JP5128800B2 - Hybrid permanent magnet rotating electric machine - Google Patents

Description

  The present invention relates to a rotating electrical machine such as a stepping motor in which a reduced main pole type stator and two permanent magnets are combined with a hybrid permanent magnet rotor in which repulsion magnetization is performed in opposite directions.

There is a demand for a rotating electrical machine such as a stepping motor that is small and has high torque and low vibration used in OA equipment. In order to solve this problem, one of the inventors has already applied for the following patent. This application relates to improvements to these prior patents.

Japanese Patent No. 3762981 US Patent USP67881260B2

1) Two rotary electric machines, such as a hybrid (hereinafter abbreviated as HB) stepping motor, which have a structure in which two unit rotors are closely connected coaxially and their permanent magnets are magnetized in opposite polarities. In order to sufficiently magnetize the magnets of this type, two unit rotors are closely connected coaxially for the magnetization after the completion of the rotor or the magnetization after the completion of the motor other than configuring the rotor using magnets magnetized alone. In order to magnetize the permanent magnets in opposite polarities to each other, when magnetizing two sets of unit rotors at the same time, there is a problem in that the permanent magnet portion cannot be sufficiently magnetized because the magnetic flux repels in the axial direction. In addition, even when two sets of unit rotors are magnetized separately with a time difference, the magnetic flux magnetizing one rotor leaks to the other rotor section and adjacent rotation of the two sets of rotors There is a problem that the elements are magnetized to have opposite polarity to the desired magnetization polarity, or the permanent magnet of one of the rotors already magnetized is demagnetized. Therefore, since the rotor is assembled using magnets magnetized alone, it is difficult to assemble by attracting iron powder and dust during assembly.
2) A normal HB type rotary electric machine having one permanent magnet is assembled into a motor, and a magnet is magnetized by inserting a completed motor into the inner diameter of the air core coil. The purpose of this is to prevent iron powder or dust from being drawn or attracted to the inner diameter of the stator to cause damage when the magnetized rotor is inserted into the stator. This type of motor is also preferably magnetized after completion and aims to solve this problem.
3) The stator of the rotating electrical machine of the present application has a main-saving pole structure (two-phase four-main pole, three-phase three-main pole, five-phase five main pole). The main pole is also called a concentrated winding. In patent documents 1 and 2 that have already been filed, the structure of the main poles (two-phase four-main poles, three-phase three-main poles, etc.) is a normal full main pole number structure of two-phase eight main poles or three-phase six main poles. On the other hand, the reason why a high torque torque can be obtained in the structure with the reduced number of main poles (also called the half main pole number with respect to the full main pole number) will be described later. However, the combination of the reduced main pole stator and a normal single rotor hybrid rotor generates unbalanced electromagnetic force, increases noise vibration, and deteriorates positioning accuracy. And in order to solve these, there exists a means of patent documents 1 and 2 mentioned above. For this reason, the motor used in the present invention maintains the characteristics of low vibration and low-layer sound, and the air gap between the stator and the rotor can be increased by that much to achieve the same level of torque as a normal structure motor. Reliability is improved. Alternatively, although a full main pole motor uses a high-energy rare earth magnet, an inexpensive permanent magnet such as ferrite can be used, so that a cost reduction effect can be expected. However, Documents 1 and 2 do not disclose a method for magnetizing the permanent magnet. Permanent magnets are magnetized with a magnetic flux density-magnetizing force characteristic (hereinafter referred to as BH curve) exceeding H that reaches the saturation of B. In the structure of magnetizing in the reverse polarity, sufficient magnetization could not be obtained with the conventional air-core coil system after the motor was completed.

