Reconfigurable nonlinear variable stiffness actuator

Abstract

The invention discloses a reconfigurable nonlinear variable stiffness actuator, and belongs to the technical field of robots. A reconfigurable nonlinear variable-stiffness actuator comprises a shell, a driving input end is arranged on one side of the shell and used for installing a frameless torque motor, an output plate is arranged on the other side of the shell and used for changing stiffness response of a system, and the reconfigurable nonlinear variable-stiffness actuator further comprises a transmission shaft which is coaxially installed in the driving input end and fixed to a rotor of the frameless torque motor. The sliding assemblies are arranged in the shell and are distributed along the circumference of the shell at equal intervals; the reed is connected to the transmission shaft and slides in the sliding assembly; curve grooves are formed in the output plate in the circumferential direction at equal intervals, the sliding assemblies slide in the curve grooves, the output plate is driven by the sliding assemblies to rotate, and the reconfigurable nonlinear variable-rigidity actuator has a wide rigidity adjusting range and can adjust output rigidity in real time according to different external loads. And the man-machine interaction safety in the use process of the robot can be effectively improved.

Description

Technical Field

[0001] The invention relates to the field of robotics technology, and in particular to a reconfigurable nonlinear variable stiffness actuator. Background Art

[0002] With the rapid development of robotics technology and industry, the interaction between humans and robots is becoming more frequent. Safety issues in the process of human-machine interaction should be given special attention. The use of flexible joints in robots is an effective solution. As a typical representative of flexible joints, variable stiffness actuators have the characteristics of bionic joints - they can adjust their stiffness according to the size of the external contact load.

[0003] At present, the existing variable stiffness drives can be divided into two types: active and passive. Active variable stiffness drives require an additional driving source for adjusting the stiffness, which leads to a larger system volume and mass, and also increases the difficulty of control. Nonlinear stiffness actuators can passively adjust their own stiffness in real time according to the size of the external load without the need for an additional power source. They are directly integrated into the joints of the robot through frameless torque motors, providing high torque density and precise motion control, which is conducive to the miniaturization and lightweight of the robot system. In addition, the stiffness adjustment range of the actuator can be increased through reconfigurable structural design.

[0004] However, existing nonlinear stiffness actuator systems are often complex in design, and their stiffness adjustment range is limited, making it difficult to meet the needs of different application scenarios. Summary of the invention

[0005] The purpose of the present invention is to solve the problems of complex design and limited stiffness adjustment range of nonlinear stiffness actuator systems in the prior art, and to propose a reconfigurable nonlinear variable stiffness actuator, which can adapt to external loads and reduce the structural complexity of the driver, improve adaptability to different usage scenarios, and thereby realize the driving of the robot and safe human-computer interaction.

[0006] In order to achieve the above object, the present invention adopts the following technical solutions:

[0007] A reconfigurable nonlinear variable stiffness actuator comprises a shell which is a hollow annular structure, a driving input end is arranged on one side of the shell for mounting a frameless torque motor, an output plate is arranged on the other side of the shell for changing the stiffness response of the system, and further comprises: a transmission shaft which is coaxially mounted in the driving input end for externally connecting a bionic joint and is tightly connected with the rotor of the frameless torque motor; a stiffness adjustment unit which is connected to the transmission shaft and rotates with the transmission shaft and is used to adjust the output stiffness of the device; wherein the output plate is provided with curved grooves equidistantly in the circumferential direction, and the shell is provided with linear grooves equidistantly in the circumferential direction, the stiffness adjustment unit slides in the curved groove and the linear groove at the same time, and the output plate is driven to rotate by the stiffness adjustment unit.

[0008] In order to be able to adjust the overall stiffness of the actuator in real time, preferably, the stiffness adjustment unit includes a reed connected to the transmission shaft, and a sliding assembly sliding in the curved groove and the straight groove, the reed is clamped in the sliding assembly, and the effective action length of the reed is adjusted by the sliding assembly.

[0009] In order to change the reconfigurable characteristics and stiffness range of the actuator, further, rectangular grooves for installing reeds are evenly opened on the outer edge surface of the transmission shaft, wherein the number of installed reeds is proportional to the reconfigurable characteristics of the device.

