Abstract: In this paper, the principle of shaft balancing without trial weights is introduced., As the principle states, the type and the axial position of the shaft unbalance are judged accurately, then the focused measuring points are divided into several closely related combinations; based on the division, the effect of correction masses on the vibration of every combination is calculated with the influence coefficient. Then, the key points for practical application are explored, such as the accurate selection of the original vibration data and the influence coefficients, especially the precise control over the residual vibrations, to achieve overall optimal shafting vibration. At the end, this method is successfully applied to the field dynamic balancing of a DongFang 1 000-MW turbo-generator set, in which the abnormal vibrations are lowered to the excellent level by primary weighting, thus effectively reduces the startup times and costs for the power plant.

Key words: turbo-generator set, vibration, shaft dynamic balancing, balancing without trial weights, correction mass, influence coefficient