Establishing relationships between fuel economy and gear ratios of bus transmission units

Abstract

The engineers of the GAZ Group developed the GAZ Vector Next 10 family of buses on the basis of the GAZon Next 10 truck. The parameters of the engine, transmission units and wheels of the new family of buses undergone significant changes, which inevitably affected their fuel economy. In this regard, the objectives of this work were formulated as the development of a methodology for determining the fuel economy of a bus and establishing relationships between these indicators and the gear ratios of transmission units. The base model of a family of buses designed for intercity passenger transportation was selected as the object of study. To assess the fuel economy of the bus, single indicators were selected: fuel consumption at given speeds and operating fuel consumption at operating speed. These indicators are determined by the graphs of the fuel and economic characteristics of the bus. The article sets out the methods for constructing the named graphs and determining the indicators of the fuel economy of the bus. The effect on the fuel consumption at given speeds of 60 and 80 km / h of gear ratios of the highest stage of five - and six-speed gearboxes and final drive with gear ratios of 3.9 and 4.55 is established. The gear ratios of the gearbox and final drive at which the bus consumes the largest and least amount of fuel per 100 km of track are determined. It is shown that a change in the gear ratios of the transmission units does not significantly affect the operational fuel consumption of the bus. The results of studies performed by the authors of the article can be used by the developer to optimize the gear ratios of the modernized GAZ family of buses Vector Next 10.