Investigation of the operating behaviour of planetary roller screws with different number of threads of spindle and nut

• Applicant: Professor Dr.-Ing. Christian Brecher
• Subject Area: Metal-Cutting and Abrasive Manufacturing Engineering ; Engineering Design, Machine Elements, Product Development
• Term: from 2014 to 2022
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 244925538

• Final Report Year: 2023

Final Report Abstract

In the project carried out, the operating behavior of planetary roller screws (PRS) in general and the operating behavior of PRS with different speeds of the spindle and the nut in particular were investigated computationally and experimentally. The project thus makes an important contribution to a better understanding of the operating behavior and its influencing parameters. In the first step, a calculation model of a PRS was developed for this purpose, which combines the methods of the first funding period for rolling contact point finding and for calculating the main curvatures in the contacts. The model was validated using stiffness measurements of several prototype PRS and showed good agreement. The deviations were only a maximum of 7.26% in the load range up to 200 kN. Based on this, extended tests were carried out on the operating behavior and validation of the transmission behavior in the extended load-speed range. To this end, a test rig was first developed on which PRS can be run under defined conditions under very high axial loads while the most important operating variables are measured. In addition, the static axial stiffness can be detected. In the tests, a large influence of the force and a small influence of the speed on the total pitch could be determined for the new PRS as a function of the component geometry. The largest measured deviation was 1.12% from the nominal value. In addition to the total pitch, the efficiency was also investigated with regard to various influences. Here, increases in the operating parameters temperature, speed and axial force led to an increase in efficiency, with the temperature influence being the highest with increases of up to 7.16%. The project concluded with the derivation of design guidelines for PRS and applications in which they are used.

Publications

• Berechnung von Planetenrollengewindetrieben. Berechnungsmethoden zur analytischen Beschreibung der Wälzkontakte von Planetenrollengewindetrieben. In: wt Werkstattstechnik Online, Jahrgang 109 (2019), Heft 05, Seite 365-369
  Brecher, Christian; Frenken, Thomas; Hildebrand, Maria; Fey, Marcel
  
• Lastverteilung in Planeten-rollengewindetrieben. Berechnungsmethoden zur Beschreibung der Lastverteilung eines Planetenrollengewindetriebs. In: wt Werkstattstechnik online, Jahrgang 110 (2020), Heft 05, Seite 322-327
  Brecher, Christian; Frenken, Thomas; Axelrad, Gabriel; Neus, Stephan
  
• Berechnung der statischen axialen Steifigkeit von Planetenrollengewindetrieben. In: ZWF Zeitschrift für wirtschaftlichen Fabrikbetrieb, Jahrgang 116 (2021), Heft 05, Seite 327-331
  Brecher, Christian; Frenken, Thomas; Neus, Stephan
  
• Experimentelle Untersuchung des Betriebs-verhaltens von Planetenrollengewindetrieben mit unterschiedlicher Gewindegangzahl der Spindel und der Mutter. In: ZWF Zeitschrift für wirtschaftlichen Fabrikbetrieb, Jahrgang 117 (2022), Heft 06, Seite 1-5
  Brecher, Christian; Axelrad, Gabriel; Neus, Stephan