In view of many defects and deficiencies of high temperature excitation coil at home and abroad

a new type of maze like excitation coil structure was proposed.Firstly

the monolayer maze like coil was manufactured by electric discharge machining (EDM) wire cutting

and the high temperature resistant insulating material was put into the gap of coils sufficiently and uniformly.Secondly

the vacuum soldering process was utilized to connect each layer.Finally

the packaged coils were used in a single degree-of-freedom (DOF) high temperature active magnetic bearings (HTAMB) test

and the HTAMB can achieve stable levitation for 20 hours at 550℃.The results show that the welding line resistance value is small

the shear strength of the selected solder and welding line shaped by copper parent metal are credible and coil insulation performance between turns and layers is fine in high temperature environment.Therefore

the high temperature excitation coil is feasible in theory and technology.The oxidized and impaired excitation coil internal structure caused by high temperature levitation test shows that the high temperature resistant insulating material used in encapsulated coil has certain flaws

and they need further research.