Escalator Braking Torque Control via Load-Dependent Solenoid Actuation
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Solution Overview
Problem
Conventional braking systems for moving walkways and escalators fail to maintain a consistent braking distance across varying load states and do not function effectively without electric power, posing safety risks and requiring frequent adjustments due to wear and increased costs associated with variable frequency drives.
Innovation Solution
A braking system comprising a main and auxiliary brake, controlled by a system that dynamically adjusts braking torque based on load calculations from sensors or external systems, ensuring constant braking distance and safe operation even in power failures, using solenoids and a redundant CPU scheme for reliability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional spring-guided emergency braking systems are used, then the system can maintain braking force without electric power, but the braking distance varies with load state and requires frequent adjustments
Solution Approach 1:
The braking system dynamically adjusts the braking force based on the load state of the escalator. The control system receives load information and modulates the solenoid activation to optimize braking torque, allowing the braking distance to remain consistent across different load conditions rather than using a fixed spring-guided mechanism
Solution Approach 2:
The system incorporates feedback mechanisms where the control means receives information about the load state and adjusts the braking torque accordingly. This closed-loop control ensures that the braking distance remains consistent regardless of whether the escalator is lightly or heavily loaded, eliminating the need for frequent manual adjustments
2Manufacturing precision
If variable frequency drives are used to adjust braking torque, then braking performance can be optimized, but the cost and device complexity increase
Solution Approach 1:
Instead of using complex variable frequency drives, the system introduces an intermediary control mechanism that modulates the solenoid activation during braking. This intermediary layer allows for dynamic braking torque adjustment through simple on/off control of the solenoid, achieving optimized braking performance without the complexity and cost of frequency conversion equipment
Solution Approach 2:
The system replaces the mechanical spring-guided braking mechanism with an electrically-controlled solenoid system. This substitution allows for precise electronic control of braking torque based on load conditions, achieving consistent braking distance control while avoiding the complexity of mechanical adjustment mechanisms
3Device complexity
If conventional brakes are used, then the system structure is simple, but the braking distance cannot be maintained constant across different load states
Solution Approach 1:
The braking system transitions from a static conventional brake design to a dynamic control system that adjusts braking torque in real-time based on load conditions. The control means modulates the solenoid activation during braking to optimize the braking force, ensuring consistent braking distance across different load states while maintaining relatively simple system structure
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 ensures consistent and safe braking distances regardless of load, reduces mechanical stress, and maintains operational reliability by dynamically adjusting braking torque and utilizing both brakes as needed, optimizing braking performance and compliance with safety standards.
Implementation Method 1
one or several linear solenoids are arranged, acting in the direction opposite to the spring or springs, such that when they are energized they are able to move the shoes from the surface of the drum or flywheel
Implementation Method 2
brake shoes which are pushed by means of springs against the side of a drum or flywheel integrally attached to the shaft of the geared motor when braking
Implementation Method 3
brake shoes which are pushed by means of springs against the side of a drum or flywheel
Data Source
AI summary
A braking system for escalators and moving walkways, includes a braking device (3) with a main brake (30) of the type which is released when there is no voltage in its electric activator, and an auxiliary brake (31) of the type which is closed when there is no voltage in its electric activator. A controller (1) controls the braking device (3), prepared for obtaining the load of the escalator or moving walkway, and calculates the braking torque required for each braking device (3) depending on the load and activating the braking device (3) for obtaining the corresponding torque while braking when a braking command is received. The auxiliary brake is activated (32) for taking the escalators or moving walkway to a safe position when there is a system failure.