and the cage induction motor 1 according to the second embodiment, an iron rust containing layer 23 is formed on the inner peripheral surface of the slot 13 as in the first embodiment. Therefore, the rotor 3 according to the second embodiment includes an aluminum oxide layer which is an insulating layer having a very high volume resistivity of 10 ¹⁵ Ω · cm or more between the rotor core 7 and the rotor conductor 15. 22 and a triiron tetroxide containing layer 14 which is iron rust having a volume resistivity of about 10 ⁶ Ω · cm. For this reason, the induced current flowing through the rotor conductor 15 does not leak into the rotor core 7 and high efficiency can be obtained.

(Third embodiment)
Next, a third embodiment of the present invention will be described with reference to FIG. In addition, the same code | symbol is attached | subjected to the same part as said 1st embodiment, and the detailed description is abbreviate | omitted. The third embodiment is different from the first embodiment in that the inner peripheral surface of the slot 13 is covered with a manganese phosphate film 24 that is a phosphate.

FIG. 7 is an enlarged partial vertical cross-sectional view of the rotor 3. The manganese phosphate film 24 which is a phosphate is generated by chemical conversion of the inner peripheral surface of the slot 13. The main component of manganese phosphate is fuorilite (PO ₃ (OH)) ₂ (PO ₄ ) ₂ · 4H ₂ O), and its composition has relatively many oxygen ions that can be supplied to and transferred to molten aluminum. include. In addition, since the phosphate crystal has a structure in which needles, hexagonal columns, etc. are grown, the contact area with the aluminum can be very large, and the molten aluminum can be easily retained during the aluminum die casting process. The gap 21 between the silicon steel plates 7a can be filled. Further, the manganese phosphate film 24 has a characteristic that a thickness of 5 to 15 μm is obtained, the peel strength is high, and the manganese phosphate film 24 is less damaged during the aluminum die casting process.

(Fourth embodiment)
Next, a fourth embodiment of the present invention will be described with reference to FIG. In addition, the same code | symbol is attached | subjected to the same part as said 1st embodiment, and the detailed description is abbreviate | omitted. The fourth embodiment is different from the first embodiment in that the inner peripheral surface of the slot 13 is covered with a zinc calcium phosphate film 25 which is a phosphate.
FIG. 8 is a partial vertical cross-sectional enlarged view of the rotor 3. The zinc calcium phosphate coating 25 that is a phosphate is formed by chemical conversion of the inner peripheral surface of the slot 13. The main components of zinc calcium phosphate are scholzeite (CaZn ₂ (PO ₄ ) ₂ .2H ₂ O) and hopite (Zn ₃ (PO ₄ ) ₂ .4H ₂ O), as in the third embodiment, The composition contains a relatively large amount of oxygen ions that can be supplied and transferred to molten aluminum. Further, the zinc calcium phosphate coating 25 is characterized in that it is soft in terms of the composition of the coating 25, has a slow chemical conversion reaction, and has little dimensional change when the coating 25 is formed.

The present invention is not limited to the embodiment described above and shown in the drawings, and the following modifications and expansions are possible.
Although the rotor 3 of the squirrel-cage induction motor 1 of the first to fourth embodiments has been described as being applied to a fully closed type, it may be an open type or a semi-open type.
In the first to fourth embodiments, the present invention has been described as applied to the squirrel-cage induction motor 1. However, the present invention is not limited to this and can also be applied to a squirrel-cage induction generator.
In the first to fourth embodiments, the present invention has been described by applying an aluminum die casting process. However, the present invention is not limited to this, and can be applied to an aluminum compound, copper, or a copper compound die casting process. is there. When the aluminum compound die casting process is performed, aluminum oxide is generated as an insulating layer, and when copper or a copper compound die casting process is performed, copper oxide (CuO, Cu ₂ O) is generated as an insulating layer.

In the rotor 3 of the first embodiment, the rotor conductor 15, the short-circuit ring 10, and the cooling fins 11 may be formed by performing a die casting process after attaching the rotating shaft 9 to the rotor core 7.
The present invention can also be applied to a squirrel-cage rotor of a double squirrel-cage rotor or more.
In addition, the number, dimensions, materials, and the like of the above-described components can be changed as appropriate.

The partial longitudinal cross-section enlarged view of the rotor of 1st embodiment of this invention Partial enlarged view of the outer periphery of the rotor core Vertical section of mold used for aluminum die-casting Partially broken perspective view of rotor Front sectional view of squirrel-cage induction motor The partial longitudinal cross-section enlarged view of the rotor of 2nd embodiment of this invention The partial longitudinal cross-section enlarged view of the rotor of 3rd embodiment of this invention Partial longitudinal cross-sectional enlarged view of the rotor of 4th embodiment of this invention

Explanation of symbols

  In the drawings, 1 is a squirrel-cage induction motor (induction machine), 3 is a rotor, 7 is a rotor core, 7a is a silicon steel plate, 13 is a slot, 14 is triiron tetroxide (containing layer), and 15 is a rotor conductor. , 22 is an aluminum oxide layer (insulating layer), 23 is an iron rust (containing layer), 24 is a manganese phosphate coating (containing layer), and 25 is a zinc calcium phosphate coating (containing layer).

