JP6197346B2 - Linear motor - Google Patents

Description

  The present invention relates to a linear motor formed by combining a stator and a mover having a coil and a magnet.

  For example, in the field of manufacturing semiconductor manufacturing devices and liquid crystal display devices, there is a feeding device that can linearly move an object to be processed such as a large-area substrate at a high speed and accurately position the object at an appropriate moving position. is necessary. This type of feeding device is generally realized by converting the rotational motion of a motor as a drive source into a linear motion by a motion conversion mechanism such as a ball screw mechanism, but since a motion conversion mechanism is interposed, There is a limit to increasing the moving speed. There is also a problem that positioning accuracy is insufficient due to the presence of mechanical errors in the motion conversion mechanism.

  In order to cope with this problem, in recent years, a feeding device using a linear motor capable of directly taking out a linear motion output as a drive source has been used. The linear motor includes a linear stator and a mover that moves along the stator. In the above-described feeding device, a moving coil type linear motor (a moving coil type linear motor) in which a large number of plate-like permanent magnets are arranged in parallel at regular intervals to constitute a stator, and an armature having magnetic pole teeth and energizing coils is used as a mover. For example, Patent Document 1) is used.

JP-A-3-139160

In a moving coil type linear motor, since magnets are arranged on the stator, the amount of magnets to be used increases as the total length of the linear motor increases (the moving distance of the mover increases). In recent years, with the increase in the price of rare earths, an increase in the amount of magnets used has caused an increase in cost.
Further, in order to increase the thrust, it is necessary to increase the number of turns of the coil. However, when the dimension in the moving direction of the winding frame is increased, the dimension in the entire moving direction of the mover increases. An increase in dimension in the moving direction of the mover has caused a decrease in the effective movable distance of the mover.
On the other hand, if an attempt is made to obtain a large thrust while shortening the dimension of the mover in the moving direction, the armature yoke that exchanges magnetic flux with the stator tends to cause magnetic saturation.

  The present invention has been made in view of the circumstances as described above, and the amount of magnets used does not increase even if the total length of the linear motor is long, and the armature yoke is reduced in size and weight by a structure that hardly causes magnetic saturation. It aims at providing a linear motor provided with a mover.

The linear motor according to the present invention is a linear motor including a stator and a mover having a coil. The stator has two plate-like portions that are long in the moving direction of the mover. Are arranged so as to be magnetically coupled with the moving area of the mover in between, and a plurality of tooth portions are provided on each of the opposing surfaces of the two plate-like portions. And the teeth of the other plate-shaped part are arranged in the moving direction so as to form a staggered pattern, and the mover has two sets of magnets inside the coil. Magnets and three yokes are alternately arranged along the moving direction, and the plurality of magnets constituting each pair of magnets are magnetized in the same direction in the moving direction, and in the opposite direction of the plate-like portion. Yes and arranged at a distance, the magnetization directions of the two sets of the set magnets Yes to face, the teeth of the yoke Characterized in that it is substantially flush to the opposite surface and the teeth and the opposing surfaces of the pair magnet.

  In the present invention, it is a minimum configuration in which two pairs of magnets composed of plate-like magnets and three plate-like yokes are arranged in a vertical posture and provided in the mover, and the number of turns of the coil can be increased. As a result, the dimension of the mover in the moving direction can be reduced, and a minimum propulsive force can be secured. In addition, since no magnet is used for the stator, the amount of magnet used does not increase even when the total length of the linear motor is long.

  The linear motor according to the present invention is characterized in that a plurality of magnets constituting each pair of magnets are arranged with a non-magnetic material in the opposing direction of the plate-like portion.

  In the present invention, the volume of the magnet in the assembled magnet is reduced, and the amount of magnetic flux flowing through the yoke is suppressed, thereby suppressing the magnetic saturation of the yoke and ensuring the thrust linearity.

  The linear motor according to the present invention is characterized in that the nonmagnetic material is a gap.

  In the present invention, since the nonmagnetic material is a gap, the mover can be reduced in weight.

  The linear motor according to the present invention is characterized in that a plurality of magnets constituting each set of magnets are arranged with ferrite magnets in the direction opposite to the plate-like portion.

  In the present invention, by providing a ferrite magnet having a relatively small magnetic force between the magnets constituting the assembled magnet, the strength of the assembled magnet is ensured while the magnetic force of the entire assembled magnet is suppressed, and the assembling property is ensured. Is possible.

  The linear motor according to the present invention is characterized in that each set magnet is composed of two magnets.

  In the present invention, since each set magnet is composed of two magnets, an increase in the number of parts can be minimized.

  The linear motor according to the present invention is characterized in that the height in the opposing direction of the plate-like portion of each of the magnet pairs and each yoke is two to four times the width in the respective moving direction.

  In the present invention, the height in the opposing direction of each plate-like portion of each assembled magnet and each yoke is set to be 2 to 4 times the width in the moving direction, so the dimension in the moving direction of the stator is increased. Without making it possible, it is possible to secure a coil winding frame.

  The linear motor according to the present invention is characterized in that a yoke sandwiched between the two sets of magnets is longer in the moving direction than the other two yokes.

  In the present invention, the yoke sandwiched between the two sets of magnets is longer in the moving direction than the other two yokes that are in contact with only one set of magnets. Since the length in the moving direction, that is, the length of the portion facing the tooth portion is determined according to the amount of magnetic flux exchanged with the magnet, the yoke is less likely to be magnetically saturated even if the amount of current flowing through the coil is increased.

  In the linear motor according to the present invention, the length of the yoke sandwiched between the two sets of magnets in the moving direction is twice as long as the other two yokes.

  In the present invention, the length in the moving direction of the yoke sandwiched between the two sets of magnets is twice as long as the other two yokes that are optimal for the amount of magnetic flux flowing. While reducing the length in the moving direction, it is possible to relax the magnetic saturation of the yoke and obtain a large thrust linear motor.

  The linear motor according to the present invention is characterized in that the width of the tooth portions in the juxtaposed direction is longer than the interval between the tooth portions.

  In the present invention, since the width of the tooth portions in the direction in which the teeth are arranged is wider than the interval between the teeth, the larger thrust can be obtained.

  In the linear motor according to the present invention, the plurality of magnets and the three yokes constituting each pair of magnets form a rectangular parallelepiped shape, and the surfaces of the magnets and the yokes on the moving direction side are the moving direction and the plate-like shape. It is inclined with respect to the direction orthogonal to the opposing direction of the part.

  In the present invention, the surfaces on the moving direction side of each assembled magnet and each yoke are inclined with respect to the direction orthogonal to the moving direction and the opposing direction of the plate-like portion. In other words, since it is a so-called skew arrangement, the detent force is reduced, and it is possible to reduce the thrust unevenness due to the difference in the relative positions of the stator and the mover.

In the linear motor according to the present invention, the tooth portion has a rectangular parallelepiped shape, and two short sides facing each other in a cross section parallel to the plate-like portion of the tooth portion are orthogonal to the moving direction and the opposing direction of the plate-like portion. Inclined with respect to the direction.

In the present invention, the tooth portion has a rectangular parallelepiped shape, and two short sides facing each other in a cross section parallel to the plate-like portion of the tooth portion are perpendicular to the moving direction and the opposing direction of the plate-like portion. It is inclined to. That is, since the tooth portions are arranged in a skew manner, the detent force is reduced, and it becomes possible to reduce the thrust unevenness due to the difference in the relative positions of the stator and the mover.

