Kennichi Asami

Application of one axis controlled magnetic bearing with a hollow shaft to non-contact rotation drive

Magnetic bearings can support a floater (rotor) without mechanical contacts in rotating machinery systems. Since the rotors can be supported by magnetic bearings without mechanical contacts, some merits are expected. For example, (1) there are no friction and wear, (2) the system can be operated at higher rotational speeds than bearing systems with mechanical contacts, (3) vibration and noise can be reduced, and (4) they are useful in the special environment because no lubrication requirements.

Trial of Superconducting Magnetic Bearings Applied to High-Speed Turbine Rotor

Vacuum technology is necessary for semiconductor industry, medical industry and food industry [1]. The vacuum technology is also necessary for the new space industry and other advanced industries [2]. Turbo molecular pumps with high speed rotors are key technology for these industries. Turbo molecular pumps are usually composed of active magnetic bearings, a high speed rotor and its controllers. Thus, the mechanism is very precise and complicated, which leads to high price. In this study, high critical temperature (Tc) superconducting magnetic bearings (SMBs) [3] [4] are tried to apply to a high speed rotor for turbo molecular pump because of some merits.

High performances of magnetic levitation system by using persistent current in superconducting coil

Magnetic levitation (suspension) technique is a very promising technology because of no mechanical contact. By using magnetic levitation technology, some wind channel tests are studied as shown in Fig. 1(a) [1][2]. In order to get larger gaps between electromagnets and levitated objects, larger forces for levitated object are necessary. Moreover, in order to get larger forces, larger currents are needed to levitate object and control it. However, in order to get larger currents there is a limit to conventional levitation systems. Then, in this paper superconducting technique is applied to levitation systems. Superconducting coil for persistent current and copper coil are used for levitating object and controlling object, respectively. This may be the first trial that superconducting coil is used for magnetic levitation.