Abstract
The paper deals with mathematical modelling and computer simulation of a gearbox system. Results of computer simulation show new possibilities of extended interpretation of a diagnostic acceleration signal if signal is obtained by synchronous summation. Four groups of factors: design, production technology, operation, change of gear condition are discussed. Results of computer simulations give the relation between inter-teeth forces and vibration (acceleration, velocity). Some results of computer simulations are referred to the results obtained in rig measurements and in field practice. The paper shows a way of increasing the expert's knowledge on the diagnostic signal, which is generated by a gearbox system, on a base of mathematical modelling and computer simulation.