Friction Liner Press-Fit Design for Sheave Installation

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Existing elevator sheave liner systems face challenges with materials of low elasticity, requiring complex installation methods, special tooling, and adverse effects on ride quality, particularly with chain connectors and wedge-shaped liners.

Innovation Solution

A friction liner with a symmetric, semicircular top surface and upwardly extending grooves on the bottom surface, featuring a press-fit design that allows for easy installation and retention within a traction sheave cavity without the need for ancillary fastening hardware, utilizing a concave profile and neck portions for secure seating.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If chain connectors are used to attach traction liners, then the liners can be secured to the sheave, but ride quality deteriorates and special tooling is required

Engineering Contradiction:
Improveliner attachment securityVSAvoidride quality
Core Design Contradiction:
ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The invention extracts and eliminates the chain connector component entirely, replacing it with a direct press-fit attachment method where the liner itself forms the connection through its geometric profile matching the sheave cavity, thereby removing the source of ride quality deterioration while maintaining attachment security

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The invention introduces a complementary geometric profile interface between the liner and sheave cavity as an intermediary attachment mechanism, where the tapered profile and retention features create a secure press-fit connection without requiring external fasteners or chain connectors

Inventive Principle:
Principle #24Intermediary (Mediator)

2Reliability

If wedge shaped liners are used that frictionally interlock, then the liners can be retained on the sheave, but installation time increases

Engineering Contradiction:
Improveliner retentionVSAvoidinstallation time
Core Design Contradiction:
ReliabilityVSLoss of time

Solution Approach 1:

The invention inverts the traditional wedge-shaped retention approach by using a press-fit design where the liner is inserted in its final position with the tapered profile facilitating easy insertion, while retention is achieved through complementary geometric features rather than friction-based wedging that requires complex installation procedures

Inventive Principle:
Principle #13The other way round (Inversion)

3Reliability

If existing sheave dimensions are modified to accommodate new liner retention methods, then liner security improves, but manufacturing complexity increases

Engineering Contradiction:
Improveliner securityVSAvoidsheave manufacturing complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The invention applies local quality by modifying only specific localized features of the sheave cavity (the profile shape and retention features) rather than changing overall sheave dimensions, allowing the majority of the sheave structure to remain unchanged and simplifying manufacturing while achieving secure liner retention

Inventive Principle:
Principle #3Local quality

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 enables easy installation and removal of the liner without affecting existing sheave dimensions, reduces the required installation force, and allows for continuous manufacturing processes, improving ride quality and eliminating the need for special tooling.

Implementation Method 1

the liner is widthwise resiliently flexible in the bottom portion

Methodology Applied
Scientific EffectElasticity: Elasticity

Implementation Method 2

A friction liner with a symmetric, semicircular top surface and upwardly extending grooves on the bottom surface, featuring a press-fit design that allows for easy installation and retention within a traction sheave cavity

Methodology Applied
Scientific EffectFriction: Friction

Data Source

PatentEP3960685B1A single groove friction liner and traction sheave
Publication Date: 2023.08.09 OTIS ELEVATOR CO
  • EP3960685B1 patent drawingFigure 1
  • EP3960685B1 patent drawingFigure 2~4
  • EP3960685B1 patent drawingFigure 5~7

AI summary

Disclosed is a system comprising a traction sheave (210) and a liner (200), the liner (200) comprising: a top surface and a bottom surface (230) mutually spaced on a height-wise axis (H), a front surface and a back surface mutually spaced on lengthwise axis (L), and a plurality of side surfaces including a first side surface and a second side surface mutually spaced in a widthwise axis (W); wherein a first cross sectional profile of the plurality of side surfaces forms a convergent-divergent profile; wherein the bottom surface (230) of the liner (200) includes a first groove (280) extending height-wise upwardly; and wherein the traction sheave (210) comprises a cavity having a same height-wise span as the liner, the cavity comprising a plurality of side surfaces having a second profile that is complementary to the first profile wherein the liner (200) comprises a nominal clearance fit when seated within the cavity.