Rotary driving device based on shape memory alloy
The rotation of the transmission tube is driven by the thermal deformation of the shape memory alloy wire, combined with the preload torque of the recovery spring, which solves the problem of insufficient output torque in a small space and realizes rotational drive with efficient energy utilization.
Patent Information
- Application Number
- CN202511000034.5
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-07-21
- Publication Date
- 2025-10-17
AI Technical Summary
Conventional rotary drive devices cannot provide sufficient output torque in a small space, and existing shape memory alloy drive devices suffer from large energy losses during the driving process and need to overcome their own extremely high torsional stiffness.
Utilizing the thermal deformation characteristics of shape memory alloy wire, the SMA wire is shortened through a heating device, driving the transmission tube to produce rotational motion, and the initial length is quickly restored through a cooling device, combined with the preload torque of the recovery spring to achieve reciprocating rotation.
It provides a larger rotational torque and rotation angle in a small space, with high energy density and improved energy utilization efficiency.
Smart Images
Figure CN120798709A_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The present application belongs to the field of intelligent material and drive design, and particularly relates to a drive device with shape memory alloy as core element to drive structure rotation. BACKGROUND
[0002] The driving performance of conventional rotary drive device is related to its size, and it cannot provide sufficient output torque in narrow working space.
[0003] Shape memory alloy is an alloy material that can produce recoverable large deformation when subjected to load or temperature change. After producing large deformation, the shape memory alloy will "remember" its initial shape and restore to the original shape when the condition is restored. The shape memory alloy can produce large output force during deformation, and the deformation is obvious, which is particularly suitable for the design of new type of drive, and the designed drive can be flexibly adjusted in size according to the requirements of working environment.
[0004] The existing shape memory alloy drive device is portable and easy to process, but it needs to overcome the great torsional stiffness of itself during the driving process, and the energy loss is large. SUMMARY
[0005] The present application discloses a rotary drive device based on shape memory alloy, which utilizes the feature that shape memory alloy wire produces deformation when heated, shortens the length of SMA wire by increasing temperature, restores the initial length of SMA wire by reducing temperature, converts the length change of SMA wire into angle change by using the structure of the device, and drives the structure to produce reciprocating rotary motion.
[0006] The present application is implemented as follows: A rotary drive device based on shape memory alloy, comprising: SMA wire, support circular tube, transmission circular tube, ball bearing, recovery spring, temperature raising device, temperature reducing device; the support circular tube is a thin-walled circular tube with a base, the transmission circular tube is a thin-walled circular tube with a connecting plate; the SMA wire is tightly attached to the outer side of the support circular tube and is spirally wound, the SMA wire smoothly passes through the SMA wire mounting hole of the base of the support circular tube and the connecting plate of the transmission circular tube, and is installed on the outer side of the support circular tube through the clamping head at both ends; the bottom end of the support circular tube has a slot for installing the recovery spring; the inner side of the support circular tube is installed with a ball bearing; the lower end of the transmission circular tube has a slot for installing the recovery spring, and the outer side of the transmission circular tube is matched with the inner ring of the ball bearing.
[0007] Further, the SMA wire is a Ni-Ti alloy wire; the length of the SMA wire is greater than the axial length of the support circular tube and the transmission circular tube; when the SMA wire changes in length due to heating, the transmission circular tube produces corresponding angle change, that is, the length change of the SMA wire is converted into reciprocating rotary motion of the drive device.
[0008] Further, the support circular tube base has a connecting hole connected with the static end; the support circular tube base is in the shape of a circular truncated cone, and is attached with a reinforcing ring; the support circular tube base has a through hole in the middle, and the diameter of the through hole is matched with the outer diameter of the support circular tube; the support circular tube base has a plurality of SMA wire mounting holes.
