Single degree of freedom yawing mechanism with positive and negative poisson's ratio structure and working method

Abstract

The present application relates to the technical field of micro-motion device, and especially relates to a single-degree-of-freedom yawing mechanism with positive and negative Poisson's ratio structure and a working method. The yawing mechanism comprises a fixing unit, a transmission unit and a yawing unit. The fixing unit comprises a bottom plate and side plates. The transmission unit is symmetrically arranged between the two side plates. The transmission unit comprises a moving plate and an elastic plate. One end of the elastic plate is connected with the bottom plate, and the other end is connected with the moving plate. The moving plate has a set gap with the side plates. The yawing unit comprises a top plate, a positive Poisson's ratio structure, a negative Poisson's ratio structure and a connecting beam. The positive Poisson's ratio structure and the negative Poisson's ratio structure are respectively located at two ends of the top plate. The two sides of the positive Poisson's ratio structure and the two sides of the negative Poisson's ratio structure are connected with the moving plate. The two sides of the top plate are connected with the side plates through the connecting beam. The present application solves the problem that the connection mode of the two ends of the yawing platform causes parasitic displacement of the yawing platform and further affects the motion accuracy.

Description

Technical Field

[0001] This invention relates to the field of micro-motion device technology, and in particular to a single-degree-of-freedom oscillating mechanism with a positive and negative Poisson's ratio structure and its working method. Background Technology

[0002] A high-precision yaw platform is a device used to control and adjust the position and orientation of components in optical or precision instruments. This platform features high-precision orientation adjustment capabilities, enabling rotation and tilting at minute angles to calibrate the relative positions between optical components, ensuring the accuracy and precision of the optical system. Capable of orientation adjustment at the micrometer or even nanometer level, it is widely used in optical imaging systems, laser processing equipment, precision measuring instruments, and other fields.

[0003] The prior art discloses a single-degree-of-freedom yaw platform, in which the two ends of its top plate (i.e., the yaw platform) are directly connected to the drive and fixing unit of the yaw mechanism. This causes the movement of the drive and fixing unit to be inconsistent with the yaw direction during actual movement, resulting in the yaw platform yawing in an unnecessary direction, which in turn affects the accuracy of the movement. Summary of the Invention

[0004] To address the shortcomings of existing technologies, the purpose of this invention is to provide a single-degree-of-freedom yaw mechanism with a positive and negative Poisson's ratio structure, thereby solving the problem that the connection method at both ends of the yaw platform causes parasitic displacement of the yaw platform, which in turn affects the motion accuracy.

[0005] To achieve the above objectives, the embodiments of the present invention provide the following technical solutions:

[0006] A single-degree-of-freedom oscillating mechanism with positive and negative Poisson's ratio structures includes: a fixed unit, a transmission unit, and an oscillating unit; the fixed unit includes a base plate and side plates, with the side plates located on both sides of the base plate; the transmission unit is symmetrically arranged between the two side plates, and includes a moving plate and an elastic plate, with one end of the elastic plate connected to the base plate and the other end connected to the moving plate, and a set gap between the moving plate and the side plates; the oscillating unit includes a top plate, a positive Poisson's ratio structure, a negative Poisson's ratio structure, and a connecting beam, with the positive and negative Poisson's ratio structures located at both ends of the top plate, and both sides of the positive and negative Poisson's ratio structures connected to the moving plate, and both sides of the top plate connected to the side plates via the connecting beam.

[0007] This invention also provides a method for operating a single-degree-of-freedom yaw mechanism with positive and negative Poisson's ratio structures as described above: the two moving plates move away from or closer to each other, causing the positive Poisson's ratio structure to pull or push the top plate, while the negative Poisson's ratio structure pushes or pulls the top plate, thereby achieving yaw motion.

