초록 ▼

A composite axial flow rotary machine blade (50) and method of blade construction is disclosed. A partial-length, spanwisely-disposed hollow spar (20) partially captures a shaped foam core (30) which extends from within the spar\s cavity (26) along a substantial length of the blade (50) in a spanwis

A composite axial flow rotary machine blade (50) and method of blade construction is disclosed. A partial-length, spanwisely-disposed hollow spar (20) partially captures a shaped foam core (30) which extends from within the spar\s cavity (26) along a substantial length of the blade (50) in a spanwise fashion. A resin-impregnated high strength, high modulus cloth (34) and graphite (32) composition overlays the spar-core assembly (36) and forms the casing (50) with airfoil regions (52, 54) of the propeller blade (10). This construction results in a rotor blade (50) with enhanced natural frequencies thereby providing for an enhanced operational speed range.

대표청구항 ▼

A rotor blade extending a given spanlength from a flange for mounting the blade to a hub spanwisely to a blade tip and having an airfoil section having a leading edge, a trailing edge and a relatively flat pressure surface extending therebetween on one side of the blade and a relatively flat suction

A rotor blade extending a given spanlength from a flange for mounting the blade to a hub spanwisely to a blade tip and having an airfoil section having a leading edge, a trailing edge and a relatively flat pressure surface extending therebetween on one side of the blade and a relatively flat suction surface extending therebetween on the opposite of the blade, the blade comprising: a spanwisely extending spar having a proximate end that provides the flange for attaching the spar to the hub and a distal end defining a hollow cavity therein and having a flared open end opening to the spar cavity disposed therein, said spar extending for a length ranging from 10% to 50% of the blade spanlength; a spanwisely extending core of lightweight foam filler extending from a proximate end disposed within the spar cavity through the opening and beyond the flared open end of the distal end of the spar a predetermined spanwise distance to a distal end of the blade tip; a first laminate wrap formed of a plurality of cloth layers disposed about the spar and the core, the first laminate wrap having a plurality of layers of high strength fibers interspersed among the plurality of cloth layers so as to spanwisely extend along the pressure and suction surfaces of the blade, thereby forming a preliminary composite assembly; additional foam filler shaped to mate with the preliminary composite assembly to form portions of the blade\s leading and trailing airfoil edges; and a second laminate wrap formed of a plurality of cloth layers disposed about the preliminary composite assembly and proximately located shaped foam filler.