WO2023195170A1

WO2023195170A1 - Module-type linear motor

Info

Publication number: WO2023195170A1
Application number: PCT/JP2022/017392
Authority: WO
Inventors: 迪廣谷; 優 ▲高▼村; ザイニアリフ; 功太郎榊原; 健太郎橋本
Original assignee: 三菱電機株式会社
Priority date: 2022-04-08
Filing date: 2022-04-08
Publication date: 2023-10-12
Also published as: KR20240034878A; JP7204058B1; JPWO2023195170A1

Abstract

A module-type linear motor (1) comprises: a stator module group (100) that has a plurality of stator modules (10) provided side by side in a stroke direction (S); and a movable element module group (200) that has a plurality of movable element modules (20) provided side by side in the stroke direction (S) and that is disposed oppositely from the stator module group (100) with a gap (Tg) therebetween. The stator modules (10) are each provided with a permanent magnet block (10a) in which Np1 poles (11) are arranged. If the number of poles (11) that are disposed oppositely from one movable element module (20) and that are from among the plurality of poles (11) of the permanent magnet blocks (10a) of the stator module group (100) is defined as Np2, then Np1>Np2.

Description

modular linear motor

The present disclosure relates to a modular linear motor in which a plurality of stator modules and a plurality of mover modules are arranged in the stroke direction.

A linear motor is composed of a mover and a stator, and the mover moves linearly in the stroke direction. In a linear motor, it is necessary to set the lengths of the mover and stator in the stroke direction depending on the desired movable range or thrust. On the other hand, when considering the manufacturability of the mover and stator, setting a plurality of lengths in the stroke direction of the product depending on the product performance leads to a deterioration in the yield of the core and an increase in the cost of manufacturing equipment.

Therefore, it has been proposed to arrange a plurality of modular movers in the stroke direction of the mover. Further, Patent Document 1 discloses that a stator having a field yoke and a plurality of permanent magnets is modularized, and a plurality of modularized stators are arranged in the stroke direction of the movable element.

Japanese Patent Application Publication No. 2004-135385

When a plurality of stator modules are arranged side by side in the stroke direction as in Patent Document 1, a portion where the magnetic flux density generated from the stator modules is asymmetric occurs in adjacent portions where adjacent stator modules touch. Therefore, there is a problem that the cogging thrust generated when the movable module group arranged across the magnetic gap moves in the stroke direction increases, and the positioning accuracy of the linear motor decreases. In particular, when the magnet on the stator side is not a normal permanent magnet with each magnetic pole, but a permanent magnet block in which multiple magnetic poles are magnetized all at once, the magnetic flux density generated by the stator module between adjacent stator modules is A region is created where the is asymmetrical.

The present disclosure has been made in view of the above, and aims to provide a modular linear motor that can reduce the cogging thrust generated when the movable module group moves in the stroke direction.

In order to solve the above-mentioned problems and achieve the objective, a modular linear motor according to the present disclosure includes a stator module group having a plurality of stator modules arranged in parallel in the stroke direction, and a stator module group having a plurality of stator modules arranged in parallel in the stroke direction. The movable module includes a plurality of mover modules, and a mover module group is arranged to face the stator module group across a gap. Each of the mover modules includes a plurality of teeth arranged at a constant pitch and a plurality of coils wound around each of the plurality of teeth. Each of the stator modules includes a permanent magnet block having a first number of magnetic poles arranged thereon. Among the plurality of magnetic poles included in the permanent magnet block of the stator module group, when the number of magnetic poles that are arranged opposite to one movable module is the second number of magnetic poles, the first number of magnetic poles is the second number of magnetic poles. It is characterized by being larger.

According to the modular linear motor of the present disclosure, it is possible to reduce the cogging thrust generated when the movable module group moves in the stroke direction.

