When piercer produce high alloy thick walled pipe

output universal coupling occur cracks

gearbox have bigger noise and abnormal vibration

and the electric motor current out of specification.Through the analysis of rolling conditions

check of gearbox strength and comparison with other piercer types

the improvement feasibility is analyzed.The conclusion of the gearbox load capacity is low

don’t meet requirement of max mill load

needing corresponding improvement design are obtained.By increasing center distance and increasing gear tooth module

the top load capacity up to 1.5 times of existing gearbox

the gearbox improvement scheme is proposed.The improvement scheme is confirmed by experts of research institute and user.