Composite drive shafts

A composite shaft, comprising:

• a plurality of composite elements arranged about an axis to form a hollow cylindrical shaft extending along the axis between a first end of the shaft and a second end of the shaft, wherein the plurality of composite elements incudes:
• a first group of the composite elements aligned parallel to the axis;
• a second group of the composite elements arranged about the axis offset by an angle α relative to the first group in a first direction;
• a third group of the composite elements arranged about the axis offset by an angle γ relative to the first group in a second direction opposite the first direction, wherein the third group is offset from the second group by an angle 2α;
• and
• a fourth group of the composite elements arranged about the axis offset by an angle θ, wherein the first, second, third, and fourth groups of composite elements form a web with one another to form the hollow cylindrical shaft,
• wherein the first end and the second end each include a respective enlarged portion extending radially outward from the hollow cylindrical shaft, wherein the respective enlarged portion of the first end and of the second end are thicker than a connecting section connecting the respective enlarged portion of the first end to the respective enlarged portion of the second end, wherein the respective enlarged portions of the first end and of the second end are each configured to be connected with respective couplings;
• and
• wherein each of the first group of composite elements, the second group of composite elements, the third group of composite elements, and the fourth group of composite elements includes a plurality of plies, wherein the plurality of plies of at least one of the first group of composite elements, the second group of composite elements, the third group of composite elements, and/or the fourth group of composite elements extend onto each of the enlarged portions of the first and second axial ends of the hollow cylindrical shaft, and further comprising:
• a fifth group of composite elements, arranged along the hollow cylindrical shaft and spaced apart from one another, wherein the fifth group of composite elements includes a plurality of plies, wherein the plurality of plies of the fifth group of composite elements is interleaved with the plurality of plies from at least one of the first group of composite elements, the second group of composite elements, the third group of composite elements, and/or the fourth group of composite elements,
• wherein the plurality of plies of the fifth group of composite elements are shorter in axial length than the plurality of plies from at least one of the first group of composite elements, the second group of composite elements, the third group of composite elements, and/or the fourth group of composite elements, and
• wherein each of the enlarged portions includes a first portion in the axial direction of constant radial thickness and a second portion in the axial direction having a tapered radial thickness, wherein the tapered radial thickness tapers in an axial direction as a function of an axial length of each ply of the fifth group of composite elements.