Research On Continuously Variable Transmission With Double Variable Diameter Pulley And Planetary Composite Drive

Continuously variable transmission is used in special cases,it requires the output speed can be in the specified range of continuous and stable change,so as to achieve the transmission speed and power balance,achieve the reduction of energy consumption.At present,the common vehicle stepless transmission device is to control the transmission ratio of the CVT,so as to achieve the purpose of speed change.But it can achieve a small range of transmission and driving power,in the need of high power transmission is obviously powerless.Therefore,the paper discusses the high efficiency,high power and long span transmission ratio CVT.Through combination innovation,a new type of CVT with double reducer belt wheel and planetary compound drive is proposed.Its main structure is composed of double reducer belt wheel drive mechanism,parallel planetary differential gear drive mechanism and synchronous differential drive mechanism.First of all,the double reducer pulley drive mechanism is different from the traditional point and line contact friction transmission form,it uses the surface contact friction transmission form,increases the friction of the contact surface,can drive more torque,because the use of the symmetrical structure principle of the double cone disk,can effectively reduce the load borne by the stepless speed regulating mechanism;Secondly,through the planetary differential gear transmission mechanism,the power convolution can be realized and the power convolution ratio can be adjusted to realize the high-power transmission.Finally,the transmission ratio span of the output can be expanded through the synchronous differential.Thus,a new type of CVT with large transmission ratio span,large transmission power and high transmission efficiency is obtained.Firstly,the paper puts forward the transmission structure design idea and working principle of the new CVT,determines its structural parameter data according to the overall design requirements,and uses the three-dimensional modeling software to design the three-dimensional model of the transmission device of the new CVT.After the parts are matched into the assembly,the interference analysis is carried out to check the accuracy of the assembly.Then through the finite element analysis to determine the rationality of parts selection,verify the feasibility of the new CVT design idea.Secondly,the corresponding mathematical model of motion is established,and the transmission characteristics of the CVT at all levels are analyzed theoretically,which shows that the speed regulation mechanism and the total transmission ratio span have the same direction change relationship,and the power transmission path of the new transmission is analyzed,and an efficient power transmission path is obtained.The transmission principle and power distribution characteristics are qualitatively verified by Matlab.Finally,ADAMS software was used to simulate its speed,torque and power under different working conditions,analyze the speed characteristic curves and stress characteristic curves of each structure,and carry out motion simulation on the speed of the output shaft,so as to obtain the range of the output speed,so as to judge the transmission ratio span.By setting up the experimental device and conducting the operation test of the continuously variable speed structure,Adopt PLC to PID control mode,collect experimental device experimental data,experimental data and theoretical data comparative analysis,verify the feasibility of the design scheme.In this paper,the method of mathematical modeling and theoretical simulation is used to verify that the designed double variable wheel and planetary compound transmission continuously variable transmission can achieve high power,high efficiency and long span transmission ratio stable transmission,which lays a theoretical and technical foundation for further research and development of this new transmission.