The present invention is realized by the following means.
"Means 1"
Stator composed of a substantially annular magnetic body having an outer shape including a polygon, and a plurality of main poles formed radially projecting from the magnetic body and forming a number of inductors at respective tips. And a unit rotor comprising a pair of rotor elements which are provided rotatably with respect to the stator via an air gap and have magnetism, and a permanent magnet which is sandwiched between the two rotor elements and is magnetized in the axial direction. And a pair of rotors each having a plurality of teeth formed on the outer peripheral surface of each rotor element of each unit rotor. The elements are arranged so that each tooth is shifted by 1/2 pitch, and both rotor elements are arranged so that the magnetization positions of the respective permanent magnets are opposite and the tooth positions of adjacent rotor elements coincide. And a conductive material is interposed between the unit rotors. A permanent magnet type rotating electric machine according to means that it is.
"Means 2"
In the means 1 , the stator and the rotor are supported by a pair of brackets covering from both sides in the axial direction, and the permanent magnets in the two sets of unit rotors are arranged outside the bracket in the axial direction and the diameter of the stator. A yoke that covers the outer side of the rotor, a bracket, a rotor element on the outer side in the axial direction of the unit rotor, a permanent magnet of the unit rotor, a rotor element on the inner side in the axial direction of the unit rotor, and a stator. A permanent magnet type rotating electrical machine that uses a magnetizing coil that generates a magnetic flux in a magnetizing magnetic path to be magnetized and is magnetized simultaneously or with a time difference .
"Means 3"
In the means 2, the yoke that covers the outside in the axial direction of the bracket covers only one of the pair of brackets, and the magnetization by energization of the magnetizing coil is permanent for the unit rotor on the one bracket side. Magnetization is performed on the permanent magnet of the unit rotor on the other bracket side by energizing the magnetizing coil with the yoke reversed and opposed to the other bracket side after the magnetization. Permanent magnet type rotating electrical machine that has means to do.
"Means 4"
Stator composed of a substantially annular magnetic body having an outer shape including a polygon, and a plurality of main poles formed radially projecting from the magnetic body and forming a number of inductors at respective tips. And a unit rotor comprising a pair of rotor elements which are provided rotatably with respect to the stator via an air gap and have magnetism, and a permanent magnet which is sandwiched between the two rotor elements and is magnetized in the axial direction. And a pair of rotors each having a plurality of teeth formed on the outer peripheral surface of each rotor element of each unit rotor. The elements are arranged such that each tooth is shifted by 1/2 pitch, and both rotor elements are arranged so that the positions of the adjacent rotor elements coincide with each other in the direction in which the magnetization direction of each permanent magnet is reversed, and In addition, a conductive material is interposed between the two rotor elements to support the rotating shaft. It is, the rotation axis of the rotor is a permanent magnet type rotating electrical machine is supported by a pair of brackets covering the both sides in the axial direction,
Each of the permanent magnets in the two sets of unit rotors has a yoke that covers the outer side in the axial direction and the outer side in the radial direction of the unit rotor in a state where the two sets of unit rotors are supported on the rotating shaft, and the unit from the yoke. Using a rotor element on the outer side in the axial direction of the rotor, a permanent magnet of the unit rotor, and a magnetizing coil for generating magnetic flux in a magnetizing magnetic path reaching the yoke through the rotor element on the inner side in the axial direction of the unit rotor A permanent magnet type rotating electrical machine that is magnetized simultaneously or with a time difference.
"Means 5"
In the means 4, the yoke covering the unit rotor covers only one of the two sets of unit rotors and covers the radially outer side of the rotor element on the inner side in the axial direction of the one unit rotor. Yes, the magnetization of the magnetizing coil is performed on the permanent magnet of the one unit rotor, and after the magnetizing, the yoke is reversed to face the other unit rotor, and the magnetizing coil is energized. A permanent magnet type rotating electrical machine having means for performing magnetization on the permanent magnet of the other unit rotor . In this case, the eddy current effect by the conductive material is the same as that of the means 2.

1) Rather than assembling the rotor after magnetizing with a permanent magnet alone, after completing the rotor or after completing the motor, adopt a simple magnetizing yoke and conductive material provided on the rotor Due to the eddy current effect, the magnetization becomes more reliable, and iron powder and facets are not attached to the rotor, so that there is no rework and the reliability can be improved.
2) Since the yoke is used in comparison with the air-core coil magnetization of the conventional HB type motor, the magnetizing power source is small and low power can be achieved.
3) An inexpensive magnet having a low magnetic energy such as a bond magnet or a ferrite magnet can be used, and a permanent magnet type rotating electrical machine excellent in cost performance can be provided.
4) A small high-torque rotating electrical machine with a simple winding with a reduced main pole and no unbalanced electromagnetic force due to a special rotor can be provided at low cost.

  This will be described below with reference to the drawings.

