JP6634341B2 - Linear motor - Google Patents

Description

  The present invention relates to a linear motor.

  Patent Literature 1 discloses a linear motion rotary actuator having a function of a linear motion motor and a function of a rotary motor. The linear motion rotary actuator disclosed in Patent Document 1 moves a θ armature winding that generates a magnetic field for rotating a cylindrical mover around its central axis, and linearly moves the mover in the central axis axial direction. And an X armature winding for generating a magnetic field. In the mover of this linear motion rotary actuator, a plurality of permanent magnets whose magnetization directions are in the radial direction are arranged side by side in the axial direction such that the polarity is alternately reversed. A permanent magnet (X magnet) magnetized in the axial direction is arranged between the permanent magnets adjacent to the mover. As a result, the magnetic flux density on the magnetic pole surface increases, and the thrust for linearly moving the mover increases.

Patent No. 5261913

  In the linear motion rotary actuator described in Patent Literature 1, the thrust is increased by arranging the X magnet between the permanent magnets as the field in the mover. However, with this configuration, the magnetic flux generated by the X armature winding passes through both the field permanent magnet and the X magnet, and the length of the magnetic path passing through the permanent magnet is equal to that of the X magnet. It gets bigger by the minute. The magnetic permeability of the permanent magnet is lower than that of the soft magnetic material that is the iron core, and when the length of the magnetic flux passing through such a permanent magnet increases, the magnetic flux density decreases accordingly. As a result, the magnetic efficiency decreases.

  The present invention has been made in view of such circumstances, and a main object of the present invention is to provide a linear motor capable of improving magnetic efficiency as compared with the related art.

  In order to solve the above-described problem, a linear motor according to one aspect of the present invention includes an armature having an armature coil, and a mover magnetic pole that passes a magnetic flux generated by the armature coil and faces the armature. And a mover having a permanent magnet constituting the mover, wherein the mover is arranged so that a magnetic pole having the same polarity as the mover magnetic pole is directed to the mover magnetic pole, and the mover magnetic pole does not pass through the magnetic flux. Further, there is an auxiliary permanent magnet for increasing the magnetic field generated in the auxiliary magnet.

  In this aspect, the plurality of permanent magnets are arranged at intervals in a circumferential direction of an axis extending in a moving direction of the mover, and are alternately reversed in polarity to be magnetized in the circumferential direction. The magnet is disposed between two adjacent permanent magnets on the center side of a circle about the axis, and the armature coil forms an annular magnetic path in a plane intersecting the moving direction. It may be configured to do so.

  In the above aspect, the plurality of permanent magnets are arranged at intervals in a circumferential direction of an axis extending in a moving direction of the mover, and are alternately reversed in polarity and magnetized in the circumferential direction, The mover has a soft magnetic yoke member between two adjacent permanent magnets, and the auxiliary permanent magnet is disposed adjacent to the yoke member on the moving direction side, The armature coil may be configured to form an annular magnetic path in a plane intersecting the moving direction.

  Further, in the above aspect, the plurality of permanent magnets are arranged apart from each other in the moving direction of the mover, and are magnetized in the moving direction such that the same magnetic pole faces two adjacent permanent magnets. The child has a yoke member of a soft magnetic material between two adjacent permanent magnets, and the auxiliary permanent magnet is arranged adjacent to the yoke member in a direction intersecting the moving direction. The armature coil may be configured to form an annular magnetic path in a plane parallel to the moving direction.

  Further, in the above aspect, the permanent magnet is arranged in a circular shape in a cross section orthogonal to the moving direction, the yoke member is arranged in a hollow annular shape in a cross section orthogonal to the moving direction, and the auxiliary permanent magnet is May be arranged on the center side of the ring formed by the yoke member.

  Further, in the above aspect, the mover extends in a moving direction of the mover, and has a concave portion or a convex portion provided with the mover magnetic pole, and the armature has the armature coil wound thereon, It may have a tooth part which constitutes an armature magnetic pole facing the mover magnetic pole, and the tooth part may be formed in a convex shape or a concave shape corresponding to the concave part or the convex part.

  According to the present invention, the magnetic efficiency can be increased as compared with the related art.

FIG. 2 is a perspective view showing the configuration of the linear motor according to the first embodiment. FIG. 2 is a plan view showing the configuration of the armature according to the first embodiment. FIG. 2 is a side view showing the configuration of the mover according to the first embodiment. FIG. 4 is a sectional view of the mover taken along line AA shown in FIG. 3. FIG. 4 is a sectional view of the mover taken along line BB shown in FIG. 3. FIG. 4 is a sectional view of the mover taken along line CC shown in FIG. 3. FIG. 4 is a cross-sectional view of the mover taken along line DD shown in FIG. 3. FIG. 3 is a cross-sectional plan view showing a magnetic path generated from an armature coil in the linear motor according to the first embodiment. FIG. 9 is a side view showing the configuration of the mover according to the second embodiment. FIG. 7 is a sectional view of the mover taken along line EE shown in FIG. 6. FIG. 7 is a sectional view of the mover taken along line FF shown in FIG. 6. FIG. 9 is a plan sectional view showing a magnetic path generated from an armature coil in the linear motor according to the second embodiment. FIG. 9 is a perspective view showing a configuration of a linear motor according to a third embodiment. FIG. 10 is a side cross-sectional view illustrating a configuration of an armature according to a third embodiment. FIG. 11 is a side view showing the configuration of the mover according to the third embodiment. FIG. 12 is a sectional view of the mover taken along line GG shown in FIG. 11. FIG. 12 is a sectional view of the mover taken along line HH shown in FIG. 11. FIG. 12 is a sectional view of the mover taken along the line II shown in FIG. 11. Sectional drawing of a mover in JJ line shown in FIG. FIG. 14 is a side sectional view showing a magnetic path generated from an armature coil in the linear motor according to the third embodiment. FIG. 10 is a plan sectional view showing a configuration of a linear motor according to a fourth embodiment. FIG. 6 is a partially enlarged plan sectional view showing another example of the shape of the teeth portion. Sectional drawing which shows the modification of the shape of a tooth part and a mover.

  Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings.

(Embodiment 1)
In the present embodiment, a description will be given of a transverse magnetic flux type linear motor in which an armature coil forms an annular closed magnetic path in a plane perpendicular to the moving direction of the mover.

  FIG. 1 is a perspective view showing the configuration of the linear motor according to the present embodiment. The linear motor 100 includes an armature 110 and a mover 120. In the following description, the moving direction of the mover 120 is referred to as the Z direction, the circumferential direction of the central axis 150 extending in the Z direction is referred to as the θ direction, and the radial direction of a circle around the central axis 150 is referred to as the r direction.

  The configuration of the armature 110 will be described with reference to FIG. FIG. 2 is a plan view showing the configuration of the armature. The armature 110 has an armature coil 111, a tooth portion 112, and a yoke portion 113. The yoke portion 113 has an annular shape having a through hole extending in the Z direction, and a plurality of teeth portions 112 are provided inside the yoke portion 113. The teeth 112 are arranged radially around the central axis 150, and each extends in the r direction.

  The yoke portion 113 and the teeth portion 112 are integrally formed as an armature member 114. The armature member 114 is made of a soft magnetic material such as soft iron and soft ferrite. The teeth 112 have a rectangular parallelepiped shape, and a conductive wire is wound around each of the teeth 112 to form an armature coil 111. The armature 110 is provided with eight such tooth portions 112.

  As shown in FIG. 1, a plurality of the armatures 110 are arranged in the Z direction.

  Next, the configuration of the mover 120 will be described. As shown in FIG. 1, the mover 120 is disposed inside the armature 110. FIG. 3 is a side view showing the configuration of the mover. As shown in FIGS. 1 and 3, the mover 120 has a columnar shape with the center axis 150 as the center. As shown in FIG. 3, the mover 120 is configured by stacking a first layer 120a, a second layer 120b, a third layer 120c, and a fourth layer 120d in the Z direction. Note that the first layer 120a, the second layer 120b, the third layer 120c, and the fourth layer 120d may be repeatedly and continuously stacked in this order in the Z direction. The mover 120 according to the present embodiment includes a set of a first layer 120a, a second layer 120b, a third layer 120c, and a fourth layer 120d.

  FIG. 4A is a sectional view of the mover taken along line AA shown in FIG. Similarly, each of FIGS. 4B to 4D is a cross-sectional view of the mover along the line BB, the line CC, and the line DD. The mover 120 has a cylindrical output shaft 160 at the center position in plan view. The output shaft 160 is a non-magnetic material such as stainless steel.

  FIG. 4B shows the configuration of the second layer 120b. In the second layer 120b, eight plate-shaped permanent magnets 121 extending in the r direction are radially arranged around a central axis 150. That is, the permanent magnets 121 are arranged at equal intervals in the θ direction. The permanent magnet 121 is magnetized in the thickness direction, that is, in the θ direction, and the polarity is alternately reversed in the order in which the permanent magnets 121 are arranged in the θ direction. That is, two adjacent permanent magnets 121 have the same magnetic poles facing each other. 4A to 4D, the arrow indicates the magnetization direction, and the polarity is S → N.

  In the second layer 120b, a yoke member 122 is arranged between the permanent magnets 121. The yoke member 122 has a shape surrounded by two radii of a ring centered on the central axis 150 and two circular arcs (an outer circular arc and an inner circular arc) between the two radii in plan view. Is a plate-shaped member. The yoke member 122 is made of a soft magnetic material such as soft iron and soft ferrite.

  The yoke member 122 is magnetized by permanent magnets 121 provided on both sides thereof. One permanent magnet 121 is sandwiched between two yoke members 122. For this reason, the magnetic flux generated from the permanent magnet 121 passes through the yoke member 122 facing the S pole of the permanent magnet 121 from the side surface of the yoke member 122 to the outside of the mover 120 as indicated by the broken arrow in the drawing. It goes out into the space (gap with the armature 110). The magnetic flux advances in the gap in the direction opposite to the magnetization direction of the permanent magnet 121, enters the yoke member 122 facing the N pole of the permanent magnet 121 from the side surface, and returns to the permanent magnet 121. For this reason, the side surface of the yoke member 122 is configured as a mover magnetic pole 122a. The mover magnetic pole 122a has the same polarity as the magnetic pole of the permanent magnet 121 facing the yoke member 122 including the mover magnetic pole 122a. That is, when the south pole of the permanent magnet 121 faces the yoke member 122, the mover magnetic pole 122a of the yoke member 122 becomes the south pole, and when the north pole of the permanent magnet 121 faces the yoke member 122, The mover magnetic pole 122a of the yoke member 122 is an N pole.