[0009] Further, the hole center of the SMA wire mounting hole forms a circle with a radius equal to the sum of the radius of the support circular tube and the diameter of the SMA wire; the SMA wire mounting hole has a certain inclination angle in the axial direction of the support circular tube, and the angle is the included angle between the columnarly wound SMA wire and the generatrix of the circular tube; the end of the mounting hole has a clamping groove; the reinforcing ring has a wire guide hole opened in the radial direction; the support circular tube supports the columnarly wound SMA wire, and supports the transmission circular tube to rotate coaxially.
[0010] Further, the transmission circular tube connecting plate has a connecting hole connected with the movable end; the transmission circular tube connecting plate is in the shape of a circular truncated cone, and is attached with a reinforcing ring; the transmission circular tube connecting plate has a through hole in the middle, and the diameter of the through hole is matched with the outer diameter of the transmission circular tube; the transmission circular tube connecting plate has a plurality of SMA wire mounting holes.
[0011] Further, the hole center of the SMA wire mounting hole forms a circle with a radius equal to the sum of the radius of the support circular tube and the diameter of the SMA wire; the SMA wire mounting hole has a certain inclination angle in the axial direction of the support circular tube, and the angle is the included angle between the columnarly wound SMA wire and the generatrix of the circular tube; the end of the mounting hole has a clamping groove; the reinforcing ring has a wire guide hole opened in the radial direction; the support circular tube supports the columnarly wound SMA wire, and supports the transmission circular tube to rotate coaxially.
[0012] Further, the outer diameter of the ball bearing is the same as the inner diameter of the support circular tube, and the inner diameter of the ball bearing is the same as the outer diameter of the transmission circular tube; the outer ring of the ball bearing is matched with the inner side of the support circular tube, and the inner ring of the ball bearing is matched with the outer side of the transmission circular tube; the top end of the support circular tube is tightly attached to the transmission circular tube connecting plate; the insertion slots of the support circular tube and the transmission circular tube for mounting the restoring spring are located at the same height; the ball bearing guides the transmission circular tube to rotate around the axis.
[0013] Further, the restoring spring is a vortex spring, and the inner and outer ends of the restoring spring have protrusions; after the support circular tube, the transmission circular tube, the ball bearing and the SMA wire are installed, the restoring spring is applied with a pre-tightening torque and a pre-torque angle; the inner and outer ends of the restoring spring are fixed in the insertion slots of the transmission circular tube and the support circular tube through the protrusions, respectively; the pre-torque angle is opposite to the winding direction of the SMA wire, so that the device itself is kept balanced.
[0014] Further, the end of the SMA wire is connected in parallel to a conductive plate, a wire passes through a wire hole of a support circular tube base or a transmission circular tube connecting plate, one end of the wire is connected to the conductive plate, and the other end of the wire is connected to a temperature rising device; the outer side of the conductive plate is insulated.
[0015] The use method of the rotary driving device based on the shape memory alloy is as follows: after the temperature rising device is powered on, the SMA wire is deformed and shortened in length by heating; the deformation of the SMA wire drives the transmission circular tube to overcome the pre-tightening torque of the restoring spring, and rotary motion is generated; the heating temperature of the SMA wire is adjusted by adjusting the power of the power supply, so that the size of the rotary torque and the rotary angle of the driving device output are controlled; the temperature reducing device is a portable air conditioner; after the power supply is turned off, the air conditioner releases cold air to rapidly cool the SMA wire, the SMA wire returns to the initial length, and the torsional resistance of the restoring spring accelerates the recovery process of the transmission circular tube, so that the driving device returns to the initial state.
[0016] Compared with the prior art, the present application has the following beneficial effects: The SMA wire in the present application is deformed and shortened in length by heating. The deformation of the SMA wire drives the transmission circular tube to overcome the pre-tightening torque of the restoring spring, and rotary motion is generated. The transmission circular tube drives the movable end to rotate, thereby realizing rotary driving of the movable end.