Linear motor according to the present invention, the tooth portion to which the two plate-shaped portion has is characterized by tilting direction before Symbol two short sides are opposite to each other.

In the present invention, the tooth portion to which the two plate-like portion having the inclination direction before Symbol two short sides is as opposite to each other. That is, since the direction in which the tooth portion is inclined is different between one and the other of the plate-like portions, it is possible to suppress the twisting that occurs when the mover is inclined to the left and right with respect to the moving direction.

  The linear motor according to the present invention includes a plate-like nonmagnetic plate provided between a side surface parallel to the moving direction of the yoke and the assembled magnet and the coil, the nonmagnetic plate, the yoke, and the assembled magnet. And an auxiliary plate made of a plate-like nonmagnetic nonconductive material provided between the coil and the coil.

  In the present invention, since the non-magnetic non-conductive material is provided between the yoke and the coil, the flow path of the eddy current flowing through the yoke is partially blocked, and the eddy current loss can be reduced. Become.

  The linear motor according to the present invention may further include a connecting portion that is connected to the nonmagnetic plate and connects three movers arranged in the moving direction.

  In the present invention, since the three movable elements are provided, it is possible to obtain a larger thrust than in the case where there is one movable element.

  In the linear motor according to the present invention, the non-magnetic plate includes plate-like first protruding plate portions and second protruding plate portions facing each other with the coil winding interposed therebetween, the first protruding plate portion, and the It has the base which connects a 2nd protrusion board part, It is characterized by the above-mentioned.

  In the present invention, since the second projecting plate portion provided outside the coil is provided, the thrust of the linear motor can be easily transmitted to the outside.

In the present invention, it is a minimum configuration in which two sets of magnets composed of plate-like magnets, three plate-like yokes are arranged in a vertical posture and provided in the mover, and the number of turns of the coil can be increased. As a result, the dimension of the mover in the moving direction can be reduced, and a minimum propulsive force can be secured. In addition, since no magnet is used for the stator, there is an effect that the amount of magnet used does not increase even when the linear motor has a long overall length.
Here, the armature yoke and the yoke used in the present specification and claims are used interchangeably.

1 is a partially broken perspective view showing an example of a schematic configuration of a linear motor according to Embodiment 1. FIG. 3 is a plan view illustrating a configuration example of a mover of the linear motor according to Embodiment 1. FIG. 1 is a cross-sectional view illustrating a schematic configuration of a linear motor according to a first embodiment. It is sectional drawing by the IV-IV line of FIG. 1 is a side view illustrating a schematic configuration of a linear motor according to a first embodiment. FIG. 4 is a diagram for explaining the principle of thrust generation of the linear motor according to the first embodiment. FIG. 4 is a diagram for explaining the principle of thrust generation of the linear motor according to the first embodiment. FIG. 4 is a diagram for explaining the principle of thrust generation of the linear motor according to the first embodiment. It is explanatory drawing about the magnetic saturation of the linear motor which concerns on Embodiment 1 and a comparative example. It is a graph which shows the relationship between the electric current sent through a coil, and the obtained thrust about each of the linear motor which concerns on Embodiment 1 and a comparative example. 5 is a plan view showing a mover of a linear motor according to Embodiment 2. FIG. It is explanatory drawing about the magnetic saturation of the armature yoke of a needle | mover. It is a graph which shows the relationship between the electric current sent through a coil, and the thrust obtained about each linear motor which concerns on Embodiment 1 and Embodiment 2. FIG. 10 is a plan view illustrating a configuration example of a mover of a linear motor according to Embodiment 3. FIG. It is sectional drawing which shows the cross section of a stator according to sectional line XV-XV in FIG. FIG. 10 is a diagram for explaining the operation of the linear motor according to the third embodiment. 10 is a graph showing the thrust of the linear motor according to the third embodiment. FIG. 6 is a plan view illustrating a configuration example of a mover 1 of a linear motor according to a fourth embodiment. FIG. 10 is a cross-sectional view illustrating a configuration of a linear motor stator 2 according to a fifth embodiment. FIG. 10 is a cross-sectional view showing a configuration of a stator 2 of a linear motor according to a sixth embodiment.

Embodiment 1
FIG. 1 is a partially broken perspective view showing an example of a schematic configuration of the linear motor according to the first embodiment. FIG. 2 is a plan view showing a configuration example of the mover 1 of the linear motor according to the first embodiment. FIG. 3 is a cross-sectional view showing a schematic configuration of the linear motor according to the first embodiment. 4 is a cross-sectional view taken along line IV-IV in FIG. FIG. 5 is a side view showing a schematic configuration of the linear motor according to the first embodiment.

  The linear motor according to the present embodiment includes a mover 1 and a stator 2. The mover 1 has a configuration in which a coil 1a is wound around a plate-like armature yoke 1b and assembled magnets 1c and 1d arranged in a vertical posture and connected. The magnets constituting the armature yoke 1b and the assembled magnets 1c and 1d have a plate shape. In the present embodiment, the mover 1 has a minimum configuration including three armature yokes 1b and one set of assembled magnets 1c and 1d. As shown in FIG. 1 or 2, the armature yoke 1b, the assembled magnet 1c, the armature yoke 1b, the assembled magnet 1d, the armature yoke 1b, the armature yoke 1b and the assembled magnet 1c or 1d are in the moving direction of the mover 1. Are alternately arranged in a vertical posture along. The assembled magnet 1c and the assembled magnet 1d are arranged so as to sandwich the central armature yoke 1b. The white arrow shown in FIG. 2 and FIG. 5 has shown the magnetization direction of each magnet which comprises each set magnet 1c, 1d. The end point of the white arrow indicates the N pole, and the start point indicates the S pole. The assembled magnet 1c and the assembled magnet 1d are magnetized along the moving direction of the mover 1, and the magnetization directions are opposed to each other. The coil 1a surrounds the armature yoke 1b and the assembled magnet 1c or 1d arranged as described above.

In the present embodiment, the width w1 of the armature yoke 1b in the moving direction is shorter than the width w2 of the assembled magnet 1c (see FIG. 5). In the armature yoke 1b, the height h1 in the opposing direction of the upper plate portion 21 and the lower plate portion 22 (vertical direction in FIG. 5) is 2 to 4 times the width w1 in the moving direction (horizontal direction in FIG. 5). . Similarly, in the magnet assembly 1c, the height h2 in the facing direction between the upper plate portion 21 and the lower plate portion 22 is 2 to 4 times the width w2 in the moving direction. The assembled magnet 1d is the same as the assembled magnet 1c. This is to secure the number of windings of the coil 1a while shortening the length of the mover 1 in the moving direction as much as possible. In the linear motor, the length of the mover 1 in the moving direction affects the effective range of motion. This is because the effective range of motion of the mover 1 in the longitudinal direction of the stator 2 becomes shorter as the length of the mover 1 in the moving direction becomes longer. Therefore, in the present embodiment, the number of turns of the coil 1a is secured and the length in the moving direction is shortened by increasing the dimension in the height direction in FIG. 5 of the mover 1 with respect to the moving direction. Has realized.
If the value of Comparative Example h1 (h2) / w1 (w2) is less than twice, it is difficult to ensure the number of turns of the coil 1a. If it exceeds 4 times, the weight of the mover increases and the thrust does not increase as the number of windings increases.

