Wear Mechanism And Surface Modification For Hydraulic System Of Special Facility

With the purpose of improving the surface properties of the hydraulic system of special institutions critical components as a starting point, the wear mechanism of the special mechanism of the hydraulic system were analyzed, in order to deposit micrometers hard coating on the surface of special Equipment hydraulic components, this technology can meet the material performance enhancement of the surface of key components. The reason of failure on shearer and aircraft hydraulic system are analyzed, with the combination of mechanical conditions and material performance requirements. The critical components were applied and designed by different surface modification programs, the material properties of key components are improved and the failure are reduced. The main points are as follows:(1) Failures on lift system of double-drum shearer are often based from oil leak caused by the key component wear, on the basis of analysis on system failures and material performance requirements. Surface modification method used on shearer key hydraulic components were putted forward, reasons of wear failure on three key parts oil pan, cylinder and plunger were analyzed, practicable methods of surface hardening were come up with. After TiN film were deposited on the surface of oil distribution disk, the surface hardness of oil distribution disk improved; diamond-like carbon film was synthesized on the steel substrate through a directional plasma kinetic system, erosion resistance of steel increased four times; preparing cladding layer on the outer surface of the plunger by laser cladding, the wear and corrosion resistance of surface of the plunger piston were both improved.(2) The cause of failure on the key components of aircraft has been explored, and the actual working conditions and working principle have been analyzed. By exploring the wear mechanism of key components in hydraulic system and giving surface modification recommendations, practical modification programs have been designed on surface of piston pump hydraulic system, gear and the cylinder. Surface strength and abrasion resistance of the hydraulic mechanism have been improved. Wear and failure on aircraft can be reduced, and the effective flight time of aircraft has been improved.(3) For sealing problem aircraft hydraulic actuator to seal the surface of the piston rod for the study, preparation of DLC films on the rod surface hardening as the basic starting point, the use of multiple ion-beam assisted deposition synthetic Ag-DLC at 440A steel substrate film. The results show that Ag-DLC film improves the rod surface; hardness from the hardness of the sample with respect to the original base material hardness (5.2GPa) significantly increased to 24GPa, friction coefficient decreased; good adhesion between the film and the substrate, film compact; and when the silver content of 10.5%, the friction properties of Ag-DLC film.