Listovhchyk L. Validation of the parameters of a double-faced hydrohammer for rock failure

The dissertation is dedicated to the study of characteristics and parameter s of the hand-operated hydrohammer with controlled work chamber using double-faced percussion mechanism. The analysis of the hand-operated hydrohammers of various designs as well as their comparison with air-hammers with another type of drive - electric, pneumatic and, and petrolic - has been performed. It has been found out that these are hydraulically operated hammers that fully meet the application requirements for mine works and have potential for improvement. A mathematical model for analysis of hand-operated air-hammer dynamic parameters that considers interaction of hydropercussion mechanism moving parts has been created; the analytical study of hammer operating mode under various conditions (change of hydraulic drive parameters and parameters of hydropercussion mechanism) has been carried out. To prove the validity of the created model the hydrohammer has been tested on the test board which included registration of its critical dynamic parameters. The creation of double-faced percussion mechanism is justified. The main feature of the mechanism is an application of the hammer second face in a form of inertial mass. The double-faced mechanism allows recoil decrease for joint faces on account of separated striking mass as well as to increase the energy transfer coefficient of the percussion into stone using the first face as an element that presses the tool against rock and the second one as a percussion mechanism.