Magnetic actuator and electromechanical system

Abstract

The actuator comprises a movable armature (2) rotating relative to a stator (1) having flanges (3a, 3b) on which magnets (5a, 5b) are mounted, a coil (9a, 9b) being mounted around one of the flanges (3a). The magnets (5a, 5b) have an axial magnetization in the z-axis and are aligned in the x-axis. The movable armature (2) is arranged between the magnets (5a, 5b) in the x-axis. The movable armature (2) is mounted on a guide (11) rotating around a y-axis perpendicular to the x- and z-axes. The movable armature (2) is separated from the magnets (5a, 5b) by air gaps (6a, 6b). Each magnet (5a, 5b) forms a static magnetic circuit (8a, 8b) with one end (2a, 2b) of the movable armature (2) and one of the flanges (3a, 3b). The coil (9a, 9b) forms a dynamic magnetic circuit with the ends (2a, 2b) of the movable armature (2) and the flanges (3a, 3b).

Description

Technical Field

[0001] This invention relates to a magnetic actuator. Background Technology

[0002] In optical devices, magnetic aiming mechanisms use magnetic actuators to translate moving parts. The moving parts are connected to interface components of the optical system, particularly mirrors. Optical magnetic aiming mechanisms using four independent magnetic actuators are known. The magnetic actuators produce the translation of the moving parts. The magnetic actuators can be coupled together, for example, in a push-pull configuration, to produce rotation of the moving parts. The moving parts are connected to a stationary part via flexible guides. The magnetic actuators used in these mechanisms belong to two main families: moving magnet actuators and moving iron actuators.

[0003] The research work discloses a mechanism that does not have four independent actuators but a single stator assembly and a moving assembly. Such teachings can be found in the publications of Yongjun Long et al., "Modeling and Analysis of a Novel Two-Axis Rotary Electromagnetic Actuator for Fast Steering Mirror" Journal of Magnetics 19(2), 130-139 (2014), and "Design of a Moving-magnet Electromagnetic Actuator for Fast Steering Mirror through Finite Element Simulation Method" Journal of Magnetics 19(3), 300-308 (2014).

[0004] However, it is clear that these mechanisms utilize an air gap between the moving component and the fixed magnetic circuit to provide limited motion. Furthermore, magnetic force is obtained through normal magnetic reluctance variations by increasing or decreasing the thickness of the air gap. For this reason, the magnetic force exerted on the moving component may cause it to "stick" to or impact the fixed component, which is detrimental to guiding the entire system.

[0005] To mitigate this risk, the publication "Modeling and Analysis of a Novel Two-AxisRotary Electromagnetic Actuator for Fast Steering Mirror" describes mounting the moving parts on a flexibly mounted rod to guide their movement. The rod's bending stiffness must be sufficiently high to prevent adhesion, which is extremely detrimental to power consumption. This construction necessitates providing magnets whose shape is not immediately compatible with the magnetization requirements, particularly their polarization directions, thus implying high production costs. Such a construction is not easily implemented or used.

[0006] Alternatively, the publication "Design of a Moving-magnet Electromagnetic Actuator for Fast Steering Mirror through Finite Element Simulation Method" proposes mounting the permanent magnet on a movable disk designed to support the mirror. This configuration increases the weight of the movable disk. Furthermore, the dynamic flux of the coil flowing through the permanent magnet increases power consumption. Finally, the mechanism utilizes the magnetic force generated by a normal reluctance change, which can cause moving parts to adhere to or impact the stator. This configuration also uses flexurally mounted rods for guidance, which is also detrimental to energy consumption.

[0007] As can be seen from the configuration of the existing technology, there is a risk of adhesion between the moving parts and the actuation device, which imposes a relatively rigid guiding mechanism and thus increases power consumption. Summary of the Invention

[0008] One object of the present invention is to provide a magnetic actuator that is easier to manufacture and consumes less power to achieve movement of a movable armature. The actuator is advantageously designed to form part of an aiming device, preferably an optical aiming device. For this purpose, the magnetic actuator includes a stator and a movable armature pivotally mounted relative to the stator.

[0009] The stator has:

[0010] - A stator core made of magnetic material, comprising first and second flanges connected by a support member.

[0011] - The first magnet is mounted on one end of the first flange.

[0012] A second magnet is mounted on one end of a second flange. The first and second magnets are axially magnetized, and a movable armature is oriented along a first axis. The first and second magnets are aligned on a second axis perpendicular to the first axis.

[0013] - At least a first coil, which is assembled around a first flange between a support and a first magnet.

[0014] A movable armature is arranged on a second axis between the first and second magnets, and its dimensions on the second and third axes are respectively larger than the dimensions of the movable armature on the first axis, with the third axis perpendicular to the first and second axes. The movable armature defines a first air gap with one end of a first flange and the first magnet, and defines a second air gap with one end of a second flange and the second magnet, and has opposing first and second ends on the second axis.

[0015] The guide mechanically connects the movable armature to the stator. The guide is configured to allow the movable armature to rotate about a first rotation axis parallel to the third axis and to prevent the movable armature from moving toward the first and second magnets on the second axis.

[0016] A first magnet is magnetically coupled to a first end and a first flange of a movable armature to form a first static magnetic circuit. A second magnet is magnetically coupled to a second end and a second flange of the movable armature to form a second static magnetic circuit. A first coil is magnetically coupled to the first and second ends of the movable armature, the first and second flanges, and the support member to form a first dynamic magnetic circuit.

[0017] Preferably, the first flange and the second flange extend upward from the support member mainly on the first axis, and the first and second magnets are arranged on the first axis in the extensions of the first and second flanges.

[0018] According to an improvement of the invention, the ratio of the thickness of the first and second magnets to the thickness of the movable armature is between 0.8 and 1.2, and the thickness is measured on the first axis.

[0019] Advantageously, the mid-plane of the first and second magnets on the first axis is the mid-plane of the movable armature.

[0020] In one improvement, first and second poles made of magnetic material are placed on first and second magnets, respectively, and the first and second poles are separated from first and second flanges by the first and second magnets.

[0021] Advantageously, the minimum distance between the first magnet and the movable armature is greater than or equal to the minimum distance between the first flange and the movable armature.

[0022] In a preferred configuration, the second coil is mounted between the support and the second magnet around the second flange, and the second coil forms part of the first dynamic magnetic circuit.

[0023] In another improvement, the guide is secured to the stator via at least a first attachment point and to a movable armature via a plurality of second attachment points. The guide includes a body defining a through-slot on a first axis, the through-slot being helical in shape and pointing towards at least the first attachment point. The through-slot separates the at least first attachment point and the plurality of second attachment points on a second and / or third axis.

[0024] Preferably, the magnetic actuator includes third and fourth magnets respectively mounted on third and fourth flanges of the stator core, the third and fourth magnets being axially magnetized, and a movable armature parallel to the first axis and aligned on the third axis. The movable armature has opposing third and fourth ends on the third axis, separated from the ends of the third and fourth flanges and from the third and fourth magnets by third and fourth air gaps. The movable armature is arranged on the third axis between the third and fourth magnets.

[0025] The third magnet, together with the third end and the third flange of the movable armature, forms a third static magnetic circuit. The fourth magnet, together with the fourth end and the fourth flange of the movable armature, forms a fourth static magnetic circuit. The additional coil, together with the third and fourth ends, the third and fourth flanges, and the support, forms an additional dynamic magnetic circuit.

[0026] In a specific configuration, the first and second magnets are magnetized in a first magnetization direction, and the third and fourth magnets are magnetized in a second magnetization direction opposite to the first magnetization direction. Alternatively, the first, second, third, and fourth magnets may have the same magnetization direction.

[0027] In a particular embodiment, the movable armature has at least one target cooperating with at least one eddy current sensor probe to detect movement of the movable armature about a first rotation axis, the at least one target and the at least one eddy current sensor probe being separated from at least a first coil and a support by the movable armature.

[0028] Advantageously, the movable armature has two pairs of targets fixed to the movable armature and aligned on a first axis and a second axis, respectively. The stator includes two pairs of eddy current sensor probes to detect the rotation of the movable armature about the first and second rotation axes via differential mode. The two pairs of eddy current sensor probes are formed by bending a conductive material on a toroidal electronic printed circuit board.

