VIBRATION REDUCTION METHOD IN TURBOMACHINE WORKING BLADES Russian patent published in 2020 - IPC F01D5/26 F01D5/10 F01D25/06 

FIELD: turbines or turbomachines.

SUBSTANCE: invention is intended for use in turbomachine building. Method of vibration reduction in working blades of turbomachine consists in that strain gauging of separate impeller blades on operating turbine machine is carried out, according to its results the most dangerous resonant frequency of vibrations of impeller blades is determined. Two sets of blades are used to assemble the impeller, each blade is alternately set on the vibration table, and the value of the dangerous inherent oscillation frequency detected during strain gauging is determined for each. Average value of dangerous natural frequency is determined for two sets, and diagram of root-mean-square deviation of values of oscillation natural frequencies of each blade is plotted. According to the graph, the value of the average dangerous natural frequency is determined and all the blades are divided into four equal groups, two of which are located closer to the value of the average dangerous natural frequency, and the remaining two are further. Two new sets of blades are assembled each of two groups according to the principle: one group of blades with values of natural frequencies more approximating to value of average dangerous intrinsic frequency, and another group of blades with values of natural frequencies more distant from this value, note here that values of eigenfrequencies of said two groups are located on different sides of average dangerous natural frequency value. Blades sets formed in this way are installed on impeller disk. At odd number of blades at their division into four equal groups on each side from average value of dangerous natural frequency one blade is withdrawn, value of natural frequency of oscillations of which is closest to average value, for each new set.

EFFECT: invention makes it possible to lay down vibration of impeller blades at the stage of assembly of turbomachine without making any changes to the design.

1 cl, 2 dwg