Design And Analysis Of Spring Energy Storage Power Generation System

The waste batteries in electric bicycles have great threat to the environment.Using the combination of the energy storage spring and the generator to the electric bicycles will largely eliminate the environmental pollution of the waste batteries.In the paper,a spring energy storage power generation system applied to the electric bicycles 1s designed,and its energy comes from the energy loading system and the braking energy recovery.The detailed structural designs of the braking energy recovery system,energy loading system,energy storage system,speed adjustment system and transmission system are carried out.The crank rocker mechanism without quick return characteristic is adopted in the energy loading system because of its uniform speed,small space size and high transmission efficiency.The characteristics of energy flow in the transmission-speed control system of the spring energy storage power generation system are analyzed.The power is used to characterize the instantaneous value of the energy.The theoretical energy transmission models of the transmission-speed control system and the whole system are established.The energy storage spring in the system is designed and analyzed in detail.Three kinds of springs(the single torsion springs the combined torsion spring and the plane scroll spring)are designed and studied,the results show that,with the same spring diameter and working circle number,the plane scroll spring has the smallest mass and radial dimension,high energy storage density,and easy installation.The position and stress distributions of the spring strips during the tightening process are analyzed,the whole stress variation law and the maximum stress distribution law in the stress concentration region of each layer when it is completely tightened are obtained.Based on the analysis results,the design and simulation analysis of the joint structure at the outer end of the plane scroll spring are earried out,the results show that,the connecting way with the fixed reverse elbow can reduce the maximum stress at the joint.The influences of the spring material properties and its cross section shape on the energy storage density are studied.The results show that,spring steel is more reasonable as the spring material,the energy storage density of I—section is the highest with the same cross section thicknessThe transmission efficiency of the speed up gear transmission system is studied.Considering the influence of the load uneven distribution during the gear meshing,the theoretical model of the minimum oil film thickness for speed up gear transmission system is established,and the change law of the minimum oil film thickness with the position of the point is obtained.Based on the film thickness ratio,the lubrication state of the transmission system is determined as the boundary lubrication state.A theoretical model for the meshing efficiency of the speed up gear transmission system is established.The influence of factors(transmission ratio,friction coefficient,pressure angle,teeth number of the drive gear and center distance)on the meshing efficiency is analyzed with MATLAB.The speed up gear model is established with ABAQUS,and the distribution laws of the contact stress along the direction of the gear surface and the Mises equivalent stress of the driven gear are studied in the meshing process.The theoretical model of the bearing friction power loss is established.Based on the above research results,the theoretical model of the total transmission efficiency of the speed up gear transmission system is established.The prototype of the spring energy storage power generation system is made,and the relationship between the output voltage and the time is obtained through the prototype experiment.The experimental results show that the prototype's performance is stable.which verifies the rationality of the design of the spring energy storage power generation system.