Modular linear motor

Abstract

The modular linear motor (1) includes: a stator module group (100) having a plurality of stator modules (10) arranged side by side in the stroke direction (S); and a moving member module group (200) having a plurality of moving member modules (20) arranged side by side in the stroke direction (S), which are relatively arranged with a gap (Tg) with respect to the stator module group (100). Each stator module (10) has a permanent magnet block (10a) in which Np1 magnetic poles (11) are arranged. When the number of magnetic poles (11) among the plurality of magnetic poles (11) included in the permanent magnet block (10a) of the stator module group (100) that are relatively arranged with respect to one moving member module (20) is set to Np2, Np1 > Np2.

Description

Technical Field

[0001] The present invention relates to a modular linear motor in which a plurality of stator modules and a plurality of movable member modules are arranged in a stroke direction. Background Art

[0002] A linear motor is composed of a movable member and a stator, and the movable member linearly moves in the stroke direction. In a linear motor, it is necessary to set the lengths of the movable member and the stator in the stroke direction corresponding to a desired movable range or thrust. On the other hand, considering the manufacturability of the movable member and the stator, setting a plurality of lengths of the product in the stroke direction corresponding to the product performance deteriorates the yield of the iron core and increases the cost of manufacturing equipment.

[0003] Therefore, it has been proposed to arrange a plurality of modular movable members in the stroke direction of the movable member. In addition, Patent Document 1 shows that a stator having an excitation yoke and a plurality of permanent magnets is modularized, and a plurality of modularized stators are arranged in the stroke direction of the movable member.

[0004] Patent Document 1: Japanese Patent Application Laid-Open No. 2004-135385 Summary of the Invention

[0005] In the case where a plurality of stator modules are arranged in a row in the stroke direction as shown in Patent Document 1, at an adjacent portion where adjacent stator modules are in contact, there is a portion where the magnetic flux density generated from the stator module becomes asymmetric. As a result, the cogging thrust generated when the movable member module group arranged with a magnetic gap moves in the stroke direction increases, and there is a problem that the positioning accuracy of the linear motor is reduced. In particular, when the magnet on the stator side is not a permanent magnet for each normal magnetic pole but a permanent magnet block in which a plurality of magnetic poles are magnetized together, a region where the magnetic flux density generated from the stator module becomes asymmetric appears between adjacent stator modules.

[0006] The present invention has been made in view of the above circumstances, and an object thereof is to obtain a modular linear motor capable of reducing the cogging thrust generated when the movable member module group moves in the stroke direction.

[0007] In order to solve the above problems and achieve the object, the modular linear motor according to the present invention is characterized in that it has: a stator module group having a plurality of stator modules arranged in parallel in the stroke direction; and a moving member module group that is relatively arranged with a gap relative to the stator module group, and the moving member module group has: auxiliary teeth arranged at both ends in the stroke direction; and a plurality of moving member modules that are arranged in parallel in the stroke direction between the auxiliary teeth, and each moving member module has: a moving core having a core seat extending in the stroke direction between the auxiliary teeth and a plurality of tooth portions arranged at a constant pitch; and a plurality of coils wound around the plurality of tooth portions respectively, and each stator module has a permanent magnet block in which a plurality of magnetic poles of a first number of magnetic poles are arranged on one magnet. When the number of magnetic poles relatively arranged with respect to one moving member module among the plurality of magnetic poles included in the permanent magnet block of the stator module group is set as the second number of magnetic poles, the first number of magnetic poles is greater than the second number of magnetic poles.

[0008] Effects of the Invention

[0009] According to the modular linear motor of the present invention, the following effect is achieved, that is, it is possible to reduce the cogging thrust generated when the moving member module group moves in the stroke direction. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] Figure 1 It is a side view showing the structure of the modular linear motor according to Embodiment 1.

[0011] Figure 2 It is a side view showing the positional relationship during magnetization of the stator module and the yoke of the modular linear motor according to Embodiment 1.

[0012] Figure 3 It is a side view showing the structure of the modular linear motor of the comparative example.

