1. November 14, 2013 Mechanical Engineering Tribology Laboratory (METL) Shenghui Jia Research Assistant Fundamentals of Hydrodynamic Lubrication

2. 2 November 14, 2013 Mechanical Engineering Tribology Laboratory (METL) Outline Personal Background Motivation & Objectives Bearing Design Evaluation - Fixed-incline slider bearing - Parallel-step slider bearing - Journal bearing Future Work

3. 3 November 14, 2013 Mechanical Engineering Tribology Laboratory (METL) Personal Background August 2009-July 2013 Department of Mechanical Engineering Dalian University of Technology ➢ Major: Mechanical Design, Manufacture and Automation ➢ Degree: Bachelor of Science ➢ GPA: 3.8/4.0 September 2013 Joined METL Research experience ➢ Mar 2012 Ultra-precision Grinding Technology for Silicon Wafer Thinning, Research Assistant. ➢ Sep 2011 Design of Low Instantaneous Point Floating Grinding Head, Project Leader.

4. 4 November 14, 2013 Mechanical Engineering Tribology Laboratory (METL) Motivation & Objectives Motivation Study and Understand Hydrodynamic Lubrication Objectives Evaluate Bearing Designs –Inclined Slider Bearings –Parallel Step Bearings Step Boundary Condition –Journal Bearings Sommerfeld Solution Half Sommerfeld Solution

5. 5 November 14, 2013 Mechanical Engineering Tribology Laboratory (METL) Fixed-incline Slider Bearing Pressure distributions of fixed-incline slider bearing Reduced Reynold’s Equation : (Non-dimensionalized) 1D 2D

6. 6 November 14, 2013 Mechanical Engineering Tribology Laboratory (METL) Parallel-step Slider Bearing Pressure distributions of parallel-step slider bearing Reduced Reynold’s Equation: ( Step Boundary Condition: constant mass ) 1D 2D

7. 7 November 14, 2013 Mechanical Engineering Tribology Laboratory (METL) Journal Bearing Full Sommerfeld solution Half Sommerfeld solution Pressure distribution of journal bearing Reduced Reynold’s Equation : Reynolds Boundary Conditions: 2D

8. 8 November 14, 2013 Mechanical Engineering Tribology Laboratory (METL) Future Work Compound Journal Bearing –Floating pin configuration results in multiple rotational degrees of freedom Bearing rotates pin rotates relative movement occurs f1, f2 –Investigate the pin velocity. Shear forces must balance for an unknown pin velocity, f1=f2. tappet Journal bearings