Dimensionamento Automatico delle trasmissioni Idrostatiche per Locomozione

The paper address~s an automatic procedure to define the minimum size (i.e. displacement) of the main units within a hydrostatic transmission for mobile vehicle applications. It is developed for one pump and one or more motors (with loss free units and with nonlinear efficiency models), and starts from a limited number of specifications: the rated engine power and speed, the overall power ratio (a dimensionless parameter which qualifies the vehicle class), the number of motors, and the choice of fixed or variable displacement motor/so Numerical results are given over a practical range of input data, and additional constraints are discussed, which come from the vehicle locomotion. Some alternatives are also discussed, which are intended to increase the feasible power ratio for a given engine power (or viceversa): (i) more power flows in the same vehicle, (ii) multiple gears with automatic shift, (iii) complex transmission architectures. As an example of the third topic, the minimum size procedure is ,applied to the scheme known as "Hydrotransmatic".