Rotating speed measurement using an optimized eddy current sensor

This paper presents the rotating speed measurement of solid iron hollow shafts using the optimum design of a rotational eddy current sensor. The rotating speed measurements are performed using the optimized sensor up to +/- 3000 rpm to evaluate sensitivity enhancement and linearity performance. The sensor is optimized for a shorter axial length and higher sensitivity with a new configuration of the coils. An aluminum shell on a solid shaft is used, which helps to improve the sensitivity and the susceptibility of the sensor to the material properties of solid iron. A 2D analytical method and a 3D time stepping finite element method are considered for the theoretical analysis of the sensor and for an assessment of the effect of this optimization on the performance. The performance of the sensor was verified by measurements. The evaluation of the speed sensor for higher speeds up to +/- 30,000 rpm is performed using the 2D analytical method.