[0008] One or more technical solutions provided in the embodiments of the present invention have at least the following technical effects or advantages:

[0009] 1. This yaw mechanism achieves the deflection motion of the top plate through the cooperation of a transmission unit and positive and negative Poisson's ratio structures. Furthermore, it employs a connection method that separates the side plate and the moving plate. The side plate is responsible for fixing the top plate, while the moving plate drives the positive and negative Poisson's ratio structures to achieve the yaw motion of the top plate, avoiding any impact on the top plate's movement when the moving plate is driven. Specifically, when the moving plate is subjected to thrust or tension, it deforms. If the top plate were fixed to the moving plate, it would be subject to a fixed constraint, resulting in unnecessary yaw in a fixed direction. This yaw mechanism effectively avoids unavoidable parasitic displacement caused by motion, improving the platform's motion accuracy.

[0010] 2. Hexagonal rods with negative Poisson's properties and hexagonal rods with positive Poisson's properties are used as driving connecting rods for the deflection table. Due to the inherent properties of the material and the design of its polygonal structure, hexagonal rods have stronger wear resistance and durability than traditional positive "V" and inverted "V" elastic beams. They can maintain stable performance for a long time and extend the service life of the connecting parts.

[0011] 3. Positive and negative Poisson's ratio structures exhibit excellent energy absorption effects, resulting in superior impact resistance for the yaw platform and a wider range of practical applications. Furthermore, the regular hexagonal and internal hexagonal structures can withstand greater loads, giving the platform superior load-bearing capacity. Traditional positive and inverted "V" shaped flexible units are prone to deformation under stress during structural yaw, which is disadvantageous in certain load-bearing or high-precision measurement environments. Compared to traditional positive and inverted "V" shaped flexible units, the regular hexagonal and internal hexagonal structures of this invention offer better stress dispersion and stability. Under dynamic environments such as vibration and impact, or in situations requiring high-precision measurements, this structure maintains excellent accuracy and stability.

[0012] 4. The fixed unit, transmission unit, and oscillation unit are integrated into a single structure. Specifically, the micro-nano oscillation stage base (fixed unit), the internal hexagonal rod (negative Poisson's ratio structure), the regular hexagonal rod (positive Poisson's ratio structure), and the oscillation stage surface (top plate) are all integrated into a single structure. This structure is compact and avoids the problems of assembly error sensitivity, poor fatigue characteristics, and low reliability caused by assembled oscillation stages, which are prone to wear, gaps, and friction during long-term operation. Moreover, the overall volume is more compact.

[0013] Advantages of additional aspects of the invention will be set forth in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. Attached Figure Description

[0014] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments recorded in this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0015] Figure 1 This is a schematic diagram of the oscillation mechanism provided in an embodiment of the present invention;

[0016] Figure 2 This is a schematic diagram of the positive Poisson's ratio structure from two equal angles, provided in an embodiment of the present invention.

[0017] Figure 3 This is a schematic diagram of the negative Poisson's ratio structure from two equal angles, provided in an embodiment of the present invention.

[0018] In the diagram: 1. Fixed unit; 101. Base plate; 102. Side plate; 2. Transmission unit; 201. Moving plate; 202. Elastic plate; 3. Yaw unit; 301. Positive Poisson's ratio structure; 302. Negative Poisson's ratio structure; 303. Top plate; 304. Connecting beam.

[0019] The distances or dimensions between parts have been exaggerated to show their positions; the diagram is for illustrative purposes only. Detailed Implementation

[0020] It should be noted that the following detailed description is illustrative and intended to provide further explanation of the invention. Unless otherwise specified, all technical and scientific terms used in this invention have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. Furthermore, it should be understood that when the terms "comprising" and / or "including" are used in this specification, they indicate the presence of features, steps, operations, devices, components, and / or combinations thereof.

[0021] As described in the background section, existing yaw platforms have their top plates directly connected to the drive and fixing units of the yaw mechanism, causing unnecessary yaw in the yaw platform and thus affecting motion accuracy. Furthermore, existing high-precision yaw mechanisms have many other shortcomings. For example, the yaw motion is achieved using a flexible hinge design with a notch, which is prone to deformation during movement, resulting in instability. The links that execute motion or change the direction of motion are prone to stress concentration, leading to reduced fatigue life. The structure cannot maintain good high precision and stability under dynamic environments such as vibration and impact. The overall structure requires assembly, resulting in unavoidable fit errors. To address these technical problems, this embodiment proposes a single-degree-of-freedom yaw mechanism with a positive and negative Poisson's ratio structure.

