Crankshaft is made of cast alloy steel. Eccentric ring gear, connection rod and bearings are mounted on it. The eccentric ring gear is herringbone. When assembly, the herringbone bore and crankshaft are of interference fit and fastened with bolts and lock nuts. Big ends of connection rod are mounted on three eccentric straps of the crankshaft via single row cylindrical roller bearings. Small ends are mounted on crosshead pin via double row cylindrical roller bearing. Double row radial spherical roller bearings are mounted at either end of the crankshaft.