JPS61164460A - Linear motor - Google Patents

Abstract

PURPOSE:To enable the movement of a mover on a stator to be controlled smoothly, by setting the multiples of 2:3 on the ratio of the quantity of the magnetic pole teeth of the mover to the quantity of the stator teeth of he stator. CONSTITUTION:A mover 2 made of magnetic substance is formed by arranging convex magnetic poles 2a, 2c and a concave magnetic pole 2b at an equal pitch P1. The convex magnetic poles 2a, 2c are arranged to confront the stator teeth 3a-3c of the stator 3 with a small space between them. The base section of the stator teeth 3a-3c is wound up with coils 4a-4c, and the longitudinal dimension of the stator teeth 3a-3c is arranged to be equal to the pitch P1 of the mover, and the pitch between the adjacent stator teeth 3a and 3b, 3b and 3c is set to be P1/3. The ratio of he tooth quantity of the stator teeth of the confronting section between the mover 2 and the stator 3 is set to be the multiples of 2:3. In this manner, the weight of the mover is reduced, and the structure is simplified, and the mover can be smoothly controlled.

Description

[Detailed Description of the Invention] [Field of Application of the Invention] The present invention relates to a linear motor, and a method for driving a movable element by specifying the ratio of the number of teeth between the movable element and the stator to 1%. The present invention relates to near motors that reduce cogging torque when driving and enable suitable operation.

[Background of the invention]

Conventionally, some rotary motors have a structure of magnetic pole teeth as described in French Patent No. 1452379, but in this case, the convex portions and concave portions of the stator are arranged at equal intervals. The convex part of the movable tooth is the same length as the convex part of the stator, and the concave part of the movable part is one part of the convex part.
72 in length, there is a drawback that four or more movable teeth (projections) are always required to move the movable element.

If the number of teeth increases, the frequency will double compared to a motor composed of convex portions with the same pitch, which poses a problem in that it is disadvantageous in terms of switching loss during control and noise imparted to the outside. ing.

[Purpose of the invention]

An object of the present invention is to enable smooth control of the movement of a mover on a stator and to provide a near motor.

[Summary of the invention]

The configuration of the linear motor according to the present invention includes a first magnetic pole portion having a plurality of tooth-shaped and uneven magnetic pole teeth made of a magnetic material and arranged at a constant length in the longitudinal direction; In the linear motor, the first magnetic pole part and the second magnetic pole part have a plurality of tooth-like uneven magnetic pole teeth made of a magnetic material facing each other with a slight air gap.
The ratio of the number of magnetic pole teeth, which are convex parts in the part facing the magnetic pole part, is 2:
It is a multiple of 3.

To add to this, the following points are true.

In order to achieve the above object, the present invention has a size ratio of 1 between the convex and concave portions of the movable teeth and the convex portions that are the magnetic poles of the stator.
:1:1, the size ratio of the concave portions of the stator is 1/3 of the convex portions of the stator, and the ratio of the number of convex portions of the mover teeth to the number of convex portions of the stator teeth. This is achieved by setting 2=3.

[Embodiments of the invention]

An embodiment of the linear motor according to the present invention will be described with reference to the drawings.

Therefore, the linear motor according to this embodiment is a three-phase linear motor.

FIG. 1 is a schematic sectional view of a linear motor according to an embodiment of the present invention in a plane parallel to the direction of movement, FIG. 2 is a front view of a plane perpendicular to the direction of movement, and FIGS. , Similarly, each schematic cross-sectional view of a plane parallel to the traveling direction, (A) of Figure 5, (Ron is each curve diagram of the magnetic flux, induced voltage, and thrust,
FIG. 7 is a diagram of the induced voltage curve generated in the phase coil, FIG. 7 is a diagram of the thrust force generated in the motor, and FIG. 8 is a schematic cross-section of a plane parallel to the traveling direction of a linear motor according to another embodiment of the present invention. figure,
FIG. 9 is a schematic cross-sectional view of a plane parallel to the traveling direction of a +7 linear motor for comparison, and FIG. 10 is a schematic cross-sectional view of a plane parallel to the traveling direction of a linear motor according to yet another embodiment of the present invention. The cross-sectional view and FIG. 11 are curve diagrams illustrating the induced voltage generated in the three-phase coil.

