JP2016178838A - Rotor for induction machine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a rotor for an induction machine capable of suppressing efficiency reduction caused by short-circuiting of a magnetic flux or generation of an eddy current in more simplified configuration, the rotor for the induction machine comprising a rotor core and a secondary conductor including a plurality of conductor bars and an end ring.SOLUTION: A rotor 1 comprises: a rotor core 20 that is fixed on a rotary shaft 10; and a secondary conductor 50 including a plurality of conductor bars 51 and an end ring 55. The rotor core 20 is configured by stacking a plurality of first core blocks 30 and a plurality of second core blocks 40. The first core block 30 is configured by stacking a plurality of first core plates 31 each including a plurality of first slots 35 communicating with the outside via a slot opening 36. The second core block 40 is configured by stacking a plurality of second core plates 41 each including a plurality of second slots 45 that are closed slots and a plurality of notches 46 that are positioned at an outer diameter side of the second slots 45.SELECTED DRAWING: Figure 4

Description

  The present invention relates to a rotor of an induction machine.

  Conventionally, a cage rotor is known as one of rotors of induction machines. Such a squirrel-cage rotor short-circuits the rotor core fixed to the rotating shaft, the plurality of conductor bars distributed around the rotating shaft in the rotor core, and the end portions of the respective conductor bars on the axial end surface of the rotor core. And a secondary conductor including an end ring.

  In these induction machines, there is a method for preventing a short circuit of magnetic flux and an eddy current on the outer diameter side surface of the rotor core as one method for suppressing a decrease in efficiency. As an invention relating to a rotor of an induction machine using this method, an invention described in Patent Document 1 is known.

  The induction motor described in Patent Document 1 includes a squirrel-cage rotor in which a secondary conductor composed of a bar and an end ring is formed on a rotor core. In Patent Document 1, a plurality of fine grooves that do not protrude from the outer peripheral surface of the rotor are formed on the outer diameter side of each slot of the rotor core. And in patent document 1, after performing aluminum die-casting with respect to each slot, the outer periphery of a rotor iron core is cut until it reaches two narrow grooves, and the convex part pinched by the two narrow grooves is formed. Eliminate and form a slit. Thus, according to the induction motor described in Patent Document 1, by forming a slit on the outer diameter side of each slot, a short circuit of magnetic flux on the outer diameter side surface of the rotor core is prevented, and thus the efficiency as the induction motor is increased. Is suppressed.

JP 09-215287 A

  Here, in the induction motor described in Patent Document 1, after the aluminum die casting is performed on each slot, the outer periphery of the rotor core is cut into two narrow grooves until reaching the two narrow grooves. In order to eliminate the sandwiched convex portion and form a slit, it is necessary to strictly limit the inflow of aluminum into each narrow groove, and it must be formed at several tens to several hundreds μm. Further, in order to eliminate the convex portion sandwiched between the two narrow grooves in a free state, all the narrow grooves need to be positioned so as to communicate with each other along the axial direction of the rotor.

  Therefore, in the case of the induction motor described in Patent Document 1, the rotor core, the bar, and the slot are necessarily arranged so as to extend substantially parallel to the axial direction of the rotor. The core plates are short-circuited by the cutting process for removing the convex portions. For this reason, the path of the short-circuit magnetic flux or eddy current on the outer diameter side of the rotor extends along the axial direction corresponding to the axial dimension of the rotor (that is, the thickness of the magnetic steel plate). As a result, the efficiency of the induction machine is reduced. Furthermore, in the induction motor described in Patent Document 1, the bars arranged in the slots cannot have a skew structure, and it has become difficult to take sufficient measures regarding cogging torque and torque ripple.

  The present invention provides a rotor of an induction machine that can suppress a decrease in efficiency due to a short circuit of magnetic flux, generation of eddy current, and the like with a simpler configuration.

