Soft inplane bearingless helicopter rotor
First Claim
Patent Images
1. A soft inplane bearingless rotor to be rigidly mounted on a helicopter mast comprising:
- (a) a unitary yoke having a flat hub section adapted to be anchored to the end of said mast and having diametrically opposed blade-supporting arms extending from said hub section, each arm having a thin flapping section adjacent said hub section and a feathering section extending from said flapping section with blade attachments at the end of each of said arms, said arms including a plurality of fiber reinforced composite parallel ribs extending span-wise with predetermined inplane spacing;
(b) a blade secured to each attachment with a cuff extending inboard to said flapping section; and
(c) bearing structure interconnecting the inboard end of said cuff and said flapping section and including inplane resilient structure for soft inplane restraint of said blade.
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Accused Products
Abstract
This invention relates to helicopter rotors and more particularly to rotor mounting involving a composite fiber-reinforced unitary yoke with resilient inplane restraints.
102 Citations
13 Claims
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1. A soft inplane bearingless rotor to be rigidly mounted on a helicopter mast comprising:
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(a) a unitary yoke having a flat hub section adapted to be anchored to the end of said mast and having diametrically opposed blade-supporting arms extending from said hub section, each arm having a thin flapping section adjacent said hub section and a feathering section extending from said flapping section with blade attachments at the end of each of said arms, said arms including a plurality of fiber reinforced composite parallel ribs extending span-wise with predetermined inplane spacing; (b) a blade secured to each attachment with a cuff extending inboard to said flapping section; and (c) bearing structure interconnecting the inboard end of said cuff and said flapping section and including inplane resilient structure for soft inplane restraint of said blade. - View Dependent Claims (2, 3, 4, 5)
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6. A soft inplane bearingless rotor to be rigidly mounted on a helicopter mast comprising:
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(a) a unitary yoke having a flat hub section adapted to be anchored to the end of said mast and having an even number of diametrically opposed blade-supporting arms extending from said hub section, each arm having a thin flapping section adjacent said hub section and a feathering section extending from said flapping section with blade attachments at the end of each of said arms, said arms comprising plural fiber reinforced composite ribs with inplane spacing; (b) a blade secured to each said blade attachment with cuff extending inboard to said flapping section; and (c) bearing structure interconnecting the inboard end of said cuff and said flapping section and including inplane resilient structure for soft inplane restraint of said blade.
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7. A soft inplane bearingless rotor to be rigidly mounted on a helicopter mast comprising:
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(a) a unitary yoke having a flat hub section adapted to be anchored to the end of said mast and having at least three uniformly spaced radial blade-supporting arms extending from said hub section, each arm having a thin flapping section adjacent said hub section and a feathering section extending from said flapping section with blade attachments at the end of each of said arms, said arms comprising plural fiber-epoxy composite parallel ribs with predetermined inplane spacing and unified by a medial fiber-epoxy flange structure; (b) a blade secured to each said blade attachment with a cuff extending inboard to said flapping section; and (c) bearing structure interconnecting the inboard end of said cuff and said flapping section and including inplane resilient structure for soft inplane restraint and damping of said blade.
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8. A soft inplane bearingless rotor to be rigidly mounted on a helicopter mast comprising:
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(a) a unitary yoke having a thick flat hub section adapted to be anchored to the end of said mast and having diametrically opposed blade-supporting arms extending from said hub section, each arm having a thin flapping section adjacent said hub section and a feathering section extending from said flapping section with blade attachments at the end of each of said arms, said arms including a plurality of fiber-epoxy parallel ribs extending span-wise and interconnected to maintain inplane spacing of said ribs; (b) means for securing a blade to each said blade attachments and for securing a cuff as to extend inboard to said flapping section; and (c) bearing structure interconnecting the inboard end of said cuff and said flapping section and including inplane resilient structure for soft inplane restraint of said blade.
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9. A soft inplane bearingless rotor to be rigidly mounted on a helicopter mast with foldable blades comprising:
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(a) a unitary yoke having a flat hub section adapted to be anchored to the end of said mast and having diametrically opposed blade-supporting arms extending from said hub section, each arm having a thin flapping section adjacent said hub section and a feathering section extending from said flapping section with a pair of tangentially spaced blade bolt attachments at the end of each of said arms, said arms including a plurality of fiber reinforced composite parallel ribs extending span-wise with predetermined inplane spacing; (b) a blade secured to each said blade bolt attachments; (c) a cuff secured to said attachments and extending inboard to said flapping section; and (d) bearing structure interconnecting the inboard end of said cuff and said flapping section and including inplane resilient structure for soft inplane restraint of said blade through said cuff. - View Dependent Claims (10, 11)
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12. A soft inplane bearingless rotor to be rigidly mounted on a helicopter mast comprising:
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(a) a unitary yoke having a flat hub section adapted to be anchored to the end of said mast and having an even number of diametrically opposed blade-supporting arms extending from said hub section, each arm having a thin flapping section adjacent said hub section and a feathering section extending from said flapping section with blade attachments at the end of each of said arms, said feathering section formed of plural stacked loops of fiber-epoxy material forming inplane spaced ribs with said loops encircling said blade attachments on diametrically opposed arms; (b) a blade secured to each said blade attachments with cuff extending inboard to said flapping section; and (c) bearing structure interconnecting the inboard end of said cuff and said flapping section and including inplane yieldable structure for soft inplane restraint of said blade.
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13. A yoke for a soft inplane bearingless rotor to be rigidly mounted on a helicopter mast comprising:
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(a) a flat hub section adapted to be anchored to the end of said mast; (b) an even number of diameterically opposed blade-supporting arms extending from said hub section; (c) each said arm having a thin flapping section adjacent said hub section and a feathering section extending from said flapping section; and (d) blade attachments at the end of each of said arms and said feathering sections including a plurality of looped fiber-epoxy material stacked to form a plurality of ribs spaced apart inplane with each said loop encircling said blade attachments on diametrically opposed arms.
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Specification