Oscillation processes in a transmission with a dual-mass flywheel while moving a car from rest
Видавництво Львівської політехніки
Lviv Politechnic Publishing House
Lviv Politechnic Publishing House
Problem statement. A wide range of modern engines, gearboxes, and massdimension characteristics of a car requires the development of efficient algorithms and methods of designing dual mass flywheels (DMFs) for the given transmission parameters. Improper selection of the design parameters of the DMF can lead to a deterioration of its properties and, consequently, to the increase of vibrations, reduction of the lifetime of the gearboxes, etc. Equally important is the problem of the DMF durability, which depends on many factors, in particular, the character of driving the car by the driver. The solution of the two mutually contradictory tasks formulated above is closely linked to the creation of simulation models of the car drive with a DMF, which will allow simulating different modes of the transmission operation, in order to optimize the parameters of the DMF to the specific design parameters of the car drive. The purpose. Taking into account the design features of the transmission and DMF, to develop and substantiate dynamic, mathematical, and stimulating models of the car drive with a DMF and to study the oscillation processes while moving a car from rest. Research methods. To construct a mathematical model of a car drive with a DMF, the Lagrange method of the 2nd kind was applied. To solve the differential equations of the car motion during acceleration and simulate oscillation processes in the transmission and DMF sections, we used numerical methods with their implementation in the MatLab Simulink environment. Results. A simulation model of a front-wheel car drive with a dual-mass flywheel has been developed in the Simulink environment. The oscillation processes in the transmission and elastic elements of the DMF by the case of moving the car of category M1 from rest were investigated. Recommendations were made to increase the lifetime of the DMF. The novelty. It has been found that the use of a DMF contributes to reducing the dynamic load applied to the drive sections, absorbing the vibration energy generated by the engine. The amplitude of torque oscillations in the transmission sections, semi-axles, and tires is approximately 1.4 times smaller in the DMF drive than in the single-mass flywheel drive. Increasing the energy dissipation coefficient in the DMF from 4 to 20 N·s·m leads to a decrease in the torque amplitude in the drive sections by 1.3–1.6 times at the beginning of moving the car from rest, reducing the duration of transient processes from 2 to 0.75 s, which eliminates the overloading of DMF elastic sections, increasing their lifetime. The practical value. A simulation model of a car drive with a DMF during the period of moving the car from rest has been developed, which makes it possible to simulate the influence of the design parameters of the drive and DMF on the loading of the elastic sections and to calculate their strength under long-term cyclic loading. Areas for further research. To investigate oscillation processes in the DMF and transmission sections under different modes of the car movement in order to determine ways to increase the DMF lifetime by reducing the influence of cyclic loading on their elastic sections.
dual-mass flywheel, car drive, transmission, oscillation process, dynamic loading
Kindratskyy B. Oscillation processes in a transmission with a dual-mass flywheel while moving a car from rest / Bohdan Kindratskyy, Roman Litvin // Ukrainian Journal of Mechanical Engineering and Materials Science. — Lviv : Lviv Politechnic Publishing House, 2019. — Vol 5. — No 1. — P. 93–104.