No-Back Brake Modulating Spring for Chatter Damping

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

No-back brakes in actuator systems are susceptible to chatter during high energy aiding loading operations, leading to early wear-out, performance degradation, and increased maintenance costs.

Innovation Solution

Incorporating a modulating spring within the no-back brake that applies a progressive compressive force to the brake section during axial displacement, mitigating chatter through damping, and tuned for specific load conditions using conically shaped springs and cylindrical washers.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a no-back brake is used to provide protection from backdriving, then safety is improved, but excessive chatter results in increased maintenance costs and down-time

Engineering Contradiction:
Improvesafety from backdrivingVSAvoidmaintenance down-time
Core Design Contradiction:
ReliabilityVSLoss of time

Solution Approach 1:

The spring element provides beforehand cushioning to the brake system, absorbing shock loads and preventing chatter-induced wear before it occurs. This proactive damping approach reduces component wear and extends maintenance intervals, decreasing maintenance down-time while maintaining safety.

Inventive Principle:
Principle #11Beforehand cushioning (Prior cushioning)

2Reliability

If a modulating spring is added to reduce chatter, then performance and reliability are enhanced, but device complexity increases

Engineering Contradiction:
Improveoperational reliabilityVSAvoidbrake system complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The spring element serves multiple functions simultaneously: it acts as a cushioning element to reduce chatter, a damping element to absorb vibrations, and a force modulation element to control brake lining engagement. This multi-functionality enhances reliability without proportionally increasing complexity, as a single component addresses multiple problem areas.

Inventive Principle:
Principle #6Universality (Multi-functionality)

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 modulating spring effectively reduces chatter and oscillations in the no-back brake, enhancing its performance and operational reliability during aiding load operations.

Implementation Method 1

a modulating spring, coupled to the shaft and coupled to the brake, configured to compress in response to the brake being displaced, wherein the modulating spring is configured to apply a selective compressive force at the brake corresponding to a distance the brake is displaced

Methodology Applied
Scientific EffectElasticity: Elasticity

Implementation Method 2

The modulating spring is compressed by the axial displacement of the brake, and provides a compressive force against the brake section (e.g., damping) to mitigate chatter within the no-back brake

Methodology Applied
Scientific EffectDamping: Damping

Data Source

PatentEP3670952B1Bi-directional no-back brake progressive modulation spring systems and methods
Publication Date: 2022.02.23 THE BOEING CO
  • EP3670952B1 patent drawingFigure 1
  • EP3670952B1 patent drawingFigure 2
  • EP3670952B1 patent drawingFigure 3A~3B

AI summary

Methods and systems according to one or more examples are provided for reducing chatter in a no-back brake during aiding load operations. In one example, an apparatus comprises a no-back brake (101), disposed within an actuator (102) coupled to an aircraft, including a shaft (225), and a ball ramp plate (215), coupled to the shaft, to receive a force comprising an air loading force and is displaced responsive to the force. The apparatus further comprises a brake (205), coupled to the shaft (225) and coupled to the ball ramp plate (215), and displaced by the ball ramp plate corresponding to a distance the ball ramp plate is displaced. The apparatus further comprises a modulating spring (201), coupled to the shaft and coupled to the brake, configured to compress in response to the brake being displaced, and the modulating spring is configured to apply a selective compressive force at the brake corresponding to a distance the brake is displaced.