A side view showing the configuration of a modular linear motor according to Embodiment 1. A side view showing the positional relationship between the stator module and the magnetizing yoke of the modular linear motor according to Embodiment 1 during magnetization. Side view showing the configuration of a comparative example modular linear motor A diagram showing the relationship between the surface magnetic flux and cogging thrust of the permanent magnet block of Embodiment 1. Diagram for explaining measurement points of surface magnetic flux of the permanent magnet block of Embodiment 1 A diagram showing surface magnetic flux waveforms of a plurality of magnetic poles of the stator module of Embodiment 1. An enlarged side view showing the configuration of the mover module of Embodiment 1 A diagram showing the relationship between the shape of the teeth flange and the cogging thrust of Embodiment 1 A side view showing the configuration of a modular linear motor according to a modification of the first embodiment. A side view showing the configuration of a modular linear motor according to Embodiment 2 A side view showing the configuration of a modular linear motor according to Embodiment 3 An enlarged side view showing the configuration of the mover module of Embodiment 3

Below, a modular linear motor according to an embodiment will be described in detail based on the drawings.

Embodiment 1.
FIG. 1 is a side view showing the configuration of a modular linear motor 1 according to the first embodiment. The modular linear motor 1 includes a stator module group 100 and a mover module group 200. The movable module group 200 is arranged to be movable relative to the stator module group 100 in the stroke direction S. The mover module group 200 is arranged to face the stator module group 100 with a magnetic gap Tg in between.

The mover module group 200 includes a plurality of mover modules 20 arranged in parallel in the stroke direction S, and auxiliary teeth 25 provided at both ends of the mover module group 200. Each mover module 20 includes a mover core 21 made of a laminated iron core and a plurality of coils 22. The mover core 21 includes a core back 21a extending in the stroke direction S, a plurality of teeth portions 21b arranged at a constant pitch in the stroke direction S, and a tooth flange portion 21c provided at the tip of the teeth portion 21b. , has. The plurality of coils 22 are wound around each of the teeth portions 21b. The tooth flange portion 21c projects in the stroke direction S from the tooth portion 21b. A slot open 21d, which is a gap, is provided between adjacent teeth flange portions 21c. In FIG. 1, three mover modules 20 constitute a mover module group 200. Moreover, in the case of FIG. 1, the mover core 21 has five teeth portions 21b.

The stator module group 100 includes a plurality of stator modules 10 arranged in parallel in the stroke direction S. Each stator module 10 includes a permanent magnet block 10a and a stator core portion 10b serving as a back yoke for fixing the permanent magnet block 10a. In the permanent magnet block 10a, a plurality of magnetized magnetic poles 11 are arranged in parallel in the stroke direction S. The polarities of adjacent magnetic poles 11 in the permanent magnet block 10a are opposite. In FIG. 1, four stator modules 10 constitute a stator module group 100. Further, the number Np1 of magnetic poles of the permanent magnet block 10a is six. The length of the permanent magnet block 10a in the stroke direction S is the same as the length of the stator core portion 10b in the stroke direction S. Among the plurality of magnetic poles 11 included in the permanent magnet block 10a of the stator module group 100, the number Np2 of magnetic poles, which is the number of magnetic poles 11 that are arranged to face one mover module 20 across the air gap Tg, is four. ing. The number of magnetic poles Np1 corresponds to the first number of magnetic poles, and the number of magnetic poles Np2 corresponds to the second number of magnetic poles. In the first embodiment, Np1>Np2. Regarding each magnet of the permanent magnet block 10a of the stator module 10, a permanent magnet block in which a plurality of magnetic poles 11 are magnetized at once is used instead of a normal permanent magnet for each magnetic pole. Therefore, it is possible to reduce the number of permanent magnets of the stator module 10 and the number of assembly steps, thereby reducing manufacturing costs.

When current is applied to the coil 22 of the mover module group 200, an attractive force is generated between the mover module group 200 and the magnetic poles 11 of the stator module group 100, and the mover module group 200 moves in the stroke direction S. Moving. The movable range of the mover module group 200 is within the range where the mover module group 200 faces the stator module group 100 via the gap Tg, and the mover module group 200 faces the stator module group in the stroke direction S. It doesn't jump out from 100.

