RELUCTANCE ACTUATOR

Description

[0001] The invention relates to a reluctance actuator comprising a magnetizable stator, at least one coil designed to generate a magnetic field in the stator, and a yoke for at least partially closing the magnetic flux of the stator.

[0002] The invention further relates to an actuator system comprising a reluctance actuator.

[0003] The invention further relates to a method for performing lifting / tilting movements of a movable element of a reluctance actuator.

[0004] Although applicable to any system, the present invention is described in relation to actuation systems for optical components.

[0005] Well-known opto-mechanical tilt / steer systems, such as fast steering mirrors (FSMs), are used in a wide variety of applications. Other well-known actuation systems are based on Lorentz actuators, as described in the non-patent literature by M. Hafez, T. Sidler, R. Salathe, G. Jansen, and J. Compter, "Design and simulations and experimental investigations of a compact single mirror tip / tilt laser scanner," Mechatronics, vol. 10, pp. 741-760, 2000, or on piezoelectric actuators, as described in the non-patent literature by FM Tapos, DJ Edinger, TR Hilby, MS Ni, BC Holmes, and DM Stubbs, "High bandwidth fast steering mirror," Optomechanics 200, Proceedings of SPIE Vol. 5877, 2005.

[0006] Actuators based on Lorentz actuators are typically used in systems with a large sampling range (up to two degrees) but limited bandwidth (only a few hundred Hz). Piezo actuators, on the other hand, are used in systems with high bandwidth (up to several kHz) but small sampling ranges (typically only a few mrad).

[0007] Reluctance actuators exhibit a higher force density compared to Lorentz actuators and larger sensing ranges compared to piezo actuators. Reluctance actuators are used in a wide variety of applications, for example, for rotational movements in rapidly controllable mirror systems.

[0008] A disadvantage of this design, however, is that the two different actuator pairs for tilting around two axes are arranged around the movable element. While this enables rapid acceleration of the moving element, it significantly increases the overall installation space of the actuator and considerably limits the maximum achievable optical (deflection) angle. Further reluctance actuators have been described, for example, in the non-patent literature M. Boulet, Design of a small fast steering mirror for airbone and aerospace applications, Master's Thesis, Massachusetts Institute of Technology, 2008, and Y. Long, C. Wang, X. Dai, X. Wei, and S. Wang, Modeling and analysis of a novel two-axis rotary electromagnetic actuator for fast steering mirror, Journal of Magnetics, vol. 19, no. 2, pp. 130-139, 2014.

[0009] Other actors have become known from WO 2016 / 124782 A1, US 2016 / 0178894 A1, US 6,906,848 B2, US 2007 / 018604 A1, US 5,798,875 A1, JP-H11-308174 A and EP 0 990 187 B1.

[0010] However, all these known reluctance actuators also share the disadvantage that the four different actuators or two pairs of actuators are arranged around the moving element, thus significantly increasing the installation space and simultaneously reducing the maximum achievable optical (deflection) angle. Ultimately, this considerably limits their possible applications and uses.

[0011] One object of the present invention is therefore to provide a reluctance actuator that is compact, flexible in its application and also enables a high bandwidth and a large deflection while maintaining high reliability.

[0012] The present invention solves the aforementioned problem with a reluctance actuator according to claim 1.

[0013] The present invention also solves the problems with an actuator system according to claim 14.

[0014] The present invention also solves the aforementioned problems with a method according to claim 15.

[0015] One of the advantages achieved is that an extremely compact and highly dynamic actuator can be provided, since the yoke, in particular, forms an essentially outer enclosure of the actuator. A further advantage of this embodiment is that the moving element has a low mass if the moving element, also called the mover, consists only of the yoke that closes the magnetic circuit; the actuator thus exhibits a high bandwidth.

[0016] A further advantage of the yoke designed as a movable element is that the movable element is not spatially arranged within the yoke that closes the magnetic circuit, but rather forms a spatial enclosure, particularly on one side, of the actuator. In other words, the yoke or the movable element is essentially located externally, in contrast to the prior art, where the yoke is located internally, as described above. This allows for very efficient use of the available installation space, as there is no overhang of, for example, the yoke or coils. In other words, the movable element is located almost at the outermost point of the entire actuator, meaning that no component of the actuator protrudes beyond the movable element.

