Flexible guide mechanism and linear actuator

Abstract

The invention relates to the technical field of precise guiding and transmission, and provides a flexible guiding mechanism and a linear actuator, the flexible guiding mechanism comprises a flexible guiding element, a lead screw and a nut, and the flexible guiding element is a hollow tubular body formed by continuously and periodically arranging a plurality of elastic corrugated units; the flexible guide element comprises a fixed end and a free end; the lead screw penetrates through the interior of the tubular body from the fixed end and extends out of the free end. The nut is connected with the free end and is in transmission connection with the lead screw. The flexible guide mechanism provided by the invention has relatively high torsion resistance, the lead screw penetrates through the interior of the tubular body from the fixed end and extends out of the free end, the flexible guide mechanism can adaptively adjust the matching coaxiality of the nut and the lead screw, and meanwhile, the flexible guide mechanism has excellent elongation and compression elasticity in the axial direction; and certain displacement and deflection flexibility are achieved in the radial direction, installation deviation or radial loads can be adapted, and the assembly requirement is lowered.

Description

Technical Field

[0001] This invention relates to the field of precision guidance and transmission technology, and in particular to a flexible guiding mechanism and a linear actuator. Background Technology

[0002] In synchrotron radiation beamlines, mirrors, as crucial optical components, are commonly used for beam deflection, harmonic suppression, and beam collimation or focusing by employing specific curved surface shapes (such as parabolic cylinders or elliptical cylinders). Achieving the designed optical functions requires high-precision control of the mirror's surface shape and precise adjustment of its spatial orientation. Currently, bending focusing mirrors often employ a four-roller bending mechanism for precise surface shape control. By applying a driving force to the free end of the bending arm in the four-roller bending mechanism, a controllable bending moment is formed at both ends of the mirror body, thereby achieving continuous adjustment of the mirror's surface curvature to meet different beam focusing requirements. A high-precision, repeatable driving force generator is the core component for achieving precise surface shape control. The mirror's spatial orientation (including angle and linear displacement) relies on the precise adjustment of a high-precision linear drive mechanism, which directly determines the beam's stability and alignment accuracy, and is a key component for attitude adjustment.

[0003] In existing technologies, the guide mechanism in bending drive devices and linear drive mechanisms is often a guide rail or a splined sleeve. While guide rails are a common standardized component, their selection faces significant limitations in ultra-high vacuum environments or situations with restricted space. Splined and sleeve guide mechanisms, through splined joints, provide coaxial guiding functionality and can be customized according to space dimensions. However, because splined joints are sliding fits, there are clearances and frictional wear, which negatively impact the positioning accuracy, transmission efficiency, and service life of the drive device. Furthermore, the coaxiality requirements for installation are extremely high; misalignment can easily cause the mechanism to jam. Additionally, the machining accuracy of the guide and mating parts is also extremely high, significantly increasing the machining difficulty and cost.

[0004] Existing bending drive devices and linear drive mechanisms mainly face problems such as high assembly precision requirements and high assembly difficulty of guide mechanisms, high processing difficulty and cost of guide parts, impact of clearance fit on positioning accuracy, low transmission efficiency and high risk of jamming due to friction and wear, and use in ultra-high vacuum environments. Summary of the Invention

[0005] This invention provides a flexible guiding mechanism and a linear actuator to solve the above-mentioned defects of the guiding mechanism in the prior art, realize adaptive adjustment of the coaxiality between the lead screw and the lead nut, eliminate motion backlash, output high-precision linear displacement and improve the positioning accuracy of the mechanism, and has a compact overall structure and low processing and assembly difficulty.

[0006] This invention provides a flexible guiding mechanism, comprising: A flexible guide element includes multiple elastic corrugated units arranged continuously and periodically to form a hollow tubular body; the flexible guide element includes a fixed end and a free end; A lead screw extends from the fixed end through the interior of the tubular body and out of the free end; The lead screw nut is connected to the free end, and the lead screw nut is connected to the lead screw drive.

[0007] According to the present invention, a flexible guiding mechanism is provided, wherein the flexible guiding element comprises a plurality of elastic corrugated units, and the elastic corrugated units are arranged in a continuous periodic manner.

