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CN-122029726-A - Rotor and rotating electrical machine

CN122029726ACN 122029726 ACN122029726 ACN 122029726ACN-122029726-A

Abstract

According to an embodiment, a rotor (100) is provided with a plurality of permanent magnets (130) and a rotor core (120) that are arranged symmetrically with respect to a rotor shaft (110) about an M axis. The rotor core (120) is formed by stacking a plurality of electromagnetic steel plates in an M-axis overlapping manner, and has a nonmagnetic region which communicates the outer peripheral surface (120 x) with the permanent magnets (130), wherein the electromagnetic steel plates are equally arranged with a plurality of magnetic poles (101) in the circumferential direction, and the magnetic poles (101) have a magnetic flux barrier band which is formed to be approximately convex toward the rotation center axis CL and is communicated with the outer peripheral surface, and which comprises a region for accommodating the permanent magnets (130), the nonmagnetic region and a bridge. In a relationship of the first and second magnetic flux barriers (122, 126) as two nonmagnetic regions, when the circumferential angle θ d1 is larger than the circumferential angle θ d2 , the circumferential angle θ q1 is larger than the circumferential angle θ q2 . When the predetermined magnetic pole 101 is observed, the adjacent magnetic pole has a shape inverted with respect to the M-axis of the predetermined magnetic pole.

Inventors

  • MAKINO HIROAKI
  • Sen Dajie
  • TERADA KEISUKE

Assignees

  • 株式会社东芝

Dates

Publication Date
20260512
Application Date
20231031

Claims (8)

  1. 1. A rotor, comprising: a rotor shaft extending in an axial direction of the rotation center shaft; A plurality of permanent magnets extending in the axial direction and arranged in line symmetry with respect to an M-axis extending perpendicularly from the rotation center axis when viewed in a cross section perpendicular to the rotation center axis, and A rotor core formed by stacking a plurality of electromagnetic steel plates mounted on the radial outer side of the rotor shaft so as to overlap with each other in the M-axis direction when viewed in the axial direction, the electromagnetic steel plates having a plurality of magnetic poles arranged equally in the circumferential direction, the magnetic poles having magnetic flux barrier strips each including a region for accommodating the permanent magnet, a nonmagnetic region, and a bridge, the magnetic flux barrier strips being formed in a substantially convex shape toward the rotation center axis and extending to the outer peripheral surface, the rotor core having the nonmagnetic region for causing the outer peripheral surface to communicate with the permanent magnet, The magnetic poles are disposed adjacent to an outer core portion in a radial direction of the magnetic flux barrier belt, an inner core portion is disposed adjacent to an inner side in a radial direction of the magnetic flux barrier belt, one of boundary points between an outer edge of the outer core portion forming the outer peripheral surface of the rotor core and an outer edge facing the nonmagnetic region, which is distant from the M axis, is defined as a boundary point P 11 , one of boundary points between an outer edge of the outer core portion forming the rotor core and an outer edge facing the nonmagnetic region, which is close to the M axis, is defined as a boundary point P 12 , one of boundary points between an outer edge of the outer peripheral surface of the inner core portion forming the outer peripheral surface of the rotor core and an outer edge facing the nonmagnetic region, which is close to the boundary point P 11 , is defined as a boundary point P 22 , which is close to the boundary point P 21 , a circumferential angle θ d1 formed by a straight line connecting the boundary point P 11 and the rotation center axis and the M axis is defined as a circumferential angle θ d1 , a straight line connecting the boundary point P 12 and the rotation center axis and a circumferential angle M axis is defined as a boundary point P3235 and a circumferential angle M axis is defined by a circumferential angle M32, and a circumferential angle between the rotation center axis and the rotation center axis is defined as a boundary point P3276 and a circumferential angle is defined by the rotation axis When a circumferential angle formed by a straight line connecting the boundary point P 22 and the rotation center axis and the M axis is set as a circumferential angle θ q2 , when the circumferential angle θ d1 is larger than the circumferential angle θ d2 , the circumferential angle θ q1 is larger than the circumferential angle θ q2 , When a predetermined magnetic pole is observed, adjacent magnetic poles have a shape inverted with respect to the M-axis of the predetermined magnetic pole.
  2. 2. The rotor of claim 1, wherein the rotor comprises a plurality of rotor blades, In the magnetic flux barrier band, a first bridge and a second bridge are formed across the M axis, The first bridge is spaced from the M-axis more than the second bridge or the first bridge has a width greater than the second bridge.
  3. 3. The rotor of claim 1, wherein the rotor comprises a plurality of rotor blades, The rotor is in a shape that satisfies at least one of a shape of the outer edge facing the nonmagnetic region including the boundary point P 11 and a shape of the outer edge facing the nonmagnetic region including the boundary point P 21 , or a shape of the outer edge facing the nonmagnetic region including the boundary point P 12 and a shape of the outer edge facing the nonmagnetic region including the boundary point P 22 .
  4. 4. The rotor of claim 1, wherein the rotor comprises a plurality of rotor blades, The rotor core has a portion where a first electromagnetic steel plate and a second electromagnetic steel plate are adjacently overlapped in the axial direction, the first electromagnetic steel plate is circumferentially arranged with only the predetermined magnetic pole, and the second electromagnetic steel plate is circumferentially arranged with only a magnetic pole having a shape inverted with respect to the M-axis of the predetermined magnetic pole.
  5. 5. The rotor of claim 1, wherein the rotor comprises a plurality of rotor blades, The rotor core includes a third electromagnetic steel plate in which the predetermined magnetic poles and the magnetic poles having a shape inverted with respect to the M-axis of the predetermined magnetic poles are alternately arranged in the circumferential direction.
  6. 6. The rotor as set forth in claim 5, wherein, The rotor core has a portion where the third electromagnetic steel plate and a fourth electromagnetic steel plate overlap adjacently in the axial direction, and the fourth electromagnetic steel plate is formed by shifting the third electromagnetic steel plate in the circumferential direction by a mechanical angle that the magnetic poles of the third electromagnetic steel plate have.
  7. 7. A rotating electrical machine, characterized by comprising: a rotor as claimed in claim 4 to 6, and The stator includes a stator core formed to surround the rotor core with a gap therebetween on a radial outer side of the rotor core, and a stator winding having portions respectively received in a plurality of stator slots formed between a plurality of stator teeth formed in the stator core, In a cross section perpendicular to the rotation center axis, A center line of a non-magnetic region formed so as to communicate the stator slots with an inner peripheral surface of the stator core in a circumferential direction when viewed on the inner peripheral surface is located on the same line as the center lines of the plurality of stator slots in the circumferential direction.
  8. 8. A rotating electrical machine, characterized by comprising: The rotor of claim 5 or 6, and The stator includes a stator core formed to surround the rotor core with a gap therebetween on a radial outer side of the rotor core, and a stator winding having portions respectively received in a plurality of stator slots formed between a plurality of stator teeth formed in the stator core, In a cross section perpendicular to the rotation center axis, The center lines of the non-magnetic regions formed so as to communicate the stator slots with the inner peripheral surface of the stator core in the circumferential direction are offset in the same direction with respect to the center lines of the plurality of stator slots in the circumferential direction when viewed on the inner peripheral surface, and are offset in the direction of the boundary point P 21 of the rotor core in the same cross section.