As shown in FIG. 3, the stator 2 has a U-shaped cross section. The stator 2 includes two plate-like portions, an upper plate portion 21 and a lower plate portion 22. The upper plate portion 21 and the lower plate portion 22 face each other with the movable element 1 in the moving range. The plate-shaped side plate portion 23 connects the upper plate portion 21 and the lower plate portion 22. As shown in FIG. 1, the stator 2 is elongated in the moving direction of the mover 1. The upper plate portion 21 includes a plurality of tooth portions 21 a on one surface facing the lower plate portion 22. The tooth portion 21 a is juxtaposed on the upper plate portion 21 along the moving direction of the mover 1. The lower plate portion 22 includes a plurality of tooth portions 22 a on a surface facing the upper plate portion 21. The tooth part 22a is juxtaposed to the lower plate part 22 along the moving direction of the mover 1. The tooth part 21a and the tooth part 22a have a substantially rectangular parallelepiped shape. The stator 2 is formed by bending a soft magnetic metal, for example, a flat rolled steel material. In addition to being formed by bending, the stator 2 may be formed by fixing a flat rolled steel material by joining such as welding or screwing. The upper plate portion 21 and the lower plate portion 22 of the stator 2 are magnetically coupled by the side plate portion 23. The tooth portion 21a and the tooth portion 22a are also formed in a rectangular parallelepiped shape by laminating soft magnetic metal plates such as steel plates. The tooth portion 21a and the tooth portion 22a formed in a rectangular parallelepiped shape are fixed to the upper plate portion 21 and the lower plate portion 22 by joining or screwing, for example, by welding.
Alternatively, a tooth portion 21a and a tooth portion 22a may be formed by digging grooves on both sides of the portion to be the tooth portion while leaving the portion to be the tooth portion of the magnetic steel plate formed in a substantially U shape. In this case, the cost of the stator 2 can be reduced as compared with the case where the tooth portion is fixed by welding or the like by welding or screwing. Furthermore, a slit may be formed by leaving a portion that becomes the tooth portion 21a and the tooth portion 22a with a plate-like member. Alternatively, the portions that become the tooth portion 21a and the tooth portion 22a may be formed in a comb shape. Although the tooth portions 21a and 22a have a rectangular parallelepiped shape, the shape is not limited thereto. As long as magnetic flux can be exchanged with the armature yoke 1b, the tooth portions 21a and 22a may have a shape other than a rectangular parallelepiped shape. For example, a semi-cylindrical shape or a trapezoidal column shape may be used. It is not an essential requirement of the stator 2 to be installed in the direction shown in FIG. It can be used in any orientation that can be installed. You may install so that the upper-plate part 21 may become a lower side or a left-right side.

As shown in FIG. 4, the assembled magnet 1c includes two permanent magnets (magnets) 10c and 11c. The permanent magnets 10c and 11c are arranged at a distance along the facing direction of the upper plate portion 21 and the lower plate portion 22 with a gap (nonmagnetic material) 12c therebetween. The set magnet 1d includes two permanent magnets (magnets) 10d and 11d. The permanent magnets 10d and 11d are arranged along the facing direction of the upper plate portion 21 and the lower plate portion 22 with a gap (nonmagnetic material) 12d therebetween. In the example shown in FIG. 4, the permanent magnets 10c and 10d are opposed to the upper plate portion 21 and the tooth portion 21a, and the permanent magnets 11c and 11d are opposed to the lower plate portion 22 and the tooth portion 22a. Although not shown in FIG. 4, the permanent magnets 10c and 11c constituting the assembled magnet 1c are magnetized in the same direction along the moving direction of the mover 1 (left and right direction on the paper surface). The permanent magnets 10d and 11d constituting the assembled magnet 1d are magnetized in the same direction along the moving direction of the mover 1. The permanent magnet 10c and the permanent magnet 10d are magnetized in directions facing each other. Similarly, the permanent magnet 11c and the permanent magnet 11d are magnetized in directions facing each other. Therefore, the magnet assembly 1c and the magnet assembly 1d are magnetized in directions facing each other. The assembled magnets 1c and 1d have a structure sandwiched between two armature cores 1b. As shown in FIGS. 1 and 3, the armature yoke 1b and the magnets 1c and 1d are the lengths in the normal direction of the opposing surfaces of the two plate portions (the upper plate portion 21 and the lower plate portion 22) (see FIG. 1). 3 in the vertical direction of the drawing) is substantially the same. The armature yoke 1b and the assembled magnets 1c and 1d are substantially flush with the surfaces facing the tooth portions 21a or the tooth portions 22a.
The permanent magnets 10c, 11c, 10d, and 11d constituting the assembled magnets 1c and 1d are neodymium magnets mainly composed of neodymium (Nd), iron (Fe), and boron (B). In addition to neodymium magnets, alnico magnets, ferrite magnets, samarium cobalt magnets, and the like may be used.
The assembled magnets 1c and 1d are each composed of two permanent magnets 10c and 11c and permanent magnets 10d and 11d. However, the number of permanent magnets constituting each assembled magnet may be three or more.

  As shown in FIGS. 3 and 5, it is desirable that the tooth portion 21a and the tooth portion 22a have the same shape and the same size. The linear motor according to the present embodiment has a minimum configuration of three armature yokes 1b provided in the mover 1.

  6, 7 and 8 are diagrams for explaining the principle of thrust generation of the linear motor according to the first embodiment. For convenience of explanation, the portion along the moving direction of the mover 1 is omitted and only the cross section of the portion orthogonal to the moving direction is displayed. An alternating current is passed through the coil 1a of the mover 1. 6 and 7, black circles indicate energization from the back of the paper to the front, and crosses indicate energization from the front to the back of the paper (the direction of the current at a certain time when an alternating current is applied). showed that). When the coil 1a is energized, a magnetic flux as shown by a dotted line in FIG. 6 is generated.

  When the number of armature yokes 1b provided in the mover 1 is three, the magnetic flux flowing from the tooth portion 22a flows into the armature yoke 1b at both ends as shown in FIG. 6, and the permanent magnets 10c, 11c, 10d, 11d After passing through, it gathers at the armature yoke 1b in the center and then goes out to the tooth portion 21a. In this way, as shown in FIG. 6, the distance between the central portions of the tooth portions 21a (22a) arranged side by side (hereinafter referred to as “pitch”) (L1 + L2) of the armature yokes 1b at both ends is set. It is possible to reduce the pitch L3 at the center in the movement direction. That is, the length of the mover 1 in the moving direction can be further reduced, and the effective range of motion can be widened.

On the other hand, when the number of armature yokes 1b included in the mover 1 is four or more, each of the pitches (L1 + L2) of the central portion in the moving direction of the tooth portions 21a (22a) arranged side by side is different. The pitch of the central part in the moving direction of the armature yoke 1b needs to be halved (1/2). If it compares in FIG. 6, since it is necessary to set it as L1 + L2 = L3 / 2 + L3 / 2 = L3, it becomes difficult to make the length of the moving direction of the needle | mover 1 small.
That is, when there are four or more armature yokes 1b, there are the following problems. When L1 + L2> L3, the interval between the adjacent armature yokes 1b becomes small. Since the field directions of the armature yoke 1b adjacent to each other through the paired magnets 1c and 1d are different from each other, the attraction and the repulsion are performed at a short distance with the one tooth portion 21a (22a). Thus, the thrust generated between the mover 1 and the stator 2 is reduced.