[0008] According to the present invention, the flexible guiding mechanism is provided in which the elastic corrugated element is a metal sheet, the elastic corrugated unit is formed by stamping, and multiple elastic corrugated units are integrated by stacking, welding and heat treatment processes.

[0009] According to a flexible guiding mechanism provided by the present invention, the flexible guiding element includes a plurality of elastic corrugated units, which are integrally formed by an integral plastic forming process, and the cross-section of the elastic corrugated units includes U-shaped, S-shaped and V-shaped.

[0010] The flexible guiding mechanism provided by the present invention further includes: The first flange abuts against the fixed end on one side; The second flange is connected to the flexible guide element on one side and to the nut on the other side.

[0011] According to a flexible guiding mechanism provided by the present invention, the contact surfaces of the lead screw and the lead nut are coated with a molybdenum disulfide or diamond-like thin film layer.

[0012] The present invention also provides a linear actuator, comprising: The flexible guiding mechanism described above; A stepper motor, wherein the output shaft of the stepper motor is a lead screw.

[0013] A linear actuator according to the present invention further includes: The mounting base is connected to the stepper motor on one side and to the flexible guide mechanism on the other side.

[0014] A linear actuator according to the present invention further includes: The limiting rod is hollow inside and is disposed on the nut of the flexible guide mechanism; An elastic element is disposed in the hollow part inside the limiting rod, and one end of the elastic element abuts against the nut. A ball-head push rod is slidably disposed in the hollow part inside the limiting rod, and one end of the ball-head push rod abuts against the other end of the elastic element. The ball head at the other end of the ball-head push rod is used to contact the force-bearing point of the force-bearing mechanism.

[0015] A linear actuator according to the present invention further includes: The ball-head push rod has one end connected to the nut of the flexible guide mechanism, and the ball head at the other end of the ball-head push rod is used to contact the force-bearing point of the force-bearing mechanism.

[0016] The present invention provides a flexible guiding mechanism and a linear actuator, which forms an internal hollow tubular body by setting multiple elastic corrugated units arranged continuously and periodically. It has strong anti-torsion characteristics, excellent elongation and compression elasticity in the axial direction, and a certain displacement and deflection flexibility in the radial direction. The lead screw passes through the interior of the tubular body from the fixed end and extends to the outside of the free end. The flexible guiding mechanism can adaptively adjust the coaxiality of the lead screw and the lead nut.

[0017] When the linear actuator is working, the stepper motor drives the lead screw to rotate, and the lead screw transmits the rotation to the lead nut. Due to the strong anti-torsion characteristics of the flexible guide element, the free end of the flexible guide element is restricted from rotating around the axis. At the same time, due to the excellent elongation and compression elasticity of the flexible guide element, the lead nut installed on the flexible guide mechanism has the ability to perform linear displacement along the axial direction. Attached Figure Description

[0018] To more clearly illustrate the technical solutions in this invention 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 some embodiments of this invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0019] Figure 1 This is a schematic diagram of the flexible guiding mechanism provided by the present invention.

[0020] Figure 2 This is a half-sectional schematic diagram of the flexible guiding mechanism provided by the present invention.

[0021] Figure 3 This is a schematic diagram of the structure of the flexible guiding element provided by the present invention.

[0022] Figure 4 This is a half-sectional schematic diagram of the flexible guiding element provided by the present invention.

[0023] Figure 5 This is a schematic diagram of the structure of the silk master provided by the present invention.

[0024] Figure 6This is a half-sectional schematic diagram of the wire mother provided by the present invention.

[0025] Figure 7 This is a schematic diagram of the reflector bending drive device according to Embodiment 1 of the present invention.

[0026] Figure 8 This is a schematic diagram of the linear displacement drive mechanism for adjusting the attitude of a reflector according to Embodiment 2 of the present invention.

