It is necessary to develop a motor with high output density, high efficiency, and high control accuracy in various industries like automobiles, robots and defense industry. Among the various types of motors, Slotless permanent magnet (PM) motors having relatively structural and electromagnetic advantages over slotted motors have been continuously developed for the precise control as a driving and servo motor. However, since the slotless motor has no tooth and corresponding slots, it requires a complex winding method, applied the skew, to maintain the structure of windings so that it makes the production process complicated and requires a lot of time and money. In this paper, design method of coreless PM motor with non-magnetic tooth-slot structures using 3D printing technology, which can replace the conventional slotless motor, is proposed.
[Body & Conclusion]
This paper proposes design method of coreless PM motor with non-magnetic tooth-slot structures using 3D printing technology. The electromagnetic characteristics of coreless motor which consists of the rotor of PM and teeth-slot structure of non-magnetic material(PC: Polycarbonates) are analyzed by finite elements analysis(FEA). Coreless PM motor with 3D printing technology and the commercial slotless motor which has the skewed-winding are designed and compare the electromagnetic output characteristics each other. The coreless motor, designed with the design method proposed in this paper can improve the difficulties of the fabrication and also have advantages of the electromagnetic output characteristics that conventional slotless motor has such as no cogging torque and high precise control with compact size. In addition, it can improve the electromagnetic output characteristics by applying the overhang of the permanent magnet of the rotor unlike the conventional slotless motor. In conclusion, the effective design method of coreless PM motor using 3-D printing which provides the reliability and convenience of the design and fabrication by getting out of the winding methods of the conventional slot-less motor is proposed.