  On the second layer 120b, an auxiliary permanent magnet 123 is provided inside the yoke member 122 in the r direction. The auxiliary permanent magnet 123 is a plate-like member having a substantially fan shape in plan view, and the radius of the circular arc matches the radius of the circular arc inside the yoke member 122. In other words, the pair of auxiliary permanent magnets 123 and the yoke member 122 form a fan shape in a plan view, and the pair of auxiliary permanent magnets 123 and the yoke member 122 are arranged between the adjacent permanent magnets 121. The auxiliary permanent magnet 123 is magnetized in the r direction, and the polarity is alternately reversed in the order arranged in the θ direction.

  The auxiliary permanent magnet 123 is arranged so that the same magnetic pole as the mover magnetic pole 122a faces the mover magnetic pole 122a. Specifically, the yoke member 122 including the S pole mover magnetic pole 122a faces the S pole of the auxiliary permanent magnet 123, and the yoke member 122 including the N pole mover magnetic pole 122a includes the auxiliary permanent magnet 123. The north pole of the magnet 123 faces. Thereby, the magnetic field generated by the auxiliary permanent magnet 123 is added to the magnetic field generated by the permanent magnet 121, and the magnetic field generated in the mover magnetic pole 122a is increased. Here, “turning the magnetic pole toward the magnetic pole of the mover” means that the magnetic pole of the auxiliary permanent magnet is placed at a position where the magnetic flux generated by the auxiliary permanent magnet 123 passes through the magnetic pole of the mover.

  FIG. 4D shows the configuration of the fourth layer 120d. The fourth layer 120d has the same configuration as the second layer 120b. In addition, the position of each permanent magnet 121 in the θ direction on the second layer 120b matches the position of each permanent magnet 121 in the θ direction on the fourth layer 120d. That is, the permanent magnets 121 in the fourth layer 120d are provided in the Z direction of the permanent magnets 121 in the second layer 120b. The position of each yoke member 122 in the θ direction on the second layer 120b matches the position of each yoke member 122 in the θ direction on the fourth layer 120d, and the position of each auxiliary permanent magnet 123 on the second layer 120b in the θ direction. And the position in the θ direction of each auxiliary permanent magnet 123 in the fourth layer 120d coincides. However, the magnetization directions of the permanent magnets 121 at the same position in the θ direction in the second layer 120b and the fourth layer 120d are opposite to each other. Similarly, in the second layer 120b and the fourth layer 120d, the magnetization directions of the auxiliary permanent magnets 123 at the same position in the θ direction are opposite to each other.

  FIG. 4A shows the configuration of the first layer 120a. Eight auxiliary permanent magnets 124 are provided on the first layer 120a. The auxiliary permanent magnet 124 is a plate-like member having a substantially fan shape in plan view, and the radius of the circular arc matches the radius of the circular arc outside the yoke member 122. The central angle of the sector of the auxiliary permanent magnet 124 is the same as the central angle of the sector formed by the pair of auxiliary permanent magnets 123 and the yoke member 122. That is, the sector shape of the auxiliary permanent magnet 124 is the same as the sector shape formed by the pair of auxiliary permanent magnets 123 and the yoke member 122.

  The auxiliary permanent magnet 124 as described above is held by a non-magnetic holding member 125. The yoke member 122 and the auxiliary permanent magnet 123 are adjacent to the auxiliary permanent magnet 124 in the Z direction. That is, the position of the auxiliary permanent magnet 124 in the θ direction matches the position of the pair of yoke members 122 and the auxiliary permanent magnet 123 in the θ direction. Therefore, the entire upper surface of one yoke member 122 is in contact with the lower surface of one auxiliary permanent magnet 124.

  The auxiliary permanent magnet 124 is magnetized in the Z direction, and the polarity is alternately reversed in the order arranged in the θ direction. More specifically, the auxiliary permanent magnet 123 is arranged so that the same magnetic pole as the mover magnetic pole 122a faces the mover magnetic pole 122a. In other words, the yoke member 122 including the S pole mover magnetic pole 122a faces the S pole of the auxiliary permanent magnet 124, and the yoke member 122 including the N pole mover magnetic pole 122a has the auxiliary permanent magnet 124 The north pole is facing. Thus, the magnetic field generated by the auxiliary permanent magnet 124 is added to the magnetic field generated by the permanent magnet 121, and the magnetic field generated by the mover magnetic pole 122a is increased.

  FIG. 4C shows the configuration of the third layer 120c. The third layer 120c has the same configuration as the first layer 120a. Further, the position of each auxiliary permanent magnet 124 in the θ direction in the first layer 120a coincides with the position in the θ direction of each auxiliary permanent magnet 124 in the third layer 120c. That is, the auxiliary permanent magnet 124 in the third layer 120c is provided in the Z direction of the auxiliary permanent magnet 124 in the first layer 120a. Further, in the first layer 120a and the third layer 120c, the auxiliary permanent magnets 124 located at the same position in the θ direction are opposite to each other in the magnetization direction. That is, in the first layer 120a and the third layer 120c, the auxiliary permanent magnets 124 located at the same position in the θ direction are arranged so that the same magnetic poles face each other.