  The width of the mover 1 in the moving direction excluding the coil 1a is narrower than the width (L1 + L2) of the width L1 of the tooth portion 21a (22a) and the interval L2 of the two tooth portions 21a (22a). In FIG. 3, the length of the tooth portion 21a and the tooth portion 22a in the left-right direction in the drawing is slightly longer than the armature yoke 1b, the permanent magnets 10c and 10d, and 11c and 11d. In this case, the air gap is virtually shortened by the fringing magnetic flux, and the magnetic fluxes from the permanent magnets 10c and 10d and 11c and 11d of the mover 1 can be efficiently passed through the stator 2. The lengths of the tooth portions 21a and 22a may be the same as the lengths of the armature yoke 1b, the permanent magnets 10c and 10d, and 11c and 11d.

  The tooth part 21a and the tooth part 22a are respectively arranged on the opposing surface side of the upper plate part 21 and the lower plate part 22 facing the stator 2 at equal intervals (L2). The longitudinal direction of the tooth part 21a and the tooth part 22a is arranged substantially perpendicular to the moving direction of the mover 1. Further, the tooth portions 21a and the tooth portions 22a are arranged in a staggered manner (in a zigzag manner) along the moving direction of the mover 1 so that the central portions in the moving direction of the mover 1 on the surfaces facing each other do not overlap. . In addition, if the whole surface of the tooth part 21a and the tooth part 22a facing each other overlaps, no thrust is generated in the mover 1.

  The above-described movable element 1 is arranged on the stator 2 configured as described above. As shown in FIG. 5, one surface of the mover 1 faces the tooth portion 21a, and the other surface faces the tooth portion 22a. One of the armature yokes 1b arranged before and after in the moving direction is opposed to the tooth portion 21a, and the other is opposed to the tooth portion 22a. The central armature yoke 1b faces the tooth portion 21a. One tooth portion 21a, 22a is provided for each magnetic period. The tooth portion 21a and the tooth portion 22a are provided at different positions (positions shifted by 1/2 magnetic cycle) at an electrical angle of 180 degrees.

  Next, the principle of thrust generation of the linear motor according to the first embodiment will be described with reference to FIG. 6, FIG. 7, and FIG. As described above, the flow of magnetic flux is generated in the mover 1 in FIG. 6 as indicated by the dotted line. That is, the magnetic flux generated in the left and right armature yokes 1b passes through the permanent magnets 10c or 10d or the permanent magnets 11c or 11d and flows into the tooth portion 21a from the central armature yoke 1b, and the upper plate portion 21, the side plate portion 23, the lower plate portion It passes through the plate part 22 and flows into the left and right armature yokes 1b from the tooth part 22a. The magnetic flux loop as described above is generated. By the magnetic flux loop, the tooth portion 21a is excited to the S pole, and the tooth portion 22a is excited to the N pole.

Next, generation of magnetic poles and generation of thrust by a permanent magnet will be described with reference to FIG. As shown in FIG. 7, when the magnet assembly 1c composed of the permanent magnets 10c and 11c and the magnet assembly 1d composed of the permanent magnets 10d and 11d are arranged opposite to the armature yoke 1b in the magnetization direction, Each armature yoke 1b has a single pole. The central armature yoke 1b is excited to the N pole, and the left and right armature yokes 1b are excited to the S pole.
On the other hand, the tooth portion 21a of the stator 2 is excited to the S pole, and the tooth portion 22a is excited to the N pole. The magnetic poles generated in the tooth portions 21a and 22a and the magnetic poles of the armature yoke 1b excited by the assembled magnets 1c and 1d are attracted or repelled, so that a thrust toward the left in FIG.

  FIG. 8 shows a state where the mover 1 has advanced a distance corresponding to an electrical angle of 180 degrees from the state of FIG. In FIG. 8, the direction of the current flowing through the coil 1a is reversed. As a result, the flow of magnetic flux from the lower side to the upper side indicated by the dotted line on the paper surface of FIG. 6 is reversed. For this reason, the tooth portion 21a is excited to the N pole, and the tooth portion 22a is equivalent to being excited to the S pole. Since the excitation of the armature yoke 1b by the assembled magnets 1c and 1d does not change, the tooth portions 21a and 22a that are attracted / repelled are opposite to those in FIG. A suction force is generated in the direction of the arrow shown in FIG. 8, and the mover 1 generates a leftward thrust with respect to the paper surface in FIG. 8. When the mover 1 advances a distance corresponding to an electrical angle of 180 degrees from the state of FIG. 8, the state is the same as that of FIG. By repeating the above operation, the mover 1 continues to move.

  Next, the significance of using a permanent magnet sandwiched between armature yokes 1b of the mover 1 as a combined magnet will be described. FIG. 9 is an explanatory diagram of magnetic saturation of the linear motor according to the first embodiment and the comparative example. FIG. 9A illustrates the linear motor according to the first embodiment. FIG. 9B illustrates a linear motor as a comparative example. The difference between the linear motor of the comparative example and the linear motor according to the first embodiment is a permanent magnet included in the mover 1. The linear motor of the comparative example includes two plate-like permanent magnets 1c and 1d. On the other hand, the linear motor according to the first embodiment includes two sets of assembled magnets 1c and 1d. The set magnets 1c and 1d include two permanent magnets 10c and 11c and permanent magnets 10d and 11d, respectively. A gap 12c (12d) is formed between the two permanent magnets 10c (10d) and 11c (11d).

  As described above, since the magnetic flux flowing through the armature yoke 1b also flows through the assembled magnets 1c, 1d or the permanent magnets 1c, 1d, the amount of magnetic flux is determined by the volume of the assembled magnets 1c, 1d or the permanent magnets 1c, 1d. In the first embodiment, by providing the gaps 12c and 12d, the volume of the permanent magnet is smaller than that of the mover 1 of the comparative example. As a result, the magnetic flux flowing through the central armature yoke 1b is reduced. On the other hand, the maximum amount of magnetic flux that can be exchanged between the armature yoke 1b and the tooth portion 21a (22a) is determined by the area of the surface where the armature yoke 1b and the tooth portion 21a (22a) face each other. Since the armature yoke 1b has a smaller area of the facing surface, it is determined by the area of the facing surface of the armature yoke 1b. When the current flowing through the coil 1a is increased, the flowing magnetic flux increases, but the magnetic flux flowing due to the magnetic saturation of the armature yoke 1b reaches a peak. 9A and 9B show the case where the same current is passed through the coil 1a. However, since the volumes of the permanent magnets are different, the amounts of magnetic flux indicated by dotted lines are different. Thus, compared with the linear motor of the comparative example, the armature yoke 1b is less likely to cause magnetic saturation in the linear motor of the present embodiment.

  FIG. 10 is a graph showing the relationship between the current flowing through the coil 1a and the obtained thrust. The horizontal axis is the current value, and the unit is ampere (A). The vertical axis is thrust, and the unit is Newton (N). FIG. 10 shows the thrust of the linear motor according to Embodiment 1, the thrust of the comparative linear motor shown in FIG. 9B, and the thrust when the armature yoke 1b of the comparative linear motor is assumed not to be saturated. Indicates a virtual value. As shown in FIG. 10, the linear motor of the comparative example has a larger thrust than the linear motor of the first embodiment in a range where the current value is small, and the thrust linearity is ensured. However, the linear motor of the comparative example cannot maintain the thrust linearity as the current value increases. On the other hand, in the linear motor of the first embodiment, the thrust is smaller than that of the comparative example in the range where the current value is small, but the thrust linearity is maintained even if the current value is increased.

