Research On The Error Of Non-circular Gears Based On The All Teeth Measurement Method

The non-circular gears are used more and more widely with the development of computer technology and numerical control technology in the industrial production. But there are no unified measuring instruments and industry standards, which greatly hinders the further development of non-circular gears. So based on the present situation, a universal all teeth measurement method is proposed for non-circular gears. The actual data is obtained and the influence of the error is analyzed according to the experimental data and the theoretical data.Based on the discrete points, a universal and applicable expression of non-circular gears is established and the pole diameter increment method is adopted to determine the measurement points. In order to improve the computational efficiency, the non-circular gear tooth profile is separated and the intersection points are calculated. In view of the interference phenomenon, the measurement points within the neighborhood and normal forecast solution is put forward and the accurate actual data is obtained.According to the real tooth profile data, the non-circular gear pitch error, the tooth profile error and tooth thickness error is calculated combining the theoretical tooth profile data. In order to evaluate precision grade, the calculation method of curvature is analyzed. By calculating the equivalent diameter and allocating the weight differently, the non-circular gears are converted to cylindrical gears.In order to further analyze the machining error, the hobbing model of non-circular gears is established and the formula of object angle and the amount of rack moving is derived. What’s more, the influence of the pressure angle, the shape and the installation bias for the tooth profile error is simulated in the software. At last, the validity of the measurement method is proved and the result shows that this method plays a general significance for the measurement of the non-circular gears.