| In the rotating shaft system,the hollow shaft is a common shaft type part,and the coaxiality error of the inner hole and the outer circle of the hollow shaft seriously affects the working performance and service life of the hollow shaft.The existing coaxiality measurement method has low measurement accuracy and complicated measurement steps,and most of them need to rotate the object to be measured.There is still difficulty in the hole-axis coaxiality of the hollow shaft with large volume and big weight,there is an urgent need to develop an inner bore and outer circle Coaxial measuring device that is suitable for hollow shaft with large size and big weight.In this paper,a coaxial hollow hole inner bore and outer circle concentricity measurement scheme is proposed,which can accurately measure the hole-axis coaxiality and other parameters of large-size and big-weight hollow shaft.The scheme is as follows: firstly,a non-diffracting light source generator is used to emit a non-diffracting beam,a common non-diffracting light straight line reference is constructed,a plurality of inner hole cross-sectional contour circles are measured,and a circular center of each cross-sectional contour circle is obtained with respect to a common non-diffracting light linear reference.The spatial position is fitted with a straight line axis of the inner hole,and the axis is used as a reference for the coaxiality evaluation;then a plurality of outer circular cross-sectional contour circles are measured,and the space of the circle center of each cross-section contour relative to the linear line of the non-diffracting light is obtained.Position,and then obtain the spatial distance of the center circle of each outer circular cross-section contour with respect to the linear axis of the fitting inner hole,and finally obtain the coaxiality of the outer circle and the inner hole.Based on the measurement scheme,this paper defines the coordinate system,deduces the transformation matrix between each coordinate system,establishes the mathematical model of the coaxiality algorithm,and deduces a complete data processing method.A special probe was designed to produce an experimental prototype of the inner hole and outer circle coaxiality measuring device.The coaxiality measurement data processing algorithm was developed and the data processing software was written.In addition,this paper also develops a calibration scheme for the zero position of the displacement sensor in the coaxiality measuring device,carries out the calibration experiment,and writes the calibration result into the program,which improves the measurement accuracy of the measuring device.Experiments were carried out using the coaxiality measuring device,and experimental data were processed to obtain experimental results.Finally,the experimental results are analyzed,and the synthetic standard uncertainty of the coaxiality measuring device is analyzed.The uncertainty of the coaxiality measurement is 10.66 um. |
