JP6192400B2 - Permanent magnet motor and magnetizing method thereof - Google Patents

Description

  The present invention relates to a permanent magnet motor, and more particularly to a technique for magnetizing a magnet provided in a rotor.

  An induction motor or a permanent magnet motor is used as a driving force for industrial equipment or the like. Since the permanent magnet motor uses the magnetic force generated by the permanent magnet provided in the rotor, there is no loss due to the current flowing in the coil provided in the rotor as in the induction motor, and the efficiency is easily improved. Moreover, a permanent magnet motor can implement | achieve a high output and a small motor by using the magnet with strong magnetic force containing rare earths, such as neodymium.

  Generally, since a magnetic material such as iron is used for the rotor core, it may be difficult to attach a permanent magnet magnetized to the rotor due to the magnetic force acting between the core and the permanent magnet. . Therefore, there is a case where so-called post-magnetization is performed in which an unmagnetized magnet is attached to the core and then magnetized. Examples of the post-magnetization method include a case where a dedicated magnetizing yoke is used, and a case where magnetization is performed using a stator motor coil (see, for example, Patent Document 1).

JP 2003-243749 A

  A dedicated magnetized yoke can be used to efficiently magnetize a magnet. However, when manufacturing a small variety of motors, it is necessary to prepare a magnetized yoke for each type of rotor. Cost will increase. On the other hand, when magnetizing using the stator motor coil, which is indispensable for the configuration of the motor, it is possible to handle a small amount of many types of products, but the motor coil is affected by flowing a large current necessary for magnetization. There is a risk of giving. Therefore, the present inventor has conceived that by providing a magnetizing coil in the rotor, it is possible to efficiently magnetize the magnet of the rotor while accommodating the manufacture of a small variety of products.

  The present invention has been made in view of such a problem, and one of the exemplary purposes of an embodiment thereof is to provide a permanent magnet motor and a method of magnetizing the permanent magnet motor that increase the magnetization efficiency while suppressing an increase in cost. .

  One embodiment of the present invention relates to a permanent magnet motor. This permanent magnet motor includes a rotor. The rotor includes a plurality of magnet members and grooves or holes extending from the upper surface to the lower surface of the rotor.

  According to this aspect, the magnetizing coil is laid along the groove or hole provided in the rotor so that the magnet member is attached to the rotor after the magnet member is attached to the rotor or after the rotor is incorporated into the stator. Magnetic treatment can be applied. Thus, the rotor can be magnetized without using a magnetizing yoke or passing a magnetizing current through the motor coil. Further, since the groove or hole extends from the upper surface to the lower surface of the rotor, the magnetizing coil can be easily detached even when the rotor is incorporated in the stator.

  Another aspect of the present invention relates to a method for magnetizing a permanent magnet motor. In this magnetizing method, after a magnet member and a magnetizing coil are attached to a rotor, an electric current is passed through the magnetizing coil to magnetize the magnet member.

  According to this aspect, by using the magnetizing coil attached to the rotor, the magnet member can be magnetized after being attached to the rotor. Thus, the rotor can be magnetized without using a magnetizing yoke or passing a magnetizing current through the motor coil.

  Note that any combination of the above-described constituent elements and the constituent elements and expressions of the present invention replaced with each other among methods, apparatuses, systems, and the like are also effective as an aspect of the present invention.

  According to an aspect of the present invention, it is possible to increase the magnetization efficiency of a permanent magnet motor while suppressing an increase in cost.

It is a top view which shows the structure of the permanent magnet electric motor which concerns on embodiment. It is an external appearance perspective view of the rotor which concerns on embodiment. It is a figure which shows the rotor which attached the several magnet member. It is a top view which shows the rotor which attached the 1st coil for magnetization. It is a top view which shows the rotor which attached the 2nd coil for magnetization and the 3rd coil for magnetization. It is a figure which shows typically the electric current sent through the coil for magnetization, and the magnetic field applied to a magnet member. It is a figure which shows how to attach the magnetizing coil which concerns on the modification 1. FIG. It is a figure which shows how to attach the magnetizing coil which concerns on the modification 2. FIG. 10 is a top view showing a state in which a magnetizing coil is attached to a rotor according to Modification 3. FIG. FIG. 10 is a top view showing a state where a magnetizing coil is attached to a rotor according to Modification 4; 10 is a top view showing a configuration of a permanent magnet electric motor according to Modification 5. FIG. FIG. 10 is a top view showing a direction in which a magnetizing coil is attached to a rotor according to Modification 6; 10 is a top view illustrating a configuration of a permanent magnet electric motor according to Modification Example 7. FIG. is there.

