Rasearch On Finite Element Analysis Of Modified Helical Gear Pair For Crane Reducer

Helical gears drive has advantages of good engagement performance, heavy loading capability and smooth transmission. It is widely used in mine, metallurgy and other fields. As the helical gear drive of crane reducer is used in high-speed and overload situations, pitting of gear surface and tooth breaking, which are respectively caused by excessive tooth contact stress and tooth root bending stress, are the main failure modes. The consequences of failure is very serious or even catastrophic. Therefore, the calculation of contact fatigue strength of gearing tooth surfaces and bending-fatigue strength of tooth root is very important in the process of gear design for crane reducer. Traditional methods of gear strength calculation are mostly the static stress analysis and approximate calculation with multiple hypotheses. Compared with the traditional computing, finite element method has advantages of rapid, accurate, reliable and flexible.As the helical gear drive has strong error sensitivity, Building accurate models of helical gears is the premise and foundation for strength analysis. Parametric modeling of involute modified helical gear by program language of APDL is deeply researched. Solid modeling of helical gear pair is builded by scanning representation method. To improve the efficiency of solid modeling and parametric finite element analysis, a special program for gear modeling with friendly User Interface is programmed by program language of UIDL.The non-linear contact finite element analysis model of helical gear pair multi-tooth engagement is established based on ANSYS. Then the dynamic simulation analysis for gear pair is carried out, the contact state and contact stress of tooth, bending stress of tooth root, and the variations of the primary driven gear's torque and rotational speed at the any meshing position are respectively obtained. The most evil place is simultaneously determined, and the static contact strength analysis was carried out in this location.The fatigue damage of gear tooth is the main reason for failure in crane reducer. This paper has a in-depth research on analysis and prediction for the gear fatigue life. Based on the finite element analysis of dynamic meshing gears and contact analysis of static strength for the worst gear location and combined with subsequent data processing, the bending fatigue life of gear is simulated according to the linear cumulative damage theory.