JPH10210729A - Three-phase hybrid type stepping motor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To avoid the partial magnetic saturation of a yoke part and generate higher torque than a conventional one. SOLUTION: A stator has twelve magnetic poles p1, p2, p3,... arranged radially, and also a rotor has 12a+2 pole teeth 4 arranged equally when defined that a is an integer of one or over, and at the face opposite to the rotor of each magnetic pole, this stepping motor is provided with one or more stator teeth 3 each, and the six magnetic poles P1, P3,... arranged at least alternately are arranged at equal pitches. Furthermore, the angle that the magnetic center lines of the said adjacent magnetic poles make repeats (3a+2)τR/3 and (3a-1)τR/3 when defined that the above rotor pole tooth pitch is τR, and the magnetic center line of above each magnetic pole conforms to the center line of the winding part of this magnetic pole, or has a slip angle of τR/4.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a three-phase hybrid type stepping motor having a stator having twelve magnetic poles.

[0002]

2. Description of the Related Art Conventionally, a stator having 12 magnetic poles has
Stator core 1 of phase hybrid type stepping motor M
As the shape of 0, for example, the shape shown in the sectional view of the stator core in FIG. 7 is well known.

In FIG. 7, each of the phases A, B, and C has four magnetic poles, for example, A-phase magnetic poles P1, P4,
When a current is applied to P7 and P10 in the positive direction, the magnetic poles P1, P4, P7 and P10 are sequentially excited to NSNS polarity, and when a current is applied to the negative direction, the magnetic poles P1, P4, P7 and P10 are sequentially excited to SNSN polarity. Windings W1, W4, W7, W10
Are wound and connected to each other. The magnetic poles of phase B are P3, P6, P9, and P12, and the magnetic poles of phase C are P3.
5, P8, P11, and P2, and the winding W
3, W6, W9, W12 and W5, W8, W11, W
2 are wound and connected, respectively.

FIG. 8 is a longitudinal sectional view of the stepping motor M. The motor M has a rotor 6 rotatably disposed on the inner peripheral surface of the stator 1 through a gap, and the rotor 6 has a permanent magnet 5 magnetized in its axial direction, On both sides of the permanent magnet 5 in the axial direction, 50 pole teeth 4 formed on the outer peripheral surface are shifted from each other by の of the pole tooth pitch and fixed so as to sandwich the permanent magnet 5. , And a shaft 7 penetrating therethrough.

[0005] Three-phase hybrid type stepping motor M
The conventional excitation method, the step angle, and 2-2 phase excitation or 3-3 phase excitation mode is a basic step angle theta _S, step angle is 1/2 of the basic step angle theta _S theta _S
/ 2/3 phase excitation method. There are 12 types of excitation states in the 2-3 phase excitation system, and changes in the excitation states are shown as follows in order. AC ', AC'B, C'
B, C'BA ', BA', BA'C, A'C, A'C
B ', CB', CB'A, B'A, B'AC '
Of the two cases, the front six cases and the rear six cases have the same combination of magnetic poles, but differ only in the direction of the current.

[0006]

FIG. 9 shows only the above-mentioned six excitation states. From FIG. 9, the excitation states in the case of the 2-2 phase excitation are AC ', C'B, BA', and the excitation states in the 3-3 phase excitation are AC'B, C'BA ', BA'C. However, there were the following problems. That is, in the case of the 2-2 phase excitation, adjacent magnetic poles have the same polarity, every other magnetic pole has the opposite polarity, and the magnetic path is relatively long as shown by the broken line in the drawing. , The torque is reduced as compared with the case where is short. In the case of 3-3 phase excitation, the magnetic path is shortened, but three magnetic poles of the same polarity are adjacent to each other, which increases the magnetic flux density of the yoke and decreases torque and increases iron loss. Was a factor.

In order to avoid magnetic saturation of the yoke, it is necessary to increase the magnetic path cross-sectional area of the yoke. If the outer diameter of the motor M is not changed, the inner diameter and rotation of the stator 1 are not changed. There is also a problem that the outer diameter of the child 6 has to be reduced, and as a result, the torque is reduced.

