Abstract: The modal balancing method and influence coefficient method are two major rotor balancing techniques commonly employed in practice. Both methods concentrate on the constant rotating speed case, i.e., the so-called “steady state” case, so we call them steady state balancing methods. In practical application, they meet more or less difficulties. In view of this, a new balancing method based on accelerating response data is proposed here. The modal unbalance angle is presented for the first time, which represents the angular location of the modal unbalance to the key-slot, and an identification method of the angle is introduced by using accelerating response data. After that, according to the modal knowledge, a pair of appropriate trial weights is determined and placed on the rotor, and then the correction masses are calculated by using the linear relationship between the modal trial weights and the corresponding modal response increment. Thus, the first two modal imbalances are balanced by utilizing the two-plane balancing method. The simulation and experimental results show that not only the residual vibration but also the frequency of run-ups in the balancing process can be reduced effectively.

Key words: aerospace propulsion, rotor, accelerating response, dynamic balancing, transient balancing, unba-lance identification