Oscillating drive element and drive unit

Abstract

The driving element is used for driving the passive element (4) to move relative to the active element (1). The active element (1) comprises a resonator (2) and an oscillation excitation device (23), and at least one arm (21) extending in an arm direction (21a). The arm (21) comprises, at the outer end, a contact element (31) which can be moved by an oscillating movement of the arm (21) in order to drive the passive element (4). The outer end of the arm (21) contains a contact element (31) which drives a contact area (41) of the passive element (4). At least one of the following cases is provided: the contact element (31) comprises an insert (80) made of a material different from the material of the resonator (2), in particular a harder material than the material of the resonator (2); in the contact region (41), a first wear suppression element (83) is arranged on the contact element (31) and a second wear suppression element (84) is arranged on the passive element (4). The passive element (4) is made of a wear-inhibiting material.

Description

TECHNICAL FIELD

[0001] The present invention relates to the field of oscillation drives. It relates to a drive element and a drive unit as claimed in the claims. BACKGROUND

[0002] US 6 768 245 B1, based on WO 01 / 41228 A1, discloses a piezoelectric motor in which a drive element consisting of a piezoelectric element and a contact element is elastically suspended and is caused to oscillate by the piezoelectric element, thereby driving another body or passive element by the contact element.

[0003] US 7 429 812 B1 discloses a piezoelectric drive unit having a resonator which comprises at least two arms arranged to extend from the same side of the resonator. Contact elements are located at the outer ends of the arms and can be brought closer together or further apart by the oscillatory movement of the arms, thereby enabling a relative movement of a passive element with respect to an active element carrying the resonator. The passive element can itself be made elastic. Alternatively or in addition, the passive element can be elastically supported with respect to the pair of arms. These measures enable an efficient transfer of the oscillatory movement of the arms and the forces resulting therefrom and / or compensate for incomplete alignment of the components. In some embodiments, the contact elements at the outer ends of the arms face outwardly, the passive element comprises two surfaces facing each other, and the resonator is arranged to move between these two surfaces. SUMMARY

[0004] There is a need to provide a drive element or drive unit which is more efficient, i.e. has a higher driving force and / or lower losses in the transfer of force between the active and passive elements, preferably in both drive directions. Furthermore, there is a need to prolong the service life of such drive devices.

[0005] These objects are achieved by a drive element and a drive unit according to the claims.

[0006] The drive element is for driving a passive element in relation to an active element, wherein the active element comprises:

[0007] a resonator and at least one excitation device for exciting oscillations in the resonator;

[0008] the resonator and the arms extend in the same plane, hereinafter referred to as the reference plane;

[0009] the arms comprise contact elements at their outer ends;

[0010] the contact elements are movable by the oscillatory movement of the arms;

[0011] the passive element is arranged to be driven by these oscillatory movements and to move in relation to the active element;

[0012] The passive element comprises a contact area arranged to be in contact with the contact element.

[0013] Wherein at least one of the following is true:

[0014] • The contact element comprises an insert made of a material different from the material of the resonator, in particular harder than the material of the resonator;

[0015] • In the contact area, a first wear-inhibiting element is arranged on the contact element and a second wear-inhibiting element is arranged on the passive element of the contact area;

[0016] • The passive element is made of a wear-inhibiting material.

[0017] The effect of a contact element comprising an insert made of a different material is that it can adjust its tribological and force transmission properties independently of the material of the resonator. The material can be harder and more wear-resistant than the resonator. However, a softer material can also be more wear-resistant.

[0018] The presence of a first wear-inhibiting element and a second wear-inhibiting element makes it possible to select a combination of materials with the desired tribological and force transmission properties. The first wear-inhibiting element can be an insert as described herein.

[0019] The advantage of making the passive element from a wear-inhibiting material is that the structure of the passive element can be simplified. This is generally easier to achieve because the passive element oscillates with a smaller amplitude of vibration or even without vibration compared to the active element, so the requirements for the dynamic properties of the passive element are lower. The second wear-inhibiting element can be achieved by manufacturing the passive element from a wear-inhibiting material.

[0020] The effect of improving the tribological and force transmission properties is to improve the friction between the contact pair, i.e. the contact element and the contact area, and thus to increase the driving efficiency.

[0021] The effect of the wear-inhibiting material is to reduce or eliminate wear of one or both contact pairs. This in turn reduces the contamination of the drive with wear material. By reducing wear, it is possible to reduce the decline in the quality of the drive and to increase the service life of the drive.