First, in Figures 1 and 2, 1 is the mover yoke, 2
is a mover, 2a-2C are magnetic pole teeth, 3 is a stator, 3a-
3c, 3m, 3nld stator teeth, 4 is a coil portion, 4a to 4C are coils, 5 is a truck, 6 is a wheel, 7 is a yoke, 8 is a magnet, and 9 is a frame.

That is, the movable element 2 includes a plurality of tooth-shaped convex magnetic pole teeth 2a made of a magnetic material and arranged on the movable element yoke 1 at a constant length Pl in the longitudinal direction thereof.

2b, it has recessed magnetic pole teeth 2C.

Thus, while maintaining a slight gap with the magnetic pole teeth 2a, 2b, the stator teeth 3a to 3c in the convex portions and the stator teeth in the concave portions are connected to the plurality of magnetic pole teeth made of magnetic material in the stator 3. The teeth 3m and 3n are made to face each other, and the length of the stator teeth 3a to 3C is Pl as shown in the figure.

In the illustrated embodiment, 2P1 is 36 in electrical angle.
It is 0 degrees.

The stator teeth 3a, 3b, 3cK are connected to the coils 4a, 4b, 4. c is wound, stator tooth 3a
-3b and 3b-3c, stator teeth 3m and 3n are arranged with an interval of Pl/3.

Here, the mover 2Fi corresponds to the first magnetic pole part, and the stator 3 corresponds to the second magnetic pole part.

Magnets 8 are arranged at both ends of the stator teeth 3a to 3C so that the same poles face the teeth on the stator 3, and the other pole surface of the magnets 8 is attached to the yoke 7. It is something that

The truck 5 includes a mover yoke 1 and magnetic pole teeth 2a.

A movable element 2 having 2b and 2C is mounted and spatially supported between the stator 3 and the yoke 7 via a wheel 6, and the only contact part is the wheel 60. .

Further, the top metal of the pedestal 9 rolls or slides on the wheels 6.

With the above configuration, the magnetic flux of the magnet 8 passes through the magnetic path shown by the broken line in FIG.

Next, the operation of the apparatus having the above structure will be explained with reference to FIGS. 3 to 7.

Figure 3 shows the case where the magnetic pole teeth 2a and stator teeth 3a overlap, and the magnetic resistance of the magnetic circuit shown by the broken line in Figure 2 is at its minimum, and Figure 4 shows the maximum magnetic resistance. This figure shows the case where the stator tooth 3a is located between the magnetic pole teeth 2a and 2b at the magnetic pole position.

As described above, the magnetic pole teeth 2a arranged on the movable element yoke 1
, 2b moves on the stator teeth 3a, the magnetic flux 10a changes as shown in FIG.

As this magnetic flux 10a changes, an induced voltage 11a is generated in the coil 4a.

The thrust of the motor is determined by the product of this induced voltage 11a and the energizing current that flows when the coil 4a is energized.If the energizing current 12a that has the same phase and shape as the waveform of the induced voltage 11a is applied, the thrust is in the positive direction. In addition, in the case of opposite phases, a thrust force in the opposite direction is generated.

Reference numeral 138 in FIG. 5(b) shows a thrust line (torque curve generated in one phase) generated in the former case of the same phase.

However, the thrust line 13a is generated in the coil 4a as shown in FIGS. 3 and 4, and is located at a location where the electrical angle is distorted by 240 degrees, that is, PK+1/3 as shown in FIG.
Each coil 4b is arranged at a position shifted from P1.
, 4c! In particular, the induced voltages 11a and llb shown in FIG.
, IIC occurs. These three induced voltages 118 to 11
By detecting the positions of the magnetic pole teeth and stator teeth and applying current of the same phase to each phase of C, the constant thrust line 14 shown in Fig. 7 is applied.
T-I'll take what I can get.