[0017] A further advantage is the large, particularly lateral, overlap of the moving element with the stator and coils: the ratio of the usable area of ​​the moving element to the overall diameter of the actuator is extremely high. The term "moving element" is to be understood in the broadest sense: synonymous terms for "moving element" are "mover" or "rotor." The moving element, as defined in the present invention, forms a yoke to close the magnetic field lines and acts as a mover or rotor. In particular, the moving element does not form a core.

[0018] Further features, advantages, and preferred embodiments of the invention are described below or become apparent therein: Advantageously, the stator has a permanent magnet section. This allows for the simple generation of a magnetic bias in the stator. The stator has an E-shaped cross-section along at least one axis, with two outer and one inner pole shoe. An E-shaped stator allows for a smaller overall diameter of the actuator compared to the commonly used C-shaped stators.

[0019] The stator has an E-shaped cross-section along two axes arranged at a specific angle to each other. This allows for simple and compact tilting about two axes independently of each other.

[0020] The angle between the two axes is conveniently set at 90°. This allows for tilting around the x- and y-axes.

[0021] Advantageously, at least one of the coils has a coil axis that is arranged essentially perpendicular to the direction of deflection of the moving element, in particular where the stator is at least partially arranged in the coil. The advantage of this is a particularly flat design in the z-direction.

[0022] Advantageously, the inner pole shoe of the E-shaped stator is identical along one axis to the inner pole shoe along the other axis. This allows for a simple and compact design. Furthermore, a single permanent magnet area on the inner pole shoe can be used to generate a magnetic bias in the four outer pole shoes.

[0023] Advantageously, the permanent magnet area is located at the inner pole shoe of the E-shaped stator. This makes it easy to achieve a magnetic bias in all pole shoes of the stator.

[0024] Advantageously, the permanent magnet section is located in the transition area where the pole shoes of the E-shaped stator are connected. This allows the magnetic bias to be transferred to the other pole shoes with particular reliability.

[0025] The movable element is movably mounted on the housing of the reluctance actuator by means of at least one bending element. This allows for simple yet reliable fixing of the movable element.

[0026] The bending element has an inner and outer area, as well as at least two suspensions, the two areas being connected to each other via these at least two suspensions. This achieves an extremely reliable yet flexible fixing and movement of the movable element.

[0027] Advantageously, at least one bending element is made of a resilient material, in particular beryllium and / or a plastic or aluminum. This allows for a lightweight, movable element while simultaneously ensuring its reliable fixation.

[0028] Advantageously, the movable element is directly connected to the at least one bending element, in particular to the inner area of ​​the at least one bending element. This enables cost-effective manufacturing, direct force transmission between the bending element and the movable element, and low inertia of both the bending element and the movable element.

[0029] Advantageously, the movable element and the bending element are formed as a single piece. This reduces manufacturing costs.

[0030] Advantageously, the movable element and the bending element are made of ferromagnetic steel, in particular spring steel. The advantages here are the compact design, the low inertia, and the position of the pivot point of the movable element close to the surface.

[0031] Advantageously, the bending element or the movable element is at least partially mirrored. In this way, it can itself serve as a mirror; the need for an additional mirror is eliminated, which reduces manufacturing costs.

[0032] Advantageously, the movable element is supported by at least one bearing, in particular a ball bearing, a point bearing in the form of a tip made of hard metal, sapphire, or the like, or a bending element, especially centrally on the inner or middle pole shoe of the stator. This allows tilting movements of the movable element in a simple and cost-effective manner by defining a point of rotation. Furthermore, forces in the z-direction are compensated, i.e., forces acting essentially parallel to the pole shoes of the stator.

[0033] Advantageously, at least one movable element is spaced apart from the stator by means of at least one air gap. This ensures both mobility and, at the same time, a substantially complete closure of the magnetic circuit between the yoke or movable element and the stator.

[0034] Advantageously, the stator has four outer pole shoes, with a coil attached to each pair of the four pole shoes, which are arranged opposite each other. This allows for simple movement of the moving element along two axes. The coils can be connected in series. If coils are arranged on all four pole shoes, two opposing coils work together to move the moving element around one axis. The moving element can then be tilted around two axes.