[0008] The present invention has been made in view of such a point,
An object of the present invention is to provide a three-phase hybrid type stepping motor that solves the above-mentioned problem, avoids partial magnetic saturation of the yoke, and generates a higher torque than the conventional one.

[0009]

The structure of a three-phase hybrid type stepping motor according to the present invention for achieving the above object is as follows.

(1) The stators are arranged radially.
When a is an integer of 1 or more, the rotor has 12a + 2 pole teeth, and the surface of each magnetic pole facing the rotor is , One or more stator pole teeth are provided, and at least every other six of the magnetic poles are disposed at an equal pitch, and the magnetic poles of the magnetic poles of the magnetic poles adjacent to each other are arranged. When the rotor pole tooth pitch is τ _R , (3a + 2) τ _R / 3 and (3a-1) τ _R / 3 are alternately repeated, and the magnetic center line of each magnetic pole is It is characterized by being coincident with the center line of the winding of the magnetic pole or having a shift angle of τ _R / 4.

(2) In the above (1), the rotor has 50 pole teeth, and a plurality of stator poles are respectively provided on a surface of each magnetic pole of the stator facing the rotor. The angle between the magnetic center lines of the magnetic poles provided with teeth and adjacent to each other alternates between 26.4 ° and 33.6 ° alternately, and the magnetic center lines of the magnetic poles are wound around the magnetic poles. It is characterized by being coincident with the line center line or having a shift angle of 1.8 °.

(3) In the above (1) or (2), the stator core is composed of two stator core portions opposed to two rotor cores which sandwich a permanent magnet magnetized in the axial direction. The two stator cores are configured such that one of the stator cores is inverted with respect to the other with respect to the winding center line of each magnetic pole, or the one winding center line is By rotating an angle of a multiple of 30 ° other than the multiple of 60 ° with respect to the other, the two are superimposed, and the pole teeth of the two rotor cores holding the permanent magnet are aligned with each other. The shift angle is 0 °.

(4) The stators are arranged radially.
When a is an integer of 1 or more, the rotor has 12a + 4 pole teeth, and the surface of each magnetic pole facing the rotor is , One or more stator pole teeth are provided, and the four magnetic poles disposed at every third are arranged at an equal pitch, and the magnetic centers of the four consecutive magnetic poles are arranged. Assuming that the rotor pole tooth pitch is τ _R , the three magnetic pole pitches formed by the line are (3a + 2) τ _R / 3, two places,
(3a-1) It is characterized in that there is one place where τ _R / 3.

(5) In the above (4), the rotor has 100 pole teeth, and a plurality of stator poles are respectively provided on a surface of each magnetic pole of the stator facing the rotor. The three magnetic pole pitches formed by the magnetic center lines of the four consecutive magnetic poles are 2 at 31.2 ° and 1 at 27.6 °. It is characterized by being a part.

Since the present invention is constructed as described above, the magnetic path in the case of 2-2 phase excitation or 3-3 phase excitation can be shortened, and partial saturation of the yoke can be avoided. Therefore, the magnetic flux density of the yoke portion is also uniform, and high torque can be achieved.

[0016]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will now be described in detail with reference to the drawings. (First Embodiment) FIGS. 1 to 5 show a first embodiment of the present invention, in which a preferred embodiment of a three-phase hybrid type stepping motor according to claims 1, 2 and 3 is shown. FIG. 1 shows a stator core 1 of the stepping motor M.
0 is a cross-sectional view showing the mutual relationship with the rotor core 2 and FIG.
Is a connection diagram of magnetic pole windings constituting each phase, FIG. 3 is a torque vector diagram of each phase, FIG. 4 is an excitation state diagram in the case of 2-2 phase excitation, and FIG. 5 is an excitation state in the case of 3-3 phase excitation. It is a state diagram.

