Electric actuator

Abstract

To provide an electric actuator which can suppress variation of pulsation due to an error in manufacture.SOLUTION: An electric actuator 1 of the present invention comprises: an armature 10 in which teeth 101 having outer shapes of 2n (n=2 or greater) polygons and coils 103 are alternately laminated in an axial direction Z; a housing 14 which holds the armature 10 to be relatively movable in the axial direction Z; a fixing plate 13 which is fixed to the housing 14; and a plurality of permanent magnets 12 which is fixed to the fixing plate 13 and arranged opposite to at least one side on the outer shapes of the teeth 101. The fixing plate 13 is fixed so that a fixing position to the housing 14 can be adjusted along the axial direction Z.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present invention relates to an electric actuator. [Background technology]

[0002] Patent Document 1 describes the configuration of an electromagnetic suspension that uses a linear motor having an armature composed of a winding and a magnetic body, and a permanent magnet section that is arranged on the outer periphery of the armature and composed of a permanent magnet and a cylindrical magnetic body, in which the armature and the permanent magnet section are linearly driven relative to one another.

[0003] Patent Document 2 describes the configuration of a linear motor that includes an armature composed of a winding and a core, and a field magnet that is arranged on the outer periphery of the armature and has alternating north and south poles, the core having a yoke, teeth, and slits, and the armature moves axially within the field magnet. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] International Publication No. 2021 / 261059 [Patent Document 2] JP 2020-78235 A Summary of the Invention [Problem to be solved by the invention]

[0005] The armatures described in Patent Document 1 and Patent Document 2 have a configuration in which coils and teeth are stacked in the axial direction, so there is a problem in that axial errors (such as dimensional tolerances, adhesives, and the thickness of insulating layers) result in large variations in pulsation after manufacture, making it difficult to suppress vibrations caused by pulsation.

[0006] The present invention has been made in consideration of the above-mentioned points, and an object of the present invention is to provide an electric actuator that is capable of suppressing variations in pulsation due to manufacturing errors. [Means for solving the problem]

[0007] In order to solve the above problems, for example, the configurations described in the claims are adopted. The present disclosure includes a number of means for solving the above problems. To give an example of such a means, "An armature in which teeth and coils having a 2n (n=2 or more) polygonal outer shape are alternately stacked in the axial direction, a housing that holds the armature so as to be relatively movable in the axial direction; a fixing plate fixed to the housing; A plurality of permanent magnets are fixed to the fixing plate and arranged to face at least one side of the outer shape of the teeth; An electric actuator having The fixed plate is fixed to the housing so that a fixed position of the fixed plate can be adjusted in the axial direction. Effect of the Invention

[0008] According to the present invention, it is possible to provide an electric actuator capable of suppressing variations in pulsation caused by manufacturing errors. Further features related to the present invention will become apparent from the description of the present specification and the accompanying drawings. In addition, problems, configurations, and effects other than those described above will become apparent from the following description of the embodiments. [Brief description of the drawings]

