叉车驱动桥应合理选用齿轮油

１．叉车驱动桥齿轮油的合理选用及使用注意事项（１）齿轮油的选用①粘度等级的选择。工业齿轮油的粘度分类是按ＧＢ３１４１—８２《工业用润滑油粘度分类》标准执行,由齿轮节线速度和齿轮材质及表面应力大小确定。②质量级别的选择。主要根据齿面接触应力确定质量级别...     

拖拉机齿轮渗碳层最佳含碳量的探讨

本文从实际出发，对拖拉机齿轮渗碳浓度与表面硬度、金相组织的关系进行试验研究，提出20CrMnTi齿轮预冷直接淬火表层最佳含碳量应为0．7％－0．8％，而不是热处理教材中认为渗碳件表层最佳含碳量为0．85％－1．05％。     

燃油稀释机油对发动机性能的影响

通过发动机台架试验,结合机油样品检测分析,进行燃油稀释的机油对发动机性能的影响研究。结果表明机油被燃油稀释后,发动机摩擦功随燃油稀释率增大而变小,但燃油稀释率增大到一定程度时,摩擦功不再继续降低;燃油稀释率较低时,发动机实际机油消耗变化不明显,但随着稀释率的增大,机油消耗呈现上升趋势,机油压力快速下降。被燃油稀释后,机油粘度降低,活塞漏气量增加。通过分析燃油稀释机油对发动机性能的影响,可以确定燃油稀释率的限值,指导发动机的开发工作。     

铝硅钛合金在汔车零部件制造使用中优势尽显

近年来，世界性能源问题变得越来越严重。这使得减轻汽车自重、降低油耗成了各大汽车生产厂提高竞争能力的关键。据有关数据介绍，汽车重量每减少50kg，每升燃油行驶的距离可增加2km；汽车重量每减轻1％，燃油消耗下降0．6％～1％。铝具有密度小、耐蚀性好等特点，且铝合金的塑性优良，铸、锻、中压工艺均适用，最适合汽车零部件生产的压铸工艺。从生产成本、零件质量、材料利用等几个方面比较，     

凸角留磨齿轮滚刀的设计及其在电力机车牵引齿轮加工中的应用

1　问题的提出韶山 6B型电力机车 (SS6B)主动齿轮和从动齿轮的基本参数为mn=13,z1=17,z2 =74 ,α =2 2 5° ,β =0° ;主动齿轮 3齿公法线长度W3=10 1 939- 0 2 8- 0 4 0mm ,分度圆直径df1=2 2 1mm ,齿顶圆直径da1=2 5 4 37mm ,齿根圆直径di1=194 31mm ;从动齿轮10齿公法线长度W10 =382 789- 0 2 4 - 0 35mm ,分度圆直径df2 =96 2mm ,齿顶圆直径da2 =10 0 0 5 94mm ,齿根圆直径di2 =94 0mm ,中心距a =6 0 2 + 0 2 0 mm ,齿轮根部圆弧半径R =4～ 5mm。主动齿轮材料为2 0CrMnMoA ,渗碳淬火 ,齿面硬度HRC >5 7,从动…     

行星齿轮变速传动的弹流润滑研究

基于弹性流体动力润滑理论,针对行星齿轮变速器内齿轮主动和太阳轮主动的2种工况,分别求出行星齿轮与太阳轮啮合以及与内齿轮啮合时,沿啮合线在啮合点的最小油膜厚度。结果表明:齿轮在节点啮合的润滑情况可以体现齿轮的润滑状况;太阳轮主动的工况,行星轮与内齿轮啮合的润滑条件最差;提高润滑油的黏度可以增加齿轮润滑油膜厚度;增加齿轮压力角的方法提高齿轮油膜厚度的效果明显;提高齿轮啮合的油膜厚度对改善齿轮的润滑状态,降低齿轮的生产成本,具有实际使用价值。     

18Cr2Ni4WA齿轮系列产品的热处理工艺改进

采煤机在矿井下工作，受使用条件的限制，采煤机中的齿轮要求强度高，属于低速重载齿轮。我单位生产的采煤机中的齿轮90％以上选用18Cr2Ni4WA合金渗碳钢。其化学成分为：wCr=1．35％～1．65％、wc=0．13％～0．19％，wNi=4．0％～4．50％、ww=0．8％～1．0％。在整个齿轮设计制造中，热处理是其质量得以保证的一个重要因素。     

