Characteristics Research Of Eddy Current Sensor In A Magnetic Suspended Spindle System

Active Magnetic Bearings (AMB) is called a technology revolution in the bearings for a lot of advantages. The signal of the magnetic suspended spindle measured by the eddy cunent sensor is the basis to carry on the control to the bearing, is one of the whole point of the system research and crux in system design process. Purpose of this paper is aiming at the problem of displacement measuring about HDD rotor suspended AMB as a five degree of freedom system, research the work characteristic of eddy current sensor in concrete work environment.The probe's linearity, temperature and dynamic characteristics are analyzed base on principal theory of eddy-current sensor, from the character of the eddy current, loss of eddy current and the coil Q value to the probe characteristic, aspect to analyze of the influence of the diameter of coil and the structure parameter of probe to the linearity characteristic, the dynamic state of the coil to characteristics, dynamic state characteristic of the demodulation circuit, temperature and magnetism characteristic of the eddy current, putting forward influences to work characteristic of the eddy current.Concretely analyzed the environment of the magnetic bearing according to the system model, the magnetism distribution and the influence of the pole coil to the magnetic, the temperature distribution, disposal method and measuring of eddy current sensors are simulated, finally put forward the influence to work characteristic of the concrete factor in the concrete environment theoretically.Designed the experiment of the work characteristic of eddy current sensor, passed a concrete experiment and analysis experiments a data, verified the factors that influence to the characteristic of eddy current by system temperature and magnetism, confirmed the error margin of the measuring system, which should be considered in the design process.Put forward the temperature compensation of direct and differs measuring;According to the demand and the magnetic force bearings coil importation signal characteristic of the control system, bring in the element method, compensate the magnetism influence of concrete environment factor from the constitution mold pieces.