Elevator Brake Torque Monitoring via Segmented Testing

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Solution Overview

Problem

Current methods for monitoring the condition of multi-brake elevator hoisting machinery provide limited information, making it difficult to perform accurate and timely maintenance, as they do not effectively determine the individual braking torque of each brake unit or predict changes in their working condition.

Innovation Solution

A method involving a test sequence where at least one brake unit is held in the open position while the rest are in the closed position, with a gradually increasing or decreasing test torque applied, monitoring movement, and registering the torque magnitude when movement starts or exceeds a limit, repeated with different configurations to determine individual braking torques and predict brake unit conditions.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If traditional brake monitoring methods are used, then the system structure remains simple, but the measurement precision of brake condition is insufficient

Engineering Contradiction:
Improvebrake condition measurement precisionVSAvoidmonitoring system complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent segments the brake system into multiple independent brake units (first brake unit, second brake unit, third brake unit) and tests each unit individually by isolating it from the others. This segmentation allows precise measurement of each brake's torque contribution without interference from other brakes, thereby improving measurement precision while keeping the test setup manageable through systematic isolation of components.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent introduces an intermediary testing mechanism where brake units are sequentially isolated and tested individually. By using intermediate test configurations where only one brake unit is engaged at a time, the system can precisely measure each brake's performance without the complexity of analyzing combined brake interactions, thus improving measurement precision while controlling system complexity through structured intermediate states.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Reliability

If comprehensive brake testing is performed, then the reliability of brake condition assessment is improved, but the loss of time for maintenance scheduling increases

Engineering Contradiction:
Improvebrake condition assessment reliabilityVSAvoidmaintenance scheduling time
Core Design Contradiction:
ReliabilityVSLoss of time

Solution Approach 1:

The patent performs preliminary testing of each brake unit individually before comprehensive system operation. By conducting isolated tests of each brake unit (first, second, and third brake units) in advance, the system gathers reliable condition data for each component separately. This preliminary action enables more efficient maintenance scheduling because the reliability assessment is already completed before full system deployment, reducing the time needed for later comprehensive evaluations.

Inventive Principle:
Principle #10Preliminary action

3Loss of information

If individual brake unit torques are determined, then the information completeness for maintenance decisions is improved, but the device complexity for torque measurement increases

Engineering Contradiction:
Improvebrake torque information completenessVSAvoidtorque measurement system complexity
Core Design Contradiction:
Loss of informationVSDevice complexity

Solution Approach 1:

The patent segments the torque measurement process by isolating each brake unit individually during testing. By measuring the torque of the first brake unit, then the second brake unit, and finally the third brake unit separately through systematic isolation, the system achieves complete torque information for each component. This segmentation approach provides comprehensive torque data without requiring complex simultaneous measurement of all brakes, as each measurement is performed in isolation using the same basic measurement apparatus.

Inventive Principle:
Principle #1Segmentation

Data Source

PatentEP4438541A1Method for monitoring elevator brakes and elevator arrangement
Publication Date: 2024.10.02 KONE OYJ
  • EP4438541A1 patent drawingFigure 1~2
  • EP4438541A1 patent drawingFigure 3~4
  • EP4438541A1 patent drawingFigure 5

AI summary

The invention relates to a method for monitoring brakes of a multi-brake hoisting machinery (2), the method comprising performing a test sequence (100), wherein the test sequence comprises: holding (101) at least one brake unit (5) in the open position while holding the rest of the brake units (5) in the closed position; and ramping (102;102') up a test torque with the motor (3), or alternatively ramping (102') down a test torque with the motor (3); and monitoring (103) movement of a component of the hoisting machine during the ramping up or down (102;102'), respectively, said component preferably being the rotor of the motor (3) or the drive member (4); and detecting (104) starting of movement of the component or that amount of movement exceeds a limit amount during the ramping up or down (102;102'), respectively; and registering (105) the magnitude of the test torque (Ttest) at the moment when the movement started or exceeded a limit amount. The method comprises repeating (200) the performing (100) a test sequence one or more times with a new test configuration, the combinations of brake units (5) held in open position and in closed position being different in the test sequences; and determining (300) an individual braking torque (Ti) of each individual brake unit (5) based on the registered magnitudes of test torques (Ttest), and determining (400) and/or predicting condition of the brake units (5) based on said individual braking torques. The invention also relates to an elevator arrangement (1) implementing the method.