MAGNETIC DEVICE FOR DETERMINING AN ANGULAR POSITION AND GENERATING A SINUSOIDAL SIGNAL, AND MULTIPHASE ROTARY ELECTRIC MACHINE INCLUDING SUCH A DEVICE

摘要

Disclosed is the selecting of the optimum characteristics of a magnetic device producing a sinusoidal signal for determination of angular position in a rotary machine. The device includes a multi-polar magnetic ring which is mobile in rotation around an axis, and creates a variable magnetic field according to an angle of rotation. In close proximity to the magnetic ring, a magnetic sensor is placed in this magnetic field, and generates the sinusoidal signal. The air gap between the sensor and ring is constituted by spacing the sensor by a distance E from the magnetic ring on a radial plane. Optimum performance is achieved when a first ratio e/E of a thickness e of the multi-polar magnetic ring in a direction which is radial relative to the air gap E is between 0.4 and 2.3. A second ratio h/e of a height h of the ring, in a direction which is axial relative to the thickness e, is between 1.5 and 8.