| Asymmetric gear have the advantages of large bearing capacity,small volume,light weight and long service life,asymmetric gear can significantly improve the transmission performance of gear and it is widely used in high-speed,heavy-duty and high-power gear transmission occasions of aerospace and aviation,and its transmission performance and service life directly affected by its manufacturing accuracy.asymmetric gears processing method is similar to that of symmetric gears,which mainly including gear milling,gear hobbing,gear shaping,gear grinding,gear shaving,etc.,Among them,hobbing is used for gear rough machining,gear grinding and shaving are used for gear finishing,but gear shaping as a generative machining method,which has the advantages of precise tooth profile processing,good processing adaptability,and can process external gears,internal gears,multi-connected gears,therefore gear shaping is an important method for gear processing.Compared with standard gear,asymmetric gear have a more complex structure and higher manufacturing and assembly requirements.How to use the gear shaping method to achieve high-efficiency processing of asymmetric gears is an urgent problem to be solved in improving the precision transmission of asymmetric gears.For this purpose,this article aiming at asymmetric gears shaping processing,this article plan to base on the principle of asymmetric involute meshing,through UG software,Abaqus finite element software,Vericut processing simulation software and other tools,next then derive the asymmetric gear tooth profile equation and helical gear helical surface equation.To achieve asymmetrical gear three-dimensional solid modeling,gear shaping tool design and angle optimization,NC gear shaping simulation error analysis and to realize asymmetric gear shaping.The specific research work is as follows:(1)Explain the meshing principle of asymmetrical involute gears.Derive the asymmetrical gear tooth profile equation and helical gear helical surface equation,and import the tooth profile equation into UG,run the law curve command to generate the asymmetrical gear tooth profile curve and helical guide line,trim and extrude to obtain an asymmetric spur gear,and sweep the symmetrical helical tooth profile along with the pattern feature and extrude.A three-dimensional model of asymmetric gear based on UG is obtained.(2)Deduce the tooth profile equation of the asymmetric gear shaping tool,based on the design principle of asymmetric gear shaping tool,determine the tool angle preliminarily and establish the three-dimensional model of the asymmetric gear shaping tool.Then use Abaqus to analyze the non-symmetrical gear inserting cutting,and use the surface response model to fit the relationship between the angle of the helical gear cutter and the asymmetrical straight gear cutter,with the slotting force and the temperature function.Finally,use the genetic algorithm to optimize the gear shaper angle.parameter;Compare and analyze the slotting force and temperature of asymmetrical gear shaping tools before and after optimization.Verify the correctness of the asymmetric gear shaping tool angle optimization.(3)Analyze the principle of asymmetric gear shaping,select a three-axis(YZC)vertical slotting machine with a CNC turntable,write a CNC machining program for gear shaping,and use Vericut to simulate asymmetric spur/helical gear shaping,Compare the simulation results of asymmetric gear shaping and the three-dimensional model of asymmetric gears.Then analyze the CNC machining errors of asymmetric gears to verify the feasibility of CNC gear shaping for asymmetric cylindrical gears.In summary,this article researching will provide theoretical guidance for the highefficiency machining of asymmetrical gears by CNC gear shaping,thereby further enhancing the application range of asymmetrical gears precision transmission. |
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