ANALYSING THE RESPONSE OF A DUAL-FLOW TRANSMISSION (HMCVT) FOR WHEELED TRACTORS ACCORDING TO EFFICIENCY AND PRODUCTIVITY CRITERIA.

Today, there is a trend in world tractor manufacturing to use continuously variable transmissions instead of mechanical stepped transmissions. The most popular continuously variable transmissions are variator, hydraulic-mechanical and electromechanical. For wheeled tractors, of course, the most common transmission is the dual-flow hydraulic-mechanical continuously variable transmission. Today, there are such models of tractors with HMCVT on the world market as John Deere, Case IH, John Deere, Fendt, Massey Ferguson. Therefore, the objective of this paper is to analyse the response of dual-flow transmissions used on wheeled tractors in terms of efficiency and productivity, taking into account the circulating modes of operation. The implementation of the outlined objective is done through the use of basic mathematical equations, supported by the experimental identification of hydromechanical losses in the hydraulic branch of the transmission. When solving the set goal, the configuration of schematic solutions of the HMCVT structure with the placement of the planetary mechanism at the output of the dual-flow system was used. The result is a scientifically based analysis of the performance indicators of HMCVT according to efficiency and productivity criteria with different configurations of the schematic structure of the transmission. The practical significance of the work is to provide recommendations for changing the efficiency and productivity of the two-flow HMCVT by varying the circuit structure. A scientific novelty is the establishment of a relationship between the design parameters of dual-flow transmissions (the energy effect of the power variation in the mechanical branch) and their performance and efficiency criteria for different circuit configurations of the output planetary mechanism. [ABSTRACT FROM AUTHOR]