Tribological behavior of pits textured multi-rollers sliding-rolling tribo-pair under periodic varied load and dry wear

To reveal the influence of pit units on the friction and wear performance of multi-rollers-sliding-rolling tribo-pairs (MRSRTs), the tribological behavior of pits textured MRSRTs with 18 rollers under periodic varied load and dry wear were researched. The texture parameters include: diameter of pits (DAOP, 200, 250, and 300 μm), depth of pits (DPOP, 10, 20, and 30 μm). The wear losses and worn surfaces of samples were obtained. The influence mechanism of pits on the tribological performance of MRSRT was also discussed. The results show that: The average coefficients of friction (COFs) of pits textured MRSRTs are all lower than that of smooth one under periodic varied load and dry wear. Their mass losses are almost all higher than that of smooth MRSRT. The influence of DPOP on the tribological properties of textured MRSRTs is significant and continuous compared with that of DAOP. The depth-diameter ratio is an important factor for the wear losses. In this work, when the DAOP is 200 μm and the DPOP is 30 μm, that is, the depth-diameter ratio is 0.15, compared with the smooth sample, the mass loss of MRSRT is reduced by about 13%, and its average COF is reduced by 30.5%. This work can provide a valuable reference for the surface design and optimization of rolling element bearings.