Next, magnetization of the stator module 10 will be explained. FIG. 2 is a side view showing the positional relationship between the stator module 10 and the magnetizing yoke 30 of the modular linear motor 1 according to the first embodiment during magnetization. The stator module 10 and the magnetizing yoke 30 are arranged to face each other with a gap interposed therebetween. The magnetizing yoke 30 includes a plurality of teeth portions 31 and a plurality of magnetizing coil portions 32 arranged in the stroke direction S. When current is applied to the magnetizing coil section 32, a substantially circular magnetizing coil magnetic field M1 is generated around the magnetizing coil section 32. As a result, a magnetic field is generated in the permanent magnet block 10a of the stator module 10, and the permanent magnet block 10a is magnetized. The six teeth portions 31 of the magnetizing yoke 30 face the permanent magnet block 10a, and the six magnetic poles 11 are magnetized at the same time. The polarities between adjacent magnetic poles 11 are opposite, as shown by the magnetization direction G. From the above, in the first embodiment, the numbers of magnetic poles Np1 and Np2 are not the numbers of poles determined by individual magnets, but are included in one permanent magnet block 10a among the magnetic poles that are multi-pole magnetized at once in the permanent magnet block 10a. and the number of magnetic poles facing the mover module 20. Since a plurality of magnetic poles are magnetized at once in this way, it is possible to reduce the number of magnetizing steps and reduce manufacturing costs.

Here, the magnetization distribution of each magnetic pole 11 is preferably symmetrical in consideration of cogging thrust. On the other hand, in the first embodiment, the orientation direction of the magnetic poles 11 in the permanent magnet block 10a is perpendicular to the stroke direction S, and the magnetization rate is determined according to the amount of magnetic field according to the magnetization direction G. . Therefore, since the direction of magnetization G and the direction of the magnetic field are different between the poles of the permanent magnet block 10a, the magnetization rate becomes relatively small. The pole gap is a region between adjacent magnetic poles 11. In this way, the space between adjacent magnetic poles 11 of the permanent magnet block 10a has a region where the magnetization rate decreases. Further, since the magnetizing yoke 30 and the stator module 10 have a linear shape, when the magnetizing yoke 30 is energized, the magnetic field distribution is different in the magnetization rate lowering region C2 at the end portion and the magnetization rate lowering region C1 at the center portion. That is, the magnetic field distribution in the reduced magnetization rate region C1 at the center of the stator module 10 and the magnetic field distribution in the reduced magnetization rate region C2 at the end of the stator module 10 are asymmetrical. In this way, when the magnet on the stator side is not a normal permanent magnet with each magnetic pole but a permanent magnet block 10a in which a plurality of magnetic poles are magnetized at once, the magnetic field between the central poles of the permanent magnet block 10a is The distribution and the magnetic field distribution between the poles at the ends are asymmetric.

Here, when the mover module group 200 moves in the stroke direction S, a cogging thrust is generated due to the attractive force between the mover core 21 of the mover module group 200 and the magnetic pole 11 of the stator module group 100. Since the cogging thrust is an attractive force between the movable core 21 and the magnetic pole 11, it occurs even when no current is flowing through the coil 22, and it is desirable to reduce it in order to improve the positioning accuracy of the linear motor.

