Abstract: To enhance the vibration and noise suppression performance of centrifugal fan systems, proposes a method based on optimizing the damping characteristics of rubber vibration isolators. By establishing a single-degree-of-freedom nonlinear viscoelastic model (on the Optistruct software platform), the effectiveness of using BUSH elements to simulate rubber materials is validated: when the damping coefficient increases from 0.2 to 0.5, the resonance amplitude decreases by 58.9%, revealing a strongly nonlinear energy dissipation mechanism. A coupled dynamic model of the fan-isolation system is further constructed, revealing that damping has a minimal impact (frequency response peak variation <1%) at frequencies below 100 Hz (impeller modes), while it significantly attenuates vibration transmission at frequencies above 100 Hz (volute modes), with a 16.3% reduction in peak amplitude observed at 203 Hz. Based on these findings, the experimental phase focuses on increasing the material loss factor while maintaining the isolator hardness (Shore A 50). The results demonstrate that the polyurethane rubber solution (loss factor 0.45) performs optimally, achieving a 2.2 dB(A) reduction in sound power level, a 14 dB(A) decrease in the 200 Hz noise peak, and reductions of 75% and 69% in vibration acceleration peak and RMS values, respectively. This study confirms that the strategy of “increasing damping while maintaining the same hardness” can effectively suppress high-frequency structural noise, offering a new approach for NVH (Noise, Vibration, and Harshness) design in household appliances and vehicles.

Key words: Rubber vibration isolator, NVH, Damping characteristics optimization, Centrifugal fan, BUSH element