The equations determining a resultant screw of two given screws are applied to thestudies on gearing and meshing theories. A kinematical classification is propo
A great attention has been paid to slowing the degradation of coal nowadays. The spiral bunker is the main measure to lower the degradation. In this paper the a
Upon the analysis of the interior and exterior pressures observed on the double-tubbing shaftwalls of the West Ventilation Shaft in Xieqiao Coal Mine of Huainan