[0017] The device of the present application can provide a larger rotary torque and rotary angle in a small space, and has high energy density. BRIEF DESCRIPTION OF DRAWINGS
[0018] Figure 1 The figure is a schematic diagram of the driving device of the present application; Figure 2 The figure is a schematic diagram of the support circular tube of the present application; Figure 3 The figure is a schematic diagram of the base details of the present application; Figure 4 The figure is a schematic diagram of the transmission circular tube of the present application; Figure 5 The figure is a schematic diagram of the connecting plate details of the present application; Figure 6 The figure is a schematic diagram of the relative distance of the support circular tube, the transmission circular tube, the restoring spring and the ball bearing after assembly of the present application; Figure 7 The figure is a schematic diagram of the connection of the SMA wire and the wire of the present application.
[0019] In the figure, 1 is the SMA wire, 2 is the support circular tube, 3 is the transmission circular tube, 4 is the restoring spring, 5 is the ball bearing, 6 is the wire, and 7 is the conductive plate. DETAILED DESCRIPTION
[0020] In order to make the purpose, technical scheme and effect of the present application more clear, definite and explicit, the present application is further described in detail by the following examples. It should be pointed out that the specific implementation described herein is only used to explain the present application, and is not used to limit the present application.
[0021] As shown in Figure 1 , the rotary drive device of the present application mainly comprises an SMA wire 1, a supporting circular tube 2, a transmission circular tube 3, a ball bearing 5, a restoring spring 4, a temperature raising device and a temperature lowering device.
[0022] The SMA wire 1 is a Ni-Ti alloy wire, and its length is greater than the axial length of the supporting circular tube 2 and the transmission circular tube 3. The SMA wire 1 is tightly attached to the outside of the supporting circular tube 2, is spirally wound, smoothly passes through the SMA wire 1 mounting hole of the base of the supporting circular tube 2 and the connecting plate of the transmission circular tube 3, and is mounted on the outside of the supporting circular tube 2 through the clamping head at both ends. When the SMA wire 1 changes in length after being heated, the transmission circular tube 3 produces a corresponding angle change, i.e. the length change of the SMA wire 1 is converted into the reciprocating rotary motion of the drive device.
[0023] As shown in Figures 2-3 , the supporting circular tube 2 is a thin-walled circular tube with a base, and the base has a connecting hole connected with the static end. The bottom end of the supporting circular tube 2 has a slot for mounting the restoring spring 4. The inside of the circular tube is mounted with the ball bearing 5. The base is in the shape of a circular table, and is attached with a reinforcing ring. There is a through hole in the middle of the base, and the diameter of the through hole is adapted to the outer diameter of the supporting circular tube 2. The base has a plurality of SMA wire 1 mounting holes. The center of the mounting hole forms a circle with a radius equal to the sum of the radius of the supporting circular tube 2 and the diameter of the SMA wire 1. The mounting hole has a certain inclination angle in the axial direction of the circular tube, and the angle is the included angle between the columnar wound SMA wire 1 and the generatrix of the circular tube. The end of the mounting hole has a clamping head slot. The reinforcing ring has a wire hole opened along the radial direction. The supporting circular tube 2 supports the SMA wire 1 to keep columnar winding, and supports the transmission circular tube 3 to rotate coaxially.
[0024] As shown in Figures 4-6 , the transmission circular tube 3 is a thin-walled circular tube with a connecting plate, and the connecting plate has a connecting hole connected with the movable end. The lower end of the transmission circular tube 3 has a slot for mounting the restoring spring 4. The outside of the circular tube is matched with the inner ring of the ball bearing 5. The connecting plate is in the shape of a circular table, and is attached with a reinforcing ring. There is a through hole in the middle of the connecting plate, and the diameter of the through hole is adapted to the outer diameter of the transmission circular tube 3. The connecting plate has a plurality of SMA wire 1 mounting holes. The center of the mounting hole forms a circle with a radius equal to the sum of the radius of the supporting circular tube 2 and the diameter of the SMA wire 1. The mounting hole has a certain inclination angle in the axial direction of the circular tube, and the angle is the included angle between the columnar wound SMA wire 1 and the generatrix of the circular tube. The end of the mounting hole has a clamping head slot. The reinforcing ring has a wire hole opened along the radial direction. The length of the transmission circular tube 3 is the axial length of the supporting circular tube 2 plus the thickness of the connecting plate. The transmission circular tube 3 rotates around its own axis under the drive of the SMA wire 1, and drives the movable end to rotate.