齿轮副总变位系数的简便求法

笔者通过中心距变动模数与变位模数对应数值计算，编制出由齿轮副中心距变动系数Y与齿数之和∑Z直接得出总变位系数∑X（表1、2）。如果要查的Y值或∑Z值是在表中相邻的Y值或∑Z值之间可用数值修正法求出∑X。例1CA6140车床床头箱齿轮Z1＝50；Z2＝51，m＝2．5a'＝127，∑X＝0．303解计算得a＝（Z1＋Z2）m／2＝126．25，则Y＝（127－126．25）／2．5＝0．3根据Y＝0．3及∑Z＝100查表得∑X＝0．306（从表中得知∑Z＝100与∑Z＝101的∑X几乎相等）。经常规计算得∑X＝0．306，与查本表法相同。若∑X＝0．303，则∑Z必大于150，这可能…     

集成发动机暖机过程的油耗仿真研究

以某前置前驱手动挡车辆为研究对象,建立了包括机械传递子系统和热交换子系统在内的整车集成模型,提出了一种考虑发动机暖机过程的车辆燃油消耗量分析方法。在对各子系统模型进行校核的基础上,利用集成模型分别进行整车冷、热机启动工况下的仿真,分析了各系统之间能量交换及整车燃油消耗。与试验结果对比表明,发动机暖机过程温度变化及整车燃油消耗的仿真结果与试验结果一致。该方法可以考虑车辆热管理子系统对油耗的影响,进而为改善车辆燃油经济性提供更多的优化方案。     

Ⅰ档从动齿轮毛坯锻造工艺

1.问题的提出图1为Ⅰ档从动齿轮零件结构,材料为20CrMnTi,该齿轮大端面有轮辐,轮毂面有制动槽和轮辐。我公司原齿轮锻坯如图2所示,由图可知,齿轮大端面轮辐锻出,轮毂面制动槽和轮辐没有锻出。按此锻造工艺,锻造坯料需1.79kg/件,材料消耗较多,制动槽和轮辐在粗车时要3道工序车出,且工序加工时间长,生产效率低。为节材降耗,降低生产成本,我们对此锻坯锻造工艺进行了改进。     

Lubricant viscosity and viscosity improver additive effects on diesel fuel economy

This work verifies the impact of lubricant viscosity and viscosity improver additives on diesel fuel economy. Eight lubricants were tested in a single-cylinder, four-stroke, direct injection diesel engine mounted on a dynamometer, under different load and speed conditions. Engine friction power was also investigated through Willans’ line. The results demonstrate that fuel economy obtained from multigrade viscosity oils is higher than that obtained from monograde viscosity oils. A linear relationship was obtained between the high temperature high shear viscosity and specific fuel consumption. The lubricant which provided lower fuel consumption also required lower friction power.     

Influence of oil temperature on gear failures

Typical gear failures like wear, scuffing, micropitting and pitting are influenced by the oil temperature in the lubrication system. High temperatures lead to low viscosities and thus thin lubricant films in the gear mesh with generally detrimental influence on failure performance. On the other hand, for gear oils with additives higher temperatures correspond with higher chemical activity and, at least in some cases, with better failure performance of the lubricant. Last, but not least, at very high temperatures even metallurgical changes have been found with a reduction in material endurance limits. Examples for the influence of oil temperature on gear failure modes, as well as their introduction into load carrying capacity calculation methods are shown. With this background, the often-applied practice of increasing the severity of a gear oil test method by increasing the oil temperature has to be revised. Adequate solutions are discussed.     

Numerical evaluation of the potential for fuel economy improvement due to boundary friction reduction within heavy-duty diesel engines

Advanced surface treatments have been developed by a number of research institutes as an approach to reduce friction at sliding interfaces. Laboratory tests have shown that some of these surface treatments can result in boundary friction reductions approaching an order of magnitude [1], [2] and [3]. While there are many potential applications for such surface treatments, friction reduction in internal combustion engines is of particular interest due to the apparent fuel savings potential. Ricardo, Inc. has performed simulations to estimate potential fuel economy improvements due to the application of such treatments at key interfaces within engines typical of those used in large trucks. The results show that fuel economy improvements in excess of 4% can be achieved from combined application of a surface treatment and reduction in lubricant viscosity, if the surfaces can be protected against wear.     

