Occlusion failure analysis and optimization design for steel piston pin hole-pin friction pair

• Published in: Engineering failure analysis 2025-03, Vol.169, p.109135, Article 109135
• Main Authors: Chen, Jikun, Lei, Jilin, Liu, Yang, Han, Yi, Jia, Dewen, Wang, Chengxi, Deng, Wei
• Format: Article
• Language: English
• Subjects: Diesel engine; Lubrication characteristics; Multi-objective optimization; Occlusion failure analysis; Steel; Steel piston; Structural optimization
• ISSN: 1350-6307
• DOI: 10.1016/j.engfailanal.2024.109135

•Application of self-developed wireless storage temperature measurement device to steel piston temperature field test.•A systematic analysis of the causes of pin hole occlusion failure in steel pistons in terms of heat transfer, mechanics, lubrication, materials, forging, etc..•The influence of the connecting rod structure on the lubrication of the piston pin bearings is discussed, and an optimization method to improve the overall lubrication performance of the piston pin bearings is explored, which provides a theoretical basis for the subsequent design of the structural parameter matching of the steel piston connecting rod assembly.•Solved the problem of occlusion failure of steel piston pin holes due to insufficient lubrication performance in engineering design. The focus of the present study was on the D25TCIF steel piston, and the underlying causes of pin hole occlusion failure were systematically analyzed. The investigation considered factors such as heat transfer, mechanics, lubrication, material properties, and forging processes. Additionally, an optimization strategy was introduced based on the cause of the failure to reduce the risk of occlusion failure of the pin hole. At the same time, the influence of the structural parameters of the connecting rod small head on the lubrication performance of the pin hole bearing was investigated, providing a theoretical basis for the matching design of the structural parameters of the double friction pair of the piston pin bearing. The findings indicate that the primary cause of pin hole occlusion failure in steel pistons is the concentration of thermo-mechanical coupling stresses and elevated temperatures within the pin hole. This condition results in the rupture of the lubricating oil film in the pin hole bearing, leading to dry friction between the piston pin and the bearing surface. The optimization method designed in the present study enhanced the minimum oil film thickness of the pin hole bearing from 0.354 μm to 0.377 μm, reflecting an increase of 6.50 %. Additionally, the minimum oil film thickness of the small head bearing was improved from 0.599 μm to 0.691 μm, corresponding to a 15.36 % increase compared to the original configuration. Meanwhile, the optimization method predicted a minimum oil film thickness of 0.382 μm for pin hole bearings and 0.693 μm for small-head bearings, with a relative error of less than 5 % from the simulated values. Such findings demonstrate that the optimization method ha