In FIG. 1, the stepping motor M
The iron core of the stator core 10 and the outer periphery are 50 pieces (formula 12a
(When a = 4 at +2), the rotor cores 2 and 2 having the pole teeth 4 formed thereon. 12 stator magnetic poles P radially arranged in the stator core 10
Each of 1, 1, P2, P3,..., P11, and P12 is provided with a plurality of stator pole teeth 3 on a surface facing the rotor cores 2 and 2, respectively.

Then, every other 6
The magnetic poles P1, P3, P5, P7, P9, P11 and P2, P4, P6, P8, P10, P12 are arranged at equal pitches (mechanical angle 60 °) and adjacent to the magnetic poles P1, P2. , P3, ‥‥‥, P11, P12
The angle formed by the magnetic center line of the above, that is, the center line of the plurality of stator pole teeth 3 disposed on each of the magnetic poles is 26.4 ° (in the above equation (3a-1) τ _R / 3, a = 4
And 33.6 ゜ (in the previous equation (3a + 2) τ _R / 3, a
= 4) is alternately repeated, and the magnetic center line of each magnetic pole is 1.8 ° (the previous equation τ) with the center line of the winding of the magnetic pole.
_R / 4).

Each stator magnetic pole P in the state of FIG.
1, P2, P3, ‥‥‥, P11, P12
Perimeter of each stator pole tooth 3 and rotor core 2
The deviation angle from the rotor pole tooth 4 provided in the rotor pole tooth 4
Tooth pitch τ_R(Electrical angle 360 °) as a unit,
Each (0/6) τ_R, (4/6) τ_R, (2/6) τ
_R, (0/6) τ_R, (4/6) τ_R, (2/6)
τ_R, (0/6) τ_R, (4/6) τ_R, (2/6) τ
_R, (0/6) τ_R, (4/6) τ_R, (2/6) τ _R
It is.

Here, (0/6) τ _R means a shift angle of 0 °, and (4/6) τ _R is 2/3 of the tooth pitch τ _R , that is, a shift angle of 240 ° in electrical angle. Means. Also,
(2/6) τ _R means 1/3 of the tooth pitch τ _R , that is, a shift angle of 120 ° in electrical angle.

Therefore, as shown in FIG.
Windings W1, W4 wound around 1, P4, P7, P10,
W7 and W10 are connected so as to have the same polarity to form the A phase, and the windings W3, W6, W9 and W12 wound around the stator magnetic poles P3, P6, P9 and P12 have the same polarity. Connected to B phase, stator poles P2, P5, P8, P
When the windings W2, W5, W8, and W11 wound around 11 are connected so as to have the same polarity to form the C-phase, when a current flows from top to bottom in FIG. As shown in FIG. 3, the torque vectors TA, TB, and TC generated in the above have a phase angle of 120 ° in electrical angle, as shown in FIG.

The torque vectors generated when a current flows through the respective phase windings in the opposite direction are -TA,-
TB and -TC, and by alternately combining the two, it is possible to generate torque vectors TA, -TC, TB, -TA, TC, and -TB that rotate in a fixed direction by 60 electrical degrees. At this time, the rotor 6 has an electrical angle of 60
(The mechanical angle is 60 ° / 50, that is, 1.2 °), so that a three-phase hybrid type stepping motor having a basic step angle of 1.2 ° can be configured.

Assume that the magnetic pole having a deviation angle of 0 ° is “A” and 1
The magnetic poles having a phase difference of 20 ° are denoted by “B”, respectively.
Assuming that the magnetic poles having a phase difference of 180 ° with respect to the above “A”, “B” and “C” are “A ′”, “B ′” and “C ′” respectively, 4 is 2-2
FIG. 5 shows the excitation states AC ', C'B, and BA' in the case of phase excitation, and FIG.
C'BA 'and BA'C are shown.

In FIG. 4A, all four magnetic poles belonging to the A phase are excited to the same polarity N.
The four magnetic poles belonging to the C-phase adjacent to the phase are excited to the polarity S opposite to the above-mentioned polarity, and the eight excited polarities alternate with NSSNSNSN. This relationship is the same for (a), (b) and (c), and the excitation state is always the same. Further, it can be seen that a short magnetic path is formed as shown by a broken line in FIG.