[0022] The oscillation excited in the resonator causes the arms to perform an oscillatory movement, which is generally parallel to a reference plane. The term "parallel to" also includes the meaning "parallel and at a distance of zero".

[0023] At least one arm extends in a direction, which is referred to below as the arm direction. If there are multiple arms, their arm directions can be parallel to each other.

[0024] In some embodiments, the first wear-inhibiting element is made of a different material, in particular a material that is harder than the material of the arm, or is made by hardening the material of the arm, or is made by coating the arm with a material other than the material of the arm.

[0025] In some embodiments, the second wear-inhibiting element is made of a different material, in particular a material that is harder than the material of the passive element, or is made by hardening the material of the passive element, or is made by coating the passive element with a material other than the material of the passive element.

[0026] In some embodiments, the respective first or second wear-inhibiting element is made of one of the following materials:

[0027] • a ceramic material, in particular a silicate, more particularly mullite;

[0028] • a plastic material, in particular a reinforced plastic material, more particularly a fiber-reinforced plastic material;

[0029] • a palladium alloy, in particular a palladium-silver alloy, for example Pd75Ag25, Pd60Ag40;

[0030] • molybdenum;

[0031] • a ceramic-metal composite material, in particular a mullite-molybdenum composite material, for example Mu / Mo-3, Mu / Mo-9;

[0032] • a nickel alloy, in particular a nickel-aluminum alloy, for example Ni-50Al, Ni-48Al, Ni-45Al;

[0033] • an amorphous nickel alloy (Vulcan alloy).

[0034] The preferred material combinations (in the order: first wear-inhibiting element 83 - second wear-inhibiting element 84) for the contact area of the first wear-inhibiting element (which can be an insert, a coating, a treated resonator material, etc.) and the second wear-inhibiting element (which can be an insert, a coating, a treated passive element material, etc.) with the passive element 4 are as follows:

[0035] • zirconium oxide - zirconium oxide;

[0036] • zirconium oxide - palladium alloy;

[0037] • aluminum oxide - zirconium oxide;

[0038] • silicon carbide - zirconium oxide;

[0039] • silicon nitrate - zirconium oxide;

[0040] • zirconium oxide - plastic or reinforced plastic.

[0041] In some embodiments, the contact surface of the insert with which the insert contacts the contact area of the passive element is shaped as a cylindrical surface. In particular, the cylindrical axis of the cylindrical surface is perpendicular to the reference plane.

[0042] In this way, in the projection onto the reference plane, the cylindrical shape of the surface does not form a sharp edge with the contact area of the passive element. This can reduce the initial wear of the insert and / or the opposing contact area caused by a highly concentrated force.

[0043] In some embodiments, the insert is shaped as a cylinder or as a half-cylinder.

[0044] In this way, both the insert and the respective connecting surface of the arm to which it is connected can be shaped simply. That is, if the insert is a cylinder, the connecting surface can be a cylindrical adhesive recess or a clamping recess. If the insert is a half-cylinder, whose planar portion is parallel to the cylindrical axis, the connecting surface can also be planar.

[0045] In some embodiments, the contact surface of the insert with which the insert contacts the contact area of the passive element is shaped as an ellipsoid, in particular as a rotational ellipsoid or as a sphere.

[0046] In this way, in any direction, the surface does not form a sharp edge with the contact area of the passive element. This makes the assembly more robust against small angular deviations, which would otherwise lead to the sharp edge coming into contact with the surface of the passive element.

[0047] In some embodiments, the insert has the shape of an ellipsoid, in particular of a rotational ellipsoid, or of a corresponding half-sphere. More particularly, the insert can have the shape of a sphere or of a half-sphere.

[0048] This has a similar effect as if the insert were cylindrical or half-cylindrical.

[0049] In some embodiments, the insert is connected to the resonator by press-fitting into a clamping recess of the resonator.

[0050] On the one hand, this facilitates precise positioning during assembly. On the other hand, compared to gluing, it eliminates the damping caused by the glue, thereby reducing power loss and increasing the efficiency of force transmission.

[0051] In some embodiments, the insert is connected to the resonator by gluing, in particular by gluing the insert to the connecting surface of the contact element, in particular to an adhesive recess of the resonator. Gluing and adhesive are considered synonymous.

[0052] Compared to clamping, this can simplify the manufacture of the resonator, thereby reducing manufacturing complexity and costs. Manufacturing tolerances can be relaxed, and the resonator can be manufactured by means of an etching or stamping process.

[0053] In some embodiments, the contact area is prestressed against the contact element, the prestress having a non-zero component (Fnz) perpendicular to the reference plane.

