Estimation of residual service life of the main units in hydraulic power equipment

Three main methods to determine residual service life of pieces are described. Based on these methods, a problem concerning the residual service life of the blade system of a turning-blade impeller was considered. An expression was derived to make necessary calculations. The following parameters were calculated: axial movement of shaft; the number of blades; dynamics coefficient for proper frequency of blade; dynamics coefficient for proper vibrations of shaft. It was found that, in redesigning high-head turning-blade hydraulic turbines, the stability of the shaft may be lost at frequencies, close to proper frequencies of lateral vibrations of the shaft.