There are mainly three components of the cogging thrust of a linear motor. The first is a slot order component determined by the stator slot order and its multiple components. The second is a pole slot order component determined by the number of slots of the mover module 20 and the least common multiple of the number of magnetic poles Np2 of the portion of the stator module 10 that is disposed opposite to the mover module 20. The third is a polar order component determined by the number Np1 of magnetic poles of the stator module 10 and its multiple component. Among these, the first slot order component is generated when the movable module group 200 passes through a region where the magnetic flux density in the air gap Tg is asymmetric. The regions where the magnetic flux density of the air gap Tg is asymmetric are the above-mentioned region C2 of decreased magnetization rate at the end of the stator module 10, the gap between the permanent magnet blocks 10a between adjacent stator modules 10, and the region of the stator core portion 10b. Occurs in gaps. In this way, the region where the magnetic flux density of the air gap Tg is asymmetrical is a region where adjacent stator modules 10 are adjacent to each other. Therefore, when the movable module group 200 moves in the part where the stator module 10 is adjacent, a cogging thrust of the slot order component is generated, and the slot order component increases depending on the number of parts where the stator module 10 is adjacent. increase Hereinafter, as shown in FIG. 1, a portion 15 where adjacent stator modules 10 are adjacent will be referred to as a stator module adjacent portion.

FIG. 3 is a side view showing the configuration of a modular linear motor of a comparative example. The modular linear motor of the comparative example includes a stator module group 300 and a mover module group 400. The stator module group 300 is composed of six stator modules 50, and the movable module group 400 is composed of three movable modules 60. The number Np1 of magnetic poles of the permanent magnet block of each stator module 50 is four. Each mover module 60 has five teeth portions, similar to the first embodiment. In the comparative example, the number Np2 of magnetic poles in the portion facing one mover module 60 with an air gap therebetween is four. In the comparative example, the movable module group 400 faces three or four stator module adjacent parts 55 depending on the position of the movable module group 400 within the movable range in the stroke direction S. In the comparative example, Np1=Np2.

On the other hand, in the first embodiment, as shown in FIG. or three stator module adjacencies 15. That is, in the first embodiment, compared to the comparative example, the number of movable module groups 200 that face the stator module adjacent portion 15 is reduced, and the maximum value of the cogging thrust generated while the movable module group 200 is moving is reduced. Or it becomes possible to reduce the average value.

In addition, in FIG. 1, the mover module group 200 is composed of three mover modules 20, and the stator module group 100 is composed of four stator modules 10, but the mover module group 200 and the stator module Each group 100 may be composed of two or more mover modules 20 and two or more stator modules 10. In addition, in FIG. 1, the number of magnetic poles Np1 of the permanent magnet block 10a is 6, and the number of magnetic poles Np2 of the portion facing one movable module 20 via the air gap Tg is 4, but Np1>Np2 If this holds true, the numbers of Np1 and Np2 may be set to other numbers.

Additionally, the auxiliary teeth 25 may be omitted. The reason is that the auxiliary teeth 25 do not significantly contribute to the cogging thrust of the slot order component described above. Further, although FIG. 2 shows a case where six magnetic poles of the permanent magnet block 10a of the stator module 10 are magnetized at the same time, other magnetization methods such as magnetizing two magnetic poles at a time may be adopted. Even in this case, a portion where the magnetic flux density is asymmetric occurs in the stator module adjacent portion 15.

Furthermore, in the first embodiment, the permanent magnet block 10a is magnetized so that the cogging thrust is reduced. FIG. 4 is a diagram showing the relationship between the surface magnetic flux and cogging thrust of the permanent magnet block 10a of the first embodiment. FIG. 5 is a diagram for explaining the measurement locations of the surface magnetic flux of the permanent magnet block 10a of the first embodiment. FIG. 6 is a diagram showing surface magnetic flux waveforms of the plurality of magnetic poles 11 of the stator module 10 of the first embodiment.

When measuring the surface magnetic flux of the permanent magnet block 10a of the stator module 10, as shown in FIG. Measurements are taken over the width W1 of the permanent magnet block 10a. A position 17 indicated by a broken line is the position where the surface magnetic flux is measured. The surface magnetic flux to be measured is the amount of magnetic flux in the vertical direction V component of the surface magnetic flux measurement results. The vertical direction V is a direction perpendicular to the stroke direction S, and is a direction in which the movable module group 200 and the stator module group 100 face each other. Note that when measuring the magnetic flux density with only one stator module 10 arranged, the magnetic flux decreases at the ends, so as shown in FIG. 5, a plurality of stator modules 10 are arranged in the stroke direction S ( In FIG. 5, three stator modules are arranged), and the magnetic flux density of one stator module 10 is measured at the center.