  Next, the improvement of the influence by the end effect will be described. The end effect means that in a linear motor, the influence of magnetic attraction and repulsive force generated at both ends of the mover affects the thrust characteristics (cogging characteristics, detent characteristics) of the motor. Conventionally, in order to reduce the end effect, measures such as making the shape of the tooth portions at both ends different from other shapes have been taken. The end effect occurs because the magnetic flux loop flows in the same direction as the moving direction (see FIG. 2 of Patent Document 1). However, in the linear motor according to the first embodiment, since the loop (magnetic flux loop) including the magnetic path passing through the stator 2 flows in a direction perpendicular to the traveling direction, it is possible to reduce the influence of the end effect. .

As described above, in the linear motor according to the first embodiment, since the permanent magnets 10c, 11c, 10d, and 11d are used only for the mover 1, even when the total length of the linear motor is increased, The amount is constant without increasing, and the cost can be reduced. In addition, the influence of the end effect can be reduced.
The mover 1 has a minimum configuration of three armature yokes 1b and two sets of magnet sets 1c and 1d. Therefore, it is possible to widen the width in the moving direction of the assembled magnets 1c and 1d included in the mover 1, and to widen the width in the moving direction of the mover 1 of the tooth portions 21a and 22a. Thereby, it becomes possible to obtain a larger thrust than the stator of the same size having a large number of armature yokes and permanent magnets.
Furthermore, each of the armature yoke 1b and the assembled magnets 1c and 1d has a height in the facing direction (up and down direction in FIG. 5) of the upper plate portion 21 and the lower plate portion 22 in the moving direction (left and right direction in FIG. 5). The width is preferably 2 to 4 times the width. Accordingly, the number of turns of the coil 1a can be increased without increasing the length of the mover 1 in the moving direction.
Permanent magnets 10c (10d) and 11c (11d) constituting the magnet assembly 1c (1d) have a gap (non-magnetic material) 12c (12d) therebetween along the opposing direction of the upper plate portion 21 and the lower plate portion 22. Therefore, the magnetic flux flowing through the armature yoke 1b is suppressed, and magnetic saturation of the armature yoke 1b hardly occurs. Thereby, the linear motor according to the present embodiment is excellent in thrust linearity. Furthermore, the mover 1 can be reduced in weight.
In the first embodiment, all the movers 1 are sandwiched between the upper plate portion 21 and the lower plate portion 22. However, in the present invention, the assembled magnets 1 c and 1 d and the armature are included in the mover 1. The yoke 1b may be sandwiched between the stators 2, and a part of the coil 1a may protrude from the stator 2.

In the present embodiment, the gap 12c (12d) is provided between the permanent magnets 10c (10d) and 11c (11d), but is not limited thereto. A non-magnetic material such as copper, stainless steel, aluminum, or brass may be provided. Further, a ceramic that is non-magnetic and non-conductive may be disposed. Moreover, it is good also as a ferrite magnet with a weak magnetic force compared with a neodymium magnet. By not providing a gap between the permanent magnets 10c (10d) and 11c (11d), the strength of the assembled magnet 1c (1d) can be increased. In addition, since it becomes easy to align the permanent magnets 10c (10d) and 11c (11d), it is possible to improve the assemblability.
In the present embodiment, each of the assembled magnets 1c and 1d is configured by two permanent magnets, but is not limited thereto. Each may be composed of three or more permanent magnets. The number of permanent magnets may be appropriately determined from the necessary magnetic force, the weight of the mover, the necessary thrust, and the like.

Embodiment 2
FIG. 11 is a plan view showing the mover 1 of the linear motor according to the second embodiment. Since the stator 2 is the same as that of the first embodiment, the description thereof is omitted.

  In the second embodiment, among the three armature yokes 1b and 10b arranged in the moving direction of the mover 1, the armature yoke 10b located in the center between the two sets of magnets is positioned on the left and right. The other two armature yokes 1b are longer in the moving direction (wide in the moving direction). As shown in FIG. 11, the width d2 of the armature yoke 10b is twice the width d1 of the armature yoke 1b. This is to make it difficult for magnetic saturation to occur when the magnetic flux flowing through the armature yokes 1b and 10b increases as the coil current increases. The armature yoke 1b located on the left and right exchanges the magnetic flux from one set of magnets 1c or 1d with the tooth portions 21a or 22a, whereas the armature yoke 10b located on the center has two sets of magnets 1c and 1c. The magnetic flux from 1d is exchanged with the tooth portion 21a or 22a. Therefore, it is preferable that the width d2 of the armature yoke 10b located at the center is twice the width d1 of the armature yoke 1b located on the left and right.

FIG. 12 is an explanatory view of the magnetic saturation of the armature yoke 1b of the mover 1. FIG. 12A shows the case of the mover 1 according to the present embodiment. FIG. 12B shows the case of the mover 1 according to the first embodiment. FIG. 12B is a reproduction of FIG. A dotted line from the tooth portion 22a through the armature yoke 1b, the assembled magnet 1c or 1d, to the tooth portion 21a through the armature yoke 1b or 10b indicates the flow of magnetic flux. In the present embodiment, the armature yoke sandwiched between the two sets of magnets 1c and 1d, that is, the armature yoke 10b located in the center, has a wider width in the moving direction than the armature yoke 1b in the first embodiment. Since the length in the moving direction is long, the density of magnetic flux flowing into the tooth portion 21a is difficult to increase, and magnetic saturation is difficult to occur. In this way, even when the current of the coil 1a is increased, the armature yoke 10b is less likely to cause magnetic saturation, so that the thrust linearity when the current of the linear motor increases is improved. Note that the flow of magnetic flux shown in FIG. 12 is shown as an example.
The width d2 is not limited to twice the width d1. If the width d2 is twice or more, the armature yoke 10b is not easily saturated. However, even if the magnetic saturation does not occur in the armature yoke 10b, the armature yoke 1b is saturated, so the width d2 is preferably twice the width d1. When the width d2 is twice or less, the armature yoke 10b is less likely to be magnetically saturated than when the width d2 is equal to the width d1, but before the armature yoke 1b is magnetically saturated, the armature yoke Magnetic saturation occurs at 10b. Since the length of the mover 1 in the moving direction is determined by the widths d1 and d2, how to set the widths d1 and d2 may be determined in consideration of the above points.

  FIG. 13 is a graph showing the relationship between the current flowing through the coil 1a and the obtained thrust for each of the linear motors according to the first and second embodiments. The horizontal axis is the current value, and the unit is ampere (A). The vertical axis is thrust, and the unit is Newton (N). As shown in FIG. 13, the linear motor according to the present embodiment (Embodiment 2) has a larger thrust than the linear motor according to Embodiment 1, and is superior in thrust linearity.

