Elevator Holding Brake Sequential Engagement and Slipping Detection
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Solution Overview
Problem
Existing elevator systems face safety risks due to malfunctioning holding brakes, which can lead to hazardous situations when the traction sheave slips, and current maintenance methods are costly and expose systems to direct safety risks.
Innovation Solution
Implementing a safety device that controls holding brakes to engage sequentially, monitors slipping, and increases motor torque to prevent hazardous situations by engaging the second brake upon detection of slipping, and includes features for remote fault notification and motor power disconnection in case of overheating.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If holding brakes are used to maintain elevator position, then safety is improved, but brake malfunction can cause hazardous situations
Solution Approach 1:
The brake system is divided into multiple independent holding brakes (at least two) that can operate separately. This segmentation allows the system to detect brake malfunction by comparing the performance of individual brakes and engage backup brakes when one fails, thereby maintaining safety while identifying hazardous conditions.
Solution Approach 2:
The system performs preliminary testing of brake friction coefficients before full operation. By measuring the friction coefficient in advance and comparing it against predetermined thresholds, the system can detect potential brake failures before they lead to hazardous situations, allowing preventive engagement of backup brakes or alerting operators.
2Reliability
If regular maintenance programs are implemented, then brake condition is ensured, but large extra costs are incurred
Solution Approach 1:
The brake system performs self-diagnosis by automatically measuring its own friction coefficients and monitoring its condition in real-time operation. This self-monitoring capability eliminates or reduces the need for costly regular maintenance programs, as the system can detect its own degradation and alert operators only when necessary.
Solution Approach 2:
The system continuously monitors changes in brake friction coefficients as a key parameter. By tracking parameter changes over time and comparing them against thresholds, the system can predict brake wear and schedule maintenance only when needed, rather than following expensive fixed-schedule maintenance programs.
3Reliability
If brake friction coefficient is reduced due to oil or wear, then brake slipping occurs, but detection and response time is limited
Solution Approach 1:
The system implements continuous feedback monitoring of brake friction coefficients during operation. By measuring the friction coefficient in real-time and comparing it against predetermined thresholds, the system can detect brake degradation immediately and automatically engage backup brakes or alert operators, minimizing the time from malfunction to response.
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
The solution effectively prevents hazardous situations by ensuring adequate friction between brake surfaces, reduces safety risks, and allows for remote monitoring, thereby improving the operational safety of elevator systems while being cost-effective and easily integratable into existing systems.
Implementation Method 1
the friction co-efficient between the braking surface and the brake pad
Data Source
Figure 1
Figure 2
AI summary
In the invention a method is presented for ensuring operating safety in an elevator system, an elevator system, and a safety device of an elevator system. The elevator system comprises at least an elevator car, elevator ropes, an elevator motor, a traction sheave and at least two holding brakes, which holding brakes are arranged to prevent movement of the elevator car when the elevator is stopped. According to the invention the first holding brake (106,107) is engaged after elevator run has ended, and the other holding brakes (106,107) are engaged with a delay. When one holding brake is engaged when the elevator is stopped and empty, motor torque is increased to a certain limit and the state of motion of the elevator and any slipping of the brake is monitored. If the brake is detected as slipping, the torque at which slipping starts is registered and a procedure for preventing a hazardous situation is performed.