[0029] In another improvement, the load is fixed to the first main surface of the movable armature, and the load is separated from the first coil and, if applicable, from the second, third and fourth coils via the movable armature.

[0030] Preferably, the load is mechanically connected to the movable armature by means of a load support, the load is fixed to the load support via a first attachment point, and the load support is mechanically connected to the stator via a second attachment point. The load support is formed of a plate that defines four first through slots on a first axis, the first slots extending along a first curved path having a first concavity from the periphery of the load support to the center of the load support to define four regions, and defining at least a third slot that extends in an arc around the center from the first slots.

[0031] The load support includes four second through slots on the first axis. The second slots extend from the periphery of the load support to the first slot along a second curved path having a first concavity. Each region includes a second slot to define two basic regions in each region, with first and second attachment points arranged alternately. A first or second attachment point separates the first slot from the subsequent second slot, and a third slot extends between the center and the second slots.

[0032] In an advantageous configuration, the guide is fixed to the first main surface of the movable armature, while the load support is fixed to the second main surface of the movable armature.

[0033] In another preferred configuration, the guide is secured to the load support by bolts passing through a through hole in the movable armature. Advantageously, at least one target is mounted on one of the bolts.

[0034] It is also advantageous to set the load as a reflective element, and preferably to place the reflective surface in the same plane as the target and / or to mount the reflective element inside the ring-shaped electronic circuit.

[0035] Another object of the present invention is to provide an electromechanical system that improves the actuation of moving parts and ensures more effective damping of moving parts when no power is applied to them.

[0036] Advantageously, an electromechanical system is provided, which is equipped with a magnetic actuator according to one of the aforementioned configurations and includes a control circuit defining a first power supply circuit for at least a first coil or a damping circuit at least connected to a terminal of the first coil. The damping circuit includes a resistor and a capacitor to form an RLC circuit. Attached Figure Description

[0037] Other advantages and features will become more apparent from the following description of specific embodiments and implementations of the invention, given for non-limiting purposes only and illustrated in the accompanying drawings, wherein:

[0038] Figure 1 A cross-sectional view of a magnetic actuator having a stator core associated with a permanent magnet and an actuation coil is schematically shown;

[0039] Figure 2A cross-sectional view of another embodiment of a magnetic actuator having a stator core associated with a permanent magnet and an actuation coil is schematically shown;

[0040] Figure 3 A top view schematically illustrates a specific configuration of a movable armature arranged between permanent magnets;

[0041] Figure 4 A perspective view of the stator core associated with permanent magnets and actuation coils is schematically shown, with a movable armature mounted between the permanent magnets;

[0042] Figure 5 A cross-sectional view of an alternative embodiment of a magnetic actuator having a stator core associated with a permanent magnet and an actuation coil is schematically shown;

[0043] Figure 6 An exploded perspective view of a mirror mounted on a moving part via a deformable load support is schematically shown, with a movable armature mounted on a guide.

[0044] Figure 7 The control circuit connected to the stator is shown schematically. Detailed Implementation

[0045] Reference Figure 1 , 2 5. The magnetic actuator includes a stator 1 cooperating with a movable armature 2. The stator 1 is considered a stationary component, and the movable armature 2 is mounted to rotate relative to the stator 1. The stator 1 includes a stator core 3 made of a magnetic material, preferably a soft magnetic material such as a ferromagnetic material. The stator core 3 may be made of FeSi, FeCo, or a material referred to as a "soft magnetic composite," such as a ferromagnetic material powder surrounded by an electrically insulating film. Advantageously, the stator core 3 does not contain any permanent magnets.

[0046] The stator 1 is configured to allow the movable armature 2 to rotate about one or two mutually perpendicular axes of rotation. The desired motion is roll and / or pitch, rather than yaw. Preferably, the movable armature 2 rotates within an angle range of less than 20°.

[0047] like Figure 1 , 2 As shown in Figures 4 and 5, the stator core 3 includes a support member 4 from which multiple flanges extend, specifically including a first flange 3a and a second flange 3b. The magnetic actuator has a first magnet 5a and a second magnet 5b cooperating with the movable armature 2. The magnets 5a / 5b are preferably permanent magnets relative to the coil because they allow a fixed magnetic field to be applied passively to define a stationary position without a power supply. The first magnet 5a and the second magnet 5b are magnetically coupled to the flanges 3a / 3b and the movable armature 2.

[0048] A first magnet 5a is located at the top of a first flange 3a, and a second magnet 5b is located at the top of a second flange 3b. The first and second magnets 5a and 5b are magnetized axially rather than radially. The magnetization direction of the two magnets 5a / 5b is parallel to the first axis z. In other words, the north-south direction of magnets 5a and 5b is parallel to the z-axis. The magnetization directions of the first and second magnets are the same, i.e., the north-south directions of the two magnets are parallel and point in the same direction. The flanges are preferably terminated by permanent magnets. Advantageously, the two magnets 5a / 5b are directly fixed to the ends of the two flanges 3a / 3b. The flanges guide the magnetic field lines originating from the magnets before they escape to the ends 2a / 2b of the movable armature 2. The magnets 5a / 5b are separated from the support 4 by the flanges 3a / 3b.

[0049] The first magnet 5a and the second magnet 5b are aligned on a second x-axis perpendicular to the first z-axis. A movable armature 2 is arranged between the first magnet 5a and the second magnet 5b. The movable armature 2, the first magnet 5a, and the second magnet 5b are aligned on the second x-axis. The movable armature 2 has a first end 2a and a second end 2b that are opposite each other on the second x-axis. Preferably, the centers of the first magnet 5a, the second magnet 5b, and the movable armature 2 are aligned on the x-axis. The centers are measured on the z-axis.

[0050] like Figure 1 , 2 As shown in Figure 3, the movable armature 2 is separated from the ends of the first magnet 5a and flange 3a by a first air gap 6a. The movable armature 2 is separated from the second magnet 5b by a second air gap 6b. The first end 2a substantially faces the first magnet 5a, and the second end 2b substantially faces the second magnet 5b. The two ends 2a / 2b are connected by a magnetic material to form a magnetic circuit that guides field lines between the two ends.

[0051] Depending on the configuration, the movable armature 2 is a solid portion or preferably a perforated portion. The movable armature 2 has a planar construction and can be in the form of a disk or a disk with multiple flat points. Advantageously, the ends 2a / 2b of the movable armature are formed by flat points facing the magnets 5a / 5b. The magnets have flat surfaces facing the ends to define a substantially constant air gap between the movable armature 2 and the magnets 5a / 5b. The air gap 6a / 6b has a thickness sufficient to prevent angular movement of the movable armature 2 from causing a collision between the movable armature 2 and the stator 1.

[0052] Typically, the magnetization lines and directions applied by the first and second magnets 5a and 5b are selected to apply static fields Hsa and Hsb, whose components on the x-axis are in opposite directions in the regions of the air gaps 6a and 6b.

[0053] The first magnet 5a, together with the first end 2a and the first flange 3a of the movable armature 2, forms a first static magnetic circuit 8a. The second magnet 5b, together with the second end 2b and the second flange 3b of the movable armature 2, forms a second static magnetic circuit 8b. Figure 1 In the embodiment shown, the two magnets 5a and 5b are arranged to be magnetized north and south with directional flanges 5a / 5b.

[0054] A rectangular magnet is advantageous because it facilitates actuator manufacturing, reduces actuator costs, and allows for better control over the applied magnetic force. The magnet can be made of SmCo or NdFeB.

[0055] The two magnets 5a and 5b are advantageously covered by soft magnetic materials forming magnetic poles 7a / 7b, and advantageously selected from FeSi, FeCo, and materials referred to as "soft magnetic composites". The stator 1 has a first pole 7a covering the first magnet 5a and a second pole 7b covering the second magnet 5b. The first pole 7a is spaced from the first flange 3a by the first magnet 5a, and the second pole 7b is spaced from the second flange 3b along the z-axis by the second magnet 5b. Preferably, each pole 7a / 7b is in direct contact with the magnet 5a / 5b. The use of magnetic poles improves the guidance of magnetic field lines in the first and second static magnetic circuits 8a and 8b and enhances the magnetic coupling with the movable armature 2. Particularly advantageously, the first flange 3a and the second flange 3b have the same structure as their associated magnets 5a / 5b and possibly their magnetic poles 7a / 7b.

