JP2013229986A - Magnetizer for magnetizing rotor subjected to row-to-row skew, and manufacturing method of rotor for motor utilizing such magnetizer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a magnetizer for magnetizing a rotor subjected to row-to-row skew, accurately according to the shape of a magnetic body.SOLUTION: In the magnetizer, a slot in which a winding is wound has at least two parallel parts extending in parallel with the central axis of a core in the magnetizer and formed while being offset each other, and a ramp connecting these parallel parts and extending to incline against the central axis. With such a magnetizer, accurate magnetization is ensured according to the outer shape of a magnetic body being attached to a rotor subjected to row-to-row skew.

Description

  The present invention relates to a magnetizing apparatus for magnetizing a stage skewed rotor and a method for manufacturing a rotor for an electric motor using such a magnetizing apparatus.

  It is known that cogging torque or torque ripple in which the magnitude of torque fluctuates during rotation in a rotary motor. On the other hand, it is possible to reduce the influence of cogging torque or torque ripple by using a rotor having a plurality of stages of magnetic poles formed so as to be shifted stepwise around the rotation axis, that is, a so-called stage skewed rotor. It has been proposed (see Patent Document 1 and Patent Document 2). If the step skewed rotor is used, the position where the cogging torque or torque ripple is generated is dispersed, and as a result, the torque is approximately leveled, so that the electric motor can be rotated more smoothly.

  As a method of forming the magnetic poles in the rotor, a method of assembling a magnetic material pre-magnetized in the rotor block, and a method of assembling the rotor after assembling the magnetic material before magnetization in the rotor block and magnetizing the magnetic material There is. In the former method, since the magnetized magnetic body is subjected to the action of magnetic force, it is difficult to accurately position the magnetic body at a desired position of the rotor block. On the other hand, the latter method has a problem that it is difficult to accurately magnetize the magnetic body assembled to the step skewed rotor block.

JP 2009-33927 A JP 2011-166951 A

  SUMMARY OF THE INVENTION An object of the present invention is to provide a magnetizing device for magnetizing more accurately according to the shape of a magnetic body in a step skewed rotor.

  According to a first aspect of the present invention, there is provided a magnetizing apparatus that magnetizes a step-skewed rotor, wherein a cylindrical iron core that can receive the rotor concentrically and a magnetizing the rotor are performed. A plurality of slots formed at predetermined intervals along the peripheral surface of the iron core facing the rotor, and windings wound around the slots, each slot having the iron core And at least two parallel portions formed parallel to the central axis and offset from each other, and connected to the at least two parallel portions and inclined with respect to the central axis of the iron core. There is provided a magnetizing device having an inclined portion extending.

  According to a second aspect of the present invention, in the first aspect, the inclined portion is curved at least at a boundary between the parallel portion and the parallel portion so that the parallel portion and the inclined portion are smoothly connected. A magnetizing device is provided.

  According to the third aspect of the present invention, there is provided a method for manufacturing a rotor for an electric motor, wherein the rotor is magnetized using the magnetizing device according to the first or second aspect.

  According to the first aspect, the slot of the magnetizing device is formed by the parallel portion and the inclined portion. That is, in this magnetizing apparatus, the shape of the slot is determined in accordance with the shape of the magnetic body arranged on the step skewed rotor. If the winding wound in such a slot is energized, the magnetic field generation range corresponds to the shape of the magnetic body of the rotor. Thereby, the magnetic body can be magnetized accurately according to the shape of the magnetic body. Therefore, the rotation of the rotor is further smoothed.

  According to the second invention, since the space between the parallel portion and the inclined portion of the slot is curved, the winding can be easily wound to improve the working efficiency and prevent the winding from being damaged. .

  According to the third aspect of the invention, it is possible to easily manufacture an electric motor that can rotate smoothly without requiring additional special equipment.

It is a perspective view which shows the magnetizing apparatus which concerns on one Embodiment of this invention. It is a general | schematic expanded view which expands and shows the magnetizing apparatus of FIG. 1 along the circumferential direction. It is a schematic sectional drawing explaining the aspect magnetized to a rotor using the magnetizing apparatus of FIG. FIG. 2 is a schematic development view conceptually showing an arrangement of magnetic pole portions when the rotor is magnetized using the magnetizing apparatus of FIG. 1. It is a general | schematic expanded view which expands and shows the magnetizing apparatus which concerns on another embodiment of this invention along the circumferential direction. It is a schematic perspective view which shows the rotor of a rotary electric motor. It is a general | schematic expanded view which expand | deploys and shows the magnetic pole part of a rotor along the circumferential direction. It is a general | schematic expanded view which expands and shows the magnetizing apparatus which concerns on a prior art along the circumferential direction. FIG. 9 is a schematic development view conceptually showing an arrangement of magnetic pole portions when the rotor is magnetized using the magnetizing apparatus of FIG. 8.

