JPH07154935A - Permanent magnet rotating electric machine - Google Patents

Abstract

PURPOSE:To provide a permanent magnet rotating electric machine suitable for drum driving of LBP or the like in which magnetic flux distribution is a sinusoidal, the torque is high and cogging torque can be reduced. CONSTITUTION:In a rotor R1 formed of a cylindrical magnetic body having a hole into which a rotating shaft is inserted in the center, a plurality of U-shaped slits 20 are provided in the periphery of this rotor at equal pitches with non-slit parts facing outward in a radial direction so that the widths (A part) of magnetic body parts between the adjacent U-shaped slits are equal to the widths (B part) of magnetic body parts which are the non-slit part in the U shape, and inside the U-shaped slits U-shaped permanent magnets or bond magnets 21 are provided, so as to magnetize the A parts and B parts of different polarity.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention is an improvement of a permanent magnet type rotating electric machine such as a permanent magnet type stepping motor having a small rotational vibration, which is particularly suitable for a laser beam printer (hereinafter abbreviated as LBP). Regarding

[0002]

2. Description of the Related Art The contents of the prior art will be described with reference to FIGS.
The configuration will be described. Conventional Example 1: FIG. 12 is a perspective view showing the structure of a two-phase permanent magnet type stepping motor or a synchronous motor of Conventional Example 1. In the figure, a stator S'comprises a first stator portion 1 and a second stator portion 2 which constitute two phases, and the first stator portion 1 is a comb which is assembled with each other on the inner peripheral side thereof. Tooth-shaped pole teeth 1a, 1b and these pole teeth 1a, 1
The annular coil 1c housed in b, and the second stator part 2 likewise has pole teeth 2a, 2b and these pole teeth 2
It is composed of an annular coil 2c housed in a and 2b. Here, the pole teeth 1a and 2a are arranged at an electrical angle offset by, for example, 90 °. R'is a rotor, and this rotor R'is composed of permanent magnets 3, a core 4, and a rotor shaft 5 which are magnetized so that N and S poles are alternately arranged on the outer peripheral side in the circumferential direction. The rotor shaft 5 is supported by the stator S'via a bearing (not shown). In this case, the split angle pitch of the crow poles of each phase of the stator S'and the magnetized pitch angle of the rotor R'are matched with each other. in this way,
A multi-pole stepping motor or synchronous motor whose rotor is a permanent magnet is efficient as a rotary field type motor because the field is given by a permanent magnet,
It is widely used for direct load drive without a reducer. In particular, stepping motors of this structure are widely used because they can be open-loop driven, do not require speed generators and encoders, etc. and enable inexpensive systems. The magnetic flux density of such a permanent magnet type rotor magnetic pole is sinusoidal as shown in FIG. The distribution characteristics of the magnetic flux density will be described in more detail below. In the two-phase permanent magnet type (hereinafter referred to as PM type) structure shown in FIG. 12, since the rotor is magnetized N and S alternately on the outer periphery of the ring-shaped permanent magnet, the magnetic flux density of the air gap is reduced. The maximum value is smaller than that of the hybrid type (hereinafter referred to as HB type), but the magnetic flux distribution in the air gap is more sinusoidal than that of the HB type as shown in Fig. 15, so the interlinkage magnetic flux λ contains much harmonic components. Therefore, the rotational torque does not include many vibration components, and the rotation is less vibrating. This is further analyzed from the mathematical formula as follows. In order to simplify the calculation, the torque equation is derived by a two-phase machine. From equations (1) to (4) below, equation (5) is obtained, and in equation (5), θ = ωt, and equation (6) is obtained. Is required. Here, λa is the a-phase interlinkage magnetic flux, λb is the b-phase interlinkage magnetic flux, φm is the maximum value of the interlinkage magnetic flux, and k ₁ and k ₂ are constants, respectively. Further, ia is the a-phase current, ib is the b-phase current, and im is the maximum value of the current. λa = φm [k ₁ cos θ + k ₃ cos 3θ] (1) λb = φm [k ₁ cos θ + k ₃ cos 3θ] (2) ia = Imcos (ωt + α) (3) ib = Imsin (ωt + α) (4) T = (dλ / dθ) i = φmIm [k ₁ sin (ωt + α−θ) -3k ₃ sin (ωt + α + 3θ)] (5) θ = Ωt T = φm Im [k ₁ sin α-3k ₃ sin (4θ + α)] (6) The second term of the equation (6) represents the vibration torque. Considering that k ₃ = 0 in the permanent magnet type, the expression (6) is a low vibration rotation motor in which the vibration component disappears.

