Opto-Electronic Torque Measurement with Elastic Element and Light Barrier

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Existing opto-electronic torque measurement devices face challenges in achieving precise and efficient torque detection without significant structural changes or special components, and often suffer from friction and error-prone measurements.

Innovation Solution

A device featuring elastic elements between components that deform with torque changes, allowing direct and accurate torque detection through light barriers, with a simple and stable construction that enables both low and high torque measurement without axial displacement, and is independent of rotation direction.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If strain gauges are attached to the shaft surface to measure torque, then torque measurement is achieved, but the shaft requires certain length and high-wear slip rings are needed for signal transmission

Engineering Contradiction:
Improvetorque measurementVSAvoidshaft length requirement and slip rings
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent replaces the mechanical strain gauge measurement system with an optoelectronic system. Two coding disks with radially distributed recesses or windows are mounted on the shaft, and light barriers detect the overlap changes as the shaft twists. This substitution eliminates the need for long shafts and high-wear slip rings, achieving torque measurement through optical rather than mechanical means.

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

2Measurement precision

If coding disks with recesses are used to measure torsion optoelectronically, then torque measurement is achieved, but the structure becomes complex with multiple disks and light sources

Engineering Contradiction:
Improvetorque measurementVSAvoidstructure with multiple disks and light sources
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent combines two coding disks into a single integrated coding element structure. The coding element has two radially distributed sets of recesses or windows that correspond to the two measurement positions, eliminating the need for separate physical disks while maintaining the optoelectronic measurement functionality. This merging reduces structural complexity while preserving measurement precision.

Inventive Principle:
Principle #5Merging (Combining)

3Measurement precision

If elastic elements are added to enable torque transmission and angular position detection, then torque measurement accuracy improves, but the device complexity increases

Engineering Contradiction:
Improvetorque measurement accuracyVSAvoiddevice structure
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent introduces elastic elements as intermediaries between the drive element and the coding element. These elastic elements transmit torque while allowing relative angular displacement, which is detected by the light barriers. The elastic elements serve as a mediator that enables both torque transmission and angular position detection without requiring complex mechanical linkages or additional sensors.

Inventive Principle:
Principle #24Intermediary (Mediator)

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

Enables precise, fast, and error-free torque measurement across a wide range, with minimal structural changes and no need for special components, utilizing elastic elements and light barriers for accurate rotational angle detection.

Implementation Method 1

at least one elastic element (13) is provided between the first (2) and the second (3) component, which is deformable according to a torque acting upon it

Methodology Applied
Scientific EffectElasticity: Elasticity

Implementation Method 2

A light source is arranged on one side of the coding disks, and a light meter in the form of photodiodes is located on the opposite side of the disks. The amount of light passing through, which changes proportionally with the torsion, is detected by the photodiodes

Methodology Applied
Scientific EffectPhotoelectric Effect: Photoelectric Effect

Data Source

PatentEP3296713B1Device for determining torque, as well as a drive for actuating a machine element
Publication Date: 2020.04.15 BUESCH ARMATUREN GEYER GMBH
  • EP3296713B1 patent drawingFigure 1
  • EP3296713B1 patent drawingFigure 2
  • EP3296713B1 patent drawingFigure 3a~3c

AI summary

The present invention relates to a device for opto-electronic torque determination comprising a first component (2), a second component (3), wherein the first component (2) is connectable to a drive element and the second component (3) to a driven element or vice versa, a first encoding element arranged on the first component (2), a second encoding element arranged on the second component (3), a first light barrier (6) that detects the rotational movement of the first encoding element, a second light barrier (7) that detects the rotational movement of the second encoding element, and an electronic evaluation unit (8) for acquiring and evaluating the signals originating from the first light barrier (6) and the second light barrier (7), wherein at least one elastic element is provided between the first (2) and the second component (3), which is deformable according to a torque acting upon it.and when the torque changes, a change in the angle of rotation of the components (2, 3) relative to each other can be detected and the torque can be determined from this.