Noise and vibration analysis of elevator traction machine

Designing low noise elevator cars has become an important issue. Elevator car noise is caused by aerodynamics and the elevator traction machine. The noise under 1000 Hz that radiates from a elevator traction machine is a particular problem because it is not easily insulated by the elevator car's walls, the structure of elevator traction machines differs from that of general electric motors. Hence, a noise evaluation method for the elevator traction machine has been developed. First, we conducted an excitation test with an excitation machine, the results of which showed the vibration mode. Then we designed the numerical model on the basis of the excitation test results and calculated structure-borne sound radiated from the elevator traction machine excited by electromagnetic force. This force was obtained from magnetic field analysis using measured current and computed Fourier transform of the time domain and the space domain. As a result, we show how calculated results matched the measured results well. We also show the space order of the excitation force that had a large influence on the noise radiated from the elevator traction machine.