JPH03164060A - Stepping motor - Google Patents

Abstract

PURPOSE:To finely divide the stepping angle of a motor by so connecting windings wound on 32 poles that six windings are alternately connected in different polarities in one phase to form four phases, and arranging the number of pole teeth of rotor poles to become (32n+4) or (32n+28) (n: integer number). CONSTITUTION:32 windings A-1-D-8 wound on poles 10-1-10-32 of a stator core 10 are so connected as to form one phase with eight windings as one set. That is, the windings A-1-A-8 are connected in series so that the polarities are different at each one to form a phase A, B-1-B-8 are similarly connected to form a phase B, C-1-C-8 are similarly connected to form a phase C, and D-1-D-8 are connected to form a phase D. The number of the pole teeth (1-19) arranged on the outer periphery of the rotor pole 16 is so arranged as to become (32n+4) or (32n+28) (n: integer number).

Description

Detailed Description of the Invention (1) Purpose of the Invention [Field of Industrial Application] The present invention is directed to the control of a stepping motor, particularly a magnetic desk drive device that operates at a minute step angle and is used as a storage device for an electronic calculator. It is used for various purposes.

[Prior Art] Figure 2 is a sectional view (a), (b) showing the structure of a conventional stepping motor, and a developed view (c) showing the relationship between the pole teeth of the stator and rotor. .

1 is a stator housing, 2 is a stator core, 3 is a stator winding, 4, 4 is a bearing, 5 is a rotor shaft, 6, 7 is a rotor magnetic pole, and 8 is a permanent magnet.

The stepping motor shown in Figure 2 has an annular yoke with eight
Magnetic poles 2-1 to 2-8 are planted at equal intervals, and windings 3-1 to 3-8 are respectively connected to the magnetic poles of the stator iron core 2, which has pole teeth at the tips of the magnetic poles. A wound stator and rotor magnetic poles 6 and 7, which face the pole teeth through a gap and have a plurality of pole teeth on their outer peripheries, are provided spaced apart on the rotor shaft 5. , 7, and a rotor which is integrally fixed to the rotor shaft and is rotatably supported by bearings 4, 4 provided in the stator housing. Second
The stepping motor shown in the figure has eight stator magnetic poles 2-1 to 2-8 arranged at equal intervals, as shown in the developed diagram (c) of the relationship between the stator and rotor pole teeth. Pole teeth are provided at the tips of the magnetic poles, and each of the eight magnetic poles has a winding 3-
1 to 3-8 are wound, and the windings 3-1 and 3-5, 3-2 and 3-6, 3-3 and 3-7, and 3-4 and 3-8 are connected in series, respectively. A four-phase winding is formed.

The rotor magnetic poles 6 and 7 have pole teeth 1a to loa (lb to 1
0b) are arranged at equal intervals with a pitch of θr, and the width of the pole teeth is approximately 1/2 of the arrangement pitch of the pole teeth or Teeth arrangement pitch o
They are arranged so as to be shifted by a pitch of 172 r.

In the developed view of (c), stator windings 3-1 and 3-5
is energized, and the magnetic poles 2-1 and 2-5 of the stator and the opposing pole teeth 1 and 6 of the rotor are aligned, respectively. In this state, the relative relationship between the other stator magnetic poles and the rotor's pole teeth is such that the rotor's pole tooth 2 is 1/1/2 of the stator magnetic pole 2-2's pole tooth.
The stator magnetic poles 2-3 do not overlap with the pole teeth of the rotor, and the stator magnetic poles 2-4 overlap with the pole teeth 5 of the rotor by 4θr. Stator magnetic pole 2-572-
The same relationship holds true for 8.

In the developed view of (c), to rotate the rotor in the right direction, turn off the current to windings 3-1 and 3-5, and then turn the windings 3-1 and 3-5 off. 3-2 and 3
-6, the rotor's pole teeth 2 and 7 are attracted to the energized magnetic poles and rotate by 1/4θr, and the stator's pole teeth align with the stator's pole teeth and stop. As described above, when the rotor pole teeth facing the stator magnetic poles excites the magnetic poles that partially overlap with the stator magnetic poles, the rotor pole teeth overlap more with the opposing stator magnetic poles. Rotate the rotor in the direction. In addition, since the rotor rotates by a fixed angle of 1/40r each time the energized winding is switched, the rotation angle is proportional to the number of times the energized winding is switched, so the position of the rotating body can be controlled with a simple control device. Because of this, stepping motors have excellent characteristics as control motors.