Also in FIG. 5, the polarity of three consecutive magnetic poles is NSN or SNS, and the polarity is repeated four times, ie, NSNNSNNNSNSN or SNSSNSSNSSNS, and a short magnetic path is formed. You can see that. As in FIG. 4, the excitation state is always the same, and it can be seen that a short magnetic path is formed.

In this embodiment, every other six magnetic poles P1, P3, P5, P7, P9, P11 and P2, P4, P6, P8, P10, P12 are arranged at equal pitch. At the same time, the magnetic center line of each magnetic pole is shifted from the center line of the winding of each magnetic pole by a mechanical angle of 1.8 °. As a result, the stator iron plate can be made symmetrical with respect to the center line of an arbitrary slot portion, for example, XX ', and the magnetic circuit can be made more uniform. In addition, since the configuration of the present stator iron plate can be rotated and stacked every 60 ° (lamination is performed while rotating a predetermined angle by 60 ° for each sheet), the stator core 10 achieves magnetic and mechanical uniformity. be able to.

Further, in the present configuration, the stator core 10
Is divided into two equal parts in the stacking direction, and one is reversed with respect to the other with respect to the center line of the winding portion of the magnetic pole as an axis, or an angle that is a multiple of 30 ° other than a multiple of 60 °, for example, 90 ° rotation Then, by superimposing the two, it is possible to shift the tooth pitch of the pole teeth 3 by １ ／ pitch in one magnetic pole.

In this case, the pole teeth 4 of the two rotor cores 2 fixed to sandwich the permanent magnet 5 are aligned with each other from both axial sides of the permanent magnet 5 in FIG. The jig for assembling the rotor 6 can be simplified. Further, in the present embodiment, the number of stator pole teeth 3 per stator magnetic pole is three, but can be four at maximum. Further, in FIG. 1, the tooth pitch of the stator pole teeth 3 is set to be the same as the tooth pitch of the rotor pole teeth 4, but the tooth pitch of the rotor pole teeth 4 may be slightly larger or smaller than that of the rotor pole teeth 4. Of course it is possible.

(Second Embodiment) FIG. 6 is a view showing a preferred embodiment of a three-phase hybrid type stepping motor according to a fourth embodiment of the present invention. FIG. 4 is a cross-sectional view of the stator core 20 of M, showing a mutual relationship with the rotor core 2. The stator iron plate of the present embodiment has four magnetic poles P1, P4, P
7, P10, or P2, P5, P8, P11, or P3, P6, P9, P12 are arranged at an equal pitch, and four consecutive magnetic poles P1, P2, P3, P4,
Or P4, P5, P6, P7, or P7, P8, P
The pitch of the three magnetic poles formed by the magnetic center lines of P9, P10, or P10, P11, P12, and P1 is 3
1.2 ゜ (in the previous equation (3a + 2) τ _R / 3, a = 8
In this case, the number of rotor pole teeth is 100), 27.6 ° (when a = 8 in the equation (3a-1) τ _R / 3), and 31.2 °. , 90 °.

In FIG. 6, the stepping motor M
The iron core of the stator core 20 and the outer periphery are 100 pieces (formula 12
In the case of a + 4, a = 8) is formed.
Rotor cores 2, 2. This place
The pole teeth 3 of the stator pole P1 and the pole teeth 4 of the rotor core 2
Are opposed to each other, each stator magnetic pole P1, P2, P
3, it is provided on the inner peripheral surface of P11, P12
The deviation angle between each stator pole tooth 3 and the rotor pole tooth 4 is
Tooth pitch τ of rotor pole tooth 4_R(Electrical angle 360 °)
Then (0/6) τ _R, (4/6) τ_R,
(2/6) τ_R, (0/6) τ_R, (4/6) τ_R,
(2/6) τ_R, (0/6) τ_R, (4/6) τ_R,
(2/6) τ_R, (0/6) τ _R, (4/6) τ_R,
(2/6) τ_RAnd becomes the same as the first embodiment.

