论文部分内容阅读
在电感式磨粒传感器中,铁磁质磨粒主要通过磁化作用改变传感器线圈的磁场分布,进而改变线圈的等效电感.建立了线圈中含有铁磁质磨粒时的磁场模型,得出了磨粒磁化场关于退磁因子的磁感应强度表达式.以球磨粒为例,通过计算球磨粒磁化场,得到球磨粒引起线圈电感变化率的解析式,并用有限元法计算了线圈的磁场,分析后发现:理论计算解与数值分析解相符,所建模型可以反映客观实际;磨粒的磁化强度由其磁导率和退磁因子共同决定,球磨粒的磁化强度可近似认为与磁导率无关;球磨粒引起的传感器线圈电感变化率随线圈单位长度上匝数的增加而减小,并趋向于一极限值;传感器线圈的电感变化率与球磨粒半径的三次方成正比,球磨粒半径在100μm以内,电感变化率在10-7数量级.本研究结论可为电感式磨粒传感器的设计提供理论指导.
In the inductive abrasive sensor, the ferromagnetic particles mainly change the magnetic field distribution of the sensor coil through magnetization, and then change the equivalent inductance of the coil.The magnetic field model with ferromagnetic particles in the coil is established, The expression of the magnetic susceptibility of the grain magnetic field on the demagnetizing factor. Taking the ball grain as an example, the analytic formula of the change rate of the inductance of the coil due to the ball abrasive grain is obtained by calculating the magnetization field of the ball abrasive grain. The magnetic field of the coil is calculated by the finite element method. It is found that the theoretical solution and the numerical solution agree with each other and the model can reflect the objective reality. The magnetization of the abrasive grain is determined by its permeability and demagnetization factor, and the magnetization of the ball abrasive grain can be approximated to be independent of the permeability. The change rate of the inductance of the sensor coil caused by the grain decreases with the increase of the number of turns in the unit length of the coil and tends to a limit value. The rate of change of the inductance of the sensor coil is proportional to the cube of the radius of the ball abrasive grain. , The rate of change of inductance is on the order of 10-7.The conclusions of this research can provide theoretical guidance for the design of inductive abrasive sensor.