Simulation of lubrication for eccentric-roller of fixed vane rotary compressor

Abstract

A new variant of the Rolling Piston Rotary Compressor, also known as the Fixed Vane Rotary Compressor, is presented in this report. The latter is developed to increase energy efficiency by reducing frictional losses during operation. However, its working principle also introduces a significant frictional loss at the rubbing surfaces between the eccentric and roller. Therefore, a detailed hydrodynamic lubrication analysis of the eccentric-roller of the Fixed Vane Rotary Compressor is carried out, using both mathematical and computational models, to solve Reynolds’ Lubrication Equation and optimize the design of the compressor.

The study concludes that, from a geometrical perspective, a large eccentric radius, small roller (outer) radius and large cylinder (inner) radius, along with a short compressor length is desired to ensure smooth operation of the compressor. In addition, a large radial clearance between eccentric and roller is desired, up to a point when the effect of reduced lubrication surface area becomes significant. The predicted values of minimum film thickness at the lubricated region of the eccentric-roller have also been checked against the surface roughness tolerances of the commonly employed machining processes, to demonstrate manufacturing feasibility in industrial applications.

Therefore, it is theoretically proven that the eccentric-roller of the Fixed Vane Rotary Compressor works in reality through the use of hydrodynamic lubrication.