[0013] Figure 4 It is a graph showing the relationship between the surface magnetic flux and the cogging thrust of the permanent magnet block of Embodiment 1.

[0014] Figure 5 It is a diagram for explaining the measurement position of the surface magnetic flux of the permanent magnet block of Embodiment 1.

[0015] Figure 6 It is a graph showing the surface magnetic flux waveforms of the plurality of magnetic poles of the stator module of Embodiment 1.

[0016] Figure 7 It is an enlarged side view showing the structure of the moving member module of Embodiment 1.

[0017] Figure 8 It is a graph showing the relationship between the shape of the tooth flange portion and the cogging thrust of Embodiment 1.

[0018] Figure 9 It is a side view showing the structure of a modular linear motor which is a modification of Embodiment 1.

[0019] Figure 10 It is a side view showing the structure of the modular linear motor according to Embodiment 2.

[0020] Figure 11 It is a side view showing the structure of the modular linear motor according to Embodiment 3.

[0021] Figure 12 It is an enlarged side view showing the structure of the movable member module of Embodiment 3. Detailed Embodiment

[0022] Hereinafter, the modular linear motor according to the embodiment will be described in detail with reference to the drawings.

[0023] Embodiment 1.

[0024] Figure 1 It is a side view showing the structure of the modular linear motor 1 according to Embodiment 1. The modular linear motor 1 has a stator module group 100 and a movable member module group 200. The movable member module group 200 is arranged so as to be freely relatively movable in the stroke direction S with respect to the stator module group 100. The movable member module group 200 is relatively arranged with respect to the stator module group 100 with a magnetic gap Tg therebetween.

[0025] The movable member module group 200 has: a plurality of movable member modules 20 which are arranged in parallel in the stroke direction S; and auxiliary teeth 25 which are provided at both end portions of the movable member module group 200. Each movable member module 20 has a movable core 21 formed of laminated iron cores and a plurality of coils 22. The movable core 21 has: a core base 21a which extends in the stroke direction S; a plurality of tooth portions 21b which are arranged at a constant pitch in the stroke direction S; and a tooth flange portion 21c which is provided at the front end of the tooth portion 21b. The plurality of coils 22 are wound around each tooth portion 21b. The tooth flange portion 21c protrudes from the tooth portion 21b in the stroke direction S. A slot 21d as a gap is provided between adjacent tooth flange portions 21c. In Figure 1 , the movable member module group 200 is composed of three movable member modules 20. In addition, in Figure 1 case, the movable core 21 has five tooth portions 21b.

[0026] The stator module group 100 has a plurality of stator modules 10 arranged side by side in the stroke direction S. Each stator module 10 has a permanent magnet block 10a and a stator core portion 10b as a back yoke for fixing the permanent magnet block 10a. In the permanent magnet block 10a, a plurality of magnetic poles 11 after magnetization are arranged side by side in the stroke direction S. The polarities of adjacent magnetic poles 11 in the permanent magnet block 10a are opposite. In Figure 1 , the stator module group 100 is composed of 4 stator modules 10. In addition, the number of magnetic poles Np1 of the permanent magnet block 10a is 6. 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. The number of magnetic poles Np2, which is the number of magnetic poles 11 that are arranged opposite to one movable member module 20 with a gap Tg therebetween among the plurality of magnetic poles 11 included in the permanent magnet block 10a of the stator module group 100, becomes 4. 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. For each magnet of the permanent magnet block 10a of the stator module 10, instead of a permanent magnet for each normal magnetic pole, a permanent magnet block in which a plurality of magnetic poles 11 are magnetized together is used. Therefore, the following effect is obtained, that is, the number of permanent magnets of the stator module 10 and the assembly man-hour are reduced, and the manufacturing cost is reduced.

[0027] If a current flows in the coil 22 of the movable member module group 200, an attractive force is generated between the movable member module group 200 and the magnetic poles 11 of the stator module group 100, and the movable member module group 200 moves in the stroke direction S. In addition, the movable range of the movable member module group 200 is within the range where the movable member module group 200 faces the stator module group 100 with a gap Tg therebetween, and the movable member module group 200 does not fly out of the stator module group 100 in the stroke direction S.