  A rotor of an induction machine according to an aspect of the present invention includes a rotating shaft that is rotatably arranged and a plurality of magnetic steel plates stacked and fixed in an axial direction of the rotating shaft. A rotor core having a plurality of slots distributed around and extending in the rotation axis direction, a plurality of conductor bars made of a conductive material arranged in each slot of the rotor core, and the rotor core in the axial direction of the rotation axis A rotor of an induction machine having a secondary conductor including an end ring that connects ends of the plurality of conductor bars to each other on the end face, wherein the rotor core constitutes a part of the slot And a first core block formed by laminating a plurality of first magnetic steel plates having a plurality of first slot portions communicating with the outside in a radially outer portion, and a part of the slot, and a radial direction Outside And a plurality of second slot portions that are partitioned from the outside and a plurality of notch portions that are formed by notching the outer edges of the magnetic steel sheet positioned radially outward with respect to each of the second slot portions. And a second core block configured by laminating a plurality of two magnetic steel plates.

  The rotor of the induction machine has a rotating shaft, a rotor core having a plurality of slots, and a secondary conductor including a plurality of conductor bars and an end ring, and the rotor core includes a first core block, It is comprised by the 2nd core block. The first core block is configured by laminating a plurality of first magnetic steel plates having a plurality of first slot portions communicating with the outside in a radially outer portion, and the second core block is a plurality of sections partitioned from the outside. And a plurality of second magnetic steel plates each having a plurality of cutout portions positioned radially outward of the second slot portions. According to the rotor of the induction machine, by configuring the rotor core using the first core block and the second core block, the path of the short-circuit magnetic flux and eddy current extending along the axial direction is changed to the first core block, It can divide for every 2nd core block. Further, the short-circuit magnetic flux generated on the outer diameter side of the conductor bar can be suppressed by a part of the first slot portion or the notch portion. According to the rotor of the induction machine, it is possible to prevent a decrease in efficiency as the induction machine by suppressing the influence of short-circuit magnetic flux and eddy current.

  An induction machine rotor according to another aspect of the present invention is the induction machine rotor according to claim 1, wherein the rotor core rotates between the first core block and the second core block. It is characterized by being configured by stacking.

  According to the rotor of the induction machine, by rolling the first core block and the second core block, the magnetic directionality of the entire rotor core can be eliminated, and the influence on the cogging torque can be reduced. Can be suppressed. Further, according to the rotor of the induction machine, by rolling the first core block and the second core block, the dimensional tolerance of the first core block configured by laminating the first magnetic steel plates, The dimensional tolerance of the 2nd core block comprised by laminating | stacking a 2nd magnetic steel plate can be eased.

  An induction machine rotor according to another aspect of the present invention is the induction machine rotor according to claim 1 or 2, wherein the first core block is disposed at an axial end portion of the rotor core. It is arranged.

  In the rotor of the induction machine, the first magnetic steel plate constituting the first core block has a plurality of first slot portions communicating with the outside in the radially outer portion. It is desirable to finally perform peripheral cutting. Here, according to the rotor of the induction machine, since the first core block is disposed at the axial end portion of the rotor core, it is possible to easily perform outer peripheral cutting on the first core block. .

  According to this invention, the 1st core block formed by laminating | stacking the 1st magnetic steel plate which has the some 1st slot part connected with the exterior, the some 2nd slot part, and the 2nd magnetism which has a some notch part By constructing a rotor core by laminating the second core block made by laminating steel plates, the path of short-circuit magnetic flux and eddy current extending along the axial direction is divided, and the influence of short-circuit magnetic flux and eddy current is affected. An induction machine rotor that can be suppressed can be provided.

It is sectional drawing which shows schematic structure of the rotor of the induction machine which concerns on this embodiment. It is a top view of the 1st core block concerning this embodiment. It is a top view of the 2nd core block concerning this embodiment. It is a side view which shows the state before the cutting process of the rotor of the induction machine which concerns on this embodiment. It is a side view which shows the state after the cutting process of the rotor of the induction machine which concerns on this embodiment.

  Hereinafter, an embodiment in which a rotor of an induction machine according to the present invention is applied to a rotor 1 which is a cage rotor used in an induction motor will be described in detail with reference to the drawings.

  First, a schematic configuration of the rotor 1 according to the present embodiment will be described in detail with reference to the drawings. The rotor 1 according to this embodiment is configured as a squirrel-cage rotor, and constitutes a squirrel-cage three-phase induction motor together with a stator that generates a rotating magnetic flux by a three-phase alternating current. In the induction motor, the rotating magnetic force generated in the rotor 1 is generated by the linkage between the rotating magnetic flux generated from the stator and the induced current generated in the conductor bar 51 of the rotor 1 configured as a cage rotor.