FIG. 1 is a structural view seen from the axial direction of a rotating electrical machine by a combination of a stator of a two-phase four-main-pole machine, which is a reduced main pole structure stator of the present invention, and a special HB type rotor. However, the winding coil is not shown. Reference numeral 18 denotes a stator core, which includes polygons and circular shapes including substantially quadrilaterals and hexagons, and 9 is a rotor. Of the four main poles (winding poles) of the stator 18, the two main poles facing each other at 180 degrees are phase currents that are passed through coils that are not shown so that they have the same phase and different polarities. Configured to be excited. At this time, for example, if only one phase is excited and the N-pole rotor faces the main pole excited by the one-phase S pole, the opposite main pole is 180 degrees magnetized by the one-phase N pole. Is in a phase relationship that is non-opposing to the N-pole rotor (opposite teeth and grooves and 180 degrees in electrical angle), and conversely, the rotor S-pole is magnetized by the above-mentioned one-phase N-pole. The poles will face the teeth. At this time, the teeth of the stator main pole and rotor teeth for two phases that are not excited have a phase relationship of 90 degrees. As shown in FIGS. 6 and 7, the number of main poles in a conventional two-phase HB type rotating electric machine is eight as described later in FIG. 6 and FIG. 7, but this configuration shown in FIG. The main pole.
2 is a cross-sectional view of the motor of FIG. 1 of the present invention including a shaft. Reference numerals 9, 11, 20, and 13 denote rotors having Nr teeth on the outer periphery made of a magnetic material, and have the same axial thickness. 29 is a conductive material disk or copper foil sheet provided between 11 and 20, and it is desirable that the rotor 9 or the like has a disk shape with an outer diameter or less and has a hole through which the shaft 14 passes in the center. It may be a square or its deformation. Reference numerals 10 and 12 are disk-like permanent magnets that are magnetized so as to have opposite polarities in the direction of the axis 14. For example, 9 and 13 are magnetized so as to have N polarity and 11 and 20 have S polarity. At this time, 9 and 13 have the same tooth position, and 11 and 20 are arranged with a shift of 1/2 of the tooth pitch. The rotor of the motor according to the present invention is constituted by connecting in the axial direction two sets of unit rotors of unit rotors A (composed of 9, 10, 11) and B (composed of 20, 12, 13). Although expressed, this uses two permanent magnets 10 and 12, and the rotors 11 and 20 sandwiched between the two permanent magnets have teeth against the rotors 9 and 13 located on both sides of the two. This is the same even if it is expressed as one special rotor whose position is shifted by 1/2. A conductive material disk 29 is provided between the two sets of unit rotors A and B, and is composed of one special rotor as described above.
Reference numerals 15 and 16 denote brackets which have a role of holding the rotor rotatably. Reference numeral 5 denotes a stator coil. The reason for providing the special rotor by the two sets of permanent magnets is to eliminate the unbalanced electromagnetic force in the radial direction generated by the combination of the four main pole stator and the normal HB type rotor. Although the two-phase type is shown in FIG. 1, the present invention is not limited to this, and a special rotor composed of a three-phase three-main pole or a five-phase five-main pole saving main pole stator and two permanent magnets may be used. Good.

  6 and 7 are diagrams showing a conventional ordinary two-phase HB type rotating electrical machine, FIG. 6 is a view seen from the axial direction, 30 is a stator of two-phase eight main poles, and 31 is a rotor. is there. FIG. 7 is a cross-sectional view including the rotor shaft of FIG. In this structure, the rotor has one permanent magnet 33, 31 and 32 are rotors having the same shape as 9, 11, and 13 in FIG. It is configured. The stator has eight main poles, and every other four stators are wound with coils for one phase (not shown). In this case, since the main poles at the opposite positions at 180 degrees are configured to have the same polarity by the excitation current, the normal attraction force in the radial direction is always canceled, and the tangential torque on the outer periphery of the rotor Only ingredients appear. On the other hand, for example, when the rotor of FIG. 7 is combined with the stator of FIG. 1, for example, when the rotor 31 is pulled upward with N polarity, the S pole 32 of the rotor is pulled downward to attract in the radial direction. Unbalanced electromagnetic force due to force, a couple due to so-called side pull is generated, which generates vibration and noise, and deteriorates positioning accuracy. On the other hand, in the configuration of FIG. 2, the rotor is symmetrical on the left and right sides from the magnetic material 29 in the central portion in the axial direction, so that two symmetric HB rotors act as if canceling the couple of unbalanced electromagnetic force. To do. For this reason, it has the outstanding effect which always cancels the couple by the unbalanced electromagnetic force of radial direction. The detailed principle is explained in detail in Patent Documents 1 and 2 invented by one of the inventors of the present application by using mathematical formulas, and the detailed explanation is omitted here. The configuration shown in FIGS. 1 and 2 of the present application is a two-phase HB type stepping motor, but can be used for a three-phase or five-phase HB type stepping motor, a two-phase or three-phase brushless motor, or a synchronous motor. It is.

