Rotary driver based on adjustable bubble buckling structure

Abstract

The rotation driver comprises a lower shell, a diameter-variable inner circular ring structure, a double-layer metal sheet circular ring and a cover plate, the lower shell is composed of a circular bottom plate and an outer circular ring structure arranged on the periphery of the circular bottom plate, and the inner circular ring structure is concentrically and fixedly connected with the lower shell; the perimeter of the double-layer metal sheet circular ring is larger than that of the outer circular ring structure, the double-layer metal sheet circular ring is arranged between the inner circular ring structure and the outer circular ring structure and partially concaves inwards to form a bubble buckling structure, and the outer side face of the non-concaved part of the double-layer metal sheet circular ring is attached to the inner side face of the outer circular ring structure. The inner side surface of the concave part is in contact with the outer side surface of the inner circular ring structure; transmission pieces and heating pieces are arranged on the left side and the right side of the lower portion of the cover plate and make contact with the inner side face of the double-layer metal sheet circular ring; the cover plate covers the lower shell and is concentrically and rotatably connected with the lower shell, and an output shaft is arranged on the cover plate. The rotary driver is simple in structure, low in energy consumption, free of lubrication and adjustable in output torque.

Description

Technical Field

[0001] The invention relates to the field of rotary actuators, and in particular to a rotary actuator based on an adjustable bubble buckling structure. Background Art

[0002] In the prior art, the main implementation form of the rotary drive is the rotary motor, among which the three-phase asynchronous motor has a fast speed, high efficiency, good stability and high reliability, so it is the most widely used and has a large demand. Although some rotary motors have the function of adjusting the speed, they cannot guarantee the improvement of the torque at the same time. Therefore, in special application scenarios such as driving mixers and turntables, the rotary motor cannot be competent alone. The single-phase series-excited motor combines the armature winding and the excitation winding to achieve voltage and speed regulation, but the required voltage is large, the power supply requirements are high, the structure is relatively complex, the maintenance cost is relatively high, and the torque cannot be effectively increased. At present, there are also ways to increase the torque by adding a frequency converter, using a reducer, adjusting the voltage and current, etc. Although the torque can be effectively increased, on the one hand, it increases the manufacturing cost and the overall size, affecting the use occasions, and on the other hand, it increases energy consumption and reduces efficiency. Therefore, it is necessary to design a new type of rotary drive to overcome the problems existing in the prior art. Summary of the invention

[0003] The object of the present invention is to provide a rotary actuator based on an adjustable bubble buckling structure, which has a simple structure, low energy consumption, no need for lubrication, and adjustable output torque.

[0004] In order to achieve the above-mentioned purpose, the technical solution adopted by the present invention is: a rotary driver based on an adjustable bubble buckling structure, comprising a lower shell, an inner ring structure with a variable diameter, a double-layer metal sheet ring and a cover plate, wherein the lower shell is composed of a circular bottom plate and an outer ring structure arranged on its outer periphery, the inner ring structure is concentrically fixedly connected to the lower shell, the circumference of the double-layer metal sheet ring is greater than the circumference of the outer ring structure, the double-layer metal sheet ring is arranged between the inner and outer ring structures and is partially concave to form a bubble buckling structure, the outer side surface of the non-concave part of the double-layer metal sheet ring is attached to the inner side surface of the outer ring structure, and the inner side surface of the concave part is in contact with the outer side surface of the inner ring structure; transmission parts and heating plates are arranged on both sides of the lower part of the cover plate, and the transmission parts and heating plates are in contact with the inner side surface of the double-layer metal sheet ring; the cover plate is arranged on the lower shell and is concentrically rotatably connected to the lower shell, and an output shaft is arranged on the cover plate.

