... coaxialinstallation. 1.3 Thediameter tolerance zone of input and output shaft is H6, the holes of fittings(such as couplings ... necessary that proper amount of butterapplies to the worm shaft input hole and keyway, avoiding assembling tootightly and ... model, distance,ratio, input connecting method, output shaft structure, input and output shaftdirection and revolving direction accord with requirement.2 ...