BALL MILL GEARBOX PROBLEM - Vibration
table 1 - ball mill shaft speeds, expected forcing & fault frequencies ball mills, forcing frequencies (cpm) shaft speeds 1x rpm motor speed 1,191 ball mill pinion speed 226 ball mill gear speed 18 gearbox (between motor & ball mill) nb ftf bsf 2x bsf bpfo bpfi input brgs, skf#22330 15 491 3,192 6,384 7,358 10,507