Fan retention shaft

Abstract

A fan retention shaft is provided for retaining a fan within a gas turbine engine in the event of fan shaft failure. The fan retention shaft has a first shaft which in use extends from the engine and a second shaft to which in use the fan is attached, the second shaft being coaxial with the first shaft and the first and second shafts defining an annular passage between them. An energy absorbing medium is disposed within the annular passage. The fan retention shaft has a retaining formation for preventing the first shaft and the second shaft from moving axially with respect to one another. The retaining formation is configured to release the first shaft and the second shaft from their relative axial positions when a threshold axial load is applied to the fan retention shaft. The energy absorbing medium is arranged to absorb kinetic energy from the second shaft as the second shaft moves axially with respect to the first shaft.

Dependencies are inferred from the claim text.