  In the induction motor, the rotor 1 is rotatably supported around the axis of the rotary shaft 10 on the radially inner side of the stator having a substantially cylindrical shape. (Not shown).

  As shown in FIG. 1, the rotor 1 has a rotor core 20 fixed to the rotary shaft 10 and having a plurality of slots 25, and a secondary conductor 50 having a plurality of conductor bars 51 and end rings 55. Yes. The rotating shaft 10 is rotatably supported by a case (not shown) via a bearing on both axial sides of the induction motor.

  The rotor core 20 according to the present embodiment has a cylindrical shape by laminating a plurality of first core blocks 30 and a plurality of second core blocks 40 configured by laminating a plurality of magnetic steel plate core plates formed in a substantially disc shape. It has a shape and has a rotation shaft hole 21 and a plurality of slots 25. Further, the outer peripheral surface of the rotor core 20 is configured so as to face the inner peripheral surface (surface on the rotating shaft 10 side) of the cylindrically formed stator with a space therebetween when configuring an induction motor. Yes. The configurations of the first core block 30 and the second core block 40 will be described in detail later with reference to the drawings.

  As shown in FIG. 1, the rotation shaft hole 21 is formed at the center of the rotor core 20 and is inserted through the rotation shaft 10. The rotor core 20 is fixed to the rotating shaft 10 inserted through the rotating shaft hole 21. A plurality of slots 25 are distributed around the rotation shaft hole 21 of the rotor core 20 at regular intervals (see FIGS. 1 to 3).

  The conductor bar 51 constituting the secondary conductor 50 is disposed in a plurality of slots 25 that are distributed around the rotation shaft hole 21 of the rotor core 20. The plurality of conductor bars 51 are formed in each slot 25 by die-casting a conductive material such as aluminum, and are distributed and arranged at equal intervals along the circumferential direction of the rotor core 20. As will be described later, each conductor bar 51 is skewed by shifting its phase at the boundary between the first core block 30 and the second core block 40. In FIG. 1, the skew is not shown for the sake of explanation.

  The end ring 55 is a member called an end ring or short circuit ring, and is disposed along both end faces of the rotor core 20 in the axial direction of the rotating shaft 10 as shown in FIG. The end ring 55 is formed in an annular shape by die-casting a conductive material such as aluminum in a forming jig (not shown) installed on the axial end surface of the rotor core 20. And is integrally formed. Thereby, each conductor bar 51 is short-circuited by being formed integrally with the pair of end rings 55.

  Next, the 1st core block 30 which comprises some rotor cores 20 which concern on this embodiment is demonstrated in detail, referring drawings. The first core block 30 is formed in a substantially cylindrical shape by laminating a plurality of first core plates 31 made of a plurality of electromagnetic steel plates formed in a substantially disc shape in the axial direction. And a plurality of first slots 35 constituting a part of the plurality of slots 25.

  As shown in FIG. 2, the first shaft hole 32 is formed so that the rotary shaft 10 can be inserted in a central portion of the first core plate 31 formed in a substantially disc shape by an electromagnetic steel plate. Accordingly, the first shaft hole 32 in the first core block 30 constitutes a part of the rotation shaft hole 21 in the rotor core 20.

  The plurality of first slots 35 are distributed around the first shaft holes 32 of the first core plate 31, and constitute a part of the plurality of slots 25 in the rotor core 20. Each first slot 35 has a slot opening 36 that communicates the inside of the first slot 35 and the outside of the first core block 30. Each slot opening 36 opens the outer peripheral surface side of the first core block 30 (that is, the rotor core 20) in the first slot 35, and has a width dimension narrower in the circumferential direction than the inside of the first slot 35. Is formed. Therefore, the first slot 35 functions as a so-called semi-open slot.

  Then, the 2nd core block 40 which comprises a part of rotor core 20 which concerns on this embodiment is demonstrated in detail, referring drawings. The second core block 40 is formed in a substantially cylindrical shape by laminating a plurality of second core plates 41 made of a plurality of electromagnetic steel plates formed in a substantially disc shape in the axial direction. The second shaft hole 42 constituting a part of the plurality of slots 25 and a plurality of second slots 45 constituting a part of the plurality of slots 25.