  Embodiments of the present invention will be described below with reference to the accompanying drawings. It should be noted that each component of the illustrated embodiment may be described in a different scale from a practical scale to aid in understanding the present invention.

  FIG. 1 is a perspective view showing a magnetizing apparatus 10 according to an embodiment of the present invention. The magnetizing device 10 is used for magnetizing a step skewed rotor (described later). The magnetizing device 10 includes a cylindrical iron core 12 and a plurality of magnetized portions 14 formed at predetermined intervals along the circumferential direction Y of the iron core 12.

  Between adjacent magnetized portions 14, a slot 20 of a groove extending substantially along the direction of the central axis X is formed. These slots 20 extend at predetermined intervals on the inner peripheral surface 12 a of the iron core 12. In other words, the outer shape of the magnetized portion 14 is defined by the inner peripheral surface 12 a of the iron core 12 and the side walls of the slots 20. Although not shown in FIG. 1 for the sake of clarity, a winding is wound around the slot 20 as will be described later.

  As can be seen from FIG. 1, the magnetized portion 14 does not have a uniform shape in a direction parallel to the central axis X of the iron core 12, and the upper magnetized portion 14 a and the lower magnetized portion 14 b are circumferential. They are formed to be offset from each other in Y. That is, both side edges of the upper magnetized portion 14a and both side edges of the lower magnetized portion 14b extend in parallel with each other while being displaced in the circumferential direction Y. An intermediate magnetized portion 14c is formed between the upper magnetized portion 14a and the lower magnetized portion 14b. The side edges of the intermediate magnetized portion 14c are inclined with respect to the side edges of the upper magnetized portion 14a and the lower magnetized portion 14b, that is, with respect to the central axis X. The upper magnetized portion 14a and the lower magnetized portion 14b are coupled to each other by the intermediate magnetized portion 14c. The upper magnetized portion 14a, the intermediate magnetized portion 14c, and the lower magnetized portion 14b are integrally formed continuously.

  It should be noted that the terms “upper” and “lower” used in the present specification merely indicate a relative positional relationship, and are merely used for convenience to describe the present invention in accordance with the illustrated state. Note that there is no.

  FIG. 2 is a schematic developed view showing the magnetizing device 10 of FIG. 1 along the circumferential direction Y in order to explain the structure of the inner periphery side of the wearing device 10. In FIG. 2, the slot 20 is schematically represented as a boundary line between adjacent magnetized portions 14. That is, FIG. 2 is shown ignoring the width of the slot 20 for clarity.

  The slot 20 includes a first parallel portion 20a extending parallel to the central axis X of the iron core 12, and a circumference parallel to the central axis X of the iron core 12 and relative to the first parallel portion 20a. The second parallel portion 20b extending so as to be offset in the direction Y, and the inclined portion extending inclined with respect to the central axis X between the first parallel portion 20a and the second parallel portion 20b 20c.

  A winding (not shown) is wound around the slot 20 in order to magnetize a magnetic body assembled to a rotor described later. In FIG. 2, the letters “N” or “S” written on the magnetized portion 14 conceptually represent the magnetic poles of the magnetic circuit generated by energizing the windings wound around the slots 20. Yes. The inclination angle θ of the inclined portion 20c with respect to the central axis X is preferably set to the largest possible angle (however, θ <90 degrees) within a range in which the winding can be wound around the entire slot 20.

  Next, the rotor 50 of the rotary motor magnetized by the magnetizing device 10 will be described with reference to FIGS. FIG. 6 is a schematic perspective view showing the rotor 50 of the rotary electric motor.

  The rotor 50 includes a shaft 52, a cylindrical rotor block 54 coupled to the outer peripheral surface of the shaft 52 by, for example, an interference fit, and a plurality of, for example, two magnetic pole arrays 56, 58 formed in the circumferential direction of the rotor block 54. And. The first magnetic pole row 56 further includes a plurality of magnetic pole portions 56a to 56h. The second magnetic pole row 58 is formed adjacent to the first magnetic pole row 56 in the direction of the central axis X, and further includes a plurality of magnetic pole portions 58a to 58h. As shown in FIG. 6, the first magnetic pole array 56 and the second magnetic pole array 58 are arranged so as to be offset from each other in the circumferential direction Y. That is, the rotor 50 is step skewed. In the magnetic pole portions 56a to 56h and 58a to 58h of the magnetic pole rows 56 and 58, letters “N” or “S” representing the magnetization direction are written.

