MIT Self-Compensating Hydrostatic Bearings 26 February 2010 Professor Alex Slocum Gerald Rothenhofer Matt Angle

A Quick Primer on Hydrostatic Bearings Are Used to Support the Crankshaft in Automotive Engines Pump Forces Fluid Into a Channel and then Between a Shaft and Journal Shaft Rides on Thin Film of Fluid Metal-to-Metal Contact and Friction are Reduced High-Pressure Lubricant Shaft Bearing Journal

Issues with Non-Self Compensating Hydrostatic Bearings Small Orifices – Used to Create Constant-Pressure Fluid Supply – Are Easily Clogged by Contaminants in Fluid (Especially Sea Water) Control Loops – ?? Water Hammer – High Flow Rates Cause Turbulence in Fluid Exit – Shaft Can Oscillate in Unsteady Flow

Why ours is cool Supply Grooves – Oriented on Inside of Bearing Assembly (Made of Two of These Pieces) – Extend ~180° to Pocket on Opposite Side of Bearing – Function as Orifices in Non-Compensating Bearings Are Self-Cleaning and Difficult to Clog Pockets – Bear Load of Shaft – Fed by Supply Channels How it Works – When Shaft is Displaced, Supply Grooves are Blocked, Pressure Reduced in Pockets on Opposite Side of Shaft – Produces Restoring force