WO2012137235A1 - Rotor for inductive motor and method for manufacturing rotor for inductive motor - Google Patents

Abstract

In order to solve problems in a rotor of a conventional inductive motor in relation to extra costs for highly rigid materials such as a iron or stainless steel that arise during manufacture of the protective ring, the high-precision positioning required during installation of the protective ring, the increase in manufacturing costs and the increase in the number of components for the rotor caused by the construction precision required to provide said positioning precision, and increases in the complexity of the manufacturing process, a rotor for an inductive motor is provided comprising: a rotary shaft (5); a rotor core (1) formed by a plurality of laminated plates; a plurality of slot grooves (2) formed so as to pass through the rotor core (1); a plurality of rotor conductors (3) provided inside of the slot grooves (2); an end ring (4) provided on top of an end surface in the direction of the shaft end of the rotor core (1) that is to conduct with each rotor conductor (3); a protective ring (7) formed by a plurality of laminated plates and comprising an outer diameter protective ring (7a) for protecting the outer periphery of the end ring (4), and an inner diameter protective ring (7b) for preventing contact between the inner periphery of the end ring (4) and the rotary shaft (5); and an end plate (8) provided on top of the end surface in the direction of the shaft end of the protective ring (7).

Description

Induction motor rotor and method of manufacturing induction motor rotor

The present invention relates to a rotor structure for an induction motor and a method for manufacturing a rotor for an induction motor.

A conventional induction motor rotor electrically connects (short-circuits) a rotor core in which electromagnetic steel plates having a plurality of slot grooves are laminated, a rotor conductor provided in each slot groove, and each rotor conductor. It is comprised by the end ring, and a rotor and a rotating shaft rotate integrally (for example, refer patent document 1).

In recent years, induction motors, particularly induction motors used in machine tools, have been used for high-speed rotation, and when the induction motor is used in a high-speed rotation range, excessive stress due to centrifugal force is generated in the rotor itself.

Compared to a rotor core laminated with electromagnetic steel plates, an end ring made of an aluminum-based metal is weak in mechanical strength, and therefore, deformation and destruction of the end ring occur due to stress due to centrifugal force. Therefore, in the rotor of an induction motor used for high-speed rotation applications, a structure for protecting an end ring using a protective ring made of a material having high mechanical strength such as iron or stainless steel is required (for example, see Patent Document 2). ).

Japanese Patent Laid-Open No. 11-346462 (page 3, FIG. 1) JP-A-1-133546 (2nd page, FIG. 1)

Since the rotor structure of the conventional induction motor is configured as described above, the protective ring protects the end ring from deformation and breakage during high-speed rotation by pressing the end ring from one direction in the outer diameter direction. . However, a high-rigidity material such as expensive iron or stainless steel is required to manufacture the protective ring, and high positioning accuracy and work accuracy enabling it are required when the protective ring is attached. For this reason, there are problems such as an increase in manufacturing cost, an increase in the number of parts, and a complicated manufacturing process in the rotor.

The present invention has been made to solve the above-described problems, and its object is to provide an end ring protection structure capable of solving an increase in the manufacturing cost, the number of parts, and the complexity of the manufacturing process that occur when a rotor is manufactured. Is to obtain a rotor of an induction motor equipped with

In the rotor of the induction motor according to the present invention, a rotating shaft, a rotor core composed of a plurality of laminated plates, a plurality of slot grooves formed so as to penetrate the rotor core, and the inside of each slot groove Protects the outer periphery of the rotor conduction part and the rotor conduction part provided on the end surface in the axial end direction of the rotor core so as to be electrically connected to each rotor conductor part. A protective ring comprising a second protective ring for preventing contact between the first protective ring and the inner periphery of the rotor conducting portion and the rotation shaft, and an end plate provided on an end surface in the axial end portion direction of the protective ring; In the rotor of the induction motor including the protective ring, the protection ring is composed of a plurality of laminated plates.

According to the present invention, since the protective ring can be manufactured using the same laminated material as that of the rotor core, no separate processing from a metal lump is required for manufacturing the protective ring. Therefore, it is possible to manufacture a protection ring at a low cost.