  The second shaft hole 42 is formed so that the rotary shaft 10 can be inserted through a central portion of the second core plate 41 formed in a substantially disc shape by an electromagnetic steel plate (see FIG. 3). Accordingly, the second shaft hole 42 in the second core block 40 forms the rotation shaft hole 21 in the rotor core 20 by cooperating with the first shaft hole 32 of the first core block 30.

  As shown in FIG. 3, the plurality of second slots 45 are distributed around the second shaft holes 42 of the second core plate 41, and the plurality of first slots 35 in the first core block 30. By cooperating, the plurality of slots 25 in the rotor core 20 are respectively configured. Unlike the first slot 35 in the first core block 30, the second slot 45 partitions the outer peripheral surface side of the second core block 40 (that is, the rotor core 20) in the second slot 45 from the outside of the second core block 40. Is blocked. Therefore, the second slot 45 functions as a so-called closed slot.

  Cutout portions 46 are formed on the outer diameter sides of the respective second slots 45. As shown in FIG. 3 and the like, each notch 46 is formed by notching the outer edge of the second core plate 41 located on the outer diameter side of the second slot 45 so as to be recessed toward the inner diameter side. Therefore, when the second core block 40 is formed by laminating the plurality of second core plates 41, a groove extending along the axial direction of the rotary shaft 10 is formed on the outer peripheral surface of the second core block 40 by the notch 46. A plurality of shaped portions are formed in the circumferential direction.

  Next, the manufacturing process of the rotor 1 according to this embodiment will be described. First, the first core block 30 is manufactured by stacking and fixing the plurality of first core plates 31, and the second core block 40 is manufactured by stacking and fixing the plurality of second core plates 41.

  The rotor core 20 is formed using the manufactured first core block 30 and second core block 40. In the present embodiment, the rotor core 20 is manufactured by stacking the three first core blocks 30 and the two second core blocks 40. Specifically, as shown in FIG. 1 and FIG. 4, lamination is performed so that the second core block 40 is positioned between the first core blocks 30. When the first core block 30 and the second core block 40 are stacked, they are rolled in units of the first core block 30 and the second core block 40 outside the mold of the manufacturing apparatus (not shown).

  Since the plurality of first core plates 31 are stacked, the first core block 30 has a magnetic directionality of the first core block 30 itself based on the magnetic directionality of the first core plate 31. Can occur. Similarly, since the plurality of second core plates 41 are laminated, due to the magnetic directionality of the second core plate 41, the directionality can also occur in the magnetism of the second core plate 41 itself. In this regard, when the rotor core 20 is produced, the first core block 30 and the second core block 30 are transferred by rolling in units of the first core block 30 and the second core block 40 outside the mold of the manufacturing apparatus (not shown). The directionality of magnetism in the core block 40 can cancel each other, and can approach the rotor core 20 having no directionality. In addition, according to the rotor 1, the dimensional tolerance of the first core block 30 and the dimensional tolerance of the second core block 40 are alleviated by rolling the first core block 30 and the second core block 40. It is also possible.

  Further, when the first core block 30 and the second core block 40 are stacked, the first slots 35 in the first core block and the second slots 45 in the second core block 40 are provided in a predetermined amount in the circumferential direction. In a displaced state, it is laminated as needed. The predetermined amount means a displacement amount in the circumferential direction that can maintain a state where each first slot 35 and each second slot 45 communicate with each other.

  Thus, by laminating the first core block 30 and the second core block 40 to constitute the rotor core 20, each slot 25 in the rotor core 20 extends so as to be displaced in the circumferential direction in the axial direction. . That is, as shown in FIG. 4, each slot 25 in the rotor core 20 has a so-called skew structure.

  Thus, after the rotor core 20 is manufactured by alternately laminating the first core block 30 and the second core block 40, the rotor core 20 is placed in a die of a die-casting device (not shown) and conductive such as aluminum By die-casting the material, the conductor bar 51 is disposed inside each slot 25, and at the same time, the end ring 55 is disposed on the axial end surface of the rotor core 20.

  As described above, since each slot 25 has a skew structure and the conductor bar 51 is disposed along the slot 25, each conductor bar 51 is also skewed. Thereby, according to the said rotor 1, a cogging torque and a torque ripple can be suppressed by making the slot 25 and the conductor bar 51 into a skew structure.

