JPH07336989A - Three-phase claw pole type permanent magnet rotary electric machine - Google Patents

Abstract

PURPOSE:To allow all magnetic fluxes to contribute to the generation of an output torque as effective magnetic fluxes by forming the permanent magnet of a rotor in a polar anisotropic permanent magnet having an anisotropic orientation and forming a structure having no back yoke in the bore of the permanent magnet. CONSTITUTION:A rotor made of a polar anisotropic permanent magnet is rotatably supported to a shaft oppositely via an air gap on the inner periphery of a stator. Even if claw poles 1a, 1b, 1c and claw poles 4a, 4b, 4c are respectively magnetically coupled, no back yoke is provided in the bore of the magnet of the rotor, and hence no internal magnetic circuit is excited, and thus magnetic fluxes passing reluctances Rab, Rbc, Rca are eliminated. All the magnetic fluxes are crossed with coils 3a, 3b, 3c as effective magnetic fluxes to contribute to the generation of an output torque. Thus, high torque can be obtained without loss of the magnetic flux.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rotary electric machine suitable for driving a drum of a laser beam printer and the like, and particularly for applications requiring low vibration and high output.

[0002]

2. Description of the Related Art The contents of the prior art shown in FIGS.
The configuration will be described. FIG. 9 is a perspective view of an inner rotor type claw pole type stator provided with a three-phase winding according to the prior art, and a claw pole having one magnetic pole 1 of each of a-phase, b-phase and c-phase constituting three phases. 1a, 1b, 1c are formed by pressing and bending a magnetic thin plate together with the claw poles 4a, 4b, 4c of the other magnetic pole 4 forming a pair with the magnetic pole 1, and are formed by both the magnetic poles 1 and 4. Yoke 2a, 2b,
The coils 3a, 3b, 3c of the respective phases are wound around 2c.

The claw poles 1a and 4a, 1b and 4
b, 1c and 4c are magnetized to have mutually different polarities by the respective phase coils 3a, 3b and 3c, and are alternately arranged. The number of each phase coil is not limited to one in each of the figures, but two or more are generally n
(N is a positive integer), and in this case, adjacent phases are arranged at 120 / n degrees.

The claw pole 4a adjacent to the magnetic pole 4
4b and 4c are connected to each other by a thin connecting portion 10, and the connecting portion 10 is magnetically saturated, so that leakage magnetic flux is reduced.

Claw poles 1a, 1b, 1c of the magnetic pole 1
The claw poles 4a, 4b and 4c of the magnetic pole 4 and the magnetic pole 4 may be joined and held without being integrally formed without the connecting portion 10, but the integral formation has a small number of parts and a joining means is not necessary. Is advantageous.

On the other hand, as shown in FIG. 10, the rotor R4 is generally composed of a cylindrical permanent magnet 8 and is generally provided with a back yoke 9 in its inner diameter portion due to radial anisotropy in order to increase the magnetic force.
N and S are alternately magnetized on the outer peripheral surface, and the magnetization pitch thereof is substantially equal to the pitch angles of the claw poles 1a and 4a, 1b and 4b, 1c and 4c. The permanent magnet 8 is fixed to the rotor shaft 7 together with the back yoke 9 and faces the inner peripheral surface of the stator shown in FIG.

In the above structure, the rotor R4 generates a rotating torque by supplying a three-phase sinusoidal current having a phase difference of 120 degrees in electrical angle to the respective phase coils 3a, 3b, 3c of the stator, thereby acting as an actuator. Operate.

[0008]

In the conventional structure as described above, the connecting portion 10 between the claw poles 4a, 4b and 4c in the magnetic pole 4 as the means for increasing the torque, and the adjacent claw poles 1a, 1b in the magnetic pole 1 are connected. It is necessary to eliminate the leakage of the magnetic flux between the phases by cutting off the connecting portion of 1c, and the back yoke 9 is provided in the inner diameter portion of the rotor permanent magnet 8. At 11, the magnetic flux that has entered the claw pole 1a from the N pole of the rotor permanent magnet 8 returns to the other claw pole 4a through the coil 3a, but from the claw pole 1a to the magnetic resistance Rab of the connecting portion of the magnetic yoke. There is an unavoidable problem that a leakage component is generated through the other claw poles 4b and 1b and further through the permanent magnet 8 and the back yoke 9 as shown by a dotted line to reduce the output torque. Eteita.

