Variable speed and torque SMA motor

Abstract

The present invention provides a variable speed and variable torque SMA motor, which includes: a control system; a drive unit array, wherein the drive unit array is connected to the control system through an SMA memory alloy wire, wherein the SMA memory alloy wire is energized, the SMA memory alloy wire contracts, and the drive unit array drives the power output device to move; after power failure, the SMA memory alloy wire extends, and the power output device rotates in the opposite direction and returns to the initial position. The control system can arbitrarily control the working mode of the drive unit array, and the control system can allow multiple drive unit arrays to work at the same time, which can improve the output torque of the power output device; when the drive unit array is started in series, since it takes a certain amount of time for the SMA memory alloy wire to cool, the next drive unit is operated during the cooling period of the previous SMA memory alloy wire, so that the speed of the power output device can be greatly improved, and the flexibility of use is greatly improved.

Description

Technical Field

[0001] The invention relates to a device for converting electric energy into mechanical energy, and in particular to a variable speed and variable torque SMA motor. Background Art

[0002] Shape memory alloy (SMA for short) motors have a large output displacement and a high power-to-weight ratio, and have broad application prospects. The current SMA motor consists of two parts: a driving element and an actuator. The driving element is the SMA material, which is mostly wire, sheet and tube. It can be made into driving elements of different shapes and specifications according to needs. Commonly used ones are linear tension wire type, spiral compression spring type, spiral tension spring type, cantilever spring type, disc spring type, spiral torsion spring type, torsion wire type and torsion metal tube type. The traditional SMA motor actuator is relatively simple and has two types: offset type and push-pull type. The offset system consists of an SMA spring and a biased ordinary tension spring. The push-pull system simply replaces the ordinary tension spring in the offset system with an SMA spring. According to the movement form of the motor, its basic structure can be divided into linear displacement type and rotational displacement type. The basic structure of the linear displacement motor is as follows Figure 5 , 6 As shown in Figure 1, the basic structure of the rotary joint motor is as follows: Figure 7 , 8 shown.

[0003] The operating principle of the motor is that, for the bias type, the SMA spring is heated, a phase change occurs, and the shape recovery force overcomes the spring tension to produce movement. When cooled, the SMA undergoes a reverse phase change, and the SMA spring is very soft at this time. Under the action of the tension spring, the driver returns to its original position. This repetition can cause the motor output displacement. For the push-pull type, the SMA on one side is heated while the SMA on the other side is cooled, and the motor has the ability to do work in both directions.

[0004] SMA motors have the following advantages: 1. High power-to-weight ratio, suitable for miniaturization; 2. Integrate sensing, control, transducer, and actuation; 3. Simple structure, easy to control; 4. Strong adaptability to the environment, not affected by factors other than temperature; 5. No vibration, noise, pollution, etc. Although SMA motors have many advantages, they are subject to the fact that SMA heating and contraction, cooling and elongation require a certain amount of time, and the response time is long. Electric heating can make the temperature rise rapidly, but the cooling process is difficult to control, and the action frequency is low. Especially when the motor has a large torque demand, the required SMA wire diameter is thicker, the heating and heat dissipation time is longer, and the action frequency is slower, which seriously restricts the applicability of the motor. Summary of the invention

[0005] The object of the present invention is to overcome the defects of the prior art and provide a variable speed and variable torque SMA motor, which has the characteristics of being able to adjust the torque and speed according to needs.

[0006] The present invention is implemented as follows: a variable speed and variable torque SMA motor, comprising:

[0007] - control system;

[0008] A control system manages a multi-current loop array targeted at heating and contracting the SMA wire;

[0009] A drive unit array; the drive unit array is connected to the control system via an SMA memory alloy wire, wherein the control system loads current to the SMA memory alloy wire, the SMA memory alloy wire contracts, and the drive unit array drives the power output device to move; after power failure, the SMA memory alloy wire extends, the power output device rotates in the opposite direction and returns to an initial position.

[0010] Furthermore, each of the driving units is an independent module, and the driving unit includes a driving wheel, a winding frame, an SMA memory alloy wire, a one-way bearing, a rotating lug, and an elastic wire. The power output device is a main shaft, and the main shaft is installed in the one-way bearing, and the one-way bearing is arranged in the driving wheel, and the driving wheel is installed in the winding frame. The SMA memory alloy wire is wound on the winding frame, wherein, when the SMA memory alloy wire is energized, the SMA memory alloy wire shrinks due to heat and drives the driving wheel and the one-way bearing to rotate, and the one-way bearing drives the main shaft to rotate; when the SMA memory alloy wire is powered off, the SMA memory alloy wire cools and stretches, and the elastic wire drives the driving wheel to rotate in the opposite direction, and the driving wheel returns to an initial position.

