Rotary Actuator Stop Module With Deformable Disk Energy Dissipation

Solution Overview

Problem

Conventional end-of-stroke stopping mechanisms for geared rotary actuators are heavy, large, and inefficient in dissipating excess rotational kinetic energy, particularly in applications like aircraft control surfaces where quick stopping is critical, and they often require upstream gears to carry the stopping torque.

Innovation Solution

A stop module utilizing a timing gear system and a low-inertia, deformable stopping disk that dissipates excess energy through predictable deformation, eliminating the need for friction and allowing for a lighter, smaller design, and is designed as a single-use mechanism.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If conventional friction-based brake plates or torsionally compliant shaft systems are used to dissipate excess rotational kinetic energy, then the stopping function is achieved, but the weight and size of the stop module increase significantly

Engineering Contradiction:

Improvestopping functionVSAvoidstop module weight

Core Design Contradiction:

ReliabilityVSWeight of moving object

Solution Approach 1:

The patent replaces the conventional friction-based mechanical braking system with a deformable element that dissipates energy through controlled deformation. Instead of using friction plates that rely on frictional contact, the invention uses a deformable element that absorbs kinetic energy through elastic or plastic deformation, thereby eliminating the need for heavy friction-based components while maintaining the stopping function

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The patent changes the physical state and properties of the stopping mechanism by using a deformable element with specific material properties. The deformable element is designed to undergo controlled deformation at specific stress thresholds, transforming the stopping mechanism from a friction-based system to one based on material deformation characteristics, which reduces weight and size

Inventive Principle:

Principle #35Parameter changes

2Reliability

If conventional friction-based brake plates are used to dissipate excess rotational kinetic energy, then the stopping function is achieved, but the size of the stop module increases

Engineering Contradiction:

Improvestopping functionVSAvoidstop module volume

Core Design Contradiction:

ReliabilityVSVolume of moving object

Solution Approach 1:

The patent replaces the conventional friction-based mechanical braking system with a deformable element that dissipates energy through controlled deformation. Instead of using friction plates that rely on frictional contact, the invention uses a deformable element that absorbs kinetic energy through elastic or plastic deformation, thereby eliminating the need for heavy friction-based components while maintaining the stopping function

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The patent changes the physical state and properties of the stopping mechanism by using a deformable element with specific material properties. The deformable element is designed to undergo controlled deformation at specific stress thresholds, transforming the stopping mechanism from a friction-based system to one based on material deformation characteristics, which reduces weight and size

Inventive Principle:

Principle #35Parameter changes

3Adaptability or versatility

If upstream gears are positioned between the stop module and motor to allow the stop module to be located downstream, then the stroke range is manageable, but the upstream gears must carry the stopping torque increasing device complexity

Engineering Contradiction:

Improvestroke range managementVSAvoidgear train complexity

Core Design Contradiction:

Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The patent extracts the stopping function from the downstream position in the gear train and relocates it to the upstream position near the motor. By placing the deformable element directly on the motor shaft or input shaft, the stopping function is separated from the gear train, eliminating the need for upstream gears to carry stopping torque and reducing overall device complexity

Inventive Principle:

Principle #2Taking out (Extraction)

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 significantly reduces weight, size, torque drag, and inertia, ensuring safe and efficient emergency stops without jamming, and can be replaced after a rare event, outperforming conventional modules in terms of weight, size, and rotational inertia.

Implementation Method 1

a low inertia, deformable stopping disk or other deformable element that can safely dissipate excess rotational kinetic energy of the rotating shaft system

Methodology Applied

Scientific EffectDeformation: Deformation

Data Source

PatentUS11781625B2Single-use non-jamming stop module for rotary drive actuator

Publication Date: 2023.10.10 MOOG INC

AI summary

A stop module for non-jamming end-of-stroke stoppage of a rotary drive actuator includes timing gears to articulate a stopping pawl, and a low inertia, deformable stopping disk arranged to safely dissipate excess rotational kinetic energy of the rotary actuator. The stop module does not rely on friction to stop and dissipate the excess kinetic energy, but instead relies on predictable deformation of a metallic stopping disk which may be provided in a stopping cartridge of the stop module. Use of a deformable element to dissipate excess energy allows the disclosed stop module to be lighter and smaller than conventional end-of-stroke stopping mechanisms.