Dynamic behaviors of gun's gear mechanism with clearance based on sencond generation wavelets and information entropy

The clearances in pitch mechanism of gun have an important influence on firing concentration. The present study designs a set-up of experimental research on gear mechanism of gun with clearances and carries out corresponding numerical simulations and experiments. The clearance in fanning geargear joint, a typical clearance in pitch mechanism of gun, is considered in the set-up. Impulse excitation is used to get dynamical response signals of gun. A method based on second generation wavelet packet decomposition and reconstruction as well as the information entropy is present to extract feature reflecting clearance from response signals. The qualitative rule between information entropy and the clearance is obtained, which is the information entropy of sensitive frequency band increases gradually with the enlargement of the clearance. The current work can be referred as a basis for dynamical clearance adjustment and the gun design.