[0011] Furthermore, the variable speed and variable torque SMA motor also includes a housing in which the main shaft is installed, one end of the main shaft is used to install a gear, an electromagnetic brake is arranged between the main shaft and the housing to prevent operation during uncontrolled periods, at least one groove is arranged on the outer side of the winding frame, and the SMA memory alloy wire is installed in the groove.

[0012] Furthermore, a winding frame is installed in the outer shell, the winding frame is coaxially arranged with the main shaft, a first terminal board and a second terminal board are installed on the winding frame, a plurality of terminal posts are installed on the first terminal board, and a plurality of sliding grooves are provided on the side wall of the winding frame, and each of the terminal posts corresponds to each of the sliding grooves.

[0013] Furthermore, the first wiring board and the second wiring board are both fixed to the outside of the winding frame, the first wiring board is located beside the sliding groove, and the first wiring board and the second wiring board are arranged opposite to each other.

[0014] Furthermore, the number of the driving unit array can be 2, 3, 4 or more as required.

[0015] Furthermore, the SMA memory alloy wire (Shape Memory Alloy, SMA for short) is a special wire that shrinks when powered, and the SMA memory alloy wire is wound on the winding frame, one end of the alloy wire is fixed to the rotating ear, and the other end of the SMA memory alloy wire is fixed to the second terminal board.

[0016] Furthermore, the current loop array is composed of cables, memory alloy wires, control systems, terminals, terminal boards, elastic wires, etc. The elastic wires are installed between the terminals and the rotary hooks to drive the reverse rotation of the driving wheel during power failure.

[0017] The drive unit array of the present invention is connected to a control system, and the control system can arbitrarily control the working mode of the drive unit array, such as parallel and serial. The control system can allow multiple drive units to work at the same time, which can improve the output torque of the power output device. Compared with the previous design, the output torque is doubled; when the drive unit array is started in series, since it takes a certain amount of time for the SMA memory alloy wire to cool, the next drive unit is operated during the cooling of the previous SMA memory alloy wire, so that the speed of the power output device can be greatly improved, and the flexibility of use is greatly improved. Therefore, through the control system, the torque and speed of the motor can be adjusted as needed. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative labor.

[0019] Figure 1 A three-dimensional diagram of the variable speed and variable torque SMA motor provided by the present invention;

[0020] Figure 2 A cross-sectional view of a variable speed and variable torque SMA motor provided by the present invention;

[0021] Figure 3 A three-dimensional exploded view of the variable speed and variable torque SMA motor provided by the present invention;

[0022] Figure 4 It is a basic structural diagram of a linear displacement motor in the prior art;

[0023] Figure 5 It is a basic structural diagram of a linear displacement motor in the prior art;

[0024] Figure 6 It is a schematic diagram of the basic structure of a rotary articulated motor in the prior art;

[0025] Figure 7 It is a schematic diagram of the basic structure of a rotary articulated motor in the prior art;

[0026] Figure 8 A framework diagram provided for the present invention. DETAILED DESCRIPTION

[0027] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0028] like Figure 1-Figure 8 A variable speed and variable torque SMA motor comprises: a control system; a multi-current loop array managed by the control system with the goal of heating and contracting an SMA wire; a drive unit array; the drive unit array is connected to the control system via an SMA memory alloy wire 4, wherein when the SMA memory alloy wire 4 is energized, the SMA memory alloy wire 4 contracts, and the drive unit array drives a power output device to move; after power is cut off, the SMA memory alloy wire 4 extends, and the power output device rotates in the opposite direction and returns to an initial position. Each of the driving units is an independent module, and the driving unit includes a driving wheel 31 (rotating wheel 31), a winding frame 2, an SMA memory alloy wire 4, a one-way bearing 32, a rotating lug (also called a metal lug), and an elastic wire 34. The power output device is a main shaft 13, and the main shaft 13 is installed in the one-way bearing 32. The one-way bearing 32 is arranged in the driving wheel 31, and the driving wheel 31 is installed in the winding frame 2. The SMA memory alloy wire 4 is wound on the winding frame 2. When the SMA memory alloy wire 4 is powered on, the SMA memory alloy wire 4 shrinks due to heat and drives the driving wheel 31 and the one-way bearing 32 to rotate, and the one-way bearing 32 drives the main shaft 13 to rotate; when the SMA memory alloy wire 4 is powered off, the SMA memory alloy wire 4 cools and stretches, and the elastic wire 34 drives the driving wheel 31 to rotate in the opposite direction, and the driving wheel 31 returns to the initial position.

