Torque Limiter Trip Indication for Directional Overload Diagnosis

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Solution Overview

Problem

Existing torque limiting devices in aircraft applications lack an effective method to indicate when they have tripped and the direction of the trip, which complicates troubleshooting and maintenance.

Innovation Solution

A torque limiter apparatus featuring a movable ring that rotates a limited amount in both clockwise and anti-clockwise directions, with a lever and indicator bar system that provides directional indication through axial movement within a cylindrical passage, while maintaining a fluid seal and allowing for easy reset.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a torque limiting device is used in aircraft actuators, then torque overload protection is achieved, but there is no indication of when or in which direction the device has tripped

Engineering Contradiction:
Improvetorque overload protectionVSAvoidtrip status and direction information
Core Design Contradiction:
ReliabilityVSLoss of information

Solution Approach 1:

The indicator mechanism is pre-configured with the movable component positioned to indicate normal operation. When torque exceeds the limit in either direction, the movable component automatically shifts to indicate the trip condition and direction, providing immediate visual feedback without requiring additional sensing or processing systems.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The torque limiting device itself generates the indication signal through the movement of its movable component. The same mechanical elements that limit torque also directly indicate the trip status and direction, eliminating the need for separate sensing systems and reducing overall system complexity.

Inventive Principle:
Principle #25Self-service

2Reliability

If a brake is activated to limit torque, then coupling overload is prevented, but the system lacks the ability to indicate trip status

Engineering Contradiction:
Improvecoupling overload preventionVSAvoidindication system complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The indication function is merged with the torque limiting mechanism itself. The movable component that is part of the brake assembly also serves as the indicator, combining two functions into a single integrated structure rather than adding a separate indication system.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The movable component serves multiple functions: it is part of the torque limiting mechanism, it indicates when torque has been limited, and it indicates the direction of the overload. This multi-functionality reduces the number of separate components needed in the system.

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

3Loss of information

If the movable component rotates freely, then it can indicate direction, but it cannot provide a limited and constrained movement for reliable indication

Engineering Contradiction:
Improvedirection indication capabilityVSAvoidmovement constraint precision
Core Design Contradiction:
Loss of informationVSManufacturing precision

Solution Approach 1:

The indicator's movement range is segmented into distinct zones: a normal operation position, a clockwise trip position, and a counter-clockwise trip position. The circumferential pocket physically segments the movement space, allowing precise indication of different states without requiring continuous measurement systems.

Inventive Principle:
Principle #1Segmentation

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 indicates when a torque limiter has tripped and in which direction, facilitating quick identification and troubleshooting of issues in aircraft actuators, enhancing maintenance efficiency.

Implementation Method 1

The indication device and the movable component may be interconnected by a lever.

Methodology Applied
Scientific EffectMechanical coupling through lever: Lever

Data Source

PatentEP3318775B1Apparatus for torque limiting device
Publication Date: 2022.07.13 HAMILTON SUNDSTRAND CORP
  • EP3318775B1 patent drawingFigure 1~3
  • EP3318775B1 patent drawingFigure 4
  • EP3318775B1 patent drawingFigure 5~6

AI summary

The present disclosure relates to an apparatus for a torque limiter, comprising an indication device configured to provide an indication that the torque limiting device has tripped, and of the direction of torque applied to the torque limiting device when the torque limiting device tripped, in use.