| As people’s living standards increasing car ownership is also increasing. More and more people are required to improve the car comfort. Gradually automobile generator noise and vibration problems gets extensive attention. Beginning in the1940s, scholars have begun to study for all types of motor noise and vibration. However, there is very few studies on the noise and vibration in the vehicle AC alternator, which is the power source for the car.This paper taking the Specific models of vehicle AC alternator as the objects of study, carries on a research on the noise and vibration of the vehicle AC alternator by signal processing methods such as spectral analysis and order analysis that based on the existing technology platform.This study provides a basis for the improvement and optimization of vehicle alternator.The main research contents and conclusions are as follows:Completed A sound-level testing of the generator in the loaded and unloaded state by the signal processing methods such as spectral analysis and order analysis:Obtained the harmonic minor component of the generator noise in the two states, and determine a resonance speed of a maximum value of the noise appears in the motor loaded state.By the analysis of amplitude-frequency characteristic of the motor noise and vibration were determined the36harmonic electromagnetic exciting force caused the noise that caused by the motor inner structure’s strong resonance is the dominant component of the noise component of the motor in low-speed segment load state, and have identified the main noise source and the exciting force transfer path.Studied the effects of geometric tolerance and physical structure of motor noise and vibration characteristics.summarized the affecting of the alternator noise and the motor improvement measures for these factors have been proposed.Contrapose the main problem of single-frequency components of the high-speed segment noise of the motor, the fan-noise vector synthesis have been proposed to optimize the distribution of the fan blades of the motor. Then improve the fan blade structure and the rotor dynamic balancing precision to reduce the noise by3-5dB in high speed period, the temperature rise of the motor declines to some extent relative to the situation before optimization. It proves the optimization improve the reliability of the motor. |