[0022] like Figure 1 , Figure 2 , Figure 3 As shown, the oscillation mechanism of this embodiment includes a fixed unit 1, a transmission unit 2, and an oscillation unit 3. The fixed unit 1 includes a base plate 101 and a side plate 102, with the side plate 102 located on both sides of the base plate 101. The transmission unit 2 is symmetrically arranged between the two side plates 102. The transmission unit 2 includes a movable plate 201 and an elastic plate 202. One end of the elastic plate 202 is connected to the base plate 101, and the other end is connected to the movable plate 201. There is a set gap between the movable plate 201 and the side plate 102. The yaw unit 3 includes a top plate 303, a positive Poisson's ratio structure 301, a negative Poisson's ratio structure 302, and a connecting beam 304. The positive Poisson's ratio structure 301 and the negative Poisson's ratio structure 302 are located at both ends of the top plate 303, and both sides of the positive Poisson's ratio structure 301 and the negative Poisson's ratio structure 302 are connected to the moving plate 201. Both sides of the top plate 303 are connected to the side plate 102 through the connecting beam 304.

[0023] The yaw unit 3 includes a positive Poisson's ratio structure 301 and a negative Poisson's ratio structure 302 arranged in parallel, a top plate 303 parallel to the bottom plate 101 of the fixed unit 1, and a connecting beam 304 fixed to the side plates 102 of the fixed unit 1. The transmission unit 2 is located in the space between the side plates 102 of the fixed unit 1. One end of the elastic plate 202 of the transmission unit 2 is connected to the bottom plate 101 of the fixed unit 1, and the other end is connected to the moving plate 201. The elastic plate 202 can undergo elastic deformation under the action of external force, thereby pushing or pulling the moving plate 201 to move, realizing the transmission function.

[0024] The parallel top plate 303 and bottom plate 101, along with the moving plate 201 in the transmission unit 2 with transmission capabilities at both ends, form a structure with an internal cavity, in which the actuator is placed. The actuator uses existing technology, as long as it can drive the transmission unit 2 to deform. By replacing different actuators, the moving plate 201 can be adjusted to produce different displacements, and the generated displacement is in the horizontal axial direction. This displacement acts on the positive Poisson's ratio structure 301 and the negative Poisson's ratio structure 302. These two structures convert the horizontal axial displacement into a vertical displacement, which acts on both sides of the top plate 303 respectively, generating tensile and thrust forces on both sides of the top plate 303, thereby achieving the deflection motion of the top plate 303 and ultimately realizing the swing motion.

[0025] This yaw mechanism achieves the deflection motion of the top plate 303 through the cooperation of the transmission unit 2 and the positive Poisson's ratio structure 301 and negative Poisson's ratio structure 302. Furthermore, it employs a connection method where the side plate 102 and the moving plate 201 are separated. The side plate 102 is responsible for fixing the top plate 303, while the moving plate 201 is responsible for driving the positive Poisson's ratio structure 301 and the negative Poisson's ratio structure 302 to achieve the yaw motion of the top plate 303. This avoids the moving plate 201 affecting the movement of the top plate 303 when it is driven. Specifically, when the moving plate 201 is subjected to thrust or tension, it deforms (or displaces). If the top plate 303 is fixed to the moving plate 201, it will be subject to fixed constraints, resulting in unnecessary yaw in a fixed direction. This yaw mechanism effectively avoids unavoidable parasitic displacement caused by motion, improving the platform's motion accuracy.

[0026] The side plate 102 is perpendicular to the base plate 101, and the base plate 101 and the side plates 102 on both sides form a U-shaped structure. The transmission unit 2 and the oscillation unit 3 are arranged within the U-shaped structure. This structure increases the stability and rigidity of the entire device, providing reliable support for the operation of the transmission unit 2 and the oscillation unit 3.

[0027] The elastic plate 202 is an L-shaped plate, comprising a vertical plate and a horizontal plate. The lower end of the vertical plate is connected to the base plate 101, the inner end of the horizontal plate is connected to the top of the vertical plate, and the outer end of the horizontal plate is connected to the moving plate 201. The L-shaped elastic plate 202 can undergo elastic deformation under external force, absorbing and transmitting energy, enabling the moving plate 201 to move smoothly.