[0010] In order to be able to adjust the effective action length of the spring leaf according to the change of the external load, the sliding assembly further includes a sliding frame, a sliding pin is fixedly installed on the sliding frame, the sliding pin is slidably connected in the curved groove and the straight groove, and a sliding shaft is symmetrically arranged in the sliding frame, an inter-axial sleeve is sleeved on the sliding shaft, ball bearings are installed at both ends of the inter-axial sleeve, and the spring leaf is clamped between the symmetrical ball bearings.

[0011] In order to be able to perform adaptive adjustments according to the thickness of the spring leaf, further, adjustment grooves are opened on both sides of the sliding frame, both ends of the sliding shaft pass through the adjustment grooves and retaining rings are installed between the outer walls of the sliding frame, and symmetrically arranged top screws are threadedly installed on the sliding frame, and the top screws on both sides are rotatably connected to the adjacent inter-axial sleeves respectively.

[0012] In order to prevent dust and foreign matter from entering the interior and affecting the operation of the equipment, preferably, the drive input end includes an end cover fixedly connected to the housing, and a mounting flange fixedly mounted on the end cover, and the stator of the frameless torque motor is fixed in the mounting flange.

[0013] In order to monitor the rotation angle of the frameless torque motor, further, the drive input end also includes a first encoder fixedly mounted on the mounting flange, and the first encoder is used to monitor the rotation angle of the frameless torque motor.

[0014] In order to monitor the rotation angle and speed of the transmission shaft, preferably, the reconfigurable nonlinear variable stiffness actuator also includes a second encoder, which is fixedly mounted on the transmission shaft and located in the housing, wherein the second encoder includes a reading head and a magnetic ring.

[0015] In order to effectively reduce vibration caused by rotation and lower wear caused by friction, preferably, a connecting bearing is provided inside the output plate, and the connecting bearing is used to support the transmission shaft.

[0016] In order to reduce mechanical wear between the output plate and the housing, preferably, the output plate is connected to the housing via a spacer sleeve, and the spacer sleeve is used to maintain a gap between the output plate and the housing.

[0017] Compared with the prior art, the present invention provides a reconfigurable nonlinear variable stiffness actuator, which has the following beneficial effects:

[0018] The reconfigurable nonlinear variable stiffness actuator, when the frameless torque motor is started, the rotor rotates together with the transmission shaft, and the rotation of the transmission shaft drives the reed to rotate. During the rotation of the reed, the sliding component drives the output plate to rotate together. When the output plate comes into contact with an external obstacle, the sliding component slides in the curved groove of the output plate. The movement of the sliding component increases the effective length of the reed, thereby reducing the output stiffness of the actuator, thereby achieving the purpose of safe interaction with the external environment. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 The overall structure of a reconfigurable nonlinear variable stiffness actuator proposed by the present invention is shown in FIG. Figure 1 ;

[0020] Figure 2 The overall structure of a reconfigurable nonlinear variable stiffness actuator proposed by the present invention is shown in FIG. Figure 2 ;

[0021] Figure 3 This is a schematic diagram of the overall structure of a reconfigurable nonlinear variable stiffness actuator without an output plate proposed by the present invention;

[0022] Figure 4 It is a schematic overall side view of a reconfigurable nonlinear variable stiffness actuator proposed by the present invention;

[0023] Figure 5 A reconfigurable nonlinear variable stiffness actuator proposed in the present invention Figure 4 Sectional view;

[0024] Figure 6 A schematic diagram of the structure of a sliding component of a reconfigurable nonlinear variable stiffness actuator proposed in the present invention.

[0025] In the figure: 1, housing; 101, linear slot;

[0026] 2. drive input end; 201. end cover; 202. mounting flange; 203. first encoder;

[0027] 3. Frameless torque motor;

[0028] 4. Output plate; 401, curved slot;

[0029] 5. Transmission shaft; 501. Rectangular groove;

[0030] 6. Reed;

[0031] 7. Sliding assembly; 701. Sliding frame; 702. Sliding pin; 703. Sliding shaft; 704. Interaxial sleeve; 705. Ball bearing; 706. Adjusting groove; 707. Retaining ring; 708. Top screw;

[0032] 8. Second encoder; 801. Reading head; 802. Magnetic ring;

[0033] 9. Connecting bearing; 10. Spacer. DETAILED DESCRIPTION

[0034] The technical solutions in the embodiments of the present invention will be described clearly and completely below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments.

