mechanisms of operation of drilling platforms of self - lift, and the platforms fitted with these mechanisms

摘要

The mechanism for manoeuvring a self-lifting platform consists of geared motors 12 installed in a framework 3 secured to the said platform 1. The output pinion 9 of each geared motor meshes with a rack 8 arranged along a generatrix of the support jacket leg 2, and it includes a number of teeth which is limited at the maximum to six. This pinion 9 includes a pitch circle diameter which is corrected positively by a value lying between 0.5 and 1.1 times the modulus and the external diameter is greater than the pitch circle diameter by a value lying between 1.65 and 1.96 times the modulus. IMAGE