| 摘要 |
FIELD: rock drilling, particularly roller bits characterized by conduits or nozzles for drilling fluids. ^ SUBSTANCE: flushing unit comprises nozzle with stepped outer surface and sealing member. The nozzle and the sealing member are secured in socket made in roller bit body channel by means of stop installed in nozzle step having lesser diameter. The nozzle is provided with additional step located from inlet side thereof and having outer diameter corresponding to inner diameter of flushing channel. Flushing unit stop is made as shear spring-loaded ring. Flushing channel sides are provided with mating annular boring. Inner and outer diameters of spring ring in compressed state are smaller than outer diameter of nozzle step having lesser diameter and greater than socket diameter. Nozzle travel, namely distance from upper end of nozzle stage having larger diameter to socket bottom is not less than lower stage height. ^ EFFECT: simplified bit structure and reduced bit cost. ^ 3 cl, 3 dwg |