  As described above, the linear motor according to the second embodiment has the following effects in addition to the effects exhibited by the linear motor according to the first embodiment. Since the width d2 of the armature yoke 10b located in the center is twice the width d1 of the armature yoke 1b located on the left and right, the armature yoke 1b, It is possible to relax the magnetic saturation of 10b and obtain a large thrust. That is, it is possible to obtain a linear motor that optimizes two matters that are in a trade-off relationship between the miniaturization of the mover 1 and the thrust of the linear motor. Thereby, there is an effect that the thrust linearity at the time of current increase is more excellent.

Embodiment 3
In the first embodiment and the second embodiment, the single-phase linear motor (unit for single phase) has been described. However, it is not limited to this. For example, in the case of configuring a three-phase drive linear motor, the pitch between the three movers is set to n times (an integer multiple of two-thirds) of 2/3 of the stator tooth pitch. It ’s fine. In this case, an integer n may be set in consideration of the length of each movable element in the longitudinal direction.

  FIG. 14 is a plan view showing a configuration example of the mover 1 of the linear motor according to the third embodiment. 15 is a sectional view showing a section taken along section line XV-XV in FIG. 14 and a section of stator 2. FIG. 15 shows a cross section of the stator 2 not shown in FIG. 14 in order to show the positional relationship between the stator 2 and the mover 1. The linear motor according to the present embodiment is a three-phase motor. The mover 1 is configured by arranging three single-phase units 1U, 1V, and 1W similar to the mover 1 in the second embodiment along the moving direction. The single phase unit corresponding to the U phase is 1 U, the single phase unit corresponding to the V phase is 1 V, and the single phase unit corresponding to the W phase is 1 W. The three single-phase units 1U, 1V, and 1W all have the same configuration. The same components as those shown in FIG. 11 are denoted by the same reference numerals as those in FIG. When comparing the mover 1 shown in FIG. 11 with each single-phase unit 1U, 1V, 1W, each single-phase unit 1U, 1V, 1W includes an auxiliary plate 31 and an output unit 32, respectively. The auxiliary plate 31 has a rectangular plate shape. The auxiliary plate 31 is made of a nonmagnetic and nonconductive material (nonmagnetic nonconductive material) such as engineering plastic (polyamide, polycarbonate) or nonmagnetic ceramic. If the auxiliary plate 31 is made of non-magnetic and non-conductive material (non-magnetic non-conductive material), the flow path of the eddy current flowing through the armature yokes 1b and 10b can be partially blocked, so that the eddy current loss is reduced. Output efficiency is improved. The auxiliary plate 31 is disposed between the coil 1a and the side surface (side surface parallel to the moving direction) of the armature yokes 1b and 10b and the assembled magnets 1c and 1d close to the side plate portion 23 in the short direction. The auxiliary plate 31 is in intimate contact with the lateral sides of the armature yokes 1b and 10b and the assembled magnets 1c and 1d.

The output portion 32 (non-magnetic plate) has a U-shaped longitudinal section and includes a first protruding plate portion 32a, a base portion 32b, and a second protruding plate portion 32c. The output unit 32 is made of a nonmagnetic material such as aluminum or nonmagnetic stainless steel.
By using a non-magnetic material, a short circuit of magnetic flux generated in the mover 1 can be prevented.
Each of the first protruding plate portion 32a and the second protruding plate portion 32c has a rectangular plate shape. The first projecting plate portion 32a and the second projecting plate portion 32c project substantially vertically upward from a base portion 32b having a rectangular plate shape. The first protruding plate portion 32a and the second protruding plate portion 32c are opposed to each other with the winding of the coil 1a interposed therebetween. The first projecting plate portion 32a is disposed between the short side surfaces (side surfaces parallel to the moving direction) of the armature yokes 1b and 10b and the assembled magnets 1c and 1d and the windings of the coil 1a. The length of the base portion 32b in the longitudinal direction (left and right direction in FIG. 14) is substantially the same as the value obtained by adding the lengths (widths) of the armature yokes 1b and 10b and the assembled magnets 1c and 1d in the short direction. The first protruding plate portion 32a is in close contact with the surface facing the side surface with which the auxiliary plate 31 is in close contact among the short side surfaces of the armature yokes 1b and 10b and the assembled magnets 1c and 1d. The auxiliary plate 31 and the first protruding plate portion 32a prevent the armature yokes 1b and 10b and the assembled magnets 1c and 1d from being displaced from each other. The mover 1 includes a connecting plate 4 (connecting portion) that is long in the moving direction. Each single-phase unit is connected by fixing the connecting plate 4 and the second protruding plate portion 32c included in each single-phase unit with a screw or the like.
The mover 1 is supported so as to be movable from the first projecting plate portion 32a, which is a non-magnetic material, via the base portion 32b and the second projecting plate portion 32c.
Since the first protruding plate portion 32a is located between the armature yokes 1b and 10b and the coil 1a, for example, when the mover 1 is supported, the mover 1 can be reduced in size as compared with the case where the side surface of the coil 1a is supported. .

  The currents flowing through the three single-phase units 1U, 1V, and 1W of the coil 1a are three-phase alternating current (symmetrical three-phase alternating current). The white arrows shown in FIG. 14 indicate the magnetization directions of the assembled magnets 1c and 1d as in FIG. In the third embodiment, the stator 2 is the same as that in the first and second embodiments, and thus the description thereof is omitted.

  FIG. 16 is a diagram for explaining the operation of the linear motor according to the third embodiment. FIG. 16 is a side view of the linear motor. The coil wire of the coil 1a passing in the left-right direction in FIG. 16 is not shown for explanation. As shown in FIG. 16, the mover phase pitch P2 is set to a value equal to four times (2/3 × 2) the value of the pitch P1 of the tooth portion 21a (22a). Further, the width L1 of the tooth portions 21a (22a) in the juxtaposed direction (the left-right direction in FIG. 16) is longer than the interval L2 (the juxtaposition interval) between the adjacent tooth portions 21a (22a). As a result, a larger thrust can be obtained. The state shown in FIG. 16 shows a state in which current flows through the U-phase and W-phase coils 1a and no current flows through the V-phase coil 1a. At this time, the principle by which the U-phase mover 1U generates thrust is the same as in the case of FIG. The principle by which the W-phase mover 1W generates thrust is the same as in the case of FIG. The principle by which the U-phase mover 1U generates thrust is the same as in FIG. In the present embodiment, as shown in FIG. 16, the length L1 of the tooth portion 21a (tooth portion 22a) along the moving direction of the mover 1 and the interval L2 between the two tooth portions 21a (tooth portion 22a). The ratio is 6 to 4. That is, the width L1 in the juxtaposed direction of the tooth portions 21a (tooth portions 22a) is longer than the juxtaposition interval L2 of the tooth portions 21a (22a).

FIG. 17 is a graph showing the thrust of the linear motor according to the third embodiment. The horizontal axis is the moving distance of the mover 1, and the unit is millimeter (mm). The vertical axis represents thrust, and the unit is Newton (N). As shown in FIG. 17, the three-phase combined thrust is about 2.5 times the single-phase peak thrust. Generally, the thrust waveform per single phase is made substantially sinusoidal, the thrust waveform after the three-phase synthesis is smoothed, and thrust pulsation is removed. However, in this case, the three-phase combined thrust is about 1.4 times the single-phase peak thrust. On the other hand, the linear motor of this embodiment has a length L1 along the moving direction of the mover 1 of the tooth portion 21a (tooth portion 22a) shown in FIG. 16 and two tooth portions 21a (tooth portions 22a). Since the ratio with the distance L2 is 6 to 4, the distribution of the thrust waveform when the relative position of the mover 1 with respect to the stator 2 changes from a sine wave shape to a trapezoidal wave shape. As a result, although the thrust pulsation increases, the three-phase combined thrust is greatly increased. That is, it is possible to achieve both miniaturization and high thrust of the linear motor.
The composite thrust periodically varies depending on the moving distance, but the current may be controlled so that the variation range is reduced by applying appropriate feedback by PID (Proportional Integral Derivative) control.

