JP4392417B2 - Permanent magnet type rotating electric machine with coil on rotor side - Google Patents

Description

  The present invention relates to a rotary electric machine such as a stepping motor, which is a permanent magnet type rotary electric machine having a coil on a rotor side surface and is combined with a hybrid type permanent magnet type rotor.

  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, the present inventor has already applied for the following patent. The present application relates to the provision of a structure suitable for the small high-resolution rotary electric machine of these prior patents.

Japanese Patent Application 2001-317708 US Patent USP67881260B2

1) In order to keep the step angle small and small in stepping motors that are easy to position, especially with rotating electrical machines that drive OA equipment and robot fingers, the number of stator phases can be increased from two to five, etc. It was necessary to increase the number of teeth. However, increasing the number of teeth of the rotor is limited by the current stamping technology, and it is difficult to reduce the tooth width below the thickness of the silicon steel plate. Small and high-resolution design is difficult for the child structure.
2) The outer rotor type is suitable for high resolution because the rotor diameter can be increased, but the temperature rises because the coil is placed inside the rotor, and the shaft support is generally cantilevered. It was not suitable for use. There has been a need for an inner rotor type having the advantages of an outer rotor.

The present invention is realized by the following means.
"Means 1"
Two rotor elements made of a magnetic material having Nr magnetic teeth uniformly on the outer periphery, and an axial direction sandwiched between the two rotor elements at a position where the tooth pitch of each magnetic tooth is shifted by 1/2 A permanent rotor magnetized on the rotor shaft is fixed to form a hybrid rotor. The rotor is opposed to the outer periphery of the rotor via an air gap, has magnetic teeth on the inner periphery, and extends in the axial direction in the circumferential direction. The 2Ns stator arms arranged evenly and 2Ns stator arms are connected to each other at both ends or at predetermined positions, and the magnetic resistance is increased at 2Ns positions that are intermediate positions of the stator arms. For each stator arm, and a magnetic hollow disc having holes or narrow necks for equality, and yokes arranged on one side and the other side in the axial direction of the rotor and wound with coils respectively. Every other Ns stators A permanent magnet type rotating electrical machine having a means in which the arm is magnetically coupled to one yoke and the remaining Ns stator arms are magnetically coupled to the other yoke to form a stator .
"Means 2"
A permanent magnet type rotating electrical machine according to means 1, wherein the axial direction of the stator coil is orthogonal to the rotor axial direction .
"Means 3"
The permanent magnet type rotating electrical machine according to means 1, wherein the axial direction of the stator coil is parallel to the rotor axial direction .
"Means 4"
Two rotor elements made of a magnetic material having Nr magnetic teeth uniformly on the outer periphery, and an axial direction sandwiched between the two rotor elements at a position where the tooth pitch of each magnetic tooth is shifted by 1/2 A permanent rotor magnetized on the rotor shaft is fixed to form a hybrid rotor. The rotor is opposed to the outer periphery of the rotor via an air gap, has magnetic teeth on the inner periphery, and extends in the axial direction in the circumferential direction. The 2Ns stator arms arranged evenly and 2Ns stator arms are connected to each other at both ends or at predetermined positions, and the magnetic resistance is increased at 2Ns positions that are intermediate positions of the stator arms. And a magnetic hollow disk having substantially uniform holes or narrow necks in the circumferential direction, and arranged on one side and the other side in the axial direction of the rotor so that the coil axis is positioned concentrically with the rotor shaft. With the coiled yoke And every other Ns stator arms of each stator arm are magnetically coupled to one yoke and the remaining Ns stator arms are magnetically coupled to the other yoke A permanent magnet type rotating electrical machine that uses the stator as a means.
"Means 5"
In the means 1 or 4, the hybrid rotor has two rotor elements made of a magnetic material having Nr magnetic teeth evenly on the outer periphery, and the tooth pitch of each magnetic tooth is determined by the both rotor elements. A unit rotor is formed by using an axially magnetized permanent magnet sandwiched in a state of being shifted by a half, and the two unit rotors are coaxially connected to the rotor shaft so that each adjacent rotor element has the same magnetization. A permanent magnet type rotating electrical machine characterized in that the magnetic teeth of each other are configured in the same position in the circumferential direction .
"Means 6"
In any one of means 1 to 5, the yokes on one side and the other side of the stator hold the outer peripheral portion of the bearing that supports the rotor shaft, and the rotor shaft passes through at least one of both yokes. Permanent magnet type rotating electrical machine using as a means.