[Problems to be solved by the invention] The angle at which the stepping motor rotates each time the energized windings are switched is called the step angle, and is an important index indicating the disassembly performance of the stepping motor.The step angle θS is the angle of rotation of the stator. If the number of phases is P and the number of pole teeth of the rotor is Nr, θs=(
360/P)/Nr. In the stepping motor having the configuration illustrated in FIG. 2, the number of phases P of the stator is 4 and the number Nr of pole teeth of the rotor is ↓0, so the step angle OS is 9 degrees. In an example of a product for practical use, the number of pole teeth of the rotor is 5 times as many as 50, five pole teeth are provided at equal intervals at the tips of the stator magnetic poles, and the step angle θS is set to 1. There is one that is composed of 8 degrees. To make the step angle OS finer, there is a way to increase the number of pole teeth of the rotor, but if the number of pole teeth is increased for a given outer diameter, the width of the pole teeth becomes narrower and the machining accuracy decreases. There is a problem that the accuracy of the step angle is reduced.

An object of the present invention is to obtain a stepping motor that allows a small step angle with a small number of rotor pole teeth.

(2) Structure of the Invention [Means for Solving Problems] In the present invention, 32 magnetic poles are arranged at equal intervals on the stator, and the windings wound around each magnetic pole are 8 times per phase. A four-phase winding is formed by connecting four windings with N and S alternating polarities, and the number of pole teeth Nr provided on the outer periphery of the rotor magnetic poles is Nr = 32n + 4 or Nr = 32n + 28 This can be achieved by arranging them in a relationship such that

(However, n is a positive integer.) [Operation] According to the configuration of the present invention, 32 stator magnetic poles are arranged at equal intervals, and the windings wound around each magnetic pole are wound in 8 turns per phase. Since the wires are connected in a certain way with N and S alternating polarities to form 4 phases, the windings of one phase are distributed at 45 degree intervals, so the radial direction that acts on the rotor is The attraction force is balanced, and the magnetic poles with four-phase windings are provided between them at 45 degrees, and the arrangement pitch of the magnetic poles for one phase is 360/
3 2=1↓. For 25 degrees, the arrangement pitch or of the pole teeth of the rotor magnetic poles is Or=360/Nr, and Nr is Nr=
3 2 n + 4 or Nr= 3 2 n + 2
8, so when the winding of a certain phase is energized and the pole teeth of the rotor facing the magnetic poles of that phase are aligned, the other three phases The angle of deviation between the rotor pole teeth and the stator magnetic poles facing each magnetic pole is 1/80r.
A stepping motor structure having a step angle of 1/8 θr can be obtained.

[Embodiment of the Invention Fig. 1 (a) is a sectional view showing the relationship between the stator and rotor pole teeth of an embodiment of the stepping motor according to the present invention.
0 is the stator iron core, 10-1-10-32 are the magnetic poles, which are arranged at equal pitches, and each magnetic pole is wound with windings A-1 to D-8, for a total of 32 windings. A set of eight windings are connected to form one phase.

That is, the windings A-4, A-2, A-3, A-4, A-5,
Eight A-6, A-7, and A-8 are connected in series so that the polarity of each one is reversed to form the A phase, and then B-IB-2, B-IB-2, B-3, B-4, B-5, B-6
, B-7, B-8, in the same way as C-1, C-
3, C-4, C-5, C-6, C-7, C-8 in the same way, and further D-1, D-2, D-3, D-4, D-5
, D-6, D-7, and D-8 are connected in series so that each one has opposite polarity to form four phases.

Pole teeth are arranged at equal pitches on the outer periphery of the rotor magnetic poles 16.
The number of pole teeth Nr is Nr = 32n + 4 or N r = 3 2 n + 2
Figure (a) shows n for the example of Nr = 3 2 n + 4.
The case where Nr=32+4=36 under the condition of = 1 is shown. In other words, the stator has 32 magnetic poles arranged at equal pitches, and the 36 rotor pole teeth are opposed to these through gaps.The relationship between the stator and rotor in this case is Developed view (
This will be explained as shown in b).

(b) The figure shows 180 degrees of the stator, and the rear part is omitted because it is symmetrical.

All the symbols shown in the figure (b) are the same as in the figure (a).

(b) In the figure, the A phase of the stator winding is energized, and the stator magnetic poles 10-1, upper 0-5.10-9.10-13, are aligned with the opposing pole teeth of the rotor. Indicates the condition.

At this time, the relationship between the magnetic poles around which the B-phase, C-phase, and D-phase windings are wound and the pole teeth of the rotor is as follows: It can be seen that the child's pole teeth are stopped at a deviation of 178θr, where the pitch of the rotor's pole teeth is or. Similarly, the relationship between the magnetic pole 10 (3,04 m) around which the C-phase winding is wound and the pole teeth of the rotor is deviated by 278θr, and the magnetic pole 10- (4 + 4 m) around which the D-phase winding is wound is deviated by 278θr. The relationship between and the rotor pole teeth is 3/8
It is shifted by 0r.

