Designs of Claw-Pole Motors for Industrial Applications

Recently, it has been shown that a special claw pole motor construction could give a torque density of 1.5 Nm/kg at a power factor of 0.87 for a servo motor application [8]. The previous investigation was restricted to motors having a maximum outer diameter of 115 mm in order to utilise available materials. This paper addresses the question whether or not such a special type of claw-pole motor, with claws both in the rotor and in the stator, can compete with conventional motors with respect to torque density, power factor, efficiency and cost, allowing the size and construction (like intemal or external rotor) to vary. Results identifying what are considered the best applications for the claw-pole motors and for what power output is presented.