Study of On-line Measuring Technology of Differential Housing

Aiming at the issue on the automatic measurement of differential housing, an on-line measurement technology of the cylindricity is discussed. According to the geometrical tolerance requirement, a contact cylindricity measurement scheme was determined. Data of measured surface was obtained through the use of linear variable differential transformer (LVDT), the transformational relation between the voltage of sensor and the geometric coordinates of measured points was studied, using the least square method (LSM) to fit the cross-section circle of measured elements, the geometric model of the measured entities was reconstructed, the mathematical model of cylindricity error was built. Measurement software was designed to calculate and show the measurement results. Actual measuring experimental results demonstrated that the method can effectively measure the cylindricity error of the differential housing, as well as further improve the measure accuracy.