Torque Limiting Coupling Slip Detection With High-Resolution Encoders

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Solution Overview

Problem

Current torque limiting couplings, especially friction couplings, lack the capability to accurately detect small slip events and do not have mechanical release protection, which can lead to overheating and reduced lifespan, and existing monitoring systems are limited in precision and cost-effective solutions.

Innovation Solution

The use of additional detectors to read phase-shifted markings on encoders with a high number of markings, such as 80 or more, allows for precise detection of slip events in degrees, enabling early detection of slips and preventing driveline damage, with a control unit triggering disengagement and incorporating a release mechanism for overload protection.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If traditional monitoring systems with limited markings (1-2 per full circle) are used, then the device complexity is low, but the measurement precision of slip events is insufficient

Engineering Contradiction:
Improveslip event detection precisionVSAvoidencoder markings quantity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The encoder circumference is divided into multiple discrete markings (at least 30, preferably 80 or more), transforming a continuous rotation measurement into discrete detectable segments. This segmentation enables precise detection of small slip events by providing multiple reference points around the full circle, directly resolving the contradiction between measurement precision and device complexity.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent transitions from detecting only full rotations (0-dimensional count) to detecting angular positions (1-dimensional continuous measurement). By measuring the angular position of markings relative to a reference point, the system achieves high-resolution slip detection without proportionally increasing complexity, as the additional information comes from spatial positioning rather than quantity multiplication.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

2Reliability

If friction couplings without mechanical release protection are used, then the ease of operation is maintained, but the reliability and lifespan are reduced due to overheating

Engineering Contradiction:
Improvecoupling lifespanVSAvoidrelease mechanism structure
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The release mechanism is pre-configured with a release element positioned to engage with a reference marking on the encoder. Before slip events cause damage, the monitoring system continuously checks angular positions and can trigger preliminary release action when predetermined slip thresholds are approached, preventing overheating and extending coupling lifespan without requiring complex real-time mechanical interventions.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The encoder provides continuous feedback on the angular position of markings, enabling the control system to monitor slip events in real-time. This feedback loop allows the system to detect small slip events, calculate cumulative slip, and trigger the release mechanism when predefined thresholds are exceeded, directly improving reliability while maintaining operational simplicity through electronic control rather than complex mechanical systems.

Inventive Principle:
Principle #23Feedback

3Measurement precision

If high-resolution encoders with 80 or more markings are used, then the measurement precision of slip events is enhanced, but the device complexity increases

Engineering Contradiction:
Improveslip angle detection accuracyVSAvoidencoder and detector system
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The encoder system serves multiple functions: it provides reference markings for slip detection, enables angular position measurement, and facilitates full rotation counting. By making the encoder multi-functional, the patent achieves high measurement precision without adding separate dedicated components for each function, thereby reducing the overall complexity increase despite using high-resolution encoders with 80 or more markings.

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

4Reliability

If continuous monitoring of slip events is implemented, then the reliability is improved through early detection, but the energy consumption increases

Engineering Contradiction:
Improvedriveline protection capabilityVSAvoidmonitoring system energy consumption
Core Design Contradiction:
ReliabilityVSUse of energy by moving object

Solution Approach 1:

Instead of continuous high-power monitoring, the system uses periodic evaluation of slip events based on encoder markings. The control unit evaluates slip at discrete intervals determined by marking passages, enabling early detection of problematic slip patterns while consuming energy only when measurements are taken and evaluations are performed, rather than maintaining constant high-power monitoring states.

Inventive Principle:
Principle #19Periodic action

Data Source

PatentEP3440371B1Torque limiting coupling
Publication Date: 2021.01.20 VOITH PATENT GMBH
  • EP3440371B1 patent drawingFigure 1~2
  • EP3440371B1 patent drawingFigure 3~4

AI summary

The invention is directed on a torque limiting coupling (3) for a driveline (2). An input side (4) of the torque limiting coupling (3) is connectable to a power unit (2) and an output side (5) is connectable to a load (6). A first speed sensor (10) is assigned to the input side (4) and a second speed sensor (20) is assigned to the output side (5) of the torque limiting coupling (3). At least one of the sensors comprises at least 30, preferable at least 40, markings.