The torque when the same rotor is combined with the two-phase four main pole and the eight main pole stator of this structure has been described in the above-mentioned literature, but will be described again.
T1 = N NriΦm
(1)
The torque for one phase is expressed by equation (5). Nr is the number of rotor teeth, N is the number of coil turns, i is the current,
Φm is an interlinkage magnetic flux between the permanent magnet magnetic flux from the rotor and the coil.
Both have the same wire diameter and the same total number of turns Nt. The total amount of magnetic flux generated from the rotor is equal to, for example, 48 when the number of teeth of both stators is equal to 48 (8 × 6 = 48 for 8 main poles, 4 × 12 = 48 for 4 main poles). Neglecting the magnetic resistance difference of the iron core, it can be approximated to the same value of Φt, so the number of turns and the magnetic flux of each main pole of the 8-main pole machine and 4-main pole machine are N8
, N4, Φ8, Φ4, the following equation is established.
Φ8 = Φt / 8
(2)
Φ4 = Φt / 4
(3)
N8 = Nt / 8
(4)
N2 = Nt / 4
(5)
From the formulas (1) to (5), the torques of the 8 main pole 4 main pole machine, T8, T4 are as follows.
T8 = 2 * 4 (Nt / 8) Nri (Φ _T / 8)
= NtNriΦt / 8
(6)
T2 = 2 * 2 (Nt / 4) Nri (Φt / 4)
= NtNriΦr / 4
(7)
From (6) and (7), the 4-main pole machine can output about twice the torque of the motor of the conventional 8-main pole machine.

Desired rotor teeth N _r in the case of the fourth main electrode is derived from the following equation.
90 / Nr = (− / +) {(360/4) −360n / Nr} (8)
However, n is an integer of 1 or more.
The left side and the right side of the equation (8) represent the step angles of this configuration, and when this is arranged, the equation (9) is obtained.
Nr = 4n ± 1
(9)
Nr is a desirable form of a two-phase four-main polar symmetric structure.
For example, when n = 19 and Nr = 75, and the two-phase machine has a step angle of (90 / Nr) degrees, a symmetrical stator rotating electric machine can be obtained with a 1.2 degree step angle.
In this case, since the stator is 90 degrees symmetrical, it can be rotated 90 degrees when stacked. If rotation stacking is possible, it is possible to eliminate the deviation of the stack thickness and cancel the magnetic direction of the silicon steel plate, and to obtain good motor characteristics. Although not desirable, Nr = 50 does not satisfy Equation (9), so the stator becomes asymmetrical and cannot be rotated 90 degrees, but a two-phase stepping motor with a step angle of 1.8 degrees.

Since two permanent magnets are used in Fig. 2, the fact that high torque can be obtained even with low grade magnets is compared with the case of using a conventional two-phase 8-main pole type magnet (configuration in Figs. 6 and 7). Show. The conventional permanent magnet used in the two-phase 8-main pole type is a rare earth magnet, a neodymium magnet, and a residual magnetic flux density Br of 1.3 [T]. On the other hand, in the case of the present application, since there are two magnets with two phases and four main poles, Br of the magnet is obtained by the following equation.

