On-machine measurement method for the geometric error of shafts with a large ratio of length to diameter

Abstract

For shafts with a large ratio of length to diameter, the existing measurement method mainly uses a contact coordinate machine. But machining errors have a strong influence on the offline measurement results, and the accumulation errors of the measurement system also make the measurement datum difficult to identify. For this reason, a new on-machine measuring method is proposed based on the spatial analytical geometry theory to achieve the measurement of the shape and position tolerance of shafts. Through the method, the measurement system combines the line laser measuring instrument and the laser displacement sensor together. Then, the ideal central axis of the workpieces can be obtained and serve as a datum. Finally, the on-machine non-contact measurement of large-size shafts with geometric errors is realized with high measurement accuracy (<0.01 mm), high measurement efficiency (time <10 mins), and strong robustness (insensitive to installation error and measuring environment).