Patent ID: 10090746

Abstract:
Step motors have a uniformed 8-stator pole design, while maintaining the number of stator teeth very close to the number of rotor teeth for better torque. A two-phase bipolar stepper includes an 8-pole stator with a plurality of stator teeth uniformly arranged on each pole. If D is the nominal inner diameter of the stator expressed in millimeters, a number of stator teeth per pole equal to D÷3 (rounded to the nearest integer) will accommodate the required winding needle space between adjacent stator poles. The step motor also has a rotor mounted for rotation within the stator with a plurality of rotor teeth. The respective numbers of rotor and stator teeth may differ at most by two or have a tooth ratio greater than 95%. The teeth should have minimum tooth width and separation of at least 0.5 mm for adequate contrasting magnetic definition (polarity and/or flux amplitude) in the rotor-stator interaction.