JP2019180132A - Rotor core, rotor, and synchronization reluctance rotary electric machine - Google Patents

Abstract

To provide a rotor core, a rotor, and a synchronization reluctance rotary electric machine in which reduction of the power factor can be inhibited while the mechanical strength is increased.SOLUTION: The rotor core includes a plurality of flux barriers, and one or more bridges provided to at least one of the plurality of flux barriers. The flux barriers are hollow portions having the common arc center near the outer circumferential portions thereof and being each formed into an arc shape. The bridges are disposed so as to bridge portions excluding ends of the flux barriers. The bridges are disposed so as not to be positioned on the same straight line passing through the arc center.SELECTED DRAWING: Figure 1

Description

  Embodiments described herein relate generally to a rotor core, a rotor, and a synchronous reluctance rotating electrical machine.

  A synchronous reluctance rotating electrical machine is a rotating electrical machine that does not have a permanent magnet or a conductor in a rotor. In a synchronous reluctance rotating electrical machine, a rotational force is generated by controlling a flow path of magnetic flux by a flux barrier that is a hollow portion having a shape along the flow of q-axis magnetic flux of a rotor core.

  In a synchronous reluctance rotating electrical machine, a magnetic flux is generated by an ineffective component of a lag current, so a problem is that the power factor is low, and a rotating machine with a low power factor requires a semiconductor element with a large current capacity. For this reason, in view of replacement of existing equipment, improvement of the power factor is the biggest problem in the synchronous reluctance rotating electrical machine. As one of the measures for improving the power factor, it is conceivable to reduce the leakage magnetic flux by narrowing the width of the outer peripheral bridge that connects the rotor core at the end of the flux barrier.

  However, if the outer bridge is made too narrow, the rotor core may be deformed or damaged when the synchronous reluctance rotating electrical machine is driven at high speed or when the synchronous reluctance rotating electrical machine is large.

Japanese Patent Laying-Open No. 2015-204664 JP 2016-133505 A

  Therefore, there are provided a rotor core, a rotor, and a synchronous reluctance rotating electric machine configured using the same, which can suppress a decrease in power factor while enhancing mechanical strength.

  The rotor core according to the embodiment includes a plurality of flux barriers and a bridge provided on at least one of the plurality of flux barriers. The flux barrier is a hollow portion configured in an arc shape having an arc center at an outer peripheral portion thereof, and the bridge is disposed so as to be bridged at a place other than an end portion of the flux barrier. The bridges are arranged so as not to be positioned on the same straight line passing through the arc center.

The top view which shows schematic structure of the rotor and stator which concern on 1st Embodiment The top view which shows schematic structure of the rotor which concerns on 2nd Embodiment.

  Hereinafter, embodiments will be described with reference to the drawings. In the following description, a direction parallel to the rotation center axis O is referred to as an axial direction. A direction in which the periphery of the rotation center axis O is circulated coaxially with the rotation center axis O is referred to as a circumferential direction. A direction perpendicular to the rotation center axis O is referred to as a radial direction. In the following description, similar elements are denoted by the same reference numerals, description thereof is omitted, and different elements are described.

(First embodiment)
The first embodiment will be described below. FIG. 1 shows a ¼ sector of the synchronous reluctance rotating electrical machine 1, that is, a ¼ circumferential angle region, in other words, one pole. In each quarter angle region, the stator 3 and the rotor 4 have the same structure.

  As shown in FIG. 1, the synchronous reluctance rotating electrical machine 1 includes a stator 3 and a rotor 4. The stator 3 is constituted by a stator core 10. In the synchronous reluctance rotating electrical machine 1, the outer peripheral surface of the stator core 10 is fitted and fixed to the inner peripheral surface of a frame (not shown). The radial center of the stator core 10 coincides with the rotation center axis O.

  The stator core 10 is formed by, for example, press molding soft magnetic powder and laminating a plurality of electromagnetic steel plates. A plurality of teeth 11 protruding toward the rotation center axis O and arranged at equal intervals in the circumferential direction are integrally formed on the inner peripheral surface of the stator core 10. Each tooth 11 is radially arranged symmetrically with respect to the rotation center axis O of the stator core 10. Each tooth 11 has a substantially rectangular cross section. Slots 12 are formed between adjacent teeth 11. A winding 13 is wound around each tooth 11 via the slots 12 by a concentrated winding method to form a coil.

  The rotor 4 is disposed on the radially inner side of the stator core 10. The rotor 4 includes a rotating shaft (not shown) that extends in the axial direction at the central portion in the radial direction, and includes a substantially cylindrical rotor core 15 that is fitted and fixed to the outer periphery of the rotating shaft. In the synchronous reluctance rotating electrical machine 1, the rotating shaft is rotatably supported by a bearing (not shown) arranged around the rotation center axis O.