[0054] This allows for a more versatile geometry between the active and passive elements. This in turn allows for more freedom in the design of the driver.

[0055] This oblique prestress is well suited for use in combination with an elliptical (including the special case of an "oval") insert, or in combination with a cylindrical shape, where the axis of the cylinder is parallel to the reference plane and at least approximately parallel to the direction of relative motion between the active and passive elements.

[0056] The prestress acts between the contact area and the contact element at least when the drive unit is not vibrating, i.e. when the excitation means are not excited. The prestress element can be constituted by the elastic part of one or more of the active elements, the elastic part of the passive element, and the elastic part in the kinematic chain connecting the active elements to the passive element.

[0057] In some embodiments with two arms, each contact area is prestressed against the respective contact element, the prestress having a component perpendicular to the reference plane.

[0058] In some embodiments, the one or more inserts are arranged asymmetrically with respect to a bisector plane parallel to the reference plane, and the resonator is substantially mirror-symmetric with respect to the bisector plane; in particular wherein the contact points of the inserts with the passive element are arranged asymmetrically with respect to the bisector plane.

[0059] This also allows for a more versatile geometry between the active and passive elements.

[0060] The drive unit is for driving the passive element in motion relative to the active element. The active element comprises at least two drive elements, the combination of the at least two drive elements together comprising a common resonator extending in the same reference plane, and a first arm and a second arm arranged for driving the same passive element, and in particular wherein the first arm and the second arm are arranged mirror-symmetrically, the axis of the resonator being its axis of symmetry.

[0061] In some embodiments, the resonator axis bisects the included angle between the arm direction of the first arm and the arm direction of the second arm. In some embodiments, the arm direction of the first arm and the arm direction of the second arm are parallel to each other.

[0062] In some embodiments of the drive unit, the first arm comprises a first contact element and a first protrusion, and the second arm comprises a second contact element and a second protrusion, and wherein the first contact element and the second contact element extend towards each other, and in particular wherein the first protrusion and the second protrusion extend away from each other.

[0063] In other words, the two arms are arranged to drive the passive element, the contact surface of which is arranged at the inner side of the arms, and thus, for each arm, the first direction (the direction of the respective protrusion) points outwards, away from the other arm, and the second direction (the direction of the respective contact element) points inwards, towards the other arm. This structure can be referred to as "inward driving", because the passive element is arranged at the inner side of the arms. Here, the term "inner side" in the context of the two arms refers to the region between the two arms. Seen from one of the arms, the direction pointing towards the other arm is the "inner side".

[0064] In some embodiments of the drive unit, the first arm comprises a first contact element and a first protrusion, and the second arm comprises a second contact element and a second protrusion, and wherein the first contact element and the second contact element extend away from each other, and in particular wherein the first protrusion and the second protrusion extend towards each other.

[0065] In other words, the two arms are arranged to drive the passive element, the contact surface of which is arranged at the outer side of the arms, and thus, for each arm, the first direction (the direction of the respective protrusion) points inwards, towards the other arm, and the second direction (the direction of the respective contact element) points outwards, away from the other arm. This structure can be referred to as "outward driving".

[0066] In some embodiments, the drive unit is configured such that, when the driver is not oscillating (i.e. the excitation means are not excited), a pre-stress exists between the respective contact element of the active element and the contact area of the passive element.

[0067] The presence of the pre-stress, in combination with the inward driving structure, results in a stabilizing force on the angle between the passive element and the active element, even when the driver is not oscillating.

[0068] In some embodiments of the drive element or drive unit, the resonator comprises a first surface and an opposite second surface, both parallel to the reference plane, and wherein one excitation means is arranged on the first surface, and optionally wherein the other excitation means is arranged on the second surface.

[0069] In some embodiments of the drive element or drive unit, the passive element is arranged to translate along a linear motion axis, which is parallel to the reference plane, and in particular for the drive unit, which is also parallel to the resonator axis.

[0070] In some embodiments of the drive element or drive unit, the passive element is arranged to rotate about a rotational motion axis parallel to a reference plane, and particularly for the drive unit, the rotational motion axis is also perpendicular to the resonator axis.

[0071] In some embodiments of the drive element or drive unit, the contact element includes a flat area.

[0072] In some embodiments of the drive element or drive unit, the resonator length is defined as the dimension of the resonator along the resonator axis from the end of the arm to the opposite end of its counterweight portion, and wherein the extension range (d) of each flat region, projected onto the reference plane, is one-tenth to one-hundredth of the resonator length, particularly one-twentieth to one-eighth of the resonator length.

