Multi-axis actuator coil and multi-axis actuator

Abstract

A multi-axis actuator coil (1) comprises: a printed board (2) that has flexibility and is wound around one shaft (4); and a plurality of coil groups (3) that are printed on the printed board (2). Different coil groups (3) are disposed so as to be aligned in a direction orthogonal to the shaft (4). Each of the coil groups (3) has a plurality of coil patterns (31) including long edge sections that extend linearly. The long edge sections of the coil patterns (31) of the same coil group (3) extend parallel to each other. The long edge sections of the coil patterns (31) of different coil groups (3) extend in directions that intersect each other.

Description

Coil for multi-axis actuator and multi-axis actuator

[0001] The present disclosure relates to a coil for a multi-axis actuator and a multi-axis actuator including the coil for a multi-axis actuator.

[0002] Conventionally, multi-axis actuators that move a mover in multiple directions have been used in semiconductor manufacturing equipment, small robots, and the like. The multi-axis actuator is equipped with a multi-axis actuator coil that generates a magnetic field for moving the mover in multiple directions. For example, Patent Document 1 discloses a multi-axis actuator coil that includes multiple Z-axis coils arranged in an axial direction and multiple θ-axis coils arranged in an axial direction around the Z-axis coils. The Z-axis coils have a cylindrical shape, and the θ-axis coils have an elliptical ring shape.

[0003] Magnet wire is used for the windings of the Z-axis coil and the θ-axis coil. The coil for a multi-axis actuator disclosed in Patent Document 1 is formed by binding the magnet wire that forms the θ-axis coil to a winding core to form an elliptical ring, and then winding the elliptical ring-shaped magnet wire around the Z-axis coil while bending it along the cylindrical surface of the Z-axis coil.

[0004] JP 2011-142725 A

[0005] However, with the technology disclosed in Patent Document 1, even if an attempt is made to wind a magnet wire formed into an elliptical ring shape around the Z-axis coil while bending it along the cylindrical surface of the Z-axis coil, the magnet wire may not deform along the cylindrical surface of the Z-axis coil. In other words, it is difficult to precisely form the magnet wire into a cylinder, resulting in problems such as unwinding and tangled windings. The above-mentioned problems become more pronounced, particularly in smaller coils, such as those for multi-axis actuators mounted on small robots. The unwinding and tangled windings cause the coil to become larger, resulting in an increase in the coil space. Therefore, it has been difficult to form a coil for a multi-axis actuator using magnet wire in a space-efficient manner.

[0006] The present disclosure has been made in view of the above, and has an object to provide a coil for a multi-axis actuator that can be formed with greater space efficiency than conventional coils.

[0007] In order to solve the above-mentioned problems and achieve the object, the present disclosure provides a coil for a multi-axis actuator, comprising a flexible printed circuit board wound around one axis, and a plurality of coil groups printed on the printed circuit board. The different coil groups are arranged side by side in a direction perpendicular to the axis. Each coil group has a plurality of coil patterns including long sides extending linearly. The long sides of the coil patterns in the same coil group extend parallel to each other. The long sides of the coil patterns in different coil groups extend in directions that intersect with each other.

[0008] The coil for a multi-axis actuator according to the present disclosure has the effect of being able to be molded with greater space efficiency than conventional coils.

[0009] 1A perspective view of a multi-axis actuator according to a first embodiment. A cross-sectional view taken along line II-II of FIG. 1. A cross-sectional view taken along line III-III of FIG. 1. A view of a coil for a multi-axis actuator according to a first embodiment, viewed along the axial direction. A view of a state of the coil for a multi-axis actuator according to a first embodiment, before being wound around a first printed circuit board, viewed along the axial direction. A side view of a coil for a multi-axis actuator according to a first embodiment, before being wound around a first printed circuit board. A view of a state of the coil for a multi-axis actuator according to a first embodiment, before being wound around a second printed circuit board, viewed along the axial direction. A side view of a coil for a multi-axis actuator according to a first embodiment, before being wound around a second printed circuit board. A side view of a coil for a multi-axis actuator according to a first embodiment. 1 is a side view showing a coil pattern of a multi-axis actuator coil according to a first modification of embodiment 1; FIG. 2 is a side view showing a coil pattern of a multi-axis actuator coil according to a second modification of embodiment 1; FIG. 3 is a side view showing a state before winding a first printed circuit board of a multi-axis actuator coil according to the second embodiment, the view showing the surface of the first printed circuit board; FIG. 4 is a side view showing a state before winding a first printed circuit board of a multi-axis actuator coil according to the second embodiment, the view showing the back surface of the first printed circuit board;FIG. 1 is a diagram showing the back surface of the second printed circuit board. FIG. 2 is a diagram of the coil for a multi-axis actuator according to the second embodiment, as viewed in the axial direction. FIG. 3 is a diagram of the coil for a multi-axis actuator according to the third embodiment, as viewed in the axial direction, before winding the printed circuit board. FIG. 4 is a side view of the coil for a multi-axis actuator according to the third embodiment, as viewed in the axial direction. FIG. 5 is a diagram of the coil for a multi-axis actuator according to the third embodiment, as viewed in the axial direction. a side view showing a state of a multi-axis actuator coil according to a fifth embodiment before being wound around a first printed circuit board; a view of a multi-axis actuator coil according to a fifth embodiment before being wound around a second printed circuit board, as viewed in the axial direction; a side view showing a state of a multi-axis actuator coil according to a fifth embodiment before being wound around a second printed circuit board; a view of a multi-axis actuator coil according to a fifth embodiment when viewed in the axial direction; a side view showing a multi-axis actuator coil according to a fifth embodiment before being wound around a first printed circuit board; a side view showing a multi-axis actuator coil according to a sixth embodiment before being wound around a first printed circuit board, the side view showing the surface of the first printed circuit board; a side view showing a multi-axis actuator coil according to a sixth embodiment before being wound around a first printed circuit board, the side view showing the surface of the first printed circuit board; a side view showing a multi-axis actuator coil according to a sixth embodiment before being wound around a first printed circuit board, the side view showing the back surface of the first printed circuit board; a side view showing a multi-axis actuator coil according to a sixth embodiment before being wound around a second printed circuit board, the side view showing the surface of the second printed circuit board;A diagram showing the back surface of the second printed circuit board. A side view schematically showing the coil and teeth for the multi-axis actuator according to the seventh embodiment, as viewed from the inner periphery towards the outer periphery of the coil for the multi-axis actuator. A perspective view showing the multi-axis actuator according to the eighth embodiment. A cross-sectional view taken along the line XXXVII-XXXVII shown in FIG. 36. A cross-sectional view taken along the line XXXVIII-XXXVIII shown in FIG. 36.

[0010] Hereinafter, a coil for a multi-axis actuator and a multi-axis actuator according to an embodiment will be described in detail with reference to the drawings.

[0011] First Embodiment First, a multi-axis actuator 100 will be described with reference to Figures 1 to 3. Figure 1 is a perspective view showing the multi-axis actuator 100 according to the first embodiment. Figure 2 is a cross-sectional view taken along line II-II in Figure 1. Figure 3 is a cross-sectional view taken along line III-III in Figure 1. As shown in Figures 1 and 2, the multi-axis actuator 100 includes a housing 6, a stator core 7, a multi-axis actuator coil 1, a magnet 8, a mover core 9, and a shaft 10.

[0012] The stator core 7 and the mover core 9 are both formed in a cylindrical shape having a central axis C. When describing the directions of each component of the multi-axis actuator 100 below, the direction parallel to the central axis C is referred to as the axial direction, the direction perpendicular to the central axis C is referred to as the radial direction, and the direction of rotation about the central axis C is referred to as the circumferential direction. The multi-axis actuator 100 is an inner mover type multi-axis actuator in which the stator core 7 is disposed on the outer periphery of the mover core 9.