Conventional Example 2: FIGS. 13 and 14 show a three-phase three-pole HB type stepping motor corresponding to Conventional Example 2. FIG. 13 is a cross-sectional side view and FIG. 14 is Y of FIG.
It is a sectional view taken along the line -Y ', showing various types of examples. In each drawing, 6 to 8 are stator magnetic poles, 6a to 8a are pole teeth respectively provided on the inner surface side, and 6c to 8c are exciting coils. 9 is a rotor formed by sandwiching a permanent magnet 10,
Reference numeral 11 is a rotor shaft, 12 is a casing, and 13 and 14 are bearings. The magnetic flux density of such an HB type rotor magnetic pole has a substantially rectangular wave shape as shown in FIG. 15B. Further, in the HB type rotor of this configuration, the N pole and the S pole are separated in the axial direction to form the magnetic teeth of the convex pole, and therefore the magnetic flux distribution in the air gap with the stator is also the magnetic pole of the convex pole. The magnetic flux density is evenly strong in the area of, and the distribution of recesses is close to zero. For this reason
The interlinkage magnetic flux λ of the rotor magnetic flux with the stator coil contains a large amount of spatial harmonics, and thus the rotational torque contains a vibration component.

[0004]

By the way, the above-mentioned conventional examples have the following problems. Conventional example 1
Case: Since the rotor is magnetized N and S alternately on the outer circumference of the ring-shaped permanent magnet, the maximum value of the magnetic flux density in the air gap is smaller than that of the HB type in Conventional Example 2, but the magnetic flux distribution in the air gap 15 has a sinusoidal distribution as compared with the HB type as shown in FIG. 15, the interlinkage magnetic flux λ contains a harmonic component and a rotational torque vibration component, respectively, so that the rotation is relatively small. However, it cannot be said that the vibration characteristics are still sufficient for the LBPs to which the present invention is applied. The torque is smaller than that of the HB type. Since it is a two-phase type, the step angle (resolution) cannot be reduced. In the case of Conventional Example 2: Compared with the permanent magnet type of Conventional Example 1, the magnetic flux density becomes large and the torque becomes large as shown in FIG. However, in the HB type rotor, the north pole and the south pole are separated in the axial direction and are magnetic poles of the convex pole. Therefore, the magnetic flux distribution in the air gap between the stator and the magnetic pole of the convex pole is also magnetic flux. The density is even and strong, and the recesses have a distribution close to zero. Therefore, the interlinkage magnetic flux λ of the rotor magnetic flux with the stator coil contains a large amount of spatial harmonics. Therefore, the rotational torque contains a vibration component. An object of the present invention is to provide a permanent magnet type rotating electric machine that solves the above-mentioned problems (problems) of conventional ones.

