Internal Combustion Engine Connecting Rod Bushing Failure Mechanism Of Friction And Wear

Most of material of connecting rod bushing of the traditional used in steel rolling back-copper-lead alloy, it is difficult to Satisfy the high efficiency operation requirements of the diesel engine. In such conditions, this kind of sliding bearing's main failure mode is wear of the bearing surface, specially fatigue wear and flaking of Large expanse alloy layer.Connecting rod bushing for a high-power diesel engine appears the failures of the pitting multiple times and spalling of alloy layer in the assessment test. The designers proposed using the QSn7-0.2 bronze molding materials and the shear spinning formation craft. The Connecting rod bushing have the characteristics of high strength, good mechanical properties and large carrying capacity,It can satisfy diesel engine's operation requirements of high efficiency and high strengthening In order to further understand the Wear life and failure mode of bronze rod bushing of spinning, this article proposed the test methods of friction and wear of simulated actual working conditions. The main contents of this paper:(1) In the basis of searching and analysising relevant literature, analysising and discussing the characteristics and the adaptation range of friction and existing wear tester. This paper describes the failure mechanism of wear, running wear process and the different superficial quality to the influence of the attrition, and it proposed the method of failure analysis of the connecting rod bushing, the main factors of bushing failure and how to prevent failure of the measures. These provide a theoretical basis for Analysis of test results of the wear.(2) This paper developed the test device which simulate the actual working conditions of connecting rod bushing. According to the requirements of Wear test, we put forward the basic idea of simulation test device. According to the working principle of the actual conditions of the piston rod, we determine the overall structure of friction and wear test device. And the specific structure and main technical parameters were analyzed. This provides test methods for the study of spinning bronze bushing.(3) To verify the feasibility of test equipment, we conducted validation tests. The results show that: the newly developed test equipment meet the test requirements. To test and verify the feasibility of Wear test, using the same batch bush samples, we carried out orthogonal test under different conditions, such as Clearance, load, speed, roughness. The results show that: The tentative data has the good uniformity, the duplication and the comparability. In the full lubrication situation, the influence of the speed is biggest to the wearing capacity, next for load and gap. When the test condition is 0.10mm, 11 tons, 360r/min, the wearing capacity reaches as high as 32mg.