JP2019193429A - Method for magnetizing rotary electric machine and magnetization yoke - Google Patents

Abstract

PROBLEM TO BE SOLVED: To suppress the deviation of the magnetized position in the longitudinal direction even if there is variation in the thickness of a rotor made of a steel plate laminate, and to suppress the production variation of the rotational vibration of the motor. SOLUTION: The magnets are composed of a rotor core 2b and magnets 2c attached to the outer periphery of the rotor core, and the magnets are arranged in a plurality of rows along the axial direction, and the magnets axially adjacent to each other are displaced in a stepwise manner in the rotational direction. In a method of magnetizing a magnet in a rotating electric machine including a rotor 2 having a stepped skew structure and a stator arranged on the outer peripheral side of the rotor, a boundary position of magnetic poles of the magnetizing yoke core 3a is oblique to the axial direction. Magnetization is performed using the magnetizing yoke 3B having a continuous skew structure that is deviated to. When the magnetizing yoke is set on the magnet for magnetizing, the magnet is magnetized with the height direction positioning surface 6b of the rotor and the step 2d of the step skew structure aligned. [Selection diagram] Fig. 13

Description

  The present invention relates to a magnetizing method and a magnetizing yoke for a rotating electrical machine, and more particularly to magnetizing a rotor magnet having a step skew structure installed in a brushless motor or the like using a magnetizing yoke having a continuous skew structure. The present invention relates to a magnetizing method and a magnetizing yoke for a suitable rotating electric machine.

  Conventionally, a rotor skew structure has been known as a design method for suppressing rotational vibration (torque ripple, cogging torque) of a rotating electrical machine. This skew structure is a stepwise arrangement in which the rotor arranged adjacent to the axial direction is stepped in the rotational direction. And a continuous skew structure in which the boundary position of the magnetic pole is inclined with respect to the axial direction.

  For a rotor magnet of a brushless motor, a step skew structure in which the rotor magnets arranged adjacent to each other in the axial direction are shifted stepwise in the rotation direction is more common. A child is used.

  For example, Patent Document 1 can be cited as a prior art document that achieves both torque ripple reduction and cogging torque reduction in a brushless motor.

  This patent document 1 is a brushless motor including a rotor having 2n magnetic poles and a stator having 3n slots, and a plurality of segment magnets are arranged in the circumferential direction while being shifted in the circumferential direction. In addition to forming a step cue structure, the stator is formed with a skew (angle θs) having a twist direction different from that of the rotor, and the magnet skew angle θm is set to an electrical angle of 60 ° or less. The skew angle θskew = θs + θm, which is the sum of the skew angle of the rotor and the rotor, is set to an electrical angle of 60 to 84 °.

JP 2009-213283 A

  However, in a brushless motor, if the rotor is designed with a two-stage skew structure and the magnetizing yoke is designed with a continuous skew structure, a part of the rotor magnet is removed from the corresponding pole of the magnetizing yoke. That is, when a rotor having a two-stage skew structure is magnetized by a magnetized yoke having a continuous skew structure, a region magnetized in the direction opposite to the magnetic pole is locally generated.

  In this state, in order to increase the sensitivity of the phase shift between the rotor and the magnetized yoke with respect to torque ripple and cogging torque, it is necessary to control the phase shift between the rotor and the magnetized yoke in order to suppress rotational vibration.

  In Patent Document 1 described above, in order to achieve both torque ripple reduction and cogging torque reduction, it is described that the skew angle is defined. However, the sensitivity of the phase shift between the rotor and the magnetized yoke with respect to torque ripple or cogging torque is increased. For this reason, there is no description at all about suppressing rotational vibration by controlling the phase shift between the rotor and the magnetized yoke.

  The present invention has been made in view of the above points, and the object of the present invention is that even if there is variation in the thickness of the rotor made of the steel sheet laminate, it is possible to suppress the longitudinal magnetization position deviation, An object of the present invention is to provide a magnetizing method and a magnetizing yoke for a rotating electrical machine that can suppress manufacturing variations in rotational vibration of a motor.

  In order to achieve the above object, a magnetizing method for a rotating electrical machine according to the present invention comprises a rotor core and a magnet attached to the outer periphery of the rotor core, and is arranged in a plurality of rows along the axial direction. The magnet in a rotating electrical machine comprising a rotor having a step skew structure in which the magnets adjacent to each other in a rotational direction are shifted stepwise in the rotation direction, and a stator disposed on the outer peripheral side of the rotor, When magnetizing using a magnet having a continuous skew structure in which the boundary position is obliquely shifted with respect to the axial direction, when the magnetizing yoke is set on the magnet for magnetizing, the rotor The magnet is magnetized in a state where the height direction positioning surface and the step of the step skew structure coincide with each other.