[0009] [Figure 1A] FIG. 1 is a perspective view showing a schematic configuration of an electric actuator according to a first embodiment. [Figure 1B] FIG. 1 is a front view showing a schematic configuration of an electric actuator according to a first embodiment. [Figure 1C] FIG. 1 is a side view showing a schematic configuration of an electric actuator according to a first embodiment. [Diagram 2] A cross-sectional view taken along line AA in FIG. 1B. [Diagram 3]FIG. 2 is an exploded view of the electric actuator according to the first embodiment. [Figure 4] FIG. 1 is a perspective view showing a schematic configuration of an armature included in an electric actuator according to a first embodiment. [Diagram 5] 3 is a developed view showing four inner walls that form a central hole of a housing provided in the electric actuator according to the first embodiment. FIG. [Figure 6A] 6 is a diagram for explaining the forces acting on the center lines of each side of the electric actuator due to the arrangement of permanent magnets shown in FIG. 5. [Figure 6B] 6 is a diagram for explaining forces acting on diagonals on each side of the electric actuator due to the arrangement of permanent magnets shown in FIG. 5. [Figure 7A] FIG. 13 is a schematic diagram of an example of the secondary side configuration of an electric actuator according to the first embodiment, showing multiple rows of parallel permanent magnets divided into five in the width direction relative to the direction of travel of the mover, with the rows gradually shifted from one side of the width direction to the other side in the axial direction. [Figure 7B] FIG. 13 is a schematic diagram of an example of the secondary side configuration of an electric actuator according to the first embodiment, showing multiple rows of parallel permanent magnets divided into three in the width direction relative to the direction of travel of the mover, with the rows gradually shifted from one side to the other in the axial direction from one side to the other in the width direction. [Figure 8A] FIG. 13 is a schematic diagram of an example of the secondary side configuration of an electric actuator according to the second embodiment, showing multiple rows of permanent magnets divided into five in the width direction relative to the direction of travel of the mover, arranged in parallel, with the rows gradually shifted from one axial side to the other from the center row in the width direction to both sides in the width direction. [Figure 8B] FIG. 13 is a schematic diagram of an example of the secondary side configuration of an electric actuator according to the second embodiment, showing multiple rows of parallel permanent magnets divided into three in the width direction relative to the direction of travel of the mover, the rows being gradually shifted from one axial side to the other from the center row in the width direction to both sides in the width direction. [Figure 9]13 is a diagram showing an example of an arrangement of permanent magnets on each surface of a housing in an example of a secondary side configuration of an electric actuator according to a second embodiment. FIG. [Figure 10] FIG. 1 is a partially sectional perspective view showing an example in which an electric actuator according to the present invention is applied to a vibration damping device. [Figure 11] FIG. 11 is a perspective view illustrating a suspension device, which is an application example of the vibration damping device in FIG. [Figure 12] 12 is a cross-sectional view of a main portion illustrating a configuration in which the suspension device of FIG. 11 is applied to a vehicle. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] Hereinafter, embodiments of the present invention will be described with reference to the drawings. Note that components with the same reference numerals in each embodiment have the same functions in each embodiment unless otherwise specified, and the description thereof will be omitted.

[0011] <Electric actuator> [First embodiment] In this embodiment, an example of an electric actuator that is small in size, has a large thrust, and can suppress pulsation caused by various variations that occur in the manufacturing process will be described with reference to Figs. 1 to 4.

[0012] Fig. 1A is a perspective view showing the schematic configuration of an electric actuator 1 according to a first embodiment, Fig. 1B is a front view showing the schematic configuration of the electric actuator 1 according to the first embodiment, and Fig. 1C is a side view showing the schematic configuration of the electric actuator 1 according to the first embodiment. Fig. 2 is a cross-sectional view taken along line AA in Fig. 1B, Fig. 3 is an exploded view of the electric actuator 1 according to the first embodiment, and Fig. 4 is a perspective view showing the schematic configuration of an armature 10 provided in the electric actuator 1 according to the first embodiment.

[0013] The electric actuator 1 includes an armature 10, a housing 14, a fixed plate 13, and a permanent magnet 12, as shown in, for example, Figs. 1A, 1B, 2, 3, and 4. The electric actuator 1 has a linear motor structure in which a force is generated between the armature 10 and the permanent magnet 12 by the armature 10 and a row of secondary permanent magnets 12, and the armature 10 and the permanent magnet 12 slide relatively along the axial direction. The armature 10 is supported in the housing 14 by a variety of methods, such as a bearing, a slide bush, a cam follower, or a sleeve, so that the gap between the armature 10 and the permanent magnet 12 is constant. In this embodiment, the structure for supporting the armature 10 in the housing 14 is not shown. The structure for supporting the armature 10 may be any method as long as it can be configured as a linear motor.