  The present invention will be described below based on preferred embodiments with reference to the drawings. The same or equivalent components, members, and processes shown in the drawings are denoted by the same reference numerals, and repeated descriptions are omitted as appropriate. The embodiments do not limit the invention but are exemplifications, and all features and combinations thereof described in the embodiments are not necessarily essential to the invention.

  An outline is described before the embodiment is specifically described. The present embodiment relates to a permanent magnet type electric motor constituted by a stator including a motor coil and a rotor including a permanent magnet, and relates to a technique for post-magnetizing a magnet provided in the rotor. Since a magnetic material such as iron is generally used as the core member of the rotor, it may be difficult to attach a permanent magnet that has been magnetized to the rotor due to the magnetic force acting between the core member and the permanent magnet. There is. Therefore, after attaching a non-magnetized magnet member to the core member, so-called “post-magnetization” is performed to magnetize the magnet member.

  As a post-magnetization method, there are a case where a dedicated magnetizing yoke is used and a case where magnetizing is performed using a motor coil of a stator. When magnetizing using a dedicated magnetizing yoke, it is efficient when manufacturing the same type of motor in large quantities, but when manufacturing a small quantity of various types of motors, according to the specifications of different types of rotors Each of the yokes must be prepared, which increases the cost. Moreover, when magnetizing using a motor coil, there exists a possibility of affecting a motor coil by flowing the large electric current required for magnetization. Therefore, in the present embodiment, by providing a magnetizing coil in the rotor, the magnet member of the rotor is magnetized without using a motor coil, while supporting the manufacture of a small variety of products.

  FIG. 1 is a cross-sectional view showing a configuration of a permanent magnet electric motor 100 according to an embodiment. The permanent magnet motor 100 includes a stator 10, a rotor 20, and a magnet member 50. The permanent magnet motor 100 generates a rotating magnetic field by causing a current to flow through the motor coil 18 provided in the stator 10 and rotates the rotor 20 to which the plurality of magnet members 50 are attached. The rotor 20 is provided with a through hole 40 for fixing a magnetizing coil used for magnetizing the magnet member 50. As shown in FIG. 2 to be described later, the magnetizing coil 60 is attached along the through holes 40 corresponding to the positions on both sides of the magnet member, so that the magnet member attached to the rotor 20 is post-magnetized. Can do.

  The stator 10 includes a yoke portion 12, a tooth portion 14, and a motor coil 18. The yoke part 12 is an annular member. A plurality of teeth portions 14 projecting in the direction from the outer periphery to the center of the yoke portion 12 are provided inside the yoke portion 12. Each of the plurality of tooth portions 14 is provided with a motor coil 18 wound in a concentrated manner. The teeth portion 14 has a protruding end portion 16 that faces the outer peripheral surface 24 of the rotor 20, and generates a rotating magnetic field inside the stator 10 by passing a current through the motor coil 18. The yoke portion 12 and the tooth portion 14 constitute a magnetic path of a rotating magnetic field generated inside the stator 10, and, for example, a material containing iron is used.

  The magnet member 50 is a member that becomes a permanent magnet by being magnetized by applying an external magnetic field. The magnet member 50 is a columnar shape having a substantially trapezoidal cross section, and has a first side surface 52 and a second side surface 54 facing away from the first side surface 52. The magnet member 50 is attached to the rotor 20 such that the first side surface 52 is in contact with the magnet insertion portion 26, and the second side surface 54 faces the protruding end portion 16 of the stator 10. The magnet member 50 is attached to the magnet insertion portion 26 of the rotor 20 in a non-magnetized state that has not been magnetized, and is magnetized after being attached to the rotor 20. When attaching the magnet member 50 to the rotor 20, an adhesive is used between the magnet insertion portion 26 and the magnet member 50, or a tape is wound from above the second side surface 54 along the outer peripheral surface 24 of the rotor 20. Or you may.

