초록 ▼

A composite shaft for transmitting torsional forces between end pieces of the shaft. The shaft includes an inner tube member with an end piece mounted at each end of the tube. A composite material is provided covering the inner tube member and at least a portion of the end pieces. The composite mate

A composite shaft for transmitting torsional forces between end pieces of the shaft. The shaft includes an inner tube member with an end piece mounted at each end of the tube. A composite material is provided covering the inner tube member and at least a portion of the end pieces. The composite material includes elongated fibers oriented at a predetermined angle which optimizes the strength of the shaft for a desired shaft performance, and the shaft is constructed to provide multiple load paths between the end pieces.

대표청구항 ▼

What is claimed is: 1. A shaft for the transmission of torsional loads, the shaft comprising: an elongated inner tube member having opposing open ends; at least one end piece located adjacent at least one end of the inner tube member; at least a portion of said end piece including a knurled exterio

What is claimed is: 1. A shaft for the transmission of torsional loads, the shaft comprising: an elongated inner tube member having opposing open ends; at least one end piece located adjacent at least one end of the inner tube member; at least a portion of said end piece including a knurled exterior surface, a composite material in contact with and covering the entire inner tube member and in contact with and covering at least a portion of the end piece; said composite material mechanically connected to said knurled exterior surface, and wherein the portion of the end piece covered by the composite material defines a convexly curved area of the end piece. 2. The shaft of claim 1 wherein the composite material includes elongated fibers, and the fibers are oriented at an angle which satisfies the condition that the angle of twist of the inner tube at failure equals the angle of twist of the composite material at failure. 3. The shaft of claim 1 wherein the composite material includes elongated fibers, and substantially all of the fibers are oriented at a single angle which satisfies the conditions that the shaft have a first natural frequency greater than a predetermined maximum rotational operating speed, the shaft have a maximum operating torque strength which exceeds a predetermined operating torque, and the angle of twist of the inner tube at failure equals the angle of twist of the composite material at failure. 4. The shaft of claim 1 wherein an end piece is provided at each end of the shaft, each end piece including at least a portion of a knurled exterior surface. 5. The shaft of claim 4 wherein torsional loads are transmitted from the end pieces to the composite material through multiple load paths. 6. The shaft of claim 5 wherein the multiple load paths comprise a direct connection between the end pieces and the composite material, and a connection from the end pieces to the inner tube and a connection from the inner tube to the composite material. 7. The shaft of claim 1 wherein the composite material includes elongated fibers which are oriented relative to the curvature of the portion of the end piece covered by the composite material such that, in the area of the portion of the end piece covered by the composite material, shear loads in the composite material are transferred longitudinally along the length of the fibers. 8. The shaft of claim 1 wherein the inner tube comprises a mandrel used in forming the composite material on the shaft. 9. The shaft of claim 8 wherein an end piece is provided at each end of the shaft and the inner tube provides alignment between the end pieces during formation of the shaft. 10. The shaft of claim 1 further including a sacrificial layer covering the composite material. 11. The shaft of claim 10 wherein the sacrificial layer comprises a layer thinner than the composite material, and includes fibers oriented at approximately 90 degrees relative to the elongated inner tube member. 12. A shaft for the transmission of torsional loads, the shaft comprising: an elongated inner tube member having opposing open ends; an end piece located adjacent each end of the inner tube member; a composite material in contact with and covering the entire inner tube member and at least a portion of each of the end pieces; said composite material mechanically attached to each of the said end pieces, and wherein the composite material includes elongated fibers, said elongated fibers being wound about said inner tube member and at least a portion of each of the said end pieces whereby shear loads in the composite material are transferred longitudinally along the length of said elongated fibers. 13. The shaft of claim 12 wherein substantially all of the fibers are oriented at a single angle which satisfies the conditions that the shaft have a first natural frequency greater than a predetermined maximum rotational operating speed, the shaft have a maximum operating torque strength which exceeds a predetermined operating torque, and the angle of twist of the inner tube at failure equals the angle of twist of the composite material at failure. 14. The shaft of claim 12 wherein torsional loads are transmitted from the end pieces to the composite material through multiple load paths. 15. The shaft of claim 14 wherein the multiple load paths comprise a direct connection between the end pieces and the composite material, and a connection from the end pieces to the inner tube and a connection from the inner tube to the composite material. 16. A shaft for the transmission of torsional loads, the shaft comprising: an elongated inner tube member having opposing open ends; at least one end piece located adjacent at least one end of the inner tube member, said end piece including a knurled exterior surface; a composite material covering the inner tube member and at least a portion of the end piece, said composite material including elongated fibers wound about the inner tube member and end piece whereby shear loads in the composite material are transferred longitudinally along the length of said elongated fibers, said composite material mechanically connected to said knurled exterior surface; and wherein the portion of the end piece covered by the composite material defines a convexly curved area of the end piece, said shaft being open ended at both ends. 17. The shaft of claim 16 wherein said elongated fibers are oriented at an angle which satisfies the condition that the angle of twist of the inner tube at failure equals the angle of twist of the composite material at failure.