Stiffness of the Roller Screw Mechanism by the Direct Method

Abstract

In this paper, the direct stiffness method is used to construct a stiffness model of the roller screw mechanism. This method models the entire roller screw mechanism as a large spring system composed of individual springs representing the various compliances. In addition to predicting the overall stiffness of the mechanism, the direct stiffness method can calculate the distribution of load across the threads of the individual bodies. With the load on the individual threads known, the contact stresses can be calculated. This allows for a better understanding of the sensitivities of stiffness and contact stresses in the mechanism with various design parameters and can ultimately be used to design roller screws that are stiffer and with lower contact stresses.

Keywords:

• Dynamics of machines
• Kinematics of machines
• Robotics/Machine control

ACKNOWLEDGMENTS

The authors gratefully acknowledge the Division of Research and Innovation of the California Department of Transportation for the support of this work through the Advanced Highway Maintenance and Construction Technology (AHMCT) Research Center at the University of California, Davis.

Notes

^#Communicated by B. Ravani.