Elevator Reduced Balance System Tension Control
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Elevator systems face challenges in balancing, leading to risks of slipping and inefficient energy usage, particularly due to the direct dependence on cabin mass and counterweight mass ratios, which affects adhesion and energy consumption.
Innovation Solution
A reduced balance elevator system with a second pulley to maintain tension and adhere to pulleys, reducing the dependence on cabin mass for grip, and a control method that adjusts speed based on load measurements to optimize energy usage and comfort.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Use of energy by moving object
If the mass of the counterweight is reduced to save energy, then energy consumption decreases, but the risk of slippage on the pulley increases
Solution Approach 1:
The patent applies counterweight principle by introducing a second pulley with a counterweight that balances the tension forces in the belt. This allows the main counterweight to be reduced for energy savings while the second counterweight system maintains sufficient tension to prevent slippage on the drive pulley.
Solution Approach 2:
The second pulley system acts as an intermediary mechanism that decouples the tension maintenance function from the main counterweight. This intermediary system ensures adequate belt tension for reliable power transmission while allowing the primary counterweight to be optimized for energy efficiency.
2Use of energy by moving object
If the cabin mass is reduced for energy efficiency, then energy consumption decreases, but the adhesion to pulleys deteriorates
Solution Approach 1:
The second counterweight system compensates for the reduced cabin mass by providing additional tension force. This ensures that the belt maintains sufficient adhesion to the drive pulley even when the cabin mass is reduced for energy efficiency purposes.
3Device complexity
If a single-drive pulley system is used to simplify the system, then device complexity decreases, but the risk of slippage increases
Solution Approach 1:
The patent segments the tension maintenance function into a separate second pulley system. This segmentation allows the main drive pulley to focus on power transmission while the second pulley specifically handles tension maintenance, preventing slippage without significantly increasing overall system complexity.
4Reliability
If the cabin speed is reduced below a predetermined speed value when load exceeds a threshold, then safety improves, but productivity decreases
Solution Approach 1:
The patent implements dynamic speed adjustment based on real-time load conditions. The control system continuously monitors the load and adjusts the cabin speed accordingly, maintaining high speed when safe and reducing speed only when necessary, thus optimizing both safety and productivity.
Solution Approach 2:
The system dynamically changes the speed parameter based on load threshold conditions. When the load exceeds the threshold, the speed parameter is adjusted below the predetermined value; otherwise, the cabin operates at optimal speed, balancing safety requirements with transport efficiency.
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
This system enhances safety and energy efficiency by minimizing slipping risks and adapting speed to load conditions, reducing energy consumption and improving user experience.
Implementation Method 1
there is a risk of the linear element slipping on the pulley when the tension ratio between the strands on either side of the pulley exceeds a certain threshold
Implementation Method 2
the contact is less dependent, or not at all, on the cabin mass, as it depends more on the balance and mechanics of the loop
Implementation Method 3
The proposed system includes a second pulley that allows the linear element(s) to be tensioned to the desired level, ensuring a strong contact with the pulleys
Implementation Method 4
If the cabin is loaded such that the load to be lifted is relatively small, the cabin movement can be achieved with relatively little power
Data Source
Figure 1~3
AI summary
An elevator system (1) comprising a car (2), a counterweight (3) having a counterweight mass value (Mcp) strictly less than the mass of the car plus half the maximum loading mass, and a control device (9) comprising receiving means for receiving a current loading measured value (Qmes), processing means for calculating a speed value depending on the current loading measured value, and transmission means for transmitting a control signal so as to cause the car to move at the calculated speed, and two pulleys (4, 5) intended to be installed at the respective ends of the elevator shaft, wherein at least one of the car and the counterweight is mounted on at least one linear element (4) that passes via the two pulleys so as to form a closed loop with said at least one of the car and the counterweight.