[0013] The housing 6 is a component that accommodates the stator core 7, magnets 8, multi-axis actuator coil 1, mover core 9, and shaft 10. The housing 6 is cylindrical with a rounded square outer surface and a circular inner surface. As shown in FIG. 3 , the housing 6 includes a cylindrical frame 6a with open axial ends and two brackets 6b disposed in the openings at both axial ends of the frame 6a. Each of the two brackets 6b has an insertion hole 6c through which the shaft 10 is inserted. A bearing 11 is disposed on the inner surface of the insertion hole 6c of each bracket 6b. The bearings 11 are components that support the shaft 10 for rotation and linear motion. The shaft 10 is supported for rotation and linear motion by the two bearings 11. The bracket 6b on the right side of FIG. 3 has a through-hole 6d formed therein, allowing the shaft 10 to protrude outside the housing 6.

[0014] As shown in Figure 2, the stator core 7 is disposed on the inner periphery of the frame 6a. The magnet 8 is provided on the outer periphery of the mover core 9. The magnet 8 faces the multi-axis actuator coil 1 in the radial direction. In this embodiment, the multi-axis actuator 100 is a moving magnet type multi-axis actuator. The mover core 9, magnet 8, and shaft 10 form a mover, and the multi-axis actuator coil 1, stator core 7, and frame 6a form a stator.

[0015] The multi-axis actuator coil 1 is disposed on the outer periphery of the magnet 8. The multi-axis actuator coil 1 is disposed with a gap between it and the magnet 8. The multi-axis actuator coil 1 is formed in a cylindrical shape. The multi-axis actuator coil 1 is disposed coaxially with the central axis C of the stator core 7 and the mover core 9. The multi-axis actuator coil 1 includes a first coil group 3A and a second coil group 3B disposed on the inner periphery of the first coil group 3A. The first coil group 3A generates a magnetic field for moving the mover in the axial direction, for example. A magnetic field is generated by passing a current through the first coil group 3A, and this magnetic field generates a thrust that moves the mover axially, thereby moving the mover axially. The second coil group 3B generates a magnetic field for rotating the mover in the circumferential direction, for example. A magnetic field is generated by passing a current through the second coil group 3B, and this magnetic field generates a torque that rotates the mover in the circumferential direction, thereby rotating the mover in the circumferential direction. Details of the multi-axis actuator coil 1 will be described later.

[0016] The stator core 7 is disposed on the outer periphery of the multi-axis actuator coil 1. In other words, the multi-axis actuator coil 1 is disposed on the inner periphery of the stator core 7. The multi-axis actuator coil 1 is attached to the inner periphery of the stator core 7 with an adhesive while being electrically insulated from the stator core 7. The printed circuit board 2 (described later) of the multi-axis actuator coil 1 contains a large amount of resin and therefore has poor heat dissipation properties. Therefore, it is preferable to use an adhesive with high heat dissipation properties. Magnetic paths are formed in multiple directions in the stator core 7. Therefore, it is preferable to use, for example, a powder magnetic core or a bulk material as the material for the stator core 7.

[0017] The shaft 10 is disposed on the inner periphery of the mover core 9. As shown in FIG. 3 , the shaft 10 extends along the central axis C. The shaft 10 is disposed coaxially with the central axis C. One axial end of the shaft 10 protrudes outside the housing 6 through the insertion hole 6c and the through-hole 6d of one bracket 6b on the right side of the paper in FIG. 3 . The other axial end of the shaft 10 protrudes outside the housing 6 through the insertion hole 6c of the other bracket 6b on the left side of the paper in FIG. 3 . The shaft 10 is movable in multiple directions. In this embodiment, the shaft 10 can move in the circumferential direction and the axial direction. The mover core 9 and the magnet 8 move in the circumferential direction and the axial direction together with the shaft 10.

[0018] A first position detector 12 and a second position detector 13 are disposed inside one of the brackets 6b on the right side of the page in FIG. 3 . The first position detector 12 is a device for detecting the circumferential angle of the shaft 10. The first position detector 12 has a first scale 12a having a plurality of magnetic poles or rulings and a first sensor 12b that detects the rotation angle of the shaft 10 from the first scale 12a. The first scale 12a is attached to the shaft 10. The first sensor 12b is attached to one of the brackets 6b. The second position detector 13 is a device for detecting the axial position of the shaft 10. The second position detector 13 has a second scale 13a having a plurality of magnetic poles or rulings and a second sensor 13b that detects the axial position of the shaft 10 from the second scale 13a. The second scale 13a is attached to the shaft 10. The second sensor 13b is attached to one of the brackets 6b.

[0019] Next, details of the multi-axis actuator coil 1 will be described with reference to FIGS. 4 to 9 . FIG. 4 is a view of the multi-axis actuator coil 1 according to the first embodiment as viewed in the axial direction. FIG. 5 is a view of the multi-axis actuator coil 1 according to the first embodiment as viewed in the axial direction before winding the first printed circuit board 2A. FIG. 6 is a side view of the multi-axis actuator coil 1 according to the first embodiment as viewed in the axial direction before winding the first printed circuit board 2A. FIG. 7 is a view of the multi-axis actuator coil 1 according to the first embodiment as viewed in the axial direction before winding the second printed circuit board 2B. FIG. 8 is a side view of the multi-axis actuator coil 1 according to the first embodiment as viewed in the axial direction before winding the second printed circuit board 2B. FIG. 9 is a side view of the multi-axis actuator coil 1 according to the first embodiment.

[0020] As shown in Fig. 4, the coil 1 for a multi-axis actuator includes a flexible printed circuit board 2 wound around one axis 4, and a plurality of coil groups 3 printed on the printed circuit board 2. In Fig. 4, the printed circuit board 2 is shown as a gray area or with diagonal hatching, and the coil groups 3 are shown with dot hatching or grid hatching. The axis 4 is an imaginary axis extending parallel to the central axis C shown in Fig. 2. Hereinafter, when describing the directions of each component of the coil 1 for a multi-axis actuator, the direction parallel to the axis 4 will be referred to as the axial direction, the direction perpendicular to the axis 4 as the orthogonal direction, and the direction in which the printed circuit board 2 is wound as the winding direction.

[0021] The printed circuit board 2 is a flexible board that can be freely deformed. In this embodiment, the printed circuit board 2 is divided in the winding direction. The printed circuit board 2 is divided into two pieces. In the following description, when distinguishing between the two printed circuit boards 2, one printed circuit board 2 will be referred to as the first printed circuit board 2A and the other printed circuit board 2 will be referred to as the second printed circuit board 2B. In FIG. 4, the first printed circuit board 2A is illustrated as a gray area. In FIG. 4, the second printed circuit board 2B is illustrated as diagonal hatching. When the first printed circuit board 2A and the second printed circuit board 2B are illustrated in FIG. 5 and subsequent figures, they will be distinguished from each other in the same manner as in FIG. 4. Each printed circuit board 2 has a front surface 21 and a back surface 22 facing away from the front surface 21. Each printed circuit board 2 has one end 23 and the other end 24 in the winding direction. The other end 24 in the winding direction of the first printed circuit board 2A and one end 23 in the winding direction of the second printed circuit board 2B are adjacent to each other in the winding direction.

[0022] In this embodiment, the number of coil groups 3 is two. In the following description, when distinguishing between the two coil groups 3, one coil group 3 will be referred to as the first coil group 3A and the other coil group 3 will be referred to as the second coil group 3B. In Fig. 4, the first coil group 3A is illustrated with dot hatching. In Fig. 4, the second coil group 3B is illustrated with grid hatching. When the first coil group 3A and the second coil group 3B are illustrated in Fig. 5 and subsequent figures, they will be distinguished from each other in the same way as in Fig. 4.

