Aromatic Polyester Fiber Rope for Lightweight Elevator Load Bearing
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
High-rise elevator systems face challenges with heavy and rigid load-bearing members, such as metal ropes and coated steel belts, which are inefficient due to their weight and stiffness, and carbon fiber belts require rigid matrices that reduce flexibility.
Innovation Solution
A lifting member for elevator systems comprising a rope formed from a plurality of load-carrying fibers, including aromatic polyester fibers, with a coating layer that includes UV stabilizers and fluoropolymers, providing improved strength-to-weight ratio and flexibility.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If metal ropes are used as load bearing members, then strength is sufficient, but weight becomes excessive for high rise elevators
Solution Approach 1:
The patent applies composite materials by combining aromatic polyester fibers with a fluoropolymer coating layer. The aromatic polyester fibers provide the necessary tensile strength while being significantly lighter than metal ropes, and the fluoropolymer coating protects the fibers without adding excessive weight, thus resolving the contradiction between strength and weight
2Weight of moving object
If carbon fiber belts are used, then strength to weight ratio improves, but flexibility deteriorates due to rigid matrix requirement
Solution Approach 1:
The patent uses a fluoropolymer coating layer as a flexible protective shell that encapsulates the aromatic polyester fibers. This coating provides protection while maintaining flexibility, allowing the load bearing member to bend around sheaves without requiring rigid matrix structures, thus preserving flexibility while achieving weight reduction
3Strength
If coated steel belts are used, then strength is adequate, but weight remains too high for high rise use
Solution Approach 1:
The patent replaces steel cords with aromatic polyester fibers in a composite structure coated with fluoropolymer. This composite material provides comparable tensile strength to steel belts while significantly reducing weight, making the load bearing member suitable for high rise elevator applications
4Reliability
If rigid matrix material is used to protect carbon fiber, then protection is adequate, but flexibility is reduced requiring larger sheaves
Solution Approach 1:
The patent employs a fluoropolymer coating layer as a flexible protective shell that encapsulates the aromatic polyester fibers. This thin film provides adequate protection against environmental factors and mechanical damage while maintaining the flexibility of the load bearing member, eliminating the need for larger sheaves
Data Source
AI summary
A lifting member for an elevator system includes a rope formed from plurality of load carrying fibers extending along a length of the lifting member. The plurality of load carrying fibers including a plurality of aromatic polyester based fibers. A coating layer at least partially encapsulates the rope. An elevator system includes a hoistway, an elevator car disposed in the hoistway and movable therein, and a lifting member operably connected to the elevator car to suspend and/or drive the elevator car along the hoistway. The lifting member includes a rope formed from plurality of load carrying fibers extending along a length of the lifting member. The plurality of load carrying fibers including a plurality of aromatic polyester based fibers. A coating layer at least partially encapsulates the rope.