[0005] Furthermore, an arc-shaped slide groove is provided on the upper circumferential direction of the cover plate for conveniently adjusting the installation position of the two transmission members on the cover plate, and the two transmission members are fixedly installed on the arc-shaped slide groove by fasteners respectively; two mutually symmetrical heating plate installation slide grooves are provided on the cover plate for conveniently adjusting the installation position of the two heating plates on the cover plate, and the two heating plates are fixedly installed on the two heating plate installation slide grooves by fasteners respectively.

[0006] Furthermore, the transmission member consists of a vertical rod and a bearing installed at the lower part of the vertical rod, and the upper part of the vertical rod is fixedly connected to the arc-shaped slide groove of the cover plate by bolts; the heating plate is installed on the heating plate mounting frame, and the heating plate mounting frame is fixedly connected to the slide groove by bolts and nuts.

[0007] Furthermore, a number of pillars for supporting the cover plate are evenly arranged along the circumferential direction at the lower part of the cover plate, and a bearing is installed at the lower end of each pillar. A corresponding annular groove is opened on the circular base plate, and the bearings at the lower end of each pillar are embedded in the annular groove to realize concentric rotation of the cover plate relative to the circular base plate.

[0008] Furthermore, the inner ring structure includes an inner ring bracket, a plurality of push rods, a turntable and a rotating shaft. The inner ring bracket is fixedly connected to the circular bottom plate. The inner ring bracket is provided with a plurality of push rod guide rails evenly distributed along the radial direction. The plurality of push rods are respectively embedded in the corresponding push rod guide rails so as to be able to slide back and forth along the radial direction; the turntable cover is provided on the ring bracket. The turntable is provided with a plurality of arc grooves. The protrusions on the plurality of push rods are respectively embedded in the corresponding arc grooves; the rotating shaft passes downward through the circular bottom plate and is rotatably connected to the middle part of the circular bottom plate. The turntable is fixedly connected to the rotating shaft.

[0009] Furthermore, the push rod is a T-shaped structure, which is composed of a sliding rod sliding along the push rod guide rail and an outward push portion vertically connected to the front end of the sliding rod, and the outward push portion has an arc surface.

[0010] The lower frame is provided with a plurality of lower push rod guides, and the lower frame is provided with a plurality of lower push rod guides, and the lower push rod guides are located on the angular bisector of the angle between the two upper push rod guides. The upper push rod guides and the lower push rod guides are respectively embedded with corresponding upper push rods and lower push rods. The inner ring structure correspondingly includes an upper turntable and a lower turntable, the upper turntable cover is arranged on the upper side of the upper frame, and the lower turntable cover is arranged on the lower side of the lower frame, and the upper turntable and the lower turntable are respectively provided with a plurality of arc grooves, and the protrusions on the upper sides of the plurality of upper push rods are respectively embedded in the corresponding arc grooves of the upper turntable, and the protrusions on the lower sides of the plurality of lower push rods are respectively embedded in the corresponding arc grooves of the lower turntable; the upper turntable and the lower turntable are both fixedly connected to the rotating shaft.

[0011] Furthermore, the expansion coefficient of the inner layer of the double-layer metal sheet ring is higher than that of the outer layer, so that the heating plate works to heat the double-layer metal sheet ring, and the bubble buckling structure of the double-layer metal sheet ring rolls clockwise / counterclockwise, and the rotational torque is transmitted to the cover plate through the transmission member. The cover plate rotates around the center of the rotation driver and outputs torque through the output shaft on the cover plate; the rotation driver can adjust the diameter of the inner ring structure to squeeze the double-layer metal sheet ring to produce bubble buckling structures of different sizes to adjust the rotational torque of the output shaft.

