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Until recently, U.S. government efforts to dramatically reduce emissions, greenhouse gases and vehicle fuel consumption have primarily focused on passenger car applications. Similar aggressive reductions need to be extended to heavy vehicles such as delivery trucks, buses, and motorhomes. However, the wide range of torques, speeds, and powers that such vehicles must operate under makes it difficult for any current powertrain system to provide the desired improvements in emissions and fuel economy. Hybrid electric powertrains provide the most promising, near-term technology that can satisfy these requirements. This paper highlights the configuration and benefits of a hybrid electric powertrain capable of operating in either a parallel or series mode. It describes the hybrid electric components in the system, including the electric motors, power electronics and batteries.

Usage of CVTs in automotive applications has begun to increase, however because of their relative newness and previous usage in nonautomotive applications, a broad base of technical information on the various types of CVT's does not exist. Most importantly though, no comparison information exists on the different types of configurations. Currently, there are a number of CVT technologies that have been used in automotive, off-road and industrial applications. This paper will highlight the characteristics, design limitations and efficiencies of the following basic CVT types: