Research On The Displacement Sensor Apply In Bearingless Slice Motor

The bearingless slice motor has simple structure and high reliability. In particular for its no touching and no attrition, it has an application advantage in the field of ultra-pure driving. Sensors account for the maximal proportion of the cost of the bearingless slice motor. For the sake of reducing the cost and making it apply to practice production as soon as possible, the low-cost Hall displacement sensor and high-powered Eddy current displacement sensor apply in bearingless slice motor are researched.The Hall displacement sensors researched in the text are divided into two kinds. The theory is deduced and magnetic field's distributing is emulated by ANSYS in the closing Hall displacement sensor. The linearity of a kind of Hall displacement sensor is improved at the foundation of accreting immobile air gap. The result of the experiments shows that the capability is all right. Designing principle of the disconnecting Hall displacement sensor is based on simplifying the structure of closing Hall displacement sensor and magnetic field's distributing is emulated by ANSYS. The key subject's dimension in the frame is confirmed through lab measurement in the closing Hall displacement sensor. Also the dynamic characteristic of the Hall displacement sensor is researched and there is no distortion under 20KHz in vibrating frequency in substance.The Eddy current displacement sensor which is studied in this paper adopts ready Eddy current probe and proximity amplifier which is frequency and amplitude modulation style. This paper analyses the dynamic characteristic in the process of Eddy current displacement sensor, improves the circuit parameter of the proximity amplifier. The laboratorial result shows the improvement in dynamic performance, which is that in the high frequency situation the performance is better than the Eddy current displacement sensor in the current market. This paper also introduce passive advance correcting circuit to improve the dynamic characteristic of Eddy current displacement sensor ulteriorly. This paper introduces the laboratorial flat roof which is fit for measuring displacement, also makes comparison between Hall displacement sensor and Eddy current displacement sensor.