Elevator Rope Multi-Layer Strand Design for Stability
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Elevator ropes for super high-rise buildings require a high safety factor, high elastic coefficient, and low elongation rate to ensure stability and riding comfort during high-speed operations, while minimizing vibration and maintaining structural integrity.
Innovation Solution
A rope design featuring a center strand and multiple layers of twisted wires with specific diameter and pitch ratios, along with optimized spacing and fill factors, to enhance structural stability and reduce vibration.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Stability of the object's composition
If the number of outer layer strands is increased from eight to ten to improve structural stability, then the structural stability and filling factor improve, but the manufacturing complexity increases
Solution Approach 1:
The rope structure is divided into multiple layers with ten inner layer strands and ten outer layer strands, each layer independently configured. This segmentation allows the complex structure to be manufactured layer by layer, making the increased complexity manageable while achieving the desired structural stability and filling factor of 64-67%.
Solution Approach 2:
The rope employs a nested multi-layer structure where the center strand is surrounded by inner layer strands, which are in turn surrounded by outer layer strands. This nested arrangement with ten strands per layer optimizes space utilization and achieves high structural stability while maintaining manufacturability through systematic layer-by-layer construction.
2Strength
If higher strength wires are used to increase breaking load, then the breaking load increases, but the sheave life decreases due to increased friction and wear
Solution Approach 1:
The patent specifies that wire strength is maintained within the range of 1770-1960 MPa, avoiding excessively high strength values that would cause severe wear on sheaves. Simultaneously, the increased number of strands (ten per layer) and optimized diameter ratios distribute the load more effectively, achieving high breaking load without requiring wires of extreme strength, thereby preserving sheave life.
Solution Approach 2:
The rope employs a composite structure combining multiple strands of high-strength wire (1770-1960 MPa) arranged in a multi-layer configuration with optimized filling factors. This composite arrangement achieves the required breaking load through collective load distribution across ten inner layer strands and ten outer layer strands, rather than relying on individually extremely strong wires, thus reducing friction-induced wear on sheaves.
3Shape
If the filling factor is increased to 64-67% by optimizing strand diameters, then the roundness and dimensional stability improve, but the manufacturing precision requirements increase
Solution Approach 1:
The patent specifies precise diameter ratios: the center strand diameter is 0.33-0.35 times the circumscribed circle diameter, inner layer strand diameter is 0.13-0.15 times, and outer layer strand diameter is 0.22-0.24 times. These parameter ranges, combined with the ten-strand-per-layer configuration, achieve a filling factor of 64-67% that ensures excellent roundness and dimensional stability while providing manufacturable tolerances.
4Reliability
If ten inner layer strands and ten outer layer strands are used instead of eight, then the breaking load and safety factor increase, but the device complexity increases
Solution Approach 1:
The rope structure is segmented into ten inner layer strands and ten outer layer strands, with each strand independently configured and assembled. This segmentation enables the high safety factor required for super high-rise buildings to be achieved through systematic, manageable construction processes, making the increased complexity practical and implementable.
Solution Approach 2:
The nested multi-layer structure with ten strands per layer creates a highly reliable configuration where load is distributed across multiple concentric layers. This nested arrangement achieves the required safety factor for super high-rise applications while maintaining manufacturability through standardized layer-by-layer assembly procedures.
Data Source
Figure 1
Figure 2
AI summary
The present invention relates to a rope for an elevator. The rope for the elevator comprises: a center strand formed by twisting a plurality of wires; inner layer strands formed by twisting the plurality of wires and arranged along the outer periphery of the center strand; and outer layer strands formed by twisting the plurality of wires and arranged along the outer periphery of the inner layer strands, wherein ten of each of the inner layer strands and the outer layer strands are prepared, the diameter of the center strand, the diameter of the inner layer strand and the diameter of the outer layer strand are respectively 0.33-0.35 times, 0.13-0.15 times and 0.22-0.24 times as large as the diameter of a first imaginary circle circumscribed around the outer layer strands, and a fill factor is 64-67%.