[0012] Furthermore, the buckling structure of the double-layer metal sheet ring bubble is determined by the following set of equilibrium equations:

[0013] x′(s)=cosθ(s), y′(s)=sinθ(s)

[0014] Kθ″-F x sinθ(s)+F yr cosθ(s)=0

[0015] Kθ″-F x sinθ(s)+F yl cosθ(s)=0

[0016] θ(s1)=β,θ(s2)=-β

[0017] Where x and y are the Cartesian coordinates of any point on the bubble buckling configuration, s represents the natural coordinate arc length of any point p on the bubble buckling configuration, θ(s) represents the angle between the tangent line of the bubble buckling configuration curve at point p and the x-axis, K is the bending stiffness of the double-layer metal ring, and F x is the internal force in the x-direction of the buckled configuration of the bubble, F yl and F yr are the y-direction internal forces of the left and right half bubble buckling configurations, s1 and s2 are the left and right endpoints of the loading area, and β is the boundary driving angle at both ends of the loading area;

[0018] In the equilibrium configuration of the loading area, the midpoint deflection of the loading area in different states is obtained; the midpoint deflection is defined as the deflection of the midpoint of the loading area relative to the horizontal axis; when the midpoint deflection in the stable state is equal to the midpoint deflection in the unstable state, the critical boundary driving angle β can be determined c , thus obtaining the critical loading curvature κ c :

[0019]

[0020] Where λ is the scale factor, s l Indicates the length of the loaded area.

[0021] Furthermore, by changing the diameter of the inner ring structure, the constraint width can be adjusted. The reduction of the constraint width and the increase of the loading position can increase the critical load, that is, the required loading temperature is higher and the generated torque is greater.

[0022] Compared with the prior art, the present invention has the following beneficial effects: the present invention provides a rotary driver based on an adjustable bubble buckling structure, the rotary driver uses the bubble buckling structure as a driver, the bubble is locally heated to produce overall rotation, effectively reducing input energy and energy consumption; changing the heating temperature can also control the rotation speed; at the same time, the device also has a variable diameter inner ring structure, which can quickly change the bubble size to adjust the output torque of the device; in addition, the device has a simple structure, is easy to manufacture, does not require lubrication, is easy to operate, and has a low manufacturing cost. Therefore, the present invention has strong practicality and broad application prospects. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 is a schematic structural diagram of a rotary driver according to an embodiment of the present invention (with the cover plate opened);

[0024] Figure 2 is a structural exploded diagram of a rotary driver according to an embodiment of the present invention;

[0025] Figure 3 is a schematic diagram of force analysis of a blister buckling structure in an embodiment of the present invention;

[0026] Figure 4 Schematic diagram of the jump change of the buckling structure of the bimetallic ring bubble in the embodiment of the present invention;

[0027] Figure 5 is a curve diagram showing the relationship between the midpoint deflection and strain energy of the local loading section and the boundary driving angle in an embodiment of the present invention;

[0028] Figure 6 Graph showing the relationship between different loading positions and constraint radii and critical boundary driving angles in an embodiment of the present invention. DETAILED DESCRIPTION

[0029] The present invention will be further described below in conjunction with the accompanying drawings and embodiments.

[0030] It should be noted that the following detailed descriptions are exemplary and are intended to provide further explanation of the present application. Unless otherwise specified, all technical and scientific terms used herein have the same meanings as those commonly understood by those skilled in the art to which the present application belongs.

[0031] It should be noted that the terms used herein are only for describing specific embodiments and are not intended to limit the exemplary embodiments according to the present application. As used herein, unless the context clearly indicates otherwise, the singular form is also intended to include the plural form. In addition, it should be understood that when the terms "comprise" and / or "include" are used in this specification, it indicates the presence of features, steps, operations, devices, components and / or combinations thereof.

