Design And Analysis Of Traction Reducer In Hub Motor For Electric Scooter

With the rapidly increase of the aging population of the world and the demand toimprove the life quality of the elderly. To develop a suitable electric scooter for theelderly which can be used both at home and outside of home, will processes a greatsocial significance and market prospect. The hub motor is the driving part of electricscooter, and also is a key component of it. The aim of this paper is to design a costeffective electric scooter with tighter structure, smaller vibration noise and higher safety.Through compare and analysis and combined with the character requirements of the hubmotor, planet traction reducer was selected as the reducer of the hub motor. Theoreticalanalysis and finite element method had been made to deeply study the problems of theloading of the pressing force, the choosing of traction oil and the contact strengthanalyzation in traction mechanism. The mainly contents of this paper are shown asbelow:①+9According to the basic structure and working theory of the electric scooterand hub motor, through the comparison and analyzation the advantages anddisadvantages of different electric motor reducer, and combined with the characters andrequirements of the hub motor of the electric scooter, planet traction reducer has beenselected as the hub motor reducer. And based on constrains of the reduction ratio andhub shell structure, a primary design of the planet traction reducer structure has beenmade.②In order to loading appropriate pressing force for traction transmission vice ofplanetary traction reducer，comparative analysis of different pressing force loadingmethods have been made. And finally, a hollow elastic planetary wheel structure hasbeen selected, and pressing force that need in traction transmission vice can be obtainedthrough the bent deformation of the planetary wheel. Planetary wheel has been createdin finite element software ANSYS Workbench, and the relation between wall thicknessof the planetary wheel and radial deflection in pressing force direction has beensimulated and analyzed, and the optimum wall thickness was obtained. Dynamicsimulation of the hollow elastic planetary wheel had been made in order to verify itsreliability. Finally, specific structure of the planetary wheel was obtained.③In order to design and choose suitable traction oil for traction reducer, theoryanalysis of traction transmission and elastic fluid dynamic lubrication had been made. Fluid dynamic theory has been used to analyze the rheological behavior of the tractionoil. Then a suitable traction oil has been selected for planetary traction reducer, and theoptimum thickness of the oil film and the film thickness ratio has been analyzed,according to the characters of different traction oil.④To prevent the advent of abrading and fatigue pitting in traction transmissionvice, the contacts in planetary traction reducer has been studied. Planetary tractionreducer model was created in three-dimension software, and then was imported toANSYS Workbench. Refining dispose of the contact region grid has been made bydifferent grid meshing methods, the magnitude and distribution of the contact regionstress had been obtained, and the strength of the planetary traction reducer has beenverified.