TURBINE WITH FLOW PATH CONFIGURATION PROVIDING FOR SEALING AND LAMINAR STREAM Russian patent published in 2008 - IPC F01D9/02 

FIELD: engines and pumps.

SUBSTANCE: turbine incorporates a rotor with a set of blades fitted thereon. Sets of aerodynamic surface nozzles, spaced apart axially, are furnished with inner and outer shroud rings arranged on their opposite ends. The blades are provided with dovetails and certain special surfaces along radially internal blade ends. The said special surfaces, aerodynamic surfaces, inner and outer shroud rings define partially the fluid medium flow path through the turbine. The said dovetails are furnished with ledges directed axially towards one of the aforesaid set of nozzles along the points located radially inside relative to the special surfaces. The nozzles of one of their sets are provided with labyrinth sealing teeth forming, along with the said ledges, a seal to reduce leakages from the flow path into the flow passage between one of the blades and one set of the said nozzles. The blade special surface front edges are located radially inside relative to the rear edges of inner shroud rings of the upstream adjacent nozzles. The dovetails incorporate outlet elements to direct the flow along the downstream dovetail side and intended to direct the fluid medium leak flow. The said outlet elements are provided with surfaces to direct the fluid medium flow into the flow part, primarily, downstream and axially. The said outlet elements form the blade ledges directed downstream to minimise the gap between the blades and adjacent set of nozzles making a downstream turbine stage part. The front edges of adjacent nozzles arranged downstream are positioned radially inside relative to the blade ledges running along the flow.

EFFECT: reduced leaks and secondary aerodynamic losses in the fluid medium flow path nearby the blades tail parts.

4 cl, 2 dwg