A NEW COMBINED TYPE OF HEV’S MULTI-ENERGY-SOURCE POWERTRAINS WITH COMPOSITE CVT

摘要

To remedy imperfection of the existent combined type of powertrains, a new HEV powertrain with composite CVT systems or CCVTs, featuring divergent and dualmode convergent power flow fore and aft, is put forward and studied. The planetary gear set of 2-DOF is replaced by CCVTs which utilizes a stepwise multi-ratio automatic gearshifter to engage alternately output shafts of the planetary assembly, in an instantaneous but smooth manner, forwarding their mechanical power and motion to output shaft with different gear ratios, so as to produce the effect of “both speed and toque variable” in a desired large range and to increase power-transmittability, efficiency. On the basis of its working principles and feasible methodology, 36 alternative topologies of the dual-mode planetary gearsets have been comparatively analyzed in detail, and the few topologies suitable for HEV applications has been finally chosen and recommended. With specific powertrain as detailed example, working principle of such new mechatronic assemblies is detailedly analyzed, general and key points for its design and realization are also discussed, its technical features and applied perspective are thus initially revealed. Its possible operation modes and corresponding operative conditions are also discussed.