Issue 42

J.-f. He et alii, Frattura ed Integrità Strutturale, 42 (2017) 263-271; DOI: 10.3221/IGF-ESIS.42.28 269 directional well drilling. In addition, the maximum abrasion rate deviation of horizontal oriented sliders with various mass of anvil is less than 1 ‱ , thus the effects of anvil mass on the abrasion property of the hydraulic hammer is acceptable. Figure 6 : Variation of anvil mass on the abrasion property of hydraulic hammer with horizontal oriented sliders. Effects of Moving Velocity of the Anvil on Abrasion Property of Horizontal Oriented Sliders As shown is Fig. 7, the abrasion property of a horizontal oriented slider is affected by the moving velocity of the anvil, which is corresponding to the specification of impact energy of hydraulic hammer. It can be concluded that the abrasion rate of a hydraulic hammer with horizontal oriented sliders is almost logarithmically varies with the moving velocity of the anvil. While the moving velocity of the anvil and horizontal oriented slider is 1m/s, the minimum abrasion rate of oriented slider is nearly 1.8%. The abrasion rate of horizontal oriented slider sharply varies with the increase of moving velocity. While the moving velocity of the anvil and oriented slider exceeds 3m/s, the maximum abrasion rate of horizontal oriented sliders will be up to 4%, which would have a significant effect on the service life of hydraulic hammers with horizontal oriented sliders. Figure 7 : Variation of moving velocity on the abrasion property of hydraulic hammer with horizontal oriented sliders. The actual simulation results are slightly different with the fitted abrasion rates. The maximum deviation between simulation results and the logarithmically fitted abrasion rate is less than 2%, which is tolerable in real time operation of hydraulic hammers with horizontal oriented sliders. Meanwhile, the abrasion rate of horizontal oriented sliders is smaller,