Elevator Brake Unit Friction Verification Method
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Elevator braking systems require efficient and reliable testing to ensure safety and functionality, especially in complex mass systems, where existing methods are costly and complicated due to the need for fully loaded cabins and risk of equipment damage.
Innovation Solution
A method to determine the effective coefficient of friction of the brake unit using a braking force measuring device and normal force measuring device, allowing for continuous monitoring and verification of brake functionality, which can be done on an unloaded car, eliminating the need for payload and reducing the risk of damage, and calculating the remaining mass to be braked in the 'worst case' scenario for reliable safety assessment.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If traditional braking systems with two separate brake systems are used, then braking reliability is improved, but testing complexity and cost increase
Solution Approach 1:
The patent combines two separate brake systems into a single integrated brake system with one brake unit that has multiple brake plates acting on a common brake track. This merging reduces the complexity of testing while maintaining braking reliability through the coordinated action of multiple brake plates within one unit.
Solution Approach 2:
The single brake unit is designed to perform multiple braking functions simultaneously - it can brake the elevator car and counterweight together, and the same unit can be tested using a universal testing method that determines the effective coefficient of friction for the entire brake system, eliminating the need for separate testing procedures.
2Reliability
If fully loaded cabins are used for testing, then braking performance under maximum load is verified, but risk of equipment damage and testing cost increase
Solution Approach 1:
The patent replaces the mechanical approach of loading the cabin with physical weights with a computational method. By measuring the holding force of the brake unit and determining the effective coefficient of friction, the system calculates the braking capacity without requiring actual loading, thereby eliminating the risk of equipment damage from test weights.
Solution Approach 2:
The patent introduces an intermediary measurement approach - instead of directly testing with loads, it uses a normal force measuring device to measure the holding force and calculates the braking capacity through the effective coefficient of friction. This intermediary method verifies braking performance under maximum load conditions without physically applying the load.
3Loss of time
If brake testing is performed with dirt and construction dust on brake track, then testing can be done immediately after assembly, but measurement accuracy of coefficient of friction deteriorates
Solution Approach 1:
The patent performs a preliminary cleaning action by rubbing the brake track with the brake plates during the first operational cycles. This preliminary action removes dirt and construction dust before the formal measurement of the effective coefficient of friction, ensuring measurement accuracy without requiring separate cleaning steps or delaying testing.
Solution Approach 2:
The patent incorporates the cleaning function into the continuous operational use of the brake system. The brake plates naturally rub against the brake track during normal operation, continuously cleaning the surface and maintaining optimal friction conditions, which allows immediate testing without compromising measurement precision.
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
This method enables efficient, safe, and reliable testing of elevator braking systems, ensuring early detection of errors and verification of system data, reducing testing costs and risks, and providing a comprehensive overview of braking safety without the need for test weights or complex setups.
Implementation Method 1
The brake unit for this purpose pressing at least one brake plate against the brake track and generating a braking force
Implementation Method 2
force measurements can be carried out inexpensively, for example using strain gauges
Data Source
Figure 1~1a
Figure 2~3
Figure 4
AI summary
The method involves calculating residual mass, which is to be braked by a brake device (11) in a worst case, of a lift system by inputting an allowable weight of conveyor load, an active mass portion of a drive and a measurement of lift acceleration. Mass is determined at the lift system as an actual unbalance of the lift system or an actual weight of a carrier unit by a brake force measuring device (20). Correct balancing of the lift system is carried out or verified by the brake force measuring device.