[0056] As described above, magnet 5a generates a first static magnetic flux flowing through a first static magnetic circuit 8a. The first static magnetic circuit 8a begins with the first magnet 5a, then passes through a first flange 3a, an air gap region 6a, an end 2a of the movable armature 2, another air gap region, and a magnetic pole 7a. This flux generates a static magnetic field Hsa in the air gap region 6a, thereby magnetizing it. Magnet 5b generates a second static magnetic flux flowing through a second static magnetic circuit 8b (similar to magnetic circuit 8a). The second static magnetic circuit 8b begins with the second magnet 5b, then passes through a second flange 3b, an air gap region 6b, an end 2b of the movable armature 2, another air gap region, and a magnetic pole 7b. This flux generates a static magnetic field Hsb in the air gap region 6b, thereby magnetizing it. The magnetic field lines of magnetic circuits 8a and 8b have components on the x and z axes in the air gaps 6a and 6b. The magnetic field lines also have components on the x and z axes in the first and second ends 2a and 2b.

[0057] exist Figure 2 In the illustrated embodiment, magnetic poles 7a and 7b are absent. The magnet can also be positioned further away from the end 2a / 2b than the end of the flange 3a / 3b that supports the magnet 5a / 5b on the x-axis. The offset of the magnet 5a / 5b relative to the flange can... Figure 1It is applied in the configuration.

[0058] Two magnetic fluxes originating from magnets 5a and 5b apply two magnetic attraction forces at the two opposite ends of the movable armature 2. The angular position of the movable armature 2 is adjusted to reduce the magnetic reluctance established along the x-axis that defines the rest position of the movable armature 2. Preferably, the two magnets 5a / 5b are identical and arranged such that the strengths (absolute values) of the resulting magnetic fields |Hsa| and |Hsb| are equal.

[0059] The stator 1 also includes at least a first coil 9a, preferably a first coil 9a and a second coil 9b, which apply a dynamic magnetic field Hd that interacts with the two opposite ends 2a and 2b of the movable armature 2. Figure 1 As shown, a dynamic magnetic circuit 8c exists between the first flange 3a, the support 4, the second flange 3b, the air gap 6b, the movable armature 2, and the air gap 6a. Typically, unlike the magnetic fields Hsa and Hsb of the magnet, the x-axis component of the dynamic magnetic field Hd is in the same direction within the air gap regions 6a and 6b.

[0060] The support 4 and the first and second flanges 3a / 3b are made of magnetic material. The support 4 is made of magnetic material to guide the field lines of the coil between the flanges. Figure 1 As shown, the stator core 3 is U-shaped when viewed in a transverse cut plane. Advantageously, the support 4 is integral or one-piece with the two flanges 3a / 3b. The support 4 can be solid or perforated. The stator core 3 guides the dynamic magnetic field lines.

[0061] Advantageously, a continuous magnetic circuit is formed by the flanges 3a / 3b and the support 4 to increase the magnetic field strength in the air gaps 6a and 6b near the two opposite ends 2a and 2b of the movable armature 2. The magnetic field lines of the magnetic circuit 8c have components on the x and z axes in the air gaps 6a and 6b. The magnetic field lines also have components on the x and z axes at the first and second ends 2a and 2b. Figure 1 The cross-sectional view along the plane containing the x and z axes is shown, which is advantageous in that the coil, magnet and flange belong to the same plane perpendicular to the axis of rotation.

[0062] A first coil 9a is arranged around a first flange 3a between a support 4 and a magnet 5a. When the first actuation coil 9a is energized, it generates a magnetic field. Advantageously, a second coil 9b is arranged around a second flange 3b to facilitate obtaining a strong magnetic field in the air gaps 6a and 6b. This second coil 9b can be redundant with the first coil 9a so that it can take over from the first coil 9a in case of failure.

[0063] The field lines are guided in the stator core 3 through the first flange 3a, then through the support 4 and the second flange 3b. The field lines exit from the second flange 3b through the air gap 6b, reach the second end 2b of the movable armature 2 made of magnetic material, and pass through the movable armature 2. The field lines connect from the first end 2a of the first movable armature 2 to the first flange 3a via the air gap 6a. The two opposite ends 2a / 2b of the movable armature 2 facing the air gaps 6a and 6b are subjected to a magnetic field generated by the magnets 5a / 5b and a magnetic field generated by the first coil 9a.

[0064] Applying current to coil 9a causes an asymmetry in the total field between air gaps 6a and 6b. Figure 1 In the example, the field Hd caused by coil 9a is oriented in the direction of the field Hsb caused by magnet 5b, and in the opposite direction to the field Hsa caused by magnet 5a. Therefore, compared to the field Hsa without applied current, the total field Hta = Hsa - Hd in air gap 6a decreases, which reduces the attraction between end 2a of the movable armature and end 3a of the flange. Conversely, compared to the field Hsb without applied current, the total field Htb = Hsb + Hd in air gap 6b increases, which increases the attraction between end 2b of the movable armature and end 3b of the flange.

[0065] like Figure 1 , 2 As shown in Figures 4, 5, and 6, to achieve rotational movement of the movable armature 2 relative to the stator 1, it is advantageous to use a guide 11 that allows the movable armature 2 to rotate about a first rotational axis that is parallel to and perpendicular to the first axis z and the second axis x. Preferably, the guide 11 is configured to prevent translational movement of the movable armature 2 on the x-axis to prevent any adhesion or contact with one of the two magnets 5a / 5b.

[0066] Advantageously, guide 11 is configured to allow rotation only about an axis of rotation perpendicular to the z-axis. Guide 11 can be configured to prevent any translation perpendicular to the z-axis. By allowing only one or more rotations about an axis of rotation perpendicular to the z-axis, the change in the magnetic field at the two opposite ends of the movable armature 2 results in a movement primarily tangential to the facing magnet surface along the z-axis. This movement is accompanied by an increase in the facing air gap surface between the end of flange 3b and the surface of the end 2b of the movable armature located in front of magnet 5b, thereby reducing the magnetic reluctance of air gap 6b without reducing the thickness of air gap 6b. This reduction in the magnetic reluctance of air gap 6b originates from a force Fb applied to the end 2b of the movable armature. Conversely, the increase in the magnetic reluctance of air gap 6a originates from a force Fa applied to the end 2a of the movable armature.

[0067] This causes the magnetic force present at the first end 2a and the second end 2b of the movable armature 2 to generate torque, thereby causing the movable armature 2 to rotate about a rotation axis that is parallel to the y-axis and perpendicular to the x-axis connecting the two ends.

[0068] The intensity of the current applied in the first coil 9a defines the force of the flux, and the direction of the current defines the direction of the flux. When the dynamic magnetic circuit passes through the two ends of the movable armature, the flux applied by the first coil 9a will be in the same direction as one of the two static magnetic circuits and opposite to the direction of the other static magnetic circuit that causes rotation. The reversal of the current direction reverses the direction of the force, thereby reversing the direction of rotation.

[0069] Coils 9a / 9b are formed by windings of at least one conductor, such as enameled copper wire. Flanges made of magnetic material guide the magnetic field lines, thereby adding to or subtracting from the dynamic magnetic field Hd originating from coils 9a and 9b and the static magnetic field Hs originating from magnets 5a and 5b in air gaps 6a and 6b.

[0070] In an advantageous embodiment, the first and second coils 9a and 9b are supplied with the same current source so that the same current flows through both coils. Preferably, the first and second coils 9a and 9b are connected in series, such that the current supplying them generates an additional field. Thus, when the same current flows, coils 9a and 9b apply magnetic fields of opposite directions and the same strength in flanges 3a and 3b. In an alternative embodiment, coils 9a and 9b are supplied with different current sources. Therefore, redundancy can be ensured for each coil, allowing the actuator to operate even in the event of a failure in the power supply coil or circuit.

