缺套—活塞环材料在往复滑动中摩擦系数的试验研究

为了研究机车柴油机缸套活塞环材料的摩擦学性能,我们设计并制造了一台往复式摩擦磨损试验机。该试验机可在一定范围内实行载荷、速度、润滑量的单因素控制,并可同时定性和定量的显示运动中的摩擦力大小。我们利用该试验机对美国ＧＥ公司采用的软氮化铸铁缸套－表面镀铬铸铁活塞环材料进行了摩擦学性能的试验研究,得出了该配对副在往复滑动中摩擦系数随载荷和速度变化的关系曲线。     

大功率柴油机活塞环-缸套摩擦学试验机的设计

设计适用于大功率以及重载柴油机活塞环-气缸套的摩擦性能试验机,对摩擦力测量和传递机构的纵向和横向测量两种方案进行对比,确定横向测量方案为优化的设计方案。横向测量方案对悬臂梁的设计有较高的要求,需要进行弹性悬臂梁的截面设计,通过计算以确定梁的刚度。在测试系统中引入虚拟仪器技术,并给出LabVIEW编程及其实现,提高了测量精度。该设计方案可以实现对大功率柴油机摩擦性能试验更好的技术支持。     

缸套/活塞环摩擦学性能试验机的设计研究

根据缸套 /活塞环胶合失效试验研究的需求 ,设计了一台集试验、测量和控制于一体的往复式摩擦磨损试验机。该设备具有加热和温度控制功能 ,采用快速响应速度的微细热偶测量接触区温度 ,同时通过四臂电桥测电阻法测量缸套 -油膜 -活塞环之间的动态接触电阻 ,以反映接触区的润滑状态。试验表明该试验机性能稳定 ,可测物理量丰富 ,是胶合试验研究可靠的实验工具     

内燃机缸套-活塞环磨合研究概述

在对缸套-活塞环磨合过程的数学模型、影响因素及磨合状态的评定参数3个方面的国内外研究现状进行概述的基础上,对其中存在的一些问题进行了探讨和分析,并对缸套-活塞环磨合过程的进一步研究提出如下建议:微凸体承载方程中考虑磨合的动态性;研制模拟缸套-活塞环工况的磨合磨损试验机,定量研究磨合中的影响因素;研究缸套-活塞环磨合状态评定参量到达稳定状态时间不同的影响因素.     

内燃机缸套和活塞环磨合过程数学建模试验研究

基于内燃机缸套活塞环摩擦学系统的研究,文章建立了活塞环动力学基本数学模型,并对缸套与活塞环之间的作用力进行分析,以此为基础得到缸套与活塞环之间的摩擦力分析模型,亦即两者磨合过程数学模型,最后,结合汽油机实例进行试验分析,得到了各种参数对缸套与活塞环磨合的影响效果。     

制冷压缩机活塞环—缸套擦伤机理及预防措施

分析了活塞式制冷压缩机活塞环－缸套擦伤的机理及影响活塞环－缸套擦伤的各种因素,并提出了减少其擦伤的一些措施。     

润滑油粘度对缸套/活塞环摩擦学性能的影响

在内燃机实际运行中,润滑油的粘度直接影响到润滑油膜的状态,因而活塞环在缸套中不同位置时的摩擦、润滑状态各不相同。文中以缸套活塞环为研究对象,建立了润滑计算模型,并运用该模型对缸内压力、温度、油膜厚度和摩擦系数进行了分析。结果表明,润滑油膜厚度和摩擦系数随转速改变而发生变化,而剪切稀化导致润滑油粘度减小是引起该变化的主要原因。最后,通过对计算结果的分析,提出了适用于缸套活塞环的润滑油粘度指标。     

发动机缸套-活塞环摩擦磨损特性试验研究

利用缸套-活塞环摩擦磨损试验台研究了速度，温度，载荷，供油等因素对缸套-活塞环系统摩擦磨损特性的影响。试验结果表明，缸套-活塞环摩擦副在发动机工作循环中润滑状态不断发生变化。在试验条件下，温度对摩擦磨损有显著影响，载荷和速度对摩擦力的影响较小。     

A Model for Wear and Friction in Cylinder Liners and Piston Rings

Abstract

A one-dimensional elstohydrodynamic mixed lubrication wear and friction model is developed. The model can predict the effects of surface roughness, asperity contact, temperature-pressure-viscosity on wear, lubrication, and friction of the piston rings and cylinder liner. Wear is predicted based on the surface asperity contact pressure. The cylinder bore wear and the ring pack friction during an engine break-in are simulated and compared with the experimental results. The influence of cylinder wall temperature and surface roughness on friction and wear is investigated. The ring pack friction due to oil viscous shearing and asperity contact is found to reach its minimum at a certain oil temperature.     

汽车发动机缸套-活塞环摩擦副磨损及对策

本文分析了汽车发动机缸套-活塞环摩擦副的磨损特点，探讨其磨损的机理，提出了减少摩擦、控制磨损的具体措施。     

表面氮化对活塞环摩擦磨损参数的影响分析

用摩擦磨损试验机对铸铁活塞环在氮化前后与高硼铜铸铁缸套配合分别进行了半小时和一小时摩擦磨损试验,测量了氮化前后的活塞环表面摩擦系数和磨损量、磨损率,并对磨痕进行了分析。结果表明:未氮化活塞环摩擦系数大于氮化环,摩擦系数变化稳定性比氮化活塞环差,未氮化环磨损量较氮化环增大了约39.6%(半小时)及51.0%(一小时),未氮化环磨损率的一小时试验比半小时试验平均升高6.7%,氮化环磨损率降低了13.7%,与未氮化环配合的缸套磨损量较与氮化环配合的缸套的磨损量和磨损率与活塞环比较规律一致,表面磨痕显示未氮化环磨损剧烈,由此氮化处理提高活塞环-缸套摩擦副的稳定性,且耐磨性得到提高。     

