Design And Research For The Main Drive Mechanism Of The Gear Shaper Based On Non-circular Gear Drive

The main drive mechanism of the conventional gear shaper usually uses crank-slider mechanism to achieve the reciprocating, cutting movement. When the crank is driven in a constant speed, the slider has a symmetrical reciprocating movement whose velocity is changeful. On the one hand, without quick-return characteristic, this movement has the same trip of the working time and the returning time, which goes against improving process efficiency; On the other hand, during the working process the speed is changed in a large range, which leads to a large impact. It will also affect the consistency and precision of the gear's surface. Nowadays, the gear shaper is developing in the direction of high-speed, so when the speed is elevated, the quick return characteristic and a constant velocity during cutting process will become more and more important. Therefore, acquiring a quick return mechanism and keeping a constant cutting speed are both important factors in the research of high speed gear shaper.According to the working principle of the gear shaper, the characteristic of the main drive mechanism was analyzed. The optional schemes were discussed and compared in order that quick return characteristic could be achieved. Finally, the scheme of using non-circular gears in the main drive mechanism was chosen.Interrelated measurement parameters of the non-circular gear drive mechanism were used as variables, and the stability of the cutting velocity and the quick return characteristic were used as the object to optimize the design. The restriction of the non-circular gear's capability was defined. The mathematical model was established. Correlative optimize method was chosen to compute it by using MATLAB software. Then the optimized result was used to establish the solid model in Solidworks, then the model was imported to ADAMS to do the kinematical analysis. The result suggested that the optimized mechanism's velocity characteristic and quick return characteristic had got obvious improvement when compared with the one without non-circular gear drive mechanism.The structure of the non-circular gear was designed. The Pitch Curve of the non-circular gear was achieved in the help of the center distance between the two non-circular gears and the drive ratio function acquired from the optimize design. The convexity of the Pitch Curve, pressure angle and undercut of the non-circular gears were checked to make sure it was in coincidence with the design requirement. The non-circular gear's dynamical balance was analyzed when running in high speed. The structure of the non-circular gear's body was designed in order that the centrifugal force made by the eccentricity of the non-circular gear was reduced. Then the dynamical simulation was made. Some research on the manufacture of the non-circular gears was made. And the method of Numerical Control manufacture was simply introduced.The structure of the driven box was designed. The digital prototype's model was established and simulated, then the simulation was analyzed, which verified the mechanism's kinematical characteristic. Aiming at the pressure and the vibration of the mechanism, some finite element analysis on some relative components was done. Through analyzing the effects brought by the inertial force, the maximum speed of the drive mechanism was achieved. Finally, the design was improved to satisfy the requirement of cutting in high speed.