Rotary position sensor for detecting rotor position - uses magnetic field sensor providing AC signal during rotor rotation

摘要

The position sensor uses at least one magnetic field sensor (23) in the magnetic circuit between the multi-pole permanent magnet rotor (10) and soft magnetic elements associated with the stator (20) or both the stator and the rotor (10). The soft magnetic elements have teeth at equal spacings, arranged in peripheral groups with equi-distant intermediate gaps, with the rotor and stator teeth offset form one another by a half division. Pref. a permanent magnet ring (14) encloses a cylindrical air-gap and is axially magnetised with a pole ring disc (13, 15) of a magnetically conductive material at each end face provided with equi-distant peripheral teeth offset by half the tooth division. USE - For detecting rotor position of relatively small electric motor.