Hybrid No-Back Rotary Assembly for Flight Control Overload Lock-Up
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Solution Overview
Problem
Aircraft flight control actuation systems face challenges in preventing loss of position control and structural overload due to disconnection failures and torque overloads, which existing technologies fail to adequately mitigate.
Innovation Solution
A rotary device assembly with no-back and torque-limiting capabilities is integrated into the flight control actuation system, featuring a ball ramp mechanism that prevents second torque from being transmitted to the input shaft when exceeding a threshold, and a torsional lock-up mechanism to prevent overload of the torque generating device.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a torque limiting device is added to the actuation system, then structural overload is prevented, but device complexity increases
Solution Approach 1:
The patent combines the no-back capability and torque-limiting capability into a single integrated rotary device assembly. The ball ramp mechanism simultaneously provides both functions: it prevents reverse torque transmission (no-back) and limits excessive torque (torque-limiting) through its geometric design, thereby reducing overall system complexity while maintaining both protective functions.
Solution Approach 2:
The rotary device assembly performs multiple functions within a single component: torque transmission, no-back prevention, and torque limiting. The ball ramp mechanism serves as a multi-functional element that provides both the no-back capability and torque-limiting capability, eliminating the need for separate devices for each function.
2Reliability
If a no-back mechanism is implemented, then position control is maintained during disconnection, but torque transmission efficiency decreases
Solution Approach 1:
The no-back mechanism is designed to engage only under specific conditions (reverse torque or excessive torque), while allowing free torque transmission during normal operation. The ball ramp mechanism maintains high transmission efficiency during normal torque application but automatically engages to prevent reverse torque or limit excessive torque, providing local quality control based on load conditions.
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 solution effectively locks the flight control surface in position and prevents structural overload by independently pre-loaded no-back capability and torsional lock-up, ensuring safe operation even under torque-limiting conditions.
Implementation Method 1
a rotary device disposed to transmit first torque from the input shaft to the output shaft and configured with no-back capability to prevent second torque applied to the output shaft from being transmitted to the input shaft
Implementation Method 2
configured with no-back capability and torsional lock-up capability to prevent an overload of the torque generating device
Data Source
AI summary
A rotary device assembly is provided and includes an input shaft coupled to a torque generating device, an output shaft and a rotary device disposed to transmit first torque from the input shaft to the output shaft and configured with no-back capability to prevent second torque applied to the output shaft from being transmitted to the input shaft in an event the second torque deceeds a torque-limiting threshold and the no-back capability and torsional lock-up capability to prevent an overload of the torque generating device in an event the second torque exceeds the torque-limiting threshold.