Turbine blade with metallic attachment and method of making the same
First Claim
1. A turbine blade comprising an elongated, molded blade of composite material consisting essentially of short fibers positioned in an epoxy resin, and a rotor retention member having an insert at a first end of said member and a hub securing end at a second opposite end of said member, said insert being integrally molded into said composite material of said molded blade at one end of said blade with said hub securing end of said member protruding from said one end of the blade for connecting the turbine blade to a hub of a turbine rotor, wherein short fibers of said composite material are aligned in parallel to each other in a longitudinal direction of said elongated blade as a result of flow of the composite material in said direction occurring during a molding of the molded blade, so as to rigidify the elongated turbine blade.
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Accused Products
Abstract
A turbine blade (1), for example, for a ram air turbine engine, and method of making the turbine blade, wherein the turbine blade (1) includes a blade retention insert member (2) having a hub connector (3). The turbine blade (1) is fabricated by using sheet molding compound consisting essentially of discontinuous short fibers (7) initially random spaced within a polymer matrix sheet. A plurality of sheets of sheet molding compound are precut to a desired configuration or shape and placed in a heated blade mold. Heat and pressure are applied to the mold causing the sheet molding compound to flow around the blade retention insert member (2) and fill the mold cavity. The flow of the sheet molding compound causes the initially randomly oriented short fibers (7) to preferentially align in the direction of flow to rigidify the turbine blade (1). Fiber woven cloth skins (8) may integrally molded with the sheet molding compound during the compression molding process to accommodate high loads, and an aluminum chopped strand veil cloth (9) may also be integrally molded into the blade (1) or layers of conductive material may be deposited on at least portions of the surface of the turbine blade (1) during a secondary operation. At least one woven cloth material (6) may also be integrally molded into the turbine blade (1) to react to bending loads and to provide additional load transfer capabilities.
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Citations
36 Claims
- 1. A turbine blade comprising an elongated, molded blade of composite material consisting essentially of short fibers positioned in an epoxy resin, and a rotor retention member having an insert at a first end of said member and a hub securing end at a second opposite end of said member, said insert being integrally molded into said composite material of said molded blade at one end of said blade with said hub securing end of said member protruding from said one end of the blade for connecting the turbine blade to a hub of a turbine rotor, wherein short fibers of said composite material are aligned in parallel to each other in a longitudinal direction of said elongated blade as a result of flow of the composite material in said direction occurring during a molding of the molded blade, so as to rigidify the elongated turbine blade.
- 16. A method of manufacturing an elongated, composite turbine blade, the method comprising the steps of providing a rotor retention member having an insert at a first end of the member and a hub securing end at a second opposite end of the member for connecting the turbine blade to a hub of a turbine rotor, providing a plurality of sheets of molding compound consisting essentially of short randomly positioned fibers arranged in a polymer matrix, precutting the sheets of molding compound into a desired configuration, placing said sheets and said insert of the retention member in a molding cavity of a mold and integrally molding the plurality of sheets and retention member in the mold by applying heat and pressure to form a composite blade by causing the molding compound to flow about said insert end of said retention member and to fill the mold cavity such that said short randomly positioned fibers are aligned in parallel to each other in a longitudinal direction of said elongated blade as a result of flow of the molding compound in said direction occurring during the molding so as to rigidify the composite turbine blade.
Specification