BRIEF DESCRIPTION OF THE DRAWINGS It is a cross-sectional view of the rotor of the induction motor which shows Example 1 of this invention. It is a side view of the rotor of the induction motor which shows Example 1 of this invention. It is sectional drawing of the rotor of the induction motor which shows Example 1 of this invention. BRIEF DESCRIPTION OF THE DRAWINGS It is a cross-sectional view of the rotor of the induction motor which shows Example 1 of this invention. It is a cross-sectional view of the rotor of the induction motor which shows Example 2 of this invention. It is a side view of the rotor of the induction motor which shows Example 2 of this invention. It is sectional drawing of the rotor of the induction motor which shows Example 2 of this invention. It is a cross-sectional view of the rotor of the induction motor which shows Example 3 of this invention. It is a side view of the rotor of the induction motor which shows Example 3 of this invention. It is sectional drawing of the rotor of the induction motor which shows Example 3 of this invention. It is a cross-sectional view of the rotor of the induction motor which shows Example 4 of this invention. It is a side view of the rotor of the induction motor which shows Example 4 of this invention. It is sectional drawing of the rotor of the induction motor which shows Example 4 of this invention. It is sectional drawing of the rotor of the induction motor which shows Example 5 of this invention. It is sectional drawing of the rotor of the induction motor which shows Example 5 of this invention. FIG. 10 is a structural diagram of a rotor caulking of an induction motor showing Embodiment 5 of the present invention. FIG. 10 is a structural diagram of a rotor caulking of an induction motor showing Embodiment 5 of the present invention. It is a cross-sectional view of the rotor of the induction motor which shows Example 6 of this invention. It is a cross-sectional view of the rotor of the induction motor which shows Example 6 of this invention.

Example 1.
1 is a cross-sectional view of a rotor of an induction motor showing Embodiment 1 of the present invention, and FIG. 2 is a side view of the rotor of the induction motor showing Embodiment 1 of the present invention. FIG. 3 is a cross-sectional view taken along a cross-section CC ′ (end ring—rotor core boundary surface) in the cross-sectional view of the rotor of the induction motor shown in FIG.

1 to 3, reference numeral 1 denotes a rotor core in which a plurality of electromagnetic steel sheets having a plurality of slot grooves are laminated, 2 denotes a plurality of slot grooves formed so as to penetrate the rotor core 1, and 3 denotes a plurality of rotations. A plurality of rotor conductors made of aluminum-based metal that pass through the inside of each slot groove 2, 4 is a rotor conduction portion, and each rotor conductor 3 is turned on in order to conduct (short-circuit). An annular end ring 5 made of an aluminum-based metal formed so as to be in contact with the end surface of the child conductor 3 in the axial end portion direction is a rotating shaft 5 made of an iron-based metal. 7 is a double annular protective ring formed by laminating a plurality of electromagnetic steel plates, the outer diameter side protective ring 7a of the end ring 4 being the first protective ring, and the end ring 4 being the second protective ring. The inner diameter side protective ring 7b is composed of two protective rings. 8 is an end plate formed by laminating a plurality of electromagnetic steel plates, and 9 is a plurality of through grooves for injecting aluminum-based metal formed on the end plate 8.

The rotor of the induction motor shown in FIG. 1 includes a step of manufacturing a rotor core 1 by stacking a plurality of plates such that a plurality of slot grooves 2 are formed before and after stacking, and a shaft end of the rotor core 1. A step of manufacturing the protective ring 7 by further laminating a plurality of plates on the end surface in the axial end portion direction of the rotor core 1 so that the end ring 4 is formed before and after the lamination while being in contact with the end surface in the portion direction. A step of manufacturing an end plate 8 on the end surface of the protective ring 7 in the axial end portion direction so as to be in contact with the end surface of the protective ring 7 in the axial end portion direction and forming a plurality of through grooves 9; A step of manufacturing a plurality of rotor conductors 3 and end rings 4 by injecting metal into a plurality of through-grooves 9 provided in the plate 8; and opening in the center of the rotor core 1, the protective ring 7 and the end plate 8; It is manufactured through a process of inserting the rotary shaft 5 into the formed through hole.