Br = 1.3 [T] × (1/2) (3/2) (4/8) = 0.4875 [T] (10)
In equation (10), (1/2) is approximately ½ the outer peripheral area of the rotor excited by one magnet compared to a conventional HB type rotor combined with a conventional eight main pole of the same size. Therefore, the magnetic flux generated from the permanent magnet may be halved, so if the magnet area is the same, the magnetic flux density of the magnet may be halved. (3/2) is the iron core because the magnetic path length of the permanent magnet is halved. The permeance at the portion is simply about twice, but the permeance is approximated to about 3/2 times in total in consideration of the decrease in the air gap and the magnetic flux density of the magnetic path. (4/8) means (4 main poles / 8 main poles), and the torque is due to being inversely proportional to the number of main poles based on the relationship between the expressions (6) and (7).
A torque equivalent to that of an 8-main pole motor using a neodymium magnet having a Br value of 1.3 [T] (Tesla) and having a Br value in the equation (10) can be obtained. The result of the equation (10) almost coincides with the magnetic field analysis result in the computer.
The value of Br corresponds to a ferrite magnet. The ferrite magnet has a Br of 0.5 [T] and a holding force Hcj of about 275 KA / m, and its demagnetization curve becomes a straight line in the second quadrant of the coordinates where the magnetic flux density is perpendicular and the holding force is taken horizontally, The operating point is the intersection of a straight line passing through the origin with the permeance coefficient of the assembled permanent magnet as the gradient and the demagnetizing curve, but the operating point magnetic flux density is approximately proportional to Br of the permanent magnet (approximately ( 6) Equation is established. Ferrite magnets are extremely cheap compared to rare earth magnets, and even if two are used, they are cheaper than neodymium magnets. Ie 0.5
[T] Sufficient practical torque can be obtained with the following magnets. If it is a magnet of 0.5 [T] or less, it is not limited to a dry or wet sintered ferrite magnet, but may be a bond (plastic) magnet using a resin as a binder. In sintered ferrite magnets, for example, an outer diameter of 25 mm and a thickness of about 2 mm are the limit for mass production, and if it is thinner than that, crack defects frequently occur. If this is used as a bond magnet, the crack defect is solved.
By adopting a low-grade permanent magnet of 0.5 [T] or less while suppressing unbalanced electromagnetic force with the two-phase four-winding pole stator and the above-described two-line rotor, a conventional expensive neodymium sintered magnet Torque can be increased or reduced by the same size as the same size motors using rare earth magnets such as samarium cobalt magnets.

  However, it is difficult with the conventional air-core coil to reversely magnetize the two permanent magnets of the rotating electrical machine having the configuration shown in FIG. 2 in the opposite directions in the axial direction. One solution is to assemble the rotor in such a way that the permanent magnets 10 and 12 previously magnetized with the permanent magnet alone in FIG. 2 are opposite in polarity to each other, and then incorporated into the stator. However, with this method, iron powder is sucked into the rotor when the rotor is assembled, or the stator is sucked into contact with the stator when the rotor is inserted into the inner diameter of the stator, so that facet and dust are interposed in the stator to reduce reliability. To be