  In the present embodiment, in addition to the effects of the linear motor according to the first or second embodiment, the following effects are achieved. Since the auxiliary plate 31 formed of a non-conductor is provided between the armature yokes 1b and 10b and the coil 1a, the flow path of eddy currents flowing through the armature yokes 1b and 10b is partially blocked, and eddy current loss Can be reduced. Since the mover is formed by connecting three single-phase units, it is possible to obtain a large thrust as compared with the case of one single-phase unit. By providing the second protruding plate portion 32c, the thrust of the linear motor can be easily transmitted to the outside.

In the present embodiment, the single-phase units are connected to each other by fixing the second projecting plate portion 32c and the connection plate 4 included in each single-phase unit 1U, 1V, 1W with screws or the like. However, the present invention is not limited thereto, and a configuration without the connecting plate 4 may be used. That is, if the second projecting plate portion 32c of each single-phase unit is integrally formed, the connecting plate 4 becomes unnecessary.
As shown in FIG. 15, the output portion 32 has a U-shaped cross section, but may have a configuration with the base portion 32 b facing up, that is, an inverted U-shaped cross section.
The configuration in which the auxiliary plate 31 is provided between the side surface in the short direction of the armature yokes 1b and 10b and the assembled magnets 1c and 1d and the coil 1a is also applicable to the first and second embodiments.

Further, in the present embodiment, the same one as the mover 1 in the second embodiment is used as a single-phase unit, and a plurality of them are connected to constitute a mover. However, the present invention is not limited to this, and the mover may be configured by using a single-phase unit similar to the mover in the first embodiment and connecting a plurality of them.
On the other hand, the configuration of the stator 2 of the present embodiment in which the width L1 in the moving direction of the mover 1 of the tooth portion 21a (22a) is made larger than the interval L2 between the adjacent tooth portions 21a (22a) is described in the first embodiment. Or in 2, it is employable. In this case, the widths of the armature yokes 1b and 10b and the assembled magnets 1c and 1d may be appropriately determined according to the width in the juxtaposed direction of the tooth portions 21a (22a) and the juxtaposition interval.
The configuration of the stator 2 of the first or second embodiment in which the width L1 in the moving direction of the mover 1 of the tooth portion 21a (22a) is made smaller than the interval L2 between the adjacent tooth portions 21a (22a) Also in the form, it can be adopted. In this case, the widths of the armature yokes 1b and 10b and the assembled magnets 1c and 1d may be appropriately determined according to the width in the juxtaposed direction of the tooth portions 21a (22a) and the juxtaposition interval.

Embodiment 4
When the assembled magnets 1c and 1d and the armature yoke 1b are arranged on the mover 1, the relative magnetic permeability periodically changes in the moving direction, so that higher-order detent force harmonic components become significant. In general, in the case of phase-independent driving, the fundamental wave and the second-order and fourth-order harmonics are canceled during the three-phase synthesis, but the third-order, sixth-order, ninth-order, and 12th-order harmonics strengthen each other. It will be.

  FIG. 18 is a plan view illustrating a configuration example of the mover 1 of the linear motor according to the fourth embodiment. Surfaces on the moving direction side of the assembled magnets 1 c and 1 d and the armature yoke 1 b are inclined with respect to the moving direction and the direction orthogonal to the opposing direction of the upper plate portion 21 and the lower plate portion 22. This is a so-called skew arrangement. The skew arrangement of the group magnets 1c and 1d means that the permanent magnets 10c and 11c constituting the group magnet 1c and the permanent magnets 10d and 11d constituting the group magnet 1d are skew arranged. That is, the surfaces of the permanent magnets 10c and 11c and the permanent magnets 10d and 11d on the moving direction side are inclined in the direction orthogonal to the moving direction and the opposing direction of the upper plate portion and the lower plate portion. Thereby, it is possible to reduce the harmonic components of the 12th order or higher. The skew angle (skew angle) is about 0 to 6 degrees. Since the stator 2 is the same as that of the first embodiment, the description thereof is omitted.

As described above, the linear motor according to the fourth embodiment has the effect of reducing the harmonic component of the detent force in addition to the effect exhibited by the linear motor according to the first embodiment.
Further, the armature yoke 1b and the assembled magnets 1c and 1d are arranged in a rectangular parallelepiped shape, but the two surfaces of the armature yoke 1b and the assembled magnets 1c and 1d facing the inner peripheral surface of the coil 1a are arranged. The coil 1a may be configured to be parallel to the inner peripheral surface. That is, one section of the armature yoke 1b permanent magnets 1c and 1d may be a parallelogram.

  Also in the second embodiment or the third embodiment, it is possible to reduce the 12th-order or higher harmonic components by arranging the assembled magnets 1c and 1d and the armature yokes 1b and 10b in a skewed manner.

Embodiment 5
FIG. 19 is a cross-sectional view showing the configuration of the stator 2 of the linear motor according to the fifth embodiment. FIG. 19 is a cross-sectional view of the linear motor stator 2 cut along the moving direction. Of the two sets of two sides facing each other in parallel with the upper plate portion 21 or the lower plate portion 22 of the tooth portions 21a and 22a, the short side (any two sides) is inclined with respect to the moving direction. The tooth portion 21a of the upper plate portion 21 and the tooth portion 22a of the lower plate portion 22 are so-called skewed. This will be described using the third tooth portion 21a from the left in FIG. The cross section of the tooth portion 21a is rectangular. A rectangle indicated by a dotted line indicates a case where the tooth portion 21a is not skewed. In FIG. 19, the moving direction of the mover 1 is the left-right direction. When the skew is not arranged, the short side of the tooth portion 21a indicated by the dotted line is parallel to the moving direction of the mover 1. In the case of the skew arrangement, the short cross-sections E1 and E2 are inclined with respect to the moving direction of the mover 1. In FIG. 19, the tooth part 22a has an end face at the tip in the protruding direction. In the second tooth portion 22a from the left in FIG. 19, a rectangle indicated by a dotted line indicates a case where the tooth portion 22a is not skewed. The short side of the end face is parallel to the moving direction of the mover 1 and is not inclined. In the case of the skew arrangement, the short sides E3 and E4 of the end face are inclined with respect to the moving direction of the mover 1. Since the cross section of the tooth portion 22a has the same shape as the end face, the short side of the cross section is similarly inclined with respect to the moving direction of the mover 1.

  The mover 1 is the same as that of any one of the first to fourth embodiments described above, and a description thereof will be omitted. In the fifth embodiment, by arranging the tooth portions 21a and the tooth portions 22a of the stator 2 in a skew manner, the armature yoke 1b (10b) of the mover 1 and the assembled magnets 1c and 1d are not skewed. It is possible to reduce the 12th-order or higher harmonic component of the detent force. In addition, when using the thing similar to the above-mentioned Embodiment 4 as the needle | mover 1, in order to reduce a detent force, the arm parts 1a and 22a of the stator 2, the armature yoke 1b of the needle | mover 1, the assembled magnet 1c, The angle formed by 1d is related. The teeth 21 a and 22 a of the stator 2, the armature yoke 1 b of the mover 1, and the assembled magnets 1 c and 1 d may be skewed so that the angle formed becomes an appropriate value.

