Rotary actuation device and method for operating the same

Abstract

The invention relates to a rotary actuation device (1) comprising a base (2), a rotor (3) and at least two groups (40, 42) of drive units, each group comprising at least two drive units (4), wherein the drive units (4) are arranged peripherally on the base (2) and between the base and the rotor (3), wherein each drive unit (4) comprises two deflectable actuation bodies (5) which are arranged in a V shape relative to each other and a friction element (6) which is connected to the two actuation bodies, and wherein the rotor (3) and the friction elements (6) are pushed towards each other in one direction by spring means (30) arranged between the drive units (4), so that when the actuation bodies (5) are not deflected, all friction elements (6) are in contact with the rotor (3) and jointly span a contact plane (K), wherein a continuous movement of the rotor (3) is achieved by phase-shifted actuation of the actuation bodies (5) of the different groups (40, 42) of drive units (4). The invention also relates to a method for operating a rotary actuation device (1).

Description

Technical Field

[0001] This invention relates to a rotary actuation device. It also relates to a method for operating such a rotary actuation device. Background Technology

[0002] The applicant's WO2017 / 158017A1 describes a rotary actuation device in Figure 7, which uses a piezoelectric walking actuator 1 with a drive unit 2, wherein, with reference to the disclosure Figure 2 Four piezoelectric actuators 213, 214, 223, and 224 are inserted into the frame 20 in a V-shaped arrangement in pairs. Each pair of actuators arranged in a V-shape relative to each other is pressed against the solid joints 212 and 222 of the base 201 by associated drive portions 21 and 22 and elastic spring portions 211 and 221 arranged between the drive portions and the base 201 of the frame 20, resulting in prestressing, particularly on the actuators.

[0003] By arranging the drive unit 2 on a base frame 4 with an elastically deformable portion in the form of a solid joint (not shown in Figure 7 of WO2017 / 158017A1), the drive portion is pressed against the rotor 3 in the form of a disc; on the other hand, the elastic properties of the frame allow the drive portion of another interacting actuator pair to either be completely passive, i.e., without electrical actuation and relying solely on mechanical arrangement or conditions, or otherwise actively, i.e., by appropriate electrical actuation of the corresponding actuator pair, to lift the rotor, which supports or assists the drive portion in being lifted from the rotor.

[0004] The disadvantage of the rotary actuator disclosed in Figure 7 of WO2017 / 158017A1 is its relatively large space requirement, especially when multiple drive units 2 are arranged around the outer circumference of the rotor.

[0005] To address the aforementioned problems, according to Figure 5 of this application (which is not the subject of this invention), for example, three drive devices according to WO2017 / 158017A1 are arranged on the inner circumference of a rotor designed as an annular disk. In this respect, it is possible to use only one drive device or two or more than three drive devices. Based on this type of arrangement of drive devices or multiple drive devices, it further facilitates the passive lifting of the drive portion of the non-driven actuator pair of the drive devices, enabling a relatively small rotary actuation device with a small adjustment surface. However, a disadvantage is that the manufacturing of the rotor or the machining of the inner circumferential surface is relatively complex, because for the actuator, it must be manufactured with very high precision while maintaining low tolerances. Furthermore, in such a solution, considerable effort is required regarding the orientation of the rotor or its axis of rotation.

[0006] US4613782 discloses a rotary actuation device in Figures 3 and 4, comprising three drive units, each drive unit comprising two piezoelectric actuators 1 and 2 arranged in a V-shape relative to each other, one end of which is supported on a common base 17 and coupled at opposite ends by a moving mechanism 18, wherein the moving mechanism 18 comprises a drive element 10 pressed against the moving mechanism 18 by a screw connected to the base 17, and wherein a compressive force or prestress is applied to the actuators 1 and 2 as a result of the motion mechanism.

[0007] Three drive units are evenly arranged on the circumference of the driven element 11, which is implemented as an annular disk, such that the three drive elements 10 have a circumferential angular distance of approximately 120° relative to each other. Since they are arranged between the base and the driven element, the external dimensions of the rotary actuator are substantially defined by the fixed wall 20 or the housing 28.

[0008] In operation, the actuators of the drive units are electrically controlled such that the drive element 10 coupled to the actuator performs high-frequency vibrations along an elliptical movement path, wherein the frequency of these vibrations is 20 kHz according to column 9, line 13 of U.S. Patent No. 4,613,782, that is, within the ultrasonic range. All three drive units are acted upon by the same high-frequency voltage signal, thereby operating synchronously.

