Fan casing and fan blade loading/unloading
AssigneeROLLS-ROYCE plc
InventorDerick A. Perry
Life of this patent
Estimating the term…
Abstract
A fan casing of a turbofan gas turbine engine has a slot which extends generally in a circumferential direction and which has an aerofoil section. A variable pitch fan blade may be removed from the turbofan by rotating the fan blade about its axis of rotation to fine pitch setting, and rotating the fan rotor so as to align the tip of the fan blade with the slot. The fan blade is detached from the fan rotor and the tip of the fan blade is inserted radially into the slot. The root portion of the fan blade is then moved in a radially outwards and axial direction to remove the fan blade. The slot in the casing allows the fan blade to be loaded by the reverse procedure. Loading/unloading of a fan blade is made possible without removing the fan casing.
Claims10
A fan assembly for a turbofan gas turbine engine comprising a fan rotor, a plurality of fan blades and an annular fan casing,
- the fan blades being removably secured to the fan rotor, the fan blades having tips at their radially outer extremity and root portions at their radially inner extremity,
- the fan casing being arranged coaxially with the fan rotor and surrounding the fan blades, the fan casing having an interior surface and an exterior surface, the fan casing having a slot, the slot being formed on the interior surface of the fan casing, the fan casing having a plug, the plug being removeably secured in the slot to form a continuation of the interior surface of the fan casing,
- the slot in the fan casing being in substantially the same plane as the fan blades, the slot in the fan casing being dimensioned so as to receive the tip of a fan blade,
- the tips of the fan blades being alignable with the slot in the interior surface of the fan casing, and the tips of the fan blades being insertable into the slot in the interior surface of the fan casing to allow loading or unloading of the fan blades.
A fan assembly as claimed in claim 2 in which the fan blades are variable pitch fan blades, the pitch of the fan blades is variable such that their tips are alignable with the slot in the interior surface of the fan casing, the root portions of the fan blades being detachable from the fan rotor such that the tips of the fan blades are insertable into the slot, the root portions of the fan blades being moveable in both radial, and axial directions to allow loading or unloading of said fan blades.
Dependencies are inferred from the claim text.