Two-Stage Overload Clutch for Controlled Winch Torque Slipping

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Solution Overview

Problem

Existing winch systems in aircraft face challenges in managing torque transmission to prevent overload, which can damage the winch or attached structures due to slipping of the clutch, necessitating a solution to effectively disconnect the motor from the drum during overload conditions.

Innovation Solution

A two-stage clutch design is implemented, featuring a clutchpack with input and output friction plates, Belleville springs, and an engagement nut system that adjusts pressure to increase friction during overload, while a ball ramp assembly sets a maximum torque transfer and allows slipping when exceeded, ensuring controlled torque transfer between the input and output shafts.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Device complexity

If a single-stage clutch is used to transmit torque from motor to drum, then the structure is simple, but the clutch slips under overload conditions causing damage to winch or attached structures

Engineering Contradiction:
Improveclutch structureVSAvoidoverload protection
Core Design Contradiction:
Device complexityVSReliability

Solution Approach 1:

The clutch is divided into two distinct stages: a first stage clutch assembly with first friction plates for normal operation, and a second stage clutch assembly with second friction plates for overload conditions. This segmentation allows each stage to handle specific torque levels, preventing damage while maintaining structural organization.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The clutch system dynamically transitions between two operational states based on torque demands. During normal operation, only the first stage clutch engages. When overload occurs, the second stage clutch engages to provide additional torque capacity or controlled slipping, adapting the system's torque handling capability to match actual conditions.

Inventive Principle:
Principle #15Dynamics

2Reliability

If clutch friction is increased to prevent slipping, then torque transmission reliability improves, but the likelihood of overload damage increases

Engineering Contradiction:
Improvetorque transmissionVSAvoidoverload damage
Core Design Contradiction:
ReliabilityVSObject-affected harmful factors

Solution Approach 1:

Friction capacity is segmented into two stages: the first friction plates provide friction for normal torque transmission, while the second friction plates provide additional friction capacity for overload conditions. This allows the system to maintain appropriate friction levels for each operational regime, preventing both slipping and overload damage.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The clutch dynamically adjusts its friction characteristics by engaging different friction plate assemblies based on torque demands. During normal operation, the first friction plates engage providing controlled friction. When overload occurs, the second friction plates engage to either increase torque capacity or provide controlled slipping, dynamically matching friction to actual needs.

Inventive Principle:
Principle #15Dynamics

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 two-stage clutch effectively manages torque transfer, preventing overload damage by increasing friction during high torque conditions and allowing controlled slipping when maximum torque is surpassed, ensuring safe operation of the winch system.

Implementation Method 1

a first spring, and a second spring arranged in parallel to the first spring. The first and second springs may be Belleville springs

Methodology Applied
Scientific EffectElasticity: Elasticity

Implementation Method 2

a clutchpack with input and output friction plates

Methodology Applied
Scientific EffectFriction: Friction

Data Source

PatentEP3751165B1Overload clutch with second stage setting
Publication Date: 2023.03.22 GOODRICH CORP
  • EP3751165B1 patent drawingFigure 1
  • EP3751165B1 patent drawingFigure 2
  • EP3751165B1 patent drawingFigure 3

AI summary

A clutch (5) having two stages for applying varied torque between an input shaft (100) and an output shaft (102) includes a clutchpack (104) having input friction plates (106) and output friction plates (108). The clutch further includes a first spring (112) configured to apply a first pressure to the clutchpack to compress the clutchpack. The clutch further includes a second spring (116) configured to apply a second pressure to the clutchpack to compress the clutchpack. The clutch further includes an engagement nut (128) configured to move in response to rotation of the output shaft relative to the input shaft to compress the second spring in order to increase an amount of the second pressure applied to the clutchpack.