  With the configuration described above, in the yoke member 122, all surfaces other than the side surface serving as the mover magnetic pole 122 a are surrounded by the output shaft 160, the permanent magnet 121, and the auxiliary permanent magnets 123 and 124. Moreover, the surfaces of the permanent magnet 121 and the auxiliary permanent magnets 123 and 124 that are in contact with the yoke member 122 are all the same magnetic pole as the mover magnetic pole 122a of the yoke member 122. This prevents magnetic flux leakage from the yoke member 122 and allows magnetic flux to enter and exit only from the mover magnetic pole 122a.

  In the linear motor 100 configured as described above, when a current flows through the armature coil 111, a magnetic field is generated around the armature coil 111. FIG. 5 is a plan sectional view showing a magnetic path generated from the armature coil 111. Current flows in two adjacent armature coils 111 in opposite directions. Thereby, a magnetic path is formed that passes through the two teeth portions 112 around which these armature coils 111 are wound, the yoke portion 113, and the space inside the armature 110. At this time, the surface of the teeth portion 112 facing the mover 120 becomes a magnetic pole (armature magnetic pole 112a). Of the two teeth portions 112 forming one magnetic path, the armature magnetic pole 112a of one of the tooth portions 112 is an S pole, and the armature magnetic pole 112a of the other tooth portion 112 is an N pole.

  The angle of each armature magnetic pole 112a in the θ direction in plan view matches the angle of each armature magnetic pole 122a in the θ direction. That is, in a plan view, the armature magnetic pole 112a and the mover magnetic pole 122a face one to one. Therefore, when a current flows through the armature coil 111, the armature magnetic pole 112a and the corresponding mover magnetic pole 122a are attracted or repelled by the magnetic force. By controlling the current flowing through the armature coil 111, the magnetic field generated by the armature coil 111 changes, whereby the mover 120 moves in the Z direction.

  The magnetic flux generated from the armature coil 111 as described above passes through the inside of the mover 120. That is, the magnetic flux emitted from the S-pole armature magnetic pole 112a enters the N-pole armature magnetic pole 122a, passes through the permanent magnet 121, exits from the S-pole armature magnetic pole 122a, and enters the N-pole armature magnetic pole 112a. . At this time, no magnetic flux passes through the auxiliary permanent magnets 123 and 124. Thereby, the permanent magnet through which the magnetic flux passes is only the permanent magnet 121, the length of the magnetic path passing through the permanent magnet can be reduced, and a decrease in the magnetic flux density is suppressed. Further, the auxiliary permanent magnets 123 and 124 increase the magnetic flux generated in the mover magnetic pole 122a. Therefore, the magnetic efficiency of the linear motor 100 is improved.

  Note that a non-magnetic material having the same shape as the auxiliary permanent magnets 123 and 124 may be provided instead of the auxiliary permanent magnets 123 and 124. In this case, although the magnetic field of the mover magnetic pole 122a cannot be increased depending on the non-magnetic material, the magnetic flux leakage from the yoke member 122 can be prevented.

(Embodiment 2)
The linear motor according to the present embodiment is a transverse magnetic flux type linear motor. Since the configuration of the armature of the linear motor according to the present embodiment is the same as the configuration of armature 110 of linear motor 100 according to the first embodiment, the same components are denoted by the same reference numerals. Description is omitted.

  FIG. 6 is a side view showing the configuration of the mover. As shown in FIG. 6, the mover 220 has a column shape centered on the central axis 150. The mover 220 is configured by stacking a first layer 220a, a second layer 220b, a third layer 220c, and a fourth layer 220d in the Z direction. Note that the first layer 220a, the second layer 220b, the third layer 220c, and the fourth layer 220d may be repeatedly and continuously stacked in this order in the Z direction. The mover 220 according to the present embodiment includes a set of a first layer 220a, a second layer 220b, a third layer 220c, and a fourth layer 220d.

  7A is a cross-sectional view of the mover taken along line EE shown in FIG. 6, and FIG. 7B is a cross-sectional view of the mover taken along line FF shown in FIG. FIG. 7A shows the configuration of the second layer 220b, and FIG. 7B shows the configuration of the fourth layer 220d. The mover 220 has a columnar output shaft 260 at the center position in plan view. The output shaft 260 is a non-magnetic material such as stainless steel.

  As shown in FIG. 7A, eight plate-shaped permanent magnets 221 extending in the r direction are radially arranged around the central axis 150 in the second layer 220b. That is, the permanent magnets 221 are arranged at equal intervals in the θ direction. The permanent magnet 221 is magnetized in the thickness direction, that is, in the θ direction, and the polarity is alternately reversed in the order in which the permanent magnets 221 are arranged in the θ direction. That is, the two adjacent permanent magnets 221 have the same magnetic poles facing each other.

  In the second layer 220b, a yoke member 222 made of a soft magnetic material is disposed between the permanent magnets 221. The yoke member 222 is a plate-like member having a fan shape centered on the central axis 150 in plan view. The yoke member 222 is made of a soft magnetic material such as soft iron and soft ferrite.

