Abstract: A seal arrangement (40) between relatively movable components (42,48) includes at least one magnet (54) on a first component (48) and at least one magnet (56) on the second component (42). A clearance (55) is defined between the at least one magnet (54) on the first component (48) and the at least one magnet (56) on the second component (42). Springs (58) bias the at least one magnet (54) on the first component (48) and the at least one magnet (56) on the second component (42) towards each other. The at least one magnet (54) on the first component (42) and the at least one magnet (56) on the second component (42) are arranged to repel each other against the spring (58) to control the clearance (55).

Abstract: A fan rotor assembly (30) for a gas turbine engine (10) comprises a fan rotor (32) and a plurality of radially extending fan blades (34). Each fan blade (34) has a root (64) which is retained in a corresponding groove (54) in the periphery of the hub (54) of the fan rotor (32). Each fan blade root (64) comprises four axially spaced root portions (66, 68, 70 and 72) which locate in a corresponding number of axially spaced groove portions (56, 58, 60 and 62). The flanks (94, 98) of two of the root portions (66, 70) are arranged at an angle to the axis of the fan rotor (32) and the flanks (96, 100) of the other two root portions (68, 72) are arranged at an angle in the opposite sense. The flanks (74, 76, 78 and 80) of the groove portions (56, 58, 60 and 62) are arranged at the same angle as the flanks (94, 96, 98 and 100) of the corresponding root portions (66, 68, 70 and 72). The arrangement provides improved retention of the fan blades (34) and reduces the weight of the fan blades (34) and fan rotor (32).

Abstract: A fan for a gas turbine engine comprises a rotary disc carrying an annular array of radially extending fan blades. Each fan blade has a root portion which is radially constrained within a generally axially extending groove formed within a disc rim. The blade root comprises two portions each radially convergent toward one another with respect to the axis of rotation of the disc. The groove within the disc also comprises two base portions each being correspondingly radially convergent toward one another. Axial retention of the blade root within the groove is achieved by the centrifugal component of the blade load acting in an opposite direction to any applied axial load in the forward or rearward direction.

Abstract: A rotor for a ducted fan gas turbine engine includes a rotor disc on which a number of circumferentially spaced apart blades are mounted. Wall members are positioned to bridge the space between adjacent blades. The wall members correspond in profile with the blades adjacent thereto. A seal is mounted on a side face of each wall member and is bonded to a flexible mounting which is bonded itself to the wall member. The flexible mounting has elastic properties so as to allow the seal to deflect relative to the wall member under centrifugal loading during operation.

Abstract: A rotor disc which is suitable for carrying the fan blades of a ducted fan gas turbine engine is constituted by two sub-discs which are maintained in axially spaced apart relationship by a plurality of spacer members. The spacer members are generally axially extending and at least partially define the operational air flow path over the disc.

Abstract: A stage of fan blades in a ducted fan gas turbine engine have the spaces between them filled by a rotary annulus wall filler which has a leading portion made from metal and a trailing portion made from a composite material. The metal portion resists the impact damage from the ingress of foreign bodies and the trailing portion provides a lighter structure.

Abstract: Each fan blade of a fan blade assembly for a ducted fan gas turbine engine is provided with a key which cooperates with the fan blade root and fan hub to axially lock the fan blade to the fan hub. Each key is deformable under excessive axial loading of its associated fan blade to minimize damage to the fan hub.

Abstract: Fan blades of a rotor stage do not have platforms and separate wall members are provided to bridge the space between adjacent blades with the wall members defining an inner wall of a flow annulus through the rotor; each wall member has a plurality of hooks which extend radially inwardly to engage correspondingly shaped hooks provided on the radially outer face of the disc and further hooks engage rings mounted on the rotor adjacent to the disc to lock the wall member in position and insure that the hooks on the wall member engage the hooks on the radially outer face of the disc.

Abstract: A fan rotor has separate wall members bridging the space between adjacent blades of the rotor to define an inner wall of a flow annulus through the rotor; each wall member is attached to the radially outer face of a disk and opposing side faces to which resilient seal strips are bonded; the seal strips have flange portions which are inclined radially inwardly along a curved edge to produce undulations to enhance the flexibility of the flange portion so that, in operation, as the fan rotor rotates about a central axis of the engine, the flange portions are deflected radially outwardly by centrifugal forces into sealing contact with the adjacent fan blade to seal the inner wall of the flow annulus.

Abstract: A fan blade assembly for a ducted fan gas turbine engine comprises a hub which carries an annular array of radially extending fan blades. Each fan blade has a root portion which locates in a corresponding groove in the hub. Aligned radial slots in the root portion and groove accommodate a U-shaped key which provides axial retention of the root portion in its groove. A flat spring attached to the underside of the root portion maintains the key in position and permits manual deflection of the key to assist blade assembly and disassembly.