[0073] In some embodiments of the driving element or driving unit, the length of the resonator is between three and five millimeters, especially four millimeters, and the extension range (d) of the flat region is between 0.05 millimeters and 0.15 millimeters, especially between 0.08 millimeters and 0.12 millimeters, especially 0.1 millimeters.

[0074] According to some embodiments of all aspects, one or more of the following situations may occur:

[0075] The resonator is formed from a flat material. In some embodiments, the resonator is cut from the blank by laser cutting. If lower tolerances are acceptable, it can be cut by etching or stamping.

[0076] An arm extending from the connecting region has its proximal end connected to either the connecting region or the excitation region, while its distal end is provided with a contact element. For two arms, their common direction of extension corresponds to the resonator axis. A resonator with an excitation device but without arms can be mirror-symmetric about the resonator axis, for example, in its projection onto a reference plane. A resonator including arms can be substantially mirror-symmetric about the resonator axis.

[0077] Regarding the resonator axis, one or more of the following situations typically exist:

[0078] • The connection area includes at least one fixed or supporting region where the resonator is connected to the base, and the fixed or supporting region is located on the axis of the resonator; and / or

[0079] • Viewed from a direction perpendicular to the reference plane, the resonator axis passes through the center of the excitation device; and / or

[0080] • The resonator axis is located in the region where the oscillation amplitude of the resonator and / or excitation device is minimal.

[0081] The oscillating motion of one or more arms can cause the corresponding contact elements to move closer or further apart, possibly due to the movement of each contact element along a generally elliptical path. The movement along each path can be clockwise or counterclockwise (viewed from within the plane of the resonator), and the orientation of the principal axis of the ellipse can vary. The direction and orientation of the movement can be controlled by adjusting the excitation frequency of the excitation device. The excitation device is typically a piezoelectric element. Further details of such actuators are described in detail in the originally cited patents US768245B1 and US429812B1. The elliptical motion can correspond to a very flat ellipse, and therefore also to almost linear or perfectly linear oscillating motion. In this case, the orientation of this oscillating motion determines the driving mode of the passive element. In particular, the orientation of the motion, combined with the amplitude of the motion, also affects the driving force.

[0082] A contact element (part of the active element) and a contact body (part of the passive element) come into contact in a contact area. The actuator may be configured such that, when it is not oscillating (i.e., when the actuation device is not energized), there is a prestress between the contact element of the active element and the contact area of ​​the passive element. If a prestress is present, the contact force associated with the prestress is typically perpendicular to the contact surface of the parts, particularly perpendicular to the contact surface within the contact area, and especially perpendicular to the tangent plane of that contact surface. This contact force or prestress may be perfectly perpendicular to the contact surface or at an angle to the normal, with only the vector component of the force perpendicular to the contact surface.

[0083] It is understood that contact may mean intermittent contact during the operation of the drive unit, as the oscillating arm intermittently contacts and moves away from the corresponding area on the contact body.

[0084] In some embodiments, the resonator of the active element is integrally formed. For example, it can be made from a single sheet of material, such as a metal sheet. In some embodiments, the material is stainless steel, particularly 1.4310 stainless steel, also known as X10CrNi18-8 steel.

[0085] In some embodiments, the resonator includes a first surface and an opposing second surface, both parallel to a reference plane, wherein an excitation device is disposed on the first surface, and optionally, another excitation device is disposed on the second surface.

[0086] Typically, passive elements are arranged to translate along a linear axis of motion that is parallel to a reference plane, and in particular to the axis of the resonator.

[0087] In some embodiments, the passive element is arranged to rotate about a rotational axis that is parallel to a reference plane and, in particular, perpendicular to the resonator axis.

[0088] In one method for operating a drive unit, an excitation device is applied voltages of different frequencies, thereby generating different motion patterns of the arm or multiple arms and the contact area according to the frequencies. The different motion patterns cause the passive element to move linearly according to the degrees of freedom defined by its suspension relative to the active element. For example, this suspension may be based on a sliding bearing or a roller bearing.

[0089] In this article, wherever parts are manufactured using single sheet metal (e.g., metal sheet), subtractive manufacturing processes (e.g., cutting, stamping, or etching) and additive manufacturing processes (e.g., selective laser melting, electron beam melting, or direct metal laser sintering) can be used.

[0090] In some embodiments, each contact element includes a flat area.