  The yoke member 222 is magnetized by permanent magnets 221 provided on both sides thereof. One permanent magnet 221 is sandwiched between two yoke members 222. For this reason, the magnetic flux generated from the permanent magnet 221 passes through the yoke member 222 facing the S pole of the permanent magnet 221 and from the side surface of the yoke member 222 to the outside of the mover 220, as indicated by the broken arrow in the drawing. It goes out into the space (gap with the armature 110). The magnetic flux advances in the gap in the direction opposite to the magnetization direction of the permanent magnet 221, enters the yoke member 222 facing the N pole of the permanent magnet 221 from the side surface, and returns to the permanent magnet 221. For this reason, the side surface of the yoke member 222 is configured as a mover magnetic pole 222a. The mover magnetic pole 222a has the same polarity as the magnetic pole of the permanent magnet 221 facing the yoke member 222 including the mover magnetic pole 222a. That is, when the S pole of the permanent magnet 221 faces the yoke member 222, the mover magnetic pole 222a of the yoke member 222 becomes the S pole, and when the N pole of the permanent magnet 221 faces the yoke member 222, The mover magnetic pole 222a of the yoke member 222 is an N pole.

  As shown in FIG. 7B, the fourth layer 220d has the same configuration as the second layer 220b. In addition, the position of each permanent magnet 221 in the θ direction on the second layer 220b matches the position of each permanent magnet 221 in the θ direction on the fourth layer 220d. That is, the permanent magnet 221 in the fourth layer 220d is provided in the Z direction of the permanent magnet 221 in the second layer 220b. The position of each yoke member 222 in the second layer 220b in the θ direction coincides with the position of each yoke member 222 in the fourth layer 220d in the θ direction. However, in the second layer 220b and the fourth layer 220d, the permanent magnets 221 located at the same position in the θ direction have the magnetization directions opposite to each other.

  The configurations of the first layer 220a and the third layer 220c are the same as the configurations of the first layer 120a and the third layer 120c described in the first embodiment. Is omitted.

  In the yoke member 222, all surfaces other than the side surface serving as the mover magnetic pole 222 a are surrounded by the permanent magnet 221, the auxiliary permanent magnet 124, and the output shaft 260. In addition, the surfaces of the permanent magnet 221 and the auxiliary permanent magnet 124 that are in contact with the yoke member 222 are all the same magnetic pole as the mover magnetic pole 222a of the yoke member 222. This prevents the magnetic flux from leaking from the yoke member 222, and the magnetic flux enters and exits only from the mover magnetic pole 222a.

  FIG. 8 is a sectional plan view showing a magnetic path generated from the armature coil 111. In the linear motor 200 configured as described above, when a current flows through the armature coil 111, the armature magnetic pole 112a and the corresponding mover magnetic pole 222a are attracted or repelled by the magnetic force. By controlling the current flowing through the armature coil 111, the magnetic field generated by the armature coil 111 changes, whereby the mover 220 moves in the Z direction.

  The magnetic flux generated from the armature coil 111 passes through the inside of the mover 220. That is, the magnetic flux emitted from the S-pole armature magnetic pole 112a enters the N-pole armature magnetic pole 222a, passes through the permanent magnet 221, exits the S-pole armature magnetic pole 222a, and enters the N-pole armature magnetic pole 112a. . At this time, no magnetic flux passes through the auxiliary permanent magnet 124. Accordingly, only the permanent magnet 221 allows the magnetic flux to pass therethrough, so that the length of the magnetic path passing through the permanent magnet can be reduced, and a decrease in the magnetic flux density is suppressed. Further, the auxiliary permanent magnet 124 increases the magnetic flux generated in the mover magnetic pole 222a. Therefore, the magnetic efficiency of the linear motor 200 is improved.

(Embodiment 3)
In the present embodiment, a vertical magnetic flux type linear motor in which an armature coil forms an annular closed magnetic path in a plane parallel to the moving direction of the mover will be described.

  FIG. 9 is a perspective view showing the configuration of the linear motor according to the present embodiment. The linear motor 300 includes an armature 310 and a mover 320.

  The configuration of the armature 310 will be described with reference to FIG. FIG. 10 is a side sectional view showing the configuration of the armature. The armature 310 has an armature coil 311 and a yoke 313. The yoke 313 has a cylindrical shape having a through hole extending in the Z direction. An annular concave portion 312 for accommodating the armature coil 311 is provided at the center of the inner surface of the yoke portion 313 in the Z direction. The recess 312 accommodates an armature coil 311 formed by winding a conductive wire in an annular shape.

  As shown in FIG. 9, a plurality of the armatures 310 are arranged in the Z direction.

  Next, the configuration of the mover 320 will be described. As shown in FIG. 9, the mover 320 is disposed inside the armature 310. FIG. 11 is a side view showing the configuration of the mover. As shown in FIGS. 9 and 11, the mover 320 has a cylindrical shape with the center axis 150 as the center. As shown in FIG. 11, the mover 320 is configured by stacking a first layer 320a, a second layer 320b, a third layer 320c, and a fourth layer 320d in the Z direction. Note that the first layer 320a, the second layer 320b, the third layer 320c, and the fourth layer 320d may be repeatedly and continuously stacked in the order in the Z direction. The mover 320 according to the present embodiment includes two sets of a first layer 320a, a second layer 320b, a third layer 320c, and a fourth layer 320d.