[0005]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, a permanent magnet type rotating electric machine according to the present invention is a rotor made of a cylindrical magnetic body having a hole through which a rotating shaft passes, and the rotor has an outer periphery. A plurality of U-shaped slits adjacent to each other, the non-slit portion is radially outward at an equal pitch, and the width of the magnetic body portion (A portion) between adjacent U-shaped slits and the non-slit portion in the U-shape The width of a certain magnetic material portion (B portion) is arranged substantially equal, and a U-shaped permanent magnet or a bonded magnet is filled in the U-shaped slit to magnetize the A portion and the B portion so as to have different polarities. It is configured to include a rotor. In this case, two U-shaped slits sandwich two plate-shaped permanent magnets, which are magnetized in the thickness direction, at the positions where two cylindrical magnetic bodies with built-in permanent magnets are offset from each other by 180 ° / Z. And the polarities of the portions A and B formed by the permanent magnets in the U-shaped slit portion and the portions A and B formed by the plate-shaped permanent magnets sandwiched therebetween.
It is desirable to have a rotor provided by magnetizing the slit permanent magnets so that the magnetic polarities of the respective parts match. However, Z is the number of pole teeth. Further, the U-shaped slit portion may not have a permanent magnet. In addition, 2Z in which at least one of the outer peripheral side and the inner peripheral side is connected by a narrow portion
It is composed of a substantially cylindrical magnetic body having an outer diameter 2r in which the slits are radially provided at equal pitches, and the slit portions of the 2Z slits are filled with bond magnets or permanent magnets and are formed by the 2Z slits. Let a be the radial length of the pole portion composed of 2Z magnetic materials, n be a positive integer of 1 or more, m = 1 or 2 or 3, k = 1 or 2, and a ≧ πr / 2Z , Z = m (3n ± 1) or Z = k (4n ± 1) or Z
= K (5n ± 2) is satisfied, and the 2Z pieces of the pole portions may be alternately magnetized to have different polarities on the outer circumference thereof. In this case, in the cylindrical magnetic body, a permanent magnet whose length in the rotation axis direction is substantially equal to that of the cylindrical magnetic body is inserted in the hole at the center of the cylindrical magnetic body, and 2Z slits are also filled with the permanent magnet. The 2Z shape of the cylindrical magnetic body is radial in the radial direction so that both ends of the cylindrical magnetic body are closely attached together with the permanent magnets inserted in the central holes.
Two magnetic bodies having Z poles of substantially the same shape as the poles of the same shape and arranged at an equal pitch are arranged so as to be offset from each other by ½ of the pitch of the Z poles. It is desirable that the Z poles are arranged so as to overlap with the 2Z pole portions of the cylindrical magnetic body every other pole, and the poles are magnetized in the rotation axis direction. Further, as shown in FIG. 4, a permanent magnet is provided in the hollow portion of a cylindrical magnetic body of 2Z poles whose outer periphery is connected in detail, and Z poles in the radial direction described in the previous section are provided.
The magnetic body with the poles is displaced from each other by ½ pitch (180 ° / Z) of Z poles, and the poles are overlapped with the 2Z poles of the cylindrical magnetic body every other one. So that
A substantially disk-shaped permanent magnet is concentrically fixed to each of the magnetic bodies having the Z poles, and a disk-shaped magnetic yoke is further fixed to each of the permanent magnets. It is desirable that they are connected by a rotating shaft made of a magnetic material and magnetized at least in the rotating shaft direction.

[0006]

In the above structure, when the sum of the lengths of two U-shaped slits in the radial direction is larger than the magnetic pole width on the outer circumference, the radial slits are filled. Since the magnetic flux generated from the permanent magnet (bonded magnet) collects on the magnetic poles on the outer circumference, the magnetic flux density of the magnetic poles can be increased as in the conventional HB type by making the sum of the radial lengths of the slits sufficiently large. . Moreover, since the N poles and the S poles are alternately arranged, the magnetic flux density becomes zero in the vicinity of the N poles and the S poles, and the magnetic poles are inverted, so that the distribution is closer to a sine wave than the HB type. , It is advantageous in reducing vibration when the motor is rotating. The HB type is a so-called three-dimensional magnetic path in which magnetic flux passes through the stator core in the axial direction of the rotor.
While the magnetic resistance increases, in the permanent magnet type rotating electric machine according to the present invention, the magnetic flux emitted from the N pole of the rotor is linked to the stator coil in a plane perpendicular to the rotor axis, and then the rotor is rotated. S
You can return to the pole. Therefore, the magnetic path length is shorter than that of the HB type, and the magnetic flux does not have to pass through the laminated iron plate in the rotation axis direction, so the magnetic resistance is also small. Further, the facing area of the rotor magnetic teeth as viewed from the rotor is also increased because the N pole and the S pole can face each other over the entire length of the stator. In the HB type, the rotor magnetic teeth are displaced by a half pitch by about ½ length.

[0007]

EXAMPLES The present invention will be described in detail with reference to the examples shown in FIGS. Example 1 The configuration of Example 1 of the present invention will be described with reference to FIGS. FIG. 1 is a cross-sectional view showing the rotor of Example 1 taken out. As shown in FIG. 1, the rotor R1 is a thin electromagnetic iron plate made of a magnetic material, which is punched out by a press or is made of iron powder. It is a rotor made of a cylindrical magnetic body with a hole through which the rotating shaft can penetrate, which can be made by integral molding such as sintering.
The slits 19a _{1 to} 19an are provided at equal pitches, and every other slit is connected with an appropriate length (depth) to form Z U-shaped slits 20. The U-shaped slit 20 is filled with the bond magnet 21,
By magnetizing the magnetic material portion A surrounded by the inside and the outer periphery of the character shape and the magnetic material B in the width portion between the U-shaped portions when the U-shaped slit 20 is adjacent so as to have different polarities at the outer peripheral portions thereof. , N poles and S poles have Z logarithms alternately on their outer circumferences to form a permanent magnet type rotary electric machine. According to the structure of the present invention, the magnetic flux density of the magnetic pole is made permanent by taking the length obtained by dividing the outer peripheral length by 2Z, that is, the sum of the two slit lengths in the radial direction of the U-shaped slit is larger than the magnetic pole width. It can be made higher than the magnetic flux density of the magnet itself. A permanent magnet may be attached to the U-shaped slit 20 instead of the U-shaped bond magnet. FIG. 2 shows a permanent magnet type rotary electric machine according to a first embodiment, which is configured by incorporating the rotor R1 shown in FIG. 1 into the stator S with an air gap therebetween. The stator S is a conventional HB type. The same stepping motor can be used as long as the number of teeth of the rotor is combined with Z. Therefore, the casing 12, the bearing 13,
14 is designated by the same reference numeral as that of FIG.

Second Embodiment: The second embodiment is constructed as shown in FIG. That is, two rotor elements 15a and 15b having the same structure as the rotor R1 shown in FIG.
The rotor R2, which is arranged with a shift of 80 ° / Z degrees, sandwiches a disk-shaped permanent magnet 16 magnetized with two poles in the middle, and is connected by a rotary shaft, is combined with the same stator S as in FIG. It was done. In this embodiment, the first embodiment
It can be expected that the effect of the above configuration and the further reinforcement of the magnetic force by the conventional HB type are achieved. That is, in the present embodiment,
The content is fitted to the outer circumference of the two-pole magnetized disk-shaped permanent magnet 16, the outer diameter of which is equal to or smaller than the outer diameter of the rotor, and the thickness of which is the same magnetic body as the thickness of the two-pole magnet described above in the radial direction. It has 2Z slits of equal pitch, and the slits are aligned with the magnetic material that is connected in detail by its outer diameter or inner diameter.
When the two rotor elements 15a and 15b shown in FIG. 2 are magnetically connected, the magnetic flux of the HB type permanent magnet 16 of the two-pole magnetization reaches the entire rotor R2, and the U-shaped permanent magnet 16 Since it is included, it becomes a strong N, S alternating magnetization rotor with little leakage flux between the N and S poles.

Embodiment 3: In this embodiment, as shown in FIG. 4, 2Z rotors are arranged on a magnetic iron plate in a chrysanthemum pattern (in this case,
Z = 4) slits 17a ₁ ~17a ₈ is provided for, in which the outer periphery is connected by detail, the rotor R3 is constituted permanent magnets 18a ₁ ~18a ₈ such as a plastic magnet is filled in the slit . At this time, the outer diameter is 2r, the length in the axial direction of the rotor is L, and 2Z slits are formed.
Let Z (in this case, 8 with n = 4) radial length be a
Then, the relation of a ≧ πr / 2Z is satisfied, and the above 2Z
The outer circumferences of the individual poles are magnetized in alternating N and S poles. The pole width on the outer circumference of the rotor is 2πrL / 2Z,
The area perpendicular to the normal of the slit magnet is aL,
In order to generate magnetic flux from the magnets on both sides and concentrate the magnetic flux in 2πrL / 2Z sufficiently, it is sufficient that 2aL ≧ 2πrL / 2Z, and a ≧ πr / 2Z. The rotor R3 'shown in FIG. 5 has the same shape as that of the rotor R3 shown in FIG. 4, but its inner circumference is modified so as to be connected by the narrow portion 19. Even if configured, it can be an N, S alternating magnet. The rotor of the embodiment is an effective rotor for a so-called permanent magnet type stepping motor (FIG. 8) of a cropole type stator, but it is a conventional HB type stepping motor.
It can also be used in combination with the stator of the rotor. In this case, in the case of a two-phase stepping motor,
The relationship of the equation (7) shown by is established.

[Equation 1] Further, in the case of a three-phase stepping motor, the relationship of the equation (8) shown in the following (Equation 2) is established.

[Equation 2] Furthermore, in the case of a 5-phase stepping motor, the relationship of the equation (9) shown in the following (Equation 3) is established.