1) To achieve high resolution with a limited outer diameter, the motor length is longer than the coil arrangement on the outer circumference of the rotor, but the inner rotor arranged on both axial sides of the rotor rotates. The diameter can be increased, resulting in high resolution. When a small stepping motor is used, a high resolution with a small step angle is obtained, positioning accuracy is improved, and the motor has no rotation unevenness . A brushless motor that is designed to have a predetermined resolution, detects the rotor position, determines the timing for supplying the excitation current, and drives the brushless motor.
2) Because of the low speed and large torque characteristics, the rotating electric machine is suitable for direct drive without using a mechanical speed reducer.
3) Since the coil can be exposed to the outside, the motor has a large effect of suppressing the temperature rise caused by copper loss.
4) compared with the conventional placing coils in the slot, since it increases the coil space factor in wound concentrate on the yoke by increasing the coil volume, it is possible to large torque reduction, in addition to the rotor large diameter effect.
5) If a dust core is used for the coil yoke, the advantages of this structure can be further improved.

This will be described below with reference to the drawings.

FIG. 1 is a front sectional view including a rotation shaft of an example of the present invention. Reference numeral 1 denotes a stator main pole arm, which has a plurality of small teeth on the inner peripheral portion thereof. Hereinafter, the stator arm is simply referred to as a stator arm, and a total of 2Ns are arranged concentrically over 360 degrees. . FIG. 8 described later shows a diagram of the stator arm 1 viewed from the rotor axial direction in the case of Ns = 2. An end ring-like magnetic hollow disk 2 connects the stator arm 1 in a birdcage-like cylindrical shape on both side surfaces thereof. Reference numeral 3 denotes a magnetic yoke provided on the side surface of the rotor. The coils 4 and 5 are wound through an insulator 6 and are in contact with the stator arm 1 through a hollow disk 2 so that current is supplied to the coils 4 and 5. When flowing, the opposite rotor shaft sides of the coils 4 and 5 have different polarities. 9,10 is a magnetic rotor element has a magnetic tooth Nr number (plurality) on its outer periphery, shifted by a half of the tooth pitch from each other by two rotor elements 9, 10 constitute a hybrid type rotor to secure the permanent magnet 11 magnetized axially clamping rotating stylus shaft 12 in position. Reference numeral 13 denotes a bearing such as a ball bearing. On the outer periphery of the rotor elements 9, 10, there are arranged 2Ns of the above-described stator arms 1 extending in the axial direction, each having magnetic teeth facing each other via an air gap, of which every other Ns pieces are arranged. the arm 1 is magnetically coupled with the yoke 3 of coils 4 and 5 is wound which arranged on the end face side of one of the rotor elements 9 side through the magnetic hollow disks 2. The remaining Ns stator arms 1 are wound around coils 7 and 8 disposed on the end face side of the other rotor 10 and have the same configuration as the yoke 3, and have a phase difference of 90 degrees in electrical angle with the yoke 3. A stator is formed by magnetically coupling with the yoke 3 ′ arranged to have .
Figure 2 is illustrated the rotor to explain and stator structure diagram as viewed in the axial direction by cutting with a substantially central portion of the yoke 3 in the axial direction of FIG. 1 are omit. It is a figure of the two-phase rotary electric machine in case of Ns = 2. Coils 4 and 5 form one phase, and coils 7 and 8 form two phases. Ns = 2 has two stator arms for one phase. In this case, the electrical angle and the mechanical angle are the same, so that the yoke 3 and the yoke 3 'are arranged to have a 90-degree angular difference in mechanical angle. If Ns is 4, the yokes 3 and 3 'are not shown in the figure, but four coils are wound around four protruding yoke portions every 90 degrees, and the electrical angle is 90 degrees with respect to each other. Thus, a two-phase rotating electric machine with a total of eight stator arms arranged with an angle difference of 45 degrees is obtained. In this case, the rotor shown in FIG. 1 does not generate radial non-parallel electromagnetic force. Total 2Ns number of arms may be connected at their opposite ends or a predetermined location in the magnetic hollow disk 2 for connecting the stator arm 1 together with a laminate of silicon hardness. A total of three magnetic hollow disks 2 may be connected and fixed at both ends and the center. Incidentally total 2Ns number of Ns pieces of arm 1 of every other arm 1 may be one protruding on the rotor axis at right angles are integrally formed from a yaw click 3. The remaining Ns arms 1 may protrude from the yoke 3 ′ in the axial direction. These can also be produced by using a sintered iron core or a compacted iron core obtained by insulating and hardening iron powder with a resin.
If a three-phase, the yoke 3 and each total of three coils of three projecting yoke portions every 120 degrees in mechanical angle provided in the yokes 3 and 3 '3'is wound, all projecting yoke If the part is arranged at every 60 degrees in mechanical angle, Ns = 3 and a three-phase rotating electric machine with a total of six stator arms is obtained. It is characterized for the coil axis direction disposed on the axial side of the rotor is orthogonal to the rotor axis. The coil axial direction that means the direction of the magnetic flux sincerely generating coil when current flows in the coil.

