Aircraft Gearbox Shaft Alignment Under Torque to Limit Parasitic Forces
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing power transmission systems in aircraft face challenges in minimizing parasitic efforts between the leading and conducted trees, which can lead to wear and damage on bonding and guidance devices.
Innovation Solution
The transmission system includes a conducting tree, a conducted tree, and a bonding device, with non-coaxial axes leading and conducted when stopped, allowing for alignment and coaxiality under torque transmission, thereby reducing parasitic efforts.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Stability of the object's composition
If the housing is made rigid to limit shaft misalignment, then misalignment is reduced, but mass increases
Solution Approach 1:
The housing incorporates elastic deformation capabilities that allow it to dynamically adapt to shaft misalignment under different operating conditions. The housing structure is designed to flex elastically under load, automatically compensating for misalignment without requiring excessive rigidity or additional active control mechanisms.
Solution Approach 2:
The housing's structural parameters are optimized to allow controlled elastic deformation within specific ranges. By changing the housing's stiffness parameters and geometric characteristics, the system achieves adequate alignment stability under normal operation while maintaining reduced mass compared to fully rigid designs.
2Object-generated harmful factors
If the intermediate shaft is made longer to minimize parasitic forces, then parasitic forces are reduced, but device complexity and space requirements increase
Solution Approach 1:
The intermediate shaft's geometric parameters, particularly its length and diameter ratios, are optimized to achieve an optimal balance between parasitic force reduction and system compactness. The shaft dimensions are specifically calculated to minimize parasitic forces generated by misalignment while maintaining a compact overall transmission system layout.
3Object-generated harmful factors
If the intermediate shaft is made flexible to tolerate misalignment, then parasitic forces are limited, but strength and stiffness are reduced
Solution Approach 1:
The intermediate shaft's material properties and geometric parameters are carefully selected and optimized to achieve the desired flexibility for tolerating misalignment while maintaining adequate strength. The shaft's moment of inertia, material modulus, and cross-sectional dimensions are specifically designed to provide the right balance between flexibility and structural integrity under operating loads.
Data Source
Figure 1
Figure 2~4
Figure 5~6
AI summary
The transmission system (10) according to the invention comprises a driving shaft (1), a driven shaft (2), and a linkage device (3) enabling said driving shaft (1) to transmit a mechanical torque to said driven shaft (2), as well as guiding devices (5, 6, 7, 8) guiding the rotation of said driving shaft (1) about a driving axis (AXMA) and said driven shaft (2) about a driven axis (AXME). When said transmission system (10) is at rest, said driving axis (AXMA) and said driven axis (AXME) are misaligned, and move closer to each other when said transmission system (10) transmits a torque from said driving shaft (1) to said driven shaft (2).