FIG. 6 shows the surface magnetic flux waveforms of the six magnetic poles 11 included in the stator module 10, which were measured by the method explained using FIG. 5. However, this measurement result is a measurement result in a state where no magnetic material exists around the stator module 10. In FIG. 6, the horizontal axis is the measurement position in the stroke direction S, and the vertical axis is the amount of magnetic flux. The surface magnetic flux waveform of each magnetic pole 11 except for the magnetic pole 11 at the left end and the magnetic pole 11 at the right end has a substantially symmetrical shape. However, the surface magnetic flux waveforms of the left end magnetic pole 11 and the right end magnetic pole 11 adjacent to the stator module adjacent portion 15 are slightly different and have an asymmetrical shape. That is, in the surface magnetic flux waveform of the magnetic pole 11 at the left end, the left peak protrudes from the right side, and in the surface magnetic flux waveform of the right end magnetic pole 11, the right peak protrudes from the left side. When the peak of the magnetic flux amount is 100%, the width W2 is the sum of the widths Wa1 to Wa6 in which the magnetic flux amount is 50% or more. That is, W2=Wa1+Wa2+Wa3+Wa4+Wa5+Wa6. The width W2 is defined as the width of the permanent magnet block 10a as W1, and is the width of a region of the width W1 where the amount of magnetic flux at a position away from the stator module 10 by the air gap Tg is 50% or more of the peak amount of magnetic flux. I can say it. In the case of FIG. 6, W2/W1 is 0.867.

In FIG. 4, the horizontal axis is W2/W1, and the vertical axis is cogging thrust. In FIG. 4, the cogging thrust is approximately constant when W2/W1 is from 60% to 66%. The cogging thrust when W2/W1 is 60% is 1.0 [p. u. ]. As shown in FIG. 4, when the range of 0.66<W2/W1<0.91, the cogging thrust is 1.0 [p. u. ]The following effects can be obtained. Therefore, in the first embodiment, the permanent magnet block 10a is magnetized so that 0.66<W2/W1<0.91.

This is because by setting 0.66<W2/W1<0.91, the symmetry of the magnetic field distribution in the end magnetization rate reduced region C2 and the magnetic field distribution in the center magnetization rate decrease region C1 is improved. This is because the magnetic flux waveform generated in the air gap Tg between the stator module 10 and the movable module 20 becomes smoother, so that the cogging thrust of the slot order component and the pole slot order component described above is reduced.

Next, the shape of the tooth flange portion 21c will be explained using FIGS. 7 and 8. FIG. 7 is an enlarged side view showing the configuration of the mover module 20 of the first embodiment. FIG. 8 is a diagram showing the relationship between the shape of the tooth flange 21c and the cogging thrust according to the first embodiment. As described above, the tips of the teeth portions 21b of the mover core 21 of the mover module 20 have the teeth flange portions 21c protruding in the stroke direction S, and there is a gap hs between adjacent teeth flange portions 21c. A slot open 21d having a diameter is provided. In FIG. 8, the horizontal axis is hs/W2, and the vertical axis is cogging thrust. However, FIG. 8 shows the relationship between hs/W2 and cogging thrust when W2/W1=0.867. Here, if the tooth flange 21c does not exist, hs/W2 is 0.475, and the cogging thrust at this time is 1.0 [p. u. ]. According to FIG. 8, by setting 0.24<hs/W2<0.45, the cogging thrust is 0.9 [p. u. ] or less, and the cogging thrust can be reduced. This is because, by providing the teeth flange portions 21c, the interval hs between the slot openings 21d between adjacent teeth portions 21b becomes smaller, and the magnetic flux waveform of the air gap Tg between the stator module 10 and the mover module 20 becomes smoother. This is because the cogging thrust of both the slot order component and the polar slot order component can be reduced.

