Sequential Elevator Brake Segments for Smooth Emergency Deceleration

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Solution Overview

Problem

Conventional electromagnetic brake systems in elevators cause passenger discomfort due to abrupt deceleration during emergency stops, especially in lighter elevator cars, leading to high deceleration rates and potential belt slippage, which is not compliant with regulatory requirements.

Innovation Solution

A brake system with multiple sequentially operated brake segments, each equipped with an electromagnetic coil to control the timing and rate of brake torque, allowing for smoother deceleration and compliance with regulatory codes by distributing brake torque over multiple segments, including an auxiliary segment to prevent over-speed conditions.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Force

If a conventional electromagnetic brake system is used in lighter elevator cars, then the brake system can provide sufficient stopping force, but the deceleration rate becomes too high causing passenger discomfort and potential belt slippage

Engineering Contradiction:
Improvebrake forceVSAvoiddeceleration rate
Core Design Contradiction:
ForceVSSpeed

Solution Approach 1:

The brake system is divided into multiple independently controllable brake segments (first, second, and third brake segments) that can be applied sequentially. This segmentation allows the total brake torque to be distributed over time, reducing the peak deceleration rate while still providing sufficient total stopping force to meet regulatory requirements for stopping 125% of rated load.

Inventive Principle:
Principle #1Segmentation

2Loss of time

If the brake torque is applied abruptly to stop the elevator car quickly, then the stopping distance is reduced, but passenger discomfort increases due to high deceleration

Engineering Contradiction:
Improvestopping timeVSAvoidpassenger discomfort
Core Design Contradiction:
Loss of timeVSObject-affected harmful factors

Solution Approach 1:

The brake segments are applied in a predetermined sequence with controlled timing. The first brake segment is applied initially, followed by the second and third segments in sequence. This preliminary planning of brake application timing allows the system to achieve stopping within regulatory time limits while distributing the deceleration load to minimize passenger discomfort.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The brake system dynamically adjusts the application timing and torque distribution across multiple brake segments based on operational requirements. The sequential application of brake segments with different timing characteristics allows the system to optimize the deceleration profile, achieving both rapid stopping and passenger comfort.

Inventive Principle:
Principle #15Dynamics

3Object-affected harmful factors

If multiple brake segments are used to reduce deceleration rate, then passenger comfort improves, but the device complexity increases

Engineering Contradiction:
Improvepassenger discomfortVSAvoidbrake system complexity
Core Design Contradiction:
Object-affected harmful factorsVSDevice complexity

Solution Approach 1:

Multiple brake segments are concentrically arranged on the same brake disc, with each segment nested within the same radial space. This nested configuration allows multiple independently controllable brake segments to be integrated into a compact structure, reducing the overall space requirement and simplifying the mechanical arrangement compared to distributed brake systems.

Inventive Principle:
Principle #7Nested doll (Nesting)

Solution Approach 2:

Multiple brake segments share common mechanical components including a single brake disc, common mounting structure, and integrated actuation system. This multi-functionality approach allows the system to achieve sequential brake application and reduced deceleration rates while minimizing the increase in overall system complexity through component sharing.

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

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 smoother and more controlled deceleration during emergency stops, reducing passenger discomfort and the risk of belt slippage, while meeting regulatory requirements for stopping 125% and 100% of the rated load, even in case of partial segment failure.

Implementation Method 1

each of the multiple of sequentially operated brake segments includes an electromagnetic coil that controls the timing and the rate of brake torque for that brake segment

Methodology Applied
Scientific EffectElectromagnetic force: Lorentz Force

Data Source

PatentEP3112305B1Electromagnetic brake system for elevator application
Publication Date: 2024.05.15 OTIS ELEVATOR CO
  • EP3112305B1 patent drawingFigure 1
  • EP3112305B1 patent drawingFigure 2~3
  • EP3112305B1 patent drawingFigure 4

AI summary

A brake for an elevator car (12) includes a multiple of sequentially operated brake segments (40A, 40B, 40C) to control a timing and a rate of brake torque for deceleration of the elevator car.