On the other hand, the magnetization system according to the present invention will be described with reference to FIG. The HB type rotating electric machine composed of the above-mentioned main-main pole stator and a special rotor composed of two permanent magnets is set in two axial directions made of magnetic material so as to wrap the shaft 14 as a core. It consists of magnetic paths A and B for magnetism. The rotating electric machines to be magnetized are those shown in FIGS. 1 and 2, and therefore the same reference numerals as those in FIGS. The set magnetizing magnetic path A is an annular yoke 1 and 2 in FIG. 3 and an annular magnetizing coil 3 wound around an insulator bobbin 4. A magnetizing current is passed through the coil 3 so that a magnetizing magnetic flux penetrating the bracket 15 from a portion protruding from the yoke 1 in the direction of the shaft 14 penetrates the magnetic rotor 9 and penetrates the permanent magnet 10, thereby passing the magnetic rotor. 11 is allowed to flow. Since this magnetization magnetic flux is generated by the coil 3, it tries to form a closed loop around the coil 3. Therefore, a part of this magnetization magnetic flux does not pass through the permanent magnet 10 from the rotor 9 but directly enters the magnetic stator 18 and returns to the yoke 1 via the yoke 2. However, since the rotor 9 and the like are usually composed of a silicon steel plate, if the saturation magnetic flux density exceeds about 1.5 {T}, most of the magnetized magnetic flux beyond that passes through the permanent magnet 10 and reaches 11 to reach the magnetism 18. Since the yoke 2 returns to the yoke 1 via the body stator, the permanent magnet 10 is magnetized. In this way, the magnetic field A, which is approximately ½ in the axial direction in the axial direction by the set magnetization magnetic path A, is excited by the annular magnetizing coil 3 and the permanent magnet on one side is approximately axial. It can be magnetized in the direction. In this case, if the bracket 15 and the ball bearing 17 are made of a magnetic material, the penetrating magnetization magnetic flux can be increased. However, if the bracket 15 is made of a non-magnetic material such as aluminum, a large air gap is interposed, and the magnetized magnetic flux is sufficiently magnetized. In order to reach 10, the key points are the portion of the yoke 1 protruding in the axial direction and the presence of the coil 3 wound on the outer periphery of the protruding portion. Therefore, the cross-sectional shape of the coil is preferably a shape in which a step is provided in the insulator 4 as shown in the drawing. In this way, the unit rotor A is magnetized. However, if a sufficient amount of magnetizing magnetic flux passes through the permanent magnet 10 of the unit rotor A, a part thereof becomes a leakage flux and also passes through the magnetic rotor 20, the permanent magnet 12, and the magnetic rotor 13 of the unit rotor B. Thus, the permanent magnet 12 of the unit rotor B is magnetized in the same direction as the permanent magnet 10 of the unit rotor A opposite to the desired polarity. In this case, if there is a conductive disk 29, an eddy current is generated in the conductive disk so that the leakage magnetic flux begins to penetrate 29, and the permanent magnet on the unit rotor B side is magnetized. It will act to prevent.
Similarly, a magnetizing current is passed through the coil 7 wound around the insulator 8, and the magnetized magnetic flux penetrated from the portion projecting from the yoke 19 in the direction of the shaft 14 through the bracket 16 and the ball bearing 17 is magnetic. The rotor 13 is penetrated, and the permanent magnet 12 is penetrated so as to have the opposite polarity in the axial direction with respect to the permanent magnet 10 on one side, and flows into the magnetic rotor 20. For the same reason, this magnetized magnetic flux constitutes a closed magnetic circuit that returns from the rotor 20 to the yoke 6 and the yoke 19 via the stator 18, so that the permanent magnet 12 is also magnetized. Also in this case, a part of the magnetic flux leaks and tries to demagnetize the already magnetized permanent magnet 10 of the unit rotor A. In this case as well, if there is a conductive disk 29, when this leakage magnetic flux begins to penetrate 29, an eddy current is generated in the conductive disk so as to cancel it, and the permanent magnet on the unit rotor A side is demagnetized. It will act to prevent it.
In this system, rotors 9, 11, 20, 13 and a stator 18 are used in addition to 1, 2 or 6, 19 as magnetic material yokes. Therefore, the magnetized magnetic flux density is magnetized in a neodymium sintered magnet having a residual magnetic flux density Br of about 1.2 {T} at a saturation magnetic flux density of about 1.5 {T} of the silicon steel plate constituting the rotor and stator. Although the force may be insufficient, when the above-described ferrite magnet having Br of about 0.5 {T} is used for the permanent magnet of this structure, the magnetization method is sufficiently suitable. It should be noted that the yoke 2 and the yoke 6 may be combined separately or 2 and 6 may be integrated.
A closed magnetic path composed of the yokes 1, 2, 9, 11, and 18 is set. A magnetic path for magnetization A, a yoke 19, a yoke 6, the rotors 13 and 20, and a stator 18 are set. In the case of the path B, the set magnetization magnetic paths A and B may be magnetized by providing a time difference with an appropriate magnetization force. In this case, if the magnetizing force is too strong, the permanent magnet 10 and the permanent magnet 12 are magnetized in the same direction, so that the magnetizing force is optimized with the magnetic path. Alternatively, it may be simultaneously magnetized with an appropriate magnetizing force. In these cases, the conductive disk 29 described above works effectively.
In FIG. 3, the magnetizing coil is shown as an annular coil concentric with the rotor shaft, but the outer periphery of the rotor at the end of the magnetizing magnetic paths A and B provided substantially perpendicular to the rotor shaft on the outer periphery of the stator. A part of the disk portion may be cut and a magnetized coil may be wound directly on a yoke portion that is substantially perpendicular to the rotor shaft, or these coils may be connected in series or as a side coil with a concentric annular coil. You may make it parallel.

