Elevator Governor Core Ring Assembly for Rope Tension Limiting

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Solution Overview

Problem

High-speed elevators using car-mounted governors face issues with excessive tensile force on the rope and the safety activating module, particularly at varying heights, leading to stringent requirements for rope design and potential wear, as well as excessive force output during braking.

Innovation Solution

A core ring assembly with axially arranged portions and a pressure generation mechanism, featuring conical contact surfaces and a gap to maintain consistent friction force, reduces the tensile force on the rope and filters out excessive force output to the safety activating module, ensuring consistent tensile force across different heights.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the governor is actuated at higher heights, then the tensile force on the rope increases, but this leads to excessive force output and potential wear

Engineering Contradiction:
Improvegovernor actuation reliabilityVSAvoidtensile force on rope
Core Design Contradiction:
ReliabilityVSForce

Solution Approach 1:

The core ring is divided into a first portion and a second portion that can rotate relative to each other. The first portion rotates by receiving actuation torque from the over-speed actuating mechanism, while the second portion rotates with the first portion by virtue of friction of contact surfaces. This segmentation allows the system to decouple the rope tension force from the safety activating module actuation force.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The core ring assembly acts as an intermediary mechanism between the over-speed actuating mechanism and the safety activating module. It transfers and transforms the actuation torque through friction-based rotation between its two portions, effectively mediating the force transmission and reducing the excessive tensile force that would otherwise be transmitted to the rope.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Strength

If the rope diameter and weight are increased to handle higher tensile forces, then the rope strength increases, but the system complexity and weight increase

Engineering Contradiction:
Improverope strengthVSAvoidrope weight
Core Design Contradiction:
StrengthVSWeight of moving object

Solution Approach 1:

By segmenting the core ring into two rotatable portions with friction-based coupling, the invention creates a force transformation mechanism that reduces the tensile force demand on the rope regardless of activation height, eliminating the need to increase rope diameter and weight for higher strength capacity.

Inventive Principle:
Principle #1Segmentation

3Device complexity

If the governor uses a traditional core ring design, then the structure is simple, but excessive force output damages the safety activating module during braking

Engineering Contradiction:
Improvecore ring structure complexityVSAvoidexcessive force output
Core Design Contradiction:
Device complexityVSObject-generated harmful factors

Solution Approach 1:

The core ring is segmented into two portions that rotate relative to each other through friction contact. This segmentation creates a natural force-limiting mechanism where the friction between contact surfaces controls the torque transmission, preventing excessive force output to the safety activating module during braking while maintaining relatively simple structure.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The friction between the contact surfaces of the two core ring portions, which could be considered a loss mechanism, is converted into a beneficial force-limiting feature. The friction prevents excessive torque transmission during braking, protecting the safety activating module from damage while maintaining structural simplicity.

Inventive Principle:
Principle #22Blessing in disguise (Convert harm into benefit)

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 core ring assembly maintains consistent tensile force on the rope and reduces excessive force output to the safety activating module, alleviating the need for increased rope diameter and weight, thus addressing the contradictions in rope design requirements and preventing wear and impact during braking.

Implementation Method 1

the second portion of the core ring rotates with the first portion of the core ring by virtue of friction of the contact surfaces

Methodology Applied
Scientific EffectFriction: Friction

Data Source

PatentEP3360834B1Ring assembly for elevator governor, governor and elevator system
Publication Date: 2021.03.03 OTIS ELEVATOR CO
  • EP3360834B1 patent drawingFigure 1
  • EP3360834B1 patent drawingFigure 2
  • EP3360834B1 patent drawingFigure 3

AI summary

The present invention provides a core ring assembly for an elevator governor, a governor and an elevator system, wherein the core ring assembly comprises: a first portion and a second portion of a core ring which are axially arranged, the first portion and the second portion of the core ring having contact surfaces therebetween; and a pressure generation mechanism for generating a pressure between the first portion and the second portion of the core ring, wherein the first portion of the core ring rotates by receiving an actuation torque from an over-speed actuating mechanism, and the second portion of the core ring rotates with the first portion of the core ring by virtue of friction of the contact surfaces and enables a safety activating module. The core ring assembly provided by the embodiment of the present invention has a peak torque limiting function and a compact structure.