LENGTHWISE OSCILLATION DAMPER Russian patent published in 2000 - IPC

FIELD: oil and gas production industry branches, namely suppression of lengthwise vibration and oscillations of drilling tower. SUBSTANCE: damper includes housing in which hollow rod with piston is arranged. Working portions of piston are in the form of upper and lower truncated cones. Piston restricts over-piston and under-piston cavities inside housing in the form of outer and inner chambers. Cross section size of outer chambers is less than that of inner chambers. Cavity of rod and piston is joined with inner chamber of under-piston cavity by means of duct provided in base of lower truncated cone. Outer chamber of over-piston cavity is joined with after-tube space by means of duct of housing. EFFECT: increased service life period of bit, enhanced efficiency and operational reliability of damper. 1 dwg