[0035] Advantageously, the stator is laminated. This reliably prevents eddy currents and increases the efficiency of the actuator.

[0036] Advantageously, only the outer pole shoes of the stator are made of multiple insulating layers. This allows the inner part to be made, for example, solely of ferromagnetic material, which simplifies its production, e.g., by turning it from solid material.

[0037] Advantageously, the inner pole shoe of the stator is cylindrical. This ensures uniform tilting in every spatial direction. Furthermore, it can be easily manufactured, for example by turning.

[0038] The yoke is advantageously made ferromagnetic. This eliminates the need for permanent magnets, etc., in the yoke or the moving element, thus enabling a low weight for the moving element.

[0039] Advantageously, the yoke is made of steel. This ensures reliable closure of the magnetic circuit via the yoke and, at the same time, a long service life for the yoke itself.

[0040] Advantageously, the movable element is essentially designed as a preferably circular, elliptical, or star-shaped disk. The disk shape allows for a flat design of the movable element. The pivot point of the movable element is thus located close to its surface. Furthermore, a compact installation space is achieved. The ratio of the disk's diameter to its thickness can be, for example, between 5 and 100,000, particularly between 10 and 10,000, or particularly between 100 and 1,000. When the movable element is designed as a star-shaped disk, the magnetic flux of the opposing coils is generated by the opposing arms of the star. This results in a lower mass for the movable element.

[0041] Advantageously, the disc is symmetrical along at least one axis. This allows for simple manufacturing while simultaneously ensuring reliable tilting of the movable element.

[0042] Advantageously, four suspension points are arranged, with the fixing point of each suspension point being offset from each other by 90° in the circumferential direction of the moving element, both on the inner and outer regions. This reliably restricts movement along the undesired degrees of freedom, while simultaneously compensating for the negative stiffness of the actuator with low stiffness in two desired directions / degrees of freedom.

[0043] Advantageously, the shape of at least one suspension point is essentially, at least partially, designed to correspond to the outer contour of the inner area of ​​the bending element. This allows for a particularly compact and symmetrical overall design of the actuator.

[0044] Advantageously, the actuator system incorporates a feedback and control device, which is connected to the reluctance actuator to control the movement of the movable element around at least one axis. This enables simple and reliable monitoring and control of the deflection of the movable element.

[0045] Advantageously, the feedback and control device includes a position measuring unit, in particular an angular position measuring unit, a current amplifier unit or a voltage amplifier unit, and / or an output current measuring unit. This allows, in particular, the measurement of essential parameters for actuating and controlling the actuator.

[0046] Advantageously, the yoke forms an essentially lateral outer boundary of the actuator. This results in a particularly compact installation space.

[0047] Further important features and advantages of the invention will become apparent from the dependent claims, the drawings, and the accompanying description of the figures based on the drawings.

[0048] It is understood that the features mentioned above and those to be explained below can be used not only in the combinations specified, but also in other combinations or on their own, without leaving the scope of the present invention.

[0049] Preferred embodiments and configurations of the invention are illustrated in the drawings and explained in more detail in the following description, where identical reference numerals refer to identical, similar, or functionally equivalent components or elements. Figure 1a a cross-sectional view of a reluctance actuator; Figure 1b a cross-sectional view of a reluctance actuator according to an embodiment of the present invention; Figure 2 a schematic representation of the operation of a reluctance actuator according to an embodiment of the present invention; Figure 3 a bending element according to an embodiment of the present invention in a non-displaced state; Figure 4 the bending element according to Figure 3 in deflected state; Figure 5a, b, each a cross-sectional view of a reluctance actuator according to an embodiment of the present invention; and Figure 6, a bending element according to an embodiment of the present invention in a non-deflected state.

[0050] Figure 1a shows a cross-sectional view of a reluctance actuator.

[0051] In Figure 1a A cross-sectional view of a hybrid actuator along a system axis is shown, along with some of its components.