[0035] In the description of the present invention, it is necessary to understand that the terms "upper", "lower", "front", "back", "left", "right", "top", "bottom", "inside", "outside", etc., indicating the orientation or position relationship are based on the orientation or position relationship shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention.

[0036] Example:

[0037] Reference Figure 1-Figure 6A reconfigurable nonlinear variable stiffness actuator comprises a housing 1 with a visual window, which is a hollow ring structure, providing physical support for the entire device and protecting the internal components from the influence of the external environment. A driving input terminal 2 is arranged on one side of the housing 1 for installing a frameless torque motor 3, and an output plate 4 is arranged on the other side of the housing 1 for changing the stiffness response of the system. The actuator also comprises: a transmission shaft 5, which is coaxially installed in the driving input terminal 2 and is used for externally connecting a bionic joint and is tightly connected with the rotor of the frameless torque motor 3. The frameless torque motor 3 is used as a power source to directly drive the frameless torque motor 3. The rotation of the transmission shaft 5 helps to reduce the overall size and improve efficiency; the stiffness adjustment unit is connected to the transmission shaft 5 and rotates with the transmission shaft 5 to adjust the output stiffness of the device; wherein, the output plate 4 is provided with curved grooves 401 equidistantly along the circumferential direction, and the housing 1 is provided with linear grooves 101 equidistantly along the circumferential direction; the stiffness adjustment unit slides in the curved grooves 401 and the linear grooves 101 at the same time, and the output plate 4 is driven by the stiffness adjustment unit to rotate, so that the stiffness adjustment unit can automatically adjust its position according to the change of the external load, thereby changing the stiffness response of the system.

[0038] When the reconfigurable nonlinear variable stiffness actuator is in use, the frameless torque motor 3 is started to drive the transmission shaft 5 to rotate. Since the stiffness adjustment unit is connected to the transmission shaft 5, it will also rotate accordingly. During this process, if the external load changes, the stiffness adjustment unit can automatically adjust its position according to the change in the external load, thereby changing the stiffness response of the system. At the same time, the stiffness adjustment unit will also slide along the curved groove 401 on the output plate 4 and the straight groove 101 on the shell 1, ensuring that the output plate 4 can be adjusted to the corresponding angle as needed, ultimately achieving precise driving of the bionic joint or other connecting components.

[0039] Reference Figure 1 and Figure 5 Preferably, the stiffness adjustment unit includes a reed 6 connected to the transmission shaft 5. Specifically, rectangular grooves 501 for installing the reed 6 are evenly opened on the outer edge surface of the transmission shaft 5, thereby fixing the reed 6. The number of reeds 6 installed is proportional to the reconfigurable characteristics of the device to change the reconfigurable characteristics and stiffness range of the actuator, and a sliding component 7 sliding in the curved groove 401 and the straight groove 101. The reed 6 is clamped in the sliding component 7, and the sliding component 7 is used to adjust the effective action length of the reed 6, so that the reed 6 can automatically adjust its position under different load conditions, thereby changing the stiffness response of the entire system.

[0040] Through the above-mentioned arrangement, when the frameless torque motor 3 drives the transmission shaft 5 to rotate, the reed 6 rotates with the transmission shaft 5. At the same time, if the external load changes, the sliding assembly 7 will slide along the curved groove 401 and the straight groove 101 according to the load size, and automatically adjust the effective action length of the reed 6. This process changes the bending degree of the reed 6, thereby adjusting the overall stiffness of the actuator in real time. This design not only realizes an adaptive response to the external load, but also significantly expands the stiffness adjustment range of the actuator, making it more suitable for a variety of application scenarios.

[0041] Reference Figure 6 The sliding assembly 7 includes a sliding frame 701, on which a sliding pin 702 is fixedly installed. The sliding pin 702 is slidably connected in the curved groove 401 and the straight groove 101, allowing the entire sliding assembly 7 to perform translational movement along these grooves, and a sliding shaft 703 symmetrically arranged in the sliding frame 701, on which an inter-axial sleeve 704 is sleeved, and ball bearings 705 are installed at both ends of the inter-axial sleeve 704 to provide low-friction support. The reed 6 is clamped between the symmetrical ball bearings 705, thereby realizing sliding friction during the length change of the reed 6, so that its effective action length can be adjusted according to the change of the external load.