FIG. 4 shows a method in which a magnetizing step is provided after the rotor is completed. When the motor is completed after completion of the motor, a silicon steel plate of a rotor or a stator is used as a part of the magnetic path. Therefore, the permanent magnetic flux density of neodymium sintered magnet or the like is about 1.2 {T} at the magnetic flux density of about 1.5 {T} of the magnetic flux density of the non-oriented silicon steel plate widely used for rotating machines. There are cases where it is not sufficient to magnetize the magnet. Also, with this method, contact with the stator is likely to occur when the rotor is inserted into the stator after magnetization, but sufficient magnetizing force of the permanent magnet is sacrificed at the expense of some of the advantages of magnetization after completion of the motor. Therefore, the method of magnetization in the completed rotor state is shown. In this case, since a silicon steel plate is not used, pure iron or the like having a high saturation magnetic flux density can be used for the yoke. Since the saturation magnetic flux density of pure iron is about 2.2 {T}, it can be magnetized even with a neodymium sintered magnet or the like. Reference numerals 21 and 25 denote yokes that generate magnetized magnetic flux in the rotor axial direction, and magnetizing coils 24 and 28 are arranged on the outer periphery thereof so that the magnetized magnetic flux is emitted in the axial direction. Since the structure of the rotor is the same as in FIG. 2, the part names and the numbers are the same. Reference numerals 22 and 26 denote external yokes which are formed in a cylindrical shape with the shaft 14 concentric and appropriately divided to incorporate the insulating bobbins 23 and 27 and the magnetizing coils 24 and 28 described above. The ends of 22 and 26 are in contact with or close to the outer periphery of the rotor. 21 and 22, 26 and 25 are brought into close contact with each other. In this case, since there are no brackets on both sides, the magnetized magnetic flux is applied to the permanent magnets 10 and 12 more fully than in the case of FIG. At this time, the effect of the conductive material 29 is the same as the magnetization after completion of the motor described above. If this magnetization is performed at the stage before the ball bearing 17 is inserted, the opposing area of the rotors 21 and 25 to the rotors 9 and 13 can be increased, and the magnetization can be facilitated. Also in this case, the two magnetizing coils may be energized simultaneously or energized with time difference. Even if the motor shown in FIGS. 1 and 2 is an outer rotor type, it can be magnetized according to this method. In FIG. 4, the magnetizing coil is shown as an annular coil concentric with the rotor shaft, but the rotor at the end of the magnetizing magnetic paths a and b provided on the outer periphery of the stator substantially perpendicularly to the rotor shaft. A part of the outer peripheral disk portion may be cut and a magnetized coil may be wound directly on a yoke portion that is substantially perpendicular to the rotor shaft, or these coils are connected in series as a side coil with a concentric annular coil. Or you may make it parallel.

Another embodiment of the magnetization after completion of the motor will be described with reference to FIG. FIG. 3 is provided with two set magnetization magnetic paths in advance, but FIG. 5 performs magnetization with only one set magnetization magnetic path. In FIG. 5, reference numerals 1 and 2 denote yokes, which are basically the same as only the set magnetic path A on one side of FIG. 3, but the axial thickness of the yoke 2 facing the outer periphery of the motor stator 2 is the center. The thickness is set so as to face the entire axial thickness of the rotor 11. In the state of FIG. 5, the magnet is magnetized with an appropriate magnetizing force, and only the permanent magnet 10 is magnetized. If the magnetizing force is too strong, the permanent magnet 12 is also magnetized, so that the magnetizing force is optimized with respect to the magnetic path. Thereafter, the motor may be pulled out of the yoke portion, reversed in the axial direction, inserted into the yoke portion, and similarly magnetized. In this case, although it takes some time to magnetize, the magnet yoke and the apparatus can be made smaller than in the case of FIG. 3, and in addition to optimizing the thickness of the yoke 2 facing the motor, the motor magnetizing position is set in the axial direction Optimal magnetization improvement such as optimization at the positive position and the reverse position can also be performed. At this time, the effect of the conductive material 29 is the same as the magnetization after completion of the motor described above.