[0052] The reluctance actuator comprises a substantially cylindrical housing G. An E-shaped stator 1 is arranged within the housing G. A permanent magnet 2 is attached to the inner pole shoe 13 of the stator, and a coil 3 is attached to each of its two outer pole shoes 14. A yoke for closing the magnetic circuit, designed as a movable element 4, is arranged externally on the top surface of the stator 1. This yoke is directly connected to a bending element 5, or restoring element, and restricts the movement of the movable element 4 by three degrees of freedom. Furthermore, a ball bearing 7 is arranged at the upper end of the inner pole shoe 13 of the stator 1. This bearing defines the pivot point of the movable element 4 and restricts its movement by a further degree of freedom.

[0053] The individual pole shoes 13, 14 of the E-shaped stator 1 of the reluctance actuator are connected to each other below the permanent magnet 2, forming a single magnetic circuit and allowing a single permanent magnet 2 to be used for the magnetic biasing of the entire system. To illustrate the basic principle of the embodiment of the invention, bores 6 are arranged above the bending element 5 on the outer upper circumference of the housing G of the actuator 1, 2, 3, 4, 5, 7, which can be used, for example, to mount sensors. An example of such sensors are eddy current sensors 8.

[0054] Figure 1b shows a cross-sectional view of a reluctance actuator according to an embodiment of the present invention.

[0055] In Figure 1b is essentially a reluctance actuator according to Figure 1a shown. In contrast to the reluctance actuator according to Figure 1aIn the reluctance actuator according to Figure 1b, the sensors 8 are not shown, and a fastening ring 17 is shown with which the bending element 5 is fixed to the housing G.

[0056] Figure 2 The figure shows in schematic form the mode of operation of a reluctance actuator according to an embodiment of the present invention.

[0057] A permanent magnet 2 is arranged at the inner pole shoe 13 of the actuator's stator 1. This magnet generates a uniform magnetic bias flux that flows through the center, the inner pole shoe 13 of the ferromagnetic stator 1, a central air gap 9c formed by the ball bearing 7 between the inner pole shoe 13 and the movable element 4, and through the ferromagnetic movable element 4. The magnetic flux then flows back via the working air gaps 9a and 9b and the left and right outer pole shoes 14 of the stator 1, respectively. The uniform magnetic bias flux is represented by line 50 in Fig. 2shown.

[0058] If the movable element 4 is in its zero position / start position / non-displaced position, the uniform magnetic bias flux flows through the left and right working air gap 9a, 9b in equal parts, so that the net torque 100 on the movable element 4 is essentially zero, provided that no current flows through the actuator coils 3.

[0059] The actuator coils 3 are connected in series, so that with a corresponding current flow through the coils 3 a magnetic flux is generated, through line 51 in Fig. 2As shown, the magnetic flux generated flows through the outer pole shoes 14 of the stator 1, the movable element 4, and the working air gaps 9a, 9b either clockwise or counterclockwise, depending on the current direction in the coils 3. Since the permanent magnet 2 exhibits a high magnetic resistance (reluctance) to external magnetic fields, the magnetic flux of the coils 3 flows more readily through the outer pole shoes 14 than through the inner pole shoe 13 of the stator 1. The uniform magnetic bias flux 50 and the time-varying magnetic coil flux 51 superimpose in the two working air gaps 9a, 9b. This results in an increased total flux in the right working air gap 9b, since both magnetic fluxes 50, 51 flow in the same direction, and a reduced magnetic flux in the left working air gap 9a, so that a net torque 100 acts on the movable element 4 in the clockwise direction.When the current direction in the coils 3 is reversed, the magnetic flux of the coils is also reversed, causing a net torque of 100 on the moving element 4 in a counterclockwise direction.

[0060] If no coil current is present, the distribution of the magnetic bias flux across the working air gap 9a, 9b is determined by the position of the movable element 4 and the resulting reluctance. During deflection, a higher magnetic flux will flow through the smaller air gap 9a, 9b, and an increased torque 100 will be generated on the movable element 4 in the direction of the original deflection. This is equivalent to a negative stiffness of the actuator and shows that the actuation principle of the actuator itself is inherently unstable due to the presence of the permanent magnet 2. The bending element 5 is therefore designed to compensate for the negative stiffness of the actuator, or rather, to stabilize the inherently unstable actuation principle. Such a bending element 5 is described in the Figure 3 and 4 shown.

