Abstract
The wear problems are vital to the planetary roller screw mechanism (PRSM) as they have a great influence on transmission accuracy, working efficiency, and service life. However, the wear characteristics of the PRSM have been rarely investigated in the past. In this paper, a multiscale adhesive wear model is established by incorporating the effective wear coefficient and considering the thread surface roughness. The variation of surface roughness is characterized by the two-dimension Majumdar–Bhushan (MB) function. The multi-asperity contact regimes are used to estimate microcontact mechanics of the rough interface. Moreover, the influences of surface roughness, material properties, and working conditions on the wear depth and precision loss of the PRSM are studied in detail. The results reveal that as the surface roughness increases, the total actual contact area, wear depth, and precision loss rate rise. In addition, the adhesive wear increases with the growth of the axial load, and decreases with the increase in the material hardness and material elastic modulus ratio to a certain extent. The investigation opens up a theoretical methodology to predict the wear volume and precision loss with regard to thread surface roughness, which lays the foundation for the design, manufacturing, and application of the PRSM.
Highlights
Accepted: 16 November 2021As an essential transmission component of linear motion of electromechanical systems, the planetary roller screw mechanism (PRSM) is widely applied in electric aircrafts [1], automobile, robots, and defense equipment
The wear is influenced by many factors, including surface roughness, material hardness, material elastic modulus, and operating condition [2], while the effect of these factors on the contact and wear mechanism of the PRSM is almost ignored
The results indicated that surface roughness, material properties, and work of adhesion had a great influence on the asperity plastic deformation, wear rate, and wear coefficient
Summary
As an essential transmission component of linear motion of electromechanical systems, the planetary roller screw mechanism (PRSM) is widely applied in electric aircrafts [1], automobile, robots, and defense equipment. In these engineering applications, high precision, heavy load, lightweight, and long service life are strongly required. In the PRSM, the wear is inevitable due to relative sliding and large contact stress, which greatly affects the transmission accuracy and lifetime in the running process. It is indispensable to calculate wear volume and predict precision loss. Sandu et al [11,12] proposed an efficient method for analyzing thread profile and predicted threaded contact area. Fu et al [13]
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