Optimization of the balancing weight and the rubber mount of air compressor for urban rapid transit

Urban rapid transit is one of the most popular and useful transportation methods these days. It uses pneumatic pressure to supply power for braking and for opening and closing doors. It is, hence, equipped with large-capacity air compressors, and passengers frequently complain about the vibration and noise from the operating air compressor. In this study, vibration reduction of the air compressor was carried out through designing the optimal balancing weight of the crankshaft and the stiffness of the mount rubber between the air compressor unit and the railway frame, and NVH experiments have been carried out on a prototype according to the proposed design. The optimal balancing weight of the crankshaft was derived using a commercial multibody dynamics program. The stiffness of the mount rubber was obtained to compromise the transferring force to the railway frame and the motion of the air compressor. The proposed design was verified by conducting experiment on a real vehicle equipped with a proposed prototype.