Design, Simulation, and Integration of a Bladeless Centrifugal Mini-Pump and Brushless Axial Flux Mini Motor for Medical Applications

This paper presents the design and simulation of an Axial Flux Permanent Magnet Synchronous Motor (AFPMSM) specifically developed for medical applications. The motor incorporates magnetic suspension technology, which allows the rotor to be suspended between two symmetrical stators, positioned at both ends. This unique configuration minimizes mechanical contact, reducing wear and tear, improving efficiency, and increasing longevity. A key feature of the motor is its axial magnetic flux path, which significantly reduces magnetic field penetration into medical fluids. This reduction is critical for sensitive fluids, like blood or biological substances, as it minimizes interference with their properties. Additionally, the axial flux design ensures minimal shear stress on the fluid, making it ideal for medical devices that require precise fluid handling with low turbulence. The rotor features four permanent magnets (PMs) placed radially on a rotor disk, enabling a compact and efficient design. The motor has a diameter of 43 mm and a height of 55 mm, making it suitable for small-scale medical devices. It is also integrated into a centrifugal pump, optimizing both mechanical and fluidic functions. In this study, we derive the governing equations and size relationships for the AFPMSM, with a theoretical background on its magnetic motion. Detailed Finite Element Analysis (FEA) simulations are performed to analyze the magnetic field distribution and torque generation. The results demonstrate the feasibility of the motor in meeting medical application requirements, including high efficiency, low shear stress, and precise fluid control.