Among the technical specifications of the balancer, there is a precision parameter: emar=1 gmm/kg (μm) the significance of this parameter means that the measuring accuracy of the balancer is in the order of microns, while the geometric machining accuracy of the workpiece is between 1 wire and 10 wire, that is, between 10 microns and 100 microns. From the specific meaning of this order of magnitude, the balance accuracy of the rotor is mainly determined by the geometric machining accuracy of the process axis. The balance accuracy of the rotor is reflected in the specific parameters: Establishment: The mass of the rotor W=30 kg, Processing runout of process shaft is e=5 wire =50 micron A rotor radius of r =200 mm And then the m of the imbalance caused by the runout of the process shaft m=W×e/r=30×50/200=7.5 g( g) U=mr=7.5×200=1500 gmm =150 gcm From this point of view, the precision of 5 wire has such a great influence, and the guarantee of 5 wire has been difficult, so the machining of balance process shaft must go through grinding process, so as to ensure the final precision purpose of balance. The correction limit of the balance process axis is: when the runout is greater than 5 wires, it is necessary to correct, otherwise the balance effect is false balance. The material of the balance process shaft is steel 45, and after tempering heat treatment is the minimum requirement. Requirements for balancing accuracy of fans G= mm/s 6.3 G=6.3 mm/sG=eω/1000G=en/10000 U=We=10000 WG/n grams U=We=mr mm m=U/r grams W kg of rotor mass e micron runout of process shaft A rotor radius of r mm 200 mm Balance m grams Rotating speed n rpm 2800 rpm U=10000×30×6.3/2800 675 gmm m=U/r g =675/200=3.375 g