[0042] Reference Figure 6 , adjustment grooves 706 are provided on the upper and lower sides of the sliding frame 701, and both ends of the sliding shaft 703 pass through the adjustment grooves 706 and are installed with retaining rings 707 between the outer wall of the sliding frame 701, ensuring that the sliding shaft 703 can move freely in the adjustment grooves 706 while maintaining the stability of the structure. The left and right sides of the sliding frame 701 are threadedly installed with symmetrically arranged top screws 708, and the top screws 708 on both sides are rotatably connected to the adjacent inter-axial sleeves 704 respectively. The position of the inter-axial sleeves 704 is fine-tuned by the top screws 708, so that the relative position between the two inter-axial sleeves 704 can be accurately controlled, which can be changed according to the thickness of the reed 6.

[0043] When the frameless torque motor 3 drives the transmission shaft 5 to rotate, the transmission shaft 5 drives the reed 6 to rotate together. Since the reed 6 is clamped between the two ball bearings 705, it can automatically adjust the bending degree according to the change of the external load. Specifically:

[0044] 1. Adaptive stiffness adjustment: When the external load changes, the pressure or tension on the reed 6 will change its bending shape, resulting in a change in its effective length. Since the reed 6 is clamped between the ball bearings 705, this change in bending shape will be converted into a sliding movement of the sliding component 7 along the curved groove 401 and the linear groove 101;

[0045] 2. Precise control: By adjusting the top screw 708, the distance between the two inter-axial sleeves 704 can be fine-tuned, which can be changed according to the thickness of the reed 6. This design not only enhances the flexibility of the system, but also improves its adaptability to different application scenarios;

[0046] 3. Stability and reliability: The sliding shaft 703 is fixed to the outer wall of the sliding frame 701 through the retaining ring 707, which ensures the stability and reliability of the sliding assembly 7 during the entire operation process. In addition, the use of the ball bearing 705 reduces friction and improves the response speed and efficiency of the system.

[0047] Through the above design, the sliding assembly 7 realizes the dynamic adjustment of the effective action length of the reed 6, so that the actuator can automatically adjust the stiffness according to the change of the external load. This mechanism not only simplifies the system design and reduces the complexity, but also significantly expands the stiffness adjustment range, making it more suitable for a variety of application scenarios, and improving the adaptability of the robot system and the safety of human-machine interaction.

[0048] It should be noted that, in order to prevent interference during operation, the frameless torque motor 3 can only drive the transmission shaft 5 to rotate at a small angle, such as a rotation angle between ±10°, to prevent the sliding component 7 from being stuck in the linear groove 101 .

[0049] Reference Figure 1 and Figure 5 The drive input end 2 includes an end cover 201 fixedly connected to the housing 1. The end cover 201 is firmly connected to the housing 1 by bolts or other fasteners to form a closed space to accommodate key components such as the transmission shaft 5 and the frameless torque motor 3, thereby ensuring the mechanical strength and sealing of the entire device, preventing dust and foreign matter from entering the interior and affecting the operation of the equipment, and a mounting flange 202 fixedly mounted on the end cover 201. The stator of the frameless torque motor 3 is fixed in the mounting flange 202. The design of the mounting flange 202 allows the frameless torque motor 3 to be tightly integrated into the overall structure of the actuator, thereby reducing the overall volume of the system and improving the mechanical rigidity and stability.

[0050] The drive input terminal 2 not only provides a stable installation foundation for the frameless torque motor 3, but also ensures the compactness and efficiency of the entire actuator structure. This integration method helps to simplify system design, improve mechanical efficiency, and enhance the safety and adaptability of human-machine interaction. In addition, the use of the frameless torque motor 3 further improves the dynamic performance and response speed of the actuator, making it suitable for more complex robot applications.

[0051] Reference Figure 1The drive input end 2 also includes a first encoder 203 fixedly mounted on the mounting flange 202, which is located near the frameless torque motor 3. The first encoder 203 is used to monitor the rotation angle of the frameless torque motor 3. The first encoder 203 detects the position change of the rotor of the frameless torque motor 3 by optical, magnetic or other technical means, and converts this information into an electrical signal to feed back to the control system. This feedback mechanism is crucial to achieving high-precision position control, especially in application scenarios requiring fast response and precise positioning.

