A STUDY ON JACK-UP GEARBOX DESIGN FOR DRILLSHIPS

A typical jack-up gearbox used in drillships is composed of a three-stage spur gearbox, which consists of gear chains, shafts and bearings, and a two-stage planetary gear. This study designed the components of the spur gearbox and planetary gear system, and assessed the carrier stability. A gear strength analysis was performed based on ISO 6336, and the system was verified as safe under a load of 18.5kW at 50hr, 100hr, and 150 hr. The shaft strength was calculated using a finite element analysis according to DIN 743, and the shafts had a satisfactory safety factor of at least 3.5 in all cases. The bearing safety factor met the standards of ISO 281 under a load of 18.5 kW at 150 hr. A structural analysis was conducted on the rack and pinion, and the stability of the assembly error was assessed