[0028] The Poisson's ratio structure 301 includes a flexible regular hexagonal structure, which comprises three pairs of symmetrically arranged elastic beams. One pair of elastic beams is parallel to the top plate 303 and the bottom plate 101, while the other two pairs are arranged obliquely with their openings facing inwards. Figure 2 As shown, the flexible positive Poisson's ratio structure 301 has three pairs of symmetrically arranged elastic beams, one pair of which is parallel to the top plate 303 and the bottom plate 101, and two pairs of inclined elastic beams are connected to this pair of elastic beams with an angle of 120° between the beams.

[0029] The positive Poisson's ratio structure 301 also includes a longitudinal beam and a transverse beam. The bottom end of the longitudinal beam is connected to the middle of the top of the regular hexagonal structure, and the top end of the longitudinal beam is connected to the top plate 303. The transverse beam is located on both sides of the regular hexagonal structure and is connected to the back side of the opening of the regular hexagonal structure. The outer end of the transverse beam is connected to the moving plate 201.

[0030] The Poisson's ratio structure 301 is located on the outermost side of the top plate 303. It has two sets of inclined elastic beams with opposite openings. The included angle of each set of elastic beams is 120°, and the openings are on the same horizontal line. The longitudinal beams are arranged vertically, with one end connected to the top plate 303 and the other end connected to the middle of the upper beam of a pair of horizontally placed elastic beams. The entire Poisson's ratio structure 301 is hexagonal. When subjected to a horizontal driving force, taking the two moving plates 201 moving away from each other as an example, the pair of transverse beams connected to the moving plates 201 are pulled by tension, causing the two pairs of opposite elastic beams to deform away from each other. This causes a pair of horizontal elastic beams parallel to the top plate 303 and the bottom plate 101 to deform closer to each other. The longitudinal beams connected to the horizontal elastic beams pull the top plate 303, causing one side of the top plate 303 to be pulled closer to the bottom plate 101.

[0031] The Poisson's ratio structure 301, through symmetrically arranged elastic beams, can evenly distribute stress under load, thereby maintaining structural stability. Simultaneously, it can effectively transmit the movement of the moving plate 201 to the top plate 303, achieving the function of pulling or pushing the top plate 303. The longitudinal and transverse beams further enhance the rigidity and stability of the Poisson's ratio structure 301, ensuring that the movement of the moving plate 201 can be more stably transmitted to the top plate 303, achieving precise yaw motion.

[0032] The negative Poisson's ratio structure 302 is a flexible internal hexagonal structure, comprising three pairs of symmetrically arranged elastic beams. One pair of elastic beams is parallel to the top plate 303 and the bottom plate 101, while the other two pairs are arranged obliquely with their openings facing outwards. Figure 3 As shown, the flexible negative Poisson's ratio structure 302 has three pairs of symmetrically arranged elastic beams. One pair of elastic beams is parallel to the top plate 303 and the bottom plate 101. One pair of elastic beams is arranged at an angle, and the openings they form face the side plate 102 and form a ">" shape. The other pair of elastic beams is arranged at an angle, and the openings they form face the other side plate 102 and form a "<" shape.

[0033] The negative Poisson's ratio structure 302 also includes a negative longitudinal beam and a negative transverse beam. The bottom end of the negative longitudinal beam is connected to the middle of the top of the inner hexagonal structure, and the top end of the negative longitudinal beam is connected to the top plate 303. The negative transverse beam is located on both sides of the inner hexagonal structure and is connected to the opening of the inner hexagonal structure. The outer end of the negative transverse beam is connected to the moving plate 201.

