Study on the general principle of normal circular-arc gear transmission

As a typical engineering application of basic principle of Bertrand conjugate surfaces, the general principle of normal circular-arc gear transmission, including paralleled-axis, intersected-axis and crossed-axis, is systematically studied. The research method, from datum surface to the directrix, is presented. The types of datum surfaces and the directrixes of all kinds of transmissions and the method to generate tooth flank of normal circular-arc gear are developed, and the investigation on the noninterference condition is performed by the curvature axis. Three typical normal circular-arc gear transmissions as loxodromic-type, geodesic-type and hyperboloidal-type under the condition of intersected-axis and crossed-axis are proposed.