Torque ripple and vibration reduction in BLDC motors using a bilayer stator structure

Brushless DC (BLDC) motors are widely used in electric mobility, robotics, and compact actuation systems because of their high efficiency and torque density; however, commutation-induced torque ripple remains a significant practical limitation. Torque ripple excites mechanical vibration, increases acoustic noise, and accelerates wear in bearings and transmission components. This article proposes a bilayer stator BLDC motor architecture in which an auxiliary stator with a controlled mechanical phase shift is excited using delayed pulses to compensate for torque deficits during main-stator commutation. The proposed structure is investigated using finite-element simulations and validated experimentally using prototype motors fabricated from commercial outrunner motor components. Results show that the proposed configuration reduces torque ripple by up to 74% and decreases total current consumption by up to 25% under comparable operating conditions. These results demonstrate that the proposed architecture provides a practical approach for achieving smoother torque production, reduced vibration, and improved efficiency in BLDC drives using commercially available hardware.