Research On The Parametric Modeling Method And Meshing Performance For The Spiral Bevel Gear

Spiral bevel gears are widely applied in automobile, aero-space and petrochemical industries to transmit power and motion between intersecting shafts instead of straight bevel gears due to their advantages such as large contact ratio, smooth transmission, high load-carrying capacity, low noise, etc. In some critical applications, such as the final drive in the auto drive axle, these gears operate at a relatively high rotational speed and transmit substantial power or even with misalignment. Accurate prediction of operational behavior is important to design stronger and lighter gears with longer service life. In addition, the tooth profile of spiral bevel gear is spherical involute and the tooth surface is irregular space curved face which make it difficult to establish the accurate 3D models. The simulation analysis of meshing and optimization design of spiral bevel gears is greatly hindered. Therefore, it is important to study on the accurate parametric modeling methord and its meshing perforamce of spiral bevel gears.Based on the meshing principle and cutting process of spiral bevel gear, the accurate parametric 3D geometric model of the gear is established by the CAD software Pro/E using the equation of spherical involute, which provides useful foundation for the futher study on its meshing perforamce.The finite element nonlinear contact model of the spiral bevel gear is developed in the FEM software ANSYS, and the static and dynamic contact analysis is investigated on its meshing performance. The influence of four types of alignment errors on contact stress, root bending stress, transmission error, vibration and noise, shift of path of contact and load-sharing ratio has been discussed in detail. And the dynamic factors, such as rotational speed, torque and friction condition, on the meshing performance are also studied. The results provide useful reference for the modification design and the assembling of spiral bevel gears in practice.The dynamic modal characteristic of spiral bevel gears is investigated by the ANSYS modal analysis model. By the results, the natural frequencies and the mode shapes in different orders are obtained. The high rotational speed and structural parameters, such as helix angle, pressure angle and profile modification coefficient, on the modal characteristic is discussed in detail. The results provide theoretical basis for the precise pre-estimate of modal characteristic, structural optimization and excitation control of spiral bevel gears.Based on the Visual Basic language, AutoCAD and Pro/E, the software named "Parametric Design of Gear V1.0" is developed. The calculation of geometric parameters,2D engineering drawing and 3D geometric model can be automatically realized by this software which provide efficient and accurate models for studies on different gear mechanism.