  FIG. 7 is a schematic development view showing the magnetic pole portions 56a to 56h and 58a to 58h of the rotor 50 developed along the circumferential direction. Referring to FIG. 7, it can be seen that the first magnetic pole row 56 is composed of eight magnetic pole portions 56a to 56h, and the second magnetic pole row 58 is composed of eight magnetic pole portions 58a to 58h. As already described with reference to FIG. 6, the first magnetic pole array 56 and the second magnetic pole array 58 are arranged offset from each other in the circumferential direction Y. For example, the magnetic pole portion 56a in the first magnetic pole row 56 having the same magnetic pole and the magnetic pole portion 58a in the second magnetic pole row 58 are arranged in an offset state.

  Next, a method for magnetizing the rotor 50 skewed as shown in FIGS. 6 and 7 using the above-described magnetizing apparatus 10 will be described with reference to FIG. FIG. 3 is a schematic cross-sectional view illustrating a mode in which the rotor 50 is magnetized using the magnetizing device 10. The magnetizing device 10 and the rotor 50 are fixed by a jig so that the magnetizing device 10 has a predetermined positional relationship so as to receive the rotor 50 substantially concentrically. Further, the magnetic pole portions 56a to 56h formed of an arbitrary magnetic material are arranged so as to face the winding 30 of the magnetizing device 10 (in FIG. 3, the magnetic pole portion 58a of the second magnetic pole row 58). ~ 58h is not visible).

  In FIG. 3, the winding 30 wound around the magnetized portion 14 through the slot 20 is conceptually represented. Among the symbols representing the winding 30, the winding 30 in which a black dot is drawn on a circle means that a current flows from the paper surface toward the viewer. In addition, the winding 30 in which an X is drawn in a circle means that a current flows in the depth direction of the paper surface away from the viewer. As shown in FIG. 3, the windings 30 are alternately wound in the opposite direction along the circumferential direction Y. Thereby, in the magnetized portion 14, a magnetic field in the opposite direction is generated along the circumferential direction Y alternately. When the winding 30 in such a state is energized, a magnetic circuit passing through the magnetized portion 14 and the magnetic pole portions 56a to 56h is generated, and the magnetic pole portions 56a to 56h, which are magnetic bodies, are magnetized. Since the windings 30 are alternately wound in opposite directions as described above, S poles and N poles are alternately formed in the magnetic pole portions 56a to 56h as shown in FIGS.

  FIG. 4 is a schematic development view conceptually showing the arrangement of the magnetic pole portions 56a to 56h and 58a to 58h when the rotor 50 is magnetized using the magnetizing apparatus 10 of FIG. The solid line in FIG. 4 represents the range of the same magnetic pole magnetized by the magnetizing device 10. The broken lines in FIG. 4 represent the physical outline of the magnetic body on which the magnetic pole portions 56a to 56h and 58a to 58h are formed.

  As apparent from FIG. 4, according to the magnetizing apparatus 10 according to the present embodiment, the physical shapes of the magnetic pole portions 56a to 56h and 58a to 58h can be made to substantially coincide with the actual magnetizing range. . Although there is a portion where a magnetic pole opposite to the magnetic pole to be formed is formed at a boundary portion between the first magnetic pole row 56 and the second magnetic pole row 58, the inclination of the slot 20 of the magnetizing device 10 is inclined. By forming the inclination angle θ of the portion 20c closer to 90 degrees, the formation range of such an opposite magnetic pole can be further reduced.

  Next, for comparison, an example in which the rotor 50 is magnetized using the prior art magnetizing device 110 will be described. FIG. 8 is a schematic development view showing the magnetizing device 110 according to the prior art developed along the circumferential direction. The slot 120 of the magnetizing device 110 extends substantially linearly so as to continuously incline with respect to the direction of the central axis X. Corresponding to the shape of the slot 120, the side edge of the magnetized portion 114 also extends in a substantially linearly inclined manner. FIG. 9 is a schematic development view conceptually showing the arrangement of the magnetic pole portions 156a to 156h and 158a to 158h when the rotor 50 is magnetized using the magnetizing device 110 of FIG. FIG. 9 is a view corresponding to FIG. 2 related to the magnetizing apparatus 10 according to the present embodiment. Similar to FIG. 4, the solid line in FIG. 9 represents the range of the same magnetic pole that is actually magnetized by the magnetizing device 110 according to the prior art. The broken lines in FIG. 9 represent the physical outline of the magnetic body on which the magnetic pole portions 156a to 156h and 158a to 158h are formed. As apparent from comparison with FIG. 4, the magnetic pole portions 156a to 156h and 158a to 158h formed using the conventional technique have a large range that is not accurately magnetized. If such a rotor is used, for example, torque fluctuation may occur, and the rotation of the electric motor becomes unstable.

