METAL CUTTING MACHINE TOOL Russian patent published in 2006 - IPC B23B41/00 

FIELD: machine tool manufacture, namely metal cutting machine tools for working coaxial openings for bearing assemblies of crank shaft in crankcase of internal combustion engines.

SUBSTANCE: rotation drive unit of boring bar includes reaction type pneumatic turbine mounted in boring bar and gas distributing mechanism having outer air pipeline, air shut-off valves, closed grooves and inner air radial ducts of turbine forming common inner air passage between outer air pipeline and turbine jets. Turbine gas distributing mechanism includes outlet openings in lids. Intermediate ring is mounted between boring bar and sleeve. Radial openings of sleeve and ring coincide one with other; annular duct of intermediate ring communicates with radial and axial openings of boring bar for forming common air passage together with outer air pipeline and jets of turbine at boring each next opening of row of coaxial openings.

EFFECT: enhanced operational reliability and safety of machine tool.

3 dwg