Development of the Concept and Layout and Structural Schemes of a Class 5...6 Tracked Tractor With an Electromechanical Power Drive

The introduction of mobile power units with electric drive increases the productivity and performance of machines, reduces their impact on the environment, and expands the possibilities for digitalization by integrating them with digital control, telemetry, and autonomous control systems. The purpose of this research is to develop a concept and design schemes for a 5...6 class tracked tractor with an electromechanical power drive, which will improve its energy efficiency and performance. The object of this research is the ET-VIM‑6 tractor, which has a frame structure, an electromechanical transmission, and a triangular-shaped undercarriage with rubber-reinforced tracks. The layout of the tractor with a triangular track outline, its frame, as well as the basic and kinematic schemes of the electromechanical power transmission have been developed. Based on the results of the calculations, the following parameters have been substantiated: the operating weight of the tractor is 13.5 tons; the power of the diesel engine is 330–350 hp; the rated power of the onboard electric motors is 105–110 kW; the position of the center of gravity; and the geometric characteristics of the propulsion system (diameter of the drive wheel and road wheels, distance between the wheels, and track width). The calculated soil pressure does not exceed 45 kPa. The speed characteristic of the electric motor and the theoretical traction characteristic of the ET-VIM‑6 tractor for a ploughed field at various gear ratios of the planetary gearbox have been constructed. Based on the traction calculation, a rational gear ratio of 28 was adopted, with a traction force ranging from 55.70 to 65.56 kN and a real speed of 1.79 to 2.70 m/s with a slip rate of 4.1 to 4.4 %. The maximum traction efficiency coefficient is 0.70. To optimize energy consumption, it is proposed to use a pulse accumulator, which will reduce the rated power of the power plant by 10–15 %. The development of a tracked tractor with an electromechanical transmission is intended to take domestic agricultural engineering to a new level, as well as to lay the methodological and technical foundations for future autonomous and digital agricultural machinery.