Gearboxes Code:
60,80,90,115,120,142,160
Ratio：1-stage:3,4,5,7,8,10
2-stage:9,10,12,15,16,20,25,30,32,35,40,50,64,70,100
3-stage: 60,80,100,120,160,200,256,320,512
Output shaft type:
S1:shaft without key
S2:shaft with key
T:special require
