Limited by the influence of the traditional clearance seal structure on the leakage and friction loss of piston pair, the energy utilization ratio of the hydraulic impactor is difficult to improve effectively. To solve this problem, a novel micro-texture clearance seal structure of impact piston cylinder was proposed, and an integrated energy consumption evaluation index considering leakage and friction loss of impact piston pair was proposed. Based on the average Reynolds equation, a comprehensive energy consumption analysis model for a textured high-frequency hydraulic impact piston pair was established, and the influence of piston texture parameters on the comprehensive energy consumption under rated working conditions was studied. The results show that the cylindrical texture clearance seal structure provided an effective way to improve the energy utilization ratio of hydraulic impactor, with energy consumption 13~15% less than the traditional structure. Variation of area rates textured made the amplitude value of integrated energy consumption of the piston pair decrease by 4~15%, and the optimum area rate was 0.2~0.4. Depth ratio of texture could also reduce the integrated energy consumption of the piston pair, but the reduction range was small.

The profile of sealing land is a sensitive factor affecting the thermo-hydrodynamic lubrication characteristics of the slipper pair. In this paper, the non-uniform wear of the running surface under the slipper was presented and defined as the boundary condition. Based on the finite volume method and the successive over-relaxation iteration method, a discrete numerical model coupled with the temperature, pressure, and thickness of the oil film was constructed. The Newton and sequential circulation methods were used to solve the coupling equations. The influence of the wear profile on the film thickness, sliding attitude, and leakage were discussed. The analyzed results show that the control of the wear on the outer side of sealing land and the contour vertex position, and the avoidance of the wear on the inner side of sealing land could improve the thermo-hydrodynamic lubrication performance of the slipper pair.