  In order to achieve the above object, the magnetized yoke of the present invention comprises a rotor core and a magnet attached to the outer periphery of the rotor core, and is arranged in a plurality of rows along the axial direction. The magnet adjacent to the rotor is disposed on the outer peripheral side of the rotor having a step skew structure in which the magnet is displaced stepwise in the rotation direction, and magnetizes the magnet, the magnetizing yoke having a substantially cylindrical shape A magnetized yoke core, a coil slot formed on the inner peripheral surface of the magnetized yoke core, and a coil wound around the coil slot, and the boundary position of the magnetic pole of the magnetized yoke core is in the axial direction. And the magnetized yoke includes a rotor holding mechanism that holds the rotor and a protruding portion in the axial direction of the rotor holding mechanism. Is characterized in that it comprises at least one pin is passed through the positioning holes of substantially round shape which is formed through in the axial direction of the rotor core.

  According to the present invention, even if there is variation in the thickness of the rotor made of the steel plate laminate, it is possible to suppress the deviation in the longitudinal magnetization position, and it is possible to suppress the manufacturing variation of the rotational vibration of the motor.

It is a perspective view which shows the electric power steering motor to which the magnetization method of the rotary electric machine of this invention is applied. It is a perspective view which shows the stator of the electric power steering motor shown in FIG. It is a perspective view which shows the rotor of the electric power steering motor shown in FIG. It is a front view of the rotor shown in FIG.2 (b). It is a half-section perspective view showing a schematic structure of a magnetizing yoke used when magnetizing a magnet of a rotating electrical machine. FIG. 5 is a perspective view of a half section of a magnetizing yoke showing a positional relationship between a rotor and a magnetizing yoke when magnetizing a magnet using the magnetizing yoke shown in FIG. 4. FIG. 6 is a plan view showing the positional relationship between the magnet and the magnetized yoke core shown in FIG. 5, with the skew step surface and the axial center of the magnetized yoke core overlapping. It is a figure which shows the direction of the magnetic flux when magnetized in the state shown in FIG. It is a result of measuring the surface magnetic flux density at a mechanical phase angle that is an axial position of the electric power steering motor, and is a diagram showing a surface magnetic flux density waveform at a position that is sufficiently away from the skew step surface in the axial direction. It is a result of having measured the surface magnetic flux density by the mechanical phase angle which is an axial position with an electric power steering motor, and is a figure which shows the surface magnetic flux density waveform of the position where an axial direction position is near from a skew level | step difference surface. FIG. 6 is a plan view showing the positional relationship between the magnet and the magnetized yoke core shown in FIG. 5, and a case where the skew step surface and the center of the yoke are shifted. It is a figure which shows the direction of the magnetic flux when a magnet is magnetized in the state shown in FIG. It is a figure which shows the state which the conventional magnetizing yoke hold | maintains a rotor at the time of magnetizing a magnet using a magnetizing yoke. It is a figure which shows the state which the magnetizing yoke of this invention hold | maintains a rotor when magnetizing a magnet using a magnetizing yoke. 1 is a perspective view showing a schematic configuration of a magnetized yoke of the present invention in a half cross section.

  Hereinafter, a magnetizing method and a magnetizing yoke for a rotating electric machine according to the present invention will be described based on the illustrated embodiments. The accompanying drawings and the following description show specific embodiments according to the principle of the present invention, but these are for understanding the present invention, and the present invention is never interpreted in a limited way. It is not intended for use.

  In the following, the rotating electrical machine according to the present invention will be described by taking an example of an electric power steering motor that assists steering of the vehicle, but it goes without saying that the present invention is also applicable to other rotating electrical machines.

  FIG. 1 shows an electric power steering motor 100 according to Embodiment 1 of the present invention.

  As shown in the figure, an electric power steering motor 100 includes a stator (stator) 1 and a rotor (rotor) 2 disposed in the stator 1 so as to face the stator 1 with a predetermined gap. It is roughly composed.

  2A shows the stator 1 shown in FIG. 1, and FIGS. 2B and 3 show the rotor 2 shown in FIG.

