Vibroacoustic bevaviour of an outer rotor permanent magnet synchronous machine

This paper deals with the investigation of the vibroacoustic behaviour of a 15kW outer rotor permanent magnet synchronous machine. A prototype is developed as part of a research project for a direct drive of a motorbike. The drive is being tested on a test bench. For this purpose, a machine mount is designed and manufactured, which allows the machine to be integrated into the test bench structure. Due to a high noise emission of the machine, the vibration behavior is examined more closely. Vibroacoustic measurements are carried out with measuring instruments for airborne sound (microphone array) and structure-borne sound (acceleration sensors, mounted in three directions). Observations were made of radiated frequencies, which are equal to integral multiples of the number of poles, as well as natural frequencies of the motor mount. Possibilities for reducing the vibrations that occur were identified.