[0034] The negative Poisson's ratio structure 302 is located on the other side of the top plate 303. It has two sets of inclined elastic beams with openings facing each other and one set of horizontally placed elastic beams. The angle between the two sets of inclined elastic beams is 120°, and the openings face the moving plate 201. The angle between the horizontally placed elastic beam and the inclined elastic beam is 60°. The negative longitudinal beam is arranged vertically, with one end connected to the top plate 303 and the other end connected to the middle of the upper beam of the pair of horizontally placed elastic beams. The entire negative Poisson's ratio structure 302 is a regular hexagon. When subjected to a horizontal driving force, taking the two moving plates 201 moving away from each other as an example, the pair of negative crossbeams connected to the moving plate 201 are pulled by tension, causing the two pairs of opening elastic beams to deform away from each other. This causes a pair of horizontal elastic beams parallel to the top plate 303 and the bottom plate 101 to deform away from each other. The negative longitudinal beam connected to the horizontal elastic beam supports the top plate 303, causing one side of the top plate 303 to be lifted away from the bottom plate 101.

[0035] Hexagonal rods with negative Poisson's properties and hexagonal rods with positive Poisson's properties are used as driving connecting rods for the deflection stage. Due to the inherent properties of the material and the design of its polygonal structure, hexagonal rods have stronger wear resistance and durability than positive "V" and inverted "V" type elastic beams, and can maintain stable performance for a long time, thus extending the service life of the connecting parts.

[0036] The flexible positive Poisson's ratio structure 301 and negative Poisson's ratio structure 302 move simultaneously. When the moving plate 201 in the transmission unit 2 causes deformation of the positive Poisson's ratio structure 301 and the negative Poisson's ratio structure 302, the positive longitudinal beam of the positive Poisson's ratio structure 301 pulls or pushes the top plate 303, while the negative longitudinal beam of the negative Poisson's ratio structure 302 pushes or pulls the top plate 303. The middle beams of the two structures move in opposite directions, thereby realizing the yaw motion of the top plate 303. The positive Poisson's ratio structure 301 and the negative Poisson's ratio structure 302 are placed on the outermost side of the yaw mechanism. The structure has uniform dimensions, reasonable deformation, stronger resistance to heavy loads and impacts, and is more reliable and stable in various vibration and impact environments.

[0037] like Figure 3 As shown, the connecting beam 304 includes a beam body, short longitudinal beams, and short transverse beams. The beam body is formed by two interlocking U-shaped beams and is parallel to the top plate 303. The short longitudinal beams are parallel to the side plate 102, with one end connected to the side plate 102 and the other end connected to the beam body. The short transverse beams are parallel to the top plate 303, with one end connected to the beam body and the other end connected to the top plate 303. The zigzag elastic beams improve the stability of the platform's movement.

[0038] The fixed unit 1, transmission unit 2, and oscillation unit 3 are integrated structures. Specifically, the micro-nano oscillation stage base (fixed unit 1), the internal hexagonal rod (negative Poisson's ratio structure 302), the regular hexagonal rod (positive Poisson's ratio structure 301), and the oscillation stage surface (top plate 303) are integrated structures, which are compact. Compared with assembled oscillation stages, which are prone to wear, gaps, and friction during long-term operation, this integrated structure avoids the problems of sensitivity to assembly errors, poor fatigue characteristics, and low reliability caused by these issues, and the overall volume is more compact.

[0039] The working method of the single-degree-of-freedom yaw mechanism with positive and negative Poisson's ratio structure 302 described above is as follows: the two moving plates 201 move away from or closer to each other, so that the positive Poisson's ratio structure 301 pulls or pushes the top plate 303, while the negative Poisson's ratio structure 302 pushes or pulls the top plate 303, thereby realizing the yaw motion.

[0040] By combining positive Poisson's ratio structure 301 and negative Poisson's ratio structure 302, the deformation characteristics of the two structures are utilized to drive the top plate 303 to achieve swaying. The positive and negative Poisson's ratio structures 301 and 302 have energy absorption characteristics, enabling them to withstand large impact loads during swaying. The structures 301 and 302 are structurally stable, and the hexagonal and polygonal rods, due to their inherent material properties and polygonal design, possess strong wear resistance and durability, maintaining stable performance for extended periods and prolonging the service life of the connecting parts. The use of a connection method that separates the fixed unit 1 and the transmission unit 2 effectively avoids unavoidable parasitic displacement caused by motion, improving the platform's motion accuracy. The integrated design avoids the problems of assembly error sensitivity, poor fatigue characteristics, and low reliability associated with integrated structures. Therefore, the overall swaying platform has advantages such as strong impact resistance, strong swaying stability, and long fatigue life, making it applicable in numerous fields.

