POTENTIALITIES OF A LIGHT THREE-WHEELED VEHICLE FOR SUSTAINABLE MOBILITY

Electric and hybrid vehicles with narrow track are very suited to sustainable urban mobility. A particular tilting three wheeled vehicle has been developed at Padova University. It is composed of a tilting front module (one wheel) and a non-tilting rear module (two wheels). The lower part of the front module is connected to the upper part of the rear module by means of four revolute joints and two rockers. Therefore, the two modules of the vehicle and the two rockers make a four-bar linkage. A specific code for kinematic, dynamic and electric analysis of this vehicle has been developed, with the aim of showing the effects of linkage set-up and mass distribution on the handling and stability characteristics. Some numerical results are presented. This particular three-wheeled vehicle is well suited both to advanced electric and hybrid propulsion systems. A section of this paper shows the characteristics of an electric version for fast urban mobility, that is named E-Snake. The performances of E-Snake were assessed by means of many road tests and were confirmed when it participated in Formula Electric and Hybrid Italy: in 2008 E-Snake was the winner of its category. The last section of the paper deals with Hy-Snake, a new version of the three wheeled vehicle for sustainable urban and sub-urban mobility. The principal feature of Hy-Snake is the series hybrid propulsion system. Some numerical results show the effectiveness of the integration between mechanical and electrical design. The propulsion system gives good performances and a proper set-up of the four-bar linkage makes the vehicle stable and easy to ride.