Selected issues of hydropneumatic suspension design for a high-speed tracked vehicle.

The effective operation of high-speed tracked vehicles in a combat vehicle configuration depends primarily on the correct identification of the expected operating conditions, already in the design or modernisation phase. This applies to both terrain, meteorological and climatic conditions. This approach considers the most unfavourable driving conditions and the level of dynamic loads acting on the vehicle hull, crew and equipment when making calculations. The dominant source of dynamic loads is movement at high speed on unpaved roads, off-road and when overcoming natural and artificial terrain obstacles of a predetermined or random nature. An important system responsible for the safety and reliability of this type of vehicle is the suspension. An appropriate design of the suspension parameters allows to reduce the negative dynamic loads (research hypothesis). The aim of the research was to develop a preliminary project of an initial suspension element – a hydropneumatic spring for a high-speed tracked vehicle - that allows minimising dynamic loads. The study used both theoretical and empirical research methods, including analysis, synthesis, deduction, induction, comparison and inference. The paper presents selected issues from the suspension design process for a high-speed tracked vehicle equipped with a hydropneumatic suspension. The problem was solved in three stages. In the first stage, the design of the hydropneumatic suspension unit, placed in the control arm, was made and the basic parameters were selected. In the second, the spring characteristic of the hydropneumatic unit was determined on the example of a hypothetical vehicle with assumed tactical and technical parameters. In the third stage, the strength of the control arm structure, under the heaviest load conditions, was checked using the Finite Element Method (FEM). The results obtained showed that the advantages of the hydropneumatic suspension, such as: progressive spring characteristics, improved vibration damping, possibility of introducing a semi-active or active suspension system, modularity of the structure and ease of maintenance and repair, make it more and more widely used in modern high-speed tracked vehicles.