[0071] One or more current sources associated with coils 9a and 9b are configured to provide different current intensities and two different current directions in one or more coils, so that the movable armature 2 can rotate continuously in two rotational directions within an accessible range.

[0072] exist Figure 1 , 2 In the advantageous embodiments shown in 4 and 5, coils 9a and 9b are formed on coil supports 10a and 10b. Coil supports 10a and 10b are made of a non-conductive material, thereby preventing any short circuit between coils 9a / 9b and the stator core 3. This construction facilitates the installation of coils 9a and 9b.

[0073] As described above, the movable armature 2 is located inside the stator 1 between the two magnets 5a and 5b. The movable armature 2 includes magnetic portions forming two ends 2a / 2b.

[0074] Advantageously, the thickness ratio between the movable armature 2 and the magnet is between 0.8 and 1.2. Preferably, the thickness of the movable armature 2 is equal to the thickness of the first and second magnets 5a / 5b on the z-axis. Preferably, the mid-plane of the stationary movable armature 2 is aligned with the mid-plane of the magnets 5a / 5b, even more preferably when the actuator is provided with magnetic poles 7a / 7b. The mid-plane corresponds to a plane equidistant from the two opposing surfaces of the magnet or the movable armature 2 on the z-axis. In the absence of magnetic poles 7a / 7b, it is advantageous to arrange the mid-plane of the movable armature so that it is aligned with the interface between the magnets 5a / 5b and the flanges 3a / 3b.

[0075] The movable armature 2 has a planar shape. Advantageously, the length of the movable armature 2 along the x-axis and its width along the y-axis are greater than its thickness along the z-axis, for example, at least three times greater. The movable armature 2 extends primarily along the x and y axes. The movable armature 2 advantageously has an axis of symmetry parallel to the z-axis. Preferably, the axis of symmetry of the movable armature 2 is collinear with the axis of symmetry of the stator core 3 or at least the flange. The movable armature 2 has opposing first and second main surfaces connected by sidewalls. The sidewalls define opposing first and second ends 2a, 2b. The first main surface is designed to receive a load that is to be rotated relative to the stator. The load can be a mirror, a sample, or any other object to be rotated.

[0076] exist Figure 1 , 2 In the embodiments shown in 3, 4, and 5, the dimension of the movable armature 2 on the x-axis is slightly smaller than the minimum distance between the separation distances of the two magnets 5a / 5b, the two flanges 3a / 3b, and the two poles 7a / 7b, to provide a magnetic air gap 6a / 6b and prevent any contact between the movable armature 2 and the flanges 3a / 3b, magnets 5a / 5b, and poles 7a / 7b when rotation occurs. The width of the air gap 6a / 6b is chosen to be smaller than the dimension of the movable armature 2 on the x-axis.

[0077] The two main surfaces of the movable armature 2 do not overlap by flanges or magnets on the z-axis, thus preventing any contact hazards. These surfaces may be strictly flat, flat with chamfers, or slightly rounded in a cutting plane containing the x and z axes, for example, the diameter of the rounding is equal to the size of the x-axis of the movable armature 2.

[0078] To prevent the movable armature 2 from adhering to the magnet, the movable armature 2 is mounted on a guide 11, which restricts or prevents movement of the movable armature 2 in a plane perpendicular to the z-axis. The movable armature 2 is mechanically connected to the stator, for example, mechanically connected to the stator core 3, via the guide 11. The guide 11 is advantageously fixedly mounted on the stator core 3. It is particularly advantageous to use a guide 11 that prevents translation of the movable armature on the x and y axes and preferably prevents any translation in the plane containing the first and second axes. It is particularly advantageous to choose a guide other than a flexure rod, because such a configuration does not preclude adhesion to the magnet while being difficult to actuate for rotation. The guide 11 is advantageously configured to prevent rotation about a third axis z. The guide defines one or more axes of rotation substantially contained within the volume of the guide 11. The guide can be configured to allow the movable armature 2 to rotate about an axis of rotation perpendicular to the z-axis and prevent translation perpendicular to the z-axis, thereby making it easier to obtain a constant or quasi-constant air gap during rotation. It also prevents the risk of adhesion when subjected to vibration.

[0079] The two flanges 3a / 3b extend primarily or only along the first axis z, which is perpendicular to the second axis x and the third axis y, from the support member 4.

[0080] The guide 11 can be fixedly mounted on the stator 1, for example, on the stator core 3. The guide 11 supports the weight of the movable armature 2 while allowing rotational movement of the movable armature 2 at least about a first axis of rotation. Advantageously, the guide is formed by a flat or substantially flat plate with openings through multiple slots, thus forming a flexible guide bearing. The slots, the attachment points of the stator 1, and the attachment points of the movable armature 2 are arranged to facilitate rotation about the x and y axes and restrict other movements. The slots are through on the z-axis.

[0081] By using a guide in the form of a plate with holes formed by slots, the movable armature 2 can rotate without having to overcome friction, thus enabling small angular movements. Rotation is achieved through deformation of a preferred area of ​​the perforated plate.

[0082] exist Figure 5 and 6In the illustrated embodiment, guide 11 is a flexible guide bearing formed by a perforated body, such as a perforated plate defining a plurality of helical or spiral segment slots. A mounting plate perpendicular to the z-axis is provided to facilitate rotation about an axis perpendicular to the z-axis. Advantageously, an attachment point between the stator and the flexible guide bearing is formed at the center of the guide bearing. The attachment point between the flexible guide bearing and the movable armature is located at the periphery of the flexible guide bearing. The flexible guide bearing can be made of a metallic material. This flexible guide bearing makes rotation about a first axis of rotation parallel to the y-axis and a second axis of rotation parallel to the x-axis easier to achieve without introducing any friction, thus facilitating small rotation angles, ensuring virtually unrestricted movement, and effectively absorbing forces without impact. Guide 11 is planar and extends primarily along the x and y axes, with a thickness less than its length and width. Advantageously, guide 11 is fixed to the bottom main surface of the movable armature 2. The guide advantageously forms a rotation axis that is contained in a plane comprising the interface between the two magnets 5a / 5b and the two flanges 3a / 3b. Advantageously, the guide includes an axis of symmetry parallel to the z-axis.

[0083] The control circuit is advantageously connected to one or more current sources. The control circuit is configured to allow current to flow in one or more coils 9a and 9b. This generates a dynamic magnetic field Hd that flows along flanges 3a and 3b and support 4 until it reaches the ends of the movable armature 2. Figure 7 A specific embodiment of the control circuit is shown.

[0084] Rotation of the movable armature 2 can be achieved by applying dynamic magnetic fields with opposite components along the two flanges 3a and 3b. Figure 1 In the configuration shown, the field Hd in air gap 6a has the same direction as the field Hsa in air gap 6a. The field Hd in air gap 6b has the opposite direction to the field Hsb in air gap 6b.

[0085] The direction of current flow in coils 9a / 9b defines the rotation direction of the movable armature. The value of the magnetic field Hd is added to or subtracted from the values ​​of the static magnetic fields Hsa and Hsb, depending on the direction of the applied current. In the first order, the total magnetic torque applied to the movable armature 2, and therefore the rotation angle, is proportional to the current intensity I. The direction of the current applied in the coil defines the sign of the rotation angle of the movable armature 2 relative to the stator core 3. The magnetic actuator can precisely define the rotation angle relative to a reference position. The illustrated configuration allows for a controllable magnetic mechanism in rotation in both directions around the rotation axis.

[0086] The present construction is particularly advantageous because it allows torque to be transmitted to the movable armature 2 without any mechanical contact, thus avoiding the need to overcome friction. The movable armature 2 has no direct contact with magnets 5a and 5b or coils 9a and 9b. The movable armature also has no contact with flanges 3a / 3b. The absence of magnets in the movable armature reduces the weight to be moved.

[0087] In an advantageous embodiment, the minimum distance separating the sidewall of the movable armature 2 from the side surface (on the x-axis) of the magnet 5a / 5b is less than the thickness of the magnet and the movable armature. Advantageously, the minimum distance separating the sidewall of the movable armature 2 from the end of the flange 3a / 3b is at least twice the thickness of the magnet and / or the movable armature, preferably at least five times smaller.