[0091] In some embodiments, the resonator length is defined as the dimension of the resonator along the resonator axis (for a symmetrical structure with multiple arms) or along the arm direction (if there is only one arm), from the end of the arm or multiple arms to the opposite end of the arm, particularly the dimension of its counterweight portion, and the extension of each flat region, projected onto a reference plane, is one-tenth to one-hundredth of the resonator length, particularly one-twentieth to one-eighth of the resonator length.

[0092] Other embodiments are clearly visible in the dependent patent claims. Attached Figure Description

[0093] The subject matter of the present invention will now be explained in more detail with reference to the exemplary embodiments shown in the accompanying drawings, which are illustrated in schematic form:

[0094] Figure 1 A driving element according to the first embodiment;

[0095] Figures 2-4 For different drive types;

[0096] Figure 5-7 shows different ways to connect the plug to the resonator;

[0097] Figure 8-10 shows the different shapes of the plug-in;

[0098] Figures 11-12 illustrate different types of passive components and different implementation methods of wear suppression components; and

[0099] Figure 13 The prestress Fn is a non-zero component Fnz perpendicular to the plane of the resonator.

[0100] The reference numerals used in the figures and their meanings are listed in summary form in the reference numeral description. In principle, the same reference numerals are used for the same parts in the figures. Detailed Implementation

[0101] Figure 1 A driving element according to a first embodiment is schematically shown, comprising an active element 1 and a passive element 4. The active element 1 includes a resonator 2 or a resonant plate 2 and an excitation device 23. The excitation device 23 is arranged to drive an excitation region 20a of the resonator 2, thereby causing an arm 21 connected to the excitation region 20a to oscillate. The arm 21 extends from the excitation region 20a of the resonator 2 along an arm direction 21a. The arm direction 21a extends along the longitudinal axis of the arm 21. This longitudinal axis passes through the region of the arm 21 connected to the excitation region of the resonator and the region where the protrusion 33 and the contact element 31 are connected to the arm 21.

[0102] The resonator 2 and arm 21 extend parallel to the reference plane. The end of the arm is provided with a contact element 31, designed to drive the movement of the passive element 4 by contacting the contact area 41 of the passive element 4. This contact area is not necessarily fixed to the moving passive element 4, but rather represents the current contact position between the contact area 31 and the passive element 4 as the passive element 4 rotates about its axis of rotation or translates relative to the driving element 1.

[0103] As described in patent US7429812B1 cited above, the excitation frequency of the voltage generator (which may be a piezoelectric element) driving the excitation device 23 can be changed, and different vibration modes of the arm will be generated depending on the frequency. For example, in one mode, the contact area 31 (projected on the reference plane) will rotate clockwise; in another mode, it will rotate counterclockwise. As another example, in one mode, the contact area 31 will move back and forth at a first angle; in another mode, it will move back and forth at a second angle. Depending on the suspension of the passive element (i.e., rotary, linear, or a combination of rotary and linear), the passive element will move accordingly.

[0104] The following embodiments all follow the same basic principles. Unless otherwise stated, the elements described so far, if present, function substantially the same. The position of the excitation device 23 relative to the resonator 2 is schematically represented by a rectangle, which corresponds to the outline of the excitation device 23 connected to one or both sides of the resonator 2.

[0105] The protrusion 33 is connected to the rest of the arm via a necked-back portion 35. This necked-back portion 35 corresponds to a region of the arm with lower bending stiffness. That is, the stiffness of the arm bending about an axis perpendicular to the reference plane 28 is lower at the necked-back portion 35 than at other locations. Therefore, the necked-back portion 35 can be considered an elastic connection. During operation, as the arm oscillates, the protrusion oscillates accordingly, including a small rotation about the necked-back portion 35. This, in turn, causes a corresponding movement in the contact element located at the same end of the arm.

[0106] The protrusion 33 extends in a first direction at a first angle α to the arm direction 21a. The contact element 31 extends in a second direction at a second angle β to the arm direction 21a.

[0107] Within the contact area 41, a first wear-inhibiting element 83 is arranged on the contact element 31, and a second wear-inhibiting element 84 is arranged on the passive element 4.

[0108] The oscillation mode of this arm is described in detail in WO2022 / 218989A1.

[0109] In some other embodiments, the necking portion 35 and / or the first protrusion 33 are not present, but the first contact element 31 still performs an oscillating motion, thereby driving the passive element 4 to move relative to the active element 1.

[0110] Most of the embodiments shown below depict an active element 1 with two arms, but the types of attachments, plugs, etc. shown can of course also be implemented with an active element 1 having one or more arms.

