Asymmetric Vane Pump Rotor for Reduced Engine Noise

The patent applies asymmetry by arranging the vanes on the inner rotor at different angular positions rather than evenly spaced. Specifically, the vanes are positioned at angles that are not multiples of 360°/number of vanes, creating an asymmetric pattern that scatters vibration energy across multiple frequencies and reduces the amplitude of structure-borne sound and airborne sound, thereby lowering noise and vibrations while maintaining manufacturing feasibility.

The patent segments the energy transmission by distributing the vanes asymmetrically, which divides the concentrated vibrational energy into multiple smaller components across different orders. This segmentation of energy transmission paths prevents the buildup of resonant vibrations and reduces overall noise emission from the pump system.

The asymmetric vane arrangement on the inner rotor scatters the pressure peaks and pulsations by distributing energy across both pump main orders and pump secondary orders. This asymmetric configuration prevents concentrated energy transmission at single frequencies, thereby reducing pulsations and improving running smoothness and quiet operation.

The patent segments the energy distribution by creating multiple vibration orders (both main and secondary orders) through asymmetric vane positioning. This segmentation disperses the energy that would otherwise concentrate in single dominant frequencies, reducing pulsations and improving operational smoothness.