  FIG. 12A is a sectional view of the mover taken along line GG shown in FIG. 11. Similarly, each of FIGS. 12B to 12D is a cross-sectional view of the mover along the line HH, the line II, and the line JJ. The mover 320 has a columnar output shaft 360 at a center position in plan view. This output shaft 360 is a non-magnetic material such as stainless steel.

  FIG. 12A shows the configuration of the first layer 320a. The first layer 320a is provided with eight permanent magnets 321. The permanent magnet 321 is a plate-like member having a substantially fan shape in plan view. The permanent magnet 321 is held by a non-magnetic holding member 325 extending radially in the r direction. The permanent magnet 321 is magnetized in the Z direction, and in all of the permanent magnets 321 of the first layer 320a, the upper surface is an N pole and the lower surface is an S pole.

  FIG. 12C shows the configuration of the third layer 320c. The third layer 320c has the same configuration as the first layer 320a. In addition, the position of each permanent magnet 321 in the first layer 320a in the θ direction matches the position of each permanent magnet 321 in the third layer 320c in the θ direction. That is, the permanent magnet 321 in the third layer 320c is provided in the Z direction of the permanent magnet 321 in the first layer 320a. The permanent magnet 321 of the third layer 320c is magnetized in the Z direction, and the magnetization direction is opposite to that of the permanent magnet 321 of the first layer 320a. That is, in all of the permanent magnets 321 of the third layer 320c, the upper surface is an S pole and the lower surface is an N pole. Thus, the permanent magnet 321 of the first layer 320a and the permanent magnet 321 of the third layer 320c face the same magnetic pole.

  FIG. 12B shows the configuration of the second layer 320b. Eight yoke members 322 are arranged on the second layer 320b. The yoke member 322 has, in plan view, a shape surrounded by two radii of a ring centered on the central axis 150 and two arcs (an outer arc and an inner arc) between the two radii. Is a plate-shaped member. The yoke member 322 is made of a soft magnetic material such as soft iron and soft ferrite.

  On the second layer 320b, an auxiliary permanent magnet 323 is provided inside the yoke member 322 in the r direction. The auxiliary permanent magnet 323 is a plate-like member having a substantially fan shape in a plan view, and the radius of the circular arc matches the radius of the circular arc inside the yoke member 322. That is, the pair of auxiliary permanent magnets 323 and the yoke member 322 form a substantially sector shape in plan view. Further, the central angle of the sector of the auxiliary permanent magnet 323 is the same as the central angle of the sector of the pair of permanent magnets 321. That is, the sector shape of the auxiliary permanent magnet 124, the sector shape formed by the pair of auxiliary permanent magnets 323 and the yoke member 322, and the sector shape of the permanent magnet 321 are the same.

  Further, the auxiliary permanent magnet 323 is magnetized in the r direction, and in all of the auxiliary permanent magnets 323 of the second layer 320b, the arc surface outside the r direction is an S pole. The holding member 325 is provided from the first layer 320a to the fourth layer 320d, and the yoke member 322 and the auxiliary permanent magnet 323 are held by the holding member 325.

  FIG. 12D shows the configuration of the fourth layer 320d. The fourth layer 320d has the same configuration as the second layer 320b. Further, the position of each yoke member 322 in the second layer 320b in the θ direction matches the position of each yoke member 322 in the fourth layer 320d in the θ direction, and the position of each auxiliary permanent magnet 323 in the second layer 320b is determined. The position in the θ direction coincides with the position in the θ direction of each auxiliary permanent magnet 323 in the fourth layer 320d. In all of the auxiliary permanent magnets 323 of the second layer 320b, the arc surface on the outer side in the r direction is an N pole.

  A yoke member 322 and an auxiliary permanent magnet 323 are arranged between the permanent magnets 321 of the first layer 320a and the third layer 320c. In other words, the position of the permanent magnet 321 in the θ direction matches the position of the pair of yoke members 322 and the auxiliary permanent magnet 323 in the θ direction. Therefore, the entire upper surface of one yoke member 322 is in contact with the lower surface of one permanent magnet 321 of the first layer 320a, and the entire lower surface of the yoke member 322 is one permanent magnet of the third layer 320c. It is in contact with the lower surface of the magnet 321.

  The yoke member 322 is magnetized by permanent magnets 321 provided above and below it. The magnetic flux generated from the permanent magnet 321 of the first layer 320a passes through the yoke member 322 from the lower surface (S pole) of the permanent magnet 321 as shown by the broken arrow in FIGS. 11, 12A to 12D. From the side surface of the armature 322, a space (gap with the armature 310) exits. The magnetic flux advances in the gap in the direction opposite to the magnetization direction of the permanent magnet 321 and returns to the N pole of the same permanent magnet 321. Further, the magnetic flux generated from the permanent magnet 321 of the third layer 320c moves from the side surface of the yoke member 322 through the yoke member 322 from the upper surface (S pole) of the permanent magnet 321 as shown by the broken arrow in the drawing. It goes out to the space outside the child 320 (gap with the armature 310). The magnetic flux advances in the gap in the direction opposite to the magnetization direction of the permanent magnet 321, enters the yoke member 322 of the fourth layer 320 d from the side, and returns to the N pole of the same permanent magnet 321. For this reason, the side surface of the yoke member 322 is configured as a mover magnetic pole 322a. The mover magnetic pole 322a has the same polarity as the magnetic pole of the permanent magnet 321 facing the yoke member 322 including the mover magnetic pole 322a. That is, the mover magnetic pole 322a of the second layer 320b becomes an S pole, and the mover magnetic pole 322a of the fourth layer 320d becomes an N pole.