FIG. 9 is a side view showing the configuration of a modular linear motor 2 according to a modification of the first embodiment. The modular linear motor 2 includes a movable module group 200 and a stator module group 500 having the same configuration as in FIG. 1 . The mover module group 200 includes three mover modules 20 and auxiliary teeth 25. The mover module 20 has five teeth portions 21b. The stator module group 500 is composed of two stator modules 50. The stator module 50 includes a permanent magnet block 50a and a stator core portion 50b. The permanent magnet block 50a has twelve magnetic poles 11. That is, the number Np1 of magnetic poles of the permanent magnet block 50a is twelve. Further, the number Np2 of magnetic poles in the portion facing one movable module 20 with an air gap therebetween is four.

In the modified modular linear motor 2, the stator module group 500 is composed of two stator modules 50, so there is only one stator module adjacent portion 15. Therefore, the cogging thrust can be further reduced.

On the other hand, as the number Np1 of magnetic poles of the permanent magnet block 50a increases, the power required to magnetize the permanent magnet block 50a increases, and time is required to cool the magnetized coil or charge the capacitor. In particular, when the number of magnetic poles Np1 is greater than three times Np2, there is a problem that productivity decreases. In the modified example shown in FIG. 9, the number of magnetic poles Np1 is 12, which is three times or less than Np2 (=4), so productivity can be improved compared to a case where the number is greater than three times. In this way, in the first embodiment, a decrease in productivity is suppressed by setting Np1≦Np2×3.

As described above, according to the first embodiment, since Np1>Np2, the number of mover module groups 200 facing the stator module adjacent portion 15 is reduced, and a plurality of magnetic poles are permanently magnetized at once. Even when a magnet block is used, it is possible to reduce the cogging thrust of the slot order component that is generated when the movable module group 200 moves in a location facing the stator module adjacent portion 15. In addition, since the permanent magnet block 10a is magnetized so that 0.66<W2/W1<0.91, the magnetic field distribution in the magnetization rate decreasing region C2 at the end and the magnetic field distribution in the magnetizing rate decreasing region C1 at the center. Furthermore, the magnetic flux generated in the air gap Tg between the stator module 10 and the mover module 20 changes smoothly, and the cogging thrust of the slot order component or the pole slot order component can be reduced. In addition, since the interval between adjacent teeth flange portions 21c is set so that 0.24<hs/W2<0.45, the magnetic flux waveform of the air gap Tg between the stator module 10 and the mover module 20 becomes smooth. , the cogging thrust of the slot order component and the polar slot order component can be further reduced.

Embodiment 2.
FIG. 10 is a side view showing the configuration of a modular linear motor 3 according to the second embodiment. The modular linear motor 3 includes a movable module group 600 and a stator module group 700. The mover module group 600 includes three mover modules 60 and auxiliary teeth 65. The mover module 60 has three teeth portions 61b. The stator module group 700 is composed of four stator modules 70. The stator module 70 includes a permanent magnet block 70a and a stator core portion 70b. The permanent magnet block 70a has four magnetic poles 11. That is, the number Np1 of magnetic poles of the permanent magnet block 70a is four. Further, the number Np2 of magnetic poles in the portion facing one movable module 60 with an air gap therebetween is two.

In this way, even if the numbers of magnetic poles Np1 and Np2 and the number of slots are different, if Np1>Np2 is established, the cogging caused by moving the movable module group 600 in the part facing the stator module adjacent part 15 can be avoided. Thrust can be reduced.

Embodiment 3.
FIG. 11 is a side view showing the configuration of a modular linear motor 4 according to the third embodiment. FIG. 12 is an enlarged side view showing the configuration of the mover module 20 according to the third embodiment. In the third embodiment, a notch 21e is added to the mover module 20 of the first embodiment. The other configurations are the same as those in Embodiment 1, and redundant explanation will be omitted.