聚酰胺用于压缩机活塞环的试验研究

通过对聚酰胺等材质的摩擦特性试验分析，提出了在一定的条件下，采用填充聚酰胺材质制作压缩机活塞环，可提高其使用寿命和减少摩擦功率的可行方案，并结合应用实例进行了分析。     

关于内燃机缸套活塞环磨合过程的数学模型

从混合润滑和磨合动力学的角度出发，以表面粗糙度和磨损率为状态参量，建立一个关于内燃机缸套、活塞环摩擦学系统磨合过程的数学模型，分析了影响磨合过程的各种参数对磨合的影响，为磨合过程的动态仿真提供了基于润滑的表面形貌分析的理论依据     

摩擦力测量机构的有限元分析设计

摩擦力的测量始终是摩擦磨损试验机的重要组成部分之一。设计实践中，涉及到测量原理、机构的选择及设计计算等一系列问题。通过比较几种常见的摩擦力测试机构的原理，介绍了采用有限元分析技术对笔者在设计过程中选用的一种弹性臂摩擦力测试机构进行结构设计，获得了较优方案。     

Investigation of Scuffing Resistance of Piston Rings Run against Piston Ring Grooves

The hot scuffing phenomenon of a piston ring in a ring groove is one of the important failure mechanisms in an automotive engine. The dynamic motion of a piston ring against the ring groove is very complicated. Five motions are usually involved, including radial sliding, circumferential sliding, impacting, rocking, and tilting. Experimental or theoretical studies in this field are rarely reported. To investigate the hot scuffing behavior of piston rings run against various coated ring grooves, a previously developed tester with the capability of simulating most of the relative motions between the ring and the ring groove at an elevated temperature has been further modified and engineered. Several coating materials on piston top ring grooves have been evaluated in terms of their scuffing resistance using the tester. The results have indicated that the anodized aluminum piston groove has the best scuffing resistance when run against a stainless steel ring, and the Ni-based composite coated aluminum ring groove is better than the tin plated ring groove or the bare ring groove but not as good as the hard anodized one.     

Friction and Wear of Low-Phosphorus Engine Oils with Additional Molybdenum and Boron Compounds,Measured on a Reciprocating Lubricant Tester

Previous research has already extensively characterized the effects of a variety of engine oils on engine performance. However, low-phosphorus engine oils, which are of growing importance due to the reduction of automotive emissions, have not been studied much. This paper sets forth the results of an initial investigation involving the effects of low-phosphorus engine oils on the friction and wear characteristics of typical engine cylinder kit components from a 3.8-liter, four-cylinder engine. For these tests, sections of molybdenum-coated piston rings were oscillated against segments of production cast iron cylinder bores. The oils were evaluated under two sets of conditions; i.e., the frequency of 20 Hz and a load of 60 N and a frequency of 40 Hz and a load of 120 N. The friction coefficients were continuously recorded, and the wear depths on the cylinder bore segments were measured at the conclusion of each experiment. The oils consisted of low-phosphorus prototype oil (LPPO) containing 0.05 wt% phosphorus, which is half the amount of ZDDP in GF–3 oils, and the LPPO treated with six different supplemental antiwear, anti-friction additives. The remaining additives in the LPPO were present in the amount required for full GF–3 formulation. The supplemental additives were selected to lower friction and replace and/or enhance antioxidant and antiwear properties lost due to lower zinc dithiophosphate (ZDDP) content. The results of low phosphorus concentration oils were compared to the results obtained with formulated ILSAC GF-3 engine oil. The oils that contained organomolybdenum ester showed the greatest benefit in friction reduction in the two different operating conditions. SEM/EDS/XPS surface analyses on the surfaces run with oils containing organomolybdenum ester showed evidence of molybdenum compound formation on the cylinder bore surface. In addition, antiwear film formation mechanisms due to surface interaction among the ZnDTP, organomolybdenum compounds, and metal oxides are discussed.     

轴向柱塞泵柱塞与缸体孔泄漏及工艺分析

为了提高轴向柱塞泵的容积效率及整体寿命,研究了柱塞和缸体孔的泄漏流量与缸体孔的转角关系,通过Matlab仿真了其曲线图,得出了泄漏流量随着缸体孔的转角增大而变大,而根据泄漏的标准在正常工作的情况下不能超过0.25ml/min,确定了其间隙在范围内其泄漏流量是较小的,为了得到这个间隙进一步对柱塞和缸体的工艺进行了详细的分析,最终通过千分尺测量柱塞与缸体孔的配合间隙是符合设计要求的,从而提高了轴向柱塞泵的容积效率和整体的寿命。     

A Study of Torn and Folded Metal (TFM) on Honed Cylinder Bore Surfaces

Torn and folded metal (TFM) on honed cylinder bore surfaces has been observed and studied for decades. However, there is no objective and quantitative method for ranking the severity of TFM. Studies on its effect on the scuffing resistance of a cylinder bore and piston skirt/piston ring are also very limited. Machined surfaces are currently evaluated and ranked qualitatively based on fax film images. The results may vary greatly depending upon the individual's experience and also the image quality. In this study, an attempt has been made to develop a method that can be used to evaluate cylinder bore surfaces objectively. A “surface index” has been developed for classifying honed bore surfaces. To further examine the effect of TFM on a cylinder bore performance, bench tests have been conducted to evaluate cylinder bore scuffing resistance and its correlation with the bore surface quality in terms of the value of the surface index.