Pitch drop friction brake
AssigneeLockheed Martin Corporation
InventorsTyler Christian Kane, Kevin A. Laitenberger
Life of this patent
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Abstract
A rotor system of a rotary wing aircraft includes a rotor hub including a hub arm, a rotor blade rotatably coupled to the hub arm about a longitudinal axis of the hub arm, and a first brake assembly. The first brake assembly includes a rod coupled to the rotor blade coupling and a brake shoe coupled to the rod. The brake shoe is configured to apply a force on the hub arm. An axial position of the rod is adjustable to vary the force of the brake shoe on the hub arm.
Claims19
A rotor system of a rotary wing aircraft, the rotor system comprising:
- a rotor hub comprising a hub arm;
- a rotor blade coupling;
- at least one bearing positioned around an inboard end of the rotor blade coupling to enable rotation of the rotor blade coupling relative to the hub arm about a longitudinal axis of the hub arm;
- and
- a first brake assembly comprising a rod coupled to the rotor blade coupling and a first brake shoe coupled to the rod, the first brake shoe configured to apply a force on the hub arm,
- wherein an axial position of the rod is adjustable to vary the force of the first brake shoe on the hub arm.
A rotary wing aircraft comprising:
- a rotor system comprising:
- a rotor hub comprising a hub arm;
- a rotor blade coupling;
- at least one bearing positioned around an inboard end of the rotor blade coupling to enable rotation of the rotor blade coupling relative to the hub arm about a longitudinal axis of the hub arm;
- and
- a tension-torsion strap coupling the rotor blade coupling to the hub arm;
- a swashplate assembly comprising a plurality of pitch control actuators configured to control the rotation of the rotor blade coupling;
- an engine or motor configured to rotate the rotor system, wherein the rotation of the rotor system is configured to lift the rotary wing aircraft;
- and
- one or more brake assemblies each comprising a rod coupled to the rotor blade coupling and a brake shoe coupled to the rod, the brake shoe configured to apply a force on the hub arm to resist a pitch change of the rotor blade coupling, wherein an axial position of the rod is adjustable to vary the force of the brake shoe on the hub arm.
A method of controlling a drop in pitch of a rotor blade coupled to a rotor hub of rotary wing aircraft by a tension-torsion strap and a rotor blade coupling, the method comprising:
- coupling a brake assembly to the rotor blade coupling, the brake assembly comprising a rod coupled to a brake shoe;
- and
- adjusting an axial position of the rod such that the brake shoe applies a force on the rotor hub, the force configured to resist the drop in pitch of the rotor blade, wherein adjusting the axial position of the rod comprises removing at least one external support from the rotor blade to confirm that the drop in pitch of the rotor blade does not exceed a predetermined maximum drop in pitch.
Dependencies are inferred from the claim text.