Claims (9)

A rotor core having a plurality of slots formed on the outer periphery;
A containing layer containing oxygen ions formed to cover the inner peripheral surface of the slot;
A plurality of rotor conductors formed by supplying conductor molten metal to the slots;
Between the rotor core and the rotor conductor, the oxygen ions from the layer containing the conductive molten metal is closed and an insulating layer made of a metal oxide produced is transferred,
The induction machine rotor , wherein the inclusion layer is an iron rust layer made of a triiron tetroxide film containing oxygen ions capable of generating the insulating layer by the transfer . A rotor core having a plurality of slots formed on the outer periphery;
A containing layer containing oxygen ions formed to cover the inner peripheral surface of the slot;
A plurality of rotor conductors formed by supplying conductor molten metal to the slots;
Between the rotor core and the rotor conductor, an insulating layer made of a metal oxide generated by transferring oxygen ions from the containing layer to the conductor molten metal,
The containing layer is formed by treating the rotor core with a mixed gas of water vapor and oxygen, and an iron rust layer made of a triiron tetraoxide film containing oxygen ions capable of generating the insulating layer by the transfer. A rotor for induction machines , characterized in that A rotor core having a plurality of slots formed on the outer periphery;
A containing layer containing oxygen ions formed to cover the inner peripheral surface of the slot;
A plurality of rotor conductors formed by supplying conductor molten metal to the slots;
Between the rotor core and the rotor conductor, an insulating layer made of a metal oxide generated by transferring oxygen ions from the containing layer to the conductor molten metal,
The inclusion layer is an iron rust layer formed by a process of immersing the rotor core in an aqueous solution of caustic soda and comprising a triiron tetroxide film containing oxygen ions capable of generating the insulating layer by the transfer. A rotor for induction machines characterized by A rotor core having a plurality of slots formed on the outer periphery;
A containing layer containing oxygen ions formed to cover the inner peripheral surface of the slot;
A plurality of rotor conductors formed by supplying conductor molten metal to the slots;
Between the rotor core and the rotor conductor, an insulating layer made of a metal oxide generated by transferring oxygen ions from the containing layer to the conductor molten metal,
The induction machine rotor , wherein the inclusion layer is a chemical conversion coating layer containing oxygen ions capable of generating the insulating layer by the transfer, and is a layer formed of a zinc calcium phosphate coating . An induction machine using the induction machine rotor according to any one of claims 1 to 4 . In the method of manufacturing a rotor for an induction machine having a rotor core having a plurality of slots formed on the outer periphery,
A layer containing oxygen ions is formed on the inner peripheral surface of the slot so as to cover it, and a molten metal is poured into the slot to form a rotor conductor, and oxygen ions are transferred from the containing layer to the molten metal. Generating an insulating layer made of a metal oxide between the rotor core and the rotor conductor;
The method for manufacturing a rotor for an induction machine, wherein the containing layer is an iron rust layer made of a triiron tetroxide film containing oxygen ions capable of generating the insulating layer by the transfer. In the method of manufacturing a rotor for an induction machine having a rotor core having a plurality of slots formed on the outer periphery,
A layer containing oxygen ions is formed on the inner peripheral surface of the slot so as to cover it, and a molten metal is poured into the slot to form a rotor conductor, and oxygen ions are transferred from the containing layer to the molten metal. Generating an insulating layer made of a metal oxide between the rotor core and the rotor conductor;
The containing layer is formed by treating the rotor core with a mixed gas of water vapor and oxygen, and an iron rust layer made of a triiron tetraoxide film containing oxygen ions capable of generating the insulating layer by the transfer. A method for manufacturing a rotor for an induction machine, characterized in that: In the method of manufacturing a rotor for an induction machine having a rotor core having a plurality of slots formed on the outer periphery,
A layer containing oxygen ions is formed on the inner peripheral surface of the slot so as to cover it, and a molten metal is poured into the slot to form a rotor conductor, and oxygen ions are transferred from the containing layer to the molten metal. Generating an insulating layer made of a metal oxide between the rotor core and the rotor conductor ;
The inclusion layer is an iron rust layer formed by a process of immersing the rotor core in an aqueous solution of caustic soda and comprising a triiron tetroxide film containing oxygen ions capable of generating the insulating layer by the transfer. A method of manufacturing a rotor for induction machines, characterized by In the method of manufacturing a rotor for an induction machine having a rotor core having a plurality of slots formed on the outer periphery,
A layer containing oxygen ions is formed on the inner peripheral surface of the slot so as to cover it, and a molten metal is poured into the slot to form a rotor conductor, and oxygen ions are transferred from the containing layer to the molten metal. Generating an insulating layer made of a metal oxide between the rotor core and the rotor conductor;
The induction layer is a chemical conversion film layer containing oxygen ions capable of generating the insulating layer by the transfer, and is a layer formed of a zinc calcium phosphate film . Production method.

Images