Failure analysis and improvement measures for crankshaft connecting rod of refrigerator compressor

•Failure analysis of refrigerator compressor crankshaft was studied.•Serious abrasive wear has occurred on the surface of the crankshaft.•The failure of the crankshaft is caused by the cutting of particles inside the compressor on the surface of the friction pair.•Nano copper layer was prepared by in-situ gas nitriding process, which provided a new modification technology for precision friction pair. With the improvement of family life quality and the implementation of energy-saving green household appliances, the volume of refrigerator increases rapidly and the energy efficiency ratio continues to decrease. However, the compressor size is required to be smaller, and the startup and shutdown are more frequent, which aggravates the wear of crankshaft connecting rod. Here, the failure compressor (300 ppm) provided by the manufacturer was disassembled and analyzed. The results showed that there were abrasive wear and adhesive wear on the surface of crankshaft and connecting rod. The source of solid particles in compressor was further analyzed, and the process control measures were proposed. In addition, combined with its failure mechanism and production process, the crankshaft surface composite treatment process was designed and bench test was carried out, which shows excellent anti-wear and self-lubricating performance.