  Here, as shown in FIG. 2, in the first core block 30 in the present embodiment, each first slot 35 communicates with the outside of the first core block 30 via a slot opening 36. Therefore, after the conductive material is die-cast and the conductor bar 51 is disposed in each slot 25 (see FIG. 4), it is necessary to perform outer peripheral cutting on the outer peripheral surface of the first core block 30. Become.

  As shown in FIGS. 4 and 5, each first core block 30 is formed to have the same diameter as each second core block 40 by performing an outer periphery cutting process for cutting the outer peripheral surface of each first core block 30. The And in the rotor 1 which concerns on this embodiment, since the axial direction edge part side of the rotor core 20 is all the 1st core block 30 (refer FIG. 1, FIG. 4), the 1st core block 30 is based on the positional relationship. It is possible to improve the work efficiency related to the outer periphery cutting.

  The outer periphery cutting process for each first core block 30 is finished, and the rotor core 20 is fixed to the rotary shaft 10, whereby the rotor 1 according to this embodiment is manufactured. According to the rotor 1 manufactured in this manner, the rotor core 20 is formed by stacking the first core block 30 and the second core block 40, so that the core plates generated by cutting work on the outer diameter side of the rotor core 20 About the short circuit, the path | route of the short circuit magnetic flux and eddy current which extend along an axial direction can be divided | segmented for every 1st core block 30 and the 2nd core block 40. FIG. Further, the slot opening 36 and the notch 46 can suppress the short-circuit magnetic flux on the outer diameter side of the conductor bar 51. Thereby, the rotor 1 according to the present embodiment can suppress the influence of the short-circuit magnetic flux and the eddy current on the outer diameter side of the rotor core 20, thereby preventing a reduction in efficiency as an induction motor.

  As described above, the rotor 1 according to the present embodiment includes the rotating shaft 10, the rotor core 20 having the plurality of slots 25, and the secondary conductor 50 including the plurality of conductor bars 51 and the end ring 55. The rotating magnetic flux generated from the stator that constitutes the induction motor and the induced current generated in each conductor bar 51 are linked to each other so as to be rotatable.

  Here, the rotor core 20 in the rotor 1 is configured by stacking the first core block 30 and the second core block 40. The first core block 30 is configured by laminating a plurality of first core plates 31 having a plurality of first slots 35 communicating with the outside through the slot openings 36 (see FIGS. 1 and 2). . The second core block 40 is configured by laminating a plurality of second core plates 41 having a plurality of second slots 45 and notches 46 (see FIGS. 1 and 3).

  According to the rotor 1 according to the present embodiment, the rotor core 20 is configured by laminating the first core block 30 and the second core block 40, thereby causing a short circuit between core plates generated by cutting along the axial direction. Thus, the path of the short-circuit magnetic flux and eddy current that extend can be divided for each of the first core block 30 and the second core block 40. Further, the short-circuit magnetic flux on the outer diameter side of the rotor core 20 (that is, the outer diameter side of the conductor bar 51) can be suppressed. Thereby, the rotor 1 according to the present embodiment can suppress the influence of the short-circuit magnetic flux and the eddy current on the outer diameter side of the rotor core 20, thereby preventing the efficiency of the induction motor from decreasing.

  In the present embodiment, when the rotor core 20 is configured, the first core block 30 and the second core block 40 are rolled up, so that the magnetic directionality in the entire rotor core 20 can be eliminated. Therefore, the influence on the cogging torque can be suppressed. Further, by rolling the first core block 30 and the second core block 40, the dimensional tolerance in the first core block 30 and the dimensional tolerance in the second core block 40 can be relaxed.

  As shown in FIG. 2 and the like, in the first core plate 31 constituting the first core block 30, the plurality of first slots 35 communicate with the outside of the first core block 30 through the slot openings 36. Therefore, after the conductor bars 51 are disposed inside the slots 25 by die casting, the outer peripheral surface of the first core block 30 is subjected to outer peripheral cutting. As shown in FIG. 4 and FIG. 5, the first core block 30 has an outer peripheral surface cut by a predetermined amount by the outer peripheral cutting, and has the same diameter as each second core block 40. And according to the rotor 1 which concerns on this embodiment, since the 1st core block 30 is arrange | positioned at the axial direction edge part side of the rotor core 20, as shown in FIG.1, FIG.4, FIG.5, the position From the relationship, it is possible to improve the work efficiency related to the outer periphery cutting for the first core block 30.

