초록 ▼

A hollow composite airfoil with an integral internal support rib of fluoroelastomer rubber is formed by bracketing the rib between two silicone rubber mandrels to form a core assembly having a desired aerodynamic shape, then building up on opposite sides of the core assembly separate stacks of lamin

A hollow composite airfoil with an integral internal support rib of fluoroelastomer rubber is formed by bracketing the rib between two silicone rubber mandrels to form a core assembly having a desired aerodynamic shape, then building up on opposite sides of the core assembly separate stacks of laminae of a composite material of graphite (or carbon) and glass fibers impregnated with an epoxy resin, with the two stacks overlapping adjacent to the leading and trailing edges of the core assembly. Heat and pressure are then applied to the core assembly with the laminae thereon to bond together the laminae of each stack, then to bond the two stacks together along the overlapping portions thereof and to bond the two stacks to the rib to form a continuous shell around the core assembly. The mandrels are then removed. One open end of the resulting hollow airfoil is plugged and that end is inserted into a recess in a mounting platform with a predetermined clearance space therebetween. An elastomeric material is then injected into the clearance space for filling it, the elastomer then being cured to bond the platform to the airfoil. A polyurethane sheath is wrapped around the airfoil and cured. Airfoils with plural ribs are also disclosed.

대표청구항 ▼

A method of fabricating a hollow airfoil comprising the steps of: providing a core assembly including an elongated support structure of one material and plural elongated mandrels of another material abutting said support structure and cooperating therewith to define the core assembly, then applying

A method of fabricating a hollow airfoil comprising the steps of: providing a core assembly including an elongated support structure of one material and plural elongated mandrels of another material abutting said support structure and cooperating therewith to define the core assembly, then applying a shell around said core assembly encompassing said core assembly except at the ends thereof and contacting said support structure, then bonding said shell only to said support structure, and then removing said mandrels through an open end of said shell leaving a hollow shell with an integral internal support structure. A method of applying a mounting platform to one end of an elongated hollow airfoil, wherein the platform has a recess therein shaped complementary to but dimensioned slightly larger than the one end of the airfoil, comprising the steps of: plugging one end of said hollow airfoil, inserting said plugged end of the airfoil into the recess in the platform with a predetermined substantially uniform clearance space between the recess of said platform and the inserted end of the airfoil, then injecting an elastomeric material into the clearance space for filling same, and then curing the elastomeric material for bonding the inserted end of the airfoil to the platform. A method of fabricating a hollow airfoil assembly comprising the steps of: providing a core assembly including an elongated support structure of one material and plural elongated mandrels of another material abutting said support structure and cooperating therewith to define the core assembly, then applying a shell around said core assembly encompassing said core assembly except at the ends thereof and contacting said support structure, then bonding said shell only to said support structure, then removing said mandrels through one open end of said shell leaving a hollow shell with an integral internal support structure and open ends, plugging one open end of said shell, providing a mounting platform having a recess therein shaped complementary to but dimensioned slightly larger than the plugged end of the shell, inserting the plugged end of the shell into the recess in the platform with a substantially uniform predetermined clearance space between the platform and the inserted end of the shell, then injecting an elastomeric material into the clearance space for filling same, and then curing the elastomeric material for bonding the inserted end of the shell to the platform.