共查询到19条相似文献,搜索用时 234 毫秒
1.
本文叙述了使用变节距螺旋撑簧缓解铸铁内撑油环内槽和螺旋撑簧过度磨损的原理,以及变节距螺旋撑簧的设计计算。举例说明。 相似文献
2.
3.
本文阐述了山区道路试验机油消耗的机理,分析了EQ61003型发动机山区道路试验机油消耗大的原因:主要是采用两道气环和螺旋撑簧铸铁油环导致山区道路试验发动机拖动工况的机油消耗倍增,并提出了油环的改进结构。 相似文献
4.
本文阐述了山区道路试验机油消耗的机理,分析了EQ6100B型发动机山区道路试验机油消耗大的原因;主要是采用两道气环和螺旋撑簧铸铁油环导致山区道路试验发动机拖动工况的机油消耗倍增,并提出了油环的改进结构。 相似文献
5.
6.
7.
螺旋撑簧油环(以下简称油环),是属于组合环。与其组合径向厚度有关的尺寸如图1所示。其中a12为组合径向厚度尺寸,a13为油环体上集油槽深加实体部位厚度的尺寸,d7为螺旋撑簧(以下简称撑簧)的外径尺寸。通常,a13标注在油环体的零件图上,d7标注在撑簧的零件图上,a12标注在油环的部件装配 相似文献
8.
国内现有中小型汽油机活塞都采用三环结构,即用两道气环和一道油环(油环为三片钢带组合油环,或开槽的整体油环,或带螺旋撑簧的开槽整体油环),难以持久稳定地防止机油上窜,常有烧机油、冒蓝烟的现象,污染环境,增加磨损,降低发动机功率和寿命. 相似文献
9.
10.
薄形螺旋撑簧同向倒角油环的标注; 公称直径d_1=90mm,环高h_1=3.5mm,带有耐热弹簧(WF)。 此环的标注为:GSF─环90×3.5KRR09/76-WF 有关:活塞环的材料,切向弹力,高温下切向弹力的损失,切向弹力的测量,平均比压,闭口间隙和开口结构,表面处理,回油孔的分布,回油孔的长度,弹簧的结构和材料,弹簧的压缩量,弹簧接口的位置,槽底直径,标记的组成,活塞环的标记,均按KRR02/76 相似文献
11.
This paper describes the role of thermal contact resistance in a high‐temperature sensible heat storage water heater using cast iron as a storage material. An experimental set‐up consisting of a cast iron cylinder and a stainless‐steel tube running through its centre was fabricated and tested. The experimental data were compared with a theoretical model. It was observed that the variation in thermal contact resistance between the cast‐iron blocks and the tube with temperature plays a dominant role in extracting the heat at a reasonably constant temperature. The contact resistance between two contacting surfaces was modelled as the composite of two parallel resistances: one due to the points where two surfaces contact each other and the other due to a gap between the surfaces, which is often air filled. An approximate contact resistance prediction was obtained by assuming the resistance due to the air gap modulated by a correction factor which accounts for the contacting surface area. Based on the results from the experimental set‐up and theoretical modelling, a prototype storage water heater using cast‐iron blocks as the storage material was designed, fabricated and tested. Copyright © 2001 John Wiley & Sons, Ltd. 相似文献
12.
There are many studies showing that the performance results for engines operating with biofuels are acceptable, although very few long-term analysis of wear and maintenance problems are shown. Three mono-cylinder compression ignition engines were tested for approximately 1000 h each, with pure diesel oil (D100), pure soy methyl ester (SME100) and pure castor oil methyl ester (CME100). The lubricating oil analysis didn’t reveal any excessive amount of metals compared to the engine with pure diesel. Viscosity decreased very soon to values below the minimum recommended due to dilution with the methyl esters, especially with SME100. The injection system analysis showed that opening pressures, hydraulic flux and corrosion levels were acceptable. The SME piston showed a very small crack. A higher amount of carbon deposits and gum formation was found over biofuel pistons, indicating poor combustion. Piston ring seating and gap were inside specification. Cylinder liners presented no damage on running surface. The valves presented abrasive and adhesive wear, contact fatigue for SME100 and marks at valve seating for CME100, considered acceptable after 1000 h of test. The results obtained show that the use of pure methyl esters fuels was acceptable for these engines regarding wear and maintenance problems. 相似文献
13.
