A fundamental study of levitation-type linear actuators using Y-Ba-Cu-O high-TC superconductors.

Fundamental characteristics of levitation-type linear actuators using Y-Ba-Cu-O high-Tc super conductors are studied theoretically and experimentally .Two types of actuators, both with the levitation using the Meissner effect (Meissner levitation), are studied.They are (1) driven by the force produced by the Meissner effect (Meissner driving), and (2) driven by the Lorentz force (Lorentz driving), respectively.The Meissner levitation has such an advantage that stable levitation is achieved without any control or external input energy except cooling.The magnetic flux distribution and the driving mode of the actuator with the proposed Meissner driving are analyzed numerically .Its opera tional features are compared with those of several other driving methods , namely, the Lorentz driving and the electrostatic driving .In experiments, the actuator with the Meissner levitation and the Meissner driving is fabricated using Y-Ba-Cu-O superconductors.The levitating force and the driving force are observed to be 200 and 25 mgf, respectively.It is found that the magnetic penetration of the superconductors degrades the both forces and the driving of the slider is not succeeded .The actuator with the Meissner levitation and the Lorentz driving is also fabricated .It is found that this actuator has sufficient forces to drive the light slider.The levitating force and the driving force are found to be 10 and 3 mgf, respectively.The acceleration of the slider is measured to be 3 .5m/s2.1.