Elevator Over-speed Protection via Electronic Trigger
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Solution Overview
Problem
Traditional elevator safety systems with mechanical governors are time-consuming to install, costly, noisy, and require many components, leading to high maintenance costs and inconvenient resetting, especially in high-speed elevators.
Innovation Solution
An electronic over-speed and over-acceleration protection system comprising a speed detector, acceleration detector, mechanical safety, electromagnetic trigger, and controller that automatically engages and resets the safety system to prevent excessive speed and acceleration, reducing noise and component count.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a traditional mechanical governor and safeties system is used, then over-speed protection is provided, but the installation is time-consuming and requires many components
Solution Approach 1:
The patent replaces the traditional mechanical governor system with an electronic control system comprising a speed detector, acceleration detector, and controller. This substitution eliminates the governor sheave assembly, governor rope, and tension sheave assembly, reducing the number of mechanical components while maintaining over-speed protection functionality through electronic sensing and control.
Solution Approach 2:
The invention extracts and removes the complex mechanical governor components (governor sheave, governor rope, tension sheave) from the elevator system by implementing an electronic alternative. This extraction simplifies the overall system architecture while preserving the essential safety function of detecting and responding to over-speed conditions.
2Reliability
If a traditional mechanical governor system is installed, then safety protection is achieved, but significant space is occupied in hoistway, pit, and machine room
Solution Approach 1:
The electronic control system with speed and acceleration detectors requires significantly less space than the mechanical governor system. The detectors and controller can be mounted in compact configurations, eliminating the need for large governor sheaves, ropes, and tensioning mechanisms that occupy substantial volume in the hoistway, pit, and machine room.
3Reliability
If traditional governor rope and sheave assemblies are used, then over-speed detection is provided, but significant noise is generated
Solution Approach 1:
The electronic detection system eliminates the noise-generating mechanical components (governor rope moving over sheaves, friction-based mechanisms) by using electronic sensors to detect speed and acceleration. This substitution provides over-speed detection functionality without the significant operational noise characteristic of traditional mechanical governor systems.
4Ease of repair
If manually resetting the governor and safeties is required, then the safety system can be reset, but it is time-consuming and costly
Solution Approach 1:
The electronic control system enables automatic resetting of the safety function without requiring manual intervention to reset the governor and safeties. The controller can automatically reset the electromagnetic trigger and restore normal operation after an over-speed event, eliminating the time-consuming manual resetting process required by traditional mechanical systems.
5Reliability
If a traditional mechanical safety system with brake pads and housings is used, then the elevator can be stopped, but the operation generates significant noise
Solution Approach 1:
The electronic control system maintains the stopping capability through electromagnetic triggers that actuate the mechanical safeties, but eliminates the noise generated by the operation of governor ropes, sheaves, and brake pad engagement. The electronic system provides precise control with minimal mechanical operation noise.
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 electronic system decreases response time, reduces false triggers, and lowers maintenance costs by automatically resetting and engaging the safeties with minimal power requirements, improving safety and efficiency in modern high-speed elevators.
Implementation Method 1
The speed detector monitors a speed of an elevator system mass including, for example, a car or a counterweight
Implementation Method 2
The acceleration detector monitors an acceleration of the mass
Implementation Method 3
an electromagnetic trigger (46) connected to the safety (24)
Data Source
AI summary
An elevator system includes an electronic system capable of triggering a machine room brake and an electromagnetic safety trigger with low hysteresis and with minimal power requirements that can be released to engage safeties, when car over-speed and/or over-acceleration is detected. The electromagnetic trigger may be reset automatically and may be released to engage the safeties, during the reset procedure. The system includes a processing system that is configured to decrease response time and to reduce the occurrence of false triggers caused by conditions unrelated to passenger safety, such as passengers jumping inside the elevator car.