The Failure on tube rod arm cylinder hydraulic excavator caused to lose production and processing time mining site. Investigation included visual inspection, chemical analysis, metallography analyze, microhardness test. Tube material used high silicon type while the standard ST52 carbon steel type. was broken crack several pieces. composition of has different in sulfur content. From hardness te...

Hydraulic support is important equipment in the fully mechanized mining face, and control performance of hydraulic multi-cylinder system directly affects smooth progress coal process, which basis for continuous advancement face. However, friction force process pulling frame complex due to underground environmental load. Moreover, parameters moving cylinder are uncertain, state cannot be measure...

A model based control scheme is designed to regu late the cylinder air charge of a camless multicylinder engine for unthrottled operation The controller con sists of a feedforward and an adaptive feedback scheme based on a control oriented model of the breathing process of an engine equipped with electro hydraulic springless valve train The nonlinear control scheme is designed to achieve cylind...