[0023] As shown in FIGS. 6 and 8 , each coil group 3 has multiple coil patterns 31. Each coil pattern 31 includes multiple linearly extending long sides 31 a and multiple short sides 31 b connecting two adjacent long sides 31 a. The coil patterns 31 are conductors formed by etching the copper foil layer of the printed circuit board 2. In the following description, when distinguishing between the coil patterns 31 of the first coil group 3A and the second coil group 3B, the coil pattern 31 of the first coil group 3A will be referred to as a first coil pattern 32, and the coil pattern 31 of the second coil group 3B will be referred to as a second coil pattern 33. FIGS. 5 to 8 illustrate a case where each coil group 3 is a three-phase coil. In FIGS. 5 to 8 , the coil patterns 31 of each phase are distinguished by changing the hatching density.

[0024] As shown in Fig. 6, the number of first coil patterns 32 in this embodiment is three. The three first coil patterns 32 are arranged side by side in the axial direction. Each first coil pattern 32 has roughly the same shape. Each first coil pattern 32 is printed on the first printed circuit board 2A in a concentrated winding manner, with loops of the same shape but different sizes wound around the same center. The shape of the first coil pattern 32 is a snake-like pattern, with the size of the rectangular loops decreasing from the outer periphery toward the inner periphery.

[0025] The first coil pattern 32 includes a plurality of first long side portions 32a extending in the winding direction and a plurality of first short side portions 32b extending in the axial direction. The first long side portions 32a and the first short side portions 32b are arranged alternately. The first long side portions 32a are portions that contribute to generating thrust that moves the mover in the axial direction. The first short side portions 32b are portions that do not contribute much to generating thrust that moves the mover in the axial direction. The first short side portions 32b serve to connect two adjacent first long side portions 32a. One end of each first coil pattern 32 is provided with a terminal 32c to which a power line from a power supply unit (not shown) is connected. Power is supplied to each first coil pattern 32 from the power supply unit (not shown) via the terminal 32c. The terminal 32c protrudes axially outward beyond one axial end face of the first printed circuit board 2A. The axial outward direction means the direction from the axial center toward the axial end face of the printed circuit board 2. A terminal 32d is provided on the other end of each first coil pattern 32, on the inner side of the loop opposite to the terminal 32c. The terminals 32d of each first coil pattern 32 are connected to each other by a pattern or jumper wire (not shown).

[0026] As shown in Figure 8, the number of second coil patterns 33 in this embodiment is six. The six second coil patterns 33 are arranged side by side in the winding direction. Each second coil pattern 33 has the same shape. Each second coil pattern 33 is printed on the second printed circuit board 2B in a concentrated winding in which loops of the same shape but different sizes are wound around the same center. The shape of the second coil pattern 33 is a zigzag pattern that decreases in size from the outer periphery toward the inner periphery.

[0027] The second coil pattern 33 includes a plurality of second long side portions 33a extending in the axial direction and a plurality of second short side portions 33b extending in the winding direction. The second long side portions 33a and the second short side portions 33b are arranged alternately. The second long side portions 33a are portions that contribute to generating torque to rotate the mover. The second short side portions 33b are portions that do not contribute much to generating torque to rotate the mover. The second short side portions 33b serve to connect two adjacent second long side portions 33a. One end of each second coil pattern 33 is provided with a terminal 33c to which a power line from a power supply unit (not shown) is connected. Power is supplied to each second coil pattern 33 from the power supply unit (not shown) via the terminal 33c. The terminal 33c protrudes axially outward beyond one axial end face of the second printed circuit board 2B. A terminal 33d is provided on the inside of the loop opposite to the terminal 33c at the other end of each second coil pattern 33. The terminals 33d of each second coil pattern 33 are connected to each other by a pattern or jumper wire (not shown).

[0028] As shown in Figures 6 and 8, the long sides 31a of the coil patterns 31 in the same coil group 3 extend parallel to each other. Specifically, the first long sides 32a of the first coil patterns 32 shown in Figure 6 extend parallel to each other. The second long sides 33a of the second coil patterns 33 shown in Figure 8 extend parallel to each other. The long sides 31a of the coil patterns 31 in different coil groups 3 extend in directions that intersect with each other. Specifically, the first long sides 32a of the first coil patterns 32 shown in Figure 6 and the second long sides 33a of the second coil patterns 33 shown in Figure 8 extend in directions that intersect with each other. In this embodiment, the first long sides 32a and the second long sides 33a extend in directions that are perpendicular to each other.

[0029] As shown in FIG. 4 , each printed circuit board 2 is wound clockwise so that the front surface 21 on which the coil group 3 is formed is located on the inner periphery and the back surface 22 is located on the outer periphery. Each printed circuit board 2 may also be wound so that the front surface 21 on which the coil group 3 is formed is located on the outer periphery and the back surface 22 is located on the inner periphery. Each printed circuit board 2 is wound along the cylindrical surface of a jig (not shown). The first printed circuit board 2A and the second printed circuit board 2B are wound continuously so that one end 23 of the second printed circuit board 2B in the winding direction is continuous with the other end 24 of the first printed circuit board 2A in the winding direction. This forms a cylindrical multi-axis actuator coil 1. As shown in FIG. 9 , the outer periphery of the multi-axis actuator coil 1 becomes the back surface 22 of the second printed circuit board 2B.

[0030] 4, the first printed circuit board 2A and the second printed circuit board 2B may or may not be connected by a fixing means such as adhesive or tape. In the latter case, after winding the first printed circuit board 2A located on the inner periphery, the second printed circuit board 2B may be wound so as to be continuous with the other end 24 of the first printed circuit board 2A in the winding direction. Since the second second printed circuit board 2B can be wound using the first printed circuit board 2A located on the inner periphery as a guide, the multi-axis actuator coil 1 can be easily formed.

[0031] The first coil group 3A is arranged on the inner periphery of a portion of the second coil group 3B. That is, the first coil group 3A and a portion of the second coil group 3B are arranged at the same position in the circumferential direction. In other words, the different coil groups 3 are arranged side by side in a direction perpendicular to the axis 4. The first printed circuit board 2A is sandwiched and arranged around the entire periphery between the first coil group 3A and the second coil group 3B, which are arranged side by side in a direction perpendicular to the axis 4. This makes it possible to prevent a short circuit between the first coil group 3A and the second coil group 3B.

[0032] Next, the effects of the multi-axis actuator coil 1 and the multi-axis actuator 100 according to this embodiment will be described.

[0033] In this embodiment, as shown in FIG. 4 , the multi-axis actuator coil 1 includes a flexible printed circuit board 2 wound around a single axis 4 and a plurality of coil groups 3 printed on the printed circuit board 2. This configuration allows the printed circuit board 2 to be easily deformed, thereby easily deforming the printed circuit board 2 along with the printed coil groups 3. That is, in this embodiment, the plurality of coil groups 3 can be easily and accurately arranged in an orthogonal direction compared to when a multi-axis actuator coil is formed using magnet wire. Therefore, in this embodiment, winding collapse and intertwining of the windings are less likely to occur, and the multi-axis actuator coil 1 can be prevented from becoming enlarged, thereby suppressing an increase in the coil space. Therefore, the multi-axis actuator coil 1 can be formed more space-efficiently than in the past. Furthermore, by suppressing an increase in the coil space, an increase in the size of the multi-axis actuator 100 and a decrease in the output density of the multi-axis actuator 100 can be suppressed.

[0034] 6 and 8, each coil group 3 has a plurality of coil patterns 31 including long sides 31a extending linearly. In addition, in this embodiment, the long sides 31a of the coil patterns 31 in the same coil group 3 extend parallel to each other. In this embodiment, the long sides 31a of the coil patterns 31 in different coil groups 3 extend in directions that intersect with each other. With these configurations, the shaft 10 shown in FIG. 3 can be moved in a plurality of directions.

