A roller taper modification method for load distribution optimization of planetary roller screw mechanism

Abstract

Planetary roller screw mechanism (PRSM) is a novel high-performance linear transmission device. The non-uniformity of load distribution over PRSM threads is a vital problem severely affecting its load-carrying capacity and service performance. This work aims to develop a PRSM load distribution improvement approach with good manufacturability and general applicability. A roller taper modification method for load distribution optimization is proposed based on the deformation compatibility and force equilibrium, then the roller grinding experiment is carried out. Finally, the effects of external load and thread number on load sharing optimization are analyzed to examine the applicability. The results show that the maximum reduction in load sharing coefficient reaches 31.4% after roller taper modification under the case studied. The taper modification of roller threads could be rapidly implemented by only adjusting the roller grinding angle. The roller grinding experiment results agree well with the theoretical values, and the maximum error is no more than 2 μm. As the external load and thread number change, the improvement approach still works well. The proposed method has been verified by comparisons with finite element simulations and available references. This work can provide theoretical guidance for the optimal design of PRSM and has good engineering application prospects.

Review on errors and transmission characteristics of the planetary roller screw mechanism

“…Based on the advantages above and multi-point contacts of the threads, it is widely used in heavy load, 1 high stiffness, 2 long service life, 3 high resistance, 4 and other complex working conditions. 5–9 With such extraordinary characteristics, the errors and transmission of the PRSM are attracting more and more attention.…”

Performance and Challenges of Planetary Roller Screw Mechanism in Complex Conditions: A Comprehensive Review of Recent Progress

“…Garrison et al [23] introduce two-fault tolerant electric actuation systems for space applications, showcasing the potential of electro-mechanical and electro-hydrostatic actuation systems to replace conventional hydraulic systems, while Lepagneul et al [24], Liu et al [25], Du et al [26], Xiao et al [27], Hu et al [28], Yao et al [29][30][31], and Guadagno et al [32] delve into the optimization, design, and manufacturing processes of PRSMs. Their research addresses the challenges of achieving uniform load distribution, minimizing contact stress, and enhancing the transmission accuracy of these mechanisms, through multi-objective optimization, advanced modeling, and innovative manufacturing techniques.…”

Meshing characteristics analysis of planetary roller screw mechanism with misalignment

“…In the last decades, extensive researches on PRSM have mainly focused on kinematic analysis, 9,10 friction efficiency, 11,12 thermal characteristics analysis, 13,14 load distribution, 15,16 fault diagnosis, 17–19 and so on. For contact positions, Jones and Velinsky 20 obtained the locations of the PRSM contact points by utilizing the principle of conjugate surfaces and analyzed the principal radii of curvature at the contact points and the angle between the principal axes.…”