Therefore, the windings wound around the respective stator magnetic poles are connected in the same manner as in FIG. A hybrid type stepping motor can be configured. Further, in the present embodiment, the number of stator pole teeth 3 per stator magnetic pole is seven, but it can be up to eight. Further, in FIG. 6, the tooth pitch of the stator pole teeth 3 is set to be the same as the tooth pitch of the rotor pole teeth 4, but the tooth pitch of the rotor pole teeth 4 may be slightly larger or smaller than that of the rotor pole teeth 4. Of course it is possible.

The technique of the present invention is not limited to the technique in the above-described embodiment, but may be implemented by means of other modes that perform the same function. Can be changed or added.
Further, in the present embodiment, a configuration in which the rotor is provided inside the stator is shown, but a configuration in which the rotor is provided outside the stator is of course also possible.

[0033]

As is apparent from the above description, according to the three-phase hybrid type stepping motor of the present invention, in the first and second aspects, the stator has 12 magnetic poles and the rotor has Is equally distributed, a is 1
When the above integer is used, there are 12a + 2 pole teeth, and stator pole teeth are provided on a surface of each magnetic pole facing the rotor, and six pole teeth are arranged at least every other pole. the magnetic pole is disposed at an equal pitch, the angle between the magnetic center line of the magnetic pole adjacent to each other, when the rotor pole teeth pitch _{τ R, (3a + 2)} τ R / 3 and (3a
-1) τ _R / 3 is alternately repeated, and the magnetic center line of each magnetic pole matches the winding center line of the magnetic pole;
Or a deviation angle of τ _R / 4, so that the magnetic path can be shortened and the torque can be increased, and the magnetic saturation of the yoke part can be made uniform by eliminating the partial magnetic saturation of the yoke part. It can be used efficiently. Therefore, iron loss during operation can be reduced, and the temperature rise can be suppressed low.

According to a third aspect of the present invention, the stator core is
Two rotor cores sandwiching a permanent magnet that is magnetized in the axial direction, two stator cores opposed to each other,
The two stator cores may be inverted with respect to one another with respect to the other, with the winding center line of each magnetic pole as an axis,
Alternatively, the center line of the one winding part is 6
By rotating an angle of a multiple of 30 ° other than a multiple of 0 °, the two are superimposed, and the pole teeth of the two rotor cores holding the permanent magnet are aligned with each other, and the deviation angle is 0 °, the pole teeth on the stator side are exactly 1 /
In order to shift the pole teeth of two rotor iron cores for fixing the permanent magnet so as to sandwich the permanent magnet from both sides in the axial direction, the tooth pitch is conventionally shifted by a half tooth pitch from each other. The required rotor assembly jig can be simplified.

According to Claims 4 and 5, when the stator has 12 magnetic poles and the rotor is equally divided and a is an integer of 1 or more, 12a + 4 pole teeth are provided. And a stator pole tooth is provided on a surface of each of the magnetic poles facing the rotor.
When at the pole of the pieces are arranged at an equal pitch, four of the three pole pitch makes the magnetic center line of each magnetic pole of successive, to the rotor pole teeth pitch τ _R, (3a +
2) Two places where τ _R / 3 and (3a-1) τ _R
Since there is only one place of / 3, the magnetic path can be made short and high torque can be achieved. In addition, the magnetic saturation of the yoke part becomes uniform by eliminating the partial magnetic saturation of the yoke part, and the yoke magnetic path is formed. It can be used efficiently. Therefore, iron loss during operation can be reduced, and the temperature rise can be suppressed low.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view of a stator core of a first embodiment of a three-phase hybrid type stepping motor according to the present invention.

FIG. 2 is a connection diagram of magnetic pole windings constituting each phase.

FIG. 3 is a torque vector diagram of each phase.

FIG. 4 is an excitation state diagram in the case of 2-2 phase excitation.
4A is an AC ′ excitation state diagram, FIG. 4B is a C′B excitation state diagram, and FIG. 4C is a BA ′ excitation state diagram.

FIG. 5 is an excitation state diagram in the case of 3-3 phase excitation.
(A) is an AC'B excitation state diagram, and (b) is C'BA '.
FIG. 5C is an excitation state diagram of BA′C.