  As shown in FIG. 2 (a), the stator 1 is schematically constituted by a stator core 1a, a stator coil 1b wound around the stator core 1a, and a housing 1c for housing them.

  On the other hand, as shown in FIGS. 2B and 3, the rotor (rotor) 2 uses a shaft 2a, a rotor core 2b fitted to the shaft 2a, and an adhesive or the like on the outer periphery of the rotor core 2b. The rotor 2 is arranged in a plurality of rows (two rows in this embodiment) along the axial direction (vertical direction in FIGS. 2B and 3). In addition, a plurality of magnets 2c adjacent in the axial direction have a step skew structure in which the skew step surface 2d is deviated stepwise in the rotational direction.

  The magnet 2c of the rotor 2 is in a non-magnetized state when attached to the rotor core 2b, and productivity is increased by performing magnetization in a later process. In other words, in order to magnetize the magnet 2c attached to the rotor core 2b, a special device for magnetization is required. If the magnet 2c is magnetized, the assembling work and the magnetizing work of the magnet 2c can be performed smoothly, and the productivity can be improved.

  FIG. 4 shows a schematic structure of the magnetizing yoke 3 used for magnetizing the magnet 2c described above.

  As shown in the figure, the magnetized yoke 3 includes a substantially cylindrical magnetized yoke core 3a, a coil slot (not shown) formed on the inner peripheral surface of the magnetized yoke core 3a, and a coil wound around the coil slot. It has a continuous skew structure in which the boundary position 3c of the magnetic pole of the magnetized yoke core 3a is obliquely displaced with respect to the axial direction.

  When a plurality of magnets 2c adjacent in the axial direction are magnetized by the continuous skew structure magnetizing yoke 3 on the rotor 2 having the step skew structure shifted in a stepwise manner in the rotation direction with the skew step surface 2d as a boundary, As described above, a region magnetized in the direction opposite to the magnetic pole is locally generated, and a part of the magnet 2c is detached from the corresponding pole of the magnetized yoke 3, and the rotor 2 and magnetized yoke with respect to torque ripple, cogging torque, etc. 3 increases the sensitivity of the phase shift.

  This mechanism will be described below with reference to FIGS.

  FIG. 5 shows an approximate positional relationship between the rotor 2 and the magnetized yoke 3 when the magnet 2c is magnetized using the magnetized yoke 3 shown in FIG.

  As shown in FIG. 5, a skew step surface 2d is formed on the continuous skew portion of the magnetized yoke 3 having a continuous skew structure in which the magnetic pole boundary position 3c of the magnetized yoke core 3a is obliquely displaced with respect to the axial direction. Two magnets 2c adjacent to each other in the axial direction having a step skew structure shifted stepwise in the rotational direction are arranged at the boundary.

  6 and 10 show the positional relationship between the magnetized yoke core 3a shown in FIG. 5 and the magnet 2c of the rotor 2 on a plane.

  FIG. 6 shows a case where the skew step surface 2d of the rotor 2 and the axial center (hereinafter referred to as the yoke center) 3d of the magnetized yoke core 3a overlap. FIG. 10 shows the case where the skew step surface 2d of the rotor 2 and the yoke center 3d The case where it has shifted is shown.

  FIG. 7 roughly shows the direction of the magnetic flux when magnetized in the state (positional relationship) shown in FIG. 6, and the fine hatched portion indicated by 2s is the S pole of the magnet 2c, and the coarse hatched portion indicated by 2n is the magnet. The 2c N pole is shown.

  As can be seen from FIG. 7, when the rotor 2 having the two skew step surfaces 2d is magnetized by the magnetizing yoke 3 having the continuous skew structure, it is magnetized in the same direction (S pole) as the magnetic pole (S pole). The region 2c2 that is magnetized in the direction opposite to the magnetic pole (S pole) (N pole) is locally generated with respect to the region 2c1 (the N pole region 2c2 is partially generated in the S pole 2s region). .

  8 and 9 show surface magnetic flux density waveforms as a result of measuring the surface magnetic flux density at a mechanical phase angle that is a certain axial position of the electric power steering motor 100 of the present embodiment.

  FIG. 8 shows a result of measurement at an axial position (a skew step surface 2d) that is formed by only a region 2c1 that is sufficiently separated from the skew step surface 2d of the rotor 2 and is magnetized in the same direction as the magnetic pole. FIG. 9 shows a region 2c1 that is close to the skew step surface 2d of the rotor 2 in the axial direction and is magnetized in the same direction as the magnetic pole, and a region that is magnetized in the opposite direction to the magnetic pole. This is a result measured at an axial position where 2c2 is present (a result measured at a position close to the skew step surface 2d of the rotor 2).

