International Scientific Journals
of Scientific Technical Union of Mechanical Engineering "Industry 4.0"

The diaphragm spring as one of the most important parts of the motor vehicles clutch assembly provides the compressive force on the pressure disk. This force is needed for generating friction between the coupling of the flywheel and the pressure disk and transmitting the torque from the engine to the transmission. Therefore the diaphragm spring is subjected to complex loads. The nominal stress for dimensioning the spring is the tangential stress, which is calculated by the terms of Almen and Laszlo. The aim of this research is analyzing the location of the diaphragm spring supporting points of the clutch assembly and its effect on the caused stresses by using the Finite Element Method.

The concept of virtual testing is generally used method for understanding the structures behavior during loading. It can be used as accurate replacement of real tests only if they are correctly modeled and verified. The regulation UNECE R66 is uniform technical prescription concerning the approval of large passenger vehicles with regard to the strength of their super structure. The rollover test is the basic approval test, but virtual tests can be the adequate testing methods of the physical test. The verified computer simulation according to the regulation can be equivalent approval method. There is a need that snow groomer vehicle sometimes accommodates larger number of people (for sport, work or rescue missions). Because of the terrain those vehicles have to pass, there is significant danger of rollover. So far, there are no regulations for testing of such a superstructure. This paper describes the effort and results in the use of virtual testing according to ECE R66 as a tool for estimating the safety of passengers inside such a vehicle. A computer simulation of a rollover test of the snow groomer vehicle was made. The virtual test was conducted according to the ECE R66 which allows this kind of testing. By following the standard guidelines for computer simulation of a rollover test the vehicle superstructure was analyzed. Series of virtual test were carried for meeting the standard requirements and the customer needs. The final snow groomer superstructure had to undertake serious reinforcement considering the passengers surviving area.

A friction clutch is mechanical assemblies built between the engine and transmission, that with friction transfers torque from the driving part to the driven (working) part (engine gearbox and other transmission). A diaphragm spring is one of the key component of a clutch assembly. A diaphragm spring is piece to high stress concentration in driving condition, this is often the cause of cracks and crashes spring. The stress of a diaphragm spring is analyzed by finite element method, measurement of stress and performed compare to stress obtained by expressions on Almen-Laszlo.