In FIGS. 1 and 2, when the stator arm 1 is formed of a stack of silicon steel plates, or when a total number of arms of 2Ns is formed separately from the yokes 3 and 3 ′ using a dust core or the like. the total 2Ns number of arms 1 evenly in magnetic hollow disks arranged circumferentially fixed at its ends to form a birdcage-like cylindrical body stator arm 1 and the magnetic hollow disk 2. Then, the hollow disc 2 may be magnetically coupled to the yokes 3 and 3 '. In this case, it is desirable that a substantially hollow portion of the magnetic hollow disk 2 that opposes each arm is provided with a hole or a narrow neck so that it is magnetically saturated so as to be magnetically insulating or have a high magnetic resistance. . The four holes shown in the hollow disk 2 in FIG. 2 are for that purpose. Generally Stated if magnetic hollow disc that is not to desired having a hole or narrow neck portion for increasing substantially uniformly reluctance of 2Ns point.

FIG. 3 is another explanatory view of the present invention. The rotor and stator arm 1 and the magnetic hollow disk 2 are the same as those in FIG. 1 and FIG. The wound coils 15, 17, 18, 19 are arranged so that the coil axis direction is parallel to the rotor axis direction. Accordingly, the yokes 14 and 14 'disposed on both axial sides of the rotor magnetically coupled to the stator arm 1 are the same, but when Ns = 2, the yokes 14 and 14' are 90 degrees from each other. Arranged in a rotated positional relationship. Figure 4 is a diagram showing the Fig and is mainly positional relation of the yoke 14 and 14 'viewed rotor and the bearing from the rotating child axis except in FIG. In FIG. 3, the shafts, rotors and bearings are given the same numbers as in FIG. The yokes 14 and 14 'can be formed of a dust core. In addition, when the coil 15 or the like is inserted instead of being wound directly, the yokes 14 and 14 'may be appropriately divided. Yoke 14 and 14 'stator arm 1 as shown in FIG. 3, may be fitted to the inner diameter of the magnetic hollow disk 2, it is readily ing ensure the air gap between the rotor This way.

FIG. 5 is still another explanatory view of the present invention. The rotor, the bearing, the stator arm 1 and the magnetic body annular plate 2 are the same as those shown in FIGS. The feature of FIG. 5 is that the coils 23 and 24 arranged on both sides of the rotor are complete annular coils, one each, and the coil axis is arranged concentrically with the rotor axis direction and is limited to the two-phase system. Is. The yokes 21 and 22 of the coils 23 and 24 are the same, but when Ns = 2, they are arranged at positions rotated 90 degrees relative to each other as shown in FIG. FIG. 6 shows the positional relationship between the stator and the yokes 21 and 22 with the illustration of the annular coils 23 and 24 and the rotor omitted. This method and that the number of coils 2 and smaller than the present invention described above, this method also coil Ru can lower the temperature rise can be exposed partially. In figures 1-6, Koiruyo click features there Ru rotor axis while retaining the bearing outer peripheral portion is at least one of the through.

