Overload Clutch Flange Sensing for Torque and Collision Detection

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Solution Overview

Problem

Existing joint torque sensors (JTS) for industrial robots are costly, complex to install, and increase the volume and weight of the robot, especially when integrated with overload clutches, and do not provide accurate collision detection at high speeds.

Innovation Solution

An overload clutch with integrated sensing means, such as capacitive-type JTS, that transmits torque between input and output flanges and disengages when torque exceeds a threshold, using deformable structures and electrodes to measure torque and detect disengagement without additional base structures.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If a base structure is added to the actuator for joint torque sensing, then torque measurement capability is improved, but volume and complexity increase

Engineering Contradiction:
Improvetorque measurement capabilityVSAvoidcomplexity of assembly and installation
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent combines the base structure function with the overload clutch components by integrating the first and second flanges directly into the clutch assembly. The sensing means are embedded within the clutch structure, merging torque sensing and overload protection functions into a single integrated component, thereby eliminating the need for separate base structures and reducing overall system complexity

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The overload clutch is designed to perform multiple functions simultaneously: it provides overload protection, enables collision detection, and serves as the base structure for torque sensing. By making the clutch multi-functional, the patent eliminates the need for additional dedicated components, reducing both volume and assembly complexity while maintaining torque measurement capability

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

2Measurement precision

If resistive-type JTS sensors are used for high accuracy torque sensing, then measurement precision is improved, but cost and assembly complexity increase

Engineering Contradiction:
Improveaccuracy of torque measurementsVSAvoidcost of assembly and installation
Core Design Contradiction:
Measurement precisionVSEase of manufacture

Solution Approach 1:

The patent replaces traditional resistive strain gauge measurements with a mechanical-deformation-based sensing approach using capacitive sensors. The sensing means detect torque through mechanical deformation of the clutch components themselves, eliminating the need for expensive resistive sensors and their complex assembly while maintaining adequate measurement accuracy for collision detection applications

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

3Measurement precision

If a JTS is stacked on top of an overload clutch for collision detection, then collision detection sensitivity is improved, but volume and assembly complexity increase

Engineering Contradiction:
Improvecollision detection sensitivityVSAvoidvolume of overload clutch
Core Design Contradiction:
Measurement precisionVSVolume of moving object

Solution Approach 1:

The patent merges the joint torque sensor and overload clutch into a single integrated unit. The sensing means are embedded within the clutch structure, with capacitive sensors positioned between the first and second flanges. This integration eliminates the need for stacking separate components, maintaining collision detection sensitivity while significantly reducing the overall volume of the assembly

Inventive Principle:
Principle #5Merging (Combining)

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 provides a compact, less complex overload clutch with integrated sensing that accurately measures torque and detects disengagement, reducing volume and complexity while enabling sensitive collision detection.

Implementation Method 1

the sensor structure is configured to measure a first capacitance between the electrode and the other of the first and second rigid bodies

Methodology Applied
Scientific EffectCapacitance: Capacitance

Implementation Method 2

a deformable structure deformable in an angular direction of the flange, the deformable structure being defined by at least one torsion spring constant

Methodology Applied
Scientific EffectDeformation: Deformation

Data Source

PatentEP4419809B1Overload clutch with joint torque and disengagement sensing
Publication Date: 2025.07.23 UNIV GENT
  • EP4419809B1 patent drawingFigure 1
  • EP4419809B1 patent drawingFigure 2
  • EP4419809B1 patent drawingFigure 3

AI summary

An overload clutch comprising an input flange and an output flange, said clutch being configured to transmit torque between the input flange and the output flange and to disengage the clutch when the torque exceeds a predetermined threshold, characterised in, that the clutch comprises one or more sensing means at least partially integrated in at least one of the input and output flanges, and that the one or more sensing means are adapted to jointly determine the torque applied to transmitted between the input flange and the output flange of the clutch and to detect the disengagement of the clutch. A device comprising the clutch, a gear unit connected to the input flange, and a motor connected to the gear unit, configured to provide torque to the input flange through the gear unit.