[0052] Reference Figure 2 and Figure 5 The reconfigurable nonlinear variable stiffness actuator also includes a second encoder 8, which is fixedly mounted on the transmission shaft 5 and located in the housing 1, wherein the second encoder 8 includes a reading head 801 and a magnetic ring 802, which are used to accurately monitor the rotation angle and speed of the transmission shaft 5.

[0053] Specifically, the magnetic ring 802 is fixedly mounted on the transmission shaft 5 and rotates with the transmission shaft 5. The magnetic ring 802 has a specific magnetic pole distribution. When it rotates, the reading head 801 can detect these changes and generate corresponding signals.

[0054] In addition to the first encoder 203 monitoring the rotation angle of the frameless torque motor 3, the second encoder 8 also provides an additional layer of monitoring, which enhances the reliability and safety of the system. If one of the encoders fails, the other encoder can still continue to provide the necessary feedback information, thereby improving the robustness of the entire system. At the same time, the second encoder 8 will not only not increase the complexity of the system, but can effectively improve the overall performance. For example, the magnetic ring 802 is directly installed on the transmission shaft 5, which reduces the intermediate links and improves the accuracy and stability of the signal.

[0055] By integrating the second encoder 8, the reconfigurable nonlinear variable stiffness actuator achieves a higher level of control accuracy and reliability. The second encoder 8 consists of a reading head 801 and a magnetic ring 802, is installed on the transmission shaft 5, and is located inside the housing 1, providing high-precision rotation angle and speed feedback. This design not only enhances the control capability of the system, but also provides redundant protection, improving the robustness and adaptability of the overall system, which makes the actuator particularly suitable for robot applications with high requirements for accuracy and reliability.

[0056] Reference Figure 1-Figure 5 A connecting bearing 9 is arranged inside the output plate 4 , and the connecting bearing 9 is used to support the transmission shaft 5 .

[0057] By providing a low-friction, high-precision support point, the connecting bearing 9 enables the transmission shaft 5 to maintain extremely high stability while rotating at high speed, which can effectively reduce vibration caused by rotation and reduce wear caused by friction.

[0058] By arranging a connecting bearing 9 inside the output plate 4, the reconfigurable nonlinear variable stiffness actuator significantly improves the rotational stability of the transmission shaft 5 and the reliability of the overall system. The connecting bearing 9 provides the necessary support, reduces friction and vibration, and enhances the rigidity and dynamic response capability of the system. In addition, this design works in coordination with other key components such as the sliding component 7 and the second encoder 8 to achieve efficient and precise motion control, which is suitable for a variety of complex robot application scenarios. This optimized design not only improves the performance of the equipment, but also extends its service life, laying a solid foundation for achieving safe and reliable human-computer interaction.

[0059] Reference Figure 2 The output plate 4 is connected to the housing 1 through a spacer 10. The spacer 10 is used to maintain a gap between the output plate 4 and the housing 1 to prevent direct contact or unnecessary friction between the two. This design helps to reduce mechanical wear, improve the reliability and life of the system, and can also help absorb small displacements caused by temperature changes or mechanical vibrations, thereby maintaining the stability and accuracy of the system.

[0060] Working principle: When the frameless torque motor 3 is started, the rotor rotates together with the transmission shaft 5, and the transmission shaft 5 drives the reed 6 to rotate while rotating. During the rotation of the reed 6, the sliding component 7 drives the output plate 4 to rotate together. When the output plate 4 comes into contact with an external obstacle, the sliding component 7 slides in the curved groove 401 of the output plate 4. The movement of the sliding component 7 increases the effective length of the reed 6, thereby reducing the output stiffness of the actuator, thereby achieving the purpose of safe interaction with the external environment;

[0061] During the rotation of the actuator, the first encoder 203 is used to monitor the rotation angle of the frameless torque motor 3 , and the second encoder 8 is used to monitor the rotation angle of the transmission shaft 5 .

[0062] The above description is only a preferred specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can make equivalent replacements or changes according to the technical scheme and inventive concept of the present invention within the technical scope disclosed by the present invention, which should be covered by the protection scope of the present invention.

