Linked Low Pitch Stop for Fail-Safe VTOL Propeller Pitch Control
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional aircraft designs face challenges in achieving efficient, low-noise, low-vibration, and safe vertical takeoff and landing (VTOL) operations, particularly in densely populated areas, with a need for robust propulsion systems that minimize single points of failure and comply with evolving regulations.
Innovation Solution
Aircraft components are designed with a distributed electrical propulsion system, including tiltable propellers and a secondary pitch control mechanism, such as a linked low pitch stop, to ensure fail-safe operation and compliance with aviation regulations, while optimizing energy efficiency and reducing weight.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a primary pitch control system is used to control propeller blade pitch angle, then pitch control precision is improved, but system reliability deteriorates due to single point of failure
Solution Approach 1:
A secondary pitch control system is implemented as a backup mechanism that activates when the primary pitch control system fails. This includes a secondary pitch rod and associated linkages that can independently control blade pitch, ensuring continuous operational capability and preventing complete system failure.
Solution Approach 2:
The pitch control system is divided into functionally distinct primary and secondary control mechanisms with different structural characteristics. The primary system handles normal precision control, while the secondary system provides fail-safe capability, allowing each subsystem to be optimized for its specific function.
2Reliability
If a secondary pitch control system is added as backup, then system reliability is improved, but device complexity increases
Solution Approach 1:
The secondary pitch control system is integrated with the existing primary control structure by sharing common elements such as the pitch rod mounting points, blade pitch linkages, and structural support components. This merging approach reduces the number of entirely separate systems needed, thereby limiting the increase in overall complexity.
Solution Approach 2:
The secondary pitch control mechanism is designed to use existing structural components for multiple purposes - the same pitch rod and linkage structures serve both primary control functions during normal operation and backup control functions when needed, maximizing component utilization and reducing redundancy.
3Adaptability or versatility
If tiltable propellers are used for VTOL operations, then adaptability is improved, but device complexity increases
Solution Approach 1:
The propeller system incorporates variable pitch capability that allows dynamic adjustment of blade pitch angle during operation. This enables the same propeller to efficiently perform both vertical takeoff/landing and horizontal cruise operations by changing pitch characteristics, rather than requiring completely different propeller configurations.
Solution Approach 2:
The pitch control system is segmented into primary and secondary independent control paths, each capable of functioning autonomously. This segmentation allows the system to maintain simplified control architecture while providing multiple operational modes and fail-safe capabilities.
Data Source
AI summary
A tilt propeller for a vertical takeoff and landing (VTOL) aircraft includes a linked low pitch stop (LLPS). The LLPS serves as a secondary pitch control system that is activated when a primary pitch control system fails. The LLPS may include a pitch rod coupled to a propeller blade yoke, and a mechanical coupling that correlates the tilt angle of the propeller with a pitch angle setting of the LLPS. The pitch rod may be separated by a gap from the mechanical coupling during normal operation. If the primary pitch control fails, the pitch rod is forced into contact with the mechanical coupling to close the gap and form a load-bearing path to control the pitch angle.