[0009] The synchronous control of the three drive units results in periods during which none of the three drive units are in contact with the driven element 11, thus causing a drive interruption. These periods of drive interruption occur at high control frequencies of the actuators of the drive units, i.e., at high rotational speeds of the driven element; within this speed state, these periods are very short and acceptable. However, the lower the control frequency or the lower the rotational speed, the more pronounced the drive interruption becomes, thus excluding known rotary actuators from US 4613782 from certain applications.

[0010] Against this background, the object of the present invention is to provide a rotary actuation device that allows for highly precise and uninterrupted adjustable movement with a compact size. Summary of the Invention

[0011] This objective is achieved by a rotary actuation device. The rotary actuation device includes at least four drive units arranged circumferentially on a base and between the base and the rotor. The drive units can be assigned to a first group and a second group, such that each group includes at least two drive units. Within the meaning of this invention, each group includes more than two drive units, wherein each group preferably includes three drive units.

[0012] Each drive unit includes two actuators arranged in a V-shape relative to each other, wherein the apex region of the resulting V-shape is achieved by a friction element connecting or coupling the two actuators to each other. Thus, the apex of the V-shape and the friction element face the rotor of the rotary actuator.

[0013] Due to the V-shaped arrangement, the angle between the two actuators of the drive unit can vary over a wide range. The angle can be between 10° and 160°. However, preferably, the angle range between 55° and 125° is preferred, and the angle range is particularly preferred to be between 85° and 95°.

[0014] The friction elements of the drive unit and the rotor are pushed towards each other in one direction by a spring device centrally arranged between the drive units, so that all friction elements are in contact with the rotor in a non-actuated or un-deflected state of the actuator. In this case, the corresponding contact points or contact surfaces together span the contact plane K. The drive unit is arranged circumferentially around the center of the spring device, achieving a particularly compact structure for the rotary actuator.

[0015] Advantageously, the spring device is integrally formed with the rotor. This integral or integrated design of the spring device and rotor results in a simpler structure for the rotary actuator and improved assembly characteristics. In this case, it is particularly advantageous that the spring device includes a slit-like recess through which the spring action of the spring device is achieved.

[0016] Furthermore, it is advantageous that, in all cases, the actuator is supported on the base by a support portion connected to the base via a joint or joint portion. The support portion and the joint or joint portion are preferably formed as a single piece or integrated with the base. The lateral force load on the actuator can be offset by the support portion, which is arranged in a hinged manner. Furthermore, mechanical tolerances caused by production or assembly can be compensated for in this way.

[0017] Furthermore, it is advantageous that the actuator has an electromechanical material and is preferably composed of such material. When a voltage is applied and a corresponding electric field is achieved, the electromechanical material undergoes mechanical deformation, which can be used for actuation or driving movement. An actuator made of electromechanical material has no mechanical parts and can very efficiently convert electrical energy into mechanical deformation or movement with very high power. It is also conceivable that the actuator comprises or is composed of a material having electrostrictive properties.

[0018] The actuator is preferably made of a piezoelectric material, and particularly preferably of a piezoelectric ceramic material. Piezoelectric or piezoelectric ceramic materials are readily available and can be operated in a very precise manner. It is also conceivable that the actuator possesses materials with electrostrictive properties.

[0019] The present invention also relates to a method for operating the aforementioned rotary actuation device, wherein different groups of drive units are controlled in a manner that is phase-shifted relative to each other. For example, in the case of a rotary actuation device comprising two groups of drive units, the drive units of the first group are controlled in a manner that is phase-shifted relative to the corresponding drive units of the second group.

[0020] In this case, it is advantageous that the control of the corresponding group of drive units is performed in such a way that a defined movement path is generated for the friction elements assigned to these drive units, the movement path including a vertical movement component arranged substantially perpendicular to the contact plane K and a horizontal movement component arranged substantially parallel to the contact plane K, and as a result, due to the vertical movement component of the force acting on the spring device, the friction element of the actuator of the corresponding other group of drive units disengages from the rotor, and due to the vertical movement component, a defined drive step of the rotor in the drive direction is generated. Attached Figure Description

[0021] The following is a description of embodiments of the rotary actuation device according to the present invention with respect to the corresponding drawings, wherein the same reference numerals denote the same parts in different drawings.

[0022] Figure 1 This is a perspective view of the rotary actuator according to the present invention.

[0023] Figure 2 It is based on Figure 1 Perspective views of the rotary actuator in different views.

