a rotor has magnets segmented in a circumferential direction of a periphery of a shaft , wherein magnetizing directions of the segmented magnets continuously vary , and a non - magnetic material or a ferromagnetic material is interposed in a circumferential gap between the segmented magnets . further , a method of manufacturing a rotor comprises steps of arranging coils so that a longitudinal direction of each of the coils is along an axis of the shaft and magnetizing the segmented magnets . still further , a rotary machine uses the rotor .