The optimization of obtaining the most uniform load distribution is important for the load carrying capacity design of the planetary roller screw mechanism (PRSM). However, the stiffness matrix of PRSM in traditional method based on the relationship between load and deformation of the thread may be destroyed when threads are no longer in contact due to machining errors, which would bring convergence problem in optimization process. In this paper, the mathematical model is firstly established to overcome the above drawbacks by proposing an improved iterative algorithm. Then, the multi-objective optimization is conducted to search the best designed pitches for the most uniform load distribution on both the screw-roller and nut-roller interfaces, and results are verified by the finite element method.

获得最均匀的载荷分布的优化对于行星滚柱丝杠机构（PRSM）的承载能力设计很重要。但是，传统的基于载荷与变形关系的方法的PRSM刚度矩阵在由于加工误差而不再接触螺纹时可能会被破坏，从而在优化过程中会带来收敛性问题。本文首先通过提出一种改进的迭代算法，建立了克服上述缺点的数学模型。然后，进行多目标优化，以搜索设计最佳的螺距，以在丝杠-滚子和螺母-滚子界面上获得最均匀的载荷分布，并通过有限元方法对结果进行验证。