[0024] Figure 3A and 3B It is about the basis Figure 1 or Figure 2 Plan view and cross-sectional view of the rotary actuator.

[0025] Figure 4A and 4B This is a schematic diagram relating to the drive unit assembly of the rotary actuator according to the present invention.

[0026] Figure 5 is a perspective view of a rotary actuator that is not part of this invention. Detailed Implementation

[0027] Figure 1 The rotary actuation device 1 according to the invention is shown in perspective. On a generally annular stainless steel base 2 connected to a base 200, a total of four drive units 4 are arranged circumferentially and at a generally 90° angle to each other, such that they are arranged in pairs radially opposite each other and overlapping each other.

[0028] Each drive unit 4 is formed of two elongated piezoelectric actuators 5, which are arranged relative to each other in such a way that they generally form a substantially V-shape, wherein the ends of the two actuators 5 of the drive unit 4 furthest from the base 2 are connected or coupled to each other via substantially triangular friction elements 6. The corresponding other end of each actuator 5 of the drive unit 4 pointing towards the base 2 is supported on a support portion 20, which is connected to the base 2 via a solid-state connector. The support portion 20 and the solid-state connector are integrally or integratedly formed with the base 2.

[0029] The central plane of the two actuators 5, which are assigned to the drive unit 4 and arranged in a V-shape relative to each other, spans a plane that defines the drive unit central plane A, wherein the drive unit central planes A of the drive units 4, which are arranged radially opposite each other, are substantially parallel to each other, and wherein the drive unit central planes A of adjacent drive units 4 are arranged substantially perpendicular to each other.

[0030] The cylindrical piezoelectric actuators are composed of piezoelectric ceramic material. They are connected to the associated connector 20 and the associated friction element 6 by material bonding, specifically by adhesive bonding. The two actuators 5 associated with the drive unit 4 form an angle of approximately 90° between them.

[0031] exist Figure 1 In the static state of the rotary actuator shown, the actuators 5 of the four drive units 4 are not electrically driven or subjected to voltage, and all four friction elements 6 are in contact with the annular friction disk 60, which is connected to the rotor 3 by means of material bonding.

[0032] The friction disk 60 is substantially parallel to and spaced apart from the base 2, and the drive unit 4 is located between the base 2 and the friction disk 60. The contact point or contact surface between the friction element 6 and the friction disk 60 is substantially located in the contact plane K (see [reference]). Figure 3B ), wherein the central plane A of the drive unit is arranged to be substantially perpendicular to the contact plane K.

[0033] The base 200 houses the cables of the actuator 5 of the guide drive unit 4, ensuring a voltage supply to the actuator 5. These internal cables are connected to the power supply line 220. The base 200 also serves to mount the rotary actuator on a higher-level unit. It is conceivable to integrate electronic components into the base 200 for controlling the rotary actuator 1, such as sensors, receivers, controllers, drivers, etc. Furthermore, it is conceivable to provide a battery or rechargeable battery for an independent power supply to the rotary actuator in the base 200.

[0034] The rotor 3 is rotatably mounted relative to the fixed base 2. A spring device 30 is integrally formed or integrated with the rotor on its inner circumference, centrally positioned between the drive units 4, so that the drive units 4 circumferentially surround or frame the spring device 30. The elastic action of the spring device 30 is achieved through slit-like recesses 32, which point circumferentially to the rotor 3 and are spaced axially. The spring device 30 of the rotor 3 elastically presses the rotor 3 or friction disc 60 against all the friction elements 6 of the drive unit 4.

[0035] Figure 2 Shown in different views according to Figure 1 The rotary actuator 1, in which the rotary actuator 1 can be seen here Figure 1 The rear side, which was blocked in the middle, is thus visible, so that the arrangement there and in Figure 1 The drive unit 4 is not visible. Because in Figure 2 There are no others in Figure 1 Features not visible in the text are therefore omitted here. Figure 2 A more detailed description.

[0036] Figure 3A A plan view (perpendicular to the viewing direction of base 2 or rotor 3) is shown according to... Figure 1 or Figure 2 The rotary actuator according to the present invention, and Figure 3B Involving Figure 3A The section marked in the middle. According to... Figure 3B In the cross-sectional view, it can be clearly seen that in the static state shown here, where there is no electrical control of the actuator of the drive unit, the two identifiable friction elements 6 are in contact with the friction disk 60, and this also applies to... Figure 3B Two other friction elements 6 are not visible. The four contact points or contact surfaces generated between the friction elements 6 and the friction disk 60 are substantially located in the plane defining the contact plane K. The central plane A of the drive unit is arranged substantially perpendicular to the contact plane K, wherein the central planes A of the drive units 4 that are radially opposite are arranged substantially parallel to each other.

