Proprotor Tilt Actuator Load Path With Passive Damping
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing VTOL aircraft designs with tiltable proprotors face catastrophic failure risks due to uncontrolled tilting when actuator shafts break, necessitating redundant actuators and overdesigned components, which increase weight and cost.
Innovation Solution
Implementing passive dampers in a secondary load path to dampen high velocity tilting of tiltable proprotors, eliminating the need for redundant actuators and overdesign by dissipating kinetic energy through hydraulic or pneumatic cylinders.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If redundant actuators and overdesigned components are introduced to prevent catastrophic failure, then reliability is improved, but weight increases
Solution Approach 1:
The patent extracts the essential safety function from the complex redundant actuator system and implements it through a simple passive damper mechanism. The damper removes the need for active redundant control systems while maintaining catastrophic failure prevention, thereby reducing weight.
Solution Approach 2:
The passive damper serves as a simple, lightweight sacrificial component that provides critical safety functionality without the complexity and weight of redundant actuators. It offers a cost-effective alternative to overdesigned permanent structures.
2Reliability
If redundant actuators and overdesigned components are introduced to prevent catastrophic failure, then reliability is improved, but manufacturing cost increases
Solution Approach 1:
The passive damper provides essential safety functionality at a fraction of the cost of redundant actuators or overdesigned components. This simple mechanism dramatically reduces manufacturing costs while maintaining catastrophic failure prevention.
3Weight of moving object
If passive dampers are implemented to dampen high velocity tilting, then weight is reduced, but device complexity is increased
Solution Approach 1:
The passive damper is a self-regulating device that automatically dampens high velocity tilting without requiring external control systems, sensors, or power sources. This self-service mechanism adds minimal complexity while achieving weight reduction.
Solution Approach 2:
The patent replaces complex active mechanical control systems with a simple passive mechanical damper. This substitution eliminates the need for motors, sensors, and control electronics, thereby reducing overall system complexity.
4Weight of moving object
If passive dampers are implemented to dampen high velocity tilting, then weight is reduced, but operational cost increases
Solution Approach 1:
The passive damper requires no operational input, power, or maintenance beyond basic installation. This self-service characteristic ensures minimal operational costs while providing continuous weight reduction benefits throughout the aircraft's service life.
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
Prevents catastrophic failure by limiting the rate of change in tilt angle, reducing aircraft weight and cost while maintaining safety, without requiring active control mechanisms.
Implementation Method 1
The force is the result of a resistance of the damping fluid applied against damper piston as it moves through the fluid. Thus, the damper dissipates energy (e.g., by converting kinetic energy to heat) as the piston moves through the damping fluid due to the resistance of the damping oil as applied to the piston.
Implementation Method 2
The unbalanced dampers similarly include a piston that slides within the cylinder and includes a plurality of apertures through which damping fluid flows while the piston moves through the cylinder but can also include pressurized gas within the cylinder in addition to the damping fluid. When a force exerted on the damper piston, the pressurized gas can compress or expand, depending on the direction of the force. As such, the pressurized gas can absorb an initial sudden force exerted on the damper piston.
Data Source
Figure 1
Figure 2
Figure 3
AI summary
A system for an aircraft includes a tiltable proprotor that is tiltable between a lift position for providing lift for the aircraft and a forward flight position for providing forward propulsion for the aircraft is provided. The system includes at least one actuator for adjusting a tilt angle of the tiltable proprotor; and at least one passive damper connected to the tiltable proprotor and configured to limit a rate of change of the tilt angle of the tiltable proprotor.