[0035] 4, in this embodiment, a printed circuit board 2 is disposed between two coil groups 3 arranged side by side in the orthogonal direction. This configuration ensures electrical insulation between the two coil groups 3. The distance between the two coil groups 3 in the orthogonal direction is determined by the thickness of the insulating layer and the thickness of the adhesive layer of the printed circuit board 2, and can be reduced to 0.1 mm if electrical insulation between the two coil groups 3 can be ensured.

[0036] The technology disclosed in Patent Document 1 requires a creepage distance between the Z-axis coil and the θ-axis coil to prevent short-circuiting between the two coils. Therefore, after precisely adjusting the positions of the two coils, the coils must be fixed with molding resin or an insulating member such as an insulator must be sandwiched between the two coils. Therefore, the technology disclosed in Patent Document 1 increases the number of work steps required to mold the coil for the multi-axis actuator and the number of components required to make the coil for the multi-axis actuator. In this regard, in the present embodiment, as shown in FIG. 4 , simply by deforming the printed circuit board 2, including the printed coil groups 3, the printed circuit board 2 is positioned between two coil groups 3 arranged in an orthogonal direction, thereby preventing short-circuiting between the two coil groups 3. This eliminates the need for insulating members such as molding resin and insulators, thereby reducing the number of work steps required to mold the coil for the multi-axis actuator 1 and the number of components required to make the coil for the multi-axis actuator 1 compared to the technology disclosed in Patent Document 1.

[0037] Next, a modification of the first embodiment will be described.

[0038] In this embodiment, as shown in FIG. 4, the printed circuit board 2 is wound in a cylindrical shape, but the printed circuit board 2 may also be wound so that the cross-sectional shape perpendicular to the axis 4 of the printed circuit board 2 is a polygonal cylindrical shape.

[0039] In this embodiment, as shown in FIG. 4 , the number of printed circuit boards 2 is two, but it may be three or more. Even when the number of printed circuit boards 2 is three or more, adjacent printed circuit boards 2 in the winding direction may or may not be connected by a fixing means such as adhesive or tape. In the latter case, after winding the printed circuit board 2 located on the inner periphery, the next printed circuit board 2 may be wound so as to be continuous with the end of the wound printed circuit board 2 in the winding direction. Since the second and subsequent printed circuit boards 2 can be wound using the printed circuit board 2 located on the inner periphery as a guide, the multi-axis actuator coil 1 can be easily formed. When the number of printed circuit boards 2 is three or more, the extension directions of the long sides 31 a of the coil groups 3 of the multiple printed circuit boards 2 may be different from each other. Furthermore, when the number of printed circuit boards 2 is three or more, the extension directions of the long sides 31 a of some of the coil groups 3 of the multiple printed circuit boards 2 may be different from each other.

[0040] 4, the first printed circuit board 2A on which the first coil group 3A is printed is wound halfway around, and the second printed circuit board 2B on which the second coil group 3B is printed is wound one full turn, but the amount of winding on each printed circuit board 2 may be changed as appropriate. For example, each printed circuit board 2 may be wound more than one turn. In this way, it is possible to accommodate a multi-axis actuator 100 that requires a larger number of turns of the coil pattern 31.

[0041] The number of coil patterns 31 in each coil group 3 shown in Figures 6 and 8 is not limited to the illustrated example and may be changed as appropriate. Also, although Figures 6 and 8 illustrate a case where each coil group 3 is a three-phase coil, this is not limiting. Each coil group 3 may be a single-phase coil or a coil with four or more phases.

[0042] The shape of the coil pattern 31 is not limited to the illustrated example and may be modified as appropriate. The shape of the coil pattern 31 may be, for example, the shape shown in FIG. 10 . FIG. 10 is a side view showing the coil pattern 31 of the coil 1 for a multi-axis actuator according to a first modification of the first embodiment. The shape of the coil pattern 31 shown in FIG. 10 is a hexagonal loop whose size decreases from the outer periphery toward the inner periphery. The long side portions 31 a extend linearly. The short side portions 31 b have a pointed shape that convex toward the outer periphery of the loop. The short side portions 31 b extend linearly from one adjacent long side portion 31 a toward the other long side portion 31 a so as to be located on the outer periphery of the loop, and then extend linearly so as to be located on the inner periphery of the loop. This modification can also achieve the same effects as the first embodiment.

[0043] The shape of the coil pattern 31 may be, for example, the shape shown in FIG. 11 . FIG. 11 is a side view showing the coil pattern 31 of the coil 1 for a multi-axis actuator according to a second modification of the first embodiment. The shape of the coil pattern 31 shown in FIG. 11 is a shape in which the size of an elliptical loop decreases from the outer periphery toward the inner periphery. The long side portions 31 a extend linearly. The short side portions 31 b are curved and convex toward the outer periphery of the loop. The short side portions 31 b extend curvedly from one adjacent long side portion 31 a toward the other long side portion 31 a so as to be positioned on the outer periphery of the loop, and then extend curvedly again so as to be positioned on the inner periphery of the loop. This modification can also achieve the same effects as the first embodiment described above.

[0044] In the present embodiment, the movement directions of the mover including the shaft 10 shown in FIG. 3 are the circumferential direction and the axial direction, but this is not intended to limit the movement direction of the mover including the shaft 10. For example, the mover including the shaft 10 may be capable of spiral motion in which it moves axially while rotating counterclockwise, or may be capable of spiral motion in which it moves axially while rotating clockwise. In this configuration, the extension direction of the long side portions 31 a of each coil group 3 shown in FIGS. 6 and 8 may be changed to a direction intersecting the axial direction and the winding direction. Even in this change, the long side portions 31 a of each coil pattern 31 in the same coil group 3 extend parallel to each other. Furthermore, the long side portions 31 a of each coil pattern 31 in different coil groups 3 extend in directions intersecting each other.

[0045] 2 and 3, the multi-axis actuator 100 includes the magnet 8, but it is not necessary to include the magnet 8. For example, the multi-axis actuator 100 may have a configuration equivalent to a Synchronous Reluctance Motor (SynRM) that rotates only by the reluctance torque of an iron core.

[0046] 2 and 3, the multi-axis actuator 100 includes the stator core 7, but it may not include the stator core 7. For example, the multi-axis actuator 100 may have a configuration equivalent to a coreless structure that does not have an iron core near the coils.

[0047] 2 and 3, the multi-axis actuator 100 includes the frame 6a, but the frame 6a may not be included. For example, the multi-axis actuator 100 may have a frameless structure in which the stator core 7 also serves as the frame.

[0048] Second Embodiment Next, with reference to FIGS. 12 to 16 , a multi-axis actuator coil 1A according to the second embodiment will be described. FIG. 12 is a side view showing the state of the multi-axis actuator coil 1A according to the second embodiment before winding around the first printed circuit board 2A, illustrating the surface 21 of the first printed circuit board 2A. FIG. 13 is a side view showing the state of the multi-axis actuator coil 1A according to the second embodiment before winding around the first printed circuit board 2A, illustrating the back surface 22 of the first printed circuit board 2A. FIG. 14 is a side view showing the state of the multi-axis actuator coil 1A according to the second embodiment before winding around the second printed circuit board 2B, illustrating the surface 21 of the second printed circuit board 2B. FIG. 15 is a side view showing the state of the multi-axis actuator coil 1A according to the second embodiment before winding around the second printed circuit board 2B, illustrating the back surface 22 of the second printed circuit board 2B. FIG. 16 is a view of the multi-axis actuator coil 1A according to the second embodiment as viewed along the axial direction. This embodiment differs from the first embodiment in that the coil groups 3 are printed on both the front surface 21 and the back surface 22 of the printed circuit board 2. In the second embodiment, parts that overlap with those in the first embodiment are given the same reference numerals and descriptions thereof will be omitted.