[0025] The outer diameter of the ball bearing 5 is the same as the inner diameter of the support circular tube 2, and the inner diameter is the same as the outer diameter of the transmission circular tube 3. The outer ring of the ball bearing 5 is matched with the inner side of the support circular tube 2, and the inner ring is matched with the outer side of the transmission circular tube 3. The top end of the support circular tube 2 is close to the connecting plate of the transmission circular tube 3, and the insertion slots of the recovery spring 4 installed on the two circular tubes are located at the same height. The ball bearing 5 guides the transmission circular tube 3 to rotate around the axis.
[0026] The recovery spring 4 is a vortex spring with protrusions at the inner and outer ends. After the support circular tube 2, the transmission circular tube 3, the ball bearing 5 and the SMA wire 1 are installed, the recovery spring 4 is pre-tightened with a torque and a pre-torsion angle, and is installed between the support circular tube 2 and the transmission circular tube 3, that is, the inner and outer ends of the recovery spring 4 are fixed in the insertion slots of the transmission circular tube 3 and the support circular tube 2 respectively through the protrusions. The direction of the pre-torsion angle is opposite to the winding direction of the SMA wire 1, so that the device itself is balanced.
[0027] As shown in Figure 7 , the number of SMA wire 1 installation holes in the schematic diagram does not represent the specific scheme in the specific implementation case. The ends of the SMA wire 1 are connected in parallel on the conductive plate 7. The lead wire 6 passes through the lead wire hole of the base or the connecting plate, one end is connected to the conductive plate 7, and the other end is connected to the heating device. The outer side of the conductive plate 7 is insulated.
[0028] After the heating device is powered on, the SMA wire 1 is deformed and shortened by heat. The deformation of the SMA wire 1 drives the transmission circular tube 3 to overcome the pre-tightening torque of the recovery spring 4, and generates a rotating motion. By adjusting the power of the power supply, the heating temperature of the SMA wire 1 is adjusted, and the size of the rotating torque and rotating angle output by the driving device is controlled.
[0029] The cooling device is a portable air conditioner. After the power is turned off, the air conditioner releases cold air to quickly cool the SMA wire 1, and the SMA wire 1 returns to the initial length. At the same time, the anti-torsion resistance of the recovery spring 4 accelerates the recovery process of the transmission circular tube 3, so that the driving device returns to the initial state.
[0030] The following specific data examples describe the device of the present application: Suppose that in a narrow working space, the distance between the stationary end and the movable end is about 500mm. The movable end needs to generate a 180° reciprocating rotation angle and output a 30Nm rotating torque.
[0031] Based on the above scenario, the axial length of the driving device is determined to be 500mm. The parameters of the main components are as follows: the support circular tube has a length of 470mm and an outer diameter of 60mm; the transmission circular tube has a length of 480mm and an outer diameter of 30mm; the number of SMA wires is 30, and each SMA wire has a working length of 570mm and a winding angle of 34°.
[0032] SMA wire is Ni-Ti shape memory alloy wire, length 600mm, cross section diameter 1mm. The working length of SMA wire is 570mm, which is coated with insulating ceramic. The SMA wire is tightly attached to the outside of the support circular tube, wound in a spiral shape, and the included angle with the circular tube bus is about 34°. It is fixed between the base and the connecting plate through the clamping head. 30 SMA wires are evenly distributed along the outside of the support circular tube.