Embodiment 6
FIG. 20 is a cross-sectional view showing the configuration of the stator 2 of the linear motor according to the sixth embodiment. It is the cross-sectional view which cut | disconnected the stator 2 of the linear motor along the moving direction. The tooth portion 21a of the upper plate portion 21 and the tooth portion 22a of the lower plate portion 22 are arranged in a skew manner. That is, the tooth part 21 a and the tooth part 22 a of the stator 2 are arranged so as to be inclined with respect to the moving direction of the mover 1. The mover 1 is the same as that of any one of the first to fourth embodiments described above, and a description thereof will be omitted.

  In the sixth embodiment, the tooth portion 21a included in the upper plate portion 21 and the tooth portion 22a included in the lower plate portion 22 are reversed in the direction of inclination of the short side of the cross section. As shown in FIG. 20, the short cross-sections E1 and E2 of the tooth portion 21a and the end face short sides E3 and E4 of the tooth portion 22a are inclined with respect to the moving direction of the mover 1. This is the same as in the fifth embodiment described above. In the sixth embodiment, the directions of inclination between the tooth portion 21a and the tooth portion 22a are reversed. That is, the inclination directions of the short cross-sections E1 and E2 of the tooth portion 21a and the end surface short sides E3 and E4 of the tooth portion 22a are opposite to each other. This is intended to suppress twisting due to the skew arrangement. By arranging the tooth portions 21a and 22a in a skew manner, the thrust generated in the linear motor is generated in a direction inclined by the skew angle from the moving direction, so that the entire mover 1 may be tilted. By reversing the inclination directions of the tooth portion 21a and the tooth portion 22a, the thrust component in the direction (lateral direction) perpendicular to the moving direction generated by the tooth portion 21a and the tooth portion 22a is reversed. Therefore, the thrust components in the lateral direction cancel each other and can be prevented from being twisted.

  As described above, the sixth embodiment has the following effects in addition to the effects of the linear motor according to the first to fourth embodiments. By arranging the tooth portion 21a and the tooth portion 22a of the stator 2 in a skew manner, the armature yoke 1b (10b) of the mover 1 and the assembled magnets 1c and 1d do not have to be skewed. Wave components can be reduced. In addition, the direction in which the tooth portion 21a and the tooth portion 22a are inclined is reversed, thereby providing an effect of preventing twisting.

  In the sixth embodiment, similarly to the fifth embodiment, it is possible to use the mover 1 in the fourth embodiment. The armature yoke 1b, the assembled magnets 1c and 1d of the mover 1, and the stator The skew angles of the two tooth portions 21a and 22a may be determined as appropriate.

The technical features (components) described in each embodiment can be combined with each other, and new technical features can be formed by combining them.
The embodiments disclosed herein are illustrative in all respects and should not be considered as restrictive. The scope of the present invention is defined not by the above-mentioned meaning but by the scope of the claims, and is intended to include all modifications within the meaning and scope equivalent to the scope of the claims.

DESCRIPTION OF SYMBOLS 1 Movable element 1a Coil 1b, 10b Armature yoke (yoke)
1c, 1d magnet (magnet)
10c, 11c, 10d, 11d Permanent magnet (magnet)
12c, 12d Air gap (non-magnetic part)
2 Stator 21 Upper plate portion 21a Tooth portion 22 Lower plate portion 22a Tooth portion 23 Side plate portion 31 Auxiliary plate 32 Output portion (nonmagnetic plate)
32a 1st protrusion board part 32b base part 32c 2nd protrusion board part 4 connection board (connection part)

Claims (15)

In a linear motor including a stator and a mover having a coil,
The stator has two plate-like portions that are long in the moving direction of the mover, and the two plate-like portions are opposed so as to be magnetically coupled with the moving region of the mover in between.
On each of the opposing surfaces of the two plate-like portions, a plurality of tooth portions are juxtaposed in the moving direction so that the tooth portions of one plate-like portion and the tooth portions of the other plate-like portion are staggered. And
The mover has two sets of magnets and three yokes alternately arranged in the coil along the moving direction, and a plurality of magnets in one set.
The plurality of magnets constituting each pair of magnets are magnetized in the same direction in the moving direction, and are arranged at a distance in the opposing direction of the plate-like portion,
The magnetization directions of the two sets of magnets are opposite to each other,
A linear motor characterized in that a surface of the yoke facing the tooth portion and a surface of the assembled magnet facing the tooth portion are substantially flush with each other . 2. The linear motor according to claim 1, wherein the plurality of magnets constituting each pair of magnets are arranged with a non-magnetic material therebetween in an opposing direction of the plate-like portion. The linear motor according to claim 2, wherein the nonmagnetic material is a gap. 2. The linear motor according to claim 1, wherein the plurality of magnets constituting each of the paired magnets are arranged with ferrite magnets therebetween in a direction opposite to the plate-like portion. Each linear magnet is comprised from two magnets. The linear motor as described in any one of Claims 1-4 characterized by the above-mentioned. The height in the opposing direction of the plate-like portion of each of the magnet pairs and each of the yokes is 2 to 4 times the width of each of the moving directions. A linear motor according to claim 1. The linear motor according to claim 1, wherein a yoke sandwiched between the two sets of magnets is longer in the moving direction than the other two yokes. The linear motor according to claim 7, wherein a length of the yoke sandwiched between the two sets of magnets in the moving direction is twice as long as the other two yokes. The linear motor according to any one of claims 1 to 8, wherein a width of the tooth portions in the juxtaposed direction is longer than an interval between the tooth portions. The plurality of magnets and the three yokes constituting each grouped magnet have a rectangular parallelepiped shape, and the surface on the moving direction side of each grouped magnet and each yoke is orthogonal to the moving direction and the opposing direction of the plate-like portion. The linear motor according to claim 1, wherein the linear motor is inclined with respect to a direction. The tooth portion has a rectangular parallelepiped shape,
The two short sides facing each other in a cross section parallel to the plate-like portion of the tooth portion are inclined with respect to the moving direction and a direction orthogonal to the opposing direction of the plate-like portion. Item 11. The linear motor according to any one of Items 10. Said teeth having two plate-like portion includes a linear motor according to claim 11, wherein the tilting direction before Symbol two short sides are opposite to each other. A plate-like nonmagnetic plate provided between a side surface of the yoke and the magnet set parallel to the moving direction and the coil; and the coil opposed to the nonmagnetic plate via the yoke and the set magnet. The auxiliary motor which consists of a plate-shaped nonmagnetic nonelectroconductive material provided between these is provided. The linear motor as described in any one of Claims 1-12 characterized by these. The linear motor according to claim 13, further comprising a connecting portion that is connected to the nonmagnetic plate and connects three movers arranged in the moving direction. The non-magnetic plate is
A plate-like first projecting plate portion and a second projecting plate portion facing each other with the winding of the coil interposed therebetween;
The linear motor according to claim 14, further comprising a base portion that connects the first protruding plate portion and the second protruding plate portion.

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