[0014] 4, the armature 10 is formed by alternately stacking flat teeth 101 and coils 103 in the Z direction, which is the axial direction of the armature 10. The armature 10 has a 2n (n=2 or more) polygonal outer shape, and in this embodiment, has a rectangular parallelepiped shape with a square or rectangular cross section that extends in the Z direction, and has four planar portions that extend parallel to the Z direction. For ease of explanation, hereinafter, a direction perpendicular to the Z direction and along a pair of parallel planar portions of the four planar portions of the armature 10 will be referred to as the X direction, and a direction perpendicular to the Z direction and the X direction will be referred to as the Y direction.

[0015] As shown in FIGS. 2 and 3, the armature 10 includes teeth 101, a center core 102, a coil 103, and an end plate 104.

[0016] The teeth 101 have a 2n (n=2 or more) polygonal shape, and in this embodiment have a square or rectangular shape. The center core 102 has a 2n (n=2 or more) polygonal shape like the teeth 101. The center core 102 is formed to be slightly smaller than the teeth 101.

[0017] In this embodiment, the center core 102 has a square external shape similar to the external shape of the teeth 101, but it may have any shape as long as it fits into the opening 103a of the coil 103, and may have, for example, a circular external shape. The teeth 101 and the center core 102 are configured by stacking multiple plate-shaped magnetic bodies 101A in the Z direction. The teeth 101 and the center core 102 are made of a magnetic material in consideration of the ease of magnetic flux flow, and thin electromagnetic steel sheets, silicon steel sheets, etc. are used as constituent materials from the viewpoint of suppressing eddy currents.

[0018] Teeth 101 can suppress loss by stacking thin plates such as electromagnetic steel sheets. However, it is difficult to control the thickness in the Z direction and set minute dimensions due to the influence of standardized plate thickness, insulating layers, adhesive layers, various tolerances, etc. The thinner the electromagnetic steel sheets of teeth 101, the greater the loss suppression effect, but on the other hand, it is difficult to control the dimensions in the Z direction.

[0019] Furthermore, the members constituting the armature 10, such as the teeth 101 and the center core 102, have insulating layers on the surfaces of the thin plates, and there are processing tolerances between the members. Therefore, when the armature 10 is constructed by stacking these members, there is a tendency for the dimensions in the Z direction to vary. This variation poses the problem that the pulsation generated by each individual member varies. On the other hand, the laminated structure of the armature 10 makes it easy to adjust the width, number, dimensions, etc. of the teeth 101 and coils 103, making it extremely useful for manufacturing a wide variety of products in small quantities.

[0020] The coil 103 has a ring shape with an opening 103a at the center large enough to accommodate the center core 102. In this embodiment, the coil 103 is shaped as a rectangular ring coil to match the outer shape of the square center core 102, but it is also possible to use a circular center core 102 or a circular coil. The center core 102 is disposed within the opening 103a of the coil 103, which allows the magnetic flux of the teeth 101 adjacent in the axial direction to easily pass through.

[0021] As shown in FIG. 2, the end plates 104 are disposed on both ends of the armature 10 in the Z direction, and sandwich and integrally fix the laminated teeth 101, center core 102, and coils 103 from both sides in the Z direction.

[0022] As shown in Figures 2, 3, and 4, the armature 10 has an axial hole that passes through the center from one end to the other end in the Z direction, and a shaft 11 is inserted into the axial holes of each of the components 101, 102, and 104 of the armature 10 and is fixed integrally thereto.

[0023] The housing 14 has a cylindrical shape with a central hole 140 of the same 2n (n=2 or more) polygonal shape as the armature 10. In this embodiment, the central hole 140 of the housing 14 also has a square cross section and a shape extending in the Z direction to correspond to the square outer shape of the armature 10. The housing 14 has a holding structure (not shown) that holds the armature 10 within the central hole 140 so as to be relatively movable in the Z direction.

[0024] A groove 142 is formed in an inner wall surface 143A of the housing 14 to hold the fixed plate 13 so as to be guidable in the Z direction relative to the housing 14. The groove 142 is formed so as to extend continuously from one end to the other end of the central hole 140 of the housing 14 in the Z direction.