  As is apparent from FIG. 9, the surface magnetic flux density waveform jumps up near zero magnetic flux density, and it is known that the surface magnetic flux density jumps remarkably at the site where the region 2c2 magnetized in the direction opposite to the magnetic pole exists.

  The jump of the surface magnetic flux density shown in FIG. 9 becomes a potential for increasing the basic order component (the order component of the least common multiple of the number of poles and the number of slots) of cogging torque and torque ripple.

However, since the two-step skew structure is generally set at an angle at which the cogging torque and torque ripple of the basic order component are zero, including the present embodiment, the surface magnetic flux waveform around the skew step surface 2d of the rotor 2 is set. If the waveform is the same, the cogging torque and torque ripple will not deteriorate even if waveform distortion occurs. For this reason, the surface magnetic flux waveform should be symmetric around the skew step surface 2d of the rotor 2 (up and down of the skew step surface 2d). However, this is important from the viewpoint of reducing cogging torque and torque ripple, but if the positional relationship between the magnetized yoke 3 and the rotor 2 is shifted, the symmetry of the waveform is lost.

  FIG. 11 is a diagram schematically showing the orientation of the magnetic poles when magnetization is performed in the positional relationship of the case (FIG. 10) in which the yoke center 3d and the skew step surface 2d are displaced in the axial direction.

  As is apparent from FIG. 11, the area 2c2 magnetized in the direction opposite to the magnetic pole is reduced in one magnet, and the area magnetized in the direction opposite to the magnetic pole in the opposite magnet across the skew step surface 2d. It can be seen that the area 2c2 is increased, and the symmetry of the surface magnetic flux around the skew step surface 2d of the rotor 2 is greatly broken.

  FIG. 12 shows a state in which the conventional magnetizing yoke 3 </ b> A holds the rotor 2 when magnetizing the magnet 2 c using the magnetizing yoke 3.

  As shown in the figure, when the rotor 2 is held by the rotor holding mechanism 5A of the magnetizing yoke 3A when the magnet 2c is magnetized using the conventional magnetizing yoke 3A, the rotation of the magnetizing yoke 3A is performed. The position of the rotor 2 in the axial direction is determined by the rotor positioning surface 6a of the child holding mechanism 5A, and the position of the skew step surface 2d in the axial direction due to variations in the dimensions of the rotor component (fixing of the magnet 2c, scattering prevention cover, etc.) 4 and the rotor core 2b. Varies from product to product, resulting in worsening of cogging torque and torque ripple.

  FIG. 13 shows a state in which the magnetizing yoke 3 </ b> B of this embodiment holds the rotor 2 when magnetizing the magnet 2 c using the magnetizing yoke 3.

  As shown in the figure, when the rotor 2 is held by the rotor holding mechanism 5B of the magnetizing yoke 3B when the magnet 2c is magnetized using the magnetizing yoke 3B of this embodiment, the rotation of the magnetizing yoke 3B is performed. The position of the rotor 2 in the axial direction is determined by the rotor positioning surface 6b of the rotor holding mechanism 5B, and the magnet 2c is fixed by the rotor holding mechanism 5B of the magnetizing yoke 3B and the pin portion 5B1 of the rotor holding mechanism 5B of the magnetizing yoke 3B. The axial position of the rotor 2 when magnetized is controlled.

  For this reason, in this embodiment, the skew step surface 2d of the rotor 2 and the rotor positioning surface 6b of the rotor holding mechanism 5B of the magnetizing yoke 3B coincide with each other. Does not affect the deterioration of cogging torque or torque ripple.

  More specifically, in this embodiment, a magnetized yoke 3B as shown in FIG. 14 is used, and when the magnetized yoke 3B is set for magnetizing the magnet 2c, the height direction of the rotor 2 is set. The magnet 2c is magnetized in a state where the level difference between the positioning surface and the skew structure coincides.

