cibsfrcict;A new motor ; Anti-Directional-Twin-Rotary Motor ( ADTRmotor for abbreviation) for an electric vehicle drive is proposed. A stator in a conventional motor is reformed to be movable, and the stator ( outer rotor) rotate in the anti-direction of the inner rotor. Several types of ADTR-motor exit, such as induction motor and synchronous motor types. tn this paper an induction motor type ADTR-motor was experimentally constructed. When ADTR-motor is used for an electrical vehicle, the direction of one of the rotors should be reversed, and both rotors rotate in the same direction, and pi-ope1 the two wheels of electrical vehicles. The torque of wheels cm he balanced without ;I differential gear.The fundamental characteristics of ADTR-motor are clarified, which are the structure, the elect rical cquivalent circuit parameters, the torque balance theory, the torque-speed characteristics, and the transient torque response under the speed sensor-less torque control. 1 .O Introduction An electric vehicle ( EV for abbreviation) is nowadays one of the solutions for zero emission vehicles. The various types of powertrain for EV are proposed, as illustrated in Fig. I , in which (a)is the conventional powertrain with a gear box and a differential gear by which thc torque of the two wheels is balanced [8]. An internal coriihust ion engine is simply replaced with an electrical motor, however the energy loss through the gear box and differential gear is not negligible. Fig. 1 (h) is the two motor drive with reduction gears through constant velocity joints[ I]. I n this scheme two pairs of motor-inverter are required, and a loss exits at the gears and constant speed joint. And the cquivalent motor inertia becomes very large if thc gear ratio is too high. which, in turns, degrades the acceleration performance. Fig. I (c) is the four-wheel-in motor drive [ 2 ] . in which each motor torque is controlled independently. No loss exits through the powertrain, however four pairs of motorinverter are required, and the under-spring-mass is not negligible due to four iiiotors. Fig. I (d) is the proposed ADTK-motor drive.13.41 AI)TK-iiiotor has two rotors, one of which is a rotor (inner rotor) in the conventional motor. and the other of which i s a stator ( outer rotor) in the conventional motor. Thus both rotors rotate in thc anti-directions. Several motor are considerable for ADTR structure, tor exarnple. induction motor, brushless dc motor and so on. In this paper a prototype of an induction motor type ADTRriiotor is introduced. Whcn an ADTR-motor drive is employed for EV powei-train. one of the rotor direction i s reversed by reversing gear. and hotti wheel shafts rotate i n the same direction. Then, the AIYI'R-niolor drive propels the two wheels of EV without differential Fwr. ;rnd the torque of the both wheels are automatically balanced, as proved Iatcr. Only onc pair of motor-inverter is required for this scheme.The advantages and disadvantages of the above four kinds of powertrain should be evaluated mainly by ( I ) acceleratio...