Since the protective ring 7 has a laminated structure of electromagnetic steel plates, it can be manufactured by extending the manufacturing process of the rotor core 1. A plurality of rotor conductors 3 and end rings 4 are manufactured by injecting aluminum-based metal into the plurality of through-grooves 9, and at the same time, the aluminum-based metal permeates into the laminated portions of the electrical steel sheets constituting the protective ring 7. As a result, it also has a role of bonding the laminated plates together. Therefore, although the protective ring 7 has a laminated structure of electromagnetic steel plates, it has a mechanical strength equivalent to that of a protective ring manufactured from a conventional metal lump due to the adhesive effect of the aluminum-based metal. Thus, unlike the conventional protection ring manufacturing by processing from one metal lump, according to the present invention, the protection ring 7 can be manufactured from the same material as the rotor core 1. Since the manufacturing process can be simplified and no additional material is required, the manufacturing cost and the number of parts can be reduced as compared with the conventional protection ring, and the cost of the induction motor can be reduced.

The outer diameter side protective ring 7 a has a role of protecting the end ring 4 from being deformed or broken due to the centrifugal force generated by the rotation of the rotor from the outer peripheral side of the end ring 4.

The inner diameter side protective ring 7 b is fixed by shrinkage with the rotating shaft 5. In general, when carrying out shrinkage, it is necessary to carry out with the same kind of materials having the same thermal expansion coefficient. Dissimilar materials with different coefficients of thermal expansion, for example, when trying to fix both iron-based metal and aluminum-based metal by shrinking, the aluminum-based metal has a larger coefficient of thermal expansion than iron-based metal. Stress associated with thermal expansion occurs, and the stress affects the iron-based metal, and the two cannot be sufficiently fixed. In the first embodiment, the inner diameter side protective ring 7b is fixed not by shrinkage between the end ring 4 and the rotating shaft 5, but by shrinkage between the same kinds of materials of the inner diameter side protective ring 7b and the rotating shaft 5. Further, the aluminum-based metal injected from the plurality of through grooves 9 to manufacture the plurality of rotor conductors 3 and the end rings 4 penetrates into the laminated portions of the electromagnetic steel plates of the inner diameter side protective ring 7b. Since they are bonded together, contact between the inner periphery of the end ring 4 and the rotating shaft 5 is prevented, and as a result, the fixing strength, that is, the rigidity of the end ring 4 is increased.

On the other hand, the end plate 8 is for fixing the outer diameter side protection ring 7a and the inner diameter side protection ring 7b, and the structure thereof is a structure in which a plurality of electromagnetic steel plates are laminated similarly to the two protection rings 7a and 7b. Therefore, it can be manufactured by extending the manufacturing process of the rotor core 1. A plurality of rotor conductors 3 and end rings 4 are manufactured by injecting aluminum-based metal into the plurality of through-grooves 9. At the same time, the aluminum-based metal permeates into the laminated portions of the electromagnetic steel plates constituting the end plate 8. As a result, it also has a role of bonding the laminated plates together. Therefore, although the end plate 8 has a laminated structure of electromagnetic steel plates, it has mechanical strength equivalent to that of an end plate manufactured from a conventional metal lump due to the adhesive effect of the aluminum-based metal.

Thus, unlike the conventional end plate manufacturing by processing from one metal lump, in the present invention, the end plate 8 can be manufactured from the same kind of material as the rotor core 1. Since the process can be simplified and no additional material is required, the manufacturing cost and the number of parts can be reduced as compared with the conventional end plate, and the cost of the induction motor can be reduced.

Further, as shown in FIG. 3, the outer diameter of the end ring 4 is made smaller than the outer diameter defined by connecting the outer edge portions of the plurality of slot grooves 2 as compared with the conventional one. The diameter can be further reduced by the amount covered with the outer diameter side protective ring 7a. Since the centrifugal force is proportional to the radius of the rotating object, the centrifugal force generated in the end ring 4 is thereby reduced as compared with the prior art, and a highly reliable induction motor can be realized.

In addition, although FIG. 1 demonstrated the case where the end plate 8 was manufactured by further laminating a plurality of electromagnetic steel plates on the end surface in the axial end portion direction of the protective ring 7, the present invention is not limited to this, as shown in FIG. The same effect can be obtained by replacing the end plate 8 with an end plate 8a made of a single steel plate.