[0061] Figure 3shows a bending element according to an embodiment of the present invention in a non-displaced state and Figure 4 a bending element according to Figure 3 in a deflected state.

[0062] In Figure 3 Figure 4 shows a bending element 5, on the underside of which the movable element 4 is arranged and directly connected to the bending element 5. The bending element 5 is essentially shaped according to the form of the movable element 4, or rather, both are accordingly coordinated with each other: Both elements 4 and 5 are in the Figure 3 , 4The bending element 5 is essentially disc-shaped and circular. On its outer surface, it has a fastening ring 17 for attaching it to the housing G of the actuator. The inner region 15 of the bending element 5 is formed by a disc, as described above. The inner region 15 and the outer region 16 of the bending element 5 are connected to each other by suspensions 12 distributed symmetrically around the circumference. The fixing points 10a of the suspension 12 on the disc 5 and the fixing points 10b of the suspension 12 on the outer region 16 are each offset by 90° in the circumferential direction; the suspensions are essentially quarter circles in shape.

[0063] Figure 4Figure 1 shows a corresponding deflection of the movable inner section 15 together with the movable element 4. The ferromagnetic movable element 4 is directly connected to the bending element 5. Due to the magnetic preload from the permanent magnet 2, there are high offset forces in the z-direction. These would damage the bending element 5, which cannot be designed with sufficient stiffness in the z-direction without also adversely increasing the stiffness in the two desired rotational degrees of freedom for tilting. To avoid this, a ball bearing 7 is used, firstly to compensate for the forces in the z-direction and secondly to define the rotation point. The bending element 5 can be made of aluminum and, as described, restricts the translational degrees of freedom in the x- and y-directions and the rotational degree of freedom about the z-axis. In other words, only rotations about the x- and y-axes are allowed for tilting.Due to the direct connection between bending element 5 and movable element 4, inertia is minimized.

[0064] Furthermore, the stator 1 can have a layered structure of several insulating materials at its outer pole shoes 14 to prevent the formation of eddy currents and their effects on the bandwidth, i.e., to reduce it. The reluctance actuator can also be equipped with a control device to determine, control, or regulate the position of the movable element 4. This device can determine, control, or regulate the position with respect to each axis. For this purpose, an amplifier, a control device for the coil current, and a control device for the tilt angle in each direction of the actuated axes of the movable element 4 can be provided, for example.

[0065] Figure 5a , bEach shows a cross-sectional view of a reluctance actuator according to an embodiment of the present invention.

[0066] In Figure 5a and Figure 5b Each is a reluctance actuator according to Figure 1b shown. In contrast to the reluctance actuator according to Figure 1b extend to the reluctance actuators according to the Figure 5a and Figure 5b The pole shoes 14 are essentially horizontal to the base plate of the housing G. The coils 3 are also arranged with their axis horizontal around the pole shoes 14. Figure 5a The pole shoe 14 is made in one piece, in Figure 5b This is a two-part structure, in which case only the outer end of a core 18 is designated as the pole shoe 14. The pole shoe 14 is adapted so that the magnetic flux is guided in a suitable manner to the yoke, or to the movable element 4. The core 18 with the pole shoe 14 can, as described above, be a single piece (see Figure 5a ) or two-part (see Figure 5b ) be executed. In Figure 5b The pole shoe 14 is arranged or fixed to the core 18. In other words, in this horizontal configuration, the pole shoe 14 is oriented upwards at its end in such a way that the magnetic field is directed towards the movable element 4. This embodiment thus enables a particularly flat design.

[0067] Figure 6 shows a bending element according to an embodiment of the present invention in a non-displaced state.

[0068] In Figure 6A bending element 4 is shown, which is star-shaped, here with rays 4 in the form of a cross with beams intersected at 90°. When the bending element 4 is mounted, the four rays 4, or arms of the cross, are positioned essentially above the respective pole shoe 14 to allow tilting about two axes. The fixing points of the suspensions for the bending element 4 and the fixing points on the outer area are analogous to the Figure 3 or Figure 4 arranged offset by 90° in the circumferential direction.

