Bearingless segment motor with a consequent pole rotor

Bearingless motors combine contactless levitation and rotation in a preferably compact system design, because the bearings as well as the motor windings are located on the same lamination stack. Using a permanent magnet excited disc shaped rotor, three of the six degrees of freedom can be passively stabilized by means of reluctance forces. The bearingless segment motor features concentrated windings on separated stator segments. However, such motors usually require the measurement of the rotor angle and the rotor position for a proper operation. An advantage of the bearingless consequent pole motor is the radial force generation by direct current (dc). Thus, no angular sensors are needed in this concept. A combination of the bearingless segment motor and the consequent pole motor leads to a new type of bearingless motor. In this case the radial force generation becomes independent from the rotor angle and a decoupled generation of motor torque is possible. This investigation focuses on the optimization of the operation characteristics, the control scheme and the comparison of the simulation results with the measurement data of a manufactured prototype.