[0009]

In the three-phase claw pole type permanent magnet type rotating electric machine according to the present invention, the number of pole pairs Z of the permanent magnet of the rotor is Z = n (3m ± 1) (where n is the stator claw). A polar-anisotropic permanent magnet having an anisotropic orientation of logarithm of pole group, m is a positive integer, and no back yoke is provided in the inner diameter portion of the permanent magnet.

[0010]

[Operation] In the configuration as described above, as shown in FIG. 8 with reference to FIG. 1, the claw poles 1a, 1 in the magnetic pole 1 are
b, 1c and claw poles 4a, 4b, 4 in the magnetic pole 4
c and magnetic resistances Rab, which are magnetically connected to each other,
Even if Rbc and Rca are present, since the rotor permanent magnet is a polar anisotropic permanent magnet and the back yoke is not provided in the inner diameter portion of the permanent magnet, there is no internal magnetic path, and therefore the magnetic resistance Ra
The magnetic fluxes passing through b, Rbc, and Rca disappear, and almost all the magnetic fluxes become effective magnetic fluxes as shown by the dotted lines.
Interlinks with 3b and 3c and contributes to output torque generation.

[0011]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a stator of an inner rotor type claw pole type permanent magnet type rotary electric machine according to the present invention, which has the same structure as that of FIG. 9 of the above-mentioned prior art example, and FIG. 2 is a polar anisotropic permanent magnet corresponding to the stator. 6 is a perspective view of a rotor R1 in which a rotor shaft 7 is coupled to an inner diameter portion of a magnet 5 via a non-magnetic core 6. FIG.

A rotor R composed of a polar anisotropic permanent magnet shown in FIG. 2 and facing the inner peripheral surface of the stator shown in FIG.
When 1 is rotatably supported, as shown in FIG. 8, the claw poles 1a, 1b, 1c in the magnetic pole 1 and the claw poles 4a, 4b, 4c in the magnetic pole 4 are magnetically coupled to each other, and the magnetic resistance Rab, Even if Rbc and Rca are present, since the back yoke is not provided in the inner diameter portion of the permanent magnet 5, there is no internal magnetic path, and therefore the magnetic resistances Rab, Rbc and Rca.
The magnetic flux passing through ca disappears, and as shown by the dotted line, almost all of the magnetic flux is linked to the respective coils 3a, 3b, 3c as effective magnetic flux and contributes to the generation of output torque. At this time, in FIG. 8, the centers of the magnetic poles 1a and 4a and the magnetic poles of the permanent magnet 5 coincide with each other, and the angle between the magnetic poles 1b and 4b and the center of the magnetic pole of the permanent magnet 5 and the magnetic poles 1c and 4c. The angle formed by the center of the magnetic poles of the permanent magnet 5 is an electrical angle of 60 degrees.
Since the number Z of pole pairs of the permanent magnet 5 is 4, the electrical angle 6 is shown in FIG.
The mechanical angle of 0 degree is 60/4 degrees, that is, 15 degrees. or,
The pitch of the magnetic poles of each phase (for example, the pitch of the magnetic poles 1a and 4a) can be selected to be 360 / (Z-2) or less or 360 / (Z + 2) or more. (However, if Z> 2)

The technical idea of the present invention can be applied to any structure of the inner rotor type or the outer rotor type and the axial gap type. The outer rotor type embodiment is shown in FIGS. Shows an example of the axial gap type. Also, the coils 3a, 3b, 3
In the direction of c, the magnetic direction of the coil is shown in FIGS.
Although it is parallel to the rotation axis direction in FIG. 6, it may be a right angle (for example, a coil is wound around the magnetic pole 4 in FIG. 1) although not shown.

In the outer rotor type stator S2 shown in FIG. 3, a coil 23a for exciting the a-phase poles 21a (side surface shadows) and 24a is provided in the yoke 22a and the b-phase pole 21 is used.
The coil 23b for exciting b and 24b is connected to the yoke 22b,
The coils 23c for exciting the c-phase poles 21c and 24c are respectively wound around the yoke 22c.

In the rotor R2 of FIG. 4, an inner peripheral surface polar anisotropic permanent magnet 25 is integrally held by a holding bottom portion 25-1 with a rotor shaft 26, and the rotor shaft 26 is rotated by a bearing (not shown). The shaft is freely supported and is arranged to face the outer peripheral surface of the stator S2 shown in FIG. 3 through a gap, and a high torque is generated when the stator S1 is energized to operate. It is similar to the inner rotor type shown in FIG.

FIG. 5 shows an axial gap type claw pole type stator S3, for example, a-phase poles 27A and 30A.
The coil 29A for exciting the coil is the yoke 28A, and the coil 29B for exciting the b-phase poles 27b and 30b is the yoke 28A.
B is a coil 2 for exciting the c-phase poles 27c and 30c
9C is wound around each yoke 28C.

