Elevator Governor Flyweight Stopper Mechanism

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Solution Overview

Problem

Conventional elevator governors generate vibrations and noises due to ratchet operation, leading to reliability issues from part wear, and fail to differentiate between ascent and descent speeds for overspeed detection.

Innovation Solution

An elevator governor with a sheave, fly-weights, a stopper, and rotational position detection means that adjusts the fly-weight's movement based on rotation direction, preventing excessive radial movement and using a stopper to stabilize the sheave during high-speed operations.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If a ratchet mechanism is used to transmit rotation to overspeed detection mechanisms with different detection speeds, then overspeed detection adapted to each ascent and descent speed is achieved, but vibrations and noises are generated and part wear increases leading to decreased reliability

Engineering Contradiction:
Improveoverspeed detection adapted to each ascent and descent speedVSAvoidgovernor reliability
Core Design Contradiction:
Adaptability or versatilityVSReliability

Solution Approach 1:

The patent extracts and removes the ratchet mechanism from the system, replacing it with a stopper mechanism that prevents the flyweight from returning to its initial position. This eliminates the harmful vibrations and noises generated by the ratchet while maintaining the ability to detect overspeed in different rotational directions through the flyweight's positional memory function.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The patent employs a flyweight that dynamically changes position based on rotational speed and direction. The flyweight moves radially outward during acceleration and remains in the accelerated position during deceleration, creating a dynamic system that adapts to different operational phases without requiring mechanical transmission elements like ratchets.

Inventive Principle:
Principle #15Dynamics

2Device complexity

If conventional governors use a single overspeed detection mechanism, then the configuration is simple, but overspeed detection cannot be differentiated between ascent and descent speeds

Engineering Contradiction:
Improvegovernor configuration simplicityVSAvoidoverspeed detection differentiation
Core Design Contradiction:
Device complexityVSAdaptability or versatility

Solution Approach 1:

The patent makes the single flyweight mechanism multi-functional by utilizing its ability to maintain positional memory in different rotational directions. The same flyweight serves both as an overspeed detector for ascent and descent operations, eliminating the need for separate detection mechanisms while maintaining configuration simplicity.

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

Solution Approach 2:

The stopper acts as an intermediary element that enables the flyweight to maintain its accelerated position during deceleration. This intermediary mechanism allows the system to differentiate between ascent and descent overspeed conditions without adding complex detection mechanisms, as the stopper's engagement and disengagement patterns differ based on rotational direction.

Inventive Principle:
Principle #24Intermediary (Mediator)

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 configuration enables effective overspeed detection with rotation dependence, reducing vibrations, noises, and part wear, while allowing for differentiated speed detection during ascent and descent.

Implementation Method 1

a fly-weight which is provided on a side surface of the sheave and increases and decreases a moving quantity to a radial outer side of the sheave in response to an increase and decrease in the rotation speed of the sheave

Methodology Applied
Scientific EffectCentrifugal force: Centrifugal Force

Data Source

PatentEP2617672B1Speed governor for elevator
Publication Date: 2018.11.28 MITSUBISHI ELECTRIC CORP
  • EP2617672B1 patent drawingFigure 1
  • EP2617672B1 patent drawingFigure 2~3
  • EP2617672B1 patent drawingFigure 4~5

AI summary

Provided is an elevator governor capable of realizing, with a simple configuration, an overspeed detection mechanism to which rotation dependence is added while preventing a decrease in reliability due to the generation of vibrations and noises and the wear of parts. For this purpose, the elevator governor includes: a sheave which changes the rotation speed in one direction in response to the ascent speed of an ascending and descending body and changes the rotation speed in the other direction in response to the descent speed of the ascending and descending body; a fly-weight which increases and decreases an outward moving quantity to a radial outer side of the sheave in response to an increase and decrease in the rotation speed of the sheave; a detector which performs overspeed detection of the sheave when the fly-weight has moved to the radial outer side by a predetermined quantity; a stopper which prevents the fly-weight from moving to the radial outer side more than the predetermined quantity in the case where the sheave rotates in a predetermined direction; rotational position detection means which detects a rotational position of the sheave; object detection means which detects the stopper in the case where the stopper has approached the object detection means; and determination means which determines a position of the stopper with respect to the sheave on the basis of the rotational position of the sheave during the detection of the stopper by the object detection means.