Ensuring energy efficiency of transmissions of cars and tractors during modernization with a change in the number of cylinders of the internal combustion engine

The article investigates the energy efficiency of motor-transmission units when using internal combustion engines with different numbers of cylinders. Transmissions, those in a unit with piston internal combustion engines are loaded with uneven torque, which is the cause of torsional vibrations of their parts. Torsional vibrations create additional dynamic loads on the transmission elements, and also reduce its efficiency. To ensure a high level of energy efficiency of the engine-transmission unit, the elastic-inertial parameters of the transmission must be matched with the amplitude-frequency characteristics of the torque of the installed engine. When replacing a serial internal combustion engines with an engine with output characteristics different from the prototype, it is necessary to assess the vibration resistance of the modernized engine-transmission unit, which was done in this work. As a criterion for vibration resistance of the modernized machine unit, the cyclic elastic efficiency of the transmission was used. This factor takes into account the natural frequency of the transmission input shaft, as well as the amplitude and frequency of vibration of the engine torque. The decisive influence on the vibration characteristics of the engine is exerted by the rotational speed of its crankshaft and the number of cylinders. When conducting a comparative assessment of the energy efficiency level of the modernized engine-transmission unit, it was assumed that before the modernization the transmission was in a unit with a single-cylinder internal combustion engine. As a result of the study, the conditions for ensuring the vibration resistance of engine transmission units have been determined, a method has been developed for comparative analysis of the energy efficiency indicators of engine transmission units with different numbers of internal combustion engine cylinders, and possible ways to increase the energy efficiency of engine units of cars and tractors during modernization with a change in the number of internal combustion engine cylinders are indicated.