Elevator Rope Pulley Encoder for Accurate Hoistway Position Detection
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Solution Overview
Problem
Existing elevator systems face reliability issues due to mechanical switches prone to wear and require significant installation and maintenance, making them unreliable for accurately determining the position of the elevator car within the hoistway.
Innovation Solution
A rope pulley with an encoder, such as a magnetic, optical, or capacitive encoder, is used to measure the rotational movement of the hoisting rope, synchronized with markers in the hoistway, to accurately determine the elevator car's position, with a safety bus node transmitting data to a controller for precise positioning.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If mechanical switches (reed switches) are used for position detection, then the elevator car position can be detected, but the system reliability deteriorates due to wear and requires significant installation and maintenance work
Solution Approach 1:
The patent replaces mechanical reed switches and permanent magnets with an encoder system that uses optical, magnetic, or capacitive fields to detect rope position. The encoder converts mechanical rope movement into electrical signals without mechanical contact, eliminating wear and improving reliability while reducing installation and maintenance complexity
Solution Approach 2:
The patent introduces an encoder as an intermediary device that indirectly measures car position by detecting rope displacement rather than directly detecting car position. This intermediary approach allows position detection without mechanical switches on the car itself, reducing installation complexity and improving reliability
2Measurement precision
If permanent magnets are installed along the hoistway for position detection, then the elevator car position can be determined, but the system requires manual adjustment and is prone to unintentional position changes
Solution Approach 1:
The patent replaces the mechanical permanent magnet system with an encoder that uses non-mechanical fields (optical, magnetic, or capacitive) to detect rope position. This eliminates the need for precise mechanical placement of magnets along the hoistway, greatly improving installation ease while maintaining measurement precision through electronic detection
3Measurement precision
If motor control is used to determine car position, then position information can be obtained, but the solution is not applicable when the motor is not replaced during modernization or preventive maintenance
Solution Approach 1:
The patent uses the hoisting rope as an intermediary that connects the car to the motor system. By detecting rope displacement through the encoder, the system can determine car position independently of the motor's presence or condition, making it universally applicable during modernization and preventive maintenance when the motor may not be replaced
Solution Approach 2:
The patent extracts the position detection function from the motor control system and creates an independent detection system based on rope displacement measurement. This extraction allows position detection to function independently of the motor's presence, improving adaptability during modernization when the motor may remain in place
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 system provides accurate, cost-effective, and robust elevator car positioning with reduced maintenance needs, ensuring high safety integrity and reliability through self-diagnostic capabilities.
Implementation Method 1
An encoder belonging to the pulley detects the rotational movement of the pulley and transmits the rotational data to a controller
Implementation Method 2
A rope pulley with an encoder, such as a magnetic, optical, or capacitive encoder
Implementation Method 3
A rope pulley with an encoder, such as a magnetic, optical, or capacitive encoder
Data Source
AI summary
A rope pulley of an elevator system is a free rotating pulley around which a hoisting rope of the elevator system can be guided. The free pulley is to be mounted to a car sling of an elevator car. The pulley includes an encoder for measuring the rotation movement of the pulley. The movement data are transmitted to a controller that converts the movement data into position data of the car in the hoistway, while further position data are gathered from identification markers that are installed in the hoistway. At least, the movement data of the rope pulley(s) are calibrated based on the position data from the identification markers. Thereby, the position of the car in the hoistway can be determined accurately and costly.