[0032] like Figure 1-2 As shown, this embodiment provides a rotation driver based on an adjustable bubble buckling structure, comprising a lower shell, an inner ring structure with adjustable diameter, a double-layer metal sheet ring 6 and a cover plate 1, wherein the lower shell is composed of a circular bottom plate 16 and an outer ring structure 10 arranged on its outer periphery, the inner ring structure and the lower shell are fixedly connected concentrically by bolts 11, the circumference of the double-layer metal sheet ring 6 is greater than the circumference of the outer ring structure, the double-layer metal sheet ring 6 is arranged between the inner and outer ring structures and The part is concave to form a bubble buckling structure, the outer side surface of the non-concave part of the double-layer metal sheet ring 6 is attached to the inner side surface of the outer ring structure 10, and the inner side surface of the concave part is in contact with the outer side surface of the inner ring structure; the left and right sides of the lower part of the cover plate 1 are provided with a transmission member 8 and a heating plate 13, and the transmission member 8 and the heating plate 13 are in contact with the inner side surface of the double-layer metal sheet ring 6; the cover plate 1 is covered on the lower shell and is connected to the lower shell concentrically for rotation, and the cover plate 1 is provided with an output shaft 18.

[0033] In order to facilitate the adjustment of the installation position of the transmission member and the heating plate on the cover plate, an arc-shaped slide groove 19 is provided on the cover plate 1 along the circumferential direction, and the two transmission members 8 are fixedly installed on the arc-shaped slide groove 19 by fasteners respectively; two mutually symmetrical heating plate installation slide grooves 20 are provided on the cover plate, and the two heating plates 13 are fixedly installed on the two heating plate installation slide grooves 20 by fasteners respectively. In this embodiment, the transmission member 8 is composed of a vertical rod and a bearing installed at the lower part of the vertical rod, and the outer side wall of the bearing contacts the inner side surface of the double-layer metal sheet ring 6, and the upper part of the vertical rod is fixedly connected to the arc-shaped slide groove 19 of the cover plate 1 by bolts 15. The heating plate 13 is installed on the heating plate mounting frame, and the heating plate mounting frame is fixedly connected to the slide groove 20 by bolts 9 and nuts 14.

[0034] The lower part of the cover plate 1 is evenly provided with a plurality of pillars 21 for supporting the cover plate along the circumferential direction, and a bearing 2 is installed at the lower end of each pillar. The circular bottom plate 16 is correspondingly provided with an annular groove 17, and the bearing 2 at the lower end of each pillar is embedded in the annular groove 17 to realize the concentric rotation of the cover plate 1 relative to the circular bottom plate 16. In this embodiment, three pillars are provided.

[0035] The inner ring structure includes an inner ring bracket 5, a plurality of push rods 4, a turntable 3 and a rotating shaft 7. The inner ring bracket 5 is fixedly connected to the circular bottom plate 16 by a plurality of bolts 11. The inner ring bracket 5 is evenly provided with a plurality of push rod guide rails 22 in the radial direction. The plurality of push rods 4 are respectively embedded in the corresponding push rod guide rails 22 so as to be able to slide forward and backward in the radial direction. The turntable 3 is covered on the ring bracket 5. The turntable 3 is provided with a plurality of arc grooves 23. The protrusions on the plurality of push rods 4 are respectively embedded in the corresponding arc grooves 23. The rotating shaft 7 passes through the circular bottom plate 16 downward and is rotatably connected to the middle part of the circular bottom plate 16 through the bearing 12. The turntable 3 is fixedly connected to the rotating shaft 7. The push rod 4 is a T-shaped structure, which is composed of a slide rod sliding along the push rod guide rail and an outward push portion vertically connected to the front end of the slide rod, and the outward push portion has an arc surface.

