Friction Torque Analysis of Planetary Roller Screw Mechanism in Roller Jamming

The load distribution model of the planetary roller screw mechanism (PRSM) is established on the basis of Hertz contact theory. The objective is to obtain a friction torque model of the PRSM in roller jamming. An example is provided to calculate the friction torque of the PRSM in roller jamming. Thereafter, the transmission efficiency is calculated. A static structural analysis is performed using the finite element method to estimate the contact stress between the threads of the PRSM components. Computational results indirectly reveal that roller jamming exerts considerable influence on the friction torque of the PRSM. Results show that the friction torque of the planetary roller screw increases when the roller is jammed and the wear of the parts is accelerated. This condition leads to structural failure. The results of this study can serve as a foundation for electromechanical actuation systems, which can be useful in designing antijamming systems for safety-critical aircraft applications.