[0029] The drive unit arrays are all connected to the control system, and the control system can arbitrarily control the working mode of the drive unit array, such as parallel and serial. The control system can allow multiple drive units to work at the same time, which can improve the output torque of the power output device. Compared with the previous design, the output torque is doubled; when the drive unit array is started in series, since it takes a certain amount of time for the SMA memory alloy wire 4 to cool, the next drive unit is operated during the cooling of the previous SMA memory alloy wire 4, so that the speed of the power output device can be greatly increased, and the flexibility of use is greatly improved. Therefore, through the control system, the torque and speed of the motor can be adjusted as needed.

[0030] The embodiment of the present invention provides a variable speed and variable torque SMA motor, and the specific structure can be seen in the following description, which includes: a housing 1, in which a main shaft 13 is installed, one end of the main shaft 13 is used to install a gear 14, and the gear 14 is exposed from the housing 1, and an electromagnetic brake 15 is arranged between the main shaft 13 and the housing 1, and the housing and the main shaft are controlled by the electromagnetic brake 15. When power is turned on, the electromagnetic brake 15 is released, and the housing and the main shaft can rotate relative to each other; a winding frame 2, installed in the housing 1, the winding frame 2 is coaxially arranged with the main shaft 13, a first terminal board 21 and a second terminal board 22 are installed on the winding frame 2, at least one terminal post 23 is installed on the first terminal board 21, and at least one sliding groove 24 is provided on the side wall of the winding frame 2, and each terminal post 23 corresponds to each sliding groove 24; a rotating wheel 3, installed in the winding frame 2, and the rotating wheel 3 includes a rotating wheel 31 and a second terminal board 22 installed on the winding frame 2. A one-way bearing 32 in the rotating wheel 31, the one-way bearing 32 is fixed to the main shaft 13, a rotating ear 33 is arranged on the outer side of the rotating wheel 31, the rotating ear 33 is located in the sliding groove 24, and the rotating ear 33 and the terminal 23 are connected by an elastic wire 34; an SMA memory alloy wire 4 (also called memory alloy wire) is wound on the winding frame 2, one end of the SMA memory alloy wire 4 is fixed to the rotating ear 33, the The other end of the SMA memory alloy wire 4 is fixed to the second wiring board 22; when the SMA memory alloy wire 4 is energized, the SMA memory alloy wire 4 contracts, and one end of the SMA memory alloy wire 4 drives the rotating lug 33 to move in the sliding groove 24, so that the rotating lug 33 rotates together with the rotating wheel 31, the one-way bearing 32, and the main shaft 13; after power is cut off, the elastic wire 34 drives the rotating wheel 31 to rotate in the opposite direction and return to the initial position.

[0031] At least one groove is arranged on the outer side of the winding frame 2, and the SMA memory alloy wire 4 is installed in the groove. The housing 1 includes a cylinder 11 and two covers 12, the two covers 12 are respectively fixed to the two ends of the cylinder 11, the winding frame 2 is fixed to the covers 12, the electromagnetic brake 15 is installed in the covers 12, and one end of the main shaft 13 is inserted into the electromagnetic brake 15.

[0032] The first wiring board 21 is provided with a plurality of terminals 23, each of which is connected to a cable 25, the cable 25 is used to connect to the positive pole of the power supply, the cable 25 is connected to the driving unit, and the second wiring board 22 is used to connect to the negative pole of the power supply. The winding frame 2 is provided with a plurality of rotating wheels 3, each of which has a rotating lug 33, the rotating lug 33 is installed in the corresponding sliding groove 24, each of which is connected to one end of each of the SMA memory alloy wires 4, and the other end of the SMA memory alloy wires 4 is fixed to the second wiring board 22, one end of each of the elastic wires 34 is fixed to each of the corresponding terminals 23, and the other end of each of the elastic wires 34 is fixed to each of the corresponding rotating lugs 33.

