초록 ▼

A reduction of the opening of the clearance between the outer air seal secured to the case of a turbo-fan engine and the tip of the turbine buckets is obtained by selectively turning on and off or modulating the cool air supply. The cool air is bled from the fan discharge duct and is directed extern

A reduction of the opening of the clearance between the outer air seal secured to the case of a turbo-fan engine and the tip of the turbine buckets is obtained by selectively turning on and off or modulating the cool air supply. The cool air is bled from the fan discharge duct and is directed externally of the engine case adjacent the seal. Circumferentially mounted spray bars are axially spaced to fit juxtaposed to the annular flanges extending from the engine case and carry a plurality of holes judiciously located to direct the flow of cool air to impinge on the side walls of the flanges to effectuate shrinkage of the case.

대표청구항 ▼

For a turbofan engine operating over a range of power having a fan discharge duct, a turbine, a casing surrounding the turbine, and turbine seal means extending inwardly from said casing means for controlling the clearance between the tip of the turbine and the turbine seal means, said means includi

For a turbofan engine operating over a range of power having a fan discharge duct, a turbine, a casing surrounding the turbine, and turbine seal means extending inwardly from said casing means for controlling the clearance between the tip of the turbine and the turbine seal means, said means including a plurality of axially spaced flanges extending outwardly from said casing, at least one tube circumferentially mounted about said engine case adjacent to said flanges, connection means interconnecting the fan discharge duct and said tube whereby the cool fan discharge air is directed to impinge on the side wall of said flanGe and said flange being sufficiently structured so that the effect of cooling causes the engine case to shrink to reduce the diameter of said air seal and the clearance between the turbine tip and said air seal and means for selectively turning the flow of air on and off at a given power condition of said range of power.