[0025] The housing 14 is provided with a fixing plate holding hole 141. The fixing plate holding hole 141 is formed in an elongated hole shape extending in the Z direction, penetrating between an inner wall surface 143A and an outer wall surface 143B of the housing 14. A fixing bolt 15 for fastening and fixing the fixing plate 13 is inserted into the fixing plate holding hole 141.

[0026] The fixing plate 13 is for fixing the multiple permanent magnets 12 to the housing 14, and is fixed to an inner wall surface 143A of the housing 14. The fixing plate 13 is fixed so that its fixed position with respect to the housing 14 can be adjusted in the Z direction. The fixing plate 13 according to this embodiment fits into the recessed groove 142, and is fixed to the housing 14 in a state where it can be adjusted to any position in the Z direction by passing the fixing bolt 15 through the fixing plate holding hole 141 and fastening it to the screw hole of the fixing plate 13.

[0027] The fixing plates 13 are provided in a plurality of rows in accordance with the arrangement of the permanent magnets 12, which will be described later, on at least one of the four inner wall surfaces 143A of the housing 14. It is preferable that the fixing plates 13 are provided in each row of the permanent magnets 12 on each inner wall surface 143A of the housing 14. The fixing plates 13 according to this embodiment are provided in parallel along the Z direction in two rows on each inner wall surface 143A of the housing 14, which has four surfaces.

[0028] The permanent magnets 12 are fixed to the surface of the fixed plate 13 opposite to the surface attached to the housing 14. The permanent magnets 12 are arranged facing at least one side of the outer shape of the teeth 101, and preferably, facing all sides of the outer shape of the teeth 101. A plurality of permanent magnets 12 are arranged in a row on the fixed plate 13 so that the N poles and S poles are alternately arranged in the Z direction. The number of permanent magnets 12 on the fixed plate 13 in this embodiment is the same on all of the fixed plates 13 fixed to the housing 14.

[0029] The permanent magnets 12 are arranged in multiple rows in parallel along the Z direction with respect to one side of the teeth 101. In this embodiment, the permanent magnets 12 are arranged in two rows in parallel along the Z direction with respect to one side of the teeth 101.

[0030] 3, the permanent magnets 12 are arranged in positions where adjacent rows are offset in the Z direction on at least one inner wall surface 143A of the housing 14. For example, one of two adjacent rows of the permanent magnets 12 is arranged offset toward one end in the Z direction, and the other row is arranged offset toward the other end in the Z direction. These multiple rows of permanent magnets 12 are arranged in positions where adjacent rows are offset in the Z direction by offsetting the positions of adjacent fixing plates in the Z direction.

[0031] The permanent magnets 12 can be arranged such that the positions of adjacent fixed plates 13 are adjusted to match the pulsation generated in the electric actuator 1. The electric actuator 1 is operated to generate pulsation. Then, the position of the permanent magnets 12 in the Z direction is adjusted by half the phase of the order of the pulsation to be suppressed. This adjustment reduces the pulsation. As shown in Figure 3, the permanent magnets 12 have the same width as the fixed plates 13, and multiple magnets 12 are arranged so that their north and south poles alternate in the Z direction.

[0032] As described above, the electric actuator 1 of this embodiment is composed of the armature 10 and secondary side members. As an example of the configuration of the secondary side members, the fixed plate 13 is disposed on the inner wall surface 143A of the housing 14, which has the fixed plate holding hole 141. The inner wall surface 143A of the housing 14 is provided with a recessed groove 142 so that the fixed plate 13 can slide relative to the housing 14 only in the Z direction, and the fixed plate 13 is attached so as to fit into the recessed groove 142. In addition, a plurality of permanent magnets 12 are disposed inside the fixed plate 13 in a row such that the north poles and south poles are alternately arranged in the Z direction.

[0033] In the electric actuator 1 of this embodiment, two fixed plates 13 are arranged to face each of the four outer surfaces 105 of the armature 10 per inner wall surface 143A of the housing 14, and are arranged so as to be divided into two in the width direction with respect to the Z direction. The fixed plates 13 divided into two in the width direction have a structure that allows their position to be moved in the Z direction together with the permanent magnets 12 arranged on the fixed plates 13.

