# Deformation of locomotive traction gear based on meshing stiffness

In recent years, China’s high-speed railway technology has made great progress. The executive meeting of the State Council deliberated and approved the medium and long term railway network planning in principle, which provides a huge opportunity for the accelerated research and development of the locomotive industry. As the core component of locomotive transmission, the main function of traction gear is to transfer the output torque of traction motor to wheel set, so that the locomotive can run normally and safely. Therefore, the reasonable engagement of traction gear has a great influence on the vibration noise and safe operation of locomotive. At present, the development of gear is developing towards the trend of high speed and heavy load, but the influence of dynamic load and other factors has become the stumbling block of this trend. The main reason for these problems is the meshing error, which is mainly caused by two factors:

(1) Manufacturing error of gear;

(2) The bending, contact and other deformations of gears after contact and loading.

The manufacturing error of gear mainly includes the base pitch error and the tooth profile error, but there are very efficient means to control it within the permitted range in the current industrial production. However, for the calculation of the gear deformation, in the process of gear transmission, the load on the gear is relatively complex, and the calculation is also relatively complex. The commonly used calculation methods of the gear deformation mainly include the numerical calculation method and the finite method The finite element method is not suitable for parametric design, although its calculation accuracy is relatively high. It will calculate the deformation of traction gear from the angle of meshing stiffness, which will lay a foundation for subsequent tooth profile modification.

(1) The load distribution between teeth calculated based on the time-varying meshing stiffness is roughly consistent with the curve obtained based on the empirical formula and a large number of experimental data. It is indirectly verified that the method of determining the load distribution between teeth by using the ratio of comprehensive meshing stiffness in the double teeth meshing area is feasible.

(2) The data show that the load distribution between teeth will change abruptly when the single tooth meshing area changes to the double tooth meshing area and when the double tooth meshing area changes to the single tooth meshing area. The single tooth meshing stiffness changes smoothly with the position of the meshing point. Generally speaking, the deformation of the driving gear will increase with the height of the meshing point, but there will also be a step mutation in the transition area, while the driven gear will be the opposite.

(3) The results show that the calculation of the deformation of the traction gear from the angle of meshing stiffness can be well applied to the displacement traction gear, and it is very convenient for parametric design.