  FIG. 2 is an external perspective view of the rotor 20 according to the embodiment. This figure shows the rotor 20 in a state where the magnet member 50 is not attached. The rotor 20 includes a cylindrical core portion 22. The core portion 22 includes an outer peripheral surface 24, a magnet insertion portion 26, an upper surface 32, a lower surface 34, and a through hole 40.

  A plurality of magnet insertion portions 26 are provided so as to be aligned in the circumferential direction along the outer peripheral surface 24 of the core portion 22. The magnet insertion portion 26 is a groove formed corresponding to the shape of the magnet member, and is formed such that the circumferential width w decreases from the center of the rotor 20 toward the outside. The magnet insertion portion 26 extends from the upper surface 32 toward the lower surface 34 so that the magnet member can be inserted in the direction of the rotation axis X.

  The through hole 40 is an attachment hole for fixing the magnetizing coil 60 and extends from the upper surface 32 to the lower surface 34. A plurality of through holes 40 are provided corresponding to positions between adjacent magnet insertion portions 26. Therefore, when a magnet member is attached to the magnet insertion portion 26, the through hole 40 is provided corresponding to the position between adjacent magnet members. Moreover, the through-hole 40 will be provided corresponding to the position of the both sides of a magnet member. At this time, the magnetizing coil 60 is attached in a loop shape through two adjacent through holes 40 and is disposed at a position surrounding the outer periphery of the magnet insertion portion 26. A magnetic field can be applied to the entire magnet member inserted into the magnet insertion portion 26 by attaching the magnetizing coil 60 to a position surrounding the outer periphery of the magnet insertion portion 26.

Next, a method for magnetizing the magnet member 50 will be described.
In the present embodiment, first, the magnet member 50 that is not magnetized is attached to the rotor 20, and then the rotor 20 to which the magnet member 50 is attached is disposed inside the stator 10. In this state, the magnetizing coil 60 is attached to the rotor 20, and the magnet member 50 is magnetized by passing an electric current through the magnetizing coil 60 attached to the rotor 20. Finally, the magnetizing coil 60 is removed from the rotor 20.

  FIG. 3 is a top view showing the rotor 20 to which a plurality of magnet members 50a, 50b, 50c (hereinafter also collectively referred to as magnet members 50) are attached, and corresponds to a partial region of FIG. It is. The first magnet member 50a is provided at a position between the through holes 40a and 40b adjacent to each other. Similarly, the second magnet member 50b is attached between the adjacent through holes 40b and 40c, and the third magnet member 50c is attached between the adjacent through holes 40c and 40d.

  FIG. 4 is a top view showing the rotor 20 to which the first magnetizing coil 60a is attached. The first magnetizing coil 60a is inserted into the through hole 40a from the lower surface of the rotor 20 toward the upper surface 32, extends to the through hole 40b adjacent to the through hole 40a along the upper surface 32, and extends from the upper surface 32 to the lower surface. It is arranged in a loop shape by being inserted through the through hole 40b. Thereby, the 1st magnetizing coil 60a is arrange | positioned so that the outer periphery of the 1st magnet member 50a may be enclosed corresponding to the 1st magnet member 50a.

  FIG. 5 is a top view showing a state in which the second magnetizing coil 60b and the third magnetizing coil 60c are attached. The second magnetizing coil 60b is disposed at a position corresponding to the second magnet member 50b by being inserted through the adjacent through holes 40b and 40c. Similarly, the third magnetizing coil 60c is disposed at a position corresponding to the third magnet member 50c by being inserted through the adjacent through holes 40c and 40d. In this manner, a plurality of magnetizing coils 60 are fixed by passing two magnetizing coils 60 through one through hole 40.

  FIG. 6 is a diagram schematically showing a current flowing through the magnetizing coil 60 and a magnetic field applied to the magnet member 50. This figure shows the arrangement of the magnet member 50 and the magnetizing coil 60 when the inner peripheral surface of the rotor is viewed from the center toward the outside, and the first side surface 52 of the magnet member 50 is on the front side of the page. A state is shown in which the second side surface 54 is arranged on the back side. For convenience of explanation, the illustration of the rotor is omitted in the figure. As illustrated, the magnetizing coil 60 is fixed so that the first side surface 52 of the magnet member 50 and the plane formed by the loop of the magnetizing coil 60 are parallel to each other.