[0034] The fixing plate 13 is fixed to the housing 14 by inserting the fixing plate holding hole 141 penetrating between the inner wall surface 143A and the outer wall surface 143B of the housing 14 into an elongated hole extending in the Z direction and fastening the fixing bolt 15 to the screw hole of the fixing plate 13. Therefore, the fixing plate 13 on which the permanent magnet 12 is arranged can be guided into the recessed groove 142 provided in the inner wall surface 143A of the housing 14 and relatively shifted in the Z direction, and the recessed groove 142 can suppress the wobble and shift in the lateral direction of the fixing plate 13 within the housing 14, and the fixing bolt 15 can fix the fixing plate 13 to any position in the Z direction with respect to the housing 14.

[0035] In this embodiment, the permanent magnet 12 arranged on one inner wall surface 143A of the housing 14 and the fixed plate 13 on which the permanent magnet 12 is arranged are divided into two in the X direction or Y direction, which is the width direction. Each fixed plate 13 can be fixed to the housing 14 at any position in the Z direction. In this embodiment, an example of the fixed plate 13 divided into two in the width direction on one inner wall surface 143A of the housing 14 is shown, but the number of fixed plates 13 is not limited as long as a similar effect is obtained. For example, a configuration in which one fixed plate 13 is arranged on one inner wall surface 143A of the housing 14, or a configuration in which three or more fixed plates 13 are arranged may be used.

[0036] The electric actuator 1 having the above-mentioned configuration is low-cost and has a high yield, and the position of the fixed plate 13 on which the rectangular permanent magnets 12 are arranged can be moved in the Z direction and fixed at any position in the Z direction. Therefore, by adjusting and fixing the fixed plate 13 to a position where the pulsation can be canceled by the phase difference between the fixed plates 13, it is possible to suppress individual variations in pulsation caused by errors caused by tolerances during assembly of the armature 10, etc. Therefore, an electric actuator 1 with low pulsation can be realized.

[0037] The electric actuator 1 can reduce pulsation by providing a difference in the Z-direction positions between the permanent magnet rows so that the phase of the permanent magnets is shifted by half the phase of the order to be suppressed. These two phases are called phase a and phase b. In this case, if an attractive force of the fundamental wave component of the frequency of the order to be suppressed is generated between the armature 10 and the magnet row of phase a, conversely, a repulsive force of the fundamental wave component is generated in the magnet row of phase b. By combining these forces, the pulsation is cancelled out. In other words, a force in the opposite direction to that of phase b is generated in phase a.

[0038] Fig. 5 shows an expanded view of four inner wall surfaces 143A1-143A4 of the housing 14. Figs. 6A and 6B are diagrams for explaining the forces acting on the electric actuator due to the arrangement of the permanent magnets shown in Fig. 5.

[0039] The fixing plates 13 are arranged on each of the inner wall surfaces 143A1-143A4 of the housing 14 in the order of 131A to 131B, 132B, 132A, 133A, 133B, 134B, and 134A. The fixing plates 131A, 132A, 133A, and 134A are located at the same position in the Z direction, and the fixing plates 131B, 132B, 133B, and 134B are located at the same position in the Z direction. There is a difference in the position in the Z direction between the fixing plates 131A, 132A, 133A, and 134A (phase a) and the fixing plates 131B, 132B, 133B, and 134B (phase b).

[0040] As shown in Fig. 5, a force F is generated in each of the permanent magnets 12 divided into two rows on each of the four inner wall surfaces 143A1-143A4 of the housing 14. In phase a where an attractive force is generated and phase b where a repulsive force is generated, a moment is generated that tends to rotate the plate from surface b to surface a. Here, in an armature having four outer surfaces 105, it is preferable to alternately arrange the phase a and the phase b on adjacent surfaces of the four inner wall surfaces 143A1-143A4 of the housing 14 as shown in Fig. 5.

