radial free play is reduced in rotor bearings of a limited rotation electromechanical actuator of the kind having a stator assembly with a plurality of stator pole faces , a rotor with a plurality of rotor pole faces , two bearings supporting opposite ends of the rotor and means for establishing magnetic flux across the gaps . in various aspects , the stator and rotor pole faces are cylindrical and the central axis of the rotor pole faces is tilted relative to the central axis of the stator pole faces ; a region of a gap between the stator and rotor pole faces produces both the radial free - play - reducing forces and at least part of the driving torque ; the gap rotor varies in size along its length but nowhere is so great as to have an effectively infinite reluctance ; the gap varies continuously along its length ; and each bearing has radial free play equal to at least 10 % of twice the difference in the diameters of the stator and rotor pole faces .