Study and Design of an Electric Self Propelled Feed Mixer

摘要

In the last years, the growing demand for more efficient vehicles has become a very discussed topic in the scientific and industrial community. Several regulations define the amount of pollutant emissions allowed for a vehicle depending on the power rating of its Internal Combustion Engine (ICE) and on the type of fuel used (Gasoline or Diesel). These regulations are defined both for automotive and industrial vehicles, describing also standard procedures for their evaluation. The case of industrial off road vehicles, also called Non Road Mobile Machineries (NRMMs), is a very particular one. Below this designation are included: 1. green maintenance machines; 2. loading and handling machines; 3. construction machines; 4. agricultural and farming machines; 5. rail vehicles and ferries for inland navigation. It is clear that the same requirements applied on the power unit for the NRMM group will have different impact depending on the specific field of application of the considered industrial vehicle. In order to meet these regulations, industrial manufacturers use special after treatment systems for exhaust gas in order to manage the amount of carbon monoxide (CO), unburnt hydrocarbons (HC), several types of nitrogen oxides (NOx) and carbon based particulate matter (measured as PM - particulate matter or PN - Particles number). The higher pollutant emissions reduction required by the most recent regulations is only possible after treatment systems way bigger than few years ago. The bigger these systems are the higher is the effort from the manufacturer point of view to integrate them on the final vehicle. This highly demanding task is pushing several companies towards the evaluation of alternative solutions. The most clever solution is to increase the overall efficiency of their machines leading to lower pollutant emissions. To achieve this goal, new powertrain solutions are explored in order to find the best efficient way to deliver power to the driveline and to the hydraulic tools. In this direction, well designed electrified architectures can play a big role in the process of pollutant emissions reduction because of the higher efficiency of their components and also because they allow more flexibility in the design stage. The object of this study can be located within this framework. The industrial vehicle considered was a self propelled vertical feed mixer, usually equipped with high power diesel engines. Studying the working cycle of this type of machines, it was possible to define the main system requirements for an alternative electrified architecture optimized for the specific field of application. Performance of several feasible architecture layout were compared in order to find the most efficient and cost effective solution able to meet those requirements. The result of this study was the design of a full electric version of the traditional machine in collaboration with the Italian manufacturer Supertino (Figure 1 -removed).