[Equation 3] In the above equations (7) to (9), the relational expression with 2Z is shown. In all of them, the left side is the step angle, the first term on the right side is the angle formed by the main pole of the stator, and the second term is the main It is the position of the rotor magnetic tooth closest to the pole, and the right side also represents the step angle. When these equations (7) to (9) are arranged, Z = m (3n ± 1) or Z = k (4n ± 1) or Z = k (5n ± 2), and this relational expression of Z can be satisfied. Will be needed. The 4-phase stepping motor is partly included in the equation of Z in the 2-phase machine.
Here, n is a positive integer of 1 or more, m is 1 or 2 or 3,
k is 1 or 2.

Next, a magnetic path when the rotor shown in FIG. 1 or 4 is combined with a stator will be described. The rotor shown in FIG. 1 or FIG. 4 according to the present invention is a conventional PM type stepping motor shown in FIG.
By combining it with a die type stator, a larger torque than that of the conventional PM type stepping motor can be expected. This is because, as described above, the magnetic flux density can be made higher than that of the permanent magnet itself by concentrating the magnetic flux of the permanent magnet on the magnetic poles. Since the PM type stator is a cropole type, even if it is combined with the rotor shown in FIG. 4, for example, the magnetic flux generated from the N pole of the PM type stator immediately passes through the stator magnetic path of the cropole. It is extremely effective because it can be returned to the S pole. However, when combined with the stator of the conventional HB type stepping motor, the magnetic flux from the N pole is
For example, as shown in FIG. 7, after passing through the stator magnetic path, the magnetic pole does not always reach the adjacent S pole. Therefore, in the case of the structure of FIG. 4, the magnetic path may open, in which case the efficiency decreases. . The PM type is naturally effective in the structure of FIG. 1, but
Even in the HB type stator, the magnetic path is always a closed magnetic path as shown by the alternate long and short dash line as shown in FIG. The rotors shown in FIGS. 1, 6 and 7 are examples when Z = 16.

Embodiment 4 FIG. 8 is a vertical cross-sectional front view showing the construction of Embodiment 4 of the present invention, and FIG. 9 is an exploded perspective view of the respective components of FIG. This embodiment is the same as the embodiment 1 shown in FIG.
A magnetic flux distribution plate 22 or 23 having Z poles in the outer peripheral direction is provided on both sides of the rotor 21, and the pole shape is 2 in FIG.
By providing Z poles of approximately the same size, as shown in FIG. 9, the two magnetic flux distribution plates 22 or 23 are shifted by ½ of the Z pole pitches, and The rotor is brought into close contact with 2Z poles of the rotor, fixed with a rotor shaft 24 made of a non-magnetic material, and magnetized in the axial direction to form a rotor. The magnetic flux distribution plate 23 is formed by partially cutting out one iron plate. FIG. 9 shows a case where the rotor 21 is sandwiched between the magnetic flux distribution plate 22 and the magnetic flux distribution plate 23 having different structures, but the rotor 21 is composed of two identical magnetic flux distribution plates 22 or magnetic flux distribution plates. It may be configured to be sandwiched between the plates 23. The function is that the permanent magnet is magnetized in two poles in the direction of the rotation axis and the magnetic flux distribution plate 22 or 23 receives the magnetic flux of the permanent magnet.
The magnetic flux is distributed and supplied from both sides of the 2Z magnetic material rotor yokes so that the magnetic flux becomes N-pole and S-pole every other piece. At this time, since the permanent magnets between the 2Z slots are magnetized in the rotation axis direction, leakage between the 2Z polls can be prevented to some extent. After axially magnetizing the rotor of the present invention shown in FIG. 8, if radial magnetization is added by a magnetizing current such that only permanent magnets (magnets) in the slot portion between 2Z pieces are radially magnetized, 2Z pieces are obtained. Since the magnets between slots are magnetized in the radial direction and the magnet in the center of the rotor is magnetized in the axial direction, leakage of 2Z magnetic materials can be prevented and a strong magnetic pole of the rotor is formed. . The prior art disclosed in Japanese Utility Model Laid-Open No. 3-124772 proposes a combination of two comb-tooth rotor yokes and filling a plastic magnet. The thickness of the part that becomes the magnetic teeth on the outer circumference of the rotor after being bent in the axial direction is determined by the plate thickness, and the width of the comb teeth becomes thinner when the number of poles increases, and the pole becomes wire-like overall and extends to the tip. The magnetic resistance increases to send the magnetic flux of the permanent magnet, and high torque cannot be expected. In the present invention, a shown in FIG.
If you choose properly, this problem can be solved. Further, there is a problem in that when the comb teeth have multiple poles, the position accuracy is not good because the pole is wire-shaped and the position accuracy is curved. In the present invention, the iron plate is punched out by a press, so the accuracy is good.

