Model Analysis And Multi-objective Optimization Of The Planet Carrier In Wind Turbine Gearbox

The planetary gear transmission is used in a variety of applications due to its severaladvantages such as low weight, great load sharing, and great efficiency. As one of the mostimportant components in the planetary gear transmission, the planet carrier has great effect onthe reliability of the transmission system. Its deformation plays an important role on thecontact stress distribution produced by gear mesh. Meanwhile, for the gearbox works highabove the ground, the lighter its quality is, the more stable the system will be. Therefore, it isnecessary to reduce the stress concentration, the strain, and the mass with the multi-objectivedesign optimization.Firstly, Static load of the planet carrier is studied by static calculation. A three-dimensionfinite element model is established, which is used for the static analysis. With theANSYS-WORKBECH, the rigidity and intensity of the planet carrier are checked.Secondly, the free modal analysis is carried out by the finite element method. the modalis calculated by Lanczos method, and the vibration mode and natural frequency can beobtained. the vibration modes mainly display the bending modes and the torsion modes.Meanwhile, the model test method is carried out with the NI instrument. The model results offinite element model analysis are compared to the experimental values. The maximum error isonly6%, which prove the accuracy of the finite element model.Finally, In order to improve the reliability of a planet carrier, a simulation method based onmulti-objective design optimization was developed in this paper. The objective of the methodwas to reduce the stress concentration, the deformation, and the quality of the planet carrier byoptimizing the structure dimension. A parametric finite element model, which enables a goodunderstanding of how the parameters affect the reliability of planet carrier, was established andsimulated by ANSYS-WORKBENCH. The efficiency of the design optimization wasimproved by using a polynomials response surface to approximate the results of finite elementanalysis and a Multi-Objective Genetic Algorithm (MOGA) to determine the direction ofoptimization. Computer simulation was carried out to verify the validity of the presentedoptimization method, by which the quality and the stability of the planet carrier weresignificantly reduced and improved, respectively. Consequently, the cost of planet carrier wasgreatly reduced. The methodology described in this paper can be effectively used to improvethe reliability of planet carrier.