FIG. 7 is a view showing a preferred rotor structure of the present invention, particularly when Ns = 2 in the two-phase system. This rotor is composed of two rotor elements 25 and 26 made of a magnetic material having Nr number of magnetic teeth evenly on the outer periphery, and a permanent magnet 29 magnetized in the axial direction at a position shifted from the tooth pitch by a half. as sandwiched by hybrid rotor unit it is a rotor fixed to the rotating stylus shaft 12, the same rotor unit constituted by rotor elements 27, 28 and the permanent magnet 30, these two sets of units The rotors are connected coaxially, and adjacent rotor elements 26 and 27 have hybrid rotors having the same tooth position and magnetization polarity. Accordingly, the tooth positions of the rotor elements 27 and 28 are also shifted from each other by ½ pitch, and the tooth positions of the rotor elements 25 and 28 are the same position. In FIG. 7, the rotor elements 25 and 28 have N polarity, and the rotor elements 26 and 27 have S polarity. FIG. 8 is a view in which the teeth of the rotor elements 26 and 27 are not shown in FIG. 7 when the positional relationship of the stator having small teeth facing the rotor of the rotor element 28 or 25 is viewed in the axial direction. Yes, this corresponds to the case where the number of rotor teeth Nr = 15 and Ns = 2. In the case of a two-phase stepping motor, the step angle can be obtained by dividing the electrical angle of 90 degrees by Nr to be 6 degrees. The pitch of the magnetic teeth of the stator arm 1 and the rotor element 28 may be the same or slightly different in order to reduce the cogging torque. The relationship between the magnetic teeth of the stator arm 1 and the rotor element 9 in FIG. 1 and the like is the same as that shown in FIG.
In the case of Ns = 2, when the four stator arms 1 are equally arranged at 90 degrees, Ns = 15 is obtained by substituting n = 4 in the equation (9) described later. The stator arm 1 of FIG. 8 may be a laminated layer of silicon steel plates or a dust core.
FIG. 9 shows an example of a magnetic hollow disk , and has a role of fixing and fixing the four stator arms 1 shown in FIG. 8 at their both end faces. At this time, the four holes formed in the hollow disk 2 are arranged approximately in the middle of the four stator arms 1 shown in FIG. The hole of the hollow disk 2 may be a narrow neck, and is for minimizing the movement of magnetic flux between the four stator arms 1 of FIG. Four hollow inner diameter of the inner diameter and the hollow disk 2 of the stator arm 1 in Figure 8 but it may also be to have a magnetic teeth corresponding to the stator arm 1 inside the hollow disk 2 as the same. 7 and 8, the magnetic path of the interlinkage magnetic flux from the rotor to the stator will be described. The magnetic flux emitted from the N-pole rotor element 28 passes through the air gap and faces the teeth at the upper position in FIG. to which the stator arm 1 with teeth do not face the rotor element 28 beneath the Figure 8 interlinked coil and strands wound on the yoke through the rotor side surface of the yoke enters the stator arm 1 To reach. In this case, although not shown, since the rotor elements 28 and 27 are shifted from each other by a half of the tooth pitch, the teeth of the S pole rotor element 27 and the stator arm 1 directly below FIG. Opposite. Therefore, the magnetic flux emitted from the N-pole rotor element 28 enters the S-pole rotor element 27 and forms a closed magnetic circuit for one phase. This is the same in FIG. In FIG. 7, the same magnetic path is also formed in the N pole rotor element 25 and the S pole rotor element 26. At this time, the stator arm 1 directly above in FIG. 8 is magnetized to the S pole by energization of the coil, and the stator arm 1 directly below is magnetized to the N pole, and one phase is excited. When the current of the one-phase coil is cut and the current is switched to the two-phase coil, the right and left stator arms 1 in FIG. 8 are magnetized in different polarities, and the step angle is 1/4 pitch of the tooth pitch of the rotor 28. Rotate.

The torque in the case of combining the same rotor with a 4-main pole structure with 2Ns = 4 (Ns = 2) in this structure and an 8-main pole stator of a conventional system described later has been described in the above-mentioned document, but again I will explain individually.
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, and Φm is the flux linkage with the coil of the permanent magnet flux from the rotor.
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 with the same value of Φ _T , so the following formula is established with the number of turns and magnetic flux of each main pole of the 8 main pole machine and 4 main pole machine as N8, N4, Φ8, Φ4 To do.
Φ8 = Φ _T / 8 (2)
Φ4 = Φ _T / 4 (3)
N8 = N _T / 8 (4)
N2 = N _T / 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 (N _T / 8) Nri (Φ _T / 8) = N _T NriΦ _T / 8 (6)
T2 = 2 * 2 (N _T / 4) Nri (Φ _T / 4) = N _T NriΦ _T / 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.