In this embodiment, as previously explained with reference to FIG. 1, the magnetic pole teeth 2a are the convex poles of the convex portions in the facing portions of the movable element 2 and the stator 3.

2b and the number of stator teeth 3a to 3C were set to 2 and 3, respectively. In other words, the ratio between the number of magnetic pole teeth arranged on the movable element yoke 1 and the number of stator teeth was set to 2. = 3.

As a result, it is possible to generate a three-phase induced voltage with a phase of 2π/3, which makes it possible to obtain low ripple thrust and to obtain uniform thrust at any location. , which can be expected to have the effect of improving controllability.

Next, FIG. 8 is a schematic cross-sectional view of a plane parallel to the traveling direction of a linear motor according to another embodiment.

In the figure, the same symbols as in Figure 1 indicate all equivalent parts, 2d, 2e.
1 is a magnetic pole tooth related to the recessed portion, and 1-1 is a movable element yoke.

That is, in the illustrated example, magnetic pole teeth 2d and 2e with a length Pl are provided on the left and right sides of the movable yoke 1 shown in FIG. 1 to form a movable yoke 1-1.

The magnetic pole teeth provided in this way have almost no effect on changes in magnetic flux, so even if the movable yoke 1-1 shown in this figure is moved, the induced voltage waveform obtained is almost the same as that in Figure 6. In addition, almost the same characteristics as the linear motor shown in FIG. 1 can be obtained.

In each of the embodiments described above, as shown in FIG.
Magnetic pole teeth 2a, 2 which are convex poles provided on the movable element yoke IA
b. If the number of 2m is not a multiple of 2 but three, the magnetic pole teeth 2a and 2m become Kx with the stator teeth 3a and 3d in phase.

Now, for example, stator teeth 3at-U phase, 3bt-V phase,
If 3c is the W phase, the stator tooth 3d is the U phase.

3e is the V phase and 3f is the W phase. In the case of FIG. 9, the coils 4a and 4dKH1 corresponding to the U phase are interlinked with about twice as much magnetic flux as the other coils, so the induced voltage waveform is as follows. 1st
As shown in FIG. 1, magnetic pole teeth 2a.

Coils 4a44 of stator teeth 3a and 3d that overlap 2m
An induced voltage of approximately twice the magnitude is generated in the d phase.

In this way, in a mover with magnetic pole teeth related to three convex poles, the induced voltage 2 generated in the coil of each phase as shown in FIG.
1a to 21C either do not have a constant size or change in size, and a phase shift occurs, resulting in very poor controllability. Therefore, as shown in FIG. 9, if the ratio between the number of magnetic pole teeth, which are convex portions provided on the movable yoke IA, and the number of facing stator teeth is in a relationship of Δ:4, good controllability is achieved. It cannot be called a motor. Furthermore, the same can be said of the above relationship that is a multiple of 3=4.

Next, FIG. 10 is a schematic cross-sectional view of a plane parallel to the traveling direction of an IJ near motor according to still another embodiment of the present invention.

In the figure, the same symbols as in Figure 1 indicate equivalent parts, 2m, 2n
are the magnetic pole teeth of the convex part, 3d to 3f are the stator teeth of the convex part, and 4d
4f is a coil, and D and 1-2 are mover yokes.

In other words, in this embodiment, the ratio between the number of magnetic pole teeth, which are convex parts in the facing portion of the movable element and the stator, and the number of stator teeth is 426, which is twice 2:3. This is what I did.

In the case of this embodiment, the movable yoke 1-1 shown in FIG.
However, it corresponds to two pieces connected in series through one recess, and the induced voltage that causes the problem is of the form shown in Figure 6, and the size is the same as that of the movable yoke that constitutes the magnetic circuit. 1-2. Magnetic pole tooth 2a.

