1. School of Mechanical Engineering Tsinghua University Beijing 100084 P. R. China
2. Luoyang Bearing Science & Technology Co., Ltd Luoyang 471039 P. R. China
3. State Key Laboratory of Special Surface Protection Materials and Application Technology Wuhan Research Institute of Materials Protection Wuhan 430030 P. R. China
4. School of Mechatronic Engineering and Automation Foshan University Foshan Guangdong 528225 P. R. China
5. National United Engineering Laboratory for Advanced Bearing Tribology Henan University of Science and Technology Luoyang 471023 P. R. China