[0033] The material of the support circular tube is stainless steel, with a length of 470mm, a tube diameter of 60mm, and a wall thickness of 2mm. The bottom end of the support circular tube has a restoring spring slot with a width of 1mm, a length of 20mm, and a depth of 2mm. The base is made of bakelite and shaped like a circular truncated cone. The outer diameter of the base is 120mm, the inner diameter is 60mm, and the height is 10mm. The reinforcing circular ring has an outer diameter of 120mm, an inner diameter of 80mm, and a height of 10mm. The base has 30 SMA wire installation holes, and the axial inclination angle of the installation hole is 34° with the circular tube bus. The hole center of the installation hole forms a circle with a diameter of 64mm. The end of the installation hole has a clamping head slot for fixing the clamping head, with a diameter of 4mm and a depth of 5mm. Wire guide holes are radially provided on the reinforcing circular ring. The wire guide hole is 20mm deep and 10mm in diameter. Four connecting holes for connecting to the static end are evenly distributed on the reinforcing circular ring, with a diameter of 10mm.
[0034] The material of the transmission circular tube is stainless steel, with a length of 480mm, a tube diameter of 30mm, and a wall thickness of 2mm. Two restoring spring slots are provided at the lower end of the circular tube, each with a width of 1mm, a length of 20mm, and a depth of 2mm. The connecting plate is made of bakelite and shaped like a circular truncated cone. The outer diameter of the connecting plate is 120mm, the inner diameter is 30mm, and the height is 10mm. The reinforcing circular ring has an outer diameter of 120mm, an inner diameter of 80mm, and a height of 10mm. The through hole in the center of the connecting plate has a diameter of 30mm. The connecting plate has 30 SMA wire installation holes, and the axial inclination angle of the installation hole is 34° with the circular tube bus. The hole center of the installation hole forms a circle with a diameter of 64mm. The end of the installation hole has a clamping head slot for fixing the clamping head, with a diameter of 4mm and a depth of 5mm. Wire guide holes are radially provided on the reinforcing circular ring. The wire guide hole is 20mm deep and 10mm in diameter. Four connecting holes for connecting to the movable end are evenly distributed on the reinforcing circular ring, with a diameter of 10mm.
[0035] The outer diameter of the ball bearing is 56mm, and the inner diameter is 30mm. Two ball bearing outer rings are fixed at appropriate positions on the inside of the support circular tube, and the inner rings cooperate with the outside of the transmission circular tube. After the bearing cooperates with the two circular tubes, the top end of the support circular tube is tightly connected to the connecting plate of the transmission circular tube.
[0036] The width of the restoring spring along the axial direction is 20 mm, the thickness is 1 mm, and the stiffness coefficient is 20 Nm / radian. After the support circular tube, the transmission circular tube, the bearing, and the SMA wire are assembled, the restoring spring is applied with a pre-tightening torque of 10 Nm and a pre-torque angle, and is installed between the support circular tube and the transmission circular tube, that is, the protrusions at the inner and outer ends of the restoring spring are respectively installed in the insertion slots of the transmission circular tube and the support circular tube. After the installation and the pre-tightening torque are applied, the outer end of the spring has a diameter of 54 mm, and the inner end has a diameter of 32 mm. The pre-torque angle and the winding angle of the SMA wire are opposite, and the device is balanced.
[0037] The ends of the SMA wires are connected in parallel on the conductive plate. Two wires pass through the wire holes of the base and the connecting plate respectively, one end of each wire is connected with the conductive plate, and the other end is connected with the temperature rising device. The conductive plate is composed of two metal circular plates with a diameter of 50 mm and a thickness of 10 mm. On one side of the metal circular plate, 31 radial grooves are uniformly distributed in the circumferential direction, and the grooves are in the shape of semicircles. After the SMA wires and the wires pass through the connection holes, the two metal circular plates are tightened with screws to connect the 30 SMA wires in parallel and connect the wires.