[0027] Figure label: 1. Flexible guide element; 2. Lead screw; 3. Nut; 4. First flange; 5. Second flange; 6. Stepper motor; 7. Mounting base; 8. Limiting rod; 9. Elastic element; 10. Ball head push rod; 11. First mounting hole; 12. Second mounting hole; 13. Third mounting hole; 14. Fourth mounting hole; 15. Internal threaded hole. Detailed Implementation

[0028] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions of this invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this invention. All other embodiments obtained by those skilled in the art based on the embodiments of this invention without creative effort are within the scope of protection of this invention.

[0029] The following is combined with Figures 1 to 6 The flexible guiding mechanism of the present invention includes a flexible guiding element, a lead screw, and a lead nut.

[0030] The flexible guide element 1 comprises multiple elastic corrugated units arranged continuously and periodically to form a hollow tubular body. In other words, the flexible guide element 1 is a flexible structure composed of several elastic corrugated units connected and arranged periodically. This flexible structure not only possesses strong anti-torsional characteristics, effectively resisting the torsional torque generated during transmission and preventing torsional deformation of the flexible guide element that could affect transmission accuracy, but also ensures the stability of power transmission. Furthermore, it exhibits elongation and compression elasticity along the axial direction, with good elastic recovery performance and a large elastic deformation capacity, preventing plastic deformation due to repeated expansion and contraction, thus meeting the stroke requirements of the lead screw nut 3 when moving axially. Simultaneously, it also possesses a certain degree of displacement and deflection flexibility along the radial direction, adapting to slight installation deviations or radial loads, reducing assembly accuracy requirements, and protecting core components such as the lead screw and lead nut.

[0031] The flexible guide element 1 includes a fixed end and a free end; the lead screw 2 passes through the interior of the tubular body from the fixed end and extends to the outside of the free end. This through-type installation method can keep the lead screw 2 and the flexible guide element 1 coaxial, improve the compactness of the overall structure, reduce eccentric shaking during the transmission process, and further improve the transmission accuracy.

[0032] The nut 3 is connected to the free end, and the shaft of the nut 3 is machined with an internal threaded hole 15 that mates with the lead screw 2. The nut 3 and the lead screw 2 are connected by a threaded engagement. The threaded engagement transmission has the advantages of simple structure, reliable self-locking, and precise displacement control. Under the linear guidance of the flexible guide element, the rotational motion of the lead screw 2 can be accurately converted into the linear motion of the nut 3.

[0033] The flexible guiding mechanism provided by this invention, when the lead screw 2 rotates, passes through the axis of the flexible guiding element 1 and is connected to the nut 3 via a threaded pair. The lead screw 2 transmits rotation to the nut 3. Due to the strong anti-torsional characteristics of the flexible guiding element 1, the free end of the flexible guiding element 1 is restricted from rotating around the axis, preventing the nut 3 from rotating synchronously with the lead screw 2. This ensures that the nut 3 only moves linearly along the axial direction, guaranteeing precise and controllable movement direction of the flexible guiding mechanism. Simultaneously, due to the excellent elongation and compressive elasticity of the flexible guiding element 1, the nut 3 installed on the flexible guiding element 1 has the ability to move linearly along the axial direction. The displacement process is smooth and stable without any jamming, adapting to different stroke requirements. Furthermore, the elasticity of the flexible guiding element 1 can buffer the axial movement of the nut 3, reducing the impact during start-up and stop, and improving the stability and safety of the mechanism's operation.

[0034] Furthermore, by placing the flexible guide element 1 in a compressed state during assembly (releasing the elastic preload), the fit clearance between the lead screw nut 3 and the lead screw 2 can be effectively eliminated, reducing or eliminating the backlash during the motion process, outputting high-precision linear displacement, and improving the positioning accuracy of the mechanism. At the same time, the radial displacement and deflection flexibility of the flexible guide element 1 also allows the lead screw nut 3 to adaptively adjust its coaxiality with the lead screw 2 during the motion relative to the lead screw 2, thereby reducing the requirements for assembly accuracy and assembly difficulty, and further achieving technical effects such as reducing the requirements for the machining accuracy of the guide parts and reducing the machining cost.

[0035] In addition, the flexible guide element 1 is an independent guide unit, which avoids the gaps and sliding friction caused by the mating of guide mechanism parts. It can effectively reduce transmission resistance, improve transmission efficiency, and avoid problems such as jamming and seizing caused by friction and wear of mating parts.