[0049] In the following description, the first coil pattern 32 on the front surface 21 of the first printed circuit board 2A shown in Fig. 12 will be referred to as the first coil pattern 32A, and the first coil pattern 32 on the back surface 22 of the first printed circuit board 2A shown in Fig. 13 will be referred to as the first coil pattern 32B. Furthermore, the second coil pattern 33 on the front surface 21 of the second printed circuit board 2B shown in Fig. 14 will be referred to as the second coil pattern 33A, and the second coil pattern 33 on the back surface 22 of the second printed circuit board 2B shown in Fig. 15 will be referred to as the second coil pattern 33B.

[0050] As shown in FIG. 12 , a terminal 32c is provided at one end of the first coil pattern 32A. The first coil pattern 32A is wound from the outer periphery toward the inner periphery, starting from the end where the terminal 32c is provided. FIG. 13 illustrates the first printed circuit board 2A shown in FIG. 12 flipped upside down and upside down. Two ends A1, B1, and C1 of the first coil pattern 32A and the first coil pattern 32B, which are located at the same position, are electrically connected via a through hole 34. The first coil pattern 32B is wound from the inner periphery toward the outer periphery, starting from one end, which is the end A1, B1, or C1 connected to the through hole 34. The rear surface 22 of the first printed circuit board 2A is provided with a connection portion 35 that electrically connects the other ends of the first coil patterns 32B of each phase. The connection portion 35 extends in the axial direction.

[0051] As shown in FIG. 14 , a terminal 33c is provided at one end of the second coil pattern 33A. The second coil pattern 33A is wound from the outer periphery toward the inner periphery, starting from the end where the terminal 33c is provided. FIG. 15 illustrates the second printed circuit board 2B shown in FIG. 14 flipped upside down and upside down. Two ends D1, . . . I1 of the second coil pattern 33A and the second coil pattern 33B, which are located at the same position, are electrically connected via through-holes 34. The second coil pattern 33B is wound from the inner periphery toward the outer periphery, starting from one end, i.e., the ends D1, . . . I1, connected to the through-holes 34. The rear surface 22 of the second printed circuit board 2B is provided with connecting portions 36 that electrically connect the other ends of the second coil patterns 33B of each phase. The connecting portions 36 extend in the winding direction. The connecting portions 35, 36 may, for example, be neutral points or may be delta-connected.

[0052] The winding direction and winding method of each printed circuit board 2 shown in FIG. 16 are the same as those of the first embodiment. That is, the first printed circuit board 2A and the second printed circuit board 2B according to the second embodiment are also wound in the same manner as those of the first embodiment. In the first printed circuit board 2A, the first coil pattern 32A is arranged on the inner periphery of the first coil pattern 32B. In the second printed circuit board 2B, the second coil pattern 33A is arranged on the inner periphery of the second coil pattern 33B. An insulating layer 5 is arranged around the entire periphery between the first coil pattern 32B and the second coil pattern 33A, which are arranged in a direction perpendicular to the axis 4. The insulating layer 5 may be a coating applied to the surface of the printed circuit board 2 on which the coil group 3 is printed, or a sandwiched object sandwiched between the printed circuit boards 2 arranged in a direction perpendicular to the axis 4. The coating may be, for example, solder resist. The sandwiched object may be, for example, an insulating sheet.

[0053] Next, the effects of the multi-axis actuator coil 1A according to this embodiment will be described.

[0054] This embodiment can achieve the same effects as those of the above-described embodiment 1. Furthermore, in this embodiment, as shown in Fig. 16, the coil group 3 is printed on both the front surface 21 and the back surface 22 of the printed circuit board 2. With this configuration, the number of turns of the coil pattern 31 can be doubled compared to when the coil group 3 is printed on only one surface of the printed circuit board 2.

[0055] 16, in this embodiment, an insulating layer 5 is disposed over the entire periphery between the first coil pattern 32B and the second coil pattern 33A, which are arranged side by side in a direction perpendicular to the axis 4. This configuration can prevent a short circuit between the first coil pattern 32B and the second coil pattern 33A.

[0056] Third Embodiment Next, a multi-axis actuator coil 1B according to a third embodiment will be described with reference to Figs. 17 to 19. Fig. 17 is a view of the multi-axis actuator coil 1B according to the third embodiment, viewed in the axial direction, before being wound around the printed circuit board 2. Fig. 18 is a side view of the multi-axis actuator coil 1B according to the third embodiment, before being wound around the printed circuit board 2. Fig. 19 is a view of the multi-axis actuator coil 1B according to the third embodiment, viewed in the axial direction. This embodiment differs from the first embodiment in that each coil group 3 is printed on a single printed circuit board 2. Note that in the third embodiment, parts that overlap with those in the first embodiment are designated by the same reference numerals, and description thereof will be omitted.

[0057] As shown in Figures 17 and 18, the first coil group 3A and the second coil group 3B are arranged side by side in the winding direction on the same printed circuit board 2. The printed circuit board 2 has one end 23 and the other end 24 in the winding direction. The first coil group 3A and the second coil group 3B are arranged in this order from the one end 23 to the other end 24 in the winding direction. The winding direction and winding method of the printed circuit board 2 shown in Figure 19 are the same as those of the first embodiment. That is, the printed circuit board 2 according to the third embodiment is also wound in the same manner as the first embodiment.

[0058] Next, the effects of the multi-axis actuator coil 1B according to this embodiment will be described.

[0059] In this embodiment, as shown in FIG. 19 , each coil group 3 is printed on a single printed circuit board 2. This configuration allows multiple coil groups 3 to be arranged in an orthogonal direction more easily and accurately. Therefore, in this embodiment, collapse of windings and crossing of windings are even less likely to occur, further suppressing the enlargement of the multi-axis actuator coil 1B and further suppressing the enlargement of the coil space. Therefore, the multi-axis actuator coil 1B can be formed with even greater space efficiency. Furthermore, because collapse of windings and crossing of windings are even more suppressed when winding the printed circuit board 2 to form the multi-axis actuator coil 1B, the electromagnetic characteristics of the multi-axis actuator 100 can be improved.

[0060] Fourth Embodiment Next, a multi-axis actuator coil 1C according to the fourth embodiment will be described with reference to FIGS. 20 to 24 . FIG. 20 is a view of the multi-axis actuator coil 1C according to the fourth embodiment, viewed in the axial direction, before winding the second printed circuit board 2B. FIG. 21 is a side view of the multi-axis actuator coil 1C according to the fourth embodiment, viewed in the axial direction, before winding the second printed circuit board 2B. FIG. 22 is a view of the multi-axis actuator coil 1C according to the fourth embodiment, viewed in the axial direction, before winding the first printed circuit board 2A. FIG. 23 is a side view of the multi-axis actuator coil 1C according to the fourth embodiment, viewed in the axial direction, before winding the first printed circuit board 2A. FIG. 24 is a view of the multi-axis actuator coil 1C according to the fourth embodiment, viewed in the axial direction. This embodiment differs from the first embodiment in that the positions of the multiple coil groups 3 in the winding direction are reversed. Note that in the fourth embodiment, parts that overlap with the first embodiment are designated by the same reference numerals, and description thereof will be omitted.

[0061] In this embodiment, the coil group 3 arranged on the inner periphery of the wound printed circuit board 2 shown in FIG. 24 is the second coil group 3B shown in FIGS. 20 and 21. In the second coil group 3B, the arrangement direction of the coil patterns 31 coincides with the winding direction, and the long side portions 31a extend in a direction perpendicular to the winding direction. The arrangement direction of the coil patterns 31 coincides with the winding direction means that the winding direction coincides with the direction in which the multiple coil patterns 31 are arranged when the printed circuit board 2 is wound. As shown in FIG. 24, a portion of the second coil group 3B is arranged on the inner periphery of the first coil group 3A. The second coil group 3B is arranged on the innermost periphery of the wound printed circuit board 2. The configuration of the first coil group 3A shown in FIGS. 22 and 23 is the same as that of the first embodiment.

