Gearboxes and similar machines containing rotating parts are complex systems with complicated structure and couplings. Generally they can be decomposed into more simple subsystems. These subsystems are usually rotating shafts with gears joined
by gear couplings and housing coupled with rotating shafts by bearings. The paper is aimed at the mathematical modelling of gearboxes with spur helical gears considered including their interior rotating shaft system and housing. The used bearing model
respects real number of rolling elements and roller contact forces acting between the journals and the outer housing. The model of a complete gearbox is created using the modal synthesis method. The kinematic transmission errors in gear couplings are viewed as sources of excitation. Vibration and noise analysis of the gearbox housing is performed by means of the created model. Four types of objective functions suitable for optimization from the radiated noise point of view are proposed. The presented methodology is applied to the simple test-gearbox. and Obsahuje seznam literatury
This paper describes the free transverse vibration analysis of a thin circular plate, subjected to in plane stretching, whilst in interaction with a cylindrical acoustic cavity. An analysis is performed which combines the equations describing the plate and the acoustic cavity to form a matrix equation which, when solved, produces the natural frequencies (latent roots) of the coupled system and associated latent vectors which describe the mode shape coefficients of the plate. After assessing the numerical convergence of the method, results are compared with those from a commercial finite element code (ANSYS). The results analysis is then extended to investigate the effect of stressing upon the free vibration of the coupled system. and Obsahuje seznam literatury