[0037] In addition, from Figure 3B As can be seen, the shaft 34 is integrally formed with the rotor 3 and protrudes through both the base 2 and the base 200, and protrudes relative to the surface of the base 200, so that the element to be positioned by the rotation actuation device 1 can be attached to or connected to the protruding part of the shaft 34.

[0038] To adjust the spring force that elastically presses the rotor 3 or friction disc 60 against the friction element 6 of the drive unit 4, a clamping nut 7 acts on the corresponding threaded portion of the shaft 34 and is supported on the bearing 8. By rotating the clamping nut 7 onto the threaded portion of the shaft 34, the shaft 34 and the rotor 3 move in the direction of the clamping nut 7 (in... Figure 3B The friction disc 60 connected to it is thus pulled to the left, and the friction element 6 of the drive unit 4 is elastically pressed against the friction element 6 of the drive unit 4 via the rotor 3.

[0039] Bearing 8 is an angular ball bearing, which is prestressed by a clamping nut 7 tightened on the threaded portion of shaft 34. The second angular ball bearing 8' is spaced apart from the first angular ball bearing 8 by a snap ring and is prestressed by a leaf spring 9 disposed between the rotor 3 and the latter.

[0040] Figure 4A and 4B Two possible arrangement variations relative to drive unit 4 are schematically shown here. Figure 4A Corresponding to according to Figure 1 The arrangement of the drive units 4 according to an exemplary embodiment of the rotary actuation device according to the invention shown in FIG3, wherein four drive units 4 are arranged circumferentially such that the angular distance between each other is substantially 90°. In this manner, two drive units are arranged radially opposite each other, wherein a corresponding pair of drive units 4 can be assigned to a group. Figure 4A In the first group 40 of the drive units 4, characterized by an unfilled frame, another pair of drive units 4, characterized by a filled frame, forms the second group 42 of the drive units 4.

[0041] According to the invention, it is used for operation. Figure 1 In the method of the corresponding rotary actuation device of Figure 3, the two groups 40 and 42 of the drive unit 4 or its actuator 5 are electrically controlled in a phase-shifted manner, preferably by a phase shift of 180°. In each drive unit 4, the control signal preferably causes an elliptical movement path to be assigned to the friction element 6 of the drive unit 4, wherein the friction element 6 assigned to the drive units 4 of groups 40 and 42 executes a synchronized movement path. Thus, for example, drive unit group 40 first causes the rotor 3 to perform a defined rotational advance or movement step adjustment, and then, that is, after the drive units 4 of group 40 have completed their advance steps, drive unit group 42 causes this advance or movement step adjustment. The groups 40 and 42 of drive units 4 thus alternately perform the defined advance steps, wherein some overlap in the driven movement is also possible in this case, that is, one group of drive units has started the next advance step while the other group of drive units has not yet fully completed its feed step.

[0042] Because the shape of the movement path of the friction element 6 of the drive unit 4 is preferably elliptical and thus includes both a horizontal movement component substantially parallel to the contact plane K and a vertical movement component substantially perpendicular to the contact plane K and substantially parallel to the central plane A of the drive unit, the drive movement of the groups 40, 42 of the drive units 4 or the vertical movement component of their respective friction elements 6 exerts a force on the spring device 30 of the rotor 3. This force counteracts the spring force applied by the spring device, wherein the spring force ensures that the rotor 3 or the friction disk 60 moves in the direction of the friction element 6. The effect thus produced, purely mechanically or passively, is that the friction elements 6 of the corresponding other group of drive units 4 that are not used for propulsion are lifted or disengaged from contact. Therefore, it is ensured that during the forward movement, the horizontal component of the movement path of the group of drive units 4 or the friction elements assigned to them is such that the friction elements of the corresponding other group of drive units 4 do not obstruct the forward movement through their contact with the friction disk 60 of the rotor 3.

[0043] Advantageously, the lifting process of the friction elements of the set of drive units, which is mechanically caused as described above, is achieved by the corresponding electrically actuated support of the actuator of the set of drive units, which also undergoes a certain length reduction.