As shown in FIG. 12, a notch 21e is provided at the center of the tip of the tooth flange 21c. Since the notch 21e has a similar shape to the slot open 21d which has the effect of reducing cogging thrust, the magnetic flux density in the air gap between the stator module 10 and the mover module 20 changes more smoothly, and the slot It becomes possible to reduce both the cogging thrust of the order component and the polar slot order component.

Specifically, the width hs0 of the notch portion 21e satisfies the relationship 0.24<hs0/W2<0.45, similar to the interval hs between the slot openings 21d, so that the stator module 10 and the mover module The magnetic flux density in the air gap between the slot and the pole 20 changes smoothly, resulting in the effect that both the cogging thrust of the slot order component and the polar slot order component can be reduced.

Note that the number of notches 21e formed at the tips of the teeth flange portions 21c is not limited to one, but may be two, or three or more. When the number of notches 21e increases, the magnetic flux density in the gap between the stator module 10 and the movable module 20 changes more smoothly, and the cogging thrust can be further reduced.

The configurations shown in the embodiments described above are examples of the contents of the present disclosure, and can be combined with other known technologies, and the configurations can be modified without departing from the gist of the present disclosure. It is also possible to omit or change parts.

1, 2, 3, 4 Modular linear motor, 10, 50, 70 Stator module, 10a, 50a, 70a Permanent magnet block, 10b, 50b, 70b Stator core part, 11 Magnetic pole, 15, 55 Stator module adjacent part, 17 position, 20, 60 mover module, 21 mover core, 21a core back, 21b, 31, 61b teeth part, 21c teeth flange, 21d slot open, 21e notch part, 22 coil, 25, 65 auxiliary Teeth, 30 Magnetizing yoke, 32 Magnetizing coil section, 100, 300, 500, 700 Stator module group, 200, 400, 600 Mover module group, C1 Central magnetization rate decrease region, C2 End magnetization Reduced magnetic flux area, G magnetizing direction, M1 magnetizing coil magnetic field, Np1, Np2 number of magnetic poles, S stroke direction, Tg air gap, V vertical direction, W1, W2, Wa1 to Wa6 width, hs interval, hs0 width.

Claims

A stator module group having a plurality of stator modules arranged in parallel in the stroke direction, and a plurality of mover modules arranged in parallel in the stroke direction, and facing the stator module group across a gap. A group of mover modules arranged,
Each of the mover modules includes a plurality of teeth arranged at a constant pitch, and a plurality of coils wound around each of the plurality of teeth,
Each of the stator modules includes a permanent magnet block in which a first number of magnetic poles are arranged,
Among the plurality of magnetic poles included in the permanent magnet block of the stator module group, when the number of magnetic poles arranged to face one mover module is the second number of magnetic poles, the first number of magnetic poles is A modular linear motor characterized in that the number of magnetic poles is greater than the number of second magnetic poles.
The modular linear motor according to claim 1, wherein a magnetic field distribution between poles at the center of the permanent magnet block and a magnetic field distribution between poles at the end are asymmetrical.
When the width of the permanent magnet block is W1, and W2 is the width of a region of the width W1 where the amount of magnetic flux at a position away from the stator module by the gap is 50% or more of the peak amount of magnetic flux,
0.66<W2/W1<0.91
The modular linear motor according to claim 2, characterized in that the permanent magnet block is magnetized so that
The tooth portion of the movable element module has a tooth flange portion protruding in the stroke direction at the tip, and when the interval between adjacent tooth flange portions is hs,
0.24<hs/W2<0.45
The modular linear motor according to claim 3, characterized in that:
One or more notches are provided on the tip surface of the tooth flange,
When the width of the notch is hs0,
0.24<hs0/W2<0.45
The modular linear motor according to claim 4, characterized in that: