Economic hybrid transmission system using clutchless geared manual transmission

Abstract

In this study, we are proposing a hybrid car of new concept promising the most economic and fuel efficient one. The architecture is derived from the conventional manual transmission with little modification by replacing the clutch with the one-way clutch and a motor-generator is placed between the one-way clutch and the gearbox. Another addition is the motion detector of the gear-shift lever that the vehicle may recognize which gear step is intended to engage by the driver. The advantages of the this new hybrid vehicle compared to other hybrid vehicles are as follows. Firstly, the drivetrain is composed of the most economic components in simplest way just by serially attaching a motor-generator to the conventional manual transmission. Secondly, the drivetrain consumes minimum amount of energy as it doesn't requires any additional actuator to control in addition to its light weight as well as the efficiency of the manual transmission. Thirdly, as the conventional clutch is eliminated and the motor-generator is assisting the gear synchronization, the operation of the gear shift is almost as easy as the automatic transmission. Fourthly, as the gear shift is performed by the driver, the driver may avoid the situation of the unwanted gear shift which may happen in the automated manual transmission. Additionally, the gear shift process takes half the time required by the automated manual transmission as there is no clutch. A prototype of the hybrid drivetrain named as the clutchless geared manual transmission (CGMT) is adopted to a small vehicle (Chevrolet Damas, 796cc, 5 speed manual transmission) adding a 7KW electric motor-generator in series. The vehicle is designed such that it may run only by the motor-generator when the vehicle speed is less than 40 kph with the engine being shut-off. Some test results will be presented.