Development of 3-D superconducting actuator using HTS bulks based on eight-poles electromagnets

We have been developing a three-dimensional (3-D) superconducting actuator with HTS bulk and electromagnets. Proposed 3-D superconducting actuator consists of the stator constructed by two-dimensional arranged electromagnets and HTS bulk superconductor as a mover. To realize the 3-D superconducting actuator with high performance, we have to investigate the shape-dependences of electromagnets and HTS bulk on levitating characteristics. In this study, we fabricated the individually controlled eight-polarities electromagnets and the two kinds of bolted joints cap cores to improve the control ability and levitation characteristics. And also, we prepared the disk-shaped and ring-shaped (with 20 mm inner diameter) HTS bulk with 60 mm diameter, and evaluated how magnetic field distribution influences the levitating characteristics as functions of levitation force and height.