Abstract:In order to investigate the leakage of the water seal of the flushing mechanism of the hydraulic rock drill under the combined action of highfrequency impact and rotational motion,on the basis of analyzing the variation of the impact velocity of the drill tail over time,the hydrodynamic characteristics of the sealing area were analyzed by solving the generalized Reynolds equation,and the calculation model of film thickness and leakage of the water seal area of the rock drill under the combined action of rotating impact was established.Based on ABAQUS,the change law of the contact stress of the water seal under variable speed in the impact cycle was analyzed,and the influence of different fluid pressure,impact velocity amplitude and rotation speed on the sealing performance was analyzed.The results show that the maximum contact pressure change is related to the inner and outer strokes.For the outer stroke,the maximum contact pressure increases with the increase of the impact speed amplitude,and decreases with the increase of the speed.While the inner stroke is opposite.The maximum contact pressure without rotating speed is obviously less than that with rotating speed,and the overall maximum contact pressure of the outer stroke is greater than that of the inner stroke at the same position.The greater the impact speed amplitude,the greater the realtime leakage and net leakage within a cycle.The realtime leakage rate is relatively close at different speeds,and the greater the speed,the smaller the net leakage,indicating that increasing the rotating speed in a certain range is beneficial to improve the sealing performance of water seal.As the liquid pressure increases,the maximum contact pressure becomes larger,the realtime leakage decreases,and the net leakage first decreases and then increases,indicating that the sealing performance of water seal is better under medium pressure.