[0062] The winding direction and winding method of each printed circuit board 2 shown in Figure 24 are generally the same as those in the first embodiment. However, in this embodiment, the second printed circuit board 2B and the first printed circuit board 2A are wound continuously so that one end 23 in the winding direction of the first printed circuit board 2A is continuous with the other end 24 in the winding direction of the second printed circuit board 2B. This results in the formation of a cylindrical multi-axis actuator coil 1C. The outer peripheral surface of the multi-axis actuator coil 1C becomes the back surface 22 of the first printed circuit board 2A and the back surface 22 of the second printed circuit board 2B.

[0063] Next, the effects of the multi-axis actuator coil 1C according to this embodiment will be described.

[0064] 24 is wound around a cylinder multiple times, the circumferential length per revolution of the printed circuit board 2 becomes longer as it approaches the outer periphery of the printed circuit board 2. Therefore, if the arrangement direction of the coil patterns 31 matches the winding direction and the width W of each coil pattern 31 in the winding direction is equal, as in the second coil group 3B shown in FIG. 21 , the more times the printed circuit board 2 is wound around the cylinder, the more phase shift occurs in which the coil patterns 31 of the same phase are shifted in the winding direction. Furthermore, the occurrence of phase shift changes the electrical phase for each revolution, which can lead to a problem of the electromagnetic characteristics of the multi-axis actuator 100 being easily degraded.

[0065] 21 and 24, in the second coil group 3B arranged on the inner periphery of the wound printed circuit board 2, the arrangement direction of the coil patterns 31 coincides with the winding direction, and the long sides 31a extend in a direction perpendicular to the winding direction. In other words, the second coil group 3B, where deterioration in the electromagnetic characteristics of the multi-axis actuator 100 due to phase shift is likely to be noticeable, is arranged on the inner periphery of the printed circuit board 2, where the occurrence of phase shift is suppressed. With this configuration, deterioration in the electromagnetic characteristics of the multi-axis actuator 100 can be suppressed compared to when the second coil group 3B is arranged on the outer periphery of the wound printed circuit board 2.

[0066] The width W of the coil pattern 31 in the winding direction may be made wider as it is positioned closer to the outer periphery of the printed circuit board 2. In this way, even if the second coil group 3B is not disposed on the inner periphery of the wound printed circuit board 2, the occurrence of phase shift is suppressed, and deterioration of the electromagnetic characteristics of the multi-axis actuator 100 can be suppressed.

[0067] Fifth Embodiment Next, a multi-axis actuator coil 1D according to the fifth embodiment will be described with reference to FIGS. 25 to 30 . FIG. 25 is a view of the multi-axis actuator coil 1D according to the fifth embodiment, viewed in the axial direction, before winding the first printed circuit board 2A. FIG. 26 is a side view of the multi-axis actuator coil 1D according to the fifth embodiment, viewed in the axial direction, before winding the first printed circuit board 2A. FIG. 27 is a view of the multi-axis actuator coil 1D according to the fifth embodiment, viewed in the axial direction, before winding the second printed circuit board 2B. FIG. 28 is a side view of the multi-axis actuator coil 1D according to the fifth embodiment, viewed in the axial direction, before winding the second printed circuit board 2B. FIG. 29 is a view of the multi-axis actuator coil 1D according to the fifth embodiment, viewed in the axial direction. FIG. 30 is a side view of the multi-axis actuator coil 1D according to the fifth embodiment. This embodiment differs from the first embodiment in that the terminals 32c and 33c are arranged together in one location in the winding direction. In the fifth embodiment, parts that overlap with those in the first embodiment are given the same reference numerals and descriptions thereof will be omitted.

[0068] 25 and 26 , each terminal 32c that protrudes axially outward from one axial end face of the first printed circuit board 2A is disposed in a position closer to the other end 24 of the first printed circuit board 2A in the winding direction. When the first printed circuit board 2A and the second printed circuit board 2B are wound, the other end 24 of the first printed circuit board 2A is a portion that continues with one end 23 of the second printed circuit board 2B. In other words, each terminal 32c is disposed in a position closer to the portion where the first printed circuit board 2A and the second printed circuit board 2B are continued. The terminals 32c are disposed side by side in the winding direction.

[0069] 27 and 28, each terminal 33c that protrudes axially outward beyond one axial end face of the second printed circuit board 2B is disposed in a position closer to one end 23 of the second printed circuit board 2B in the winding direction. In other words, each terminal 33c is disposed in a position closer to the portion where the first printed circuit board 2A and the second printed circuit board 2B are continuous. Each terminal 33c is disposed side by side in the winding direction.

[0070] In the illustrated example, each terminal 33c serves as a source of current for each phase. In the illustrated example, terminals 33d1 and 33e1 are connected, terminals 33d2 and 33e2 are connected, and terminals 33d3 and 33e3 are connected. Furthermore, in the illustrated example, terminals 33d4, 33d5, and 33d6 are connected at the neutral point. Examples of methods for connecting terminals 33d1 and 33e1, terminals 33d2 and 33e2, and terminals 33d3 and 33e3 include connection using a pattern formed on the back surface 22 that extends to the back surface 22 via a through-hole, or connection using a jumper wire.

[0071] The winding direction and winding method of each printed circuit board 2 shown in Figure 29 are the same as those of the first embodiment. That is, the first printed circuit board 2A and the second printed circuit board 2B according to the fifth embodiment are also wound in the same manner as those of the first embodiment. When the first printed circuit board 2A and the second printed circuit board 2B are wound in this manner, as shown in Figure 30, the terminals 32c and 33c are arranged side by side in the winding direction in the portion where the first coil group 3A and the second coil group 3B are continuous in the winding direction. That is, the terminals 32c and 33c of each coil pattern 31 of each coil group 3 are arranged together in one location in the winding direction.

[0072] Next, the effects of the multi-axis actuator coil 1D according to this embodiment will be described.

[0073] 30, in this embodiment, the terminals 32c, 33c of each coil pattern 31 of each coil group 3 are arranged together in one location in the winding direction. With this configuration, the power supply lines connecting the multi-axis actuator 100 and the power supply unit can be grouped together, which simplifies the wiring and makes it easier to supply power to the multi-axis actuator 100.

[0074] Sixth Embodiment Next, a multi-axis actuator coil 1E according to the sixth embodiment will be described with reference to FIGS. 31 and 34. FIG. 31 is a side view showing the state of the multi-axis actuator coil 1E according to the sixth embodiment before winding around the first printed circuit board 2A, and is a diagram showing the front surface 21 of the first printed circuit board 2A. FIG. 32 is a side view showing the state of the multi-axis actuator coil 1E according to the sixth embodiment before winding around the first printed circuit board 2A, and is a diagram showing the back surface 22 of the first printed circuit board 2A. FIG. 33 is a side view showing the state of the multi-axis actuator coil 1E according to the sixth embodiment before winding around the second printed circuit board 2B, and is a diagram showing the front surface 21 of the second printed circuit board 2B. FIG. 34 is a side view showing the state of the multi-axis actuator coil 1E according to the sixth embodiment before winding around the second printed circuit board 2B, and is a diagram showing the back surface 22 of the second printed circuit board 2B. This embodiment differs from the first embodiment in that the coil pattern 31 is wound in a distributed manner. In the sixth embodiment, parts that overlap with those in the first embodiment are given the same reference numerals and descriptions thereof will be omitted.

