Optimization of components and layouts of hydromechanical transmissions

In the agricultural and work machine sectors, hydromechanical transmission competes with traditional mechanical transmission. However, the double energy conversion taking place in hydrostatic transmission lowers the efficiency of the entire transmission. Thus, the dimensioning of hydromechanical transmission must not only meet the functional requirements of speed and power to be transmitted, but must also identify the particular combination of layout and the components that leads to the maximum efficiency. In this study, a general answer to this problem will be given. The design is transformed into a mathematical programming problem, whose goal is the optimisation of both the configuration and internal components of the transmission. The structure of the transmissions is described by means of graph theory, and the resolution of the optimisation problem is obtained by means of a 'direct search' algorithm based on the swarm method.