14.
以一款非道路高压共轨柴油机为研究对象,结合活塞温度场试验研究,建立了活塞组件运动学模型。着重研究了不同配缸间隙、开口端倒角对柴油机窜气量及缸内润滑油消耗的影响规律,运用响应曲面法分析了活塞环开口间隙对窜气量的影响,在此基础上对顶环及二环开口间隙参数进行优化,得到最优解。分析结果表明:配缸间隙的增大使得润滑油消耗增大,最大增幅为7.54%,配缸间隙对窜气量影响较小。顶环开口端倒角对窜气量影响较为明显,顶环开口端倒角从0增加到1mm,窜气量增大13%。顶环及二环开口间隙对柴油机窜气量影响具有线性关系,油环开口间隙对柴油机窜气量影响较小。顶环开口间隙0.42mm、二环开口间隙0.48mm为最优解,此时窜气量为13.11L/min。 相似文献
15.
活塞环存有端隙,因磨损端隙增大会造成密封不严,端隙对口密封原理失效所产生的高温燃气泄漏,使发动机气缸压缩压力降低、燃烧反应不充分、怠速不稳、热效率降低、动力不足乃至启动困难、烧机油加重、形成积碳、增加尾气排放的污染物.高温气体窜入曲轴箱时,使活塞环受热弹力失效,活塞异常膨胀变形,引发机油结胶活塞环卡死或拉缸、造成机油温... 相似文献
16.
润滑油对发动机有非常重要的作用,发动机中影响机油消耗的因素也很多。本文针对不同的缸盖护罩、活塞、二道气环和油环背压,在电控汽油机上进行了机油消耗量的试验和分析。试验结果表明:总机油消耗主要包括活塞部分机油消耗和强制通风口机油消耗两部分,其中活塞部分机油消耗占总机油消耗的90%以上;改进型缸盖护罩能有效冷凝机油蒸汽,降低机油的蒸发消耗;对二道气环的改进能减少活塞环的磨损,并提高刮油效果;确保活塞与气缸贴合的更好,能有效阻止窜气的发生;油环背压的增加能够改善刮油效果,但由于同时增加了活塞环的磨损,在实验后期机油消耗量反而增加。 相似文献
17.
润滑油对发动机有非常重要的作用,发动机中影响机油消耗的因素也很多。本文针对不同的缸盖护罩、活塞、二道气环和油环背压,在电控汽油机上进行了机油消耗量的试验和分析。试验结果表明:总机油消耗主要包括活塞部分机油消耗和强制通风口机油消耗两部分,其中活塞部分机油消耗占总机油消耗的90%以上;改进型缸盖护罩能有效冷凝机油蒸汽,降低机油的蒸发消耗;对二道气环的改进能减少活塞环的磨损,并提高刮油效果;确保活塞与气缸贴合的更好,能有效阻止窜气的发生;油环背压的增加能够改善刮油效果,但由于同时增加了活塞环的磨损,在实验后期机油消耗量反而增加。 相似文献
18.
活塞环—缸套润滑状态周向不均匀性的研究 总被引:7,自引:2,他引:7
本文基于活塞环接触压力分布、活塞环偏摆、活塞环开口间隙位置的分析研究,指出了活塞环-缸套润滑状态周向不均匀性的客观存在。应用二维平均流量模型和微凸体接触方程,并考虑活塞系统的偏摆和润滑油粘度变化,提出了一个新的活塞环-缸套润滑状态的分析计算模型,给出了活塞环-缸套油膜厚度的三维分布,定量探讨了活塞环接触压力分布形状、活塞环偏摆、活塞环开口间隙位置对周向油膜厚度不均匀性的影响。 相似文献