[0041] While the specific embodiments of the present invention have been described above in conjunction with the accompanying drawings, this is not intended to limit the scope of protection of the present invention. Those skilled in the art should understand that various modifications or variations that can be made by those skilled in the art without creative effort based on the technical solutions of the present invention are still within the scope of protection of the present invention.

Claims

1. A single-degree-of-freedom oscillating mechanism with a positive and negative Poisson's ratio structure, characterized in that, include: Fixed unit, transmission unit, and oscillation unit; The fixing unit includes a base plate and side plates, with the side plates located on both sides of the base plate; The transmission unit is symmetrically arranged between the two side plates. The transmission unit includes a moving plate and an elastic plate. One end of the elastic plate is connected to the bottom plate and the other end is connected to the moving plate. There is a set gap between the moving plate and the side plate. The yaw unit includes a top plate, a positive Poisson's ratio structure, a negative Poisson's ratio structure, and a connecting beam. The positive Poisson's ratio structure and the negative Poisson's ratio structure are located at both ends of the top plate, and both sides of the positive Poisson's ratio structure and both sides of the negative Poisson's ratio structure are connected to the moving plate. The two sides of the top plate are connected to the side plate through the connecting beam. The side plate is perpendicular to the bottom plate, and the bottom plate and the side plates on both sides form a U-shaped structure. The transmission unit and the swing unit are arranged inside the U-shaped structure. The elastic plate is an L-shaped plate, including a vertical plate and a horizontal plate. The lower end of the vertical plate is connected to the bottom plate, the inner end of the horizontal plate is connected to the top of the vertical plate, and the outer end of the horizontal plate is connected to the movable plate. The positive Poisson's ratio structure includes a flexible regular hexagonal structure, which includes three pairs of symmetrically arranged elastic beams, one pair of which is parallel to the top plate and the bottom plate, and the other two pairs are arranged at an angle with their openings facing inward. The positive Poisson's ratio structure also includes a positive longitudinal beam and a positive transverse beam. The bottom end of the positive longitudinal beam is connected to the middle of the top of the regular hexagonal structure, and the top end of the positive longitudinal beam is connected to the top plate. The positive transverse beam is located on both sides of the regular hexagonal structure and is connected to the back side of the opening of the regular hexagonal structure. The outer end of the positive transverse beam is connected to the moving plate. The negative Poisson's ratio structure is a flexible internal hexagonal structure, which includes three pairs of symmetrically arranged elastic beams. One pair of elastic beams is parallel to the top plate and the bottom plate, while the other two pairs are arranged at an angle and open outwards. The negative Poisson's ratio structure also includes a negative longitudinal beam and a negative transverse beam. The bottom end of the negative longitudinal beam is connected to the middle of the top of the inner hexagonal structure, and the top end of the negative longitudinal beam is connected to the top plate. The negative transverse beam is located on both sides of the inner hexagonal structure and is connected to the opening of the inner hexagonal structure. The outer end of the negative transverse beam is connected to the moving plate. The connecting beam includes a beam body, short longitudinal beams, and short transverse beams. The beam body is formed by two interlocking U-shaped beams and is parallel to the top plate. The short longitudinal beams are parallel to the side plates, with one end connected to the side plates and the other end connected to the beam body. The short transverse beams are parallel to the top plate, with one end connected to the beam body and the other end connected to the top plate.

2. The single-degree-of-freedom oscillating mechanism with a positive and negative Poisson's ratio structure as described in claim 1, characterized in that, The fixed unit, transmission unit, and oscillation unit are an integrated structure.

3. A method for operating a single-degree-of-freedom oscillating mechanism with a positive and negative Poisson's ratio structure as described in any one of claims 1-2, characterized in that, The two moving plates move away from or closer to each other, causing the positive Poisson's ratio structure to pull or push the top plate, while the negative Poisson's ratio structure pushes or pulls the top plate, thus achieving yaw motion.

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