Embodiment 5: FIG. 10 and FIG. 11 are a longitudinal sectional front view and an exploded perspective view showing the construction of Embodiment 5 of the present invention, respectively. The slot part sandwiched by 2Z magnetic bodies in FIG.
As shown in FIG. 10 and FIG. 11, on both sides of the rotating body 25 filled with a permanent magnet such as a plastic magnet,
The magnetic flux distribution plates 26a and 26b are 1 /
Two pitches are closely contacted to each other, thin permanent magnets 27a and 27b of neodymium or the like are arranged on both outer sides thereof, and magnetic bodies 28a and 28b are further closely contacted to both outer sides thereof,
This magnetic material is connected by the magnetic material rotation shaft 29 at the inner diameter hollow portions of the above 2Z poles, and then magnetized into two poles so that the magnetic fluxes of the two permanent magnets become the north pole and the south pole, respectively. By magnetizing every other 2n poles, the same effect as in FIG. 8 can be obtained. The two permanent magnets 27a and 27b form a magnetic path including the stator by the magnetic body rotation shaft 29, and a strong magnetic field can be created. In the configuration of FIGS. 10 and 11, if a magnetic plate such as the magnetic body 28a (28b) is inserted between the magnetic flux distribution plate 26a (26b) and the permanent magnet 27a (27b), a stronger magnetic field can be created.

1 to 3 showing the above-mentioned embodiments of the present invention.
The rotor shown in FIG. 11 is a rotor in which a conventional PM type two-phase machine, a cropole stator, is wound around a bobbin, and the outer circumference of a cylindrical ring coil made of ferrite or the like is magnetized into Z logarithms alternately with N and S poles. −
If it is used as a substitute for the motor, the torque can be higher than that of the conventional PM type motor. However, in the above-mentioned PM type two-phase machine, the claw pole is formed by bending the comb tooth-shaped pole and the inner diameter of the stator. Therefore, the uniformity of the air gap is not good due to the effect of the spring back of the bent pole, which is disadvantageous for vibrations and the like. On the other hand, as shown in FIG.
When the B-type stator is combined with the rotor of the present invention, the air gap becomes uniform, and the true value of the present invention is further exhibited.

FIG. 15 is a schematic diagram comparing the magnetic flux densities of the conventional HB type and the one-pole permanent magnet of the present invention of FIG. 1, for example. The HB type has a magnetic flux density as shown in B of FIG. In contrast to the rectangular wave, the N-pole and S-pole alternating type of the present invention has a sine wave shape as shown in FIG.

[0015]

Since the permanent magnet type rotating electric machine of the present invention is constructed as described above, it has the following excellent effects. High torque equivalent to that of HB type stepping motor and low vibration and noise characteristics of conventional PM type can be realized by an inexpensive method, and multipolarization is possible. Since the facing area of the stator and the rotor is twice as large as that of the conventional HB type, the flux linkage can be increased accordingly. Since the N pole and S pole are adjacent instead of the magnetic teeth of the convex pole like in the HB type rotor, the magnetic flux density is distributed in a sinusoidal shape and the cogging torque of the stator non-excitation can be reduced, and the step during microstep drive can be reduced. The angular accuracy is also improved.

[Brief description of drawings]

FIG. 1 is a cross-sectional view of a rotor of a rotary electric machine that is Embodiment 1 of the present invention.

2 is a vertical sectional front view including the rotor shaft of FIG. 1. FIG.

FIG. 3 is a vertical sectional front view showing a configuration of a second embodiment of the present invention.

FIG. 4 is a cross-sectional view of a rotor of a rotating electric machine that is Embodiment 3 of the present invention.

FIG. 5 is a transverse cross-sectional view of a rotor configured by modifying the one shown in FIG. 4 of the third embodiment of the present invention.

FIG. 6 is an explanatory diagram showing a state of magnetic flux of the rotor and the stator of the first embodiment.

FIG. 7 is an explanatory diagram showing a state of magnetic flux of the rotor and the stator of the first embodiment.

FIG. 8 is a transverse sectional view of a rotor of a rotating electric machine that is Embodiment 4 of the present invention.

FIG. 9 is an exploded perspective view of FIG.

