Measurement of Mechanical Loss in Linear Compressor

Abstract

Linear compressor is a reciprocating compressor, in which a piston is driven directly by a linear motor with linear motion. The linear compressor has an advantage that contact force between the piston and a cylinder is small compared with conventional reciprocating compressors because the linear compressor doesn’t have a crank mechanism. However, the influence of the mechanical loss on the performance becomes large in a miniature size linear compressor, and the mechanical loss in the small linear compressor was not investigated in detail. In this study, measurement of the mechanical loss in the linear compressor is examined by measuring the side contact force between the piston and the cylinder. As a result, it is found that when a support spring shrinks around BDC, the piston leans in a certain direction and makes contact with the cylinder. The frictional force by the contact between the piston and the cylinder is smaller than a viscous force by lubricant in the linear compressor used in this study.