[0028] Next, the magnetization of the stator module 10 will be described. Figure 2It is a side view showing the positional relationship during magnetization of the stator module 10 and the yoke 30 of the modular linear motor 1 according to Embodiment 1. The stator module 10 and the yoke 30 are arranged opposite to each other with a gap therebetween. The yoke 30 has a plurality of tooth portions 31 and a plurality of magnetization coil portions 32 arranged in the stroke direction S. When current flows through the magnetization coil portion 32, a substantially circular magnetization coil magnetic field M1 is generated around the magnetization coil portion 32. Thereby, a magnetic field is generated in the permanent magnet block 10a of the stator module 10, and the permanent magnet block 10a is magnetized. Six tooth portions 31 of the yoke 30 face the permanent magnet block 10a, and six magnetic poles 11 are magnetized simultaneously. The polarities between adjacent magnetic poles 11 are opposite as shown by the magnetization direction G. As described above, in Embodiment 1, the number of magnetic poles Np1, Np2 is not the number of poles determined by individual magnets, but is the number of magnetic poles included in one permanent magnet block 10a among the magnetic poles magnetized in multiple poles at once in the permanent magnet block 10a and the number of magnetic poles facing the movable member module 20. Since multiple magnetic poles are magnetized at once as described above, the effect of reducing the magnetization man-hour and thus reducing the manufacturing cost is obtained.

[0029] Here, if the cogging thrust is considered, the magnetization distribution of each magnetic pole 11 is preferably a symmetric shape. On the other hand, in Embodiment 1, 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 corresponding to the magnetic field amount in the magnetization direction G. Therefore, between the magnetic poles in the permanent magnet block 10a, since the magnetization direction G and the magnetic field direction have different orientations, the magnetization rate becomes relatively small. The inter-pole region refers to the region between adjacent magnetic poles 11. As described above, the inter-pole region adjacent to the magnetic poles 11 of the permanent magnet block 10a has a region where the magnetization rate is reduced. In addition, since the yoke 30 and the stator module 10 are linear, when the yoke 30 is energized, the magnetic field distributions in the magnetization rate reduction region C2 at the end and the magnetization rate reduction region C1 at the center are different. That is, the magnetic field distributions in the magnetization rate reduction region C1 at the center of the stator module 10 and the magnetization rate reduction region C2 at the end of the stator module 10 are asymmetric. As described above, when the magnets on the stator side are not permanent magnets for each normal magnetic pole, but the permanent magnet block 10a magnetized with multiple magnetic poles at once is used, the magnetic field distributions between the magnetic poles at the center and at the end in the permanent magnet block 10a are asymmetric.

[0030] Here, when the movable member module group 200 moves in the stroke direction S, a cogging thrust is generated due to the attraction between the movable core 21 of the movable member module group 200 and the magnetic poles 11 of the stator module group 100. Since the cogging thrust is the attraction between the movable core 21 and the magnetic poles 11, it is generated even when no current flows through the coil 22, and it is preferable to reduce the cogging thrust in order to improve the positioning accuracy of the linear motor.

[0031] As the cogging thrust of a linear motor, there are mainly three components. The first is the slot order component determined by the slot order of the stator and its multiple components. The second is the pole-slot order component determined by the least common multiple of the number of slots of the movable member module 20 and the number of magnetic poles Np2 of the part of the stator module 10 that is relatively arranged with respect to the movable member module 20. The third is the pole order component determined by the number of magnetic poles Np1 of the stator module 10 and its multiple components. Among them, the first slot order component is generated because the movable member module group 200 passes through a region where the magnetic flux density in the air gap Tg becomes asymmetric. The region where the magnetic flux density of the air gap Tg becomes asymmetric is generated in the magnetization rate reduction region C2 at the end of the aforementioned stator module 10, the gap between the permanent magnet blocks 10a between adjacent stator modules 10, and the gap of the stator core portion 10b. As described above, the region where the magnetic flux density of the air gap Tg becomes asymmetric becomes the adjacent part of the adjacent stator modules 10. Thus, when the movable member module group 200 moves in the adjacent part of the stator module 10, a cogging thrust of the slot order component is generated, and the slot order component increases corresponding to the number of adjacent parts of the stator module 10. After that, as Figure 1 shown, the adjacent part 15 of the adjacent stator modules 10 is referred to as the stator module adjacent part.

