Electromagnetic Brake Wear Detection via Coil Current Ratio

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Solution Overview

Problem

Conventional brake monitoring methods for hoisting devices are time-consuming, prone to errors, and require manual labor, leading to increased downtime and safety risks due to the inability to detect brake wear and malfunction in a timely manner, especially in high-risk environments like harbour cranes.

Innovation Solution

A method and device that monitor the condition of electromagnetic brakes by determining the electric current and current ratio as the braking surfaces move from a closed to an open state, allowing for predictive maintenance and reducing downtime by using a portable monitoring system that can be installed on hoisting devices.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If manual monitoring of brake friction surface thickness is performed using a slide gauge, then measurement capability is achieved, but time consumption and labor requirements increase significantly

Engineering Contradiction:
Improvebrake friction surface thickness measurementVSAvoidmaintenance time
Core Design Contradiction:
Measurement precisionVSLoss of time

Solution Approach 1:

The patent replaces the mechanical slide gauge measurement system with an electromagnetic monitoring system. The electromagnetic brake's coil current characteristics are analyzed to detect friction surface wear, eliminating the need for physical contact measurement and dramatically reducing maintenance time while maintaining measurement capability.

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

Solution Approach 2:

The brake system performs self-diagnosis by monitoring its own electromagnetic characteristics. The system uses the coil current data already present in the brake's operation to automatically detect wear conditions, eliminating the need for external manual measurement tools and reducing labor requirements.

Inventive Principle:
Principle #25Self-service

2Reliability

If manual brake monitoring is performed, then brake condition can be assessed, but safety risks increase due to maintenance personnel working at height

Engineering Contradiction:
Improvebrake condition assessmentVSAvoidsafety risk to maintenance personnel
Core Design Contradiction:
ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The patent replaces manual physical inspection with electromagnetic field-based monitoring. By analyzing the electrical characteristics of the brake coil, the system can assess brake condition remotely without requiring personnel to physically access high-risk areas, thereby eliminating safety risks while maintaining assessment reliability.

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

Solution Approach 2:

The patent introduces electromagnetic field measurements as an intermediary between the brake system and the monitoring function. Instead of direct physical contact with the brake components, the system uses electrical current characteristics as a mediator to infer wear conditions, enabling remote assessment and eliminating safety risks.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Reliability

If brake maintenance is performed using conventional methods, then brake condition can be checked, but production downtime increases

Engineering Contradiction:
Improvebrake maintenance capabilityVSAvoidproduction availability
Core Design Contradiction:
ReliabilityVSProductivity

Solution Approach 1:

The brake system continuously self-monitors its own condition through electromagnetic characteristic analysis during normal operation. This eliminates the need for scheduled shutdowns for inspection, as the brake provides its own diagnostic data, maintaining full production availability while ensuring maintenance capability.

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The monitoring system operates continuously during brake usage without interruption. The electromagnetic measurements are taken during normal brake operation, ensuring that the useful action of both production and monitoring occurs simultaneously without downtime, maximizing productivity while maintaining reliability.

Inventive Principle:
Principle #20Continuity of useful action

4Reliability

If multiple brakes in hoisting devices are monitored manually, then individual brake conditions can be assessed, but maintenance complexity increases due to the number of brakes and their variations

Engineering Contradiction:
Improvebrake condition monitoringVSAvoidmaintenance complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent develops a universal monitoring method that works across different brake models and manufacturers by analyzing common electromagnetic characteristics (coil current patterns). This single approach can monitor multiple varied brakes simultaneously, reducing maintenance complexity while maintaining comprehensive monitoring capability.

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

Solution Approach 2:

The system monitors changes in electromagnetic parameters (coil current magnitude, timing, and patterns) to detect wear across different brake types. By focusing on parameter changes rather than absolute values, the method adapts to variations between brakes while maintaining consistent monitoring effectiveness, simplifying the management of multiple diverse brakes.

Inventive Principle:
Principle #35Parameter changes

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 predictive maintenance, reduces downtime, and improves safety by allowing for timely detection of brake wear and malfunction, facilitating the scheduling of maintenance before failures occur and ensuring the continued operation of critical equipment like harbour cranes.

Implementation Method 1

magnetizing means that, in response to the electric current supplied to them, are arranged to generate a magnetic field

Methodology Applied
Scientific EffectElectromagnetic induction: Electromagnetic Induction

Data Source

PatentEP2904699B1Brake monitoring
Publication Date: 2020.12.16 KONECRANES GLOBAL OY
  • EP2904699B1 patent drawingFigure 1~2b
  • EP2904699B1 patent drawingFigure 3a~4b
  • EP2904699B1 patent drawingFigure 5~6

AI summary

Monitoring a brake (402) that comprises first (202,204) and second (206,204) braking surfaces and magnetizing means (210) that, in response to the electric current supplied to them, are arranged to generate a magnetic field that is arranged to move the braking surfaces (202,204,206) from a closed state, in which the braking surfaces are connected to each other, to an open state, in which the braking surfaces (202,204,206) are separated from each other. Determining the electric current of the brake as the braking surfaces (202,204,206) begin to move from the closed state to the open state, determining the maximum electric current of the magnetizing means (201) of the brake (402) in the open state, determining the condition of the brake (402) as a current ratio from the electric current measured as the braking surfaces (202,204,206) start to move to the maximum electric current.