Claims

1. A reconfigurable nonlinear variable stiffness actuator, comprising a housing (1) which is a hollow ring structure, characterized in that: A drive input terminal (2) is provided on one side of the housing (1) for mounting a frameless torque motor (3), and an output plate (4) is provided on the other side of the housing (1) for changing the stiffness response of the system, and further comprising: A transmission shaft (5) is coaxially mounted inside the drive input end (2) and is used for externally connecting a bionic joint and is tightly connected to the rotor of the frameless torque motor (3); A stiffness adjustment unit, connected to the transmission shaft (5), rotates together with the transmission shaft (5), and is used to adjust the output stiffness of the device; The output plate (4) is provided with curved grooves (401) at equal intervals in the circumferential direction, and the housing (1) is provided with linear grooves (101) at equal intervals in the circumferential direction; the stiffness adjustment unit slides in the curved grooves (401) and the linear grooves (101) at the same time, and the stiffness adjustment unit drives the output plate (4) to rotate.

2. The reconfigurable nonlinear variable stiffness actuator according to claim 1, characterized in that: The stiffness adjustment unit comprises a leaf spring (6) connected to the transmission shaft (5), and A sliding assembly (7) slides in the curved groove (401) and the straight groove (101), the reed (6) is clamped in the sliding assembly (7), and the sliding assembly (7) is used to adjust the effective action length of the reed (6).

3. The reconfigurable nonlinear variable stiffness actuator according to claim 2, characterized in that: The outer edge surface of the transmission shaft (5) is evenly provided with rectangular grooves (501) for mounting the spring leaf (6). The number of reeds (6) installed is proportional to the reconfigurable characteristics of the device.

4. The reconfigurable nonlinear variable stiffness actuator according to claim 2, characterized in that: The sliding assembly (7) comprises a sliding frame (701), a sliding pin (702) is fixedly mounted on the sliding frame (701), and the sliding pin (702) is slidably connected in the curved groove (401) and the linear groove (101), and A sliding shaft (703) is symmetrically arranged in the sliding frame (701), an inter-axial sleeve (704) is sleeved on the sliding shaft (703), ball bearings (705) are installed at both ends of the inter-axial sleeve (704), and the spring leaf (6) is clamped between the symmetrical ball bearings (705).

5. The reconfigurable nonlinear variable stiffness actuator according to claim 4, characterized in that: Adjustment grooves (706) are provided on both sides of the sliding frame (701), and both ends of the sliding shaft (703) pass through the adjustment grooves (706) and are provided with retaining rings (707) between the sliding shaft and the outer wall of the sliding frame (701). The sliding frame (701) is threadedly provided with symmetrically arranged top screws (708), and the top screws (708) on both sides are rotatably connected to the adjacent inter-axial sleeves (704) respectively.

6. The reconfigurable nonlinear variable stiffness actuator according to claim 1, characterized in that: The driving input end (2) comprises an end cover (201) fixedly connected to the housing (1), and A mounting flange (202) is fixedly mounted on the end cover (201), and a stator of the frameless torque motor (3) is fixed in the mounting flange (202).

7. The reconfigurable nonlinear variable stiffness actuator according to claim 6, characterized in that: The drive input end (2) further comprises a first encoder (203) fixedly mounted on the mounting flange (202), wherein the first encoder (203) is used to monitor the rotation angle of the frameless torque motor (3).

8. The reconfigurable nonlinear variable stiffness actuator according to claim 1, characterized in that: The reconfigurable nonlinear variable stiffness actuator further comprises a second encoder (8) fixedly mounted on the transmission shaft (5) and located inside the housing (1). Wherein, the second encoder (8) comprises a reading head (801) and a magnetic ring (802).

9. The reconfigurable nonlinear variable stiffness actuator according to claim 1, characterized in that: A connecting bearing (9) is arranged inside the output plate (4), and the connecting bearing (9) is used to support the transmission shaft (5).

10. The reconfigurable nonlinear variable stiffness actuator according to claim 1, characterized in that: The output plate (4) is connected to the housing (1) via a spacer (10), and the spacer (10) is used to maintain a gap between the output plate (4) and the housing (1).

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