Dynamic model of roller bit with nine degrees of freedom;

Computer simulation for the side-cutting of roller bits;

Model to determine rock drillability by roller bit;

The calculation of contact stress of rock bit floating ring journal bearing under disalignment;

Application of computer simulating technology in rock bit floating-ring journal bearings;

The coupling function analysis of the thread-locking ring of rock bit on axial load;

There are many causes inducing rock bit cone break, in which the effect of its machining on the cone is more serious.

Simulation of rock disintegrating process by roller cone bits;

Applicant research of bored piles into the hard rock with roller cone bit;

Design and processing control of slide bearing clearance of roller cone bit.;