Helical-Channel Drive Shaft for Flexibility Without Torsional Loss
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Solution Overview
Problem
Conventional drive shafts face challenges in balancing stiffness under torque with flexibility under bending and axial loading, while also dealing with high costs, complex fabrication, and potential damage risks, particularly in welded areas, and require additional space due to diaphragm usage.
Innovation Solution
A drive shaft design incorporating helically oriented channels in multiple concentric tube bodies with symmetric channel angles and optional sleeves to enhance torsional stiffness while maintaining flexibility, eliminating the need for diaphragms.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If conventional axi-symmetric diaphragms are used to provide flexibility under bending and axial loading, then flexibility is improved, but manufacturing cost and fabrication complexity increase significantly
Solution Approach 1:
The patent changes the geometric parameters of the tube by introducing helical channels with specific pitch angles (15-45 degrees) and dimensional ratios (channel width to wall thickness between 0.5-2.0). These parameter modifications enable the tube to achieve flexibility under bending and axial loads while maintaining structural integrity, eliminating the need for complex diaphragm assemblies
Solution Approach 2:
The patent applies local quality by creating non-uniform channel distributions along the tube length. The helical channels are concentrated in specific axial regions rather than being uniformly distributed, allowing targeted flexibility enhancement in areas where it is most needed while maintaining stiffness in other regions
2Adaptability or versatility
If conventional diaphragms are used to provide flexibility, then bending flexibility is improved, but torsional stiffness decreases due to smaller tube diameter
Solution Approach 1:
The patent utilizes the curvature of helical channels winding through the tube wall at specific angles. This curved geometry allows the tube to flex under bending loads while the helical path resists torsional deformation, effectively decoupling bending flexibility from torsional stiffness
Solution Approach 2:
The patent creates a composite structural system by combining the base tube material with the helical channel geometry. The interaction between the tube wall and the helical channels forms a composite structure that exhibits both bending flexibility and torsional stiffness simultaneously
3Adaptability or versatility
If conventional diaphragms are used in drive shafts, then flexibility is achieved, but manufacturing time and cost increase due to advance ordering and welding requirements
Solution Approach 1:
The patent extracts and eliminates the diaphragm component entirely from the drive shaft assembly. By integrating the flexibility function directly into the tube structure through helical channels, the separate diaphragm part and its associated welding operations are removed, significantly reducing manufacturing time and eliminating advance ordering requirements
4Adaptability or versatility
If conventional diaphragms are used, then flexibility is provided, but reliability decreases due to welded areas being the weakest parts
Solution Approach 1:
The patent removes the welded diaphragm connections from the system, eliminating the reliability issues associated with welded areas. The flexibility function is instead achieved through the integral helical channel geometry, which has no weak connection points
Solution Approach 2:
The patent creates a monolithic composite structure where the helical channels are an integral part of the tube. This eliminates separate components and connections, removing potential failure points while maintaining the desired flexibility characteristics
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The design provides improved torsional stiffness and flexibility with reduced manufacturing costs, time, and space requirements, ensuring structural integrity and compliance with quality standards, suitable for various applications including aircraft and automotive systems.
Implementation Method 1
The one or more first body channels can be configured to increase bending and/or axial flexibility of the first tube body while only allowing for a less than proportional reduction in torsional stiffness
Data Source
Figure 1~2
Figure 2A~2C
Figure 2D~3B
AI summary
A drive shaft includes a first tube body (101) having one or more first body channels (103) defined through a wall thickness (105) thereof, the one or more channels configured to increase bending and/or axial flexibility of the first tube body while only allowing for a less than proportional reduction in torsional stiffness of the first tube body. A second tube body (107) can be concentrically disposed relative to the first tube body and connected to the first tube body at a first end portion and a second end portion. The second tube body can include one or more second body channels (113) defined through a wall thickness (115) thereof, the one or more channels configured to increase bending and/or axial flexibility of the second tube body while only allowing for a less than proportional reduction in torsional stiffness of the second tube body.