1. School of Mechanical and Automotive Engineering, Qingdao University of Technology, Qingdao, China
2. Shandong Key Laboratory of Mining Machinery Engineering, Shandong University of Science and Technology, Qingdao, China
3. China Coal Equipment Research Institute, Beijing, China
4. School of Aero-Engine, Zhengzhou University of Aeronautics, Zhengzhou, Henan, China