The invention relates to an oil lubricated anti-sway mill bolt. When pumping the oil, it upper interface, post piston, hollow rod, and transmission interface are driven by the oil pump to move up and down; the pump cylinder and sealing elements are individually sealed by post piston and oil tube; the sealing elements are not moved; the base oil separated from the well liquid pumped by oil pump via the transmission interface is collected to fill the upper circular space of hollow rod and oil tube; in normal production, the well liquid via the hole of transmission interface enters into the hollow rod and the post piston to be discharged from the through hole of upper interface; since the circular spaces of hollow rod and oil tube are filled with base oil, the abrasion between them can be avoided; the milling part of tube post is at its bottom. The invention has less hollow rods, lower material cost, less bearing force and higher reliability, while the hollow rod is at the lower part of rod post. |