[0111] Figures 2 to 4 Exemplary driver types to which the present invention can be applied are shown. The driver elements shown in the figure all have inserts 80, but the inserts can also be replaced with other types of wear suppression elements. Each resonator 2 is located within or parallel to the reference plane 28. Figure 2 and Figure 3 An active element 1 is shown, which has two driving elements sharing a resonator 2 located in the same reference plane, and a first arm 21 and a second arm 22 for driving the same passive element 4. The first arm 21 and the second arm 22 are arranged in a mirror-symmetric manner, with the resonator axis 24 as their axis of symmetry. The first arm 21 and the second arm 22 each contain a first contact element 31 and a second contact element 32, with a plug 80 connected to their ends. Figure 2 In the driver shown, the first contact element 31 and the second contact element 32 extend toward each other, and the passive element 4 is disposed between the two contact elements and moves along the direction of the resonator axis 24. Figure 3 In the illustrated drive, the first contact element 31 and the second contact element 32 extend away from each other, and the passive element (not shown) is arranged to have two drive portions, which have a first contact area and a second contact area outside the contact elements. Figure 4 In the drive shown, there is only one (first) contact element 31, and the passive element (not shown) is supported by the support arm 8.

[0112] Typically, the active element combined with the active element 1 shown herein can be moved according to the shape and arrangement shown in WO2022 / 218989A1. WO2022 / 218989A1 is incorporated herein by reference in its entirety. See especially... Figure 9 , Figure 10 See Figure 11 and the relevant parts of the instruction manual.

[0113] Figures 5 through 7 illustrate different ways in which the plug 80 can be connected to the resonator 2. The plug 80 shown in the figures is cylindrical or semi-cylindrical, but in each case, plugs 80 of other shapes can also be connected in a similar manner.

[0114] Figures 5a-5b The diagram shows the plug 80 being fixed in the resonator 2 via a press-fit. A clamping groove 87 is formed on the resonator 2, its size slightly smaller than the outline of the plug 80, and the plug 80 can be clamped in the clamping groove 87 without adhesive or other types of connection. In the illustrated embodiment, the clamping groove 87 is shaped as part of an inner cylinder, and the plug 80 is cylindrical.

[0115] Figures 6a-6b and Figures 7a-7b The insert 80 is shown to be fixed to the resonator 2 by adhesive (e.g., gluing, welding, or brazing). The resonator 2 includes a connecting surface 85 at its first contact element 31 and second contact element 32, and the insert 80 has a correspondingly shaped surface that is bonded to the connecting surface 85. Figures 6a-6b In this embodiment, the plug-in 80 is partially cylindrical or semi-cylindrical, and the connecting surface 85 is a flat surface. Figures 7a-7b In one embodiment, the plug-in 80 is shaped as a complete cylinder and has an adhesive groove 86 that mates with the plug-in 80, rather than a flat connecting surface 85.

[0116] Figure 8 to Figure 10 The plug-in 80 shows other different shapes besides the ones already shown. Figures 8a-8b A spherical insert 80 is shown. For example, it is connected by adhesive to the adhesive groove 86 of the corresponding first contact element 31 or second contact element 32. Figure 9 A cylindrical insert 80 is shown, the length of which is greater than the thickness of the resonator 2. That is, the insert 80 extends outward in one or two directions beyond the boundary plane corresponding to the outer surface of the resonator 2, which is parallel to the reference plane 28. This increases the contact area between the active element 1 and the passive element 4. Figure 10 A hemispherical insert 80 is shown bonded to a flat connecting surface 85.

[0117] Figure 11 to Figure 12Different types of passive elements 4 and different implementations of wear suppression elements are shown. (Compared to...) Figure 2 Unlike the solid components constituting the passive element 4, the passive element 4 itself is elastic. That is, the first contact area 41 (interacting with the first arm 21) and the second contact area 42 (interacting with the second arm 22) are arranged to be elastically movable relative to each other. As shown by the tweezer-like structure in the figure, the first contact area 41 and the second contact area 42 can be elastically mounted on the same body of the passive element 4. Figure 11 shows that the second wear-inhibiting element 84 is an independent element arranged on each of the contact areas. Figure 12 The second wear-inhibiting element 84 is shown as a hardened portion of the material in each contact area. In an embodiment not shown, the second wear-inhibiting element 84 is implemented by an entire component made of a wear-inhibiting material on which the first contact area 41 or the second contact area 42 is disposed.