  The rotor core 15 is formed by laminating a plurality of thin disc-shaped rotor steel plates 15a in the rotation axis direction. The rotor steel plate 15a is formed, for example, by pressing and shaping soft magnetic powder into a substantially disk shape and punching the through hole 16, the flux barrier 20, and the like. Hereinafter, the description will focus on the rotor core 15, but the description relating to the rotor core 15 also applies to the rotor steel plate 15a constituting the rotor core 15. In the first embodiment, an example in which three flux barriers 20 are formed is illustrated.

  The outer peripheral portion 15b of the rotor core 15 is set such that a predetermined air gap is formed between each of the teeth 11 facing in the radial direction. Further, a through hole 16 penetrating in the axial direction is formed at the radial center of the rotor core 15. A rotary shaft (not shown) is press-fitted into the through hole 16.

  In the rotor core 15, flux barriers 20 (20 a, 20 b, 20 c) that are three-layer cavities are formed side by side in the radial direction in each of the ¼ circumferential angle regions. In the following description, the flux barriers 20a, 20b, and 20c are collectively referred to as the flux barrier 20. In the flux barrier 20, a first flux barrier 20a is formed on the radially outermost side with respect to the rotation center axis O, and a second flux barrier 20b and a third flux barrier are sequentially formed from the first flux barrier 20a toward the radially inner side. 20c are formed side by side. The third flux barrier 20c is disposed on the innermost side in the radial direction with respect to the rotation center axis O.

  The flux barrier 20 is formed along the flow of magnetic flux formed when the winding 13 is energized. As a result, a direction in which the magnetic flux easily flows and a direction in which the magnetic flux hardly flows are formed in the rotor core 15.

  Regions other than the flux barriers 20a, 20b, and 20c are magnetic paths 21 (21a, 21b, 21c, and 21d). The magnetic paths 21 are provided between the flux barriers 20, between the outermost first flux barrier 20 a and the outer peripheral portion 15 b, and between the innermost third flux barrier 20 c and the through hole 16. .

  In the present embodiment, when a region where a plurality of flux barriers 20a, 20b, and 20c arranged in a circumferential angle region of ¼ circumference is formed is a flux barrier forming region 200, the adjacent flux barrier forming region 200 is used. The gap is in the direction in which the magnetic flux easily flows, that is, the direction in which the flow of magnetic flux is not hindered by each flux barrier forming region 200. A virtual line along the direction in which the magnetic flux easily flows is referred to as a q-axis. A virtual line extending in a radial direction perpendicular to the q axis electrically and magnetically is referred to as a d axis. The d-axis is a line extending in the radial direction at the center between the flux barrier formation regions 200. The direction perpendicular to the d-axis is referred to as the longitudinal direction of the flux barrier 20. Each flux barrier 20 has a multilayer structure in the radial direction along the d-axis. In the case of the embodiment, the flux barrier 20 has a three-layer structure. In addition, one pole of the rotor core 15 means a region between adjacent q axes.

  Here, when the synchronous reluctance rotating electrical machine 1 is operated, the direction of the magnetic flux excited in the rotor core 15 is the d-axis direction, and the direction perpendicular to the d-axis electrically and magnetically is the q-axis. In the present embodiment, the d-axis is not limited to the case where the d-axis is perpendicular to the q-axis electrically and magnetically, but may have a certain angle width from the perpendicular angle, for example, a mechanical angle of about 10 degrees. . In the embodiment, the d-axis and the q-axis have a mechanical angle of 45 degrees.

  The individual flux barriers 20 are curved so as to have a substantially crescent shape or an arc shape that is convex inward in the radial direction, that is, in the direction of the rotation central axis O, so as to be located at the innermost radial direction at a position that intersects the d axis. Has been. Each flux barrier 20 has an arc shape that is curved so that both longitudinal ends thereof are located on the outer peripheral portion of the rotor core 15. Each flux barrier 20 is formed to have a curvature that is closer to both ends in the longitudinal direction in a direction along the q-axis and that is closer to the center in the longitudinal direction so as to be orthogonal to the d-axis.

  In the q-axis direction, thin portions between the longitudinal ends of each flux barrier 20 and the outer peripheral portion 15b of the rotor core 15 are bridges (hereinafter referred to as outer peripheral bridges) 26, respectively. In addition, bridges (hereinafter referred to as “center bridges”) 27, 28, and 29 that are configured to be bridged in places other than the end portions of the flux barriers 20 that are hollow portions are formed at the center of each flux barrier 20. ing. The flux barrier 20 is divided into a plurality by central bridges 27, 28, and 29. Since the 1st flux barrier 20a is constituted comparatively small, it is thought that the mechanical strength of rotor core 15 is not lowered so much. Therefore, although the central bridge is not provided in the embodiment, a configuration in which a central bridge is provided may be employed.

