ROLLER BIT WITH ASYMMETRIC FLUSHING Russian patent published in 2014 - IPC E21B10/16 E21B10/18 

FIELD: mining.

SUBSTANCE: proposed roller bit comprises legs with inclined pins with roller cones with cast or honed teeth, sludge withdrawal channel and flushing assemblies arranged between roller cones. All roller cones feature skewed teeth. Note here that first roller cone is arranged between flushing assemblies and has teeth inclined to pin axis so that total axial component of force of all skewed teeth acting on hydraulic fluid of the roller cone bottom is directed from periphery to centre and that of adjacent roller cones is directed in opposite direction.

EFFECT: higher efficiency due to high-quality cleanup of well bottom of sludge by optimisation of its evacuation to annular space.

2 cl, 2 dwg