[0036] Specifically, in some feasible embodiments of the present invention, the elastic corrugated unit is a metal sheet. The metal material has high strength, high elastic limit and excellent wear and fatigue resistance, which can effectively improve the structural load-bearing capacity and service life of the elastic corrugated element, and avoid breakage, plastic deformation or performance degradation under long-term repeated expansion and contraction conditions. At the same time, the metal sheet has excellent thermal conductivity, which can quickly dissipate the frictional heat generated during transmission, prevent local overheating from causing material performance degradation, and ensure stable operation of the element.

[0037] The flexible guiding element can be obtained by stacking and welding multiple elastic corrugated units, or it can be integrally formed through a plastic forming process. The welding process enables standardized mass production. By precisely controlling the thickness, shape, and number of elastic corrugated unit diaphragms, the required axial stiffness and elongation / compression can be achieved to meet the axial movement stroke requirements of the free end. The integral plastic forming process can produce a seamless structure with good reliability and wall thickness uniformity. The inner and outer surfaces of the structure are smooth without dead corners, and it has excellent ultra-high vacuum compatibility.

[0038] More specifically, one embodiment of the flexible guide element 1 is a vacuum-welded bellows.

[0039] In some feasible embodiments of the present invention, the flexible guiding element includes a plurality of elastic corrugated units, which are arranged continuously and periodically to form a hollow tubular body, and the cross-section of the elastic corrugated units includes U-shape, S-shape, and V-shape.

[0040] Among them, the U-shaped elastic corrugated unit has a smooth sidewall transition, which can provide a large axial elastic deformation space, can stably withstand axial tension and pressure, and has uniform stress distribution, ensuring the service life of the component under repeated expansion and contraction conditions.

[0041] The S-shaped elastic corrugated unit has high radial flexibility and can simultaneously absorb axial, angular, and radial composite displacements.

[0042] The V-shaped flexible corrugated unit can be configured with more corrugations per unit length, providing a more compact structure.

[0043] Specifically, such as Figure 3 and Figure 4 As shown, in some feasible embodiments of the present invention, a first flange 4 and a second flange 5 are also included. The first flange 4 and the second flange 5 are set as the connection parts between the flexible guide element and other parts to prevent the elastic corrugations from directly contacting and connecting other parts, avoid damage to the main body of the flexible guide element 1, and at the same time improve the structural strength and assembly flexibility of the connection parts.

[0044] The first flange 4 abuts against the fixed end on one side; the contact between the first flange 4 and the fixed end is achieved through the planar contact, which can evenly distribute the force on the fixed end, prevent excessive local pressure from causing deformation of the fixed end of the flexible guide element, and at the same time facilitate the accurate positioning of the installation position of the flexible guide element 1, ensuring its coaxiality with the lead screw 2.

[0045] The second flange 5 is connected to the flexible guide element 1 on one side. The structural rigidity of the second flange 5 can enhance the load-bearing capacity of the free end of the flexible guide element 1, and prevent the free end from being damaged due to stress concentration caused by the connecting nut 3. At the same time, it can realize a smooth transition connection between the flexible guide element 1 and the nut 3. The other side of the second flange 5 is connected to the nut 3. The flange connection can ensure the connection between the nut 3 and the flexible guide element 1, prevent the nut 3 from loosening or shifting during axial movement, and facilitate the disassembly and maintenance of the nut, reducing the later maintenance cost.

[0046] Furthermore, the first flange 4 is also provided with a first mounting hole 11, which is used to connect the first flange 4 to the fastener.

[0047] Specifically, in some feasible embodiments of the present invention, the second flange 5 is provided with a second mounting hole 12, which can be a threaded hole to facilitate the threaded connection between the nut 3 and the second flange 5. Alternatively, the nut 3 and the second flange 5 can also adopt other connection methods, as long as a fixed connection between the nut 3 and the second flange 5 can be achieved.