  The arc center common to each flux barrier 20 is a substantially point P located on the d-axis and in the vicinity of the outer peripheral portion 15b. The central bridge 27 is a central portion of the second flux barrier 20b and is located on a substantially d axis passing through the point P. The central bridge 27 is configured in a rectangular shape, and the direction in which the central bridge 27 extends, that is, the extending direction or the bridging direction of the central bridges 33, 34, 35, and 36 with respect to the second flux barrier 20b substantially coincides with the d-axis direction. It is configured.

  The bridge side portions 27a and 27a that constitute both side portions of the central bridge 27 are configured in a substantially straight shape, and the linear direction is configured to substantially coincide with the d-axis direction. The direction is substantially the direction of the point P, which is the center of the arc common to the flux barriers 20 formed to have a substantially crescent shape or a substantially arc shape.

  The central bridges 28 and 29 are provided in the third flux barrier 20c. The central bridges 28 and 29 are disposed at positions that divide the third flux barrier 20c into approximately three equal parts. If the lines passing through the point P and having an angle of plus or minus θ degrees with respect to the d axis are L1 and L2, the central bridges 28 and 29 are located on L1 and L2, respectively.

  The central bridges 28 and 29 are configured in a rectangular shape, and the extending direction or the bridging direction of the central bridges 28 and 29 in the third flux barrier 20c are configured to substantially coincide with the L1 and L2 directions, respectively. The bridge side portions 28a, 28a, 29a, 29a constituting both side portions of the central bridges 28 and 29 are configured in a substantially linear shape, and the linear directions are configured to substantially coincide with the L1 direction and the L2 direction. Yes.

  Therefore, the extending direction or the bridging direction of the central bridges 27, 28, 29 configured in a rectangular shape and the linear directions of the bridge side portions 27a, 28a, 29a configured in a substantially linear shape are configured in a substantially arc shape. Further, it is directed in the direction of a substantially point P that is the center of the arc common to the plurality of flux barriers 20. Further, the d-axis, L1, and L2 do not overlap. Therefore, none of the central bridges 27, 28, 29 are located on the same line.

According to the rotor core 15 according to the first embodiment, the following effects are obtained.
Central bridges 27, 28, and 29 are provided on the flux barrier 20. More specifically, a central bridge 27 is provided on the second flux barrier 20b, and central bridges 28 and 29 are provided on the third flux barrier 20c. Thereby, the mechanical strength of the flux barrier 20 formation area with low mechanical strength can be improved. Therefore, the mechanical strength of the rotor core 15 and the rotor 4 constituted thereby is improved, and deformation and breakage can be suppressed. Therefore, the mechanical strength of the synchronous reluctance rotating electrical machine 1 configured using the rotor 4 is improved, and breakage can be suppressed.

  Further, the central bridges 27, 28, 29 provided on the flux barrier 20 are located on the same straight line passing through the point P that is the intersection of the d-axis and the outer peripheral portion 15b (that is, on the d-axis, L1, L2). Not done. Therefore, since the magnetic paths formed by the central bridges 27, 28 and 29 are not located on the same straight line, the magnetic resistance of the rotor core 15 and the rotor 4 formed using this can be increased. Leakage magnetic flux from the central bridges 27, 28, 29 can be reduced. Therefore, it is possible to suppress a decrease in torque and power factor performance of the rotor 4 formed using the rotor core 15 and the synchronous reluctance rotating electrical machine 1 formed using the rotor 4.

  Also, if the central bridges 27, 28, 29 are locally arranged, the local mechanical strength of the flux barrier 20 forming region is strengthened, while the portion where the mechanical strength is weak is generated. Eventually, deformation and breakage occur due to this weak spot, so that the mechanical strength of the entire rotor core 15 cannot be improved. According to the configuration of the rotor core 15 according to the first embodiment, the central bridges 27, 28, and 29 are arranged substantially evenly distributed, so that the mechanical strength of the entire flux barrier 20 formation region is efficiently improved. Can be made. Accordingly, the deformation and breakage of the rotor core 15, the rotor 4, and the synchronous reluctance rotating electrical machine 1 can be suppressed, and the effect of improving the mechanical strength can be increased.