FIG. 6 is a sectional view of a stator core of a three-phase hybrid type stepping motor according to a second embodiment of the present invention.

FIG. 7 is a sectional view of a stator core of a conventional three-phase hybrid type stepping motor.

FIG. 8 is a schematic longitudinal sectional view of a conventional three-phase stepping motor.

FIG. 9 is a diagram showing the previous six excitation states among the twelve ways in the case of 2-3 phase excitation of the hybrid type stepping motor in FIG. 7; FIG. 9A is an AC ′ excitation state diagram;
9B is an AC'B excitation state diagram, FIG. 9C is a C'B excitation state diagram, FIG. 9D is a C'BA 'excitation state diagram, FIG.
FIG. 9E is a BA ′ excitation state diagram, and FIG. 9F is a BA′C excitation state diagram.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Stator 2 Rotor core 3 Stator pole tooth 4 Rotor pole tooth 6 Rotor 7 axis 10, 20 Stator core M Hybrid type stepping motor P1, P2, P3, ‥‥‥, P11, P12 Stator magnetic pole W1 , W2, W3, ‥‥‥, W11, W12 winding (magnetic pole winding)

Claims (5)

[Claims] The stator has twelve magnetic poles arranged radially, and the rotor has 12a + 2 pole teeth equally arranged, where a is an integer of 1 or more. And
At least one stator pole tooth is provided on a surface of each of the magnetic poles facing the rotor, and at least every other six of the magnetic poles are arranged at an equal pitch. In addition, the angle formed by the magnetic center lines of the magnetic poles adjacent to each other is (3) when the rotor pole tooth pitch is τ _R.
a + 2) τ _R / 3 and (3a-1) τ _R / 3 are alternately repeated, and the magnetic center line of each magnetic pole matches the winding center line of the magnetic pole, or τ _R / 4 A three-phase hybrid type stepping motor characterized by having a deviation angle of: 2. The rotor has 50 pole teeth, and a plurality of stator pole teeth are provided on a surface of each magnetic pole of the stator facing the rotor, respectively. The angle between the magnetic center lines of the magnetic poles adjacent to each other is 26.4.
゜ and 33.6 ° are alternately repeated, and the magnetic center line of the magnetic pole coincides with the center line of the winding portion of the magnetic pole, or has a shift angle of 1.8 °. Item 3. A three-phase hybrid type stepping motor according to item 1. 3. The stator core comprises two stator cores opposed to two rotor cores sandwiching a permanent magnet magnetized in the axial direction, and the two stator cores are One of the magnetic poles may be turned upside down with respect to the other with respect to the center line of the winding portion of each magnetic pole, or the center line of the one winding portion may be shifted by 30 degrees other than a multiple of 60 ° with respect to the other.
倍 is rotated by an angle of a multiple of ゜, the two are superimposed, and the pole teeth of the two rotor cores sandwiching the permanent magnet are aligned with each other, and the deviation angle is 0 °. The three-phase hybrid type stepping motor according to claim 1 or 2, wherein 4. The stator has twelve magnetic poles arranged radially, and the rotor has 12a + 4 pole teeth, evenly arranged, where a is an integer of 1 or more. And
At least one stator pole tooth is provided on a surface of each of the magnetic poles facing the rotor, and the four magnetic poles arranged at every third are arranged at an equal pitch. The three magnetic pole pitches formed by the magnetic center lines of the four consecutive magnetic poles are as follows: When the rotor pole tooth pitch is τ _R ,
(3a + 2) τ _R / 3 and two places (3a−
1) A three-phase hybrid type stepping motor characterized in that τ _R / 3 is one point. 5. The rotor has 100 pole teeth,
A plurality of stator pole teeth are provided on a surface of each of the magnetic poles of the stator facing the rotor.
27. The three magnetic pole pitches formed by the magnetic center lines of the magnetic poles are each 21.2.
The three-phase hybrid type stepping motor according to claim 4, wherein the position of 6 ° is one position.