Description

Rotor and rotating electrical machine Technical Field The present invention relates to a rotor and a rotating electrical machine. Background As a permanent magnet motor, a so-called buried magnet motor is known in which permanent magnets are arranged inside an iron core. The embedded magnet type motor includes a stator in which a stator coil is disposed on a substantially cylindrical stator core having a plurality of stator slots, and a permanent magnet rotor provided radially inward of the stator and rotatably provided with respect to the stator. The permanent magnet rotor has a rotor shaft rotatably provided around a rotation center axis and a rotor core externally fitted and fixed to the rotor shaft. The rotor core has a number of magnet accommodating holes corresponding to the number of poles. The magnet housing hole houses a permanent magnet. With such a configuration, in the permanent magnet motor, when current is supplied to the stator coil, a rotational torque is applied to the rotor by interaction between magnetic flux generated on the primary side (stator side) and magnetic flux of the permanent magnet in the rotor. Prior art literature Patent literature Patent document 1 Japanese patent No. 3769943 Patent document 2 Japanese patent application laid-open No. 2001-186699 Patent document 3 Japanese patent No. 3938726 Patent document 4 Japanese patent application laid-open No. 2012-29351 Disclosure of Invention Technical problem to be solved by the invention In general, since there are magnetic irregularities between the rotor and the stator due to the presence of the stator grooves, torque irregularities (torque pulsation) that increase or decrease in the value of the rotational torque are generated in the rotor due to the irregularities, and this causes mechanical vibration and noise during rotation. As an effective means for reducing torque ripple, there is known a method of disposing electromagnetic steel plates at equal intervals in a circumferential direction, which is a rotation direction, when laminating electromagnetic steel plates of a stator or a rotor in an axial direction, that is, a method of performing so-called skew. However, in this case, there is a problem that the man-hour at the time of manufacture increases and the number of parts increases. Therefore, as means for reducing torque ripple, several other examples are known. Fig. 13 is a cross-sectional view showing a schematic example of a conventional rotor core 2. Fig. 14 is a schematic layout diagram showing a lamination of the conventional rotor core structure. In the pattern of the rotor core 2 shown in fig. 13, each magnetic pole is symmetrical in the circumferential direction. As shown in fig. 14, the laminated portions 2p of the symmetrical pattern of the respective magnetic poles and the laminated portions 2r formed by shifting the laminated portions 2p in the circumferential direction are stacked in the axial direction. Thus, by stacking in the axial direction with a shift in the circumferential direction, a so-called skew effect of reducing torque ripple can be obtained. In such skew of the rotor, there is a problem in that a magnet embedded in the rotor is skewed, and a demagnetizing field is concentrated at an end portion of the magnet at a portion adjacent to a different lamination portion, thereby demagnetizing the portion. In addition, a method is known in which torque ripple generated in each magnetic pole is canceled by making the shapes of the permanent magnet and the housing hole asymmetric for each magnetic pole. Fig. 15 is a partial cross-sectional view of a first pattern portion illustrating a second example of the configuration of a conventional rotor core 2. Fig. 15 shows the pattern in one pole. The two permanent magnets 130 of the same shape are arranged symmetrically to each other about the central axis. Further, a first magnet accommodating hole 2a and a second magnet accommodating hole 2b are formed on both sides of the center shaft. In addition, the first magnetic flux barriers 2f that communicate the first magnet housing holes 2a with the outer circumferential surface 2x of the rotor core 2 and the second magnetic flux barriers 2g that communicate the second magnet housing holes 2b with the outer circumferential surface 2x of the rotor core 2 are different from each other. The shape of the inner core portion 2d, which is a portion radially inward of the first magnet housing hole 2a and the second magnet housing hole 2b, is symmetrical about the central axis. On the other hand, the shape of the outer core part 2c, which is a portion radially outside the first magnet housing hole 2a and the second magnet housing hole 2b, is asymmetric about the central axis. The torque ripple is canceled by using a second pattern portion that is formed by reversing the first pattern portion in the forward and reverse directions. However, in the case of a motor using reluctance torque, there is a problem in that the ske