[0118] Figure 13 A combination of connecting elements for connecting the plug 80 to the contact element 31 is shown. One or more plugs 80 are arranged asymmetrically with respect to a pair of boundary planes corresponding to the outer surface of the resonator 2 and parallel to the reference plane 28. In other words, the active element 1, in particular the resonator 2, can be mirror-symmetrical with respect to the bisecting plane parallel to the reference plane 28. Then, one or more plugs 80 are arranged asymmetrically with respect to this bisecting plane. Thus, the contact points of the plugs 80 with the passive element 4 can also be arranged asymmetrically with respect to the pair of boundary planes or the bisecting plane.

[0119] The insert 80 is placed within or rests against the adhesive groove 86 and is secured by adhesive. In the illustrated embodiment, the adhesive groove 86 is a notch shaped like an inner cylinder or a portion of an inner cylinder. The insert 80 is spherical and is placed close to the edge of the cylinder or portion of the cylinder. This precisely defines the position of the insert 80 on the arm and contact element 31. The adhesive is located inside the inner cylinder and contacts the inner surface of the inner cylinder and the outer surface of the insert 80. This establishes an adhesive bond between the insert 80 and the resonator 2. In some embodiments, the shape of the adhesive groove 86 corresponds to the outer surface of the insert 80. It can be a groove shape on a surface of the resonator parallel to the reference plane 28.

[0120] In an embodiment not shown in the figure, the plug-in 80 is ellipsoidal or spherical and is located inside the inner cylinder or part of the inner cylinder. It can be clamped and / or glued in this position.

[0121] Figure 14a and 14bThe diagram shows the contact area 41 pressed against the contact element 31 under the action of a prestress Fn, which has a non-zero component Fnz perpendicular to the reference plane 28. This force structure is well-suited for use with inserts 80 that are ellipsoidal, spherical, or partially spherical in shape, or have a cylindrical surface parallel to the direction of motion of the passive element 4 (typically parallel to the resonator axis 24).

[0122] While the present invention has been described in the present embodiments, it should be clearly understood that the invention is not limited thereto, but may be practiced in various other ways within the scope of the claims.

Claims

1. A driving element for driving a passive element (4) to move relative to an active element (1), wherein, The active element (1) includes: A resonator (2) and at least one excitation device (23) for exciting the oscillation in the resonator (2); The resonator (2) includes at least one arm (21); The resonator (2) and the arm (21) extend about the same plane, which is hereinafter referred to as the reference plane (28); The arm (21) includes a contact element (31) at its outer end; The contact element (31) is movable by the oscillating motion of the arm (21); The passive element (4) is arranged to be driven by the oscillating motion and to move relative to the active element (1); The passive element (4) includes a contact area (41) arranged to contact the contact element (31); Its characteristic is that at least one of the following situations exists: • The contact element (31) includes a plug (80) made of a material different from that of the resonator (2), and in particular a material that is harder than that of the resonator (2); • A first wear-inhibiting element (83) is arranged on the contact element (31), and a second wear-inhibiting element (84) is arranged on the passive element (4) within the contact area (41); • Passive components (4) are made of wear-inhibiting materials.

2. The driving element according to claim 1, wherein, The first wear-inhibiting element (83) is made of a material different from that of the arm (21), particularly a material with a higher hardness than that of the arm (21), or is made by hardening the material of the arm (21), or by coating the arm (21) with a material other than that of the arm (21).

3. The driving element according to claim 1 or 2, wherein, The second wear-inhibiting element (84) is made of a material different from that of the surrounding area of ​​the passive element (4), in particular a material with a higher hardness than that of the surrounding area of ​​the passive element (4), or is made by hardening the material of the passive element (4), or by coating the passive element (4) with a material other than that of the passive element (4).

4. The driving element according to any one of claims 1 to 3, wherein, The first wear-inhibiting element or the second wear-inhibiting element (83, 84) is made of one of the following materials: • Ceramic materials, especially silicate ceramics, and even more so mullite; • Plastic materials, especially reinforced plastic materials, and even more so fiber-reinforced plastic materials; • Palladium alloys, especially palladium-silver alloys, such as Pd75Ag25 and Pd60Ag40; •molybdenum; • Ceramic-metal composites, especially mullite-molybdenum composites, such as Mu / Mo-3 and Mu / Mo-9; • Nickel alloys, especially nickel-aluminum alloys, such as Ni-50Al, Ni-48Al, and Ni-45Al; • Amorphous nickel alloys (Vulcan alloys).

5. The drive element according to any one of claims 1 to 4, wherein the first wear-inhibiting element (83) and the second wear-inhibiting element (84) are any of the following material combinations, in order: • Zirconium oxide - Zirconium oxide; • Zirconia-palladium alloy; • Alumina-zirconia; • Silicon carbide-zirconium oxide; •Silicon nitrate-zirconium oxide; • Zirconia - plastic or reinforced plastic.

