Skip to Main Content
 

Global Search Box

 
 
 
 

ETD Abstract Container

Abstract Header

Evaluation and Prediction of Elastohydrodynamic Lubrication Film Thickness Under Conditions of Severe Sliding and Zero Entrainment

Abstract Details

2018, Doctor of Philosophy, Case Western Reserve University, EMC - Mechanical Engineering.
The Hamrock-Dowson expressions for theoretical minimum and central film thickness of non-conformal contacts in fully flooded elastohydrodynamic lubrication (EHL) predict film collapse in the case of zero entrainment velocity (ZEV); however, past experiments show that films exist and support appreciable loads under this condition. To explore this phenomenon further, as well as the intermediate sliding speeds between pure sliding (ZEV) and pure rolling, a previously established experimental tribometer was resurrected and returned to useful service. Through independent control of two servo motors and a variable pressure loading mechanism, the tribometer is able to generate sliding velocities up to 8.0 m/s, entrainment velocities up to 3.0 m/s, and contact pressures up to 1.5 GPa or 364 N between two spherical test specimens. Using polyalphaolefin (PAO) NYE 182 as the working lubricant, the fluid film generated under these varying conditions was measured by a capacitance method integral to the design of the tribometer. While the lubricant was subjected to zero entrainment speeds, separating films of 0.52 ± 0.22 µm and 0.46 ± 0.15 µm were recorded at contact pressures of 0.5 GPa and 0.6 GPa (13.5 N and 23.3 N), respectively. The experimental results acquired during the present study are used to empirically extend the theoretical film equations to predict film thickness over the entire range of sliding speeds, from pure rolling to pure sliding, including zero entrainment velocity.
Joseph Prahl, Dr (Committee Chair)
James T'ien, Dr (Committee Member)
Paul Barnhart, Dr (Committee Member)
Kenneth Loparo, Dr (Committee Member)
411 p.

Recommended Citations

Citations

  • Hegedus, P. (2018). Evaluation and Prediction of Elastohydrodynamic Lubrication Film Thickness Under Conditions of Severe Sliding and Zero Entrainment [Doctoral dissertation, Case Western Reserve University]. OhioLINK Electronic Theses and Dissertations Center. http://rave.ohiolink.edu/etdc/view?acc_num=case1513786919757098

    APA Style (7th edition)

  • Hegedus, Phil. Evaluation and Prediction of Elastohydrodynamic Lubrication Film Thickness Under Conditions of Severe Sliding and Zero Entrainment. 2018. Case Western Reserve University, Doctoral dissertation. OhioLINK Electronic Theses and Dissertations Center, http://rave.ohiolink.edu/etdc/view?acc_num=case1513786919757098.

    MLA Style (8th edition)

  • Hegedus, Phil. "Evaluation and Prediction of Elastohydrodynamic Lubrication Film Thickness Under Conditions of Severe Sliding and Zero Entrainment." Doctoral dissertation, Case Western Reserve University, 2018. http://rave.ohiolink.edu/etdc/view?acc_num=case1513786919757098

    Chicago Manual of Style (17th edition)