Date of Graduation


Document Type


Degree Type



Statler College of Engineering and Mineral Resources


Mechanical and Aerospace Engineering

Committee Chair

Chris M. Atkinson.


Near term Hybrid Electric Vehicles (HEVs) generally employ current automotive transmissions. These automatic and manual transmissions are based on designs that are many years old. These older transmission designs do not allow multiple power inputs/outputs to be connected to the transmission. These types of designs significantly limit the flexibility in terms of overall function and component packaging for hybrid vehicles. This study was conducted to determine the feasibility of creating a transmission for hybrid vehicle applications with multiple power inputs/outputs.;The Torque and Speed Control Transmission (TSCT) is a combination of a planetary geartrain and a Continuously Variable Transmission (CVT). By combining these two types of power transmission devices, a new transmission is created that has much greater flexibility. This combination of a planetary geartrain with a CVT allows for a power split operation under certain conditions. This type of operation is beneficial as it allows for the power through the CVT to be varied independently of engine power and vehicle speed.;The TSCT was studied to determine the most beneficial mechanical layout of components. Six possible drivetrain layouts were analyzed. A final drivetrain configuration was chosen that allows six distinct modes of operation. This configuration was chosen for correct component rotations throughout all modes and ease of control. A common shaft from the engine is connected to both the CVT input and the sun gear of the planetary geartrain. A high power electric motor is attached to the planetary carrier and the output from the CVT is connected to the ring gear and a high power alternator. Vehicle propulsive power is extracted from a geared connection to the ring gear. This mechanical layout allows for Convention Vehicle, Electric Vehicle, Series HEV, Geared Neutral, and two Parallel HEV modes.