Analysis Of Gear Motor Integrated With Shape Memory Alloy

The movable teeth driven actuators integrated with shape memory alloy have advantages that simple structure,high power density and carrying capacity.The actuators are suitable for aerospace and special robots areas where the compact structures are required.In this paper,a movable tooth driven reducer motor integrated with shape memory alloy is proposed.It combines the principles of shape memory alloy driving and movable teeth driving transmission to realize the output at a low speed and a high torque.For the motor,the structural design,analyzing working principle and the output characteristics,optimizing the moving trajectory of the wave generator are completed.In this paper,a new configuration of the reducer motor is proposed based on the principles of shape memory alloy driving and movable teeth transmission.The structure of the motor is simple,and more convenient to realize lightweight and dexterity.The shape memory alloy wires are wound around the insulative and plastic coat is used for wave genetor,it increases the length of the wires and realizes the given eccentric motion.In this paper,the equation of constitutive relation about phase transition and reverse phase transition of shape memory alloy is introduced.Based on the constitutive relation,the working principle of the motor is analyzed.The heat conduction equation is given to study the temperature rise of shape memory alloy wire and its distribution.Based on the electrical signal,the stress and strain of the shape memory alloy wire in the working process is calculated and the working parameters of the motor are optimized.The equation of shape memory alloy in the resistivity changes,the equation of moving trajectory of the wave generator,the equation of the energy loss are given.The energy loss in working progress is analyzed.The force equations in drive parts and the equation of the output torque are deduced,and the stress and the output torque are studied.Changes of the stress and output torque with transmission parameters are analyzed.The output performance of the motor is given.The optimization of the tooth profile for the center wheel is completed,and the backlash in transmission is analyzed.The continuous working conditions of the transmission part are given.The parameters of the compression spring are determined.The parameter design of the motor prototype is done.The speed of the prototype reached 1.2r/min,and the error between measured and calculated speed was 6.67%.It verifies analysis of the theory in this paper.