  When magnetizing the magnet member 50, a current in the opposite direction is passed through the adjacent magnetizing coil 60 so that the polarity of the adjacent magnet member 50 is reversed. A magnetic field directed from the first side surface 52 to the second side surface 54 with respect to the magnet member 50 by passing a current in a clockwise direction on the paper surface through the first magnetizing coil 60a and the third magnetizing coil 60c. Apply. Accordingly, the first magnet member 50a and the third magnet member 50c are magnetized so that the second side surface 54 facing the stator has an N pole.

  On the other hand, a magnetic field from the second side surface 54 toward the first side surface 52 is applied to the magnet member 50 by passing a current in the counterclockwise direction to the second magnetizing coil 60b. As a result, the second magnet member 50b is magnetized so that the second side face 54 facing the stator becomes an S pole.

  Finally, the magnetizing coil 60 attached to the rotor 20 is removed. By pulling out the magnetizing coil 60 inserted through the through hole 40 from the through hole 40, the magnetizing coil 60 can be easily removed. At this time, a part of the magnetizing coil 60, for example, a portion extending along the upper surface or the lower surface of the rotor 20 may be cut. As a result, the permanent magnet motor 100 from which the magnetizing coil, which is not essential as a configuration of the motor, is removed, is obtained.

  Hereinafter, the effect which the permanent magnet motor 100 concerning this embodiment shows is described.

  The permanent magnet motor 100 can post-magnetize the magnet member 50 by attaching a magnetizing coil to the through hole 40 provided in the rotor 20. Therefore, it is not necessary to prepare a dedicated yoke for post-magnetization, and the cost for post-magnetization can be reduced.

  Since the permanent magnet motor 100 performs post-magnetization using a magnetizing coil provided in the rotor 20, coil characteristics suitable for magnetization can be employed. If post-magnetization is performed using a motor coil, it is generally necessary to pass a larger current than the current when the motor is driven. Therefore, it is necessary to select a motor coil characteristic that can cope with magnetization. . On the other hand, in this embodiment, since the magnetizing coil and the motor coil are different, coil characteristics suitable for each application can be selected. Thereby, the magnetization efficiency of the magnet member 50 can be improved without sacrificing the output characteristics as an electric motor.

  Since the permanent magnet motor 100 is provided with the through hole 40 at a position corresponding to the arrangement of the magnet member 50, the magnet member 50 can be efficiently magnetized by fixing the magnetizing coil 60 to the through hole 40. it can. Temporarily, when magnetizing using a motor coil, the number of teeth portions around which the motor coil is wound and the number of magnet members provided on the rotor do not correspond one-to-one, so that some magnets correspond to the teeth. Even if it becomes, a part of magnet will be in the position shifted from the teeth. If it does so, dispersion | variation will arise in the magnetic force magnetized by a magnet member by the positional relationship of a magnet member and teeth. On the other hand, since the permanent magnet motor 100 can arrange the magnetizing coils 60 corresponding to the magnet members 50, all the magnet members 50 can be magnetized efficiently.

  Moreover, since the magnetizing coils 60 can be arranged corresponding to the plurality of magnet members 50, the plurality of magnet members 50 can be magnetized at a time. Furthermore, by making the position of the through hole 40 close to the magnet member 50, the magnetizing coil 60 can be arranged close to the magnet member 50, and a stronger magnetic field can be applied to the magnet member 50. Magnetization efficiency can be increased.

  Although the permanent magnet motor 100 has the through hole 40 to which the magnetizing coil 60 is attached, the magnetizing coil 60 is removed when the motor is driven. By adopting a configuration that does not include the magnetizing coil 60 that is not essential for driving the motor, it is possible to suppress an increase in the weight of the rotor 20 at the time of driving the motor, and to suppress an influence such as a decrease in motor output. Can do.

  Since the permanent magnet motor 100 is provided with the through hole 40 extending from the upper surface to the lower surface of the rotor 20, the magnetizing coil 60 can be easily attached / detached even when the rotor 20 is disposed inside the stator 10. can do. Thereby, it is possible to save the trouble of taking out the rotor 20 from the inside of the stator 10 for attaching / detaching the magnetizing coil 60 and arranging the rotor 20 inside the stator 10 again after the magnetizing coil 60 is attached / detached. This operation is very troublesome because a strong magnetic force is generated between the stator 10 and the rotor 20 to which the magnetized magnet member 50 is attached. Therefore, providing the through hole 40 from the upper surface to the lower surface of the rotor 20 eliminates the trouble of moving the rotor 20 from the inside of the stator 10 in order to detach the magnetizing coil 60, thereby reducing the manufacturing cost. be able to.