[0069] In summary, the invention, and in particular at least one embodiment, has the following advantages: Low moving mass, resulting in high bandwidth, since the moving element consists only of the ferromagnetic yoke that closes the magnetic circuit, without permanent magnets, plunger, etc. The moving element is not located inside the yoke that closes the magnetic circuit, but forms a one-sided closure of the actuator, which has the advantage that the available installation space is used very well, since: ∘ there are no protrusions from, for example, the yoke or coils, i.e., the mover is located almost at the outermost point of the entire actuator, so that no component of the actuator protrudes beyond it; ∘ large lateral overlap of the mover in relation to the yoke and the coils, i.e.The ratio of the usable area of ​​the mover to the total diameter of the actuator is very high; the flat design of the mover results in a pivot point of the mover almost on the surface of the moving element (ideally, the pivot point would be on the surface); the E-shaped stator in cross-section offers a small overall diameter of the actuator (in contrast to the commonly used C-shaped stators).

[0070] The present invention thus provides a compact, highly dynamic actuator that can be used in a variety of applications, including, for example, the rapid tilting of mirrors for scanning optical systems in the fields of optical communication, scan measurement technology, target tracking, etc.

[0071] Although the present invention has been described with reference to preferred embodiments, it is not limited to these, but can be modified in many ways. In other words, it is expressly pointed out that the embodiments of the device according to the invention described above serve only to illustrate the claimed teaching, but do not limit it to these embodiments.

[0072] Regarding further advantageous embodiments of the device according to the invention, reference is made to the general part of the description and to the attached claims in order to avoid repetition. Reference sign list

[0073] 1 Stator 2 Permanent magnet 3 Actuator coil(s) 4 Movable element / yoke 4 Beams / arms 5 Bending element 6 Bore(s) 7 Ball bearing 8 Eddy current sensor 9a, 9b, 9c Air gap 10a, 10b Fixing point 12 Suspension 13 Inner pole shoe 14 Outer pole shoe 15 Inner area 16 Outer area 17 Mounting ring 17a Screw 18 Core 50 Magnetic flux bias 51 Magnetic flux coil 100 Torque direction Housing

Claims

1. Reluctance actuator comprising a magnetisable stator (1), at least two coils (3) which are constructed to produce a magnetic field in the stator (1), and a yoke (4) for at least partially closing the magnetic flux of the stator (1), wherein the yoke (4) is in the form of a movable element for lifting / tilting movements, wherein the stator (1) has a permanently magnetic region, and wherein the stator (1) is constructed, in cross-section along two axes which are arranged with respect to each other at a specific angle, in an E-shaped manner with two outer and one inner pole shoe(s) (14, 13), and wherein the movable element (4) is movably arranged by means of at least one bending element (5) on a housing (G) of the reluctance actuator and is constructed to carry out lifting / tilting movements about at least two axes, wherein at least one of the at least two coils (3) is arranged per axis, and wherein the at least one bending element (5) has an inner region (15) and an outer region (16) and at least two suspensions (12), wherein the two regions (15, 16) are connected to each other by means of the at least two suspensions (12), and wherein the outer region (16) of the bending element (5) is arranged on a housing (G) of the reluctance actuator, and wherein the bending element (5) is secured from the outer side thereof to the housing (G) by means of a circumferential securing ring (17).

2. Reluctance actuator according to claim 1, characterized in that the angle between the two axes of the stator (1) is 90°.

3. Reluctance actuator according to claim 1 or 2, characterized in that at least one of the coils (3) has a coil axis which is arranged substantially perpendicularly to the deflection direction of the movable element (4), in particular wherein the stator (1) is arranged at least partially in the coil (3).

4. Reluctance actuator according to any one of claims 1 to 3, characterized in that the inner pole shoe (13) of the E-shaped stator (1) along one axis is identical to the inner pole shoe (13) along the second axis.

5. Reluctance actuator according to any one of claims 1 to 4, characterized in that the permanently magnetic region is arranged on the inner pole shoe (13) of the E-shaped stator (1), preferably wherein the permanently magnetic region is arranged in the transition region of the region which connects the pole shoes (13, 14) of the E-shaped stator (1).

6. Reluctance actuator according to any one of claims 1 to 5, characterized in that the at least one bending element (5) is produced from aluminium and / or titanium.

