Elevator Sheave Liner Wear Indicators for Timely Replacement

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Solution Overview

Problem

Existing elevator systems face challenges in economically and reliably determining when sheave liners need replacement, leading to unnecessary costs and downtime due to either premature or delayed replacement, which affects the reliability and maintenance efficiency of the roping system.

Innovation Solution

The introduction of an elevator sheave liner with a liner body featuring a plurality of blind holes of varying depths and widths, providing a visible indication of wear over time, allowing for efficient and straightforward assessment of the liner's condition without requiring special tools or instruments.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If sheave liners are replaced frequently to ensure safety, then reliability of the roping system is improved, but productivity deteriorates due to unnecessary downtime and increased maintenance costs

Engineering Contradiction:
Improvereliability of the roping systemVSAvoidelevator availability
Core Design Contradiction:
ReliabilityVSProductivity

Solution Approach 1:

The blind holes are pre-formed at different depths and positions on the sheave liner during manufacturing. These holes serve as predetermined wear indicators that will progressively become visible as the liner wears, allowing maintenance personnel to assess liner condition without special tools or complex measurements.

Inventive Principle:
Principle #10Preliminary action

2Productivity

If sheave liners are replaced infrequently to maximize productivity, then elevator availability is improved, but reliability deteriorates due to increased risk of roping wear and failure

Engineering Contradiction:
Improveelevator availabilityVSAvoidroping system safety
Core Design Contradiction:
ProductivityVSReliability

Solution Approach 1:

The visible blind holes provide direct visual feedback on the wear condition of the sheave liner. As the liner material wears away, previously hidden blind holes become visible through the outer surface, creating a clear feedback mechanism that indicates when the liner has reached critical wear thresholds and requires replacement.

Inventive Principle:
Principle #23Feedback

3Measurement precision

If complex measurement tools and procedures are used to assess liner wear, then measurement precision is improved, but device complexity and ease of operation worsen

Engineering Contradiction:
Improvewear assessment accuracyVSAvoidease of wear assessment
Core Design Contradiction:
Measurement precisionVSEase of operation

Solution Approach 1:

The blind holes create visual contrast changes on the sheave liner surface as they become visible through wear. This color/visibility change provides an intuitive, easy-to-interpret indicator of wear progression that requires no specialized knowledge or tools, simply visual inspection by maintenance personnel.

Inventive Principle:
Principle #32Color changes

Data Source

PatentEP3613696B1Elevator sheave liner including wear indicators
Publication Date: 2021.12.08 OTIS ELEVATOR CO
  • EP3613696B1 patent drawingFigure 1
  • EP3613696B1 patent drawingFigure 2~6
  • EP3613696B1 patent drawingFigure 7~9

AI summary

An illustrative example embodiment of an elevator sheave liner includes a liner body (33) having a first surface (34) configured to engage an elevator load bearing member and an oppositely facing second surface (36). The liner body (33) includes a plurality of blind holes (40, 42, 44) in the second surface (36) including at least a first blind hole (40) and a second blind hole (44). The first blind hole (40) has a first depth (D1) and the second blind hole has (44) a second, different depth (D2). A material of the liner body (33) has a first thickness (T1) between the first blind hole (40) and the first surface (34) and a second, different thickness (T2) between the second blind hole (44) and the first surface (34).