The Influence of 3D Modification on Dynamic Load Sharing Performance of Power Six-Branch Herringbone Gear Transmission System

In marine power systems, due to the coupling effect of multi-source excitation such as time-varying meshing stiffness, transmission error, and backlash, the multi-branch gear transmission system has some shortcomings, such as uneven distribution of branch load and excessive vibration. This paper uses a new 3D modification technology to reduce the uneven load problem. The system coupling nonlinear dynamic model with multi-source excitation is established, and the dynamic load coefficient (DLC) and load sharing coefficient (LSC) of each gear pair are obtained by numerical methods. According to branch transmission characteristics and actual engineering processing costs, a method for determining 3D modified gear is proposed. The multi-objective optimization model of 3D modification parameters is established by minimizing the amplitude of DLC and LSC to obtain optimal modification parameters. The influence of modification methods and modification parameters on the dynamic load sharing performance under different working conditions is analyzed. The results show that 3D modification is better than tooth profile or axial modification in improving the system dynamic load sharing performance. In scheme 1, the dynamic load sharing performance of each branch of the system is the best as a whole, but with the change of the amount of modification, the system dynamic performance decreases. Compared with gear 4i, the change of 3D modification parameters of gear 1 has a greater influence on the load sharing performance of each branch of the system. The power input gears 1 and 4i of level I and level II must be modified at the same time to achieve load sharing of each branch. The research results will provide a theoretical basis for the load sharing design of power multi-branch gear transmission systems.