CFRP Propeller Shaft Layer Structure for Lower Material Cost

The patent applies different grades of carbon fibers to different layers of the CFRP tube based on their specific functional requirements. The helical layer uses high-strength, high-elasticity carbon fibers to provide torsion and bending strength, while the hoop layers use lower-grade, more cost-effective carbon fibers for protective functions. This local differentiation of material quality resolves the contradiction by matching material properties to functional needs rather than uniformly using high-strength materials throughout.

The patent creates a composite structure combining different grades of carbon fibers with resin materials in specific layer configurations. The helical layer comprises carbon fibers with tensile strength of 3.0 GPa or more and tensile elasticity of 200 GPa or more, while the hoop layers use carbon fibers with lower strength properties. This composite approach allows the structure to achieve necessary mechanical performance through strategic material combination rather than relying on expensive high-strength materials for all layers.

The patent implements local quality differentiation by assigning high-strength carbon fibers specifically to the helical layer where they are most needed for structural integrity during power transmission, while using lower-strength fibers in the hoop layers where the primary function is protective rather than load-bearing. This localized material assignment maintains overall structural integrity while reducing adoption cost by avoiding unnecessary use of expensive high-strength materials in non-critical areas.

The patent employs lower-grade, more cost-effective carbon fibers for the hoop layers that serve protective functions such as preventing chipping and providing collision energy control. These outer protective layers can be designed with less expensive materials since they do not need to withstand the same torsional and bending loads as the helical layer, thereby reducing adoption cost while maintaining adequate protective functionality.

The patent strategically places low-priced carbon fibers with low to middle strength and elasticity exclusively in the hoop layers where they perform protective functions such as preventing chipping and absorbing collision energy, rather than in the helical layer where high strength is required for torsion and bending. This local quality assignment ensures that cost reduction does not compromise the torsion and bending strength of the critical load-bearing helical layer.

The patent creates a composite structure where the helical layer uses high-strength carbon fibers to provide the necessary torsion and bending strength, while the hoop layers use lower-strength, lower-cost carbon fibers for protective functions. The combination of these different material grades in a composite structure allows the overall shaft to achieve both cost reduction and maintained mechanical performance by assigning each material type to its most appropriate functional role.

The patent employs low-priced carbon fibers with low to middle strength and elasticity for the hoop layers that serve as protective outer shells. These hoop layers are designed to absorb collision energy and prevent chipping of the CFRP tube through their sacrificial protective function. By using lower-cost materials for these protective layers, the patent reduces overall cost while maintaining adequate collision energy control and chipping protection capabilities.

The patent creates a composite structure where the combination of the helical layer and hoop layers with different material properties provides both structural integrity and protective functions. The hoop layers made of lower-strength carbon fibers work in conjunction with the high-strength helical layer to provide collision energy control and chipping protection, demonstrating that appropriate material combination can achieve protective functionality without requiring expensive high-strength materials throughout the entire structure.