[0036] In this embodiment, the inner circular ring bracket 5 is composed of an upper frame and a lower frame, the upper frame is provided with a plurality of upper push rod guide rails evenly distributed radially upward, and the lower frame is provided with a plurality of lower push rod guide rails evenly distributed radially downward, the lower push rod guide rail is located on the angular bisector of the angle between the two upper push rod guide rails, and the upper push rod guide rails and the lower push rod guide rails are respectively embedded with corresponding upper push rods 41 and lower push rods 42, and the inner circular ring structure correspondingly includes an upper turntable 3 and a lower turntable 24, the upper turntable 3 is covered on the upper side of the upper frame, and the lower turntable 24 is covered on the lower side of the lower frame, and the upper turntable 3 and the lower turntable 24 are respectively provided with a plurality of arc grooves, and the convex blocks on the upper sides of the plurality of upper push rods are respectively embedded in the corresponding arc grooves of the upper turntable, and the convex blocks on the lower sides of the plurality of lower push rods are respectively embedded in the corresponding arc grooves of the lower turntable; the upper turntable 3 and the lower turntable 24 are both fixedly connected to the rotating shaft 7. The lower end of the rotating shaft 7 is provided with a hexagonal hole, which can be connected with an external driving shaft to drive the rotating shaft 7 to rotate, thereby changing the diameter of the inner ring structure.

[0037] In this embodiment, the radius of the outer ring structure R1 = 67 mm, and the radius of the inner ring structure R2 = 33.5-46.5 mm. The thermal curvature of the bimetallic ring is 38°C. -1 , length 421mm, width 15mm.

[0038] The stress of the blister buckling structure is as follows Figure 3 The buckling structure of the double-layer metal sheet ring bubble is determined by the following set of equilibrium equations:

[0039] x′(s)=cosθ(s), y′(s)=sinθ(s)

[0040] Kθ″-F x sinθ(s)+F yr cosθ(s)=0

[0041] Kθ″-Fx sinθ(s)+F yl cosθ(s)=0

[0042] θ(s1)=β,θ(s2)=-β

[0043] Among them, x and y are the Cartesian coordinates of any point on the bubble buckling configuration, s represents the natural coordinate arc length of any point p on the bubble buckling configuration, θ(s) represents the angle between the tangent line of the bubble buckling configuration curve at point p and the x-axis, the x-axis coincides with the vector formed by s1 and s2, the y-axis conforms to the right-hand rule, K is the bending stiffness of the double-layer metal ring, F x is the internal force in the x-direction of the buckled configuration of the bubble, F yl and F yr are the y-direction internal forces of the left and right bubble buckling configurations, s1 and s2 are the left and right endpoints of the loading area, and β is the boundary driving angle at both ends of the loading area.

[0044] In the equilibrium configuration of the loading area, the midpoint deflection of the loading area in different states can be obtained. The midpoint deflection is defined as the deflection of the midpoint of the loading area relative to the horizontal axis, such as Figure 3 When the midpoint deflection of the stable state 1 is equal to the midpoint deflection of the unstable state, the critical boundary driving angle β can be determined. c , so the critical loading curvature κ can be obtained c :

[0045]

[0046] Where λ is the scale factor, s l Indicates the length of the loaded area.

[0047] like Figure 4-5 As shown, the expansion coefficient of the inner layer of the bimetallic ring 6 is higher than that of the outer layer. After the right heating plate is powered on to work, the temperature of the loading area increases, and the double-layer metal ring at the contact position is heated. The boundary driving angle of the loading section increases, and the midpoint deflection of the loading section increases first and then decreases. At the same time, the strain energy increases. When the midpoint deflection decreases to the same as the midpoint deflection in the unstable state, the loading section jumps to the stable state II, and the bubble rotates counterclockwise, as shown in FIG. Figure 4 As shown, the rotational torque is transmitted to the cover plate 1 through the transmission member 8, so that the counterclockwise torque is output through the output shaft on the cover plate 1. After heating the left heating plate, the rotation driver outputs the clockwise torque.

[0048] The rotary driver can adjust the rotation torque of the output shaft by adjusting the diameter of the inner ring structure and squeezing the double-layer metal ring to produce bubble buckling structures of different sizes. When adjusting the diameter of the inner ring structure, the installation position of the transmission member and the heating plate on the cover plate should also be adjusted accordingly, so that the transmission member 8 and the heating plate 13 are in contact with the bimetallic ring 6.

