Elevator Car Twin Frame Structure for Torsional Resistance
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Solution Overview
Problem
Existing self-supporting elevator car designs face challenges in achieving torsional resistance and minimizing construction space while maintaining driving comfort, due to issues with resonance and complex manufacturing processes.
Innovation Solution
A support structure comprising two closed frames made of closed hollow profiles, arranged around the car and connected by bridges, which eliminates the need for self-supporting gratings and reduces the risk of twisting by providing massive support at the center of gravity, thus minimizing space usage and resonance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Stability of the object's composition
If self-supporting elevator car designs use grating constructions connected by sheet metal panels, then the car achieves self-support capability, but the torsional resistance is insufficient particularly when the car size and area increase
Solution Approach 1:
The support structure is segmented into two separate closed frames (first and second closed frames) positioned at different locations around the car. Each frame independently provides structural support and torsional resistance, with the frames being connectable to each other for enhanced stability. This segmentation allows each frame to effectively resist torsional forces without overloading a single structure.
Solution Approach 2:
The invention uses composite construction combining closed frames (made of metal profiles or tubes) with sheet metal panels. The closed frames provide rigid structural support and torsional resistance, while the sheet metal panels provide enclosure and additional structural contribution. This composite approach creates a self-supporting car that achieves both self-support capability and adequate torsional resistance.
2Strength
If closed frames are positioned to optimally support the car structure, then torsional resistance is enhanced, but the construction space in the shaft head increases
Solution Approach 1:
The closed frames are positioned in multiple spatial dimensions around the car - one frame can be positioned above the car and another below the car, or at different lateral positions. This multi-dimensional arrangement allows the support structures to be distributed in space, providing adequate torsional resistance while minimizing the projection in any single dimension, particularly in the shaft head area.
Solution Approach 2:
The closed frames are strategically positioned at specific locations where they provide maximum structural efficiency. The frames are connectable at optimized positions to achieve the best balance between torsional resistance and space utilization. This local optimization ensures that the support structures are placed where they are most needed rather than uniformly distributed.
3Ease of manufacture
If rigid constructions are used for car roof and car floor connected by sheet metal panels, then the manufacturing complexity is reduced, but the resonance damping becomes difficult to achieve
Solution Approach 1:
The invention changes the structural parameters by using closed frames with substantial mass and moment of inertia compared to simple sheet metal connections. These frames have different vibrational characteristics and natural frequencies that help dampen resonance. The closed frame construction provides inherent vibration damping while maintaining ease of manufacture through standardized profile sections.
Data Source
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AI summary
The lift has two frames (2a, 2b) rigidly connected to one another by bridges to result in a unified, fixed carrying structure in the shape of a twin frame. The frames are located symmetrically to a side of guide rails, and are arranged at a distance from one another in such a manner that a space remains between the frames for accommodating a lift element. Each of the frames is an integral component of two side walls and a ceiling of a lift car, and rests with entire surfaces from outside against the side walls and the ceiling of the car.