Experiments on a Bearingless Synchronous Reluctance Motor with Load

A prototype of a synchronous reluctance type, magnetically-levitated motor system was developped and tested. This sytem is built with a horizontal configraton. The rotor of the system is non-contact-levitated by two bearingless motors. In a non-load operation, the axial directon is supported by a passive stiffness which is consequent to these motors. Four poles of each bearingless motor were set as magnetic poles for the drive (torque), while two poles of the same were set as those for the control (radial force). Static load characteristics of the bearing less motors were measured using both magnets Jor the radial load and force sensors, set at both ends of the shaft. It was confirmed that the system was capable of rotation at 12,000 rpm under a non-torque-load state. A torque load was applied by a DC generator and measured by a torque meter, connected bJj a flexible coupling, and an output of 2.12 k W was confirmed at 8,000 rpm. Measurement was also made on the vibration amplitude of the rotor by changing the phase lag of the magnetic flux for drive versus the one for control. The following discusses experimental results and considerations.