[0049] like Figure 6 As shown in the figure, the critical boundary driving angle increases as the loading position increases and decreases as the constraint width increases; the critical boundary driving angle is related to the critical load, the larger the loading position, the larger the critical load, the larger the constraint width, the smaller the critical load. Therefore, the rotary driver can control the magnitude of the output torque by changing the loading position and the radius of the inner ring structure.

[0050] The above is only a preferred embodiment of the present invention, and does not limit the present invention in other forms. Any technician familiar with the profession may use the above disclosed technical content to change or modify it into an equivalent embodiment with equivalent changes. However, any simple modification, equivalent change and modification made to the above embodiment according to the technical essence of the present invention without departing from the technical solution of the present invention still belongs to the protection scope of the technical solution of the present invention.

Claims

1. A rotary actuator based on an adjustable bubble buckling structure, characterized in that: It includes a lower shell, an inner circular ring structure with a variable diameter, a double-layer metal sheet circular ring and a cover plate, wherein the lower shell is composed of a circular bottom plate and an outer circular ring structure arranged on its outer periphery, the inner circular ring structure is concentrically fixedly connected to the lower shell, the circumference of the double-layer metal sheet circular ring is greater than the circumference of the outer circular ring structure, the double-layer metal sheet circular ring is arranged between the inner and outer circular ring structures and is partially concave to form a bubble buckling structure, the outer side surface of the non-concave part of the double-layer metal sheet circular ring is attached to the inner side surface of the outer circular ring structure, and the inner side surface of the concave part is in contact with the outer side surface of the inner circular ring structure; transmission parts and heating plates are arranged on both sides of the lower part of the cover plate, and the transmission parts and heating plates are in contact with the inner side surface of the double-layer metal sheet circular ring; the cover plate is arranged on the lower shell and is concentrically rotatably connected to the lower shell, and the cover plate is provided with an output shaft.

2. The rotary actuator based on the adjustable bubble buckling structure according to claim 1, characterized in that: An arc-shaped slide groove is provided on the upper circumferential direction of the cover plate for conveniently adjusting the installation positions of the two transmission members on the cover plate, and the two transmission members are fixedly installed on the arc-shaped slide groove by fasteners respectively; two mutually symmetrical heating plate installation slide grooves are provided on the cover plate for conveniently adjusting the installation positions of the two heating plates on the cover plate, and the two heating plates are fixedly installed on the two heating plate installation slide grooves by fasteners respectively.

3. The rotary actuator based on the adjustable bubble buckling structure according to claim 2, characterized in that: The transmission member consists of a vertical rod and a bearing installed at the lower part of the vertical rod. The upper part of the vertical rod is fixedly connected to the arc-shaped slide groove of the cover plate by bolts; the heating plate is installed on the heating plate mounting frame, and the heating plate mounting frame is fixedly connected to the slide groove by bolts and nuts.

4. The rotary actuator based on the adjustable bubble buckling structure according to claim 1, characterized in that: The lower part of the cover plate is evenly arranged with a number of pillars for supporting the cover plate along the circumferential direction, and a bearing is installed at the lower end of each pillar. The circular bottom plate is correspondingly provided with an annular groove, and the bearings at the lower end of each pillar are embedded in the annular groove to realize the concentric rotation of the cover plate relative to the circular bottom plate.

5. The rotary actuator based on the adjustable bubble buckling structure according to claim 1, characterized in that: The inner ring structure includes an inner ring bracket, a plurality of push rods, a turntable and a rotating shaft. The inner ring bracket is fixedly connected to the circular bottom plate. The inner ring bracket is provided with a plurality of push rod guide rails evenly distributed along the radial direction. The plurality of push rods are respectively embedded in the corresponding push rod guide rails so as to be able to slide back and forth along the radial direction. The turntable cover is provided on the ring bracket. The turntable is provided with a plurality of arc grooves. The protrusions on the plurality of push rods are respectively embedded in the corresponding arc grooves. The rotating shaft passes downward through the circular bottom plate and is rotatably connected to the middle part of the circular bottom plate. The turntable is fixedly connected to the rotating shaft.