  Next, a magnetizing apparatus 10 'according to another embodiment of the present invention different from the above-described embodiment will be described with reference to FIG. The magnetizing device 10 ′ has substantially the same configuration as the magnetizing device 10 of FIG. 1 described above, and only the shape of the slot 40 and the magnetized portion 42 is different from the magnetizing device 10. Therefore, in the following description, the description overlapping with the contents already described in relation to the magnetizing device 10 will be omitted as appropriate.

  FIG. 5 is a schematic development view showing the magnetizing device 10 ′ developed along the circumferential direction. The slot 40 has a first parallel portion 40a and a second parallel portion 40b extending in parallel to the central axis X. The slot 40 further includes an inclined portion 40c extending obliquely with respect to the central axis X between the first parallel portion 40a and the second parallel portion 40b. As shown in FIG. 5, the inclined portion 40c is formed with a curved portion 40d at the boundary between the first parallel portion 40a and the second parallel portion 40b.

  According to the magnetizing apparatus 10 ′ having such a configuration, the first parallel part 40 a and the second parallel part 40 b are more smoothly connected by the inclined part 40 c. Therefore, the process of winding the winding around the slot 40 is facilitated. In addition, since the corner is not formed in the slot 40, the winding can be prevented from being bent with the corner of the slot 40 as a fulcrum. Therefore, damage to the winding can be prevented. Although the example in which the curved portion 40d is formed at the boundary between the first parallel portion 40a and the second parallel portion 40b has been described, the entire inclined portion 40c may be curved.

  According to the magnetizing apparatuses 10 and 10 'according to the present invention as described above, the magnetic body can be magnetized accurately according to the physical shape of the magnetic body assembled to the step skewed rotor. Therefore, the rotation of the rotor is smoothed. Furthermore, if the skew angles are substantially the same, the magnetic pole portions 56a to 56h and 58a to 58h can be applied to another type of rotor having different dimensions in the direction of the central axis X. Therefore, it is possible to provide the magnetizing devices 10 and 10 'having high versatility. As described above, according to the magnetizing device 10.10 'according to the present invention, it is not necessary to use a plurality of types of magnetizing devices in combination, and it is possible to accurately magnetize the stage skewed rotor. Therefore, manufacturing equipment can be simplified.

  The embodiments described above with reference to the drawings are only some of the possible examples of the present invention. For example, the magnetizing devices 10 and 10 ′ according to the above-described embodiment are applied to a rotor that is step-skewed at one place, that is, a rotor having two-stage magnetic pole portions including a first magnetic pole row and a second magnetic pole row. However, the present invention may be applied to a rotor having three or more magnetic pole portions that are skewed at two or more locations. In this case, the parallel part of the slot is formed in a number equal to the number of steps of the magnetic pole part. Similar to the above-described embodiment, an inclined portion that is inclined with respect to the central axis X is formed between the parallel portions of the slot.

DESCRIPTION OF SYMBOLS 10 Magnetizing apparatus 10 'Magnetizing apparatus 12 Iron core 12a Inner peripheral surface (peripheral surface)
14 Magnetized portion 20 Slot 30 Winding 20a First parallel portion (parallel portion)
20b 2nd parallel part (parallel part)
20c Inclined portion 40 Slot 40a First parallel portion (parallel portion)
40b 2nd parallel part (parallel part)
40c Inclined portion 40d Curved portion 42 Magnetized portion 50 Rotor X Center axis Y Circumferential direction

Claims (3)

A magnetizing device for magnetizing a step skewed rotor,
A cylindrical iron core that can receive the rotor concentrically;
A plurality of slots formed at predetermined intervals along the peripheral surface of the iron core that faces the rotor when the rotor is magnetized;
A winding wound around the slot,
Each of the slots extends parallel to the central axis of the core and is offset from each other, and connects the at least two parallel portions to each other. And a sloping portion extending obliquely with respect to the central axis of the magnetizing device.   The magnetizing device according to claim 1, wherein the inclined portion is curved at least at a boundary between the parallel portion and the parallel portion so that the parallel portion and the inclined portion are smoothly connected.   A method for manufacturing a rotor for an electric motor, wherein the rotor is magnetized using the magnetizing apparatus according to claim 1.

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