Load Distribution of Planetary Roller Screw Mechanism with Error, Thread Wear and Temperature Change

In order to reveal the coupling effect of error, thread wear and temperature change on load distribution of planetary roller screw mechanism (PRSM), a load distribution model of PRSM with error, thread wear and temperature change is developed based on deformation coordination relationship in this paper. Compared with the existing finite element model and the spring model, the maximum relative error is 8.36%, which verifies the correctness of the presented model and can be used to study the load distribution. Furthermore, the load distribution trend without errors, with errors and wear, as well as temperature change is studied. The results indicated that the error is the main factor, which leads to load uneven and fluctuation, wear intensifies the load uneven and fluctuation, and temperature change leads to the change of load distribution and shows symmetric distribution in the middle of the thread as reference. The maximum load increases 9.2% when temperature change is 80℃, therefore, the temperature change leads to load increase of some thread, which will further intensifies overload risk. Besides, the load distribution is relative even when temperature change is 40℃, and the control of temperature change can be regard as a method to improve load distribution of PRSM.