Error Detection And Analysis Method For Curve-face Gear

A new type of gear drive, the curve-face gear drive, composed of a curve-face gear and a non-circular gear with mutual engagement, was proposed to achieve variable ratio transmission of motion and power between the intersection axes. It incorporates the characteristic of non-circular gears, non-circular bevel gears and face gears. Consequently, it has a prospect of application in practical project applications. The design of curve-face gear drive was gradually improved in recent years. But in the matter of the error detection of the curve-face gear, there is no practical possibility for a reliable metrological traceability to national or international measurement standards can be provided. It also restricts the development of the gear drive. Accordingly, it is an extremely urgent to resolve these issue, and the research will have positive significance on the development of this gear drive.This research subject was based on the national natural science foundation of China(51275537) and mainly studies the theory to detect and analyze the geometric errors of curve-face gear. The test items and evaluation methods in view of the accuracy and stability in curve-face gear transmission was proposed, which draws lessons from the government standards of the system of accuracy of bevel gears and hypoid gears. The detailed research contents are listed as follow.① According to the spatial gear engagement theory, combine with the differential geometry and the spatial coordinate transformation theory, the basic transmission theory and meshing coordinate were studied and proposed. Meanwhile, the parametric equations of pitch curves were deduced. Furthermore, the parametric equation of tooth surface of the curve-face gear was obtained by combining the parametric equation of the cylindrical gear cutter’s tooth surface and conjugate tooth profiles theory. Thereby, the computing methods of the coordinate values and normal vector values of the mathematical points on the tooth surfaces were obtained. At the same time, three-dimensional models of the non-circular gear and the curve-face gear was built by virtual manufacturing.② In accordance with the government standards of the system of accuracy of gear detection, as well as the detection methods of face gears, spiral bevel gears and oval bevel gears at home and abroad, the test items and evaluation methods of curve-face gear was put forward.③ On the basis of the theories of numerical control processing and Additive Manufacturing, the gear parts of non-circular gear and curve-face gear were respectively processed by the 3-axis CNC milling machine, the 5-axis machining center and the powder laser printer. After that, each of the gear parts was measured on the gear measuring center. Moreover, in line with the fundamental principles of gear measuring center, the radius compensation of the probe and the coordinate transformation formulas of the surveying coordinate systems and the design coordinate systems were proposed.④ The calculation and analysis system of geometric errors of curve-face gear was programed based on the MATLAB and VB. Therefore, in accordance with the comparison of the theoretical calculated coordinate data and the measured data obtained from the gear measuring center, the individual circular pitch errors and the total cumulative pitch errors of non-circular gear parts and curve-face gear parts were acquired. Meanwhile, the tooth profile total deviations, the tooth profile deviations and the tooth profile slope deviations of non-circular gear parts, as well as the tooth relative errors of curve-face gear parts were obtained.