  As described above, in the yoke member 322 of the second layer 320b, the permanent magnet 321 and the auxiliary permanent magnet 323 are in contact with a surface different from the side surface serving as the mover magnetic pole 322a. The remaining surface of the yoke member 322 is in contact with the non-magnetic holding member 325. In addition, the surfaces of the permanent magnet 321 and the auxiliary permanent magnet 323 that are in contact with the yoke member 322 are all the same magnetic pole (S-pole) as the mover magnetic pole 322a of the yoke member 322. This prevents the magnetic flux from leaking from the yoke member 322 and allows the magnetic flux to enter and exit only from the mover magnetic pole 322a.

  The auxiliary permanent magnet 323 is arranged so that the same magnetic pole as the mover magnetic pole 322a faces the mover magnetic pole 322a. That is, in the second layer 320b, the S pole of the auxiliary permanent magnet 323 faces the yoke member 322 including the mover magnetic pole 322a of the S pole. On the other hand, in the fourth layer 320d, the N pole of the auxiliary permanent magnet 323 faces the yoke member 322 including the N pole mover magnetic pole 322a. Thereby, the magnetic field generated by the auxiliary permanent magnet 323 is added to the magnetic field generated by the permanent magnet 321, and the magnetic field generated in the mover magnetic pole 322 a is increased.

  In the linear motor 300 configured as described above, when a current flows through the armature coil 311, a magnetic field is generated around the armature coil 311. FIG. 13 is a side sectional view showing a magnetic path generated from the armature coil 311. Current flows in two adjacent armature coils 311 in opposite directions. Thereby, an annular magnetic path is formed around the cross section of each armature coil 311. At this time, the inner peripheral surface of the yoke portion 313 becomes the armature magnetic pole 313a.

  When a current flows through the armature coil 311, the armature magnetic pole 313 a and the mover magnetic pole 322 a are attracted or repelled by the magnetic force. By controlling the current flowing through the armature coil 311, the magnetic field generated by the armature coil 311 changes, whereby the mover 320 moves in the Z direction.

  The magnetic flux generated from armature coil 311 as described above passes through mover 320. That is, the magnetic flux emitted from the S-pole armature magnetic pole 313a enters the N-pole mover magnetic pole 322a, passes through the permanent magnet 321 and exits from the S-pole armature magnetic pole 322a to enter the N-pole armature magnetic pole 313a. . At this time, no magnetic flux passes through the auxiliary permanent magnet 323. Thereby, the permanent magnet through which the magnetic flux passes is only the permanent magnet 321, and the length of the magnetic path passing through the permanent magnet can be reduced, and a decrease in the magnetic flux density is suppressed. Further, the magnetic flux generated in the mover magnetic pole 322a is increased by the auxiliary permanent magnet 323. Therefore, the magnetic efficiency of the linear motor 300 is improved.

(Embodiment 4)
The linear motor according to the present embodiment is a transverse magnetic flux type linear motor.

  FIG. 14 is a plan sectional view showing the configuration of the linear motor 400 according to the present embodiment. As shown in FIG. 14, the linear motion motor 400 includes an armature 410 and a mover 420.

  In the armature 410, the tip of the teeth portion 412 (the end facing the mover 420) projects in an arc shape in plan view. That is, the armature magnetic pole 412a is formed in a convex shape. On the other hand, in the mover 420, the outer surface of the yoke member 422 (the surface facing the armature 410) is concave in an arc shape in plan view. That is, the mover magnetic pole 422a is formed in a concave shape. The convex shape at the tip of the teeth portion 412 and the concave shape on the lid side surface of the yoke member 422 correspond to each other, and the armature magnetic pole 412a and the mover magnetic pole 422a interfere with each other at a certain distance over the whole. do not do.

  The concave shape on the outer surface of the mover 420 extends over the entire length in the Z direction. That is, in the mover 420, not only the yoke member 422, but also the outer side surfaces of the auxiliary permanent magnets in the first and third layers are depressed in an arc like the yoke member 422. Accordingly, the mover 420 can move in the Z direction without interfering with the armature 410.

  The other configuration of the linear motor 400 according to the present embodiment is the same as the configuration of the linear motor 100 according to the first embodiment. Therefore, the same components are denoted by the same reference numerals, and description thereof will be omitted. Omitted.

