The influence of friction between elements of dual-mass flywheel on oscillatory phenomena in a car transmission

Automobile manufacturers, when designing new cars, are increasingly faced with the need to reduce the weight of components in order to achieve the required level of fuel consumption and environmental standards. As a result, internal combustion engines (ICEs) with a small number of cylinders are designed and manufactured, which allows to achieve an increase in output power due to increased pressure in the cylinder and more efficient fuel combustion. As a result of this, torsional vibrations occur on the crankshaft, which are transmitted and negatively affect the transmission, causing it to fail prematurely. The damping properties of dual-mass flywheel (DMF) in a straight line depend on their structure and design parameters. All modern DMF contain a certain amount of thick lubricant, which in one way or another improves its characteristics. But in addition to parts, flywheels that constantly work in an environment with lubricant, there are also elements between which dry friction occurs, which also affects the damping characteristics of the flywheel. Therefore, it can be assumed that its presence affects the elastic-damping properties of the DMF. The purpose of the work is to develop simulation models and study the effect of friction between DMF elements on oscillatory processes in the car transmission and to develop recommendations for reducing the load on DMF elements and transmission links. The effect of dry and viscous friction between the elements of a DMF on the damping of oscillations in the links of its elastic-damping system and the drive links of the car was studied. It is shown that an increase in the coefficient of dry friction between DMF elements from 0 to 0.3 does not provide a noticeable damping of oscillations in the drive links and tension in the DMF springs. The coefficient of viscous friction between the links of the DMF has a significant influence on the amount of tension in the springs of the DMF. To increase the resource of the DMF, it is advisable to install separators made of polymer material between the elastic links with a small coefficient of friction between it and the steel body of the DMF.