[0088] The proposed structure is highly advantageous because it allows the moving parts to move about a rotation axis by means of a single magnetic actuator of the type of moving iron. This configuration is advantageous because it reduces the weight of the device compared to devices that require multiple actuators to perform rotation about a single axis.

[0089] In the illustrated configuration, one or more coils 9a / 9b form a dynamic magnetic circuit flowing through the stator core and the movable armature. Even when two coils are used, a single magnetic field linked to the dynamic magnetic circuit flows through the movable armature. Compared to prior art configurations where each end is associated with a dynamic magnetic field, the power supply difference between coils 9a and 9b or the different aging processes between coils are easier to manage.

[0090] In existing technologies, magnetic reluctance is achieved by varying the thickness of the air gap along the z-axis. This makes actuator design very complex because the air gap value changes considerably during rotation and can cause the movable armature, magnet, or disk to adhere to the core. In contrast, according to the present invention, magnetic reluctance is achieved by varying the air gap surface arranged perpendicular to the x-axis. This frees up the top and bottom of the movable armature to allow for greater rotation angles while preventing magnetic adhesion and collisions with the stator.

[0091] Reference Figure 3 , 4 5. The magnetic actuator can be configured to produce angular motion about two rotational axes, x and y, which are respectively parallel to each other and perpendicular to the z-axis. The rotation of the movable armature 2 about the x-axis is achieved through a configuration identical to the aforementioned configuration, but offset by 90° about the z-axis. Figure 2 As shown, the movable armature 2 includes third and fourth terminals 2c and 2d that cooperate with third and fourth magnets 5c and 5d. The third and fourth terminals 2c and 2d are connected via a magnetic circuit.

[0092] The stator core 3 includes third and fourth flanges 3c and 3d, the first ends of which are covered by third magnet 5c and fourth magnet 5d, respectively. The third magnet 5c and fourth magnet 5d are magnets with axial magnetization parallel to the z-axis.

[0093] The movable armature 2 is arranged between the third and fourth magnets 5c and 5d, and aligned with them on the y-axis. The movable armature 2 is separated from the third and fourth magnets 5c and 5d by a third air gap 6c and a fourth air gap 6d, respectively. In the absence of bias voltage on the coils 9a, 9b, 9c, and 9d, the movable armature 2 and the two pairs of magnets advantageously belong to the same plane. This plane is perpendicular to the z-axis.

[0094] The third and fourth magnets 5c and 5d form third and fourth static magnetic circuits respectively with the third flange 3c and the third end 2c of the movable armature 2 on one side, and with the fourth flange 3d and the fourth end 2d of the movable armature 2 on the other side. The opposing third and fourth ends 2c / 2d are aligned on the y-axis. For the previous embodiment, it is advantageous to use magnetic poles 7c and 7d on the third and fourth magnets 5c / 5d.

[0095] An auxiliary coil 9c is assembled around a third flange 3c. The auxiliary coil 9c generates a second dynamic magnetic field with field lines guided by the third flange 3d, the support 4, and the fourth flange 3d, extending to the fourth end of the movable armature 2. Field lines originating from the fourth end 2d of the movable armature 2 pass through the movable armature by means of a magnetic material until they reach the third end 2c, and then the third flange 3c.

[0096] The third and fourth magnets 5c / 5d define the resting position of the movable armature about the x-axis. An additional actuation coil 9c applies a magnetic field, causing the movable armature 2 to rotate along the x-axis in one direction or the other.

[0097] As previously mentioned, it is advantageous to use third and fourth coils 9c and 9b respectively mounted around the third flange 3c and the fourth flange 3d, so that the dynamic magnetic field lines generated in the third and fourth air gaps 6c / 6d are the same, thereby changing the strength of the magnetic coupling present between the movable armature 2, the ends of the flanges 3c and 3d and the two magnets 5c and 5d.

[0098] The first set of coils 9a / 9b and magnets 5a / 5b ensures rotation about the y-axis, while the second set of coils 9c / 9d and magnets 5c / 5d ensures rotation about the x-axis.

[0099] Magnetic operation with two axes of rotation is similar to operation with a single axis of rotation, but with a flux density distribution and a more complex field line distribution. Each pair of magnets is arranged with axial polarization so that the movable armature is oriented along the z-axis. For two magnets facing each other on either the x-axis or y-axis, i.e., for two magnets cooperating to ensure that the magnetization directions of the two magnets rotating about one of the axes of rotation are the same. Advantageously, the pair of magnets rotating about the first axis has a magnetization direction opposite to that of the pair rotating about the second axis. In other words, the first and second magnets 5a / 5b have magnetization directions opposite to those of the third and fourth magnets 5c / 5d. When observed around the movable armature 2, the change in magnetization direction exists along the z-axis. This configuration allows for a reduction in the actuator's dipole moment and the maintenance of a weak quadrupole moment. However, four magnets with the same magnetization direction can also be used.

[0100] By activating only coils 9a and 9b, the movable armature 2 can be rotated about the y-axis. By activating only coils 9c and 9d, the movable armature 2 can be rotated about the x-axis. By activating coils 9a, 9b, 9c, and 9d, rotations about both axes of rotation can be combined.

[0101] Advantageously, coils 9c and 9d are powered by the same current source and are connected in series as described with respect to coils 9a and 9b. Other embodiments are also possible.

[0102] It is advantageous to make the four magnets identical in terms of magnetic field strength and their possible dimensions, as this makes actuation of the movable armature 2 easier to achieve. In the illustrated embodiment, the actuator includes only two magnets to achieve rotation about the axis of rotation, i.e., four magnets to achieve rotation about two perpendicular axes. Preferably, the magnets are contained in a plane that also contains the movable armature. The actuation coil belongs to another plane offset from the plane of the magnets. A half-space defined by the mid-plane of the movable armature 2 and perpendicular to the z-axis separates the actuation coil from the load to be moved. The magnetic field lines generated by the magnets and guided by the flange deviate from the flange from the side surface in the direction of the bottom main surface of the movable armature.

[0103] A magnetic actuator can be incorporated into an optical aiming device that includes a radiation source and / or a sensor of the radiation.

[0104] Mirror 12 or any other reflective element can be mounted on the top surface of the movable armature 2. Mirror 12 can be configured to reflect optical and / or infrared radiation. It is also possible that reflective element 12 is configured to reflect another type of electromagnetic radiation. This configuration is particularly advantageous because the top surface of the movable armature 2 is not directly connected to another part located outside the movable armature 2 (e.g., on the core), which would hinder or complicate the rotation of the movable armature 2. The bottom surface of the movable armature 2 faces the stator core. Mirror 12 is fixedly mounted on the top surface of the movable armature, so that rotation of the movable armature 2 results in the same rotation of mirror 12.

[0105] Mirror 12 can be configured to cooperate with a radiation source, such as a laser. The radiation source emits a light beam that strikes the mirror, and the orientation of mirror 12 causes the reflected light beam to be sent back to the sensor. By changing the orientation of mirror 12, the light beam can be sent back to multiple different sensors. The orientation of mirror 12 also allows the position of the sensor to be adapted to changes in the position of the radiation source. Depending on the embodiment, the radiation source or sensor can be movable relative to the stator core 3.

[0106] The optical aiming device can be used in an optical communication system between two objects, such as two satellites. Each object has an optical aiming device associated with an optical signal transmitter and / or receiver. The angular position of mirror 12 can be controlled by a loop to guide the light beam from the first object to the second object, taking into account the movement between the objects. The angular position of mirror 12 can also be controlled by a loop to guide the received light beam to the optical signal sensor. As the signal source moves, the orientation of the mirror must be changed to reflect it onto the sensor.

[0107] In another embodiment, the reflecting device is replaced by a sample holder or the sample to be analyzed. For example, an actuator may be incorporated into the diffractometer. The movable armature includes a reference sample. Rotation of the movable armature orients the reference sample toward an electromagnetic radiation beam (e.g., X-rays) or particles (e.g., neutrons) to cause the beam to diffract. The reference sample may be replaced by a sample holder, or the movable armature may include both a reference sample and a sample holder.