  As described above, according to the first embodiment, it is possible to provide the rotor core 15, the rotor 4, and the synchronous reluctance rotating electrical machine 1 using the same, which can suppress the decrease in the power factor while enhancing the mechanical strength. Can do.

(Second Embodiment)
Next, a second embodiment will be described with reference to FIG. FIG. 2 illustrates only the rotor steel plate 15a without the stator 3 of the synchronous reluctance rotating electrical machine 1.

  In the second embodiment, the rotor core 15 is provided with four layers of flux barriers 22 (22a, 22b, 22c, 22d). More specifically, four flux barriers 22 are provided in the order of flux barriers 22a, 22b, 22c, and 22d from the outer peripheral side of the rotor core 15 toward the radially inner side. Each flux barrier 22 has a crescent shape or an arc shape, and the common arc center is a point P. An outer peripheral bridge 26 is provided at the end of each flux barrier 22.

  Regions other than the flux barrier 22 (22a, 22b, 22c, 22d) are magnetic paths 23 (23a, 23b, 23c, 23d, 23e). The magnetic path 23 is formed between the flux barriers 22, between the outermost first flux barrier 23 a and the outer peripheral portion 15 b, and between the radially innermost fourth flux barrier 20 d and the through hole 16. Yes.

  Each flux barrier 22 is provided with a central bridge 30, 31, 32, 33, 34, 35, 36. As in the first embodiment, the outermost first flux barrier 22a is not provided with a central bridge. One central bridge 30 is provided at the center of the second flux barrier 22b located second from the outermost periphery. Two central bridges 31 and 32 are provided on the third flux barrier 22c third from the outermost periphery. Four central bridges 33, 34, 35, and 36 are provided in the fourth flux barrier 22d located fourth from the outermost periphery.

  In the rotor core 15, straight lines passing through the point P and having an angle of plus or minus θ degrees with respect to the d axis are denoted as Q1 and Q2. Further, straight lines passing through the point P and having an angle of plus or minus α degrees with respect to the d-axis are R1 and R2. Also, let S1 and S2 be straight lines passing through the point P and having an angle of plus or minus β degrees with respect to the d-axis. In this case, the relationship between the angles is θ <α <β.

  The central bridge 30 is a central portion of the second flux barrier 22b and is located substantially on the d axis. The central bridge 30 is configured in a rectangular shape, and the extending direction or the bridging direction of the central bridge 30 with respect to the second flux barrier 22b is configured to substantially coincide with the d-axis direction. The bridge side portions 30a, 30a constituting both side portions of the central bridge 30 are configured in a substantially linear shape, and the linear direction is configured to substantially coincide with the d-axis direction.

  The center bridges 31 and 32 are provided in the third flux barrier 22c. The central bridges 31 and 32 are disposed at positions that divide the third flux barrier 22c into approximately three equal parts. Central bridges 31 and 32 are located on R1 and R2, respectively.

  The central bridges 31 and 32 are configured in a rectangular shape, and the extending direction or the bridging direction of the central bridges 31 and 32 with respect to the third flux barrier 22c are configured to substantially coincide with the R1 and R2 directions, respectively. The bridge side portions 31a and 31a constituting both side portions of the central bridge 31 are configured in a substantially linear shape, and the linear direction is configured to substantially coincide with the R1 direction. The bridge side portions 32a and 32a constituting both side portions of the central bridge 32 are configured in a substantially linear shape, and the linear direction is configured to substantially coincide with the R2 direction.

  The central bridges 33, 34, 35, and 36 are disposed on the fourth flux barrier 22d. The central bridge 33 is located on S1, the central bridge 34 is located on Q1, the central bridge 35 is located on Q2, and the central bridge 36 is located on S2.

  The central bridges 33, 34, 35, and 36 are formed in a rectangular shape, and the extending direction or the bridging direction of the central bridges 33, 34, 35, and 36 with respect to the fourth flux barrier 22d is the S1, Q1, Q2, and S2 directions, respectively. It is comprised so that it may correspond substantially.

  The bridge side portions 33a and 33a constituting both side portions of the central bridge 33 are configured in a substantially linear shape, and the linear direction is configured to substantially coincide with the S1 direction. The bridge side portions 34a, 34a of the central bridge 34 are configured in a substantially linear shape, and the linear direction is configured to substantially coincide with the Q1 direction. The bridge side portions 35a, 35a constituting both side portions of the central bridge 35 are configured in a substantially linear shape, and the linear direction is configured to substantially coincide with the Q2 direction. The bridge side portions 36a, 36a constituting both side portions of the central bridge 36 are configured in a substantially linear shape, and the linear direction is configured to substantially coincide with the S2 direction.

