Bearing characteristic analysis and modification design of differential planetary roller screw mechanism
QIAO Guan
ZHANG Xiaomin
LIAO Rong
TANG Shufeng
MA Shangjun
Abstract：[Objective]The differential planetary roller screw mechanism is a new type of transmission mechanism in which the screw thread is meshed with the roller ring groove,as well as the mesh between the roller ring groove and the nut ring groove.The bearing characteristics of a new type of five-stage differential planetary roller screw mechanism was investigated.[Methods]The analysis model was established and the bearing characteristics were analyzed based on the finite element method.Besides,the influence of different design parameters on the bearing characteristics was analyzed.Finally,the modification design was carried out.[Results]The results show that the stress,the load and strain of the ring groove of the contact section between the roller and the nut are larger than those of the contact section between the roller and the screw.The maximum values of stress,ring groove load and strain in the two sections of the contact between the roller and the screw are located at the leftmost end of the meshing contact.The maximum values of stress and strain in the three sections of the contact between the roller and the nut are located at the rightmost end of the meshing contacts.It is proved that there is an uneven load distribution in the differential planetary roller screw mechanism.The relevant design parameters of the ring groove teeth have an important influence on the load distribution.When the tooth surface arc radius is 1.5 mm,the angle of the ring groove teeth is 50° and the chamfer radius of the ring groove teeth is 0.02 mm,the load of the ring groove teeth in the contact section between the roller and the screw is the most uniform.When the tooth crest modification amount is 0.63 mm or the tooth root modification amount is 0.84 mm,the bearing and stress distribution of the ring groove teeth in the contact section between the roller and the screw are uniform.The modification design effectively improves the uneven bearing of the roller ring groove teeth,which is beneficial to prolong the service life of the differential planetary roller screw mechanism.
Keywords：Differential planetary roller screw mechanismFinite element methodBearing characteristic analysisDesign parameterModification design
Publication Date：2026-03-15
Online Publishing Date：2026-09-12(First online date of this platform, not the publication date of the document)
Pages：10( 1-10 )