As you know, excessive distortion on a gearbox will be casuing the failure of gearing and bearing. I have a case that insufficient bearing contact caused by gear casing distortion resulted in high bearing temperature after several months running always. The varnish removal system is being used to maintain this compressor running at an elevated bearing temperature now. The soft feet of gearbox and piping stress on the casing already have been checked , no problem. but the leveling offset at both ends of gearbox already got obvious out of allowable tolerance. it looks like this distortion is actually caused by the heavy compressor volute hanging on lower casing of the gearbox or due to some thermal bowing happening on this gearbox casing.
Does anyone know if any standand is calling for any requirement -e.g. this welding casing should have enough stiffness to reduce any deformation caused by those over-hung volutes and a good thermal stability during the running , as well as how to make this realized during the gearbox casing design.
Thanks for your help in advance.