  Although the present invention has been described based on the embodiments, the present invention is not limited to the above-described embodiments, and various improvements and modifications can be made without departing from the spirit of the present invention. For example, although aluminum etc. were mentioned as a electrically conductive material which comprises the conductor bar 51 and the end ring 55 which are the secondary conductors 50, it is not limited to this aspect. For example, copper, an aluminum alloy, or a copper alloy may be used. The conductor bar 51 and the end ring 55 may be made of different materials.

  In the embodiment described above, the first core block 30 is configured by stacking a plurality of first core plates 31. In this regard, when the first core block 30 is formed, each first slot 35 in a certain first core plate 31 is made to correspond to each first slot 35 in the first core plate 31 positioned on the other side in the axial direction. Lamination can also be performed at a position displaced by a predetermined amount in the circumferential direction. Thereby, since each 1st slot 35 in the 1st core block 30 can be made into a skew structure, a cogging torque and a torque ripple can further be suppressed.

Further, in the above-described embodiment, the second core block 40 is configured by stacking a plurality of second core plates 41. When forming the second core block 40, as in the first core block 30, each second slot 45 in a certain second core plate 41 is placed in each second core plate 41 located on the other side in the axial direction. The two slots 45 may be stacked at a position displaced by a predetermined amount in the circumferential direction. Thereby, since each 2nd slot 45 in the 2nd core block 40 can be made into a skew structure, a cogging torque and a torque ripple can further be suppressed.
Further, in the above-described embodiment, the configuration adopting transposition and skew is used, but the present invention is not limited to this aspect, and it is possible to adopt a configuration that does not perform translocation or skew. .
In the above-described embodiment, the rotor core 20 is configured by using the three first core blocks 30 and the two second core blocks 40. However, the present invention is not limited to this combination. Absent. Further, the number of core plates constituting each core block may be various as long as it is one or more and does not interfere with the lamination and die casting.

  In the above-described embodiment, the rotor core 20 is divided into two types: the first core block 30 formed by stacking the first core plates 31 and the second core block 40 formed by stacking the second core plate 41. Although configured, the rotor core 20 may be configured using more types of core blocks. The type of the core block in this case refers to a different core plate shape that constitutes the core block. For example, when the opening width of the slot opening 36 is different, or a notch portion in the radial direction or the circumferential direction A case where the size of 46 is different can be mentioned.

DESCRIPTION OF SYMBOLS 1 Rotor 10 Rotating shaft 20 Rotor core 25 Slot 30 1st core block 31 1st core plate 35 1st slot 36 Slot opening 40 2nd core block 41 2nd core plate 45 2nd slot 46 Notch 50 Secondary conductor 51 Conductor Bar 55 End Ring

Claims (3)

A rotating shaft rotatably disposed;
A rotor core having a plurality of slots that are laminated and fixed around the rotation axis and extending in the rotation axis direction;
A plurality of conductor bars made of a conductive material disposed in each slot of the rotor core, and an end ring that connects ends of the plurality of conductor bars to each other on an end surface of the rotor core in the axial direction of the rotation shaft; A rotor of an induction machine comprising:
The rotor core is
A first core block configured by laminating a plurality of first magnetic steel plates that constitute a part of the slot and have a plurality of first slot portions that communicate with the outside in a radially outer portion;
A plurality of second slot portions constituting a part of the slot and partitioned from the outside in the radially outer portion, and an outer edge of the magnetic steel sheet positioned radially outward with respect to each of the second slot portions are cut. A second core block configured by laminating a plurality of second magnetic steel plates each having a plurality of notched portions formed by cutting, and
A rotor for an induction machine, characterized in that the rotor is configured. A rotor for an induction machine according to claim 1,
The rotor core is
An induction machine rotor comprising: the first core block and the second core block being transposed. A rotor for an induction machine according to claim 1 or claim 2,
The first core block is
A rotor of an induction machine, wherein the rotor is arranged at an axial end portion of the rotor core.

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