[0032] Figure 3 is a side view showing the structure of a modular linear motor of a comparative example. The modular linear motor of the comparative example has a stator module group 300 and a movable member module group 400. The stator module group 300 is composed of six stator modules 50, and the movable member module group 400 is composed of three movable member modules 60. The number of magnetic poles Np1 of the permanent magnet blocks of each stator module 50 is four. Each movable member module 60 has five tooth portions in the same manner as in the first embodiment. In the comparative example, the number of magnetic poles Np2 of the part that is relatively arranged with respect to one movable member module 60 across the air gap becomes four. In the comparative example, within the movable range of the movable member module group 400 in the stroke direction S, the movable member module group 400 faces three or four stator module adjacent parts 55 according to the position of the movable member module group 400. In the comparative example, Np1 = Np2.

[0033] In contrast, in the first embodiment, as Figure 1 shown, Np1 > Np2, so within the movable range of the movable member module group 200 in the stroke direction S, the movable member module group 200 faces two or three stator module adjacent parts 15 according to the position of the movable member module group 200. That is, in the first embodiment, compared with the comparative example, the number of the movable member module group 200 facing the stator module adjacent part 15 is smaller, and the maximum value or average value of the cogging thrust generated during the movement of the movable member module group 200 can be reduced.

[0034] In addition, in Figure 1In this case, a movable member module group 200 is constituted by three movable member modules 20, and a stator module group 100 is constituted by four stator modules 10. However, it is sufficient that the movable member module group 200 and the stator module group 100 are each constituted by two or more movable member modules 20 and stator modules 10. Additionally, in Figure 1 the number of magnetic poles Np1 of the permanent magnet block 10a is set to six, and the number of magnetic poles Np2 of the portion disposed opposite to one movable member module 20 with a gap Tg therebetween is set to four. However, if Np1 > Np2 holds, the numbers of Np1 and Np2 may be set to other numbers.

[0035] Additionally, the auxiliary teeth 25 may be removed. The reason is that the auxiliary teeth 25 do not contribute significantly to the cogging thrust of the aforementioned slot order component. Additionally, in Figure 2 the case where the permanent magnet block 10a of the stator module 10 is magnetized with six magnetic poles simultaneously is shown, but other magnetization methods such as magnetization in units of two magnetic poles may also be employed. In this case, a portion where the magnetic flux density becomes asymmetric also occurs at the adjacent part 15 of the stator module.

[0036] Additionally, in the first embodiment, the permanent magnet block 10a is magnetized to reduce the cogging thrust. Figure 4 is a diagram showing the relationship between the surface magnetic flux and the cogging thrust of the permanent magnet block 10a of the first embodiment. Figure 5 is a diagram for explaining the measurement position of the surface magnetic flux of the permanent magnet block 10a of the first embodiment. Figure 6 is a diagram showing the surface magnetic flux waveforms of the multiple magnetic poles 11 of the stator module 10 of the first embodiment.

[0037] When measuring the surface magnetic flux of the permanent magnet block 10a of the stator module 10, as Figure 5 shown, the magnetic flux of the stator module 10 at a position separated from the permanent magnet block 10a by a gap Tg is measured over the width W1 of the permanent magnet block 10a in the stroke direction S. The position 17 indicated by the dashed line is the position where the surface magnetic flux is measured. The measured surface magnetic flux is the magnetic flux of the component in the vertical direction V among the surface magnetic flux measurement results. The vertical direction V is a direction perpendicular to the stroke direction S and is the direction in which the movable member module group 200 and the stator module group 100 face each other. Additionally, when measuring the magnetic flux density with only one stator module 10 disposed, the magnetic flux decreases at the end portions. Therefore, as Figure 5 shown, a plurality of stator modules 10 are disposed in the stroke direction S (three are disposed in Figure 5 ), and the magnetic flux density of one stator module 10 is measured at its central portion.

