Elevator Brake Coil Configuration for Comfortable Stopping

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Solution Overview

Problem

Existing elevator systems experience rapid and uncomfortable braking due to high instantaneous brake torque, which is not effectively controlled, leading to passenger discomfort during emergency stops.

Innovation Solution

The elevator system employs a controller to switch the electrical configuration of coils between parallel and series connections based on operating modes (motoring or regenerative) to control the braking time by altering the voltage distribution across the coils, allowing for adjustable braking times.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a single electrical coil is used in the brake, then the brake torque is high and the stopping distance is short, but the braking time is too short causing passenger discomfort

Engineering Contradiction:
Improvestopping distanceVSAvoidbraking time
Core Design Contradiction:
ReliabilityVSDuration of action of moving object

Solution Approach 1:

The brake system is segmented into two separate coils (first coil and second coil) instead of using a single coil. This allows independent control of each coil's electrical configuration, enabling the system to extend braking time by controlling the de-energization sequence while maintaining the reliability of short stopping distance through adequate brake torque.

Inventive Principle:
Principle #1Segmentation

2Speed

If the coil drops immediately in emergency stop, then the brake response is fast, but the high instantaneous torque causes passenger discomfort

Engineering Contradiction:
Improvebrake response speedVSAvoidpassenger discomfort
Core Design Contradiction:
SpeedVSObject-affected harmful factors

Solution Approach 1:

In emergency stop scenarios, the system performs preliminary action by first de-energizing one coil while maintaining the other coil energized. This staged approach allows the brake torque to be applied more gradually, extending the braking time and reducing instantaneous torque peaks that cause passenger discomfort, while still achieving fast overall response.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The brake system uses periodic action by controlling the de-energization of coils in a staged sequence rather than simultaneously. This creates a controlled temporal pattern of torque application that reduces shock and discomfort to passengers while maintaining effective braking performance.

Inventive Principle:
Principle #19Periodic action

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

This solution enables precise control over braking time, allowing for slower or faster braking depending on the elevator's operational mode, thereby enhancing passenger comfort and system efficiency.

Implementation Method 1

the brake includes a first coil and a second coil, each coil having an electrical configuration that alters a voltage distribution across the coils

Methodology Applied
Scientific EffectMagnetic field: Magnetic Field

Implementation Method 2

A brake is used to stop rotation of the traction sheave and halt motion of the elevator car

Methodology Applied
Scientific EffectFriction: Friction

Data Source

PatentEP3429950B1Management of multiple coil brake for elevator system
Publication Date: 2022.03.09 OTIS ELEVATOR CO
  • EP3429950B1 patent drawingFigure 1
  • EP3429950B1 patent drawingFigure 2
  • EP3429950B1 patent drawingFigure 3

AI summary

An elevator system includes an elevator car; a machine to impart motion to the elevator car; a brake to stop rotation of the machine, the brake comprising a first coil and a second coil, wherein removing power from the first coil and the second coil applies the brake to the machine; and a controller in communication with the brake, the controller configured to connect the first coil and the second coil in one of a first electrical configuration and a second electrical configuration.