Abstract
KEYWORDS:
parametrical vibration, main bearing cover zone, stiffness, FEM, Holographic Interferometry
ABSTRACT:
The authors based their study on the well-known fact, that the parametrical vibration problem, class of Hill-Mathieu, has a main influence on the dynamic behaviour of the internal combustion engines. This class of parametrical vibrations is evident in the main bearing zone, especially in the suspended solution one, because the rigidity, respectively the spring stiffness in two main axis (directions) k1/k2 reaches at least 10-15%. The authors conceived and realised several stands for Holographic Interferometry investigations, presented in this paper. For a Romanian tractor's 6 in-line vertical engine, model 2601-050, the authors evaluated, by Holographic Interferometry and FEM, the main spring stiffness values k1, k2 and the stiffness ellipse, too. Miscellaneous bearing top solutions, various bearing loading models and various values of the pre-stressing screw's force were analyzed by FEM and Holographic Interferometry. The authors' subsequent researches are focused at optimizing also the geometry of the bearing top' fixing screws.
Based on these experimental and theoretical results, became possible to optimise the main bearing zone for several new engines.