FIG. 10 is a cross-sectional view of a rotor of a rotating electric machine that is Embodiment 5 of the present invention.

11 is an exploded perspective view of FIG.

FIG. 12 is a perspective view showing a PM type stepping motor according to the prior art with a part thereof cut away.

FIG. 13 is a conventional hybrid type stepping motor.
FIG.

FIG. 14 is a conventional hybrid type stepping motor.
FIG.

FIG. 15 is a characteristic diagram showing a distribution diagram of magnetic flux densities of HB type and PM type rotor magnetic poles in order to compare the present invention and the conventional example.

[Explanation of symbols] 20: U-shaped slit 21: Permanent magnet or bonded magnet R1: Rotor

Claims (6)

[Claims] 1. A rotor made of a cylindrical magnetic body having a hole through which a rotating shaft penetrates in the center, and a plurality of U-shaped slits are provided in the vicinity of the outer periphery of the rotor. The width of the magnetic body portion (A portion) between the adjacent U-shaped slits facing outward and the width of the magnetic body portion (B portion) which is a non-slit portion in the U-shape are arranged substantially equal to each other, and the U-shaped slits described above are provided. A permanent magnet type rotating electric machine characterized in that a U-shaped permanent magnet or a bond magnet is filled in the inside of the rotor, and the rotor is magnetized so that the parts A and B have different polarities. 2. A plurality of U-shaped slits according to claim 1, wherein two cylindrical magnetic bodies containing a permanent magnet are offset by 180 ° / Z from each other, and are pre-polarized in the thickness direction. The polarities of the portions A and B formed by the permanent magnets of the U-shaped slit portion sandwiching the plate-shaped permanent magnet, and the magnetic polarities of the portions A and B formed by the plate-shaped permanent magnets sandwiched therebetween. Permanent magnet type rotating electric machine equipped with a rotor formed by magnetizing slit permanent magnets so that they coincide with each other. However, Z is the number of pole teeth. 3. The permanent magnet type rotating electric machine according to claim 2, wherein the U-shaped slit portion is not provided with a permanent magnet. 4. A 2Z number of slits are formed of a substantially cylindrical magnetic body having an outer diameter 2r in which at least one of the outer diameter side and the inner diameter side is connected to each other with a narrow width portion and 2Z number of slits are provided radially at equal pitches. The slit part is filled with a permanent magnet such as a bond magnet, and the radial length of the pole part composed of 2Z magnetic bodies formed by 2Z slits is a, and n is a positive integer of 1 or more. , M = 1 or 2 or 3, k = 1 or 2, and a
≧ πr / 2Z, Z = m (3n ± 1) or Z = k
(4n ± 1) or Z = k (5n ± 2) is satisfied, and
A permanent magnet type rotating electric machine having a rotor, wherein 2Z pieces of the pole portions are alternately magnetized to have different polarities on the outer periphery thereof. 5. The cylindrical magnetic body according to claim 4, wherein a permanent magnet having a length in the rotational axis direction substantially equal to that of the cylindrical magnetic body is inserted into the hole at the center of the cylindrical magnetic body, and 2Z slit portions are also provided. The 2Z shape of the cylindrical magnetic body is filled with permanent magnets, and each shape is radial in the radial direction so that both ends of the cylindrical magnetic body are closely attached together with the permanent magnets inserted in the center holes.
Two magnetic bodies having Z poles of substantially the same shape as the poles of the same shape and arranged at an equal pitch are arranged so as to be offset from each other by ½ of the pitch of the Z poles. Permanent magnet type rotation having a rotor characterized in that Z poles are made to overlap every other 2Z pole portions of the cylindrical magnetic body and are magnetized in two poles in the rotation axis direction. Electric machinery. 6. A permanent magnet is provided in a hollow portion of a cylindrical magnetic body of 2Z poles whose outer periphery is connected by a narrow portion, and Z poles in the radial direction according to claim 5. The magnets that are held are displaced from each other by ½ pitch (180 ° / Z) of Z poles, and the poles are overlapped with every other 2Z poles of the cylindrical magnet. The disk-shaped permanent magnets are closely attached to each of the magnetic bodies having Z poles, and the disk-shaped magnetic yoke is fixed to each of the permanent magnets. A permanent magnet type rotating electric machine having a rotor, characterized in that the yokes are connected by a rotating shaft made of a magnetic material and magnetized at least in the rotating shaft direction.