[0108] In a particular embodiment, an internal sensor system formed by targets 13a / 13b and probes 14a / 14b is integrated into the actuator. One or more targets 13a and 13b are fixedly mounted on the movable armature 2. Targets 13a and 13b cooperate with sensors 14a and 14b, which are configured to measure the position of the movable armature 2 relative to the stator core 3 and thus follow the rotation of the movable armature 2 relative to the stator core 3. Advantageously, sensors 14a / 14b are eddy current type magnetic sensor probes. Advantageously, targets 13a / 13b are aligned on the x-axis for maximum sensitivity to rotation about the y-axis. Advantageously, targets 13a, 13b and probes 14a, 14b are separated from the stator core 3 and / or from the coils 9a / 9b via the movable armature 2, thus being located on the side where the load 12 is located. In an advantageous manner, the surfaces of targets 13a / 13b facing probes 14a / 14b are located in the same plane as the reflective surface of the mirror 12 forming the load, which allows for precise measurement of the movement of the reflective surface of mirror 12. Magnetic sensors, capacitive sensors, and optical sensors can also be used to measure the linear travel of the region of the movable armature 2 and derive the associated rotation angle.

[0109] Sensor probes 14a / 14b are configured to measure the distance separating the target 13a / 13b from the associated sensor 14a / 14b. Sensors 14a / 14b are associated with control circuitry configured to calculate the rotation angle of the movable armature 2 after measuring the approach and departure of the sensor 14a / 14b from the target 13a / 13b. Advantageously, the two targets 13a / 13b are arranged on an axis perpendicular to the rotation axis of the movable armature 2. These two targets 13a / 13b cooperate with two sensors. One sensor detects the approach of the target, while the other detects the departure, thus determining the direction of rotation. The signal strength allows the value of the rotation angle to be determined. Operation could also be performed using a single sensor, but this is less advantageous due to lower accuracy. By using two sensors on a single rotation axis, differential measurements can be performed, thereby compensating for the thermal expansion effect of the movable armature or stator due to heating of the drive coil. The actuator can take advantage of the absence of internal sensors to achieve maximum angular travel. These travels are then monitored using external sensors.

[0110] It is particularly advantageous to manufacture the stator core 3 from a thermally conductive material such as metal. This enables good transfer of heat flux originating from coils 9a, 9b, 9c, and 9d. Good heat dissipation limits heat transfer to the movable armature 2, which includes a reflective element 12 whose optical properties and / or dimensions may vary with temperature.

[0111] Advantageously, the stator core 3 is coupled to a heat sink to eliminate some of the heat generated by coils 9a, 9b, 9c, and 9d. The heat sink interface is advantageously arranged on the support 4. The use of a heat sink allows for the use of higher current values. Since the movable armature 2 is not physically coupled to the stator core 3, heat present in the stator core 3 is difficult to flow to the movable armature 2. Figure 4 In the illustrated embodiment, the actuation coil is submerged in resin 15 to facilitate heat dissipation. The resin is thermally connected to the heat sink interface.

[0112] like Figure 6 As shown, it is advantageous to mount the load support 17 on the top surface of the movable armature 2 so as to transmit the rotational movement of the movable armature 2 without causing any deformation of the mirror 12. The load support 17 is more preferably configured to make the reflecting element 12 insensitive to temperature changes within at least a given temperature range. The load support 17 prevents modification and deformation of the reflecting element due to temperature changes caused by the actuator, especially the coil. The load support 17 is configured to limit the heat flux between the movable armature 2 and the reflecting element 12.

[0113] exist Figure 5 and 6 In the preferred embodiment shown, the reflecting device 12 is a mirror comprising four fixed lugs. The mirror is mounted on the movable armature 2 via a load support 17. The load support 17 performs the mechanical connection between the load 12 and the movable armature 2. The load support 17 is in the form of a plate, comprising multiple regions mechanically connected to each other to form a single or integral element, but also having regions that can move relative to each other in a nearly independent manner along the z-axis. The load 12 is secured to the load support 17 via a first attachment point, here in the form of bolts 20b. The load support 17 is mechanically connected to the movable armature 2 via a second attachment point, here in the form of bolts 20a.

[0114] Each region has a load support 17 and attachment points for the load 12 and the movable armature 2. Each region is separated from the adjacent region on the z-axis by a first through slot 18a.

[0115] Advantageously, each region is divided into two basic regions by a second slot 18b. One basic region has an attachment point to the load 12, while the other basic region has an attachment point to the movable armature 2. To increase mechanical independence and near-translational movement of the attachment points along the z-axis, it is advantageous to provide third and preferably fourth slots 18c and 18d extending in arcs. Preferably, the third and fourth slots substantially define two concentric circles. The third and fourth slots 18c, 18d extend away from slot 18a in opposite directions, such that each attachment point is mechanically connected to a retaining ring that mechanically connects all attachment points.

[0116] The load support 17 includes a plurality of through slots or recesses 18a, 18b, 18c and 18d arranged to enhance the flexibility of the attachment point or the point having the movable armature 2 and the reflective element 12 along the z-axis when the load support 17 is mounted perpendicular to the z-axis.

[0117] The load support 17 is divided into a plurality of peripheral attachment points, which are separated from each other by a first groove 18a, which begins at the outer end of the load support and extends toward the center of the load support. The load support increases flexibility along the z-axis to compensate for static uncertainties, such as possible height differences (along the z-axis) at the attachment points with the reflector. The load support 17 is secured to the movable armature 2 by bolts 20a that pass through holes 19a and cooperate with nuts 21a. Bolts 20a advantageously perform fixation on the target 13 forming the nut 21a. The attachment point of the planar mirror support to the mirror 12 can be a through hole 19b that mates with bolts 20b and possibly nuts 21b and preferably with washers 22b.

[0118] The load support 17 is formed of a plate having a preferably substantially circular outer shape. The load support 17 advantageously comprises four distinct regions that are repeated by rotational symmetry. Two successive regions are separated by a first groove 18a extending from the outer circumference along the central direction of the load support 17. The center of the bearing is advantageously the center of symmetry. The first groove 18a is not a straight groove, but rather a curved groove preferably having a radius of curvature and advantageously a constant radius of curvature. The different regions are mechanically connected to each other by retaining rings. The first groove 18a stops before the retaining rings. Each region includes an attachment point to the load 12 and an attachment point to the movable armature 2. The support has two regions aligned on the x-axis and two regions aligned on the y-axis.

[0119] Each region is divided into two basic regions, each including a fixing rod and / or a through hole. The two basic regions are separated by a second through groove 18b, which extends from the outer circumference of the plate to the adjacent first groove 18a. The through groove 18b is curved to have a curvature in the same direction as the first groove 18a and has a larger radius of curvature than the first groove 18a. The second through groove 18b and the first groove 18a advantageously have the same concavity orientation. One of the basic regions is fixed to the movable armature 2, while the other basic region is fixed to the load 12.

[0120] In addition to the first groove 18a and the through groove 18b, the plate also has third and fourth series of through grooves 18c / 18d. The two series of grooves extend around a center in the form of arcs with two different radii of curvature. Advantageously, the two series of through grooves share the same center. Each region of the third series of through grooves 18c includes one through groove, and each third through groove 18c extends from the first groove 18a along a first direction (i.e., clockwise or counterclockwise) to the adjacent first groove 18a without reaching the adjacent first groove 18a to maintain the mechanically fixed area.

[0121] Each region of the fourth series of through slots 18d includes one through slot 18d, and each fourth through slot 18d extends from the first slot 18a to the adjacent first slot 18a in a second direction opposite to the first direction, without reaching the adjacent first slot 18a to maintain the mechanically fixed region.

[0122] This configuration of the load support 17 allows each region to deform relative to its adjacent region on the z-axis, and allows deformation between two basic regions of the same region on the z-axis. Static uncertainties between different elements relating to fixing the reflective element 12 to the movable armature, particularly height differences (on the z-axis), can be at least partially compensated for, thereby reducing mechanical strain induced in the reflective element 12.

