Elevator Speed Detection System Reducing Hardware Complexity
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Solution Overview
Problem
Existing elevator speed monitoring systems require complex and costly hardware for effective operation, leading to maintenance challenges and safety risks due to potential excess speed and brake failure issues.
Innovation Solution
A simplified detection system using a two-channel computer with measuring systems for drive pulley and counterweight movement, initiating retardation and activating a brake if speed limits are exceeded, ensuring safe standstill conditions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a motorized cable drum with separate sensors for motor shaft and drum shaft is used to monitor speed, then speed monitoring capability is achieved, but device complexity and cost increase
Solution Approach 1:
The patent combines the monitoring of motor shaft and drum shaft into a single integrated sensor system that detects the position and speed of the elevator car directly, eliminating the need for separate sensors on each shaft while maintaining comprehensive speed monitoring capability
Solution Approach 2:
The measuring system is designed to perform multiple functions simultaneously: it monitors both the position and speed of the elevator car, detects excess speed conditions, and provides signals for both retardation and brake activation, replacing multiple specialized sensors with a single multi-functional device
2Measurement precision
If multiple sensors and complex hardware are installed for speed monitoring, then monitoring precision is improved, but maintenance difficulty and cost increase
Solution Approach 1:
The patent extracts the essential measurement function from complex multi-sensor hardware and implements it through a simplified measuring system that directly detects car position and speed, removing unnecessary components while preserving measurement precision
Solution Approach 2:
The invention replaces expensive, complex sensor hardware with a more economical measuring system that achieves the same monitoring precision, reducing both initial cost and long-term maintenance expenses
3Reliability
If complex monitoring hardware is used, then safety monitoring capability is improved, but initial cost and maintenance cost increase
Solution Approach 1:
The patent replaces complex mechanical sensor systems with an electrical/electronic measuring system that uses electrical signals to detect speed and position, reducing mechanical component count while enhancing safety monitoring capability and lowering costs
Data Source
AI summary
A method and detection system monitors the speed of an elevator car and, in case of excess speed caused by brake failure of a motor brake or shaft fracture of a drive pulley shaft, a safety circuit is opened and the detection system is transferred from a normal operational state (State 1) to a retardation state (State 2) in which it is monitored whether the elevator car is retarded after defined speed presets. After a successful retardation, the detection system is transferred to a state of standstill monitoring (State 3) in which it is monitored whether the elevator car leaves its standstill position. If the presets of State 2 or State 3 are not fulfilled, the detection system is transferred to a braking state of the brake (State 4) in which a brake which fixes the elevator car is activated.