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US 7,399,158 B2Granted
Blade arrangement
AssigneeROLLS-ROYCE plc
InventorsIan C D Care, Alison J McMillan, Seamus Garvey
Life of this patent
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AssigneeROLLS-ROYCE plc
InventorsIan C D Care, Alison J McMillan, Seamus Garvey
Estimating the term…
A blade arrangement 31 includes an array of radially extending blades 20, which may for example comprise a fan of a gas turbine engine for an aircraft. The blades 20 are mounted for rotation about a central axis X-X. The blade arrangement 31 further includes a damping arrangement 32 comprising means 34 for inducing an axi-symmetric magnetic field whose axis of symmetry coincides with the central axis X-X of rotation of the blades 20. The damping arrangement 32 is configured such that when the magnetic field is induced, any movement of the blade 20 other than pure rotation about the central axis results in the magnetic field causing a force to be exerted on the blade 20, the force resisting such movement. The damping arrangement may be provided with means for inducing the magnetic field only when there is an increased likelihood of vibration of the blades, for example when a foreign body has entered the air intake of the engine.
A blade arrangement including an array of radially extending blades mounted for rotation about a central axis, characterised in that the blade arrangement further includes a damping arrangement comprising means for inducing an axi-symmetric magnetic field whose axis of symmetry coincides with the central axis of rotation of the blades, the damping arrangement being configured such that when the magnetic field is induced, any movement of a blade other than pure rotation about the central axis results in the magnetic field causing a force to be exerted on the blade, the force resisting such movement.
A method of damping blades of a blade arrangement including an array of radially extending blades mounted for rotation about a central axis, characterised in that the method includes the step of inducing an axi-symmetric magnetic field whose axis of symmetry coincides with the central axis of rotation of the blades, the magnetic field being such that any movement of a blade other than pure rotation about the central axis results in the magnetic field causing a force to be exerted on the blade, the force resisting such movement.
Dependencies are inferred from the claim text.