[0075] Figure 32 illustrates the first printed circuit board 2A shown in Figure 31 flipped upside down and upside down. As shown in Figures 31 and 32, each first coil pattern 32 is printed on the first printed circuit board 2A in a distributed winding pattern in which identically shaped loops are wound with their centers offset at regular intervals in the axial direction. In this embodiment, there are three first coil patterns 32 on each of the front surface 21 and back surface 22 of the first printed circuit board 2A. The three first coil patterns 32 on the front surface 21 are arranged side by side in the axial direction. The three first coil patterns 32 on the back surface 22 are arranged side by side in the axial direction. Here, the number of coils in the first coil group 3A is defined as the number of axial areas in which first coil patterns 32 of the same phase exist, counted without distinction between the front surface 21 and the back surface 22 of the first printed circuit board 2A. Furthermore, the axial area in which the first coil patterns 32 of the same phase exist is divided based on the first long side 32a (described later), and areas other than the first long side 32a are not taken into consideration. Therefore, when viewed from the front surface 21 to the back surface 22 of the first printed circuit board 2A, if the axial area in which the first long side 32a of the first coil patterns 32 of the same phase exist on the front surface 21 and the axial area in which the first long side 32a of the first coil patterns 32 of the same phase exist on the back surface 22 are located at the same axial position, they are counted as one coil. On the other hand, when viewed from the front surface 21 to the back surface 22 of the first printed circuit board 2A, if the axial area in which the first long side 32a of the first coil patterns 32 of the same phase exist on the front surface 21 and the axial area in which the first long side 32a of the first coil patterns 32 of the same phase exist on the back surface 22 are located at different axial positions, they are counted as different coils. 31 and 32, there are three axial areas on the front surface 21 where the first long side portions 32a of the first coil patterns 32 of the same phase are present, and three axial areas on the back surface 22 where the first long side portions 32a of the first coil patterns 32 of the same phase are present, and the axial positions of the six axial areas are different from one another. Therefore, the number of coils in the first coil group 3A is counted as six.Two ends J1...J5, K1...K5, L1...L5 at the same position on the front surface 21 and back surface 22 of the first printed circuit board 2A are electrically connected via through holes 34. The first coil patterns 32 are alternately arranged on the front surface 21 and back surface 22 of the first printed circuit board 2A. The first coil pattern 32 on the front surface 21 of the first printed circuit board 2A extends halfway around the front surface 21, then crosses over to the back surface 22 of the first printed circuit board 2A via the through holes 34, and the first coil pattern 32 on the back surface 22 extends halfway around the back surface 22. The number of turns of each of the six first coil patterns 32 is the product of the number of turns of each first coil pattern 32 before winding the first printed circuit board 2A and the number of layers of the first printed circuit board 2A stacked in the orthogonal direction. The number of turns of each of the six first coil patterns 32 may be determined arbitrarily.

[0076] The first coil pattern 32 includes a plurality of first long side portions 32a and a plurality of first short side portions 32b extending in the winding direction. The first short side portions 32b serve to connect the two first long side portions 32a on the front and back sides. The first short side portions 32b shown in FIG. 31 extend while inclining toward one side in the axial direction as they move away from the first long side portions 32a. The first short side portions 32b shown in FIG. 32 extend while inclining toward the other side in the axial direction as they move away from the first long side portions 32a.

[0077] In this embodiment, the first coil pattern 32 is illustrated as a three-phase star-connected pattern in which each phase is composed of two coils. One end terminal 32c of the first coil pattern 32 on the front surface 21, which extends outside the first printed circuit board 2A, is the current inflow point. The other ends of the first coil pattern 32 on the back surface 22, which are located inside the first printed circuit board 2A, are connected at a connection 35, which is the neutral point. While this embodiment illustrates a case in which coils of the same phase are connected and there are two coils per phase, a pattern having more than one or two coils per phase may also be used. Furthermore, while this embodiment illustrates a star-connected pattern, a different connection pattern, such as a delta connection, may also be used.

[0078] Figure 34 illustrates the second printed circuit board 2B shown in Figure 33 flipped upside down and upside down. As shown in Figures 33 and 34, each second coil pattern 33 is printed on the second printed circuit board 2B in a distributed winding manner, in which loops of the same shape are wound with their centers shifted at regular intervals in the winding direction. In this embodiment, there are 18 second coil patterns 33. In this embodiment, there are nine second coil patterns 33 on each of the front surface 21 and the back surface 22 of the second printed circuit board 2B. The nine second coil patterns 33 on the front surface 21 are arranged side by side in the winding direction. The nine second coil patterns 33 on the back surface 22 are arranged side by side in the winding direction. Here, the number of coils in the second coil group 3B is defined as the number of areas in the winding direction where second coil patterns 33 of the same phase exist, counted without distinction between the front surface 21 and the back surface 22 of the second printed circuit board 2B. Furthermore, the division of the area in the winding direction where the second coil pattern 33 of the same phase exists is performed based on the second long side 33 a described below, and parts other than the second long side 33 a are not taken into consideration. Therefore, when viewed in a direction from the front surface 21 to the back surface 22 of the second printed circuit board 2B, if the winding direction area where the second long side 33 a of the second coil pattern 33 of the same phase exists on the front surface 21 and the winding direction area where the second long side 33 a of the second coil pattern 33 of the same phase exists on the back surface 22 are located at the same position in the winding direction, they are counted as one coil. On the other hand, when viewed in a direction from the front surface 21 to the back surface 22 of the second printed circuit board 2B, if the winding direction area where the second long side 33 a of the second coil pattern 33 of the same phase exists on the front surface 21 and the winding direction area where the second long side 33 a of the second coil pattern 33 of the same phase exists on the back surface 22 are located at different positions in the winding direction, they are counted as different coils. For example, in Figures 33 and 34, there are nine areas in the winding direction on the front surface 21 where the second long side portions 33a of the second coil patterns 33 of the same phase are present, and nine areas in the winding direction on the back surface 22 where the second long side portions 33a of the second coil patterns 33 of the same phase are present, and six of these areas have different winding direction positions and six areas have the same winding direction positions.Therefore, the number of coils is counted as 12. Two ends M1...M5, N1...N5, O1...O5 that are in the same position on the front surface 21 and the back surface 22 of the second printed circuit board 2B are electrically connected via the through holes 34. Two ends P1...P5, Q1...Q5, R1...R5 that are in the same position on the front surface 21 and the back surface 22 of the second printed circuit board 2B are electrically connected via the through holes 34. Two ends S1...S5, T1...T5, U1...U5 that are in the same position on the front surface 21 and the back surface 22 of the second printed circuit board 2B are electrically connected via the through holes 34.

[0079] The second coil patterns 33 are alternately arranged on the front surface 21 and the back surface 22 of the second printed circuit board 2B. The second coil pattern 33 on the front surface 21 of the second printed circuit board 2B extends halfway around the front surface 21, then crosses over to the back surface 22 of the second printed circuit board 2B via the through holes 34, and the second coil pattern 33 on the back surface 22 extends halfway around the back surface 22. The number of turns of each of the 18 second coil patterns 33 is the product of the number of turns of each second coil pattern 33 before winding around the second printed circuit board 2B and the number of layers of the second printed circuit board 2B stacked in the diametrical direction. The number of turns of each of the 18 second coil patterns 33 may be determined arbitrarily. The second coil pattern 33 includes a plurality of second long side portions 33a and a plurality of second short side portions 33b extending in the axial direction. The second short side portion 33b serves to connect the two second long side portions 33a on the front and back sides.

[0080] Next, the effects of the multi-axis actuator coil 1E according to this embodiment will be described.

[0081] This embodiment can achieve the same effects as the first embodiment described above. Furthermore, in this embodiment, the coil patterns 31 are wound using distributed winding, which increases the number of effective interlinking magnetic fluxes and improves the output density of the multi-axis actuator 100. While lap winding is illustrated as an example of the distributed winding of each coil pattern 31 in this embodiment, this is not limiting. The distributed winding of each coil pattern 31 may be, for example, wave winding. Furthermore, one coil pattern 31 of the multiple coil groups 3 may be printed on the printed circuit board 2 using concentrated winding, and the other coil pattern 31 of the multiple coil groups 3 may be printed on the printed circuit board 2 using distributed winding.

