Air conditioning compressor crankshaft roundness measurement based on a laser profiler

Abstract

Crankshafts are key components of air conditioning compressors. The good roundness of a crankshaft has positive effects on the operating stability, service life, working efficiency, and noise radiation of the compressor. This study proposes a line point cloud data merging method for measuring crankshaft roundness using a laser profiler. First, a crankshaft roundness measurement system for air conditioning compressors is developed, and a high-accuracy 2D laser displacement sensor is employed to collect the line point cloud data. Second, the steps of the merging method are divided into two parts: (1) the radial merging to eliminate the effects of eccentricity; (2) the circumferential merging to remove overlapping data points of two adjacent profiles. Then, a pin gauge is used to select the point cloud region of the profile line for data merging. Experimental results show that the measurement repeatability of the proposed system can be controlled at the micrometer level. Besides, the roundness measured from the merged data is very close to the roundness measuring instrument measurements, which verifies the accuracy of the measurement system and the validity of the line point data merging algorithm.