[0048] In addition, the output end of the nut 3 is provided with a third mounting hole 13, which can be used to install accessories according to actual usage requirements. A fourth mounting hole 14 is provided at the end of the nut 3 facing the flexible guide element 1. The fourth mounting hole 14 is used to fix the nut 3 to the flexible guide element 1. It should be noted that the position and specifications of the fourth mounting hole 14 must correspond to the second mounting hole 12.

[0049] In specific embodiments, the material of the mother wire 3 can be copper alloy, polyether ether ketone, polyimide, etc., but is not limited to these. Materials with good mechanical strength, self-lubricating properties and suitability for ultra-high vacuum are all within the scope of consideration.

[0050] Specifically, in some feasible embodiments of the present invention, the contact surfaces of the lead screw 2 and the lead nut 3 are coated with a molybdenum disulfide or diamond-like film layer to reduce the friction coefficient of the threaded engagement of the lead screw 2 and the lead nut 3 and improve the transmission efficiency.

[0051] A second aspect of the present invention provides a linear actuator, comprising a stepper motor 6 and a flexible guide mechanism as described in any embodiment. The output shaft of the stepper motor 6 is the lead screw 2 of the flexible guide mechanism, and the stepper motor 6 provides power for the rotation of the lead screw 2.

[0052] Specifically, in some feasible embodiments of the present invention, a mounting base 7 is also included. One side of the mounting base 7 is connected to the stepper motor 6, and the other side of the mounting base 7 is connected to the first flange 4 of the flexible guide mechanism. The mounting base 7 facilitates the connection between the stepper motor 6 and the flexible guide mechanism.

[0053] like Figure 7 As shown, specifically, in some feasible embodiments of the present invention, the linear actuator is used as a driving force generating device for the bending mechanism of the bending focusing lens, and the specific structure is as follows: Figure 1 Based on this, it also includes a limiting rod 8, an elastic element 9, and a ball-head push rod 10. The limiting rod 8 is hollow inside and is mounted on the nut 3 of the flexible guide mechanism. The elastic element 9 is located in the hollow part of the limiting rod 8, and one end of the elastic element 9 abuts against the nut 3; the ball-head push rod 10 is slidably mounted in the hollow part of the limiting rod 8, and one end of the ball-head push rod 10 abuts against the other end of the elastic element 9, with the ball head at the other end of the ball-head push rod 10 used to contact the force-bearing point of the force-bearing mechanism.

[0054] Specifically, the elastic element 9 can be a compression spring.

[0055] A limiting rod 8 is fixedly installed in the third mounting hole 13 of the lead screw nut. The compression spring and the ball-end push rod 10 are located inside the limiting rod 8, coaxial with the lead screw nut 3, and sequentially arranged at the output end of the lead screw nut 3. In actual use, the rotation of the lead screw 2 drives the lead screw nut 3 to output linear displacement. The lead screw nut 3 compresses the pressure spring, and the pressure spring force is applied to the ball-end push rod 10. The ball head of the ball-end push rod 10 contacts the force-bearing point of the force-bearing mechanism, further transmitting the force to the force-bearing point of the bending mechanism, thereby realizing the output of driving force.

[0056] It should be noted that one embodiment of the flexible guide element 1 is a vacuum-welded bellows. The vacuum-welded bellows is made of several elastic corrugated sheets welded together and is widely used in the vacuum field. Its elongation and compression are usually 10% and 60% of its natural length, respectively, and its design and production have been standardized, so they will not be described in detail here. The vacuum-welded bellows can be used as an excellent implementation of the flexible guide element 1 in this invention. In actual use, the number of elastic corrugated sheets and the natural length of the flexible structure in the flexible guide element can be determined according to the needs of the linear displacement output stroke.

[0057] like Figure 8 As shown, specifically, in some feasible embodiments of the present invention, the linear actuator is used as a linear displacement driving device in the reflector attitude adjustment mechanism, and the specific structure is as follows: Figure 1 Based on this, it also includes a ball-head push rod 10. One end of the ball-head push rod 10 is connected to the third mounting hole 13 of the nut 3 of the flexible guide mechanism, and the ball head at the other end of the ball-head push rod 10 is used to contact the force-bearing point of the force-bearing mechanism.