FIG. 6 also shows an axial gap type stator S4 in which a plurality of slits 32A, 32B and 32C are provided in the magnetic path forming portion 31 of each phase to form a pole. Are formed in a "H" shape so that the magnetic resistance of the portions of the slits on the side close to each other is increased to cause the magnetic saturation of the connecting portion, so that the same function as that of the claw pole described above is achieved. Is.

FIG. 7 is a perspective view of a rotor R3 commonly corresponding to the axial gap type stators shown in FIGS. 5 and 6. As in the radial gap type, the rotor R3 is a polar anisotropic type in which a predetermined number of magnetic poles are formed on the surface. It is composed of a permanent magnet.

The inner rotor type shown in FIGS. 1 and 2 or the outer rotor type shown in FIGS. 3 and 4 and FIGS.
In any of the axial gap type configurations shown in FIGS. 6 and 7, when the a, b, and c phases are evenly arranged at 120 / n degrees (mechanical angles), the present invention is based on the number of magnetic pairs Z of the rotor. It is established by restricting by the formula shown in Formula 1.

[Equation 1] However, in Equation 1, Z is the number of pole pairs of the permanent magnet, and n and m are positive integers. When the rotating electrical machine of the present invention is operated as a three-phase permanent magnet type stepping motor, the left side of the above equation (1) represents the step angle, the first term on the right side thereof represents the angle between adjacent phases, and the right side also represents the step angle. In fact, rearranging this results in Z = n (3m ± 1) …………………… (2).

Since the three-phase claw pole type permanent magnet type rotary electric machine according to the present invention has the above-mentioned structure, the following effects are brought about. (1) Even if the poles of each phase are integrally connected, since the rotor permanent magnet is not provided with the back yoke, there is no loss of magnetic flux and it is easy to realize high torque. (2) The structure is simple and the number of parts is small,
It is advantageous in terms of cost. (3) The three-phase type is superior to the two-phase type in smoothness of rotation. (4) Since it is a three-phase type, star connection and delta connection are possible, and the drive circuit as a stepping motor can be simply configured.

[Brief description of drawings]

FIG. 1 is a perspective view showing an inner rotor type stator in an example of a three-phase claw pole type permanent magnet type rotating electric machine according to the present invention.

FIG. 2 is a perspective view of an example of an inner rotor type rotor according to the present invention corresponding to the stator shown in FIG.

FIG. 3 is a perspective view showing an outer rotor type stator in an example of a three-phase claw pole type permanent magnet type rotating electric machine according to the present invention.

FIG. 4 is a perspective view of an example of an outer rotor type rotor according to the present invention corresponding to the stator shown in FIG.

FIG. 5 is a perspective view showing an axial gap type stator in an example of a three-phase claw pole type permanent magnet type rotating electric machine according to the present invention.

FIG. 6 is a perspective view showing a stator of another example of the axial gap type of the three-phase claw pole type permanent magnet type rotary electric machine according to the present invention.

7 is a perspective view of an example of an axial gap type rotor according to the present invention corresponding to the stator shown in FIGS. 5 and 6. FIG.

FIG. 8 is a principle view of a three-phase claw pole type permanent magnet type rotating electric machine according to the present invention.

FIG. 9 is a perspective view showing an inner rotor type stator in an example of a conventional three-phase claw pole type permanent magnet type rotating electric machine.

FIG. 10 is a perspective view of an example of a conventional inner rotor type rotor corresponding to the stator shown in FIG.

FIG. 11 is a principle view of a conventional three-phase claw pole type permanent magnet type rotating electric machine.

[Explanation of symbols]

1 one magnetic pole: magnetic pole 1 1a, 1b, 1c claw pole 2a, 2b, 2c of magnetic pole 1 yoke 3a, 3b, 3c formed by magnetic pole 1 and magnetic pole 2 coil 4 wound on each yoke 4 other magnetic pole : Magnetic pole 4 5 Polar anisotropic permanent magnet 6 Core 7 Rotor shaft 8 Radial anisotropic permanent magnet 4a, 4b, 4c Claw pole 21 of magnetic pole 4 One magnetic pole: Magnetic pole 1 21a, 21b, 21c Claw of magnetic pole 1 Pole 22a, 22b, 22c Yoke 23a, 23b, 23c formed of magnetic pole 1 and magnetic pole 4 Coil wound around each yoke 24 Other magnetic pole: Magnetic pole 4 24a, 24b, 24c Claw pole 25 of magnetic pole 4 Inner circumference Face-pole anisotropic permanent magnet 25-1 Holding bottom 26 Rotor shaft 27 One magnetic pole: Magnetic pole 1 27A, 27B, 27C Claw pole 28A, 28B, 28 of magnetic pole 1 Yoke 29A, 29B, 29C Coil wound around each yoke 30 Other magnetic pole: Magnetic pole 4 30A, 30B, 30C Claw pole 31 of magnetic pole 4 Magnetic path forming portions 32A, 32B, 32C Slits S1, S2, S3, S4 Stator R1, R2, R3, R4 Rotor Rab, Rbc, Rca Magnetic resistance of magnetic circuit connecting portion 10 Magnetic pole 4 connecting portion