[0041] 6A and 6B are schematic diagrams showing forces acting on the electric actuator 1 formed by combining the permanent magnets 12 shown in FIG.

[0042] 6A shows the balance between the X-axis and Y-axis of the electric actuator 1 and the moment acting on each of the inner wall surfaces 143A1-143A4. The X-axis is a central axis passing through the center of the electric actuator 1 in the Z direction and the center of a pair of parallel flat surfaces of the electric actuator 1, and the Y-axis is a central axis passing through the center of the electric actuator 1 in the Z direction and the center of another pair of parallel flat surfaces of the electric actuator 1. The X-axis and Y-axis are also referred to as center lines of each side of the teeth 101 when the armature 10 is viewed from the Z direction.

[0043] In FIG. 6A , the numbers of magnets in phase a and phase b separated into the upper and lower parts of the figure on either side of the X-axis are fixed plate 131A arranged on inner wall surface 143A1, fixed plate 133B arranged on inner wall surface 143A3, and fixed plates 134A and 134B arranged on inner wall surface 143A4: fixed plate 131B arranged on inner wall surface 143A1, fixed plates 132A and 132B arranged on inner wall surface 143A2, and fixed plate 133A arranged on inner wall surface 143A3, which are equal and balanced. Similarly, the numbers of a-phase and b-phase magnets, which are divided into the left and right sides of the Y-axis in the figure, are the same and balanced, being the fixed plates 131A and 131B arranged on the inner wall surface 143A1, the fixed plate 132B arranged on the inner wall surface 143A2, and the fixed plate 134A arranged on the inner wall surface 143A4, the fixed plate 132A arranged on the inner wall surface 143A2, the fixed plates 133A and 133B arranged on the inner wall surface 143A3, and the fixed plate 134B arranged on the inner wall surface 143A4. Furthermore, the moments generated on the a-phase surface and the b-phase surface also rotate in opposite directions on the adjacent surfaces (for example, the inner wall surface 143A1 and the inner wall surface 143A2, or the inner wall surface 143A1 and the inner wall surface 143A4), and vibrations caused by rotation around the O-axis, which is the center line of the electric actuator 1, can also be suppressed.

[0044] 6B, the forces acting on both sides of the axes D and E connecting the diagonals of the inner wall surfaces 143A1-143A4 of the electric actuator 1 are also balanced, and the forces acting in the diagonal directions are also balanced. In other words, the rows of permanent magnets 12 are arranged so that the attractive forces of the permanent magnets 12 and the armature 10 are symmetrical with respect to the X-axis and Y-axis, which are parallel axes connecting the center lines of the inner wall surfaces 143A1-143A4, and the D-axis and E-axis connecting the diagonals of the inner wall surfaces 143A1-143A4 of the electric actuator 1, thereby suppressing the moments around the X-axis, Y-axis, D-axis, E-axis, and O-axis. The D-axis and E-axis are also referred to as the diagonals of the teeth 101 when the armature 10 is viewed from the Z direction.

[0045] In the above embodiment, an example was shown in which there are gaps between the permanent magnets 12 and the armature 10 on four sides, and the row of permanent magnets 12 on one side is divided into two in the width direction, but the row of permanent magnets 12 can also be applied to an electric actuator having a 2n-sided shape (n=2 or more) and divided into at least two or more parts in the horizontal direction relative to the moving direction of the mover by arranging the row of permanent magnets 12 so that the attractive forces of the permanent magnets 12 and the armature 10 are symmetrical with respect to the X-axis and Y-axis connecting the center lines of the four inner wall surfaces 143A, and the D-axis and E-axis connecting the diagonal corners of each inner wall surface 143A. The electric actuator 1 of this embodiment is characterized by a structure in which the forces and rotational forces generated by the armature 10 and the permanent magnets 12 can be offset by two of the four faces.

[0046] FIG. 7A is a schematic diagram of an example of the secondary side configuration of the electric actuator 1 in which the permanent magnet 12 is divided into five in the X direction or Y direction, which is the lateral width direction relative to the moving direction of the mover.