[0044] according to Figure 4B It is conceivable that a group of drive units 40, 42 comprises three drive units 4, with a total of six drive units arranged circumferentially, wherein there is an angular distance of approximately 60° between adjacent drive units. In this case, the drive units of one group are always arranged between two drive units of the other group, so that the drive units within a group have an angular distance of approximately 120° relative to each other. When using two groups of drive units of three drive units each, a specific advantage is that the mechanical lifting of the friction elements of the drive units not used for propulsion is improved during the forward step caused by the other group of drive units.

[0045] Apart from Figure 4A and 4B Besides the two arrangements of the drive units shown, other configurations are possible, where each of the two groups of drive units includes more than three drive units. It is also possible to provide more than two groups of drive units, where the drive units in each group are phase-shifted relative to each other. For example, according to... Figure 4B The six configured drive units can be assigned to three sets of radially opposite drive units, and the three sets of drive units can be controlled in a circular manner.

[0046] Figure Labels 1 Rotary drive device 2. Base 3 rotors 4 drive units 5. Actuator (of drive unit 4) 6 (Drive Unit 4) Friction Element 7. Tighten the nut 8, 8′ angular contact ball bearings 9. Disc Spring 20 Support section 30 Spring device 32 (of spring device 30) slit-like recess 34 (shaft of rotor 3) 40 First group of drive units 4 42 Second group of drive units 4 60 Friction disc 200 base 220 power cord A Drive Unit Central Plane K contact plane

Claims

1. A rotary actuator (1), having Base (2) Rotor (3), and At least two groups (40, 42) of drive units (4), each group comprising at least two of the drive units (4). The drive unit (4) is circumferentially arranged on the base (2) and viewed axially between the base (2) and the rotor (3). Each drive unit (4) includes two deflectable actuators (5) and a friction element (6). The two deflectable actuators (5) are arranged in a V-shape relative to each other and span the central plane (A). The ends of the two deflectable actuators away from the base (2) are connected via the friction element (6). The rotor (3) and the friction elements (6) are pressed toward each other in one direction by a spring device (30) arranged between the at least two sets of drive units (4), and the two deflectable actuators (5) are arranged such that when the two deflectable actuators (5) are not deflected, all the friction elements (6) are in contact with the rotor (3) and together cross the contact plane (K), the central plane (A) of the drive unit being arranged substantially perpendicular to the contact plane (K). The continuous movement of the rotor (3) is achieved by phase offset actuation of the two deflectable actuators (5) of different groups (40, 42) of the drive unit (4).

2. The rotary actuation device (1) according to claim 1, wherein the spring device (30) is integrally formed with the rotor (3).

3. The rotary actuator (1) according to claim 1, wherein the spring device (30) includes a slit-shaped groove (32).

4. The rotary actuator (1) according to claim 1, wherein each of the two deflectable actuators (5) is supported on the base (2) via a support portion (20), the support portion (20) being connected to the base (2) via a connector.

5. The rotary actuation device (1) according to claim 1, wherein the rotor (3) includes a friction disc (60) for contacting the friction element (6).

6. The rotary actuator (1) according to claim 1, wherein the shaft (34) is integrally formed with the rotor (3) and protrudes through the base (2), wherein the shaft (34) is used to attach an element to be positioned by the rotary actuator (1).

7. The rotary actuator (1) according to claim 1, wherein the two deflectable actuators (5) comprise electromechanical materials.

8. The rotary actuator (1) according to claim 1, wherein the two deflectable actuators (5) are made of electromechanical materials.

9. The rotary actuator (1) according to claim 7 or 8, wherein the two deflectable actuators (5) are made of piezoelectric material.

10. The rotary actuator (1) according to claim 9, wherein the two deflectable actuators (5) are composed of piezoelectric ceramic material.

11. A method for operating a rotary actuator (1) according to claim 1, wherein different groups (40, 42) of the drive units (4) are actuated relative to each other in a phase-shifted manner.

12. The method for operating a rotary actuator (1) according to claim 11, wherein the actuation effect of the respective groups (40, 42) of the drive units (4) influences the defined movement path of the friction elements (6) associated with these drive units (4), the movement path comprising a vertical movement component arranged substantially perpendicular to the contact plane (K) and a horizontal movement component arranged substantially parallel to the contact plane (K), and the friction elements (6) of the two deflectable actuators (5) of the corresponding other group of drive units (4) disengage from the rotor (3) due to the action of the vertical movement component against the force of the spring device (30), and the horizontal movement component generates a defined drive step of the rotor (3) in the drive direction.

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