• CN: 11-2187/TH
  • ISSN: 0577-6686

Journal of Mechanical Engineering ›› 2025, Vol. 61 ›› Issue (5): 202-213.doi: 10.3901/JME.2025.05.202

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Meshing Theory and Contact Characteristics Analysis of the Recirculating Planetary Roller Screw Mechanism

QIAO Guan1, LIU Fule1, TANG Shufeng1,2, LI Zongxue1, FU Xiaojun3   

  1. 1. School of Mechanical Engineering, Inner Mongolia University of Technology, Hohhot 010051;
    2. Inner Mongolia Key Laboratory of Special Service Intelligent Robotics, Hohhot 010051;
    3. Shaanxi Engineering Laboratory for Transmissions and Controls, Northwestern Polytechnical University, Xi'an 710072
  • Received:2024-04-30 Revised:2024-08-22 Published:2025-04-15

Abstract: According to the structural characteristics of the recirculating planetary roller screw mechanism that the rollers have no helix angle, the spiral raceway surface equations of the screw, roller and nut are established, and the spatial meshing model of recirculating planetary roller screw mechanism is calculated. The meshing point position and axial clearance are formulated, and the influence of the flank angle and the pitch on the meshing point position and axial clearance are discussed, respectively. Besides, the main curvature of the recirculating planetary roller screw mechanism is derived based on the principle of differential geometry. The Hertzian contact theory is used to solve the main curvature difference, contact ellipse area and maximum contact stress between the roller and the raceway, and the influence of the flank angle and the pitch on the contact characteristics are investigated. The results show that the meshing point position on the screw-roller interface always deviates from the line between the screw and roller axis, and the meshing point on the screw and roller is located toward the top of their thread. If the flank angles of the roller and the nut are equal, the meshing point position on the roller-nut interface will be located at the tangent point of the pitch diameter of the two threads. The nominal radius of the part can be used instead of the meshing radius to approximately calculate the principal curvature of the recirculating planetary roller screw mechanism. With the flank angle increases, the principal curvature difference and the contact ellipse area of the two contact interfaces simultaneously decrease, and the maximum contact stress on the thread teeth gradually increases. Increasing the pitch causes the principal curvature difference to increase gradually. However, the contact ellipse area and maximum contact stress do not change significantly. Therefore, in order to achieve the optimal design of the recirculating planetary roller screw mechanism, it is not advisable to set an excessively large flank angle.

Key words: recirculating planetary roller screw mechanism, helical surface, meshing mechanism, contact characteristics

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