[0047] The secondary side configuration example of the electric actuator 1 shown in Fig. 7A is configured in the same way as the electric actuator 1 described above, with the permanent magnets 12 arranged in parallel in multiple rows, with the rows gradually shifted from one side to the other side in the axial direction (Z direction) from one side to the other side in the width direction (X direction or Y direction) with respect to the moving direction of the mover. As a result, the electric actuator 1 according to this embodiment shown in Fig. 7A can suppress pulsations of multiple orders and adjust subtle pulsations when there are many divisions in the width direction.

[0048] Fig. 7B is a schematic diagram of an example of the secondary side configuration of the electric actuator 1 in which the permanent magnet 12 is divided into three in the X-direction or Y-direction, which is the width direction relative to the moving direction of the mover. The secondary side configuration example of the electric actuator 1 shown in Fig. 7B has the same effect as the secondary side configuration example of the electric actuator 1 shown in Fig. 7A.

[0049] In addition, compared to a linear motor having a cylindrical gap, the electric actuator 1 of this embodiment cannot tolerate rotation between the armature 10 and the secondary side. However, since the fixed plate 13 is fixed to the housing 14 so as to be adjustably movable in the Z direction, rotation between the armature 10 and the secondary side can be suppressed, making it less likely that damage will occur due to contact between the armature 10 and the secondary side.

[0050] [Second embodiment] A second embodiment of the electric actuator 1 will be described with reference to FIGS.

[0051] FIG. 8A is a schematic diagram of a secondary side configuration example of the electric actuator 1 in which the permanent magnet 12 is divided into five in the X direction or Y direction, which is the lateral width direction relative to the moving direction of the mover.

[0052] The secondary side configuration example of the electric actuator 1 shown in FIG. 8A has five divisions in the width direction, as in FIG. 7A, but combines a V-shaped arrangement in which the permanent magnets 12 are arranged in parallel on one inner wall surface 143A, and an inverted V-shaped arrangement in which the permanent magnets 12 are arranged in a position gradually shifted from one side to the other in the axial direction (Z direction) from the center row in the width direction (X direction or Y direction) to both sides in the width direction. In the electric actuator 1 according to this embodiment shown in FIG. 8A, when the permanent magnets 12 are arranged in a V-shaped or inverted V-shaped arrangement, the rotational force on one inner wall surface 143A becomes symmetrical in the width direction, and the moment can be offset for each surface. In other words, the electric actuator 1 according to this embodiment shown in FIG. 8A can be laid out without considering the combination of the permanent magnets 12 on the four inner wall surfaces 143A of the housing 14. Therefore, the electric actuator 1 according to this embodiment shown in FIG. 8A can be varied depending on the required pulsation specifications, such as suppressing pulsations of different orders on each of the four inner wall surfaces 143A of the housing 14, or suppressing pulsations of the same order.

[0053] Fig. 8B shows an example of the secondary side configuration of the electric actuator 1 in which the permanent magnet 12 is divided into three in the X-direction or Y-direction, which is the width direction relative to the moving direction of the mover. The secondary side configuration example of the electric actuator 1 shown in Fig. 8B has the same effect as the secondary side configuration example of the electric actuator 1 shown in Fig. 8A.

[0054] FIG. 9 shows an example of the arrangement of the permanent magnets 12 on each inner wall surface 143A of the housing 14 in the secondary side configuration example of the electric actuator 1 shown in FIG. 8A. The inner wall surfaces 143A of the housing 14 on which the four permanent magnets 12 facing the armature 10 are arranged are marked with the symbols (A), (B), (C), and (D), respectively. On the four inner wall surfaces 143A of the housing 14, the inner wall surfaces 143A marked with the symbols (A) and (C) face each other, and the inner wall surfaces 143A marked with the symbols (B) and (D) face each other. The permanent magnets 12 are arranged in the same manner (inverted V-shaped arrangement) on the inner wall surfaces 143A marked with the symbols (A) and (C) that face each other. Also, the permanent magnets 12 are arranged in the same manner (V-shaped arrangement) on the inner wall surfaces 143A marked with the symbols (B) and (D) that face each other. By arranging the permanent magnets 12 in this manner, the electric actuator 1 of this embodiment shown in FIG. 8A generates similar attractive forces on the inner wall surfaces 143A indicated by symbols (A) and (C) and the inner wall surfaces 143A indicated by symbols (B) and (D), respectively, and the attractive forces of the opposing inner wall surfaces 143A can cancel each other out, thereby reducing the burden on the shaft 11.