  With the above configuration, the magnetic flux generated by the armature 410 can be transmitted and received without fail between the armature magnetic pole 412a at the tip of the teeth portion 412 and the mover magnetic pole 422a. FIG. 15 is a partially enlarged plan sectional view showing another example of the shape of the teeth portion. As shown in FIG. 15, in the linear motion motor of this example, the width of the teeth portion 512 increases at the distal end, and thin extension portions 513 are provided on both sides of the distal end portion of the teeth portion 512. The generation of the leakage magnetic flux is suppressed by the extension portion 513. However, if the volume of the extension 513 is small, magnetic saturation may occur. Further, since the extended portions 513 of the adjacent tooth portions 512 are close to each other, a magnetic flux leakage may occur. On the other hand, in the linear motor 400 according to the present embodiment, the teeth portion 412 does not have a projecting portion having a small volume, so that the occurrence of magnetic saturation can be suppressed. Further, since the concave portion provided on the mover 420 covers the tip of the teeth portion 412, the generation of the leakage magnetic flux can be suppressed. Further, the absence of the protruding portions adjacent to each other in the adjacent teeth portions 512 also contributes to the suppression of the generation of the leakage magnetic flux.

(Other embodiments)
In the above-described first to fourth embodiments, the mover is formed of the first to fourth layers. However, the present invention is not limited to this. The configuration of the first to fourth layers may be repeatedly and continuously arranged in a line.

  Also, in the above-described fourth embodiment, in the lateral magnetic flux type linear motor, the tip of the tooth portion 412 is formed in a convex shape, and the side surface of the mover 420 has a concave shape corresponding to the convex shape of the tooth portion 412. Although the configuration in which the portion is provided has been described, the present invention is not limited to this. FIG. 16 is a plan cross-sectional view showing a modification of the shapes of the teeth portion and the mover. As shown in (a) and (b) of FIG. 16, the tip of the tooth portion may be configured to be concave, and a convex portion corresponding to the concave shape of the tooth portion may be provided on a side surface of the mover. In the example shown in FIG. 16A, the tip of the tooth portion is rectangularly recessed in a plan view, and a portion of the movable element facing the tooth portion protrudes in a rectangular shape in a plan view. In the example shown in FIG. 16 (b), the tip of the tooth portion is depressed in an arc shape in plan view, and the portion of the mover facing the tooth portion protrudes in an arc shape in plan view. By doing so, the gap is covered by the teeth portion, so that magnetic flux leakage can be prevented.

  INDUSTRIAL APPLICABILITY The linear motor of the present invention is useful as a linear motor in which a mover including a permanent magnet is linearly moved by a magnetic field generated by supplying a current to an armature coil.

100, 200, 300, 400 Linear motor 110, 310, 410 Armature 111, 311 Armature coil 112, 412 Teeth portion 112a, 313a, 412a Armature magnetic pole 113, 313 Yoke portion 114 Armature member 120, 220, 320 , 420 mover 120a, 220a, 320a first layer 120b, 220b, 320b second layer 120c, 220c, 320c third layer 120d, 220d, 320d fourth layer 121,221,321 permanent magnet 122,222,322,422 Yoke members 122a, 222a, 322a, 422a Mover magnetic poles 123, 124, 323 Auxiliary permanent magnets 125, 325 Holding member 150 Central axis 160, 260, 360 Output shaft 312 Recess

Claims (4)

An armature having an armature coil;
A mover having a permanent magnet constituting a mover magnetic pole through which magnetic flux generated by the armature coil passes and facing the armature;
With
The mover is further provided with an auxiliary permanent magnet arranged to direct a magnetic pole having the same polarity as the mover magnetic pole toward the mover magnetic pole, and increasing a magnetic field generated in the mover magnetic pole without passing the magnetic flux. ,
The plurality of permanent magnets are arranged at intervals in the circumferential direction of an axis extending in the moving direction of the mover, and are alternately reversed in polarity and magnetized in the circumferential direction,
The mover has a yoke member of a soft magnetic material between two adjacent permanent magnets,
The auxiliary permanent magnet is disposed adjacent to the yoke member and the moving direction side,
The armature coil is configured to form an annular magnetic path in a plane intersecting the moving direction,
Linear motor. An armature having an armature coil;
A mover having a permanent magnet constituting a mover magnetic pole through which magnetic flux generated by the armature coil passes and facing the armature;
With
The mover is further provided with an auxiliary permanent magnet arranged to direct a magnetic pole having the same polarity as the mover magnetic pole toward the mover magnetic pole, and increasing a magnetic field generated in the mover magnetic pole without passing the magnetic flux. ,
The plurality of permanent magnets are arranged apart in the moving direction of the mover, and are magnetized in the moving direction such that the same magnetic poles face each other in two adjacent permanent magnets,
The mover has a yoke member of a soft magnetic material between two adjacent permanent magnets,
The auxiliary permanent magnet is disposed adjacent to the yoke member in a direction intersecting the moving direction,
The armature coil is configured to form an annular magnetic path in a plane parallel to the movement direction,
Linear motor. The permanent magnet is arranged in a circular shape in a cross section orthogonal to the moving direction,
The yoke member is disposed in a hollow annular shape in a cross section orthogonal to the moving direction,
The auxiliary permanent magnet is disposed on a center side of a ring formed by the yoke member,
The linear motor according to claim 2 . The mover extends in the moving direction of the mover, and has a concave portion or a convex portion provided with the mover magnetic pole,
The armature has a teeth portion around which the armature coil is wound and which constitutes an armature magnetic pole facing the mover magnetic pole,
The teeth portion is formed in a convex or concave shape corresponding to the concave portion or the convex portion,
Linear motor according to any one of claims 1 to 3.

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