[0038] In Figure 6 is shown by Figure 5The surface magnetic flux waveform of the six magnetic poles 11 included in the stator module 10 measured by the method described. However, this measurement result is the result of measurement in a state where there is no magnet around the stator module 10. In Figure 6 , the horizontal axis is the measurement position in the stroke direction S, and the vertical axis is the magnetic flux. The surface magnetic flux waveforms of the respective magnetic poles 11 except for the magnetic pole 11 at the left end and the magnetic pole 11 at the right end have a substantially symmetric shape. However, the surface magnetic flux waveforms of the magnetic pole 11 at the left end and the magnetic pole 11 at the right end adjacent to the stator module adjacent portion 15 are slightly different and become an asymmetric shape. That is, in the surface magnetic flux waveform of the magnetic pole 11 at the left end, the peak on the left side protrudes more than the right side, and in the surface magnetic flux waveform of the magnetic pole 11 at the right end, the peak on the right side protrudes more than the left side. When the peak value of the magnetic flux is set to 100%, the sum of the widths Wa1 to Wa6 of the ranges where the magnetic flux is greater than or equal to 50% is set as the width W2. That is, W2 = Wa1 + Wa2 + Wa3 + Wa4 + Wa5 + Wa6. The width W2 also refers to the width of the region where the magnetic flux at the position separated from the stator module 10 by the gap Tg in the width W1 of the permanent magnet block 10a is greater than or equal to 50% of the peak magnetic flux. In Figure 6 's case, W2 / W1 becomes 0.867.

[0039] In Figure 4 , the horizontal axis is set as W2 / W1, and the vertical axis is set as the cogging thrust. In Figure 4 , when W2 / W1 is from 60% to 66%, the cogging thrust becomes substantially constant. The cogging thrust when W2 / W1 is 60% is set as 1.0 [p.u.]. As Figure 4 shows, in the range of 0.66 < W2 / W1 < 0.91, the effect that the cogging thrust is less than or equal to 1.0 [p.u.] is obtained. Therefore, in the first embodiment, the permanent magnet block 10a is magnetized in such a way that 0.66 < W2 / W1 < 0.91.

[0040] The reason is that by setting 0.66 < W2 / W1 < 0.91, the symmetry of the magnetic field distribution in the magnetization rate reduction region C2 at the end and the magnetic field distribution in the magnetization rate reduction region C1 at the center is improved, and the magnetic flux waveform generated in the gap Tg between the stator module 10 and the movable member module 20 becomes smooth. Therefore, the cogging thrust of the aforementioned slot order component and the pole-slot order component is reduced.

[0041] Next, the shape of the tooth flange portion 21c is described using Figure 7 and Figure 8 . Figure 7 is an enlarged side view showing the structure of the movable member module 20 of the first embodiment. Figure 8This is a diagram showing the relationship between the shape of the tooth flange portion 21c and the cogging thrust in Embodiment 1. As described above, the front end of the tooth portion 21b of the movable core 21 of the movable member module 20 has a tooth flange portion 21c protruding in the stroke direction S, and a slotted groove 21d with a gap hs is provided between adjacent tooth flange portions 21c. In Figure 8 the horizontal axis is set to hs / W2 and the vertical axis is set to the cogging thrust. However, Figure 8 shows the relationship between hs / W2 and the cogging thrust when W2 / W1 = 0.867. Here, in the absence of the tooth flange portion 21c, hs / W2 becomes 0.475, and the cogging thrust at this time is set to 1.0 [p.u.]. According to Figure 8 by setting 0.24 < hs / W2 < 0.45, the cogging thrust can be set to be less than or equal to 0.9 [p.u.], and the cogging thrust can be reduced. The reason is that by providing the tooth flange portion 21c, the gap hs between adjacent tooth portions 21b becomes smaller, the magnetic flux waveform of the gap Tg between the stator module 10 and the movable member module 20 becomes smoother, and the cogging thrust of the slot order component and the pole-slot order component can be reduced together.