[0038] After the above components are assembled, the support circular tube is connected to the static end through the connecting hole of the base, and the transmission circular tube is installed on the movable end through the connecting hole of the connecting plate.
[0039] The SMA wires are heated to rise in temperature, the length is shortened, the transmission circular tube is driven to overcome the pre-tightening torque of the restoring spring, and the rotational movement along the axial direction is generated. The support circular tube and the static end are fixed and immovable, the transmission circular tube drives the movable end to rotate, so that the movable end and the static end generate a relative rotation angle of about 180°, and the device outputs a rotational torque of about 30 Nm.
[0040] When the power is turned off, the portable air conditioner releases cold air, the SMA wires are quickly cooled, and the length is elongated. At the same time, the torsional resistance of the restoring spring 4 accelerates the recovery process of the driving device. The power of the power supply can be adjusted according to the size of the torsion angle change amount, so that the movable end generates a corresponding torsion angle change amount.
[0041] The above only describes one application of the present application. Without departing from the principles of the present application, the materials and structural sizes of the components can be appropriately improved according to the use situation to ensure the safety and reliability of the structure. After overcoming all the torque, the device can achieve ideal rotational driving in the use situation, and these improvements are also considered as the protection range of the present application.
Claims
1. A rotation drive device based on shape memory alloy, characterized in that: The device comprises: SMA wire (1), supporting circular tube (2), transmission circular tube (3), ball bearing (5), restoring spring (4), heating device, cooling device; the supporting circular tube (2) is a thin-walled circular tube with a base, and the transmission circular tube (3) is a thin-walled circular tube with a connecting plate; The SMA wire (1) is tightly attached to the outside of the supporting circular tube (2) and is wound in a spiral shape. The SMA wire (1) smoothly passes through the SMA wire mounting holes of the base of the supporting circular tube (2) and the connecting plate of the transmission circular tube (3), and is mounted on the outside of the supporting circular tube (2) through the clamps at both ends. A slot for mounting a restoring spring (4) is provided at the bottom end of the supporting circular tube (2); and a ball bearing (5) is mounted on the inside of the supporting circular tube (2). The lower end of the transmission tube (3) is provided with a slot for installing a restoring spring (4), and the outer side of the transmission tube (3) is matched with the inner ring of the ball bearing (5).
2. A rotation drive device based on shape memory alloy according to claim 1, characterized in that: The SMA wire (1) is a Ni-Ti alloy wire; the length of the SMA wire (1) is greater than the axial length of the supporting circular tube (2) and the transmission circular tube (3); When the SMA wire (1) changes in length due to heat, the transmission tube (3) produces a corresponding angle change, that is, the length change of the SMA wire (1) is converted into a reciprocating rotational motion of the driving device.
3. The shape memory alloy-based rotation drive device according to claim 1, characterized in that: The base of the supporting circular tube (2) has a connection hole connected to the stationary end; the base of the supporting circular tube (2) is in the shape of a truncated cone with a reinforcing ring attached thereon; the base of the supporting circular tube (2) has a through hole in the middle thereof, the diameter of the through hole being adapted to the outer diameter of the supporting circular tube (2); the base of the supporting circular tube (2) has a plurality of mounting holes for SMA wires (1).
4. The shape memory alloy-based rotation drive device according to claim 3, characterized in that: The radius of the circle formed by the center of the SMA wire (1) mounting hole is equal to the sum of the radius of the supporting circular tube (2) and the diameter of the SMA wire (1); the SMA wire (1) mounting hole has a certain tilt angle in the axial direction of the supporting circular tube (2), which is the angle between the cylindrically wound SMA wire (1) and the circular tube busbar; a clamping head groove is provided at the end of the mounting hole, and a wire hole is provided in the radial direction on the reinforcing circular ring; the supporting circular tube (2) supports the SMA wire (1) to maintain the cylindrical winding, and supports the transmission circular tube (3) to rotate coaxially with it.