Example 2
5 is a cross-sectional view of a rotor of an induction motor showing Embodiment 2 of the present invention, and FIG. 6 is a side view of the rotor of the induction motor showing Embodiment 2 of the present invention. FIG. 7 is a sectional view taken along a section DD ′ (stepped end ring—boundary surface of the rotor core) in the transverse sectional view of the rotor of the induction motor shown in FIG. 5 to 7, reference numeral 4a denotes an annular stepped end ring made of an aluminum-based metal formed so that the outer diameter decreases stepwise in the direction of the shaft end, and 10 denotes a plurality of electrical steel sheets having different outer diameters. , An outer diameter side of the stepped end ring 4a, which is a double annular stepped protective ring formed by laminating the outer diameter in the direction of the shaft end so as to decrease stepwise. The stepped protective ring 10a and the inner diameter side stepped protective ring 10b of the stepped end ring 4a which is the second protective ring are constituted by two protective rings.

As in the first embodiment, the stepped protection ring 10 has a laminated structure of electromagnetic steel plates, and therefore the stepped protection ring 10 can be manufactured by extending the manufacturing process of the rotor core 1. Therefore, since the manufacturing process of the stepped protection ring 10 can be simplified and no additional material is required, the manufacturing cost and the number of parts can be reduced as compared with the conventional protection ring.

The outer diameter side stepped protection ring 10a has a role of protecting the deformation and destruction of the stepped end ring 4a caused by the centrifugal force generated by the rotation of the rotor from the outer peripheral side of the stepped end ring 4a. The inner diameter side stepped protection ring 10b is fixed by shrinkage with the rotating shaft 5, and has a role of increasing the rigidity of the stepped end ring 4a. The outer diameter side stepped protective ring 10a is installed so as to reduce the outer diameter of the stepped end ring 4a. Since the centrifugal force is proportional to the radius of the rotating object, the centrifugal force generated in the stepped end ring 4a itself is reduced stepwise because the outer diameter of the stepped end ring 4a is reduced stepwise.

Thus, since the stepped protection ring 10 can reduce the structure in the rotation axis direction, that is, the outer diameter of the stepped end ring 4a, the stepped protection ring 10 protects the stepped end ring 4a. At the same time, since it is possible to reduce the centrifugal force generated in the stepped end ring 4a itself, a highly reliable induction motor can be realized.

Further, as shown in FIG. 7, the stepped end ring 4a has an outer diameter smaller than an outer diameter defined by connecting the outer edge portions of the plurality of slot grooves 2, thereby making the stepped end compared to the conventional case. The outer diameter of the ring 4a can be further reduced by the amount covered with the outer diameter side stepped protective ring 10a. Since the centrifugal force is proportional to the radius of the rotating object, the centrifugal force generated in the stepped end ring 4a becomes smaller than that in the prior art, and a highly reliable induction motor can be realized.

In the rotor structure of the induction motor showing Embodiment 2 of the present invention, the number of stacked layers of the stepped end ring 4a and the two stepped protective rings 10a and 10b is five, and the number of steps is four. Although the case has been described, the present invention is not limited to this, and the same effect can be obtained if the number of stages is plural.

Example 3
As shown in the third embodiment, the same effect can be obtained even if the rotor of the induction motor described in the first embodiment is further fixed using a rivet pin. 8 is a cross-sectional view of a rotor of an induction motor showing Embodiment 3 of the present invention, and FIG. 9 is a side view of the rotor of the induction motor showing Embodiment 3 of the present invention. FIG. 10 is a step view at a cross-section EE ′ (end ring—rotor core boundary surface) in the cross-sectional view of the rotor of the induction motor shown in FIG.

8 to 10, reference numeral 11 denotes a solid rivet pin, in which a rotor of an induction motor is provided with a plurality of through holes concentrically along the rotation axis direction, and the rivet pin 11 is inserted into each through hole. Fix it. The rivet pin 11 further increases the fastening force in the rotation axis direction by caulking from both ends of the rotor.

Further, by changing the rivet pin 11 from solid to hollow, air can be circulated inside the rotor, and the fastening force in the rotation axis direction is increased by caulking from both ends of the rotor, and the rotor is cooled. The effect is improved.

Example 4
As shown in the fourth embodiment, the same effect can be obtained even if the rotor of the induction motor described in the second embodiment is further fixed using a rivet pin. FIG. 11 is a cross-sectional view of the rotor of the induction motor showing the fourth embodiment of the present invention, and FIG. 12 is a side view of the rotor of the induction motor showing the fourth embodiment of the present invention. FIG. 13 is a step view at a section FF ′ (stepped end ring—boundary surface of the rotor core) in the transverse cross section of the rotor of the induction motor shown in FIG.