Here, (inner) is the number of the magnetic pole, and m is an integer from 1 to 7.

Therefore, in order to operate the illustrated stepping motor, turn off the power to the A phase and energize the B phase, where the rotor's pole teeth are shifted by 1/8θr, and the rotor will rotate to the right by 1/8θr.
It is clear that the stator's magnetic pole 10-2 and the rotor's pole teeth align and stop, and the illustrated stepping motor operates with a step angle of 1/8 (lr).

Since or is 360/36=10 (degrees) and the step angle is 1/8θr, it is 1.25 (degrees). Considering the above relationship between the stator magnetic poles and the rotor pole teeth from a different perspective, 32 stator magnetic poles are arranged at equal pitches,
Thirty-six rotor pole teeth are arranged opposite to this.

Therefore, the pitch of the pole teeth of the rotor that opposes the l pitch of the stator magnetic poles is 3 6/3 2 = 1.1 2 5, which means that the arrangement pitch of the stator magnetic poles is the same as the pitch of the rotor pole teeth. It shows that it is 1.1 2 5 times as much as that,
1.125-1='0.125 represents the standard deviation angle between the rotor pole teeth and the stator magnetic poles, and the rotor pole tooth pitch O
It shows 1/8 of r.

Furthermore, considering the case where n=1 in the example of Nr=32n+28, Nr=32+28=60, and the ratio of the rotor pole teeth to the stator magnetic poles is 60/32-4.875. , this indicates that the rotor does not contain more than two pole teeth, so 2-1.8
75=0.125, which also represents the standard deviation angle between the rotor pole teeth and the stator magnetic poles, and represents 1/8 of the pitch or of the rotor pole teeth. Table 1 shows n in the formula
The relationship between the number of pole teeth Nr of the rotor and the step angle OS of the rotor corresponding to is shown.

Table 1 (however, angle values are shown to the third decimal place) Figure 1 is an example in which the number of pole teeth of the rotor in Table 1 is 36, and in the case of the conventional technology, the rotor Even when the number of pole teeth of the rotor is 50, the step angle Os is 1.8 degrees, whereas in the embodiment of the present invention, even when the number of pole teeth of the rotor is 36, the step angle Os is 1.8 degrees. Furthermore, in the conventional technology, even if the number of pole teeth is 100, the step angle is 0.9 degrees, whereas in the present invention, the number of pole teeth of the rotor is 10.
If it is 0, the step angle will be 0.45 degrees, which can be about 1/2 the step angle for the same number of pole teeth on the rotor.

[Effects of the Invention] Since the stepping motor of the present invention has the above-described structure, the step angle can be reduced even if the number of pole teeth of the rotor is small, and the number of magnetic poles for one phase can be reduced by eight. By distributing them at equal intervals around the entire circumference and energizing them at the same time, the radial attractive force between the stator magnetic poles and the pole teeth of the rotor magnetic poles becomes easier to balance, reducing rotor vibration and reducing noise. This has the effect of making it easy to configure a stepping motor.

[Brief explanation of the drawing]

Fig. 1 is a sectional view (a) and a developed view (b) showing the arrangement of the pole teeth of the stator magnetic poles and rotor magnetic poles of the stepping motor according to the present invention, and Fig. 2 shows the structure of the stepping motor according to the prior art. FIG. 3 is a developed view showing the relationship between the sectional views (a) and (b) shown and the pole teeth of the stator magnetic poles and the rotor magnetic poles. Explanation of symbols 1... Stator housing, 2... Stator iron core, 3...
... Stator winding, 4, 4... Bearing, 5... Rotor shaft, 6, 7... Rotor magnetic pole, 8... Permanent magnet, 2-1
~2-8, 10-1 ~ 10-32... Magnetic pole of stator,
3-Eng~3-8,A-]~A-8,B-1~B-8,C
-1-C-8, D-↓~D-8... Stator winding, 1
a~l O a, (1 b~l O bL=pole teeth of rotor magnetic poles.

Claims (1)

[Scope of Claims] A stator including a plurality of magnetic poles each having a winding wound around an annular yoke, planted at equal intervals, and having respective pole teeth at the tips of the magnetic poles;
In a stepping motor having a rotor having a permanent magnet sandwiched between a plurality of rotor magnetic poles that face the pole teeth of the stator through an air gap and have a plurality of pole teeth on the outer periphery, the plurality of stator magnetic poles The number of windings is 32, and the windings wound around each magnetic pole are connected so that 8 windings are connected for one phase so that N and S have alternating polarity to form a 4-phase winding, and the rotor A stepping motor characterized in that the number Nr of pole teeth provided on the outer periphery of the magnetic pole is arranged in the following relationship: Nr=32n+4 or Nr=32n+28. (However, n is a positive integer.)