5. The rotation drive device based on shape memory alloy according to claim 1, characterized in that: The transmission tube (3) connecting plate has a connecting hole connected to the movable end; the transmission tube (3) connecting plate is in the shape of a truncated cone with a reinforcing ring attached thereon; a through hole is provided in the middle of the transmission tube (3) connecting plate, the diameter of the through hole being adapted to the outer diameter of the transmission tube (3); and the transmission tube (3) connecting plate has a plurality of SMA wire mounting holes.
6. The shape memory alloy-based rotation drive device according to claim 5, characterized in that: The radius of the circle formed by the center of the installation hole of the transmission circular tube (3) is the sum of the radius of the support circular tube (2) and the diameter of the SMA wire (1); the installation hole of the transmission circular tube (3) has a certain inclination angle in the axial direction of the circular tube, and the angle is the angle between the cylindrically wound SMA wire 1 and the busbar of the circular tube; a clamping head groove is provided at the end of the installation hole of the transmission circular tube (3), and a wire hole is provided in the radial direction on the reinforcing ring. The length of the transmission circular tube (3) is the axial length of the support circular tube (2) plus the thickness of the connecting plate. The transmission circular tube (3) rotates around its own axis under the drive of the SMA wire (1), driving the movable end to rotate.
7. The shape memory alloy-based rotation drive device according to claim 1, characterized in that: The outer diameter of the ball bearing (5) is the same as the inner diameter of the supporting circular tube (2), and the inner diameter of the ball bearing (5) is the same as the outer diameter of the transmission circular tube (3); the outer ring of the ball bearing (5) is matched with the inner side of the supporting circular tube (2), and the inner ring of the ball bearing (5) is matched with the outer side of the transmission circular tube (3); the top end of the supporting circular tube (2) is closely attached to the connecting plate of the transmission circular tube (3); the slots for installing the restoring spring (4) of the supporting circular tube (2) and the transmission circular tube (3) are located at the same height, and the ball bearing (5) guides the transmission circular tube (3) to rotate around the axis.
8. The shape memory alloy-based rotation drive device according to claim 1, characterized in that: The restoring spring (4) is a vortex spring, and the restoring spring (4) has protrusions at both inner and outer ends. After the supporting circular tube (2), the transmission circular tube (3), the ball bearing (5) and the SMA wire (1) are installed, the restoring spring (4) is applied with a pre-tightening torque and a pre-torsion angle, and is installed between the supporting circular tube (2) and the transmission circular tube (3), that is, the inner and outer ends of the restoring spring (4) are fixed in the slots of the transmission circular tube (3) and the supporting circular tube (2) respectively through the protrusions, and the direction of the pre-torsion angle is opposite to the winding direction of the SMA wire (1), so that the device itself remains balanced.
9. The shape memory alloy-based rotation drive device according to claim 1, characterized in that: The ends of the SMA wires (1) are connected in parallel to the conductive plate (7), the wire (6) passes through the wire hole of the base of the supporting circular tube (2) or the connecting plate of the transmission circular tube (3), one end of the wire (6) is connected to the conductive plate (7), and the other end of the wire (6) is connected to the heating device; the outer side of the conductive plate (7) is insulated.
10. A rotation drive device based on a shape memory alloy according to any one of claims 1 to 9, characterized in that: After the heating device is powered on, the SMA wire (1) is deformed by the heat and its length is shortened; the deformation of the SMA wire (1) drives the transmission tube (3) to overcome the preload torque of the recovery spring (4) and generate a rotational motion; the heating temperature of the SMA wire (1) is adjusted by adjusting the power of the power supply, and the output rotation torque and the rotation angle of the driving device are controlled; the cooling device is a portable air conditioner; after the power is turned off, the air conditioner releases cold air to quickly cool the SMA wire (1), and the SMA wire (1) is restored to its initial length. At the same time, the torsional resistance of the recovery spring (4) accelerates the recovery process of the transmission tube (3), and the driving device is restored to its initial state.