[0055] <Vibration control device> A vibration control device 30 using the electric actuator 1 of the present invention will be described with reference to FIGS.

[0056] 10 is a partially sectional perspective view showing an example in which the electric actuator 1 of the present invention is applied to a vibration control device 30. The above-mentioned electric actuator 1 is incorporated into the vibration control device 30. In vibration control devices 30 such as ultra-precision machine tools that require minute vibration suppression and inspection devices for semiconductors and the like that inspect minute areas, vibration of the equipment due to pulsation has a significant effect on processing accuracy and inspection accuracy, so by using the electric actuator 1 of the present invention, which can suppress pulsation, higher accuracy can be obtained.

[0057] <Suspension device> FIG. 11 is a perspective view illustrating a suspension device 40 which is an application example of the vibration-damping device 30 of FIG. 10, and FIG. 12 is a cross-sectional view of a main part illustrating a configuration in which the suspension device 40 of FIG. 11 is applied to a vehicle. A rod 32 is connected to the shaft 11 of the electric actuator 1. The rod 32 is connected to a wheel 201 via a shaft 202. On the other hand, a spring 31 is provided between the vibration-damping device 30 and a vehicle body 200. In recent years, further comfort of vehicles is desired with the spread of autonomous driving. The suspension device 40 which is an application example of the vibration-damping device 30 to which the electric actuator 1 of the present invention is applied makes it possible to change the vibration suppression mode according to preferences such as human senses and individual differences, and the frequency at which vibration is suppressed according to vibration characteristics that differ depending on the structure of the vehicle body and the type of vehicle. [Explanation of symbols]

[0058] 1...electric actuator, 10...armature, 101...teeth, 103...coil, 12...permanent magnet, 13...fixed plate, 14...housing, Z...axis direction

Claims

1. an armature in which teeth and coils each having a 2n (n=2 or more) polygonal outer shape are alternately stacked in the axial direction; a housing that holds the armature so as to be relatively movable in the axial direction; a fixing plate fixed to the housing; A plurality of permanent magnets are fixed to the fixed plate and arranged to face at least one side of the outer shape of the teeth; An electric actuator having The fixed plate is fixed to the housing so that a fixed position of the fixed plate can be adjusted in the axial direction.

2. The plurality of permanent magnets are arranged in parallel along the axial direction with respect to one side of the teeth, 2. The electric actuator according to claim 1, wherein the fixed plates are provided separately for each row of the permanent magnets.

3. 3. The electric actuator according to claim 2, wherein adjacent rows of the permanent magnets are arranged at positions shifted from each other in the axial direction.

4. The teeth have a square or rectangular outer shape, 4. The electric actuator according to claim 3, wherein the plurality of permanent magnets are arranged at positions such that the attractive force with the armature is symmetrical with respect to the center lines of each side of the teeth and the diagonal lines of the teeth when the armature is viewed in the axial direction.

5. 5. The electric actuator according to claim 4, wherein the plurality of permanent magnets are arranged at positions that are gradually shifted from one side to the other side in the axial direction from one row to the other side in the width direction of the plurality of parallel rows.

6. 5. The electric actuator according to claim 4, wherein the plurality of permanent magnets are arranged at positions gradually shifted from one side to the other side in the axial direction from a central row in the lateral direction of the plurality of rows arranged in parallel to the rows on both sides in the lateral direction.

7. 5. The electric actuator according to claim 4, wherein the teeth are configured by stacking a plurality of plate-shaped magnetic bodies in the axial direction.

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