In this paper, the concepts of theory of gearing are developed by the synthesis of the results of our reseachs for years into theorical development and practical application of the generation of gear. A method of the reverse synthesis of the gearing is introduced in the third part. | Vietnam Journal of Mechanics, VAST, Vol. 33, No. 3 (2011), pp. 194 – 202 NEW CONCEPTS OF THEORY OF GEARING AND A METHOD FOR REVERSE SYNTHESIS OF THE GEARING Nguyen Thien Phuc Hanoi University of Science and Technology Abstract. In this paper, the concepts of theory of gearing are developed by the synthesis of the results of our reseachs for years into theorical development and practical application of the generation of gear. A method of the reverse synthesis of the gearing is introduced in the third part. Keywords: Theory of gearing, contact ellipse, elastohydrodynamic film, reverse synthesis. 1. INTRODUCTION The contents of this paper cover the following main topics: 1) Gearing with the required contact ellipse 2) Gearing with the elastohydrodynamic film thickness 3) Generation of gear without the restriction of the use classic method of manufacturing 4) Innovation on the development of gear drives in the trend of the modern mechatronics. Several new concepts of theory of gearing are based on the main results of our research into the mentioned topics [1] and on the lastest developments in its practical applications. Follow these concepts we can develop new approaches for the design and manufacturing of the gears and propose a method for the reverse synthesis of the gearing. 2. NEW CONCEPTS OF THE THEORY OF GEARING . Gearing with the required contact ellipse Up to now most people take great pains in research into the establishment of gearing with contact line. According to the viewpoint, the tooth surfaces are in the line contact at every instant. However, this is not practical because the inaccuracies in the manufacture and assembly are always occurred, so it is impossible to avoid. Such inaccuracies can cause stress concentrations on the edges and tips of the gear teeth. There are many researchs into the localization of tooth contact. The tooth surfaces with the localized contact may be generated by shaping, hobbing or grinding etc. Among these we show .
