Abstract
We have developed a diagnostic algorithm for estimating the spring load and sliding resistance of elevator brake shoe drive mechanisms. Elevator brake drums are released by the attractive magnetic force of a solenoid coil. The spring load and the sliding resistance hinder the solenoid coil from releasing the elevator brake drums. These two factors affect the response delay of brakes. To calculate the sliding resistance, we need to know the biased magnetization of the core, however the biased magnetization is hard to measure. We estimated the sliding resistance using a coupled magnetic field and a mechanical model. The model consists of components for calculating the biased magnetization and lever deformation. We can also use the model to estimate the spring load. The proposed algorithm was tested using data from a machine in a site. The testing showed that the algorithm had the ability to estimate the spring load with 2% precision, and the sliding resistance with 5% precision.