  Since the rotating electric machine magnetized according to the present invention can produce a high torque with an inexpensive magnet, it is possible to provide a low-cost and high-torque motor for the use of copying machines and printers that are office automation equipment, and the air gap can be increased, resulting in low vibration. It is expected to make a significant industrial contribution. In addition, application to medical equipment, FA equipment, robots, amusement machines, and housing equipment is also highly expected.

Diagram of the rotating electrical machine of the present invention Side sectional view of FIG. Magnetization method diagram of the present invention Another magnetizing system diagram of the present invention Magnetization method diagram after motor completion Diagram of conventional 2-phase HB type rotating machine Side sectional view of a conventional two-phase HB type rotating machine

Explanation of symbols

1, 2, 6, 19, 21, 22, 25, 26: magnetized yoke,
4, 8, 23, 27: Insulated bobbins
3, 7, 24, 28: Magnetized coil,
9, 11, 13, 20, 31, 32: rotor,
5: Coil 14: Rotating shaft,
10, 12, 33: Permanent magnet 29: Conductive material 15, 16: Bracket 17: Ball bearing 18, 30: Stator

Claims (5)

Stator composed of a substantially annular magnetic body having an outer shape including a polygon, and a plurality of main poles formed radially projecting from the magnetic body and forming a number of inductors at respective tips. And a unit rotor comprising a pair of rotor elements which are provided rotatably with respect to the stator via an air gap and have magnetism, and a permanent magnet which is sandwiched between the two rotor elements and is magnetized in the axial direction. And a pair of rotors each having a plurality of teeth formed on the outer peripheral surface of each rotor element of each unit rotor. The elements are arranged so that each tooth is shifted by 1/2 pitch, and both unit rotors are arranged so that the tooth positions of adjacent rotor elements coincide with each other in the direction in which the magnetization direction of each permanent magnet is reversed , and And a conductive material interposed between the adjacent rotor elements. Is supported by a shaft, a permanent magnet type rotating electrical machine, characterized in that the rotation axis of the rotor is supported by a pair of brackets covering the stator and the rotor from both sides in the axial direction. The two sets each of the permanent magnets in the rotor unit of the yoke for covering the radially outer axially outwardly and said stator of said bracket, bracket from the yoke, axially outer rotor element of the unit rotor, Using a permanent magnet of the unit rotor, a rotor element on the inner side in the axial direction of the unit rotor, and a magnetizing coil for generating a magnetic flux in a magnetizing magnetic path reaching the yoke through the stator, a time difference is provided. The permanent magnet type rotating electric machine according to claim 1, wherein the permanent magnet type rotating electric machine is magnetized.   The yoke that covers the outside in the axial direction of the bracket covers only one of the pair of brackets, and the magnetizing by energizing the magnetizing coil is performed on the permanent magnet of the unit rotor on the one bracket side. The magnet is magnetized with respect to the permanent magnet of the unit rotor on the other bracket side by energizing the magnetizing coil with the yoke reversed to the other bracket side after the magnetization. The permanent magnet type rotating electrical machine according to claim 2. Each of the permanent magnets in the two sets of rotor units is a both said rotor unit in a state of being supported by the rotary shaft by interposing a conductive material between each adjacent two rotor elements, the rotor unit A yoke that covers the outer side in the axial direction and the outer side in the radial direction, and this yoke reaches the yoke through the rotor element on the outer side in the axial direction of the unit rotor, the permanent magnet of the unit rotor, and the rotor element on the inner side in the axial direction of the unit rotor. 2. The permanent magnet type rotating electrical machine according to claim 1, wherein the permanent magnet type rotating electric machine is magnetized at the same time or with a time difference using a magnetizing coil that generates magnetic flux in the magnetizing magnetic path.   The yoke covering the unit rotor covers only one of the two sets of unit rotors and covers the radially outer side of the rotor element on the inner side in the axial direction of the one unit rotor. Magnetization by energization of the magnetic coil is performed on the permanent magnet of the one unit rotor, and after the magnetization, the yoke is reversely opposed to the other unit rotor to energize the magnetizing coil. The permanent magnet type rotating electric machine according to claim 4, wherein the permanent magnet of the other unit rotor is magnetized.

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