Ball Ramp No-Back Brake With Limited Authority Damping
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Solution Overview
Problem
Existing no-back brakes used in aircraft control surface actuators are susceptible to chatter, leading to vibration, noise, and torque oscillations that degrade performance and increase maintenance costs.
Innovation Solution
A no-back brake system featuring a ball ramp mechanism, a drag brake assembly, a main brake assembly, and a limited authority damper assembly with an outer spacing ring, an inner damping ring, and springs to reduce dynamic interaction and chatter.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a no-back brake system is used to protect against back-driving in aircraft control surface actuators, then reliability is improved, but chatter occurs causing vibration, noise, and torque oscillations that degrade performance
Solution Approach 1:
A damper assembly is introduced as an intermediary component between the drag brake assembly and the main brake assembly. This damper includes a damping ring with damping elements that absorb and dissipate vibrational energy, thereby eliminating chatter and harmful oscillations while preserving the no-back brake's protective function against back-driving
Solution Approach 2:
The damping elements in the damping ring are designed with specific material properties and geometric parameters (such as circumferential spacing and configuration) that are optimized to change the dynamic characteristics of the brake system, reducing Q-factor and minimizing torque oscillations while maintaining the necessary braking authority
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 proposed no-back brake system effectively reduces chatter, stabilizing the dynamic interaction and enhancing the performance and safety of aircraft control surface actuators by minimizing vibration and noise.
Implementation Method 1
a first spring disposed between the outer spacing ring and the inner damping ring
Data Source
AI summary
A no-back brake system for an actuator includes a ball ramp mechanism. A drag brake assembly is configured to be coupled to a first portion of the ball ramp mechanism. A main brake assembly is configured to be coupled to an actuator and a second portion of the ball ramp mechanism. A limited authority damper assembly is disposed between the drag brake assembly and the main brake assembly. The limited authority damper assembly includes an outer spacing ring configured to be coupled to the drive shaft of the actuator, an inner damping ring coupled to the outer spacing ring and the drag brake assembly, and a first spring disposed between the outer spacing ring and the inner damping ring.