METHOD FOR REDUCING VIBRATORY STRESSES IN WORKING BLADES OF TURBOMACHINE Russian patent published in 2021 - IPC G01M15/14 

FIELD: machine building.

SUBSTANCE: invention is intended for use in turbomachine building and can be widely used for reduction of vibration stress in blades of impellers of turbomachines. Vane blades of separate impeller of turbomachine are subjected to tensometry. Most dangerous resonance frequency of vibrations of the blades is determined, the effect of changing the geometry of the blade of the impeller to dangerous resonance frequency is calculated. Depending on the operating conditions, possible variations of the blade geometry are determined. Effect of such change of blade geometry on strength and rigidity properties of the blade is calculated. Optimum change is selected, which has less effect on reduction of blade life, which is laid in production technology of two types of blades, locally differing in geometry at span of tolerance for manufacturing of rated blade one to larger side, and second to smaller side, or two types of blades - of nominal shape and locally differing in geometry at span of tolerance for manufacturing of rated blade in larger or lower side. Then, for impeller with even number of blades, impeller blades of two types are made equally and arranged on impeller through one. For an impeller with an odd number of blades, two sets of blades of different types with an odd number of blades are made in any of the sets and placed on the impeller through one with arrangement in any one place of the impeller of two blades of an odd set in a row.

EFFECT: reduced vibration of blades of all turbomachine-type impellers, including mono-wheels, without artificial addition of additional circumferential non-uniformity in temperature field and without complication of turbomachine control system, which, as a result, reduces overall level of vibrations, improves reliability and service life of turbomachine as a whole.

1 cl, 1 dwg