The crankshaft is mainly equipped with a heavy gear ring, a connecting rod, and bearings. Tooth profile of the heavy gear rings is in herringbone tooth, and inner hole of the heavy gear ring and crankshaft are in interference fit and they are fastened with bolts and jam nuts. The big end of the connecting rod is connected to three eccentric straps respectively through single row short cylindrical roller bearings and the small end is mounted on cross head pin via double row cylindrical roller bearing. Double row centripetal spherical roller bearings are mounted at each end of the crankshaft.