[0042] Figure 9 is a side view showing the structure of the modular linear motor 2 which is a modification of Embodiment 1. The modular linear motor 2 includes a movable member module group 200 and a stator module group 500 having the same structure as Figure 1 . The movable member module group 200 includes three movable member modules 20 and auxiliary teeth 25. The movable member module 20 has five tooth portions 21b. The stator module group 500 is composed of two stator modules 50. The stator module 50 has 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 of magnetic poles Np1 of the permanent magnet block 50a is 12. In addition, the number of magnetic poles Np2 of the portion disposed opposite to one movable member module 20 across the gap is four.

[0043] In the modular linear motor 2 of the modification, since the stator module group 500 is composed of two stator modules 50, there is only one adjacent portion 15 of the stator modules. Therefore, the cogging thrust can be further reduced.

[0044] On the other hand, the larger the number of magnetic poles Np1 of the permanent magnet block 50a, the greater the power required for magnetizing the permanent magnet block 50a, and the more time is required for cooling the magnetizing coil or charging the capacitor. In particular, if the number of magnetic poles Np1 is greater than three times the number of magnetic poles Np2, there is a problem of reduced productivity. In Figure 9In the illustrated modification example, the number of magnetic poles Np1 is 12, which is less than or equal to three times Np2 (= 4). Therefore, compared with the case where it is greater than three times, the productivity can be improved. As described above, in Embodiment 1, by setting Np1 ≤ Np2 × 3, a decrease in productivity is suppressed.

[0045] As described above, according to Embodiment 1, since Np1 > Np2 is set, the number of movable member module groups 200 facing the adjacent portion 15 of the stator module becomes smaller. Even when using a permanent magnet block magnetized with a plurality of magnetic poles at once, it is possible to reduce the cogging thrust of the slot step component generated by moving at the portion where the movable member module group 200 faces the adjacent portion 15 of the stator module. In addition, the permanent magnet block 10a is magnetized so that 0.66 < W2 / W1 < 0.91. Therefore, the symmetry of the magnetic field distribution in the magnetization rate reduction region C2 at the end and the magnetic field distribution in the magnetization rate reduction region C1 at the center is improved, and the magnetic flux generated in the gap Tg between the stator module 10 and the movable member module 20 changes smoothly, and it is possible to reduce the cogging thrust of the slot step component or the pole-slot step component. In addition, the interval between the adjacent tooth flange portions 21c is set so that 0.24 < hs / W2 < 0.45. Therefore, the magnetic flux waveform in the gap Tg between the stator module 10 and the movable member module 20 becomes smooth, and it is possible to further reduce the cogging thrust of the slot step component and the pole-slot step component.

[0046] Embodiment 2.

[0047] Figure 10 FIG. is a side view showing the structure of the modular linear motor 3 according to Embodiment 2. The modular linear motor 3 includes a movable member module group 600 and a stator module group 700. The movable member module group 600 includes three movable member modules 60 and auxiliary teeth 65. The movable member module 60 has three tooth portions 61b. The stator module group 700 is composed of four stator modules 70. The stator module 70 has 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 of magnetic poles Np1 of the permanent magnet block 70a is 4. In addition, the number of magnetic poles Np2 in the portion disposed opposite to one movable member module 60 with a gap therebetween is two.

[0048] As described above, even when the number of magnetic poles Np1, Np2, and the number of slots are different, if Np1 > Np2 holds, it is also possible to reduce the cogging thrust generated by moving at the portion where the movable member module group 600 faces the adjacent portion 15 of the stator module.

[0049] Embodiment 3.

[0050] Figure 11 FIG. is a side view showing the structure of the modular linear motor 4 according to Embodiment 3.Figure 12 It is an enlarged side view showing the structure of the movable member module 20 of Embodiment 3. In Embodiment 3, a cutout portion 21e is added to the movable member module 20 of Embodiment 1. The other structures are the same as those of Embodiment 1, and repeated descriptions are omitted.