2b, 2m, 2n, stator teeth 3a to 3f, and those corresponding to the yoke 7 in FIG. 1, etc., would be about twice as large if there were no magnetic saturation.

In this way, for a ratio of 2:3, 2.3, 4°...
..., by multiplying by n, it is possible to obtain induced voltages of a constant magnitude with a phase shift of 2π/3 in three phases, and as shown in Fig. 7. This has the effect of obtaining a constant thrust line 14.

In Fig. 5 above, the waveform of the induced voltage is shown as a sine wave, but depending on the size of the gap between the mover and the stator, it becomes a trapezoidal wave or a step shape. However, even in such cases, it is possible to obtain a constant thrust line.

Furthermore, in each embodiment, the first magnetic pole part is used as a mover and the second magnetic pole part is used as a stator, but in this case, the first magnetic pole part is used as a stator and the second magnetic pole part is used as a mover. Even if this method is used, the same effect can be expected.

〔Effect of the invention〕

According to the present invention, the structure of the magnetic pole portion corresponding to the movable element can be simplified, so that the weight of the movable element can be reduced, and a high thrust and low thrust caliper linear near motor can be provided.

[Brief explanation of the drawing]

FIG. 1 is a schematic sectional view of a linear motor according to an embodiment of the present invention in a plane parallel to the direction of movement, FIG. 2 is a front view of a plane perpendicular to the direction of movement, and FIGS. , Similarly, each schematic cross-sectional view of the plane parallel to the traveling direction, (a) and (b) of FIG. 5 is each curve diagram of the magnetic flux, induced voltage, and thrust, and FIG.
FIG. 7 is a diagram of the induced voltage curve generated in the phase coil, FIG. 7 is a diagram of the thrust force generated in the motor, and FIG. 8 is a schematic cross-section of a plane parallel to the traveling direction of a linear motor according to another embodiment of the present invention. figure,
FIG. 9 is a schematic sectional view of a plane parallel to the traveling direction of a linear motor for comparison, and FIG. 10 is a schematic sectional view of a plane parallel to the traveling direction of a linear motor according to yet another embodiment of the present invention. The cross-sectional view and FIG. 11 are explanatory curve diagrams of induced voltages generated in three-phase coils. 1.1-1.1-2...Mover coil, 2...Mover, 2a to 2e-, 2m, 2n...Magnetic pole tooth, 3...
・Stator, 3a to 3f, 3m, 3n...Stator tooth, 4
...Coil part, 4a-4f...Coil, 5...Dolly, 6...Wheel 9.7...Yoke, 8...Magnet,
9... Frame, 10a... Magnetic flux 11a... Induced voltage, 12a... Current flowing, 14-), Push rod 1 Note ZZI￥l No. 31 纂4田851￥11 Figure 6 is also a name. Figure 9 IO diagram

Claims (1)

[Scope of Claims] 1. A first magnetic pole part having a plurality of tooth-shaped uneven magnetic pole teeth made of a magnetic material and arranged at a constant length in the longitudinal direction; In a linear motor comprising a second magnetic pole part having a plurality of tooth-like uneven magnetic pole teeth made of a magnetic material facing each other with a slight air gap, the first magnetic pole part and the second magnetic pole part are A linear motor characterized in that the ratio of the number of magnetic pole teeth, which are convex portions in the opposing portion, is a multiple of 2:3. 2. In the device described in claim 1, the lengths in the longitudinal direction of the convex portion and the concave portion of the first magnetic pole portion and the convex portion of the second magnetic pole portion are equal, and the concave portion of the second magnetic pole portion is made equal. 1/ of the convex part
A linear motor with a length of 3. 3. A linear motor according to claim 1 or 2, in which the first magnetic pole part is a mover and the second magnetic pole part is a stator. 4. A linear motor according to claim 3, wherein the mover is composed only of a magnetic material such as an uneven iron core.