[0123] In the illustrated configuration, the coils are arranged entirely between the plane containing the movable armature 2 and the magnets 5a / 5b / 5c / 5d and the support 4, thereby limiting the space occupied in the upper region of the movable armature 2, which is designed to function with a reflective device or other elements. Unlike the configuration proposed in Yongjun Long's aforementioned publication, "Modeling and Analysis of a Novel Two-Axis Rotary Electromagnetic Actuator for Fast Steering Mirror," the moving parts are not arranged in a disc-shaped component formed by the coils surrounding the mirror. The illustrated configuration allows for a larger angular travel.

[0124] exist Figure 5In the illustrated embodiment, the support 4 has a central hole to allow the wires of the actuating coils 9a-9d to exit. Flanges 3a-3d continue to extend from the support 4. The flanges are fixed to the support 4 to form an integral assembly. Coils 9a, 9b, 9c, and 9d are housed in a cylinder 16 and submerged in resin 15 for heat dissipation. The support 4 and flanges 3a-3d are fixed to a first housing element 23a. Coils 9a-9d are fixedly mounted in the cylinder 16 and a second housing element 23b, fixed to the first housing element 23a, is secured by resin 15. Preferably, the cylinder 16 and the second housing element 23b form an integral component.

[0125] The third housing element 23c is fixed to the second housing element 23b. The second housing element 23b defines a mounting plate 24, to which the guide 11 is fixed by bolts 25 or any other fixing device. The movable armature 2 is fixed to the mounting plate 24 by the guide 11 and a plurality of bolts 20a. The guide 11 is fixedly mounted to the stator 1 by means of the mounting plate 24, which is fixed to the housing 23c or forms part of the housing 23.

[0126] Mirror 12 is mounted on the first surface of the movable armature 2 via load support 17. Target 13 is also mounted around mirror 12 on the first surface of the movable armature 2, for example, at the end of bolt 20a. Sensor probe 14 is advantageously mounted on or integrated into a ring-shaped printed circuit board (PCB) facing target 13 via eddy current. The advantage of arranging four probes in a single PCB is improved probe repeatability and easier assembly and interconnection, while also reducing costs. The probe is advantageously a bend made of conductive material formed on the electronic circuitry.

[0127] The PCB circuit is secured to a fourth housing element 23d, which is fixed to the second housing element 23b, via a third housing element 23c. The sensor 14 is fixedly mounted relative to the housing and the stator 1. The fourth housing element 23d defines a through-hole facing the reflective element on the z-axis to allow electromagnetic radiation to pass through.

[0128] The subassemblies, including the third housing element 23c, mounting plate 24, bolt 25, guide 11, movable armature 2, load support 17, target 13 and mirror 12, form the detachable optical head of the second housing element 23b and the fourth housing element 23d. This makes inspection and installation in the actuator easier, thereby reducing costs.

[0129] Magnetic actuators include or are associated with control circuitry, such as... Figure 7The control circuit shown has one or more inputs designed to receive rotational setpoints, such as signals Cx and Cy, to be applied to the movable armature 2. The control circuit may have inputs designed to receive data relative to rotation about the x-axis (Cx) and inputs designed to receive data relative to rotation about the y-axis (Cy). Based on the received data, the control circuit applies a first current Ix to the first coil or a pair of coils to cause rotation about the x-axis, and applies a second current Iy to the second coil or a pair of coils to cause rotation about the y-axis. The strength and flow direction of the first current Ix are defined according to the desired rotation. The strength and flow direction of the second current Iy are also defined according to the desired rotation. For example, a first current control amplifier 27 can be used to power the first coil 9a or both coils 9a / 9b. The same can be done when powering the third coil 9c or both coils 9c / 9d with the second current control amplifier 27.

[0130] As shown in the figure, it is advantageous to receive first data from sensors 14a / 14b to assess the effective rotation of the movable armature 2 about a first rotation axis and, if necessary, adjust the current value to obtain the desired tilt angle. Second data from the second pair of sensors can be used to monitor rotation about the rotation axis and adjust the applied current value. The control circuit may have third and fourth inputs connected to the first and second pairs of sensors to receive signals representing effective rotations S1 and S2. The control circuit may also have additional first and second inputs designed to connect to external sensors, such as an optical sensor that receives flux reflected by a reflector. Data from the external sensors is used to adjust the static and / or dynamic angular position of the movable armature. When the actuator operates with an element movable relative to the actuator, the external sensors enable servo control of the position of the movable armature 2. The external sensors may emit signals SE1 and SE2 representing effective rotation or rotation that holds the beam in the desired position.

[0131] The control circuit may include a damping circuit, which is used to dampen the movement of the actuator when the actuator is not energized. The damping circuit forms an RLC circuit with one or more coils.

[0132] A first switch 26 is installed to connect one or more coils involved in causing rotation about the y-axis to a current source or a damping circuit. The damping circuit has an electrical load advantageously formed by a resistor R, preferably connected in series with a capacitor C. The damping circuit is connected to one or more coils via a first terminal and to a fixed potential, such as ground, via a second terminal.

[0133] A second switch 26 can be installed to connect one or more coils involved in causing rotation about the x-axis to a current source or a damping circuit. The damping circuit has an electrical load advantageously formed by a resistor connected in series with a capacitor. The damping circuit is connected to one or more coils via a first terminal and to a fixed potential, such as ground, via a second terminal. The two switches can be operated independently by signals Dx and Dy applied to their control electrodes.

[0134] This damping circuit dampens vibrations caused by the mechanism's resonance. When the mechanism is subjected to external vibrations or shocks encountered by an embedded system (e.g., in a satellite during launch), mechanical resonance of the mechanism, formed by the moment of inertia and the rotational stiffness of the movable armature, is excited. This resonance tends to cause the movable armature 2, including the mirror, to oscillate, which is undesirable. Due to the magnets 5a, 5b, 5c, and 5d, the oscillating motion of the movable armature 2 generates flux changes in the stator circuit, resulting in voltage changes at the terminals of coils 9a, 9b, 9c, and 9d. If a damping circuit is connected, these voltage changes will generate current changes Ix and Iy, allowing electrical power to be dissipated through resistor R. This resistive damping limits the oscillating motion of the movable armature 2.

Claims

1. A magnetic actuator comprising a stator (1) and a movable armature (2) mounted in rotation with respect to the stator (1), wherein the stator (1) having: - a stator core (3) made of a magnetic material comprising a first and a second flange (3a, 3b) connected by a support (4), - a first magnet (5a) mounted on one end of the first flange (3a), - a second magnet (5b) mounted on one end of the second flange (3b), the first and second magnets (5a, 5b) having an axial magnetization with a magnetization axis directed along a first axis (z), the first and second magnets (5a, 5b) being aligned along a second axis (x) perpendicular to the first axis (z), - at least a first coil (9a) fitted around the first flange (3a) between the support (4) and the first magnet (5a), wherein the movable armature (2) is arranged between the first and second magnets (5a, 5b) along the second axis (x) and has dimensions along the second axis (x) and along a third axis (y) perpendicular to the first axis (z) and to the second axis (x) which are respectively greater than a dimension of the movable armature (2) along the first axis (z), the movable armature (2) defining with one end of the first flange (3a) and the first magnet (5a) a first air gap (6a) and with one end of the second flange (3b) and the second magnet (5b) a second air gap (6b), the movable armature (2) having opposite first and second ends (2a, 2b) along the second axis (x), wherein a guide (11) mechanically connects the movable armature (2) to the stator (1), the guide (11) being configured to allow rotation of the movable armature (2) around a first axis of rotation parallel to the third axis (y) and to prevent translational movement of the movable armature (2) along the second axis (x) towards the first magnet (5a) and the second magnet (5b), wherein the first magnet (5a) is magnetically coupled with the first end (2a) of the movable armature (2) and with the first flange (3a) to form a first static magnetic circuit (8a), wherein the second magnet (5b) is magnetically coupled with the second end (2b) of the movable armature (2) and with the second flange (3b) to form a second static magnetic circuit (8b), and wherein the first coil (9a) is magnetically coupled with the first and second ends (2a, 2b) of the movable armature (2), with the first and second flanges (3a, 3b) and with the support (4) to form a first dynamic magnetic circuit.