  Therefore, the extending direction of the central bridges 30, 31, 32, 33, 34, 35, 36 configured in a rectangular shape, and the bridge side portions 30a, 31a, 32a, 33a, 34a, 35a configured in a substantially linear shape, The linear direction of 36a is directed to the direction of the substantially point P that is the center of the arc common to the flux barriers 20 configured in a substantially arc shape. Further, the d-axis, Q1, Q2, R1, R2, S1, and S2 do not overlap. Accordingly, none of the central bridges 30, 31, 32, 33, 34, 35, 36 are located on the same line.

  According to the second embodiment described above, the same effects as those of the first embodiment are obtained. Furthermore, the number of central bridges 30 increases as the flux barrier 22 is located closer to the inside in the radial direction. As for the number of the central bridges 30, one central bridge 30 is arranged in the second flux barrier 22 b located on the outermost periphery among the flux barriers 22 provided with the central bridge, and the central bridge 30 is the center of the flux barrier 22. It is arrange | positioned on d axis located in a part. Two central bridges 31 and 32 are disposed on the third flux barrier 22c located radially inward next to the second flux barrier 22b, so that the center distance of the third flux barrier 22c is avoided and the distance is substantially equal. Is arranged. Further, four central bridges 34 to 36 are arranged on the fourth flux barrier 22d located on the inner side in the next radial direction, and are arranged so as to have a substantially equal distance while avoiding the central arrangement of the fourth flux barrier 22d. Yes.

  As described above, the number of the central bridges 30 arranged on the flux barrier 22 is increased as the distance from the outermost periphery is increased, that is, the inner side in the radial direction is approached. An even number of central bridges 30 are arranged on the flux barrier 22 (in this case, flux barriers 22c and 22d) located on the radially inner side of 22b). Thereby, it is possible to avoid the central bridge 30 being arranged on the same straight line while improving the mechanical strength of the stator 3. Thereby, since the magnetic path formed by the central bridges 30 to 36 is not located on the same straight line, the magnetic resistance of the rotor core 15, that is, the rotor 4 formed using this, can be increased. Leakage magnetic flux from the bridges 30 to 36 can be reduced. Therefore, the torque and power factor performance of the rotor 4 formed using the rotor core 15 and the synchronous reluctance rotating electrical machine 1 formed using the rotor 4 can be improved.

  As mentioned above, although several embodiment of this invention was described, these embodiment is shown as an example and is not intending limiting the range of invention. These novel embodiments can be implemented in various other forms, and various omissions, replacements, and changes can be made without departing from the scope of the invention. These embodiments and modifications thereof are included in the scope and gist of the invention, and are included in the invention described in the claims and the equivalents thereof.

  DESCRIPTION OF SYMBOLS 1 ... Synchronous reluctance rotary electric machine, 3 ... Stator, 4 ... Rotor, 10 ... Stator iron core, 15 ... Rotor iron core, 15a ... Rotor steel plate, 15b ... Outer peripheral part, 20, 20a, 20b, 20c, 22, 22a, 22b, 22c, 22d ... flux barrier, 26 ... end bridge, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36 ... central bridge, 27a, 28a, 29a, 30a, 31a, 32a, 33a, 34a, 35a, 36a ... Bridge side

Claims (8)

Multiple flux barriers;
One or more bridges provided on at least one of the plurality of flux barriers,
The flux barrier is a hollow portion configured in an arc shape having a common arc center in the vicinity of the outer peripheral portion thereof,
The bridge is arranged so as to crosslink at a place other than the end of the flux barrier,
The bridge is arranged not to be located on the same straight line passing through the arc center.
Rotor core.   The rotor core according to claim 1, wherein the bridge is formed in a substantially rectangular shape, and an extending direction thereof is directed to the center of the arc.   The rotor core according to claim 1, wherein the bridge is configured in a substantially rectangular shape, and a direction of a straight line forming a side portion thereof is directed to the center of the arc.   One bridge is formed in the outermost flux barrier among the flux barriers in which the bridge is formed, and an even number of bridges are formed in the flux barrier positioned radially inward of the outermost flux barrier. Item 4. The rotor core according to any one of Items 1 to 3.   The bridge formed on the outermost flux barrier is formed at the center of the outermost flux barrier, and the bridge formed on the flux barrier located radially inside the outermost barrier is a flux barrier. The rotor core according to claim 4, wherein the rotor core is not formed at the center of the rotor core.   The rotor core according to claim 4 or 5, wherein the number of bridges provided in the flux barrier increases as the flux barrier is positioned radially inward.   A rotor constituted by the rotor core according to claim 1.   The synchronous reluctance rotary electric machine comprised using the rotor of Claim 7.

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