  Since the permanent magnet motor 100 is post-magnetized with the rotor 20 disposed inside the stator 10, the teeth portion 14 of the stator 10 is also temporarily magnetized by the magnetic field generated by the magnetizing coil 60. The Rukoto. For this reason, compared with the case where there is no stator 10 around the rotor 20, the magnetic field applied to the magnet member 50 can be strengthened. Thus, the magnetizing efficiency to the magnet member 50 can be improved by using the stator 10 at the time of magnetization.

  Moreover, the above-mentioned magnetization method is not only for newly manufacturing the permanent magnet motor 100, but also for re-magnetization for recovering the magnetic force of the magnet member 50 when the magnetic force of the magnet member 50 is weakened over time. Can be used. In this case, since the magnetizing process can be performed without taking out the rotor 20 from the inside of the stator 10, the effort of re-magnetization can be reduced.

  The present invention has been described based on the embodiments. Those skilled in the art will understand that these embodiments are exemplifications, and that various modifications can be made to combinations of the respective constituent elements and processing processes, and such modifications are also within the scope of the present invention. By the way. Hereinafter, such modifications will be described.

(Modification 1)
FIG. 7 is a view showing how to attach the magnetizing coil 60 according to the first modification. In the above-described embodiment, the magnetizing coil 60 is fixed to the two through holes 40a and 40b. However, in the first modification, the magnetizing coil 60 is fixed using one through hole 40a and the recess 56. . The recess 56 is formed by the outer peripheral surface 24 of the rotor 20 and the side surface of the magnet member 50 protruding from the outer peripheral surface 24. At this time, the magnetizing coil 60 is fixed so that the first side surface 52 of the magnet member 50 and the plane formed by the loop of the magnetizing coil 60 intersect. As described above, even when the magnetizing coil 60 is fixed by combining the through hole 40 and the concave portion 56, the magnetizing coil 60 can be fixed so as to surround the outer periphery of the magnet member 50.

  If the angle at which the first side surface 52 of the magnet member 50 intersects the plane formed by the loop of the magnetizing coil 60 is increased, the magnetic field component orthogonal to the first side surface 52 is reduced and the magnetization efficiency is increased. May decrease. Therefore, when the magnetizing coil 60 is fixed using the recess 56, the through hole 40 is disposed near the outer peripheral surface 24, and a plane formed by the first side surface 52 and the loop of the magnetizing coil 60. It is desirable to reduce the angle at which the crosses.

(Modification 2)
FIG. 8 is a diagram illustrating how to attach the magnetizing coil according to the second modification. As in the first modification, the magnetizing coil 60a is attached using the recess 56a located on the right side of the first magnet member 50a and the through hole 40a located on the left side of the first magnet member 50a. In the second modification, another magnetizing coil 60b is attached in addition to this. Another magnetizing coil 60b is attached using a recess 56b located on the left side of the first magnet member 50a and a through hole 40b located on the right side of the first magnet member 50a. Therefore, in the second modification, two magnetizing coils 60 are attached to one magnet member 50, and the magnetizing coils 60 are attached so as to intersect at the upper surface and the lower surface of the rotor 20.

  By attaching the two magnetizing coils 60 intersecting in this way, the magnetic field components along the first side surface 52 of the magnet member 50 cancel each other, and a magnetic field perpendicular to the first side surface 52 is applied to the magnet member 50. be able to. As a result, the magnetizing process can be performed so that the direction of the magnetic force magnetized by the magnet member 50 is perpendicular to the first side surface 52 and the second side surface 54 of the magnet member 50, and the magnet member 50 is more efficiently magnetized. Can be magnetized.