2. The magnetic actuator of claim 1, wherein, the first flange (3a) and the second flange (3b) extend along the first axis (z) away from the support (4) and the first and second magnets (5a, 5b) are arranged in the extension of the first and second flanges (3a, 3b) along the first axis (z).

3. The magnetic actuator of claim 1 or 2, wherein, the ratio of the thickness of the first and second magnets (5a, 5b) to the thickness of the movable armature (2) is between 0.8 and 1.2, the thicknesses being measured along the first axis (z).

4. The magnetic actuator of claim 1 or 2, wherein, the median plane of the first and second magnets (5a, 5b) along the first axis (z) is the median plane of the movable armature (2).

5. The magnetic actuator of claim 1 or 2, wherein, - first and second poles (7a, 7b) made of magnetic material are placed on the first and second magnets (5a, 5b), respectively, said first and second poles (7a, 7b) being separated from the first and second flanges (3a, 3b) by the first and second magnets (5a, 5b).

6. The magnetic actuator of claim 1 or 2, wherein, - the minimum distance between the first magnet (5a) and the movable armature (2) is greater than or equal to the minimum distance between the first flange (3a) and the movable armature (2).

7. The magnetic actuator of claim 1 or 2, wherein, - a second coil (9b) is mounted around the second flange (3b) between the support (4) and the second magnet (5b), said second coil (9b) forming part of the first dynamic magnetic circuit.

8. The magnetic actuator of claim 7, wherein, - the guide (11) is fixed to the stator (1) by at least a first attachment point (25) and to the movable armature (2) by a plurality of second attachment points (20a), wherein the guide (11) comprises a main body defining a through slot in the first axis (z), the through slot being in the form of a helix pointing towards at least the first attachment point (25), and wherein the through slot separates at least the first attachment point (25) and the plurality of second attachment points (20a) in the second axis (x) and / or in the third axis (y).

9. The magnetic actuator according to claim 1 or 2, comprising third and fourth magnets (5c, 5d) mounted on third and fourth flanges (3c, 3d) of the stator core (3), respectively, said third and fourth magnets (5c, 5d) having an axial magnetization with their magnetization axis parallel to the first axis (z) and the third and fourth magnets (5c, 5d) being aligned in the third axis (y), the movable armature (2) having opposite third and fourth ends (2c, 2d) in the third axis (y) separated from the ends of the third and fourth flanges (3c, 3d) and from the third and fourth magnets (5c, 5d) by a third air gap (6c) and a fourth air gap (6d), the movable armature (2) being arranged between the third and fourth magnets (5c, 5d) in the third axis (y), wherein - the third magnet (5c) forms with the third end (2c) of the movable armature (2) and the third flange (3c) a third static magnetic circuit, - the fourth magnet (5d) forms with the fourth end (2d) of the movable armature (2) and the fourth flange (3d) a fourth static magnetic circuit, and wherein the magnetic actuator further comprises an additional coil forming an additional dynamic magnetic circuit with the third and fourth ends (2c, 2d), the third and fourth flanges (3c, 3d) and the support (4).

10. The magnetic actuator of claim 9, wherein, - the magnetization of the first and second magnets (5a, 5b) is in a first magnetization direction, and wherein the magnetization of the third and fourth magnets (5c, 5d) is in a second magnetization direction opposite to the first magnetization direction.

11. The magnetic actuator of claim 9, wherein, - the first, second, third and fourth magnets (5a, 5b, 5c, 5d) have a magnetization in the same magnetization direction. - the magnetization of the first and second magnets (5a, 5b) is in a first magnetization direction, and wherein the magnetization of the third and fourth magnets (5c, 5d) is in a second magnetization direction opposite to the first magnetization direction. - the first, second, third and fourth magnets (5a, 5b, 5c, 5d) have a magnetization in the same magnetization direction.

12. The magnetic actuator of claim 1 or 2, wherein, The movable armature (2) has at least one target (13a, 13b) cooperating with at least one eddy current sensor probe (14a, 14b) to detect the movement of the movable armature (2) around the first axis of rotation, the at least one target (13a, 13b) and the at least one eddy current sensor probe (14a, 14b) being separated from the at least first coil (9a) and from the support (4) by the movable armature (2).

13. The magnetic actuator of claim 9, wherein, The movable armature (2) has two pairs of targets (13a, 13b) fixed mounted on the movable armature (2) and aligned on the second axis (x) and on the third axis (y) respectively, wherein the stator (1) comprises two pairs of eddy current sensor probes (14a, 14b) to detect the rotation of the movable armature (2) around the first axis of rotation and around the second axis of rotation by differential mode, and wherein the two pairs of eddy current sensor probes (14a, 14b) are formed by coils made of electrically conductive material on a ring-shaped electronic printed circuit board.

14. The magnetic actuator of claim 1 or 2, wherein, A load (12) is fixed on a first main surface of the movable armature (2), the load (12) being separated from the first coil (9a) by the movable armature (2).

15. The magnetic actuator of claim 14, wherein, The load (12) is mechanically connected to the movable armature (2) by means of a load support (17), the load (12) being fixed to the load support (17) by a first attachment point, the load support (17) being mechanically connected to the movable armature (2) by a second attachment point, The load support (17) is formed by a plate defining four first slots (18a) through the plate along the first axis (z), the first slots (18a) extending from the periphery of the load support (17) in a direction towards the center of the load support (17) along a first curved path having a first concavity to define four regions, and defining at least third slots (18c, 18d) extending from the first slots (18a) in an arc of a circle around the center.

16. The magnetic actuator of claim 15, wherein, The load support (17) comprises four second slots (18b) through the plate along the first axis (z), the four second slots (18b) extending from the periphery of the load support (17) in a direction towards the first slots (18a) along a second curved path having a first concavity, each region comprising a second slot (18b) to define two elementary regions in each region, the first and second attachment points being arranged alternately, the first attachment point or the second attachment point separating a first slot (18a) and a successive second slot (18b), the third slots (18c, 18d) extending between the center and the four second slots (18b).

17. The magnetic actuator of claim 15, wherein, The guide (11) is fixed on a first main surface of the movable armature (2) and the load support (17) is fixed on a second main surface of the movable armature (2).

18. The magnetic actuator of claim 17, wherein, The guide (11) is fixed to the load support (17) by means of a bolt (20a) passing through a through hole of the movable armature (2).

19. The magnetic actuator of claim 12, wherein: - the load (12) is fixed on a first main surface of the movable armature (2), said load (12) being separated from the first coil (9a) by the movable armature (2), - said load (12) is mechanically connected to the movable armature (2) by a load support (17), - said load (12) is fixed to the load support (17) by a first attachment point, said load support (17) being mechanically connected to the movable armature (2) by a second attachment point, - said load support (17) is formed by a plate defining four first slots (18a) passing through the plate along a first axis (z), the first slots (18a) extending from a periphery of the load support (17) in a direction towards a center of the load support (17) along a first curved path having a first concavity to define four regions, and defining at least a third slot (18c, 18d) extending from the first slots (18a) in an arc of a circle around said center, - said guide (11) is fixed on a first main surface of the movable armature (2) and said load support (17) is fixed on a second main surface of the movable armature (2), - said guide (11) is fixed to the load support (17) by a bolt (20a) passing through a through hole of the movable armature (2), and - said at least one target (13a, 13b) is mounted on one of the bolts (20a).

20. The magnetic actuator of claim 14, wherein, The load is a reflective element (12).

21. The magnetic actuator of claim 20, wherein, The reflective element (12) is fitted inside a ring-shaped electronic printed circuit board.

22. The magnetic actuator of claim 9, wherein, The additional coil comprises a third and a fourth coil (9c, 9d) and the load (12) is fixed on a first main surface of the movable armature (2), said load (12) being separated from the first coil (9a) and from the second, third and fourth coils (9b, 9c, 9d) by the movable armature (2).

23. An electromechanical system comprising the magnetic actuator of claim 1 or 2, wherein, The electromechanical system comprises a control circuit defining a first power supply circuit of at least the first coil or a resistive damping circuit connected to at least a terminal of the first coil (9a), the resistive damping circuit comprising a resistor and a capacitor to form an RLC circuit.

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