Composite Elevator Belt for Lightweight Flexible Hoisting

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Solution Overview

Problem

Elevator systems face challenges with load-bearing members such as metal ropes and belts, which are heavy, inflexible, and have reduced high-temperature performance, particularly in high-rise applications, and existing solutions like carbon fiber composites do not adequately address these issues.

Innovation Solution

A belt system utilizing a tension member formed from aromatic polyester-based fibers, encapsulated in a jacket material, with a fabric construction that includes load-carrying fibers like carbon, glass, and aramid fibers, and a matrix material, providing improved flexibility and strength while reducing weight.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Strength

If metal ropes or traditional belts are used as load bearing members, then sufficient strength and stiffness are achieved, but the weight increases and flexibility decreases

Engineering Contradiction:
Improvetensile strengthVSAvoidbelt weight
Core Design Contradiction:
StrengthVSWeight of moving object

Solution Approach 1:

The belt uses a composite construction with aromatic polyester fibers (providing strength and stiffness) combined with carbon fiber composites (providing high strength-to-weight ratio). This composite approach allows the belt to achieve sufficient tensile strength while significantly reducing weight compared to traditional metal ropes or solid belts.

Inventive Principle:
Principle #40Composite materials

2Weight of moving object

If carbon fiber composite tension members are used, then weight is reduced and strength is improved, but flexibility decreases due to rigid thermoset matrix

Engineering Contradiction:
Improvetension member weightVSAvoidflexibility
Core Design Contradiction:
Weight of moving objectVSEase of operation

Solution Approach 1:

The patent changes the matrix material parameter from rigid thermoset to aromatic polyester fiber reinforcement within a flexible belt structure. This parameter change maintains the weight advantages of carbon fiber while restoring flexibility through the fiber orientation and matrix selection, allowing the belt to bend around sheaves effectively.

Inventive Principle:
Principle #35Parameter changes

3Weight of moving object

If carbon fiber composites with thermoset matrix are used, then strength-to-weight ratio is improved, but high temperature performance decreases

Engineering Contradiction:
Improvetension member weightVSAvoidhigh temperature performance
Core Design Contradiction:
Weight of moving objectVSTemperature

Solution Approach 1:

The belt employs a hybrid composite material system where aromatic polyester fibers provide thermal stability and resistance to degradation at elevated temperatures, while carbon fiber components maintain the high strength-to-weight ratio. This composite approach addresses both the weight reduction goal and the high temperature performance requirement simultaneously.

Inventive Principle:
Principle #40Composite materials

4Temperature

If steel elements are used for tension members, then high temperature performance is maintained, but weight increases and flexibility decreases

Engineering Contradiction:
Improvehigh temperature performanceVSAvoidtension member weight
Core Design Contradiction:
TemperatureVSWeight of moving object

Solution Approach 1:

The patent changes the material composition parameter from steel elements to aromatic polyester fiber-reinforced composite. This parameter change reduces density and weight while maintaining adequate high temperature performance through the selection of thermally stable aromatic polyester fibers that resist degradation in elevator operating conditions.

Inventive Principle:
Principle #35Parameter changes

Data Source

PatentEP3403978B1Elevator system belt
Publication Date: 2021.03.31 OTIS ELEVATOR CO
  • EP3403978B1 patent drawingFigure 1
  • EP3403978B1 patent drawingFigure 2~3
  • EP3403978B1 patent drawingFigure 4

AI summary

A belt (16) for an elevator system includes a tension member (24) extending at least partially across a belt width and extending longitudinally along a length of the belt (16), the tension member (24) formed at least partially from a plurality of aromatic polyester based fibers, and a jacket material (28) at least partially encapsulating the tension member (24). An elevator system includes a hoistway, an elevator car located in the hoistway and movable therein, and such a belt operably connected to the elevator car to suspend and/or drive the elevator car along the hoistway.