[0033] The first wiring board 21 and the second wiring board 22 are both fixed to the outside of the winding frame 2. The first wiring board 21 is located next to the sliding groove 24. The first wiring board 21 and the second wiring board 22 are arranged opposite to each other. A spline 131 is arranged on the main shaft 13. The spline 131 is in the shape of a long strip. The spline 131 protrudes from the side of the main shaft 13. The one-way bearing 32 has an outer wheel and an inner wheel. The outer wheel is fixed to the rotating wheel 31. The inner wheel is provided with a slot 321. The spline 131 is buckled in the slot 321. The winding frame 2 is cylindrical. The sliding groove 24 is arranged along the arc direction of the circle where the winding frame 2 is located.

[0034] When in use, the control system 26 gives an electrical signal, and current flows through the cable 25. The current enters the elastic wire 34 through the terminal post 23 on the second wiring board 22, and the current flows into the rotary hook 3 through the elastic wire 34, and flows into one end of the SMA memory alloy wire 4 through the rotary hook 33, flows out from the other end of the SMA memory alloy wire 4, and then flows through the second wiring board 22. The second wiring board 22 is connected to the negative pole of the power supply to form a loop. The housing and the spindle are loosened, and the housing and the spindle can rotate relative to each other. The SMA memory alloy wire 4 contracts after power is turned on. Since the other end of the SMA memory alloy wire 4 is fixed on the second wiring board 22, so the contraction of the SMA memory alloy wire 4 will drive the rotating ear 33 connected to one end of the SMA memory alloy wire 4 to move, and the rotating ear 33 makes a circular motion in the sliding groove 24 along the plane where the sliding groove 24 sits, and the rotating ear 33 drives the rotating wheel 31 to rotate, and the rotating wheel 31 drives the one-way bearing 32 to rotate, and the one-way bearing 32 drives the main shaft 13 to rotate together, that is, the rotating ear 33, the rotating wheel 31, the one-way bearing 32, and the main shaft 13 rotate together as a whole, and the main shaft 13 drives the gear 14 to rotate, and the contraction length of the SMA memory alloy wire 4 can be adjusted by the size of the current, so that the rotation angle of the main shaft 13 can be accurately adjusted. After the control system 26 gives a power-off signal, no current flows through the cable 25, and the SMA memory alloy wire 4 stretches to restore to its normal length. Since the rotating lug 33 and the terminal 23 are connected by the elastic wire 34, the elastic wire 34 is in a stretched state at this time, and the elastic wire 34 pulls the rotating lug 33 in the opposite direction, and the rotating lug 33 drives the rotating wheel 31 to rotate. Since the rotating wheel 31 and the main shaft 13 are connected by the one-way bearing 32, the rotating lug 33 and the rotating wheel 31 will rotate together, while the main shaft 13 does not rotate, that is, the one-way bearing 32 rotates idly. When the rotating wheel 31 returns to the initial position under the elastic force of the rotating lug 33, the control system 26 loads current to the SMA memory alloy wire 4 again to shrink the SMA memory alloy wire 4, and the rotating wheel 31, the one-way bearing 32, and the rotating shaft rotate as a whole, and the cycle motion is repeated to realize the operation of the motor.

[0035] The present invention designs a drive unit array, wherein the control system is connected to the drive unit array, wherein each drive unit comprises a rotating wheel, a main shaft, a winding frame, and an SMA memory alloy wire, wherein the rotating wheel is mounted on the winding frame, and the SMA memory alloy wire is wound on the winding frame, wherein when the SMA memory alloy wire is powered on, the SMA memory alloy wire contracts, causing the rotating wheel to rotate, thereby driving the main shaft to rotate; after power is cut off, the SMA memory alloy wire stretches, and the rotating wheel rotates in the opposite direction and returns to the initial position, thereby realizing the operation of the motor. Taking the configuration of an array of 9 drive units as an example, each drive unit corresponds to each rotating wheel, which can realize It can realize 1 to 9 times of torque and speed adjustment. Of course, it can also be set to 3, four, five, etc., so as to greatly improve the output torque. Since it takes a certain amount of time for the SMA memory alloy wire to cool down, when the SMA memory alloy wire is powered on and heated in turn, the cooling time coincides with the heating time. The time is reduced, the SMA memory alloy wire shrinks due to heat, and the superposition of the contraction of multiple SMA memory alloy wires will increase the speed of the motor, which can greatly improve the speed of the spindle and make the spindle rotate to a certain angle in the shortest time. At the same time, the angle of rotation of this SMA memory alloy wire is precisely controlled, which not only embodies the requirements of speed but also accuracy.

