Search Results

Due to their harsh operating environments, military vehicle drive trains have special requirements. These special requirements are usually represented by hill climbing ability, obstacle negotiation, battlefield cross country travel, hard acceleration, high speed, etc. These special requirements need the vehicle drive train to have a wider torque and speed range characteristics than commercial vehicles. We have proved that larger constant power ratio in electric motor can significantly enhance the vehicle acceleration performance. In other words, for the same acceleration performance, large constant power ratio can minimize the power rating of the traction motor drive, thus minimizing the power rating of the power source (batteries for instance). Actually, extension of the constant power range can also significantly enhance the gradeability, which is crucial for military vehicles.

An electromechanical gear is presented along with design examples utilizing the electromechanical gear in hybrid electric vehicle drive trains. The designs feature the electromechanical gear (the Transmotor) in place of traditional mechanical transmissions and/or gearing mechanisms. The transmotor is an electric motor suspended by its shafts, in which both the stator and the rotor are allowed to rotate freely. The motor thus can provide positive or negative rotational energy to its shafts by either consuming or generating electrical energy. A design example is included in which the transmotor is installed on the output shaft of an internal combustion engine. In this arrangement the transmotor can either increase or decrease shaft speed by applying or generating electrical power, allowing the ICE to operate with a constant speed.