(Modification 3)
FIG. 9 is a top view illustrating a state in which the magnetizing coil 60 is attached to the rotor 20 according to the third modification. Modification 3 is different from the above-described embodiment in that the cross-section of the through hole 40 is not an isotropic circle but an anisotropic substantially elliptical shape. The cross section of the through-hole 40 has an anisotropic shape with a wider circumferential width w ₂ than the radial width w ₁ from the center of the rotor 20 toward the outer periphery. For example, in the cross-section of the through hole 40, the radial width w ₁ corresponds to the thickness of one magnetizing coil 60, while the circumferential width w ₂ has _two magnetizing coils 60. Corresponds to the thickness of the minute. Thus, the two magnetizing coils 60 are inserted in the circumferential direction away from each other in one through hole 40.

  In the third modification, the cross-sectional area that must be ensured for the insertion of the two magnetizing coils 60 is made smaller than that of the circular shape by making the cross-section of the through hole 40 anisotropic. Can do. By reducing the cross-sectional area of the through hole 40, it is possible to secure the strength of the rotor 20 necessary for holding the magnet member 50 and make the place where the through hole 40 is provided closer to the magnet member 50. it can. Thereby, the magnetization efficiency to the magnet member 50 can be improved without impairing the reliability of the permanent magnet electric motor 100.

(Modification 4)
FIG. 10 is a top view illustrating a state in which the magnetizing coil 60 is attached to the rotor 20 according to the fourth modification. Similar to the second modification, the fourth modification differs from the above-described embodiment in that the cross-section of the through hole 40 is not an isotropic circle but an anisotropic substantially elliptical shape. The cross-section of the through-hole 40 has an anisotropic shape in which the radial width w ₁ is wider than the circumferential width w ₂ . For example, the cross-section of the through-hole 40, whereas the width w ₁ in the radial direction corresponds to the two pins of the magnetizing coil 60, the width w ₂ in the circumferential direction corresponds to one roll of the magnetizing coil 60 Have a size to As a result, the two magnetizing coils 60 are inserted in one through hole 40 so as to be separated in the radial direction.

  Also in the modified example 4, by making the cross section of the through-hole 40 an anisotropic shape, the cross-sectional area that must be secured for the insertion of the two magnetizing coils 60 is made smaller than in the case of the circular shape. Can do. By reducing the cross-sectional area of the through hole 40, it is possible to secure the strength of the rotor 20 necessary for holding the magnet member 50 and make the place where the through hole 40 is provided closer to the magnet member 50. it can. Thereby, the magnetization efficiency to the magnet member 50 can be improved without impairing the reliability of the permanent magnet electric motor 100.

(Modification 5)
FIG. 11 is a top view showing the configuration of the permanent magnet electric motor 100 according to the fifth modification. Modification 5 is different from the above-described embodiment in that a groove 42 is provided on the inner peripheral surface 28 of the rotor 20 instead of the through hole for fixing the magnetizing coil. The groove portion 42 has a rectangular cross section perpendicular to the axial direction, and continuously extends from the upper surface 32 to the lower surface 34 of the rotor 20. The groove part 42 is provided with two or more corresponding to the position between the adjacent magnet insertion parts 26 similarly to the above-mentioned embodiment.

  FIG. 12 is a top view showing how to attach the magnetizing coil 60 to the rotor 20 according to the fifth modification. The magnetizing coil 60 is fixed by being fitted into two adjacent groove portions 42 while maintaining a loop shape corresponding to the attachment position. Thereby, compared with the case where the magnetizing coil is inserted through the through hole, the magnetizing coil 60 can be easily attached and detached.

  In the rotor 20 according to the modified example 5 as well, as shown in FIGS. 7 and 8, as shown in FIGS. The coil 60 may be fixed.

(Modification 6)
FIG. 13 is a top view showing the configuration of the permanent magnet electric motor 100 according to the sixth modification. Modification 5 is different from the above-described embodiment in that a groove 42 is provided on the outer peripheral surface 24 of the rotor 20 instead of the through hole for fixing the magnetizing coil. The groove portion 42 has a rectangular cross section perpendicular to the axial direction, and continuously extends from the upper surface 32 to the lower surface 34 of the rotor 20. The groove part 42 is provided with two or more corresponding to the position between the adjacent magnet insertion parts 26 similarly to the above-mentioned embodiment.

  Corresponding to the magnet member 50 attached to the outer peripheral surface 24, the magnetizing coil 60 can be disposed closer to the magnet member 50 by providing the groove portion 42 on the outer peripheral surface 24. Thereby, magnetization efficiency can be improved.