[0036] The present invention has the following advantages:

[0037] 1. Through the control system's effect on the drive unit array, multiple drive units can work together to greatly improve the output torque. Multiple drive wheels rotate at the same time, which can greatly improve the output torque.

[0038] 2. The sequential movement of the drive unit array can be realized by controlling the drive unit array through the control system. Since the cooling of the SMA memory alloy wire requires a certain amount of time, when the SMA memory alloy wire is powered on and heated in sequence, the cooling time coincides with the heating time. When the time is reduced, the speed of the motor will increase, which can greatly improve the speed of the spindle and make the spindle rotate to a certain angle in the shortest time. At the same time, the angle of rotation of the SMA memory alloy wire is precisely controlled, which reflects the requirements of speed and accuracy at the same time.

[0039] 3. The SMA motor of the present invention is controlled by a control system, and can start the drive unit in a variety of combinations and sequences according to scene requirements, or obtain a variety of motor speeds and torques by means of current changes and the like.

[0040] 4. The present invention designs an integral insulating, high temperature resistant, high lubricity plastic winding frame, which greatly reduces friction during movement.

[0041] 5. The present invention designs elastic wires to increase the service life of wire connections, utilizes the resistance-temperature-contraction characteristics, and utilizes the resistance characteristics to establish negative feedback of motor speed, adjust the motor speed, and facilitate precise control

[0042] 6. The present invention utilizes speed negative feedback, detects load changes, designs a dynamic control program, adjusts the number, timing and current value of driving wheel starts, and realizes an ideal load-speed curve.

[0043] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A variable speed and variable torque SMA motor, characterized in that: include: - control system; A drive unit array, wherein the drive unit array is connected to the control system via an SMA memory alloy wire, wherein when the SMA memory alloy wire is energized, the SMA memory alloy wire contracts, and the drive unit array drives the power output device to move; after power failure, the SMA memory alloy wire extends, and the power output device rotates in the opposite direction and returns to an initial position; each of the drive units is an independent module, and the drive unit includes a drive wheel, a winding frame, an SMA memory alloy wire, a one-way bearing, a rotating lug, and an elastic wire, and the power output device is a main shaft, and the main shaft is arranged in the one-way bearing, The one-way bearing is arranged in the driving wheel, the driving wheel is installed in the winding frame, and the SMA memory alloy wire is wound on the winding frame, wherein when the SMA memory alloy wire is powered on, the SMA memory alloy wire shrinks due to heat and drives the driving wheel and the one-way bearing to rotate, and the one-way bearing drives the main shaft to rotate; when the SMA memory alloy wire is powered off, the SMA memory alloy wire cools and stretches, and the elastic wire drives the driving wheel to rotate in the opposite direction, and the driving wheel returns to the initial position; the variable speed and variable torque SMA motor also includes a shell, in which the main shaft is installed, one end of the main shaft is used to install a gear, the main shaft and An electromagnetic brake is arranged between the shells, at least one groove is arranged on the outer side of the winding frame, and the SMA memory alloy wire is installed in the groove; a winding frame is installed in the shell, the winding frame is coaxially arranged with the main shaft, a first terminal board and a second terminal board are arranged on the winding frame, a plurality of terminal posts are arranged on the first terminal board, a plurality of sliding grooves are arranged on the side wall of the winding frame, and each terminal post corresponds to each sliding groove; the first terminal board and the second terminal board are both fixed to the outer side of the winding frame, the first terminal board is located next to the sliding groove, and the first terminal board and the second terminal board are arranged on the outer side of the winding frame. The wire boards are arranged relatively to each other; wherein, a rotating wheel is installed in the winding frame, the rotating wheel includes a driving wheel and a one-way bearing installed in the driving wheel, the one-way bearing is fixed to the main shaft, a rotating ear is arranged on the outer side of the driving wheel, the rotating ear is located in the sliding groove, the rotating ear and the terminal are connected by an elastic wire, the SMA memory alloy wire is a special wire that shrinks when powered, the SMA memory alloy wire is wound on the winding frame, one end of the alloy wire is fixed to the rotating ear, and the other end of the SMA memory alloy wire is fixed to the second terminal board.

2. A variable speed and variable torque SMA motor as claimed in claim 1, characterized in that: The number of the driving units can be 2, 3, 4 or more as required.

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