An Experimental Investigation of the Influence of the Lubricant Viscosity and Additives on Gear Wear

The influence of lubricant viscosity and additives on the average wear rate of spur gear pairs was investigated experimentally. The gear specimens of a comprehensive gear durability test program that made use of seven lubricants covering a range of viscosities were examined to measure gear tooth wear. The measured wear was related to the as-manufactured surface roughness, the elastohydrodynamic film thickness, and the experimentally determined contact fatigue lives of the same specimens. In general, the wear rate was found to be inversely proportional to the viscosity of the lubricant and to the lambda ratio (also sometimes called the specific film thickness). The data also show an exponential trend between the average wear rates and the surface fatigue lives. Lubricants with similar viscosities but differing additives and compositions had somewhat differing gear surface fatigue lives and wear rates.     

Effect of mechanical shear on the thin‐film properties of base oil‐polymer mixtures

The thickness and frictional characteristics of thin lubricant films are known to affect the fuel economy properties of oils. The base oil and polymer compositions of the lubricant are generally considered to be critical chemical factors that can influence these thin‐film lubricant properties in new oils. However, it is important to produce lubricants with good fuel economy properties that are maintained after the lubricant is degraded. Lubricants in use can undergo oxidation and mechanical shear degradation. The effect of oxidation degradation on thin‐film physical properties has previously been studied. This paper investigates the effect of mechanical shearing on thin‐film properties. Dispersant olefin copolymers are found to reduce thin‐film friction in simple mixtures and in fully formulated oils. In simple mixtures, shearing the dispersant olefin copolymers does not affect the friction‐reducing ability of these polymers. In fully formulated oils, even though shearing diminishes to a degree the friction‐reducing ability of dispersant olefin copolymers, these copolymers can still provide significant friction reduction.     

Friction modifiers in engine and gear oils

Reducing friction is an important target for any lubricant oil formulator. There are several ways, such as utilisation of multi‐grade oils with low viscosity at low temperature, or use of friction modifiers, to reduce friction in automotive engines and transmissions and thus save fuel. A good means to obtain an energy‐saving lubricant is by the addition of a friction‐reducing additive in a high‐range multigrade oil. This paper presents some considerations on the action mechanism of friction modifiers and the results obtained in engine and gear oils with two new nitrogen‐, sulphur‐, and boron‐containing additives.     

Influence of Lubricants on Power Loss of Cylindrical Gears©

The total power loss of gears was measured in a back-to-back gear test rig. Test equipment, measuring principle and evaluation of the data are described. The influence of different lubricant type, viscosity and temperature on mesh and churning losses was investigated. The churning losses depended mainly on the viscosity of the lubricant and on the operating conditions, not on the lubricant type. The mesh power loss depended mainly on the type of lubricant, not on viscosity, temperature, or oil additives.

Churning losses can be reduced by using low viscosity lubricants. Mesh power loss can be reduced by as much as 50 percent of the power loss of mineral oils by using polyglycol-type lubricants. In wide application ranges, viscosity and oil additives do not influence mesh power loss. An experimentally-based equation for the coefficient of friction in the gear mesh is given. Earlier derived equations for the mesh power loss of different gear geometry were confirmed.     

Influence of tooth profile and oil formulation on gear power loss

Nowadays power losses are a main concern in transmission systems and the friction between gear teeth during the meshing cycle is one of the main sources. The friction losses reduction is mandatory to promote lower energy consumption, lower operating temperatures, lower oil oxidation and lower risk of failures.In this study the power losses reduction is obtained using two different approaches: using lower modulus helical gears and significant positive profiles shifts and using gear oil formulations with different base oils.The adopted geometries proved to reduce the power losses considerably, promoting a reduction of oil operating temperature up to 20 K.     

高性能蜗轮蜗杆油的研制

研制的蜗轮蜗杆油经过MHK-500梯母肯试验并且经分析检测,结果表明,新配制的蜗轮蜗杆油具有优异的摩擦磨损性能,使蜗轮磨损大大降低,油品的抗氧化和抗乳化性能都有大幅度提高。     

工业齿轮油摩擦特性的初步研究

齿轮油是工业生产中广泛使用的润滑剂,其摩擦性能对节能减排及设备寿命有重要影响。使用改进的MS-800四球试验机,对1种工业白油和2种工业齿轮油在多个不同滑动速度和不同负载下进行摩擦因数测试试验。结果表明:2种工业齿轮油的摩擦因数都显著低于工业白油,并且它们之间也有明显的区分性;从3种润滑剂的摩擦特性来看,速度是影响摩擦因数的显著因素,随着速度的提高,摩擦因数显著下降;载荷对摩擦因数的影响较小,影响规律也比较复杂。