7. Reluctance actuator according to any one of claims 1 to 6, characterized in that the movable element (4) is connected directly to the at least one bending element (5), in particular to the inner region (15) of the at least one bending element (5), and / or in that the movable element (4) and the bending element (5) are constructed in one piece, and / or in that the movable element (4) and the bending element (5) are produced from ferromagnetic steel, in particular spring steel, and / or in that the bending element (4) or the movable element (5) is / are constructed to be at least partially metal-coated.

8. Reluctance actuator according to any one of claims 1 to 7, characterized in that the movable element (4) is supported by means of at least one bearing (7), in particular in the form of a ball bearing, a point bearing in the form of a tip made of hard metal or sapphire or in the form of a bending bar, in particular centrally on the inner pole shoe (13) of the stator (1), and / or in that the movable element (4) is arranged by means of at least one air gap (9a, 9b, 9c) with spacing from the stator (1) and / or in that the stator (1) has four outer pole shoes (14), wherein a coil (3) is arranged on two of the four pole shoes (14) which are arranged opposite each other in each case.

9. Reluctance actuator according to any one of claims 1 to 8, characterized in that the stator (1) is constructed in a laminated manner, in particular wherein only the outer pole shoes (14) of the stator (1) are produced from a plurality of insulating layers.

10. Reluctance actuator according to any one of claims 1 to 9, characterized in that the inner pole shoe (13) of the stator (1) is constructed in a cylindrical manner.

11. Reluctance actuator according to any one of claims 1 to 10, characterized in that the yoke (4) is constructed in a ferromagnetic manner, and / or in that the yoke (4) is produced from steel and / or in that the movable element (4) is constructed substantially as a preferably circular, elliptical or star-like disc, preferably wherein the disc is formed symmetrically along at least one axis.

12. Reluctance actuator according to any one of claims 1 to 11, characterized in that four suspensions (12) are arranged, wherein the securing location of the respective suspension (12) on the inner region (15) and on the outer region (16) of the movable element (4) is arranged to be offset with respect to each other in the circumferential direction through 90° in each case, preferably wherein the shape of the at least one suspension (12) is constructed to substantially at least partially correspond to the path of the outer contour of the inner region (15) and / or the movable element (4).

13. Reluctance actuator according to any one of claims 1 to 12, characterized in that the yoke (4) forms a substantially lateral outer termination of the actuator.

14. Actuator system comprising a reluctance actuator, characterized in that the reluctance actuator is constructed according to any one of claims 1 to 13, and is arranged at least partially in a non-magnetic housing (G), for example, an aluminium housing, in particular wherein a feedback and control device is arranged and connected to the reluctance actuator in order to control the movement of the movable element (4) about at least one axis, preferably wherein the feedback and control device comprises a position measurement unit, in particular an angular position measurement unit, a current amplification unit or a voltage amplification unit and / or an output current measurement unit.

15. Method for carrying out lifting / tilting movements of a movable element (4) of a reluctance actuator, wherein the reluctance actuator is provided with a magnetisable stator (1), at least two coils (3) which are constructed to produce a magnetic field in the stator (1) and a yoke (4) for at least partially closing the magnetic flux, wherein the stator (1) is provided with a permanently magnetic region and wherein the stator (1) is constructed, in cross-section along two axes which are arranged with respect to each other at a specific angle, in an E-shaped manner with two outer and one inner pole shoe(s) (14, 13), and wherein the yoke (4) is in the form of a movable element for lifting / tilting movements and is moved by means of control of the magnetic field, and wherein the movable element (4) is movably arranged by means of at least one bending element (5) on a housing (G) of the reluctance actuator and is constructed to carry out lifting / tilting movements about at least two axes, wherein at least one of the at least two coils (3) is arranged per axis, and wherein the at least one bending element (5) is provided with an inner region (15) and an outer region (16) and at least two suspensions (12), wherein the two regions (15, 16) are connected to each other by means of the at least two suspensions (12), and wherein the outer region (16) of the bending element (5) is arranged on a housing (G) of the reluctance actuator, and wherein the bending element (5) is secured from the outer side thereof to the housing (G) by means of a circumferential securing ring (17).