11 to 13, reference numeral 11a denotes a solid rivet pin, in which a rotor of an induction motor is provided with a plurality of through holes concentrically along the rotation axis direction, and the rivet pin 11a is inserted into each through hole. Fix it. The rivet pin 11a further increases the fastening force in the direction of the rotation axis by caulking from both ends of the rotor.

Further, by changing the rivet pin 11a from solid to hollow, air can be circulated inside the rotor, and the fastening force in the direction of the rotation axis is increased by caulking from both ends of the rotor, and the rotor is cooled. The effect is improved.

Example 5 FIG.
In the third and fourth embodiments, the configuration in which the rotor of the induction motor is fixed using rivet pins has been described. However, as shown in the fifth embodiment, the rotor of the induction motor is fixed by pulling caulking. The same effect can be obtained. 14 and 15 are sectional views of the rotor of the induction motor showing Embodiment 5 of the present invention, and FIGS. 16 and 17 are structural views of the caulking of the rotor of the induction motor showing Embodiment 5 of the present invention. It is.

As shown in FIG. 14, the outer diameter side protection rings 7 a or the inner diameter side protection rings 7 b are removed and fixed by caulking 31 so that the rotor can be handled as an integral protection structure. Further, as shown in FIG. 15, the outer diameter side stepped protective rings 10 a are pulled out and fixed by caulking 32, and the inner diameter side stepped protective rings 10 b are pulled out and fixed by caulking 31, so that the rotor is integrally protected Can be treated as

As shown in FIG. 16, the outer diameter side protective ring 7a, the inner diameter side protective ring 7b, and the inner diameter side stepped protective ring 10b are respectively formed with recesses, and the manufactured outer diameter side protective ring 7a and inner diameter side protective ring 7b are manufactured. Then, the concave portions of the inner diameter side stepped protection ring 10b are overlapped and pressed, so that the outer diameter side protection ring 7a, the inner diameter side protection ring 7b, and the inner diameter side stepped protection ring 10b can be formed as an integral structure. In addition, as shown in FIG. 17, a concave portion is also produced in the outer diameter side stepped protective ring 10a, a circular hole is formed on one side of the concave portion, and a concave portion of each manufactured outer diameter side stepped protective ring 10a is formed. Can be manufactured by sequentially shifting in the inner diameter direction and pressurizing the outer diameter side stepped protective ring 10a corresponding to the stepped portion. In this way, the rotor can be integrated with caulking.

Example 6
In the first embodiment and the second embodiment, the case where the plurality of rotor conductors 3 are manufactured by injecting aluminum-based metal from the plurality of through grooves 9 is described. However, as shown in FIGS. The same effect can be obtained when a plurality of copper metal conductor bars 41 and 42 are applied to the rotor conductor 3. In FIG. 19, the leading end of each conductor bar 42 on the stepped end ring 4 a side is cut obliquely along the rotational axis direction so as to be within the stepped end ring 4 a.

The rotor of the induction motor shown in FIG. 18 includes a step of manufacturing a rotor core 1 by stacking a plurality of plates such that a plurality of slot grooves 2 are formed before and after stacking, and a shaft end of the rotor core 1. A step of manufacturing the protective ring 7 by further laminating a plurality of plates on the end surface in the axial end portion direction of the rotor core 1 so that the end ring 4 is formed before and after the lamination while being in contact with the end surface in the portion direction. The step of inserting the conductor bar 41 into the plurality of slot grooves 2 and the axial end portion of the protective ring 7 so as to be in contact with the end surface in the axial end direction of the protective ring 7 and to form the plurality of through grooves 9 A step of further manufacturing the end plate 8 on the end surface in the direction, a step of manufacturing the end ring 4 by injecting metal into the plurality of through grooves 9 provided in the end plate 8, the rotor core 1 and the protective ring 7 and manufactured through a process of inserting the rotary shaft 5 into a through hole formed in the center of the end plate 8 It is.

