摘要: |
Traditional cone clutch synchronizer which is mostly used in vehicle uses friction to implement synchronization to accomplish gearshift.That leads to some disadvantages.In this paper a new mechanism concept named Harpoon-shift is proposed.It is designed as an alternative to the traditional synchronizer in automatic transmission.Harpoon-shift has simpler structure to manufacture than the traditional synchronizer.Additionally,a simpler electromotor control system is used to replace complex hydraulic system to change gears during shifting.Harpoon-shift will offers potential energy economy improvements by improved drivetrain efficiency and better vehicle ac celeration ability.Firstly the mechanical structure of Harpoon-shift is showed as virtual mechanical model designed by ProE.It has 5 main components including one idler gear with integral groove ring,one guide ring,one flexible component between the guide ring and the groove ring,one Harpoon-shift hub one Harpoon shift sleeve.Harpoon-shift makes use of an indirect engagement,which gives a pre-acceleration to the chosen gear to realize the smooth gearshift.The mathematic modeling,simulation and analysis of the new mechanism concept are presented in this paper as a separated part from gearbox.According to that the components of Harpoon shift are on the same shaft and the main motion is rotation.the modeling is built with one DOF.Mechanism engagement is demonstrated in rigid body models with detailed interactional torque models considering the geometrical limitation.to establish its variation over its process.The parameters e.g.mass,stiffness.angles of engagement are variable in simulation model.The parameter studying makes contributions to comparisons and optimization of Harpoon-shift structure.Then an optimized structure is chosen for comparison of torque interrupt with traditional synchronizer.which shows significant advantage of the new concept. |