An improved high precision measuring method for shaft bending deflection

•An available measuring method is presented for columnar parts bending deflection.•High precision measuring algorithm is proposed after strict mathematical analysis.•Closed analytic solution method is gotten and won't produce any principle error.•Parameters sensitivity analysis is studied for the method adaptability assessment.•Experimental calibration method is provided and experimental validation is made.

The circular-section columnar parts, such as shaft, rod and pipe etc., are widely used in all kinds of machines. The bending deformation of such parts will seriously affect the assembly precision and working performance of the machines. A high efficiency and precision measuring method for bending deflection is needed. With a classic contact-detection mechanism at low cost composed of a displacement sensor, a lever and a shaft supporting device, a high precision measuring algorithm is proposed and deduced after strict mathematical analysis in this paper, and which is a closed analytic algorithm and will not produce any principle error. The parameters sensitivity auditing is carried out and the result shows the measuring method has high adaptability. Furthermore, the corresponding experimental calibration method of the current measurement technology is provided, and an experimental validation on the bending deformation of a particular shaft is carried out. The result shows in depth the proposed method has high accuracy.