Sensorless motor and pump having a consequent rotor

A motor in which drive current supplied to a winding is controlled in accordance with a rotational position of a rotor detected from a waveform of an induced voltage between phases, the motor comprising:

• a stator including:
• 3×n teeth, wherein the teeth are arranged in a circumferential direction and extend inward in a radial direction, and slots are formed between adjacent teeth in the circumferential direction;
• and
• windings associated with three phases such that each tooth is wound with a winding associated with one of the three phases;
• and
• a rotor including a rotor core, which is arranged inward in the radial direction from the stator, n number of magnets arranged in the circumferential direction of the rotor core, and n number of salient poles arranged in the rotor core, wherein the magnets function as first magnetic poles, the salient poles function as second magnetic poles, and each of the salient poles is spaced apart by a gap from the adjacent ones of the magnets in the circumferential direction, wherein
• an angular interval between the adjacent magnets is substantially the same as an angular interval between the teeth that are wound with windings associated with the same phase of the three phases,
• n is a natural number,
• the magnets and the gap are arranged inward in the radial direction from an outer contour of the rotor core, and
• an electrical angle between two ends of each magnet is set to be smaller than an electrical angle between two ends of each salient pole and set so as to prevent the waveform of the induced voltage from being asymmetric relative to each peak.