Graph-Based Algorithm for the Evaluation of the Mechanical Efficiency of Epicyclic Gear Drive in Hybrid Scooters

Abstract

Efficiency in transportation of goods and people are crucial objectives for the sustainability of society and the protection of its environment. In the particular case of urban mobility, the current trend is toward the applications of hybrid propulsion, if not purely electric. The growing dimensions of urban areas suggest that a particular attention needs to be addressed to vehicles’ energy requirements, air quality and noise pollution. Hybrid technology satisfies the needs of small engines, with low emissions and high energy-efficiency. Therefore, for efficient power management of small internal combustion engines and electric sources, reduced costs and energy efficient gear transmission systems are required. A scheme of hybrid gear transmission, proposed by Sheu, with the aim of minimizing the emissions and fuel consumption, will be herein analysed to estimate the overall mechanical efficiency. In particular, we will discuss an application of a methodology based on graph theory for a systematic and unified analysis of the gear train mechanical efficiency, in all six driving modes. The phases of the proposed analysis are summarized in Table 1.

Table 1 Phases of the proposed mechanical efficiency analysis procedure