The desired number of rotor teeth Nr in the case of the four main poles 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, Nr = 75 when n = 19, or Nr = 125 when n = 31, and (90 / Nr) degrees for the two-phase machine is the step angle, so that the step angle is 1.2 degrees and 0.72 degrees symmetrical, respectively. A rotating electric machine having a stator shape is obtained. Further, a symmetric stator electric rotating machine having a step angle of 2 degrees with n = 11 and Nr = 45 is obtained. In the case of Nr = 45 and a 2 degree step angle, if the rotor diameter is 14.33 mm and the tooth width and tooth gap width are 1: 1, the tooth width ratio is 50%, and the rotor tooth width is about 0.5 mm. Therefore, a standard 0.5 mm-thick silicon steel plate can be used. In the structure of the present invention, the stator outer diameter can be 20 mm, so that a small high-resolution product with a motor size of 20 mm and a step angle of 2 degrees can be obtained. If a quasi-standard silicon steel plate having a thickness of 0.35 mm is used, the tooth width ratio is 35%, which is close to the ideal ratio, and a high-performance, compact, high-resolution product can be obtained. This is the smallest and high-resolution specification practical in the industry.
Further, in this case, the stator arm 1 is uniformly arranged by 90 degrees, so that it is easy to ensure the arrangement accuracy and manufacture is easy. Although not desirable, Nr = 50 does not satisfy Equation (9), so the stator has an asymmetric shape, and a two-phase stepping motor with a step angle of 1.8 degrees.

Figure 10 shows a cross-sectional view perpendicular to the axis of rotation of the conventional two-phase hybrid stearyl Tsu pin Ngumota. Reference numeral 31 denotes a rotor element, which is an example having 50 teeth. There is a permanent magnet on the rear side, and the same rotor element 31 is arranged with a half shift of the tooth pitch. Reference numeral 32 denotes a stator core having an 8-main pole (8-winding pole) structure in order to eliminate unbalanced electromagnetic force. For this reason, as described above, the torque with respect to the four main poles is about half for the same rotor. However, when the four-pole structure is used, a radial unbalanced electromagnetic force is generated, which causes vibration noise. Therefore, it is desirable to use the above-described rotor of FIG. 7 in order to prevent the occurrence of unbalanced electromagnetic force in the radial direction with a four-main pole structure having a large torque. The reason why the radial unbalanced electromagnetic force is not generated in the four-main pole structure is described in the above-mentioned patent document, and therefore the detailed description thereof is omitted. However, referring to FIGS. Since the rotors 25 and 28 are attracted to the upper stator arm 1 and the rotors 26 and 27 are attracted to the lower stator arm 1, the vertical force and moment force acting on the rotor shaft 12 are cancelled. .
The step angle θ of the hybrid stepping motor is given by the following equation.
θ = 180 ° / PNr (10)
Where P is the number of phases.
When the number of rotor teeth Nr is 50 in FIG. 10 in the two-phase method, the equation (10) is satisfied, P = 2, and therefore the step angle is 1.8 °. In order to reduce the step angle and increase the resolution in the equation (10), P or Nr may be increased. However, if the number of phases is changed from two to five, the drive circuit becomes expensive. Further, when the number of rotor teeth is increased and the motor size is limited, when the rotor element is press punched, if the tooth width becomes smaller than the thickness of the silicon steel plate, press punching becomes difficult. In the structure of FIG. 10, the stator teeth are arranged on the outer periphery of the rotor and the coils are arranged outside thereof, so that the rotor diameter is considerably smaller than the motor diameter. The problem comes out.
Therefore, the outer rotor may be used to increase the rotor diameter, but the outer rotor makes the structure complicated and expensive, and the temperature rises because the coil comes inside the rotor. It is an advantage and effect of the present invention that these can be solved by the inner rotor type. This structure is an inner rotor type and can be configured with the largest rotor diameter.
In general, the torque generated by the motor is given by time.
T = kD2L (11)
Here, D is the rotor outer diameter, L is the rotor effective length, and k is a constant.
As a result, the product according to the present invention has a large D in the inner rotor and the effect is effective by the square, which is advantageous for increasing the torque.

  Since the rotating electrical machine according to the present invention is an inner rotor type and has high torque and high resolution, it is suitable for driving a finger of a robot as a copying machine, a printer, or a small motor, which is an OA device, and is expected to greatly contribute industrially. In addition, application to medical equipment, FA equipment, game machines, and housing equipment is also highly expected.

It is a cutting front view showing one example of the rotary electric machine by the present invention. FIG. 2 is a cut side view of FIG . 1. It is a cutting | disconnection front view which shows another Example of the rotary electric machine by this invention. It is the side view which removed a part of FIG . It is a cutting | disconnection front view which shows another Example of the rotary electric machine by this invention . It is the side view which removed a part of FIG. FIG. 6 is a cut front view of a stator and a rotor showing another embodiment of the rotating electrical machine according to the present invention. FIG. 8 is a side view of FIG. 7 . It is a side view which shows a magnetic body hollow disc. It is a side view of a stator and a rotor showing a conventional rotating electrical machine.

1: Stator main pole arm 2: Magnetic hollow disk 3, 3 ', 14, 14', 21, 22: Stator yoke 4, 5 , 7, 8 , 15, 17 , 18, 19, 23, 24 : Coil 9, 10, 25, 26, 27, 28 : Rotor element 11, 29, 30: Permanent magnet 12: Rotor shaft 13: Bearing

Claims (6)

Two rotor elements made of a magnetic material having Nr magnetic teeth evenly on the outer periphery, and an axial direction sandwiched between the two rotor elements at a position where the tooth pitch of each magnetic tooth is shifted by 1/2 A permanent rotor is fixed to the rotor shaft to form a hybrid rotor,
2Ns stator arms facing the outer periphery of the rotor via air gaps, each having magnetic teeth on the inner periphery, extending in the axial direction and evenly arranged in the circumferential direction, and 2Ns stator arms Are connected at both ends or at predetermined locations, and magnetic hollow discs having holes or narrow necks for increasing the magnetic resistance at the 2Ns locations that are intermediate positions of the stator arms, A yoke disposed on one side and the other side in the axial direction of the rotor and wound with a coil, and every other Ns stator arms of the stator arms are connected to the yoke on the one side. and with magnetically coupled, the permanent magnet type rotating electrical machine, characterized in that the remaining Ns pieces of the stator arms constituting said other side of the yoke and magnetically coupled to the stator. The permanent magnet type rotating electrical machine according to claim 1, wherein an axial direction of a coil of the stator is orthogonal to the axial direction of the rotor . The permanent magnet type rotating electrical machine according to claim 1, wherein an axial direction of a coil of the stator is parallel to the axial direction of the rotor . Two rotor elements made of a magnetic material having Nr magnetic teeth evenly on the outer periphery, and an axial direction sandwiched between the two rotor elements at a position where the tooth pitch of each magnetic tooth is shifted by 1/2 A permanent rotor is fixed to the rotor shaft to form a hybrid rotor,
2Ns stator arms facing the outer periphery of the rotor via air gaps, each having magnetic teeth on the inner periphery, extending in the axial direction and evenly arranged in the circumferential direction, and 2Ns stator arms And a magnetic hollow disk having holes or narrow necks for increasing the magnetic resistance at 2Ns positions, which are intermediate positions of the stator arms, and substantially uniformly in the circumferential direction. Each of the stator arms includes a yoke disposed on one side and the other side in the axial direction of the rotor and wound with a coil so that a coil axis is positioned concentrically with the rotor shaft. Every other Ns stator arms are magnetically coupled to the one yoke, and the remaining Ns stator arms are magnetically coupled to the other yoke to form a stator. It is characterized in that it was Permanent magnet electric motor that. The hybrid rotor has two rotor elements made of a magnetic material having Nr magnetic teeth uniformly on the outer periphery, and the tooth pitch of each magnetic tooth is shifted by 1/2 due to the two rotor elements. A unit rotor is formed using a permanent magnet magnetized in the axial direction sandwiched in a state, and the two unit rotors are coaxially connected to the rotor shaft, and the adjacent rotor elements have the same magnetization characteristics and are mutually connected. 5. The permanent magnet type rotating electrical machine according to claim 1, wherein the magnetic teeth are arranged at the same position in the circumferential direction . The yokes on one side and the other side of the stator hold an outer peripheral portion of a bearing that supports the rotor shaft, and the rotor shaft passes through at least one of the two yokes. Item 6. The permanent magnet type rotating electrical machine according to any one of Items 1 to 5 .

Images