Research On A Chuck-type Adjustable Diameter CVT

The continuously variable transmission can realize the continuous change of the output speed in a certain range under the condition of constant input speed,so as to meet the requirements of various working conditions of equipment or production system in the operation process.At present,most of the mechanical CVT is driven by friction.According to the difference of contact form,it can be divided into point contact type and line contact type.Because of the small contact area between transmission components,the point-contact type and line-contact type CVT can not bear large positive pressure,so the mechanical CVT mainly has the disadvantages of small transmission torque and low transmission efficiency,which limits its application in many machinery.Therefore,it is of great significance to develop a new surface-contact type CVT,which can realize the transmission of high torque and high efficiencyThis paper proposes a new type of chuck-type adjustable diameter CVT.The new CVT uses the belt transmission mode of the combination of chuck-type adjustable diameter pulley and multi wedge belt in the transmission to realize the surface-contact type friction transmission of the pulley and the transmission belt.Firstly,the paper introduces the design idea of the new CVT and gives its overall structure.According to the design requirements,the relevant dimension parameters of the new CVT are analyzed and calculated,and its three-dimensional model is established by SolidWorks software.Through the assembly analysis and interference check to ensure the correctness of the model and the feasibility of the design scheme.Then,combined with the structural characteristics of the chuck-type adjustable diameter pulley and the classical calculation formula of the effective circumferential force,the calculation formula of the effective circumferential force of the chuck-type adjustable diameter pulley drive is derived.The variation law of the maximum effective circumferential force of the chuck-type adjustable diameter pulley is analyzed,and the driving ability of the chuck-type adjustable diameter pulley with high torque is verified.The force analysis of the most critical and weak parts in the power transmission process of the chuck-type adjustable diameter CVT shows that their performance and structure meet the requirements of high torque transmission.Based on ADAMS,the virtual prototype model of the chuck-type adjustable diameter CVT is established,and the dynamic simulation of the CVT under various working conditions is carried out.The transmission ratio error rate,transmission efficiency and speed fluctuation are analyzed.The results show that the new CVT has good speed ratio transmission effect,high efficiency of power transmission and transmission stability.Moreover,PID control method based on PLC is used to design the speed control system of the chuck-type adjustable diameter CVT.Finally,the physical prototype of the chuck-type adjustable diameter CVT is trial manufactured,and the experiment of transmission ratio error and speed fluctuation is carried out.The test results also show that the new CVT has good transmission effect of speed ratio and can realize stable transmission.The method of theoretical simulation and experimental analysis is applied in this paper.It is proved that the new surface-contact type CVT can realize the stable transmission with high torque and high efficiency.It lays the foundation for the research and development of a new type of CVT with high torque and high efficiency.