6. The driving element according to any one of the preceding claims, wherein, The contact surface of the plug (80) that contacts the contact area (41) of the passive element (4) has a cylindrical shape, and in particular, the cylindrical axis of the cylindrical surface is perpendicular to the reference plane (28).

7. The driving element according to claim 6, wherein, The plug-in (80) has a cylindrical or semi-cylindrical shape.

8. The driving element according to any one of claims 1 to 5, wherein, The portion of the contact surface of the plug (80) that contacts the contact area (41) of the passive element (4) has an ellipsoidal shape, particularly a rotational ellipsoid or spherical shape.

9. The driving element according to claim 8, wherein, The plug (80) has an ellipsoidal shape, especially a rotational ellipsoidal shape.

10. The driving element according to any one of the preceding claims, wherein, The plug (80) is attached to the resonator (2) by pressing the plug into the clamping groove (87) of the resonator (2).

11. The driving element according to any one of the preceding claims, wherein the insert (80) is connected to the resonator (2) by bonding the insert to the connection surface (85) of the contact element (31), in particular to the adhesive groove (86) of the resonator (2).

12. The drive element according to any one of the preceding claims, wherein the contact area (41) presses against the contact element (31) with a prestress (Fn) having a non-zero component (Fnz) perpendicular to the reference plane (28).

13. The driving element according to any one of the preceding claims, wherein one or more plugs (80) are arranged asymmetrically with respect to the bisector plane, which is parallel to the reference plane (28) and the resonator (2) is substantially mirror-symmetrical with respect to the bisector plane; in particular, wherein the contact points of the plugs (80) and the passive element (4) are arranged asymmetrically with respect to the bisector plane.

14. A driving unit for driving a passive element (4) to move relative to an active element (1), wherein the active element (1) comprises at least two driving elements according to any one of claims 1 to 13, the combination of the at least two driving elements comprising a common resonator (2) extending about a common reference plane, and a first arm (21) and a second arm (22) arranged for driving the common passive element (4), and particularly wherein, The first arm (21) and the second arm (22) are arranged in a mirror symmetric manner, and the resonator axis (24) is its axis of symmetry.

15. The drive unit according to claim 14, wherein, The first arm (21) includes a first contact element (31) and a first protrusion (33), and the second arm (22) includes a second contact element (32) and a second protrusion (34), wherein: • Alternatively, the first contact element (31) and the second contact element (32) extend toward each other, and in particular, the first protrusion (33) and the second protrusion (34) extend away from each other; • Alternatively, the first contact element (31) and the second contact element (32) extend away from each other, and in particular, the first protrusion (33) and the second protrusion (34) extend toward each other.

16. The driving element according to any one of claims 1 to 13, or the driving unit according to claim 14 or 15, wherein, The driving element or the driving unit is configured such that when the drive is not oscillating, i.e. when the excitation device (23) is not energized, there is a prestress between the contact element (31) of the active element (1) and the contact area (41) of the passive element (4).

17. The driving element according to any one of claims 1 to 13, or the driving unit according to any one of claims 14 to 16, wherein the passive element (4) is arranged to translate along a linear motion axis (26) parallel to a reference plane (28), and especially for the driving unit, the linear motion axis (26) is also parallel to the resonator axis (24).

18. The driving element according to any one of claims 1 to 13, or the driving unit according to any one of claims 14 to 16, wherein the passive element (4) is arranged to rotate about a rotational motion axis (29), the rotational motion axis (29) being parallel to a reference plane (28), and in particular, for the driving unit, the rotational motion axis (29) being perpendicular to the resonator axis (24).

19. The driving element according to any one of claims 1 to 13, or the driving unit according to any one of claims 14 to 18, wherein the resonator length is defined as the dimension of the resonator along the resonator axis (24) from the end of the arm (21, 22) to the opposite end of its counterweight portion, and wherein the extension (d) of each flat region projected onto the reference plane (28) is one-tenth to one-hundredth of the resonator length, especially one-twentieth to one-eighth of the resonator length.

20. The driving element according to any one of claims 1 to 13, or the driving unit according to any one of claims 14 to 19, wherein the length of the resonator (2) is 3 to 5 mm, especially 4 mm, and the extension range (d) of the flat region is 0.05 mm to 0.15 mm, especially 0.08 mm to 0.12 mm, especially 0.1 mm.

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