  As shown in FIG. 14, the magnetizing yoke 3B of this embodiment used at this time is a substantially cylindrical magnetizing yoke core 3a and a coil slot (not shown) formed on the inner peripheral surface of the magnetizing yoke core 3a. ) And a magnetized yoke coil 3b wound around the coil slot, and has a continuous skew structure in which the magnetic pole boundary position 3c of the magnetized yoke core 3a is offset obliquely with respect to the axial direction. The magnetic yoke 3B protrudes in the axial direction of the rotor holding mechanism 5B of the magnetizing yoke 3B that holds the rotor 2 and the rotor holding mechanism 5B of the magnetizing yoke 3B, and penetrates in the axial direction of the rotor core 2b. And at least one (eight in this embodiment) pin portion 5B1 that is passed through a substantially round positioning hole 2b1 (see FIG. 2B).

  The pin portion 5B1 described above has a substantially cylindrical shape, and is passed through a positioning hole 2b1 formed so as to penetrate the rotor core 2b in the axial direction, and the pin portion 5B1 abuts against a skew step surface 2d viewed from the positioning hole 2b1. Thus, the height direction positioning surface of the rotor 2 and the height direction position of the step of the step skew structure are controlled.

  In this embodiment, the number of positioning holes 2b1 of the rotor core 2b is the same as the number of poles of the rotor core 2b, and the shape of the positioning holes 2b1 of the rotor core 2b is different between the N pole and the S pole. The number of 2b1 is the same as the number of pole pairs.

  Further, at least two pin portions 5B1 described above are installed, the axial positions of the tips of the pin portions 5B1 are all the same, and the pin portion 5B1 has a pin diameter formed on the rotor core 2b. It is smaller than the diameter of the hole 2b1, the gap between the pin diameter of the pin portion 5B1 and the hole diameter of the rotor core 2b is 0.5 mm or less, and when the skew step surface 2d of the pin portion 5B1 is magnetized, the magnetization yoke core 3a Located at the center of the longitudinal dimension.

  The reason why the gap between the pin diameter of the pin portion 5B1 and the hole diameter of the rotor core 2b is 0.5 mm or less is to suppress the rotational displacement of the magnetizing yoke 3B and the magnet 2c.

  That is, even if the positional relationship between the magnetizing yoke 3B and the magnet 2c is shifted in the rotational direction, the region 2c2 magnetized in the direction opposite to the magnetic pole becomes asymmetrical above and below the skew step surface 2d. Experience has shown that pulsation is affected if it deviates 1 ° in the rotational direction from the ideal arrangement.

  The allowable value of the gap between the pin diameter of the pin portion 5B1 and the hole diameter of the rotor core 2b varies depending on the center distance between the shaft 2a and the positioning hole 2b1.

  In the case of the electric power steering motor 100 described in the present embodiment, it is difficult if the gap is not 0.27 mm or less, but specifically, the allowable gap is calculated by the following equation.

Clearance = 1 ° / 360 * 2π * Center distance between the shaft 2a and the positioning hole 2b1 The clearance between the pin diameter of the pin portion 5B1 and the hole diameter of the rotor core 2b described in this embodiment is 0.5 mm, and the positioning with the shaft 2a It is a condition that the center distance of the hole 2b1 is 60 mm or less, and if the size exceeds this, there will be no problem even if magnetized with a general roughness structure. When applied to the steering motor 100, the gap between the pin diameter of the pin portion 5B1 and the hole diameter of the rotor core 2b is preferably 0.5 mm or less.

  The pin portion 5B1 described above uses a non-magnetic material such as resin, brass, or SUS.

  By adopting such a present embodiment, even if there is a variation in the thickness of the rotor made of the steel plate laminate, it is possible to suppress the deviation of the magnetizing position in the longitudinal direction, and to suppress the manufacturing variation of the rotational vibration of the motor. be able to.

  In addition, this invention is not limited to an above-described Example, Various modifications are included. For example, the above-described embodiments have been described in detail for easy understanding of the present invention, and are not necessarily limited to those having all the configurations described. Further, a part of the configuration of one embodiment can be replaced with the configuration of another embodiment, and the configuration of another embodiment can be added to the configuration of one embodiment. Further, it is possible to add, delete, and replace other configurations for a part of the configuration of each embodiment.

  DESCRIPTION OF SYMBOLS 1 ... Stator (stator), 1a ... Stator core, 1b ... Stator coil, 1c ... Housing, 2 ... Rotor (rotor), 2a ... Shaft, 2b ... Rotor core, 2b1 ... Rotor core positioning hole, 2c ... Magnet, 2c1 ... Area magnetized in the same direction as the magnetic pole, 2c2 ... Area magnetized in the opposite direction to the magnetic pole, 2d ... Skew step surface, 2s ... S pole of the magnet, 2n ... N pole of the magnet, 3, 3A, 3B ... Magnetized yoke, 3a ... magnetized yoke core, 3b ... magnetized yoke coil, 3c ... boundary position of magnetic pole of magnetized yoke core, 3d ... axial center of magnetized yoke core (yoke center), 4 ... rotor component, 5A, 5B: Rotor holding mechanism, 5B1: Pin portion of rotor holding mechanism, 6a, 6b: Rotor positioning surface, 100: Electric power steering motor.

