The article analyses the functioning of epicyclical gear train with closed circuit hydrosystem, where the driving element is the sun gear and driven one is the carrier or vice versa. Control element is the ring gear, which rotates or can be stopped by the closed circuit hydrosystem.
We have conducted a theoretical research of efficiency in such epicyclical gear train. Using the means of computer modelling, we have obtained graphical dependences of the transmission efficiency from its parameters.
The analytical and graphical dependences have been obtained allow visually verifying the change of efficiency value and evaluating it in terms of self-braking.