Vibration Analysis of Single-Phase Claw-Pole BLDC Fan Drives With Different Claw Geometries

Fractional horsepower single-phase brushless DC (BLDC) machines are commonly used in auxiliary drives in automotive applications. Although the noise and vibration levels of these small machines may be generally low, and much lower than those of the propulsion drive(s), they may have detrimental effects on the passengers' comfort, notably when mounted close to the passengers or when generating noise in adjacent structures. This study focuses on a low-cost single-phase BLDC machine with a claw-pole stator structure and compares its vibration performance across various claw geometries to determine the most effective approach to minimize vibration. In total, seven different claw shapes were designed and prototyped for this analysis. In addition to conventional rectangular -shaped claws, not only the two previously presented modifications of skewing and adding auxiliary slots are applied to the claw geometry, but trapezoidal claw shapes are also analyzed. Here, the influences of claw length as well as of the asymmetric air-gap profile on vibration performance are studied. The results indicate that the asymmetric trapezoidal claw shape exhibits the best vibration performance, among the investigated designs.