Claims (9)

It is composed of a rotor core and magnets attached to the outer periphery of the rotor core, and is arranged in a plurality of rows along the axial direction, and the stepwise skew structure in which the magnets adjacent in the axial direction are displaced stepwise in the rotational direction. Magnetization of a rotating electrical machine having a rotor and a stator disposed on the outer peripheral side of the rotor is magnetized in a continuous skew structure in which the boundary position of the magnetic poles of the magnetized yoke core is obliquely shifted with respect to the axial direction. When magnetizing with a yoke,
When the magnetizing yoke is set on the magnet for magnetizing, the magnet is magnetized in a state where the height direction positioning surface of the rotor and the step of the step skew structure coincide with each other. How to magnetize rotating electrical machines. A method for magnetizing a rotating electrical machine according to claim 1,
At least one positioning hole penetrating in the axial direction is formed in the rotor core,
Control of the height direction positioning surface of the rotor and the step height of the step skew structure is performed using at least one of the positioning hole of the rotor core and the skew step surface seen from the positioning hole, and after that control A magnetizing method for a rotating electric machine, wherein the magnet is magnetized. A method for magnetizing a rotating electric machine according to claim 2,
The shape of the positioning hole of the rotor core is substantially round,
The magnetized yoke has a rotor holding mechanism for holding the rotor, and the rotor holding mechanism is provided with at least one substantially cylindrical pin protruding in the axial direction;
By passing the pin through the positioning hole of the rotor core and abutting the pin against a skew step surface seen from the positioning hole, the height direction positioning surface of the rotor and the height direction position of the step of the step skew structure are adjusted. A magnetizing method for a rotating electric machine, characterized by performing control. A method for magnetizing a rotating electrical machine according to claim 2 or 3,
A magnetizing method for a rotating electrical machine, wherein the number of positioning holes of the rotor core is the same as the number of poles of the rotor core. A method for magnetizing a rotating electrical machine according to claim 4,
The shape of the positioning hole of the rotor core is different between N pole and S pole,
A magnetizing method for a rotating electrical machine, wherein the number of positioning holes is the same as the number of pole pairs. It is composed of a rotor core and magnets attached to the outer periphery of the rotor core, and is arranged in a plurality of rows along the axial direction, and the stepwise skew structure in which the magnets adjacent in the axial direction are displaced stepwise in the rotational direction. A magnetizing yoke arranged on the outer peripheral side of a rotor and magnetizing the magnet;
The magnetized yoke comprises a substantially cylindrical magnetized yoke core, a coil slot formed on the inner peripheral surface of the magnetized yoke core, and a coil wound around the coil slot, and the magnetic pole of the magnetized yoke core Is a continuous skew structure in which the boundary position is obliquely displaced with respect to the axial direction,
The magnetizing yoke includes a rotor holding mechanism that holds the rotor, and a substantially circular positioning hole that protrudes in the axial direction of the rotor holding mechanism and extends in the axial direction of the rotor core. A magnetized yoke comprising at least one pin that is passed therethrough. The magnetized yoke according to claim 6, wherein
The pin of the rotor holding mechanism has a substantially cylindrical shape, and the pin passes through the positioning hole formed penetrating in the axial direction of the rotor core, and the pin abuts on a skew step surface seen from the positioning hole. Thus, the height direction positioning surface of the rotor and the height direction position of the step of the step skew structure are controlled. The magnetized yoke according to claim 6 or 7,
At least two pins are installed, the axial positions of the tips of the pins are all the same, and the pin diameter of the pins is smaller than the diameter of the positioning hole formed in the rotor core, The gap between the pin diameter of the pin and the diameter of the positioning hole of the rotor core is 0.5 mm or less,
The magnetized yoke according to claim 1, wherein the skew step surface of the pin is at the center of the longitudinal dimension of the magnetized yoke core at the moment of magnetization. The magnetized yoke according to any one of claims 6 to 8,
The magnetizing yoke, wherein the pin is a non-magnetic material.

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