Experimental Research on Static Stiffness of the Planetary Roller Screw Mechanism

This paper investigates the static stiffness characteristics of the planetary roller screw mechanism (PRSM). Firstly, an analytical model of elastic deformation in the PRSM considering contact deformation, combined deformation of screw shaft and thread deformations is established. Then, an accuracy coefficient is introduced to take into account the effect of machining error and assembly error on elastic deformation. Secondly, the stiffness tests of the PRSM are performed under different loads and nut positions. Lastly, the correctness of the analytical results is verified via the comparison with experimental results. The results show that the analytical results are in good agreement with the experimental results, and the stiffness variations under different loads and nut positions are obtained.