Electromagnetic two-phase stepper motor for use in e.g. motor vehicle indicator instruments, has magnetic circuits with electromagnets, and narrow and broad stator poles formed with air gaps and arranged reciprocally over poles of rotor

摘要

The motor has a disk-shaped rotor (1) having a permanent magnet, and four rotor poles arranged in circumferential direction of changing polarity at a 90-degree angle. The motor also includes magnetic circuits (2,3) having electromagnets (4,5) aligned with the stator poles and having center lines aligned to the rotor axis in 90-degree angle. Each magnetic circuit has broad and extended stator poles (19,20) and narrow and focusing stator poles (21,22) arranged reciprocally over a pole of the rotor. Air gaps (23,24) are formed between stator poles.