(Modification 7)
In the embodiment and the modification described above, the permanent magnet motor 100 is configured not to include the magnetizing coil 60. However, as a modification, a permanent magnet motor including a magnetizing coil fixed to the through hole may be used. . In this case, the magnetizing coil 60 is not removed from the rotor 20 after the magnet member 50 is magnetized using the magnetizing coil 60. Thereby, when the magnetic force of the magnet member 50 is weakened over time, the remagnetization process can be performed without reattaching the magnetizing coil 60. Thereby, the effort of re-magnetization can be reduced significantly.

(Modification 8)
In the magnetizing method in the above-described embodiment, the magnetizing coil 60 is attached and the magnetizing process is performed in a state where the rotor 20 is disposed inside the stator 10, but the rotation outside the stator 10 is performed. It is good also as attaching the magnetizing coil 60 with respect to the child 20, and performing a magnetization process. Further, the step of attaching the magnetizing coil 60 to the rotor 20 is performed outside the stator 10, and thereafter, the rotor 20 to which the magnetizing coil 60 is attached is arranged inside the stator 10 and magnetized. It is good also as giving. Thereby, the magnetizing coil 60 can be attached to the rotor 20 more easily.

(Modification 9)
In the above-described embodiment and modification, the case where the magnet member is magnetized using only the magnetizing coil provided in the rotor without using the motor coil for magnetizing has been described. It is good also as using a motor coil together. By using the motor coil together, even if the magnetic field applied by the magnetizing coil is insufficient for magnetization, the magnetic field applied by the motor coil can be added, and it is strong enough for magnetization. A magnetic field can be obtained. In this case, since the value of the current passed through the motor coil for magnetization can be reduced as compared with the case of magnetizing using only the motor coil, the influence on the motor coil can be reduced.

(Modification 10)
In the above-described embodiment and modification, the case where the cross-sectional shape of the through hole is a circle or an ellipse is shown, but the shape of the through hole is not limited to this, and may be a polygon such as a rectangle or a hexagon.

(Modification 11)
In the above-described embodiment and the modification, the case where the magnets are magnetized so that the polarities of the adjacent magnet members are opposite to each other is illustrated, but the polarities magnetized to each of the plurality of magnet members are not limited thereto. . For example, the magnet member disposed in the circumferential direction may be magnetized so that the polarity changes every second or third.

(Modification 12)
In the above-described embodiment and modification, the case of the “surface magnet type motor” in which the magnet member is attached along the outer peripheral surface of the rotor is exemplified. However, the “embedded magnet type motor” in which the magnet member is embedded inside the rotor. The above-described technique may be applied.

  DESCRIPTION OF SYMBOLS 10 ... Stator, 18 ... Motor coil, 20 ... Rotor, 26 ... Magnet insertion part, 32 ... Upper surface, 34 ... Lower surface, 40 ... Through-hole, 42 ... Groove part, 50 ... Magnet member, 60 ... Magnetization coil, 100: Permanent magnet motor.

Claims (6)

A permanent magnet motor with a rotor,
The rotor is
A cylindrical core, and
A plurality of magnet members arranged in a circumferential direction along the outer periphery of the core portion;
A groove or hole extending from the upper surface to the lower surface of the core portion,
The core portion has a protruding portion that protrudes radially outward at a position between adjacent magnet members,
The permanent magnet motor, wherein the groove or hole is provided at the same position in the circumferential direction as the protrusion . The permanent magnet motor according to claim 1 , wherein the groove or hole has an anisotropic cross-sectional shape. The permanent magnet motor according to claim 1 or 2, further comprising a coil which is laid along the groove or hole. Wear in the permanent magnet motor according to any one of claims 1 to 3, the magnet member and the magnetizing coil after attaching to the rotor, the magnet member by applying a current to the magnetizing coil A method of magnetizing a permanent magnet motor characterized by magnetizing. The method of magnetizing a permanent magnet motor according to claim 4 , wherein the magnetizing coil is removed from the rotor after magnetizing the magnet member. In the state in which the the rotor inside the stator, magnetizing method of the permanent magnet motor according to claim 4 or 5, characterized in that magnetizing the magnet member.

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