Study of resistance of components of the electric starter system of automotive and tractor engines aimed to selection of their optimal ratios

BACKGROUND: Regardless design advance of any vehicle or tractor, it cannot be ready for operation unless its power unit (mainly powerful diesel engine) is started by rotating the crankshaft with a rotation velocity no less than the minimal starting rotation velocity and overcoming rotation resistance. For this purpose, various starter systems, mostly electric starters, are used. Ensuring the working process of the electric starter system (ESS) of automotive and tractor engines, particular laws relate parameters and indicators of a battery, a starter circuit and a starter with each other. This paper covers the study of the main structural parameter: internal resistance of the ESS components, which affects on selection of nominal parameters of a battery and a starter.

AIM: Analysis of parameters and indicators of a battery and a starter in the conditions of low temperature engine start, having a significant influence of their internal resistance, ratio of which affects on weight, size and economic indicators of the main components of the electric starter system.

METHODS: This study is a part of the whole methodology of design of electric starter systems of automotive and tractor internal combustion engines, based on the synthesis of fundamental laws of electromagnetic induction; the second Kirchhoff’s law and the scaling theory using the system of relative values.

RESULTS: Considering the fact that expensive strategic materials, such as lead and copper, which resources are limited in the world, are used in manufacturing of batteries and starters, the right selection of their parameters during the design process allows minimizing weight, size and cost of the ESS components. For solving this problem, the graphical method of defining of resistance ratio between a battery and a starter in the ESS using the Gibbs triangle system, which is significantly easier and clearly evident for performing calculations, is proposed in the paper.

CONCLUSION: The problem of analytical definition of main parameters of the electric starter system of automotive and tractor engines in the worldwide experience of automotive and tractor engineering is still unsolved due to absence of mathematical apparatus of recalculation of the starter parameters at the working point to the nominal conditions. The algorithm of solving this problem in the part of definition of main structural parameters, which are resistance of a battery and a starter at their combined operation in this system, to minimize lead and copper consumption during their manufacturing is given in this paper.