1 rotor core, 2 slot groove, 3 rotor conductor, 4 stepped end ring, 5 rotating shaft, 7 protective ring, 7a outer diameter side protective ring, 7b inner diameter side protective ring, 8 end plate, 8a end plate, 9 Through groove, 10 stepped protective ring, 10a outer diameter side stepped protective ring, 10b inner diameter side stepped protective ring, 11 rivet pin, 11a rivet pin, 31 punched crimp, 32 punched crimp, 41 conductor bar, 42 conductor bar.

Claims (12)

A rotating shaft, a rotor core composed of a plurality of laminated plates, a plurality of slot grooves formed so as to penetrate the rotor core, and a plurality of rotor conductor portions provided inside each slot groove; A rotor conducting portion provided on an end surface of the rotor core in the direction of the axial end of the rotor core to conduct with each rotor conductor, a first protective ring for protecting the outer periphery of the rotor conducting portion, and the rotor An induction motor comprising: a protective ring made of a second protective ring that prevents contact between the inner periphery of the conducting portion and the rotating shaft; and an end plate provided on an end surface in the axial end portion direction of the protective ring. In the rotor,
The rotor of an induction motor, wherein the protection ring is composed of a plurality of laminated plates. The induction motor rotor according to claim 1, wherein the end plate includes a plurality of laminated plates. 3. The induction motor according to claim 1, wherein an outer diameter of the rotor conducting portion on the rotor conductor portion side is larger than an outer diameter of the rotor conducting portion on the end plate side. Rotor. 4. The outer diameter of the rotor conducting portion on the rotor conductor portion side is smaller than an outer diameter connecting outer edge portions of the plurality of slot grooves. 5. The rotor of the induction motor described. 5. The induction motor according to claim 1, wherein the rotor core, the protective ring, and the end plate are provided with a plurality of recesses, and the recesses are overlapped and fixed by caulking. Rotor. 6. The rotor core, the protective ring, and the end plate are provided with a plurality of through holes, a rivet pin is passed through each through hole, and the rivet pin is used for fixing. The induction motor rotor described in 1. The rotor of an induction motor according to claim 6, wherein the rivet pin is a hollow rivet pin. The plurality of rotor conductor portions and the rotor conduction portion are manufactured by injecting metal from a plurality of through grooves provided in the end plate. A rotor for an induction motor according to claim 1. The plurality of rotor conductor portions are each composed of a conductor bar, and a leading end portion of each conductor bar is installed in an open space formed between the first protection ring and the second protection ring. The rotor of the induction motor in any one of Claims 1 thru | or 7. The rotor of an induction motor according to claim 9, wherein the rotor conduction portion is manufactured by injecting metal from a plurality of through grooves provided in the end plate. A method of manufacturing the rotor of the induction motor,
Stacking a plurality of plates so that the plurality of slot grooves are formed before and after stacking, and manufacturing the rotor core;
A plurality of plates are further stacked on the end surface of the rotor core in the axial end direction so that the rotor conductive portion is formed before and after stacking, while being in contact with the end surface in the axial end direction of the rotor core. Manufacturing the protective ring,
The step of manufacturing the end plate further on the end surface in the axial end portion direction of the protective ring so as to be in contact with the end surface in the axial end portion direction of the protective ring and forming a plurality of the through grooves;
Producing a plurality of the rotor conductor portions and the rotor conduction portions by injecting metal into the plurality of through-grooves provided in the end plate;
Inserting the rotary shaft into a through hole formed in the center of the rotor core, the protective ring, and the end plate;
The method of manufacturing a rotor for an induction motor according to claim 8, comprising: A method of manufacturing the rotor of the induction motor,
Stacking a plurality of plates so that the plurality of slot grooves are formed before and after stacking, and manufacturing the rotor core;
A plurality of plates are further stacked on the end surface of the rotor core in the axial end direction so that the rotor conductive portion is formed before and after stacking, while being in contact with the end surface of the rotor core in the axial end direction. Manufacturing the protective ring,
Inserting the conductor bar inside the plurality of slot grooves;
The step of manufacturing the end plate further on the end surface in the axial end portion direction of the protective ring so as to be in contact with the end surface in the axial end portion direction of the protective ring and to form a plurality of the through grooves;
Producing the rotor conduction part by injecting metal into the plurality of through-grooves provided in the end plate;
Inserting the rotary shaft into a through hole formed in the center of the rotor core, the protective ring, and the end plate;
The method of manufacturing a rotor for an induction motor according to claim 10, comprising:

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