[0082] Seventh Embodiment Next, a multi-axis actuator coil 1F and a multi-axis actuator 100A according to the seventh embodiment will be described with reference to FIG. 35 . FIG. 35 is a side view schematically illustrating the multi-axis actuator coil 1F and teeth 7a according to the seventh embodiment, viewed from the inner periphery toward the outer periphery of the multi-axis actuator coil 1F. This embodiment differs from the first embodiment in that the multi-axis actuator coil 1F is mounted on a multi-axis actuator 100A having teeth 7a. Note that in the seventh embodiment, parts that overlap with those in the first embodiment are designated by the same reference numerals and will not be described again. The printed circuit board 2 is not shown in FIG. 35 .

[0083] The first long side 32a of the first coil pattern 32 and the second long side 33a of the second coil pattern 33 intersect with each other. The first long side 32a of the first coil pattern 32 and the second long side 33a of the second coil pattern 33 are arranged in a lattice pattern when viewed in the orthogonal direction. A plurality of lattice-shaped holes 25 are formed in the printed circuit board 2 (not shown). Each hole 25 is formed in a portion where the first long side 32a and the second long side 33a do not intersect. In this embodiment, each hole 25 is formed in a portion surrounded by two adjacent first long sides 32a and two adjacent second long sides 33a.

[0084] The stator core 7 has a plurality of teeth 7a arranged in each of the plurality of holes 25. The stator core 7 also has a core back (not shown) to which the teeth 7a are connected. The core back is divided into multiple sections in the winding direction. A plurality of teeth 7a are connected to each core back. The multi-axis actuator coil 1F is held by the stator core 7 via the multiple teeth 7a.

[0085] Next, the effects of the multi-axis actuator coil 1F and the multi-axis actuator 100A according to this embodiment will be described.

[0086] In this embodiment, the first long side 32a of the first coil pattern 32 and the second long side 33a of the second coil pattern 33 are arranged in a lattice pattern when viewed in the orthogonal direction. A plurality of lattice-shaped holes 25 are formed in the printed circuit board 2. The stator core 7 has a plurality of teeth 7a arranged in each of the plurality of holes 25. With this configuration, the multi-axis actuator coil 1F is held in the stator core 7 via the plurality of teeth 7a. This increases the stator-side inductance compared to a state in which the teeth 7a are not present, thereby improving the output density of the multi-axis actuator 100A and enabling the multi-axis actuator 100A to be further increased in output and made more compact.

[0087] Eighth Embodiment Next, a multi-axis actuator 100B according to the eighth embodiment will be described with reference to FIGS. 36 to 38 . FIG. 36 is a perspective view showing the multi-axis actuator 100B according to the eighth embodiment. FIG. 37 is a cross-sectional view taken along line XXXVII-XXXVII shown in FIG. 36 . FIG. 38 is a cross-sectional view taken along line XXXVIII-XXXVIII shown in FIG. 36 . This embodiment differs from the first embodiment in that it is a moving coil type multi-axis actuator 100B in which the mover is made up of a multi-axis actuator coil 1G, a mover core 9, and a shaft 10, and the stator is made up of a magnet 8, a stator core 7, and a frame 6a. In the eighth embodiment, parts that overlap with those in the first embodiment are designated by the same reference numerals, and description thereof will be omitted.

[0088] As shown in FIGS. 36 to 38, the configurations of the housing 6, shaft 10, bearing 11, first position detector 12 and second position detector 13 are the same as those in the first embodiment.

[0089] 37, the stator core 7 is disposed on the inner periphery of the frame 6a and is fitted into the inner periphery of the frame 6a.

[0090] The multi-axis actuator coil 1G is arranged on the outer periphery of the mover core 9. The multi-axis actuator coil 1G is arranged so that the first coil group 3A is located on the inner periphery with respect to the second coil group 3B.

[0091] The magnet 8 is provided on the outer periphery of the multi-axis actuator coil 1G. The magnet 8 is disposed with a gap between it and the multi-axis actuator coil 1G. The magnet 8 faces the multi-axis actuator coil 1G in the radial direction.

[0092] The mover core 9 is disposed on the inner periphery of the multi-axis actuator coil 1G. In other words, the multi-axis actuator coil 1G is attached to the outer periphery of the mover core 9. The shaft 10 is disposed on the inner periphery of the mover core 9. The mover core 9 and the multi-axis actuator coil 1G move together with the shaft 10 in the circumferential and axial directions.

[0093] Next, the effects of the multi-axis actuator 100B according to this embodiment will be described.

[0094] In this embodiment, the mover can be moved in multiple directions while achieving the same effects as in the first embodiment. Furthermore, if the multi-axis actuator coil 1G has a small number of turns, the mover can be made lighter, improving the responsiveness of the multi-axis actuator 100B. Furthermore, when the multi-axis actuator coil 1G is directly formed into a cylindrical shape, it is possible to form the multi-axis actuator coil 1G while winding the printed circuit board 2 directly around the mover core 9, eliminating the need to prepare a separate cylindrical forming jig.

[0095] The configurations shown in the above embodiments are merely examples, and may be combined with other known technologies, or different embodiments may be combined with each other. It is also possible to omit or modify parts of the configurations as long as they do not deviate from the gist of the invention.

[0096] 1, 1A, 1B, 1C, 1D, 1E, 1F, 1G Coil for multi-axis actuator, 2 Printed circuit board, 2A First printed circuit board, 2B Second printed circuit board, 3 Coil group, 3A First coil group, 3B Second coil group, 4 Axis, 5 Insulating layer, 6 Housing, 6a Frame, 6b Bracket, 6c Insertion hole, 6d Through hole, 7 Stator core, 7a Teeth, 8 Magnet, 9 Mover core, 10 Shaft, 11 Bearing, 12 First position detector, 12a First scale, 12b First sensor, 13 Second position detector, 13a Second scale, 13b Second sensor, 21 Front surface, 22 Back surface, 23 One end, 24 Other end, 25 Hole, 31 Coil pattern, 31a Long side portion, 31b Short side portion, 32, 32A, 32B First coil pattern, 32a; first long side portion, 32b; first short side portion, 32c, 32d, 33c, 33d, 33d1, 33d2, 33d3, 33d4, 33d5, 33d6, 33e1, 33e2, 33e3; terminals, 33, 33A, 33B; second coil pattern, 33a; second long side portion, 33b; second short side portion, 34; through holes, 35, 36; connection portions, 100, 100A, 100B; multi-axis actuator.

Claims

1. A coil for a multi-axis actuator comprising: a flexible printed circuit board wound around one axis; and a plurality of coil groups printed on the printed circuit board, wherein the different coil groups are arranged side by side in a direction perpendicular to the axis, and each of the coil groups has a plurality of coil patterns including long sides extending in a straight line, the long sides of each of the coil patterns in the same coil group extend parallel to each other, and the long sides of each of the coil patterns in the different coil groups extend in directions that intersect with each other.

2. A coil for a multi-axis actuator according to claim 1, wherein each of said coil groups is printed on one of said printed circuit boards.

3. A coil for a multi-axis actuator as described in claim 1 or 2, characterized in that the coil group arranged on the inner side of the wound printed circuit board has an arrangement direction of the coil pattern that coincides with the winding direction of the printed circuit board, and the long side portion extends in a direction perpendicular to the winding direction.

4. A coil for a multi-axis actuator as described in any one of claims 1 to 3, characterized in that the terminals of each of the coil patterns of each of the coil groups are arranged together in one location in the winding direction of the printed circuit board.

5. A multi-axis actuator comprising: a coil for a multi-axis actuator according to any one of claims 1 to 4; and a shaft arranged on the inner circumference of the coil for a multi-axis actuator.

6. The multi-axis actuator according to claim 5, further comprising a magnet arranged on the outer or inner periphery of said multi-axis actuator coil so as to face said multi-axis actuator coil.

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