| With the rapid development of aviation, aerospace, robot, automation, ship andvehicle etc., the accuracy and backlash of important equipment transmission systems areposed a very stringent requirement especially under special and extreme conditions.Since the existing transmission systems of different types cannot meet the need for thedevelopment of important equipments, Professor Wang Jiaxu in the State KeyLaboratory of Mechanical Transmission of Chongqing University invented a precisefiltering driving gear reducer (patent number: ZL201010104359.5). Compared with theother gear reducer, it has the advantages of high stiffness, small volume, light weightand easy to process etc., and the most important is that the reducer can easily adjust itsmeshing clearance by changing the axial position of the beveloid gear, realize precisetransmission. It is quite fitful to the precise servo transmission that is strict to backlash.So it has a high practical value and a splendid future. Therefore, in such a background,this paper focuses on the structure design, backlash and contact stress analysis of thisnew type beveloid gear reducer with small tooth number difference. This research canbe mainly summarized as follows:①Under ascertaining the technical requirements of this new type gear reducer,especially its interface size, complete the structure design of the reducer, including areasonable optimized distribution of the numbers of teeth and a calculation of itsgeometrical size; the checksums of the contact ratio, topping, interference of itsoverlapping teeth and actual headspace.②Based on the SolidWorks3D design software, the precise tooth surface ofbeveloid gear is generated, and the solid models of each parts and assembled model ofthe new reducer is built. Then transformed assembling model to ADAMS software andset up the Virtual Prototype model of the new type reducer. The function STEP is usedto define motion and loading of the reducer. Simulation with Virtual Prototype andelicited kinesis relation diagram, force diagram, time and frequency domain diagram ofeach parts and components.③The mathematical models of the backlash of the internal gearing beveloid gearpair and the reducer are presented in accordance with the structural features in order toensure backlash can meet the predetermining demand. Not only the influence ofadjusting value of bevoloid gear on the reducer’s lost backlash can be analyzed，but also the precision class of gears and the backlash type can be determined to reach therequired backlash by using this models．④Vector approach proposed by Litvin is adopted to obtain the mathematical modelof rack cutter and beveloid gear based on theory of gearing and generating process ofbeveloid gear. These parametric equations are used to establish the meshing model ofbeveloid gear pairs. Then model for the analysis of tooth contact stress of straightbeveloid gears with parallel axes is proposed. The approach is based on application ofinfluence coefficient methods that accommodates the influence of tooth deformation ongear mesh quality. By assuming that the influence coefficients of each tooth-pair areindependent of each other, the proposed approach is extended to condition multipletooth-pair contact. Computer program has been written to calculate the distribution ofcontact pressure. Results have been validated by comparison with studies carried out bythe finite element method. Modification investigation on the beveloid gear is alsoconducted. |
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