Claims (6)

[Claims] 1. A 3n pair (n) comprising stator poles which are concentrically arranged in a plane direction perpendicular to the rotor axis and which form three pairs to form a pair respectively, and a coil wound around one of the yokes. Is a positive integer) and a stator formed of a group of claw poles, and a rotor provided with a permanent magnet rotatably opposed to the stator pole via a small air gap, and n pairs of claws for each phase. The pole group is excited by the respective coils so that the poles alternately show different polarities. When the n pairs of claw pole groups for the first phase are aligned with the magnetic pole centers of the rotor, The absolute value of the angle formed by the magnetic pole center of each n-pair claw pole group for three phases and the magnetic pole center of the rotor is 60 in electrical angle.
In the inner rotor type three-phase claw pole type permanent magnet type rotary electric machine arranged at 60 degrees (mechanical angle: 60 / Z degrees), the permanent magnet of the rotor is provided with an anisotropic orientation of 2Z poles. A three-phase claw pole type permanent magnet type rotating electrical machine characterized by being a permanent permanent magnet. 2. The number Z of pole pairs of the polar anisotropic permanent magnet of the rotor is Z = n (3m ± 1) (where m is a positive integer). Three-phase claw pole type permanent magnet type rotating electrical machine 3. A 3n pair (n) comprising stator poles which are concentrically arranged in a plane direction perpendicular to the rotor axis and which form a pair of three phases, and a coil wound around one of the yokes. Is a positive integer) and a stator formed of a group of claw poles, and a rotor provided with a permanent magnet rotatably opposed to the stator pole via a small air gap, and n pairs of claws for each phase. The pole group is excited by the respective coils so that the poles alternately show different polarities, and when the magnetic pole centers of the n pairs of claw pole groups for the first phase are aligned with the magnetic pole centers of the rotor, , And an outer angle of the angle between the magnetic pole center of the claw pole group of each n pairs for the third phase and the magnetic pole center of the rotor is 60 degrees in electrical angle (60 / Z degree in mechanical angle). In the rotor type three-phase claw pole type permanent magnet type rotating electric machine, the rotation A three-phase claw pole type permanent magnet type rotary electric machine, wherein the child permanent magnet is a polar anisotropic permanent magnet having an anisotropic orientation of 2Z poles. 4. The pole-pair number Z of the polar anisotropic permanent magnet of the rotor is Z = n (3m ± 1) (where m is a positive integer). Three-phase claw pole type permanent magnet type rotating electrical machine 5. A 3n pair (n) comprising stator poles which are concentrically arranged in a plane direction perpendicular to the rotor axis and which form three phases to form a pair, and a coil wound around one of the yokes. Is a positive integer) and a stator formed of a group of claw poles, and a rotor provided with a permanent magnet rotatably opposed to the stator pole via a small air gap, and n pairs of claws for each phase. The pole group is excited by the respective coils so that the poles alternately show different polarities, and when the magnetic pole centers of the n pairs of claw pole groups for the first phase are aligned with the magnetic pole centers of the rotor, Also, the absolute value of the angle formed by the magnetic pole center of each n-pair claw pole group for the third phase and the magnetic pole center of the rotor is arranged at an electrical angle of 60 degrees and an mechanical angle of 60 / Z degrees. In the gap type three-phase claw pole type permanent magnet type rotating electric machine, The permanent magnet of the rotor is a polar anisotropic permanent magnet having an anisotropic orientation of 2Z poles, and the back yoke is not provided on the surface of the permanent magnet that does not face the stator pole. Phase claw pole type permanent magnet type rotating electrical machine. 6. The rotor according to claim 5, wherein the number Z of pole pairs of the polar anisotropic permanent magnet of the rotor is Z = n (3m ± 1) (where m is a positive integer). Three-phase claw pole type permanent magnet type rotating electrical machine