Optimization of the Crankshaft Journal Bearings Efficiency

Abstract

The hermetic compressor is widely used in household refrigerators. About 10% (10-15W) of the power consumption of the compressor is converted to heat due to the friction losses in the journal bearings, and about 76.4 million kWh of energy is spent on friction losses in the annual energy consumption of refrigerators sold in one year. In this work, the energy efficiency of the refrigerator compressor is increased by the reduction of friction losses in journal bearings. The model for kinematic and dynamic analysis of the crankshaft-connecting rod in the hermetic compressor is established to determine the forces acting on the crankshaft and the load-bearing capacity in journal bearings. For all these investigations, in-house built MATLAB codes are used. The results of the kinematic analysis are compared to the CAD analysis. The eccentric ratio for hydrodynamic lubrication conditions is determined. The bearing dimensions are optimized to minimize energy loss.