Design and analysis of a permanent magnet motor integrated with journal bearing

In the application for artificial hearts, the journal bearing is one part of the integrated magnetic design of the “inside-out” PM motor. During blood pumping, a small quantity of blood enters the gap between the rotor and stator, creating a thin hydrodynamic film which separates and lubricates the rotating and stationary surfaces. In this integrated design, the stator-rotor axial magnetic attraction also acts as the thrust “journal bearing”. This paper presents a design and detailed analysis for a PM motor integrated with journal bearing. Application of Halbach array permanent magnet structure for high torque density, cogging torque minimization, and design optimization by 2-D and 3-D finite element method specifically for a blood-pump system are discussed