Brake Noise Reduction of Elevator Traction Machine Based on Particle Dampers

To overcome the relatively high sound pressure level noise generated by the elevator traction machine during the braking process, this study proposes a vibration and noise reduction solution based on particle dampers. Firstly, the vibration characteristics of the brake wheel and brake pads are investigated through finite element analysis, and the key vibration modes are identified by correlating the principal vibration frequencies obtained from whole-machine vibration and noise tests. On the basis of these findings and by considering the symmetry and spatial layout of the brake wheel structure, an innovative cavity design is introduced in the brake wheel to accommodate particle dampers. Then, coupled EDEM-ADAMS simulation technology is employed to optimize the parameters of solid particles, with a focus on addressing three critical technical issues:(1) the selection of damping particle material (to avoid the interference from magnetic fields, pure aluminum is ultimately selected); (2) the analysis of energy dissipation process of the particle damper within the cavity (with the adoption of discrete element analysis); and (3) the optimization of particle radius and filling ratio of the damper (by integrating the discrete element analysis with the multi-body dynamics simulation). Finally, an experimental validation is conducted in a semi-anechoic chamber, by setting a timed braking control strategy with a 5-second cycle, using an acceleration sensor array to collect vibration signals, and synchronously recording sound pressure level data. The results indicate that, the installation of particle dampers helps to reduce the average sound pressure level during the braking process by 20.7%, thus confirming the effectiveness of the proposed solution. This research provides a novel technical approach to noise control of electromagnetic braking systems and is of significant engineering application value.