[0051] As Figure 12 shown, a cutout portion 21e is provided at the central portion of the front end of the tooth flange portion 21c. The cutout portion 21e has a shape similar to that of the slot 21d having the effect of reducing the cogging thrust. Therefore, the magnetic flux density in the gap between the stator module 10 and the movable member module 20 changes more smoothly, and the cogging thrust of the slot order component and the pole-slot order component can be reduced together.

[0052] Specifically, the width hs0 of the cutout portion 21e is the same as the interval hs of the slot 21d, and the relationship of 0.24 < hs0 / W2 < 0.45 holds. Therefore, the magnetic flux density in the gap between the stator module 10 and the movable member module 20 changes smoothly, and the effect that the cogging thrust of the slot order component and the pole-slot order component can be reduced together is obtained.

[0053] In addition, the cutout portion 21e formed at the front end of the tooth flange portion 21c is not limited to one, and may be two or three or more. When the number of cutout portions 21e increases, the magnetic flux density in the gap between the stator module 10 and the movable member module 20 changes more smoothly, and the cogging thrust can be further reduced.

[0054] The structures shown in the above embodiments represent a part of the content of the present invention, and can also be combined with other known technologies. Without departing from the gist of the present invention, they can be appropriately combined, or a part of the structure can be omitted or changed.

[0055] Description of reference numerals

[0056] 1, 2, 3, 4 Modular linear motor, 10, 50, 70 Stator module, 10a, 50a, 70a Permanent magnet block, 10b, 50b, 70b Stator core, 11 Magnetic pole, 15, 55 Adjacent portion of stator module, 17 Position, 20, 60 Movable member module, 21 Movable core, 21a Core seat, 21b, 31, 61b Tooth portion, 21c Tooth flange portion, 21d Slot, 21e Cutout portion, 22 Coil, 25, 65 Auxiliary tooth, 30 Yoke, 32 Magnetizing coil portion, 100, 300, 500, 700 Stator module group, 200, 400, 600 Movable member module group, C1 Region with reduced magnetization rate at the center, C2 Region with reduced magnetization rate at the end, G Magnetizing direction, M1 Magnetizing coil magnetic field, Np1, Np2 Number of magnetic poles, S Stroke direction, Tg Gap, V Vertical direction, W1, W2, Wa1~Wa6 Width, hs Interval, hs0 Width.

Claims

1. A modular linear motor, characterized in that, comprising: a stator module group having a plurality of stator modules arranged side by side in a stroke direction; and a movable member module group disposed opposite to the stator module group with a gap therebetween, the movable member module group having: auxiliary teeth disposed at both ends in the stroke direction; and a plurality of movable member modules arranged side by side in the stroke direction between the auxiliary teeth, each of the movable member modules having: a movable core having a core seat extending in the stroke direction between the auxiliary teeth and a plurality of tooth portions arranged at a constant pitch; and a plurality of coils wound around the plurality of tooth portions respectively, each of the stator modules having a permanent magnet block in which a plurality of magnetic poles of a first number of magnetic poles are arranged in one magnet, when the number of magnetic poles disposed opposite to one movable member module among the plurality of magnetic poles included in the permanent magnet block of the stator module group is defined as a second number of magnetic poles, the first number of magnetic poles is greater than the second number of magnetic poles.

2. The modular linear motor according to claim 1, wherein the magnetic field distribution between poles at the central portion of the permanent magnet block and the magnetic field distribution between poles at the end portion are asymmetric.

3. The modular linear motor according to claim 2, wherein when the width of the permanent magnet block is defined as W1 and the width of a region where the magnetic flux is greater than or equal to 50% of the peak magnetic flux at a position separated from the stator module by the gap among the width W1 is defined as W2, the permanent magnet block is magnetized such that 0.66 < W2 / W1 < 0.

91.

4. The modular linear motor according to claim 3, wherein the tooth portion of the movable member module has a tooth flange portion protruding in the stroke direction at the front end, and when the interval between adjacent tooth flange portions is defined as hs, it is set that 0.24 < hs / W2 < 0.

45.

5. The modular linear motor according to claim 4, wherein at least one cutout portion is provided on the front end surface of the tooth flange portion, when the width of the cutout portion is defined as hs0, it is set that 0.24 < hs0 / W2 < 0.45.

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