УДК 621.9.02 Zsuzsa Balajti, Illйs Dudбs UP TO DATE METHOD FOR DESCRIBING THE BEARING PATTERN OF SPIROID DRIVING Spiroid driving (mating of conical worm with face gear) gains greater importance in gear drive techniques because of its advantageous features (large transmission ratio, good efficiency, small size and large transmittable power). <...> Even though it has considerable advantages, its industrial adoption is restricted because of its sophisticated production geometry. <...> In this work we show those coordinate systems, in which the necessary calculations for detecting the bearing pattern psition were carried out and produce the transformation matrixes of these coordinate systems. <...> Following in this work we determine the equation of the hob, and describe the mating rule of the conical worm and face gear. <...> In addition the equation of contacting points between the tooth surface is described. <...> In the increase in efficiency of manufacturing processes and product quality, the most important element has been computer-aided engineering. <...> Spiroid driving (mating of a conical worm with a face gear) gains greater importance in driving technique because of its advantageous features (large transmission ratio, good efficiency, small size and large transmittable power [4]). <...> Even though it has considerable advantages, its industrial adoption is restricted because of it is sophisticated production geometry [2]. <...> The Fig. 1. describes the model of spiroid driving and the model and the spiroid drive have been developed by the authors [1]. determine the equation of the hob, and describe the law of mating of the conical worm and the face gear, and additionally the equation of contacting points between the tooth surfaces. <...> The contact points between the conical worm and face gear are calculated by software and the location of a defined area of the bearing pattern is determined by Coons-patch. <...> Additionally after the analysis to all points of the bearing pattern will be fitted an interpolation surface with the generalization of Coons patches, which is called Gordon surface. 2. <...> The model of spiroid driving In this work we show those co-ordinate systems, in which the necessary location calculations have been carried out, and produce the transformation matrixes of these coordinate systems. <...> S1 ating the tooth surface of the face gear signed and S2 are the co-ordinate <...>