Surface Error Evaluation of Non-circular Bevel Gear of Variable Ratio Differential

Based on the data obtained from the three-coordinate measuring and pre-processing,a NURBS method to reconstruct the complex surface of non-circular bevel gear and a two-step matching method to implement the complex surface error evaluation is proposed. The curve and surface reconstruction of the teeth surface is carried out by NURBS interpolation,and the least square approximation is adopted to gain the model of the reconstruction surface. Integrating ICP and BFGS algorithm,an error evaluation model is built,and the measuring data is initially matched and precisely matched to the design model. The model is solved by MATLAB programming,the Euclid transformation matrix is gotten and then the surface profile error of the gear can be achieved. Finally,the obtained error is 0. 053 22 mm,which meets the requirements of gear design. The calculating results show that this method has high accuracy and speed to reconstruct the surface and can solve the error evaluation problem for the complicated surface.