6. The rotary actuator based on the adjustable bubble buckling structure according to claim 5, characterized in that: The push rod is a T-shaped structure, which consists of a slide rod sliding along the push rod guide rail and an outward push portion vertically connected to the front end of the slide rod, and the outward push portion has an arc surface.

7. The rotary actuator based on the adjustable bubble buckling structure according to claim 5, characterized in that: The lower frame is provided with a plurality of lower push rod guides, and the lower frame is provided with a plurality of lower push rod guides, and the lower push rod guides are located on the angular bisector of the angle between the two upper push rod guides. The upper push rod guides and the lower push rod guides are respectively embedded with corresponding upper push rods and lower push rods. The inner ring structure correspondingly includes an upper turntable and a lower turntable. The upper turntable cover is arranged on the upper side of the upper frame, and the lower turntable cover is arranged on the lower side of the lower frame. The upper turntable and the lower turntable are respectively provided with a plurality of arc grooves, and the protrusions on the upper sides of the plurality of upper push rods are respectively embedded in the corresponding arc grooves of the upper turntable, and the protrusions on the lower sides of the plurality of lower push rods are respectively embedded in the corresponding arc grooves of the lower turntable; the upper turntable and the lower turntable are both fixedly connected to the rotating shaft.

8. The rotary actuator based on the adjustable bubble buckling structure according to claim 1, characterized in that: The expansion coefficient of the inner layer of the double-layer metal sheet ring is higher than that of the outer layer, so that the heating plate works and heats the double-layer metal sheet ring. The bubble buckling structure of the double-layer metal sheet ring rolls clockwise / counterclockwise and transmits the rotational torque to the cover plate through the transmission member. The cover plate rotates around the center of the rotation driver and outputs the torque through the output shaft on the cover plate. The rotation driver can adjust the diameter of the inner ring structure and squeeze the double-layer metal sheet ring to produce bubble buckling structures of different sizes to adjust the rotational torque of the output shaft.

9. The rotary actuator based on the adjustable bubble buckling structure according to claim 8, characterized in that: The buckling structure of the double-layer metal sheet ring bubble is determined by the following set of equilibrium equations: x′(s)=cosθ(s), y′(s)=sinθ(s) Kθ″-F x sinθ(s)+F yr cosθ(s)=0 Kθ″-F x sinθ(s)+F yl cosθ(s)=0 θ(s1)=β,θ(s2)=-β Where x and y are the Cartesian coordinates of any point on the bubble buckling configuration, s represents the natural coordinate arc length of any point p on the bubble buckling configuration, θ(s) represents the angle between the tangent line of the bubble buckling configuration curve at point p and the x-axis, K is the bending stiffness of the double-layer metal ring, and F x is the internal force in the x-direction of the buckled configuration of the bubble, F yl and F yr are the y-direction internal forces of the left and right half bubble buckling configurations, s1 and s2 are the left and right endpoints of the loading area, and β is the boundary driving angle at both ends of the loading area; In the equilibrium configuration of the loading area, the midpoint deflection of the loading area in different states is obtained; the midpoint deflection is defined as the deflection of the midpoint of the loading area relative to the horizontal axis; when the midpoint deflection in the stable state is equal to the midpoint deflection in the unstable state, the critical boundary driving angle β can be determined c , thus obtaining the critical loading curvature κ c : Where λ is the scale factor, s l Indicates the length of the loaded area.

10. The rotary actuator based on the adjustable bubble buckling structure according to claim 8, characterized in that: The constraint width can be adjusted by changing the diameter of the inner ring structure. The reduction of the constraint width and the increase of the loading position can increase the critical load, that is, the required loading temperature is higher and the generated torque is greater.

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