Elevator Brake Condition Monitoring via Frequency Converter Deceleration Analysis
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing methods for monitoring the condition of mechanical brakes in elevators are unreliable, often requiring physical inspection, leading to over- or under-replacement of brake pads, and can complicate systems with additional sensors.
Innovation Solution
Utilizing the frequency converter to gather deceleration data during normal operation, comparing it to reference data from new brake pads, and generating an alarm if deceleration performance drops, thus enabling brake condition monitoring without interrupting service or using separate sensors.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If visual inspection of brake pads is performed, then maintenance personnel can check brake wear, but the elevator must be temporarily out of service and the inspection is not very reliable
Solution Approach 1:
The frequency converter performs self-diagnosis of brake condition by analyzing deceleration data from its existing sensors during normal operation, eliminating the need for manual inspection and service interruptions. The system monitors its own operational parameters to detect brake wear automatically.
Solution Approach 2:
The patent replaces manual visual inspection with automated electronic monitoring using the frequency converter's existing sensors and processing capabilities. The mechanical inspection process is substituted with electronic data analysis of deceleration patterns.
2Reliability
If brake pads are replaced regularly based on operation time, then brake wear can be predicted, but the replacement does not take into account environmental conditions and brake pads may be changed all too often or all too seldom
Solution Approach 1:
The system continuously monitors deceleration performance and compares it against reference values to provide feedback on actual brake condition. This feedback loop enables condition-based maintenance decisions rather than fixed-schedule replacement, preventing both premature and delayed maintenance.
Solution Approach 2:
The patent transitions from fixed-time replacement schedules to dynamic condition-based replacement by monitoring deceleration parameters. The maintenance decision is based on actual performance degradation rather than accumulated operating hours, adapting to varying environmental conditions and usage patterns.
3Reliability
If separate sensors are used to detect brake pad movement, then brake condition can be monitored, but the system becomes complex and susceptible to defective operation
Solution Approach 1:
The frequency converter's existing sensors and processing unit are made multi-functional by utilizing them for both motor control and brake condition monitoring. The same hardware infrastructure serves dual purposes, eliminating the need for dedicated brake sensors and reducing system complexity.
Solution Approach 2:
The patent merges the brake monitoring function with the existing frequency converter system. By combining multiple monitoring functions into a single integrated system, the patent reduces the number of separate components and potential failure points while improving overall system reliability.
Data Source
Figure 1
Figure 2
Figure 3
AI summary
A method and arrangement for detecting a working condition of a mechanical brake of vertical transport equipment, the vertical transport equipment comprising a frequency converter, an electrical motor and a mechanical brake. In the method, movement of the vertical transport equipment being controlled using the frequency converter that is adapted to feed electrical power to a motor and the mechanical brake is adapted to mechanically hold a car or load of the vertical transport equipment when said car or load is stationary. The method comprises storing data relating to deceleration of the car or load for use as reference data, controlling the mechanical brake into a closed position for decelerating movement of the car or load, determining test data relating to the deceleration of the car or load from measured information or from a control system of the frequency converter, comparing the reference data with the test data, and producing an alarm signal on the basis of the comparison between the reference data and the test data.