[0058] In actual use, the lead screw 2 in the stepper motor 6 rotates, driving the lead screw nut 3 and the ball-head push rod 10 installed at the output end of the lead screw nut 3 to output linear displacement. The ball head of the ball-head push rod 10 contacts the displacement input end in the attitude adjustment device. For example, when the attitude adjustment device is an angle turntable, the linear actuator is fixed on the stationary platform of the angle turntable, and the ball-head push rod 10 contacts the moving platform of the angle turntable. The stationary platform and the moving platform of the angle turntable are connected by a rotating shaft, which has the function of relative rotation. When the ball-head push rod 10 outputs linear displacement, it can drive the moving platform of the angle turntable to rotate around the rotating shaft, thereby realizing the angle attitude adjustment of the reflector. Similarly, the specific embodiment of the flexible guide element 1 and the material selection of the lead screw nut can be the scheme described in the above embodiments, and will not be repeated here.

[0059] In summary, the flexible guiding mechanism and linear actuator provided by this invention can achieve high-precision linear displacement output. Compared with existing devices, they have the advantages of simple and compact structure, adaptive adjustment of coaxiality between moving parts, easy processing and assembly, no introduction of axial friction to improve transmission efficiency and reduce the risk of mechanism jamming, providing preload force for the threaded fit between the nut 3 and the lead screw 2 to eliminate fit clearance and improve the output accuracy of the mechanism, and being suitable for ultra-high vacuum environments.

[0060] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A flexible guiding mechanism, characterized in that, include: The flexible guide element (1) includes multiple elastic corrugated units, which are arranged continuously and periodically to form a hollow tubular body; the flexible guide element (1) includes a fixed end and a free end; The lead screw (2) extends from the fixed end through the interior of the tubular body and out of the free end; The lead screw (3) is connected to the free end, and the lead screw (2) is connected to the lead screw (2) for transmission.

2. The flexible guiding mechanism according to claim 1, characterized in that, The flexible guiding element comprises multiple elastic corrugated units, which are arranged in a continuous and periodic manner.

3. The flexible guiding mechanism according to claim 2, characterized in that, The elastic corrugated unit is a metal sheet, which is formed by stamping. Multiple elastic corrugated units are assembled into one piece through stacking, welding, and heat treatment processes.

4. The flexible guiding mechanism according to claim 1, characterized in that, The flexible guiding element includes multiple elastic corrugated units, which are integrally formed by an integral plastic forming process. The cross-section of the elastic corrugated units includes U-shaped, S-shaped, and V-shaped.

5. The flexible guiding mechanism according to any one of claims 1-4, characterized in that, Also includes: The first flange (4) abuts against the fixed end on one side; The second flange (5) is connected to the flexible guide element (1) on one side, and the other end of the second flange (5) is connected to the nut (3).

6. The flexible guiding mechanism according to any one of claims 1-5, characterized in that, The contact surfaces of the lead screw (2) and the lead nut (3) are coated with a molybdenum disulfide or diamond-like thin film layer.

7. A linear actuator, characterized in that, include: The flexible guiding mechanism as described in any one of claims 1 to 6; Stepper motor (6), the output shaft of which is the lead screw (2) of the flexible guide mechanism.

8. The linear actuator according to claim 7, characterized in that, Also includes: The mounting base (7) is connected to the stepper motor (6) on one side and to the flexible guide mechanism on the other side.

9. The linear actuator according to claim 7 or 8, characterized in that, Also includes: The limiting rod (8) is hollow inside and is disposed on the nut (3) of the flexible guide mechanism; An elastic element (9) is disposed in the hollow part inside the limiting rod (8), and one end of the elastic element (9) abuts against the nut (3); The ball-head push rod (10) is slidably disposed in the hollow part inside the limiting rod (8), and one end of the ball-head push rod (10) abuts against the other end of the elastic member (9), and the ball head at the other end of the ball-head push rod (10) is used to contact the force point of the force-bearing mechanism.

10. The linear actuator according to claim 7 or 8, characterized in that, Also includes: The ball-head push rod (10) is connected at one end to the nut (3) of the flexible guide mechanism, and the ball head at the other end of the ball-head push rod (10) is used to contact the force point of the force-bearing mechanism.

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